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Crewe C. Energetic Stress-Induced Metabolic Regulation by Extracellular Vesicles. Compr Physiol 2023; 13:5051-5068. [PMID: 37358503 PMCID: PMC10414774 DOI: 10.1002/cphy.c230001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/27/2023]
Abstract
Recent studies have demonstrated that extracellular vesicles (EVs) serve powerful and complex functions in metabolic regulation and metabolic-associated disease, although this field of research is still in its infancy. EVs are released into the extracellular space from all cells and carry a wide range of cargo including miRNAs, mRNA, DNA, proteins, and metabolites that have robust signaling effects in receiving cells. EV production is stimulated by all major stress pathways and, as such, has a role in both restoring homeostasis during stress and perpetuating disease. In metabolic regulation, the dominant stress signal is a lack of energy due to either nutrient deficits or damaged mitochondria from nutrient excess. This stress signal is termed "energetic stress," which triggers a robust and evolutionarily conserved response that engages major cellular stress pathways, the ER unfolded protein response, the hypoxia response, the antioxidant response, and autophagy. This article proposes the model that energetic stress is the dominant stimulator of EV release with a focus on metabolically important cells such as hepatocytes, adipocytes, myocytes, and pancreatic β-cells. Furthermore, this article will discuss how the cargo in stress-stimulated EVs regulates metabolism in receiving cells in both beneficial and detrimental ways. © 2023 American Physiological Society. Compr Physiol 13:5051-5068, 2023.
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Affiliation(s)
- Clair Crewe
- Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, Missouri, USA
- Department of Internal Medicine, Division of Endocrinology, Metabolism and Lipid Research, Washington University School of Medicine, St. Louis, Missouri, USA
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Li S, Feng F, Deng Y. Resveratrol Regulates Glucose and Lipid Metabolism in Diabetic Rats by Inhibition of PDK1/AKT Phosphorylation and HIF-1α Expression. Diabetes Metab Syndr Obes 2023; 16:1063-1074. [PMID: 37090841 PMCID: PMC10115207 DOI: 10.2147/dmso.s403893] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Accepted: 04/07/2023] [Indexed: 04/25/2023] Open
Abstract
Purpose To explore the underlying mechanism of the anti-diabetic effect of resveratrol (RSV) on regulating glycolipid metabolism in diabetic rats induced by streptozotocin (STZ) and a high-fat diet (HFD). Methods Male Wistar rats were randomized into three groups. Two groups were fed a high-fat diet and intraperitoneally injected with STZ (35 mg/kg), with one group also treated with RSV (30 mg/kg/d), and the third, control group was fed a normal diet. After 12 weeks, blood lipid levels and fasting blood glucose (FBG) were assessed. Histopathological changes were evaluated by hematoxylin-eosin (HE) staining and periodic acid-Schiff (PAS) staining. The protein expression of hypoxia-inducible factor 1α (HIF-1α) was assessed by Western blotting and immunofluorescence, and the proteins level of 3-phosphoinositide-dependent protein kinase 1 (PDK1), phosphorylated-PDK1 (p-PDK1), phosphorylated-protein kinase B (p-AKT), glucose transporter 1 (GLUT1) and low-density lipoprotein receptor (LDLR) in the liver were analyzed by Western blotting. The mRNA levels of Hif-1α, Glut1 and Ldlr in the liver were determined by RT-qPCR. Results RSV treatment significantly reduced liver/body weight ratio (L/W, P < 0.05), FBG (P < 0.01) and serum concentrations of total cholesterol (TC, P < 0.05), triglycerides (TG, P < 0.01) and low-density lipoprotein-cholesterol (LDL-C, P < 0.05) in diabetic rats. RSV also improved diabetic symptoms, attenuated liver steatosis and increased liver glycogen accumulation. RSV treatment significantly downregulated the proteins expression of p-PDK1 and p-AKT (P < 0.01) and the levels of HIF-1α (P < 0.05) and GLUT1 (P < 0.01), while significantly upregulating the level of LDLR (P < 0.05). Conclusion RSV was effective in improving glycolipid metabolism in diabetic rats, probably by inhibiting the PDK1/AKT/HIF-1α pathway and regulation of its downstream target levels. These findings may provide new insight into the mechanism of action of RSV in the treatment of diabetes.
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Affiliation(s)
- Siyun Li
- Department of Pharmacy, The Third Affiliated Hospital of Southern Medical University, Guangzhou, People’s Republic of China
| | - Fuzhen Feng
- Department of Pharmacy, The Sixth Affiliated Hospital, School of Medicine, South China University of Technology, Foshan, People’s Republic of China
| | - Yanhui Deng
- Department of Pharmacy, The Third Affiliated Hospital of Southern Medical University, Guangzhou, People’s Republic of China
- Correspondence: Yanhui Deng, Department of Pharmacy, The Third Affiliated Hospital of Southern Medical University, 183 West Zhongshan Road, Tianhe District, Guangzhou, 510630, People’s Republic of China, Tel +86 020 62784810, Email
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Brugaletta G, Greene E, Ramser A, Maynard CW, Tabler TW, Sirri F, Anthony NB, Orlowski S, Dridi S. Effect of Cyclic Heat Stress on Hypothalamic Oxygen Homeostasis and Inflammatory State in the Jungle Fowl and Three Broiler-Based Research Lines. Front Vet Sci 2022; 9:905225. [PMID: 35692291 PMCID: PMC9174949 DOI: 10.3389/fvets.2022.905225] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2022] [Accepted: 04/20/2022] [Indexed: 11/23/2022] Open
Abstract
Heat stress (HS) is devastating to poultry production sustainability due its detrimental effects on performance, welfare, meat quality, and profitability. One of the most known negative effects of HS is feed intake depression, which is more pronounced in modern high-performing broilers compared to their ancestor unselected birds, yet the underlying molecular mechanisms are not fully defined. The present study aimed, therefore, to determine the hypothalamic expression of a newly involved pathway, hypoxia/oxygen homeostasis, in heat-stressed broiler-based research lines and jungle fowl. Three populations of broilers (slow growing ACRB developed in 1956, moderate growing 95RB from broilers available in 1995, and modern fast growing MRB from 2015) and unselected Jungle fowl birds were exposed to cyclic heat stress (36°C, 9 h/day for 4 weeks) in a 2 × 4 factorial experimental design. Total RNAs and proteins were extracted from the hypothalamic tissues and the expression of target genes and proteins was determined by real-time quantitative PCR and Western blot, respectively. It has been previously shown that HS increased core body temperature and decreased feed intake in 95RB and MRB, but not in ACRB or JF. HS exposure did not affect the hypothalamic expression of HIF complex, however there was a line effect for HIF-1α (P = 0.02) with higher expression in JF under heat stress. HS significantly up regulated the hypothalamic expression of hemoglobin subunits (HBA1, HBBR, HBE, HBZ), and HJV in ACRB, HBA1 and HJV in 95RB and MRB, and HJV in JF, but it down regulated FPN1 in JF. Additionally, HS altered the hypothalamic expression of oxygen homeostasis- up and down-stream signaling cascades. Phospho-AMPKThr172 was activated by HS in JF hypothalamus, but it decreased in that of the broiler-based research lines. Under thermoneutral conditions, p-AMPKThr172 was higher in broiler-based research lines compared to JF. Ribosomal protein S6K1, however, was significantly upregulated in 95RB and MRB under both environmental conditions. HS significantly upregulated the hypothalamic expression of NF-κB2 in MRB, RelB, and TNFα in ACRB, abut it down regulated RelA in 95RB. The regulation of HSPs by HS seems to be family- and line-dependent. HS upregulated the hypothalamic expression of HSP60 in ACRB and 95RB, down regulated HSP90 in JF only, and decreased HSP70 in all studied lines. Taken together, this is the first report showing that HS modulated the hypothalamic expression of hypoxia- and oxygen homeostasis-associated genes as well as their up- and down-stream mediators in chickens, and suggests that hypoxia, thermotolerance, and feed intake are interconnected, which merit further in-depth investigations.
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Affiliation(s)
- Giorgio Brugaletta
- Department of Poultry Science, Center of Excellence for Poultry Science, University of Arkansas, Fayetteville, AR, United States
- Department of Agricultural and Food Sciences, Alma Mater Studiorum – University of Bologna, Bologna, Italy
| | - Elizabeth Greene
- Department of Poultry Science, Center of Excellence for Poultry Science, University of Arkansas, Fayetteville, AR, United States
| | - Alison Ramser
- Department of Poultry Science, Center of Excellence for Poultry Science, University of Arkansas, Fayetteville, AR, United States
| | - Craig W. Maynard
- Department of Poultry Science, Center of Excellence for Poultry Science, University of Arkansas, Fayetteville, AR, United States
| | - Travis W. Tabler
- Department of Poultry Science, Center of Excellence for Poultry Science, University of Arkansas, Fayetteville, AR, United States
| | - Federico Sirri
- Department of Agricultural and Food Sciences, Alma Mater Studiorum – University of Bologna, Bologna, Italy
| | - Nicholas B. Anthony
- Department of Poultry Science, Center of Excellence for Poultry Science, University of Arkansas, Fayetteville, AR, United States
| | - Sara Orlowski
- Department of Poultry Science, Center of Excellence for Poultry Science, University of Arkansas, Fayetteville, AR, United States
| | - Sami Dridi
- Department of Poultry Science, Center of Excellence for Poultry Science, University of Arkansas, Fayetteville, AR, United States
- *Correspondence: Sami Dridi
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Holzner LMW, Murray AJ. Hypoxia-Inducible Factors as Key Players in the Pathogenesis of Non-alcoholic Fatty Liver Disease and Non-alcoholic Steatohepatitis. Front Med (Lausanne) 2021; 8:753268. [PMID: 34692739 PMCID: PMC8526542 DOI: 10.3389/fmed.2021.753268] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Accepted: 09/10/2021] [Indexed: 12/20/2022] Open
Abstract
Non-alcoholic fatty liver disease (NAFLD) and its more severe form non-alcoholic steatohepatitis (NASH) are a major public health concern with high and increasing global prevalence, and a significant disease burden owing to its progression to more severe forms of liver disease and the associated risk of cardiovascular disease. Treatment options, however, remain scarce, and a better understanding of the pathological and physiological processes involved could enable the development of new therapeutic strategies. One process implicated in the pathology of NAFLD and NASH is cellular oxygen sensing, coordinated largely by the hypoxia-inducible factor (HIF) family of transcription factors. Activation of HIFs has been demonstrated in patients and mouse models of NAFLD and NASH and studies of activation and inhibition of HIFs using pharmacological and genetic tools point toward important roles for these transcription factors in modulating central aspects of the disease. HIFs appear to act in several cell types in the liver to worsen steatosis, inflammation, and fibrosis, but may nevertheless improve insulin sensitivity. Moreover, in liver and other tissues, HIF activation alters mitochondrial respiratory function and metabolism, having an impact on energetic and redox homeostasis. This article aims to provide an overview of current understanding of the roles of HIFs in NAFLD, highlighting areas where further research is needed.
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Affiliation(s)
- Lorenz M W Holzner
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom
| | - Andrew J Murray
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom
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Koehler S, Springer A, Issel N, Klinger S, Strube C, Breves G. Changes in porcine nutrient transport physiology in response to Ascaris suum infection. Parasit Vectors 2021; 14:533. [PMID: 34649607 PMCID: PMC8515719 DOI: 10.1186/s13071-021-05029-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Accepted: 09/20/2021] [Indexed: 11/10/2022] Open
Abstract
Background The roundworm Ascaris suum is one of the parasites with the greatest economic impact on pig farming. In this context, lower weight gain is hypothesized to be due to decreased nutrient absorption. This study aims at characterizing the effects of A. suum infection on intestinal nutrient transport processes and potential molecular mechanisms. Methods Three groups of six piglets each were infected orally (10,000 embryonated A. suum eggs) in a single dose (“single infection”). Another three groups were infected orally (1000 embryonated eggs) for 10 consecutive days (“trickle infection”). Animals were necropsied 21, 35 and 49 days post-infection (dpi). Three groups served as respective controls. The Ussing chamber technique was applied for the functional characterization of small intestinal tissues [short-circuit currents (Isc) as induced by glucose, alanine and peptides; 3H-glucose net flux rates; tissue conductance (Gt)]. Transcription and expression levels of relevant cytokines and nutrient transporters were evaluated (qPCR/western blot). Results Peptide- and alanine-induced changes in Isc were significantly decreased in the jejunum and ileum of the trickle-infected group at 49 dpi and in the ileum of the single-infected group at 49 dpi. No significant differences regarding glucose transport were observed between the Ascaris-infected groups and the control group in Ussing chamber experiments. Transcription levels of the glucose and peptide transporters as well as of selected transcription factors (transcription of signal transducer and activator of transcription 6 [STAT6] and hypoxia-inducible factor 1-alpha [Hif-1α]) were significantly increased in response to both infection types after some periods. The transcription of interleukins 4 and 13 varied between decrease and increase regarding the respective time points, as did the protein expression of glucose transporters. The expression of the peptide transporter PepT1 was significantly decreased in the ileal single-infected group at 35 dpi. Hif-1α was significantly increased in the ileal tissue from the single-infected group at 21 dpi and in the trickle-infected group at 35 dpi. The expression levels of Na+/K+-ATPase and ASCT1 remained unaffected. Conclusions In contrast to the current hypothesis, these results indicate that the nutrient deprivation induced by A. suum cannot be explained by transcriptional or expression changes alone and requires further studies. Graphical abstract ![]()
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Affiliation(s)
- Sarina Koehler
- Institute for Parasitology, Centre for Infection Medicine, University of Veterinary Medicine Hannover, Hanover, Germany
| | - Andrea Springer
- Institute for Parasitology, Centre for Infection Medicine, University of Veterinary Medicine Hannover, Hanover, Germany
| | - Nicole Issel
- Institute for Physiology and Cell Biology, University of Veterinary Medicine Hannover, Hanover, Germany
| | - Stefanie Klinger
- Institute for Physiology and Cell Biology, University of Veterinary Medicine Hannover, Hanover, Germany
| | - Christina Strube
- Institute for Parasitology, Centre for Infection Medicine, University of Veterinary Medicine Hannover, Hanover, Germany
| | - Gerhard Breves
- Institute for Physiology and Cell Biology, University of Veterinary Medicine Hannover, Hanover, Germany.
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Mesarwi OA, Moya EA, Zhen X, Gautane M, Zhao H, Wegbrans Giró P, Alshebli M, McCarley KE, Breen EC, Malhotra A. Hepatocyte HIF-1 and Intermittent Hypoxia Independently Impact Liver Fibrosis in Murine NAFLD. Am J Respir Cell Mol Biol 2021; 65:390-402. [PMID: 34003729 DOI: 10.1165/rcmb.2020-0492oc] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Obstructive sleep apnea (OSA) is associated with insulin resistance, lipid dysregulation, and hepatic steatosis and fibrosis in nonalcoholic fatty liver disease (NAFLD). We have previously shown that hepatocyte hypoxia inducible factor-1 (HIF-1) mediates the development of liver fibrosis in a mouse model of NAFLD. We hypothesized that intermittent hypoxia (IH) modeling OSA would worsen hepatic steatosis and fibrosis in murine NAFLD, via HIF-1. Mice with hepatocyte-specific deletion of Hif1a (Hif1a-/-hep) and wild-type (Hif1aF/F) controls were fed a high trans-fat diet to induce NAFLD with steatohepatitis. Half from each group were exposed to IH, and the other half to intermittent air. Glucose tolerance test was performed prior to sacrifice. Liver collagen and triglycerides were determined. Mitochondrial efficiency was assessed in fresh liver tissue at sacrifice. Hepatic malondialdehyde concentration and pro-inflammatory cytokine levels were assessed, and genes of collagen and fatty acid metabolism were queried. Hif1a-/-hep mice gained less weight than Hif1aF/F mice (-2.3 grams, p=0.029). There was also a genotype-independent effect of IH on body weight, with less weight gain in IH (p=0.003). Fasting glucose, HOMA-IR, and glucose tolerance test were all improved in Hif1a-/-hep mice. Liver collagen was increased in IH (p=0.033), and reduced in Hif1a-/-hep mice (p<0.001), without any significant exposure/genotype interaction. Liver TNF-α and IL-1β were significantly increased in IH, and decreased in Hif1a-/-hep. We conclude that HIF-1 signaling worsens the metabolic profile and hastens NAFLD progression, and that IH may worsen liver fibrosis. These effects are plausibly mediated by hepatic inflammatory stress.
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Affiliation(s)
- Omar A Mesarwi
- University of California San Diego, 8784, Division of Pulmonary, Critical Care and Sleep Medicine, La Jolla, California, United States;
| | - Esteban A Moya
- University of California San Diego, 8784, Division of Pulmonary, Critical Care, and Sleep Medicine, La Jolla, California, United States
| | - Xin Zhen
- University of California San Diego, 8784, La Jolla, California, United States
| | - Mary Gautane
- University of California San Diego, 8784, La Jolla, California, United States
| | - Huyai Zhao
- University of California San Diego, 8784, La Jolla, California, United States
| | - Paula Wegbrans Giró
- Imperial College London, 4615, Department of Bioengineering, London, United Kingdom of Great Britain and Northern Ireland
| | - Mouza Alshebli
- Abu Dhabi Health Services Co, 155078, Abu Dhabi, United Arab Emirates
| | - Kendall E McCarley
- University of Houston, 14743, Department of Educational Psychology, Houston, Texas, United States
| | - Ellen C Breen
- University of California San Diego, 8784, Division of Pulmonary, Critical Care, and Sleep Medicine, La Jolla, California, United States
| | - Atul Malhotra
- University of California San Diego, 8784, Division of Pulmonary, Critical Care, and Sleep Medicine, La Jolla, California, United States
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Pek NMQ, Liu KJ, Nichane M, Ang LT. Controversies Surrounding the Origin of Hepatocytes in Adult Livers and the in Vitro Generation or Propagation of Hepatocytes. Cell Mol Gastroenterol Hepatol 2020; 11:273-290. [PMID: 32992051 PMCID: PMC7695885 DOI: 10.1016/j.jcmgh.2020.09.016] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 09/21/2020] [Accepted: 09/22/2020] [Indexed: 12/21/2022]
Abstract
Epithelial cells in the liver (known as hepatocytes) are high-performance engines of myriad metabolic functions and versatile responders to liver injury. As hepatocytes metabolize amino acids, alcohol, drugs, and other substrates, they produce and are exposed to a milieu of toxins and harmful byproducts that can damage themselves. In the healthy liver, hepatocytes generally divide slowly. However, after liver injury, hepatocytes can ramp up proliferation to regenerate the liver. Yet, on extensive injury, regeneration falters, and liver failure ensues. It is therefore critical to understand the mechanisms underlying liver regeneration and, in particular, which liver cells are mobilized during liver maintenance and repair. Controversies continue to surround the very existence of hepatic stem cells and, if they exist, their spatial location, multipotency, degree of contribution to regeneration, ploidy, and susceptibility to tumorigenesis. This review discusses these controversies. Finally, we highlight how insights into hepatocyte regeneration and biology in vivo can inform in vitro studies to propagate primary hepatocytes with liver regeneration-associated signals and to generate hepatocytes de novo from pluripotent stem cells.
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Affiliation(s)
| | | | | | - Lay Teng Ang
- Correspondence Address correspondence to: Lay Teng Ang, PhD, Stanford Institute for Stem Cell Biology & Regenerative Medicine, Stanford-UC Berkeley Siebel Stem Cell Institute, Stanford University School of Medicine, Stanford, California 94305.
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Takikawa A, Usui I, Fujisaka S, Tsuneyama K, Okabe K, Nakagawa T, Nawaz A, Kado T, Jojima T, Aso Y, Hayakawa Y, Yagi K, Tobe K. Macrophage-specific hypoxia-inducible factor-1α deletion suppresses the development of liver tumors in high-fat diet-fed obese and diabetic mice. J Diabetes Investig 2019; 10:1411-1418. [PMID: 30897274 PMCID: PMC6825928 DOI: 10.1111/jdi.13047] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Revised: 03/12/2019] [Accepted: 03/15/2019] [Indexed: 12/12/2022] Open
Abstract
AIMS/INTRODUCTION Chronic inflammation of the liver is often observed with obesity or type 2 diabetes. In these pathological conditions, the immunological cells, such as macrophages, play important roles in the development or growth of liver cancer. Recently, it was reported that hypoxia-inducible factor-1α (HIF-1α) is a key molecule for the acquisition of inflammatory M1 polarity of macrophages. In the present study, we examined the effects of altered macrophage polarity on obesity- and diabetes-associated liver cancer using macrophage-specific HIF-1α knockout (KO) mice. MATERIALS AND METHODS To induce liver cancer in the mice, diethylnitrosamine, a chemical carcinogen, was used. Both KO mice and wild-type littermates were fed either a high-fat diet (HFD) or normal chow. They were mainly analyzed 6 months after HFD feeding. RESULTS Development of liver cancer after HFD feeding was 45% less in KO mice than in wild-type littermates mice. Phosphorylation of extracellular signal-regulated kinase 2 was also lower in the liver of KO mice. Those effects of HIF-1α deletion in macrophages were not observed in normal chow-fed mice. Furthermore, the size of liver tumors did not differ between KO and wild-type littermates mice, even those on a HFD. These results suggest that the activation of macrophage HIF-1α by HFD is involved not in the growth, but in the development of liver cancer with the enhanced oncogenic extracellular signal-regulated kinase 2 signaling in hepatocytes. CONCLUSIONS The activation of macrophage HIF-1α might play important roles in the development of liver cancer associated with diet-induced obesity and diabetes.
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Affiliation(s)
- Akiko Takikawa
- First Department of Internal MedicineUniversity of ToyamaToyamaJapan
| | - Isao Usui
- First Department of Internal MedicineUniversity of ToyamaToyamaJapan
- Department of Endocrinology and MetabolismDokkyo Medical UniversityTochigiJapan
| | - Shiho Fujisaka
- First Department of Internal MedicineUniversity of ToyamaToyamaJapan
| | - Koichi Tsuneyama
- Department of Pathology and Laboratory MedicineInstitute of Biomedical SciencesTokushima University Graduate SchoolTokushimaJapan
| | - Keisuke Okabe
- First Department of Internal MedicineUniversity of ToyamaToyamaJapan
- Department of Metabolism and NutritionGraduate School of Medicine and Pharmaceutical Science for ResearchUniversity of ToyamaToyamaJapan
| | - Takashi Nakagawa
- Department of Metabolism and NutritionGraduate School of Medicine and Pharmaceutical Science for ResearchUniversity of ToyamaToyamaJapan
| | - Allah Nawaz
- First Department of Internal MedicineUniversity of ToyamaToyamaJapan
| | - Tomonobu Kado
- First Department of Internal MedicineUniversity of ToyamaToyamaJapan
| | - Teruo Jojima
- Department of Endocrinology and MetabolismDokkyo Medical UniversityTochigiJapan
| | - Yoshimasa Aso
- Department of Endocrinology and MetabolismDokkyo Medical UniversityTochigiJapan
| | - Yoshihiro Hayakawa
- Division of Pathogenic BiochemistryDepartment of BioscienceInstitute of Natural MedicineUniversity of ToyamaToyamaJapan
| | - Kunikimi Yagi
- First Department of Internal MedicineUniversity of ToyamaToyamaJapan
| | - Kazuyuki Tobe
- First Department of Internal MedicineUniversity of ToyamaToyamaJapan
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Zhou X, Zhang R, Zou Z, Shen X, Xie T, Xu C, Dong J, Liao L. Hypoglycaemic effects of glimepiride in sulfonylurea receptor 1 deficient rat. Br J Pharmacol 2018; 176:478-490. [PMID: 30471094 DOI: 10.1111/bph.14553] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Revised: 10/30/2018] [Accepted: 11/02/2018] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND AND PURPOSE Sulfonylureas (SUs) have been suggested to have an insulin-independent blood glucose-decreasing activity due to an extrapancreatic effect. However, a lack of adequate in vivo evidence makes this statement controversial. Here, we aimed to evaluate whether glimepiride has extrapancreatic blood glucose-lowering activity in vivo. EXPERIMENTAL APPROACH Sulfonylurea receptor 1 deficient (SUR1-/- ) rats were created by means of transcription activator-like effector nucleases (TALEN)-mediated gene targeting technology. Type 2 diabetic models were established by feeding a high-fat diet and administering a low-dose of streptozotocin. These rats were then randomly divided into four groups: glimepiride, gliclazide, metformin and saline. All rats were treated for 2 weeks. KEY RESULTS Glimepiride decreased blood glucose levels and increased insulin sensitivity without elevating insulin levels. Gliclazide showed similar effects as glimepiride. Both agents were weaker than metformin. Further mechanistic investigations revealed that glimepiride increased hepatic glycogen synthesis and decreased gluconeogenesis, which were accompanied by the activation of Akt in the liver. Moreover, glimepiride increased both total and membrane glucose transporter 4 (GLUT4) levels in muscle and fat, which might be attributed to insulin receptor-independent IRS1/Akt activation. CONCLUSION AND IMPLICATIONS Glimepiride possesses an extrapancreatic blood glucose-lowering effect in vivo, which might be attributed to its direct effect on insulin-sensitive tissues. Therefore, the combination of glimepiride with multiple insulin injections should not be excluded per se.
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Affiliation(s)
- Xiaojun Zhou
- Department of Endocrinology, Shandong Provincial Qianfoshan Hospital, Shandong University, Jinan, China
| | - Rui Zhang
- Department of Endocrinology, Shandong Provincial Qianfoshan Hospital, Shandong University, Jinan, China
| | - Zhiwei Zou
- Department of Endocrinology, Qilu Hospital of Shandong University, Jinan, China
| | - Xue Shen
- Department of Endocrinology, Shandong Provincial Qianfoshan Hospital, Shandong University of Traditional Chinese Medicine, Jinan, China
| | - Tianyue Xie
- Department of Endocrinology, Shandong Provincial Qianfoshan Hospital, Shandong University of Traditional Chinese Medicine, Jinan, China
| | - Chunmei Xu
- Department of Endocrinology, Shandong Provincial Qianfoshan Hospital, Shandong University, Jinan, China
| | - Jianjun Dong
- Department of Endocrinology, Qilu Hospital of Shandong University, Jinan, China
| | - Lin Liao
- Department of Endocrinology, Shandong Provincial Qianfoshan Hospital, Shandong University, Jinan, China
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Abstract
Hypoxia-inducible factors (HIFs), a family of transcription factors activated by hypoxia, consist of three α-subunits (HIF1α, HIF2α and HIF3α) and one β-subunit (HIF1β), which serves as a heterodimerization partner of the HIFα subunits. HIFα subunits are stabilized from constitutive degradation by hypoxia largely through lowering the activity of the oxygen-dependent prolyl hydroxylases that hydroxylate HIFα, leading to their proteolysis. HIF1α and HIF2α are expressed in different tissues and regulate target genes involved in angiogenesis, cell proliferation and inflammation, and their expression is associated with different disease states. HIFs have been widely studied because of their involvement in cancer, and HIF2α-specific inhibitors are being investigated in clinical trials for the treatment of kidney cancer. Although cancer has been the major focus of research on HIF, evidence has emerged that this pathway has a major role in the control of metabolism and influences metabolic diseases such as obesity, type 2 diabetes mellitus and non-alcoholic fatty liver disease. Notably increased HIF1α and HIF2α signalling in adipose tissue and small intestine, respectively, promotes metabolic diseases in diet-induced disease models. Inhibition of HIF1α and HIF2α decreases the adverse diet-induced metabolic phenotypes, suggesting that they could be drug targets for the treatment of metabolic diseases.
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Affiliation(s)
- Frank J Gonzalez
- Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD, USA.
| | - Cen Xie
- Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD, USA
| | - Changtao Jiang
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University, Key Laboratory of Molecular Cardiovascular Science, Ministry of Education, Beijing, China.
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Gaspar JM, Velloso LA. Hypoxia Inducible Factor as a Central Regulator of Metabolism - Implications for the Development of Obesity. Front Neurosci 2018; 12:813. [PMID: 30443205 PMCID: PMC6221908 DOI: 10.3389/fnins.2018.00813] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Accepted: 10/18/2018] [Indexed: 12/19/2022] Open
Abstract
The hypothalamus plays a major role in the regulation of food intake and energy expenditure. In the last decade, it was demonstrated that consumption of high-fat diets triggers the activation of an inflammatory process in the hypothalamus, inducing neurofunctional alterations and contributing to the development of obesity. Hypoxia-inducible factors (HIFs) are key molecules that regulate cellular responses to inflammation and hypoxia, being essential for the normal cell function and survival. Currently, evidence points to a role of HIF pathway in metabolic regulation that could also be involved in the progression of obesity and metabolic diseases. The challenge is to understand how HIF modulation impacts body mass gain and metabolic disorders such as insulin resistance. Distinct animal models with tissue-specific knocking-out or overexpression of hypoxia signaling pathway genes revealed a cell-specificity in the activation of HIF pathways, and some of them have opposite phenotypes among the various HIFs gain- and loss-of-function mouse models. In this review, we discuss the major findings that provide support for a role of HIF pathway involvement in the regulation of metabolism, especially in glucose and energy homeostasis.
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Affiliation(s)
- Joana M Gaspar
- Post-Graduation in Biochemistry, Department of Biochemistry, Federal University of Santa Catarina, Florianópolis, Brazil.,Laboratório de Bioenergética e Estresse Oxidativo, Departamento de Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis, Brazil
| | - Lício A Velloso
- Laboratory of Cell Signaling, Obesity and Comorbidities Research Center, University of Campinas, Campinas, Brazil.,National Institute of Science and Technology on Neuroimmunomodulation, Rio de Janeiro, Brazil
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Gaspar JM, Mendes NF, Corrêa-da-Silva F, Lima-Junior JCD, Gaspar RC, Ropelle ER, Araujo EP, Carvalho HM, Velloso LA. Downregulation of HIF complex in the hypothalamus exacerbates diet-induced obesity. Brain Behav Immun 2018; 73:550-561. [PMID: 29935943 DOI: 10.1016/j.bbi.2018.06.020] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Revised: 05/30/2018] [Accepted: 06/20/2018] [Indexed: 11/25/2022] Open
Abstract
Hypothalamic hypoxia-inducible factor-1 (HIF-1) can regulate whole-body energy homeostasis in response to changes in blood glucose, suggesting that it acts as a sensor for systemic energy stores. Here, we hypothesized that hypothalamic HIF-1 could be affected by diet-induced obesity (DIO). We used eight-week old, male C57Bl6 mice, fed normal chow diet or with high fat diet for 1, 3, 7, 14 and 28 days. The expression of HIF-1alpha and HIF-1beta was measured by PCR and western blotting and its hypothalamic distribution was evaluated by fluorescence microscopy. Inhibition of HIF-1beta in arcuate nucleus of hypothalamus was performed using stereotaxic injection of shRNA lentiviral particles and animals were grouped under normal chow diet or high fat diet for 14 days. Using bioinformatics, we show that in humans, the levels of HIF-1 transcripts are directly correlated with those of hypothalamic transcripts for proteins involved in inflammation, regulation of apoptosis, autophagy, and the ubiquitin/proteasome system; furthermore, in rodents, hypothalamic HIF-1 expression is directly correlated with the phenotype of increased energy expenditure. In mice, DIO was accompanied by increased HIF-1 expression. The inhibition of hypothalamic HIF-1 by injection of an shRNA resulted in a further increase in body mass, a decreased basal metabolic rate, increased hypothalamic inflammation, and glucose intolerance. Thus, hypothalamic HIF-1 is increased during DIO, and its inhibition worsens the obesity-associated metabolic phenotype. Thus, hypothalamic HIF-1 emerges as a target for therapeutic intervention against obesity.
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Affiliation(s)
- Joana M Gaspar
- Laboratory of Cell Signaling, University of Campinas, Obesity and Comorbidities Research Center, Campinas, São Paulo, Brazil
| | - Natália Ferreira Mendes
- Laboratory of Cell Signaling, University of Campinas, Obesity and Comorbidities Research Center, Campinas, São Paulo, Brazil; Faculty of Nursing, University of Campinas, Campinas, São Paulo, Brazil
| | - Felipe Corrêa-da-Silva
- Laboratory of Cell Signaling, University of Campinas, Obesity and Comorbidities Research Center, Campinas, São Paulo, Brazil
| | - José C de Lima-Junior
- Laboratory of Cell Signaling, University of Campinas, Obesity and Comorbidities Research Center, Campinas, São Paulo, Brazil
| | - Rodrigo C Gaspar
- Laboratory of Molecular Biology of Exercise, University of Campinas (UNICAMP), Limeira, São Paulo, Brazil
| | - Eduardo R Ropelle
- Laboratory of Molecular Biology of Exercise, University of Campinas (UNICAMP), Limeira, São Paulo, Brazil
| | - Eliana P Araujo
- Laboratory of Cell Signaling, University of Campinas, Obesity and Comorbidities Research Center, Campinas, São Paulo, Brazil; Faculty of Nursing, University of Campinas, Campinas, São Paulo, Brazil
| | - Humberto M Carvalho
- Department of Physical Education, Federal University of Santa Catarina, Florianópolis, Santa Catarina, Brazil
| | - Lício A Velloso
- Laboratory of Cell Signaling, University of Campinas, Obesity and Comorbidities Research Center, Campinas, São Paulo, Brazil.
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13
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Jiménez-Jiménez C, Lara-Chica M, Palomares B, Collado JA, Lopez-Miranda J, Muñoz E, Calzado MA. Effect of N-acyl-dopamines on beta cell differentiation and wound healing in diabetic mice. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2018; 1865:1539-1551. [PMID: 30327197 DOI: 10.1016/j.bbamcr.2018.08.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Revised: 08/12/2018] [Accepted: 08/14/2018] [Indexed: 12/19/2022]
Abstract
N-acyl-dopamines are endolipids with neuroprotective, antiinflammatory and immunomodulatory properties. Previously, we showed the ability of these compounds to induce HIF-1α stabilization. Hypoxia and HIF-1α play an important role in the most relevant stages of diabetic pathogenesis. This work analyzes the possible role of these molecules on beta cell differentiation, insulin production and diabetic foot ulcer. Hypoxia response pathway has been characterized in beta-cell differentiation in rat pancreatic acinar cell line and human islet-derived precursor cells. Protein and mRNA expression of key proteins in this process have been analyzed, as well as those involved in beta cells reprogramming. The effect of N-acyl-dopamines on hypoxia response pathway, beta cells reprogramming and insulin production have been studied in both cell types, as well as its role in angiogenesis models in vitro and wound closure in type 2 diabetic mice. Our results show how the hypoxia response pathway is altered during beta cells differentiation, accompanied by an induction of the transcription factor HIF-1α. We demonstrate how some N-acyl-dopamines induce beta cell differentiation and insulin production in two different cell models. In parallel, these endolipids promote angiogenesis in vitro and wound closure in type 2 diabetic mice. These results provide a biological mechanism through which some endolipids could induce beta cell differentiation. We demonstrate how N-acyl-dopamines can modulate insulin production and, in parallel, reverse HIF-1α inhibition in a wound healing model in diabetic mice. Therefore, the potential use of the pharmacological modulation of N-acyl-dopamines may have implications for diabetes prevention and treatment strategies.
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Affiliation(s)
- Carla Jiménez-Jiménez
- Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC), Córdoba, Spain; Departamento de Biología Celular, Fisiología e Inmunología, Universidad de Córdoba, Córdoba, Spain
| | - Maribel Lara-Chica
- Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC), Córdoba, Spain; Departamento de Biología Celular, Fisiología e Inmunología, Universidad de Córdoba, Córdoba, Spain
| | - Belén Palomares
- Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC), Córdoba, Spain; Departamento de Biología Celular, Fisiología e Inmunología, Universidad de Córdoba, Córdoba, Spain
| | - Juan Antonio Collado
- Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC), Córdoba, Spain; Departamento de Biología Celular, Fisiología e Inmunología, Universidad de Córdoba, Córdoba, Spain
| | - J Lopez-Miranda
- Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC), Córdoba, Spain; Unidad de lípidos y aterosclerosis, Hospital Universitario Reina Sofía, Córdoba, Universidad de Córdoba, Ciber Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Spain
| | - Eduardo Muñoz
- Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC), Córdoba, Spain; Departamento de Biología Celular, Fisiología e Inmunología, Universidad de Córdoba, Córdoba, Spain
| | - Marco A Calzado
- Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC), Córdoba, Spain; Departamento de Biología Celular, Fisiología e Inmunología, Universidad de Córdoba, Córdoba, Spain.
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Morello E, Sutti S, Foglia B, Novo E, Cannito S, Bocca C, Rajsky M, Bruzzì S, Abate ML, Rosso C, Bozzola C, David E, Bugianesi E, Albano E, Parola M. Hypoxia-inducible factor 2α drives nonalcoholic fatty liver progression by triggering hepatocyte release of histidine-rich glycoprotein. Hepatology 2018; 67:2196-2214. [PMID: 29266399 DOI: 10.1002/hep.29754] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Revised: 12/12/2017] [Accepted: 12/18/2017] [Indexed: 12/11/2022]
Abstract
UNLABELLED Mechanisms underlying progression of nonalcoholic fatty liver disease (NAFLD) are still incompletely characterized. Hypoxia and hypoxia-inducible factors (HIFs) have been implicated in the pathogenesis of chronic liver diseases, but the actual role of HIF-2α in the evolution of NAFLD has never been investigated in detail. In this study, we show that HIF-2α is selectively overexpressed in the cytosol and the nuclei of hepatocytes in a very high percentage (>90%) of liver biopsies from a cohort of NAFLD patients at different stages of the disease evolution. Similar features were also observed in mice with steatohepatitis induced by feeding a methionine/choline-deficient diet. Experiments performed in mice carrying hepatocyte-specific deletion of HIF-2α and related control littermates fed either a choline-deficient L-amino acid-defined or a methionine/choline-deficient diet showed that HIF-2α deletion ameliorated the evolution of NAFLD by decreasing parenchymal injury, fatty liver, lobular inflammation, and the development of liver fibrosis. The improvement in NAFLD progression in HIF-2α-deficient mice was related to a selective down-regulation in the hepatocyte production of histidine-rich glycoprotein (HRGP), recently proposed to sustain macrophage M1 polarization. In vitro experiments confirmed that the up-regulation of hepatocyte HRGP expression was hypoxia-dependent and HIF-2α-dependent. Finally, analyses performed on specimens from NAFLD patients indicated that HRGP was overexpressed in all patients showing hepatocyte nuclear staining for HIF-2α and revealed a significant positive correlation between HIF-2α and HRGP liver transcript levels in these patients. CONCLUSIONS These results indicate that hepatocyte HIF-2α activation is a key feature in both human and experimental NAFLD and significantly contributes to the disease progression through the up-regulation of HRGP production. (Hepatology 2018;67:2196-2214).
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Affiliation(s)
- Elisabetta Morello
- Department of Clinical and Biological Sciences, University of Turin, Turin, Italy
| | - Salvatore Sutti
- Department of Medical Sciences, University of Turin, Turin, Italy.,Department of Health Sciences and Interdisciplinary Research Center for Autoimmune Diseases, University Amedeo Avogadro of East Piedmont, Novara, Italy
| | - Beatrice Foglia
- Department of Clinical and Biological Sciences, University of Turin, Turin, Italy
| | - Erica Novo
- Department of Clinical and Biological Sciences, University of Turin, Turin, Italy
| | - Stefania Cannito
- Department of Clinical and Biological Sciences, University of Turin, Turin, Italy
| | - Claudia Bocca
- Department of Clinical and Biological Sciences, University of Turin, Turin, Italy
| | - Martina Rajsky
- Department of Clinical and Biological Sciences, University of Turin, Turin, Italy
| | - Stefania Bruzzì
- Department of Health Sciences and Interdisciplinary Research Center for Autoimmune Diseases, University Amedeo Avogadro of East Piedmont, Novara, Italy
| | | | - Chiara Rosso
- Department of Medical Sciences, University of Turin, Turin, Italy
| | - Cristina Bozzola
- Department of Health Sciences and Interdisciplinary Research Center for Autoimmune Diseases, University Amedeo Avogadro of East Piedmont, Novara, Italy
| | - Ezio David
- Pathology Unit, S. Giovanni Battista Hospital, Turin, Italy
| | | | - Emanuele Albano
- Department of Health Sciences and Interdisciplinary Research Center for Autoimmune Diseases, University Amedeo Avogadro of East Piedmont, Novara, Italy
| | - Maurizio Parola
- Department of Clinical and Biological Sciences, University of Turin, Turin, Italy
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15
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Scott CH, Cha KM, Ngai J, Jiang C, Cheng K, Stokes RA, Ho KWK, George J, Gonzalez FJ, Gunton JE. Hepatic Aryl hydrocarbon Receptor Nuclear Translocator (ARNT) regulates metabolism in mice. PLoS One 2017; 12:e0186543. [PMID: 29190746 PMCID: PMC5708799 DOI: 10.1371/journal.pone.0186543] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Accepted: 09/11/2017] [Indexed: 01/09/2023] Open
Abstract
Background & aims Aryl hydrocarbon Receptor Nuclear Translocator (ARNT) and its partners hypoxia-inducible factors (HIF)-1α and HIF-2α are candidate factors for the well-known link between the liver, metabolic dysfunction and elevation in circulating lipids and glucose. Methods: Hepatocyte-specific ARNT-null (LARNT), HIF-1α-null (LHIF1α) and HIF-2α-null (LHIF2α) mice were created. Results LARNT mice had increased fasting glucose, impaired glucose tolerance, increased glucose production, raised post-prandial serum triglycerides (TG) and markedly lower hepatic ATP versus littermate controls. There was increased expression of G6Pase, Chrebp, Fas and Scd-1 mRNAs in LARNT animals. Surprisingly, LHIF1α and LHIF2α mice exhibited no alterations in any metabolic parameter assessed. Conclusions These results provide convincing evidence that reduced hepatic ARNT can contribute to inappropriate hepatic glucose production and post-prandial dyslipidaemia. Hepatic ARNT may be a novel therapeutic target for improving post-prandial hypertriglyceridemia and glucose homeostasis.
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Affiliation(s)
- Christopher H. Scott
- The Westmead Institute for Medical Research, The University of Sydney, Sydney, NSW. Australia
- Diabetes and Transcription Factors Group, Garvan Institute of Medical Research, Sydney, NSW, Australia
| | - Kuan-Minn Cha
- The Westmead Institute for Medical Research, The University of Sydney, Sydney, NSW. Australia
- Diabetes and Transcription Factors Group, Garvan Institute of Medical Research, Sydney, NSW, Australia
| | - Jason Ngai
- Diabetes and Transcription Factors Group, Garvan Institute of Medical Research, Sydney, NSW, Australia
| | - Changtao Jiang
- Laboratory of Metabolism, National Cancer Institute, Bethesda, Maryland, United States of America
| | - Kim Cheng
- The Westmead Institute for Medical Research, The University of Sydney, Sydney, NSW. Australia
- Diabetes and Transcription Factors Group, Garvan Institute of Medical Research, Sydney, NSW, Australia
| | - Rebecca A. Stokes
- The Westmead Institute for Medical Research, The University of Sydney, Sydney, NSW. Australia
- Diabetes and Transcription Factors Group, Garvan Institute of Medical Research, Sydney, NSW, Australia
| | - Kenneth W. K. Ho
- Diabetes and Transcription Factors Group, Garvan Institute of Medical Research, Sydney, NSW, Australia
| | - Jacob George
- The Westmead Institute for Medical Research, The University of Sydney, Sydney, NSW. Australia
- Storr Liver Unit, Westmead Institute for Medical Research, The University of Sydney, Sydney, NSW. Australia
| | - Frank J. Gonzalez
- Laboratory of Metabolism, National Cancer Institute, Bethesda, Maryland, United States of America
| | - Jenny E. Gunton
- The Westmead Institute for Medical Research, The University of Sydney, Sydney, NSW. Australia
- Diabetes and Transcription Factors Group, Garvan Institute of Medical Research, Sydney, NSW, Australia
- St. Vincent’s Clinical School, University of NSW, Sydney, NSW, Australia
- Department of Diabetes and Endocrinology, Westmead Hospital, Sydney, NSW Australia
- * E-mail:
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Abstract
Endocrine is an important and tightly regulated system for maintaining body homeostasis. Endocrine glands produce hormones, which are released into blood stream to guide the target cells responding to all sorts of stimulations. For maintaining body homeostasis, the secretion and activity of a particular hormone needs to be adjusted in responding to environmental challenges such as changes in nutritional status or chronic stress. Hypoxia, a status caused by reduced oxygen availability or imbalance of oxygen consumption/supply in an organ or within a cell, is a stress that affects many physiological and pathological processes. Hypoxic stress in endocrine organs is especially critical because endocrine glands control body homeostasis. Local hypoxia affects not only the particular gland but also the downstream cells/organs regulated by hormones secreted from this gland. Hypoxia-inducible factors (HIFs) are transcription factors that function as master regulators of oxygen homeostasis. Recent studies report that aberrant expression of HIFs in endocrine organs may result in the development and/or progression of diseases including diabetes, endometriosis, infertility and cancers. In this article, we will review recent findings in HIF-mediated endocrine organ dysfunction and the systemic syndromes caused by these disorders.
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Affiliation(s)
- Hsiu-Chi Lee
- Institute of Basic Medical SciencesCollege of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Shaw-Jenq Tsai
- Institute of Basic Medical SciencesCollege of Medicine, National Cheng Kung University, Tainan, Taiwan
- Department of PhysiologyCollege of Medicine, National Cheng Kung University, Tainan, Taiwan
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17
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Manresa MC, Taylor CT. Hypoxia Inducible Factor (HIF) Hydroxylases as Regulators of Intestinal Epithelial Barrier Function. Cell Mol Gastroenterol Hepatol 2017; 3:303-315. [PMID: 28462372 PMCID: PMC5404106 DOI: 10.1016/j.jcmgh.2017.02.004] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Accepted: 02/09/2017] [Indexed: 12/12/2022]
Abstract
Human health is dependent on the ability of the body to extract nutrients, fluids, and oxygen from the external environment while at the same time maintaining a state of internal sterility. Therefore, the cell layers that cover the surface areas of the body such as the lung, skin, and gastrointestinal mucosa provide vital semipermeable barriers that allow the transport of essential nutrients, fluid, and waste products, while at the same time keeping the internal compartments free of microbial organisms. These epithelial surfaces are highly specialized and differ in their anatomic structure depending on their location to provide appropriate and effective site-specific barrier function. Given this important role, it is not surprising that significant disease often is associated with alterations in epithelial barrier function. Examples of such diseases include inflammatory bowel disease, chronic obstructive pulmonary disease, and atopic dermatitis. These chronic inflammatory disorders often are characterized by diminished tissue oxygen levels (hypoxia). Hypoxia triggers an adaptive transcriptional response governed by hypoxia-inducible factors (HIFs), which are repressed by a family of oxygen-sensing HIF hydroxylases. Here, we review recent evidence suggesting that pharmacologic hydroxylase inhibition may be of therapeutic benefit in inflammatory bowel disease through the promotion of intestinal epithelial barrier function through both HIF-dependent and HIF-independent mechanisms.
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Key Words
- CD, Crohn’s disease
- DMOG, dimethyloxalylglycine
- DSS, dextran sodium sulfate
- Epithelial Barrier
- FIH, factor inhibiting hypoxia-inducible factor
- HIF, hypoxia-inducible factor
- Hypoxia
- Hypoxia-Inducible Factor (HIF) Hydroxylases
- IBD, inflammatory bowel disease
- IL, interleukin
- Inflammatory Bowel Disease
- NF-κB, nuclear factor-κB
- PHD, hypoxia-inducible factor–prolyl hydroxylases
- TFF, trefoil factor
- TJ, tight junction
- TLR, Toll-like receptor
- TNF-α, tumor necrosis factor α
- UC, ulcerative colitis
- ZO, zonula occludens
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Affiliation(s)
- Mario C. Manresa
- Conway Institute of Biomolecular and Biomedical Research, Belfield, Dublin, Ireland
- Charles Institute of Dermatology, Belfield, Dublin, Ireland
| | - Cormac T. Taylor
- Conway Institute of Biomolecular and Biomedical Research, Belfield, Dublin, Ireland
- Charles Institute of Dermatology, Belfield, Dublin, Ireland
- Systems Biology Ireland, School of Medicine and Medical Science, University College Dublin, Belfield, Dublin, Ireland
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18
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Arai T, Ono Y, Arimura Y, Sayama K, Suzuki T, Shinjo S, Kanai M, Abe SI, Semba K, Goda N. Type I neuregulin1α is a novel local mediator to suppress hepatic gluconeogenesis in mice. Sci Rep 2017; 7:42959. [PMID: 28218289 PMCID: PMC5317163 DOI: 10.1038/srep42959] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Accepted: 01/17/2017] [Indexed: 12/18/2022] Open
Abstract
Neuregulin1 is an epidermal growth factor (EGF)-like domain-containing protein that has multiple isoforms and functions as a local mediator in the control of various cellular functions. Here we show that type I isoform of neuregulin1 with an α-type EGF-like domain (Nrg1α) is the major isoform in mouse liver and regulates hepatic glucose production. Forced expression of Nrg1α in mouse liver enhanced systemic glucose disposal and decreased hepatic glucose production with reduced fasting blood glucose levels. Nuclear forkhead box protein O1 (FoxO1) and its downstream targets, PEPCK and G6Pase, were suppressed in liver and isolated hepatocytes by Nrg1α overexpression. In contrast, silencing of Nrg1α enhanced glucose production with increased PEPCK and G6Pase expressions in cAMP/dexamethasone-stimulated hepatocytes. Mechanistically, the recombinant α-type EGF-like domain of NRG1α (rNRG1α) stimulated the ERBB3 signalling pathway in hepatocytes, resulting in decreased nuclear FoxO1 accumulation via activation of both the AKT and ERK pathways. In addition, acute treatment with rNRG1α also suppressed elevation of blood glucose levels after both glucose and pyruvate challenge. Although a liver-specific deletion of Nrg1 gene in mice showed little effect on systemic glucose metabolism, these results suggest that NRG1α have a novel regulatory function in hepatic gluconeogenesis by regulating the ERBB3-AKT/ERK-FoxO1 cascade.
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Affiliation(s)
- Takatomo Arai
- Department of Life Science and Medical Bioscience, School of Advanced Science and Engineering, Waseda University, Tokyo, 162-8480, Japan
| | - Yumika Ono
- Department of Life Science and Medical Bioscience, School of Advanced Science and Engineering, Waseda University, Tokyo, 162-8480, Japan
| | - Yujiro Arimura
- Department of Life Science and Medical Bioscience, School of Advanced Science and Engineering, Waseda University, Tokyo, 162-8480, Japan
| | - Keimon Sayama
- Department of Life Science and Medical Bioscience, School of Advanced Science and Engineering, Waseda University, Tokyo, 162-8480, Japan
| | - Tomohiro Suzuki
- Department of Life Science and Medical Bioscience, School of Advanced Science and Engineering, Waseda University, Tokyo, 162-8480, Japan
| | - Satoko Shinjo
- Department of Life Science and Medical Bioscience, School of Advanced Science and Engineering, Waseda University, Tokyo, 162-8480, Japan
| | - Mai Kanai
- Department of Life Science and Medical Bioscience, School of Advanced Science and Engineering, Waseda University, Tokyo, 162-8480, Japan
| | - Shin-Ichi Abe
- Center for General Education, Kumamoto Health Science University, Kumamoto, 861-5598, Japan
| | - Kentaro Semba
- Department of Life Science and Medical Bioscience, School of Advanced Science and Engineering, Waseda University, Tokyo, 162-8480, Japan
| | - Nobuhito Goda
- Department of Life Science and Medical Bioscience, School of Advanced Science and Engineering, Waseda University, Tokyo, 162-8480, Japan
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Hepatocyte Hypoxia Inducible Factor-1 Mediates the Development of Liver Fibrosis in a Mouse Model of Nonalcoholic Fatty Liver Disease. PLoS One 2016; 11:e0168572. [PMID: 28030556 PMCID: PMC5193414 DOI: 10.1371/journal.pone.0168572] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Accepted: 12/03/2016] [Indexed: 12/21/2022] Open
Abstract
Background Obstructive sleep apnea (OSA) is associated with the progression of non-alcoholic fatty liver disease (NAFLD) to steatohepatitis and fibrosis. This progression correlates with the severity of OSA-associated hypoxia. In mice with diet induced obesity, hepatic steatosis leads to liver tissue hypoxia, which worsens with exposure to intermittent hypoxia. Emerging data has implicated hepatocyte cell signaling as an important factor in hepatic fibrogenesis. We hypothesized that hepatocyte specific knockout of the oxygen sensing α subunit of hypoxia inducible factor-1 (HIF-1), a master regulator of the global response to hypoxia, may be protective against the development of liver fibrosis. Methods Wild-type mice and mice with hepatocyte-specific HIF-1α knockout (Hif1a-/-hep) were fed a high trans-fat diet for six months, as a model of NAFLD. Hepatic fibrosis was evaluated by Sirius red stain and hydroxyproline assay. Liver enzymes, fasting insulin, and hepatic triglyceride content were also assessed. Hepatocytes were isolated from Hif1a-/-hep mice and wild-type controls and were exposed to sustained hypoxia (1% O2) or normoxia (16% O2) for 24 hours. The culture media was used to reconstitute type I collagen and the resulting matrices were examined for collagen cross-linking. Results Wild-type mice on a high trans-fat diet had 80% more hepatic collagen than Hif1a-/-hep mice (2.21 μg collagen/mg liver tissue, versus 1.23 μg collagen/mg liver tissue, p = 0.03), which was confirmed by Sirius red staining. Body weight, liver weight, mean hepatic triglyceride content, and fasting insulin were similar between groups. Culture media from wild-type mouse hepatocytes exposed to hypoxia allowed for avid collagen cross-linking, but very little cross-linking was seen when hepatocytes were exposed to normoxia, or when hepatocytes from Hif1a-/-hep mice were used in hypoxia or normoxia. Conclusions Hepatocyte HIF-1 mediates an increase in liver fibrosis in a mouse model of NAFLD, perhaps due to liver tissue hypoxia in hepatic steatosis. HIF-1 is necessary for collagen cross-linking in an in vitro model of fibrosis.
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20
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Takikawa A, Mahmood A, Nawaz A, Kado T, Okabe K, Yamamoto S, Aminuddin A, Senda S, Tsuneyama K, Ikutani M, Watanabe Y, Igarashi Y, Nagai Y, Takatsu K, Koizumi K, Imura J, Goda N, Sasahara M, Matsumoto M, Saeki K, Nakagawa T, Fujisaka S, Usui I, Tobe K. HIF-1α in Myeloid Cells Promotes Adipose Tissue Remodeling Toward Insulin Resistance. Diabetes 2016; 65:3649-3659. [PMID: 27625023 DOI: 10.2337/db16-0012] [Citation(s) in RCA: 76] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Accepted: 09/08/2016] [Indexed: 01/05/2023]
Abstract
Adipose tissue hypoxia is an important feature of pathological adipose tissue expansion. Hypoxia-inducible factor-1α (HIF-1α) in adipocytes reportedly induces oxidative stress and fibrosis, rather than neoangiogenesis via vascular endothelial growth factor (VEGF)-A. We previously reported that macrophages in crown-like structures (CLSs) are both hypoxic and inflammatory. In the current study, we examined how macrophage HIF-1α is involved in high-fat diet (HFD)-induced inflammation, neovascularization, hypoxia, and insulin resistance using mice with myeloid cell-specific HIF-1α deletion that were fed an HFD. Myeloid cell-specific HIF-1α gene deletion protected against HFD-induced inflammation, CLS formation, poor vasculature development in the adipose tissue, and systemic insulin resistance. Despite a reduced expression of Vegfa in epididymal white adipose tissue (eWAT), the preadipocytes and endothelial cells of HIF-1α-deficient mice expressed higher levels of angiogenic factors, including Vegfa, Angpt1, Fgf1, and Fgf10 in accordance with preferable eWAT remodeling. Our in vitro study revealed that lipopolysaccharide-treated bone marrow-derived macrophages directly inhibited the expression of angiogenic factors in 3T3-L1 preadipocytes. Thus, macrophage HIF-1α is involved not only in the formation of CLSs, further enhancing the inflammatory responses, but also in the inhibition of neoangiogenesis in preadipocytes. We concluded that these two pathways contribute to the obesity-related physiology of pathological adipose tissue expansion, thus causing systemic insulin resistance.
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Affiliation(s)
- Akiko Takikawa
- First Department of Internal Medicine, University of Toyama, Toyama, Japan
| | - Arshad Mahmood
- First Department of Internal Medicine, University of Toyama, Toyama, Japan
| | - Allah Nawaz
- First Department of Internal Medicine, University of Toyama, Toyama, Japan
| | - Tomonobu Kado
- First Department of Internal Medicine, University of Toyama, Toyama, Japan
| | - Keisuke Okabe
- First Department of Internal Medicine, University of Toyama, Toyama, Japan
| | - Seiji Yamamoto
- Department of Pathology, University of Toyama, Toyama, Japan
| | | | - Satoko Senda
- First Department of Internal Medicine, University of Toyama, Toyama, Japan
| | - Koichi Tsuneyama
- Department of Diagnostic Pathology, University of Toyama, Toyama, Japan
- Department of Pathology and Laboratory Medicine, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan
| | - Masashi Ikutani
- Department of Immunobiology and Pharmacological Genetics, Advanced Biomedicine Genome Pharmaceutical Science, Graduate School of Medicine and Pharmaceutical Science for Research, University of Toyama, Toyama, Japan
| | - Yasuharu Watanabe
- Department of Immunobiology and Pharmacological Genetics, Advanced Biomedicine Genome Pharmaceutical Science, Graduate School of Medicine and Pharmaceutical Science for Research, University of Toyama, Toyama, Japan
| | - Yoshiko Igarashi
- Division of Kampo Diagnostics, Institute of Natural Medicine, University of Toyama, Toyama, Japan
| | - Yoshinori Nagai
- Department of Immunobiology and Pharmacological Genetics, Advanced Biomedicine Genome Pharmaceutical Science, Graduate School of Medicine and Pharmaceutical Science for Research, University of Toyama, Toyama, Japan
- PRESTO, Japan Science and Technology Agency, Saitama, Japan
| | - Kiyoshi Takatsu
- Department of Immunobiology and Pharmacological Genetics, Advanced Biomedicine Genome Pharmaceutical Science, Graduate School of Medicine and Pharmaceutical Science for Research, University of Toyama, Toyama, Japan
- Toyama Prefectural Institute for Pharmaceutical Research, Toyama, Japan
| | - Keiichi Koizumi
- Department of Pathology and Laboratory Medicine, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan
| | - Johji Imura
- Department of Diagnostic Pathology, University of Toyama, Toyama, Japan
| | - Nobuhito Goda
- Department of Life Science and Medical Bioscience, School of Advanced Science and Engineering, Waseda University, Tokyo, Japan
| | | | - Michihiro Matsumoto
- Department of Molecular Metabolic Regulation, Diabetes Research Center, Research Institute, National Center for Global Health and Medicine, Tokyo, Japan
| | - Kumiko Saeki
- Department of Disease Control, Research Institute, National Center for Global Health and Medicine, Tokyo, Japan
| | - Takashi Nakagawa
- Frontier Research Core for Life Science, University of Toyama, Toyama, Japan
| | - Shiho Fujisaka
- First Department of Internal Medicine, University of Toyama, Toyama, Japan
| | - Isao Usui
- First Department of Internal Medicine, University of Toyama, Toyama, Japan
| | - Kazuyuki Tobe
- First Department of Internal Medicine, University of Toyama, Toyama, Japan
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Lefere S, Van Steenkiste C, Verhelst X, Van Vlierberghe H, Devisscher L, Geerts A. Hypoxia-regulated mechanisms in the pathogenesis of obesity and non-alcoholic fatty liver disease. Cell Mol Life Sci 2016; 73:3419-31. [PMID: 27091156 PMCID: PMC11108443 DOI: 10.1007/s00018-016-2222-1] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2016] [Revised: 04/05/2016] [Accepted: 04/07/2016] [Indexed: 02/06/2023]
Abstract
The pandemic rise in obesity has resulted in an increased incidence of metabolic complications. Non-alcoholic fatty liver disease is the hepatic manifestation of the metabolic syndrome and has become the most common chronic liver disease in large parts of the world. The adipose tissue expansion and hepatic fat accumulation characteristics of these disorders compromise local oxygen homeostasis. The resultant tissue hypoxia induces adaptive responses to restore oxygenation and tissue metabolism and cell survival. Hypoxia-inducible factors (HIFs) function as master regulators of this hypoxia adaptive response, and are in turn hydroxylated by prolyl hydroxylases (PHDs). PHDs are the main cellular oxygen sensors and regulate HIF proteasomal degradation in an oxygen-dependent manner. HIFs and PHDs are implicated in numerous physiological and pathological conditions. Extensive research using genetic models has revealed that hypoxia signaling is also a key mechanism in adipose tissue dysfunction, leading to adipose tissue fibrosis, inflammation and insulin resistance. Moreover, hypoxia affects liver lipid metabolism and deranges hepatic lipid accumulation. This review summarizes the molecular mechanisms through which the hypoxia adaptive response affects adipocyte and hepatic metabolism, and the therapeutic possibilities of modulating HIFs and PHDs in obesity and fatty liver disease.
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Affiliation(s)
- Sander Lefere
- Department of Gastroenterology and Hepatology, Ghent University Hospital, De Pintelaan 185, 1K12IE, 9000, Ghent, Belgium.
| | - Christophe Van Steenkiste
- Department of Gastroenterology and Hepatology, Ghent University Hospital, De Pintelaan 185, 1K12IE, 9000, Ghent, Belgium
- Department of Gastroenterology and Hepatology, Maria Middelares Hospital, Ghent, Belgium
| | - Xavier Verhelst
- Department of Gastroenterology and Hepatology, Ghent University Hospital, De Pintelaan 185, 1K12IE, 9000, Ghent, Belgium
| | - Hans Van Vlierberghe
- Department of Gastroenterology and Hepatology, Ghent University Hospital, De Pintelaan 185, 1K12IE, 9000, Ghent, Belgium
| | - Lindsey Devisscher
- Department of Gastroenterology and Hepatology, Ghent University Hospital, De Pintelaan 185, 1K12IE, 9000, Ghent, Belgium
| | - Anja Geerts
- Department of Gastroenterology and Hepatology, Ghent University Hospital, De Pintelaan 185, 1K12IE, 9000, Ghent, Belgium
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Ma F, Hu L, Yu M, Wang F. Emodin Decreases Hepatic Hypoxia-Inducible Factor-1[Formula: see text] by Inhibiting its Biosynthesis. THE AMERICAN JOURNAL OF CHINESE MEDICINE 2016; 44:997-1008. [PMID: 27430909 DOI: 10.1142/s0192415x16500555] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Hypoxia-inducible factor-1 (HIF-1) is an [Formula: see text] dimeric transcription factor. Because HIF-1[Formula: see text] is instable with oxygen, HIF-1 is scarce in normal mammalian cells. However, HIF-1[Formula: see text] is expressed in pathological conditions such as cancer and obesity. Inhibiting HIF-1[Formula: see text] may be of therapeutic value for these pathologies. Here, we investigated whether emodin, derived from the herb of Rheum palmatum L, which is also known as Chinese rhubarb, and is native to China, regulates HIF-1[Formula: see text] expression. Male C57BL/6 mice without or with diet-induced obesity were treated with emodin for two weeks, while control mice were treated with vehicle. HIF-1[Formula: see text] expression was determined by Western blot. We found that emodin inhibited obesity-induced HIF-1[Formula: see text] expression in liver and skeletal muscle but did not regulate HIF-1[Formula: see text] expression in the kidneys or in intra-abdominal fat. In vitro, emodin inhibited HIF-1[Formula: see text] expression in human HepG2 hepatic cells and Y1 adrenocortical cells. Further, we investigated the mechanisms of HIF-1[Formula: see text] expression in emodin-treated HepG2 cells. First, we found that HIF-1[Formula: see text] had normal stability in the presence of emodin. Thus, emodin did not decrease HIF-1[Formula: see text] by stimulating its degradation. Importantly, emodin decreased the activity of the signaling pathways that led to HIF-1[Formula: see text] biosynthesis. Interestingly, emodin increased HIF-1[Formula: see text] mRNA in HepG2 cells. This may be a result of feedback in response to the emodin-induced decrease in the protein of HIF-1[Formula: see text]. In conclusion, emodin decreases hepatic HIF-1[Formula: see text] by inhibiting its biosynthesis.
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Affiliation(s)
- Feifei Ma
- * Department of Nutrition and Food Hygiene, School of Public Health, Tianjin Medical University, Tianjin 300070, China
| | - Lijuan Hu
- † Tianjin Institute of Integrative Medicine for Acute Abdominal Diseases, Nankai Hospital, Tianjin 300100, China
| | - Ming Yu
- * Department of Nutrition and Food Hygiene, School of Public Health, Tianjin Medical University, Tianjin 300070, China
| | - Feng Wang
- † Tianjin Institute of Integrative Medicine for Acute Abdominal Diseases, Nankai Hospital, Tianjin 300100, China
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23
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Affiliation(s)
- Loranne Agius
- Institutes of Cellular Medicine and Ageing and Health, Medical School, Newcastle University, Newcastle upon Tyne, NE2 4HH United Kingdom;
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24
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Anti-diabetes effect of chronic intermittent hypobaric hypoxia through improving liver insulin resistance in diabetic rats. Life Sci 2016; 150:1-7. [PMID: 26883978 DOI: 10.1016/j.lfs.2016.02.053] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2015] [Revised: 01/06/2016] [Accepted: 02/12/2016] [Indexed: 12/16/2022]
Abstract
AIM Cumulating evidence demonstrated that chronic intermittent hypobaric hypoxia (CIHH) had beneficial effects on the body. The present study was to investigate the anti-diabetes effect of CIHH in type-2 diabetic rats for the first time. MAIN METHODS Sprague-Dawley rats were randomly divided into 4 groups: control group (CON), diabetes mellitus group (DM, induced by high-fat diet combined with low-dose streptozotocin), CIHH treatment group (CIHH, simulated 5000-m altitude, 6h per day for 28 days), and diabetes mellitus plus CIHH treatment group (DM+CIHH). Histopathology of liver, systolic arterial blood pressure (SAP), blood biochemicals, glucose and insulin tolerance were determined. The expression of proteins associated with insulin signaling pathway as well as hypoxia induced factors were assayed. KEY FINDINGS Diabetic rats showed impaired glucose tolerance, dyslipidemia, hepatic steatosis and hepatic insulin resistance in addition to increased SAP. However, SAP, serum triglyceride and cholesterol were decreased, and hepatic steatosis and insulin resistance were improved in DM+CIHH rats. Furthermore, the protein expression of glucokinase (GCK), insulin receptor substrates (IRS-1 and IRS-2), and HIF1α were increased, while the expression of phosphoenolpyruvate carboxykinase (PEPCK), was markedly reduced in DM+CIHH rats. SIGNIFICANCE We conclude that CIHH treatment has anti-diabetes effects through ameliorating insulin resistance via hepatic HIF-insulin signaling pathway in type-2 diabetic rats.
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25
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Mesarwi OA, Shin MK, Drager LF, Bevans-Fonti S, Jun JC, Putcha N, Torbenson MS, Pedrosa RP, Lorenzi-Filho G, Steele KE, Schweitzer MA, Magnuson TH, Lidor AO, Schwartz AR, Polotsky VY. Lysyl Oxidase as a Serum Biomarker of Liver Fibrosis in Patients with Severe Obesity and Obstructive Sleep Apnea. Sleep 2015; 38:1583-91. [PMID: 26085300 DOI: 10.5665/sleep.5052] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Indexed: 12/12/2022] Open
Abstract
STUDY OBJECTIVES Obstructive sleep apnea (OSA) is associated with the progression of nonalcoholic fatty liver disease (NAFLD). We hypothesized that the hypoxia of OSA increases hepatic production of lysyl oxidase (LOX), an enzyme that cross-links collagen, and that LOX may serve as a biomarker of hepatic fibrosis. DESIGN Thirty-five patients with severe obesity underwent liver biopsy, polysomnography, and serum LOX testing. A separate group with severe OSA had serum LOX measured before and after 3 mo of CPAP or no therapy, as did age-matched controls. LOX expression and secretion were measured in mouse hepatocytes following exposure to hypoxia. SETTING The Johns Hopkins Bayview Sleep Disorders Center, and the Hypertension Unit of the Heart Institute at the University of São Paulo Medical School. MEASUREMENTS AND RESULTS In the bariatric cohort, the apnea-hypopnea index was higher in patients with hepatic fibrosis than in those without fibrosis (42.7 ± 30.2 events/h, versus 16.2 ± 15.5 events/h; P = 0.002), as was serum LOX (84.64 ± 29.71 ng/mL, versus 45.46 ± 17.16 ng/mL; P < 0.001). In the sleep clinic sample, patients with severe OSA had higher baseline LOX than healthy controls (70.75 ng/mL versus 52.36 ng/mL, P = 0.046), and serum LOX decreased in patients with OSA on CPAP (mean decrease 20.49 ng/mL) but not in untreated patients (mean decrease 0.19 ng/mL). Hypoxic mouse hepatocytes demonstrated 5.9-fold increased LOX transcription (P = 0.046), and enhanced LOX protein secretion. CONCLUSIONS The hypoxic stress of obstructive sleep apnea may increase circulating lysyl oxidase (LOX) levels. LOX may serve as a biomarker of liver fibrosis in patients with severe obesity and nonalcoholic fatty liver disease.
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Affiliation(s)
- Omar A Mesarwi
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Mi-Kyung Shin
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Luciano F Drager
- Hypertension Unit, Heart Institute (InCor), University of São Paulo Medical School, São Paulo, Brazil
| | - Shannon Bevans-Fonti
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Jonathan C Jun
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Nirupama Putcha
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD
| | | | - Rodrigo P Pedrosa
- Sleep Laboratory, Pulmonary Division, University of São Paulo Medical School, São Paulo, Brazil
| | - Geraldo Lorenzi-Filho
- Sleep Laboratory, Pulmonary Division, University of São Paulo Medical School, São Paulo, Brazil
| | - Kimberley E Steele
- Department of Surgery, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Michael A Schweitzer
- Department of Surgery, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Thomas H Magnuson
- Department of Surgery, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Anne O Lidor
- Department of Surgery, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Alan R Schwartz
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Vsevolod Y Polotsky
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD
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Xia N, Tang Z, Wang C, Xu G, Nie X, Zhang W, Zhao Y, Wang S, Zhu X, Cui S. PCBP2 regulates hepatic insulin sensitivity via HIF-1α and STAT3 pathway in HepG2 cells. Biochem Biophys Res Commun 2015; 463:116-22. [DOI: 10.1016/j.bbrc.2015.04.150] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2015] [Accepted: 04/30/2015] [Indexed: 10/23/2022]
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Ameri K, Jahangiri A, Rajah AM, Tormos KV, Nagarajan R, Pekmezci M, Nguyen V, Wheeler ML, Murphy MP, Sanders TA, Jeffrey SS, Yeghiazarians Y, Rinaudo PF, Costello JF, Aghi MK, Maltepe E. HIGD1A Regulates Oxygen Consumption, ROS Production, and AMPK Activity during Glucose Deprivation to Modulate Cell Survival and Tumor Growth. Cell Rep 2015; 10:891-899. [PMID: 25683712 DOI: 10.1016/j.celrep.2015.01.020] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2014] [Revised: 10/27/2014] [Accepted: 01/09/2015] [Indexed: 02/07/2023] Open
Abstract
Hypoxia-inducible gene domain family member 1A (HIGD1A) is a survival factor induced by hypoxia-inducible factor 1 (HIF-1). HIF-1 regulates many responses to oxygen deprivation, but viable cells within hypoxic perinecrotic solid tumor regions frequently lack HIF-1α. HIGD1A is induced in these HIF-deficient extreme environments and interacts with the mitochondrial electron transport chain to repress oxygen consumption, enhance AMPK activity, and lower cellular ROS levels. Importantly, HIGD1A decreases tumor growth but promotes tumor cell survival in vivo. The human Higd1a gene is located on chromosome 3p22.1, where many tumor suppressor genes reside. Consistent with this, the Higd1a gene promoter is differentially methylated in human cancers, preventing its hypoxic induction. However, when hypoxic tumor cells are confronted with glucose deprivation, DNA methyltransferase activity is inhibited, enabling HIGD1A expression, metabolic adaptation, and possible dormancy induction. Our findings therefore reveal important new roles for this family of mitochondrial proteins in cancer biology.
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Affiliation(s)
- Kurosh Ameri
- Department of Pediatrics/Biomedical Sciences, University of California San Francisco, San Francisco, CA 94143, USA
| | - Arman Jahangiri
- Department of Neurological Surgery, University of California San Francisco, San Francisco, CA 94143, USA
| | - Anthony M Rajah
- Department of Pediatrics/Biomedical Sciences, University of California San Francisco, San Francisco, CA 94143, USA
| | - Kathryn V Tormos
- Department of Pediatrics/Biomedical Sciences, University of California San Francisco, San Francisco, CA 94143, USA
| | - Ravi Nagarajan
- Department of Neurological Surgery, University of California San Francisco, San Francisco, CA 94143, USA
| | - Melike Pekmezci
- Department of Pathology, University of California San Francisco, San Francisco, CA 94143, USA
| | - Vien Nguyen
- Department of Biomedical Sciences, University of California San Francisco, San Francisco, CA 94143, USA
| | - Matthew L Wheeler
- Department of Microbiology/Immunology, University of California San Francisco, San Francisco, CA 94143, USA
| | | | - Timothy A Sanders
- Department of Pediatrics/Biomedical Sciences, University of California San Francisco, San Francisco, CA 94143, USA
| | - Stefanie S Jeffrey
- Department of Surgery, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Yerem Yeghiazarians
- Department of Medicine/CVRI/Eli and Edythe Broad Center for Regeneration Medicine, University of California San Francisco, San Francisco, CA 94143, USA
| | - Paolo F Rinaudo
- Department of Obstetrics, Gynecology/Reproductive Sciences, University of California San Francisco, San Francisco, CA 94143, USA
| | - Joseph F Costello
- Department of Neurological Surgery, University of California San Francisco, San Francisco, CA 94143, USA
| | - Manish K Aghi
- Department of Neurological Surgery, University of California San Francisco, San Francisco, CA 94143, USA
| | - Emin Maltepe
- Department of Pediatrics/Biomedical Sciences, University of California San Francisco, San Francisco, CA 94143, USA.
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Behari J, Li H, Liu S, Stefanovic-Racic M, Alonso L, O'Donnell CP, Shiva S, Singamsetty S, Watanabe Y, Singh VP, Liu Q. β-catenin links hepatic metabolic zonation with lipid metabolism and diet-induced obesity in mice. THE AMERICAN JOURNAL OF PATHOLOGY 2014; 184:3284-98. [PMID: 25300578 DOI: 10.1016/j.ajpath.2014.08.022] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2013] [Revised: 08/18/2014] [Accepted: 08/21/2014] [Indexed: 02/08/2023]
Abstract
β-catenin regulates the establishment of hepatic metabolic zonation. To elucidate the functional significance of liver metabolic zonation in the chronically overfed state in vivo, we fed a high-fat diet (HFD) to hepatocyte-specific β-catenin transgenic (TG) and knockout (KO) mice. Chow-fed TG and KO mice had normal liver histologic findings and body weight. However, HFD-fed TG mice developed prominent perivenous steatosis with periportal sparing. In contrast, HFD-fed KO mice had increased lobular inflammation and hepatocyte apoptosis. HFD-fed TG mice rapidly developed diet-induced obesity and systemic insulin resistance, but KO mice were resistant to diet-induced obesity. However, β-catenin did not directly affect hepatic insulin signaling, suggesting that the metabolic effects of β-catenin occurred via a parallel pathway. Hepatic expression of key glycolytic and lipogenic genes was higher in HFD-fed TG and lower in KO mice compared with wild-type mice. KO mice also exhibited defective hepatic fatty acid oxidation and fasting ketogenesis. Hepatic levels of hypoxia inducible factor-1α, an oxygen-sensitive transcriptional regulator of glycolysis and a known β-catenin binding partner, were higher in HFD-fed TG and lower in KO mice. KO mice had attenuated perivenous hypoxia, suggesting disruption of the normal sinusoidal oxygen gradient, a major determinant of liver carbohydrate and liver metabolism. Canonical Wnt signaling in hepatocytes is essential for the development of diet-induced fatty liver and obesity.
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Affiliation(s)
- Jaideep Behari
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania.
| | - Huanan Li
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Shiguang Liu
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Maja Stefanovic-Racic
- Division of Endocrinology and Metabolism, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Laura Alonso
- Division of Endocrinology and Metabolism, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Christopher P O'Donnell
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Sruti Shiva
- Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Srikanth Singamsetty
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Yoshio Watanabe
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Vijay P Singh
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Qing Liu
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
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29
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Zhang GM, Zhu Y, Ye DW. Metabolic syndrome and renal cell carcinoma. World J Surg Oncol 2014; 12:236. [PMID: 25069390 PMCID: PMC4118156 DOI: 10.1186/1477-7819-12-236] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2013] [Accepted: 07/20/2014] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Metabolic syndrome (MS) is a cluster of metabolic abnormalities, which has been regarded as a pivotal risk factor for cardiovascular diseases. Recent studies focusing on the relationship between MS and cancer have recognized the significant role of MS on carcinogenesis. Likewise, growing evidence suggests that MS has a strong association with increased renal cell carcinoma (RCC) risk. This review outlines the link between MS and RCC, and some underlying mechanisms responsible for MS-associated RCC. MATERIALS AND METHODS A National Center for Biotechnology Information PubMed search (http://www.pubmed.gov) was conducted using medical subject headings 'metabolic syndrome', 'obesity', 'hypertension', 'diabetes', 'dyslipidemia', and 'renal cell carcinoma'. RESULTS This revealed that a variety of molecular mechanisms secondary to MS are involved in RCC formation, progression, and metastasis. A deeper understanding of these molecular mechanisms may provide some strategies for the prevention and treatment of RCC. CONCLUSIONS In summary, there is a large body of evidence regarding the link between MS and RCC, within which each component of MS is considered to have a close causal association with RCC.
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Affiliation(s)
| | | | - Ding-Wei Ye
- Department of Urology, Fudan University Shanghai Cancer Center, No, 270, Dongan Rd, Shanghai 200032, China.
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30
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Catrina SB. Impaired hypoxia-inducible factor (HIF) regulation by hyperglycemia. J Mol Med (Berl) 2014; 92:1025-34. [PMID: 25027070 DOI: 10.1007/s00109-014-1166-x] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2013] [Revised: 05/06/2014] [Accepted: 05/08/2014] [Indexed: 12/13/2022]
Abstract
The mechanisms that contribute to the development of diabetes complications remain unclear. A defective reaction of tissues to hypoxia has recently emerged as a new pathogenic mechanism and consists of a complex repression of hypoxia-inducible factor (HIF), which is the main regulator of the adaptive response to hypoxia. This paper discusses the mechanisms by which hyperglycaemia contributes to HIF repression in diabetes. Furthermore, a comprehensive analysis of the functional relevance of these new findings to the development of chronic diabetes complications is provided, along with examples from animal models and clinics.
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Affiliation(s)
- Sergiu-Bogdan Catrina
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska University Hospital, L1:01, 17176, Stockholm, Sweden,
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31
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Notari L, Riera DC, Sun R, Bohl JA, McLean LP, Madden KB, van Rooijen N, Vanuytsel T, Urban JF, Zhao A, Shea-Donohue T. Role of macrophages in the altered epithelial function during a type 2 immune response induced by enteric nematode infection. PLoS One 2014; 9:e84763. [PMID: 24465430 PMCID: PMC3900397 DOI: 10.1371/journal.pone.0084763] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2013] [Accepted: 11/18/2013] [Indexed: 01/10/2023] Open
Abstract
Parasitic enteric nematodes induce a type 2 immune response characterized by increased production of Th2 cytokines, IL-4 and IL-13, and recruitment of alternatively activated macrophages (M2) to the site of infection. Nematode infection is associated with changes in epithelial permeability and inhibition of sodium-linked glucose absorption, but the role of M2 in these effects is unknown. Clodronate-containing liposomes were administered prior to and during nematode infection to deplete macrophages and prevent the development of M2 in response to infection with Nippostrongylus brasiliensis. The inhibition of epithelial glucose absorption that is associated with nematode infection involved a macrophage-dependent reduction in SGLT1 activity, with no change in receptor expression, and a macrophage-independent down-regulation of GLUT2 expression. The reduced transport of glucose into the enterocyte is compensated partially by an up-regulation of the constitutive GLUT1 transporter consistent with stress-induced activation of HIF-1α. Thus, nematode infection results in a “lean” epithelial phenotype that features decreased SGLT1 activity, decreased expression of GLUT2 and an emergent dependence on GLUT1 for glucose uptake into the enterocyte. Macrophages do not play a role in enteric nematode infection-induced changes in epithelial barrier function. There is a greater contribution, however, of paracellular absorption of glucose to supply the energy demands of host resistance. These data provide further evidence of the ability of macrophages to alter glucose metabolism of neighboring cells.
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Affiliation(s)
- Luigi Notari
- Department of Medicine and Mucosal Biology Research Center, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Diana C. Riera
- Department of Pediatrics, Walter Reed Army Medical Center, Washington, DC, United States of America
- Department of Pediatrics, Uniformed Services University of the Health Sciences, Bethesda, Maryland, United States of America
| | - Rex Sun
- Department of Medicine and Mucosal Biology Research Center, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Jennifer A. Bohl
- Department of Medicine and Mucosal Biology Research Center, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Leon P. McLean
- Department of Medicine and Mucosal Biology Research Center, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Kathleen B. Madden
- Department of Pediatrics, Uniformed Services University of the Health Sciences, Bethesda, Maryland, United States of America
| | - Nico van Rooijen
- Vrije Universiteit, VUMC, Department of Molecular Cell Biology, Amsterdam, The Netherlands
| | - Tim Vanuytsel
- Translational Research Center for Gastrointestinal Disorders, University Hospital Gasthuisberg, University of Leuven, Leuven, Belgium
| | - Joseph F. Urban
- United States Department of Agriculture, Agricultural Research Service, Beltsville Human Nutrition Research Center, Diet, Genomics, & Immunology Laboratory, Beltsville, Maryland, United States of America
| | - Aiping Zhao
- Department of Medicine and Mucosal Biology Research Center, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Terez Shea-Donohue
- Department of Medicine and Mucosal Biology Research Center, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
- * E-mail:
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32
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Nuclear localization of the mitochondrial factor HIGD1A during metabolic stress. PLoS One 2013; 8:e62758. [PMID: 23646141 PMCID: PMC3639984 DOI: 10.1371/journal.pone.0062758] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2013] [Accepted: 03/25/2013] [Indexed: 12/14/2022] Open
Abstract
Cellular stress responses are frequently governed by the subcellular localization of critical effector proteins. Apoptosis-inducing Factor (AIF) or Glyceraldehyde 3-Phosphate Dehydrogenase (GAPDH), for example, can translocate from mitochondria to the nucleus, where they modulate apoptotic death pathways. Hypoxia-inducible gene domain 1A (HIGD1A) is a mitochondrial protein regulated by Hypoxia-inducible Factor-1α (HIF1α). Here we show that while HIGD1A resides in mitochondria during physiological hypoxia, severe metabolic stress, such as glucose starvation coupled with hypoxia, in addition to DNA damage induced by etoposide, triggers its nuclear accumulation. We show that nuclear localization of HIGD1A overlaps with that of AIF, and is dependent on the presence of BAX and BAK. Furthermore, we show that AIF and HIGD1A physically interact. Additionally, we demonstrate that nuclear HIGD1A is a potential marker of metabolic stress in vivo, frequently observed in diverse pathological states such as myocardial infarction, hypoxic-ischemic encephalopathy (HIE), and different types of cancer. In summary, we demonstrate a novel nuclear localization of HIGD1A that is commonly observed in human disease processes in vivo.
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Shin MK, Drager LF, Yao Q, Bevans-Fonti S, Yoo DY, Jun JC, Aja S, Bhanot S, Polotsky VY. Metabolic consequences of high-fat diet are attenuated by suppression of HIF-1α. PLoS One 2012; 7:e46562. [PMID: 23049707 PMCID: PMC3462192 DOI: 10.1371/journal.pone.0046562] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2012] [Accepted: 08/31/2012] [Indexed: 12/16/2022] Open
Abstract
Obesity is associated with tissue hypoxia and the up-regulation of hypoxia inducible factor 1 alpha (HIF-1α). Prior studies in transgenic mice have shown that HIF-1α plays a role in the metabolic dysfunction associated with obesity. Therefore, we hypothesized that, after the development of diet-induced obesity (DIO), metabolic function could be improved by administration of HIF-1α antisense oligonucleotides (ASO). DIO mice were treated with HIF-1α ASO or with control ASO for 8 weeks and compared with an untreated group. We found that HIF-1α ASO markedly suppressed Hif-1α gene expression in adipose tissue and the liver. HIF-1α ASO administration induced weight loss. Final body weight was 41.6±1.4 g in the HIF-1α ASO group vs 46.7±0.9 g in the control ASO group and 47.9±0.8 g in untreated mice (p<0.001). HIF-1α ASO increased energy expenditure (13.3±0.6 vs 12±0.1 and 11.9±0.4 kcal/kg/hr, respectively, p<0.001) and decreased the respiratory exchange ratio (0.71±0.01 vs 0.75±0.01 and 0.76±0.01, respectively, p<0.001), which suggested switching metabolism to fat oxidation. In contrast, HIF-1a ASO had no effect on food intake or activity. HIF-1α ASO treatment decreased fasting blood glucose (195.5±8.4 mg/dl vs 239±7.8 mg/dl in the control ASO group and 222±8.2 mg/dl in untreated mice, p<0.01), plasma insulin, hepatic glucose output, and liver fat content. These findings demonstrate that the metabolic consequences of DIO are attenuated by HIF-1α ASO treatment.
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Affiliation(s)
- Mi-Kyung Shin
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Luciano F. Drager
- Hypertension Unit, Heart Institute (InCor), University of Saõ Paulo Medical School, Saõ Paulo, Brazil
| | - Qiaoling Yao
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Shannon Bevans-Fonti
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Doo-Young Yoo
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Jonathan C. Jun
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Susan Aja
- Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Sanjay Bhanot
- Isis Pharmaceuticals, Inc., Carlsbad, California, United States of America
| | - Vsevolod Y. Polotsky
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
- * E-mail:
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Girgis CM, Cheng K, Scott CH, Gunton JE. Novel links between HIFs, type 2 diabetes, and metabolic syndrome. Trends Endocrinol Metab 2012; 23:372-80. [PMID: 22766319 DOI: 10.1016/j.tem.2012.05.003] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/29/2012] [Revised: 05/03/2012] [Accepted: 05/05/2012] [Indexed: 12/25/2022]
Abstract
Hypoxia inducible factors (HIFs) are master-regulators of cellular responses to hypoxia, and thus are crucial for survival. HIFs also play a role in regulating cellular processes in β-cells, liver, muscle, and adipose tissue, have effects on the regulation of weight, and play a role in type 2 diabetes (T2D). Indeed, in people with T2D the HIF pathway is dyregulated in major metabolic tissues involved in the pathogenesis of diabetes. This review covers the contrasting, complementary and conflicting effects of decreasing and increasing HIFs in various tissues, and shows that a delicate balance exists between HIF levels and optimal metabolic function. We propose that increasing the activity of HIFs might be a potential therapeutic strategy for treating T2D.
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Affiliation(s)
- Christian M Girgis
- Garvan Institute of Medical Research, 384 Victoria Street, Darlinghurst, NSW 2010, Australia
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Hypoxia-inducible factors and their roles in energy metabolism. Int J Hematol 2012; 95:457-63. [PMID: 22535382 DOI: 10.1007/s12185-012-1069-y] [Citation(s) in RCA: 132] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2012] [Revised: 03/29/2012] [Accepted: 03/29/2012] [Indexed: 01/03/2023]
Abstract
Over the course of evolution, aerobic organisms have developed sophisticated systems for responding to alterations in oxygen concentration, as oxygen acts as a final electron acceptor in oxidative phosphorylation for energy production. Hypoxia-inducible factor (HIF) plays a central role in the adaptive regulation of energy metabolism, by triggering a switch from mitochondrial oxidative phosphorylation to anaerobic glycolysis in hypoxic conditions. HIF also reduces oxygen consumption in mitochondria by inhibiting conversion of pyruvate to acetyl CoA, suppressing mitochondrial biogenesis and activating autophagy of mitochondria concomitantly with reduction in reactive oxygen species production. In addition, metabolic reprogramming in response to hypoxia through HIF activation is not limited to the regulation of carbohydrate metabolism; it occurs in lipid metabolism as well. Recent studies using in vivo gene-targeting technique have revealed unexpected, but novel functions of HIF in energy metabolism in a context- and cell type-specific manner, and shed light on the possibility of pharmaceutical targeting HIF as a new therapy against many diseases, including cancer, diabetes, and fatty liver.
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