bims-amsmem 2022-05-29 papers

bims-amsmem

Biomed News

on AMPK signaling mechanism in energy metabolism

Issue of 2022–05–29
23 papers selected by
Dipsikha Biswas, Københavns Universitet

Metabolic regulation by the intestinal metformin-AMPK axis.
MicroRNA-299a-5p Protects against Spinal Cord Injury through Activating AMPK Pathway.
Adiponectin Reduces Lipid Content in Chicken Myoblasts by Activating AMPK Signaling Pathway.
Activation of the AMPK-ULK1 pathway mediated protective autophagy by sevoflurane anesthesia restrains LPS-induced acute lung injury (ALI).
Metformin and Cancer, an Ambiguanidous Relationship.
SREBP and central nervous system disorders: genetic overlaps revealed by in silico analysis.
Prolonged Myocardial Regenerative Capacity in Neonatal Opossum.
Higenamine Attenuates Doxorubicin-Induced Cardiac Remodeling and Myocyte Apoptosis by Suppressing AMPK Activation.
Blockage of Fibronectin 1 Ameliorates Myocardial Ischemia/Reperfusion Injury in Association with Activation of AMP-LKB1-AMPK Signaling Pathway.
Ginsenoside compound K ameliorates palmitate-induced atrophy in C2C12 myotubes via promyogenic effects and AMPK/autophagy-mediated suppression of endoplasmic reticulum stress.
Dysfunction of the energy sensor NFE2L1 triggers uncontrollable AMPK signaling and glucose metabolism reprogramming.
Soyasapogenol C from Fermented Soybean (Glycine Max) Acting as a Novel AMPK/PPARα Dual Activator Ameliorates Hepatic Steatosis: A Novel SANDA Methodology.
Harmine prevents 3-nitropropionic acid-induced neurotoxicity in rats via enhancing NRF2-mediated signaling: Involvement of p21 and AMPK.
Empagliflozin-Enhanced Antioxidant Defense Attenuates Lipotoxicity and Protects Hepatocytes by Promoting FoxO3a- and Nrf2-Mediated Nuclear Translocation via the CAMKK2/AMPK Pathway.
JCI‑20679 suppresses the proliferation of glioblastoma stem cells by activating AMPK and decreasing NFATc2 expression levels.
Anti-Obesity Effect of Dyglomera® Is Associated with Activation of the AMPK Signaling Pathway in 3T3-L1 Adipocytes and Mice with High-Fat Diet-Induced Obesity.
Panax notoginseng saponin R1 attenuates allergic rhinitis through AMPK/Drp1 mediated mitochondrial fission.
Role of human organic cation transporter-1 (OCT-1/SLC22A1) in modulating the response to metformin in patients with type 2 diabetes.
Impairment of Glucose Metabolism and Suppression of Stemness in MCF-7/SC Human Breast Cancer Stem Cells by Nootkatone.
Liver Graft Hypothermic Static and Oxygenated Perfusion (HOPE) Strategies: A Mitochondrial Crossroads.
Prospective Application of Ferroptosis in Hypoxic Cells for Tumor Radiotherapy.
Shabyar Ameliorates High Glucose Induced Retinal Pigment Epithelium Injury Through Suppressing Aldose Reductase and AMPK/mTOR/ULK1 Autophagy Pathway.
miR-145-5p affects autophagy by targeting CaMKIIδ in atherosclerosis.

Nat Commun. 2022 May 23. 13(1): 2851

Metabolic regulation by the intestinal metformin-AMPK axis.

Song-Yang Zhang, Tony K T Lam.

DOI: https://doi.org/10.1038/s41467-022-30477-3
Oxid Med Cell Longev. 2022 ;2022 8659587

MicroRNA-299a-5p Protects against Spinal Cord Injury through Activating AMPK Pathway.

Zong-Ze Zhang, Shu-Yue Xian, Chong Bao, Feng Chen.

Objective: Inflammation and oxidative stress are implicated in the pathogenesis of spinal cord injury (SCI). The present study is aimed at investigating the function and molecular basis of microRNA-299a-5p (miR-299a-5p) during SCI in mice.
Methods: Mice were exposed to SCI surgery and then intrathecally injected with the agomir, antagomir, or matched negative controls of miR-299a-5p to overexpress or silence miR-299a-5p. To inhibit AMP-activated protein kinase (AMPK), mice were intraperitoneally injected with compound C (CC). To overexpress pH domain and leucine-rich repeat protein phosphatase 1 (PHLPP1), lentiviral vectors were used.
Results: The miR-299a-5p expression in the spinal cord was dramatically reduced by SCI stimulation. The miR-299a-5p agomir prevents, while the miR-299a-5p antagomir exacerbates inflammation, oxidative stress, and SCI in mice. Mechanistically, we found that miR-299a-5p directly inhibited PHLPP1 and subsequently activated AMPK pathway. The PHLPP1 overexpression of AMPK inhibition with either genetic or pharmacologic methods dramatically abolished the miR-299a-5p agomir-mediated protective effects against SCI.
Conclusion: miR-299a-5p protects against spinal cord injury through activating AMPK pathway.

DOI: https://doi.org/10.1155/2022/8659587
Biosci Rep. 2022 May 23. pii: BSR20212549. [Epub ahead of print]

Adiponectin Reduces Lipid Content in Chicken Myoblasts by Activating AMPK Signaling Pathway.

Qingmei Hu, Dan Wang, Hai Lin, Haifang Li, Jingpeng Zhao, Hong Chao Jiao, Xiaojuan Wang.

  Studies in mammals have shown that adiponectin is secreted mainly by adipocytes, and it plays a crucial role in glucose and lipid metabolism in muscles. Clarifying the crosstalk role of adiponectin between adipose tissue and skeletal muscle tissue is very important for internal homeostasis. The glucose and lipid metabolism of chicken is different from that of mammals, and the role of adiponectin in chickens is unclear. Therefore, it is of great significance to study the effect and mechanism of adiponectin on lipid metabolism in chickens. In this study, the regulating effect of adiponectin on lipid metabolism in chicken myoblasts was explored by adding a certain concentration of exogenous recombinant adiponectin. Results showed that adiponectin reduced intracellular lipid content, increasing the mRNA expression of adiponectin receptor and cellular uptake of glucose and fatty acids. In addition, adiponectin activated the 5' adenosine monophosphate activated protein kinase (AMPK) signaling pathway. The above results suggested that adiponectin reduced intracellular lipid content, mainly by binding to adiponectin receptor, activating AMPK pathway, increasing cellular uptake of glucose and fatty acids, and promoting lipid oxidation.

Keywords:  AMPK; adiponectin; chicken myoblast; lipid metabolism

DOI:  https://doi.org/10.1042/BSR20212549
Int Immunopharmacol. 2022 May 20. pii: S1567-5769(22)00353-8. [Epub ahead of print]108 108869

Activation of the AMPK-ULK1 pathway mediated protective autophagy by sevoflurane anesthesia restrains LPS-induced acute lung injury (ALI).

Zhiling Fu, Xiuying Wu, Fushuang Zheng, Yan Zhang.

   BACKGROUND: Sevoflurane anesthesia is deemed as potential therapeutic drug for lipopolysaccharide (LPS)-induced acute lung injury (ALI), but the molecular mechanisms have not been fully delineated.
AIM: The present study explored the specific molecular mechanism of sevoflurane regulating autophagy to reduce LPS induced ALI.
METHODS: Male C57BL/6J mice and mouse pulmonary microvascular endothelial cells (MPVECs) were treated with LPS to construct ALI models, and the levels of inflammation, apoptosis and autophagy were detected after treatment with sevoflurane. Meanwhile, cells were treated with autophagy inhibitor or AMP-activated protein kinase (AMPK)/unc-51 like autophagy activating kinase 1 (ULK1) pathway inhibitor in vitro to detect their effects on cell survival.
RESULTS: Sevoflurane reduced inflammation, recovered cell division so as to suppress cell apoptosis and maintain cell survival, and activated autophagic flux in LPS-induced ALI models in vivo and in vitro. Of note, the suppressing effects of sevoflurane on LPS-induced cell death were abrogated by inhibiting autophagy. Moreover, we evidenced that sevoflurane promoted activation of the AMPK/ULK1 pathway in LPS-induced ALI models. Blockage of this pathway abrogated the promoting effects of sevoflurane on cell autophagy and cell viability in LPS-treated cells.
CONCLUSION: Collectively, sevoflurane suppresses apoptosis and inflammation via activating protective autophagy, thereby ameliorating LPS-induced ALI, and the AMPK/ULK1/ PIKFYVE pathway is responsible for the process.

Keywords:  AMP-activated protein kinase; Acute lung injury; Lipopolysaccharide; Protective autophagy; Sevoflurane; Unc-51 like autophagy activating kinase 1

DOI:  https://doi.org/10.1016/j.intimp.2022.108869
Pharmaceuticals (Basel). 2022 May 19. pii: 626. [Epub ahead of print]15(5):

Metformin and Cancer, an Ambiguanidous Relationship.

Sarah J Skuli, Safwan Alomari, Hallie Gaitsch, A'ishah Bakayoko, Nicolas Skuli, Betty M Tyler.

  The deregulation of energetic and cellular metabolism is a signature of cancer cells. Thus, drugs targeting cancer cell metabolism may have promising therapeutic potential. Previous reports demonstrate that the widely used normoglycemic agent, metformin, can decrease the risk of cancer in type 2 diabetics and inhibit cell growth in various cancers, including pancreatic, colon, prostate, ovarian, and breast cancer. While metformin is a known adenosine monophosphate-activated protein kinase (AMPK) agonist and an inhibitor of the electron transport chain complex I, its mechanism of action in cancer cells as well as its effect on cancer metabolism is not clearly established. In this review, we will give an update on the role of metformin as an antitumoral agent and detail relevant evidence on the potential use and mechanisms of action of metformin in cancer. Analyzing antitumoral, signaling, and metabolic impacts of metformin on cancer cells may provide promising new therapeutic strategies in oncology.

Keywords:  AMPK; PI3K; cancer metabolism; diabetes; drug repurposing; metformin; therapeutics

DOI:  https://doi.org/10.3390/ph15050626
J Integr Neurosci. 2022 May 16. 21(3): 95

SREBP and central nervous system disorders: genetic overlaps revealed by in silico analysis.

Mary Jasmin Ang, Changjong Moon.

   BACKGROUND: The central nervous system (CNS) is enriched in lipids; despite this, studies exploring the functional roles of lipids in the brain are still limited. Sterol regulatory element binding protein (SREBP) signaling is a transcriptomic pathway that predominantly participates in the maintenance of lipid homeostasis; however, its involvement in the CNS dysfunction is not well-established. In this study, we aimed to characterize and pinpoint specific genes of the SREBP pathway which may be implicated in neurodegenerative, neurological, and neuropsychiatric diseases.
METHODS: In silico bioinformatic analysis was performed using the open-source databases DisGeNET and MSigDB. Protein-protein interaction data were visualized and analyzed using STRING, after which GO (Gene Ontology) and KEGG (Kyoto Encyclopedia of Genes and Genomes) enrichment analyses were conducted via DAVID (Database for Annotation, Visualization and Integrated Discovery).
RESULTS: Several common genes were identified between the SREBP pathway and CNS disorders. In GO enrichment analysis, the most enriched biological processes included lipid, cholesterol, and steroid biosynthetic processes; the most enriched molecular functions were transcription factor-related; and the most enriched subcellular compartments revealed that the genes involved in CNS disorders were mainly associated with the enzyme complexes of acetyl-CoA carboxylase (ACC) and fatty acid synthase (FASN). In KEGG enrichment analysis, the most enriched pathway was the AMP-activated protein kinase (AMPK) signaling pathway, and the top-ranked genes significantly enriched under this pathway were ACACA, ACACB, FASN, HMGCR, MTOR, PPARGC1A, PRKAA1, SCD, SIRT1, and SREBF1.
CONCLUSIONS: The findings of this study strengthen the evidence linking the involvement of lipid homeostasis in CNS functions. We suggest herein the roles of downstream ACC and FASN enzymes and upstream AMPK signaling in the SREBP pathway as mechanisms underlying neurodegenerative, neurological, and neuropsychiatric CNS disorders.

Keywords:  AMPK; Lipids; Neurodegenerative; Neurological; Neuropsychiatric; SREBP

DOI:  https://doi.org/10.31083/j.jin2103095
Circulation. 2022 May 26. 101161CIRCULATIONAHA121055269

Prolonged Myocardial Regenerative Capacity in Neonatal Opossum.

Chihiro Nishiyama, Yuichi Saito, Akane Sakaguchi, Mari Kaneko, Hiroshi Kiyonari, Yuqing Xu, Yuichiro Arima, Hideki Uosaki, Wataru Kimura.

   BACKGROUND: Early neonates of both large and small mammals are able to regenerate the myocardium through cardiomyocyte proliferation for only a short period after birth. This myocardial regenerative capacity declines in parallel with withdrawal of cardiomyocytes from the cell cycle in the first few postnatal days. No mammalian species examined to date has been found capable of a meaningful regenerative response to myocardial injury later than 1 week after birth.
METHODS: We examined cardiomyocyte proliferation in neonates of the marsupial opossum (Monodelphis domestica) by immunostaining at various times after birth. The regenerative capacity of the postnatal opossum myocardium was assessed after either apex resection or induction of myocardial infarction at postnatal day 14 or 29, whereas that of the postnatal mouse myocardium was assessed after myocardial infarction at postnatal day 7. Bioinformatics data analysis, immunofluorescence staining, and pharmacological and genetic intervention were applied to determine the role of AMPK (5'-AMP-activated protein kinase) signaling in regulation of the mammalian cardiomyocyte cell cycle.
RESULTS: Opossum neonates were found to manifest cardiomyocyte proliferation for at least 2 weeks after birth at a frequency similar to that apparent in early neonatal mice. Moreover, the opossum heart at postnatal day 14 showed substantial regenerative capacity both after apex resection and after myocardial infarction injury, whereas this capacity had diminished by postnatal day 29. Transcriptomic and immunofluorescence analyses indicated that AMPK signaling is activated in postnatal cardiomyocytes of both opossum and mouse. Pharmacological or genetic inhibition of AMPK signaling was sufficient to extend the postnatal window of cardiomyocyte proliferation in both mouse and opossum neonates as well as of cardiac regeneration in neonatal mice.
CONCLUSIONS: The marsupial opossum maintains cardiomyocyte proliferation and a capacity for myocardial regeneration for at least 2 weeks after birth. As far as we are aware, this is the longest postnatal duration of such a capacity among mammals examined to date. AMPK signaling was implicated as an evolutionarily conserved regulator of mammalian postnatal cardiomyocyte proliferation.

Keywords:  AMPK; cardiomyocytes; heart regeneration; marsupialia; opossums

DOI:  https://doi.org/10.1161/CIRCULATIONAHA.121.055269
Front Cell Dev Biol. 2022 ;10 809996

Higenamine Attenuates Doxorubicin-Induced Cardiac Remodeling and Myocyte Apoptosis by Suppressing AMPK Activation.

Cuiliu Jin, Yu Chai, Zhimin Hu, Wencong Tian, Wang Ling, Jing Li, Meiping Wu.

  Background: As an effective antitumor drug, doxorubicin (DOX) is primarily used to treat solid tumors and hematologic malignancies. However, increasing evidence has emerged indicating its cardiotoxicity, and few solutions have been proposed to counter this side effect. Higenamine (HG) is a natural compound widely found in many Chinese herbs and also serves as a component in many healthcare products. Several studies have demonstrated its cardioprotective effect in different models, but little is known about the underlying influences of HG against myocardial damage from DOX-induced chronic cardiotoxicity. Methods and Results: C57BL/6 mice and neonatal rat ventricular cardiomyocytes (NRVMs) were used to evaluate the cardioprotective effect of HG against DOX-induced myocardial damage. In mice, DOX (intraperitoneally injected 5 mg/kg every 3 days for 4 weeks) significantly increased cardiomyocyte apoptosis, cardiac atrophy, and cardiac dysfunction, which were significantly attenuated by HG (intragastrically administered with 10 mg/kg every day for 4 weeks). In NRVMs, DOX (3 μM for 24 h) significantly increased cell apoptosis and the level of reactive oxygen species while reducing the level of superoxide dismutase and mitochondrial membrane potential. Remarkably, HG can reverse these pathological changes caused by DOX. Interestingly, the protective effect of HG on DOX-induced cardiotoxicity was independent of the activation of the beta-2 adrenergic receptor (β2-AR), known for mediating the effect of HG on antagonizing ischemia/reperfusion-induced cardiac apoptosis. Furthermore, HG attenuated the abnormal activation of phosphorylated adenosine-activated protein kinase (AMPK). Consistently, AMPK agonists (AICAR) can eliminate these pharmacological actions of HG. Conclusion: Collectively, our results suggested that HG alleviated DOX-induced chronic myocardial injury by suppressing AMPK activation and ROS production.

Keywords:  adenosine-activated protein kinase; cardiac remodeling; doxorubicin; higenamine; myocyte apoptosis

DOI:  https://doi.org/10.3389/fcell.2022.809996
Oxid Med Cell Longev. 2022 ;2022 6196173

Blockage of Fibronectin 1 Ameliorates Myocardial Ischemia/Reperfusion Injury in Association with Activation of AMP-LKB1-AMPK Signaling Pathway.

Yun-Long Zhang, Pang-Bo Li, Xiao Han, Bo Zhang, Hui-Hua Li.

Myocardial ischemia/reperfusion injury (I/RI) is closely associated with energy substrate metabolism. Fibronectin 1 (Fn1) was markedly elevated in the heart of I/R pigs and ischemic patients, but its role in myocardial I/RI is controversial and the precise mechanism involved remains elusive. Herein, we tested whether blockage of Fn1 with its inhibitor (fibronectin tetrapeptide, RGDS) would alleviate myocardial I/RI. Wild-type (WT) mice were administered with RGDS once 3 h before I/R operation and once at 24 or 48 h postreperfusion, and sacrificed at 24 or 72 h post-I/R, respectively. Cardiac function was evaluated by echocardiography. Myocardial infarction size, apoptosis, fibrosis, and inflammation were examined via histological staining. Uptake of glucose and fatty acids were detected by positron emission tomography (PET) and computer tomography (CT) with [18F]-2-fluoro-2-deoxy-D-glucose (FDG) and [18F]-fluoro-6-thia-heptadecanoic acid (FTHA), respectively. Our results showed that administration of RGDS to mice remarkably limited the I/R-induced myocardial infarct size, myocyte apoptosis, inflammation, oxidative stress, and fibrosis and improved cardiac contractile dysfunction. These protective effects were associated with upregulation of the AMP/ATP ratio and the activation of LKB1-AMPK signaling, which subsequently increased AS160-GLUT4-mediated glucose and fatty acid uptake, improved mitochondrial dynamic imbalance, and inactivated TGF-β and NF-κB signals in the I/R heart. In conclusion, the current study identified that blocking Fn1 protects against myocardial I/RI likely through activating the LKB1-AMPK-dependent signals and highlights that inhibition of Fn1 may be a novel therapeutic option for treating ischemic heart diseases.

DOI: https://doi.org/10.1155/2022/6196173
J Ginseng Res. 2022 May;46(3): 444-453

Ginsenoside compound K ameliorates palmitate-induced atrophy in C2C12 myotubes via promyogenic effects and AMPK/autophagy-mediated suppression of endoplasmic reticulum stress.

Tae Jin Kim, Do Hyeon Pyun, Myeong Jun Kim, Ji Hoon Jeong, A M Abd El-Aty, Tae Woo Jung.

   Background: Compound K (CK) is among the protopanaxadiol (PPD)-type ginsenoside group, which produces multiple pharmacological effects. Herein, we examined the effects of CK on muscle atrophy under hyperlipidemic conditions along with its pro-myogenic effects. Further, the molecular pathways underlying the effects of CK on skeletal muscle have been justified.
Methods: C2C12 myotubes were treated with palmitate and CK. C2C12 myoblasts were differentiated using CK for 4-5 days. For the in vivo experiments, CK was administered to mice fed on a high-fat diet for 8 weeks. The protein expression levels were analyzed using western blotting analysis. Target protein suppression was performed using small interfering (si) RNA transfection. Histological examination was performed using Jenner-Giemsa and H&E staining techniques.
Results: CK treatment attenuated ER stress markers, such as eIF2α phosphorylation and CHOP expression and impaired myotube formation in palmitate-treated C2C12 myotubes and skeletal muscle of mice fed on HFD. CK treatment augmented AMPK along with autophagy markers in skeletal muscle cells in vitro and in vivo experiments. AMPK siRNA or 3-MA, an autophagy inhibitor, abrogated the impacts of CK in C2C12 myotubes. CK treatment augmented p38 and Akt phosphorylation, leading to an enhancement of C2C12 myogenesis. However, AMPK siRNA abolished the effects of CK in C2C12 myoblasts.
Conclusion: These findings denote that CK prevents lipid-induced skeletal muscle apoptosis via AMPK/autophagy-mediated attenuation of ER stress and induction of myoblast differentiation. Therefore, we may suggest the use of CK as a potential therapeutic approach for treating muscle-wasting conditions associated with obesity.

Keywords:  AMPK; Autophagy; Compound K; ER stress; Myogenesis; Sarcopenia

DOI:  https://doi.org/10.1016/j.jgr.2021.09.002
Cell Death Dis. 2022 May 25. 13(5): 501

Dysfunction of the energy sensor NFE2L1 triggers uncontrollable AMPK signaling and glucose metabolism reprogramming.

Lu Qiu, Qiufang Yang, Wenshan Zhao, Yadi Xing, Peng Li, Xiaowen Zhou, Haoming Ning, Ranran Shi, Shanshan Gou, Yalan Chen, Wenjie Zhai, Yahong Wu, Guodong Li, Zhenzhen Chen, Yonggang Ren, Yanfeng Gao, Yiguo Zhang, Yuanming Qi.

The antioxidant transcription factor NFE2L1 (also called Nrf1) acts as a core regulator of redox signaling and metabolism homeostasis, and thus, its dysfunction results in multiple systemic metabolic diseases. However, the molecular mechanism(s) by which NFE2L1 regulates glycose and lipid metabolism remains elusive. Here, we found that loss of NFE2L1 in human HepG2 cells led to a lethal phenotype upon glucose deprivation and NFE2L1 deficiency could affect the uptake of glucose. Further experiments revealed that glycosylation of NFE2L1 enabled it to sense the energy state. These results indicated that NFE2L1 can serve as a dual sensor and regulator of glucose homeostasis. The transcriptome, metabolome, and seahorse data further revealed that disruption of NFE2L1 could reprogram glucose metabolism to aggravate the Warburg effect in NFE2L1-silenced hepatoma cells, concomitant with mitochondrial damage. Co-expression and Co-immunoprecipitation experiments demonstrated that NFE2L1 could directly interact and inhibit AMPK. Collectively, NFE2L1 functioned as an energy sensor and negatively regulated AMPK signaling through directly interacting with AMPK. The novel NFE2L1/AMPK signaling pathway delineate the mechanism underlying of NFE2L1-related metabolic diseases and highlight the crosstalk between redox homeostasis and metabolism homeostasis.

DOI: https://doi.org/10.1038/s41419-022-04917-3
Int J Mol Sci. 2022 May 13. pii: 5468. [Epub ahead of print]23(10):

Soyasapogenol C from Fermented Soybean (Glycine Max) Acting as a Novel AMPK/PPARα Dual Activator Ameliorates Hepatic Steatosis: A Novel SANDA Methodology.

Radha Arulkumar, Hee Jin Jung, Sang Gyun Noh, Hae Young Chung.

  (1) Background: Soyasapogenol C (SSC), a derivative of soyasapogenol B (SSB), is specifically found high in many fermented soybean (Glycine max) products, including Cheonggukjang (in Korean). However, the biological activities for preventing and treating hepatic steatosis, and the precise underlying mechanisms of SSC, remain to be explored. (2) Methods: A novel SANDA (structural screening, ADMET prediction, network pharmacology, docking validation, and activity evaluation) methodology was used to examine whether SSC exerts hepatoprotective effects in silico and in vitro. (3) Results: SSC had better ADMET characteristics and a higher binding affinity with predicted targets chosen from network pathway analysis than SSB. SSC induced the phosphorylation of AMP-activated protein kinase (AMPK) and stimulated the nuclear translocation of peroxisome proliferator-activated receptor alpha (PPARα), further enhancing PPAR response element (PPRE) binding activity in HepG2 cells. Concurrently, SSC significantly inhibited triglyceride accumulation, which was associated with the suppression of lipogenesis genes and the enhancement of fatty acid oxidation gene expression in HepG2 cells. (4) Conclusions: Soyasapogenol C, discovered using a novel SANDA methodology from fermented soybean, is a novel AMPK/PPARα dual activator that is effective against hepatic steatosis. Dietary supplementation with soyasapogenol C may prevent the development of hepatic steatosis and other diseases associated with fat accumulation in the liver.

Keywords:  AMP-activated protein kinase; SANDA methodology; fermented soybean; hepatic steatosis; peroxisome proliferator-activated receptors alpha; soyasapogenol C

DOI:  https://doi.org/10.3390/ijms23105468
Eur J Pharmacol. 2022 May 24. pii: S0014-2999(22)00307-7. [Epub ahead of print] 175046

Harmine prevents 3-nitropropionic acid-induced neurotoxicity in rats via enhancing NRF2-mediated signaling: Involvement of p21 and AMPK.

Mohamed Z Habib, Mariane G Tadros, Hadwa A Abd-Alkhalek, Magda I Mohamad, Dalia M Eid, Fatma E Hassan, Hend Elhelaly, Yasser El Faramawy, Sawsan Aboul-Fotouh.

  Oxidative stress induced neurotoxicity is increasingly perceived as an important neuropathologic mechanism underlying the motor and behavioral phenotypes associated with Huntington's disease (HD). Repeated exposure to 3-nitropropionic acid (3-NP) induces neurotoxic changes which closely simulate the neuropathological and behavioral characteristics of HD. This study aimed at evaluating the prophylactic effects of the dual-specificity tyrosine phosphorylation regulated kinase 1A (DYRK1A) inhibitor "harmine" against 3-NP-indued neurotoxicity and HD-like symptoms. The potential prophylactic effect of harmine (10 mg/kg/day; intraperitoneal) was investigated on 3-NP-induced motor and cognitive HD-like deficits, nuclear factor erythroid 2 like 2 (NRF2), AMP kinase (AMPK) and p21 protein levels and the gene expression of haem oxygenase-1 (Ho-1), NAD(P)H: quinone oxidoreductase-1 (Nqo-1) and p62 in addition to redox imbalance and histological neurotoxic changes in the striatum, prefrontal cortex, and hippocampus of male Wistar rats. Harmine successfully increased the protein levels of NRF2, AMPK and p21 and the gene expression of Ho-1, Nqo-1 and p62, restored redox homeostasis, and reduced CASPASE-3 level. This was reflected in attenuation of 3-NP-induced neurodegenerative changes and improvement of rats' motor and cognitive performance. This study draws attention to the protective role of harmine against 3-NP-induced motor and cognitive dysfunction that could be mediated via enhancing NRF2-mediated signaling with subsequent amelioration of oxidative stress injury via NRF2 activators, p21 and AMPK, in the striatum, prefrontal cortex, and hippocampus which could offer a promising therapeutic tool to slow the progression of HD.

Keywords:  3-Nitropropionic acid; AMPK; Harmine; Huntington's disease; NRF2; Neurotoxicity

DOI:  https://doi.org/10.1016/j.ejphar.2022.175046
Antioxidants (Basel). 2022 Apr 19. pii: 799. [Epub ahead of print]11(5):

Empagliflozin-Enhanced Antioxidant Defense Attenuates Lipotoxicity and Protects Hepatocytes by Promoting FoxO3a- and Nrf2-Mediated Nuclear Translocation via the CAMKK2/AMPK Pathway.

Yangyang Wang, Yipei Ding, Pengbo Sun, Wanqiu Zhang, Qilei Xin, Ningchao Wang, Yaoyun Niu, Yang Chen, Jingyi Luo, Jinghua Lu, Jin Zhou, Naihan Xu, Yaou Zhang, Weidong Xie.

  Lipotoxicity is an important factor in the development and progression of nonalcoholic steatohepatitis. Excessive accumulation of saturated fatty acids can increase the substrates of the mitochondrial electron transport chain in hepatocytes and cause the generation of reactive oxygen species, resulting in oxidative stress, mitochondrial dysfunction, loss of mitochondrial membrane potential, impaired triphosphate (ATP) production, and fracture and fragmentation of mitochondria, which ultimately leads to hepatocellular inflammatory injuries, apoptosis, and necrosis. In this study, we systematically investigated the effects and molecular mechanisms of empagliflozin on lipotoxicity in palmitic acid-treated LO2 cell lines. We found that empagliflozin protected hepatocytes and inhibited palmitic acid-induced lipotoxicity by reducing oxidative stress, improving mitochondrial functions, and attenuating apoptosis and inflammation responses. The mechanistic study indicated that empagliflozin significantly activated adenosine 5'-monophosphate (AMP)-activated protein kinase alpha (AMPKα) through Calcium/Calmodulin dependent protein kinase kinase beta (CAMKK2) instead of liver kinase B1 (LKB1) or TGF-beta activated kinase (TAK1). The activation of empagliflozin on AMPKα not only promoted FoxO3a phosphorylation and thus forkhead box O 3a (FoxO3a) nuclear translocation, but also promoted Nrf2 nuclear translocation. Furthermore, empagliflozin significantly upregulated the expressions of antioxidant enzymes superoxide dismutase (SOD) and HO-1. In addition, empagliflozin did not attenuate lipid accumulation at all. These results indicated that empagliflozin mitigated lipotoxicity in saturated fatty acid-induced hepatocytes, likely by promoting antioxidant defense instead of attenuating lipid accumulation through enhanced FoxO3a and Nrf2 nuclear translocation dependent on the CAMKK2/AMPKα pathway. The CAMKK2/AMPKα pathway might serve as a promising target in treatment of lipotoxicity in nonalcoholic steatohepatitis.

Keywords:  AMPK; CAMKK2; NASH; empagliflozin; lipotoxicity

DOI:  https://doi.org/10.3390/antiox11050799
Mol Med Rep. 2022 Jul;pii: 238. [Epub ahead of print]26(1):

JCI‑20679 suppresses the proliferation of glioblastoma stem cells by activating AMPK and decreasing NFATc2 expression levels.

Shota Ando, Naoto Kojima, Chiami Moyama, Mitsugu Fujita, Kaito Ohta, Hiromi Ii, Susumu Nakata.

  The prognosis of glioblastoma, which is the most frequent type of adult‑onset malignant brain tumor, is extremely poor. Therefore, novel therapeutic strategies are needed. Previous studies report that JCI‑20679, which is synthesized based on the structure of naturally occurring acetogenin, inhibits mitochondrial complex I and suppresses the growth of various types of cancer cells. However, the efficacy of JCI‑20679 on glioblastoma stem cells (GSCs) is unknown. The present study demonstrated that JCI‑20679 inhibited the growth of GSCs derived from a transposon system‑mediated murine glioblastoma model more efficiently compared with the growth of differentiation‑induced adherent cells, as determined by a trypan blue staining dye exclusion test. The inhibition of proliferation was accompanied by the blockade of cell‑cycle entry into the S‑phase, as assessed by a BrdU incorporation assay. JCI‑20679 decreased the mitochondrial membrane potential, suppressed the oxygen consumption rate and increased mitochondrial reactive oxygen species generation, indicating that JCI‑20679 inhibited mitochondrial activity. The mitochondrial inhibition was revealed to increase phosphorylated (phospho)‑AMPKα levels and decrease nuclear factor of activated T‑cells 2 (NFATc2) expression, and was accompanied by a decrease in calcineurin phosphatase activity. Depletion of phospho‑AMPKα by knockdown of AMPKβ recovered the JCI‑20679‑mediated decrease in NFATc2 expression levels, as determined by western blotting and reverse transcription‑quantitative PCR analysis. Overexpression of NFATc2 recovered the JCI‑20679‑mediated suppression of proliferation, as determined by a trypan blue staining dye exclusion test. These results suggest that JCI‑20679 inhibited mitochondrial oxidative phosphorylation, which activated AMPK and reduced NFATc2 expression levels. Moreover, systemic administration of JCI‑20679 extended the event‑free survival rate in a mouse model transplanted with GSCs. Overall, these results suggested that JCI‑20679 is a potential novel therapeutic agent against glioblastoma.

Keywords:  AMPK; JCI‑20679; glioblastoma; glioblastoma stem‑cell; mitochondria; nuclear factor of activated T‑cells 2

DOI:  https://doi.org/10.3892/mmr.2022.12754
Molecules. 2022 May 20. pii: 3288. [Epub ahead of print]27(10):

Anti-Obesity Effect of Dyglomera® Is Associated with Activation of the AMPK Signaling Pathway in 3T3-L1 Adipocytes and Mice with High-Fat Diet-Induced Obesity.

Hae-Lim Kim, Sung-Kwon Lee, Da-Eun Min, Bong-Keun Choi, Dong-Ryung Lee.

  Dyglomera® is an aqueous ethanol extract of the fruit pods of Dichrostachys glomerata, a Cameroonian spice. Several studies have shown its anti-diabetic and anti-obesity effects. However, the underlying mechanisms for such effects remain unclear. Thus, the objective of this study was to investigate the anti-obesity effect of Dyglomera® and its underlying mechanisms in mice with high-fat diet-induced obesity and 3T3-L1 adipocytes. Our results revealed that Dyglomera® inhibited adipogenesis and lipogenesis by regulating AMPK phosphorylation in white adipose tissues (WATs) and 3T3-L1 adipocytes and promoted lipolysis by increasing the expression of lipolysis-related proteins. These results suggest that Dyglomera® can be used as an effective dietary supplement for treating obesity due to its modulating effect on adipogenesis/lipogenesis and lipolysis.

Keywords:  3T3-L1 adipocytes; Dichrostachys glomerata extract; Dyglomera®; adipogenesis; anti-obesity; high-fat diet-induced obesity; lipogenesis; lipolysis

DOI:  https://doi.org/10.3390/molecules27103288
Biochem Pharmacol. 2022 May 24. pii: S0006-2952(22)00200-3. [Epub ahead of print] 115106

Panax notoginseng saponin R1 attenuates allergic rhinitis through AMPK/Drp1 mediated mitochondrial fission.

Yalin Zhang, Yilan Song, Chongyang Wang, Jingzhi Jiang, Siqi Liu, Qiaoyun Bai, Liangchang Li, Hainan Jin, Yongde Jin, Guanghai Yan.

  We investigated whether panax notoginseng saponin (PNS-R1) attenuates allergic rhinitis (AR) through AMPK/Drp1-mediated mitochondrial fission. AR model was established in mice by ovalbumin (OVA). In vitro, human nasal epithelial cells (HNEpCs) were stimulated using recombinant human interleukin 13 (IL-13). PNS-R1 was administrated in vivo and in vitro. Then, HE staining of nasal tissue, ELISA detection of immunoglobulin E (IgE) and proinflammatory cytokine levels in serum and nasal lavage fluid, flow cytometry analysis of Th1/Th2 ratio and apoptosis, TUNEL staining, Western blot, detection of reactive oxygen species (ROS) and mitochondrial ROS, immunofluorescence analysis of Tom20 and mitochondrial fission protein Drp1 co-localization, and, mitochondrial membrane potential detection, were performed. PNS-R1 attenuated allergic symptoms in AR mice, decreased OVA-specific IgE, IL-4, IL-6, IL-8, IL-13, and TNF-α levels, and restored the Th1/Th2 imbalance. Meanwhile, we found that PNS-R1 treatment significantly reduced apoptosis, ROS production, and co-localization of Tom20 and Drp1 in the nasal epithelium of AR mice. In vitro, we found that PNS-R1 upregulated mitochondrial membrane potential and reduced ROS and mitochondrial ROS production as well as cleaved-caspase-3/9, Bax, Cyt-c, Apaf-1 expression and mitochondrial fission. Mechanistically, we found that PNS-R1 downregulated Drp1 phosphorylation (Ser 616) and Drp1 translocation in an AMPK-dependent manner, promoted MFN2 expression, and reduced TXNIP, NLRP3, caspase-1, and IL-1β expression. PNS-R1 may protect mitochondrial integrity by inhibiting AMPK/Drp1 and TXNIP/NLRP3 signaling pathway, thereby alleviating AR symptoms in mice. PNS-R1 may have great potential as a therapeutic agent for AR.

Keywords:  AMPK; Drp1; NLRP3; PNS-R1; TXNIP; mitochondrial fission

DOI:  https://doi.org/10.1016/j.bcp.2022.115106
BMC Endocr Disord. 2022 May 26. 22(1): 140

Role of human organic cation transporter-1 (OCT-1/SLC22A1) in modulating the response to metformin in patients with type 2 diabetes.

Fizalah Kawoosa, Zafar A Shah, Shariq R Masoodi, Asif Amin, Roohi Rasool, Khalid M Fazili, Abid Hamid Dar, Asif Lone, Samir Ul Bashir.

   BACKGROUND: Organic cation transporter 1 primarily governs the action of metformin in the liver. There are considerable inter-individual variations in metformin response. In light of this, it is crucial to obtain a greater understanding of the influence of OCT1 expression or polymorphism in the context of variable responses elicited by metformin treatment.
RESULTS: We observed that the variable response to metformin in the responders and non-responders is independent of isoform variation and mRNA expression of OCT-1. We also observed an insignificant difference in the serum metformin levels of the patient groups. Further, molecular docking provided us with an insight into the hotspot regions of OCT-1 for metformin binding. Genotyping of these regions revealed SNPs 156T>C and 1222A>G in both the groups, while as 181C>T and 1201G>A were found only in non-responders. The 181T>C and 1222A>G changes were further found to alter OCT-1 structure in silico and affect metformin transport in vitro which was illustrated by their effect on the activation of AMPK, the marker for metformin activity.
CONCLUSION: Taken together, our results corroborate the role of OCT-1 in the transport of metformin and also point at OCT1 genetic variations possibly affecting the transport of metformin into the cells and hence its subsequent action in responders and non-responders.

Keywords:  AMPK; Metformin; Organic cation transporter 1(OCT-1/SLC22A1)

DOI:  https://doi.org/10.1186/s12902-022-01033-3
Pharmaceutics. 2022 Apr 21. pii: 906. [Epub ahead of print]14(5):

Impairment of Glucose Metabolism and Suppression of Stemness in MCF-7/SC Human Breast Cancer Stem Cells by Nootkatone.

Yen Thi-Kim Nguyen, Ngoc Bao To, Vi Nguyen-Phuong Truong, Hee Young Kim, Meran Keshawa Ediriweera, Yoongho Lim, Somi Kim Cho.

  Targeting cancer stem cell metabolism has emerged as a promising therapeutic strategy for cancer treatment. Breast cancer stem cells (BCSCs) exert distinct metabolism machinery, which plays a major role in radiation and multidrug resistance. Therefore, exploring the mechanisms involved in energy utilization of BCSCs could improve the effectiveness of therapeutic strategies aimed at their elimination. This study was conducted to clarify the glucose metabolism machinery and the function of nootkatone, a bioactive component of grapefruit, in regulating glucose metabolism and stemness characteristics in human breast carcinoma MCF-7 stem cells (MCF-7SCs). In vivo experiments, transcriptomic analysis, seahorse XF analysis, MTT assay, Western blotting, mammosphere formation, wound healing, invasion assay, flow cytometric analysis, reverse transcription-quantitative polymerase chain reaction, and in silico docking experiments were performed. MCF-7SCs showed a greater tumorigenic capacity and distinct gene profile with enrichment of the genes involved in stemness and glycolysis signaling pathways compared to parental MCF-7 cells, indicating that MCF-7SCs use glycolysis rather than oxidative phosphorylation (OXPHOS) for their energy supply. Nootkatone impaired glucose metabolism through AMPK activation and reduced the stemness characteristics of MCF-7SCs. In silico docking analysis demonstrated that nootkatone efficiently bound to the active site of AMPK. Therefore, this study indicates that regulation of glucose metabolism through AMPK activation could be an attractive target for BCSCs.

Keywords:  AMPK; breast cancer stem cells; cancer metabolism; glycolysis; nootkatone; oxidative phosphorylation

DOI:  https://doi.org/10.3390/pharmaceutics14050906
Int J Mol Sci. 2022 May 20. pii: 5742. [Epub ahead of print]23(10):

Liver Graft Hypothermic Static and Oxygenated Perfusion (HOPE) Strategies: A Mitochondrial Crossroads.

Raquel G Bardallo, Rui T Da Silva, Teresa Carbonell, Carlos Palmeira, Emma Folch-Puy, Joan Roselló-Catafau, René Adam, Arnau Panisello-Rosello.

  Marginal liver grafts, such as steatotic livers and those from cardiac death donors, are highly vulnerable to ischemia-reperfusion injury that occurs in the complex route of the graft from "harvest to revascularization". Recently, several preservation methods have been developed to preserve liver grafts based on hypothermic static preservation and hypothermic oxygenated perfusion (HOPE) strategies, either combined or alone. However, their effects on mitochondrial functions and their relevance have not yet been fully investigated, especially if different preservation solutions/effluents are used. Ischemic liver graft damage is caused by oxygen deprivation conditions during cold storage that provoke alterations in mitochondrial integrity and function and energy metabolism breakdown. This review deals with the relevance of mitochondrial machinery in cold static preservation and how the mitochondrial respiration function through the accumulation of succinate at the end of cold ischemia is modulated by different preservation solutions such as IGL-2, HTK, and UW (gold-standard reference). IGL-2 increases mitochondrial integrity and function (ALDH2) when compared to UW and HTK. This mitochondrial protection by IGL-2 also extends to protective HOPE strategies when used as an effluent instead of Belzer MP. The transient oxygenation in HOPE sustains the mitochondrial machinery at basal levels and prevents, in part, the accumulation of energy metabolites such as succinate in contrast to those that occur in cold static preservation conditions. Additionally, several additives for combating oxygen deprivation and graft energy metabolism breakdown during hypothermic static preservation such as oxygen carriers, ozone, AMPK inducers, and mitochondrial UCP2 inhibitors, and whether they are or not to be combined with HOPE, are presented and discussed. Finally, we affirm that IGL-2 solution is suitable for protecting graft mitochondrial machinery and simplifying the complex logistics in clinical transplantation where traditional (static preservation) and innovative (HOPE) strategies may be combined. New mitochondrial markers are presented and discussed. The final goal is to take advantage of marginal livers to increase the pool of suitable organs and thereby shorten patient waiting lists at transplantation clinics.

Keywords:  ALDH2; AMPK; glycocalyx; liver graft preservation; succinate

DOI:  https://doi.org/10.3390/ijms23105742
Antioxidants (Basel). 2022 May 07. pii: 921. [Epub ahead of print]11(5):

Prospective Application of Ferroptosis in Hypoxic Cells for Tumor Radiotherapy.

Jing Su, Qin Zhao, Zhuangzhuang Zheng, Huanhuan Wang, Chenbin Bian, Lingbin Meng, Ying Xin, Xin Jiang.

  Radiation therapy plays an increasingly important role in cancer treatment. It can inhibit the progression of various cancers through radiation-induced DNA breakage and reactive oxygen species (ROS) overload. Unfortunately, solid tumors, such as breast and lung cancer, often develop a hypoxic microenvironment due to insufficient blood supply and rapid tumor proliferation, thereby affecting the effectiveness of radiation therapy. Restraining hypoxia and improving the curative effect of radiotherapy have become difficult problems. Ferroptosis is a new type of cell death caused by lipid peroxidation due to iron metabolism disorders and ROS accumulation. It plays an important role in both hypoxia and radiotherapy and can enhance the radiosensitivity of hypoxic tumor cells by amplifying oxidative stress or inhibiting antioxidant regulation. In this review, we summarize the internal relationship and related mechanisms between ferroptosis and hypoxia, thus exploring the possibility of inducing ferroptosis to improve the prognosis of hypoxic tumors.

Keywords:  AMPK; Nrf-2; ferroptosis; hypoxia; lipid peroxidation; radiotherapy; reactive oxygen species (ROS)

DOI:  https://doi.org/10.3390/antiox11050921
Front Pharmacol. 2022 ;13 852945

Shabyar Ameliorates High Glucose Induced Retinal Pigment Epithelium Injury Through Suppressing Aldose Reductase and AMPK/mTOR/ULK1 Autophagy Pathway.

Xiao Yan Liu, Jun Peng, Fei He, Xirali Tursun, Shu Ping Li, Xue Lei Xin, Haji Akber Aisa.

  Shabyar (SBA) is a traditional medicine formula for relieving vision loss caused by factors including diabetic retinopathy (DR) in clinics. However, the mechanism of it on retina protective effect still unclear. The present study aimed to investigate whether its protective effect was related to aldose reductase (AR) inhibition and retinal pigment epithelial cell injury mediated by autophagy or not. Human retinal pigment epithelial cells (ARPE-19) induced by high glucose was used as a model in vitro, with Epalrestat (EPL, AR inhibitor) and Difrarel (DFR, DR therapeutic drug) as positive controls. Western blotting and Polyol pathway products assay showed that SBA reduced the expression of AR protein and the content of ROS, and sorbitol, increased the level of Na+-K+-ATPase and alleviated cell edema. Western blotting and DCFH-DA probe assay showed that SBA decreased pAMPK/AMPK and pULK1/ULK1 which associated with autophagy initiation, down-regulated Beclin-1, Atg3, Atg5, Atg7, LC3 II and Bax/Bcl2 ratio, and up-regulated pmTOR/mTOR, SQSTM1/p62 and mitochondrial membrane potential (MMP), reduces intracellular autophagosomes. Real-Time PCR assay showed that SBA had no significant effect on mRNA expression of AR and mTOR. These data demonstrated that SBA treatment inhibits the autophagy of ARPE-19 through the AMPK/mTOR/ULK1 signaling pathway, and reduced early-stage apoptosis occurred by high glucose. These findings reveal the protective role and mechanism of SBA on retinal pigment epithelium, and provide experimental basis for the clinical application of SBA in the treatment of DR.

Keywords:  aldose reductase; autophagy; retinal pigment epithelium; shabyar; traditional medicine formula

DOI:  https://doi.org/10.3389/fphar.2022.852945
Int J Cardiol. 2022 May 18. pii: S0167-5273(22)00751-3. [Epub ahead of print]

miR-145-5p affects autophagy by targeting CaMKIIδ in atherosclerosis.

Xinxin Zhang, Ling Zai, Ziqi Tao, Daiqian Wu, Mingying Lin, Jing Wan.

   BACKGROUND: Atherosclerosis (AS) is a chronic progressive inflammatory disease involving many cells. miR-145-5p mediates the biological phenotypes of human aortic vascular smooth muscle cells (HAVSMCs) and influences the progression of AS, but the potential mechanism needs further study.
METHODS: Total RNA was extracted from patient plasma and arteries to determine the expression of miR-145-5p. The CaMKIIδ pathway and genes were predicted as the target of miR-145-5p by bioinformatics approaches. The interaction between miR-145-5p and CaMKIIδ was confirmed by RT-qPCR and Dual Luciferase Reporter Assay System. Western blot analysis, immunofluorescence staining, transmission electron microscopy (TEM) and protein tracing on HAVSMCs transduced with mCherry-GFP-LC3 lentiviral vectors to determine the mechanism by which miR-145-5p affects the atherosclerotic disease process.
RESULTS: The expression of miR-145-5p was downregulated in blood and arteries specimens of patients with coronary stenosis. Correspondingly, CaMKIIδ was upregulated and miR-145-5p was downregulated in hypoxic HAVSMCs. CaMKIIδ was predicted and confirmed as a downstream target of miR-145-5p. In addition, CaMKIIδ induced the upregulation of autophagy-related proteins by activating the AMPK/mTOR/ULK1 signalling pathway. Moreover, we confirmed that miR-145-5p inhibits CaMKIIδ expression by binding to a specific sequence in the CaMKIIδ 3' UTR and affects autophagy. Crucially, CaMKIIδ was promoted by the downregulation of miR-145-5p and then activating autophagy in HAVSMCs through the AMPK/mTOR/ULK1 signalling pathway to affect the AS progress.
CONCLUSIONS: miR-145-5p regulates CaMKIIδ, leading to altered autophagy in HAVSMCs. This alteration plays an important role in AS progression.

Keywords:  AMPK/mTOR/ULK1; Atherosclerosis; Autophagy; CaMKIIδ; miR-145-5p

DOI:  https://doi.org/10.1016/j.ijcard.2022.05.039