1
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Freemantle JB, Shah D, Lynch DM, Ciulli A, Hundal HS, Hardie DG. The pro-drug C13 activates AMPK by two distinct mechanisms. Biochem J 2024; 481:1203-1219. [PMID: 39222030 DOI: 10.1042/bcj20240425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2024] [Revised: 08/28/2024] [Accepted: 09/02/2024] [Indexed: 09/04/2024]
Abstract
The AMP-activated protein kinase (AMPK) is a sensor of cellular energy status that is expressed in almost all eukaryotic cells. In the canonical activation mechanism, it is activated by increases in AMP:ATP and ADP:ATP ratios that signify declining cellular energy status. Once activated, AMPK phosphorylates numerous targets that promote catabolic pathways generating ATP, while inhibiting anabolic and other processes that consume ATP, thus acting to restore energy homeostasis. Pharmacological agents that activate AMPK have been useful in identifying downstream targets and have potential as drugs for treatment of metabolic disorders such as Type 2 diabetes and non-alcoholic fatty liver disease. One such agent is C13, a pro-drug with a phosphonate bis(isobutyryloxymethyl) ester moiety, with the isobutyryloxymethyl groups increasing membrane permeability. Following cellular uptake, C13 is cleaved to release C2, an AMP analogue and potent AMPK activator that is specific for complexes containing the α1 (but not the α2) catalytic subunit isoform. This has previously been assumed to be the sole mechanism by which C13 activates AMPK, with potential roles for the isobutyryloxymethyl groups being ignored. We now report that, following cleavage from C13, these protective groups are metabolized to formaldehyde, an agent that inhibits mitochondrial function and increases cellular AMP:ATP ratios, thus providing additional AMPK activation by the canonical mechanism.
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Affiliation(s)
- Jordana B Freemantle
- Division of Cell Signalling and Immunology, Sir James Black Centre, School of Life Sciences, University of Dundee, Dundee DD1 5EH, U.K
| | - Dinesh Shah
- Division of Cell Signalling and Immunology, Sir James Black Centre, School of Life Sciences, University of Dundee, Dundee DD1 5EH, U.K
| | - Dylan M Lynch
- Centre for Targeted Protein Degradation, School of Life Sciences, University of Dundee, 1 James Lindsay Place, Dundee DD1 5JJ, U.K
| | - Alessio Ciulli
- Centre for Targeted Protein Degradation, School of Life Sciences, University of Dundee, 1 James Lindsay Place, Dundee DD1 5JJ, U.K
| | - Harinder S Hundal
- Division of Cell Signalling and Immunology, Sir James Black Centre, School of Life Sciences, University of Dundee, Dundee DD1 5EH, U.K
| | - D Grahame Hardie
- Division of Cell Signalling and Immunology, Sir James Black Centre, School of Life Sciences, University of Dundee, Dundee DD1 5EH, U.K
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2
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Yang H, Zingaro VA, Lincoff J, Tom H, Oikawa S, Oses-Prieto JA, Edmondson Q, Seiple I, Shah H, Kajimura S, Burlingame AL, Grabe M, Ruggero D. Remodelling of the translatome controls diet and its impact on tumorigenesis. Nature 2024; 633:189-197. [PMID: 39143206 DOI: 10.1038/s41586-024-07781-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2023] [Accepted: 07/03/2024] [Indexed: 08/16/2024]
Abstract
Fasting is associated with a range of health benefits1-6. How fasting signals elicit changes in the proteome to establish metabolic programmes remains poorly understood. Here we show that hepatocytes selectively remodel the translatome while global translation is paradoxically downregulated during fasting7,8. We discover that phosphorylation of eukaryotic translation initiation factor 4E (P-eIF4E) is induced during fasting. We show that P-eIF4E is responsible for controlling the translation of genes involved in lipid catabolism and the production of ketone bodies. Inhibiting P-eIF4E impairs ketogenesis in response to fasting and a ketogenic diet. P-eIF4E regulates those messenger RNAs through a specific translation regulatory element within their 5' untranslated regions (5' UTRs). Our findings reveal a new signalling property of fatty acids, which are elevated during fasting. We found that fatty acids bind and induce AMP-activated protein kinase (AMPK) kinase activity that in turn enhances the phosphorylation of MAP kinase-interacting protein kinase (MNK), the kinase that phosphorylates eIF4E. The AMPK-MNK-eIF4E axis controls ketogenesis, revealing a new lipid-mediated kinase signalling pathway that links ketogenesis to translation control. Certain types of cancer use ketone bodies as an energy source9,10 that may rely on P-eIF4E. Our findings reveal that on a ketogenic diet, treatment with eFT508 (also known as tomivosertib; a P-eIF4E inhibitor) restrains pancreatic tumour growth. Thus, our findings unveil a new fatty acid-induced signalling pathway that activates selective translation, which underlies ketogenesis and provides a tailored diet intervention therapy for cancer.
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Affiliation(s)
- Haojun Yang
- Helen Diller Family Comprehensive Cancer Center, UCSF, San Francisco, CA, USA
- School of Medicine and Department of Urology, UCSF, San Francisco, CA, USA
| | - Vincenzo Andrea Zingaro
- Helen Diller Family Comprehensive Cancer Center, UCSF, San Francisco, CA, USA
- School of Medicine and Department of Urology, UCSF, San Francisco, CA, USA
| | - James Lincoff
- Department of Pharmaceutical Chemistry, UCSF, San Francisco, CA, USA
- Cardiovascular Research Institute, UCSF, San Francisco, CA, USA
| | - Harrison Tom
- Helen Diller Family Comprehensive Cancer Center, UCSF, San Francisco, CA, USA
- School of Medicine and Department of Urology, UCSF, San Francisco, CA, USA
| | - Satoshi Oikawa
- Division of Endocrinology, Diabetes and Metabolism, Beth Israel Deaconess Medical Center, Harvard Medical School and Howard Hughes Medical Institute, Boston, MA, USA
| | | | - Quinn Edmondson
- Department of Pharmaceutical Chemistry, UCSF, San Francisco, CA, USA
- Cardiovascular Research Institute, UCSF, San Francisco, CA, USA
| | - Ian Seiple
- Department of Pharmaceutical Chemistry, UCSF, San Francisco, CA, USA
- Cardiovascular Research Institute, UCSF, San Francisco, CA, USA
| | - Hardik Shah
- Metabolomics Platform, Comprehensive Cancer Center, The University of Chicago, Chicago, IL, USA
| | - Shingo Kajimura
- Division of Endocrinology, Diabetes and Metabolism, Beth Israel Deaconess Medical Center, Harvard Medical School and Howard Hughes Medical Institute, Boston, MA, USA
| | - Alma L Burlingame
- Helen Diller Family Comprehensive Cancer Center, UCSF, San Francisco, CA, USA
- Department of Pharmaceutical Chemistry, UCSF, San Francisco, CA, USA
| | - Michael Grabe
- Department of Pharmaceutical Chemistry, UCSF, San Francisco, CA, USA
- Cardiovascular Research Institute, UCSF, San Francisco, CA, USA
| | - Davide Ruggero
- Helen Diller Family Comprehensive Cancer Center, UCSF, San Francisco, CA, USA.
- School of Medicine and Department of Urology, UCSF, San Francisco, CA, USA.
- Department of Cellular and Molecular Pharmacology, UCSF, San Francisco, CA, USA.
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3
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Wang S, Wang K, Yue D, Yang X, Pan X, Kong F, Zhao R, Bie Q, Tian D, Zhu S, He B, Bin Z. MT1G induces lipid droplet accumulation through modulation of H3K14 trimethylation accelerating clear cell renal cell carcinoma progression. Br J Cancer 2024; 131:641-654. [PMID: 38906969 PMCID: PMC11333765 DOI: 10.1038/s41416-024-02747-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Revised: 05/30/2024] [Accepted: 06/03/2024] [Indexed: 06/23/2024] Open
Abstract
BACKGROUND Lipid droplet formation is a prominent histological feature in clear cell renal cell carcinoma (ccRCC), but the significance and mechanisms underlying lipid droplet accumulation remain unclear. METHODS Expression and clinical significance of MT1G in ccRCC were analyzed by using TCGA data, GEO data and scRNASeq data. MT1G overexpression or knockdown ccRCC cell lines were constructed and in situ ccRCC model, lung metastasis assay, metabolomics and lipid droplets staining were performed to explore the role of MT1G on lipid droplet accumulation in ccRCC. RESULTS Initially, we observed low MT1G expression in ccRCC tissues, whereas high MT1G expression correlated with advanced disease stage and poorer prognosis. Elevated MT1G expression promoted ccRCC growth and metastasis both in vitro and in vivo. Mechanistically, MT1G significantly suppressed acylcarnitine levels and downstream tricarboxylic acid (TCA) cycle activity, resulting in increased fatty acid and lipid accumulation without affecting cholesterol metabolism. Notably, MT1G inhibited H3K14 trimethylation (H3K14me3) modification. Under these conditions, MT1G-mediated H3K14me3 was recruited to the CPT1B promoter through direct interaction with specific promoter regions, leading to reduced CPT1B transcription and translation. CONCLUSIONS Our study unveils a novel mechanism of lipid droplet accumulation in ccRCC, where MT1G inhibits CPT1B expression through modulation of H3K14 trimethylation, consequently enhancing lipid droplet accumulation and promoting ccRCC progression. Graphical abstract figure Schematic diagram illustrating MT1G/H3K14me3/CPT1B-mediated lipid droplet accumulation promoted ccRCC progression via FAO inhibition.
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Affiliation(s)
- Sen Wang
- Department of Laboratory Medicine, Affiliated Hospital of Jining Medical University, Jining Medical University, Jining, Shandong, 272007, China
- Postdoctoral Mobile Station of Shandong University of Traditional Chinese Medicine, Jinan, Shandong, 250355, China
| | - Kexin Wang
- Department of Medical Imaging, Affiliated Hospital of Jining Medical University, Jining, Shandong, 272007, China
| | - Dong Yue
- Department of Urology, Affiliated Hospital of Jining Medical University, Jining, Shandong Province, 272007, China
| | - Xiaxia Yang
- Department of Laboratory Medicine, Affiliated Hospital of Jining Medical University, Jining Medical University, Jining, Shandong, 272007, China
| | - Xiaozao Pan
- Department of Laboratory Medicine, Affiliated Hospital of Jining Medical University, Jining Medical University, Jining, Shandong, 272007, China
| | - Feifei Kong
- Department of Laboratory Medicine, Affiliated Hospital of Jining Medical University, Jining Medical University, Jining, Shandong, 272007, China
| | - Rou Zhao
- Department of Laboratory Medicine, Affiliated Hospital of Jining Medical University, Jining Medical University, Jining, Shandong, 272007, China
| | - Qingli Bie
- Department of Laboratory Medicine, Affiliated Hospital of Jining Medical University, Jining Medical University, Jining, Shandong, 272007, China
| | - Dongxing Tian
- Department of Laboratory Medicine, Affiliated Hospital of Jining Medical University, Jining Medical University, Jining, Shandong, 272007, China
| | - Shuqing Zhu
- Department of Digestive Endoscopy, Affiliated Hospital of Jining Medical University, Jining, Shandong Province, 272007, China
| | - Baoyu He
- Department of Laboratory Medicine, Affiliated Hospital of Jining Medical University, Jining Medical University, Jining, Shandong, 272007, China.
| | - Zhang Bin
- Department of Laboratory Medicine, Affiliated Hospital of Jining Medical University, Jining Medical University, Jining, Shandong, 272007, China.
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4
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Ghatak S, Diedrich JK, Talantova M, Bhadra N, Scott H, Sharma M, Albertolle M, Schork NJ, Yates JR, Lipton SA. Single-Cell Patch-Clamp/Proteomics of Human Alzheimer's Disease iPSC-Derived Excitatory Neurons Versus Isogenic Wild-Type Controls Suggests Novel Causation and Therapeutic Targets. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024; 11:e2400545. [PMID: 38773714 PMCID: PMC11304297 DOI: 10.1002/advs.202400545] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2024] [Revised: 04/03/2024] [Indexed: 05/24/2024]
Abstract
Standard single-cell (sc) proteomics of disease states inferred from multicellular organs or organoids cannot currently be related to single-cell physiology. Here, a scPatch-Clamp/Proteomics platform is developed on single neurons generated from hiPSCs bearing an Alzheimer's disease (AD) genetic mutation and compares them to isogenic wild-type controls. This approach provides both current and voltage electrophysiological data plus detailed proteomics information on single-cells. With this new method, the authors are able to observe hyperelectrical activity in the AD hiPSC-neurons, similar to that observed in the human AD brain, and correlate it to ≈1400 proteins detected at the single neuron level. Using linear regression and mediation analyses to explore the relationship between the abundance of individual proteins and the neuron's mutational and electrophysiological status, this approach yields new information on therapeutic targets in excitatory neurons not attainable by traditional methods. This combined patch-proteomics technique creates a new proteogenetic-therapeutic strategy to correlate genotypic alterations to physiology with protein expression in single-cells.
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Affiliation(s)
- Swagata Ghatak
- Neurodegeneration New Medicines CenterThe Scripps Research InstituteLa JollaCA92037USA
- Department of Molecular MedicineThe Scripps Research InstituteLa JollaCA92037USA
- Present address:
School of Biological SciencesNational Institute of Science Education and Research (NISER)‐Bhubaneswar, an OCC of Homi Bhabha National InstituteJataniOdisha752050India
| | - Jolene K. Diedrich
- Department of Molecular MedicineThe Scripps Research InstituteLa JollaCA92037USA
| | - Maria Talantova
- Neurodegeneration New Medicines CenterThe Scripps Research InstituteLa JollaCA92037USA
- Department of Molecular MedicineThe Scripps Research InstituteLa JollaCA92037USA
| | - Nivedita Bhadra
- Quantitative Medicine and Systems BiologyThe Translational Genomics Research InstitutePhoenixAZ85004USA
| | - Henry Scott
- Neurodegeneration New Medicines CenterThe Scripps Research InstituteLa JollaCA92037USA
- Department of Molecular MedicineThe Scripps Research InstituteLa JollaCA92037USA
| | - Meetal Sharma
- Neurodegeneration New Medicines CenterThe Scripps Research InstituteLa JollaCA92037USA
- Department of Molecular MedicineThe Scripps Research InstituteLa JollaCA92037USA
| | - Matthew Albertolle
- Neurodegeneration New Medicines CenterThe Scripps Research InstituteLa JollaCA92037USA
- Department of Molecular MedicineThe Scripps Research InstituteLa JollaCA92037USA
- Present address:
Drug Metabolism and Pharmacokinetics DepartmentTakeda Development Center AmericasSan DiegoCA92121USA
| | - Nicholas J. Schork
- Quantitative Medicine and Systems BiologyThe Translational Genomics Research InstitutePhoenixAZ85004USA
| | - John R. Yates
- Department of Molecular MedicineThe Scripps Research InstituteLa JollaCA92037USA
| | - Stuart A. Lipton
- Neurodegeneration New Medicines CenterThe Scripps Research InstituteLa JollaCA92037USA
- Department of Molecular MedicineThe Scripps Research InstituteLa JollaCA92037USA
- Department of NeurosciencesSchool of MedicineUniversity of California, San DiegoLa JollaCA92093USA
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5
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Xia L, Chen J, Huang J, Lin X, Jiang J, Liu T, Huang N, Luo Y. The role of AMPKα subunit in Alzheimer's disease: In-depth analysis and future prospects. Heliyon 2024; 10:e34254. [PMID: 39071620 PMCID: PMC11279802 DOI: 10.1016/j.heliyon.2024.e34254] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2024] [Revised: 06/29/2024] [Accepted: 07/05/2024] [Indexed: 07/30/2024] Open
Abstract
The AMP-activated protein kinase α (AMPKα) subunit is the catalytic subunit in the AMPK complex, playing a crucial role in AMPK activation. It has two isoforms: AMPKα1 and AMPKα2. Emerging evidence suggests that the AMPKα subunit exhibits subtype-specific effects in Alzheimer's disease (AD). This review discusses the role of the AMPKα subunit in the pathogenesis of AD, including its impact on β-amyloid (Aβ) pathology, Tau pathology, metabolic disorders, inflammation, mitochondrial dysfunction, inflammasome and pyroptosis. Additionally, it reviews the distinct roles of its isoforms, AMPKα1 and AMPKα2, in AD, which may provide more precise targets for future drug development in AD.
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Affiliation(s)
- Lingqiong Xia
- Department of Neurology, Third Affiliated Hospital of Zunyi Medical University (The First People's Hospital of Zunyi), Zunyi, Guizhou, China
| | - Jianhua Chen
- Department of Neurology, Third Affiliated Hospital of Zunyi Medical University (The First People's Hospital of Zunyi), Zunyi, Guizhou, China
| | - Juan Huang
- Key Laboratory of Basic Pharmacology and Joint International Research Laboratory of Ethnomedicine of Ministry of Education, Zunyi Medical University, Guizhou, China
| | - Xianmei Lin
- Guizhou University of Traditional Chinese Medicine, Guiyang, Guizhou, China
| | - Jingyu Jiang
- Department of Gastroenterology, Guizhou Aerospace Hospital, Zunyi, Guizhou, China
| | - Tingting Liu
- National Drug Clinical Trial Institution, Third Affiliated Hospital of Zunyi Medical University (The First People's Hospital of Zunyi), Zunyi, Guizhou, China
| | - Nanqu Huang
- National Drug Clinical Trial Institution, Third Affiliated Hospital of Zunyi Medical University (The First People's Hospital of Zunyi), Zunyi, Guizhou, China
| | - Yong Luo
- Department of Neurology, Third Affiliated Hospital of Zunyi Medical University (The First People's Hospital of Zunyi), Zunyi, Guizhou, China
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6
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Smiles WJ, Ovens AJ, Kemp BE, Galic S, Petersen J, Oakhill JS. New developments in AMPK and mTORC1 cross-talk. Essays Biochem 2024:EBC20240007. [PMID: 38994736 DOI: 10.1042/ebc20240007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2024] [Revised: 06/27/2024] [Accepted: 06/28/2024] [Indexed: 07/13/2024]
Abstract
Metabolic homeostasis and the ability to link energy supply to demand are essential requirements for all living cells to grow and proliferate. Key to metabolic homeostasis in all eukaryotes are AMPK and mTORC1, two kinases that sense nutrient levels and function as counteracting regulators of catabolism (AMPK) and anabolism (mTORC1) to control cell survival, growth and proliferation. Discoveries beginning in the early 2000s revealed that AMPK and mTORC1 communicate, or cross-talk, through direct and indirect phosphorylation events to regulate the activities of each other and their shared protein substrate ULK1, the master initiator of autophagy, thereby allowing cellular metabolism to rapidly adapt to energy and nutritional state. More recent reports describe divergent mechanisms of AMPK/mTORC1 cross-talk and the elaborate means by which AMPK and mTORC1 are activated at the lysosome. Here, we provide a comprehensive overview of current understanding in this exciting area and comment on new evidence showing mTORC1 feedback extends to the level of the AMPK isoform, which is particularly pertinent for some cancers where specific AMPK isoforms are implicated in disease pathogenesis.
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Affiliation(s)
- William J Smiles
- Metabolic Signalling Laboratory, St. Vincent's Institute of Medical Research, Fitzroy, VIC 3065, Australia
- Research Program for Receptor Biochemistry and Tumour Metabolism, Department of Paediatrics, University Hospital of the Paracelsus Medical University, Salzburg, Austria
| | - Ashley J Ovens
- Protein Engineering in Immunity and Metabolism, St. Vincent's Institute of Medical Research, Fitzroy, VIC 3065, Australia
| | - Bruce E Kemp
- Protein Chemistry and Metabolism, St. Vincent's Institute of Medical Research, Fitzroy, VIC 3065, Australia
- Department of Medicine, University of Melbourne, Parkville, VIC 3010, Australia
- Mary Mackillop Institute for Health Research, Australian Catholic University, Fitzroy, Vic 3065, Vic. Australia
| | - Sandra Galic
- Department of Medicine, University of Melbourne, Parkville, VIC 3010, Australia
- Metabolic Physiology, St. Vincent's Institute of Medical Research, Fitzroy, VIC 3065, Australia
| | - Janni Petersen
- Flinders Health and Medical Research Institute, Flinders Centre for Innovation in Cancer, Flinders University, Adelaide, SA 5042, Australia
- Nutrition and Metabolism, South Australia Health and Medical Research Institute, Adelaide, SA 5000, Australia
| | - Jonathan S Oakhill
- Metabolic Signalling Laboratory, St. Vincent's Institute of Medical Research, Fitzroy, VIC 3065, Australia
- Department of Medicine, University of Melbourne, Parkville, VIC 3010, Australia
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7
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Peng F, Lu J, Su K, Liu X, Luo H, He B, Wang C, Zhang X, An F, Lv D, Luo Y, Su Q, Jiang T, Deng Z, He B, Xu L, Guo T, Xiang J, Gu C, Wang L, Xu G, Xu Y, Li M, Kelley KW, Cui B, Liu Q. Oncogenic fatty acid oxidation senses circadian disruption in sleep-deficiency-enhanced tumorigenesis. Cell Metab 2024; 36:1598-1618.e11. [PMID: 38772364 DOI: 10.1016/j.cmet.2024.04.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Revised: 03/15/2024] [Accepted: 04/25/2024] [Indexed: 05/23/2024]
Abstract
Circadian disruption predicts poor cancer prognosis, yet how circadian disruption is sensed in sleep-deficiency (SD)-enhanced tumorigenesis remains obscure. Here, we show fatty acid oxidation (FAO) as a circadian sensor relaying from clock disruption to oncogenic metabolic signal in SD-enhanced lung tumorigenesis. Both unbiased transcriptomic and metabolomic analyses reveal that FAO senses SD-induced circadian disruption, as illustrated by continuously increased palmitoyl-coenzyme A (PA-CoA) catalyzed by long-chain fatty acyl-CoA synthetase 1 (ACSL1). Mechanistically, SD-dysregulated CLOCK hypertransactivates ACSL1 to produce PA-CoA, which facilitates CLOCK-Cys194 S-palmitoylation in a ZDHHC5-dependent manner. This positive transcription-palmitoylation feedback loop prevents ubiquitin-proteasomal degradation of CLOCK, causing FAO-sensed circadian disruption to maintain SD-enhanced cancer stemness. Intriguingly, timed β-endorphin resets rhythmic Clock and Acsl1 expression to alleviate SD-enhanced tumorigenesis. Sleep quality and serum β-endorphin are negatively associated with both cancer development and CLOCK/ACSL1 expression in patients with cancer, suggesting dawn-supplemented β-endorphin as a potential chronotherapeutic strategy for SD-related cancer.
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Affiliation(s)
- Fei Peng
- Institute of Cancer Stem Cell, Dalian Medical University, Dalian, Liaoning, China
| | - Jinxin Lu
- Institute of Cancer Stem Cell, Dalian Medical University, Dalian, Liaoning, China
| | - Keyu Su
- Institute of Cancer Stem Cell, Dalian Medical University, Dalian, Liaoning, China; State Key Laboratory of Oncology in South China, Psychobehavioral Cancer Research Center, Guangdong Provincial Clinical Research Center for Cancer, Sun Yat-sen University Cancer Center, Guangzhou, Guangdong, China
| | - Xinyu Liu
- Key Laboratory of Separation Sciences for Analytical Chemistry, National Chromatographic R&A Center, Dalian Institute of Chemical Physics, Chinese Academy of Sciences (CAS), Dalian, Liaoning, China
| | - Huandong Luo
- Institute of Cancer Stem Cell, Dalian Medical University, Dalian, Liaoning, China
| | - Bin He
- Institute of Cancer Stem Cell, Dalian Medical University, Dalian, Liaoning, China
| | - Cenxin Wang
- Institute of Cancer Stem Cell, Dalian Medical University, Dalian, Liaoning, China
| | - Xiaoyu Zhang
- Institute of Cancer Stem Cell, Dalian Medical University, Dalian, Liaoning, China
| | - Fan An
- Institute of Cancer Stem Cell, Dalian Medical University, Dalian, Liaoning, China
| | - Dekang Lv
- Institute of Cancer Stem Cell, Dalian Medical University, Dalian, Liaoning, China
| | - Yuanyuan Luo
- Institute of Cancer Stem Cell, Dalian Medical University, Dalian, Liaoning, China; Key Laboratory of Separation Sciences for Analytical Chemistry, National Chromatographic R&A Center, Dalian Institute of Chemical Physics, Chinese Academy of Sciences (CAS), Dalian, Liaoning, China
| | - Qitong Su
- Institute of Cancer Stem Cell, Dalian Medical University, Dalian, Liaoning, China
| | - Tonghui Jiang
- Institute of Cancer Stem Cell, Dalian Medical University, Dalian, Liaoning, China
| | - Ziqian Deng
- Institute of Cancer Stem Cell, Dalian Medical University, Dalian, Liaoning, China
| | - Bin He
- State Key Laboratory of Oncology in South China, Psychobehavioral Cancer Research Center, Guangdong Provincial Clinical Research Center for Cancer, Sun Yat-sen University Cancer Center, Guangzhou, Guangdong, China
| | - Lingzhi Xu
- Department of Oncology, The Second Affiliated Hospital, Dalian Medical University, Dalian, Liaoning, China
| | - Tao Guo
- Department of Thoracic Surgery, The First Affiliated Hospital of Dalian Medical University, Dalian, Liaoning, China
| | - Jin Xiang
- State Key Laboratory of Oncology in South China, Psychobehavioral Cancer Research Center, Guangdong Provincial Clinical Research Center for Cancer, Sun Yat-sen University Cancer Center, Guangzhou, Guangdong, China
| | - Chundong Gu
- Department of Thoracic Surgery, The First Affiliated Hospital of Dalian Medical University, Dalian, Liaoning, China
| | - Ling Wang
- Department of Oncology, The First Affiliated Hospital of Dalian Medical University, Dalian, Liaoning, China
| | - Guowang Xu
- Key Laboratory of Separation Sciences for Analytical Chemistry, National Chromatographic R&A Center, Dalian Institute of Chemical Physics, Chinese Academy of Sciences (CAS), Dalian, Liaoning, China
| | - Ying Xu
- Cambridge-Soochow University Genomic Resource Center, Soochow University, Suzhou, Jiangsu, China
| | - Mindian Li
- Department of Cardiovascular Medicine, Center for Circadian Metabolism and Cardiovascular Disease, Southwest Hospital, Army Medical University, Chongqing, China
| | - Keith W Kelley
- Department of Pathology, College of Medicine and Department of Animal Sciences, College of ACES, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Bai Cui
- Institute of Cancer Stem Cell, Dalian Medical University, Dalian, Liaoning, China; State Key Laboratory of Oncology in South China, Psychobehavioral Cancer Research Center, Guangdong Provincial Clinical Research Center for Cancer, Sun Yat-sen University Cancer Center, Guangzhou, Guangdong, China.
| | - Quentin Liu
- Institute of Cancer Stem Cell, Dalian Medical University, Dalian, Liaoning, China; State Key Laboratory of Oncology in South China, Psychobehavioral Cancer Research Center, Guangdong Provincial Clinical Research Center for Cancer, Sun Yat-sen University Cancer Center, Guangzhou, Guangdong, China.
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8
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MacMillan S, Burns DP, O'Halloran KD, Evans AM. SubSol-HIe is an AMPK-dependent hypoxia-responsive subnucleus of the nucleus tractus solitarius that coordinates the hypoxic ventilatory response and protects against apnoea in mice. Pflugers Arch 2024; 476:1087-1107. [PMID: 38635058 PMCID: PMC11166843 DOI: 10.1007/s00424-024-02957-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Revised: 03/24/2024] [Accepted: 03/31/2024] [Indexed: 04/19/2024]
Abstract
Functional magnetic resonance imaging (fMRI) suggests that the hypoxic ventilatory response is facilitated by the AMP-activated protein kinase (AMPK), not at the carotid bodies, but within a subnucleus (Bregma -7.5 to -7.1 mm) of the nucleus tractus solitarius that exhibits right-sided bilateral asymmetry. Here, we map this subnucleus using cFos expression as a surrogate for neuronal activation and mice in which the genes encoding the AMPK-α1 (Prkaa1) and AMPK-α2 (Prkaa2) catalytic subunits were deleted in catecholaminergic cells by Cre expression via the tyrosine hydroxylase promoter. Comparative analysis of brainstem sections, relative to controls, revealed that AMPK-α1/α2 deletion inhibited, with right-sided bilateral asymmetry, cFos expression in and thus activation of a neuronal cluster that partially spanned three interconnected anatomical nuclei adjacent to the area postrema: SolDL (Bregma -7.44 mm to -7.48 mm), SolDM (Bregma -7.44 mm to -7.48 mm) and SubP (Bregma -7.48 mm to -7.56 mm). This approximates the volume identified by fMRI. Moreover, these nuclei are known to be in receipt of carotid body afferent inputs, and catecholaminergic neurons of SubP and SolDL innervate aspects of the ventrolateral medulla responsible for respiratory rhythmogenesis. Accordingly, AMPK-α1/α2 deletion attenuated hypoxia-evoked increases in minute ventilation (normalised to metabolism), reductions in expiration time, and increases sigh frequency, but increased apnoea frequency during hypoxia. The metabolic response to hypoxia in AMPK-α1/α2 knockout mice and the brainstem and spinal cord catecholamine levels were equivalent to controls. We conclude that within the brainstem an AMPK-dependent, hypoxia-responsive subnucleus partially spans SubP, SolDM and SolDL, namely SubSol-HIe, and is critical to coordination of active expiration, the hypoxic ventilatory response and defence against apnoea.
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Affiliation(s)
- Sandy MacMillan
- Centre for Discovery Brain Sciences, College of Medicine and Veterinary Medicine, Hugh Robson Building, University of Edinburgh, Edinburgh, EH8 9XD, UK
| | - David P Burns
- Department of Physiology, School of Medicine, College of Medicine & Health, University College Cork, Cork, Ireland
| | - Ken D O'Halloran
- Department of Physiology, School of Medicine, College of Medicine & Health, University College Cork, Cork, Ireland
| | - A Mark Evans
- Centre for Discovery Brain Sciences, College of Medicine and Veterinary Medicine, Hugh Robson Building, University of Edinburgh, Edinburgh, EH8 9XD, UK.
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9
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Smith TKT, Ghorbani P, LeBlond ND, Nunes JRC, O'Dwyer C, Ambursley N, Fong-McMaster C, Minarrieta L, Burkovsky LA, El-Hakim R, Trzaskalski NA, Locatelli CAA, Stotts C, Pember C, Rayner KJ, Kemp BE, Loh K, Harper ME, Mulvihill EE, St-Pierre J, Fullerton MD. AMPK-mediated regulation of endogenous cholesterol synthesis does not affect atherosclerosis in a murine Pcsk9-AAV model. Atherosclerosis 2024:117608. [PMID: 38880706 DOI: 10.1016/j.atherosclerosis.2024.117608] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Revised: 05/09/2024] [Accepted: 05/30/2024] [Indexed: 06/18/2024]
Abstract
BACKGROUND AND AIMS Dysregulated cholesterol metabolism is a hallmark of atherosclerotic cardiovascular diseases, yet our understanding of how endogenous cholesterol synthesis affects atherosclerosis is not clear. The energy sensor AMP-activated protein kinase (AMPK) phosphorylates and inhibits the rate-limiting enzyme in the mevalonate pathway HMG-CoA reductase (HMGCR). Recent work demonstrated that when AMPK-HMGCR signaling was compromised in an Apoe-/- model of hypercholesterolemia, atherosclerosis was exacerbated due to elevated hematopoietic stem and progenitor cell mobilization and myelopoiesis. We sought to validate the significance of the AMPK-HMGCR signaling axis in atherosclerosis using a non-germline hypercholesterolemia model with functional ApoE. METHODS Male and female HMGCR S871A knock-in (KI) mice and wild-type (WT) littermate controls were made atherosclerotic by intravenous injection of a gain-of-function Pcsk9D374Y-adeno-associated virus followed by high-fat and high-cholesterol atherogenic western diet feeding for 16 weeks. RESULTS AMPK activation suppressed endogenous cholesterol synthesis in primary bone marrow-derived macrophages from WT but not HMGCR KI mice, without changing other parameters of cholesterol regulation. Atherosclerotic plaque area was unchanged between WT and HMGCR KI mice, independent of sex. Correspondingly, there were no phenotypic differences observed in hematopoietic progenitors or differentiated immune cells in the bone marrow, blood, or spleen, and no significant changes in systemic markers of inflammation. When lethally irradiated female mice were transplanted with KI bone marrow, there was similar plaque content relative to WT. CONCLUSIONS Given previous work, our study demonstrates the importance of preclinical atherosclerosis model comparison and brings into question the importance of AMPK-mediated control of cholesterol synthesis in atherosclerosis.
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Affiliation(s)
- Tyler K T Smith
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada; Centre for Infection, Immunity and Inflammation, Ottawa, ON, Canada; Ottawa Institute of Systems Biology, Ottawa, ON, Canada
| | - Peyman Ghorbani
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada; Centre for Infection, Immunity and Inflammation, Ottawa, ON, Canada; Ottawa Institute of Systems Biology, Ottawa, ON, Canada
| | - Nicholas D LeBlond
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Julia R C Nunes
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada; Centre for Infection, Immunity and Inflammation, Ottawa, ON, Canada; Ottawa Institute of Systems Biology, Ottawa, ON, Canada
| | - Conor O'Dwyer
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada; Centre for Infection, Immunity and Inflammation, Ottawa, ON, Canada; Ottawa Institute of Systems Biology, Ottawa, ON, Canada
| | - Nia Ambursley
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Claire Fong-McMaster
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada; Ottawa Institute of Systems Biology, Ottawa, ON, Canada
| | - Lucía Minarrieta
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada; Centre for Infection, Immunity and Inflammation, Ottawa, ON, Canada; Ottawa Institute of Systems Biology, Ottawa, ON, Canada
| | - Leah A Burkovsky
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Rama El-Hakim
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Natasha A Trzaskalski
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada; University of Ottawa Heart Institute, Ottawa, ON, Canada
| | - Cassandra A A Locatelli
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada; University of Ottawa Heart Institute, Ottawa, ON, Canada
| | - Cameron Stotts
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada; University of Ottawa Heart Institute, Ottawa, ON, Canada
| | - Ciara Pember
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Katey J Rayner
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada; Centre for Infection, Immunity and Inflammation, Ottawa, ON, Canada; University of Ottawa Heart Institute, Ottawa, ON, Canada
| | - Bruce E Kemp
- Protein Chemistry and Metabolism, St. Vincent's Institute of Medical Research, Fitzroy, Australia; Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, Australia; Department of Medicine, University of Melbourne, Melbourne, Australia
| | - Kim Loh
- Diabetes and Metabolic Disease, St. Vincent's Institute of Medical Research, Fitzroy, Australia; Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, Australia; Department of Medicine, University of Melbourne, Melbourne, Australia
| | - Mary-Ellen Harper
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada; Centre for Infection, Immunity and Inflammation, Ottawa, ON, Canada; Ottawa Institute of Systems Biology, Ottawa, ON, Canada
| | - Erin E Mulvihill
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada; Centre for Infection, Immunity and Inflammation, Ottawa, ON, Canada; Ottawa Institute of Systems Biology, Ottawa, ON, Canada; University of Ottawa Heart Institute, Ottawa, ON, Canada
| | - Julie St-Pierre
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada; Centre for Infection, Immunity and Inflammation, Ottawa, ON, Canada; Ottawa Institute of Systems Biology, Ottawa, ON, Canada
| | - Morgan D Fullerton
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada; Centre for Infection, Immunity and Inflammation, Ottawa, ON, Canada; Centre for Catalysis Research and Innovation, Ottawa, ON, Canada; Ottawa Institute of Systems Biology, Ottawa, ON, Canada.
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10
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Lin C, Tian Q, Guo S, Xie D, Cai Y, Wang Z, Chu H, Qiu S, Tang S, Zhang A. Metabolomics for Clinical Biomarker Discovery and Therapeutic Target Identification. Molecules 2024; 29:2198. [PMID: 38792060 PMCID: PMC11124072 DOI: 10.3390/molecules29102198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2024] [Revised: 04/10/2024] [Accepted: 04/25/2024] [Indexed: 05/26/2024] Open
Abstract
As links between genotype and phenotype, small-molecule metabolites are attractive biomarkers for disease diagnosis, prognosis, classification, drug screening and treatment, insight into understanding disease pathology and identifying potential targets. Metabolomics technology is crucial for discovering targets of small-molecule metabolites involved in disease phenotype. Mass spectrometry-based metabolomics has implemented in applications in various fields including target discovery, explanation of disease mechanisms and compound screening. It is used to analyze the physiological or pathological states of the organism by investigating the changes in endogenous small-molecule metabolites and associated metabolism from complex metabolic pathways in biological samples. The present review provides a critical update of high-throughput functional metabolomics techniques and diverse applications, and recommends the use of mass spectrometry-based metabolomics for discovering small-molecule metabolite signatures that provide valuable insights into metabolic targets. We also recommend using mass spectrometry-based metabolomics as a powerful tool for identifying and understanding metabolic patterns, metabolic targets and for efficacy evaluation of herbal medicine.
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Affiliation(s)
- Chunsheng Lin
- Graduate School and Second Affiliated Hospital, Heilongjiang University of Chinese Medicine, Harbin 150040, China; (C.L.); (S.G.); (Y.C.); (Z.W.)
| | - Qianqian Tian
- Faculty of Social Sciences, The University of Hong Kong, Hong Kong 999077, China;
| | - Sifan Guo
- Graduate School and Second Affiliated Hospital, Heilongjiang University of Chinese Medicine, Harbin 150040, China; (C.L.); (S.G.); (Y.C.); (Z.W.)
- International Advanced Functional Omics Platform, Scientific Experiment Center, International Joint Research Center on Traditional Chinese and Modern Medicine, Hainan Engineering Research Center for Biological Sample Resources of Major Diseases (First Affiliated Hospital of Hainan Medical University), Key Laboratory of Tropical Cardiovascular Diseases Research of Hainan Province, Hainan Medical University, Xueyuan Road 3, Haikou 571199, China; (D.X.); (S.Q.); (S.T.)
| | - Dandan Xie
- International Advanced Functional Omics Platform, Scientific Experiment Center, International Joint Research Center on Traditional Chinese and Modern Medicine, Hainan Engineering Research Center for Biological Sample Resources of Major Diseases (First Affiliated Hospital of Hainan Medical University), Key Laboratory of Tropical Cardiovascular Diseases Research of Hainan Province, Hainan Medical University, Xueyuan Road 3, Haikou 571199, China; (D.X.); (S.Q.); (S.T.)
| | - Ying Cai
- Graduate School and Second Affiliated Hospital, Heilongjiang University of Chinese Medicine, Harbin 150040, China; (C.L.); (S.G.); (Y.C.); (Z.W.)
- International Advanced Functional Omics Platform, Scientific Experiment Center, International Joint Research Center on Traditional Chinese and Modern Medicine, Hainan Engineering Research Center for Biological Sample Resources of Major Diseases (First Affiliated Hospital of Hainan Medical University), Key Laboratory of Tropical Cardiovascular Diseases Research of Hainan Province, Hainan Medical University, Xueyuan Road 3, Haikou 571199, China; (D.X.); (S.Q.); (S.T.)
| | - Zhibo Wang
- Graduate School and Second Affiliated Hospital, Heilongjiang University of Chinese Medicine, Harbin 150040, China; (C.L.); (S.G.); (Y.C.); (Z.W.)
- International Advanced Functional Omics Platform, Scientific Experiment Center, International Joint Research Center on Traditional Chinese and Modern Medicine, Hainan Engineering Research Center for Biological Sample Resources of Major Diseases (First Affiliated Hospital of Hainan Medical University), Key Laboratory of Tropical Cardiovascular Diseases Research of Hainan Province, Hainan Medical University, Xueyuan Road 3, Haikou 571199, China; (D.X.); (S.Q.); (S.T.)
| | - Hang Chu
- Department of Biomedical Sciences, Beijing City University, Beijing 100193, China;
| | - Shi Qiu
- International Advanced Functional Omics Platform, Scientific Experiment Center, International Joint Research Center on Traditional Chinese and Modern Medicine, Hainan Engineering Research Center for Biological Sample Resources of Major Diseases (First Affiliated Hospital of Hainan Medical University), Key Laboratory of Tropical Cardiovascular Diseases Research of Hainan Province, Hainan Medical University, Xueyuan Road 3, Haikou 571199, China; (D.X.); (S.Q.); (S.T.)
| | - Songqi Tang
- International Advanced Functional Omics Platform, Scientific Experiment Center, International Joint Research Center on Traditional Chinese and Modern Medicine, Hainan Engineering Research Center for Biological Sample Resources of Major Diseases (First Affiliated Hospital of Hainan Medical University), Key Laboratory of Tropical Cardiovascular Diseases Research of Hainan Province, Hainan Medical University, Xueyuan Road 3, Haikou 571199, China; (D.X.); (S.Q.); (S.T.)
| | - Aihua Zhang
- Graduate School and Second Affiliated Hospital, Heilongjiang University of Chinese Medicine, Harbin 150040, China; (C.L.); (S.G.); (Y.C.); (Z.W.)
- International Advanced Functional Omics Platform, Scientific Experiment Center, International Joint Research Center on Traditional Chinese and Modern Medicine, Hainan Engineering Research Center for Biological Sample Resources of Major Diseases (First Affiliated Hospital of Hainan Medical University), Key Laboratory of Tropical Cardiovascular Diseases Research of Hainan Province, Hainan Medical University, Xueyuan Road 3, Haikou 571199, China; (D.X.); (S.Q.); (S.T.)
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11
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Liu A, Kage F, Abdulkareem AF, Aguirre-Huamani MP, Sapp G, Aydin H, Higgs HN. Fatty acyl-coenzyme A activates mitochondrial division through oligomerization of MiD49 and MiD51. Nat Cell Biol 2024; 26:731-744. [PMID: 38594588 DOI: 10.1038/s41556-024-01400-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Accepted: 03/05/2024] [Indexed: 04/11/2024]
Abstract
Mitochondrial fission occurs in many cellular processes, but the regulation of fission is poorly understood. We show that long-chain acyl-coenzyme A (LCACA) activates two related mitochondrial fission proteins, MiD49 and MiD51, by inducing their oligomerization, which activates their ability to stimulate the DRP1 GTPase. The 1:1 stoichiometry of LCACA:MiD in the oligomer suggests interaction in the previously identified nucleotide-binding pocket, and a point mutation in this pocket reduces LCACA binding and LCACA-induced oligomerization for MiD51. In cells, this LCACA binding mutant does not assemble into puncta on mitochondria or rescue MiD49/51 knockdown effects on mitochondrial length and DRP1 recruitment. Furthermore, cellular treatment with BSA-bound oleic acid, which causes increased LCACA, promotes mitochondrial fission in an MiD49/51-dependent manner. These results suggest that LCACA is an endogenous ligand for MiDs, inducing mitochondrial fission and providing a potential mechanism for fatty-acid-induced mitochondrial division. Finally, MiD49 or MiD51 oligomers synergize with Mff, but not with actin filaments, in DRP1 activation, suggesting distinct pathways for DRP1 activation.
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Affiliation(s)
- Ao Liu
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth College, Hanover, NH, USA
| | - Frieda Kage
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth College, Hanover, NH, USA
| | - Asan F Abdulkareem
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth College, Hanover, NH, USA
- Department of Molecular and Systems Biology, Geisel School of Medicine at Dartmouth College, Hanover, NH, USA
| | - Mac Pholo Aguirre-Huamani
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth College, Hanover, NH, USA
- Department of Molecular and Systems Biology, Geisel School of Medicine at Dartmouth College, Hanover, NH, USA
| | - Gracie Sapp
- Department of Biochemistry, University of Colorado Boulder, Boulder, CO, USA
| | - Halil Aydin
- Department of Biochemistry, University of Colorado Boulder, Boulder, CO, USA
| | - Henry N Higgs
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth College, Hanover, NH, USA.
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12
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Sharma AK, Khandelwal R, Wolfrum C. Futile lipid cycling: from biochemistry to physiology. Nat Metab 2024; 6:808-824. [PMID: 38459186 DOI: 10.1038/s42255-024-01003-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Accepted: 02/02/2024] [Indexed: 03/10/2024]
Abstract
In the healthy state, the fat stored in our body isn't just inert. Rather, it is dynamically mobilized to maintain an adequate concentration of fatty acids (FAs) in our bloodstream. Our body tends to produce excess FAs to ensure that the FA availability is not limiting. The surplus FAs are actively re-esterified into glycerides, initiating a cycle of breakdown and resynthesis of glycerides. This cycle consumes energy without generating a new product and is commonly referred to as the 'futile lipid cycle' or the glyceride/FA cycle. Contrary to the notion that it's a wasteful process, it turns out this cycle is crucial for systemic metabolic homeostasis. It acts as a control point in intra-adipocyte and inter-organ cross-talk, a metabolic rheostat, an energy sensor and a lipid diversifying mechanism. In this Review, we discuss the metabolic regulation and physiological implications of the glyceride/FA cycle and its mechanistic underpinnings.
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Affiliation(s)
- Anand Kumar Sharma
- Laboratory of Translational Nutrition Biology, Institute of Food, Nutrition and Health, ETH Zurich, Schwerzenbach, Switzerland.
| | - Radhika Khandelwal
- Laboratory of Translational Nutrition Biology, Institute of Food, Nutrition and Health, ETH Zurich, Schwerzenbach, Switzerland
| | - Christian Wolfrum
- Laboratory of Translational Nutrition Biology, Institute of Food, Nutrition and Health, ETH Zurich, Schwerzenbach, Switzerland.
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13
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Qi Y, Zhang YM, Gao YN, Chen WG, Zhou T, Chang L, Zang Y, Li J. AMPK role in epilepsy: a promising therapeutic target? J Neurol 2024; 271:748-771. [PMID: 38010498 DOI: 10.1007/s00415-023-12062-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Revised: 10/11/2023] [Accepted: 10/12/2023] [Indexed: 11/29/2023]
Abstract
Epilepsy is a complex and multifaceted neurological disorder characterized by spontaneous and recurring seizures. It poses significant therapeutic challenges due to its diverse etiology and often-refractory nature. This comprehensive review highlights the pivotal role of AMP-activated protein kinase (AMPK), a key metabolic regulator involved in cellular energy homeostasis, which may be a promising therapeutic target for epilepsy. Current therapeutic strategies such as antiseizure medication (ASMs) can alleviate seizures (up to 70%). However, 30% of epileptic patients may develop refractory epilepsy. Due to the complicated nature of refractory epilepsy, other treatment options such as ketogenic dieting, adjunctive therapy, and in limited cases, surgical interventions are employed. These therapy options are only suitable for a select group of patients and have limitations of their own. Current treatment options for epilepsy need to be improved. Emerging evidence underscores a potential association between impaired AMPK functionality in the brain and the onset of epilepsy, prompting an in-depth examination of AMPK's influence on neural excitability and ion channel regulation, both critical factors implicated in epileptic seizures. AMPK activation through agents such as metformin has shown promising antiepileptic effects in various preclinical and clinical settings. These effects are primarily mediated through the inhibition of the mTOR signaling pathway, activation of the AMPK-PI3K-c-Jun pathway, and stimulation of the PGC-1α pathway. Despite the potential of AMPK-targeted therapies, several aspects warrant further exploration, including the detailed mechanisms of AMPK's role in different brain regions, the impact of AMPK under various conditional circumstances such as neural injury and zinc toxicity, the long-term safety and efficacy of chronic metformin use in epilepsy treatment, and the potential benefits of combination therapy involving AMPK activators. Moreover, the efficacy of AMPK activators in refractory epilepsy remains an open question. This review sets the stage for further research with the aim of enhancing our understanding of the role of AMPK in epilepsy, potentially leading to the development of more effective, AMPK-targeted therapeutic strategies for this challenging and debilitating disorder.
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Affiliation(s)
- Yingbei Qi
- School of Pharmaceutical Science and Technology, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou, 310024, Zhejiang, China
- National Center for Drug Screening, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yong-Mei Zhang
- School of Pharmaceutical Science and Technology, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou, 310024, Zhejiang, China
- National Center for Drug Screening, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Ya-Nan Gao
- National Center for Drug Screening, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
- China Pharmaceutical University, Nanjing, 210009, Jiangsu, China
| | - Wen-Gang Chen
- National Center for Drug Screening, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
- China Pharmaceutical University, Nanjing, 210009, Jiangsu, China
| | - Ting Zhou
- National Center for Drug Screening, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Liuliu Chang
- National Center for Drug Screening, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yi Zang
- National Center for Drug Screening, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China.
| | - Jia Li
- School of Pharmaceutical Science and Technology, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou, 310024, Zhejiang, China.
- National Center for Drug Screening, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China.
- University of Chinese Academy of Sciences, Beijing, 100049, China.
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14
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Min SH, Song DK, Lee CH, Roh E, Kim MS. Hypothalamic AMP-Activated Protein Kinase as a Whole-Body Energy Sensor and Regulator. Endocrinol Metab (Seoul) 2024; 39:1-11. [PMID: 38356211 PMCID: PMC10901667 DOI: 10.3803/enm.2024.1922] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Revised: 01/05/2024] [Accepted: 01/09/2024] [Indexed: 02/16/2024] Open
Abstract
5´-Adenosine monophosphate (AMP)-activated protein kinase (AMPK), a cellular energy sensor, is an essential enzyme that helps cells maintain stable energy levels during metabolic stress. The hypothalamus is pivotal in regulating energy balance within the body. Certain neurons in the hypothalamus are sensitive to fluctuations in food availability and energy stores, triggering adaptive responses to preserve systemic energy equilibrium. AMPK, expressed in these hypothalamic neurons, is instrumental in these regulatory processes. Hypothalamic AMPK activity is modulated by key metabolic hormones. Anorexigenic hormones, including leptin, insulin, and glucagon-like peptide 1, suppress hypothalamic AMPK activity, whereas the hunger hormone ghrelin activates it. These hormonal influences on hypothalamic AMPK activity are central to their roles in controlling food consumption and energy expenditure. Additionally, hypothalamic AMPK activity responds to variations in glucose concentrations. It becomes active during hypoglycemia but is deactivated when glucose is introduced directly into the hypothalamus. These shifts in AMPK activity within hypothalamic neurons are critical for maintaining glucose balance. Considering the vital function of hypothalamic AMPK in the regulation of overall energy and glucose balance, developing chemical agents that target the hypothalamus to modulate AMPK activity presents a promising therapeutic approach for metabolic conditions such as obesity and type 2 diabetes mellitus.
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Affiliation(s)
- Se Hee Min
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Diabetes Center, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea
| | - Do Kyeong Song
- Department of Internal Medicine, Ewha Womans University College of Medicine, Seoul, Korea
| | - Chan Hee Lee
- Program of Material Science for Medicine and Pharmaceutics, Hallym University, Chuncheon, Korea
| | - Eun Roh
- Department of Internal Medicine, College of Medicine, Hallym University, Chuncheon, Korea
| | - Min-Seon Kim
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Diabetes Center, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea
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15
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Rahman AA, Butcko AJ, Songyekutu E, Granneman JG, Mottillo EP. Direct effects of adipocyte lipolysis on AMPK through intracellular long-chain acyl-CoA signaling. Sci Rep 2024; 14:19. [PMID: 38167670 PMCID: PMC10761689 DOI: 10.1038/s41598-023-50903-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Accepted: 12/27/2023] [Indexed: 01/05/2024] Open
Abstract
Long-chain acyl-CoAs (LC-acyl-CoAs) are important intermediary metabolites and are also thought to function as intracellular signaling molecules; however, the direct effects of LC-acyl-CoAs have been difficult to determine in real-time and dissociate from Protein Kinase A (PKA) signaling. Here, we examined the direct role of lipolysis in generating intracellular LC-acyl-CoAs and activating AMPK in white adipocytes by pharmacological activation of ABHD5 (also known as CGI-58), a lipase co-activator. Activation of lipolysis in 3T3-L1 adipocytes independent of PKA with synthetic ABHD5 ligands, resulted in greater activation of AMPK compared to receptor-mediated activation with isoproterenol, a β-adrenergic receptor agonist. Importantly, the effect of pharmacological activation of ABHD5 on AMPK activation was blocked by inhibiting ATGL, the rate-limiting enzyme for triacylglycerol hydrolysis. Utilizing a novel FRET sensor to detect intracellular LC-acyl-CoAs, we demonstrate that stimulation of lipolysis in 3T3-L1 adipocytes increased the production of LC-acyl-CoAs, an effect which was blocked by inhibition of ATGL. Moreover, ATGL inhibition blocked AMPKβ1 S108 phosphorylation, a site required for allosteric regulation. Increasing intracellular LC-acyl-CoAs by removal of BSA in the media and pharmacological inhibition of DGAT1 and 2 resulted in greater activation of AMPK. Finally, inhibiting LC-acyl-CoA generation reduced activation of AMPK; however, did not lower energy charge. Overall, results demonstrate that lipolysis in white adipocytes directly results in allosteric activation of AMPK through the generation of LC-acyl-CoAs.
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Affiliation(s)
- Abir A Rahman
- Hypertension and Vascular Research Division, Department of Internal Medicine, Henry Ford Hospital, 6135 Woodward Ave., Detroit, MI, 48202, USA
| | - Andrew J Butcko
- Hypertension and Vascular Research Division, Department of Internal Medicine, Henry Ford Hospital, 6135 Woodward Ave., Detroit, MI, 48202, USA
- Department of Physiology, Wayne State University School of Medicine, Detroit, MI, 48202, USA
| | - Emmanuel Songyekutu
- Department of Physiology, Wayne State University School of Medicine, Detroit, MI, 48202, USA
| | - James G Granneman
- Center for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, MI, 48202, USA
| | - Emilio P Mottillo
- Hypertension and Vascular Research Division, Department of Internal Medicine, Henry Ford Hospital, 6135 Woodward Ave., Detroit, MI, 48202, USA.
- Department of Physiology, Wayne State University School of Medicine, Detroit, MI, 48202, USA.
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16
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Hawley SA, Russell FM, Ross FA, Hardie DG. BAY-3827 and SBI-0206965: Potent AMPK Inhibitors That Paradoxically Increase Thr172 Phosphorylation. Int J Mol Sci 2023; 25:453. [PMID: 38203624 PMCID: PMC10778976 DOI: 10.3390/ijms25010453] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Revised: 12/07/2023] [Accepted: 12/18/2023] [Indexed: 01/12/2024] Open
Abstract
AMP-activated protein kinase (AMPK) is the central component of a signalling pathway that senses energy stress and triggers a metabolic switch away from anabolic processes and towards catabolic processes. There has been a prolonged focus in the pharmaceutical industry on the development of AMPK-activating drugs for the treatment of metabolic disorders such as Type 2 diabetes and non-alcoholic fatty liver disease. However, recent findings suggest that AMPK inhibitors might be efficacious for treating certain cancers, especially lung adenocarcinomas, in which the PRKAA1 gene (encoding the α1 catalytic subunit isoform of AMPK) is often amplified. Here, we study two potent AMPK inhibitors, BAY-3827 and SBI-0206965. Despite not being closely related structurally, the treatment of cells with either drug unexpectedly caused increases in AMPK phosphorylation at the activating site, Thr172, even though the phosphorylation of several downstream targets in different subcellular compartments was completely inhibited. Surprisingly, the two inhibitors appear to promote Thr172 phosphorylation by different mechanisms: BAY-3827 primarily protects against Thr172 dephosphorylation, while SBI-0206965 also promotes phosphorylation by LKB1 at low concentrations, while increasing cellular AMP:ATP ratios at higher concentrations. Due to its greater potency and fewer off-target effects, BAY-3827 is now the inhibitor of choice for cell studies, although its low bioavailability may limit its use in vivo.
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Affiliation(s)
| | | | | | - D. Grahame Hardie
- Division of Cell Signalling & Immunology, School of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, UK; (S.A.H.); (F.A.R.)
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17
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Guo X, Blanc V, Davidson NO, Velazquez H, Chen TM, Moledina DG, Moeckel GW, Safirstein RL, Desir GV. APOBEC-1 deletion enhances cisplatin-induced acute kidney injury. Sci Rep 2023; 13:22255. [PMID: 38097707 PMCID: PMC10721635 DOI: 10.1038/s41598-023-49575-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Accepted: 12/09/2023] [Indexed: 12/17/2023] Open
Abstract
Cisplatin (CP) induces acute kidney injury (AKI) whereby proximal tubules undergo regulated necrosis. Repair is almost complete after a single dose. We now demonstrate a role for Apolipoprotein B mRNA editing enzyme, catalytic polypeptide 1 (Apobec-1) that is prominently expressed at the interface between acute and chronic kidney injury (CKD), in the recovery from AKI. Apobec-1 knockout (KO) mice exhibited greater mortality than in wild type (WT) and more severe AKI in both CP- and unilateral ischemia reperfusion (IR) with nephrectomy. Specifically, plasma creatinine (pCr) 2.6 ± 0.70 mg/dL for KO, n = 10 and 0.16 ± 0.02 for WT, n = 6, p < 0.0001 in CP model and 1.34 ± 0.22 mg/dL vs 0.75 ± 0.06, n = 5, p < 0.05 in IR model. The kidneys of Apobec-1 KO mice showed increased necrosis, increased expression of KIM-1, NGAL, RIPK1, ASCL4 and increased lipid accumulation compared to WT kidneys (p < 0.01). Neutrophils and activated T cells were both increased, while macrophages were reduced in kidneys of Apobec-1 KO animals. Overexpression of Apobec-1 in mouse proximal tubule cells protected against CP-induced cytotoxicity. These findings suggest that Apobec-1 mediates critical pro-survival responses to renal injury and increasing Apobec-1 expression could be an effective strategy to mitigate AKI.
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Affiliation(s)
- Xiaojia Guo
- Section of Nephrology, Department of Internal Medicine, Yale School of Medicine, New Haven, CT, USA
| | - Valerie Blanc
- Division of Gastroenterology, Department of Medicine, Washington University School of Medicine, St. Louis, MO, 63105, USA
| | - Nicholas O Davidson
- Division of Gastroenterology, Department of Medicine, Washington University School of Medicine, St. Louis, MO, 63105, USA
| | - Heino Velazquez
- Section of Nephrology, Department of Internal Medicine, Yale School of Medicine, New Haven, CT, USA
- Veteran's Affair Medical Center, West Haven, CT, USA
| | - Tian-Min Chen
- Section of Nephrology, Department of Internal Medicine, Yale School of Medicine, New Haven, CT, USA
| | - Dennis G Moledina
- Section of Nephrology, Department of Internal Medicine, Yale School of Medicine, New Haven, CT, USA
- Clinical and Translational Research Accelerator, Department of Internal Medicine, Yale School of Medicine, New Haven, CT, USA
| | | | - Robert L Safirstein
- Section of Nephrology, Department of Internal Medicine, Yale School of Medicine, New Haven, CT, USA.
- Veteran's Affair Medical Center, West Haven, CT, USA.
| | - Gary V Desir
- Section of Nephrology, Department of Internal Medicine, Yale School of Medicine, New Haven, CT, USA.
- Veteran's Affair Medical Center, West Haven, CT, USA.
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18
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Ross FA, Hawley SA, Russell FM, Goodman N, Hardie DG. Frequent loss-of-function mutations in the AMPK-α2 catalytic subunit suggest a tumour suppressor role in human skin cancers. Biochem J 2023; 480:1951-1968. [PMID: 37962491 PMCID: PMC10754287 DOI: 10.1042/bcj20230380] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Revised: 11/07/2023] [Accepted: 11/13/2023] [Indexed: 11/15/2023]
Abstract
The AMP-activated protein kinase (AMPK) is a sensor of cellular energy status activated by increases in AMP or ADP relative to ATP. Once activated, it phosphorylates targets that promote ATP-generating catabolic pathways or inhibit ATP-consuming anabolic pathways, helping to restore cellular energy balance. Analysis of human cancer genome studies reveals that the PRKAA2 gene (encoding the α2 isoform of the catalytic subunit) is often subject to mis-sense mutations in cancer, particularly in melanoma and non-melanoma skin cancers, where up to 70 mis-sense mutations have been documented, often accompanied by loss of the tumour suppressor NF1. Recently it has been reported that knockout of PRKAA2 in NF1-deficient melanoma cells promoted anchorage-independent growth in vitro, as well as growth as xenografts in immunodeficient mice in vivo, suggesting that AMPK-α2 can act as a tumour suppressor in that context. However, very few of the mis-sense mutations in PRKAA2 that occur in human skin cancer and melanoma have been tested to see whether they cause loss-of-function. We have addressed this by making most of the reported mutations and testing their activity when expressed in AMPK knockout cells. Of 55 different mis-sense mutations (representing 75 cases), 9 (12%) appeared to cause a total loss of activity, 18 (24%) a partial loss, 11 (15%) an increase in phenformin-stimulated kinase activity, while just 37 (49%) had no clear effect on kinase activity. This supports the idea that AMPK-α2 acts as a tumour suppressor in the context of human skin cancer.
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Affiliation(s)
- Fiona A. Ross
- Division of Cell Signalling & Immunology, School of Life Sciences, University of Dundee, Scotland, U.K
| | - Simon A. Hawley
- Division of Cell Signalling & Immunology, School of Life Sciences, University of Dundee, Scotland, U.K
| | - Fiona M. Russell
- Division of Cell Signalling & Immunology, School of Life Sciences, University of Dundee, Scotland, U.K
| | - Nicola Goodman
- Division of Cell Signalling & Immunology, School of Life Sciences, University of Dundee, Scotland, U.K
| | - D. Grahame Hardie
- Division of Cell Signalling & Immunology, School of Life Sciences, University of Dundee, Scotland, U.K
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19
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Day EA, Townsend LK, Rehal S, Batchuluun B, Wang D, Morrow MR, Lu R, Lundenberg L, Lu JH, Desjardins EM, Smith TK, Raphenya AR, McArthur AG, Fullerton MD, Steinberg GR. Macrophage AMPK β1 activation by PF-06409577 reduces the inflammatory response, cholesterol synthesis, and atherosclerosis in mice. iScience 2023; 26:108269. [PMID: 38026185 PMCID: PMC10654588 DOI: 10.1016/j.isci.2023.108269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Revised: 09/01/2023] [Accepted: 10/17/2023] [Indexed: 12/01/2023] Open
Abstract
Atherosclerotic cardiovascular disease is characterized by both chronic low-grade inflammation and dyslipidemia. The AMP-activated protein kinase (AMPK) inhibits cholesterol synthesis and dampens inflammation but whether pharmacological activation reduces atherosclerosis is equivocal. In the current study, we found that the orally bioavailable and highly selective activator of AMPKβ1 complexes, PF-06409577, reduced atherosclerosis in two mouse models in a myeloid-derived AMPKβ1 dependent manner, suggesting a critical role for macrophages. In bone marrow-derived macrophages (BMDMs), PF-06409577 dose dependently activated AMPK as indicated by increased phosphorylation of downstream substrates ULK1 and acetyl-CoA carboxylase (ACC), which are important for autophagy and fatty acid oxidation/de novo lipogenesis, respectively. Treatment of BMDMs with PF-06409577 suppressed fatty acid and cholesterol synthesis and transcripts related to the inflammatory response while increasing transcripts important for autophagy through AMPKβ1. These data indicate that pharmacologically targeting macrophage AMPKβ1 may be a promising strategy for reducing atherosclerosis.
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Affiliation(s)
- Emily A. Day
- Centre for Metabolism, Obesity and Diabetes Research, Department of Medicine, McMaster University, Hamilton, ON, Canada
- Division of Endocrinology and Metabolism, Department of Medicine, McMaster University, ON, Canada
| | - Logan K. Townsend
- Centre for Metabolism, Obesity and Diabetes Research, Department of Medicine, McMaster University, Hamilton, ON, Canada
- Division of Endocrinology and Metabolism, Department of Medicine, McMaster University, ON, Canada
| | - Sonia Rehal
- Centre for Metabolism, Obesity and Diabetes Research, Department of Medicine, McMaster University, Hamilton, ON, Canada
- Division of Endocrinology and Metabolism, Department of Medicine, McMaster University, ON, Canada
| | - Battsetseg Batchuluun
- Centre for Metabolism, Obesity and Diabetes Research, Department of Medicine, McMaster University, Hamilton, ON, Canada
- Division of Endocrinology and Metabolism, Department of Medicine, McMaster University, ON, Canada
| | - Dongdong Wang
- Centre for Metabolism, Obesity and Diabetes Research, Department of Medicine, McMaster University, Hamilton, ON, Canada
- Division of Endocrinology and Metabolism, Department of Medicine, McMaster University, ON, Canada
| | - Marisa R. Morrow
- Centre for Metabolism, Obesity and Diabetes Research, Department of Medicine, McMaster University, Hamilton, ON, Canada
- Division of Endocrinology and Metabolism, Department of Medicine, McMaster University, ON, Canada
| | - Rachel Lu
- Centre for Metabolism, Obesity and Diabetes Research, Department of Medicine, McMaster University, Hamilton, ON, Canada
- Division of Endocrinology and Metabolism, Department of Medicine, McMaster University, ON, Canada
| | - Lucie Lundenberg
- Centre for Metabolism, Obesity and Diabetes Research, Department of Medicine, McMaster University, Hamilton, ON, Canada
- Division of Endocrinology and Metabolism, Department of Medicine, McMaster University, ON, Canada
| | - Jessie H. Lu
- Centre for Metabolism, Obesity and Diabetes Research, Department of Medicine, McMaster University, Hamilton, ON, Canada
- Division of Endocrinology and Metabolism, Department of Medicine, McMaster University, ON, Canada
| | - Eric M. Desjardins
- Centre for Metabolism, Obesity and Diabetes Research, Department of Medicine, McMaster University, Hamilton, ON, Canada
- Division of Endocrinology and Metabolism, Department of Medicine, McMaster University, ON, Canada
| | - Tyler K.T. Smith
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, Centre for Infection, Immunity and Inflammation, Ottawa Institute of Systems Biology, Centre for Catalysis Research and Innovation, University of Ottawa, Ottawa, ON, Canada
| | - Amogelang R. Raphenya
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON, Canada
| | - Andrew G. McArthur
- Centre for Metabolism, Obesity and Diabetes Research, Department of Medicine, McMaster University, Hamilton, ON, Canada
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON, Canada
| | - Morgan D. Fullerton
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, Centre for Infection, Immunity and Inflammation, Ottawa Institute of Systems Biology, Centre for Catalysis Research and Innovation, University of Ottawa, Ottawa, ON, Canada
| | - Gregory R. Steinberg
- Centre for Metabolism, Obesity and Diabetes Research, Department of Medicine, McMaster University, Hamilton, ON, Canada
- Division of Endocrinology and Metabolism, Department of Medicine, McMaster University, ON, Canada
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON, Canada
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20
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Sharma AK, Wolfrum C. DGAT inhibition at the post-absorptive phase reduces plasma FA by increasing FA oxidation. EMBO Mol Med 2023; 15:e18209. [PMID: 37789773 PMCID: PMC10630880 DOI: 10.15252/emmm.202318209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Revised: 09/12/2023] [Accepted: 09/18/2023] [Indexed: 10/05/2023] Open
Abstract
In this Correspondence, A. Sharma & C. Wolfrum report that DGAT1/2 pharmacological inhibition at post-absorptive phase in mice leads to increased fatty acid oxidation and reduced plasma fatty acid levels, which could open new therapeutic avenues to avoid GI complications observed in clinical trials.
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Affiliation(s)
- Anand Kumar Sharma
- Laboratory of Translational Nutrition BiologyInstitute of Food, Nutrition and Health, ETH ZurichSchwerzenbachSwitzerland
| | - Christian Wolfrum
- Laboratory of Translational Nutrition BiologyInstitute of Food, Nutrition and Health, ETH ZurichSchwerzenbachSwitzerland
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21
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Terry AR, Nogueira V, Rho H, Ramakrishnan G, Li J, Kang S, Pathmasiri KC, Bhat SA, Jiang L, Kuchay S, Cologna SM, Hay N. CD36 maintains lipid homeostasis via selective uptake of monounsaturated fatty acids during matrix detachment and tumor progression. Cell Metab 2023; 35:2060-2076.e9. [PMID: 37852255 DOI: 10.1016/j.cmet.2023.09.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Revised: 04/11/2023] [Accepted: 09/21/2023] [Indexed: 10/20/2023]
Abstract
A high-fat diet (HFD) promotes metastasis through increased uptake of saturated fatty acids (SFAs). The fatty acid transporter CD36 has been implicated in this process, but a detailed understanding of CD36 function is lacking. During matrix detachment, endoplasmic reticulum (ER) stress reduces SCD1 protein, resulting in increased lipid saturation. Subsequently, CD36 is induced in a p38- and AMPK-dependent manner to promote preferential uptake of monounsaturated fatty acids (MUFAs), thereby maintaining a balance between SFAs and MUFAs. In attached cells, CD36 palmitoylation is required for MUFA uptake and protection from palmitate-induced lipotoxicity. In breast cancer mouse models, CD36-deficiency induced ER stress while diminishing the pro-metastatic effect of HFD, and only a palmitoylation-proficient CD36 rescued this effect. Finally, AMPK-deficient tumors have reduced CD36 expression and are metastatically impaired, but ectopic CD36 expression restores their metastatic potential. Our results suggest that, rather than facilitating HFD-driven tumorigenesis, CD36 plays a supportive role by preventing SFA-induced lipotoxicity.
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Affiliation(s)
- Alexander R Terry
- Department of Biochemistry and Molecular Genetics, College of Medicine, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Veronique Nogueira
- Department of Biochemistry and Molecular Genetics, College of Medicine, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Hyunsoo Rho
- Department of Biochemistry and Molecular Genetics, College of Medicine, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Gopalakrishnan Ramakrishnan
- Department of Biochemistry and Molecular Genetics, College of Medicine, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Jing Li
- Department of Biochemistry and Molecular Genetics, College of Medicine, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Soeun Kang
- Department of Biochemistry and Molecular Genetics, College of Medicine, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Koralege C Pathmasiri
- Department of Chemistry, College of Liberal Arts and Sciences, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Sameer Ahmed Bhat
- Department of Biochemistry and Molecular Genetics, College of Medicine, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Liping Jiang
- Department of Biochemistry and Molecular Genetics, College of Medicine, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Shafi Kuchay
- Department of Biochemistry and Molecular Genetics, College of Medicine, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Stephanie M Cologna
- Department of Chemistry, College of Liberal Arts and Sciences, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Nissim Hay
- Department of Biochemistry and Molecular Genetics, College of Medicine, University of Illinois at Chicago, Chicago, IL 60607, USA; Research and Development Section, Jesse Brown VA Medical Center, Chicago, IL 60612, USA.
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22
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Göransson O, Kopietz F, Rider MH. Metabolic control by AMPK in white adipose tissue. Trends Endocrinol Metab 2023; 34:704-717. [PMID: 37673765 DOI: 10.1016/j.tem.2023.08.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Revised: 08/10/2023] [Accepted: 08/11/2023] [Indexed: 09/08/2023]
Abstract
White adipose tissue (WAT) plays an important role in the integration of whole-body metabolism by storing fat and mobilizing triacylglycerol when needed. The released free fatty acids can then be oxidized by other tissues to provide ATP. AMP-activated protein kinase (AMPK) is a key regulator of metabolic pathways, and can be targeted by a new generation of direct, small-molecule activators. AMPK activation in WAT inhibits insulin-stimulated lipogenesis and in some situations also inhibits insulin-stimulated glucose uptake, but AMPK-induced inhibition of β-adrenergic agonist-stimulated lipolysis might need to be re-evaluated in vivo. The lack of dramatic effects of AMPK activation on basal metabolism in WAT could be advantageous when treating type 2 diabetes with pharmacological pan-AMPK activators.
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Affiliation(s)
- Olga Göransson
- Lund University, Department of Experimental Medical Science, BMC, 221 84 Lund, Sweden.
| | - Franziska Kopietz
- Lund University, Department of Experimental Medical Science, BMC, 221 84 Lund, Sweden
| | - Mark H Rider
- Université catholique de Louvain (UCLouvain) and de Duve Institute, Avenue Hippocrate 75, 1200 Brussels, Belgium
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23
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Guo J, Yan E, He L, Wang Y, Xiang Y, Zhang P, Liu X, Yin J. Dietary Supplementation with Lauric Acid Improves Aerobic Endurance in Sedentary Mice via Enhancing Fat Mobilization and Glyconeogenesis. J Nutr 2023; 153:3207-3219. [PMID: 37696395 DOI: 10.1016/j.tjnut.2023.09.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Revised: 08/18/2023] [Accepted: 09/07/2023] [Indexed: 09/13/2023] Open
Abstract
BACKGROUND Lauric acid (LA), a major, natural, medium-chain fatty acid, is considered an efficient energy substrate for intense exercise and in patients with long-chain fatty acid β-oxidation disorders. However, few studies have focused on the role of LA in exercise performance and related glucolipid metabolism in vivo. OBJECTIVES We aimed to investigate the effect of dietary supplementation with LA on exercise performance and related metabolic mechanisms. METHODS Male C57BL/6N mice (14 wk old) were fed a basal diet or a diet containing 1% LA, and a series of exercise tests, including a high-speed treadmill test, aerobic endurance exercises, a 4-limb hanging test, and acute aerobic exercises, were performed. RESULTS Dietary supplementation with 1.0% LA accelerated the recovery from fatigue after explosive exercise (P < 0.05) and improved aerobic endurance and muscle strength in sedentary mice (P = 0.039). Lauric acid intake not only changed muscle fatty acid profiles, including increases in C12:0 and n-6/n-3 PUFAs (P < 0.001) and reductions in C18:0, C20:4n-6, C22:6n-3, and n-3 PUFAs (P < 0.05) but also enhanced fat mobilization from adipose tissue and fatty acid oxidation in the liver, at least partly via the AMP-activated protein kinase-acetyl CoA carboxylase pathway (P < 0.05). Likewise, LA supplementation promoted liver glyconeogenesis and conserved muscular glycogen during acute aerobic exercise (P < 0.05), which was accompanied by an increase in the mitochondrial DNA copy number and Krebs cycle activity in skeletal muscle (P < 0.05). CONCLUSIONS Dietary supplemental LA serves as an efficient energy substrate for sedentary mice to improve aerobic exercise endurance and muscle strength through regulation of glucolipid metabolism. These findings imply that LA supplementation might be a promising nutritional strategy to improve aerobic exercise performance in sedentary people.
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Affiliation(s)
- Jianxin Guo
- State Key Laboratory of Animal Nutrition and Feeding, College of Animal Science and Technology, China Agricultural University, Beijing, China
| | - Enfa Yan
- State Key Laboratory of Animal Nutrition and Feeding, College of Animal Science and Technology, China Agricultural University, Beijing, China
| | - Linjuan He
- State Key Laboratory of Animal Nutrition and Feeding, College of Animal Science and Technology, China Agricultural University, Beijing, China
| | - Yubo Wang
- State Key Laboratory of Animal Nutrition and Feeding, College of Animal Science and Technology, China Agricultural University, Beijing, China
| | - Yifan Xiang
- State Key Laboratory of Animal Nutrition and Feeding, College of Animal Science and Technology, China Agricultural University, Beijing, China
| | - Pengguang Zhang
- State Key Laboratory of Animal Nutrition and Feeding, College of Animal Science and Technology, China Agricultural University, Beijing, China
| | - Xiangze Liu
- State Key Laboratory of Animal Nutrition and Feeding, College of Animal Science and Technology, China Agricultural University, Beijing, China
| | - Jingdong Yin
- State Key Laboratory of Animal Nutrition and Feeding, College of Animal Science and Technology, China Agricultural University, Beijing, China; Molecular design breeding Frontier Science Center of the Ministry of Education, China.
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24
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Freemantle JB, Hardie DG. AMPK promotes lysosomal and mitochondrial biogenesis via folliculin:FNIP1. LIFE METABOLISM 2023; 2:load027. [PMID: 37621729 PMCID: PMC10445941 DOI: 10.1093/lifemeta/load027] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Accepted: 06/21/2023] [Indexed: 08/26/2023]
Abstract
The AMP-activated protein kinase (AMPK) is known to maintain the integrity of cellular mitochondrial networks by (i) promoting fission, (ii) inhibiting fusion, (iii) promoting recycling of damaged components via mitophagy, (iv) enhancing lysosomal biogenesis to support mitophagy, and (v) promoting biogenesis of new mitochondrial components. While the AMPK targets underlying the first three of these effects are known, a recent paper suggests that direct phosphorylation of the folliculin-interacting protein 1 (FNIP1) by AMPK may be involved in the remaining two.
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Affiliation(s)
- Jordana B Freemantle
- Division of Cell Signalling & Immunology, School of Life Sciences, University of Dundee, Dundee, DD1 5EH, Scotland, United Kingdom
| | - D Grahame Hardie
- Division of Cell Signalling & Immunology, School of Life Sciences, University of Dundee, Dundee, DD1 5EH, Scotland, United Kingdom
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25
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Townsend LK, Steinberg GR. AMPK and the Endocrine Control of Metabolism. Endocr Rev 2023; 44:910-933. [PMID: 37115289 DOI: 10.1210/endrev/bnad012] [Citation(s) in RCA: 17] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Revised: 03/10/2023] [Accepted: 04/24/2023] [Indexed: 04/29/2023]
Abstract
Complex multicellular organisms require a coordinated response from multiple tissues to maintain whole-body homeostasis in the face of energetic stressors such as fasting, cold, and exercise. It is also essential that energy is stored efficiently with feeding and the chronic nutrient surplus that occurs with obesity. Mammals have adapted several endocrine signals that regulate metabolism in response to changes in nutrient availability and energy demand. These include hormones altered by fasting and refeeding including insulin, glucagon, glucagon-like peptide-1, catecholamines, ghrelin, and fibroblast growth factor 21; adipokines such as leptin and adiponectin; cell stress-induced cytokines like tumor necrosis factor alpha and growth differentiating factor 15, and lastly exerkines such as interleukin-6 and irisin. Over the last 2 decades, it has become apparent that many of these endocrine factors control metabolism by regulating the activity of the AMPK (adenosine monophosphate-activated protein kinase). AMPK is a master regulator of nutrient homeostasis, phosphorylating over 100 distinct substrates that are critical for controlling autophagy, carbohydrate, fatty acid, cholesterol, and protein metabolism. In this review, we discuss how AMPK integrates endocrine signals to maintain energy balance in response to diverse homeostatic challenges. We also present some considerations with respect to experimental design which should enhance reproducibility and the fidelity of the conclusions.
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Affiliation(s)
- Logan K Townsend
- Centre for Metabolism Obesity and Diabetes Research, Hamilton, ON L8S 4L8, Canada
- Division of Endocrinology and Metabolism, Department of Medicine, McMaster University, Hamilton, ON L8S 4L8, Canada
| | - Gregory R Steinberg
- Centre for Metabolism Obesity and Diabetes Research, Hamilton, ON L8S 4L8, Canada
- Division of Endocrinology and Metabolism, Department of Medicine, McMaster University, Hamilton, ON L8S 4L8, Canada
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON L8S 4L8, Canada
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26
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Pu M, Zheng W, Zhang H, Wan W, Peng C, Chen X, Liu X, Xu Z, Zhou T, Sun Q, Neculai D, Liu W. ORP8 acts as a lipophagy receptor to mediate lipid droplet turnover. Protein Cell 2023; 14:653-667. [PMID: 37707322 PMCID: PMC10501187 DOI: 10.1093/procel/pwac063] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Accepted: 11/22/2022] [Indexed: 09/15/2023] Open
Abstract
Lipophagy, the selective engulfment of lipid droplets (LDs) by autophagosomes for lysosomal degradation, is critical to lipid and energy homeostasis. Here we show that the lipid transfer protein ORP8 is located on LDs and mediates the encapsulation of LDs by autophagosomal membranes. This function of ORP8 is independent of its lipid transporter activity and is achieved through direct interaction with phagophore-anchored LC3/GABARAPs. Upon lipophagy induction, ORP8 has increased localization on LDs and is phosphorylated by AMPK, thereby enhancing its affinity for LC3/GABARAPs. Deletion of ORP8 or interruption of ORP8-LC3/GABARAP interaction results in accumulation of LDs and increased intracellular triglyceride. Overexpression of ORP8 alleviates LD and triglyceride deposition in the liver of ob/ob mice, and Osbpl8-/- mice exhibit liver lipid clearance defects. Our results suggest that ORP8 is a lipophagy receptor that plays a key role in cellular lipid metabolism.
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Affiliation(s)
- Maomao Pu
- Metabolic Medicine Center, International Institutes of Medicine, the Fourth Affiliated Hospital, Zhejiang University School of Medicine, Yiwu 322000, China
| | - Wenhui Zheng
- Metabolic Medicine Center, International Institutes of Medicine, the Fourth Affiliated Hospital, Zhejiang University School of Medicine, Yiwu 322000, China
| | - Hongtao Zhang
- Metabolic Medicine Center, International Institutes of Medicine, the Fourth Affiliated Hospital, Zhejiang University School of Medicine, Yiwu 322000, China
| | - Wei Wan
- Metabolic Medicine Center, International Institutes of Medicine, the Fourth Affiliated Hospital, Zhejiang University School of Medicine, Yiwu 322000, China
| | - Chao Peng
- National Center for Protein Science Shanghai, Institute of Biochemistry and Cell Biology, Shanghai Institutes of Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Xuebo Chen
- Metabolic Medicine Center, International Institutes of Medicine, the Fourth Affiliated Hospital, Zhejiang University School of Medicine, Yiwu 322000, China
| | - Xinchang Liu
- Metabolic Medicine Center, International Institutes of Medicine, the Fourth Affiliated Hospital, Zhejiang University School of Medicine, Yiwu 322000, China
| | - Zizhen Xu
- Metabolic Medicine Center, International Institutes of Medicine, the Fourth Affiliated Hospital, Zhejiang University School of Medicine, Yiwu 322000, China
| | - Tianhua Zhou
- Metabolic Medicine Center, International Institutes of Medicine, the Fourth Affiliated Hospital, Zhejiang University School of Medicine, Yiwu 322000, China
| | - Qiming Sun
- Metabolic Medicine Center, International Institutes of Medicine, the Fourth Affiliated Hospital, Zhejiang University School of Medicine, Yiwu 322000, China
| | - Dante Neculai
- Metabolic Medicine Center, International Institutes of Medicine, the Fourth Affiliated Hospital, Zhejiang University School of Medicine, Yiwu 322000, China
| | - Wei Liu
- Metabolic Medicine Center, International Institutes of Medicine, the Fourth Affiliated Hospital, Zhejiang University School of Medicine, Yiwu 322000, China
- Joint Institute of Genetics and Genomics Medicine between Zhejiang University and University of Toronto, Hangzhou 310058, China
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27
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Abstract
Traditional views of cellular metabolism imply that it is passively adapted to meet the demands of the cell. It is becoming increasingly clear, however, that metabolites do more than simply supply the substrates for biological processes; they also provide critical signals, either through effects on metabolic pathways or via modulation of other regulatory proteins. Recent investigation has also uncovered novel roles for several metabolites that expand their signalling influence to processes outside metabolism, including nutrient sensing and storage, embryonic development, cell survival and differentiation, and immune activation and cytokine secretion. Together, these studies suggest that, in contrast to the prevailing notion, the biochemistry of a cell is frequently governed by its underlying metabolism rather than vice versa. This important shift in perspective places common metabolites as key regulators of cell phenotype and behaviour. Yet the signalling metabolites, and the cognate targets and transducers through which they signal, are only beginning to be uncovered. In this Review, we discuss the emerging links between metabolism and cellular behaviour. We hope this will inspire further dissection of the mechanisms through which metabolic pathways and intermediates modulate cell function and will suggest possible drug targets for diseases linked to metabolic deregulation.
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Affiliation(s)
| | - Jared Rutter
- Department of Biochemistry, University of Utah, Salt Lake City, UT, USA.
- Howard Hughes Medical Institute, University of Utah School of Medicine, Salt Lake City, UT, USA.
- Diabetes & Metabolism Research Center, University of Utah, Salt Lake City, UT, USA.
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Steinberg GR, Hardie DG. New insights into activation and function of the AMPK. Nat Rev Mol Cell Biol 2023; 24:255-272. [PMID: 36316383 DOI: 10.1038/s41580-022-00547-x] [Citation(s) in RCA: 201] [Impact Index Per Article: 201.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/23/2022] [Indexed: 11/06/2022]
Abstract
The classical role of AMP-activated protein kinase (AMPK) is as a cellular energy sensor activated by falling energy status, signalled by increases in AMP to ATP and ADP to ATP ratios. Once activated, AMPK acts to restore energy homeostasis by promoting ATP-producing catabolic pathways while inhibiting energy-consuming processes. In this Review, we provide an update on this canonical (AMP/ADP-dependent) activation mechanism, but focus mainly on recently described non-canonical pathways, including those by which AMPK senses the availability of glucose, glycogen or fatty acids and by which it senses damage to lysosomes and nuclear DNA. We also discuss new findings on the regulation of carbohydrate and lipid metabolism, mitochondrial and lysosomal homeostasis, and DNA repair. Finally, we discuss the role of AMPK in cancer, obesity, diabetes, nonalcoholic steatohepatitis (NASH) and other disorders where therapeutic targeting may exert beneficial effects.
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Affiliation(s)
- Gregory R Steinberg
- Centre for Metabolism, Obesity and Diabetes Research, McMaster University, Hamilton, Ontario, Canada.
- Department of Medicine, McMaster University, Hamilton, Ontario, Canada.
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada.
| | - D Grahame Hardie
- Division of Cell Signalling & Immunology, School of Life Sciences, University of Dundee, Dundee, UK.
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Abstract
Few metabolites can claim a more central and versatile role in cell metabolism than acetyl coenzyme A (acetyl-CoA). Acetyl-CoA is produced during nutrient catabolism to fuel the tricarboxylic acid cycle and is the essential building block for fatty acid and isoprenoid biosynthesis. It also functions as a signalling metabolite as the substrate for lysine acetylation reactions, enabling the modulation of protein functions in response to acetyl-CoA availability. Recent years have seen exciting advances in our understanding of acetyl-CoA metabolism in normal physiology and in cancer, buoyed by new mouse models, in vivo stable-isotope tracing approaches and improved methods for measuring acetyl-CoA, including in specific subcellular compartments. Efforts to target acetyl-CoA metabolic enzymes are also advancing, with one therapeutic agent targeting acetyl-CoA synthesis receiving approval from the US Food and Drug Administration. In this Review, we give an overview of the regulation and cancer relevance of major metabolic pathways in which acetyl-CoA participates. We further discuss recent advances in understanding acetyl-CoA metabolism in normal tissues and tumours and the potential for targeting these pathways therapeutically. We conclude with a commentary on emerging nodes of acetyl-CoA metabolism that may impact cancer biology.
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Affiliation(s)
- David A Guertin
- Program in Molecular Medicine, UMass Chan Medical School, Worcester, MA, USA.
| | - Kathryn E Wellen
- Department of Cancer Biology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA.
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Mi Y, Qi G, Vitali F, Shang Y, Raikes AC, Wang T, Jin Y, Brinton RD, Gu H, Yin F. Loss of fatty acid degradation by astrocytic mitochondria triggers neuroinflammation and neurodegeneration. Nat Metab 2023; 5:445-465. [PMID: 36959514 PMCID: PMC10202034 DOI: 10.1038/s42255-023-00756-4] [Citation(s) in RCA: 44] [Impact Index Per Article: 44.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2022] [Accepted: 02/03/2023] [Indexed: 03/25/2023]
Abstract
Astrocytes provide key neuronal support, and their phenotypic transformation is implicated in neurodegenerative diseases. Metabolically, astrocytes possess low mitochondrial oxidative phosphorylation (OxPhos) activity, but its pathophysiological role in neurodegeneration remains unclear. Here, we show that the brain critically depends on astrocytic OxPhos to degrade fatty acids (FAs) and maintain lipid homeostasis. Aberrant astrocytic OxPhos induces lipid droplet (LD) accumulation followed by neurodegeneration that recapitulates key features of Alzheimer's disease (AD), including synaptic loss, neuroinflammation, demyelination and cognitive impairment. Mechanistically, when FA load overwhelms astrocytic OxPhos capacity, elevated acetyl-CoA levels induce astrocyte reactivity by enhancing STAT3 acetylation and activation. Intercellularly, lipid-laden reactive astrocytes stimulate neuronal FA oxidation and oxidative stress, activate microglia through IL-3 signalling, and inhibit the biosynthesis of FAs and phospholipids required for myelin replenishment. Along with LD accumulation and impaired FA degradation manifested in an AD mouse model, we reveal a lipid-centric, AD-resembling mechanism by which astrocytic mitochondrial dysfunction progressively induces neuroinflammation and neurodegeneration.
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Affiliation(s)
- Yashi Mi
- Center for Innovation in Brain Science, University of Arizona Health Sciences, Tucson, AZ, USA
| | - Guoyuan Qi
- Center for Innovation in Brain Science, University of Arizona Health Sciences, Tucson, AZ, USA
| | - Francesca Vitali
- Center for Innovation in Brain Science, University of Arizona Health Sciences, Tucson, AZ, USA
- Department of Neurology, College of Medicine Tucson, University of Arizona, Tucson, AZ, USA
| | - Yuan Shang
- Center for Innovation in Brain Science, University of Arizona Health Sciences, Tucson, AZ, USA
| | - Adam C Raikes
- Center for Innovation in Brain Science, University of Arizona Health Sciences, Tucson, AZ, USA
| | - Tian Wang
- Center for Innovation in Brain Science, University of Arizona Health Sciences, Tucson, AZ, USA
- Department of Neurology, College of Medicine Tucson, University of Arizona, Tucson, AZ, USA
| | - Yan Jin
- Center of Translational Science, Florida International University, Port St. Lucie, FL, USA
| | - Roberta D Brinton
- Center for Innovation in Brain Science, University of Arizona Health Sciences, Tucson, AZ, USA
- Department of Neurology, College of Medicine Tucson, University of Arizona, Tucson, AZ, USA
- Department of Pharmacology, College of Medicine Tucson, University of Arizona, Tucson, AZ, USA
- Graduate Interdisciplinary Program in Neuroscience, University of Arizona, Tucson, AZ, USA
| | - Haiwei Gu
- Center of Translational Science, Florida International University, Port St. Lucie, FL, USA
| | - Fei Yin
- Center for Innovation in Brain Science, University of Arizona Health Sciences, Tucson, AZ, USA.
- Department of Pharmacology, College of Medicine Tucson, University of Arizona, Tucson, AZ, USA.
- Graduate Interdisciplinary Program in Neuroscience, University of Arizona, Tucson, AZ, USA.
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31
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AMPK inhibits liver gluconeogenesis: fact or fiction? Biochem J 2023; 480:105-125. [PMID: 36637190 DOI: 10.1042/bcj20220582] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 12/21/2022] [Accepted: 01/04/2023] [Indexed: 01/14/2023]
Abstract
Is there a role for AMPK in the control of hepatic gluconeogenesis and could targeting AMPK in liver be a viable strategy for treating type 2 diabetes? These are frequently asked questions this review tries to answer. After describing properties of AMPK and different small-molecule AMPK activators, we briefly review the various mechanisms for controlling hepatic glucose production, mainly via gluconeogenesis. The different experimental and genetic models that have been used to draw conclusions about the role of AMPK in the control of liver gluconeogenesis are critically discussed. The effects of several anti-diabetic drugs, particularly metformin, on hepatic gluconeogenesis are also considered. We conclude that the main effect of AMPK activation pertinent to the control of hepatic gluconeogenesis is to antagonize glucagon signalling in the short-term and, in the long-term, to improve insulin sensitivity by reducing hepatic lipid content.
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Evans AM. Of Mice and Men and Plethysmography Systems: Does LKB1 Determine the Set Point of Carotid Body Chemosensitivity and the Hypoxic Ventilatory Response? ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2023; 1427:163-173. [PMID: 37322347 DOI: 10.1007/978-3-031-32371-3_18] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Our recent studies suggest that the level of liver kinase B1 (LKB1) expression in some way determines carotid body afferent discharge during hypoxia and to a lesser extent during hypercapnia. In short, phosphorylation by LKB1 of an as yet unidentified target(s) determines a set point for carotid body chemosensitivity. LKB1 is the principal kinase that activates the AMP-activated protein kinase (AMPK) during metabolic stresses, but conditional deletion of AMPK in catecholaminergic cells, including therein carotid body type I cells, has little or no effect on carotid body responses to hypoxia or hypercapnia. With AMPK excluded, the most likely target of LKB1 is one or other of the 12 AMPK-related kinases, which are constitutively phosphorylated by LKB1 and, in general, regulate gene expression. By contrast, the hypoxic ventilatory response is attenuated by either LKB1 or AMPK deletion in catecholaminergic cells, precipitating hypoventilation and apnea during hypoxia rather than hyperventilation. Moreover, LKB1, but not AMPK, deficiency causes Cheyne-Stokes-like breathing. This chapter will explore further the possible mechanisms that determine these outcomes.
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Affiliation(s)
- A Mark Evans
- Centre for Discovery Brain Sciences, Hugh Robson Building, University of Edinburgh, Edinburgh, UK.
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AMPK directly phosphorylates TBK1 to integrate glucose sensing into innate immunity. Mol Cell 2022; 82:4519-4536.e7. [PMID: 36384137 DOI: 10.1016/j.molcel.2022.10.026] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Revised: 05/18/2022] [Accepted: 10/25/2022] [Indexed: 11/17/2022]
Abstract
Nutrient sensing and damage sensing are two fundamental processes in living organisms. While hyperglycemia is frequently linked to diabetes-related vulnerability to microbial infection, how body glucose levels affect innate immune responses to microbial invasion is not fully understood. Here, we surprisingly found that viral infection led to a rapid and dramatic decrease in blood glucose levels in rodents, leading to robust AMPK activation. AMPK, once activated, directly phosphorylates TBK1 at S511, which triggers IRF3 recruitment and the assembly of MAVS or STING signalosomes. Consistently, ablation or inhibition of AMPK, knockin of TBK1-S511A, or increased glucose levels compromised nucleic acid sensing, while boosting AMPK-TBK1 cascade by AICAR or TBK1-S511E knockin improves antiviral immunity substantially in various animal models. Thus, we identify TBK1 as an AMPK substrate, reveal the molecular mechanism coupling a dual sensing of glucose and nuclei acids, and report its physiological necessity in antiviral defense.
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The phosphorylation of AMPKβ1 is critical for increasing autophagy and maintaining mitochondrial homeostasis in response to fatty acids. Proc Natl Acad Sci U S A 2022; 119:e2119824119. [PMID: 36409897 PMCID: PMC9860314 DOI: 10.1073/pnas.2119824119] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Fatty acids are vital for the survival of eukaryotes, but when present in excess can have deleterious consequences. The AMP-activated protein kinase (AMPK) is an important regulator of multiple branches of metabolism. Studies in purified enzyme preparations and cultured cells have shown that AMPK is allosterically activated by small molecules as well as fatty acyl-CoAs through a mechanism involving Ser108 within the regulatory AMPK β1 isoform. However, the in vivo physiological significance of this residue has not been evaluated. In the current study, we generated mice with a targeted germline knock-in (KI) mutation of AMPKβ1 Ser108 to Ala (S108A-KI), which renders the site phospho-deficient. S108A-KI mice had reduced AMPK activity (50 to 75%) in the liver but not in the skeletal muscle. On a chow diet, S108A-KI mice had impairments in exogenous lipid-induced fatty acid oxidation. Studies in mice fed a high-fat diet found that S108A-KI mice had a tendency for greater glucose intolerance and elevated liver triglycerides. Consistent with increased liver triglycerides, livers of S108A-KI mice had reductions in mitochondrial content and respiration that were accompanied by enlarged mitochondria, suggestive of impairments in mitophagy. Subsequent studies in primary hepatocytes found that S108A-KI mice had reductions in palmitate- stimulated Cpt1a and Ppargc1a mRNA, ULK1 phosphorylation and autophagic/mitophagic flux. These data demonstrate an important physiological role of AMPKβ1 Ser108 phosphorylation in promoting fatty acid oxidation, mitochondrial biogenesis and autophagy under conditions of high lipid availability. As both ketogenic diets and intermittent fasting increase circulating free fatty acid levels, AMPK activity, mitochondrial biogenesis, and mitophagy, these data suggest a potential unifying mechanism which may be important in mediating these effects.
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35
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Federica R, Edda R, Daniela R, Simone B, Giulia N, Gabriele L, Marta M, Marco P, Gianluca B, Elena N, Matteo C, Serena S, Matteo R, Amedeo A, Salvatore CA. Characterization of the “gut microbiota-immunity axis” and microbial lipid metabolites in atrophic and potential celiac disease. Front Microbiol 2022; 13:886008. [PMID: 36246269 PMCID: PMC9561818 DOI: 10.3389/fmicb.2022.886008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Accepted: 08/30/2022] [Indexed: 11/29/2022] Open
Abstract
Introduction Potential celiac disease (pCD) is characterized by genetic predisposition, positive anti-endomysial and anti-tissue transglutaminase antibodies, but a normal or almost normal jejunal mucosa (e.g., minor histological abnormalities without villous atrophy). To gain further insights into basic mechanisms involved in the development of intestinal villous atrophy, we evaluated and compared the microbial, lipid, and immunological signatures of pCD and atrophic CD (aCD). Materials and methods This study included 17 aCD patients, 10 pCD patients, and 12 healthy controls (HC). Serum samples from all participants were collected to analyze free fatty acids (FFAs). Duodenal mucosa samples of aCD and pCD patients were taken to evaluate histology, tissue microbiota composition, and mucosal immune response. Results We found no significant differences in the mucosa-associated microbiota composition of pCD and aCD patients. On the other hand, in pCD patients, the overall abundance of serum FFAs showed relevant and significant differences in comparison with aCD patients and HC. In detail, compared to HC, pCD patients displayed higher levels of propionic, butyric, valeric, 2-ethylhexanoic, tetradecanoic, hexadecanoic, and octadecanoic acids. Instead, aCD patients showed increased levels of propionic, isohexanoic, and 2-ethylhexanoic acids, and a lower abundance of isovaleric and 2-methylbutyricacids when compared to HC. In addition, compared to aCD patients, pCD patients showed a higher abundance of isobutyric and octadecanoic acid. Finally, the immunological analysis of duodenal biopsy revealed a lower percentage of CD4+ T lymphocytes in pCD infiltrate compared to that observed in aCD patients. The functional characterization of T cells documented a pro-inflammatory immune response in both aCD and pCD patients, but the pCD patients showed a higher percentage of Th0/Th17 and a lower percentage of Th1/Th17. Conclusion The results of the present study show, for the first time, that the duodenal microbiota of patients with pCD does not differ substantially from that of aCD; however, serum FFAs and local T cells displayed a distinctive profile between pCD, aCD, and HC. In conclusion, our result may help to shed new light on the “gut microbiota-immunity axis,” lipid metabolites, and duodenal immune response in overt CD and pCD patients, opening new paradigms in understanding the pathogenesis behind CD progression.
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Affiliation(s)
- Ricci Federica
- Department of Biomedical, Experimental and Clinical Sciences “Mario Serio” University of Florence, Tuscany Regional Referral Center for Adult Celiac Disease, Florence, Italy
| | - Russo Edda
- Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
| | - Renzi Daniela
- Department of Biomedical, Experimental and Clinical Sciences “Mario Serio” University of Florence, Tuscany Regional Referral Center for Adult Celiac Disease, Florence, Italy
| | - Baldi Simone
- Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
| | - Nannini Giulia
- Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
| | - Lami Gabriele
- Department of Biomedical, Experimental and Clinical Sciences “Mario Serio” University of Florence, Tuscany Regional Referral Center for Adult Celiac Disease, Florence, Italy
| | - Menicatti Marta
- Department of Neuroscience, Pharmaceutical and Child Health Area (NEUROFARBA), Florence, Italy
| | - Pallecchi Marco
- Department of Neuroscience, Pharmaceutical and Child Health Area (NEUROFARBA), Florence, Italy
| | - Bartolucci Gianluca
- Department of Neuroscience, Pharmaceutical and Child Health Area (NEUROFARBA), Florence, Italy
| | - Niccolai Elena
- Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
| | - Cerboneschi Matteo
- Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
| | - Smeazzetto Serena
- Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
| | - Ramazzotti Matteo
- Department of Biomedical, Experimental and Clinical Sciences “Mario Serio” University of Florence, Florence, Italy
| | - Amedei Amedeo
- Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
- *Correspondence: Amedei Amedeo,
| | - Calabrò Antonino Salvatore
- Department of Biomedical, Experimental and Clinical Sciences “Mario Serio” University of Florence, Tuscany Regional Referral Center for Adult Celiac Disease, Florence, Italy
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Petsouki E, Cabrera SNS, Heiss EH. AMPK and NRF2: Interactive players in the same team for cellular homeostasis? Free Radic Biol Med 2022; 190:75-93. [PMID: 35918013 DOI: 10.1016/j.freeradbiomed.2022.07.014] [Citation(s) in RCA: 39] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 07/11/2022] [Accepted: 07/19/2022] [Indexed: 11/27/2022]
Abstract
NRF2 (Nuclear factor E2 p45-related factor 2) is a stress responsive transcription factor lending cells resilience against oxidative, xenobiotic, and also nutrient or proteotoxic insults. AMPK (AMP-activated kinase), considered as prime regulator of cellular energy homeostasis, not only tunes metabolism to provide the cell at any time with sufficient ATP or building blocks, but also controls redox balance and inflammation. Due to observed overlapping cellular responses upon AMPK or NRF2 activation and common stressors impinging on both AMPK and NRF2 signaling, it is plausible to assume that AMPK and NRF2 signaling may interdepend and cooperate to readjust cellular homeostasis. After a short introduction of the two players this narrative review paints the current picture on how AMPK and NRF2 signaling might interact on the molecular level, and highlights their possible crosstalk in selected examples of pathophysiology or bioactivity of drugs and phytochemicals.
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Affiliation(s)
- Eleni Petsouki
- Department of Pharmaceutical Sciences, Division of Pharmacognosy, University of Vienna, Faculty of Life Sciences, Althanstrasse 14, 1090 Vienna, Austria
| | - Shara Natalia Sosa Cabrera
- Department of Pharmaceutical Sciences, Division of Pharmacognosy, University of Vienna, Faculty of Life Sciences, Althanstrasse 14, 1090 Vienna, Austria; Vienna Doctoral School of Pharmaceutical, Nutritional and Sport Sciences (VDS PhaNuSpo), University of Vienna, Austria
| | - Elke H Heiss
- Department of Pharmaceutical Sciences, Division of Pharmacognosy, University of Vienna, Faculty of Life Sciences, Althanstrasse 14, 1090 Vienna, Austria.
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Lockridge A, Hanover JA. A nexus of lipid and O-Glcnac metabolism in physiology and disease. Front Endocrinol (Lausanne) 2022; 13:943576. [PMID: 36111295 PMCID: PMC9468787 DOI: 10.3389/fendo.2022.943576] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Accepted: 07/27/2022] [Indexed: 11/13/2022] Open
Abstract
Although traditionally considered a glucose metabolism-associated modification, the O-linked β-N-Acetylglucosamine (O-GlcNAc) regulatory system interacts extensively with lipids and is required to maintain lipid homeostasis. The enzymes of O-GlcNAc cycling have molecular properties consistent with those expected of broad-spectrum environmental sensors. By direct protein-protein interactions and catalytic modification, O-GlcNAc cycling enzymes may provide both acute and long-term adaptation to stress and other environmental stimuli such as nutrient availability. Depending on the cell type, hyperlipidemia potentiates or depresses O-GlcNAc levels, sometimes biphasically, through a diversity of unique mechanisms that target UDP-GlcNAc synthesis and the availability, activity and substrate selectivity of the glycosylation enzymes, O-GlcNAc Transferase (OGT) and O-GlcNAcase (OGA). At the same time, OGT activity in multiple tissues has been implicated in the homeostatic regulation of systemic lipid uptake, storage and release. Hyperlipidemic patterns of O-GlcNAcylation in these cells are consistent with both transient physiological adaptation and feedback uninhibited obesogenic and metabolic dysregulation. In this review, we summarize the numerous interconnections between lipid and O-GlcNAc metabolism. These links provide insights into how the O-GlcNAc regulatory system may contribute to lipid-associated diseases including obesity and metabolic syndrome.
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Affiliation(s)
- Amber Lockridge
- Laboratory of Cell and Molecular Biology, National Institute for Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, United States
| | - John A. Hanover
- Laboratory of Cell and Molecular Biology, National Institute for Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, United States
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Identification of Adipocytokine Pathway-Related Genes in Epilepsy and Its Effect on the Peripheral Immune Landscape. Brain Sci 2022; 12:brainsci12091156. [PMID: 36138892 PMCID: PMC9497159 DOI: 10.3390/brainsci12091156] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2022] [Revised: 08/25/2022] [Accepted: 08/28/2022] [Indexed: 11/16/2022] Open
Abstract
Epilepsy is a multifactorial neurological disorder with recurrent epileptic seizures. Current research stresses both inflammatory and autoimmune conditions as enablers in the pathophysiological process of epilepsy. In view of the growing concern about the role of adipocytokines in antiepileptic and modulating immune responses, we aimed to investigate the relevance of the adipocytokine signaling pathway in the pathological process of epilepsy and its impacts on peripheral immune characteristics. In this study, expression profiles of 142 peripheral blood samples were downloaded from the Gene Expression Omnibus (GEO) database. Adipocytokine pathway-related genes were screened out by feature selection using machine-learning algorithms. A nomogram was then constructed and estimated for the efficacy of diagnosis. Cluster analysis was employed for the recognization of two distinct epilepsy subtypes, followed by an estimation of the immune cell infiltration levels using single-sample gene-set enrichment analysis (ssGSEA). The biological characteristics were analyzed by functional enrichment analysis. The aberrant regulation of adipocytokine signaling pathway was found in the peripheral blood of patients with epilepsy. Twenty-one differently expressed adipocytokine pathway-related genes were identified and five (RELA, PRKAB1, TNFRSF1A, CAMKK2, and CPT1B) were selected to construct a nomogram. Subsequent validations of its forecasting ability revealed that this model has satisfactory predictive value. The immune cell infiltration degrees, such as those of innate immune cells and lymphocytes, were found to significantly correlate to the levels of adipocytokine pathway-related genes. Additionally, 239 differentially expressed genes (DEGs) were identified and their biological functions were mainly enriched in the regulation of the immune response. In conclusion, our results confirmed the predictive value of adipocytokine pathway-related genes for epilepsy and explored their effects on immune infiltration, thereby improving our understanding of the pathogenesis of epilepsy and providing assistance in the diagnosis and treatment of epilepsy.
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Moral-Sanz J, Lewis SA, MacMillan S, Meloni M, McClafferty H, Viollet B, Foretz M, Del-Pozo J, Mark Evans A. AMPK deficiency in smooth muscles causes persistent pulmonary hypertension of the new-born and premature death. Nat Commun 2022; 13:5034. [PMID: 36028487 PMCID: PMC9418192 DOI: 10.1038/s41467-022-32568-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Accepted: 08/05/2022] [Indexed: 11/10/2022] Open
Abstract
AMPK has been reported to facilitate hypoxic pulmonary vasoconstriction but, paradoxically, its deficiency precipitates pulmonary hypertension. Here we show that AMPK-α1/α2 deficiency in smooth muscles promotes persistent pulmonary hypertension of the new-born. Accordingly, dual AMPK-α1/α2 deletion in smooth muscles causes premature death of mice after birth, associated with increased muscularisation and remodeling throughout the pulmonary arterial tree, reduced alveolar numbers and alveolar membrane thickening, but with no oedema. Spectral Doppler ultrasound indicates pulmonary hypertension and attenuated hypoxic pulmonary vasoconstriction. Age-dependent right ventricular pressure elevation, dilation and reduced cardiac output was also evident. KV1.5 potassium currents of pulmonary arterial myocytes were markedly smaller under normoxia, which is known to facilitate pulmonary hypertension. Mitochondrial fragmentation and reactive oxygen species accumulation was also evident. Importantly, there was no evidence of systemic vasculopathy or hypertension in these mice. Moreover, hypoxic pulmonary vasoconstriction was attenuated by AMPK-α1 or AMPK-α2 deletion without triggering pulmonary hypertension.
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Affiliation(s)
- Javier Moral-Sanz
- Centre for Discovery Brain Sciences and Cardiovascular Science, College of Medicine and Veterinary Medicine, Hugh Robson Building, University of Edinburgh, Edinburgh, EH8 9XD, UK
| | - Sophronia A Lewis
- Centre for Discovery Brain Sciences and Cardiovascular Science, College of Medicine and Veterinary Medicine, Hugh Robson Building, University of Edinburgh, Edinburgh, EH8 9XD, UK
| | - Sandy MacMillan
- Centre for Discovery Brain Sciences and Cardiovascular Science, College of Medicine and Veterinary Medicine, Hugh Robson Building, University of Edinburgh, Edinburgh, EH8 9XD, UK
| | - Marco Meloni
- Centre for Cardiovascular Science, Queen's Medical Research Institute, University of Edinburgh, Edinburgh, EH16 4TJ, UK
| | - Heather McClafferty
- Centre for Discovery Brain Sciences and Cardiovascular Science, College of Medicine and Veterinary Medicine, Hugh Robson Building, University of Edinburgh, Edinburgh, EH8 9XD, UK
| | - Benoit Viollet
- Université Paris Cité, CNRS, INSERM, Institut Cochin, F-75014, Paris, France
| | - Marc Foretz
- Université Paris Cité, CNRS, INSERM, Institut Cochin, F-75014, Paris, France
| | - Jorge Del-Pozo
- R(D)SVS, University of Edinburgh Easter Bush Campus, EH25 9RG, Roslin, Edinburgh, UK
| | - A Mark Evans
- Centre for Discovery Brain Sciences and Cardiovascular Science, College of Medicine and Veterinary Medicine, Hugh Robson Building, University of Edinburgh, Edinburgh, EH8 9XD, UK.
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40
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Kopietz F, Degerman E, Göransson O. AMPKβ isoform expression patterns in various adipocyte models and in relation to body mass index. Front Physiol 2022; 13:928964. [PMID: 35991175 PMCID: PMC9386264 DOI: 10.3389/fphys.2022.928964] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Accepted: 06/30/2022] [Indexed: 11/13/2022] Open
Abstract
AMP-activated protein kinase (AMPK) activation is considered a useful strategy for the treatment of type 2 diabetes (T2D). It is unclear whether the expression and/or activity of AMPK in adipocytes is dysregulated in obesity. Also, the expression/activity pattern of AMPKβ isoforms, which are targets for AMPK activators, in adipocytes remains elusive. In this study we show that the two AMPKβ isoforms make roughly equal contributions to AMPK activity in primary human and mouse adipocytes, whereas in cultured 3T3-L1 adipocytes of mouse origin and in primary rat adipocytes, β1-associated activity clearly dominates. Additionally, we found that obesity is not associated with changes in AMPK subunit expression or kinase activity in adipocytes isolated from subcutaneous adipose tissue from individuals with various BMI.
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Kirchweger B, Wasilewicz A, Fischhuber K, Tahir A, Chen Y, Heiss EH, Langer T, Kirchmair J, Rollinger JM. In Silico and In Vitro Approach to Assess Direct Allosteric AMPK Activators from Nature. PLANTA MEDICA 2022; 88:794-804. [PMID: 35915889 DOI: 10.1055/a-1797-3030] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The 5'-adenosine monophosphate-activated protein kinase (AMPK) is an important metabolic regulator. Its allosteric drug and metabolite binding (ADaM) site was identified as an attractive target for direct AMPK activation and holds promise as a novel mechanism for the treatment of metabolic diseases. With the exception of lusianthridin and salicylic acid, no natural product (NP) is reported so far to directly target the ADaM site. For the streamlined assessment of direct AMPK activators from the pool of NPs, an integrated workflow using in silico and in vitro methods was applied. Virtual screening combining a 3D shape-based approach and docking identified 21 NPs and NP-like molecules that could potentially activate AMPK. The compounds were purchased and tested in an in vitro AMPK α 1 β 1 γ 1 kinase assay. Two NP-like virtual hits were identified, which, at 30 µM concentration, caused a 1.65-fold (± 0.24) and a 1.58-fold (± 0.17) activation of AMPK, respectively. Intriguingly, using two different evaluation methods, we could not confirm the bioactivity of the supposed AMPK activator lusianthridin, which rebuts earlier reports.
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Affiliation(s)
- Benjamin Kirchweger
- Department of Pharmaceutical Sciences, University of Vienna, Vienna, Austria
- Vienna Doctoral School of Pharmaceutical, Nutritional and Sport Sciences (PhaNuSpo), University of Vienna, Vienna, Austria
| | - Andreas Wasilewicz
- Department of Pharmaceutical Sciences, University of Vienna, Vienna, Austria
- Vienna Doctoral School of Pharmaceutical, Nutritional and Sport Sciences (PhaNuSpo), University of Vienna, Vienna, Austria
| | - Katrin Fischhuber
- Department of Pharmaceutical Sciences, University of Vienna, Vienna, Austria
| | - Ammar Tahir
- Department of Pharmaceutical Sciences, University of Vienna, Vienna, Austria
| | - Ya Chen
- Department of Pharmaceutical Sciences, University of Vienna, Vienna, Austria
| | - Elke H Heiss
- Department of Pharmaceutical Sciences, University of Vienna, Vienna, Austria
| | - Thierry Langer
- Department of Pharmaceutical Sciences, University of Vienna, Vienna, Austria
| | - Johannes Kirchmair
- Department of Pharmaceutical Sciences, University of Vienna, Vienna, Austria
| | - Judith M Rollinger
- Department of Pharmaceutical Sciences, University of Vienna, Vienna, Austria
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42
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Spatial regulation of AMPK signaling revealed by a sensitive kinase activity reporter. Nat Commun 2022; 13:3856. [PMID: 35790710 PMCID: PMC9256702 DOI: 10.1038/s41467-022-31190-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Accepted: 06/06/2022] [Indexed: 12/13/2022] Open
Abstract
AMP-activated protein kinase (AMPK) is a master regulator of cellular energetics which coordinates metabolism by phosphorylating a plethora of substrates throughout the cell. But how AMPK activity is regulated at different subcellular locations for precise spatiotemporal control over metabolism is unclear. Here we present a sensitive, single-fluorophore AMPK activity reporter (ExRai AMPKAR), which reveals distinct kinetic profiles of AMPK activity at the mitochondria, lysosome, and cytoplasm. Genetic deletion of the canonical upstream kinase liver kinase B1 (LKB1) results in slower AMPK activity at lysosomes but does not affect the response amplitude at lysosomes or mitochondria, in sharp contrast to the necessity of LKB1 for maximal cytoplasmic AMPK activity. We further identify a mechanism for AMPK activity in the nucleus, which results from cytoplasmic to nuclear shuttling of AMPK. Thus, ExRai AMPKAR enables illumination of the complex subcellular regulation of AMPK signaling.
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43
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LKB1 is the gatekeeper of carotid body chemosensing and the hypoxic ventilatory response. Commun Biol 2022; 5:642. [PMID: 35768580 PMCID: PMC9243028 DOI: 10.1038/s42003-022-03583-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Accepted: 06/14/2022] [Indexed: 11/08/2022] Open
Abstract
The hypoxic ventilatory response (HVR) is critical to breathing and thus oxygen supply to the body and is primarily mediated by the carotid bodies. Here we reveal that carotid body afferent discharge during hypoxia and hypercapnia is determined by the expression of Liver Kinase B1 (LKB1), the principal kinase that activates the AMP-activated protein kinase (AMPK) during metabolic stresses. Conversely, conditional deletion in catecholaminergic cells of AMPK had no effect on carotid body responses to hypoxia or hypercapnia. By contrast, the HVR was attenuated by LKB1 and AMPK deletion. However, in LKB1 knockouts hypoxia evoked hypoventilation, apnoea and Cheyne-Stokes-like breathing, while only hypoventilation and apnoea were observed after AMPK deletion. We therefore identify LKB1 as an essential regulator of carotid body chemosensing and uncover a divergence in dependency on LKB1 and AMPK between the carotid body on one hand and the HVR on the other.
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44
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Pham T, Walden E, Huard S, Pezacki J, Fullerton MD, Baetz K. Fine tuning Acetyl-CoA Carboxylase 1 activity through localization: Functional genomics reveal a role for the lysine acetyltransferase NuA4 and sphingolipid metabolism in regulating Acc1 activity and localization. Genetics 2022; 221:6591204. [PMID: 35608294 PMCID: PMC9339284 DOI: 10.1093/genetics/iyac086] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2022] [Accepted: 05/10/2022] [Indexed: 11/29/2022] Open
Abstract
Acetyl-CoA Carboxylase 1 catalyzes the conversion of acetyl-CoA to malonyl-CoA, the committed step of de novo fatty acid synthesis. As a master regulator of lipid synthesis, acetyl-CoA carboxylase 1 has been proposed to be a therapeutic target for numerous metabolic diseases. We have shown that acetyl-CoA carboxylase 1 activity is reduced in the absence of the lysine acetyltransferase NuA4 in Saccharomyces cerevisiae. This change in acetyl-CoA carboxylase 1 activity is correlated with a change in localization. In wild-type cells, acetyl-CoA carboxylase 1 is localized throughout the cytoplasm in small punctate and rod-like structures. However, in NuA4 mutants, acetyl-CoA carboxylase 1 localization becomes diffuse. To uncover mechanisms regulating acetyl-CoA carboxylase 1 localization, we performed a microscopy screen to identify other deletion mutants that impact acetyl-CoA carboxylase 1 localization and then measured acetyl-CoA carboxylase 1 activity in these mutants through chemical genetics and biochemical assays. Three phenotypes were identified. Mutants with hyper-active acetyl-CoA carboxylase 1 form 1 or 2 rod-like structures centrally within the cytoplasm, mutants with mid-low acetyl-CoA carboxylase 1 activity displayed diffuse acetyl-CoA carboxylase 1, while the mutants with the lowest acetyl-CoA carboxylase 1 activity (hypomorphs) formed thick rod-like acetyl-CoA carboxylase 1 structures at the periphery of the cell. All the acetyl-CoA carboxylase 1 hypomorphic mutants were implicated in sphingolipid metabolism or very long-chain fatty acid elongation and in common, their deletion causes an accumulation of palmitoyl-CoA. Through exogenous lipid treatments, enzyme inhibitors, and genetics, we determined that increasing palmitoyl-CoA levels inhibits acetyl-CoA carboxylase 1 activity and remodels acetyl-CoA carboxylase 1 localization. Together this study suggests yeast cells have developed a dynamic feed-back mechanism in which downstream products of acetyl-CoA carboxylase 1 can fine-tune the rate of fatty acid synthesis.
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Affiliation(s)
- Trang Pham
- Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, K1H 8M5 Canada.,Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, K1H 8M5 Canada
| | - Elizabeth Walden
- Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, K1H 8M5 Canada.,Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, K1H 8M5 Canada
| | - Sylvain Huard
- Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, K1H 8M5 Canada.,Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, K1H 8M5 Canada
| | - John Pezacki
- Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, K1H 8M5 Canada.,Department of Chemistry and Biomolecular Sciences, Faculty of Science, University of Ottawa, Ottawa K1N6N5 Canada
| | - Morgan D Fullerton
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, K1H 8M5 Canada
| | - Kristin Baetz
- Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, K1H 8M5 Canada.,Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, K1H 8M5 Canada.,Department of Biological Sciences, Faculty of Science, University of Calgary, Calgary T2N 1N4, Canada
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45
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Structure-function analysis of the AMPK activator SC4 and identification of a potent pan AMPK activator. Biochem J 2022; 479:1181-1204. [PMID: 35552369 PMCID: PMC9317966 DOI: 10.1042/bcj20220067] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 05/11/2022] [Accepted: 05/13/2022] [Indexed: 11/17/2022]
Abstract
The AMP-activated protein kinase (AMPK) αβγ heterotrimer is a primary cellular energy sensor and central regulator of energy homeostasis. Activating skeletal muscle AMPK with small molecule drugs improves glucose uptake and provides an opportunity for new strategies to treat type 2 diabetes and insulin resistance, with recent genetic and pharmacological studies indicating the α2β2γ1 isoform combination as the heterotrimer complex primarily responsible. With the goal of developing α2β2-specific activators, here we perform structure/function analysis of the 2-hydroxybiphenyl group of SC4, an activator with tendency for α2-selectivity that is also capable of potently activating β2 complexes. Substitution of the LHS 2-hydroxyphenyl group with polar-substituted cyclohexene-based probes resulted in two AMPK agonists, MSG010 and MSG011, which did not display α2-selectivity when screened against a panel of AMPK complexes. By radiolabel kinase assay, MSG010 and MSG011 activated α2β2γ1 AMPK with one order of magnitude greater potency than the pan AMPK activator MK-8722. A crystal structure of MSG011 complexed to AMPK α2β1γ1 revealed a similar binding mode to SC4 and the potential importance of an interaction between the SC4 2-hydroxyl group and α2-Lys31 for directing α2-selectivity. MSG011 induced robust AMPK signalling in mouse primary hepatocytes and commonly used cell lines, and in most cases this occurred in the absence of changes in phosphorylation of the kinase activation loop residue α-Thr172, a classical marker of AMP-induced AMPK activity. These findings will guide future design of α2β2-selective AMPK activators, that we hypothesise may avoid off-target complications associated with indiscriminate activation of AMPK throughout the body.
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46
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Sanders MJ, Ratinaud Y, Neopane K, Bonhoure N, Day EA, Ciclet O, Lassueur S, Naranjo Pinta M, Deak M, Brinon B, Christen S, Steinberg GR, Barron D, Sakamoto K. Natural (dihydro)phenanthrene plant compounds are direct activators of AMPK through its allosteric drug and metabolite-binding site. J Biol Chem 2022; 298:101852. [PMID: 35331736 PMCID: PMC9108889 DOI: 10.1016/j.jbc.2022.101852] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Revised: 03/15/2022] [Accepted: 03/16/2022] [Indexed: 11/26/2022] Open
Abstract
AMP-activated protein kinase (AMPK) is a central energy sensor that coordinates the response to energy challenges to maintain cellular ATP levels. AMPK is a potential therapeutic target for treating metabolic disorders, and several direct synthetic activators of AMPK have been developed that show promise in preclinical models of type 2 diabetes. These compounds have been shown to regulate AMPK through binding to a novel allosteric drug and metabolite (ADaM)–binding site on AMPK, and it is possible that other molecules might similarly bind this site. Here, we performed a high-throughput screen with natural plant compounds to identify such direct allosteric activators of AMPK. We identified a natural plant dihydrophenathrene, Lusianthridin, which allosterically activates and protects AMPK from dephosphorylation by binding to the ADaM site. Similar to other ADaM site activators, Lusianthridin showed preferential activation of AMPKβ1-containing complexes in intact cells and was unable to activate an AMPKβ1 S108A mutant. Lusianthridin dose-dependently increased phosphorylation of acetyl-CoA carboxylase in mouse primary hepatocytes, which led to a corresponding decrease in de novo lipogenesis. This ability of Lusianthridin to inhibit lipogenesis was impaired in hepatocytes from β1 S108A knock-in mice and mice bearing a mutation at the AMPK phosphorylation site of acetyl-CoA carboxylase 1/2. Finally, we show that activation of AMPK by natural compounds extends to several analogs of Lusianthridin and the related chemical series, phenanthrenes. The emergence of natural plant compounds that regulate AMPK through the ADaM site raises the distinct possibility that other natural compounds share a common mechanism of regulation.
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Affiliation(s)
- Matthew J Sanders
- Nestlé Institute of Health Sciences, Nestlé Research, Société des Produits Nestlé S.A., Lausanne, Switzerland.
| | - Yann Ratinaud
- Nestlé Institute of Health Sciences, Nestlé Research, Société des Produits Nestlé S.A., Lausanne, Switzerland
| | - Katyayanee Neopane
- Nestlé Institute of Health Sciences, Nestlé Research, Société des Produits Nestlé S.A., Lausanne, Switzerland; School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Nicolas Bonhoure
- Nestlé Institute of Health Sciences, Nestlé Research, Société des Produits Nestlé S.A., Lausanne, Switzerland
| | - Emily A Day
- Centre for Metabolism, Obesity, and Diabetes Research, McMaster University, Hamilton, Ontario, Canada; Department of Medicine and Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada
| | - Olivier Ciclet
- Nestlé Institute of Health Sciences, Nestlé Research, Société des Produits Nestlé S.A., Lausanne, Switzerland
| | - Steve Lassueur
- Nestlé Institute of Health Sciences, Nestlé Research, Société des Produits Nestlé S.A., Lausanne, Switzerland
| | - Martine Naranjo Pinta
- Nestlé Institute of Health Sciences, Nestlé Research, Société des Produits Nestlé S.A., Lausanne, Switzerland
| | - Maria Deak
- Nestlé Institute of Health Sciences, Nestlé Research, Société des Produits Nestlé S.A., Lausanne, Switzerland
| | - Benjamin Brinon
- Nestlé Institute of Health Sciences, Nestlé Research, Société des Produits Nestlé S.A., Lausanne, Switzerland
| | - Stefan Christen
- Nestle Institute of Food Safety and Analytical Sciences, Nestlé Research, Société des Produits Nestlé S.A., Lausanne, Switzerland
| | - Gregory R Steinberg
- Centre for Metabolism, Obesity, and Diabetes Research, McMaster University, Hamilton, Ontario, Canada; Department of Medicine and Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada
| | - Denis Barron
- Nestlé Institute of Health Sciences, Nestlé Research, Société des Produits Nestlé S.A., Lausanne, Switzerland
| | - Kei Sakamoto
- Nestlé Institute of Health Sciences, Nestlé Research, Société des Produits Nestlé S.A., Lausanne, Switzerland; Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark.
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47
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Integrating adipocyte insulin signaling and metabolism in the multi-omics era. Trends Biochem Sci 2022; 47:531-546. [PMID: 35304047 DOI: 10.1016/j.tibs.2022.02.009] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Revised: 02/08/2022] [Accepted: 02/21/2022] [Indexed: 12/16/2022]
Abstract
Insulin stimulates glucose uptake into adipocytes via mTORC2/AKT signaling and GLUT4 translocation and directs glucose carbons into glycolysis, glycerol for TAG synthesis, and de novo lipogenesis. Adipocyte insulin resistance is an early indicator of type 2 diabetes in obesity, a worldwide health crisis. Thus, understanding the interplay between insulin signaling and central carbon metabolism pathways that maintains adipocyte function, blood glucose levels, and metabolic homeostasis is critical. While classically viewed through the lens of individual enzyme-substrate interactions, advances in mass spectrometry are beginning to illuminate adipocyte signaling and metabolic networks on an unprecedented scale, yet this is just the tip of the iceberg. Here, we review how 'omics approaches help to elucidate adipocyte insulin action in cellular time and space.
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48
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Abstract
SignificanceThe study provided a long-sought molecular mechanism that could explain the link between fatty acid metabolism and cancer metastasis. Further understanding may lead to new strategies to inhibit cancer metastasis. The chemical proteomic approach developed here will be useful for discovering other regulatory mechanisms of protein function by small molecule metabolites.
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49
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Li Y, Li Z, Ngandiri DA, Llerins Perez M, Wolf A, Wang Y. The Molecular Brakes of Adipose Tissue Lipolysis. Front Physiol 2022; 13:826314. [PMID: 35283787 PMCID: PMC8907745 DOI: 10.3389/fphys.2022.826314] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Accepted: 01/10/2022] [Indexed: 12/11/2022] Open
Abstract
Adaptation to changes in energy availability is pivotal for the survival of animals. Adipose tissue, the body’s largest reservoir of energy and a major source of metabolic fuel, exerts a buffering function for fluctuations in nutrient availability. This functional plasticity ranges from energy storage in the form of triglycerides during periods of excess energy intake to energy mobilization via lipolysis in the form of free fatty acids for other organs during states of energy demands. The subtle balance between energy storage and mobilization is important for whole-body energy homeostasis; its disruption has been implicated as contributing to the development of insulin resistance, type 2 diabetes and cancer cachexia. As a result, adipocyte lipolysis is tightly regulated by complex regulatory mechanisms involving lipases and hormonal and biochemical signals that have opposing effects. In thermogenic brown and brite adipocytes, lipolysis stimulation is the canonical way for the activation of non-shivering thermogenesis. Lipolysis proceeds in an orderly and delicately regulated manner, with stimulation through cell-surface receptors via neurotransmitters, hormones, and autocrine/paracrine factors that activate various intracellular signal transduction pathways and increase kinase activity. The subsequent phosphorylation of perilipins, lipases, and cofactors initiates the translocation of key lipases from the cytoplasm to lipid droplets and enables protein-protein interactions to assemble the lipolytic machinery on the scaffolding perilipins at the surface of lipid droplets. Although activation of lipolysis has been well studied, the feedback fine-tuning is less well appreciated. This review focuses on the molecular brakes of lipolysis and discusses some of the divergent fine-tuning strategies in the negative feedback regulation of lipolysis, including delicate negative feedback loops, intermediary lipid metabolites-mediated allosteric regulation and dynamic protein–protein interactions. As aberrant adipocyte lipolysis is involved in various metabolic diseases and releasing the brakes on lipolysis in thermogenic adipocytes may activate thermogenesis, targeting adipocyte lipolysis is thus of therapeutic interest.
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50
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Morrison KR, Smiles WJ, Ling NXY, Hoque A, Shea G, Ngoei KRW, Yu D, Murray-Segal L, Scott JW, Galic S, Kemp BE, Petersen J, Oakhill JS. An AMPKα2-specific phospho-switch controls lysosomal targeting for activation. Cell Rep 2022; 38:110365. [PMID: 35172150 DOI: 10.1016/j.celrep.2022.110365] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 10/28/2021] [Accepted: 01/19/2022] [Indexed: 12/12/2022] Open
Abstract
AMP-activated protein kinase (AMPK) and mechanistic target of rapamycin complex 1 (mTORC1) are metabolic kinases that co-ordinate nutrient supply with cell growth. AMPK negatively regulates mTORC1, and mTORC1 reciprocally phosphorylates S345/7 in both AMPK α-isoforms. We report that genetic or torin1-induced loss of α2-S345 phosphorylation relieves suppression of AMPK signaling; however, the regulatory effect does not translate to α1-S347 in HEK293T or MEF cells. Dephosphorylation of α2-S345, but not α1-S347, transiently targets AMPK to lysosomes, a cellular site for activation by LKB1. By mass spectrometry, we find that α2-S345 is basally phosphorylated at 2.5-fold higher stoichiometry than α1-S347 in HEK293T cells and, unlike α1, phosphorylation is partially retained after prolonged mTORC1 inhibition. Loss of α2-S345 phosphorylation in endogenous AMPK fails to sustain growth of MEFs under amino acid starvation conditions. These findings uncover an α2-specific mechanism by which AMPK can be activated at lysosomes in the absence of changes in cellular energy.
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Affiliation(s)
- Kaitlin R Morrison
- Flinders Health and Medical Research Institute, Flinders University, Adelaide, SA 5042, Australia
| | - William J Smiles
- Metabolic Signalling Laboratory, St Vincent's Institute of Medical Research, School of Medicine, University of Melbourne, Melbourne, VIC 3065, Australia
| | - Naomi X Y Ling
- Metabolic Signalling Laboratory, St Vincent's Institute of Medical Research, School of Medicine, University of Melbourne, Melbourne, VIC 3065, Australia
| | - Ashfaqul Hoque
- Metabolic Signalling Laboratory, St Vincent's Institute of Medical Research, School of Medicine, University of Melbourne, Melbourne, VIC 3065, Australia
| | - Gabrielle Shea
- Flinders Health and Medical Research Institute, Flinders University, Adelaide, SA 5042, Australia
| | - Kevin R W Ngoei
- Protein Chemistry & Metabolism Unit, St Vincent's Institute of Medical Research, School of Medicine, University of Melbourne, Melbourne, VIC 3065, Australia
| | - Dingyi Yu
- Protein Chemistry & Metabolism Unit, St Vincent's Institute of Medical Research, School of Medicine, University of Melbourne, Melbourne, VIC 3065, Australia
| | - Lisa Murray-Segal
- Protein Chemistry & Metabolism Unit, St Vincent's Institute of Medical Research, School of Medicine, University of Melbourne, Melbourne, VIC 3065, Australia
| | - John W Scott
- Protein Chemistry & Metabolism Unit, St Vincent's Institute of Medical Research, School of Medicine, University of Melbourne, Melbourne, VIC 3065, Australia; Mary MacKillop Institute for Health Research, Australian Catholic University, Fitzroy, VIC 3000, Australia; The Florey Institute of Neuroscience and Mental Health, Parkville, Melbourne, VIC 3052, Australia
| | - Sandra Galic
- Protein Chemistry & Metabolism Unit, St Vincent's Institute of Medical Research, School of Medicine, University of Melbourne, Melbourne, VIC 3065, Australia
| | - Bruce E Kemp
- Protein Chemistry & Metabolism Unit, St Vincent's Institute of Medical Research, School of Medicine, University of Melbourne, Melbourne, VIC 3065, Australia; Mary MacKillop Institute for Health Research, Australian Catholic University, Fitzroy, VIC 3000, Australia
| | - Janni Petersen
- Flinders Health and Medical Research Institute, Flinders University, Adelaide, SA 5042, Australia; Nutrition and Metabolism, South Australia Health and Medical Research Institute, Adelaide, SA, Australia.
| | - Jonathan S Oakhill
- Metabolic Signalling Laboratory, St Vincent's Institute of Medical Research, School of Medicine, University of Melbourne, Melbourne, VIC 3065, Australia.
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