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Sinha RA, Yen PM. Metabolic Messengers: Thyroid Hormones. Nat Metab 2024; 6:639-650. [PMID: 38671149 DOI: 10.1038/s42255-024-00986-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Accepted: 01/15/2024] [Indexed: 04/28/2024]
Abstract
Thyroid hormones (THs) are key hormones that regulate development and metabolism in mammals. In man, the major target tissues for TH action are the brain, liver, muscle, heart, and adipose tissue. Defects in TH synthesis, transport, metabolism, and nuclear action have been associated with genetic and endocrine diseases in man. Over the past few years, there has been renewed interest in TH action and the therapeutic potential of THs and thyromimetics to treat several metabolic disorders such as hypercholesterolemia, dyslipidaemia, non-alcoholic fatty liver disease (NAFLD), and TH transporter defects. Recent advances in the development of tissue and TH receptor isoform-targeted thyromimetics have kindled new hope for translating our fundamental understanding of TH action into an effective therapy. This review provides a concise overview of the historical development of our understanding of TH action, its physiological and pathophysiological effects on metabolism, and future therapeutic applications to treat metabolic dysfunction.
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Affiliation(s)
- Rohit A Sinha
- Department of Endocrinology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India.
| | - Paul M Yen
- Laboratory of Hormonal Regulation, Cardiovascular and Metabolic Disorders Program, Duke-NUS Medical School, Singapore, Singapore.
- Div. Endocrinology, Metabolism, and Nutrition, Department of Medicine, Duke Molecular Physiology Institute, Duke University School of Medicine, Durham, NC, USA.
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Sinha RA. Targeting nuclear receptors for NASH/MASH: From bench to bedside. Liver Res 2024; 8:34-45. [PMID: 38544909 PMCID: PMC7615772 DOI: 10.1016/j.livres.2024.03.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 04/17/2024]
Abstract
The onset of metabolic dysfunction-associated steatohepatitis (MASH) or non-alcoholic steatohepatitis (NASH) represents a tipping point leading to liver injury and subsequent hepatic complications in the natural progression of what is now termed metabolic dysfunction-associated steatotic liver diseases (MASLD), formerly known as non-alcoholic fatty liver disease (NAFLD). With no pharmacological treatment currently available for MASH/NASH, the race is on to develop drugs targeting multiple facets of hepatic metabolism, inflammation, and pro-fibrotic events, which are major drivers of MASH. Nuclear receptors (NRs) regulate genomic transcription upon binding to lipophilic ligands and govern multiple aspects of liver metabolism and inflammation. Ligands of NRs may include hormones, lipids, bile acids, and synthetic ligands, which upon binding to NRs regulate the transcriptional activities of target genes. NR ligands are presently the most promising drug candidates expected to receive approval from the United States Food and Drug Administration as a pharmacological treatment for MASH. This review aims to cover the current understanding of NRs, including nuclear hormone receptors, non-steroid hormone receptors, circadian NRs, and orphan NRs, which are currently undergoing clinical trials for MASH treatment, along with NRs that have shown promising results in preclinical studies.
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Affiliation(s)
- Rohit A Sinha
- Department of Endocrinology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India
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Raza S, Rajak S, Singh R, Zhou J, Sinha RA, Goel A. Cell-type specific role of autophagy in the liver and its implications in non-alcoholic fatty liver disease. World J Hepatol 2023; 15:1272-1283. [PMID: 38192406 PMCID: PMC7615497 DOI: 10.4254/wjh.v15.i12.1272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Revised: 11/07/2023] [Accepted: 12/08/2023] [Indexed: 12/25/2023] Open
Abstract
Autophagy, a cellular degradative process, has emerged as a key regulator of cellular energy production and stress mitigation. Dysregulated autophagy is a common phenomenon observed in several human diseases, and its restoration offers curative advantage. Non-alcoholic fatty liver disease (NAFLD), more recently renamed metabolic dysfunction-associated steatotic liver disease, is a major metabolic liver disease affecting almost 30% of the world population. Unfortunately, NAFLD has no pharmacological therapies available to date. Autophagy regulates several hepatic processes including lipid metabolism, inflammation, cellular integrity and cellular plasticity in both parenchymal (hepatocytes) and non-parenchymal cells (Kupffer cells, hepatic stellate cells and sinusoidal endothelial cells) with a profound impact on NAFLD progression. Understanding cell type-specific autophagy in the liver is essential in order to develop targeted treatments for liver diseases such as NAFLD. Modulating autophagy in specific cell types can have varying effects on liver function and pathology, making it a promising area of research for liver-related disorders. This review aims to summarize our present understanding of cell-type specific effects of autophagy and their implications in developing autophagy centric therapies for NAFLD.
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Affiliation(s)
- Sana Raza
- Department of Endocrinology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Uttar Pradesh, Lucknow 226014, India
| | - Sangam Rajak
- Department of Endocrinology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Uttar Pradesh, Lucknow 226014, India
| | - Rajani Singh
- Department of Hepatology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Uttar Pradesh, Lucknow 226014, India
| | - Jin Zhou
- CVMD, Duke-NUS Medical School, Singapore 169857, Singapore
| | - Rohit A Sinha
- Department of Endocrinology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Uttar Pradesh, Lucknow 226014, India
| | - Amit Goel
- Department of Hepatology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Uttar Pradesh, Lucknow 226014, India.
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Tewari A, Rajak S, Raza S, Gupta P, Chakravarti B, Srivastava J, Chaturvedi CP, Sinha RA. Targeting Extracellular RNA Mitigates Hepatic Lipotoxicity and Liver Injury in NASH. Cells 2023; 12:1845. [PMID: 37484201 PMCID: PMC7614796 DOI: 10.3390/cells12141845] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/25/2023] Open
Abstract
Non-alcoholic steatohepatitis (NASH) is a clinically serious stage of non-alcoholic fatty liver disease (NAFLD). Histologically characterized by hepatocyte ballooning, immune cell infiltration, and fibrosis, NASH, at a molecular level, involves lipid-induced hepatocyte death and cytokine production. Currently, there are very few diagnostic biomarkers available to screen for NASH, and no pharmacological intervention is available for its treatment. In this study, we show that hepatocyte damage induced by lipotoxicity results in the release of extracellular RNAs (eRNAs), which serve as damage-associated molecular patterns (DAMPs) that stimulate the expression of pro-apoptotic and pro-inflammatory cytokines, aggravate inflammation, and lead to cell death in HepG2 cells. Furthermore, the inhibition of eRNA activity by RNase 1 significantly increases cellular viability and reduces NF-kB-mediated cytokine production. Similarly, RNase 1 administration significantly improves hepatic steatosis, inflammatory and injury markers in a murine NASH model. Therefore, this study, for the first time, underscores the therapeutic potential of inhibiting eRNA action as a novel strategy for NASH treatment.
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Affiliation(s)
- Archana Tewari
- Department of Endocrinology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow 226014, India
| | - Sangam Rajak
- Department of Endocrinology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow 226014, India
| | - Sana Raza
- Department of Endocrinology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow 226014, India
| | - Pratima Gupta
- Department of Endocrinology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow 226014, India
| | - Bandana Chakravarti
- Department of Endocrinology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow 226014, India
| | - Jyotika Srivastava
- Stem Cell Research Facility, Department of Hematology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow 226014, India
| | - Chandra P. Chaturvedi
- Stem Cell Research Facility, Department of Hematology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow 226014, India
| | - Rohit A. Sinha
- Department of Endocrinology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow 226014, India
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Rajak S, Tewari A, Raza S, Gupta P, Chakravarti B, Anjum B, Tripathi M, Singh BK, Yen PM, Goel A, Ghosh S, Sinha RA. Pharmacological inhibition of CFTR attenuates nonalcoholic steatohepatitis (NASH) progression in mice. Biochim Biophys Acta Mol Basis Dis 2023; 1869:166662. [PMID: 36754244 DOI: 10.1016/j.bbadis.2023.166662] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2023] [Revised: 01/30/2023] [Accepted: 01/31/2023] [Indexed: 02/08/2023]
Abstract
Nonalcoholic steatohepatitis (NASH) is considered a pivotal stage in nonalcoholic fatty liver disease (NAFLD) progression and increases the risk of end-stage liver diseases such as fibrosis, cirrhosis, and hepatocellular carcinoma (HCC). The etiology of NASH is multifactorial and identifying reliable molecular players has proven difficult. Presently, there are no approved drugs for NASH treatment, which has become a leading cause of liver transplants worldwide. Here, using public human transcriptomic NAFLD dataset, we uncover Cystic fibrosis transmembrane conductance receptor (CFTR) as a differentially expressed gene in the livers of human NASH patients. Similarly, murine Cftr expression was also found to be upregulated in two mouse models of diet-induced NASH. Furthermore, the pharmacological inhibition of CFTR significantly reduced NASH progression in mice and its overexpression aggravated lipotoxicity in human hepatic cells. These results, thus, underscore the involvement of murine Cftr in the pathogenesis of NASH and raise the intriguing possibility of its pharmacological inhibition in human NASH.
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Affiliation(s)
- Sangam Rajak
- Department of Endocrinology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow 226014, India
| | - Archana Tewari
- Department of Endocrinology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow 226014, India
| | - Sana Raza
- Department of Endocrinology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow 226014, India
| | - Pratima Gupta
- Department of Endocrinology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow 226014, India
| | - Bandana Chakravarti
- Department of Endocrinology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow 226014, India
| | - Baby Anjum
- Department of Endocrinology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow 226014, India
| | - Madhulika Tripathi
- Cardiovascular and Metabolic Disorders Program, Duke-NUS Medical School, Singapore, Singapore
| | - Brijesh K Singh
- Cardiovascular and Metabolic Disorders Program, Duke-NUS Medical School, Singapore, Singapore
| | - Paul M Yen
- Cardiovascular and Metabolic Disorders Program, Duke-NUS Medical School, Singapore, Singapore; Duke Molecular Physiology Institute and Dept of Medicine, Duke University School of Medicine, Durham, NC, USA
| | - Amit Goel
- Department of Gastroenterology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow 226014, India
| | - Sujoy Ghosh
- Cardiovascular and Metabolic Disorders Program, Duke-NUS Medical School, Singapore, Singapore
| | - Rohit A Sinha
- Department of Endocrinology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow 226014, India.
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Raza S, Rajak S, Srivastava J, Tewari A, Gupta P, Chakravarti B, Ghosh S, Chaturvedi CP, Sinha RA. ULK1 inhibition attenuates telomerase activity in hepatic cells. Biochim Biophys Acta Mol Cell Res 2022; 1869:119355. [PMID: 36113664 DOI: 10.1016/j.bbamcr.2022.119355] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Revised: 08/12/2022] [Accepted: 08/28/2022] [Indexed: 06/15/2023]
Abstract
Autophagy and telomere maintenance are two cellular survival processes that show a strong correlation during human ageing and cancer growth, however, their causal relationship remains unclear. In this study, using an unbiased transcriptomics approach, we uncover a novel role of autophagy genes in regulating telomere extension and maintenance pathways. Concomitantly, the pharmacological inhibition of ULK1 (Unc-51 like autophagy activating kinase 1) attenuated human telomerase reverse transcriptase (hTERT) gene expression and telomerase activity in HepG2 cells. Furthermore, the suppression of telomerase activity upon ULK1 inhibition was associated with telomere shortening and onset of cellular senescence in HepG2 cells. These results, thus, demonstrate a direct role of autophagy in maintaining cellular longevity via regulation of telomerase activity, which may have implications in the pathophysiology of ageing and cancers.
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Affiliation(s)
- Sana Raza
- Department of Endocrinology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India
| | - Sangam Rajak
- Department of Endocrinology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India
| | - Jyotika Srivastava
- Stem Cell Research Facility, Department of Hematology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India
| | - Archana Tewari
- Department of Endocrinology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India
| | - Pratima Gupta
- Department of Endocrinology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India
| | - Bandana Chakravarti
- Department of Endocrinology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India
| | - Sujoy Ghosh
- Centre for Computational Biology, Duke-NUS Medical School, Singapore
| | - Chandra P Chaturvedi
- Stem Cell Research Facility, Department of Hematology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India
| | - Rohit A Sinha
- Department of Endocrinology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India.
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Rajak S, Gupta P, Anjum B, Raza S, Tewari A, Ghosh S, Tripathi M, Singh BK, Sinha RA. Role of AKR1B10 and AKR1B8 in the pathogenesis of non-alcoholic steatohepatitis (NASH) in mouse. Biochim Biophys Acta Mol Basis Dis 2021; 1868:166319. [PMID: 34954342 DOI: 10.1016/j.bbadis.2021.166319] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 10/18/2021] [Accepted: 12/05/2021] [Indexed: 01/07/2023]
Abstract
Non-alcoholic steatohepatitis (NASH) is a clinically important spectrum of non-alcoholic fatty liver disease (NAFLD) in humans. NASH is a stage of NAFLD progression wherein liver steatosis accompanies inflammation and pro-fibrotic events. Presently, there are no approved drugs for NASH, which has become a leading cause of liver transplant worldwide. To discover novel drug targets for NASH, we analyzed a human transcriptomic NASH dataset and found Aldo-keto reductase family 1 member B10 (AKR1B10) as a significantly upregulated gene in livers of human NASH patients. Similarly murine Akr1b10 and Aldo-keto reductase family 1 member B8 (Akr1b8) gene, which is a murine ortholog of human AKR1B10, were also found to be upregulated in a mouse model of diet-induced NASH. Furthermore, pharmacological inhibitors of AKR1B10 significantly reduced the pathological features of NASH such as steatosis, inflammation and fibrosis in mouse. In addition, genetic silencing of both mouse Akr1b10 and Akr1b8 significantly reduced the expression of proinflammatory cytokines from hepatocytes. These results thus underscore the involvement of murine AKR1B10 and AKR1B8 in the pathogenesis of murine NASH and raise an intriguing possibility of a similar role of AKR1B10 in human NASH.
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Affiliation(s)
- Sangam Rajak
- Department of Endocrinology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow 226014, India
| | - Pratima Gupta
- Department of Endocrinology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow 226014, India
| | - Baby Anjum
- Department of Endocrinology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow 226014, India
| | - Sana Raza
- Department of Endocrinology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow 226014, India
| | - Archana Tewari
- Department of Endocrinology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow 226014, India
| | - Sujoy Ghosh
- Centre for Computational Biology, Duke-NUS Medical School, Singapore; Cardiovascular and Metabolic Disorder Program, Duke-NUS Medical School, Singapore
| | - Madhulika Tripathi
- Cardiovascular and Metabolic Disorder Program, Duke-NUS Medical School, Singapore
| | - Brijesh K Singh
- Cardiovascular and Metabolic Disorder Program, Duke-NUS Medical School, Singapore
| | - Rohit A Sinha
- Department of Endocrinology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow 226014, India.
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Pal S, Singh M, Porwal K, Rajak S, Das N, Rajput S, Trivedi AK, Maurya R, Sinha RA, Siddiqi MI, Sanyal S, Chattopadhyay N. Adiponectin receptors by increasing mitochondrial biogenesis and respiration promote osteoblast differentiation: Discovery of isovitexin as a new class of small molecule adiponectin receptor modulator with potential osteoanabolic function. Eur J Pharmacol 2021; 913:174634. [PMID: 34785210 DOI: 10.1016/j.ejphar.2021.174634] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2021] [Revised: 10/29/2021] [Accepted: 11/11/2021] [Indexed: 10/19/2022]
Abstract
Previously, we established adiponectin receptors (AdipoRs) as osteoanabolic target. To discover small molecule agonists of AdipoRs, we studied apigenin and apigenin-6C-glucopyranose (isovitexin) that induced osteoblast differentiation. In-silico, in vitro and omics-based studies were performed. Molecular docking using the crystal structures of AdipoRs showed different interaction profiles of isovitexin and apigenin. In osteoblasts, isovitexin but not apigenin rapidly phosphorylated AMP-activated protein kinase (pAMPK) which is downstream of AdipoRs and a master regulator of cellular energy metabolism, and upregulated expression of AdipoRs. Blocking AMPK abolished the osteogenic effect of isovitexin and its effect on AdipoR expression. Isovitexin upregulated the expression of peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α), the mitochondrial biogenesis factor in osteoblasts, and the effect was blocked by AMPK inhibition. Upregulation of PGC-1α by isovitexin was accompanied by increased mitochondrial membrane proteins and mitochondrial DNA (mtDNA). Isovitexin via AdipoRs and PGC-1α induced oxidative phosphorylation (OxPhos) and ATP synthesis that resulted in osteoblast differentiation. Isovitexin had no agonistic/antagonistic activity and stimulatory/inhibitory effect in screening platforms for G protein-coupled receptors and kinases, respectively. In vivo, isovitexin upregulated AdipoRs and osteogenic genes, and increased mtDNA in rat calvarium. We conclude that isovitexin selectively via AdipoRs induced osteoblast differentiation that was fuelled by mitochondrial respiration.
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Affiliation(s)
- Subhashis Pal
- Division of Endocrinology, CSIR-Central Drug Research Institute, Council of Scientific and Industrial Research, Lucknow, 226031, India
| | - Maninder Singh
- Division of Molecular and Structural Biology, CSIR-Central Drug Research Institute, Council of Scientific and Industrial Research, Lucknow, 226031, India
| | - Konica Porwal
- Division of Endocrinology, CSIR-Central Drug Research Institute, Council of Scientific and Industrial Research, Lucknow, 226031, India
| | - Sangam Rajak
- Department of Endocrinology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, 226014, India
| | - Nabanita Das
- Division of Biochemistry and Structural Biology, CSIR-Central Drug Research Institute, Council of Scientific and Industrial Research, Lucknow, 226031, India
| | - Swati Rajput
- Division of Endocrinology, CSIR-Central Drug Research Institute, Council of Scientific and Industrial Research, Lucknow, 226031, India
| | - Arun K Trivedi
- Division of Biochemistry and Structural Biology, CSIR-Central Drug Research Institute, Council of Scientific and Industrial Research, Lucknow, 226031, India
| | - Rakesh Maurya
- Division of Medicinal & Process Chemistry, CSIR-Central Drug Research Institute, Council of Scientific and Industrial Research, Lucknow, 226031, India
| | - Rohit A Sinha
- Department of Endocrinology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, 226014, India
| | - Mohammad I Siddiqi
- Division of Molecular and Structural Biology, CSIR-Central Drug Research Institute, Council of Scientific and Industrial Research, Lucknow, 226031, India
| | - Sabyasachi Sanyal
- Division of Biochemistry and Structural Biology, CSIR-Central Drug Research Institute, Council of Scientific and Industrial Research, Lucknow, 226031, India
| | - Naibedya Chattopadhyay
- Division of Endocrinology, CSIR-Central Drug Research Institute, Council of Scientific and Industrial Research, Lucknow, 226031, India.
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Rajak S, Yen PM, Sinha RA. MTORC1-dependent crinophagy regulates glucagon content in pancreatic α-cells. Autophagy 2021; 17:3269-3270. [PMID: 34382918 DOI: 10.1080/15548627.2021.1961074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
Hormone synthesis and secretion is a highly regulated process governed by metabolic cues. Although peptide hormone action is largely governed by the rate of its synthesis and secretion by endocrine cells, and the levels of its receptors on the target cells, intracellular degradation of the hormone-containing secretory vesicles by lysosomes (crinophagy) adds an additional layer of regulation. In our recent study, we uncovered the regulatory mechanism governing the crinophagic turnover of GCG (glucagon), a glycoprotein hormone secreted by pancreatic α-cells. Our results showed that inhibition of MTORC1 induces crinophagy-mediated degradation of glucagon and decreases its secretion in response to hypoglycemia. Furthermore, we demonstrated that crinophagy-regulated glucagon turnover does not involve macroautophagy. These results suggest that modulation of crinophagy may serve as a novel therapeutic strategy to regulate hormone secretion in endocrine and metabolic pathologies.
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Affiliation(s)
- Sangam Rajak
- Department of Endocrinology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India
| | - Paul M Yen
- Program of Cardiovascular and Metabolic Disorders, Duke-NUS Medical School, Singapore, Singapore
| | - Rohit A Sinha
- Department of Endocrinology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India
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Rajak S, Xie S, Tewari A, Raza S, Wu Y, Bay BH, Yen PM, Sinha RA. MTORC1 inhibition drives crinophagic degradation of glucagon. Mol Metab 2021; 53:101286. [PMID: 34224916 PMCID: PMC8327649 DOI: 10.1016/j.molmet.2021.101286] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2021] [Revised: 06/29/2021] [Accepted: 06/29/2021] [Indexed: 11/28/2022] Open
Abstract
Objective Crinophagy is a secretory granule-specific autophagic process that regulates hormone content and secretion in endocrine cells. However, despite being one of the earliest described autophagic processes, its mechanism of action and regulation in mammalian cells remains unclear. Methods and results Here, we examined mammalian crinophagy and its modulation that regulate hormone secretion in a glucagon-producing mouse pancreatic α-cell line, alpha TC1 clone 9 (αTC9), and in vivo. Western blot, electron microscopy, and immunofluorescence analyses were performed to study crinophagy and glucagon secretion in αTC9 cells and C57BL/6 mice, in response to the mammalian target of rapamycin complex 1 (MTORC1) inhibitor rapamycin. Amino acid depletion and pharmacological inhibition of MTORC1 increased the shuttling of glucagon-containing secretory granules into lysosomes for crinophagic degradation to reduce glucagon secretion through a macroautophagy-independent mechanism. Furthermore, MTORC1 inhibition reduced both intracellular and secreted glucagon in rapamycin-treated mice, in response to hypoglycaemia. Conclusion In summary, we have identified a novel crinophagic mechanism of intracellular glucagon turnover in pancreatic α-cells regulated by MTORC1 signalling. Crinophagy regulates α-cell glucagon levels. MTORC1 inhibition induces glucagon crinophagy. Glucagon crinophagy is macroautophagy-independent.
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Affiliation(s)
- Sangam Rajak
- Department of Endocrinology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, 226014, India
| | - Sherwin Xie
- Program of Cardiovascular and Metabolic Disorders, Duke-NUS Medical School, 8 College Road, 169587, Singapore
| | - Archana Tewari
- Department of Endocrinology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, 226014, India
| | - Sana Raza
- Department of Endocrinology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, 226014, India
| | - Yajun Wu
- Department of Anatomy, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Boon-Huat Bay
- Department of Anatomy, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Paul M Yen
- Program of Cardiovascular and Metabolic Disorders, Duke-NUS Medical School, 8 College Road, 169587, Singapore
| | - Rohit A Sinha
- Department of Endocrinology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, 226014, India.
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Abstract
The incidence of non-alcoholic fatty liver disease (NAFLD) is rising rapidly across the globe. NAFLD pathogenesis is largely driven by an imbalance in hepatic energy metabolism and at present, there is no approved drug for its treatment. The liver plays a crucial role in micronutrient metabolism and deregulation of this micronutrient metabolism may contribute to the pathogenesis of NAFLD. Vitamins regulate several enzymatic processes in the liver, and derangement in vitamin metabolism is believed to play a critical role in NAFLD progression. The anti-oxidant activities of vitamin C and E have been attributed to mitigate hepatocyte injury, and alterations in the serum levels of vitamin D, vitamin B12 and folate have shown a strong correlation with NAFLD severity. This review aims to highlight the role of these vitamins, which represent promising therapeutic targets for the management of NAFLD.
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Affiliation(s)
- Sana Raza
- Corresponding author: Dr. Rohit A. Sinha (), Dr. Sana Raza ()
| | | | | | - Rohit A. Sinha
- Corresponding author: Dr. Rohit A. Sinha (), Dr. Sana Raza ()
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Zhou J, Singh BK, Ho JP, Lim A, Bruinstroop E, Ohba K, Sinha RA, Yen PM. MED1 mediator subunit is a key regulator of hepatic autophagy and lipid metabolism. Autophagy 2021; 17:4043-4061. [PMID: 33734012 DOI: 10.1080/15548627.2021.1899691] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Hepatic macroautophagy/autophagy and fatty acid metabolism are transcriptionally regulated by nuclear receptors (NRs); however, it is not known whether their transcriptional co-activators are involved in autophagy. We thus examined MED1 (mediator complex subunit 1), a key component of the Mediator Complex that directly interacts with NRs, on these processes. We found that MED1 knockdown (KD) in cultured hepatic cells decreased autophagy and mitochondrial activity that was accompanied by decreased transcription of genes involved in these processes. Lipophagy and fatty acid β-oxidation also were impaired. These effects also occurred after thyroid hormone stimulation, nutrient-replete or -deplete conditions, and in liver-specific Med1 KD (Med1 LKD) mice under fed and fasting conditions. Together, these findings showed that Med1 played a key role in hepatic autophagy, mitochondria function, and lipid metabolism under these conditions. Additionally, we identified downregulated hepatic genes in Med1 LKD mice, and subjected them to ChIP Enrichment Analysis. Our findings showed that the transcriptional activity of several NRs and transcription factors (TFs), including PPARA and FOXO1, likely were affected by Med1 LKD. Finally, Med1 expression and autophagy also were decreased in two mouse models of nonalcoholic fatty liver disease (NAFLD) suggesting that decreased Med1 may contribute to hepatosteatosis. In summary, MED1 plays an essential role in regulating hepatic autophagy and lipid oxidation during different hormonal and nutrient conditions. Thus, MED1 may serve as an integrator of multiple transcriptional pathways involved in these metabolic processes.Abbreviations: BAF: bafilomycin A1; db/db mice; Leprdb/db mice; ECAR: extracellular acidification rate; KD: knockdown; MED1: mediator complex subunit 1; NAFLD: nonalcoholic fatty liver disease; OCR: oxygen consumption rate; PPARA/PPARα: peroxisomal proliferator activated receptor alpha; TF: transcription factor; TFEB: transcription factor EB; tf-LC3: tandem fluorescence RFP-GFP-LC3; TG: triglyceride; TH: Thyroid hormone; TR: thyroid hormone receptors; V-ATPase: vacuolar-type H+-ATPase; WDF: Western diet with 15% fructose in drinking water.
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Affiliation(s)
- Jin Zhou
- Program of Cardiovascular & Metabolic Disorders, Duke-NUS Medical School Singapore, Singapore
| | - Brijesh K Singh
- Program of Cardiovascular & Metabolic Disorders, Duke-NUS Medical School Singapore, Singapore
| | - Jia Pei Ho
- Program of Cardiovascular & Metabolic Disorders, Duke-NUS Medical School Singapore, Singapore
| | - Andrea Lim
- Program of Cardiovascular & Metabolic Disorders, Duke-NUS Medical School Singapore, Singapore
| | - Eveline Bruinstroop
- Department of Endocrinology and Metabolism, Amsterdam UMC, Amsterdam, The Netherlands
| | - Kenji Ohba
- Program of Cardiovascular & Metabolic Disorders, Duke-NUS Medical School Singapore, Singapore
| | - Rohit A Sinha
- Program of Cardiovascular & Metabolic Disorders, Duke-NUS Medical School Singapore, Singapore.,Department of Endocrinology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow India
| | - Paul M Yen
- Program of Cardiovascular & Metabolic Disorders, Duke-NUS Medical School Singapore, Singapore.,Duke Molecular Physiology Institute and Department of Medicine, Duke University Medical Center, Durham, NC USA
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13
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Abstract
Non-alcoholic fatty liver disease (NAFLD) is the most prevalent liver disorder worldwide. It comprises a spectrum of conditions that range from steatosis to non-alcoholic steatohepatitis, with progression to cirrhosis and hepatocellular carcinoma. Currently, there is no FDA-approved pharmacological treatment for NAFLD. The pathogenesis of NAFLD involves genetic and environmental/host factors, including those that cause changes in intestinal microbiota and their metabolites. In this review, we discuss recent findings on the relationship(s) of microbiota signature with severity of NAFLD and the role(s) microbial metabolites in NAFLD progression. We discuss how metabolites may affect NAFLD progression and their potential to serve as biomarkers for NAFLD diagnosis or therapeutic targets for disease management.
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Affiliation(s)
- Jin Zhou
- Program of Cardiovascular and Metabolic Disorders, Duke-NUS Medical School, Singapore 169857, Singapore
| | - Madhulika Tripathi
- Program of Cardiovascular and Metabolic Disorders, Duke-NUS Medical School, Singapore 169857, Singapore
| | - Rohit A Sinha
- Department of Endocrinology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow 226014, India
| | - Brijesh Kumar Singh
- Program of Cardiovascular and Metabolic Disorders, Duke-NUS Medical School, Singapore 169857, Singapore
| | - Paul M Yen
- Program of Cardiovascular and Metabolic Disorders, Duke-NUS Medical School, Singapore 169857, Singapore.,Duke Molecular Physiology Institute, Durham, NC 27701, USA.,Duke University School of Medicine, Durham, NC 27710, USA
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14
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Abstract
Non-alcoholic fatty liver disease (NAFLD) is the most prevalent chronic liver disorder worldwide. It comprises simple steatosis and non-alcoholic steatohepatitis (NASH), which can further progress to cirrhosis and hepatocellular carcinoma. The pathogenesis of NAFLD involves genetic, environmental, and endocrine factors, and several molecular mechanisms have been identified. In this review, we discuss the recent findings on the role of autophagy, in particular lipophagy and mitophagy, in hepatic lipid oxidation. We discuss the pre-clinical and clinical evidence suggesting that impairment of autophagy exacerbates NAFLD progression and restoration of autophagy exerts beneficial effects on NAFLD. We discuss how thyroid hormone (TH) simultaneously regulates lipophagy, mitophagy, and mitochondrial biogenesis to increase β-oxidation of fatty acids and reduce steatosis in the liver. Lastly, we discuss the recent clinical progress in using TH or thyromimetics in treating NAFLD/NASH.
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Affiliation(s)
- Jin Zhou
- Program of Cardiovascular and Metabolic Disorders, Duke-NUS Medical School, Singapore 169857, Singapore
| | - Rohit A. Sinha
- Department of Endocrinology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow 226014, India
| | - Paul M. Yen
- Program of Cardiovascular and Metabolic Disorders, Duke-NUS Medical School, Singapore 169857, Singapore
- Department of Medicine Duke Molecular Physiology Institute, Duke University Medical Center, Durham, NC 27710, USA
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15
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Rajak S, Raza S, Tewari A, Yadav S, Ghosh S, Yen PM, Sinha RA. Autophagic protein ULK1 regulates FOXM1 signalling in human hepatoma cells. Biochem Biophys Res Commun 2020; 532:570-575. [PMID: 32900486 DOI: 10.1016/j.bbrc.2020.08.068] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Accepted: 08/19/2020] [Indexed: 10/23/2022]
Abstract
Hepatocellular cancer (HCC) is one of the leading causes of mortality worldwide. Unfortunately, a limited choice of anti-cancer drugs is available for treatment, owing to their minimal efficacy and development of acquired resistance. Autophagy, a cellular survival pathway, often exhibits a pleiotropic role in HCC progression. Studies show increased autophagy in established HCC, promoting the survival of HCC cells in the tumour microenvironment. Therefore, novel anti-autophagy drugs hold promise for preventing HCC progression. Here, using a non-biased transcriptomics analysis in HepG2 cells we demonstrate the existence of an autophagy-FOXM1 nexus regulating growth in HepG2 cells. Additionally, we show that suppression of autophagy by an Unc-51 Like Autophagy Activating Kinase 1(ULK1) inhibitor not only attenuates the expression of FOXM1 and its transcriptional targets, but also has a synergistic effect on the inhibition of HepG2 growth when combined with FOXM1 inhibitors. Thus, the autophagic protein, ULK1, is a promising candidate for preventing HCC progression. Collectively, our results provide new insight into the role of autophagy in HCC growth and are a proof-of concept for combinatorial therapy using ULK1 and FOXM1 inhibitors.
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Affiliation(s)
- Sangam Rajak
- Department of Endocrinology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, 226014, India
| | - Sana Raza
- Department of Endocrinology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, 226014, India
| | - Archana Tewari
- Department of Endocrinology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, 226014, India
| | - Shivmurat Yadav
- Department of Endocrinology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, 226014, India
| | - Sujoy Ghosh
- Centre for Computational Biology, Duke-NUS Medical School, 8 College Road, 169857, Singapore
| | - Paul M Yen
- Program of Cardiovascular and Metabolic Disorders, Duke-NUS Medical School, 8 College Road, 169587, Singapore
| | - Rohit A Sinha
- Department of Endocrinology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, 226014, India.
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16
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Rajak S, Iannucci LF, Zhou J, Anjum B, George N, Singh BK, Ghosh S, Yen PM, Sinha RA. Loss of ULK1 Attenuates Cholesterogenic Gene Expression in Mammalian Hepatic Cells. Front Cell Dev Biol 2020; 8:523550. [PMID: 33083385 PMCID: PMC7554540 DOI: 10.3389/fcell.2020.523550] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The hepatic mevalonate (MVA) pathway, responsible for cholesterol biosynthesis, is a therapeutically important metabolic pathway in clinical medicine. Using an unbiased transcriptomics approach, we uncover a novel role of Unc-51 like autophagy activating kinase 1 (ULK1) in regulating the expression of the hepatic de novo cholesterol biosynthesis/MVA pathway genes. Genetic silencing of ULK1 in non-starved mouse (AML-12) and human (HepG2) hepatic cells as well as in mouse liver followed by transcriptome and pathway analysis revealed that the loss of ULK1 expression led to significant down-regulation of genes involved in the MVA/cholesterol biosynthesis pathway. At a mechanistic level, loss of ULK1 led to decreased expression of SREBF2/SREBP2 (sterol regulatory element binding factor 2) via its effects on AKT-FOXO3a signaling and repression of SREBF2 target genes in the MVA pathway. Our findings, therefore, discover ULK1 as a novel regulator of cholesterol biosynthesis and a possible druggable target for controlling cholesterol-associated pathologies.
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Affiliation(s)
- Sangam Rajak
- Department of Endocrinology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India
| | - Liliana F Iannucci
- Program of Cardiovascular and Metabolic Disorders, Duke-NUS Medical School, Singapore, Singapore.,Department of Biology, University of Padua, Padua, Italy
| | - Jin Zhou
- Program of Cardiovascular and Metabolic Disorders, Duke-NUS Medical School, Singapore, Singapore
| | - B Anjum
- Department of Endocrinology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India
| | - Nelson George
- Department of Endocrinology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India
| | - Brijesh K Singh
- Program of Cardiovascular and Metabolic Disorders, Duke-NUS Medical School, Singapore, Singapore
| | - Sujoy Ghosh
- Program of Cardiovascular and Metabolic Disorders, Duke-NUS Medical School, Singapore, Singapore
| | - Paul M Yen
- Program of Cardiovascular and Metabolic Disorders, Duke-NUS Medical School, Singapore, Singapore
| | - Rohit A Sinha
- Department of Endocrinology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India
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17
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Affiliation(s)
- Rohit A Sinha
- Departmet of Endocrinology, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, India
| | - Eveline Bruinstroop
- Departmet of Endocrinology, Amsterdam UMC-Locatie VUMC, Amsterdam, the Netherlands
| | - Brijesh K Singh
- Cardiovascular and Metabolic Disorders Program, Duke-NUS Medical School, Singapore, Singapore
| | - Paul M Yen
- Cardiovascular and Metabolic Disorders Program, Duke-NUS Medical School, Singapore, Singapore
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18
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Kumar A, Kalita J, Sinha RA, Singh G, B A, Shukla M, Tiwari S, Dhole TN, Misra UK. Impaired Autophagy Flux is Associated with Proinflammatory Microglia Activation Following Japanese Encephalitis Virus Infection. Neurochem Res 2020; 45:2184-2195. [PMID: 32613347 DOI: 10.1007/s11064-020-03080-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Revised: 05/05/2020] [Accepted: 06/25/2020] [Indexed: 12/18/2022]
Abstract
Role of autophagy in Japanese encephalitis viral (JEV) infection is not well known. In the present study, we reported the role of autophagy flux in microglia activation, neurobehavioral function and neuronal death using a mouse model of JEV. Markers for autophagy (LC3-II/I, SQSTM1/P62, phos-Akt, phos-AMPK), and neuronal death (cleaved caspase 12, H2Ax, polyubiquitin) were investigated by western blot at 1, 3 and 7 days post inoculation. Cathepsin D was measured in cerebral cotex of JEV infected mice spectrophotometrically. Microglia activation and pro-inflammatory cytokines (IL1β, TNF-α, IFNγ, IL6) were measured by immunohistochemistry, western blot and qPCR analysis. In order to determine the neuroinflammatory changes and autophagy mediated neuronal cell death, BV2-microglia and N2a-neuronal cells were used. Autophagy activation marker LC3-II/I and its substrate SQSTM1/P62 were significantly increased while cathepsin D activity was decreased on day 7 post inoculation in cerebral cortex. Microglia in cortex were activated and showed higher expression of proinflammatory mRNA of IL1β, TNF-α, IFNγ and IL6, with increased DNA damage (H2AX) and neuronal cell death pathways in hippocampus and neurobehavioral dysfunction. Similar observations on JEV infection mediated autophagy flux inhibition and neuronal cell death was found in N2a neuronal cell. Collectively, our study provides evidence on the role of autophagy regulation, microglial activation and neurodegeneration following JEV infection.
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Affiliation(s)
- Alok Kumar
- Department of Molecular Medicine and Biotechnology, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Raebareily Road, Lucknow, 226014, Uttar Pradesh, India.
| | - J Kalita
- Department of Neurology, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Raebareily Road, Lucknow, 226014, Uttar Pradesh, India
| | - Rohit A Sinha
- Department of Endocrinology, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Raebareily Road, Lucknow, 226014, Uttar Pradesh, India
| | - Gajendra Singh
- Department of Molecular Medicine and Biotechnology, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Raebareily Road, Lucknow, 226014, Uttar Pradesh, India
| | - Anjum B
- Department of Endocrinology, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Raebareily Road, Lucknow, 226014, Uttar Pradesh, India
| | - Mukti Shukla
- Department of Microbiology, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Raebareily Road, Lucknow, 226014, Uttar Pradesh, India
| | - Swasti Tiwari
- Department of Molecular Medicine and Biotechnology, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Raebareily Road, Lucknow, 226014, Uttar Pradesh, India
| | - T N Dhole
- Department of Microbiology, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Raebareily Road, Lucknow, 226014, Uttar Pradesh, India
| | - U K Misra
- Department of Neurology, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Raebareily Road, Lucknow, 226014, Uttar Pradesh, India.
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19
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Pal S, Porwal K, Rajak S, Sinha RA, Chattopadhyay N. Selective dietary polyphenols induce differentiation of human osteoblasts by adiponectin receptor 1-mediated reprogramming of mitochondrial energy metabolism. Biomed Pharmacother 2020; 127:110207. [PMID: 32422565 DOI: 10.1016/j.biopha.2020.110207] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Revised: 04/18/2020] [Accepted: 04/28/2020] [Indexed: 12/30/2022] Open
Abstract
Anabolic therapies for osteoporosis including dietary polyphenols promote osteoblast function by influencing its energy metabolism. Among the dietary polyphenols, the beneficial skeletal effects of genistein (an isoflavone), kaempferol (a flavone), resveratrol (RES, a stilbenoid) and epigallocatechin gallate (EGCG, a catechin) have been reported in preclinical studies. We studied the action mechanism of these nutraceuticals on osteoblast bioenergetics. All stimulated differentiation of human fetal osteoblasts (hFOB). However, only EGCG and RES stimulated mitochondrial parameters including basal and maximum respiration, spare respiratory capacity and ATP production (a measure of the activity of electron transport chain/ETC). Increases in these parameters were due to increased mitochondrial biogenesis and consequent upregulation of several mitochondrial proteins including those involved in ETC. Rotenone blocked the osteogenic effect of EGCG and RES suggesting the mediatory action of mitochondria. Both compounds rapidly activated AMPK, and dorsomorphin (an AMPK inhibitor) abolished ATP production stimulated by these compounds. Moreover, EGCG and RES upregulated the mitochondrial biogenesis factor, PGC-1α which is downstream of AMPK activation, and silencing PGC-1α blocked their stimulatory effects on ATP production and hFOB differentiation. Adiponectin receptor 1 (AdipoR1) is an upstream regulator of PGC-1α, and both compounds increased the expression of AdipoR1 but not AdipoR2. Silencing AdipoR1 blocked the upregulation of EGCG/RES-induced PGC-1α and hFOB differentiation. In rat calvarium, both compounds increased AdipoR1, PGC-1α, and RunX2 (the osteoblast transcription factor) with a concomitant increase in mitochondrial copy number and ATP levels. We conclude that EGCG and RES display osteogenic effects by reprogramming osteoblastic bioenergetics by acting as the AdipoR1 agonists.
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Affiliation(s)
- Subhashis Pal
- Division of Endocrinology, CSIR-Central Drug Research Institute, Council of Scientific and Industrial Research, Lucknow, 226031, India
| | - Konica Porwal
- Division of Endocrinology, CSIR-Central Drug Research Institute, Council of Scientific and Industrial Research, Lucknow, 226031, India
| | - Sangam Rajak
- Department of Endocrinology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, 226014, India
| | - Rohit A Sinha
- Department of Endocrinology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, 226014, India
| | - Naibedya Chattopadhyay
- Division of Endocrinology, CSIR-Central Drug Research Institute, Council of Scientific and Industrial Research, Lucknow, 226031, India.
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20
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Sinha RA, Rajak S, Singh BK, Yen PM. Hepatic Lipid Catabolism via PPARα-Lysosomal Crosstalk. Int J Mol Sci 2020; 21:ijms21072391. [PMID: 32244266 PMCID: PMC7170715 DOI: 10.3390/ijms21072391] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 03/01/2020] [Accepted: 03/02/2020] [Indexed: 12/13/2022] Open
Abstract
Peroxisome proliferator-activated receptors (PPARs) are ligand-activated transcription factors which belong to the nuclear hormone receptor superfamily. They regulate key aspects of energy metabolism within cells. Recently, PPARα has been implicated in the regulation of autophagy-lysosomal function, which plays a key role in cellular energy metabolism. PPARα transcriptionally upregulates several genes involved in the autophagy-lysosomal degradative pathway that participates in lipolysis of triglycerides within the hepatocytes. Interestingly, a reciprocal regulation of PPARα nuclear action by autophagy-lysosomal activity also exists with implications in lipid metabolism. This review succinctly discusses the unique relationship between PPARα nuclear action and lysosomal activity and explores its impact on hepatic lipid homeostasis under pathological conditions such as non-alcoholic fatty liver disease (NAFLD).
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Affiliation(s)
- Rohit A. Sinha
- Department of Endocrinology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow 226014, India;
- Correspondence: or
| | - Sangam Rajak
- Department of Endocrinology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow 226014, India;
| | - Brijesh K. Singh
- Program of Cardiovascular and Metabolic Disorders, Duke-NUS Medical School, 8 College Road, Singapore 169587, Singapore (P.M.Y.)
| | - Paul M. Yen
- Program of Cardiovascular and Metabolic Disorders, Duke-NUS Medical School, 8 College Road, Singapore 169587, Singapore (P.M.Y.)
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21
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Upadhyay A, Sinha RA, Kumar A, Godbole MM. Time-restricted feeding ameliorates maternal high-fat diet-induced fetal lung injury. Exp Mol Pathol 2020; 114:104413. [PMID: 32151561 DOI: 10.1016/j.yexmp.2020.104413] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Revised: 01/24/2020] [Accepted: 03/06/2020] [Indexed: 11/18/2022]
Abstract
Maternal inflammation ensuing from high-fat diet (HFD) intake during pregnancy is related to spontaneous preterm birth and respiratory impairment among premature infants. Recently, a circadian aligned dietary intervention referred to as Time-restricted feeding (TRF) has been reported to have beneficial metabolic effects. This study aimed to assess the effects of maternal TRF on fetal lung injury caused by maternal HFD intake. Female Wistar rats were kept on following three dietary regimens; Ad libitum normal chow diet (NCD-AL), Ad libitum HFD (HFD-AL) and Time-restricted fed HFD (HFD-TRF) from 5 months before mating and continued through pregnancy. Fetal lung samples were collected on the embryonic day 18.5, and apoptotic and inflammatory markers were assessed using TUNEL assay, western blotting, and qRT-PCR. Our results showed that TRF considerably prevented maternal HFD-induced apoptosis in fetal lung tissue that corroborated with a reduction in caspase activation and increased levels of anti-apoptotic BCL2 family proteins together with a lower level of ER-stress and autophagy markers including ATF6, CHOP and LC3-II. Besides, fetal lungs from HFD-TRF dams exhibited reduced expression of inflammatory genes that correlated with reduction and apoptotic injury throughout fetal development. Our results thus put forth TRF as a unique non-pharmacological approach to boost perinatal health beneath metabolic stress.
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Affiliation(s)
- Aditya Upadhyay
- Department of Molecular Medicine and Biotechnology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow 226014, India
| | - Rohit A Sinha
- Department of Endocrinology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow 226014, India.
| | - Alok Kumar
- Department of Molecular Medicine and Biotechnology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow 226014, India
| | - Madan M Godbole
- Department of Molecular Medicine and Biotechnology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow 226014, India.
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22
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Zhou J, Ng B, Ko NSJ, Fiedler LR, Khin E, Lim A, Sahib NE, Wu Y, Chothani SP, Schafer S, Bay BH, Sinha RA, Cook SA, Yen PM. Titin truncations lead to impaired cardiomyocyte autophagy and mitochondrial function in vivo. Hum Mol Genet 2020; 28:1971-1981. [PMID: 30715350 DOI: 10.1093/hmg/ddz033] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2018] [Revised: 01/21/2019] [Accepted: 01/31/2019] [Indexed: 01/21/2023] Open
Abstract
Titin-truncating variants (TTNtv) are the most common genetic cause of dilated cardiomyopathy. TTNtv occur in ~1% of the general population and causes subclinical cardiac remodeling in asymptomatic carriers. In rat models with either proximal or distal TTNtv, we previously showed altered cardiac metabolism at baseline and impaired cardiac function in response to stress. However, the molecular mechanism(s) underlying these effects remains unknown. In the current study, we used rat models of TTNtv to investigate the effect of TTNtv on autophagy and mitochondrial function, which are essential for maintaining cellular metabolic homeostasis and cardiac function. In both the proximal and distal TTNtv rat models, we found increased levels of LC3B-II and p62 proteins, indicative of diminished autophagic degradation. The accumulation of autophagosomes and p62 protein in cardiomyocytes was also demonstrated by electron microscopy and immunochemistry, respectively. Impaired autophagy in the TTNtv heart was associated with increased phosphorylation of mTOR and decreased protein levels of the lysosomal protease, cathepsin B. In addition, TTNtv hearts showed mitochondrial dysfunction, as evidenced by decreased oxygen consumption rate in cardiomyocytes, increased levels of reactive oxygen species and mitochondrial protein ubiquitination. We also observed increased acetylation of mitochondrial proteins associated with decreased NAD+/NADH ratio in the TTNtv hearts. mTORC1 inhibitor, rapamycin, was able to rescue the impaired autophagy in TTNtv hearts. In summary, TTNtv leads to impaired autophagy and mitochondrial function in the heart. These changes not only provide molecular mechanisms that underlie TTNtv-associated ventricular remodeling but also offer potential targets for its intervention.
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Affiliation(s)
- Jin Zhou
- Cardiovascular and Metabolic Disorders Program, Duke-National University of Singapore, Singapore, Singapore
| | - Benjamin Ng
- Cardiovascular and Metabolic Disorders Program, Duke-National University of Singapore, Singapore, Singapore.,National Heart Centre Singapore, Singapore, Singapore
| | - Nicole S J Ko
- Cardiovascular and Metabolic Disorders Program, Duke-National University of Singapore, Singapore, Singapore
| | - Lorna R Fiedler
- Cardiovascular and Metabolic Disorders Program, Duke-National University of Singapore, Singapore, Singapore
| | - Ester Khin
- Cardiovascular and Metabolic Disorders Program, Duke-National University of Singapore, Singapore, Singapore
| | - Andrea Lim
- Cardiovascular and Metabolic Disorders Program, Duke-National University of Singapore, Singapore, Singapore
| | - Norliza E Sahib
- Cardiovascular and Metabolic Disorders Program, Duke-National University of Singapore, Singapore, Singapore
| | - Yajun Wu
- Department of Anatomy, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Sonia P Chothani
- Cardiovascular and Metabolic Disorders Program, Duke-National University of Singapore, Singapore, Singapore
| | - Sebastian Schafer
- Cardiovascular and Metabolic Disorders Program, Duke-National University of Singapore, Singapore, Singapore.,National Heart Centre Singapore, Singapore, Singapore
| | - Boon-Huat Bay
- Department of Anatomy, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Rohit A Sinha
- Cardiovascular and Metabolic Disorders Program, Duke-National University of Singapore, Singapore, Singapore.,Department of Endocrinology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India
| | - Stuart A Cook
- Cardiovascular and Metabolic Disorders Program, Duke-National University of Singapore, Singapore, Singapore.,National Heart Centre Singapore, Singapore, Singapore.,National Heart and Lung Institute, Imperial College London, London, UK
| | - Paul M Yen
- Cardiovascular and Metabolic Disorders Program, Duke-National University of Singapore, Singapore, Singapore.,Duke Molecular Physiology Institute, Departments of Medicine and Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC, USA
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23
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Pandey R, Shukla P, Anjum B, Gupta HP, Pal S, Arjaria N, Gupta K, Chattopadhyay N, Sinha RA, Bandyopadhyay S. Estrogen deficiency induces memory loss via altered hippocampal HB-EGF and autophagy. J Endocrinol 2020; 244:53-70. [PMID: 31648182 DOI: 10.1530/joe-19-0197] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Accepted: 09/19/2019] [Indexed: 11/08/2022]
Abstract
Estrogen deficiency reduces estrogen receptor-alpha (ERα) and promotes apoptosis in the hippocampus, inducing learning-memory deficits; however, underlying mechanisms remain less understood. Here, we explored the molecular mechanism in an ovariectomized (OVX) rat model, hypothesizing participation of autophagy and growth factor signaling that relate with apoptosis. We observed enhanced hippocampal autophagy in OVX rats, characterized by increased levels of autophagy proteins, presence of autophagosomes and inhibition of AKT-mTOR signaling. Investigating upstream effectors of reduced AKT-mTOR signaling revealed a decrease in hippocampal heparin-binding epidermal growth factor (HB-EGF) and p-EGFR. Moreover, 17β-estradiol and HB-EGF treatments restored hippocampal EGFR activation and alleviated downstream autophagy process and neuronal loss in OVX rats. In vitro studies using estrogen receptor (ERα)-silenced primary hippocampal neurons further corroborated the in vivo observations. Additionally, in vivo and in vitro studies suggested the participation of an attenuated hippocampal neuronal HB-EGF and enhanced autophagy in apoptosis of hippocampal neurons in estrogen- and ERα-deficient conditions. Subsequently, we found evidence of mitochondrial loss and mitophagy in hippocampal neurons of OVX rats and ERα-silenced cells. The ERα-silenced cells also showed a reduction in ATP production and an HB-EGF-mediated restoration. Finally in concordance with molecular studies, inhibition of autophagy and treatment with HB-EGF in OVX rats restored cognitive performances, assessed through Y-Maze and passive avoidance tasks. Overall, our study, for the first time, links neuronal HB-EGF/EGFR signaling and autophagy with ERα and memory performance, disrupted in estrogen-deficient condition.
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Affiliation(s)
- Rukmani Pandey
- Developmental Toxicology Laboratory, Systems Toxicology & Health Risk Assessment Group, CSIR-Indian Institute of Toxicology Research (CSIR-IITR), Vishvigyan Bhavan, Lucknow, Uttar Pradesh, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, Uttar Pradesh, India
| | - Pallavi Shukla
- Developmental Toxicology Laboratory, Systems Toxicology & Health Risk Assessment Group, CSIR-Indian Institute of Toxicology Research (CSIR-IITR), Vishvigyan Bhavan, Lucknow, Uttar Pradesh, India
| | - Baby Anjum
- Department of Endocrinology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, Uttar Pradesh, India
| | - Himanshu Pawankumar Gupta
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, Uttar Pradesh, India
- Embryotoxicology Laboratory, Environmental Toxicology Group, CSIR-Indian Institute of Toxicology Research (CSIR-IITR), Vishvigyan Bhavan, Lucknow, Uttar Pradesh, India
| | - Subhashis Pal
- Division of Endocrinology, CSIR-Central Drug Research Institute (CSIR-CDRI), Lucknow, Uttar Pradesh, India
| | - Nidhi Arjaria
- Electron Microscopy Laboratory, CSIR-Indian Institute of Toxicology Research (CSIR-IITR), Vishvigyan Bhawan, Lucknow, Uttar Pradesh, India
| | - Keerti Gupta
- Developmental Toxicology Laboratory, Systems Toxicology & Health Risk Assessment Group, CSIR-Indian Institute of Toxicology Research (CSIR-IITR), Vishvigyan Bhavan, Lucknow, Uttar Pradesh, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, Uttar Pradesh, India
| | - Naibedya Chattopadhyay
- Division of Endocrinology, CSIR-Central Drug Research Institute (CSIR-CDRI), Lucknow, Uttar Pradesh, India
| | - Rohit A Sinha
- Department of Endocrinology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, Uttar Pradesh, India
| | - Sanghamitra Bandyopadhyay
- Developmental Toxicology Laboratory, Systems Toxicology & Health Risk Assessment Group, CSIR-Indian Institute of Toxicology Research (CSIR-IITR), Vishvigyan Bhavan, Lucknow, Uttar Pradesh, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, Uttar Pradesh, India
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24
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Abstract
Non-alcoholic fatty liver disease (NAFLD) and its advanced complication, non-alcoholic steatohepatitis (NASH), have become leading causes of hepatocellular carcinoma (HCC) worldwide. In this review, we discuss the role of metabolic, gut microbial, immune and endocrine mediators which promote the progression of NAFLD to HCC. In particular, this progression involves multiple hits resulting from lipotoxicity, oxidative stress, inhibition of hepatic autophagy and inflammation. Furthermore, dysbiosis in the gut associated with obesity also promotes HCC via induction of proinflammatory cytokines and Toll like receptor signalling as well as altered bile metabolism. Additionally, compromised T-cell function and impaired hepatic hormonal action promote the development of NASH-associated HCC. Lastly, we discuss the current challenges involved in the diagnosis and treatment of NAFLD/NASH-associated HCC.
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Affiliation(s)
- Sana Raza
- Department of Bioscience, Integral University, Lucknow 226026, India
| | - Sangam Rajak
- Department of Endocrinology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow 226014, India
| | - Baby Anjum
- Department of Endocrinology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow 226014, India
| | - Rohit A Sinha
- Department of Endocrinology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow 226014, India
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25
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Widjaja AA, Singh BK, Adami E, Viswanathan S, Dong J, D'Agostino GA, Ng B, Lim WW, Tan J, Paleja BS, Tripathi M, Lim SY, Shekeran SG, Chothani SP, Rabes A, Sombetzki M, Bruinstroop E, Min LP, Sinha RA, Albani S, Yen PM, Schafer S, Cook SA. Inhibiting Interleukin 11 Signaling Reduces Hepatocyte Death and Liver Fibrosis, Inflammation, and Steatosis in Mouse Models of Nonalcoholic Steatohepatitis. Gastroenterology 2019; 157:777-792.e14. [PMID: 31078624 DOI: 10.1053/j.gastro.2019.05.002] [Citation(s) in RCA: 153] [Impact Index Per Article: 30.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2019] [Revised: 04/09/2019] [Accepted: 05/02/2019] [Indexed: 02/07/2023]
Abstract
BACKGROUND & AIMS We studied the role of interleukin 11 (IL11) signaling in the pathogenesis of nonalcoholic steatohepatitis (NASH) using hepatic stellate cells (HSCs), hepatocytes, and mouse models of NASH. METHODS We stimulated mouse and human fibroblasts, HSCs, or hepatocytes with IL11 and other cytokines and analyzed them by imaging, immunoblot, and functional assays and enzyme-linked immunosorbent assays. Mice were given injections of IL11. Mice with disruption of the interleukin 11 receptor subunit alpha1 gene (Il11ra1-/-) mice and Il11ra1+/+ mice were fed a high-fat methionine- and choline-deficient diet (HFMCD) or a Western diet with liquid fructose (WDF) to induce steatohepatitis; control mice were fed normal chow. db/db mice were fed with methionine- and choline-deficient diet for 12 weeks and C57BL/6 NTac were fed with HFMCD for 10 weeks or WDF for 16 weeks. Some mice were given intraperitoneal injections of anti-IL11 (X203), anti-IL11RA (X209), or a control antibody at different timepoints on the diets. Livers and blood were collected; blood samples were analyzed by biochemistry and liver tissues were analyzed by histology, RNA sequencing, immunoblots, immunohistochemistry, hydroxyproline, and mass cytometry time of flight assays. RESULTS HSCs incubated with cytokines produced IL11, resulting in activation (phosphorylation) of ERK and expression of markers of fibrosis. Livers of mice given injections of IL11 became damaged, with increased markers of fibrosis, hepatocyte cell death and inflammation. Following the HFMCD or WDF, livers from Il11ra1-/- mice had reduced steatosis, fibrosis, expression of markers of inflammation and steatohepatitis, compared to and Il11ra1+/+ mice on the same diets. Depending on the time of administration of anti-IL11 or anti-IL11RA antibodies to wild-type mice on the HFMCD or WDF, or to db/db mice on the methionine and choline-deficient diet, the antibodies prevented, stopped, or reversed development of fibrosis and steatosis. Blood samples from Il11ra1+/+ mice fed the WDF and given injections of anti-IL11 or anti-IL11RA, as well as from Il11ra1-/- mice fed WDF, had lower serum levels of lipids and glucose than mice not injected with antibody or with disruption of Il11ra1. CONCLUSIONS Neutralizing antibodies that block IL11 signaling reduce fibrosis, steatosis, hepatocyte death, inflammation and hyperglycemia in mice with diet-induced steatohepatitis. These antibodies also improve the cardiometabolic profile of mice and might be developed for the treatment of NASH.
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Affiliation(s)
- Anissa A Widjaja
- Cardiovascular and Metabolic Disorders Program, Duke-National University of Singapore Medical School, Singapore
| | - Brijesh K Singh
- Cardiovascular and Metabolic Disorders Program, Duke-National University of Singapore Medical School, Singapore
| | - Eleonora Adami
- Cardiovascular and Metabolic Disorders Program, Duke-National University of Singapore Medical School, Singapore
| | - Sivakumar Viswanathan
- Cardiovascular and Metabolic Disorders Program, Duke-National University of Singapore Medical School, Singapore
| | - Jinrui Dong
- Cardiovascular and Metabolic Disorders Program, Duke-National University of Singapore Medical School, Singapore
| | - Giuseppe A D'Agostino
- Cardiovascular and Metabolic Disorders Program, Duke-National University of Singapore Medical School, Singapore
| | - Benjamin Ng
- Cardiovascular and Metabolic Disorders Program, Duke-National University of Singapore Medical School, Singapore; National Heart Research Institute Singapore, National Heart Centre Singapore, Singapore
| | - Wei Wen Lim
- Cardiovascular and Metabolic Disorders Program, Duke-National University of Singapore Medical School, Singapore; National Heart Research Institute Singapore, National Heart Centre Singapore, Singapore
| | - Jessie Tan
- Cardiovascular and Metabolic Disorders Program, Duke-National University of Singapore Medical School, Singapore; National Heart Research Institute Singapore, National Heart Centre Singapore, Singapore
| | - Bhairav S Paleja
- Translational Immunology Institute, SingHealth/Duke-NUS Academic Medical Centre, Singapore
| | - Madhulika Tripathi
- Cardiovascular and Metabolic Disorders Program, Duke-National University of Singapore Medical School, Singapore
| | - Sze Yun Lim
- National Heart Research Institute Singapore, National Heart Centre Singapore, Singapore
| | - Shamini Guna Shekeran
- Cardiovascular and Metabolic Disorders Program, Duke-National University of Singapore Medical School, Singapore
| | - Sonia P Chothani
- Cardiovascular and Metabolic Disorders Program, Duke-National University of Singapore Medical School, Singapore
| | - Anne Rabes
- Department of Tropical Medicine and Infectious Diseases, University Medical Center, Rostock, Germany
| | - Martina Sombetzki
- Department of Tropical Medicine and Infectious Diseases, University Medical Center, Rostock, Germany
| | - Eveline Bruinstroop
- Cardiovascular and Metabolic Disorders Program, Duke-National University of Singapore Medical School, Singapore
| | - Lio Pei Min
- National Heart Research Institute Singapore, National Heart Centre Singapore, Singapore
| | - Rohit A Sinha
- Department of Endocrinology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India
| | - Salvatore Albani
- Translational Immunology Institute, SingHealth/Duke-NUS Academic Medical Centre, Singapore
| | - Paul M Yen
- Cardiovascular and Metabolic Disorders Program, Duke-National University of Singapore Medical School, Singapore
| | - Sebastian Schafer
- Cardiovascular and Metabolic Disorders Program, Duke-National University of Singapore Medical School, Singapore; National Heart Research Institute Singapore, National Heart Centre Singapore, Singapore
| | - Stuart A Cook
- Cardiovascular and Metabolic Disorders Program, Duke-National University of Singapore Medical School, Singapore; National Heart Research Institute Singapore, National Heart Centre Singapore, Singapore; National Heart and Lung Institute, Imperial College London, London, UK; MRC-London Institute of Medical Sciences, Hammersmith Hospital Campus, London, UK.
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26
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Abstract
Background: Thyroid hormones (THs) exert a strong influence on mammalian lipid metabolism at the systemic and hepatic levels by virtue of their roles in regulating circulating lipoprotein, triglyceride (TAG), and cholesterol levels, as well as hepatic TAG storage and metabolism. These effects are mediated by intricate sensing and feedback systems that function at the physiological, metabolic, molecular, and transcriptional levels in the liver. Dysfunction in the pathways involved in lipid metabolism disrupts hepatic lipid homeostasis and contributes to the pathogenesis of metabolic diseases, such as nonalcoholic fatty liver disease (NAFLD) and hypercholesterolemia. There has been strong interest in understanding and employing THs, TH metabolites, and TH mimetics as lipid-modifying drugs. Summary: THs regulate many processes involved in hepatic TAG and cholesterol metabolism to decrease serum cholesterol and intrahepatic lipid content. TH receptor β analogs designed to have less side effects than the natural hormone are currently being tested in phase II clinical studies for NAFLD and hypercholesterolemia. The TH metabolites, 3,5-diiodo-l-thyronine (T2) and T1AM (3-iodothyronamine), have different beneficial effects on lipid metabolism compared with triiodothyronine (T3), although their clinical application is still under investigation. Also, prodrugs and glucagon/T3 conjugates have been developed that direct TH to the liver. Conclusions: TH-based therapies show clinical promise for the treatment of NAFLD and hypercholesterolemia. Strategies for limiting side effects of TH are being developed and may enable TH metabolites and analogs to have specific effects in the liver for treatments of these conditions. These liver-specific effects and potential suppression of the hypothalamic/pituitary/thyroid axis raise the issue of monitoring liver-specific markers of TH action to assess clinical efficacy and dosing of these compounds.
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Affiliation(s)
- Rohit A. Sinha
- Department of Endocrinology, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, India
| | - Eveline Bruinstroop
- Laboratory of Hormonal Regulation, Cardiovascular and Metabolic Disorders Program, Duke-NUS Medical School, Singapore, Singapore
- Department of Endocrinology & Metabolism, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Brijesh K. Singh
- Laboratory of Hormonal Regulation, Cardiovascular and Metabolic Disorders Program, Duke-NUS Medical School, Singapore, Singapore
| | - Paul M. Yen
- Laboratory of Hormonal Regulation, Cardiovascular and Metabolic Disorders Program, Duke-NUS Medical School, Singapore, Singapore
- Division of Endocrinology, Metabolism, and Nutrition, Department of Medicine, Duke Molecular Physiology Institute, Duke University School of Medicine, Durham, North Carolina
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27
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Upadhyay A, Anjum B, Godbole NM, Rajak S, Shukla P, Tiwari S, Sinha RA, Godbole MM. Time-restricted feeding reduces high-fat diet associated placental inflammation and limits adverse effects on fetal organ development. Biochem Biophys Res Commun 2019; 514:415-421. [PMID: 31053302 DOI: 10.1016/j.bbrc.2019.04.154] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Accepted: 04/22/2019] [Indexed: 12/18/2022]
Abstract
Maternal nutrition has become a major public health concern over recent years and is a known predictor of adverse long-term metabolic derangement in offspring. Time-restricted feeding (TRF), wherein food consumption is restricted to the metabolically active phase of the day, is a dietary approach that improves metabolic parameters when consuming a high-fat diet (HFD). Here, we tested whether TRF could reduce maternal HFD associated inflammation and thereby mitigate defects in fetal organ developmental. Female rats were kept on following three dietary regimens; Ad libitum normal chow diet (NCD-AL), Ad libitum HFD (HFD-AL) and Time-restricted fed HFD (HFD-TRF) from 5 months prior to mating and continued throughout pregnancy. Rat dams were sacrificed at embryonic day 18.5 (ED18.5) and placental tissues from these rats were processed for the analysis of cellular apoptosis, inflammatory cytokines (TNFα and IL-6), oxidative stress, endoplasmic reticulum (ER) stress and autophagy. Furthermore, fetal hepatic triglyceride (TG) content and fetal lung maturation were assessed at ED18.5. Biochemical analysis revealed that HFD-TRF rat had significantly lower serum TG levels and body weight compared to HFD-AL rats. Additionally, TRF significantly blocked HFD-induced placental apoptosis and inflammation via minimizing cellular stress, and restoring autophagic flux. In addition, fetal hepatosteatosis and delayed fetal lung maturation induced by HFD was significantly ameliorated in HFD-TRF compared to HFD-AL. Collectively, our results suggest that reducing placental inflammation via TRF could prevent adverse fetal metabolic outcomes in pregnancies complicated by maternal obesity.
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Affiliation(s)
- Aditya Upadhyay
- Dept. of Molecular Medicine & Biotechnology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India; Dr. A.P.J. Abdul Kalam Technical University Uttar Pradesh, Lucknow, India
| | - B Anjum
- Dept. of Molecular Medicine & Biotechnology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India; Dept of Endocrinology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India
| | - Nachiket M Godbole
- Dept. of Microbiology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India
| | - Sangam Rajak
- Dept of Endocrinology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India
| | - Pooja Shukla
- Dept of Pathology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India
| | - Swasti Tiwari
- Dept. of Molecular Medicine & Biotechnology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India
| | - Rohit A Sinha
- Dept of Endocrinology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India.
| | - Madan M Godbole
- Dept. of Molecular Medicine & Biotechnology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India.
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28
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Tan HWS, Anjum B, Shen HM, Ghosh S, Yen PM, Sinha RA. Lysosomal inhibition attenuates peroxisomal gene transcription via suppression of PPARA and PPARGC1A levels. Autophagy 2019; 15:1455-1459. [PMID: 31032705 DOI: 10.1080/15548627.2019.1609847] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
Abstract
Lysosomes influence dynamic cellular processes such as nutrient sensing and transcriptional regulation. To explore novel transcriptional pathways regulated by lysosomes, we performed microarray analysis followed by qPCR validation in a mouse hepatocyte cell line, AML12, treated with bafilomycin A1 (lysosomal v-type H+-translocating ATPase inhibitor). Pathway enrichment analysis revealed significant downregulation of gene sets related to peroxisomal biogenesis and peroxisomal lipid oxidation upon lysosomal inhibition. Mechanistically, pharmacological inhibition of lysosomes as well as genetic knockdown of Tfeb led to downregulation of the peroxisomal master regulator PPARA and its coactivator PPARGC1A/PGC1α. Consistently, ectopic induction of PPARA transcriptional activity rescues the effects of lysosomal inhibition on peroxisomal gene expression. Collectively, our results uncover a novel metabolic regulation of peroxisomes by lysosomes via PPARA-PPARGC1A transcriptional signalling. Abbreviations: Acox1: acyl-Coenzyme A oxidase 1, palmitoyl; Acot: acyl-CoA thioesterase; ACAA: acetyl-Coenzyme A acyltransferase; ABCD3/PMP70: ATP-binding cassette, sub-family D (ALD), member 3; BafA1: bafilomycin A1; Crot: carnitine O-octanoyltransferase; CTSB: cathepsin B; Decr2: 2-4-dienoyl-Coenzyme A reductase 2, peroxisomal; Ech1: enoyl coenzyme A hydratase 1, peroxisomal; Ehhadh: enoyl-Coenzyme A, hydratase/3-hydroxyacyl Coenzyme A dehydrogenase; FDR: false discovery rate; Hsd17b4: hydroxysteroid (17-beta) dehydrogenase 4; NES: normalized enrichment score; NOM: nominal; Pex: peroxin; PPARA: peroxisome proliferator activated receptor alpha; PPARGC1A: peroxisome proliferator activated receptor, gamma, coactivator 1 alpha; TFEB: transcription factor EB.
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Affiliation(s)
- Hayden Weng Siong Tan
- a Department of Physiology , Yong Loo Lin School of Medicine, National University of Singapore , Singapore , Singapore.,b Program of Cardiovascular and Metabolic Disorders , Duke-NUS Medical School , Singapore , Singapore.,c School for Integrative Sciences and Engineering, National University of Singapore , Singapore , Singapore
| | - B Anjum
- d Department of Endocrinology , Sanjay Gandhi Postgraduate Institute of Medical Sciences , Lucknow , India
| | - Han-Ming Shen
- a Department of Physiology , Yong Loo Lin School of Medicine, National University of Singapore , Singapore , Singapore.,c School for Integrative Sciences and Engineering, National University of Singapore , Singapore , Singapore
| | - Sujoy Ghosh
- b Program of Cardiovascular and Metabolic Disorders , Duke-NUS Medical School , Singapore , Singapore
| | - Paul M Yen
- b Program of Cardiovascular and Metabolic Disorders , Duke-NUS Medical School , Singapore , Singapore
| | - Rohit A Sinha
- d Department of Endocrinology , Sanjay Gandhi Postgraduate Institute of Medical Sciences , Lucknow , India
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29
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Pal S, Maurya SK, Chattopadhyay S, Pal China S, Porwal K, Kulkarni C, Sanyal S, Sinha RA, Chattopadhyay N. The osteogenic effect of liraglutide involves enhanced mitochondrial biogenesis in osteoblasts. Biochem Pharmacol 2019; 164:34-44. [PMID: 30885766 DOI: 10.1016/j.bcp.2019.03.024] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Accepted: 03/14/2019] [Indexed: 12/31/2022]
Abstract
Liraglutide (Lira), a long-acting glucagon-like peptide 1 receptor (GLP1R) agonist reduces glycosylated hemoglobin in type 2 diabetes mellitus patients. Lira is reported to have bone conserving effect in ovariectomized (OVX) rats. Here, we investigated the osteoanabolic effect of Lira and studied the underlying mechanism. In established osteopenic OVX rats, Lira completely restored bone mass and strength comparable to parathyroid hormone (PTH 1-34). Body mass index normalized bone mineral density of Lira was higher than PTH. The serum levels of osteogenic surrogate pro-collagen type 1 N-terminal pro-peptide (P1NP) and surface referent bone formation parameters were comparable between Lira and PTH. GLP1R, adiponectin receptor 1 (AdipoR1) and peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC1α) levels in bones were downregulated in the OVX group but restored in the Lira group whereas PTH had no effect. In cultured osteoblasts, Lira time-dependently increased GLP1R, AdipoR1 and PGC1α expression. In osteoblasts, Lira rapidly phosphorylated AMP-dependent protein kinase (AMPK), the cellular energy sensor. Exendin 3, a selective GLP1R antagonist and PKA inhibitor H89 blocked Lira-induced increases in osteoblast differentiation, and expression levels of AdipoR1 and PGC1α. Furthermore, H89 inhibited Lira-induced phosphorylation of AMPK and dorsomorphin, an AMPK inhibitor blocked the Lira-induced increases in osteoblast differentiation and AdipoR1 and PGC1α levels. Lira increased mitochondrial number, respiratory proteins and respiration in osteoblasts in vitro and in vivo, and blocking mitochondrial respiration mitigated Lira-induced osteoblast differentiation. Taken together, our data show that Lira has a strong osteoanabolic effect which involves upregulation of mitochondrial function.
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Affiliation(s)
- Subhashis Pal
- Division of Endocrinology and Center for Research in Anabolic Skeletal Target in Health and Illness (ASTHI), Central Drug Research Institute (CDRI), Council of Scientific and Industrial Research (CSIR), Lucknow 226031, India
| | - Shailendra K Maurya
- Division of Endocrinology and Center for Research in Anabolic Skeletal Target in Health and Illness (ASTHI), Central Drug Research Institute (CDRI), Council of Scientific and Industrial Research (CSIR), Lucknow 226031, India
| | - Sourav Chattopadhyay
- Division of Biochemistry, Central Drug Research Institute (CDRI), Council of Scientific and Industrial Research (CSIR), Lucknow 226031, India
| | - Shyamsundar Pal China
- Division of Endocrinology and Center for Research in Anabolic Skeletal Target in Health and Illness (ASTHI), Central Drug Research Institute (CDRI), Council of Scientific and Industrial Research (CSIR), Lucknow 226031, India
| | - Konica Porwal
- Division of Endocrinology and Center for Research in Anabolic Skeletal Target in Health and Illness (ASTHI), Central Drug Research Institute (CDRI), Council of Scientific and Industrial Research (CSIR), Lucknow 226031, India
| | - Chirag Kulkarni
- Division of Endocrinology and Center for Research in Anabolic Skeletal Target in Health and Illness (ASTHI), Central Drug Research Institute (CDRI), Council of Scientific and Industrial Research (CSIR), Lucknow 226031, India; AcSIR, CSIR-Central Drug Research Institute Campus, Lucknow 226031, India
| | - Sabyasachi Sanyal
- Division of Biochemistry, Central Drug Research Institute (CDRI), Council of Scientific and Industrial Research (CSIR), Lucknow 226031, India
| | - Rohit A Sinha
- Department of Endocrinology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow 226014, India
| | - Naibedya Chattopadhyay
- Division of Endocrinology and Center for Research in Anabolic Skeletal Target in Health and Illness (ASTHI), Central Drug Research Institute (CDRI), Council of Scientific and Industrial Research (CSIR), Lucknow 226031, India; AcSIR, CSIR-Central Drug Research Institute Campus, Lucknow 226031, India.
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30
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Kumar P, Godbole NM, Chaturvedi CP, Singh RS, George N, Upadhyay A, Anjum B, Godbole MM, Sinha RA. Mechanisms involved in epigenetic down-regulation of Gfap under maternal hypothyroidism. Biochem Biophys Res Commun 2018; 502:375-381. [PMID: 29852171 DOI: 10.1016/j.bbrc.2018.05.173] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Accepted: 05/26/2018] [Indexed: 10/14/2022]
Abstract
Thyroid hormones (TH) of maternal origin are crucial regulator of mammalian brain development during embryonic period. Although maternal TH deficiency during the critical periods of embryonic neo-cortical development often results in irreversible clinical outcomes, the fundamental basis of these abnormalities at a molecular level is still obscure. One of the key developmental process affected by maternal TH insufficiency is the delay in astrocyte maturation. Glial fibrillary acidic protein (Gfap) is a predominant cell marker of mature astrocyte and is regulated by TH status. Inspite, of being a TH responsive gene during neocortical development the mechanistic basis of Gfap transcriptional regulation by TH has remained elusive. In this study using rat model of maternal hypothyroidism, we provide evidence for an epigenetic silencing of Gfap under TH insufficiency and its recovery upon TH supplementation. Our results demonstrate increased DNA methylation coupled with decreased histone acetylation at the Gfap promoter leading to suppression of Gfap expression under maternal hypothyroidism. In concordance, we also observed a significant increase in histone deacetylase (HDAC) activity in neocortex of TH deficient embryos. Collectively, these results provide novel insight into the role of TH regulated epigenetic mechanisms, including DNA methylation, and histone modifications, which are critically important in mediating precise temporal neural gene regulation.
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Affiliation(s)
- Praveen Kumar
- Department of Molecular Medicine & Biotechnology, Sanjay Gandhi Postgraduate Institute of Medical Science, Lucknow, 226014, India
| | - Nachiket M Godbole
- Department of Microbiology, Sanjay Gandhi Postgraduate Institute of Medical Science, Lucknow, 226014, India
| | - Chandra P Chaturvedi
- Stem Cell Research Facility, Department of Hematology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, 226014, India
| | - Ravi S Singh
- Department of Molecular Medicine & Biotechnology, Sanjay Gandhi Postgraduate Institute of Medical Science, Lucknow, 226014, India
| | - Nelson George
- Department of Endocrinology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, 226014, India
| | - Aditya Upadhyay
- Department of Molecular Medicine & Biotechnology, Sanjay Gandhi Postgraduate Institute of Medical Science, Lucknow, 226014, India
| | - B Anjum
- Department of Molecular Medicine & Biotechnology, Sanjay Gandhi Postgraduate Institute of Medical Science, Lucknow, 226014, India
| | - Madan M Godbole
- Department of Molecular Medicine & Biotechnology, Sanjay Gandhi Postgraduate Institute of Medical Science, Lucknow, 226014, India.
| | - Rohit A Sinha
- Department of Endocrinology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, 226014, India.
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31
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Yau WW, Singh BK, Lesmana R, Zhou J, Sinha RA, Wong KA, Wu Y, Bay BH, Sugii S, Sun L, Yen PM. Thyroid hormone (T 3) stimulates brown adipose tissue activation via mitochondrial biogenesis and MTOR-mediated mitophagy. Autophagy 2018; 15:131-150. [PMID: 30209975 DOI: 10.1080/15548627.2018.1511263] [Citation(s) in RCA: 123] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The thyroid hormone triiodothyronine (T3) activates thermogenesis by uncoupling electron transport from ATP synthesis in brown adipose tissue (BAT) mitochondria. Although T3 can induce thermogenesis by sympathetic innervation, little is known about its cell autonomous effects on BAT mitochondria. We thus examined effects of T3 on mitochondrial activity, autophagy, and metabolism in primary brown adipocytes and BAT and found that T3 increased fatty acid oxidation and mitochondrial respiration as well as autophagic flux, mitophagy, and mitochondrial biogenesis. Interestingly, there was no significant induction of intracellular reactive oxygen species (ROS) despite high mitochondrial respiration and UCP1 induction by T3. However, when cells were treated with Atg5 siRNA to block autophagy, induction of mitochondrial respiration by T3 decreased, and was accompanied by ROS accumulation, demonstrating a critical role for autophagic mitochondrial turnover. We next generated an Atg5 conditional knockout mouse model (Atg5 cKO) by injecting Ucp1 promoter-driven Cre-expressing adenovirus into Atg5Flox/Flox mice to examine effects of BAT-specific autophagy on thermogenesis in vivo. Hyperthyroid Atg5 cKO mice exhibited lower body temperature than hyperthyroid or euthyroid control mice. Metabolomic analysis showed that T3 increased short and long chain acylcarnitines in BAT, consistent with increased β-oxidation. T3 also decreased amino acid levels, and in conjunction with SIRT1 activation, decreased MTOR activity to stimulate autophagy. In summary, T3 has direct effects on mitochondrial autophagy, activity, and turnover in BAT that are essential for thermogenesis. Stimulation of BAT activity by thyroid hormone or its analogs may represent a potential therapeutic strategy for obesity and metabolic diseases. Abbreviations: ACACA: acetyl-Coenzyme A carboxylase alpha; AMPK: AMP-activated protein kinase; Acsl1: acyl-CoA synthetase long-chain family member 1; ATG5: autophagy related 5; ATG7: autophagy related 7; ATP: adenosine triphosphate; BAT: brown adipose tissue; cKO: conditional knockout; COX4I1: cytochrome c oxidase subunit 4I1; Cpt1b: carnitine palmitoyltransferase 1b, muscle; CQ: chloroquine; DAPI: 4',6-diamidino-2-phenylindole; DIO2: deiodinase, iodothyronine, type 2; DMEM: Dulbecco's modified Eagle's medium; EIF4EBP1: eukaryotic translation initiation factor 4E binding protein 1; Fabp4: fatty acid binding protein 4, adipocyte; FBS: fetal bovine serum; FCCP: carbonyl cyanide-4-(trifluoromethoxy)phenylhydrazone; FGF: fibroblast growth factor; FOXO1: forkhead box O1; GAPDH: glyceraldehyde-3-phosphate dehydrogenase; GFP: green fluorescent protein; Gpx1: glutathione peroxidase 1; Lipe: lipase, hormone sensitive; MAP1LC3B: microtubule-associated protein 1 light chain 3; mRNA: messenger RNA; MTORC1: mechanistic target of rapamycin kinase complex 1; NAD: nicotinamide adenine dinucleotide; Nrf1: nuclear respiratory factor 1; OCR: oxygen consumption rate; PBS: phosphate-buffered saline; PCR: polymerase chain reaction; PPARGC1A: peroxisome proliferative activated receptor, gamma, coactivator 1 alpha; Pnpla2: patatin-like phospholipase domain containing 2; Prdm16: PR domain containing 16; PRKA: protein kinase, AMP-activated; RPS6KB: ribosomal protein S6 kinase; RFP: red fluorescent protein; ROS: reactive oxygen species; SD: standard deviation; SEM: standard error of the mean; siRNA: small interfering RNA; SIRT1: sirtuin 1; Sod1: superoxide dismutase 1, soluble; Sod2: superoxide dismutase 2, mitochondrial; SQSTM1: sequestosome 1; T3: 3,5,3'-triiodothyronine; TFEB: transcription factor EB; TOMM20: translocase of outer mitochondrial membrane 20; UCP1: uncoupling protein 1 (mitochondrial, proton carrier); ULK1: unc-51 like kinase 1; VDAC1: voltage-dependent anion channel 1; WAT: white adipose tissue.
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Affiliation(s)
- Winifred W Yau
- a Laboratory of Hormonal Regulation , Cardiovascular and Metabolic Disorders Program, Duke-NUS Medical School , Singapore
| | - Brijesh K Singh
- a Laboratory of Hormonal Regulation , Cardiovascular and Metabolic Disorders Program, Duke-NUS Medical School , Singapore
| | - Ronny Lesmana
- a Laboratory of Hormonal Regulation , Cardiovascular and Metabolic Disorders Program, Duke-NUS Medical School , Singapore.,b Physiology Division, Department of Anatomy, Physiology and Biology Cell, Faculty of Medicine , Universitas Padjadjaran , Bandung , Indonesia.,c Central laboratory , Universitas Padjadjaran , Bandung , Indonesia
| | - Jin Zhou
- a Laboratory of Hormonal Regulation , Cardiovascular and Metabolic Disorders Program, Duke-NUS Medical School , Singapore
| | - Rohit A Sinha
- a Laboratory of Hormonal Regulation , Cardiovascular and Metabolic Disorders Program, Duke-NUS Medical School , Singapore.,d Department of Endocrinology , Sanjay Gandhi Postgraduate Institute of Medical Sciences , Lucknow , India
| | - Kiraely A Wong
- a Laboratory of Hormonal Regulation , Cardiovascular and Metabolic Disorders Program, Duke-NUS Medical School , Singapore
| | - Yajun Wu
- e Department of Anatomy , Yong Loo Lin School of Medicine, National University of Singapore , Singapore
| | - Boon-Huat Bay
- e Department of Anatomy , Yong Loo Lin School of Medicine, National University of Singapore , Singapore
| | - Shigeki Sugii
- a Laboratory of Hormonal Regulation , Cardiovascular and Metabolic Disorders Program, Duke-NUS Medical School , Singapore.,f Fat Metabolism and Stem Cell Group , Singapore Bioimaging Consortium, A*STAR , Singapore
| | - Lei Sun
- a Laboratory of Hormonal Regulation , Cardiovascular and Metabolic Disorders Program, Duke-NUS Medical School , Singapore
| | - Paul M Yen
- a Laboratory of Hormonal Regulation , Cardiovascular and Metabolic Disorders Program, Duke-NUS Medical School , Singapore.,g Sarah W. Stedman Nutrition and Metabolism Center, Departments of Medicine and Pharmacology and Cancer Biology , Duke University Medical Center , Durham , NC , USA
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Bruinstroop E, Dalan R, Cao Y, Bee YM, Chandran K, Cho LW, Soh SB, Teo EK, Toh SA, Leow MKS, Sinha RA, Sadananthan SA, Michael N, Stapleton HM, Leung C, Angus PW, Patel SK, Burrell LM, Lim SC, Sum CF, Velan SS, Yen PM. Low-Dose Levothyroxine Reduces Intrahepatic Lipid Content in Patients With Type 2 Diabetes Mellitus and NAFLD. J Clin Endocrinol Metab 2018; 103:2698-2706. [PMID: 29718334 DOI: 10.1210/jc.2018-00475] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Accepted: 04/24/2018] [Indexed: 12/15/2022]
Abstract
CONTEXT Nonalcoholic fatty liver disease (NAFLD) is highly prevalent in patients with type 2 diabetes mellitus (T2DM) and associated with significant morbidity and mortality. Thyroid hormone (TH) increases β-oxidation of fatty acids and decreases intrahepatic lipid content (IHLC) in rodents with NAFLD. OBJECTIVE We investigated the possibility of low intrahepatic TH concentration in NAFLD and studied the effect of TH treatment in humans. DESIGN/SETTING This was a phase 2b single-arm study in six hospitals in Singapore. Intrahepatic thyroid hormone concentrations were measured in rats with induced NAFLD. PATIENTS Euthyroid patients with T2DM and steatosis measured by ultrasonography. INTERVENTION Levothyroxine was titrated to reach a thyroid-stimulating hormone level of 0.34 to 1.70 mIU/L before a 16-week maintenance phase. MAIN OUTCOME MEASURES The primary outcome measure was change in IHLC measured by proton magnetic resonance spectroscopy after treatment. RESULTS Twenty male patients were included in the per-protocol analysis [mean ± SD: age, 47.8 ± 7.8 years; body mass index (BMI), 30.9 ± 4.4 kg/m2; baseline IHLC, 13% ± 4%]. After treatment, IHLC was decreased 12% (±SEM, 26%) relative to baseline (absolute change, -2%; 95% CI, -3 to 0; P = 0.046). Small decreases in BMI (P = 0.044), visceral adipose tissue volume (P = 0.047), and subcutaneous adipose tissue volume (P = 0.045) were observed. No significant changes in glucose regulation or lipid profile occurred. CONCLUSION This study demonstrated the efficacy and safety of low-dose TH therapy for NAFLD in men. TH or TH analogs may be beneficial for this condition.
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Affiliation(s)
- Eveline Bruinstroop
- Cardiovascular & Metabolic Disorders Program, Duke-NUS Graduate Medical School, Singapore
- Department of Endocrinology and Metabolism, Amsterdam, Netherlands
| | - Rinkoo Dalan
- Department of Endocrinology, Tan Tock Seng Hospital, Singapore
- NTU-Lee Kong Chian School of Medicine, Singapore
| | - Yang Cao
- Singapore Clinical Research Institute, Singapore
| | - Yong Mong Bee
- Department of Endocrinology, Singapore General Hospital, Singapore
| | | | - Li Wei Cho
- Department of Endocrinology, Changi General Hospital, Singapore
| | - Shui Boon Soh
- Department of Endocrinology, Changi General Hospital, Singapore
| | - Eng Kiong Teo
- Department of Gastroenterology, Changi General Hospital, Singapore
| | - Sue-Anne Toh
- Department of Endocrinology, National University Health System, Singapore
| | - Melvin Khee Shing Leow
- Cardiovascular & Metabolic Disorders Program, Duke-NUS Graduate Medical School, Singapore
- Department of Endocrinology, Tan Tock Seng Hospital, Singapore
- Singapore Institute for Clinical Sciences, A*STAR, Singapore
| | - Rohit A Sinha
- Cardiovascular & Metabolic Disorders Program, Duke-NUS Graduate Medical School, Singapore
| | | | - Navin Michael
- Singapore Institute for Clinical Sciences, A*STAR, Singapore
| | - Heather M Stapleton
- Duke University, Nicholas School of the Environment, A220 LSRC, Durham, North Carolina
| | - Christopher Leung
- Department of Medicine, University of Melbourne, Austin Health, Heidelberg, Melbourne, Victoria, Australia
- Department of Gastroenterology, Austin Health, Heidelberg, Victoria, Australia
- Department of General Medicine, Austin Health, Heidelberg, Victoria, Australia
| | - Peter W Angus
- Department of Medicine, University of Melbourne, Austin Health, Heidelberg, Melbourne, Victoria, Australia
- Department of Gastroenterology, Austin Health, Heidelberg, Victoria, Australia
| | - Sheila K Patel
- Department of Medicine, University of Melbourne, Austin Health, Heidelberg, Melbourne, Victoria, Australia
| | - Louise M Burrell
- Department of Medicine, University of Melbourne, Austin Health, Heidelberg, Melbourne, Victoria, Australia
- Department of General Medicine, Austin Health, Heidelberg, Victoria, Australia
| | - Su Chi Lim
- Department of Endocrinology, Khoo Teck Puat Hospital, Singapore
- Saw Swee Hock School of Public Health, National University Health System, Singapore
| | - Chee Fang Sum
- Department of Endocrinology, Khoo Teck Puat Hospital, Singapore
- Diabetes Centre, Admiralty Medical Centre, Singapore
| | - S Sendhil Velan
- Singapore Institute for Clinical Sciences, A*STAR, Singapore
- Singapore Bioimaging Consortium, Singapore
| | - Paul M Yen
- Cardiovascular & Metabolic Disorders Program, Duke-NUS Graduate Medical School, Singapore
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Singh BK, Sinha RA, Tripathi M, Mendoza A, Ohba K, Sy JAC, Xie SY, Zhou J, Ho JP, Chang CY, Wu Y, Giguère V, Bay BH, Vanacker JM, Ghosh S, Gauthier K, Hollenberg AN, McDonnell DP, Yen PM. Thyroid hormone receptor and ERRα coordinately regulate mitochondrial fission, mitophagy, biogenesis, and function. Sci Signal 2018; 11:eaam5855. [PMID: 29945885 DOI: 10.1126/scisignal.aam5855] [Citation(s) in RCA: 69] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2023]
Abstract
Thyroid hormone receptor β1 (THRB1) and estrogen-related receptor α (ESRRA; also known as ERRα) both play important roles in mitochondrial activity. To understand their potential interactions, we performed transcriptome and ChIP-seq analyses and found that many genes that were co-regulated by both THRB1 and ESRRA were involved in mitochondrial metabolic pathways. These included oxidative phosphorylation (OXPHOS), the tricarboxylic acid (TCA) cycle, and β-oxidation of fatty acids. TH increased ESRRA expression and activity in a THRB1-dependent manner through the induction of the transcriptional coactivator PPARGC1A (also known as PGC1α). Moreover, TH induced mitochondrial biogenesis, fission, and mitophagy in an ESRRA-dependent manner. TH also induced the expression of the autophagy-regulating kinase ULK1 through ESRRA, which then promoted DRP1-mediated mitochondrial fission. In addition, ULK1 activated the docking receptor protein FUNDC1 and its interaction with the autophagosomal protein MAP1LC3B-II to induce mitophagy. siRNA knockdown of ESRRA, ULK1, DRP1, or FUNDC1 inhibited TH-induced autophagic clearance of mitochondria through mitophagy and decreased OXPHOS. These findings show that many of the mitochondrial actions of TH are mediated through stimulation of ESRRA expression and activity, and co-regulation of mitochondrial turnover through the PPARGC1A-ESRRA-ULK1 pathway is mediated by their regulation of mitochondrial fission and mitophagy. Hormonal or pharmacologic induction of ESRRA expression or activity could improve mitochondrial quality in metabolic disorders.
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Affiliation(s)
- Brijesh K Singh
- Laboratory of Hormonal Regulation, Cardiovascular and Metabolic Disorders Program, Duke-National University of Singapore (NUS) Medical School, Singapore 169857, Singapore.
| | - Rohit A Sinha
- Laboratory of Hormonal Regulation, Cardiovascular and Metabolic Disorders Program, Duke-National University of Singapore (NUS) Medical School, Singapore 169857, Singapore
- Department of Endocrinology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Raebareli Road, Lucknow 226014, Uttar Pradesh, India
| | - Madhulika Tripathi
- Laboratory of Hormonal Regulation, Cardiovascular and Metabolic Disorders Program, Duke-National University of Singapore (NUS) Medical School, Singapore 169857, Singapore
| | - Arturo Mendoza
- Division of Endocrinology, Diabetes, and Metabolism, Beth Israel Deaconess Medical Center, Harvard Medical School, Center for Life Sciences, 330 Brookline Avenue, Boston, MA 02215, USA
| | - Kenji Ohba
- Laboratory of Hormonal Regulation, Cardiovascular and Metabolic Disorders Program, Duke-National University of Singapore (NUS) Medical School, Singapore 169857, Singapore
- Department of Internal Medicine, Enshu Hospital, Hamamatsu, Shizuoka 430-0929, Japan
| | - Jann A C Sy
- Laboratory of Hormonal Regulation, Cardiovascular and Metabolic Disorders Program, Duke-National University of Singapore (NUS) Medical School, Singapore 169857, Singapore
| | - Sherwin Y Xie
- Laboratory of Hormonal Regulation, Cardiovascular and Metabolic Disorders Program, Duke-National University of Singapore (NUS) Medical School, Singapore 169857, Singapore
| | - Jin Zhou
- Laboratory of Hormonal Regulation, Cardiovascular and Metabolic Disorders Program, Duke-National University of Singapore (NUS) Medical School, Singapore 169857, Singapore
| | - Jia Pei Ho
- Laboratory of Hormonal Regulation, Cardiovascular and Metabolic Disorders Program, Duke-National University of Singapore (NUS) Medical School, Singapore 169857, Singapore
| | - Ching-Yi Chang
- Department of Pharmacology and Cancer Biology, Duke University School of Medicine, C238A Levine Science Research Center, Durham, NC 27710, USA
| | - Yajun Wu
- Department of Anatomy, Yong Loo Lin School of Medicine, NUS, Singapore
| | - Vincent Giguère
- Goodman Cancer Research Centre, McGill University, 1160 Pine Avenue West, Montreal, Québec H3A 1A3, Canada
| | - Boon-Huat Bay
- Department of Anatomy, Yong Loo Lin School of Medicine, NUS, Singapore
| | - Jean-Marc Vanacker
- Institut de Génomique Fonctionnelle de Lyon, Université de Lyon, Université Lyon 1, CNRS, Ecole Normale Supérieure de Lyon, 46 Allée d'Italie, 69364 Lyon Cedex 07, France
| | - Sujoy Ghosh
- Laboratory of Hormonal Regulation, Cardiovascular and Metabolic Disorders Program, Duke-National University of Singapore (NUS) Medical School, Singapore 169857, Singapore
| | - Karine Gauthier
- Institut de Génomique Fonctionnelle de Lyon, Université de Lyon, Université Lyon 1, CNRS, Ecole Normale Supérieure de Lyon, 46 Allée d'Italie, 69364 Lyon Cedex 07, France
| | - Anthony N Hollenberg
- Division of Endocrinology, Diabetes, and Metabolism, Beth Israel Deaconess Medical Center, Harvard Medical School, Center for Life Sciences, 330 Brookline Avenue, Boston, MA 02215, USA
| | - Donald P McDonnell
- Department of Internal Medicine, Enshu Hospital, Hamamatsu, Shizuoka 430-0929, Japan
| | - Paul M Yen
- Laboratory of Hormonal Regulation, Cardiovascular and Metabolic Disorders Program, Duke-National University of Singapore (NUS) Medical School, Singapore 169857, Singapore.
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Abstract
It has been known for a long time that thyroid hormones have prominent effects on hepatic fatty acid and cholesterol synthesis and metabolism. Indeed, hypothyroidism has been associated with increased serum levels of triglycerides and cholesterol as well as non-alcoholic fatty liver disease (NAFLD). Advances in areas such as cell imaging, autophagy and metabolomics have generated a more detailed and comprehensive picture of thyroid-hormone-mediated regulation of hepatic lipid metabolism at the molecular level. In this Review, we describe and summarize the key features of direct thyroid hormone regulation of lipogenesis, fatty acid β-oxidation, cholesterol synthesis and the reverse cholesterol transport pathway in normal and altered thyroid hormone states. Thyroid hormone mediates these effects at the transcriptional and post-translational levels and via autophagy. Given these potentially beneficial effects on lipid metabolism, it is possible that thyroid hormone analogues and/or mimetics might be useful for the treatment of metabolic diseases involving the liver, such as hypercholesterolaemia and NAFLD.
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Affiliation(s)
- Rohit A. Sinha
- Laboratory of Hormonal Regulation, Cardiovascular and Metabolic Disorders Programme, Duke-NUS Medical School, Singapore, Singapore
- Department of Endocrinology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India
- ;
| | - Brijesh K. Singh
- Laboratory of Hormonal Regulation, Cardiovascular and Metabolic Disorders Programme, Duke-NUS Medical School, Singapore, Singapore
| | - Paul M. Yen
- Laboratory of Hormonal Regulation, Cardiovascular and Metabolic Disorders Programme, Duke-NUS Medical School, Singapore, Singapore
- ;
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35
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Zhou J, Sinha RA, Lesmana R, Yau WWY, Yen PM. Pharmacological Inhibition of Lysosomal Activity as a Method For Monitoring Thyroid Hormone-induced Autophagic Flux in Mammalian Cells In Vitro. Methods Mol Biol 2018; 1801:111-122. [PMID: 29892821 PMCID: PMC6020991 DOI: 10.1007/978-1-4939-7902-8_11] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Autophagy is an evolutionarily conserved intracellular catabolic process that is essential for cellular housekeeping and nutrient homeostasis. Recently, we provided evidence that thyroid hormone (TH) is a major inducer of autophagy in mammalian cells. Here, we describe a method for detecting TH-induced autophagic flux in hepatic, muscle, and brown adipocyte cells using lysosomal inhibitor bafilomycin A1 (BafA1) and conventional Western blot techniques.
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Affiliation(s)
- Jin Zhou
- Program of Cardiovascular and Metabolic Disorders, Duke-NUS Medical School Singapore, Singapore, Singapore
| | - Rohit A Sinha
- Program of Cardiovascular and Metabolic Disorders, Duke-NUS Medical School Singapore, Singapore, Singapore
- Department of Endocrinology, SGPGIMS, Lucknow, India
| | - Ronny Lesmana
- Department of Physiology, Universitas Padjadjaran, Bandung, Indonesia
| | - Winifred W Y Yau
- Program of Cardiovascular and Metabolic Disorders, Duke-NUS Medical School Singapore, Singapore, Singapore
| | - Paul M Yen
- Program of Cardiovascular and Metabolic Disorders, Duke-NUS Medical School Singapore, Singapore, Singapore.
- Duke Molecular Physiology Institute, Department of Medicine, Duke University Medical Center, Durham, NC, USA.
- Duke Molecular Physiology Institute, Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC, USA.
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36
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Farah BL, Landau DJ, Wu Y, Sinha RA, Loh A, Bay BH, Koeberl DD, Yen PM. Renal endoplasmic reticulum stress is coupled to impaired autophagy in a mouse model of GSD Ia. Mol Genet Metab 2017; 122:95-98. [PMID: 28888852 PMCID: PMC5722666 DOI: 10.1016/j.ymgme.2017.08.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Revised: 08/23/2017] [Accepted: 08/24/2017] [Indexed: 10/18/2022]
Abstract
GSD Ia (von Gierke Disease, Glycogen Storage Disease Type Ia) is a devastating genetic disorder with long-term sequelae, such as non-alcoholic fatty liver disease and renal failure. Down-regulated autophagy is involved in the development of hepatic metabolic dysfunction in GSD Ia; however, the role of autophagy in the renal pathology is unknown. Here we show that autophagy is impaired and endoplasmic reticulum (ER) stress is increased in the kidneys of a mouse model of GSD Ia. Induction of autophagy by rapamycin also reduces this ER stress. Taken together, these results show an additional role for autophagy down-regulation in the pathogenesis of GSD Ia, and provide further justification for the use of autophagy modulators in GSD Ia.
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Affiliation(s)
- Benjamin L Farah
- Cardiovascular and Metabolic Disorders Program, Duke-NUS Medical School, Singapore, Singapore
| | - Dustin J Landau
- Division of Medical Genetics, Department of Pediatrics, Duke University Medical School, Durham, NC, USA; Molecular Genetics and Microbiology, Duke University, Durham, NC, USA
| | - Yajun Wu
- Department of Anatomy, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Rohit A Sinha
- Cardiovascular and Metabolic Disorders Program, Duke-NUS Medical School, Singapore, Singapore
| | - Alwin Loh
- Division of Pathology, Singapore General Hospital, Singapore
| | - Boon-Huat Bay
- Department of Anatomy, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Dwight D Koeberl
- Division of Medical Genetics, Department of Pediatrics, Duke University Medical School, Durham, NC, USA; Molecular Genetics and Microbiology, Duke University, Durham, NC, USA
| | - Paul M Yen
- Cardiovascular and Metabolic Disorders Program, Duke-NUS Medical School, Singapore, Singapore; Duke Molecular Physiology Institute, Duke University School of Medicine, Durham, NC, USA.
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Iannucci LF, Cioffi F, Senese R, Goglia F, Lanni A, Yen PM, Sinha RA. Metabolomic analysis shows differential hepatic effects of T 2 and T 3 in rats after short-term feeding with high fat diet. Sci Rep 2017; 7:2023. [PMID: 28515456 PMCID: PMC5435676 DOI: 10.1038/s41598-017-02205-1] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Accepted: 04/07/2017] [Indexed: 01/16/2023] Open
Abstract
Nonalcoholic fatty liver disease (NAFLD) is a major health problem worldwide, and is often associated with lipotoxic injury, defective mitochondrial function, and insulin resistance. Thyroid hormones (THs) are important regulators of hepatic lipid metabolism. Among the THs, diiodothyronine (T2) and triiodothyronine (T3) have shown promising results in lowering hepatic fat content in various models of NAFLD. In this study, we used a targeted metabolomics approach to investigate the differential effects of T2 and T3 on the early metabolic adaptation in the livers of rats fed high fat diet (HFD), a period when hepatosteatosis is reversible. Our results showed that both T2 and T3 strongly induced autophagy and intra-hepatic acylcarnitine flux but prevented the generation of sphingolipid/ceramides in animals fed HFD. Interestingly, although both T2 and T3 decreased hepatic fat content, only T2 was able to rescue the impairment in AKT and MAPK/ERK pathways caused by HFD. In summary, we have identified and characterized the effects of T2 and T3 on hepatic metabolism during short-term exposure to HFD. These findings illuminate the common and divergent metabolic pathways by T2 and T3 that also may be important in the prevention and treatment of NAFLD.
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Affiliation(s)
- Liliana F Iannucci
- Program of Cardiovascular and Metabolic Disorders, Duke-NUS Medical School Singapore8 College Road, 169857, Singapore, Singapore.,Dipartimento di Scienze e Tecnologie Ambientali, Biologiche e Farmaceutiche, Seconda Università degli Studi della Campania "Luigi Vanvitelli" Napoli, Caserta, Italy
| | - Federica Cioffi
- Dipartimento di Scienze e Tecnologie, Università degli Studi del Sannio, Benevento, Italy
| | - Rosalba Senese
- Dipartimento di Scienze e Tecnologie Ambientali, Biologiche e Farmaceutiche, Seconda Università degli Studi della Campania "Luigi Vanvitelli" Napoli, Caserta, Italy
| | - Fernando Goglia
- Dipartimento di Scienze e Tecnologie, Università degli Studi del Sannio, Benevento, Italy
| | - Antonia Lanni
- Dipartimento di Scienze e Tecnologie Ambientali, Biologiche e Farmaceutiche, Seconda Università degli Studi della Campania "Luigi Vanvitelli" Napoli, Caserta, Italy.
| | - Paul M Yen
- Program of Cardiovascular and Metabolic Disorders, Duke-NUS Medical School Singapore8 College Road, 169857, Singapore, Singapore.
| | - Rohit A Sinha
- Program of Cardiovascular and Metabolic Disorders, Duke-NUS Medical School Singapore8 College Road, 169857, Singapore, Singapore.
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Sinha RA, Singh BK, Yen PM. Reciprocal Crosstalk Between Autophagic and Endocrine Signaling in Metabolic Homeostasis. Endocr Rev 2017; 38:69-102. [PMID: 27901588 DOI: 10.1210/er.2016-1103] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Accepted: 11/28/2016] [Indexed: 12/19/2022]
Abstract
Autophagy is a cellular quality control and energy-providing process that is under strict control by intra- and extracellular stimuli. Recently, there has been an exponential increase in autophagy research and its implications for mammalian physiology. Autophagy deregulation is now being implicated in many human diseases, and its modulation has shown promising results in several preclinical studies. However, despite the initial discovery of autophagy as a hormone-regulated process by De Duve in the early 1960s, endocrine regulation of autophagy still remains poorly understood. In this review, we provide a critical summary of our present understanding of the basic mechanism of autophagy, its regulation by endocrine hormones, and its contribution to endocrine and metabolic homeostasis under physiological and pathological settings. Understanding the cross-regulation of hormones and autophagy on endocrine cell signaling and function will provide new insight into mammalian physiology as well as promote the development of new therapeutic strategies involving modulation of autophagy in endocrine and metabolic disorders.
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Affiliation(s)
- Rohit A Sinha
- Program of Cardiovascular and Metabolic Disorders, Duke-National University of Singapore Medical School Singapore, Singapore 169016
| | - Brijesh K Singh
- Program of Cardiovascular and Metabolic Disorders, Duke-National University of Singapore Medical School Singapore, Singapore 169016
| | - Paul M Yen
- Program of Cardiovascular and Metabolic Disorders, Duke-National University of Singapore Medical School Singapore, Singapore 169016
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Iannucci LF, Sun J, Singh BK, Zhou J, Kaddai VA, Lanni A, Yen PM, Sinha RA. Corrigendum to "Short chain fatty acids induce UCP2-mediated autophagy in hepatic cells" [Biochem. Biophys. Res. Commun. 480 (2016) 461-467]. Biochem Biophys Res Commun 2017; 482:1517. [PMID: 27899181 DOI: 10.1016/j.bbrc.2016.11.116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
- Liliana F Iannucci
- Dipartimento di Scienze e Tecnologie Ambientali, Biologiche e Farmaceutiche, Seconda Universitá degli Studi di Napoli, Caserta, Italy
| | - Jingfeng Sun
- Program of Cardiovascular and Metabolic Disorders, Duke-NUS Medical School, 8 College Road, Singapore, 169857, Singapore
| | - Brijesh K Singh
- Program of Cardiovascular and Metabolic Disorders, Duke-NUS Medical School, 8 College Road, Singapore, 169857, Singapore
| | - Jin Zhou
- Program of Cardiovascular and Metabolic Disorders, Duke-NUS Medical School, 8 College Road, Singapore, 169857, Singapore
| | - Vincent A Kaddai
- Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, 3004, Australia
| | - Antonia Lanni
- Dipartimento di Scienze e Tecnologie Ambientali, Biologiche e Farmaceutiche, Seconda Universitá degli Studi di Napoli, Caserta, Italy
| | - Paul M Yen
- Program of Cardiovascular and Metabolic Disorders, Duke-NUS Medical School, 8 College Road, Singapore, 169857, Singapore
| | - Rohit A Sinha
- Program of Cardiovascular and Metabolic Disorders, Duke-NUS Medical School, 8 College Road, Singapore, 169857, Singapore.
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Iannucci LF, Sun J, Singh BK, Zhou J, Kaddai VA, Lanni A, Yen PM, Sinha RA. Short chain fatty acids induce UCP2-mediated autophagy in hepatic cells. Biochem Biophys Res Commun 2016; 480:461-467. [PMID: 27773823 DOI: 10.1016/j.bbrc.2016.10.072] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Accepted: 10/19/2016] [Indexed: 02/07/2023]
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Sinha RA, Singh BK, Zhou J, Wu Y, Farah BL, Ohba K, Lesmana R, Gooding J, Bay BH, Yen PM. Thyroid hormone induction of mitochondrial activity is coupled to mitophagy via ROS-AMPK-ULK1 signaling. Autophagy 2016; 11:1341-57. [PMID: 26103054 DOI: 10.1080/15548627.2015.1061849] [Citation(s) in RCA: 122] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Currently, there is limited understanding about hormonal regulation of mitochondrial turnover. Thyroid hormone (T3) increases oxidative phosphorylation (OXPHOS), which generates reactive oxygen species (ROS) that damage mitochondria. However, the mechanism for maintenance of mitochondrial activity and quality control by this hormone is not known. Here, we used both in vitro and in vivo hepatic cell models to demonstrate that induction of mitophagy by T3 is coupled to oxidative phosphorylation and ROS production. We show that T3 induction of ROS activates CAMKK2 (calcium/calmodulin-dependent protein kinase kinase 2, β) mediated phosphorylation of PRKAA1/AMPK (5' AMP-activated protein kinase), which in turn phosphorylates ULK1 (unc-51 like autophagy activating kinase 1) leading to its mitochondrial recruitment and initiation of mitophagy. Furthermore, loss of ULK1 in T3-treated cells impairs both mitophagy as well as OXPHOS without affecting T3 induced general autophagy/lipophagy. These findings demonstrate a novel ROS-AMPK-ULK1 mechanism that couples T3-induced mitochondrial turnover with activity, wherein mitophagy is necessary not only for removing damaged mitochondria but also for sustaining efficient OXPHOS.
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Affiliation(s)
- Rohit A Sinha
- a Program of Cardiovascular and Metabolic Disorders; Duke-NUS Graduate Medical School ; Singapore
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Farah BL, Landau DJ, Sinha RA, Brooks ED, Wu Y, Fung SYS, Tanaka T, Hirayama M, Bay BH, Koeberl DD, Yen PM. Induction of autophagy improves hepatic lipid metabolism in glucose-6-phosphatase deficiency. J Hepatol 2016; 64:370-379. [PMID: 26462884 DOI: 10.1016/j.jhep.2015.10.008] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2015] [Revised: 10/07/2015] [Accepted: 10/07/2015] [Indexed: 02/07/2023]
Abstract
BACKGROUND & AIMS Glucose-6-phosphatase (G6Pase α, G6PC) deficiency, also known as von Gierke's disease or GSDIa, is the most common glycogen storage disorder. It is characterized by a decreased ability of the liver to convert glucose-6-phosphate (G6P) to glucose leading to glycogen and lipid over-accumulation progressing to liver failure and/or hepatomas and carcinomas. Autophagy of intracellular lipid stores (lipophagy) has been shown to stimulate fatty acid β-oxidation in hepatic cells. Thus, we examined autophagy and its effects on reducing hepatic lipid over-accumulation in several cell culture and animal models of GSDIa. METHODS Autophagy in G6PC-deficient hepatic cell lines, mice, and dogs was measured by Western blotting for key autophagy markers. Pro-autophagic Unc51-like kinase 1 (ULK1/ATG1) was overexpressed in G6PC-deficient hepatic cells, and lipid clearance and oxidative phosphorylation measured. G6PC(-/-) mice and GSDIa dogs were treated with rapamycin and assessed for liver function. RESULTS Autophagy was impaired in the cell culture, mouse, and canine models of GSDIa. Stimulation of the anti-autophagic mTOR, and inhibition of the pro-autophagic AMPK pathways occurred both in vitro and in vivo. Induction of autophagy by ULK1/ATG1 overexpression decreased lipid accumulation and increased oxidative phosphorylation in G6PC-deficient hepatic cells. Rapamycin treatment induced autophagy and decreased hepatic triglyceride and glycogen content in G6PC(-/-) mice, as well as reduced liver size and improved circulating markers of liver damage in GSDIa dogs. CONCLUSIONS Autophagy is impaired in GSDIa. Pharmacological induction of autophagy corrects hepatic lipid over-accumulation and may represent a new therapeutic strategy for GSDIa.
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Affiliation(s)
- Benjamin L Farah
- Cardiovascular and Metabolic Disorders Program, Duke-NUS Graduate Medical School Singapore, Singapore
| | - Dustin J Landau
- Division of Medical Genetics, Department of Pediatrics, Duke University Medical Center, Durham, NC, USA
| | - Rohit A Sinha
- Cardiovascular and Metabolic Disorders Program, Duke-NUS Graduate Medical School Singapore, Singapore
| | - Elizabeth D Brooks
- Division of Medical Genetics, Department of Pediatrics, Duke University Medical Center, Durham, NC, USA; Division of Laboratory Animal Resources, Duke University Medical Center, Durham, NC, USA
| | - Yajun Wu
- Department of Anatomy, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Suet Yin Sarah Fung
- Cancer and Stem Cell Biology Program, Duke-NUS Graduate Medical School Singapore, Singapore
| | | | | | - Boon-Huat Bay
- Department of Anatomy, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Dwight D Koeberl
- Division of Medical Genetics, Department of Pediatrics, Duke University Medical Center, Durham, NC, USA; Department of Molecular Genetics and Microbiology, Duke University, Durham, NC, USA.
| | - Paul M Yen
- Cardiovascular and Metabolic Disorders Program, Duke-NUS Graduate Medical School Singapore, Singapore; Sarah W. Stedman Nutrition and Metabolism Center, Departments of Medicine and Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC, USA.
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Lesmana R, Sinha RA, Singh BK, Zhou J, Ohba K, Wu Y, Yau WWY, Bay BH, Yen PM. Thyroid Hormone Stimulation of Autophagy Is Essential for Mitochondrial Biogenesis and Activity in Skeletal Muscle. Endocrinology 2016; 157:23-38. [PMID: 26562261 DOI: 10.1210/en.2015-1632] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Thyroid hormone (TH) and autophagy share similar functions in regulating skeletal muscle growth, regeneration, and differentiation. Although TH recently has been shown to increase autophagy in liver, the regulation and role of autophagy by this hormone in skeletal muscle is not known. Here, using both in vitro and in vivo models, we demonstrated that TH induces autophagy in a dose- and time-dependent manner in skeletal muscle. TH induction of autophagy involved reactive oxygen species (ROS) stimulation of 5'adenosine monophosphate-activated protein kinase (AMPK)-Mammalian target of rapamycin (mTOR)-Unc-51-like kinase 1 (Ulk1) signaling. TH also increased mRNA and protein expression of key autophagy genes, microtubule-associated protein light chain 3 (LC3), Sequestosome 1 (p62), and Ulk1, as well as genes that modulated autophagy and Forkhead box O (FOXO) 1/3a. TH increased mitochondrial protein synthesis and number as well as basal mitochondrial O2 consumption, ATP turnover, and maximal respiratory capacity. Surprisingly, mitochondrial activity and biogenesis were blunted when autophagy was blocked in muscle cells by Autophagy-related gene (Atg)5 short hairpin RNA (shRNA). Induction of ROS and 5'adenosine monophosphate-activated protein kinase (AMPK) by TH played a significant role in the up-regulation of Peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PPARGC1A), the key regulator of mitochondrial synthesis. In summary, our findings showed that TH-mediated autophagy was essential for stimulation of mitochondrial biogenesis and activity in skeletal muscle. Moreover, autophagy and mitochondrial biogenesis were coupled in skeletal muscle via TH induction of mitochondrial activity and ROS generation.
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MESH Headings
- AMP-Activated Protein Kinases/chemistry
- AMP-Activated Protein Kinases/metabolism
- Animals
- Autophagy/drug effects
- Autophagy-Related Protein 5
- Autophagy-Related Protein-1 Homolog
- Cell Line
- Gene Expression Regulation/drug effects
- Kinetics
- Male
- Mice, Inbred C57BL
- Microtubule-Associated Proteins/antagonists & inhibitors
- Microtubule-Associated Proteins/genetics
- Microtubule-Associated Proteins/metabolism
- Mitochondria, Muscle/drug effects
- Mitochondria, Muscle/metabolism
- Mitochondria, Muscle/ultrastructure
- Mitochondrial Dynamics/drug effects
- Muscle, Skeletal/cytology
- Muscle, Skeletal/drug effects
- Muscle, Skeletal/metabolism
- Muscle, Skeletal/ultrastructure
- Myoblasts, Skeletal/cytology
- Myoblasts, Skeletal/drug effects
- Myoblasts, Skeletal/metabolism
- Myoblasts, Skeletal/ultrastructure
- Oxygen Consumption/drug effects
- Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha
- Protein Serine-Threonine Kinases/chemistry
- Protein Serine-Threonine Kinases/metabolism
- RNA Interference
- Reactive Oxygen Species/agonists
- Reactive Oxygen Species/metabolism
- Signal Transduction/drug effects
- TOR Serine-Threonine Kinases/antagonists & inhibitors
- TOR Serine-Threonine Kinases/metabolism
- Thyroxine/metabolism
- Thyroxine/pharmacology
- Transcription Factors/agonists
- Transcription Factors/genetics
- Transcription Factors/metabolism
- Triiodothyronine/metabolism
- Triiodothyronine/pharmacology
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Affiliation(s)
- Ronny Lesmana
- Laboratory of Hormonal Regulation (R.L., R.A.S., B.K.S., J.Z., K.O., W.WY.Y., P.M.Y.), Program of Cardiovascular and Metabolic Disorders, Duke-National University of Singapore Graduate Medical School, Singapore 169857; Department of Physiology (R.L.), Universitas Padjadjaran, Bandung 45363, Indonesia; Department of Anatomy (Y.W., B.-H.B.), Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117599; and Duke Molecular Physiology Institute and Department of Medicine (P.M.Y.), Duke University Medical Center, Durham, North Carolina 27710, USA
| | - Rohit A Sinha
- Laboratory of Hormonal Regulation (R.L., R.A.S., B.K.S., J.Z., K.O., W.WY.Y., P.M.Y.), Program of Cardiovascular and Metabolic Disorders, Duke-National University of Singapore Graduate Medical School, Singapore 169857; Department of Physiology (R.L.), Universitas Padjadjaran, Bandung 45363, Indonesia; Department of Anatomy (Y.W., B.-H.B.), Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117599; and Duke Molecular Physiology Institute and Department of Medicine (P.M.Y.), Duke University Medical Center, Durham, North Carolina 27710, USA
| | - Brijesh K Singh
- Laboratory of Hormonal Regulation (R.L., R.A.S., B.K.S., J.Z., K.O., W.WY.Y., P.M.Y.), Program of Cardiovascular and Metabolic Disorders, Duke-National University of Singapore Graduate Medical School, Singapore 169857; Department of Physiology (R.L.), Universitas Padjadjaran, Bandung 45363, Indonesia; Department of Anatomy (Y.W., B.-H.B.), Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117599; and Duke Molecular Physiology Institute and Department of Medicine (P.M.Y.), Duke University Medical Center, Durham, North Carolina 27710, USA
| | - Jin Zhou
- Laboratory of Hormonal Regulation (R.L., R.A.S., B.K.S., J.Z., K.O., W.WY.Y., P.M.Y.), Program of Cardiovascular and Metabolic Disorders, Duke-National University of Singapore Graduate Medical School, Singapore 169857; Department of Physiology (R.L.), Universitas Padjadjaran, Bandung 45363, Indonesia; Department of Anatomy (Y.W., B.-H.B.), Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117599; and Duke Molecular Physiology Institute and Department of Medicine (P.M.Y.), Duke University Medical Center, Durham, North Carolina 27710, USA
| | - Kenji Ohba
- Laboratory of Hormonal Regulation (R.L., R.A.S., B.K.S., J.Z., K.O., W.WY.Y., P.M.Y.), Program of Cardiovascular and Metabolic Disorders, Duke-National University of Singapore Graduate Medical School, Singapore 169857; Department of Physiology (R.L.), Universitas Padjadjaran, Bandung 45363, Indonesia; Department of Anatomy (Y.W., B.-H.B.), Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117599; and Duke Molecular Physiology Institute and Department of Medicine (P.M.Y.), Duke University Medical Center, Durham, North Carolina 27710, USA
| | - Yajun Wu
- Laboratory of Hormonal Regulation (R.L., R.A.S., B.K.S., J.Z., K.O., W.WY.Y., P.M.Y.), Program of Cardiovascular and Metabolic Disorders, Duke-National University of Singapore Graduate Medical School, Singapore 169857; Department of Physiology (R.L.), Universitas Padjadjaran, Bandung 45363, Indonesia; Department of Anatomy (Y.W., B.-H.B.), Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117599; and Duke Molecular Physiology Institute and Department of Medicine (P.M.Y.), Duke University Medical Center, Durham, North Carolina 27710, USA
| | - Winifred W Y Yau
- Laboratory of Hormonal Regulation (R.L., R.A.S., B.K.S., J.Z., K.O., W.WY.Y., P.M.Y.), Program of Cardiovascular and Metabolic Disorders, Duke-National University of Singapore Graduate Medical School, Singapore 169857; Department of Physiology (R.L.), Universitas Padjadjaran, Bandung 45363, Indonesia; Department of Anatomy (Y.W., B.-H.B.), Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117599; and Duke Molecular Physiology Institute and Department of Medicine (P.M.Y.), Duke University Medical Center, Durham, North Carolina 27710, USA
| | - Boon-Huat Bay
- Laboratory of Hormonal Regulation (R.L., R.A.S., B.K.S., J.Z., K.O., W.WY.Y., P.M.Y.), Program of Cardiovascular and Metabolic Disorders, Duke-National University of Singapore Graduate Medical School, Singapore 169857; Department of Physiology (R.L.), Universitas Padjadjaran, Bandung 45363, Indonesia; Department of Anatomy (Y.W., B.-H.B.), Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117599; and Duke Molecular Physiology Institute and Department of Medicine (P.M.Y.), Duke University Medical Center, Durham, North Carolina 27710, USA
| | - Paul M Yen
- Laboratory of Hormonal Regulation (R.L., R.A.S., B.K.S., J.Z., K.O., W.WY.Y., P.M.Y.), Program of Cardiovascular and Metabolic Disorders, Duke-National University of Singapore Graduate Medical School, Singapore 169857; Department of Physiology (R.L.), Universitas Padjadjaran, Bandung 45363, Indonesia; Department of Anatomy (Y.W., B.-H.B.), Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117599; and Duke Molecular Physiology Institute and Department of Medicine (P.M.Y.), Duke University Medical Center, Durham, North Carolina 27710, USA
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Singh BK, Sinha RA, Zhou J, Tripathi M, Ohba K, Wang ME, Astapova I, Ghosh S, Hollenberg AN, Gauthier K, Yen PM. Hepatic FOXO1 Target Genes Are Co-regulated by Thyroid Hormone via RICTOR Protein Deacetylation and MTORC2-AKT Protein Inhibition. J Biol Chem 2015; 291:198-214. [PMID: 26453307 DOI: 10.1074/jbc.m115.668673] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Indexed: 12/21/2022] Open
Abstract
MTORC2-AKT is a key regulator of carbohydrate metabolism and insulin signaling due to its effects on FOXO1 phosphorylation. Interestingly, both FOXO1 and thyroid hormone (TH) have similar effects on carbohydrate and energy metabolism as well as overlapping transcriptional regulation of many target genes. Currently, little is known about the regulation of MTORC2-AKT or FOXO1 by TH. Accordingly, we performed hepatic transcriptome profiling in mice after FOXO1 knockdown in the absence or presence of TH, and we compared these results with hepatic FOXO1 and THRB1 (TRβ1) ChIP-Seq data. We identified a subset of TH-stimulated FOXO1 target genes that required co-regulation by FOXO1 and TH. TH activation of FOXO1 was directly linked to an increase in SIRT1-MTORC2 interaction and RICTOR deacetylation. This, in turn, led to decreased AKT and FOXO1 phosphorylation. Moreover, TH increased FOXO1 nuclear localization, DNA binding, and target gene transcription by reducing AKT-dependent FOXO1 phosphorylation in a THRB1-dependent manner. These events were associated with TH-mediated oxidative phosphorylation and NAD(+) production and suggested that downstream metabolic effects by TH can post-translationally activate other transcription factors. Our results showed that RICTOR/MTORC2-AKT can integrate convergent hormonal and metabolic signals to provide coordinated and sensitive regulation of hepatic FOXO1-target gene expression.
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Affiliation(s)
- Brijesh K Singh
- From the Laboratory of Hormonal Regulation, Cardiovascular and Metabolic Disorders Program and
| | - Rohit A Sinha
- From the Laboratory of Hormonal Regulation, Cardiovascular and Metabolic Disorders Program and
| | - Jin Zhou
- From the Laboratory of Hormonal Regulation, Cardiovascular and Metabolic Disorders Program and
| | - Madhulika Tripathi
- From the Laboratory of Hormonal Regulation, Cardiovascular and Metabolic Disorders Program and the Stroke Trial Unit, National Neuroscience Institute Singapore, 11 Jalan Tan Tock Seng, Singapore 308433, Singapore
| | - Kenji Ohba
- From the Laboratory of Hormonal Regulation, Cardiovascular and Metabolic Disorders Program and
| | - Mu-En Wang
- From the Laboratory of Hormonal Regulation, Cardiovascular and Metabolic Disorders Program and the Department of Animal Science and Technology, National Taiwan University, Taipei 10617, Taiwan
| | - Inna Astapova
- the Division of Endocrinology, Diabetes and Metabolism, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts 02115, and
| | - Sujoy Ghosh
- From the Laboratory of Hormonal Regulation, Cardiovascular and Metabolic Disorders Program and Centre for Computational Biology, Duke-National University of Singapore Graduate Medical School, Singapore 169857, Singapore
| | - Anthony N Hollenberg
- the Division of Endocrinology, Diabetes and Metabolism, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts 02115, and
| | - Karine Gauthier
- the Institut de Génomique Fonctionnelle de Lyon, Université de Lyon, Université Lyon 1, CNRS, Ecole Normale Supérieure de Lyon, 46, Allée d'Italie 69364, Lyon Cedex 07, France
| | - Paul M Yen
- From the Laboratory of Hormonal Regulation, Cardiovascular and Metabolic Disorders Program and
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45
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Aw DKL, Sinha RA, Tan HC, Loh LM, Salvatore D, Yen PM. Studies of molecular mechanisms associated with increased deiodinase 3 expression in a case of consumptive hypothyroidism. J Clin Endocrinol Metab 2014; 99:3965-71. [PMID: 24646062 DOI: 10.1210/jc.2013-3408] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
CONTEXT Consumptive hypothyroidism (CH) is a rare form of hypothyroidism due to increased catabolic activity of type 3 iodothyronine deiodinase (DIO3) that can occur in large tumors. PATIENTs with CH typically present with markedly increased requirements for exogenous thyroid hormone and resolution after removal of the source of ectopic DIO3. DIO3 is encoded by DIO3, an imprinted gene expressed on the paternal allele that is located in a DIO3/delta-like 1 homolog (DLK1) gene locus regulated by a common control region, intergenic differentially methylated region (IGDMR). Because DIO3 is an imprinted gene, loss of imprinting at the IGDMR is thought to play a role in its increased expression; however, the molecular mechanism for DIO3 in CH currently is not known. OBJECTIVE The aim of the study was to determine the molecular mechanism for CH in an adult patient. SETTING The study was conducted in the Department of Endocrinology of a tertiary care center in Singapore. PATIENT We report the case of an adult Asian female patient with a large intrathoracic fibrous tumor and severe hypothyroidism that resolved after tumor resection. RESULTS The patient's tumor expressed increased levels of DIO3 and DLK1 mRNA and protein levels. Methylation-specific PCR of the IGDMR showed similar hypomethylation in placenta, thyroid, leukocytes, and tumor. Western blotting showed activation of sonic hedgehog (SHH) and MAPK signaling pathways that can increase DIO3 and DLK1 expression. CONCLUSIONS Loss of imprinting did not account for overexpression of DIO3 in the patient's tumor. Instead SHH and MAPK/ERK pathway activation was associated with systemic thyroid hormone catabolism and growth of the tumor. These findings raise the possibility that other tumors that have increased SHH and MAPK/ERK signaling also may have intratumor or systemic effects on thyroid hormone function.
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Affiliation(s)
- Darius K L Aw
- Laboratory of Hormonal Regulation (D.K.L.A., R.A.S., P.M.Y.), Cardiovascular and Metabolic Disorders Program, Duke-NUS Graduate Medical School, Singapore 169857; Department of Endocrinology (H.C.T., L.M.L.), Singapore General Hospital, Singapore 169608; and Department of Clinical Medicine and Surgery (D.S.), University of Naples "Federico II," 80138 Naples, Italy
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Sinha RA, Singh BK, Yen PM. Thyroid hormone regulation of hepatic lipid and carbohydrate metabolism. Trends Endocrinol Metab 2014; 25:538-45. [PMID: 25127738 DOI: 10.1016/j.tem.2014.07.001] [Citation(s) in RCA: 147] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2014] [Revised: 06/21/2014] [Accepted: 07/07/2014] [Indexed: 02/07/2023]
Abstract
Thyroid hormone (TH) has important roles in regulating hepatic lipid, cholesterol, and glucose metabolism. Recent findings suggest that clinical conditions such as non-alcoholic fatty liver disease and type 2 diabetes mellitus, which are associated with dysregulated hepatic metabolism, may involve altered intracellular TH action. In addition, TH has key roles in lipophagy in lipid metabolism, mitochondrial quality control, and the regulation of metabolic genes. In this review, we discuss recent findings regarding the functions of TH in hepatic metabolism, the relationship between TH and metabolic disorders, and the potential therapeutic use of thyromimetics to treat metabolic dysfunction in the liver.
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Affiliation(s)
- Rohit A Sinha
- Cardiovascular and Metabolic Disorders Program, Duke-NUS Graduate Medical School, 8 College Road, Singapore 169547, Singapore
| | - Brijesh K Singh
- Cardiovascular and Metabolic Disorders Program, Duke-NUS Graduate Medical School, 8 College Road, Singapore 169547, Singapore
| | - Paul M Yen
- Cardiovascular and Metabolic Disorders Program, Duke-NUS Graduate Medical School, 8 College Road, Singapore 169547, Singapore; Sarah W. Stedman Nutrition and Metabolism Center, Departments of Medicine and Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC 27705, USA.
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Farah BL, Sinha RA, Wu Y, Singh BK, Zhou J, Bay BH, Yen PM. β-Adrenergic agonist and antagonist regulation of autophagy in HepG2 cells, primary mouse hepatocytes, and mouse liver. PLoS One 2014; 9:e98155. [PMID: 24950230 PMCID: PMC4064960 DOI: 10.1371/journal.pone.0098155] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2013] [Accepted: 04/29/2014] [Indexed: 12/13/2022] Open
Abstract
Autophagy recently has been shown to be involved in normal hepatic function and in pathological conditions such as non-alcoholic fatty liver disease. Adrenergic signalling also is an important regulator of hepatic metabolism and function. However, currently little is known about the potential role of adrenergic signaling on hepatic autophagy, and whether the β-adrenergic receptor itself may be a key regulator of autophagy. To address these issues, we investigated the actions of the β2-adrenergic receptor agonist, clenbuterol on hepatic autophagy. Surprisingly, we found that clenbuterol stimulated autophagy and autophagic flux in hepatoma cells, primary hepatocytes and in vivo. Similar effects also were observed with epinephrine treatment. Interestingly, propranolol caused a late block in autophagy in the absence and presence of clenbuterol, both in cell culture and in vivo. Thus, our results demonstrate that the β2-adrenergic receptor is a key regulator of hepatic autophagy, and that the β-blocker propranolol can independently induce a late block in autophagy.
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Affiliation(s)
- Benjamin L. Farah
- Cardiovascular and Metabolic Disorders Program, Duke-NUS Graduate Medical School Singapore, Singapore
| | - Rohit A. Sinha
- Cardiovascular and Metabolic Disorders Program, Duke-NUS Graduate Medical School Singapore, Singapore
| | - Yajun Wu
- Department of Anatomy, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Brijesh K. Singh
- Cardiovascular and Metabolic Disorders Program, Duke-NUS Graduate Medical School Singapore, Singapore
| | - Jin Zhou
- Cardiovascular and Metabolic Disorders Program, Duke-NUS Graduate Medical School Singapore, Singapore
| | - Boon-Huat Bay
- Department of Anatomy, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Paul M. Yen
- Cardiovascular and Metabolic Disorders Program, Duke-NUS Graduate Medical School Singapore, Singapore
- Sarah W. Stedman Nutrition and Metabolism Center, Departments of Medicine and Pharmacology and Cancer Biology, Duke University Medical Center, Durham, North Carolina, United States of America
- * E-mail:
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Aw DKL, Sinha RA, Xie SY, Yen PM. Differential AMPK phosphorylation by glucagon and metformin regulates insulin signaling in human hepatic cells. Biochem Biophys Res Commun 2014; 447:569-73. [PMID: 24735537 DOI: 10.1016/j.bbrc.2014.04.031] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2014] [Accepted: 04/07/2014] [Indexed: 01/10/2023]
Abstract
Insulin and glucagon signaling in the liver are major contributors to glucose homeostasis. Patients with Type 1 and Type 2 diabetes have impaired glycemic control due, in part, to dysregulation of the opposing actions of these hormones. While hyperglucagonemia is a common feature in diabetes, its precise role in insulin resistance is not well understood. Recently, metformin, an AMPK activator, was shown to regulate hepatic glucose output via inhibition of glucagon-induced cAMP/PKA signaling; however, the mechanism for how PKA inhibition leads to AMPK activation in human hepatic cells is not known. Here we show that glucagon impairs insulin-mediated AKT phosphorylation in human hepatic cell line Huh7. This impairment of AKT activation by glucagon is due to PKA-mediated inhibition of AMPK via increased inhibitory phosphorylation of AMPK(Ser173) and reduced activating phosphorylation of AMPK(Thr172). In contrast, metformin decreases PKA activity, leading to decreased pAMPK(Ser173) and increased pAMPK(Thr172). These data support a novel mechanism involving PKA-dependent AMPK phosphorylation that provides new insight into how glucagon and metformin modulate hepatic insulin resistance.
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Affiliation(s)
- Darius Kang Lie Aw
- Laboratory of Hormonal Regulation, Cardiovascular and Metabolic Disorders Program, Duke-NUS Graduate Medical School, Singapore
| | - Rohit A Sinha
- Laboratory of Hormonal Regulation, Cardiovascular and Metabolic Disorders Program, Duke-NUS Graduate Medical School, Singapore
| | - Sherwin Ying Xie
- Laboratory of Hormonal Regulation, Cardiovascular and Metabolic Disorders Program, Duke-NUS Graduate Medical School, Singapore
| | - Paul M Yen
- Laboratory of Hormonal Regulation, Cardiovascular and Metabolic Disorders Program, Duke-NUS Graduate Medical School, Singapore; Sarah W. Stedman Nutrition and Metabolism Center, Department of Medicine, Duke University Medical Center, Durham, NC, USA.
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Sinha RA, Farah BL, Singh BK, Siddique MM, Li Y, Wu Y, Ilkayeva OR, Gooding J, Ching J, Zhou J, Martinez L, Xie S, Bay BH, Summers SA, Newgard CB, Yen PM. Caffeine stimulates hepatic lipid metabolism by the autophagy-lysosomal pathway in mice. Hepatology 2014; 59:1366-80. [PMID: 23929677 DOI: 10.1002/hep.26667] [Citation(s) in RCA: 246] [Impact Index Per Article: 24.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2013] [Accepted: 07/30/2013] [Indexed: 12/14/2022]
Abstract
UNLABELLED Caffeine is one of the world's most consumed drugs. Recently, several studies showed that its consumption is associated with lower risk for nonalcoholic fatty liver disease (NAFLD), an obesity-related condition that recently has become the major cause of liver disease worldwide. Although caffeine is known to stimulate hepatic fat oxidation, its mechanism of action on lipid metabolism is still not clear. Here, we show that caffeine surprisingly is a potent stimulator of hepatic autophagic flux. Using genetic, pharmacological, and metabolomic approaches, we demonstrate that caffeine reduces intrahepatic lipid content and stimulates β-oxidation in hepatic cells and liver by an autophagy-lysosomal pathway. Furthermore, caffeine-induced autophagy involved down-regulation of mammalian target of rapamycin signaling and alteration in hepatic amino acids and sphingolipid levels. In mice fed a high-fat diet, caffeine markedly reduces hepatosteatosis and concomitantly increases autophagy and lipid uptake in lysosomes. CONCLUSION These results provide novel insight into caffeine's lipolytic actions through autophagy in mammalian liver and its potential beneficial effects in NAFLD.
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Affiliation(s)
- Rohit A Sinha
- Program of Cardiovascular and Metabolic Disorders, Duke-NUS Graduate Medical School, Singapore
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Mohan V, Sinha RA, Pathak A, Rastogi L, Kumar P, Pal A, Godbole MM. Maternal thyroid hormone deficiency affects the fetal neocorticogenesis by reducing the proliferating pool, rate of neurogenesis and indirect neurogenesis. Exp Neurol 2012; 237:477-88. [PMID: 22892247 DOI: 10.1016/j.expneurol.2012.07.019] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2012] [Revised: 06/26/2012] [Accepted: 07/31/2012] [Indexed: 01/25/2023]
Abstract
Neuronal progenitor cell proliferation and their optimum number are indispensable for neurogenesis, which is determined by cell cycle length and cell cycle quitting rate of the dividing progenitors. These processes are tightly orchestrated by transcription factors like Tbr2, Pax6, and E2f-1. Radial glia and intermediate progenitor cells (IPC) through direct and indirect neurogenesis maintain surface area and neocortical thickness during development. Here we show that fetal neurogenesis is maternal thyroid hormone (MTH) dependent with differential effect on direct and indirect neurogenesis. MTH deficiency (MTHD) impairs direct neurogenesis through initial down-regulation of Pax6 and diminished progenitor pool with recovery even before the onset of fetal thyroid function (FTF). However, persistent decrease in Tbr2 positive IPCs, diminished NeuN positivity in layers I-III of neocortex, and reduced cortical thickness indicate a non-compensatory impairment in indirect neurogenesis. TH deficiency causes disrupted cell cycle kinetics and deranged neurogenesis. It specifically affects indirect neurogenesis governed by intermediate progenitor cells (IPCs). TH replacement in hypothyroid dams partially restored the rate of neurogenesis in the fetal neocortex. Taken together we describe a novel role of maternal TH in promoting IPCs derived neuronal differentiation in developing neo-cortex. We have also shown for the first time that ventricular zone progenitors are TH responsive as they express its receptor, TR alpha-1, transporters (MCT8) and deiodinases. This study highlights the importance of maternal thyroid hormone (TH) even before the start of the fetal thyroid function.
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Affiliation(s)
- Vishwa Mohan
- Department of Endocrinology, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow 226014, UP India
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