bims-amsmem 2022-03-20 papers

bims-amsmem

Biomed News

on AMPK signaling mechanism in energy metabolism

Issue of 2022–03–20
thirty-one papers selected by
Dipsikha Biswas, Københavns Universitet

AMP-activated protein kinase activation in skeletal muscle modulates exercise-induced uncoupled protein 1 expression in brown adipocyte in mouse model.
Opposing effects on regulated insulin secretion of acute vs chronic stimulation of AMP-activated protein kinase.
FSH mediates estradiol synthesis in hypoxic granulosa cells by activating glycolytic metabolism through the HIF-1α/AMPK/GLUT1 signaling pathway.
Protective effects of heterophyllin B against bleomycin-induced pulmonary fibrosis in mice via AMPK activation.
A novel AMPK activator shows therapeutic potential in hepatocellular carcinoma by suppressing HIF1α-mediated aerobic glycolysis.
Abelmoschus esculentus subfractions ameliorate hepatic lipogenesis and lipid uptake via regulating dipeptidyl peptidase-4-With improving insulin resistance.
Regulation of basal autophagy by calmodulin availability.
MAP kinase-dependent autophagy controls phorbol myristate acetate-induced macrophage differentiation of HL-60 leukemia cells.
Effects of Antibacterial Co-Cr-Mo-Cu Alloys on Osteoblast Proliferation, Differentiation, and the Inhibition of Apoptosis.
Platycodon grandiflorum root fermentation broth reduces inflammation in a mouse IBD model through the AMPK/NF-κB/NLRP3 pathway.
Atractylenolide III ameliorates Non-Alcoholic Fatty Liver Disease by activating Hepatic Adiponectin Receptor 1-Mediated AMPK Pathway.
Ferritinophagy is involved in Bisphenol A-induced ferroptosis of renal tubular epithelial cells through the activation of the AMPK-mTOR-ULK1 pathway.
Ameliorative Effects of Malonyl Ginsenoside from Panax ginseng on Glucose-Lipid Metabolism and Insulin Resistance via IRS1/PI3K/Akt and AMPK Signaling Pathways in Type 2 Diabetic Mice.
Ferulic acid and berberine, via Sirt1 and AMPK, may act as cell cleansing promoters of healthy longevity.
Dihydromyricetin protects against Doxorubicin-induced cardiotoxicity through activation of AMPK/mTOR pathway.
Knockdown of MAGE-A6 enhanced the irradiation sensitivity of non-small cell lung cancer cells by activating the AMPK pathway.
SERPINB1 overexpression protects myocardial damage induced by acute myocardial infarction through AMPK/mTOR pathway.
Dopamine D3 receptor signaling alleviates mouse rheumatoid arthritis by promoting Toll-like receptor 4 degradation in mast cells.
Role of Cannabidiol and Tetrahydrocannabivarin on Paclitaxel-induced neuropathic pain in rodents.
B7-H4 expression promotes non-small cell lung cancer progression via AMPK/mTOR signaling.
Exercise-Generated β-Aminoisobutyric Acid (BAIBA) Reduces Cardiomyocyte Metabolic Stress and Apoptosis Caused by Mitochondrial Dysfunction Through the miR-208b/AMPK Pathway.
PGC-1α affects skeletal muscle and adipose tissue development by regulating mitochondrial biogenesis.
Adiponectin receptor agonist AdipoRon improves skeletal muscle function in aged mice.
Sirt3 ameliorates mitochondrial dysfunction and oxidative stress through regulating mitochondrial biogenesis and dynamics in cardiomyoblast.
Social isolation triggers oxidative status and impairs systemic and hepatic insulin sensitivity in normoglycemic rats.
Parallel kinase pathways stimulate actin polymerization at depolarized mitochondria.
TSLP regulates mitochondrial ROS-induced mitophagy via histone modification in human monocytes.
Empagliflozin Inhibits Hepatic Gluconeogenesis and Increases Glycogen Synthesis by AMPK/CREB/GSK3β Signalling Pathway.
SESN1 attenuates the Ox‑LDL‑induced inflammation, apoptosis and endothelial‑mesenchymal transition of human umbilical vein endothelial cells by regulating AMPK/SIRT1/LOX1 signaling.
Bilobalide Exerts Anti-Inflammatory Effects on Chondrocytes Through the AMPK/SIRT1/mTOR Pathway to Attenuate ACLT-Induced Post-Traumatic Osteoarthritis in Rats.
Honokiol ameliorates cisplatin-induced acute kidney injury via inhibition of mitochondrial fission.

J Physiol. 2022 Mar 17.

AMP-activated protein kinase activation in skeletal muscle modulates exercise-induced uncoupled protein 1 expression in brown adipocyte in mouse model.

Hye Jin Kim, Youn Ju Kim, Je Kyung Seong.

   KEY POINTS: Exercise promotes thermogenesis by activating uncoupling protein 1 (UCP1), which leads to a decrease in the body weight gain and body fat content. However, little is known about the role of exerkines in modulating UCP1 expression and subsequent brown adipose tissue (BAT) activation. Four weeks of voluntary wheel running exercise reduces body weight and fat content. Exercise induces the increase in AMP-activated protein kinase (AMPK) and slow-type muscle fibre marker genes in skeletal muscles and promotes UCP1 expression in white and brown adipose tissues. Incubation of brown adipocytes with serum isolated from exercise-trained mice significantly increased their UCP1 gene and protein levels; moreover, conditioned media of AMPK-activator-treated C2C12 myotubes induces increased UCP1 expression in brown adipocytes. These results highlight that aerobic exercise-induced skeletal muscle AMPK has a significant effect on UCP1 expression in BAT.
ABSTRACT: Aerobic exercise is an effective intervention in preventing obesity and is, also an important factor associated with thermogenesis. There is an increasing interest in factors and mechanisms induced by aerobic exercise that can influence the metabolism and thermogenic activity in an individual. Recent studies suggest that exercise-induced circulating factors, which are (known as "exerkines") able to modulate activation of brown adipose tissue (BAT) and browning of white adipose tissue. However, the underlying molecular mechanisms associated with the effect of exercise-induced peripheral factors on BAT activation remain poorly understood. Furthermore, the role of exercise training in BAT activation is still debatable. Hence, the purpose of our study is to assess whether exercise training affects the expression of uncoupled protein 1 (UCP1) in brown adipocytes via release of different blood factors. Four weeks of exercise training significantly decreased the body weight gain and fat mass gain. Furthermore, trained mice exhibit higher levels of energy expenditure and UCP1 expression compared with untrained mice. Surprisingly, treatment with serum from exercise-trained mice increased the expression of UCP1 in differentiated brown adipocytes. To gain a better understanding of these mechanisms, we analysed the conditioned media obtained after treating the C2C12 myotubes with an AMP-activated protein kinase (AMPK) activator (AICAR; 5-aminoimidazole-4-carboxamide ribonucleotide), which leads to an increased expression of UCP1 when added to brown adipocytes. Our observations suggest the possibility of aerobic exercise-induced BAT activation via activation of AMPK in skeletal muscles. Abstract figure legend Exercise induces the release of several factors called 'exerkines' that can help to modulate the metabolic as well as thermogenic activity of an individual. However, there is limited knowledge regarding the underlying molecular mechanisms that enable these factors to stimulate brown adipose tissue activity. Our study demonstrates that exercise-induces activation of AMP-activated protein kinase in skeletal muscles, which, in turn, presumably through the release of exerkines from muscles, can modulate the uncoupled protein 1 expression in brown adipocytes. We believe that this paper provides an understanding of the molecular basis of adipocyte browning during aerobic exercise, and this knowledge may be useful in developing novel strategies for preventing the onset of/overcoming obesity. This article is protected by copyright. All rights reserved.

Keywords:  AMPK; BAT activation; UCP1; brown adipocyte; exercise; exerkine; myokine

DOI:  https://doi.org/10.1113/JP282999
Diabetologia. 2022 Mar 16.

Opposing effects on regulated insulin secretion of acute vs chronic stimulation of AMP-activated protein kinase.

Marie-Sophie Nguyen-Tu, Joseph Harris, Aida Martinez-Sanchez, Pauline Chabosseau, Ming Hu, Eleni Georgiadou, Alice Pollard, Pablo Otero, Livia Lopez-Noriega, Isabelle Leclerc, Kei Sakamoto, Dieter Schmoll, David M Smith, David Carling, Guy A Rutter.

   AIMS/HYPOTHESIS: Although targeted in extrapancreatic tissues by several drugs used to treat type 2 diabetes, the role of AMP-activated protein kinase (AMPK) in the control of insulin secretion is still debatable. Previous studies have used pharmacological activators of limited selectivity and specificity, and none has examined in primary pancreatic beta cells the actions of the latest generation of highly potent and specific activators that act via the allosteric drug and metabolite (ADaM) site.
METHODS: AMPK was activated acutely in islets isolated from C57BL6/J mice, and in an EndoC-βH3 cell line, using three structurally distinct ADaM site activators (991, PF-06409577 and RA089), with varying selectivity for β1- vs β2-containing complexes. Mouse lines expressing a gain-of-function mutation in the γ1 AMPK subunit (D316a) were generated to examine the effects of chronic AMPK stimulation in the whole body, or selectively in the beta cell.
RESULTS: Acute (1.5 h) treatment of wild-type mouse islets with 991, PF-06409577 or RA089 robustly stimulated insulin secretion at high glucose concentrations (p<0.01, p<0.05 and p<0.001, respectively), despite a lowering of glucose-induced intracellular free Ca2+ dynamics in response to 991 (AUC, p<0.05) and to RA089 at the highest dose (25 μmol/l) at 5.59 min (p<0.05). Although abolished in the absence of AMPK, the effects of 991 were observed in the absence of the upstream kinase, liver kinase B1, further implicating 'amplifying' pathways. In marked contrast, chronic activation of AMPK, either globally or selectively in the beta cell, achieved using a gain-of-function mutant, impaired insulin release in vivo (p<0.05 at 15 min following i.p. injection of 3 mmol/l glucose) and in vitro (p<0.01 following incubation of islets with 17 mmol/l glucose), and lowered glucose tolerance (p<0.001).
CONCLUSIONS/INTERPRETATION: AMPK activation exerts complex, time-dependent effects on insulin secretion. These observations should inform the design and future clinical use of AMPK modulators.

Keywords:  991; AMP-activated protein kinase; AMPK; ATP/ADP; Beta cell; Ca2 +; Insulin secretion; LKB1; PF-06409577; RA089; Type 2 diabetes

DOI:  https://doi.org/10.1007/s00125-022-05673-x
J Biol Chem. 2022 Mar 14. pii: S0021-9258(22)00270-8. [Epub ahead of print] 101830

FSH mediates estradiol synthesis in hypoxic granulosa cells by activating glycolytic metabolism through the HIF-1α/AMPK/GLUT1 signaling pathway.

Gang Wu, Chengyu Li, Jingli Tao, Zhaojun Liu, Xiaoxuan Li, Ziyu Zang, Chen Fu, Jiayuan Wei, Yaxing Yang, Qian Zhu, Jia-Qing Zhang, Ming Shen, Honglin Liu.

  Owing to the avascular environment within ovarian follicles, granulosa cells (GCs) are believed to live in a hypoxic niche. Follicle-stimulating hormone (FSH)-mediated steroidogenesis is crucial for normal growth and maturation of ovarian follicles, but it remains unclear how FSH stimulates estradiol (E2) synthesis under hypoxic conditions. Here, we aimed to explore whether FSH affects the ATP production required for estrogen synthesis from the perspective of glucose metabolism. It was observed that the levels of both E2 and HIF-1α were markedly increased in a dose-dependent manner in mouse ovarian GCs after the injection of FSH in vivo, indicating that hypoxia/HIF-1α may be relevant to FSH-induced E2 synthesis. By treating hypoxic GCs with FSH in vitro, we further revealed that the activation of the AMP-activated protein kinase (AMPK)/GLUT1 pathway, which in turn stimulates ATP generation, may be essential for FSH-mediated E2 production during hypoxia. In contrast, inhibition of AMPK or GLUT1 with siRNAs/antagonist both repressed glycolysis, ATP production, and E2 synthesis, despite FSH treatment. Moreover, blocking HIF-1α activity using siRNAs/PX-478 suppressed AMPK activation, GLUT1 expression and E2 levels in FSH-treated GCs. Finally, the in vitro findings were verified in vivo, which showed markedly increased AMPK activity, GLUT1 expression, glycolytic flux, ATP levels, and E2 concentrations in ovarian GCs following FSH injection. Taken together, these findings uncovered a novel mechanism for FSH regulating E2 synthesis in hypoxic GCs by activating glycolytic metabolism through the HIF-1α/AMPK/GLUT1 pathway.

Keywords:  E2; FSH; Glycolysis; Granulosa cell; Hypoxia

DOI:  https://doi.org/10.1016/j.jbc.2022.101830
Eur J Pharmacol. 2022 Mar 10. pii: S0014-2999(22)00086-3. [Epub ahead of print] 174825

Protective effects of heterophyllin B against bleomycin-induced pulmonary fibrosis in mice via AMPK activation.

Wen Shi, Jiatong Hao, Yanliang Wu, Chang Liu, Kuniyoshi Shimizu, Renshi Li, Chaofeng Zhang.

  Pulmonary fibrosis (PF) is a chronic interstitial lung disease with unkown etiology. In the present study, we evaluated the anti-fibrotic effects of heterophyllin B, a natural product from radix pseudostellariae having anti-inflammatory and tyrosinase inhibitory activities. In bleomycin (BLM)-induced PF mouse model, heterophyllin B treatments (5 or 20 mg/kg/d) significantly attenuated BLM-induced alveolar cavity collapse, inflammatory cell infiltration, alveolar wall thickening and collagen deposition. When compared to model group, heterophyllin B treatments also increased adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) phosphorylation levels by 359% (P < 0.001) and reduced the expression of stimulator of interferon genes (STING) by 73% (P < 0.001). Furthermore, co-administration of heterophyllin B with AMPK inhibitor dorsomorphin (Compound C) significantly blocked the improvement effects of heterophyllin B on BLM-damaged lung tissue, and also increased the protein expression of STING which was inhibited by heterophyllin B in fibrotic lungs (P < 0.001). It is known that alveolar epithelia and lung fibroblasts exert prominent roles in the fibrosis progression. In the present study we found that, in vitro, heterophyllin B significantly inhibited alveolar epithelial mesenchymal transition (EMT) and lung fibroblast transdifferentiation. We also found that the inhibition of heterophyllin B on lung fibroblast transdifferentiation and STING expression was reversed by Compound C. To summarize, heterophyllin B exhibited protective effects on BLM-induced lung fibrosis potentially by inhibiting TGF-Smad2/3 signalings and AMPK-mediated STING signalings.

Keywords:  AMPK activation; Heterophyllin B; Pulmonary fibrosis; STING

DOI:  https://doi.org/10.1016/j.ejphar.2022.174825
Mol Oncol. 2022 Mar 17.

A novel AMPK activator shows therapeutic potential in hepatocellular carcinoma by suppressing HIF1α-mediated aerobic glycolysis.

Hsing-I Tseng, Yi-Siang Zeng, Ying-Chung Jimmy Lin, Jui-Wen Huang, Chih-Lung Lin, Meng-Hsuan Lee, Fan-Wei Yang, Te-Ping Fang, Ai-Chung Mar, Jung-Chen Su.

  Hepatocellular carcinoma (HCC) is characterized by rapid growth, early vascular invasion and high metastasis. Currently available FDA-approved drugs show low therapeutic efficacy, limiting HCC treatment to chemotherapy. We designed and synthesized a novel small molecule, SCT-1015, that allosterically activated adenosine monophosphate-activated protein kinase (AMPK) to suppress the aerobic glycolysis in HCC. SCT-1015 was shown to bind the AMPK α- and β-subunit interface, thereby exposing the kinase α domain to the upstream kinases, resulting in the increased AMPK activity. SCT-1015 dramatically reduced HCC cell growth in vitro and tumor growth in vivo. We further found that AMPK formed protein complexes with hypoxia-inducible factor 1-alpha (HIF1α), and that SCT-1015-activated AMPK promoted hydroxylation of HIF1α (402P and 564P), resulting in HIF1α degradation by the ubiquitin-proteasome system. With declined HIF1α abundance, many glycolysis-related enzymes were down-regulated, suppressing aerobic glycolysis and promoting oxidative phosphorylation. These results indicated that SCT-1015 channelled HCC cells into an unfavourable metabolic status. Overall, we reported SCT-1015, as a direct activator of AMPK signaling that held therapeutic potential in HCC.

Keywords:  AMPK; HIF1α; SCT-1015; hepatocellular carcinoma

DOI:  https://doi.org/10.1002/1878-0261.13211
PLoS One. 2022 ;17(3): e0265444

Abelmoschus esculentus subfractions ameliorate hepatic lipogenesis and lipid uptake via regulating dipeptidyl peptidase-4-With improving insulin resistance.

Chiung-Huei Peng, Yaw-Bee Ker, Hsin-Hua Li, Sing-Hua Tsou, Chih-Li Lin, Chien-Ning Huang.

Nonalcoholic fatty liver disease (NAFLD) is recognized as the liver component of metabolic syndrome. The regulation of hepatic lipid should be emphasized to prevent accompanying illness. As AMP-activated protein kinase (AMPK) and sterol regulatory element binding protein (SREBP) regulate lipid metabolism, CD36 and fatty acid synthase (FAS) promote lipid uptake and lipogenesis respectively, while acetyl-CoA carboxylase (ACC) is an indicator of negative feedback. The increase of IRS-1 phosphorylation at the residue ser307 (p-ser307-IRS-1) and decrease of p-ser473-Akt (p-Akt) are viewed as the insulin resistance markers, and our previous reports suggested dipeptidyl peptidase-4 (DPP-4) mediates insulin resistance, the crucial factor of metabolic syndrome. Abelmoschus esculentus (AE) fruit is well-known for its antidiabetic utility. We had isolated several AE subfractions by successive steps, and found that F1 and F2 were especially valid in suppressing DPP-4 signaling. Since little is known if AE works on NAFLD, now we first attempt to investigate whether AE is useful to attenuate hepatic lipogenesis and lipid uptake in liver cells, along with improving the metabolic targets. We demonstrated that AE subfractions attenuated the hepatic lipid accumulation induced by free fatty acids. Treatment of AE alleviated FAS and returned the level of p-ser79-ACC (p-ACC). Although F1 was more effective on AMPK, F2 seemed more stable to attenuate SREBP-1. Moreover, as fatty acids stimulated the expression of CD36, F2 showed a superior effect to down-regulate the lipid uptake. Both AE subfractions reduced the generation of ROS, decreased the level of p-ser307-IRS-1, and restored the expression of p-Akt. Moreover, treatment of DPP-4 inhibitor linagliptin revealed that, AE could prevent the hepatic lipogenesis, oxidative burden, and the related insulin resistance via downregulating DPP-4. In conclusion, the present investigation revealed that AE, especially F2, is potential to be developed as adjuvant to prevent NAFLD.

DOI: https://doi.org/10.1371/journal.pone.0265444
FEBS J. 2022 Mar 14.

Regulation of basal autophagy by calmodulin availability.

Jennifer Giles, Vanessa Lopez, Elizabeth McConnaha, Matthew Hayden, Caleb Kragenbring, David Carli, Eric Wauson, Quang-Kim Tran.

  Macroautophagy (hereafter autophagy) is a process that degrades cellular components to maintain homeostasis. The Ca2+ sensor calmodulin (CaM) regulates numerous cell functions but is a limiting factor due to its insufficient availability for all target proteins. However, evidence that CaM availability regulates basal autophagy is lacking. Here, we have tested this hypothesis. CaM antagonists W-7, trifluoperazine and CGS9343b cause autophagosome accumulation and inhibit basal autophagic flux in the same manner as does chloroquine. These reagents promote the activity of AMP-activated protein kinase (AMPK) but not that of the mechanistic target of rapamycin (mTOR). Competitive binding assays using CaM sensors with different Ca2+ dependencies showed that chloroquine directly binds CaM in a Ca2+ -dependent fashion. The CaM antagonists have disparate effects on cytoplasmic Ca2+ , triggering from none to robust signals, indicating that their consistent inhibition of autophagy is due to inhibition of CaM and not Ca2+ . Chelating intracellular Ca2+ reduces the effect of the CaM antagonists to accumulate LC3-II, indicating that they do so by inhibiting CaM-dependent activities at basal Ca2+ level. The CaM antagonists cause lysosomal alkalinisation. Consistently, buffering CaM with a high-affinity CaM-binding protein that binds CaM at resting Ca2+ level increases lysosomal pH. Enhanced CaM buffering using a chimeric protein that contains two high-affinity CaM-binding sites that can collectively bind CaM at a large range of Ca2+ further increases lysosomal pH and increases LC3-II accumulation and AMPK activity, but not that of mTOR. These data demonstrate that CaM availability is required for basal autophagy.

Keywords:  autophagy; calmodulin; calmodulin antagonists; chloroquine; lysosomal acidification

DOI:  https://doi.org/10.1111/febs.16432
Life Sci. 2022 Mar 15. pii: S0024-3205(22)00181-3. [Epub ahead of print] 120481

MAP kinase-dependent autophagy controls phorbol myristate acetate-induced macrophage differentiation of HL-60 leukemia cells.

Milos Mandic, Maja Misirkic-Marjanovic, Ljubica Vucicevic, Maja Jovanovic, Mihajlo Bosnjak, Vladimir Perovic, Biljana Ristic, Darko Ciric, Ljubica Harhaji-Trajkovic, Vladimir Trajkovic.

  We investigated the mechanisms and the role of autophagy in the differentiation of HL-60 human acute myeloid leukemia cells induced by protein kinase C (PKC) activator phorbol myristate acetate (PMA). PMA-triggered differentiation of HL-60 cells into macrophage-like cells was confirmed by cell-cycle arrest accompanied by elevated expression of macrophage markers CD11b, CD13, CD14, CD45, EGR1, CSF1R, and IL-8. The induction of autophagy was demonstrated by the increase in intracellular acidification, accumulation/punctuation of autophagosome marker LC3-II, and the increase in autophagic flux. PMA also increased nuclear translocation of autophagy transcription factors TFEB, FOXO1, and FOXO3, as well as the expression of several autophagy-related (ATG) genes in HL-60 cells. PMA failed to activate autophagy inducer AMP-activated protein kinase (AMPK) and inhibit autophagy suppressor mechanistic target of rapamycin complex 1 (mTORC1). On the other hand, it readily stimulated the phosphorylation of mitogen-activated protein (MAP) kinases extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinase (JNK) via a protein kinase C-dependent mechanism. Pharmacological or genetic inhibition of ERK or JNK suppressed PMA-triggered nuclear translocation of TFEB and FOXO1/3, ATG expression, dissociation of pro-autophagic beclin-1 from its inhibitor BCL2, autophagy induction, and differentiation of HL-60 cells into macrophage-like cells. Pharmacological or genetic inhibition of autophagy also blocked PMA-induced macrophage differentiation of HL-60 cells. Therefore, MAP kinases ERK and JNK control PMA-induced macrophage differentiation of HL-60 leukemia cells through AMPK/mTORC1-independent, TFEB/FOXO-mediated transcriptional and beclin-1-dependent post-translational activation of autophagy.

Keywords:  Autophagy; Beclin-1; Differentiation; ERK; JNK; Leukemia

DOI:  https://doi.org/10.1016/j.lfs.2022.120481
Orthop Surg. 2022 Mar 16.

Effects of Antibacterial Co-Cr-Mo-Cu Alloys on Osteoblast Proliferation, Differentiation, and the Inhibition of Apoptosis.

Jing-Zhu Duan, Yang Yang, Huan Wang.

   OBJECTIVES: To investigate the effects of antibacterial Co-Cr-Mo-Cu alloys with different Cu contents on osteoblast proliferation, differentiation, and the inhibition of apoptosis to optimize the selection of surgical implantation.
METHODS: Microstructure, phase structure, and ion release were evaluated using X-ray diffraction, scanning electron microscopy (SEM), and inductively coupled plasma (ICP) spectrometry. The effects on osteoblast proliferation, differentiation, and apoptosis were characterized by cell proliferation assay, alkaline phosphatase (ALP) activity assay, and western blotting, respectively.
RESULTS: Compared to the original Co-Cr-Mo alloys, the released Cu ions from Co-Cu alloys promoted osteoblast proliferation and differentiation and inhibited apoptosis. It can be noted that the optical density (OD490) and the ALP activity have increased to 1.237 and 1.053, respectively, in Co-2Cu alloy (0.604 and 0.171 for original Co-Cr-Mo alloy). Meanwhile, these effects were evaluated through the upregulation of ROS levels and 4E-binding protein 1 (4E-BP1) expression and the downregulation of adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) and p-AMPK. Moreover, the antibacterial properties of the Co-Cu alloys were also enhanced, as demonstrated by the strong antibacterial activity of Cu phases in Co-Cu alloys incubated with Staphylococcus aureus, in which more than 99.8% of the bacteria has been killed.
CONCLUSIONS: The addition of Cu element in the Co-Cr-Mo alloys could induce OB proliferation and differentiation and inhibited OB apoptosis. Meanwhile, it can be recognized that the Co-Cu alloys with 2wt% Cu exhibit the highest performance among all the samples, indicating that the effects of osteoblast differentiation and the inhibition of apoptosis are highly dependent on the adding of Cu elements. Co-Cr-Mo-Cu alloys with an excellent antibacterial property could be used as a tool to improve osteogenic ability and antibacterial properties in orthopaedic implant operations.

Keywords:  Antibacterial property; Co-Cr-Mo alloy; Osteoblast differentiation; Osteoblast proliferation; Released Cu ion

DOI:  https://doi.org/10.1111/os.13253
Food Funct. 2022 Mar 16.

Platycodon grandiflorum root fermentation broth reduces inflammation in a mouse IBD model through the AMPK/NF-κB/NLRP3 pathway.

Zhe Wang, Chunhai Li, Xi He, Kang Xu, Zhipeng Xue, Ting Wang, Zhenshang Xu, Xinli Liu.

The effect of Platycodon grandiflorum (PG) on colitis and its underlying mechanism were rarely studied. In this study, Lactobacillus rhamnosus 217-1 was used to ferment PG roots, and the concentrations of platycodin-D, flavonoids, and polyphenols and the DPPH free radical scavenging rate were significantly increased. Treatment with a PG root fermentation broth (PGRFB) could reduce dextran sulfate sodium (DSS) induced ulcerative colitis (UC) in mice. Meanwhile, the PGRFB significantly reduced the content of inflammatory factors in mouse serum and the expression of inflammatory factor mRNA in the intestinal tract, regulated the polarization of M1/M2 macrophages, and increased the expression of tight junction protein mRNA in intestinal epithelial cells. In summary, it was proved that the PGRFB could inhibit the nuclear factor kappa B (NF-κB) signaling pathway and the expression of Nod-like receptor protein 3 (NLRP3) inflammasomes by activating AMP-activated protein kinase (AMPK) and lowering the release of pro-inflammatory cytokines.

DOI: https://doi.org/10.1039/d1fo03969e
Int J Biol Sci. 2022 ;18(4): 1594-1611

Atractylenolide III ameliorates Non-Alcoholic Fatty Liver Disease by activating Hepatic Adiponectin Receptor 1-Mediated AMPK Pathway.

Qian Li, Jia-Xin Tan, Yong He, Fang Bai, Shi-Wei Li, Yi-Wen Hou, Long-Shan Ji, Ya-Ting Gao, Xin Zhang, Zhen-Hua Zhou, Zhuo Yu, Miao Fang, Yue-Qiu Gao, Man Li.

  Background: Nonalcoholic fatty liver disease (NAFLD) is the most frequent cause of chronic liver diseases worldwide. At present, there are no effective pharmacological therapies for NAFLD except lifestyle intervention-mediated weight loss. Atractylenolide III (ATL III), the major bioactive component found in Atractylode smacrocephala Koidz, has been shown to exert anti-oxidant, anti-tumor, anti-allergic response, anti-bacterial effects and cognitive protection. Here we investigate the therapeutic potential and underlying mechanisms of ATL III for the treatment of NAFLD. Methods: Male C57BL/6J mice were fed a high-fat diet (HFD) and treated with ATL III. Lipid accumulation was analyzed by Oil Red O staining in liver tissues and free fatty acids (FFAs)-treated hepatocytes. AMP-activated protein (AMPK) and sirtuin 1(SIRT1) signaling pathways were inhibited by Compound C and EX527 in vitro, respectively. Small-interfering RNA (siRNA) was used to knockdown adiponectin receptor 1 (AdipoR1) expression in HepG2 cells. Results: ATL III treatment ameliorated liver injury and hepatic lipid accumulation in the HFD-induced NAFLD mouse model as demonstrated by that ATL III administration significantly reduced serum levels of alanine aminotransferase, glutamic oxaloacetic transaminase, triglycerides, total cholesterol and low-density lipoprotein. Furthermore, treatment with ATL III alleviated hepatic oxidative stress, inflammation and fibrosis in the HFD feeding model. To study the underlying mechanisms, we performed Computer Aided Design assay and found that open-formed AdipoR1 and adiponectin receptor 2 were the potential receptors targeted by ATL III. Interestingly, HFD feeding or FFAs treatment only reduced hepatic AdipoR1 expression, while such reduction was abolished by ATL III administration. In addition, in vitro treatment with ATL III activated the AdipoR1 downstream AMPK /SIRT1 signaling pathway and reduced lipid deposition in HepG2 cells, which was diminished by silencing AdipoR1. Finally, inhibition of AMPK or SIRT1, the AdipoR1 downstream signaling, abolished the protective effects of ATL III on lipid deposition and oxidative stress in FFAs-treated HepG2 cells. Conclusion: Our findings suggest that ATL III is a therapeutic drug for the treatment of NAFLD and such protective effect is mediated by activating hepatic AdipoR1-mediated AMPK/SIRT1 signaling pathway.

Keywords:  AMPK; ATL III; AdipoR1; SIRT1; inflammation; oxidative stress

DOI:  https://doi.org/10.7150/ijbs.68873
Food Chem Toxicol. 2022 Mar 12. pii: S0278-6915(22)00107-7. [Epub ahead of print]163 112909

Ferritinophagy is involved in Bisphenol A-induced ferroptosis of renal tubular epithelial cells through the activation of the AMPK-mTOR-ULK1 pathway.

Lijuan Bao, Caijun Zhao, Lianjun Feng, Yihong Zhao, Shiyu Duan, Min Qiu, Keyi Wu, Naisheng Zhang, Xiaoyu Hu, Yunhe Fu.

  Bisphenol A (BPA) is a common environmental contaminant, whose exposure is associated with the progression of various kidney diseases. BPA exposure has turned out to be associated with cytotoxicity to renal tubular epithelial cells, but its underlying mechanism remains unknown. Herein, we found that BPA induced ferroptosis in kidney and renal tubular epithelial cells, as showed by increased intracellular iron accumulation, lipid peroxidation and cells death upon BPA exposure. Additionally, utilization of ferrostatin-1 and desferrioxamine, typical ferroptosis inhibitors, can fundamentally diminish cells death. Intriguingly, we discovered that autophagy inhibitor chloroquine can shield renal tubular epithelial cells from BPA-caused ferroptosis. Furthermore, we found that ferritinophagy, a phenomenon that degradation of ferritin and inducing subsequent iron overload, occurred after BPA exposure and excessive iron promoted ferroptosis through Fenton reaction. We next demonstrated that BPA activated the AMPK-mTOR-ULK1 signaling pathway. In turn, AMPK, mTOR, and ULK1 knockdown dramatically mitigated BPA-induced TCMK-1 cells death, and decreased MDA and LC3 levels, but increased FTH protein content. These results indicate that activation of the AMPK-mTOR-ULK1 signaling is involved in BPA-induced ferritinophagy. In conclusion, renal dysfunction and renal tubular epithelial damage induced by BPA are linked to ferroptosis, which depends on the activation of ferritinophagy through AMPK-mTOR-ULK1 axis.

Keywords:  Autophagy; BPA; Ferritinophagy; Ferroptosis; Renal tubular

DOI:  https://doi.org/10.1016/j.fct.2022.112909
Am J Chin Med. 2022 Mar 10. 1-20

Ameliorative Effects of Malonyl Ginsenoside from Panax ginseng on Glucose-Lipid Metabolism and Insulin Resistance via IRS1/PI3K/Akt and AMPK Signaling Pathways in Type 2 Diabetic Mice.

Dong-Sheng Wang, Jia-Mei Wang, Fu-Rui Zhang, Feng-Jie Lei, Xin Wen, Jia Song, Guang-Zhi Sun, Zhi Liu.

  Our previous study has revealed that malonyl-ginsenosides from Panax ginseng (PG-MGR) play a crucial role in the treatment of T2DM. However, its potential mechanism was still unclear. In this study, we investigated the anti-diabetic mechanisms of action of PG-MGR in high fat diet-fed (HFD) and streptozotocin-induced diabetic mice and determined the main constituents of PG-MGR responsible for its anti-diabetic effects. Our results showed that 16 malonyl ginsenosides were identified in PG-MGR by HPLC-ESI-MS/MS. PG-MGR treatment significantly reduced fasting blood glucose (FBG), triglyceride (TG), total cholesterol (TC), and low-density lipoprotein cholesterol (LDL-C) levels and improved insulin resistance and glucose tolerance. Simultaneously, PG-MGR treatment improved liver injury by decreasing aspartate aminotransferase (AST) and alanine aminotransferase (ALT) expression. Furthermore, Western blot analysis demonstrated that the protein expression levels of p-PI3K/PI3K, p-AKT/AKT, p-AMPK/AMPK, p-ACC/ACC and GLUT4 in liver and skeletal muscle were significantly up-regulated after PG-MGR treatment, and the protein expression levels of p-IRS-1/IRS-1, Fas and SREBP-1c were significantly reduced. These findings revealed that PG-MGR has the potential to improve glucose and lipid metabolism and insulin resistance by activating the IRS-1/PI3K/AKT and AMPK signal pathways.

Keywords:  Insulin Resistance; Malonyl Ginsenosides; Mechanism; Panax Ginseng

DOI:  https://doi.org/10.1142/S0192415X22500367
Open Heart. 2022 Mar;pii: e001801. [Epub ahead of print]9(1):

Ferulic acid and berberine, via Sirt1 and AMPK, may act as cell cleansing promoters of healthy longevity.

James J DiNicolantonio, Mark F McCarty, Simon Iloki Assanga, Lidianys Lewis Lujan, James H O'Keefe.

  Ferulic acid, a bacterial metabolite of anthocyanins, seems likely to be a primary mediator of the health benefits associated with anthocyanin-rich diets, and has long been employed in Chinese cardiovascular medicine. In rodent studies, it has exerted wide-ranging antioxidant and anti-inflammatory effects, the molecular basis of which remains rather obscure. However, recent studies indicate that physiologically relevant concentrations of ferulic acid can boost expression of Sirt1 at mRNA and protein levels in a range of tissues. Sirt1, a class III deacetylase, functions to detect a paucity of oxidisable substrate, and in response works in various ways to promote cellular survival and healthful longevity. Sirt1 promotes 'cell cleansing' and cell survival by boosting autophagy, mitophagy, mitochondrial biogenesis, phase 2 induction of antioxidant enzymes via Nrf2, and DNA repair-while inhibiting NF-kB-driven inflammation, apoptosis, and cellular senescence, and boosting endothelial expression of the protective transcription factor kruppel-like factor 2. A deficit of the latter appears to mediate the endothelial toxicity of the SARS-CoV-2 spike protein. Ferulic acid also enhances the activation of AMP-activated kinase (AMPK) by increasing expression and activity of its activating kinase LKB1-whereas AMPK in turn amplifies Sirt1 activity by promoting induction of nicotinamide phosphoribosyltranferase, rate-limiting for generation of Sirt1's obligate substrate NAD+. Curiously, AMPK acts by independent mechanisms to potentiate many of the effects mediated by Sirt1. Hence, it is proposed that ferulic acid may exert complementary or synergistic health-promoting effects when used in conjunction with clinically useful AMPK activators, such as the nutraceutical berberine. Additional nutraceuticals which might have potential for amplifying certain protective effects of ferulic acid/berberine are also discussed.

Keywords:  carotid artery diseases; coronary angiography; echocardiography

DOI:  https://doi.org/10.1136/openhrt-2021-001801
Phytomedicine. 2022 Mar 02. pii: S0944-7113(22)00105-2. [Epub ahead of print]99 154027

Dihydromyricetin protects against Doxorubicin-induced cardiotoxicity through activation of AMPK/mTOR pathway.

Xiaoqi Li, Xin Wang, Binyu Wang, Weiqun Chi, Zhangyi Li, Min Zhang, Yifu Shen, Xu Liu, Youmei Lu, Yu Liu.

   BACKGROUND: Doxorubicin (DOX) is a highly effective broad-spectrum antitumor agent, but its clinical administration is limited by self-induced cardiotoxicity. Dihydromyricetin (DHM) is a flavonoid compound extracted from the Japanese raisin tree. Evidence that DHM has neovascular protective properties makes it a candidate for studying cardiotoxicity prevention strategy. However, it remains unknown if DHM can protect against cardiotoxicity caused by DOX.
PURPOSE: The present study was performed to evaluate the protective effect of DHM on DOX-induced cardiotoxicity in vivo and in vitro.
METHODS: C57BL/6 mice were intraperitoneally injected with DOX to construct cardiac injury model in vivo, and AC16 cells were exposed to DOX to induce cell injury in vitro. Left ventricular function of mice were detected by echocardiography, the apoptosis of mice cardiac tissue and AC16 cells were detected by TUNEL and Hoechst33342/PI double staining. The expression of apoptosis and autophagy related proteins were detected by western blotting, immunohistochemical staining and immunofluorescence staining.
RESULTS: Echocardiographic results showed that DOX-induced cardiotoxicity were significantly alleviated by DHM pretreatment. DOX induced cardiotoxicity of mice by inhibiting AMPK activation, increasing apoptosis and decreasing autophagy. However, under the same conditions, the heart tissue of DHM-pretreated mice showed increased autophagy and decreased apoptosis via activation AMPK/mTOR pathway. The same results were observed in vitro, and it was also found that DHM can inhibit the production of intracellular ROS in vitro.
CONCLUSION: DHM protects against cardiotoxicity by inhibiting apoptosis and oxidative stress and it can allevate theautophagy inhibition caused by DOX through AMPK/mTOR pathway. DHM preconditioning may be a breakthrough in protecting DOX-induced cardiotoxicity in the future clinical applications.

Keywords:  AMPK; Autophagy; Cardiotoxicity; Dihydromyricetin; Doxorubicin

DOI:  https://doi.org/10.1016/j.phymed.2022.154027
Environ Toxicol. 2022 Mar 14.

Knockdown of MAGE-A6 enhanced the irradiation sensitivity of non-small cell lung cancer cells by activating the AMPK pathway.

Jialiang Zhou, Qiang Fan, Jie Li, Jia Wu, Jianfeng Huang, Yunxia Zhang, Xiuyun He.

  Non-small cell lung cancer is a common respiratory tumor. The mortality rate of lung cancer patients has continued to rise in recent years. Several studies revealed that the expression of melanoma antigen 6 (MAGE-A6) promoted the development of multiple types of cancer. In addition, the suppression of AMPK pathway could restrict the radiosensitization of prostate cancer cells. Inhibition of MAGE-A6 activated the AMPK pathway in colorectal cancer cells. However, whether the MAGE-A6 could regulate the radiosensitivity of non-small cell lung cancer cells by regulating of the AMPK pathway is unclear. In this study, we established the MAGE-A6 knockdown in A549 and H1299 cells. Next, the apoptosis and proliferation of these cells were detected by the flow cytometry analysis and colony formation assay after the irradiation, respectively. Then, the expression of p-AMPKα1 and p-S6K1 in these cells was explored by the western blotting. After that, we inhibited the expression of AMPKα1 in MAGE-A6 knockdown cells. The proliferation and apoptosis of these cells were detected with colony formation assay and flow cytometry analysis. Finally, the tumor formation of these cells was detected in nude mice. Our results showed that inhibition of MAGE-A6 suppressed the proliferation and aggravated the apoptosis of A549 and H1299 cells after the irradiation. Knockdown of MAGE-A6 activated the expression of p-AMPKα1 and repressed the expression of p-S6K1 in these cells. Suppression of AMPKα1 in MAGE-A6 knockdown cells abolished these effects. Knockdown of MAGE-A6 also enhanced the radiosensitivity of these cells in vivo. These results suggested that inhibition of MAGE-A6 promoted the radiosensitivity of non-small cell lung cancer cells by activating AMPK pathway. Therefore, MAGE-6 has the potential to be explored as the therapeutic target for the treatment of non-small cell lung cancer in clinical.

Keywords:  AMPK; MAGE-A6; apoptosis; non-small cell lung cancer; radiosensitivity

DOI:  https://doi.org/10.1002/tox.23519
BMC Cardiovasc Disord. 2022 Mar 15. 22(1): 107

SERPINB1 overexpression protects myocardial damage induced by acute myocardial infarction through AMPK/mTOR pathway.

Hongliang Wang, Jun Hua, Shiyuan Chen, Ying Chen.

   BACKGROUND: SERPINB1 is involved in the development of a variety of diseases. The purpose of this study was to explore the effect of SERPINB1 on acute myocardial infarction (AMI).
METHODS: Serum SERPINB1 level of AMI patients was measured for receiver operating characteristic curve analysis. The AMI rat model was constructed to observe myocardial damage, and the H9C2 cell oxygen glucose deprivation (OGD) model was constructed to detect cell viability. Transthoracic echocardiography was used to assess the cardiac function. TTC staining and HE staining were used to detect pathologic changes of myocardial tissues. The apoptosis of myocardial tissues and cells were measured by TUNLE staining and flow cytometry assay. CCK-8 assay to measure cell viability. SERPINB1 expression was measured by qRT-PCR. Protein expression was measured by western blot.
RESULTS: The serum SERPINB1 level was down-regulated in AMI patients. AMI modeling reduced the SERPINB1 expression level, induced inflammatory cells infiltrated, and myocardial apoptosis. OGD treatment inhibited cell viability and promoted apoptosis. The AMPK/mTOR pathway was inhibited in AMI rats and OGD-treated H9C2 cells. Overexpression of SERPINB1 reduced infarct size and myocardial apoptosis of AMI rats, inhibited apoptosis of H9C2 cells, and activated AMPK/mTOR pathway. However, AMPK inhibitor Dorsomorphin reversed the protective effect of SERPINB1 on myocardial cells.
CONCLUSION: SERPINB1 overexpression relieved myocardial damage induced by AMI via AMPK/mTOR pathway.

Keywords:  AMPK/mTOR pathway; Acute myocardial infarction; Apoptosis; SERPINB1

DOI:  https://doi.org/10.1186/s12872-022-02454-7
Cell Death Dis. 2022 Mar 15. 13(3): 240

Dopamine D3 receptor signaling alleviates mouse rheumatoid arthritis by promoting Toll-like receptor 4 degradation in mast cells.

Biao Wang, Xueyi Li, Ming Li, Yan Geng, Na Wang, Yaofeng Jin, Wen Zhang, Ke Xu, Jing Wang, Li Tao, Simin Lai, Kunyi Wu, Jing Lei, Jing Wang, Ting Zhou, Ke Li, Yanjiong Chen, Li Xue.

Dopamine receptors are involved in several immunological diseases. We previously found that dopamine D3 receptor (D3R) on mast cells showed a high correlation with disease activity in patients with rheumatoid arthritis, but the mechanism remains largely elusive. In this study, a murine collagen-induced arthritis (CIA) model was employed in both DBA/1 mice and D3R knockout mice. Here, we revealed that D3R-deficient mice developed more severe arthritis than wild-type mice. D3R suppressed mast cell activation in vivo and in vitro via a Toll-like receptor 4 (TLR4)-dependent pathway. Importantly, D3R promoted LC3 conversion to accelerate ubiquitin-labeled TLR4 degradation. Mechanistically, D3R inhibited mTOR and AKT phosphorylation while enhancing AMPK phosphorylation in activated mast cells, which was followed by autophagy-dependent protein degradation of TLR4. In total, we found that D3R on mast cells alleviated inflammation in mouse rheumatoid arthritis through the mTOR/AKT/AMPK-LC3-ubiquitin-TLR4 signaling axis. These findings identify a protective function of D3R against excessive inflammation in mast cells, expanding significant insight into the pathogenesis of rheumatoid arthritis and providing a possible target for future treatment.

DOI: https://doi.org/10.1038/s41419-022-04695-y
Int Immunopharmacol. 2022 Mar 15. pii: S1567-5769(22)00177-1. [Epub ahead of print]107 108693

Role of Cannabidiol and Tetrahydrocannabivarin on Paclitaxel-induced neuropathic pain in rodents.

Anil Kumar Kalvala, Arvind Bagde, Peggy Arthur, Sunil Kumar Surapaneni, Nimma Ramesh, Aakash Nathani, Mandip Singh.

  The purpose of this study was to evaluate if phytocannabinoids, synthetic cannabidiol (CBD), and tetrahydrocannabivarin (THCV), and their combination, could protect mice from Paclitaxel-induced peripheral neuropathy (PIPN). Six groups of C57BL/6J mice (n = 6) were used in this study. The mice were given paclitaxel (PTX) (8 mg/kg/day, i.p.) on days 1, 3, 5, and 7 to induce neuropathy. Mice were evaluated for behavioral parameters, and dorsal root ganglions (DRG) were collected from the animals and subjected to RNA sequencing and westernblot analysis at the end of the study. On cultured DRGs derived from adult male rats, immunocytochemistry and mitochondrial functional assays were also performed. When compared to individual treatments, the combination of CBD and THCV improved thermal and mechanical neurobehavioral symptoms in mice by twofold. Targets for CBD and THCV therapy were identified by KEGG (RNA sequencing). PTX reduced the expression of p-AMPK, SIRT1, NRF2, HO1, SOD2, and catalase while increasing the expression of PI3K, p-AKT, p-P38 MAP kinase, BAX, TGF-β, NLRP3 inflammasome, and caspase 3 in DRG homogenates of mice. Combination therapy outperformed monotherapy in reversing these protein expressions. The addition of CBD and THCV to DRG primary cultures reduced mitochondrial superoxides while increasing mitochondrial membrane potentials. WAY100135 and rimonabant altered the neuroprotective effects of CBD and THCV respectively by blocking 5-HT1A and CB1 receptors in mice and DRG primary cultures. The entourage effect of CBD and THCV against PIPN appears to protect neurons in mice via 5HT1A and CB1 receptors respectively.

Keywords:  5-HT1A receptors; AMPK; CB1 receptors; Cannabidiol; Peripheral Neuropathy; Tetrahydrocannabivarin

DOI:  https://doi.org/10.1016/j.intimp.2022.108693
Exp Mol Pathol. 2022 Mar 09. pii: S0014-4800(22)00015-6. [Epub ahead of print] 104755

B7-H4 expression promotes non-small cell lung cancer progression via AMPK/mTOR signaling.

Mengxuan Li, Nan Che, Ying Feng, Xingzhe Liu, Lihua Piao, Yanhua Xuan, Yu Jin.

  Several studies have demonstrated that B7-H4 is highly expressed in a variety of cancers and often affects tumor development. However, its role in cancer stemness and epithelial-to-mesenchymal transition (EMT) in non-small cell lung cancer (NSCLC) has not been reported. Here, we investigated the relationship between B7-H4 expression and cancer stemness and EMT by immunohistochemistry in 106 NSCLC tissues obtained from patients. The results confirmed that B7-H4 is highly expressed in NSCLC tissues and closely correlated with the expression of EMT-related proteins (Snail, Vimentin) and cancer stemness-related proteins (SOX2, SOX9, and CD44). Immunofluorescence assay indicated that B7-H4 colocalized with SOX2 and SOX9 in the nuclei of NSCLC cells. Additionally, upon knocking down B7-H4, the expression of SOX2, SOX9, and CD44, as well as of Snail and Vimentin was inhibited, whereas E-cadherin expression was enhanced in NSCLC cells. Meanwhile, inhibiting the expression of B7-H4 resulted in reduced invasion and migration ability of NSCLC cells. Mechanistically, silencing B7-H4 activated the adenosine monophosphate-activated protein kinase /mammalian target of rapamycin signaling, which in turn, negatively regulated cell proliferation, stemness, and migration. In conclusion, our results suggest that B7-H4 expression is high in NSCLC tissues, and it has an effect on EMT and cancer stemness. This further suggests that B7-H4 has a potential role in promoting the progression of NSCLC and thereby could be a potential therapeutic target in NSCLC treatment.

Keywords:  B7-H4; Cancer stem-like cells; Epithelial-mesenchymal transition; Non-small cell lung cancer

DOI:  https://doi.org/10.1016/j.yexmp.2022.104755
Front Cardiovasc Med. 2022 ;9 803510

Exercise-Generated β-Aminoisobutyric Acid (BAIBA) Reduces Cardiomyocyte Metabolic Stress and Apoptosis Caused by Mitochondrial Dysfunction Through the miR-208b/AMPK Pathway.

Yanan Yu, Wewei Chen, Ming Yu, Jinsha Liu, Huan Sun, Ping Yang.

   Objective: To explore the cardioprotective effects of exercise-derived β-aminoisobutyric (BAIBA) on cardiomyocyte apoptosis and energy metabolism in a rat model of heart failure (HF).
Methods: In male Sprague-Dawley rats (8-week-old), myocardial infarction (MI) was used to induce HF by ligating the left anterior descending branch of the coronary artery. In the Sham group, the coronary artery was threaded but not ligated. After HF development, Sham and HF rats were exercised 60 min daily, 5 days/week on a treadmill for 8 weeks (50-60% maximal intensity) and exercise-induced cardiac remodeling after MI were assessed using echocardiography, hematoxylin and eosin (H&E), Masson's Trichrome, and TUNEL staining for the detection of apoptosis-associated factors in cardiac tissue. High-throughput sequencing and mass spectrometry were used to measure BAIBA production and to explore its cardioprotective effects and molecular actions. To further characterize the cardioprotective effects of BAIBA, an in vitro model of apoptosis was generated by applying H2 O 2 to H9C2 cells to induce mitochondrial dysfunction. In addition, cells were transfected with either a miR-208b analog or a miR-208b inhibitor. Apoptosis-related proteins were detected by Western Blotting (WB). ATP production was also assessed by luminometry. After administration of BAIBA and Compound C, the expression of proteins related to apoptosis, mitochondrial function, lipid uptake, and β-oxidative were determined. Changes in the levels of reactive oxygen species (ROS) were assessed by fluorescence microscopy. In addition, alterations in membrane potential (δψm) were obtained by confocal microscopy.
Results: Rats with HF after MI are accompanied by mitochondrial dysfunction, metabolic stress and apoptosis. Reduced expression of apoptosis-related proteins was observed, together with increased ATP production and reduced mitochondrial dysfunction in the exercised compared with the Sham (non-exercised) HF group. Importantly, exercise increased the production of BAIBA, irrespective of the presence of HF. To assess whether BAIBA had similar effects to exercise in ameliorating HF-induced adverse cardiac remodeling, rats were treated with 75 mg/kg/ day of BAIBA and we found BAIBA had a similar cardioprotective effect. Transcriptomic analyses found that the expression of miR-208b was increased after BAIBA administration, and subsequent transfection with an miR-208b analog ameliorated both the expression of apoptosis-related proteins and energy metabolism in H2O2-treated H9C2 cells. In combining transcriptomic with metabolomic analyses, we identified AMPK as a downstream target for BAIBA in attenuating metabolic stress in HF. Further cell experiments confirmed that BAIBA increased AMPK phosphorylation and had a cardioprotective effect on downstream fatty acid uptake, oxidative efficiency, and mitochondrial function, which was prevented by the AMPK inhibitor Compound C.
Conclusion: Exercise-generated BAIBA can reduce cardiomyocyte metabolic stress and apoptosis induced by mitochondrial dysfunction through the miR-208b/AMPK pathway.

Keywords:  exercise; heart failure; lipid metabolism; metabolic stress; mitochondrial dysfunction

DOI:  https://doi.org/10.3389/fcvm.2022.803510
Mol Genet Genomics. 2022 Mar 15.

PGC-1α affects skeletal muscle and adipose tissue development by regulating mitochondrial biogenesis.

Shaofen Kong, Bolin Cai, Qinghua Nie.

  The discovery and interpretation of peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α) protein in mitochondrial biogenesis, skeletal muscle and adipose tissue development has broad research prospects, so it is important to review the related studies of PGC-1α in detail and comprehensively. PGC-1α is a protein composed of 798 amino acids (aa) with a molecular weight of about 91 kDa. PGC-1α is involved in the operation of the respiratory chain by combining with deacetylase and phosphorylase to bind some nuclear receptors. In addition, PGC-1α affects skeletal muscle and adipose metabolism by regulating mitochondrial oxidative phosphorylation. Recently, new data suggest that regulating mitochondrial metabolism in adipose tissue may be an effective adjunct to the treatment of obesity. In addition, dietary resveratrol, which has an effective anti-obesity effect, has been shown to promote mitochondrial biosynthesis by activating AMPK/PGC-1α axis, as well as to regenerate muscle damaged by obesity. In this review, we combined previous studies to explore the latest studies, showing that PGC-1α can regulate mitochondrial biogenesis and is regulated by AMPK and SIRT1. Furthermore, PGC-1α is a favored protein, which not only regulates muscle fiber type, inhibits muscle atrophy, but also participates in browning of white adipose tissue (WAT) and regulates body heat production. So, we concluded that PGC-1α is a key gene in mitochondrial biogenesis and plays an important role in the regulation and regulation of mitochondrial biogenesis along with other genes involved in the process. Meanwhile, PGC-1α acts as a core metabolic regulator in adipose tissue and skeletal muscle. This review comprehensively summarizes a large number of research findings. First, the role of PGC-1α in mitochondrial biogenesis was clarified, and then the key role of PGC-1α in the development of skeletal muscle and adipose tissue was reevaluated. Furthermore, the role of PGC-1α in some human diseases was discussed. Finally, the role of PGC-1α as a major gene in poultry was pointed out, and the future research direction was proposed.

Keywords:  Adipose tissue; Mitochondria; Mitochondrial biogenesis; PGC-1α; Skeletal muscle

DOI:  https://doi.org/10.1007/s00438-022-01878-2
Elife. 2022 Mar 17. pii: e71282. [Epub ahead of print]11

Adiponectin receptor agonist AdipoRon improves skeletal muscle function in aged mice.

Priya Balasubramanian, Anne E Schaar, Grace E Gustafson, Alex B Smith, Porsha R Howell, Angela Greenman, Scott Baum, Ricki J Colman, Dudley W Lamming, Gary M Diffee, Rozalyn M Anderson.

  The loss of skeletal muscle function with age, known as sarcopenia, significantly reduces independence and quality of life and can have significant metabolic consequences. Although exercise is effective in treating sarcopenia it is not always a viable option clinically, and currently there are no pharmacological therapeutic interventions for sarcopenia. Here we show that chronic treatment with pan-adiponectin receptor agonist AdipoRon improved muscle function in male mice by a mechanism linked to skeletal muscle metabolism and tissue remodeling. In aged mice, 6 weeks of AdipoRon treatment improved skeletal muscle functional measures in vivo and ex vivo. Improvements were linked to changes in fiber type, including an enrichment of oxidative fibers, and an increase in mitochondrial activity. In young mice, 6 weeks of AdipoRon treatment improved contractile force and activated the energy sensing kinase AMPK and the mitochondrial regulator PGC-1a (peroxisome proliferator activated receptor gamma coactivator 1 alpha). In cultured cells, the AdipoRon induced stimulation of AMPK and PGC-1a was associated with increased mitochondrial membrane potential, reorganization of mitochondrial architecture, increased respiration, and increased ATP production. Furthermore, the ability of AdipoRon to stimulate AMPK and PGC1a was conserved in nonhuman primate cultured cells. These data show that AdipoRon is an effective agent for the prevention of sarcopenia in mice and indicate that its effects translate to primates, suggesting it may also be a suitable therapeutic for sarcopenia in clinical application.

Keywords:  cell biology; mouse; rhesus macaque

DOI:  https://doi.org/10.7554/eLife.71282
Cell Signal. 2022 Mar 15. pii: S0898-6568(22)00070-5. [Epub ahead of print] 110309

Sirt3 ameliorates mitochondrial dysfunction and oxidative stress through regulating mitochondrial biogenesis and dynamics in cardiomyoblast.

Paramesha Bugga, Md Jahangir Alam, Roshan Kumar, Subhashis Pal, Naibedya Chattopadyay, Sanjay Kumar Banerjee.

  Sirtuins are the endogenously present anti-aging protein deacetylases that regulate the mitochondrial biogenesis and function. Especially Sirt3, a mitochondrial sirtuin, is well known for maintaining mitochondrial function and health. In the present study, we have explored the novel role of Sirt3 in mitochondrial biogenesis and shown the role of Sirt3 in mito-nuclear communication through AMPK-α in Sirt3 knockdown and Sirt3 overexpressed H9c2 cells. The study found that impaired mitochondrial function in Sirt3-knockdown H9c2 cells was associated with decreased expression of mitochondrial DNA encoded genes, reduced SOD2 expression and activity. The study also revealed that Sirt3 knockdown affects mitochondrial biogenesis and dynamics. To further confirm the role of Sirt3 on mitochondrial biogenesis and health, we did Sirt3 overexpression in H9c2 cells. Sirt3 overexpression enhanced the expression of mitochondrial DNA encoded genes, increased SOD2 activity and altered mitochondrial dynamics. Sirt3 overexpression also caused an increase in mitochondrial biogenesis gene and protein (PGC-1α and TFAM) expression. All these changes were confirmed with mitochondrial functional parameters like basal respiration, maximal respiratory capacity, spare respiratory capacity and ATP production. We found decreased mitochondrial function in Sirt3-knockdown H9c2 cells when compared to control H9c2 cells. Together our data conclude that Sirt3 regulates cardiac mitochondrial health and function through the Sirt3-AMPKα-PGC-1α axis.

Keywords:  AMPK; Cardiomyoblast; Mitochondrial biogenesis; Mitochondrial dynamics; SOD2; Sirt3

DOI:  https://doi.org/10.1016/j.cellsig.2022.110309
Biomed Pharmacother. 2022 Mar 12. pii: S0753-3322(22)00208-6. [Epub ahead of print]149 112820

Social isolation triggers oxidative status and impairs systemic and hepatic insulin sensitivity in normoglycemic rats.

Maria Bove, Adriano Lama, Stefania Schiavone, Claudio Pirozzi, Paolo Tucci, Vladyslav Sikora, Giovanna Trinchese, Gaetano Corso, Maria Grazia Morgese, Luigia Trabace.

  Drug-naïve psychotic patients show metabolic and hepatic dysfunctions. The rat social isolation model of psychosis allows to investigate mechanisms leading to these disturbances to which oxidative stress crucially contributes. Here, we investigated isolation-induced central and peripheral dysfunctions in glucose homeostasis and insulin sensitivity, along with redox dysregulation. Social isolation did not affect basal glycemic levels and the response to glucose and insulin loads in the glucose and insulin tolerance tests. However, HOMA-Index value were increased in isolated (ISO) rats. A hypothalamic reduction of AKT phosphorylation and a trend toward an increase in AMPK phosphorylation were observed following social isolation, accompanied by reduced GLUT-4 levels. Social isolation also induced a reduction of phosphorylation of the insulin receptor, of AKT and GLUT-2, and a decreased phosphorylation of AMPK in the liver. Furthermore, a significant reduction in hepatic CPT1 and PPAR-α levels was detected. ISO rats also showed significant elevations in hepatic ROS amount, lipid peroxidation and NOX4 expression, whereas no differences were detected in NOX2 and NOX1 levels. Expression of SOD2 in the mitochondrial fraction and SOD1 in the cytosolic fraction was not altered following social isolation, whereas SOD activity was increased. Furthermore, a decrease of hepatic CAT and GSH amount was observed in ISO rats compared to GRP animals. Our data suggest that the increased oxidant status and antioxidant capacity modifications may trigger hepatic and systemic insulin resistance, by altering signal hormone pathway and sustaining subsequent alteration of glucose homeostasis and metabolic impairment observed in the social isolation model of psychosis.

Keywords:  Hypothalamus; Insulin; Liver; Oxidative stress; Social isolation

DOI:  https://doi.org/10.1016/j.biopha.2022.112820
Curr Biol. 2022 Mar 08. pii: S0960-9822(22)00328-1. [Epub ahead of print]

Parallel kinase pathways stimulate actin polymerization at depolarized mitochondria.

Tak Shun Fung, Rajarshi Chakrabarti, Jana Kollasser, Klemens Rottner, Theresia E B Stradal, Frieda Kage, Henry N Higgs.

  Mitochondrial damage (MtD) represents a dramatic change in cellular homeostasis, necessitating metabolic changes and stimulating mitophagy. One rapid response to MtD is a rapid peri-mitochondrial actin polymerization termed ADA (acute damage-induced actin). The activation mechanism for ADA is unknown. Here, we use mitochondrial depolarization or the complex I inhibitor metformin to induce ADA. We show that two parallel signaling pathways are required for ADA. In one pathway, increased cytosolic calcium in turn activates PKC-β, Rac, WAVE regulatory complex, and Arp2/3 complex. In the other pathway, a drop in cellular ATP in turn activates AMPK (through LKB1), Cdc42, and FMNL formins. We also identify putative guanine nucleotide exchange factors for Rac and Cdc42, Trio and Fgd1, respectively, whose phosphorylation states increase upon mitochondrial depolarization and whose suppression inhibits ADA. The depolarization-induced calcium increase is dependent on the mitochondrial sodium-calcium exchanger NCLX, suggesting initial mitochondrial calcium efflux. We also show that ADA inhibition results in enhanced mitochondrial shape changes upon mitochondrial depolarization, suggesting that ADA inhibits these shape changes. These depolarization-induced shape changes are not fragmentation but a circularization of the inner mitochondrial membrane, which is dependent on the inner mitochondrial membrane protease Oma1. ADA inhibition increases the proteolytic processing of an Oma1 substrate, the dynamin GTPase Opa1. These results show that ADA requires the combined action of the Arp2/3 complex and formin proteins to polymerize a network of actin filaments around mitochondria and that the ADA network inhibits the rapid mitochondrial shape changes that occur upon mitochondrial depolarization.

Keywords:  AMPK; Arp2/3 complex; CCCP; FMNL formins; OMA1; OPA1; PKCβ; actin; calcium; mitochondrial depolarization

DOI:  https://doi.org/10.1016/j.cub.2022.02.058
Cell Biosci. 2022 Mar 15. 12(1): 32

TSLP regulates mitochondrial ROS-induced mitophagy via histone modification in human monocytes.

Yi-Ching Lin, Yu-Chih Lin, Mei-Lan Tsai, Wei-Ting Liao, Chih-Hsing Hung.

   BACKGROUND: Thymic stromal lymphopoietin (TSLP) is a Th2-like cytokine involved in asthma pathogenesis. Excessive reactive oxygen species (ROS) production can lead to airway inflammation, hyperresponsiveness and remodeling. Mitophagy, followed by ROS production, is the selective degradation of mitochondria by autophagy and often occurs in defective mitochondria. In the present study, we aimed to examine the effects of TSLP on ROS production and mitophagy in human monocytes and to investigate the underlying mechanisms, including epigenetic regulation.
RESULTS: TSLP induced ROS generation, and the effects were reversed by the antioxidant N-acetylcysteine (NAC) in THP-1 cells. Transmission electron microscopy images showed donut-shaped mitochondria that lost the cristae ultrastructure after TSLP stimulation. A decrease in mitochondrial membrane potential, decreased MTCO2 expression, and increased mitochondrial DNA release after TSLP stimulation were found. TSLP enhanced mitochondrial complex I and complex II/III activity and increased mitochondrial copy numbers and the expression of the complex II SHDA gene. TSLP-induced SHDA expression was inhibited by the histone acetyltransferase inhibitor anacardic acid (AA) and the histone methyltransferase inhibitor methylthioadenosine (MTA), and chromatin immunoprecipitation assays revealed that TSLP enhanced H3 acetylation, H4 acetylation, and H3K4 and H3K36 trimethylation in the SHDA promoter. Confocal laser microscopy showed that TSLP treatment increased the signals of the mitophagy-related proteins PINK1, LC3, phospho-parkin and phospho-ubiquitin, and pretreatment with AA and MTA reduced TSLP-induced PINK1 and LC3 accumulation in mitochondria. Western blot analysis showed that TSLP significantly increased phosphor-AMPK signal intensity, and the effects were inhibited by the antioxidant NAC. The increased signal intensities of the mitophagy-related proteins PINK1, Parkin and LC3 I/II were decreased by dorsomorphin, an AMPK inhibitor. TSLP decreased M1-related cytokine CXCL-10 production and increased M2-related cytokine CCL-1 and CCL-22 production, which was suppressed by the mitophagy inhibitor Mdivi-1 and PINK1 gene knockdown.
CONCLUSIONS: Epithelial-derived TSLP regulates ROS production and mitophagy through AMPK activation and histone modification and alters M1/M2 chemokine expression in human monocytes.

Keywords:  Chemokine; Histone modification; Mitophagy; Monocytes; Reactive oxygen species (ROS); TSLP

DOI:  https://doi.org/10.1186/s13578-022-00767-w
Front Physiol. 2022 ;13 817542

Empagliflozin Inhibits Hepatic Gluconeogenesis and Increases Glycogen Synthesis by AMPK/CREB/GSK3β Signalling Pathway.

Xiaochen Yu, Ziyu Meng, Ting Fang, Xiaohuan Liu, Ying Cheng, Linxin Xu, Xiangyang Liu, Xiaoyu Li, Mei Xue, Ting Li, Bei Sun, Liming Chen.

  Increases in glucose production and decreases in hepatic glycogen storage induce glucose metabolic abnormalities in type 2 diabetes (T2DM). Empagliflozin, a sodium-dependent glucose transporter 2 (SGLT2) inhibitor, is an effective hypoglycemic drug; however, the effects of empagliflozin on hepatic gluconeogenesis and glycogenesis are still unclear. In this study, we investigated the effects and mechanisms of empagliflozin on hepatic gluconeogenesis and glycogenesis in vivo and in vitro. Empagliflozin was administered via gavage to db/db mice for 8 weeks, and human hepatocyte HL7702 cells were treated with empagliflozin after palmitic acid (PA) stimulation. Compared with the control db/db mice, empagliflozin-treated mice showed a significant reduction in urine glucose levels, blood glucose levels, body weight and intraperitoneal glucose tolerance test (IPGTT) blood glucose levels. Moreover, the expression levels and activities of key gluconeogenesis enzymes PEPCK and G6Pase were dramatically reduced in the empagliflozin-treated mice, and the protein expression levels of AMPK/CREB/GSK3β signalling pathway-related molecules were significantly changed. In HL7702 cells, empagliflozin ameliorated glucose production and PEPCK and G6Pase expression and activity. Empagliflozin could also prevent the decreases in glycogen content and regulate the protein expression levels of AMPK/CREB/GSK3β signalling pathway-related molecules. Then, we selected the AMPK agonist AICAR and inhibitor compound C to further verify the effects of the AMPK signalling pathway on hepatic gluconeogenesis and glycogen synthesis. The results of the 5-Aminoimidazole-4-carboxamide1-β-D-ribofuranoside (AIACR) intervention in HL7702 cells were consistent with those of empagliflozin treatment, and the effects of empagliflozin were abolished by compound C. In summary, empagliflozin could maintain glucose homoeostasis by reducing gluconeogenesis and increasing glycogenesis through the AMPK/CREB/GSK3β signalling pathway.

Keywords:  AMPK/CREB/GSK3β signalling pathway; SGLT2 inhibitor; empagliflozin; gluconeogenesis; glycogenesis

DOI:  https://doi.org/10.3389/fphys.2022.817542
Mol Med Rep. 2022 May;pii: 161. [Epub ahead of print]25(5):

SESN1 attenuates the Ox‑LDL‑induced inflammation, apoptosis and endothelial‑mesenchymal transition of human umbilical vein endothelial cells by regulating AMPK/SIRT1/LOX1 signaling.

Feng Gao, Yongcheng Zhao, Bin Zhang, Chunwei Xiao, Zhanfa Sun, Yuan Gao, Xueyong Dou.

  Endothelial cells are an important component of the heart and vasculature and form a crucial link between the cardiovascular system and the immune system. Sestrin 1 (SESN1) has an important role in atherosclerosis by inhibiting NOD‑like receptor family pyrin domain containing 3 inflammasome activation. However, whether SESN1 is involved in human umbilical vein endothelial cell (HUVEC) injury caused by atherosclerosis has remained to be elucidated. The present study aimed to investigate the functions of SESN1 in the inflammatory response, apoptosis and endothelial‑mesenchymal transition (EndMT) of HUVECs following stimulation with oxidized low‑density lipoprotein (Ox‑LDL). SESN1 expression at the mRNA and protein levels was detected using reverse transcription‑quantitative PCR (RT‑qPCR) and western blot analysis. Following SESN1 overexpression in Ox‑LDL‑stimulated HUVECs, cell viability was determined using a Cell Counting Kit‑8 assay. Terminal deoxynucleotidyl transferase‑mediated nick‑end labeling staining was employed to detect cell apoptosis and western blot analysis was used to determine the levels of apoptosis‑related proteins. RT‑qPCR, ELISA and western blot were utilized to determine the levels of inflammatory factors. Immunofluorescence staining, RT‑qPCR and western blot analysis were employed to assess the EndMT of Ox‑LDL‑stimulated HUVECs. The results revealed that SESN1 exhibited a low expression in HUVECs following Ox‑LDL stimulation. SESN1 overexpression suppressed inflammation, apoptosis and EndMT in Ox‑LDL‑induced HUVECs. In addition, SESN1 stimulated adenosine monophosphate‑activated protein kinase catalytic subunit α1/sirtuin 1 signaling to suppress Ox‑LDL receptor‑1 expression. An AMPK and SIRT1 inhibitor reversed the effects of SESN1 overexpression on the inflammatory response, apoptosis and EndMT of HUVECs exposed to Ox‑LDL. Taken together, the present study demonstrated that SENS1 exerts a suppressive effect on Ox‑LDL‑induced inflammation, apoptosis and EndMT of HUVECs, suggesting that SENS1 may be used as a novel biomarker for endothelial injury‑related disorders.

Keywords:  AMP‑activated protein kinase catalytic subunit alpha 1; Sestrin 1; apoptosis; atherosclerosis; endothelial‑mesenchymal transition; inflammation

DOI:  https://doi.org/10.3892/mmr.2022.12678
Front Pharmacol. 2022 ;13 783506

Bilobalide Exerts Anti-Inflammatory Effects on Chondrocytes Through the AMPK/SIRT1/mTOR Pathway to Attenuate ACLT-Induced Post-Traumatic Osteoarthritis in Rats.

Tianwen Ma, Liangyu Lv, Yue Yu, Lina Jia, Xiaopeng Song, XinYu Xu, Ting Li, Xuanbo Sheng, Haoran Wang, Jiantao Zhang, Li Gao.

  Although osteoarthritis (OA) significantly affects the quality of life of the elderly, there is still no effective treatment strategy. The standardized Ginkgo biloba L. extract preparation has been shown to have a wide range of therapeutic effects. Bilobalide, a unique ingredient of Ginkgo biloba, has anti-inflammatory and antioxidant pharmacological properties, but its mechanism of action on OA remains unknown. In this study, we investigated the effects of bilobalide on the development of OA through in vivo and in vitro experiments, as well as its potential anti-inflammatory mechanisms. The in vitro experiments demonstrated that bilobalide significantly inhibited the production of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), and matrix metalloproteinase 13 (MMP13) in ATDC5 chondrocytes induced by Interleukin-1β (IL-1β). At the molecular level, bilobalide induced chondrocyte autophagy by activating the AMPK/SIRT1/mTOR signaling pathway, which increased the expression of autophagy-related Atg genes, up-regulated the expression of LC3 protein, and reduced the expression of the p62 protein. In vivo, bilobalide exerted significant anti-inflammatory and anti-extracellular matrix (ECM) degradation effects in a rat model of post-traumatic OA (PTOA) induced by anterior cruciate ligament transection (ACLT). Bilobalide could relieve joint pain in PTOA rats, inhibit the expression of iNOS and COX-2 protein in cartilage via the AMPK/SIRT1/mTOR pathway, and reduce the level of ECM degradation biomarkers in serum. In conclusion, bilobalide exhibits vigorous anti-inflammatory activity, presenting it as an interesting potential therapeutic agent for OA.

Keywords:  ACLT; AMPK/SIRT1/mTOR; autophagy; bilobalide; inflammation; osteoarthritis

DOI:  https://doi.org/10.3389/fphar.2022.783506
Br J Pharmacol. 2022 Mar 16.

Honokiol ameliorates cisplatin-induced acute kidney injury via inhibition of mitochondrial fission.

Rui-Wen Mao, Shan-Ping He, Jun-Gang Lan, Wu-Zheng Zhu.

   BACKGROUND AND PURPOSE: Mitochondrial damage and oxidative stress are the crucial contributors to the tubular cell injury and death in acute kidney injury (AKI). Novel therapeutic strategies targeting mitochondria protection and halting the progression of AKI are urgently needed. Honokiol (HKL) is a small-molecule polyphenol that exhibits extraordinary cytoprotective effects, such as anti-inflammatory and anti-oxidative properties. Thus, we wonder whether HKL could ameliorate cisplatin-induced AKI via preventing mitochondrial dysfunction.
EXPERIMENTAL APPROACH: AKI was induced by cisplatin administration. Biochemical and histological analysis were applied to determine kidney injury. The effect of HKL on mitochondrial function and morphology were evaluated by immunohistochemistry, transmission electron microscopy, immunoblot and immunofluorescence. To investigate the mechanism of HKL in mitochondrial dynamics remodeling and resistance to apoptosis, we did transfection experiments, immunoblot, immunoprecipitation and flow cytometry assay.
KEY RESULTS: We demonstrated that the prominent mitochondrial fragmentation occurred in experimental models of cisplatin-induced nephrotoxicity, which was coupled with radical oxygen species (ROS) overproduction, deterioration of mitochondrial function, release of apoptogenic factors, and consequent apoptosis. HKL treatment exhibited notable renoprotection and attenuated these perturbations. Mechanically, we show that HKL treatment recovered the expression of SIRT3 and improved AMPK activity in tubular cells exposure to cisplatin, which preserved the Drp1 phosphorylation at Ser637 and blocked its translocation to mitochondria, consequently preventing mitochondrial fragmentation and subsequent cell injury and death.
CONCLUSIONS AND IMPLICATIONS: Our results indicate that HKL may protect against cisplatin-induced AKI by preserving mitochondrial integrity and fitness through a mechanism of SIRT3/AMPK-dependent mitochondrial dynamics remodeling.

Keywords:  SIRT3; acute kidney injury; honokiol; mitochondrial fission; mtROS

DOI:  https://doi.org/10.1111/bph.15837