bims-amsmem 2023-04-23 papers

bims-amsmem

Biomed News

on AMPK signaling mechanism in energy metabolism

Issue of 2023–04–23
eleven papers selected by
Dipsikha Biswas, Københavns Universitet

AMPK is mitochondrial medicine for neuromuscular disorders.
Induction of lysosomal and mitochondrial biogenesis by AMPK phosphorylation of FNIP1.
AMPK activation protects against prostate cancer by inducing a catabolic cellular state.
AdipoRon Engages Microglia to Antinociception through the AdipoR1/AMPK Pathway in SNI Mice.
Carnosol Inhibits the Proliferation, Migration, and Invasion of Hepatocellular Carcinoma Cells in vitro by Regulating the AMPK Signaling Pathway.
TBC1D4-S711 controls skeletal muscle insulin sensitization after exercise and contraction.
Hydrogen inhalation enhances autophagy via the AMPK/mTOR pathway, thereby attenuating doxorubicin-induced cardiac injury.
Doxorubicin downregulates autophagy to promote apoptosis-induced dilated cardiomyopathy via regulating the AMPK/mTOR pathway.
ADP enhances the allosteric activation of eukaryotic elongation factor 2 kinase by calmodulin.
ALOX5 Promotes Autophagy-dependent Ferroptosis by Activating the AMPK/mTOR Pathway in Melanoma.
RBM4 dictates ESCC cell fate switch from cellular senescence to glutamine-addiction survival through inhibiting LKB1-AMPK-axis.

Trends Mol Med. 2023 Apr 19. pii: S1471-4914(23)00070-9. [Epub ahead of print]

AMPK is mitochondrial medicine for neuromuscular disorders.

Andrew I Mikhail, Sean Y Ng, Stephanie R Mattina, Vladimir Ljubicic.

  Duchenne muscular dystrophy (DMD), myotonic dystrophy type 1 (DM1), and spinal muscular atrophy (SMA) are the most prevalent neuromuscular disorders (NMDs) in children and adults. Central to a healthy neuromuscular system are the processes that govern mitochondrial turnover and dynamics, which are regulated by AMP-activated protein kinase (AMPK). Here, we survey mitochondrial stresses that are common between, as well as unique to, DMD, DM1, and SMA, and which may serve as potential therapeutic targets to mitigate neuromuscular disease. We also highlight recent advances that leverage a mutation-agnostic strategy featuring physiological or pharmacological AMPK activation to enhance mitochondrial health in these conditions, as well as identify outstanding questions and opportunities for future pursuit.

Keywords:  Duchenne muscular dystrophy; mitophagy; myotonic dystrophy type 1; skeletal muscle; spinal muscular atrophy

DOI:  https://doi.org/10.1016/j.molmed.2023.03.008
Science. 2023 Apr 21. 380(6642): eabj5559

Induction of lysosomal and mitochondrial biogenesis by AMPK phosphorylation of FNIP1.

Nazma Malik, Bibiana I Ferreira, Pablo E Hollstein, Stephanie D Curtis, Elijah Trefts, Sammy Weiser Novak, Jingting Yu, Rebecca Gilson, Kristina Hellberg, Lingjing Fang, Arlo Sheridan, Nasun Hah, Gerald S Shadel, Uri Manor, Reuben J Shaw.

Cells respond to mitochondrial poisons with rapid activation of the adenosine monophosphate-activated protein kinase (AMPK), causing acute metabolic changes through phosphorylation and prolonged adaptation of metabolism through transcriptional effects. Transcription factor EB (TFEB) is a major effector of AMPK that increases expression of lysosome genes in response to energetic stress, but how AMPK activates TFEB remains unresolved. We demonstrate that AMPK directly phosphorylates five conserved serine residues in folliculin-interacting protein 1 (FNIP1), suppressing the function of the folliculin (FLCN)-FNIP1 complex. FNIP1 phosphorylation is required for AMPK to induce nuclear translocation of TFEB and TFEB-dependent increases of peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC1α) and estrogen-related receptor alpha (ERRα) messenger RNAs. Thus, mitochondrial damage triggers AMPK-FNIP1-dependent nuclear translocation of TFEB, inducing sequential waves of lysosomal and mitochondrial biogenesis.

DOI: https://doi.org/10.1126/science.abj5559
Cell Rep. 2023 Apr 15. pii: S2211-1247(23)00407-2. [Epub ahead of print]42(4): 112396

AMPK activation protects against prostate cancer by inducing a catabolic cellular state.

Lucy Penfold, Angela Woods, Alice E Pollard, Julia Arizanova, Eneko Pascual-Navarro, Phillip J Muckett, Marian H Dore, Alex Montoya, Chad Whilding, Louise Fets, Joao Mokochinski, Theodora A Constantin, Anabel Varela-Carver, Damien A Leach, Charlotte L Bevan, Alexander Yu Nikitin, Zoe Hall, David Carling.

  Emerging evidence indicates that metabolic dysregulation drives prostate cancer (PCa) progression and metastasis. AMP-activated protein kinase (AMPK) is a master regulator of metabolism, although its role in PCa remains unclear. Here, we show that genetic and pharmacological activation of AMPK provides a protective effect on PCa progression in vivo. We show that AMPK activation induces PGC1α expression, leading to catabolic metabolic reprogramming of PCa cells. This catabolic state is characterized by increased mitochondrial gene expression, increased fatty acid oxidation, decreased lipogenic potential, decreased cell proliferation, and decreased cell invasiveness. Together, these changes inhibit PCa disease progression. Additionally, we identify a gene network involved in cell cycle regulation that is inhibited by AMPK activation. Strikingly, we show a correlation between this gene network and PGC1α gene expression in human PCa. Taken together, our findings support the use of AMPK activators for clinical treatment of PCa to improve patient outcome.

Keywords:  AMPK; CP: Cancer; CP: Metabolism; PGC1α; cell cycle regulation; fatty acid oxidation; high-fat diet; lipogenesis; metabolism; metastasis; mitochondria; prostate cancer

DOI:  https://doi.org/10.1016/j.celrep.2023.112396
Mediators Inflamm. 2023 ;2023 7661791

AdipoRon Engages Microglia to Antinociception through the AdipoR1/AMPK Pathway in SNI Mice.

Qian Fang, Jie Li, Yaping Wang, Xinli Liu, Yu Shi, Jiali Chen, Hongrui Zhan, Yanyan Zeng, Wen Wu.

Background: Microglia-associated neuroinflammation plays a crucial role in the initiation and development of neuropathic pain (NeuP). AdipoRon is an analog of adiponectin that exerts an anti-inflammatory effect in various diseases through the adiponectin receptor 1 (AdipoR1) signaling mechanism. Adenosine monophosphate-activated protein kinase (AMPK) is a downstream target of AdipoR1, and the AdipoR1/AMPK pathway is involved in the regulation of inflammation. This study is aimed at investigating whether AdipoRon could alleviate NeuP by inhibiting the expression of microglia-derived tumor necrosis factor-alpha (TNF-α) through the AdipoR1/AMPK pathway.
Methods: In vivo, the NeuP model was established in mice through the spared nerve injury. The von Frey test was used to detect the effect of AdipoRon on the mechanical paw withdrawal threshold. Western Blot was performed to detect the effects of AdipoRon on the expression of TNF-α, AdipoR1, AMPK, and p-AMPK. Immunofluorescence was performed to observe the effects of AdipoRon on spinal microglia. In vitro, lipopolysaccharide (LPS) was used to induce inflammatory responses in BV2 cells. The effect of AdipoRon on cell proliferation was detected by CCK-8. qPCR was used to examine the effects of AdipoRon on the expression of TNF-α and polarization markers. And the effect of AdipoRon on the AdipoR1/AMPK pathway was confirmed by Western Blot.
Results: Intraperitoneal injection of AdipoRon alleviated mechanical nociception in SNI mice, and the application of AdipoRon reduced the expression of TNF-α and the number of microglia in the ipsilateral spinal cord. Additionally, AdipoRon decreased the protein level of AdipoR1 and increased the protein level of p-AMPK in the ipsilateral spinal cord. In vitro, AdipoRon inhibited BV2 cell proliferation and reversed LPS-induced TNF-α expression and polarization imbalance. Furthermore, AdipoRon reversed the LPS-induced increase in AdipoR1 expression and decrease in p-AMPK expression in BV2 cells.
Conclusions: AdipoRon may alleviate NeuP by reducing microglia-derived TNF-α through the AdipoR1/AMPK pathway.

DOI: https://doi.org/10.1155/2023/7661791
Anticancer Agents Med Chem. 2023 Apr 18.

Carnosol Inhibits the Proliferation, Migration, and Invasion of Hepatocellular Carcinoma Cells in vitro by Regulating the AMPK Signaling Pathway.

Shuang Kong, Wenchang Xiao, Tengfei Ma, Yun Chen, Hongjie Shi, Jun Tu, Jiahua Zou, Meng Zhang.

 BACKGROUND: Hepatocellular carcinoma (HCC) is one of the most malignant cancers in the world, and its 5-year survival rate is low. At present, for advanced primary liver cancer, the clinical treatment often adopts the systemic method, but there is no effective targeted treatment. The average survival time of patients with liver cancer after drug treatment is only 3-5 months. Aim: In this study, we aimed to reveal the effect of carnosol on HCC and provide new possibilities for the drug therapy of HCC. Obejective: The objective of this study is to observe the effect of carnosol on the tumor phenotype and signaling pathway of HCC cells. Method: We treated two different human HCC cells, HepG2 and Huh7, with carnosol. The cells were analyzed using the CCK-8 assay for viability and proliferation. The cell migration and invasion were detected by Transwell assay. The molecular markers of cell proliferation, apoptosis, migration, invasion, and signaling pathways were detected by RT-PCR and WB. In addition, we performed rescue experiments with inhibitors to verify the affected signaling pathway. Result: The results showed that carnosol could significantly inhibit HCC cell viability, effort, colony formation, migration, and invasion. Moreover, Carnosol promoted the apoptosis of HCC cells. Mechanically, carnosol activated the AMPK-p53 pathway. Conclusion: To conclude, our study demonstrated that carnosol could inhibit proliferation, migration, invasion, and promote apoptosis via activating AMPK-p53 in HCC cells.

Keywords: AMPK; HepG2; Huh7; carnosol; hepatocellular carcinoma; p53

DOI: https://doi.org/10.2174/1871520623666230418093254
Diabetes. 2023 Apr 19. pii: db220666. [Epub ahead of print]

TBC1D4-S711 controls skeletal muscle insulin sensitization after exercise and contraction.

Rasmus Kjøbsted, Jonas M Kristensen, Nicolas O Eskesen, Kohei Kido, Klara Fjorder, Ditte F Damgaard, Jeppe K Larsen, Nicoline R Andersen, Jesper B Birk, Anders Gudiksen, Jonas T Treebak, Peter Schjerling, Henriette Pilegaard, Jørgen F P Wojtaszewski.

The ability of insulin to stimulate glucose uptake in skeletal muscle is important for whole-body glycemic control. Insulin-stimulated skeletal muscle glucose uptake is improved in the period after a single bout of exercise and accumulating evidence suggests that phosphorylation of TBC1D4 by the protein kinase AMPK is the primary mechanism responsible for this phenomenon. To investigate this, we generated a TBC1D4 knock-in mouse model with a serine-to-alanine point mutation at residue 711 that is phosphorylated in response to both insulin and AMPK activation. Female TBC1D4-S711A mice exhibited normal growth and eating behavior as well as intact wholebody glycemic control on chow and high-fat diets. Moreover, muscle contraction increased glucose uptake, glycogen utilization and AMPK activity similarly in wild-type and TBC1D4-S711A mice. In contrast, improvements in whole-body and muscle insulin sensitivity after exercise and contractions were only evident in wild-type mice and occurred concomitantly with enhanced phosphorylation of TBC1D4-S711. These results provide genetic evidence to support that TBC1D4-S711 serves as a major point of convergence for AMPK- and insulin-induced signaling that mediates the insulin-sensitizing effect of exercise and contractions on skeletal muscle glucose uptake.

DOI: https://doi.org/10.2337/db22-0666
Int Immunopharmacol. 2023 Apr 18. pii: S1567-5769(23)00392-2. [Epub ahead of print]119 110071

Hydrogen inhalation enhances autophagy via the AMPK/mTOR pathway, thereby attenuating doxorubicin-induced cardiac injury.

Tianjiao Ma, Lei Yang, Binmei Zhang, Xin Lv, Feifei Gong, Wei Yang.

   AIMS: Doxorubicin is a drug widely used in clinical cancer treatment, but severe cardiotoxicity limits its clinical application. Autophagy disorder is an important factor in the mechanism of doxorubicin-induced cardiac injury. As the smallest molecule in nature, hydrogen has various biological effects such as anti-oxidation, anti-apoptosis and regulation of autophagy. Hydrogen therapy is currently considered to be an emerging therapeutic method, but the effect and mechanism of hydrogen on doxorubicin-induced myocardial injury have not been determined. The purpose of this study was to investigate the protective effect of hydrogen inhalation on doxorubicin-induced chronic myocardial injury and its effect and mechanism on autophagy.
METHODS: In this study, we established a chronic heart injury model by intraperitoneal injection of doxorubicin in rats for 30 days, accumulating 20 mg/kg. The effect of hydrogen inhalation on the cardiac function in rats was explored by echocardiography, Elisa, and H&E staining. To clarify the influence of autophagy, we detected the expression of LC3 and related autophagy proteins in vivo and in vitro by immunofluorescence and western blot.In order to further explore the mechanism of autophagy, we added pathway inhibitors and used western blot to preliminarily investigate the protective effect of hydrogen inhalation on myocardial injury caused by doxorubicin.
RESULTS: Hydrogen inhalation can improve doxorubicin-induced cardiac function decline and pathological structural abnormalities in rats. It was confirmed by immunofluorescence that hydrogen treatment could restore the expression of autophagy marker protein LC3 (microtubule-associated protein 1 light chain 3) in cardiomyocytes reduced by doxorubicin, while reducing cardiomyocyte apoptosis. Mechanistically, Western blot results consistently showed that hydrogen treatment up-regulated the ratio of p-AMPK (phosphorylated AMP-dependent protein kinase) to AMPK and down-regulated p-mTOR (phosphorylated mammalian target of rapamycin) and mTOR ratio.
CONCLUSIONS: These results suggest that hydrogen inhalation can activate autophagy through the AMPK/mTOR pathway and protect against myocardial injury induced by doxorubicin. Hydrogen inhalation therapy may be a potential treatment for doxorubicin-induced myocardial injury.

Keywords:  AMPK/mTOR pathway; Autophagy; Doxorubicin; Hydrogen; Myocardial injury

DOI:  https://doi.org/10.1016/j.intimp.2023.110071
Biomed Pharmacother. 2023 Apr 13. pii: S0753-3322(23)00479-1. [Epub ahead of print]162 114691

Doxorubicin downregulates autophagy to promote apoptosis-induced dilated cardiomyopathy via regulating the AMPK/mTOR pathway.

Sheng Zhang, Xueping Wei, Haijin Zhang, Youping Wu, Junsong Jing, Rongrong Huang, Ting Zhou, Jingjin Hu, Yueguo Wu, Yuanyuan Li, Zhenqiang You.

  The broad-spectrum antineoplastic drug doxorubicin (DOX) has one of the most serious chronic side effects on the heart, dilated cardiomyopathy, but the precise molecular mechanisms underlying disease progression subsequent to long latency periods remain puzzling. Here, we established a model of DOX-induced dilated cardiomyopathy. In a cardiac cytology exploration, we found that differentially expressed genes in the KEGG signaling pathway enrichment provided a novel complex network of mTOR bridging autophagy and oxidative stress. Validation results showed that DOX caused intracellular reactive oxygen species accumulation in cardiomyocytes, disrupted mitochondria, led to imbalanced intracellular energy metabolism, and triggered cardiomyocyte apoptosis. Apoptosis showed a negative correlation with DOX-regulated cardiomyocyte autophagy. To evaluate whether the inhibition of mTOR could upregulate autophagy to protect cardiomyocytes, we used rapamycin to restore autophagy depressed by DOX. Rapamycin increased cardiomyocyte survival by easing the autophagic flux blocked by DOX. In addition, rapamycin reduced oxidative stress, prevented mitochondrial damage, and restored energy metabolic homeostasis in DOX-treated cardiomyocytes. In vivo, we used metformin (Met) which is an AMPK activator to protect cardiac tissue to alleviate DOX-induced dilated cardiomyopathy. In this study, Met significantly attenuated the oxidative stress response of myocardial tissue caused by DOX and activated cardiomyocyte autophagy to maintain cardiomyocyte energy metabolism and reduce cardiomyocyte apoptosis by downregulating mTOR activity. Overall, our study revealed the role of autophagy and apoptosis in DOX-induced dilated cardiomyopathy and demonstrated the potential role of regulation of the AMPK/mTOR axis in the treatment of DOX-induced dilated cardiomyopathy.

Keywords:  AMPK; Apoptosis; Autophagy; Dilated cardiomyopathy; Doxorubicin; MTOR

DOI:  https://doi.org/10.1016/j.biopha.2023.114691
Proc Natl Acad Sci U S A. 2023 Apr 25. 120(17): e2300902120

ADP enhances the allosteric activation of eukaryotic elongation factor 2 kinase by calmodulin.

Andrea Piserchio, Kimberly J Long, Luke S Browning, Amanda L Bohanon, Eta A Isiorho, Kevin N Dalby, Ranajeet Ghose.

  Protein translation, one of the most energy-consumptive processes in a eukaryotic cell, requires robust regulation, especially under energy-deprived conditions. A critical component of this regulation is the suppression of translational elongation through reduced ribosome association of the GTPase eukaryotic elongation factor 2 (eEF-2) resulting from its specific phosphorylation by the calmodulin (CaM)-activated α-kinase eEF-2 kinase (eEF-2K). It has been suggested that the eEF-2K response to reduced cellular energy levels is indirect and mediated by the universal energy sensor AMP-activated protein kinase (AMPK) through direct stimulatory phosphorylation and/or downregulation of the eEF-2K-inhibitory nutrient-sensing mTOR pathway. Here, we provide structural, biochemical, and cell-biological evidence of a direct energy-sensing role of eEF-2K through its stimulation by ADP. A crystal structure of the nucleotide-bound complex between CaM and the functional core of eEF-2K phosphorylated at its primary stimulatory site (T348) reveals ADP bound at a unique pocket located on the face opposite that housing the kinase active site. Within this basic pocket (BP), created at the CaM/eEF-2K interface upon complex formation, ADP is stabilized through numerous interactions with both interacting partners. Biochemical analyses using wild-type eEF-2K and specific BP mutants indicate that ADP stabilizes CaM within the active complex, increasing the sensitivity of the kinase to CaM. Induction of energy stress through glycolysis inhibition results in significantly reduced enhancement of phosphorylated eEF-2 levels in cells expressing ADP-binding compromised BP mutants compared to cells expressing wild-type eEF-2K. These results suggest a direct energy-sensing role for eEF-2K through its cooperative interaction with CaM and ADP.

Keywords:  alpha-kinase; calmodulin; protein translation; serine/threonine kinase

DOI:  https://doi.org/10.1073/pnas.2300902120
Biochem Pharmacol. 2023 Apr 18. pii: S0006-2952(23)00145-4. [Epub ahead of print] 115554

ALOX5 Promotes Autophagy-dependent Ferroptosis by Activating the AMPK/mTOR Pathway in Melanoma.

Min Wang, Guang Zeng, Bingrui Xiong, Xiaobin Zhu, Jia Guo, Danyang Chen, Shanshan Zhang, Min Luo, Liang Guo, Lin Cai.

   BACKGROUND: Melanoma has become more common, and its therapeutic management has remained challenging in recent decades. The purpose of our study is to explore new prognostic therapeutic markers of melanoma and to find new therapeutic methods and therapeutic targets of novel drugs, which have great significance.
METHOD: First, the arachidonate 5-lipoxygenase (ALOX5) gene associated with both autophagy and ferroptosis was identified by R version 4.2.0. We used human melanoma and para-cancer tissues, human melanoma cell lines, and melanoma-bearing mouse tissues. We used qRT-PCR, Western blotting, immunohistochemistry, immunofluorescence staining, CCK-8, iron ion assay, GSH assay, and MDA assay. In vivo, the ferroptosis activation and antitumor effects of recombinant human ALOX5 protein were evaluated using a xenograft model.
RESULT: We report that the downregulation of ALOX5 in melanoma is positively correlated with the prognosis of patients and is an independent prognostic factor. Elevated ALOX5 contributes to autophagy and ferroptosis in vitro and in vivo. At the same time, inhibition of autophagy can reduce ferroptosis enhanced by ALOX5, and autophagy and ALOX5 have a synergistic effect. The results of the mechanistic study showed that the increase in ALOX5 could activate the AMPK/mTOR pathway and inhibit GPX4 expression, promoting the occurrence of autophagy-dependent ferroptosis, while the decrease in p-AMPK/AMPK inhibited the occurrence of ferroptosis.
CONCLUSION: ALOX5 deficiency was resistant to autophagy and ferroptosis by inhibiting the AMPK/mTOR pathway. Therefore, it can provide new targets and methods for melanoma drug development.

Keywords:  ALOX5; AMPK-mTOR pathway; Autophagy; Ferroptosis; Melanoma

DOI:  https://doi.org/10.1016/j.bcp.2023.115554
Signal Transduct Target Ther. 2023 Apr 21. 8(1): 159

RBM4 dictates ESCC cell fate switch from cellular senescence to glutamine-addiction survival through inhibiting LKB1-AMPK-axis.

Lei Chen, Wenjing Zhang, Dan Chen, Quan Yang, Siwen Sun, Zhenwei Dai, Zhengzheng Li, Xuemei Liang, Chaoqun Chen, Yuexia Jiao, Lili Zhi, Lianmei Zhao, Jinrui Zhang, Xuefeng Liu, Jinyao Zhao, Man Li, Yang Wang, Yangfan Qi.

Cellular senescence provides a protective barrier against tumorigenesis in precancerous or normal tissues upon distinct stressors. However, the detailed mechanisms by which tumor cells evade premature senescence to malignant progression remain largely elusive. Here we reported that RBM4 adversely impacted cellular senescence to favor glutamine-dependent survival of esophageal squamous cell carcinoma (ESCC) cells by dictating the activity of LKB1, a critical governor of cancer metabolism. The level of RBM4 was specifically elevated in ESCC compared to normal tissues, and RBM4 overexpression promoted the malignant phenotype. RBM4 contributed to overcome H-RAS- or doxorubicin-induced senescence, while its depletion caused P27-dependent senescence and proliferation arrest by activating LKB1-AMPK-mTOR cascade. Mechanistically, RBM4 competitively bound LKB1 to disrupt the LKB1/STRAD/MO25 heterotrimeric complex, subsequently recruiting the E3 ligase TRIM26 to LKB1, promoting LKB1 ubiquitination and degradation in nucleus. Therefore, such molecular process leads to bypassing senescence and sustaining cell proliferation through the activation of glutamine metabolism. Clinically, the ESCC patients with high RBM4 and low LKB1 have significantly worse overall survival than those with low RBM4 and high LKB1. The RBM4 high/LKB1 low expression confers increased sensitivity of ESCC cells to glutaminase inhibitor CB-839, providing a novel insight into mechanisms underlying the glutamine-dependency to improve the efficacy of glutamine inhibitors in ESCC therapeutics.

DOI: https://doi.org/10.1038/s41392-023-01367-x