251
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Lawan A, Min K, Zhang L, Canfran-Duque A, Jurczak MJ, Camporez JPG, Nie Y, Gavin TP, Shulman GI, Fernandez-Hernando C, Bennett AM. Skeletal Muscle-Specific Deletion of MKP-1 Reveals a p38 MAPK/JNK/Akt Signaling Node That Regulates Obesity-Induced Insulin Resistance. Diabetes 2018; 67:624-635. [PMID: 29317435 PMCID: PMC5860856 DOI: 10.2337/db17-0826] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2017] [Accepted: 01/03/2018] [Indexed: 12/16/2022]
Abstract
Stress responses promote obesity and insulin resistance, in part, by activating the stress-responsive mitogen-activated protein kinases (MAPKs), p38 MAPK, and c-Jun NH2-terminal kinase (JNK). Stress also induces expression of MAPK phosphatase-1 (MKP-1), which inactivates both JNK and p38 MAPK. However, the equilibrium between JNK/p38 MAPK and MKP-1 signaling in the development of obesity and insulin resistance is unclear. Skeletal muscle is a major tissue involved in energy expenditure and glucose metabolism. In skeletal muscle, MKP-1 is upregulated in high-fat diet-fed mice and in skeletal muscle of obese humans. Mice lacking skeletal muscle expression of MKP-1 (MKP1-MKO) showed increased skeletal muscle p38 MAPK and JNK activities and were resistant to the development of diet-induced obesity. MKP1-MKO mice exhibited increased whole-body energy expenditure that was associated with elevated levels of myofiber-associated mitochondrial oxygen consumption. miR-21, a negative regulator of PTEN expression, was upregulated in skeletal muscle of MKP1-MKO mice, resulting in increased Akt activity consistent with enhanced insulin sensitivity. Our results demonstrate that skeletal muscle MKP-1 represents a critical signaling node through which inactivation of the p38 MAPK/JNK module promotes obesity and insulin resistance.
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Affiliation(s)
- Ahmed Lawan
- Department of Pharmacology, Yale University School of Medicine, New Haven, CT
| | - Kisuk Min
- Department of Pharmacology, Yale University School of Medicine, New Haven, CT
| | - Lei Zhang
- Department of Pharmacology, Yale University School of Medicine, New Haven, CT
| | - Alberto Canfran-Duque
- Department of Comparative Medicine, Yale University School of Medicine, New Haven, CT
- Program in Integrative Cell Signaling and Neurobiology of Metabolism, Yale University School of Medicine, New Haven, CT
| | - Michael J Jurczak
- Cellular & Molecular Physiology and Department of Internal Medicine, Section of Endocrinology and Metabolism, Yale University School of Medicine, New Haven, CT
| | - Joao Paulo G Camporez
- Cellular & Molecular Physiology and Department of Internal Medicine, Section of Endocrinology and Metabolism, Yale University School of Medicine, New Haven, CT
| | - Yaohui Nie
- Department of Health and Kinesiology, Purdue University, West Lafayette, IN
| | - Timothy P Gavin
- Department of Health and Kinesiology, Purdue University, West Lafayette, IN
| | - Gerald I Shulman
- Cellular & Molecular Physiology and Department of Internal Medicine, Section of Endocrinology and Metabolism, Yale University School of Medicine, New Haven, CT
| | - Carlos Fernandez-Hernando
- Department of Comparative Medicine, Yale University School of Medicine, New Haven, CT
- Program in Integrative Cell Signaling and Neurobiology of Metabolism, Yale University School of Medicine, New Haven, CT
| | - Anton M Bennett
- Department of Pharmacology, Yale University School of Medicine, New Haven, CT
- Department of Comparative Medicine, Yale University School of Medicine, New Haven, CT
- Program in Integrative Cell Signaling and Neurobiology of Metabolism, Yale University School of Medicine, New Haven, CT
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252
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Guo XX, An S, Yang Y, Liu Y, Hao Q, Tang T, Xu TR. Emerging role of the Jun N-terminal kinase interactome in human health. Cell Biol Int 2018; 42:756-768. [DOI: 10.1002/cbin.10948] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Accepted: 02/03/2018] [Indexed: 01/06/2023]
Affiliation(s)
- Xiao-Xi Guo
- Faculty of Life Science and Technology; Kunming University of Science and Technology; Kunming Yunnan 650500 China
| | - Su An
- Faculty of Life Science and Technology; Kunming University of Science and Technology; Kunming Yunnan 650500 China
| | - Yang Yang
- Faculty of Life Science and Technology; Kunming University of Science and Technology; Kunming Yunnan 650500 China
| | - Ying Liu
- Faculty of Life Science and Technology; Kunming University of Science and Technology; Kunming Yunnan 650500 China
| | - Qian Hao
- Faculty of Life Science and Technology; Kunming University of Science and Technology; Kunming Yunnan 650500 China
| | - Tao Tang
- Faculty of Medicine; Kunming University of Science and Technology; Kunming Yunnan 650500 China
| | - Tian-Rui Xu
- Faculty of Life Science and Technology; Kunming University of Science and Technology; Kunming Yunnan 650500 China
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253
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Cherian PT, Al-Khairi I, Sriraman D, Al-Enezi A, Al-Sultan D, AlOtaibi M, Al-Enezi S, Tuomilehto J, Al-Mulla F, Abubaker JA, Abu-Farha M. Increased Circulation and Adipose Tissue Levels of DNAJC27/RBJ in Obesity and Type 2-Diabetes. Front Endocrinol (Lausanne) 2018; 9:423. [PMID: 30131766 PMCID: PMC6090877 DOI: 10.3389/fendo.2018.00423] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/18/2018] [Accepted: 07/05/2018] [Indexed: 12/29/2022] Open
Abstract
Heat shock response is an essential cellular stress response. Dysregulation of various heat shock proteins (HSPs), within the heat shock response (HSR) pathway, play a vital role in this host-defense mechanism contributing to obesity-induced insulin resistance and type 2 diabetes (T2D). Previously, we have reported changes in the expression levels of several HSPs such as HSP40, HSP60, HSP70, and HSP90 in obese compared with lean individuals. DNAJC27 is a member of the HSP40 protein family that was previously identified as a body mass index (BMI) associated locus in genome-wide association (GWAS) studies. However, not much is known about the changes in DNAJC27 expression levels in obesity and T2D. In the present study, we aimed at understanding changes in DNAJC27 expression levels in plasma, peripheral blood mononuclear cells (PBMCs) and adipose tissue in association with obesity and T2D. A total of 277 individuals enrolled including 160 non-diabetic (96 non-obese and 64 obese) and 117 T2D (45 non-obese and 72 obese) individuals. Plasma level of DNAJC27 was significantly higher in obese individuals (6.28 ± 0.64 ng/mL) compared with non-obese individuals (4.8 ± 0.45 ng/mL) with P = 0.043. Dividing the population based on diabetes status showed that there was a significant increase in the plasma level of DNAJC27 in obese (6.90 ± 1.3 ng/mL) compared with non-obese individuals (3.81 ± 0.43 ng/mL) (P = 0.033) in the non-diabetic group. Similarly, DNAJC27 expression level was also higher in PBMCs and adipose tissue of obese individuals. DNAJC27 was found to be associated with leptin and resistin, adipokines known to be dysregulated in obesity, that stimulate inflammatory processes leading to metabolic disorders. In conclusion, our data show that DNAJC27 is elevated in obese and T2D individuals and was positively associated with obesity biomarkers such as leptin and resistin suggesting that this protein may play a role in the pathophysiology of these disorders.
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Affiliation(s)
- Preethi T. Cherian
- Biochemistry and Molecular Biology Unit, Dasman Diabetes Institute, Kuwait City, Kuwait
| | - Irina Al-Khairi
- Biochemistry and Molecular Biology Unit, Dasman Diabetes Institute, Kuwait City, Kuwait
| | - Devarajan Sriraman
- National Dasman Diabetes Biobank, Dasman Diabetes Institute, Kuwait City, Kuwait
| | - Ahmad Al-Enezi
- Biochemistry and Molecular Biology Unit, Dasman Diabetes Institute, Kuwait City, Kuwait
| | - Dalal Al-Sultan
- Biochemistry and Molecular Biology Unit, Dasman Diabetes Institute, Kuwait City, Kuwait
| | - Mohammed AlOtaibi
- Biochemistry and Molecular Biology Unit, Dasman Diabetes Institute, Kuwait City, Kuwait
| | - Saad Al-Enezi
- Biochemistry and Molecular Biology Unit, Dasman Diabetes Institute, Kuwait City, Kuwait
- Functional Genomic Unit, Dasman Diabetes Institute, Kuwait City, Kuwait
| | | | - Fahd Al-Mulla
- Functional Genomic Unit, Dasman Diabetes Institute, Kuwait City, Kuwait
| | - Jehad A. Abubaker
- Biochemistry and Molecular Biology Unit, Dasman Diabetes Institute, Kuwait City, Kuwait
- *Correspondence: Jehad A. Abubaker
| | - Mohamed Abu-Farha
- Biochemistry and Molecular Biology Unit, Dasman Diabetes Institute, Kuwait City, Kuwait
- Mohamed Abu-Farha ;
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254
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Bagi Z. Too much TRAFfic at the crossroads of diabetes and endothelial dysfunction. Am J Physiol Heart Circ Physiol 2018; 314:H65-H67. [PMID: 29101184 DOI: 10.1152/ajpheart.00614.2017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Zsolt Bagi
- Vascular Biology Center and Department of Medicine, Medical College of Georgia, Augusta University , Augusta, Georgia
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255
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Zheng W, Zhou J, Song S, Kong W, Xia W, Chen L, Zeng T. Dipeptidyl-Peptidase 4 Inhibitor Sitagliptin Ameliorates Hepatic Insulin Resistance by Modulating Inflammation and Autophagy in ob/ob Mice. Int J Endocrinol 2018; 2018:8309723. [PMID: 30123267 PMCID: PMC6079465 DOI: 10.1155/2018/8309723] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Revised: 06/12/2018] [Accepted: 06/19/2018] [Indexed: 02/06/2023] Open
Abstract
Obesity and type 2 diabetes are the most common metabolic diseases globally. They are associated with inflammation, oxidative stress, autophagy, and insulin resistance. Sitagliptin, a dipeptidyl-peptidase 4 inhibitor, has been reported to show multiple biological activities beyond the antidiabetic property. This study was aimed at investigating the effect of sitagliptin on hepatic steatosis, insulin resistance, inflammation, and autophagy and exploring the underlying molecular mechanism. In the current study, ob/ob mice, a mouse model of genetic obesity and diabetes, were administered via gavage with sitagliptin 50 mg/kg daily for 4 weeks. Changes in glycolipid metabolism, inflammatory responses, and autophagy in the liver were evaluated. Body weight gain, lipid metabolic disorder, and hepatic steatosis as well as systemic and hepatic insulin sensitivity in ob/ob mice were significantly attenuated after sitagliptin treatment. Furthermore, sitagliptin decreased inflammatory responses by regulating macrophage M1/M2 polarization and inhibiting the activities of NF-κB and JNK. Moreover, sitagliptin increased the levels of phosphorylation of AMPK and decreased those of mTOR. This study indicates that sitagliptin significantly ameliorates the development of hepatic steatosis and insulin resistance in ob/ob mice by inhibiting inflammatory responses and activating autophagy via AMPK/mTOR signaling pathway.
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Affiliation(s)
- Wenbin Zheng
- Department of Endocrinology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Jing Zhou
- Department of Endocrinology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
- Department of Nutrition and Food Science, Texas A&M University, College Station, TX, USA
| | - Shasha Song
- Department of Endocrinology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Wen Kong
- Department of Endocrinology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Wenfang Xia
- Department of Endocrinology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Lulu Chen
- Department of Endocrinology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Tianshu Zeng
- Department of Endocrinology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
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256
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P53 modulates hepatic insulin sensitivity through NF-κB and p38/ERK MAPK pathways. Biochem Biophys Res Commun 2017; 495:2139-2144. [PMID: 29258820 DOI: 10.1016/j.bbrc.2017.12.085] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Accepted: 12/15/2017] [Indexed: 12/16/2022]
Abstract
Besides its well-established oncosuppressor activity, the role of p53 in regulating metabolic pathways has been recently identified. Nevertheless, the function of p53 with respect to insulin resistance appears highly controversial. To address this issue, we investigated the expression of p53 in experimental model of insulin resistance. Then we used activator (nutlin-3α) and inhibitor (pifithrin-α, PFT-α) of p53 in HepG2 cell. Here we showed that p53 protein level was decreased in the hepatic tissue of high-fat diet-induced insulin resistance mice, genetically diabetic ob/ob mice and palmitate (PA) treated HepG2 cells. And high expression of phosphor-p38, ERK1/2 and nuclear factor kappa B (NF-κB) p65 accompanied with low expression of p53. But activation of p53 with nutlin-3α prevented PA-induced reduction of glucose consumption and suppression of insulin signaling pathways. At the same time, nutlin-3α downregulated the activation of NF-κB, p38 and ERK1/2 pathways upon stimulation with PA. In contrast, inhibition of p53 with PFT-α decreased glucose consumption and suppressed insulin signaling pathway. Furthermore, PFT-α activated NF-κB, p38 and ERK1/2 pathways in HepG2 cells. Overall, these results suggest that p53 is involved in improving insulin sensitivity of hepatic cells via inhibition of mitogen-activated protein kinases (MAPKs) and NF-κB pathways.
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257
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Xiao B, Li L, Xu C, Zhao S, Lin L, Cheng J, Yang W, Cong W, Kan G, Cui S. Transcriptome sequencing of the naked mole rat ( Heterocephalus glaber) and identification of hypoxia tolerance genes. Biol Open 2017; 6:1904-1912. [PMID: 29138211 PMCID: PMC5769652 DOI: 10.1242/bio.028548] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
The naked mole rat (NMR; Heterocephalus glaber) is a small rodent species found in regions of Kenya, Ethiopia and Somalia. It has a high tolerance for hypoxia and is thus considered one of the most important natural models for studying hypoxia tolerance mechanisms. The various mechanisms underlying the NMR's hypoxia tolerance are beginning to be understood at different levels of organization, and next-generation sequencing methods promise to expand this understanding to the level of gene expression. In this study, we examined the sequence and transcript abundance data of the muscle transcriptome of NMRs exposed to hypoxia using the Illumina HiSeq 2500 system to clarify the possible genomic adaptive responses to the hypoxic underground surroundings. The RNA-seq raw FastQ data were mapped against the NMR genome. We identified 2337 differentially expressed genes (DEGs) by comparison of the hypoxic and control groups. Functional annotation of the DEGs by gene ontology (GO) analysis revealed enrichment of hypoxia stress-related GO categories, including ‘biological regulation’, ‘cellular process’, ‘ion transport’ and ‘cell-cell signaling’. Enrichment of DEGs in signaling pathways was analyzed against the Kyoto Encyclopedia of Genes and Genomes (KEGG) database to identify possible interactions between DEGs. The results revealed significant enrichment of DEGs in focal adhesion, the mitogen-activated protein kinase (MAPK) signaling pathway and the glycine, serine and threonine metabolism pathway. Furthermore, inhibition of DEGs (STMN1, MAPK8IP1 and MAPK10) expression induced apoptosis and arrested cell growth in NMR fibroblasts following hypoxia. Thus, this global transcriptome analysis of NMRs can provide an important genetic resource for the study of hypoxia tolerance in mammals. Furthermore, the identified DEGs may provide important molecular targets for biomedical research into therapeutic strategies for stroke and cardiovascular diseases. Summary: The identified differentially expressed genes in naked mole rat exposed to hypoxia may provide an important genetic resource for further analyses of mammalian tolerance to hypoxia and molecular targets for the prevention of ischemic diseases. This article has an associated First Person interview with the first author of the paper as part of the supplementary information.
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Affiliation(s)
- Bang Xiao
- Laboratory Animal Centre, The Second Military Medical University, Shanghai 200433, China
| | - Li Li
- Department of Training, The Second Military Medical University, Shanghai 20043, China
| | - Chang Xu
- School of Kinesiology, Shanghai University of Sport, Shanghai 200438, China
| | - Shanmin Zhao
- Laboratory Animal Centre, The Second Military Medical University, Shanghai 200433, China
| | - Lifang Lin
- Laboratory Animal Centre, The Second Military Medical University, Shanghai 200433, China
| | - Jishuai Cheng
- Laboratory Animal Centre, The Second Military Medical University, Shanghai 200433, China
| | - Wenjing Yang
- Laboratory Animal Centre, The Second Military Medical University, Shanghai 200433, China
| | - Wei Cong
- Laboratory Animal Centre, The Second Military Medical University, Shanghai 200433, China
| | - Guanghan Kan
- China Astronaut Research and Training Center, Beijing 100094, China
| | - Shufang Cui
- Laboratory Animal Centre, The Second Military Medical University, Shanghai 200433, China
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258
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Lone J, Parray HA, Yun JW. Nobiletin induces brown adipocyte-like phenotype and ameliorates stress in 3T3-L1 adipocytes. Biochimie 2017; 146:97-104. [PMID: 29217172 DOI: 10.1016/j.biochi.2017.11.021] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Accepted: 11/30/2017] [Indexed: 12/27/2022]
Abstract
Browning of white adipocytes (beiging) is an attractive therapeutic strategy against obesity and its associated metabolic complications. Nobiletin (NOB) is a polymethoxylated flavone present in citrus fruits and has been reported to have anti-obesity effects. Here, we report that nobiletin exerts dual modulatory effects on adipocytes via induction of browning in 3T3-L1 white adipocytes and amelioration of stress in adipocytes. Nobiletin-induced beiging was investigated by determining expression levels of beige-specific genes and proteins by RT-PCR and immunoblot analysis, respectively. Nobiletin treatment rapidly elevated the expression levels of beige-specific genes such as Cd137, Cidea, Tbx1, and Tmem26. Further, nobiletin enhanced expression of the key transcription factors C/EBPβ, PPARδ, and PPARα, which are responsible for remodeling of white adipocytes. Nobiletin also strikingly activated HIB1B brown adipocytes and induced mitochondrial biogenesis in 3T3-L1 white adipocytes. In addition, nobiletin altered the expression of several lipid metabolism-related proteins such as ACOX1, CPT1, FAS, p-PLIN, SREBP and SIRT1. Moreover, nobiletin ameliorated stress in adipocytes by inhibiting expression levels of key stress molecules such as JNK and c-JUN. Nobiletin-induced browning could be mediated by tight regulation of kinases, as nobiletin induced PKA and p-AMPK at the protein expression level, and inhibition of PKA and p-AMPK by H-89 and dorsomorphin, respectively, abolished expression of the thermogenic markers PGC-1α and UCP1. Taken together, our findings suggest that nobiletin plays a modulatory role in adipocytes via induction of browning in 3T3-L1 white adipocytes and activation of HIB1B brown adipocytes combined with amelioration of stress in adipocytes, thereby exhibiting therapeutic potential against obesity.
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Affiliation(s)
- Jameel Lone
- Department of Biotechnology, Daegu University, Kyungsan, Kyungbuk, 38543, Republic of Korea
| | - Hilal Ahmad Parray
- Department of Biotechnology, Daegu University, Kyungsan, Kyungbuk, 38543, Republic of Korea
| | - Jong Won Yun
- Department of Biotechnology, Daegu University, Kyungsan, Kyungbuk, 38543, Republic of Korea.
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259
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Habibian JS, Jefic M, Bagchi RA, Lane RH, McKnight RA, McKinsey TA, Morrison RF, Ferguson BS. DUSP5 functions as a feedback regulator of TNFα-induced ERK1/2 dephosphorylation and inflammatory gene expression in adipocytes. Sci Rep 2017; 7:12879. [PMID: 29018280 PMCID: PMC5635013 DOI: 10.1038/s41598-017-12861-y] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Accepted: 09/14/2017] [Indexed: 12/12/2022] Open
Abstract
Adipose tissue inflammation is a central pathological element that regulates obesity-mediated insulin resistance and type II diabetes. Evidence demonstrates that extracellular signal-regulated kinase (ERK 1/2) activation (i.e. phosphorylation) links tumor necrosis factor α (TNFα) to pro-inflammatory gene expression in the nucleus. Dual specificity phosphatases (DUSPs) inactivate ERK 1/2 through dephosphorylation and can thus inhibit inflammatory gene expression. We report that DUSP5, an ERK1/2 phosphatase, was induced in epididymal white adipose tissue (WAT) in response to diet-induced obesity. Moreover, DUSP5 mRNA expression increased during obesity development concomitant to increases in TNFα expression. Consistent with in vivo findings, DUSP5 mRNA expression increased in adipocytes in response to TNFα, parallel with ERK1/2 dephosphorylation. Genetic loss of DUSP5 exacerbated TNFα-mediated ERK 1/2 signaling in 3T3-L1 adipocytes and in adipose tissue of mice. Furthermore, inhibition of ERK 1/2 and c-Jun N terminal kinase (JNK) signaling attenuated TNFα-induced DUSP5 expression. These data suggest that DUSP5 functions in the feedback inhibition of ERK1/2 signaling in response to TNFα, which resulted in increased inflammatory gene expression. Thus, DUSP5 potentially acts as an endogenous regulator of adipose tissue inflammation; although its role in obesity-mediated inflammation and insulin signaling remains unclear.
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Affiliation(s)
- Justine S Habibian
- University of Nevada, Department of Agriculture, Nutrition, and Veterinary Sciences, Reno, Reno, Nevada, 89557, USA
| | - Mitra Jefic
- University of Nevada, Department of Agriculture, Nutrition, and Veterinary Sciences, Reno, Reno, Nevada, 89557, USA
| | - Rushita A Bagchi
- University of Colorado Denver-Anschutz Medical Campus, Department of Medicine, Division of Cardiology and Consortium for Fibrosis Research & Translation, Aurora, Colorado, 80045, USA
| | - Robert H Lane
- Medical College of Wisconsin, Department of Pediatrics, Milwaukee, Wisconsin, 53226, USA
| | - Robert A McKnight
- University of Utah, Department of Pediatrics, Salt Lake City, Utah, 84108, USA
| | - Timothy A McKinsey
- University of Colorado Denver-Anschutz Medical Campus, Department of Medicine, Division of Cardiology and Consortium for Fibrosis Research & Translation, Aurora, Colorado, 80045, USA
| | - Ron F Morrison
- University of North Carolina Greensboro, Department of Nutrition, Greensboro, North Carolina, 27412, USA.
| | - Bradley S Ferguson
- University of Nevada, Department of Agriculture, Nutrition, and Veterinary Sciences, Reno, Reno, Nevada, 89557, USA.
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260
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Nicholls HT, Hornick JL, Cohen DE. Phosphatidylcholine transfer protein/StarD2 promotes microvesicular steatosis and liver injury in murine experimental steatohepatitis. Am J Physiol Gastrointest Liver Physiol 2017; 313:G50-G61. [PMID: 28385694 PMCID: PMC5538832 DOI: 10.1152/ajpgi.00379.2016] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/20/2016] [Revised: 03/31/2017] [Accepted: 03/31/2017] [Indexed: 01/31/2023]
Abstract
Mice fed a methionine- and choline-deficient (MCD) diet develop steatohepatitis that recapitulates key features of nonalcoholic steatohepatitis (NASH) in humans. Phosphatidylcholine is the most abundant phospholipid in the surfactant monolayer that coats and stabilizes lipid droplets within cells, and choline is required for its major biosynthetic pathway. Phosphatidylcholine-transfer protein (PC-TP), which exchanges phosphatidylcholines among membranes, is enriched in hepatocytes. PC-TP also regulates fatty acid metabolism through interactions with thioesterase superfamily member 2. We investigated the contribution of PC-TP to steatohepatitis induced by the MCD diet. Pctp-/- and wild-type control mice were fed the MCD diet for 5 wk and were then euthanized for histopathologic and biochemical analyses, as well as determinations of mRNA and protein expression. Whereas all mice developed steatohepatitis, plasma alanine aminotransferase and aspartate aminotransferase activities were only elevated in wild-type mice, indicating that Pctp-/- mice were protected from MCD diet-induced hepatocellular injury. Reduced hepatotoxicity due to the MCD diet in the absence of PC-TP expression was further evidenced by decreased activation of c-Jun and reduced plasma concentrations of fibroblast growth factor 21. Despite similar total hepatic concentrations of phosphatidylcholines and other lipids, the relative abundance of microvesicular lipid droplets within hepatocytes was reduced in Pctp-/- mice. Considering that the formation of larger lipid droplets may serve to protect against lipotoxicity in NASH, our findings suggest a pathogenic role for PC-TP that could be targeted in the management of this condition.NEW & NOTEWORTHY Phosphatidylcholine-transfer protein (PC-TP) is a highly specific phosphatidylcholine-binding protein that we previously showed to regulate hepatocellular nutrient metabolism through its interacting partner thioesterase superfamily member 2 (Them2). This study identifies a pathogenic role for PC-TP, independent of Them2, in the methionine- and choline-deficient diet model of experimental steatohepatitis. Our current observations suggest that PC-TP promotes liver injury by mediating the intermembrane transfer of phosphatidylcholines, thus stabilizing more pathogenic microvesicular lipid droplets.
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Affiliation(s)
- Hayley T. Nicholls
- 1Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts; and
| | - Jason L. Hornick
- 2Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - David E. Cohen
- 1Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts; and
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261
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Zimmermann G, Rieder U, Bajic D, Vanetti S, Chaikuad A, Knapp S, Scheuermann J, Mattarella M, Neri D. A Specific and Covalent JNK-1 Ligand Selected from an Encoded Self-Assembling Chemical Library. Chemistry 2017; 23:8152-8155. [PMID: 28485044 PMCID: PMC5557334 DOI: 10.1002/chem.201701644] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Indexed: 01/05/2023]
Abstract
We describe the construction of a DNA-encoded chemical library comprising 148 135 members, generated through the self-assembly of two sub-libraries, containing 265 and 559 members, respectively. The library was designed to contain building blocks potentially capable of forming covalent interactions with target proteins. Selections performed with JNK1, a kinase containing a conserved cysteine residue close to the ATP binding site, revealed the preferential enrichment of a 2-phenoxynicotinic acid moiety (building block A82) and a 4-(3,4-difluorophenyl)-4-oxobut-2-enoic acid moiety (building block B272). When the two compounds were joined by a short PEG linker, the resulting bidentate binder (A82-L-B272) was able to covalently modify JNK1 in the presence of a large molar excess of glutathione (0.5 mm), used to simulate intracellular reducing conditions. By contrast, derivatives of the individual building blocks were not able to covalently modify JNK1 in the same experimental conditions. The A82-L-B272 ligand was selective over related kinases (BTK and GAK), which also contain targetable cysteine residues in the vicinity of the active site.
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Affiliation(s)
- Gunther Zimmermann
- Department of Chemistry and Applied Biosciences, Swiss Federal Institute of Technology (ETH Zürich), Vladimir-Prelog-Weg 4, CH-8093 Zürich (Switzerland)
| | - Ulrike Rieder
- Philochem AG, Libernstrasse 3, CH-8112 Otelfingen (Switzerland)
| | - Davor Bajic
- Department of Chemistry and Applied Biosciences, Swiss Federal Institute of Technology (ETH Zürich), Vladimir-Prelog-Weg 4, CH-8093 Zürich (Switzerland)
| | - Sara Vanetti
- Philochem AG, Libernstrasse 3, CH-8112 Otelfingen (Switzerland)
| | - Apirat Chaikuad
- Institute of Pharmaceutical Chemistry and Buchmann Institute for Life Sciences (BMLS), Goethe University, Max-von-Laue-Strasse 9, D-60438 Frankfurt (Germany)
- Nuffield Department of Clinical Medicine, Structural Genomics Consortium and Target Discovery Institute, University of Oxford, Old Road Campus Research Building, Roosevelt Drive, Oxford, OX3 7DQ, UK
| | - Stefan Knapp
- Institute of Pharmaceutical Chemistry and Buchmann Institute for Life Sciences (BMLS), Goethe University, Max-von-Laue-Strasse 9, D-60438 Frankfurt (Germany)
- Nuffield Department of Clinical Medicine, Structural Genomics Consortium and Target Discovery Institute, University of Oxford, Old Road Campus Research Building, Roosevelt Drive, Oxford, OX3 7DQ, UK
| | - Jörg Scheuermann
- Department of Chemistry and Applied Biosciences, Swiss Federal Institute of Technology (ETH Zürich), Vladimir-Prelog-Weg 4, CH-8093 Zürich (Switzerland)
| | | | - Dario Neri
- Department of Chemistry and Applied Biosciences, Swiss Federal Institute of Technology (ETH Zürich), Vladimir-Prelog-Weg 4, CH-8093 Zürich (Switzerland)
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Stafeev IS, Vorotnikov AV, Ratner EI, Menshikov MY, Parfyonova YV. Latent Inflammation and Insulin Resistance in Adipose Tissue. Int J Endocrinol 2017; 2017:5076732. [PMID: 28912810 PMCID: PMC5585607 DOI: 10.1155/2017/5076732] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Accepted: 07/17/2017] [Indexed: 02/06/2023] Open
Abstract
Obesity is a growing problem in modern society and medicine. It closely associates with metabolic disorders such as type 2 diabetes mellitus (T2DM) and hepatic and cardiovascular diseases such as nonalcoholic fatty liver disease, atherosclerosis, myocarditis, and hypertension. Obesity is often associated with latent inflammation; however, the link between inflammation, obesity, T2DM, and cardiovascular diseases is still poorly understood. Insulin resistance is the earliest feature of metabolic disorders. It mostly develops as a result of dysregulated insulin signaling in insulin-sensitive cells, as compared to inactivating mutations in insulin receptor or signaling proteins that occur relatively rare. Here, we argue that inflammatory signaling provides a link between latent inflammation, obesity, insulin resistance, and metabolic disorders. We further hypothesize that insulin-activated PI3-kinase pathway and inflammatory signaling mediated by several IκB kinases may constitute negative feedback leading to insulin resistance at least in the fat tissue. Finally, we discuss perspectives for anti-inflammatory therapies in treating the metabolic diseases.
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Affiliation(s)
- I. S. Stafeev
- Russian Cardiology Research and Production Centre, Moscow 121552, Russia
- Faculty of Basic Medicine, M.V. Lomonosov Moscow State University, Moscow 119192, Russia
- *I. S. Stafeev:
| | - A. V. Vorotnikov
- Russian Cardiology Research and Production Centre, Moscow 121552, Russia
- M.V. Lomonosov Moscow State University Medical Center, Moscow 119192, Russia
| | - E. I. Ratner
- Russian Cardiology Research and Production Centre, Moscow 121552, Russia
- Endocrinology Research Centre, Moscow 117031, Russia
| | - M. Y. Menshikov
- Russian Cardiology Research and Production Centre, Moscow 121552, Russia
| | - Ye. V. Parfyonova
- Russian Cardiology Research and Production Centre, Moscow 121552, Russia
- Faculty of Basic Medicine, M.V. Lomonosov Moscow State University, Moscow 119192, Russia
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