201
|
De novo adipocyte differentiation from Pdgfrβ + preadipocytes protects against pathologic visceral adipose expansion in obesity. Nat Commun 2018; 9:890. [PMID: 29497032 PMCID: PMC5832777 DOI: 10.1038/s41467-018-03196-x] [Citation(s) in RCA: 108] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Accepted: 01/24/2018] [Indexed: 02/07/2023] Open
Abstract
Pathologic expansion of white adipose tissue (WAT) in obesity is characterized by adipocyte hypertrophy, inflammation, and fibrosis; however, factors triggering this maladaptive remodeling are largely unknown. Here, we test the hypothesis that the potential to recruit new adipocytes from Pdgfrβ+ preadipocytes determines visceral WAT health in obesity. We manipulate levels of Pparg, the master regulator of adipogenesis, in Pdgfrβ+ precursors of adult mice. Increasing the adipogenic capacity of Pdgfrβ+ precursors through Pparg overexpression results in healthy visceral WAT expansion in obesity and adiponectin-dependent improvements in glucose homeostasis. Loss of mural cell Pparg triggers pathologic visceral WAT expansion upon high-fat diet feeding. Moreover, the ability of the TZD class of anti-diabetic drugs to promote healthy visceral WAT remodeling is dependent on mural cell Pparg. These data highlight the protective effects of de novo visceral adipocyte differentiation in these settings, and suggest Pdgfrβ+ adipocyte precursors as targets for therapeutic intervention in diabetes. Adipocyte hyperplasia is thought to have beneficial metabolic effects in obesity, but definitive evidence is lacking. Here, Shao et al. promote de novo formation of adipocytes in visceral white adipose tissue (WAT) of adult mice through inducible overexpression of Pparg in Pdgfrβ+ preadipocytes and show that this protects from pathological WAT remodeling.
Collapse
|
202
|
Haczeyni F, Bell-Anderson KS, Farrell GC. Causes and mechanisms of adipocyte enlargement and adipose expansion. Obes Rev 2018; 19:406-420. [PMID: 29243339 DOI: 10.1111/obr.12646] [Citation(s) in RCA: 124] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Revised: 09/28/2017] [Accepted: 10/23/2017] [Indexed: 02/06/2023]
Abstract
Adipose tissue plays a significant role in whole body energy homeostasis. Obesity-associated diabetes, fatty liver and metabolic syndrome are closely linked to adipose stress and dysfunction. Genetic predisposition, overeating and physical inactivity influence the expansion of adipose tissues. Under conditions of constant energy surplus, adipocytes become hypertrophic and adipose tissues undergo hyperplasia so as to increase their lipid storage capacity, thereby keeping circulating blood glucose and fatty acids below toxic levels. Nonetheless, adipocytes have a saturation point where they lose capacity to store more lipids. At this stage, when adipocytes are fully lipid-engorged, they express stress signals. Adipose depots (particularly visceral compartments) from obese individuals with a severe metabolic phenotype are characterized by the high proportion of hypertrophic adipocytes. This review focuses on the mechanisms of adipocyte enlargement in relation to adipose fatty acid and cholesterol metabolism, and considers how this may be related to adipose dysfunction.
Collapse
Affiliation(s)
- F Haczeyni
- Liver Research Group, Australian National University Medical School at The Canberra Hospital, Canberra, ACT, Australia
| | - K S Bell-Anderson
- Charles Perkins Centre, School of Life and Environmental Sciences, University of Sydney, Sydney, NSW, Australia
| | - G C Farrell
- Liver Research Group, Australian National University Medical School at The Canberra Hospital, Canberra, ACT, Australia
| |
Collapse
|
203
|
The unique fold and lability of the [2Fe-2S] clusters of NEET proteins mediate their key functions in health and disease. J Biol Inorg Chem 2018; 23:599-612. [PMID: 29435647 PMCID: PMC6006223 DOI: 10.1007/s00775-018-1538-8] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Accepted: 01/26/2018] [Indexed: 02/08/2023]
Abstract
NEET proteins comprise a new class of [2Fe-2S] cluster proteins. In human, three genes encode for NEET proteins: cisd1 encodes mitoNEET (mNT), cisd2 encodes the Nutrient-deprivation autophagy factor-1 (NAF-1) and cisd3 encodes MiNT (Miner2). These recently discovered proteins play key roles in many processes related to normal metabolism and disease. Indeed, NEET proteins are involved in iron, Fe-S, and reactive oxygen homeostasis in cells and play an important role in regulating apoptosis and autophagy. mNT and NAF-1 are homodimeric and reside on the outer mitochondrial membrane. NAF-1 also resides in the membranes of the ER associated mitochondrial membranes (MAM) and the ER. MiNT is a monomer with distinct asymmetry in the molecular surfaces surrounding the clusters. Unlike its paralogs mNT and NAF-1, it resides within the mitochondria. NAF-1 and mNT share similar backbone folds to the plant homodimeric NEET protein (At-NEET), while MiNT's backbone fold resembles a bacterial MiNT protein. Despite the variation of amino acid composition among these proteins, all NEET proteins retained their unique CDGSH domain harboring their unique 3Cys:1His [2Fe-2S] cluster coordination through evolution. The coordinating exposed His was shown to convey the lability to the NEET proteins' [2Fe-2S] clusters. In this minireview, we discuss the NEET fold and its structural elements. Special attention is given to the unique lability of the NEETs' [2Fe-2S] cluster and the implication of the latter to the NEET proteins' cellular and systemic function in health and disease.
Collapse
|
204
|
Bhaskaran S, Pharaoh G, Ranjit R, Murphy A, Matsuzaki S, Nair BC, Forbes B, Gispert S, Auburger G, Humphries KM, Kinter M, Griffin TM, Deepa SS. Loss of mitochondrial protease ClpP protects mice from diet-induced obesity and insulin resistance. EMBO Rep 2018; 19:embr.201745009. [PMID: 29420235 DOI: 10.15252/embr.201745009] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2017] [Revised: 12/08/2017] [Accepted: 12/22/2017] [Indexed: 01/08/2023] Open
Abstract
Caseinolytic peptidase P (ClpP) is a mammalian quality control protease that is proposed to play an important role in the initiation of the mitochondrial unfolded protein response (UPRmt), a retrograde signaling response that helps to maintain mitochondrial protein homeostasis. Mitochondrial dysfunction is associated with the development of metabolic disorders, and to understand the effect of a defective UPRmt on metabolism, ClpP knockout (ClpP-/-) mice were analyzed. ClpP-/- mice fed ad libitum have reduced adiposity and paradoxically improved insulin sensitivity. Absence of ClpP increased whole-body energy expenditure and markers of mitochondrial biogenesis are selectively up-regulated in the white adipose tissue (WAT) of ClpP-/- mice. When challenged with a metabolic stress such as high-fat diet, despite similar caloric intake, ClpP-/- mice are protected from diet-induced obesity, glucose intolerance, insulin resistance, and hepatic steatosis. Our results show that absence of ClpP triggers compensatory responses in mice and suggest that ClpP might be dispensable for mammalian UPRmt initiation. Thus, we made an unexpected finding that deficiency of ClpP in mice is metabolically beneficial.
Collapse
Affiliation(s)
- Shylesh Bhaskaran
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
| | - Gavin Pharaoh
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA.,Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Rojina Ranjit
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
| | - Ashley Murphy
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
| | - Satoshi Matsuzaki
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
| | - Binoj C Nair
- The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Brittany Forbes
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
| | - Suzana Gispert
- Experimental Neurology, Goethe University Medical School, Frankfurt am Main, Germany
| | - Georg Auburger
- Experimental Neurology, Goethe University Medical School, Frankfurt am Main, Germany
| | - Kenneth M Humphries
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
| | - Michael Kinter
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
| | - Timothy M Griffin
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
| | - Sathyaseelan S Deepa
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
| |
Collapse
|
205
|
Zi Xu YX, Ande SR, Mishra S. Prohibitin: A new player in immunometabolism and in linking obesity and inflammation with cancer. Cancer Lett 2018; 415:208-216. [DOI: 10.1016/j.canlet.2017.12.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Revised: 11/30/2017] [Accepted: 12/01/2017] [Indexed: 12/13/2022]
|
206
|
Wachnowsky C, Fidai I, Cowan JA. Iron-sulfur cluster biosynthesis and trafficking - impact on human disease conditions. Metallomics 2018; 10:9-29. [PMID: 29019354 PMCID: PMC5783746 DOI: 10.1039/c7mt00180k] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Iron-sulfur clusters (Fe-S) are one of the most ancient, ubiquitous and versatile classes of metal cofactors found in nature. Proteins that contain Fe-S clusters constitute one of the largest families of proteins, with varied functions that include electron transport, regulation of gene expression, substrate binding and activation, radical generation, and, more recently discovered, DNA repair. Research during the past two decades has shown that mitochondria are central to the biogenesis of Fe-S clusters in eukaryotic cells via a conserved cluster assembly machinery (ISC assembly machinery) that also controls the synthesis of Fe-S clusters of cytosolic and nuclear proteins. Several key steps for synthesis and trafficking have been determined for mitochondrial Fe-S clusters, as well as the cytosol (CIA - cytosolic iron-sulfur protein assembly), but detailed mechanisms of cluster biosynthesis, transport, and exchange are not well established. Genetic mutations and the instability of certain steps in the biosynthesis and maturation of mitochondrial, cytosolic and nuclear Fe-S cluster proteins affects overall cellular iron homeostasis and can lead to severe metabolic, systemic, neurological and hematological diseases, often resulting in fatality. In this review we briefly summarize the current molecular understanding of both mitochondrial ISC and CIA assembly machineries, and present a comprehensive overview of various associated inborn human disease states.
Collapse
Affiliation(s)
- C Wachnowsky
- Department of Chemistry and Biochemistry, The Ohio State University, 100 West 18th Avenue, Columbus, Ohio 43210, USA.
| | | | | |
Collapse
|
207
|
Li H, Wu G, Fang Q, Zhang M, Hui X, Sheng B, Wu L, Bao Y, Li P, Xu A, Jia W. Fibroblast growth factor 21 increases insulin sensitivity through specific expansion of subcutaneous fat. Nat Commun 2018; 9:272. [PMID: 29348470 PMCID: PMC5773530 DOI: 10.1038/s41467-017-02677-9] [Citation(s) in RCA: 102] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Accepted: 12/19/2017] [Indexed: 02/08/2023] Open
Abstract
Although the pharmacological effects of fibroblast growth factor 21 (FGF21) are well-documented, uncertainty about its role in regulating excessive energy intake remains. Here, we show that FGF21 improves systemic insulin sensitivity by promoting the healthy expansion of subcutaneous adipose tissue (SAT). Serum FGF21 levels positively correlate with the SAT area in insulin-sensitive obese individuals. FGF21 knockout mice (FGF21KO) show less SAT mass and are more insulin-resistant when fed a high-fat diet. Replenishment of recombinant FGF21 to a level equivalent to that in obesity restores SAT mass and reverses insulin resistance in FGF21KO, but not in adipose-specific βklotho knockout mice. Moreover, transplantation of SAT from wild-type to FGF21KO mice improves insulin sensitivity in the recipients. Mechanistically, circulating FGF21 upregulates adiponectin in SAT, accompanied by an increase of M2 macrophage polarization. We propose that elevated levels of endogenous FGF21 in obesity serve as a defense mechanism to protect against systemic insulin resistance. FGF21 has a number of beneficial metabolic effects. Here, Li et al. show that FGF21 promotes the healthy expansion of subcutaneous white adipose tissue, promoting the healthy expansion of fat tissue as a regulatory mechanism to maintain systemic insulin sensitivity during nutrient excess.
Collapse
Affiliation(s)
- Huating Li
- Department of Endocrinology and Metabolism, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Clinical Center of Diabetes, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, 200233, China.,State Key Laboratory of Pharmaceutical Biotechnology, Hong Kong, China.,Department of Medicine, The University of Hong Kong, Hong Kong, China
| | - Guangyu Wu
- Department of Endocrinology and Metabolism, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Clinical Center of Diabetes, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, 200233, China.,Department of Medicine, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Qichen Fang
- Department of Endocrinology and Metabolism, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Clinical Center of Diabetes, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, 200233, China
| | - Mingliang Zhang
- Department of Endocrinology and Metabolism, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Clinical Center of Diabetes, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, 200233, China
| | - Xiaoyan Hui
- State Key Laboratory of Pharmaceutical Biotechnology, Hong Kong, China.,Department of Medicine, The University of Hong Kong, Hong Kong, China
| | - Bin Sheng
- Department of Computer Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Liang Wu
- Department of Endocrinology and Metabolism, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Clinical Center of Diabetes, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, 200233, China.,Department of Medicine, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Yuqian Bao
- Department of Endocrinology and Metabolism, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Clinical Center of Diabetes, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, 200233, China
| | - Peng Li
- Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Aimin Xu
- State Key Laboratory of Pharmaceutical Biotechnology, Hong Kong, China. .,Department of Medicine, The University of Hong Kong, Hong Kong, China.
| | - Weiping Jia
- Department of Endocrinology and Metabolism, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Clinical Center of Diabetes, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, 200233, China.
| |
Collapse
|
208
|
Geldenhuys WJ, Benkovic SA, Lin L, Yonutas HM, Crish SD, Sullivan PG, Darvesh AS, Brown CM, Richardson JR. MitoNEET (CISD1) Knockout Mice Show Signs of Striatal Mitochondrial Dysfunction and a Parkinson's Disease Phenotype. ACS Chem Neurosci 2017; 8:2759-2765. [PMID: 28880525 DOI: 10.1021/acschemneuro.7b00287] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Mitochondrial dysfunction is thought to play a significant role in neurodegeneration observed in Parkinson's disease (PD), yet the mechanisms underlying this pathology remain unclear. Here, we demonstrate that loss of mitoNEET (CISD1), an iron-sulfur containing protein that regulates mitochondrial bioenergetics, results in mitochondrial dysfunction and loss of striatal dopamine and tyrosine hydroxylase. Mitochondria isolated from mice lacking mitoNEET were dysfunctional as revealed by elevated reactive oxygen species (ROS) and reduced capacity to produce ATP. Gait analysis revealed a shortened stride length and decreased rotarod performance in knockout mice, consistent with the loss of striatal dopamine. Together, these data suggest that mitoNEET KO mice exhibit many of the characteristics of early neurodegeneration in PD and may provide a novel drug discovery platform to evaluate compounds for enhancing mitochondrial function in neurodegenerative disorders.
Collapse
Affiliation(s)
- Werner J. Geldenhuys
- Department
of Pharmaceutical Sciences, School of Pharmacy, West Virginia University, Morgantown, West Virginia 26506, United States
| | - Stanley A. Benkovic
- Department
of Pharmaceutical Sciences, School of Pharmacy, West Virginia University, Morgantown, West Virginia 26506, United States
| | - Li Lin
- Department
of Pharmaceutical Sciences and Center for Neurodegenerative Disease
and Aging, Northeast Ohio Medical University, College of Pharmacy, Rootstown, Ohio 44272, United States
| | - Heather M. Yonutas
- Department
of Neuroscience; University of Kentucky Chandler College of Medicine, Lexington, Kentucky 40536, United States
| | - Samuel D. Crish
- Department
of Pharmaceutical Sciences and Center for Neurodegenerative Disease
and Aging, Northeast Ohio Medical University, College of Pharmacy, Rootstown, Ohio 44272, United States
| | - Patrick G. Sullivan
- Department
of Neuroscience; University of Kentucky Chandler College of Medicine, Lexington, Kentucky 40536, United States
| | - Altaf S. Darvesh
- Department
of Pharmaceutical Sciences and Center for Neurodegenerative Disease
and Aging, Northeast Ohio Medical University, College of Pharmacy, Rootstown, Ohio 44272, United States
| | - Candice M. Brown
- Department
of Microbiology, Immunology, and Cell Biology; School of Medicine, West Virginia University, Morgantown, West Virginia 26506, United States
| | - Jason R. Richardson
- Department
of Pharmaceutical Sciences and Center for Neurodegenerative Disease
and Aging, Northeast Ohio Medical University, College of Pharmacy, Rootstown, Ohio 44272, United States
| |
Collapse
|
209
|
Xiong W, Zhao X, Garcia-Barrio MT, Zhang J, Lin J, Chen YE, Jiang Z, Chang L. MitoNEET in Perivascular Adipose Tissue Blunts Atherosclerosis under Mild Cold Condition in Mice. Front Physiol 2017; 8:1032. [PMID: 29311966 PMCID: PMC5742148 DOI: 10.3389/fphys.2017.01032] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2017] [Accepted: 11/28/2017] [Indexed: 02/04/2023] Open
Abstract
Background: Perivascular adipose tissue (PVAT), which surrounds most vessels, is de facto a distinct functional vascular layer actively contributing to vascular function and dysfunction. PVAT contributes to aortic remodeling by producing and releasing a large number of undetermined or less characterized factors that could target endothelial cells and vascular smooth muscle cells, and herein contribute to the maintenance of vessel homeostasis. Loss of PVAT in mice enhances atherosclerosis, but a causal relationship between PVAT and atherosclerosis and the possible underlying mechanisms remain to be addressed. The CDGSH iron sulfur domain 1 protein (referred to as mitoNEET), a mitochondrial outer membrane protein, regulates oxidative capacity and adipose tissue browning. The roles of mitoNEET in PVAT, especially in the development of atherosclerosis, are unknown. Methods: The brown adipocyte-specific mitoNEET transgenic mice were subjected to cold environmental stimulus. The metabolic rates and PVAT-dependent thermogenesis were investigated. Additionally, the brown adipocyte-specific mitoNEET transgenic mice were cross-bred with ApoE knockout mice. The ensuing mice were subsequently subjected to cold environmental stimulus and high cholesterol diet challenge for 3 months. The development of atherosclerosis was investigated. Results: Our data show that mitoNEET mRNA was downregulated in PVAT of both peroxisome proliferator-activated receptor gamma coactivator 1-alpha (Pgc1α)- and beta (Pgc1β)-knockout mice which are sensitive to cold. MitoNEET expression was higher in PVAT of wild type mice and increased upon cold stimulus. Transgenic mice with overexpression of mitoNEET in PVAT were cold resistant, and showed increased expression of thermogenic genes. ApoE knockout mice with mitoNEET overexpression in PVAT showed significant downregulation of inflammatory genes and showed reduced atherosclerosis development upon high fat diet feeding when kept in a 16°C environment. Conclusion: mitoNEET in PVAT is associated with PVAT-dependent thermogenesis and prevents atherosclerosis development. The results of this study provide new insights on PVAT and mitoNEET biology and atherosclerosis in cardiovascular diseases.
Collapse
Affiliation(s)
- Wenhao Xiong
- Key Laboratory for Atherosclerology of Hunan Province, Institute of Cardiovascular Disease, University of South China, Hengyang, China.,Cardiovascular Research Center, University of Michigan, Ann Arbor, MI, United States
| | - Xiangjie Zhao
- Cardiovascular Research Center, University of Michigan, Ann Arbor, MI, United States
| | | | - Jifeng Zhang
- Cardiovascular Research Center, University of Michigan, Ann Arbor, MI, United States
| | - Jiandie Lin
- Life Science Institute, University of Michigan, Ann Arbor, MI, United States
| | - Y Eugene Chen
- Department of Cardiac Surgery, University of Michigan, Ann Arbor, MI, United States
| | - Zhisheng Jiang
- Key Laboratory for Atherosclerology of Hunan Province, Institute of Cardiovascular Disease, University of South China, Hengyang, China
| | - Lin Chang
- Cardiovascular Research Center, University of Michigan, Ann Arbor, MI, United States
| |
Collapse
|
210
|
Structure of the human monomeric NEET protein MiNT and its role in regulating iron and reactive oxygen species in cancer cells. Proc Natl Acad Sci U S A 2017; 115:272-277. [PMID: 29259115 DOI: 10.1073/pnas.1715842115] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
The NEET family is a relatively new class of three related [2Fe-2S] proteins (CISD1-3), important in human health and disease. While there has been growing interest in the homodimeric gene products of CISD1 (mitoNEET) and CISD2 (NAF-1), the importance of the inner mitochondrial CISD3 protein has only recently been recognized in cancer. The CISD3 gene encodes for a monomeric protein that contains two [2Fe-2S] CDGSH motifs, which we term mitochondrial inner NEET protein (MiNT). It folds with a pseudosymmetrical fold that provides a hydrophobic motif on one side and a relatively hydrophilic surface on the diametrically opposed surface. Interestingly, as shown by molecular dynamics simulation, the protein displays distinct asymmetrical backbone motions, unlike its homodimeric counterparts that face the cytosolic side of the outer mitochondrial membrane/endoplasmic reticulum (ER). However, like its counterparts, our biological studies indicate that knockdown of MiNT leads to increased accumulation of mitochondrial labile iron, as well as increased mitochondrial reactive oxygen production. Taken together, our study suggests that the MiNT protein functions in the same pathway as its homodimeric counterparts (mitoNEET and NAF-1), and could be a key player in this pathway within the mitochondria. As such, it represents a target for anticancer or antidiabetic drug development.
Collapse
|
211
|
Scroyen I, Hemmeryckx B, Lijnen HR. From mice to men – mouse models in obesity research: What can we learn? Thromb Haemost 2017; 110:634-40. [DOI: 10.1160/th12-11-0873] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2012] [Accepted: 01/26/2013] [Indexed: 12/30/2022]
Abstract
summaryObesity has become a world-wide epidemic and is associated with diseases such as diabetes, dyslipidaemia, cardiovascular disease and certain types of cancers. Understanding the adipose tissue developmental process, involving adipogenesis, angiogenesis and extracellular matrix remodelling, is therefore crucial to reveal the pathobiology of obesity. Experimental mouse models are extensively used to gain new insights into these processes and to evaluate the role of new key players, in particular proteolytic system components, in adipose tissue development and obesity. In this paper, we will review available in vitro and in vivo murine models of obesity and discuss their value in understanding the mechanisms contributing to obesity.
Collapse
|
212
|
Role of Mitochondrial Complex IV in Age-Dependent Obesity. Cell Rep 2017; 16:2991-3002. [PMID: 27626667 DOI: 10.1016/j.celrep.2016.08.041] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Revised: 09/14/2015] [Accepted: 08/14/2016] [Indexed: 12/18/2022] Open
Abstract
Aging is associated with progressive white adipose tissue (WAT) enlargement initiated early in life, but the molecular mechanisms involved remain unknown. Here we show that mitochondrial complex IV (CIV) activity and assembly are already repressed in white adipocytes of middle-aged mice and involve a HIF1A-dependent decline of essential CIV components such as COX5B. At the molecular level, HIF1A binds to the Cox5b proximal promoter and represses its expression. Silencing of Cox5b decreased fatty acid oxidation and promoted intracellular lipid accumulation. Moreover, local in vivo Cox5b silencing in WAT of young mice increased the size of adipocytes, whereas restoration of COX5B expression in aging mice counteracted adipocyte enlargement. An age-dependent reduction in COX5B gene expression was also found in human visceral adipose tissue. Collectively, our findings establish a pivotal role for CIV dysfunction in progressive white adipocyte enlargement during aging, which can be restored to alleviate age-dependent WAT expansion.
Collapse
|
213
|
Lakhia R, Yheskel M, Flaten A, Quittner-Strom EB, Holland WL, Patel V. PPARα agonist fenofibrate enhances fatty acid β-oxidation and attenuates polycystic kidney and liver disease in mice. Am J Physiol Renal Physiol 2017; 314:F122-F131. [PMID: 28903946 DOI: 10.1152/ajprenal.00352.2017] [Citation(s) in RCA: 85] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Peroxisome proliferator-activated receptor α (PPARα) is a nuclear hormone receptor that promotes fatty acid β-oxidation (FAO) and oxidative phosphorylation (OXPHOS). We and others have recently shown that PPARα and its target genes are downregulated, and FAO and OXPHOS are impaired in autosomal dominant polycystic kidney disease (ADPKD). However, whether PPARα and FAO/OXPHOS are causally linked to ADPKD progression is not entirely clear. We report that expression of PPARα and FAO/OXPHOS genes is downregulated, and in vivo β-oxidation rate of 3H-labeled triolein is reduced in Pkd1RC/RC mice, a slowly progressing orthologous model of ADPKD that closely mimics the human ADPKD phenotype. To evaluate the effects of upregulating PPARα, we conducted a 5-mo, randomized, preclinical trial by treating Pkd1RC/RC mice with fenofibrate, a clinically available PPARα agonist. Fenofibrate treatment resulted in increased expression of PPARα and FAO/OXPHOS genes, upregulation of peroxisomal and mitochondrial biogenesis markers, and higher β-oxidation rates in Pkd1RC/RC kidneys. MRI-assessed total kidney volume and total cyst volume, kidney-weight-to-body-weight ratio, cyst index, and serum creatinine levels were significantly reduced in fenofibrate-treated compared with untreated littermate Pkd1RC/RC mice. Moreover, fenofibrate treatment was associated with reduced kidney cyst proliferation and infiltration by inflammatory cells, including M2-like macrophages. Finally, fenofibrate treatment also reduced bile duct cyst number, cyst proliferation, and liver inflammation and fibrosis. In conclusion, our studies suggest that promoting PPARα activity to enhance mitochondrial metabolism may be a useful therapeutic strategy for ADPKD.
Collapse
Affiliation(s)
- Ronak Lakhia
- Department of Internal Medicine and Division of Nephrology, University of Texas Southwestern Medical Center , Dallas, Texas
| | - Matanel Yheskel
- Department of Internal Medicine and Division of Nephrology, University of Texas Southwestern Medical Center , Dallas, Texas
| | - Andrea Flaten
- Department of Internal Medicine and Division of Nephrology, University of Texas Southwestern Medical Center , Dallas, Texas
| | - Ezekiel B Quittner-Strom
- Department of Internal Medicine and Touchstone Diabetes Center University of Texas Southwestern Medical Center , Dallas, Texas
| | - William L Holland
- Department of Internal Medicine and Touchstone Diabetes Center University of Texas Southwestern Medical Center , Dallas, Texas
| | - Vishal Patel
- Department of Internal Medicine and Division of Nephrology, University of Texas Southwestern Medical Center , Dallas, Texas
| |
Collapse
|
214
|
Zhang X, Liu Y, Shao H, Zheng X. Obesity Paradox in Lung Cancer Prognosis: Evolving Biological Insights and Clinical Implications. J Thorac Oncol 2017; 12:1478-1488. [PMID: 28757418 DOI: 10.1016/j.jtho.2017.07.022] [Citation(s) in RCA: 68] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2017] [Revised: 07/18/2017] [Accepted: 07/22/2017] [Indexed: 01/16/2023]
Abstract
The survival rate of lung cancer remains low despite the progress of surgery and chemotherapy. With the increasing comorbidity of obesity in patients with lung cancer, new challenges are emerging in the management of this patient population. A key issue of interest is the prognostic effect of obesity on surgical and chemotherapeutic outcomes in patients with lung cancer, which is fueled by the growing observation of survival benefits in overweight or obese patients. This unexpected inverse relationship between obesity and lung cancer mortality, called the obesity paradox, remains poorly understood. The evolving insights into the heterogeneity of obesity phenotypes and associated biological connections with lung cancer progression in recent years may help explain some of the seemingly paradoxical relationship, and well-designed clinical studies looking at the causal role of obesity-associated molecules are expected. Here, we examine potential biological mechanisms behind the protective effects of obesity in lung cancer. We highlight the need to clarify the clinical implications of this relationship toward an updated intervention strategy in the clinical care of patients with lung cancer and obesity.
Collapse
Affiliation(s)
- Xueli Zhang
- Department of Pharmacy, Zhongda Hospital, School of Medicine, Southeast University, Nanjing, People's Republic of China
| | - Yamin Liu
- Department of Pharmacy, Zhongda Hospital, School of Medicine, Southeast University, Nanjing, People's Republic of China
| | - Hua Shao
- Department of Pharmacy, Zhongda Hospital, School of Medicine, Southeast University, Nanjing, People's Republic of China
| | - Xiao Zheng
- School of Pharmacy, China Pharmaceutical University, Nanjing, People's Republic of China.
| |
Collapse
|
215
|
Hepler C, Shao M, Xia JY, Ghaben AL, Pearson MJ, Vishvanath L, Sharma AX, Morley TS, Holland WL, Gupta RK. Directing visceral white adipocyte precursors to a thermogenic adipocyte fate improves insulin sensitivity in obese mice. eLife 2017; 6. [PMID: 28722653 PMCID: PMC5552276 DOI: 10.7554/elife.27669] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Accepted: 07/18/2017] [Indexed: 01/01/2023] Open
Abstract
Visceral adiposity confers significant risk for developing metabolic disease in obesity whereas preferential expansion of subcutaneous white adipose tissue (WAT) appears protective. Unlike subcutaneous WAT, visceral WAT is resistant to adopting a protective thermogenic phenotype characterized by the accumulation of Ucp1+ beige/BRITE adipocytes (termed ‘browning’). In this study, we investigated the physiological consequences of browning murine visceral WAT by selective genetic ablation of Zfp423, a transcriptional suppressor of the adipocyte thermogenic program. Zfp423 deletion in fetal visceral adipose precursors (Zfp423loxP/loxP; Wt1-Cre), or adult visceral white adipose precursors (PdgfrbrtTA; TRE-Cre; Zfp423loxP/loxP), results in the accumulation of beige-like thermogenic adipocytes within multiple visceral adipose depots. Thermogenic visceral WAT improves cold tolerance and prevents and reverses insulin resistance in obesity. These data indicate that beneficial visceral WAT browning can be engineered by directing visceral white adipocyte precursors to a thermogenic adipocyte fate, and suggest a novel strategy to combat insulin resistance in obesity. DOI:http://dx.doi.org/10.7554/eLife.27669.001 Mammals have different types of fat cells in their bodies. White fat cells store energy for later use, and brown and beige fat cells burn energy to help keep the body warm. Individuals who are obese typically have too many white fat cells in and around their belly. This belly fat, also called visceral fat, accumulates around the organs and is believed to contribute to metabolic diseases, such as diabetes and heart disease. Individuals who are obese also have relatively few brown and beige energy-burning fat cells. Boosting the amount of brown and beige fat in individuals who are obese has been proposed as a potential way to reduce their risk of metabolic disease. One way to do this would be to encourage white visceral fat cells to become more like energy-burning beige or brown fat cells. Recent research has shown that white fat cells contain higher amounts of a protein called Zfp423 than brown or beige fat cells. This protein turns off the genes that fat cells use to burn energy and so keeps white fat cells in an energy-storing state. Now, Hepler et al. show that genetically modifying mice to turn off the gene that produces Zfp423 specifically in the precursor cells that become white fat cells causes more energy-burning beige cells to appear in their visceral fat. The genetically modified mice were better able to tolerate cold than normal mice. When placed on a high-fat diet, the modified mice were also less likely to become resistant to the effects of the hormone insulin – a process that can lead to the development of type 2 diabetes and may be linked to heart disease. This suggests that treatments that prevent Zfp423 from working in fat cells could help to treat or prevent diabetes and heart disease in people who are obese. Before such treatments can be developed, further work is needed to investigate how Zfp423 works in more detail, and to confirm that it has the same effects in human fat cells as it does in mice. DOI:http://dx.doi.org/10.7554/eLife.27669.002
Collapse
Affiliation(s)
- Chelsea Hepler
- Touchstone Diabetes Center, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, United States
| | - Mengle Shao
- Touchstone Diabetes Center, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, United States
| | - Jonathan Y Xia
- Touchstone Diabetes Center, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, United States
| | - Alexandra L Ghaben
- Touchstone Diabetes Center, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, United States
| | - Mackenzie J Pearson
- Touchstone Diabetes Center, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, United States
| | - Lavanya Vishvanath
- Touchstone Diabetes Center, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, United States
| | - Ankit X Sharma
- Touchstone Diabetes Center, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, United States
| | - Thomas S Morley
- Touchstone Diabetes Center, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, United States
| | - William L Holland
- Touchstone Diabetes Center, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, United States
| | - Rana K Gupta
- Touchstone Diabetes Center, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, United States
| |
Collapse
|
216
|
Abstract
MitoNEET (mNEET) is a dimeric mitochondrial outer membrane protein implicated in many facets of human pathophysiology, notably diabetes and cancer, but its molecular function remains poorly characterized. In this study, we generated and analyzed mNEET KO cells and found that in these cells the mitochondrial network was disturbed. Analysis of 3D-EM reconstructions and of thin sections revealed that genetic inactivation of mNEET did not affect the size of mitochondria but that the frequency of intermitochondrial junctions was reduced. Loss of mNEET decreased cellular respiration, because of a reduction in the total cellular mitochondrial volume, suggesting that intermitochondrial contacts stabilize individual mitochondria. Reexpression of mNEET in mNEET KO cells restored the WT morphology of the mitochondrial network, and reexpression of a mutant mNEET resistant to oxidative stress increased in addition the resistance of the mitochondrial network to H2O2-induced fragmentation. Finally, overexpression of mNEET increased strongly intermitochondrial contacts and resulted in the clustering of mitochondria. Our results suggest that mNEET plays a specific role in the formation of intermitochondrial junctions and thus participates in the adaptation of cells to physiological changes and to the control of mitochondrial homeostasis.
Collapse
|
217
|
Garcia-Carrizo F, Priego T, Szostaczuk N, Palou A, Picó C. Sexual Dimorphism in the Age-Induced Insulin Resistance, Liver Steatosis, and Adipose Tissue Function in Rats. Front Physiol 2017; 8:445. [PMID: 28744221 PMCID: PMC5504177 DOI: 10.3389/fphys.2017.00445] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Accepted: 06/12/2017] [Indexed: 01/01/2023] Open
Abstract
Age-linked metabolic disturbances, such as liver steatosis and insulin resistance, show greater prevalence in men than in women. Thus, our aim was to analyze these sex-related differences in male and female Wistar rats (aged 26 days and 3, 7, and 14 months), and to assess their potential relationship with alterations in the capacity of adipose tissue expansion and the dysregulation of the main adipokines produced by the adipose tissue, leptin and adiponectin. Adiposity-related parameters, blood parameters, the expression of genes related to expandability and inflammation (WAT), lipid metabolism (liver), and leptin and insulin signaling (both tissues) were measured. In females, adiposity index and WAT DNA content gradually increased with age, whereas males peaked at 7 months. A similar sex-dependent pattern was observed for leptin expression in WAT, while Mest expression levels decreased with age in males but not in females. Females also showed increased expression of the proliferation marker PCNA in the inguinal WAT compared to males. In males, leptin/adiponectin ratio greatly increased from 7 to 14 months in a more acute manner than in females, along with an increase in HOMA-IR index and hepatic triacylglyceride content, while no changes were observed in females. In liver, 14-month-old males displayed decreased mRNA levels of Insr, Ampkα2, and Cpt1a compared with levels at 7 months. Males also showed decreased mRNA levels of Obrb (both tissues), and increased expression levels of Cd68 and Emr1 (WAT) with age. In conclusion, females are more protected from age-related metabolic disturbances, such as insulin resistance, hepatic lipid deposition, and WAT inflammation compared to males. This may be related to their greater capacity for WAT expansion-reflected by a greater Mest/leptin mRNA ratio-and to their ability to maintain adiponectin levels and preserve leptin sensitivity with aging.
Collapse
Affiliation(s)
- Francisco Garcia-Carrizo
- Laboratory of Molecular Biology, Nutrition and Biotechnology (Nutrigenomics), University of the Balearic IslandsPalma de Mallorca, Spain.,CIBER Fisiopatología de la Obesidad y Nutrición (CIBEROBN)Palma de Mallorca, Spain
| | - Teresa Priego
- Laboratory of Molecular Biology, Nutrition and Biotechnology (Nutrigenomics), University of the Balearic IslandsPalma de Mallorca, Spain.,CIBER Fisiopatología de la Obesidad y Nutrición (CIBEROBN)Palma de Mallorca, Spain
| | - Nara Szostaczuk
- Laboratory of Molecular Biology, Nutrition and Biotechnology (Nutrigenomics), University of the Balearic IslandsPalma de Mallorca, Spain.,CIBER Fisiopatología de la Obesidad y Nutrición (CIBEROBN)Palma de Mallorca, Spain
| | - Andreu Palou
- Laboratory of Molecular Biology, Nutrition and Biotechnology (Nutrigenomics), University of the Balearic IslandsPalma de Mallorca, Spain.,CIBER Fisiopatología de la Obesidad y Nutrición (CIBEROBN)Palma de Mallorca, Spain
| | - Catalina Picó
- Laboratory of Molecular Biology, Nutrition and Biotechnology (Nutrigenomics), University of the Balearic IslandsPalma de Mallorca, Spain.,CIBER Fisiopatología de la Obesidad y Nutrición (CIBEROBN)Palma de Mallorca, Spain
| |
Collapse
|
218
|
Patel SP, Cox DH, Gollihue JL, Bailey WM, Geldenhuys WJ, Gensel JC, Sullivan PG, Rabchevsky AG. Pioglitazone treatment following spinal cord injury maintains acute mitochondrial integrity and increases chronic tissue sparing and functional recovery. Exp Neurol 2017; 293:74-82. [PMID: 28365473 PMCID: PMC5473659 DOI: 10.1016/j.expneurol.2017.03.021] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Revised: 03/13/2017] [Accepted: 03/27/2017] [Indexed: 11/26/2022]
Abstract
Pioglitazone is an FDA-approved PPAR-γ agonist drug used to treat diabetes, and it has demonstrated neuroprotective effects in multiple models of central nervous system (CNS) injury. Acute treatment after spinal cord injury (SCI) in rats is reported to suppress neuroinflammation, rescue injured tissues, and improve locomotor recovery. In the current study, we additionally assessed the protective efficacy of pioglitazone treatment on acute mitochondrial respiration, as well as functional and anatomical recovery after contusion SCI in adult male C57BL/6 mice. Mice received either vehicle or pioglitazone (10mg/kg) at either 15min or 3h after injury (75kdyn at T9) followed by a booster at 24h post-injury. At 25h, mitochondria were isolated from spinal cord segments centered on the injury epicenters and assessed for their respiratory capacity. Results showed significantly compromised mitochondrial respiration 25h following SCI, but pioglitazone treatment that was initiated either at 15min or 3h post-injury significantly maintained mitochondrial respiration rates near sham levels. A second cohort of injured mice received pioglitazone at 15min post injury, then once a day for 5days post-injury to assess locomotor recovery and tissue sparing over 4weeks. Compared to vehicle, pioglitazone treatment resulted in significantly greater recovery of hind-limb function over time, as determined by serial locomotor BMS assessments and both terminal BMS subscores and gridwalk performance. Such improvements correlated with significantly increased grey and white matter tissue sparing, although pioglitazone treatment did not abrogate long-term injury-induced inflammatory microglia/macrophage responses. In sum, pioglitazone significantly increased functional neuroprotection that was associated with remarkable maintenance of acute mitochondrial bioenergetics after traumatic SCI. This sets the stage for dose-response and delayed administration studies to maximize pioglitazone's efficacy for SCI while elucidating the precise role that mitochondria play in governing its neuroprotection; the ultimate goal to develop novel therapeutics that specifically target mitochondrial dysfunction.
Collapse
Affiliation(s)
- Samir P Patel
- Spinal Cord and Brain Injury Research Center, College of Medicine, University of Kentucky, Lexington, KY 40536-0509, USA; Department of Physiology, College of Medicine, University of Kentucky, Lexington, KY 40536-0509, USA
| | - David H Cox
- Spinal Cord and Brain Injury Research Center, College of Medicine, University of Kentucky, Lexington, KY 40536-0509, USA
| | - Jenna L Gollihue
- Spinal Cord and Brain Injury Research Center, College of Medicine, University of Kentucky, Lexington, KY 40536-0509, USA; Department of Physiology, College of Medicine, University of Kentucky, Lexington, KY 40536-0509, USA
| | - William M Bailey
- Spinal Cord and Brain Injury Research Center, College of Medicine, University of Kentucky, Lexington, KY 40536-0509, USA
| | - Werner J Geldenhuys
- Department of Pharmaceutical Sciences, School of Pharmacy, West Virginia University, Morgantown, WV 26506, USA
| | - John C Gensel
- Spinal Cord and Brain Injury Research Center, College of Medicine, University of Kentucky, Lexington, KY 40536-0509, USA; Department of Physiology, College of Medicine, University of Kentucky, Lexington, KY 40536-0509, USA
| | - Patrick G Sullivan
- Spinal Cord and Brain Injury Research Center, College of Medicine, University of Kentucky, Lexington, KY 40536-0509, USA; Department of Neuroscience, College of Medicine, University of Kentucky, Lexington, KY 40536-0509, USA
| | - Alexander G Rabchevsky
- Spinal Cord and Brain Injury Research Center, College of Medicine, University of Kentucky, Lexington, KY 40536-0509, USA; Department of Physiology, College of Medicine, University of Kentucky, Lexington, KY 40536-0509, USA.
| |
Collapse
|
219
|
Angiopoietin-like 4 directs uptake of dietary fat away from adipose during fasting. Mol Metab 2017; 6:809-818. [PMID: 28752045 PMCID: PMC5518724 DOI: 10.1016/j.molmet.2017.06.007] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Revised: 06/09/2017] [Accepted: 06/14/2017] [Indexed: 12/28/2022] Open
Abstract
Objective Angiopoietin-like 4 (ANGPTL4) is a fasting-induced inhibitor of lipoprotein lipase (LPL) and a regulator of plasma triglyceride metabolism. Here, we examined the kinetics of Angptl4 induction and tested the hypothesis that ANGPTL4 functions physiologically to reduce triglyceride delivery to adipose tissue during nutrient deprivation. Methods Gene expression, LPL activity, and triglyceride uptake were examined in fasted and fed wild-type and Angptl4−/− mice. Results Angptl4 was strongly induced early in fasting, and this induction was suppressed in mice with access to food during the light cycle. Fasted Angptl4−/− mice manifested increased LPL activity and triglyceride uptake in adipose tissue compared to wild-type mice. Conclusions Angptl4 is induced early in fasting to divert uptake of fatty acids and triglycerides away from adipose tissues. •Angptl4 is induced within the first few hours of fasting. •Angptl4 expression is driven by fasting rather than circadian rhythms. •Fasted Angptl4−/− mice have increased triglyceride uptake in adipose tissue. •Angptl4−/− mice also have increased LPL activity specifically in adipose tissue. •Data support a model where ANGPTL4 acts locally in adipose during fasting.
Collapse
|
220
|
Suksdorfin Promotes Adipocyte Differentiation and Improves Abnormalities in Glucose Metabolism via PPARγ Activation. Lipids 2017; 52:657-664. [DOI: 10.1007/s11745-017-4269-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2017] [Accepted: 05/31/2017] [Indexed: 12/13/2022]
|
221
|
Dapagliflozin suppresses glucagon signaling in rodent models of diabetes. Proc Natl Acad Sci U S A 2017; 114:6611-6616. [PMID: 28584109 DOI: 10.1073/pnas.1705845114] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Sodium-glucose cotransporter 2 (SGLT2) inhibitors are a class of antidiabetic drug used for the treatment of diabetes. These drugs are thought to lower blood glucose by blocking reabsorption of glucose by SGLT2 in the proximal convoluted tubules of the kidney. To investigate the effect of inhibiting SGLT2 on pancreatic hormones, we treated perfused pancreata from rats with chemically induced diabetes with dapagliflozin and measured the response of glucagon secretion by alpha cells in response to elevated glucose. In these type 1 diabetic rats, glucose stimulated glucagon secretion by alpha cells; this was prevented by dapagliflozin. Two models of type 2 diabetes, severely diabetic Zucker rats and db/db mice fed dapagliflozin, showed significant improvement of blood glucose levels and glucose disposal, with reduced evidence of glucagon signaling in the liver, as exemplified by reduced phosphorylation of hepatic cAMP-responsive element binding protein, reduced expression of phosphoenolpyruvate carboxykinase 2, increased hepatic glycogen, and reduced hepatic glucose production. Plasma glucagon levels did not change significantly. However, dapagliflozin treatment reduced the expression of the liver glucagon receptor. Dapagliflozin in rodents appears to lower blood glucose levels in part by suppressing hepatic glucagon signaling through down-regulation of the hepatic glucagon receptor.
Collapse
|
222
|
Influence of the definition of "metabolically healthy obesity" on the progression of coronary artery calcification. PLoS One 2017; 12:e0178741. [PMID: 28575097 PMCID: PMC5456095 DOI: 10.1371/journal.pone.0178741] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Accepted: 05/18/2017] [Indexed: 12/25/2022] Open
Abstract
OBJECTIVES Debates whether metabolically healthy obesity (MHO) increases the cardiovascular risk might be due to the metabolic instability of MHO or the absence of a perfect definition of MHO. Therefore, we aimed to investigate the influence of the MHO phenotype on the coronary artery calcium score (CACS) progression according to definition of MHO. METHODS We analyzed a retrospective cohort with a CACS of 0 at baseline and available serial CACS measurements taken ≥ 12 months apart (n = 1,218). Obesity was defined as BMI ≥ 25 kg/m2, and MHO was defined as obesity accompanied by ≤ 1 (MHO class I) or 0 (MHO class II) components of metabolic syndrome (MetS). RESULTS During a median follow-up of 45 months, 32.2% of MHO class I and 10.2% of MHO class II subjects developed MetS. Compared to non-obese/metabolically healthy subjects (reference group), hazard ratios (HR) for development of MetS were 2.174 (95% confidence interval [CI]: 1.513-3.124) and 1.166 (95% CI: 0.434-3.129) for MHO class I and II subjects, respectively. The MHO class I subjects showed a significantly increased risk of CACS progression as compared to the reference group (HR: 1.653; 95% CI: 1.144-2.390), whereas MHO class II subjects did not (HR: 1.195; 95% CI: 0.514-2.778). Among subjects with MHO class I, no significant CACS progression was observed in the subjects who maintained metabolic health during follow-up (HR: 1.448; 95% CI: 0.921-2.278). CONCLUSIONS The risks of metabolic deterioration and CACS progression were significant in subjects with MHO class I, but not in those with MHO class II.
Collapse
|
223
|
Antonopoulos AS, Tousoulis D. The molecular mechanisms of obesity paradox. Cardiovasc Res 2017; 113:1074-1086. [DOI: 10.1093/cvr/cvx106] [Citation(s) in RCA: 124] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/22/2017] [Accepted: 05/24/2017] [Indexed: 11/14/2022] Open
|
224
|
Heritage M, Jaskowski L, Bridle K, Campbell C, Briskey D, Britton L, Fletcher L, Vitetta L, Subramaniam VN, Crawford D. Combination curcumin and vitamin E treatment attenuates diet-induced steatosis in Hfe-/- mice. World J Gastrointest Pathophysiol 2017; 8:67-76. [PMID: 28573069 PMCID: PMC5437504 DOI: 10.4291/wjgp.v8.i2.67] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/28/2016] [Revised: 12/01/2016] [Accepted: 03/02/2017] [Indexed: 02/06/2023] Open
Abstract
AIM To investigate the synergistic hepato-protective properties of curcumin and vitamin E in an Hfe-/- high calorie diet model of steatohepatitis.
METHODS Hfe-/- C57BL/6J mice were fed either a high calorie diet or a high calorie diet with 1 mg/g curcumin; 1.5 mg/g vitamin E; or combination of 1 mg/g curcumin + 1.5 mg/g vitamin E for 20 wk. Serum and liver tissue were collected at the completion of the experiment. Liver histology was graded by a pathologist for steatosis, inflammation and fibrosis. RNA and protein was extracted from liver tissue to examine gene and protein expression associated with fatty acid oxidation, mitochondrial biogenesis and oxidative stress pathways.
RESULTS Hfe-/- mice fed the high calorie diet developed steatohepatitis and pericentral fibrosis. Combination treatment with curcumin and vitamin E resulted in a greater reduction of percent steatosis than either vitamin E or curcumin therapy alone. Serum alanine aminotransferase and non-alcoholic fatty liver disease (NAFLD) activity score were decreased following combination therapy with curcumin and vitamin E compared with high calorie diet alone. No changes were observed in inflammatory or fibrosis markers following treatment. Epididymal fat pad weights were significantly reduced following combination therapy, however total body weight and liver weight were unchanged. Combination therapy increased the mRNA expression of AdipoR2, Ppar-α, Cpt1a, Nrf-1 and Tfb2m suggesting enhanced fatty acid oxidation and mitochondrial biogenesis. In addition, combination treatment resulted in increased catalase activity in Hfe-/- mice.
CONCLUSION Combination curcumin and vitamin E treatment decreases liver injury in this steatohepatitis model, indicating that combination therapy may be of value in NAFLD.
Collapse
|
225
|
Moreno-Navarrete JM, Ortega F, Rodríguez A, Latorre J, Becerril S, Sabater-Masdeu M, Ricart W, Frühbeck G, Fernández-Real JM. HMOX1 as a marker of iron excess-induced adipose tissue dysfunction, affecting glucose uptake and respiratory capacity in human adipocytes. Diabetologia 2017; 60:915-926. [PMID: 28243792 DOI: 10.1007/s00125-017-4228-0] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Accepted: 02/01/2017] [Indexed: 10/20/2022]
Abstract
AIMS/HYPOTHESIS Iron excess in adipose tissue is known to promote adipose tissue dysfunction. Here, we aimed to investigate the possible role of haem oxygenase 1 (HMOX1) in iron excess-induced adipose tissue dysfunction. METHODS Cross-sectionally, HMOX1 gene expression in subcutaneous and visceral adipose tissue was analysed in two independent cohorts (n = 234 and 40) in relation to obesity. We also evaluated the impact of weight loss (n = 21), weight gain (in rats, n = 20) on HMOX1 mRNA; HMOX1 mRNA levels during human adipocyte differentiation; the effects of inflammation and iron on adipocyte HMOX1; and the effects of HMOX1-induced activity on adipocyte mitochondrial respiratory function, glucose uptake and adipogenesis. RESULTS Adipose tissue HMOX1 was increased in obese participants (p = 0.01) and positively associated with obesity-related metabolic disturbances, and markers of iron accumulation, inflammation and oxidative stress (p < 0.01). HMOX1 was negatively correlated with mRNAs related to mitochondrial biogenesis, the insulin signalling pathway and adipogenesis (p < 0.01). These associations were replicated in an independent cohort. Bariatric surgery-induced weight loss led to reduced HMOX1 (0.024 ± 0.010 vs 0.010 ± 0.004 RU, p < 0.0001), whereas in rats, high-fat diet-induced weight gain resulted in increased Hmox1 mRNA levels (0.22 ± 0.15 vs 0.54 ± 0.22 RU, p = 0.005). These changes were in parallel with changes in BMI and adipose tissue markers of iron excess, adipogenesis and inflammation. In human adipocytes, iron excess and inflammation led to increased HMOX1 mRNA levels. HMOX1 induction (by haem arginate [hemin] administration), resulted in a significant reduction of mitochondrial respiratory capacity (including basal respiration and spare respiratory capacity), glucose uptake and adipogenesis in parallel with increased expression of inflammatory- and iron excess-related genes. CONCLUSIONS/INTERPRETATION HMOX1 is an important marker of iron excess-induced adipose tissue dysfunction and metabolic disturbances in human obesity.
Collapse
Affiliation(s)
- José María Moreno-Navarrete
- Department of Diabetes, Endocrinology and Nutrition, Institut d'Investigació Biomèdica de Girona (IdIBGi), Hospital of Girona 'Dr Josep Trueta', Carretera de França s/n, 17007, Girona, Spain.
- Centro de Investigación Biomédica en Red de Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III (ISCIII), Spain, .
| | - Francisco Ortega
- Department of Diabetes, Endocrinology and Nutrition, Institut d'Investigació Biomèdica de Girona (IdIBGi), Hospital of Girona 'Dr Josep Trueta', Carretera de França s/n, 17007, Girona, Spain
- Centro de Investigación Biomédica en Red de Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III (ISCIII), Spain
| | - Amaia Rodríguez
- Centro de Investigación Biomédica en Red de Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III (ISCIII), Spain
- Metabolic Research Laboratory, Clínica Universidad de Navarra, Pamplona, 31008, Spain
| | - Jèssica Latorre
- Department of Diabetes, Endocrinology and Nutrition, Institut d'Investigació Biomèdica de Girona (IdIBGi), Hospital of Girona 'Dr Josep Trueta', Carretera de França s/n, 17007, Girona, Spain
- Centro de Investigación Biomédica en Red de Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III (ISCIII), Spain
| | - Sara Becerril
- Centro de Investigación Biomédica en Red de Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III (ISCIII), Spain
- Metabolic Research Laboratory, Clínica Universidad de Navarra, Pamplona, 31008, Spain
| | - Mònica Sabater-Masdeu
- Department of Diabetes, Endocrinology and Nutrition, Institut d'Investigació Biomèdica de Girona (IdIBGi), Hospital of Girona 'Dr Josep Trueta', Carretera de França s/n, 17007, Girona, Spain
- Centro de Investigación Biomédica en Red de Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III (ISCIII), Spain
| | - Wifredo Ricart
- Department of Diabetes, Endocrinology and Nutrition, Institut d'Investigació Biomèdica de Girona (IdIBGi), Hospital of Girona 'Dr Josep Trueta', Carretera de França s/n, 17007, Girona, Spain
- Centro de Investigación Biomédica en Red de Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III (ISCIII), Spain
- Department of Medicine, Universitat de Girona, Girona, 17007, Spain
| | - Gema Frühbeck
- Centro de Investigación Biomédica en Red de Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III (ISCIII), Spain
- Metabolic Research Laboratory, Clínica Universidad de Navarra, Pamplona, 31008, Spain
| | - José Manuel Fernández-Real
- Department of Diabetes, Endocrinology and Nutrition, Institut d'Investigació Biomèdica de Girona (IdIBGi), Hospital of Girona 'Dr Josep Trueta', Carretera de França s/n, 17007, Girona, Spain.
- Centro de Investigación Biomédica en Red de Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III (ISCIII), Spain, .
- Department of Medicine, Universitat de Girona, Girona, 17007, Spain.
| |
Collapse
|
226
|
Wang Y, Landry AP, Ding H. The mitochondrial outer membrane protein mitoNEET is a redox enzyme catalyzing electron transfer from FMNH 2 to oxygen or ubiquinone. J Biol Chem 2017; 292:10061-10067. [PMID: 28461337 DOI: 10.1074/jbc.m117.789800] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Revised: 04/29/2017] [Indexed: 01/20/2023] Open
Abstract
Increasing evidence suggests that mitoNEET, a target of the type II diabetes drug pioglitazone, is a key regulator of energy metabolism in mitochondria. MitoNEET is anchored to the mitochondrial outer membrane via its N-terminal α helix domain and hosts a redox-active [2Fe-2S] cluster in its C-terminal cytosolic region. The mechanism by which mitoNEET regulates energy metabolism in mitochondria, however, is not fully understood. Previous studies have shown that mitoNEET specifically interacts with the reduced flavin mononucleotide (FMNH2) and that FMNH2 can quickly reduce the mitoNEET [2Fe-2S] clusters. Here we report that the reduced mitoNEET [2Fe-2S] clusters can be readily oxidized by oxygen. In the presence of FMN, NADH, and flavin reductase, which reduces FMN to FMNH2 using NADH as the electron donor, mitoNEET mediates oxidation of NADH with a concomitant reduction of oxygen. Ubiquinone-2, an analog of ubiquinone-10, can also oxidize the reduced mitoNEET [2Fe-2S] clusters under anaerobic or aerobic conditions. Compared with oxygen, ubiquinone-2 is more efficient in oxidizing the mitoNEET [2Fe-2S] clusters, suggesting that ubiquinone could be an intrinsic electron acceptor of the reduced mitoNEET [2Fe-2S] clusters in mitochondria. Pioglitazone or its analog NL-1 appears to inhibit the electron transfer activity of mitoNEET by forming a unique complex with mitoNEET and FMNH2 The results suggest that mitoNEET is a redox enzyme that may promote oxidation of NADH to facilitate enhanced glycolysis in the cytosol and that pioglitazone may regulate energy metabolism in mitochondria by inhibiting the electron transfer activity of mitoNEET.
Collapse
Affiliation(s)
- Yiming Wang
- From the Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana 70803
| | - Aaron P Landry
- From the Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana 70803
| | - Huangen Ding
- From the Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana 70803
| |
Collapse
|
227
|
Fuster JJ, Ouchi N, Gokce N, Walsh K. Obesity-Induced Changes in Adipose Tissue Microenvironment and Their Impact on Cardiovascular Disease. Circ Res 2017; 118:1786-807. [PMID: 27230642 DOI: 10.1161/circresaha.115.306885] [Citation(s) in RCA: 402] [Impact Index Per Article: 57.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Accepted: 02/16/2016] [Indexed: 02/07/2023]
Abstract
Obesity is causally linked with the development of cardiovascular disorders. Accumulating evidence indicates that cardiovascular disease is the collateral damage of obesity-driven adipose tissue dysfunction that promotes a chronic inflammatory state within the organism. Adipose tissues secrete bioactive substances, referred to as adipokines, which largely function as modulators of inflammation. The microenvironment of adipose tissue will affect the adipokine secretome, having actions on remote tissues. Obesity typically leads to the upregulation of proinflammatory adipokines and the downregulation of anti-inflammatory adipokines, thereby contributing to the pathogenesis of cardiovascular diseases. In this review, we focus on the microenvironment of adipose tissue and how it influences cardiovascular disorders, including atherosclerosis and ischemic heart diseases, through the systemic actions of adipokines.
Collapse
Affiliation(s)
- José J Fuster
- From the Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA (J.J.F., N.G., K.W.); and Department of Molecular Cardiology, Nagoya University School of Medicine, Nagoya, Japan (N.O.).
| | - Noriyuki Ouchi
- From the Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA (J.J.F., N.G., K.W.); and Department of Molecular Cardiology, Nagoya University School of Medicine, Nagoya, Japan (N.O.)
| | - Noyan Gokce
- From the Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA (J.J.F., N.G., K.W.); and Department of Molecular Cardiology, Nagoya University School of Medicine, Nagoya, Japan (N.O.)
| | - Kenneth Walsh
- From the Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA (J.J.F., N.G., K.W.); and Department of Molecular Cardiology, Nagoya University School of Medicine, Nagoya, Japan (N.O.).
| |
Collapse
|
228
|
Testroet ED, Sherman P, Yoder C, Testroet A, Reynolds C, O'Neil M, Lei SM, Beitz DC, Baas TJ. A novel and robust method for testing bimodality and characterizing porcine adipocytes of adipose tissue of 5 purebred lines of pig. Adipocyte 2017; 6:102-111. [PMID: 28425850 PMCID: PMC5477704 DOI: 10.1080/21623945.2017.1304870] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Adipocyte sizes from adipose tissue of mature animals form a bimodal distribution, thus reporting mean cell size is misleading. The objectives of this study were to develop a robust method for testing bimodality of porcine adipocytes, describe the size distribution with an informative metric, and statistically test hypertrophy and appearance of new small adipocytes, possibly resulting from hyperplasia or lipid filling of previously divided fibroblastic cells. Ninety-three percent of adipose samples measured were bimodal (P < 0.0001); therefore, we describe and propose a method of testing hyperplasia or lipid filling of previously divided fibroblastic cells based upon the probability of an adipocyte falling into 2 chosen competing “bins” as adiposity increases. We also conclude that increased adiposity is correlated positively with an adipocyte being found in the minor mode (r = 0.46) and correlated negatively with an adipocyte being found in the major mode (r = −0.22), providing evidence of either hyperplasia or lipid filling of previously divided fibroblastic cells. We additionally conclude that as adiposity increases, the mode of the major distribution of cells occurs at a larger diameter of adipocyte, indicating hypertrophy.
Collapse
Affiliation(s)
- Eric D. Testroet
- Department of Animal Science, Iowa State University, Ames, IA, USA
| | - Peter Sherman
- Department of Statistics, Iowa State University, Ames, IA, USA
| | | | - Amber Testroet
- Department of Agronomy, Iowa State University, Ames, IA, USA
| | - Carmen Reynolds
- Department of Animal Science, Iowa State University, Ames, IA, USA
| | - Mathew O'Neil
- Department of Animal Science, Iowa State University, Ames, IA, USA
| | - Soi Meng Lei
- Department of Animal Science, Iowa State University, Ames, IA, USA
| | - Donald C. Beitz
- Department of Animal Science, Iowa State University, Ames, IA, USA
| | - Tom J. Baas
- Department of Animal Science, Iowa State University, Ames, IA, USA
| |
Collapse
|
229
|
Kavanagh K, Davis AT, Peters DE, Le Grand A, Bharadwaj MS, Molina AJA. Regulators of mitochondrial quality control differ in subcutaneous fat of metabolically healthy and unhealthy obese monkeys. Obesity (Silver Spring) 2017; 25:689-696. [PMID: 28236433 PMCID: PMC5373959 DOI: 10.1002/oby.21762] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Revised: 12/07/2016] [Accepted: 12/09/2016] [Indexed: 01/01/2023]
Abstract
OBJECTIVE Obesity exists with and without accompanying cardiometabolic disease, termed metabolically unhealthy obesity (MUO) and healthy obesity (MHO), respectively. Underlying differences in the ability of subcutaneous (SQ) fat to respond to nutrient excess are emerging as a key pathway. This study aimed to document the first spontaneous animal model of MHO and MUO and differences in SQ adipose tissue. METHODS Vervet monkeys (Chlorocebus aethiops; N = 171) were screened for metabolic syndrome. A subset of MHO and MUO monkeys (n = 6/group) had SQ fat biopsies collected for histological evaluations and examination of key mitochondrial proteins. RESULTS Obesity was seen in 20% of monkeys, and within this population, 31% were healthy, which mirrors human prevalence estimates. MUO monkeys had more than 60% lower adiponectin concentrations despite similar fat cell size, uncoupling protein 3, and activated macrophage abundance. However, alternatively activated/anti-inflammatory macrophages were 70% lower. Deficiencies of 50% or more in mitochondrial quality control regulators and selected mitochondrial fission and fusion markers were observed in the SQ fat of MUO monkeys despite comparable mitochondrial content. CONCLUSIONS A novel and translatable spontaneously obese animal model of MHO and MUO, occurring independently of dietary factors, was characterized. Differences in mitochondrial quality and inflammatory cell populations of subcutaneous fat may underpin divergent metabolic health.
Collapse
Affiliation(s)
- Kylie Kavanagh
- Wake Forest School of Medicine, Department of Pathology, Wake Forest University Health Sciences, Winston-Salem, NC, USA 27157
| | - Ashley T Davis
- Wake Forest School of Medicine, Department of Pathology, Wake Forest University Health Sciences, Winston-Salem, NC, USA 27157
| | - Diane E Peters
- Wake Forest School of Medicine, Department of Pathology, Wake Forest University Health Sciences, Winston-Salem, NC, USA 27157
| | - Andre Le Grand
- Wake Forest School of Medicine, Animal Resources Program, Wake Forest University Health Sciences, Winston-Salem, NC, USA 27157
| | - Manish S Bharadwaj
- Wake Forest School of Medicine, Internal Medicine, Wake Forest University Health Sciences, Winston-Salem, NC, USA 27157
| | - Anthony JA Molina
- Wake Forest School of Medicine, Internal Medicine, Wake Forest University Health Sciences, Winston-Salem, NC, USA 27157
| |
Collapse
|
230
|
An YA, Sun K, Joffin N, Zhang F, Deng Y, Donzé O, Kusminski CM, Scherer PE. Angiopoietin-2 in white adipose tissue improves metabolic homeostasis through enhanced angiogenesis. eLife 2017; 6. [PMID: 28355132 PMCID: PMC5391203 DOI: 10.7554/elife.24071] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Accepted: 03/28/2017] [Indexed: 01/12/2023] Open
Abstract
Despite many angiogenic factors playing crucial roles in metabolic homeostasis, effects of angiopoietin-2 (ANG-2) in adipose tissue (AT) remain unclear. Utilizing a doxycycline-inducible AT-specific ANG-2 overexpression mouse model, we assessed the effects of ANG-2 in AT expansion upon a high-fat diet (HFD) challenge. ANG-2 is significantly induced, with subcutaneous white AT (sWAT) displaying the highest ANG-2 expression. ANG-2 overexpressing mice show increased sWAT vascularization and are resistant to HFD-induced obesity. In addition, improved glucose and lipid metabolism are observed. Mechanistically, the sWAT displays a healthier expansion pattern with increased anti-inflammatory macrophage infiltration. Conversely, ANG-2 neutralization in HFD-challenged wild-type mice shows reduced vascularization in sWAT, associated with impaired glucose tolerance and lipid clearance. Blocking ANG-2 causes significant pro-inflammatory and pro-fibrotic changes, hallmarks of an unhealthy AT expansion. In contrast to other pro-angiogenic factors, such as vascular endothelial growth factor-A (VEGF-A), this is achieved without any enhanced beiging of white AT. DOI:http://dx.doi.org/10.7554/eLife.24071.001
Collapse
Affiliation(s)
- Yu A An
- Touchstone Diabetes Center, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, United States
| | - Kai Sun
- Touchstone Diabetes Center, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, United States.,Center for Metabolic and Degenerative Diseases, The Brown Foundation Institute of Molecular Medicine, University of Texas Health Science Center at Houston, Houston, United States
| | - Nolwenn Joffin
- Touchstone Diabetes Center, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, United States
| | - Fang Zhang
- Touchstone Diabetes Center, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, United States.,Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Yingfeng Deng
- Touchstone Diabetes Center, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, United States
| | | | - Christine M Kusminski
- Touchstone Diabetes Center, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, United States
| | - Philipp E Scherer
- Touchstone Diabetes Center, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, United States.,Department of Cell Biology, The University of Texas Southwestern Medical Center, Dallas, United States
| |
Collapse
|
231
|
Hajarnis S, Lakhia R, Yheskel M, Williams D, Sorourian M, Liu X, Aboudehen K, Zhang S, Kersjes K, Galasso R, Li J, Kaimal V, Lockton S, Davis S, Flaten A, Johnson JA, Holland WL, Kusminski CM, Scherer PE, Harris PC, Trudel M, Wallace DP, Igarashi P, Lee EC, Androsavich JR, Patel V. microRNA-17 family promotes polycystic kidney disease progression through modulation of mitochondrial metabolism. Nat Commun 2017; 8:14395. [PMID: 28205547 PMCID: PMC5316862 DOI: 10.1038/ncomms14395] [Citation(s) in RCA: 133] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Accepted: 12/22/2016] [Indexed: 12/31/2022] Open
Abstract
Autosomal dominant polycystic kidney disease (ADPKD) is the most frequent genetic cause of renal failure. Here we identify miR-17 as a target for the treatment of ADPKD. We report that miR-17 is induced in kidney cysts of mouse and human ADPKD. Genetic deletion of the miR-17∼92 cluster inhibits cyst proliferation and PKD progression in four orthologous, including two long-lived, mouse models of ADPKD. Anti-miR-17 treatment attenuates cyst growth in short-term and long-term PKD mouse models. miR-17 inhibition also suppresses proliferation and cyst growth of primary ADPKD cysts cultures derived from multiple human donors. Mechanistically, c-Myc upregulates miR-17∼92 in cystic kidneys, which in turn aggravates cyst growth by inhibiting oxidative phosphorylation and stimulating proliferation through direct repression of Pparα. Thus, miR-17 family is a promising drug target for ADPKD, and miR-17-mediated inhibition of mitochondrial metabolism represents a potential new mechanism for ADPKD progression. Autosomal dominant polycystic kidney disease (ADPKD) is a life-threatening genetic disease that leads to renal failure. Here Hajarnis et al. show that miR-17 modulates cyst progression in ADPKD through metabolic reprogramming of mitochondria and its inhibition slows cyst development and improves renal functions.
Collapse
Affiliation(s)
- Sachin Hajarnis
- Department of Internal Medicine and Division of Nephrology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Ronak Lakhia
- Department of Internal Medicine and Division of Nephrology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Matanel Yheskel
- Department of Internal Medicine and Division of Nephrology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Darren Williams
- Department of Internal Medicine and Division of Nephrology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| | | | - Xueqing Liu
- Regulus Therapeutics Inc., San Diego, California 92121, USA
| | - Karam Aboudehen
- Department of Medicine and Division of Nephrology, University of Minnesota Medical School, Minneapolis, Minnesota 55455, USA
| | - Shanrong Zhang
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Kara Kersjes
- Regulus Therapeutics Inc., San Diego, California 92121, USA
| | - Ryan Galasso
- Regulus Therapeutics Inc., San Diego, California 92121, USA
| | - Jian Li
- Regulus Therapeutics Inc., San Diego, California 92121, USA
| | - Vivek Kaimal
- Regulus Therapeutics Inc., San Diego, California 92121, USA
| | - Steven Lockton
- Regulus Therapeutics Inc., San Diego, California 92121, USA
| | - Scott Davis
- Regulus Therapeutics Inc., San Diego, California 92121, USA
| | - Andrea Flaten
- Department of Internal Medicine and Division of Nephrology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Joshua A Johnson
- Department of Internal Medicine and Touchstone Diabetes Center, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| | - William L Holland
- Department of Internal Medicine and Touchstone Diabetes Center, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Christine M Kusminski
- Department of Internal Medicine and Touchstone Diabetes Center, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Philipp E Scherer
- Department of Internal Medicine and Touchstone Diabetes Center, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Peter C Harris
- Department of Nephrology and Hypertension, Mayo College of Medicine, Rochester, Minnesota 55905, USA
| | - Marie Trudel
- Molecular Genetics and Development, Institut de Recherches Cliniques de Montreal, Universite de Montreal, Faculte de Medecine, Montréal, Québec H2W 1R7, Canada
| | - Darren P Wallace
- Department of Medicine and the Kidney Institute, University of Kansas Medical Center, Kansas City, Kansas 66160, USA
| | - Peter Igarashi
- Department of Medicine and Division of Nephrology, University of Minnesota Medical School, Minneapolis, Minnesota 55455, USA
| | - Edmund C Lee
- Regulus Therapeutics Inc., San Diego, California 92121, USA
| | | | - Vishal Patel
- Department of Internal Medicine and Division of Nephrology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| |
Collapse
|
232
|
Inupakutika MA, Sengupta S, Nechushtai R, Jennings PA, Onuchic JN, Azad RK, Padilla P, Mittler R. Phylogenetic analysis of eukaryotic NEET proteins uncovers a link between a key gene duplication event and the evolution of vertebrates. Sci Rep 2017; 7:42571. [PMID: 28205535 PMCID: PMC5311916 DOI: 10.1038/srep42571] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Accepted: 01/12/2017] [Indexed: 12/17/2022] Open
Abstract
NEET proteins belong to a unique family of iron-sulfur proteins in which the 2Fe-2S cluster is coordinated by a CDGSH domain that is followed by the “NEET” motif. They are involved in the regulation of iron and reactive oxygen metabolism, and have been associated with the progression of diabetes, cancer, aging and neurodegenerative diseases. Despite their important biological functions, the evolution and diversification of eukaryotic NEET proteins are largely unknown. Here we used the three members of the human NEET protein family (CISD1, mitoNEET; CISD2, NAF-1 or Miner 1; and CISD3, Miner2) as our guides to conduct a phylogenetic analysis of eukaryotic NEET proteins and their evolution. Our findings identified the slime mold Dictyostelium discoideum’s CISD proteins as the closest to the ancient archetype of eukaryotic NEET proteins. We further identified CISD3 homologs in fungi that were previously reported not to contain any NEET proteins, and revealed that plants lack homolog(s) of CISD3. Furthermore, our study suggests that the mammalian NEET proteins, mitoNEET (CISD1) and NAF-1 (CISD2), emerged via gene duplication around the origin of vertebrates. Our findings provide new insights into the classification and expansion of the NEET protein family, as well as offer clues to the diverged functions of the human mitoNEET and NAF-1 proteins.
Collapse
Affiliation(s)
| | - Soham Sengupta
- Department of Biological Sciences, University of North Texas, Denton TX 76203, USA
| | - Rachel Nechushtai
- The Alexander Silberman Institute of Life Science, Hebrew University of Jerusalem, Edmond J. Safra Campus at Givat Ram, Jerusalem 91904, Israel
| | - Patricia A Jennings
- Department of Chemistry &Biochemistry, University of California at San Diego, La Jolla, CA 92093, USA
| | - Jose' N Onuchic
- Center for Theoretical Biological Physics and Department of Physics and Astronomy, Chemistry and Biosciences, 239 Brockman Hall, 6100 Main Street- MS-61, Rice University, Houston, TX 77005, USA
| | - Rajeev K Azad
- Department of Biological Sciences, University of North Texas, Denton TX 76203, USA.,Department of Mathematics, University of North Texas, Denton, TX 76203, USA
| | - Pamela Padilla
- Department of Biological Sciences, University of North Texas, Denton TX 76203, USA
| | - Ron Mittler
- Department of Biological Sciences, University of North Texas, Denton TX 76203, USA
| |
Collapse
|
233
|
Julien SG, Kim SY, Brunmeir R, Sinnakannu JR, Ge X, Li H, Ma W, Yaligar J, KN BP, Velan SS, Röder PV, Zhang Q, Sim CK, Wu J, Garcia-Miralles M, Pouladi MA, Xie W, McFarlane C, Han W, Xu F. Narciclasine attenuates diet-induced obesity by promoting oxidative metabolism in skeletal muscle. PLoS Biol 2017; 15:e1002597. [PMID: 28207742 PMCID: PMC5331945 DOI: 10.1371/journal.pbio.1002597] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Accepted: 01/23/2017] [Indexed: 12/19/2022] Open
Abstract
Obesity develops when caloric intake exceeds metabolic needs. Promoting energy expenditure represents an attractive approach in the prevention of this fast-spreading epidemic. Here, we report a novel pharmacological strategy in which a natural compound, narciclasine (ncls), attenuates diet-induced obesity (DIO) in mice by promoting energy expenditure. Moreover, ncls promotes fat clearance from peripheral metabolic tissues, improves blood metabolic parameters in DIO mice, and protects these mice from the loss of voluntary physical activity. Further investigation suggested that ncls achieves these beneficial effects by promoting a shift from glycolytic to oxidative muscle fibers in the DIO mice thereby enhancing mitochondrial respiration and fatty acid oxidation (FAO) in the skeletal muscle. Moreover, ncls strongly activates AMPK signaling specifically in the skeletal muscle. The beneficial effects of ncls treatment in fat clearance and AMPK activation were faithfully reproduced in vitro in cultured murine and human primary myotubes. Mechanistically, ncls increases cellular cAMP concentration and ADP/ATP ratio, which further lead to the activation of AMPK signaling. Blocking AMPK signaling through a specific inhibitor significantly reduces FAO in myotubes. Finally, ncls also enhances mitochondrial membrane potential and reduces the formation of reactive oxygen species in cultured myotubes. Narciclasine is a natural compound that attenuates diet-induced obesity in mice by promoting energy expenditure; it also induces a number of beneficial metabolic effects and activates AMPK signaling in skeletal muscle. Obesity results from the imbalance of food intake and energy expenditure. Since the restriction of food intake is difficult and inefficient in maintaining long-term weight loss, enhancing energy expenditure is now an attractive approach in combating obesity. Here, we analysed the role in this process of a natural compound called narciclasine. We showed that narciclasine treatment reduces excess fat accumulation in peripheral metabolic tissues, improves blood metabolic parameters and insulin sensitivity in obese mice, and protects these mice from the loss of voluntary physical activity. Further investigation suggested that narciclasine enhances mitochondrial respiration and fatty acid consumption in the skeletal muscle. In addition, narciclasine strongly activates the AMP-activated protein kinase (AMPK) signaling, which is a central sensor of the cellular energy status and a key player in maintaining energy homeostasis, specifically in the skeletal muscle. Mechanistically, we found that narciclasine increases cAMP concentration and ADP/ATP ratio in muscle cells, which further lead to AMPK activation. Finally, we observed that narciclasine increases mitochondrial membrane potential and reduces the production of reactive oxygen species in muscle cells. Our findings suggest that narciclasine is a natural compound that attenuates diet-induced obesity in mice by promoting energy expenditure.
Collapse
MESH Headings
- AMP-Activated Protein Kinases/metabolism
- Adenosine Diphosphate/metabolism
- Adenosine Triphosphate/metabolism
- Amaryllidaceae Alkaloids/pharmacology
- Amaryllidaceae Alkaloids/therapeutic use
- Animals
- Biomarkers/metabolism
- Cell Respiration/drug effects
- Cells, Cultured
- Cyclic AMP/metabolism
- Diet/adverse effects
- Diet, High-Fat
- Energy Metabolism/drug effects
- Enzyme Activation/drug effects
- Fatty Acids/metabolism
- Humans
- Male
- Membrane Potential, Mitochondrial/drug effects
- Mice
- Mice, Inbred C57BL
- Mitochondria/drug effects
- Mitochondria/metabolism
- Muscle Fibers, Skeletal/drug effects
- Muscle Fibers, Skeletal/metabolism
- Muscle Fibers, Slow-Twitch/drug effects
- Muscle Fibers, Slow-Twitch/metabolism
- Muscle, Skeletal/drug effects
- Muscle, Skeletal/metabolism
- Obesity/drug therapy
- Obesity/metabolism
- Oxidation-Reduction/drug effects
- Phenanthridines/pharmacology
- Phenanthridines/therapeutic use
- Physical Conditioning, Animal
- Protective Agents/pharmacology
- Protective Agents/therapeutic use
- Reactive Oxygen Species/metabolism
- Signal Transduction/drug effects
Collapse
Affiliation(s)
- Sofi G. Julien
- Singapore Institute for Clinical Sciences, Agency for Science, Technology and Research (A*STAR), Singapore, Republic of Singapore
| | - Sun-Yee Kim
- Singapore Institute for Clinical Sciences, Agency for Science, Technology and Research (A*STAR), Singapore, Republic of Singapore
- Laboratory of Metabolic Medicine, Singapore Bioimaging Consortium, A*STAR, Singapore, Republic of Singapore
| | - Reinhard Brunmeir
- Singapore Institute for Clinical Sciences, Agency for Science, Technology and Research (A*STAR), Singapore, Republic of Singapore
| | - Joanna R. Sinnakannu
- Singapore Institute for Clinical Sciences, Agency for Science, Technology and Research (A*STAR), Singapore, Republic of Singapore
| | - Xiaojia Ge
- Singapore Institute for Clinical Sciences, Agency for Science, Technology and Research (A*STAR), Singapore, Republic of Singapore
| | - Hongyu Li
- Laboratory of Metabolic Medicine, Singapore Bioimaging Consortium, A*STAR, Singapore, Republic of Singapore
| | - Wei Ma
- Laboratory of Metabolic Medicine, Singapore Bioimaging Consortium, A*STAR, Singapore, Republic of Singapore
| | - Jadegoud Yaligar
- Magnetic Resonance Spectroscopy and Metabolic Imaging Group, Singapore Bioimaging Consortium, A*STAR, Singapore, Republic of Singapore
| | - Bhanu Prakash KN
- Magnetic Resonance Spectroscopy and Metabolic Imaging Group, Singapore Bioimaging Consortium, A*STAR, Singapore, Republic of Singapore
| | - Sendhil S. Velan
- Magnetic Resonance Spectroscopy and Metabolic Imaging Group, Singapore Bioimaging Consortium, A*STAR, Singapore, Republic of Singapore
| | - Pia V. Röder
- Institute of Molecular and Cell Biology, A*STAR, Singapore, Republic of Singapore
| | - Qiongyi Zhang
- Singapore Institute for Clinical Sciences, Agency for Science, Technology and Research (A*STAR), Singapore, Republic of Singapore
| | - Choon Kiat Sim
- Singapore Institute for Clinical Sciences, Agency for Science, Technology and Research (A*STAR), Singapore, Republic of Singapore
| | - Jingyi Wu
- Center for Stem Cell Biology and Regenerative Medicine, MOE Key Laboratory of Bioinformatics, THU-PKU Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, China
| | - Marta Garcia-Miralles
- Translational Laboratory in Genetic Medicine, A*STAR, Singapore, Republic of Singapore
| | - Mahmoud A. Pouladi
- Translational Laboratory in Genetic Medicine, A*STAR, Singapore, Republic of Singapore
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Republic of Singapore
| | - Wei Xie
- Center for Stem Cell Biology and Regenerative Medicine, MOE Key Laboratory of Bioinformatics, THU-PKU Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, China
| | - Craig McFarlane
- Singapore Institute for Clinical Sciences, Agency for Science, Technology and Research (A*STAR), Singapore, Republic of Singapore
| | - Weiping Han
- Laboratory of Metabolic Medicine, Singapore Bioimaging Consortium, A*STAR, Singapore, Republic of Singapore
- Institute of Molecular and Cell Biology, A*STAR, Singapore, Republic of Singapore
| | - Feng Xu
- Singapore Institute for Clinical Sciences, Agency for Science, Technology and Research (A*STAR), Singapore, Republic of Singapore
- Institute of Molecular and Cell Biology, A*STAR, Singapore, Republic of Singapore
- * E-mail:
| |
Collapse
|
234
|
Bergner M, Dechert S, Demeshko S, Kupper C, Mayer JM, Meyer F. Model of the MitoNEET [2Fe-2S] Cluster Shows Proton Coupled Electron Transfer. J Am Chem Soc 2017; 139:701-707. [PMID: 28055193 PMCID: PMC5812485 DOI: 10.1021/jacs.6b09180] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
MitoNEET is an outer membrane protein whose exact function remains unclear, though a role of this protein in redox and iron sensing as well as in controlling maximum mitochondrial respiratory rates has been discussed. It was shown to contain a redox active and acid labile [2Fe-2S] cluster which is ligated by one histidine and three cysteine residues. Herein we present the first synthetic analogue with biomimetic {SN/S2} ligation which could be structurally characterized in its diferric form, 52-. In addition to being a high fidelity structural model for the biological cofactor, the complex is shown to mediate proton coupled electron transfer (PCET) at the {SN} ligated site, pointing at a potential functional role of the enzyme's unique His ligand. Full PCET thermodynamic square schemes for the mitoNEET model 52- and a related homoleptic {SN/SN} capped [2Fe-2S] cluster 42- are established, and kinetics of PCET reactivity are investigated by double-mixing stopped-flow experiments for both complexes. While the N-H bond dissociation free energy (BDFE) of 5H2- (230 ± 4 kJ mol-1) and the free energy ΔG°PCET for the reaction with TEMPO (-48.4 kJ mol-1) are very similar to values for the homoleptic cluster 4H2- (232 ± 4 kJ mol-1, -46.3 kJ mol-1) the latter is found to react significantly faster than the mitoNEET model (data for 5H2-: k = 135 ± 27 M-1 s-1, ΔH‡ = 17.6 ± 3.0 kJ mol-1, ΔS‡ = -143 ± 11 J mol-1 K-1, and ΔG‡ = 59.8 kJ mol-1 at 293 K). Comparison of the PCET efficiency of these clusters emphasizes the relevance of reorganization energy in this process.
Collapse
Affiliation(s)
- Marie Bergner
- Institute of Inorganic Chemistry, Georg-August-University Göttingen, Tammannstr. 4, D-37077 Göttingen, Germany
| | - Sebastian Dechert
- Institute of Inorganic Chemistry, Georg-August-University Göttingen, Tammannstr. 4, D-37077 Göttingen, Germany
| | - Serhiy Demeshko
- Institute of Inorganic Chemistry, Georg-August-University Göttingen, Tammannstr. 4, D-37077 Göttingen, Germany
| | - Claudia Kupper
- Institute of Inorganic Chemistry, Georg-August-University Göttingen, Tammannstr. 4, D-37077 Göttingen, Germany
| | - James M. Mayer
- Yale University, 225 Prospect Street, New Haven, Connecticut 06511, USA
| | - Franc Meyer
- Institute of Inorganic Chemistry, Georg-August-University Göttingen, Tammannstr. 4, D-37077 Göttingen, Germany
| |
Collapse
|
235
|
Stiban J, So M, Kaguni LS. Iron-Sulfur Clusters in Mitochondrial Metabolism: Multifaceted Roles of a Simple Cofactor. BIOCHEMISTRY (MOSCOW) 2017; 81:1066-1080. [PMID: 27908232 DOI: 10.1134/s0006297916100059] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Iron-sulfur metabolism is essential for cellular function and is a key process in mitochondria. In this review, we focus on the structure and assembly of mitochondrial iron-sulfur clusters and their roles in various metabolic processes that occur in mitochondria. Iron-sulfur clusters are crucial in mitochondrial respiration, in which they are required for the assembly, stability, and function of respiratory complexes I, II, and III. They also serve important functions in the citric acid cycle, DNA metabolism, and apoptosis. Whereas the identification of iron-sulfur containing proteins and their roles in numerous aspects of cellular function has been a long-standing research area, that in mitochondria is comparatively recent, and it is likely that their roles within mitochondria have been only partially revealed. We review the status of the field and provide examples of other cellular iron-sulfur proteins to highlight their multifarious roles.
Collapse
Affiliation(s)
- Johnny Stiban
- Birzeit University, Department of Biology and Biochemistry, West Bank Birzeit, 627, Palestine.
| | | | | |
Collapse
|
236
|
Holland WL, Xia JY, Johnson JA, Sun K, Pearson MJ, Sharma AX, Quittner-Strom E, Tippetts TS, Gordillo R, Scherer PE. Inducible overexpression of adiponectin receptors highlight the roles of adiponectin-induced ceramidase signaling in lipid and glucose homeostasis. Mol Metab 2017; 6:267-275. [PMID: 28271033 PMCID: PMC5323887 DOI: 10.1016/j.molmet.2017.01.002] [Citation(s) in RCA: 124] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Revised: 12/27/2016] [Accepted: 01/05/2017] [Indexed: 02/06/2023] Open
Abstract
Objective Adiponectin and the signaling induced by its cognate receptors, AdipoR1 and AdipoR2, have garnered attention for their ability to promote insulin sensitivity and oppose steatosis. Activation of these receptors promotes the deacylation of ceramide, a lipid metabolite that appears to play a causal role in impairing insulin signaling. Methods Here, we have developed transgenic mice that overexpress AdipoR1 or AdipoR2 under the inducible control of a tetracycline response element. These represent the first inducible genetic models that acutely manipulate adiponectin receptor signaling in adult mouse tissues, which allows us to directly assess AdipoR signaling on glucose and lipid metabolism. Results Overexpression of either adiponectin receptor isoform in the adipocyte or hepatocyte is sufficient to enhance ceramidase activity, whole body glucose metabolism, and hepatic insulin sensitivity, while opposing hepatic steatosis. Importantly, metabolic improvements fail to occur in an adiponectin knockout background. When challenged with a leptin-deficient genetic model of type 2 diabetes, AdipoR2 expression in adipose or liver is sufficient to reverse hyperglycemia and glucose intolerance. Conclusion These observations reveal that adiponectin is critical for AdipoR-induced ceramidase activation which enhances hepatic glucose and lipid metabolism via rapidly acting “cross-talk” between liver and adipose tissue sphingolipids. Adiponectin receptor signaling in adipose prompts beneficial effects on whole-body glucose and lipid metabolism. The small molecule adiponectin receptor antagonist AdipoRon lowers hepatic ceramides. Depletion of ceramides in adipocytes results in diminished hepatic ceramide accumulation. Depletion of ceramides in hepatocytes results in diminished adipose sphingolipid accumulation. Adiponectin is essential for the beneficial effects of adiponectin receptors on glucose, ceramide, and lipid metabolism.
Collapse
Affiliation(s)
- William L Holland
- Touchstone Diabetes Center, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX 75390-8549, USA.
| | - Jonathan Y Xia
- Touchstone Diabetes Center, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX 75390-8549, USA
| | - Joshua A Johnson
- Touchstone Diabetes Center, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX 75390-8549, USA
| | - Kai Sun
- Center for Metabolic and Degenerative Diseases, Institute of Molecular Medicine, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Mackenzie J Pearson
- Touchstone Diabetes Center, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX 75390-8549, USA
| | - Ankit X Sharma
- Touchstone Diabetes Center, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX 75390-8549, USA
| | - Ezekiel Quittner-Strom
- Touchstone Diabetes Center, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX 75390-8549, USA
| | - Trevor S Tippetts
- Touchstone Diabetes Center, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX 75390-8549, USA
| | - Ruth Gordillo
- Touchstone Diabetes Center, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX 75390-8549, USA
| | - Philipp E Scherer
- Touchstone Diabetes Center, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX 75390-8549, USA; Department of Cell Biology, The University of Texas Southwestern Medical Center, Dallas, TX 75390-8549, USA
| |
Collapse
|
237
|
Landry AP, Wang Y, Cheng Z, Crochet RB, Lee YH, Ding H. Flavin nucleotides act as electron shuttles mediating reduction of the [2Fe-2S] clusters in mitochondrial outer membrane protein mitoNEET. Free Radic Biol Med 2017; 102:240-247. [PMID: 27923678 PMCID: PMC5209285 DOI: 10.1016/j.freeradbiomed.2016.12.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Revised: 10/18/2016] [Accepted: 12/01/2016] [Indexed: 10/20/2022]
Abstract
MitoNEET, a primary target of type II diabetes drug pioglitazone, has an essential role in regulating energy metabolism, iron homeostasis, and production of reactive oxygen species in mitochondria. Structurally, mitoNEET is anchored to the mitochondrial outer membrane via its N-terminal transmembrane α-helix. The C-terminal cytosolic domain of mitoNEET hosts a redox active [2Fe-2S] cluster via three cysteine and one histidine residues. Here we report that the reduced flavin nucleotides can rapidly reduce the mitoNEET [2Fe-2S] clusters under anaerobic or aerobic conditions. In the presence of NADH and flavin reductase, 1 molecule of flavin nucleotide is sufficient to reduce about 100 molecules of the mitoNEET [2Fe-2S] clusters in 4min under aerobic conditions. The electron paramagnetic resonance (EPR) measurements show that flavin mononucleotide (FMN), but not flavin adenine dinucleotide (FAD), has a specific interaction with mitoNEET. Molecular docking models further reveal that flavin mononucleotide binds mitoNEET at the region between the N-terminal transmembrane α-helix and the [2Fe-2S] cluster binding domain. The closest distance between the [2Fe-2S] cluster and the bound flavin mononucleotide in mitoNEET is about 10Å, which could facilitate rapid electron transfer from the reduced flavin nucleotide to the [2Fe-2S] cluster in mitoNEET. The results suggest that flavin nucleotides may act as electron shuttles to reduce the mitoNEET [2Fe-2S] clusters and regulate mitochondrial functions in human cells.
Collapse
Affiliation(s)
- Aaron P Landry
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803, USA
| | - Yiming Wang
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803, USA
| | - Zishuo Cheng
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803, USA
| | - Robert B Crochet
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803, USA
| | - Yong-Hwan Lee
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803, USA
| | - Huangen Ding
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803, USA.
| |
Collapse
|
238
|
Shao M, Hepler C, Vishvanath L, MacPherson KA, Busbuso NC, Gupta RK. Fetal development of subcutaneous white adipose tissue is dependent on Zfp423. Mol Metab 2017; 6:111-124. [PMID: 28123942 PMCID: PMC5220400 DOI: 10.1016/j.molmet.2016.11.009] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Revised: 11/11/2016] [Accepted: 11/15/2016] [Indexed: 01/08/2023] Open
Abstract
OBJECTIVE Zfp423 is a multi zinc-finger transcription factor expressed in preadipocytes and mature adipocytes in vivo. Our recent work has revealed a critical role for Zfp423 in maintaining the fate of white adipocytes in adult mice through suppression of the beige cell thermogenic gene program; loss of Zfp423 in mature adipocytes of adult mice results in a white-to-beige phenotypic switch. However, the exact requirements of Zfp423 in the fetal stages of early adipose development in vivo have not been clarified. METHOD Here, we utilize two models that confer adipose-specific Zfp423 inactivation during fetal adipose development (Adiponectin-Cre; Zfp423loxP/loxP and Adiponectin-rtTA; TRE-Cre; Zfp423loxP/loxP). We assess the impact of fetal adipose Zfp423 deletion on the initial formation of adipose tissue and evaluate the metabolic consequences of challenging these animals with high-fat diet feeding. RESULTS Deletion of Zfp423 during fetal adipose development results in a different phenotype than is observed when deleting Zfp423 in adipocytes of adult mice. Inactivation of Zfp423 during fetal adipose development results in arrested differentiation, specifically of inguinal white adipocytes, rather than a white-to-beige phenotypic switch that occurs when Zfp423 is inactivated in adult mice. This is likely explained by the observation that adiponectin driven Cre expression is active at an earlier stage of the adipocyte life cycle during fetal subcutaneous adipose development than in adult mice. Upon high-fat diet feeding, obese adipose Zfp423-deficient animals undergo a pathological adipose tissue expansion, associated with ectopic lipid deposition and systemic insulin resistance. CONCLUSIONS Our results reveal that Zfp423 is essential for the terminal differentiation of subcutaneous white adipocytes during fetal adipose tissue development. Moreover, our data highlight the striking adverse effects of pathological subcutaneous adipose tissue remodeling on visceral adipose function and systemic nutrient homeostasis in obesity. Importantly, these data reveal the distinct phenotypes that can occur when adiponectin driven transgenes are activated in fetal vs. adult adipose tissue.
Collapse
Affiliation(s)
- Mengle Shao
- Touchstone Diabetes Center, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Chelsea Hepler
- Touchstone Diabetes Center, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Lavanya Vishvanath
- Touchstone Diabetes Center, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Karen A MacPherson
- Touchstone Diabetes Center, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Napoleon C Busbuso
- Touchstone Diabetes Center, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Rana K Gupta
- Touchstone Diabetes Center, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
| |
Collapse
|
239
|
Abstract
Obesity is a worldwide epidemic that predisposes individuals to cardiometabolic complications, such as type 2 diabetes mellitus (T2DM) and nonalcoholic fatty liver disease (NAFLD), which are all related to inappropriate ectopic lipid deposition. Identification of the pathogenic molecular mechanisms and effective therapeutic approaches are highly needed. The peroxisome proliferator-activated receptors (PPARs) modulate several biological processes that are perturbed in obesity, including inflammation, lipid and glucose metabolism and overall energy homeostasis. Here, we review how PPARs regulate the functions of adipose tissues, such as adipogenesis, lipid storage and adaptive thermogenesis, under healthy and pathological conditions. We also discuss the clinical use and mechanism of PPAR agonists in the treatment of obesity comorbidities such as dyslipidaemia, T2DM and NAFLD. First generation PPAR agonists, primarily those acting on PPARγ, are associated with adverse effects that outweigh their clinical benefits, which led to the discontinuation of their development. An improved understanding of the physiological roles of PPARs might, therefore, enable the development of safe, new PPAR agonists with improved therapeutic potential.
Collapse
Affiliation(s)
- Barbara Gross
- Université de Lille, INSERM, CHU Lille, Institut Pasteur de Lille, U1011-EGID, F-59000 Lille, France
| | - Michal Pawlak
- International Institute of Molecular and Cell Biology, 4 Ks. Trojdena Street, 02-109 Warsaw, Poland
| | - Philippe Lefebvre
- Université de Lille, INSERM, CHU Lille, Institut Pasteur de Lille, U1011-EGID, F-59000 Lille, France
| | - Bart Staels
- Université de Lille, INSERM, CHU Lille, Institut Pasteur de Lille, U1011-EGID, F-59000 Lille, France
| |
Collapse
|
240
|
Abstract
PURPOSE OF REVIEW Purpose of review: It is becoming increasingly clear that some obese individuals do not develop dyslipidemia and instead remain healthy, while some normal weight individuals become dyslipidemic and unhealthy. RECENT FINDINGS The present review examines the similarities and differences between healthy and unhealthy individuals with and without obesity and discusses putative underlying mechanisms of dyslipidemia. The presence of dyslipidemia and compromised metabolic health in both lean and obese individuals suggests that the obese phenotype per se does not represent a main independent risk factor for the development of dyslipidemia and that dyslipidemia, rather than obesity, may be the driver of metabolic diseases. Notably, adipose tissue dysfunction and ectopic lipid deposition, in particular in the liver, seems a common trait of unhealthy individuals.
Collapse
Affiliation(s)
- David H Ipsen
- Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Ridebanevej 9, 1870, Frederiksberg C, Denmark
| | - Pernille Tveden-Nyborg
- Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Ridebanevej 9, 1870, Frederiksberg C, Denmark
| | - Jens Lykkesfeldt
- Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Ridebanevej 9, 1870, Frederiksberg C, Denmark.
| |
Collapse
|
241
|
Casteras S, Abdul-Wahed A, Soty M, Vulin F, Guillou H, Campana M, Le Stunff H, Pirola L, Rajas F, Mithieux G, Gautier-Stein A. The suppression of hepatic glucose production improves metabolism and insulin sensitivity in subcutaneous adipose tissue in mice. Diabetologia 2016; 59:2645-2653. [PMID: 27631137 DOI: 10.1007/s00125-016-4097-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Accepted: 08/05/2016] [Indexed: 12/13/2022]
Abstract
AIMS/HYPOTHESIS Despite the strong correlation between non-alcoholic fatty liver disease and insulin resistance, hepatic steatosis is associated with greater whole-body insulin sensitivity in several models. We previously reported that the inhibition of hepatic glucose production (HGP) protects against the development of obesity and diabetes despite severe steatosis, thanks to the secretion of specific hepatokines such as fibroblast growth factor 21 (FGF21) and angiopoietin-related growth factor. In this work, we focused on adipose tissue to assess whether liver metabolic fluxes might, by interorgan communication, control insulin signalling in lean animals. METHODS Insulin signalling was studied in the adipose tissue of mice lacking the catalytic subunit of glucose 6-phosphatase, the key enzyme in endogenous glucose production, in the liver (L-G6pc -/- mice). Morphological and metabolic changes in the adipose tissues were characterised by histological analyses, gene expression and protein content. RESULTS Mice lacking HGP exhibited improved insulin sensitivity of the phosphoinositide 3-kinase/Akt pathway in the subcutaneous adipose tissue associated with a browning of adipocytes. The suppression of HGP increased FGF21 levels in lean animals, and increased FGF21 was responsible for the metabolic changes in the subcutaneous adipose tissue but not for its greater insulin sensitivity. The latter might be linked to an increase in the ratio of monounsaturated to saturated fatty acids released by the liver. CONCLUSIONS Our work provides evidence that HGP controls subcutaneous adipose tissue browning and insulin sensitivity through two pathways: the release of beneficial hepatokines and changes in hepatic fatty acids profile.
Collapse
Affiliation(s)
- Sylvie Casteras
- Inserm U1213, Faculté Laennec, 7 rue Guillaume Paradin, 69372, Lyon cedex 08, France
- Université de Lyon, Lyon, France
- Université Lyon1, Villeurbanne, France
| | - Aya Abdul-Wahed
- Inserm U1213, Faculté Laennec, 7 rue Guillaume Paradin, 69372, Lyon cedex 08, France
- Université de Lyon, Lyon, France
- Université Lyon1, Villeurbanne, France
| | - Maud Soty
- Inserm U1213, Faculté Laennec, 7 rue Guillaume Paradin, 69372, Lyon cedex 08, France
- Université de Lyon, Lyon, France
- Université Lyon1, Villeurbanne, France
| | - Fanny Vulin
- Inserm U1213, Faculté Laennec, 7 rue Guillaume Paradin, 69372, Lyon cedex 08, France
- Université de Lyon, Lyon, France
- Université Lyon1, Villeurbanne, France
| | - Hervé Guillou
- INRA, ToxAlim UMR1331 (Research Center in Food Toxicology), Toulouse, France
| | - Mélanie Campana
- Unité Biologie Fonctionnelle et Adaptative -UMR CNRS 8251, Université Paris- Diderot (7), Paris, France
- I2BC - UMR 9198 Université Paris Sud, Gif sur Yvette, France
| | - Hervé Le Stunff
- Unité Biologie Fonctionnelle et Adaptative -UMR CNRS 8251, Université Paris- Diderot (7), Paris, France
- I2BC - UMR 9198 Université Paris Sud, Gif sur Yvette, France
| | - Luciano Pirola
- Université de Lyon, Lyon, France
- Université Lyon1, Villeurbanne, France
- Laboratoire de Recherche en Cardiovasculaire, Métabolisme, Diabétologie et Nutrition, CarMeN, Oullins, France
| | - Fabienne Rajas
- Inserm U1213, Faculté Laennec, 7 rue Guillaume Paradin, 69372, Lyon cedex 08, France
- Université de Lyon, Lyon, France
- Université Lyon1, Villeurbanne, France
| | - Gilles Mithieux
- Inserm U1213, Faculté Laennec, 7 rue Guillaume Paradin, 69372, Lyon cedex 08, France
- Université de Lyon, Lyon, France
- Université Lyon1, Villeurbanne, France
| | - Amandine Gautier-Stein
- Inserm U1213, Faculté Laennec, 7 rue Guillaume Paradin, 69372, Lyon cedex 08, France.
- Université de Lyon, Lyon, France.
- Université Lyon1, Villeurbanne, France.
| |
Collapse
|
242
|
Koval AM, Jagger BR, Wheeler RA. Distinguishing the Protonation State of the Histidine Ligand to the Oxidized Iron-Sulfur Cluster from the MitoNEET Family of Proteins. Chemphyschem 2016; 18:39-41. [PMID: 27870532 DOI: 10.1002/cphc.201600957] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Indexed: 11/10/2022]
Abstract
The iron-sulfur cluster located in the recently discovered human mitoNEET protein (and related proteins) is structurally similar to the more well-known ferredoxin and Rieske clusters. Although its biological function is uncertain, the iron-sulfur cluster in mitoNEET has been proposed to undergo proton-coupled electron transfer involving the histidine ligand to the cluster. The cluster is also released from the protein at low pH. This contribution reports density functional calculations to model the structures, vibrations, and Heisenberg coupling constants (J) for high-spin (HS), broken symmetry (BS) singlet, and extended broken symmetry (EBS) singlet states of the oxidized iron-sulfur cluster from mitoNEET. This work suggests that J values or 15 N isotopic frequency shifts may provide methods for determining experimentally whether the histidine ligand to the oxidized iron-sulfur cluster in human mitoNEET and mitoNEET-related proteins is protonated or deprotonated.
Collapse
Affiliation(s)
- Ashlyn M Koval
- Department of Chemistry and Biochemistry, Duquesne University, 600 Forbes Avenue, Pittsburgh, PA, 15282, USA
| | - Benjamin R Jagger
- Department of Chemistry and Biochemistry, Duquesne University, 600 Forbes Avenue, Pittsburgh, PA, 15282, USA
| | - Ralph A Wheeler
- Department of Chemistry and Biochemistry, Northern Illinois University, 1425 W. Lincoln Hwy., DeKalb, IL, 60115, USA
| |
Collapse
|
243
|
Fujikawa T, Castorena CM, Pearson M, Kusminski CM, Ahmed N, Battiprolu PK, Kim KW, Lee S, Hill JA, Scherer PE, Holland WL, Elmquist JK. SF-1 expression in the hypothalamus is required for beneficial metabolic effects of exercise. eLife 2016; 5. [PMID: 27874828 PMCID: PMC5119890 DOI: 10.7554/elife.18206] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Accepted: 11/14/2016] [Indexed: 12/31/2022] Open
Abstract
Exercise has numerous beneficial metabolic effects. The central nervous system (CNS) is critical for regulating energy balance and coordinating whole body metabolism. However, a role for the CNS in the regulation of metabolism in the context of the exercise remains less clear. Here, using genetically engineered mice we assessed the requirement of steroidogenic factor-1 (SF-1) expression in neurons of the ventromedial hypothalamic nucleus (VMH) in mediating the beneficial effects of exercise on metabolism. We found that VMH-specific deletion of SF-1 blunts (a) the reductions in fat mass, (b) improvements in glycemia, and (c) increases in energy expenditure that are associated with exercise training. Unexpectedly, we found that SF-1 deletion in the VMH attenuates metabolic responses of skeletal muscle to exercise, including induction of PGC-1α expression. Collectively, this evidence suggests that SF-1 expression in VMH neurons is required for the beneficial effects of exercise on metabolism.
Collapse
Affiliation(s)
- Teppei Fujikawa
- Department of Internal Medicine, Division of Hypothalamic Research, University of Texas Southwestern Medical Center, Dallas, United States
| | - Carlos M Castorena
- Department of Internal Medicine, Division of Hypothalamic Research, University of Texas Southwestern Medical Center, Dallas, United States
| | - Mackenzie Pearson
- Touchstone Diabetes Center, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, United States
| | - Christine M Kusminski
- Touchstone Diabetes Center, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, United States
| | - Newaz Ahmed
- Department of Internal Medicine, Division of Hypothalamic Research, University of Texas Southwestern Medical Center, Dallas, United States
| | - Pavan K Battiprolu
- Department of Internal Medicine, Division of Cardiology, University of Texas Southwestern Medical Center, Dallas, United States
| | - Ki Woo Kim
- Department of Pharmacology, Wonju College of Medicine, Yonsei University, Wonju, South Korea.,Department of Global Medical Science, Wonju College of Medicine, Yonsei University, Wonju, South Korea.,Institute of Lifestyle Medicine and Nuclear Receptor Research Consortium, Wonju College of Medicine, Yonsei University, Wonju, South Korea
| | - Syann Lee
- Department of Internal Medicine, Division of Hypothalamic Research, University of Texas Southwestern Medical Center, Dallas, United States
| | - Joseph A Hill
- Department of Internal Medicine, Division of Cardiology, University of Texas Southwestern Medical Center, Dallas, United States.,Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, United States
| | - Philipp E Scherer
- Touchstone Diabetes Center, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, United States.,Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, United States
| | - William L Holland
- Touchstone Diabetes Center, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, United States
| | - Joel K Elmquist
- Department of Internal Medicine, Division of Hypothalamic Research, University of Texas Southwestern Medical Center, Dallas, United States.,Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, United States
| |
Collapse
|
244
|
Fujikawa T, Castorena CM, Pearson M, Kusminski CM, Ahmed N, Battiprolu PK, Kim KW, Lee S, Hill JA, Scherer PE, Holland WL, Elmquist JK. SF-1 expression in the hypothalamus is required for beneficial metabolic effects of exercise. eLife 2016; 5:e18206. [PMID: 27874828 DOI: 10.7554/elife.15092.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Accepted: 11/14/2016] [Indexed: 05/26/2023] Open
Abstract
Exercise has numerous beneficial metabolic effects. The central nervous system (CNS) is critical for regulating energy balance and coordinating whole body metabolism. However, a role for the CNS in the regulation of metabolism in the context of the exercise remains less clear. Here, using genetically engineered mice we assessed the requirement of steroidogenic factor-1 (SF-1) expression in neurons of the ventromedial hypothalamic nucleus (VMH) in mediating the beneficial effects of exercise on metabolism. We found that VMH-specific deletion of SF-1 blunts (a) the reductions in fat mass, (b) improvements in glycemia, and (c) increases in energy expenditure that are associated with exercise training. Unexpectedly, we found that SF-1 deletion in the VMH attenuates metabolic responses of skeletal muscle to exercise, including induction of PGC-1α expression. Collectively, this evidence suggests that SF-1 expression in VMH neurons is required for the beneficial effects of exercise on metabolism.
Collapse
Affiliation(s)
- Teppei Fujikawa
- Department of Internal Medicine, Division of Hypothalamic Research, University of Texas Southwestern Medical Center, Dallas, United States
| | - Carlos M Castorena
- Department of Internal Medicine, Division of Hypothalamic Research, University of Texas Southwestern Medical Center, Dallas, United States
| | - Mackenzie Pearson
- Touchstone Diabetes Center, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, United States
| | - Christine M Kusminski
- Touchstone Diabetes Center, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, United States
| | - Newaz Ahmed
- Department of Internal Medicine, Division of Hypothalamic Research, University of Texas Southwestern Medical Center, Dallas, United States
| | - Pavan K Battiprolu
- Department of Internal Medicine, Division of Cardiology, University of Texas Southwestern Medical Center, Dallas, United States
| | - Ki Woo Kim
- Department of Pharmacology, Wonju College of Medicine, Yonsei University, Wonju, South Korea
- Department of Global Medical Science, Wonju College of Medicine, Yonsei University, Wonju, South Korea
- Institute of Lifestyle Medicine and Nuclear Receptor Research Consortium, Wonju College of Medicine, Yonsei University, Wonju, South Korea
| | - Syann Lee
- Department of Internal Medicine, Division of Hypothalamic Research, University of Texas Southwestern Medical Center, Dallas, United States
| | - Joseph A Hill
- Department of Internal Medicine, Division of Cardiology, University of Texas Southwestern Medical Center, Dallas, United States
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, United States
| | - Philipp E Scherer
- Touchstone Diabetes Center, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, United States
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, United States
| | - William L Holland
- Touchstone Diabetes Center, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, United States
| | - Joel K Elmquist
- Department of Internal Medicine, Division of Hypothalamic Research, University of Texas Southwestern Medical Center, Dallas, United States
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, United States
| |
Collapse
|
245
|
Lee J. Mitochondrial drug targets in neurodegenerative diseases. Bioorg Med Chem Lett 2016; 26:714-720. [PMID: 26806044 DOI: 10.1016/j.bmcl.2015.11.032] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Revised: 11/06/2015] [Accepted: 11/10/2015] [Indexed: 12/14/2022]
Abstract
Growing evidence suggests that mitochondrial dysfunction is the main culprit in neurodegenerative diseases. Given the fact that mitochondria participate in diverse cellular processes, including energetics, metabolism, and death, the consequences of mitochondrial dysfunction in neuronal cells are inevitable. In fact, new strategies targeting mitochondrial dysfunction are emerging as potential alternatives to current treatment options for neurodegenerative diseases. In this review, we focus on mitochondrial proteins that are directly associated with mitochondrial dysfunction. We also examine recently identified small molecule modulators of these mitochondrial targets and assess their potential in research and therapeutic applications.
Collapse
Affiliation(s)
- Jiyoun Lee
- Department of Global Medical Science, Sungshin University, Seoul 142-732, Republic of Korea.
| |
Collapse
|
246
|
Antonopoulos AS, Oikonomou EK, Antoniades C, Tousoulis D. From the BMI paradox to the obesity paradox: the obesity-mortality association in coronary heart disease. Obes Rev 2016; 17:989-1000. [PMID: 27405510 DOI: 10.1111/obr.12440] [Citation(s) in RCA: 111] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Revised: 05/15/2016] [Accepted: 05/23/2016] [Indexed: 12/13/2022]
Abstract
Despite a strong association between body weight and mortality in the general population, clinical evidence suggests better clinical outcome of overweight or obese individuals with established coronary heart disease. This finding has been termed the 'obesity paradox', but its existence remains a point of debate, because it is mostly observed when body mass index (BMI) is used to define obesity. Inherent limitations of BMI as an index of adiposity, as well as methodological biases and the presence of confounding factors, may account for the observed findings of clinical studies. In this review, our aim is to present the data that support the presence of a BMI paradox in coronary heart disease and then explore whether next to a BMI paradox a true obesity paradox exists as well. We conclude by attempting to link the obesity paradox notion to available translational research data supporting a 'healthy', protective adipose tissue phenotype. © 2016 World Obesity.
Collapse
Affiliation(s)
- A S Antonopoulos
- 1st Cardiology Department, Hippokration Hospital, Athens Medical School, Athens, Greece. .,Division of Cardiovascular Medicine, University of Oxford, Oxford, UK.
| | - E K Oikonomou
- 1st Cardiology Department, Hippokration Hospital, Athens Medical School, Athens, Greece.,Division of Cardiovascular Medicine, University of Oxford, Oxford, UK
| | - C Antoniades
- Division of Cardiovascular Medicine, University of Oxford, Oxford, UK
| | - D Tousoulis
- 1st Cardiology Department, Hippokration Hospital, Athens Medical School, Athens, Greece
| |
Collapse
|
247
|
Myeloid Cell-Specific Lipin-1 Deficiency Stimulates Endocrine Adiponectin-FGF15 Axis and Ameliorates Ethanol-Induced Liver Injury in Mice. Sci Rep 2016; 6:34117. [PMID: 27666676 PMCID: PMC5036185 DOI: 10.1038/srep34117] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Accepted: 09/07/2016] [Indexed: 02/08/2023] Open
Abstract
Lipin-1 is a phosphatidate phosphohydrolase (PAP) required for the generation of diacylglycerol during glycerolipid synthesis, and exhibits dual functions in the regulation of lipid metabolism. Lipin-1 has been implicated in the pathogenesis of alcoholic liver disease (ALD). In the present study, we assessed lipin-1 function in myeloid cells in ALD using a myeloid cell-specific lipin-1 knockout (mLipin-1KO) mouse model. Utilizing the Gao-binge ethanol feeding protocol, matched mLipin-1KO mice and littermate loxP control (WT) mice were pair-fed with either an ethanol-containing diet or an ethanol-free diet (control). Surprisingly, deletion of lipin-1 in myeloid cells dramatically attenuated liver inflammatory responses and ameliorated liver injury that would normally occur following the ethanol feeding protocol, but slightly exacerbated the ethanol-induced steatosis in mice. Mechanistically, myeloid cell-specific lipin-1 deficiency concomitantly increased the fat-derived adiponectin and ileum-derived fibroblast growth factor (FGF) 15. In concordance with concerted elevation of circulating adiponectin and FGF15, myeloid cell-specific lipin-1 deficiency diminished hepatic nuclear factor kappa B (NF-κB) activity, limited liver inflammatory responses, normalized serum levels of bile acids, and protected mice from liver damage after ethanol challenge. Our novel data demonstrate that myeloid cell-specific deletion of lipin-1 ameliorated inflammation and alcoholic hepatitis in mice via activation of endocrine adiponectin-FGF15 signaling.
Collapse
|
248
|
Geldenhuys WJ, Yonutas HM, Morris DL, Sullivan PG, Darvesh AS, Leeper TC. Identification of small molecules that bind to the mitochondrial protein mitoNEET. Bioorg Med Chem Lett 2016; 26:5350-5353. [PMID: 27687671 DOI: 10.1016/j.bmcl.2016.09.009] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Revised: 09/02/2016] [Accepted: 09/03/2016] [Indexed: 01/01/2023]
Abstract
MitoNEET (CISD1) is a 2Fe-2S iron-sulfur cluster protein belonging to the zinc-finger protein family. Recently mitoNEET has been shown to be a major role player in the mitochondrial function associated with metabolic type diseases such as obesity and cancers. The anti-diabetic drug pioglitazone and rosiglitazone were the first identified ligands to mitoNEET. Since little is known about structural requirements for ligand binding to mitoNEET, we screened a small set of compounds to gain insight into these requirements. We found that the thiazolidinedione (TZD) warhead as seen in rosiglitazone was not an absolutely necessity for binding to mitoNEET. These results will aid in the development of novel compounds that can be used to treat mitochondrial dysfunction seen in several diseases.
Collapse
Affiliation(s)
- Werner J Geldenhuys
- Department of Pharmaceutical Sciences, School of Pharmacy, West Virginia University, 1 Medical Center Drive, Morgantown, WV 26506, USA.
| | - Heather M Yonutas
- Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, KY 40536, USA; Anatomy and Neurobiology, University of Kentucky, Lexington, KY 40536, USA
| | - Daniel L Morris
- Department of Chemistry and Biochemistry, University of Akron, Akron, OH 44325, USA
| | - Patrick G Sullivan
- Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, KY 40536, USA; Anatomy and Neurobiology, University of Kentucky, Lexington, KY 40536, USA
| | - Altaf S Darvesh
- Department of Pharmaceutical Sciences, Northeast Ohio Medical University, Rootstown, OH 44240, USA
| | - Thomas C Leeper
- Department of Chemistry and Biochemistry, University of Akron, Akron, OH 44325, USA
| |
Collapse
|
249
|
CISD1 inhibits ferroptosis by protection against mitochondrial lipid peroxidation. Biochem Biophys Res Commun 2016; 478:838-44. [DOI: 10.1016/j.bbrc.2016.08.034] [Citation(s) in RCA: 226] [Impact Index Per Article: 28.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Accepted: 08/05/2016] [Indexed: 02/07/2023]
|
250
|
Hu X, Jogasuria A, Wang J, Kim C, Han Y, Shen H, Wu J, You M. MitoNEET Deficiency Alleviates Experimental Alcoholic Steatohepatitis in Mice by Stimulating Endocrine Adiponectin-Fgf15 Axis. J Biol Chem 2016; 291:22482-22495. [PMID: 27573244 DOI: 10.1074/jbc.m116.737015] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2016] [Revised: 08/25/2016] [Indexed: 12/13/2022] Open
Abstract
MitoNEET (mNT) (CDGSH iron-sulfur domain-containing protein 1 or CISD1) is an outer mitochondrial membrane protein that donates 2Fe-2S clusters to apo-acceptor proteins. In the present study, using a global mNT knock-out (mNTKO) mouse model, we investigated the in vivo functional role of mNT in the development of alcoholic steatohepatitis. Experimental alcoholic steatohepatitis was achieved by pair feeding wild-type (WT) and mNTKO mice with Lieber-DeCarli ethanol-containing diets for 4 weeks. Strikingly, chronically ethanol-fed mNTKO mice were completely resistant to ethanol-induced steatohepatitis as revealed by dramatically reduced hepatic triglycerides, decreased hepatic cholesterol level, diminished liver inflammatory response, and normalized serum ALT levels. Mechanistic studies demonstrated that ethanol administration to mNTKO mice induced two pivotal endocrine hormones, namely, adipose-derived adiponectin and gut-derived fibroblast growth factor 15 (Fgf15). The elevation in circulating levels of adiponectin and Fgf15 led to normalized hepatic and serum levels of bile acids, limited hepatic accumulation of toxic bile, attenuated inflammation, and amelioration of liver injury in the ethanol-fed mNTKO mice. Other potential mechanisms such as reduced oxidative stress, activated Sirt1 signaling, and diminished NF-κB activity also contribute to hepatic improvement in the ethanol-fed mNTKO mice. In conclusion, the present study identified adiponectin and Fgf15 as pivotal adipose-gut-liver metabolic coordinators in mediating the protective action of mNT deficiency against development of alcoholic steatohepatitis in mice. Our findings may help to establish mNT as a novel therapeutic target and pharmacological inhibition of mNT may be beneficial for the prevention and treatment of human alcoholic steatohepatitis.
Collapse
Affiliation(s)
- Xudong Hu
- From the College of Pharmacy, Northeast Ohio Medical University, Rootstown, Ohio 44272.,the Department of Biology, School of Basic Medical Science, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China, and
| | - Alvin Jogasuria
- From the College of Pharmacy, Northeast Ohio Medical University, Rootstown, Ohio 44272
| | - Jiayou Wang
- From the College of Pharmacy, Northeast Ohio Medical University, Rootstown, Ohio 44272
| | - Chunki Kim
- From the College of Pharmacy, Northeast Ohio Medical University, Rootstown, Ohio 44272
| | - Yoonhee Han
- From the College of Pharmacy, Northeast Ohio Medical University, Rootstown, Ohio 44272
| | - Hong Shen
- From the College of Pharmacy, Northeast Ohio Medical University, Rootstown, Ohio 44272.,the Department of Liver Diseases, Guangdong Hospital of Traditional Chinese Medicine in Zhuhai, Zhuhai 519015, China
| | - Jiashin Wu
- From the College of Pharmacy, Northeast Ohio Medical University, Rootstown, Ohio 44272
| | - Min You
- From the College of Pharmacy, Northeast Ohio Medical University, Rootstown, Ohio 44272,
| |
Collapse
|