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Hu Y, Wang R, Liu J, Wang Y, Dong J. Lipid droplet deposition in the regenerating liver: A promoter, inhibitor, or bystander? Hepatol Commun 2023; 7:e0267. [PMID: 37708445 PMCID: PMC10503682 DOI: 10.1097/hc9.0000000000000267] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Accepted: 07/29/2023] [Indexed: 09/16/2023] Open
Abstract
Liver regeneration (LR) is a complex process involving intricate networks of cellular connections, cytokines, and growth factors. During the early stages of LR, hepatocytes accumulate lipids, primarily triacylglycerol, and cholesterol esters, in the lipid droplets. Although it is widely accepted that this phenomenon contributes to LR, the impact of lipid droplet deposition on LR remains a matter of debate. Some studies have suggested that lipid droplet deposition has no effect or may even be detrimental to LR. This review article focuses on transient regeneration-associated steatosis and its relationship with the liver regenerative response.
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Affiliation(s)
- Yuelei Hu
- Department of Hepatobiliary and Pancreatic Surgery, The First Hospital of Jilin University, Jilin University, Changchun, China
| | - Ruilin Wang
- Department of Cadre’s Wards Ultrasound Diagnostics. Ultrasound Diagnostic Center, The First Hospital of Jilin University, Jilin University, Changchun, China
| | - Juan Liu
- Research Unit of Precision Hepatobiliary Surgery Paradigm, Chinese Academy of Medical Sciences, Beijing, China
- Hepatopancreatobiliary Center, Beijing Tsinghua Changgung Hospital, School of Clinical Medicine, Tsinghua University, Beijing, China
- Institute for Organ Transplant and Bionic Medicine, Tsinghua University, Beijing, China
- Clinical Translational Science Center, Beijing Tsinghua Changgung Hospital, Tsinghua University, Beijing, China
| | - Yunfang Wang
- Research Unit of Precision Hepatobiliary Surgery Paradigm, Chinese Academy of Medical Sciences, Beijing, China
- Hepatopancreatobiliary Center, Beijing Tsinghua Changgung Hospital, School of Clinical Medicine, Tsinghua University, Beijing, China
- Institute for Organ Transplant and Bionic Medicine, Tsinghua University, Beijing, China
- Clinical Translational Science Center, Beijing Tsinghua Changgung Hospital, Tsinghua University, Beijing, China
| | - Jiahong Dong
- Department of Hepatobiliary and Pancreatic Surgery, The First Hospital of Jilin University, Jilin University, Changchun, China
- Research Unit of Precision Hepatobiliary Surgery Paradigm, Chinese Academy of Medical Sciences, Beijing, China
- Hepatopancreatobiliary Center, Beijing Tsinghua Changgung Hospital, School of Clinical Medicine, Tsinghua University, Beijing, China
- Institute for Organ Transplant and Bionic Medicine, Tsinghua University, Beijing, China
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2
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Xia Y, Ge G, Xiao H, Wu M, Wang T, Gu C, Yang H, Geng D. REPIN1 regulates iron metabolism and osteoblast apoptosis in osteoporosis. Cell Death Dis 2023; 14:631. [PMID: 37749079 PMCID: PMC10519990 DOI: 10.1038/s41419-023-06160-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Revised: 09/06/2023] [Accepted: 09/15/2023] [Indexed: 09/27/2023]
Abstract
Osteoporosis is not well treated due to the difficulty of finding commonalities between the various types of it. Iron homeostasis is a vital component in supporting biochemical functions, and iron overload is recognized as a common risk factor for osteoporosis. In this research, we found that there is indeed evidence of iron accumulation in the bone tissue of patients with osteoporosis and REPIN1, as an origin specific DNA binding protein, may play a key role in this process. We revealed that sh-Repin1 therapy can rescue bone loss in an iron-overload-induced osteoporosis mouse model. Knockdown of Repin1 can inhibit apoptosis and enhance the resistance of osteoblasts to iron overload toxicity. REPIN1 promoted apoptosis by regulating iron metabolism in osteoblasts. Mechanistically, knockdown of Repin1 decreased the expression of Lcn2, which ameliorated the toxic effects of intracellular iron overload. The anti-iron effect of lentivirus sh-Repin1 was partially reversed or replicated by changing LCN2 expression level via si-RNA or plasmid, which indirectly verified the key regulatory role of LCN2 as a downstream target. Furthermore, the levels of BCL2 and BAX, which play a key role in the mitochondrial apoptosis pathway, were affected. In summary, based on the results of clinical specimens, animal models and in vitro experiments, for the first time, we proved the key role of REPIN1 in iron metabolism-related osteoporosis.
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Affiliation(s)
- Yu Xia
- Department of Orthopedics, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, China
| | - Gaoran Ge
- Department of Orthopedics, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, China
| | - Haixiang Xiao
- Department of Orthopedics, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, China
| | - Mingzhou Wu
- Department of Orthopedics, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, China
- Taicang TCM Hospital Affiliated to Nanjing University of Chinese Medicine, Taicang, China
| | - Tianhao Wang
- Department of Orthopedics, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, China
| | - Chengyong Gu
- Suzhou Hospital of Nanjing Medical University, Suzhou Municipal Hospital (North District), Suzhou, China.
| | - Huilin Yang
- Department of Orthopedics, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, China.
| | - Dechun Geng
- Department of Orthopedics, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, China.
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3
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Pragya SU, Pragya SC, Griswold AJ, Gu E, Mehta ND, Uddin P, Veeramachaneni P, Mehta N, Mehta D, Abomoelak B. Preksha Dhyāna Meditation Effect on the DNA Methylation Signature in College Students. JOURNAL OF INTEGRATIVE AND COMPLEMENTARY MEDICINE 2023; 29:224-233. [PMID: 36749149 DOI: 10.1089/jicm.2022.0713] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Introduction: The stress and psychological factors affect the human transcriptomic and epigenomic landscapes. Preksha Dhyana meditation (PM) was found to be effective, in novice healthy college student meditators, at the cognitive skills and transcriptomic levels. Recently published data showed that PM induced alterations at the transcriptome level in healthy and novice college students. Methods: To decipher potential mechanisms underlying the PM effect at the cellular level, array-based methylation analyses in peripheral blood were performed at baseline and 8 weeks postintervention in 34 participants. Results: Overall, 470 CpG sites were nominally differentially methylated (p ≤ 0.05 and change magnitude from ≥3% to ≤ -3%) between baseline and 8 weeks postintervention with 180 sites hypermethylated and 290 sites hypomethylated. Pathway analysis of the genes linked to the differentially methylated sites revealed the enrichment of several molecular and cellular signaling pathways, especially metabolic and brain function signaling pathways. Conclusions: Besides its beneficial effects on cognitive skills and transcriptome alterations, the current data indicate that PM meditation also affects the DNA methylation profile of novice and healthy college students 8 weeks postintervention. Clinical Trial Registration number: NCT03779269.
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Affiliation(s)
- Samani U Pragya
- Department of Religions and Philosophies, University of London, London, United Kingdom
| | - Samani C Pragya
- Department of Biostatistics, Robert Stempel College of Public Health and Social Work, Florida International University, Miami, FL, USA
| | - Anthony J Griswold
- John P. Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Esther Gu
- John P. Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Neelam D Mehta
- Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA
| | - Parvin Uddin
- College of Arts, Sciences and Education, Florida International University, Miami, FL, USA
| | | | - Naina Mehta
- Neurodevelopmental Pediatrician, Behavioral and Developmental Center, Orlando Health, Orlando, FL, USA
| | - Devendra Mehta
- Gastrointestinal Translational Laboratory, Arnold Palmer Hospital for Children, Orlando, FL, USA
| | - Bassam Abomoelak
- Gastrointestinal Translational Laboratory, Arnold Palmer Hospital for Children, Orlando, FL, USA
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4
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The Crowded Uterine Horn Mouse Model for Examining Postnatal Metabolic Consequences of Intrauterine Growth Restriction vs. Macrosomia in Siblings. Metabolites 2022; 12:metabo12020102. [PMID: 35208177 PMCID: PMC8880550 DOI: 10.3390/metabo12020102] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2021] [Revised: 01/13/2022] [Accepted: 01/19/2022] [Indexed: 01/27/2023] Open
Abstract
Differential placental blood flow and nutrient transport can lead to both intrauterine growth restriction (IUGR) and macrosomia. Both conditions can lead to adult obesity and other conditions clustered as metabolic syndrome. We previously showed that pregnant hemi-ovariectomized mice have a crowded uterine horn, resulting in siblings whose birth weights differ by over 100% due to differential blood flow based on uterine position. We used this crowded uterus model to compare IUGR and macrosomic male mice and also identified IUGR males with rapid (IUGR-R) and low (IUGR-L) postweaning weight gain. At week 12 IUGR-R males were heavier than IUGR-L males and did not differ from macrosomic males. Rapid growth in IUGR-R males led to glucose intolerance compared to IUGR-L males and down-regulation of adipocyte signaling pathways for fat digestion and absorption and type II diabetes. Macrosomia led to increased fat mass and altered adipocyte size distribution compared to IUGR males, and down-regulation of signaling pathways for carbohydrate and fat digestion and absorption relative to IUGR-R. Clustering analysis of gonadal fat transcriptomes indicated more similarities than differences between IUGR-R and macrosomic males compared to IUGR-L males. Our findings suggest two pathways to adult metabolic disease: macrosomia and IUGR with rapid postweaning growth rate.
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A Human REPIN1 Gene Variant: Genetic Risk Factor for the Development of Nonalcoholic Fatty Liver Disease. Clin Transl Gastroenterol 2020; 11:e00114. [PMID: 31922994 PMCID: PMC7056046 DOI: 10.14309/ctg.0000000000000114] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
OBJECTIVES We tested the hypothesis that a genetic deletion (Del) variant in the REPIN1 gene is associated with the severity of nonalcoholic fatty liver disease (NAFLD) in humans. METHODS Sixty-three donors of liver biopsies from individuals with obesity and different degrees of NAFLD and fibrosis were screened for a Del REPIN1 gene variant and liver REPIN1 mRNA expression. RESULTS In 8 homozygous Del carriers, we found significantly lower NAFLD activity and fibrosis scores compared with 55 wild-type allele carriers. DISCUSSION A Del variant of REPIN1 may be associated with a lower risk of the development of NAFLD.
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Kaartinen MT, Arora M, Heinonen S, Rissanen A, Kaprio J, Pietiläinen KH. Transglutaminases and Obesity in Humans: Association of F13A1 to Adipocyte Hypertrophy and Adipose Tissue Immune Response. Int J Mol Sci 2020; 21:E8289. [PMID: 33167412 PMCID: PMC7663854 DOI: 10.3390/ijms21218289] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 10/30/2020] [Accepted: 11/01/2020] [Indexed: 12/11/2022] Open
Abstract
Transglutaminases TG2 and FXIII-A have recently been linked to adipose tissue biology and obesity, however, human studies for TG family members in adipocytes have not been conducted. In this study, we investigated the association of TGM family members to acquired weight gain in a rare set of monozygotic (MZ) twins discordant for body weight, i.e., heavy-lean twin pairs. We report that F13A1 is the only TGM family member showing significantly altered, higher expression in adipose tissue of the heavier twin. Our previous work linked adipocyte F13A1 to increased weight, body fat mass, adipocyte size, and pro-inflammatory pathways. Here, we explored further the link of F13A1 to adipocyte size in the MZ twins via a previously conducted TWA study that was further mined for genes that specifically associate to hypertrophic adipocytes. We report that differential expression of F13A1 (ΔHeavy-Lean) associated with 47 genes which were linked via gene enrichment analysis to immune response, leucocyte and neutrophil activation, as well as cytokine response and signaling. Our work brings further support to the role of F13A1 in the human adipose tissue pathology, suggesting a role in the cascade that links hypertrophic adipocytes with inflammation.
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Affiliation(s)
- Mari T. Kaartinen
- Faculty of Medicine (Experimental Medicine), McGill University, Montreal, QC H3A 0J7, Canada;
- Faculty of Dentistry (Biomedical Sciences), McGill University, Montreal, QC H3A 0J7, Canada
| | - Mansi Arora
- Faculty of Medicine (Experimental Medicine), McGill University, Montreal, QC H3A 0J7, Canada;
| | - Sini Heinonen
- Obesity Research Unit, Research Program for Clinical and Molecular Metabolism, Faculty of Medicine, University of Helsinki, 00014 Helsinki, Finland; (S.H.); (A.R.); (K.H.P.)
| | - Aila Rissanen
- Obesity Research Unit, Research Program for Clinical and Molecular Metabolism, Faculty of Medicine, University of Helsinki, 00014 Helsinki, Finland; (S.H.); (A.R.); (K.H.P.)
| | - Jaakko Kaprio
- Department of Public Health, University of Helsinki, 00100 Helsinki, Finland;
| | - Kirsi H. Pietiläinen
- Obesity Research Unit, Research Program for Clinical and Molecular Metabolism, Faculty of Medicine, University of Helsinki, 00014 Helsinki, Finland; (S.H.); (A.R.); (K.H.P.)
- Abdominal Center, Obesity Center, Endocrinology, University of Helsinki and Helsinki University Central Hospital, 00014 Helsinki, Finland
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7
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Angin M, Volant S, Passaes C, Lecuroux C, Monceaux V, Dillies MA, Valle-Casuso JC, Pancino G, Vaslin B, Le Grand R, Weiss L, Goujard C, Meyer L, Boufassa F, Müller-Trutwin M, Lambotte O, Sáez-Cirión A. Metabolic plasticity of HIV-specific CD8 + T cells is associated with enhanced antiviral potential and natural control of HIV-1 infection. Nat Metab 2019; 1:704-716. [PMID: 32694646 DOI: 10.1038/s42255-019-0081-4] [Citation(s) in RCA: 62] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Accepted: 06/05/2019] [Indexed: 12/27/2022]
Abstract
Spontaneous control of human immunodeficiency virus (HIV) is generally associated with an enhanced capacity of CD8+ T cells to eliminate infected CD4+ T cells, but the molecular characteristics of these highly functional CD8+ T cells are largely unknown. In the present study, using single-cell analysis, it was shown that HIV-specific, central memory CD8+ T cells from spontaneous HIV controllers (HICs) and antiretrovirally treated non-controllers have opposing transcriptomic profiles. Genes linked to effector functions and survival are upregulated in cells from HICs. In contrast, genes associated with activation, exhaustion and glycolysis are upregulated in cells from non-controllers. It was shown that HIV-specific CD8+ T cells from non-controllers are largely glucose dependent, whereas those from HICs have more diverse metabolic resources that enhance both their survival potential and their capacity to develop anti-HIV effector functions. The functional efficiency of the HIV-specific CD8+ T cell response in HICs is thus engraved in their memory population and related to their metabolic programme. Metabolic reprogramming in vitro through interleukin-15 treatment abrogated the glucose dependency and enhanced the antiviral potency of HIV-specific CD8+ T cells from non-controllers.
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Affiliation(s)
- Mathieu Angin
- Institut Pasteur, Unité HIV Inflammation et Persistance, Paris, France
| | - Stevenn Volant
- Institut Pasteur, Hub Bioinformatique et Biostatistique, Paris, France
| | - Caroline Passaes
- Institut Pasteur, Unité HIV Inflammation et Persistance, Paris, France
| | - Camille Lecuroux
- CEA, Immunology of Viral Infections and Autoimmune Diseases, IDMIT Department/IBFJ, Université Paris Sud, Fontenay-aux-Roses, France
| | - Valérie Monceaux
- Institut Pasteur, Unité HIV Inflammation et Persistance, Paris, France
| | | | | | | | - Bruno Vaslin
- CEA, Immunology of Viral Infections and Autoimmune Diseases, IDMIT Department/IBFJ, Université Paris Sud, Fontenay-aux-Roses, France
| | - Roger Le Grand
- CEA, Immunology of Viral Infections and Autoimmune Diseases, IDMIT Department/IBFJ, Université Paris Sud, Fontenay-aux-Roses, France
| | - Laurence Weiss
- Assistance Publique Hôpitaux de Paris, Hôpital Européen Georges Pompidou, Paris, France
- Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Cecile Goujard
- Assistance Publique Hôpitaux de Paris, Hôpital Bicêtre, Service de Médecine Interne et Immunologie Clinique, Le Kremlin-Bicêtre, France
| | - Laurence Meyer
- Centre de Recherche en Epidémiologie et Santé des Populations, Université Paris Sud, Le Kremlin-Bicêtre, France
| | - Faroudy Boufassa
- Centre de Recherche en Epidémiologie et Santé des Populations, Université Paris Sud, Le Kremlin-Bicêtre, France
| | | | - Olivier Lambotte
- CEA, Immunology of Viral Infections and Autoimmune Diseases, IDMIT Department/IBFJ, Université Paris Sud, Fontenay-aux-Roses, France
- Assistance Publique Hôpitaux de Paris, Hôpital Bicêtre, Service de Médecine Interne et Immunologie Clinique, Le Kremlin-Bicêtre, France
| | - Asier Sáez-Cirión
- Institut Pasteur, Unité HIV Inflammation et Persistance, Paris, France.
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8
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Abshagen K, Mense L, Fischer F, Liebig M, Schaeper U, Navarro G, Glass Ä, Frank M, Klöting N, Vollmar B. Repin1 deficiency in liver tissue alleviates NAFLD progression in mice. J Adv Res 2019; 16:99-111. [PMID: 30899593 PMCID: PMC6413308 DOI: 10.1016/j.jare.2018.11.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Revised: 11/20/2018] [Accepted: 11/21/2018] [Indexed: 02/06/2023] Open
Abstract
There is an increasing prevalence of obesity and metabolic syndrome, which promote the development of non-alcoholic fatty liver disease (NAFLD), a disease that can evolve into cirrhosis and hepatocellular carcinoma. Repin1 loss was previously shown to have beneficial effects on lipid and glucose metabolism and obesity regulation. Herein, we characterized NAFLD in mice with hepatic deletion of Repin1 (LRep1-/-). For this purpose, liver disease was analysed in male LRep1-/- and wild-type mice treated with streptozotocin/high fat diet or a control diet over a period of 20 wks. Streptozotocin/high fat diet treated LRep1-/- mice showed a significant decrease in systemic and hepatic lipid accumulation, accompanied by diminished chronic inflammation and a subsequent reduction in liver injury. Remarkably, Repin1-deficient mice exhibited a lower tumour prevalence and tumour frequency, as well as a reduced liver weight/body weight index. A therapeutic approach using Repin1 siRNA in the early phase of NAFLD verified the observed beneficial effects of Repin1 deficiency. This study provides evidence that loss of Repin1 in the liver attenuates NAFLD progression, most likely by reducing fat accumulation and alleviating chronic tissue inflammation. Thus, modulating Repin1 expression may become a novel strategy and potential tool to inhibit NAFLD progression.
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Affiliation(s)
- Kerstin Abshagen
- Rudolf-Zenker-Institute for Experimental Surgery, University Medicine Rostock, Schillingallee 69a, 18057 Rostock, Germany
| | - Lars Mense
- Rudolf-Zenker-Institute for Experimental Surgery, University Medicine Rostock, Schillingallee 69a, 18057 Rostock, Germany
| | - Felix Fischer
- Rudolf-Zenker-Institute for Experimental Surgery, University Medicine Rostock, Schillingallee 69a, 18057 Rostock, Germany
| | - Marie Liebig
- Rudolf-Zenker-Institute for Experimental Surgery, University Medicine Rostock, Schillingallee 69a, 18057 Rostock, Germany
| | - Ute Schaeper
- Silence Therapeutics GmbH, Robert Rössle Straße 10, 13125 Berlin, Germany
| | - Gemma Navarro
- Silence Therapeutics GmbH, Robert Rössle Straße 10, 13125 Berlin, Germany
| | - Änne Glass
- Institute for Biostatistics and Informatics in Medicine and Ageing Research, University Medicine Rostock, Ernst-Heydemann-Straße 8, 18057 Rostock, Germany
| | - Marcus Frank
- Medical Biology and Electron Microscopy Centre, University Medicine Rostock, Strempelstraße 14, 18057 Rostock, Germany
| | - Nora Klöting
- Integrated Research and Treatment Center (IFB) AdiposityDiseases, University of Leipzig, Liebigstraße 19-21, 04103 Leipzig, Germany
| | - Brigitte Vollmar
- Rudolf-Zenker-Institute for Experimental Surgery, University Medicine Rostock, Schillingallee 69a, 18057 Rostock, Germany
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9
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Liver-specific Repin1 deficiency impairs transient hepatic steatosis in liver regeneration. Sci Rep 2018; 8:16858. [PMID: 30442920 PMCID: PMC6237840 DOI: 10.1038/s41598-018-35325-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Accepted: 11/02/2018] [Indexed: 02/06/2023] Open
Abstract
Transient hepatic steatosis upon liver resection supposes functional relationships between lipid metabolism and liver regeneration. Repin1 has been suggested as candidate gene for obesity and dyslipidemia by regulating key genes of lipid metabolism and lipid storage. Herein, we characterized the regenerative potential of mice with a hepatic deletion of Repin1 (LRep1−/−) after partial hepatectomy (PH) in order to determine the functional significance of Repin1 in liver regeneration. Lipid dynamics and the regenerative response were analyzed at various time points after PH. Hepatic Repin1 deficiency causes a significantly decreased transient hepatic lipid accumulation. Defects in lipid uptake, as analyzed by decreased expression of the fatty acid transporter Cd36 and Fatp5, may contribute to attenuated and shifted lipid accumulation, accompanied by altered extent and chronological sequence of liver cell proliferation in LRep1−/− mice. In vitro steatosis experiments with primary hepatocytes also revealed attenuated lipid accumulation and occurrence of smaller lipid droplets in Repin1-deficient cells, while no direct effect on proliferation in HepG2 cells was observed. Based on these results, we propose that hepatocellular Repin1 might be of functional significance for early accumulation of lipids in hepatocytes after PH, facilitating efficient progression of liver regeneration.
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10
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Krüger J, Berger C, Weidle K, Schleinitz D, Tönjes A, Stumvoll M, Blüher M, Kovacs P, Klöting N. Metabolic effects of genetic variation in the human REPIN1 gene. Int J Obes (Lond) 2018; 43:821-831. [PMID: 29915365 DOI: 10.1038/s41366-018-0123-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Revised: 04/06/2018] [Accepted: 04/17/2018] [Indexed: 12/11/2022]
Abstract
BACKGROUND Replication initiator 1 (Repin1) is a zinc finger protein highly expressed in liver and adipose tissue. The Repin1 resides within a quantitative trait locus (QTL) for body weight and triglyceride levels in the rat, and its hepatic deletion in mice results in improved insulin sensitivity and lower body weight. Here, we analyzed whether genetic variation within the Repin1 affects parameters of glucose and lipid metabolism. METHODS We sequenced REPIN1 in 48 non-related Caucasian subjects. We discovered a 12 base pair deletion (12 bp del; rs3832490), which was subsequently genotyped in two well-characterized cohorts (N = 3013) to test for associations with metabolic traits. Functional consequences of the variant were investigated in HepG2 cells in vitro. RESULTS In human cohorts, we show that the 12 bp del associates with improved glucose metabolism (lower fasting plasma glucose, fasting plasma insulin, and HOMA IR). Cells transfected with the plasmid carrying the 12 bp del variant are characterized by increased GLUT2 and fatty acid translocase CD36 expression and more lipid droplets. CONCLUSION Our data suggest that genetic variation in human REPIN1 plays a role in glucose and lipid metabolism by differentially affecting the expression of REPIN1 target genes including glucose and fatty acid transporters.
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Affiliation(s)
- Jacqueline Krüger
- Leipzig University Medical Center, IFB Adiposity Diseases, University of Leipzig, 04103, Leipzig, Germany
| | - Claudia Berger
- Leipzig University Medical Center, IFB Adiposity Diseases, University of Leipzig, 04103, Leipzig, Germany.,German Diabetes Center Leipzig, University of Leipzig, 04103, Leipzig, Germany
| | - Kerstin Weidle
- Leipzig University Medical Center, IFB Adiposity Diseases, University of Leipzig, 04103, Leipzig, Germany
| | - Dorit Schleinitz
- Leipzig University Medical Center, IFB Adiposity Diseases, University of Leipzig, 04103, Leipzig, Germany
| | - Anke Tönjes
- Department of Medicine, University of Leipzig, 04103, Leipzig, Germany
| | - Michael Stumvoll
- Department of Medicine, University of Leipzig, 04103, Leipzig, Germany
| | - Matthias Blüher
- Department of Medicine, University of Leipzig, 04103, Leipzig, Germany
| | - Peter Kovacs
- Leipzig University Medical Center, IFB Adiposity Diseases, University of Leipzig, 04103, Leipzig, Germany.
| | - Nora Klöting
- Leipzig University Medical Center, IFB Adiposity Diseases, University of Leipzig, 04103, Leipzig, Germany.
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11
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Weiner J, Kranz M, Klöting N, Kunath A, Steinhoff K, Rijntjes E, Köhrle J, Zeisig V, Hankir M, Gebhardt C, Deuther-Conrad W, Heiker JT, Kralisch S, Stumvoll M, Blüher M, Sabri O, Hesse S, Brust P, Tönjes A, Krause K. Thyroid hormone status defines brown adipose tissue activity and browning of white adipose tissues in mice. Sci Rep 2016; 6:38124. [PMID: 27941950 PMCID: PMC5150531 DOI: 10.1038/srep38124] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Accepted: 11/07/2016] [Indexed: 12/28/2022] Open
Abstract
The present study aimed to determine the effect of thyroid hormone dysfunction on brown adipose tissue activity and white adipose tissue browning in mice. Twenty randomized female C57BL/6NTac mice per treatment group housed at room temperature were rendered hypothyroid or hyperthyroid. In-vivo small animal 18F-FDG PET/MRI was performed to determine the effects of hypo- and hyperthyroidism on BAT mass and BAT activity. Ex-vivo14C-acetate loading assay and assessment of thermogenic gene and protein expression permitted analysis of oxidative and thermogenic capacities of WAT and BAT of eu-, hyper and hypothyroid mice. 18F-FDG PET/MRI revealed a lack of brown adipose tissue activity in hypothyroid mice, whereas hyperthyroid mice displayed increased BAT mass alongside enhanced 18F-FDG uptake. In white adipose tissue of both, hyper- and hypothyroid mice, we found a significant induction of thermogenic genes together with multilocular adipocytes expressing UCP1. Taken together, these results suggest that both the hyperthyroid and hypothyroid state stimulate WAT thermogenesis most likely as a consequence of enhanced adrenergic signaling or compensation for impaired BAT function, respectively.
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Affiliation(s)
- Juliane Weiner
- Department of Endocrinology and Nephrology, University Hospital, Leipzig, Germany
| | - Mathias Kranz
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Research Site Leipzig, Department of Neuroradiopharmaceuticals, Leipzig, Germany
| | - Nora Klöting
- Department of Endocrinology and Nephrology, University Hospital, Leipzig, Germany.,University of Leipzig, IFB Adiposity Diseases, Leipzig, Germany
| | - Anne Kunath
- German Center for Diabetes Research (DZD), Leipzig, Germany
| | - Karen Steinhoff
- Department of Nuclear Medicine, University Hospital, Leipzig, Germany
| | - Eddy Rijntjes
- Institute of Experimental Endocrinology, Charité University Hospital, Berlin, Germany
| | - Josef Köhrle
- Institute of Experimental Endocrinology, Charité University Hospital, Berlin, Germany
| | - Vilia Zeisig
- Department of Nuclear Medicine, University Hospital, Leipzig, Germany
| | - Mohammed Hankir
- University of Leipzig, IFB Adiposity Diseases, Leipzig, Germany
| | - Claudia Gebhardt
- Department of Endocrinology and Nephrology, University Hospital, Leipzig, Germany
| | - Winnie Deuther-Conrad
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Research Site Leipzig, Department of Neuroradiopharmaceuticals, Leipzig, Germany
| | - John T Heiker
- Department of Endocrinology and Nephrology, University Hospital, Leipzig, Germany
| | - Susan Kralisch
- Department of Endocrinology and Nephrology, University Hospital, Leipzig, Germany.,University of Leipzig, IFB Adiposity Diseases, Leipzig, Germany
| | - Michael Stumvoll
- Department of Endocrinology and Nephrology, University Hospital, Leipzig, Germany.,University of Leipzig, IFB Adiposity Diseases, Leipzig, Germany
| | - Matthias Blüher
- Department of Endocrinology and Nephrology, University Hospital, Leipzig, Germany.,University of Leipzig, IFB Adiposity Diseases, Leipzig, Germany
| | - Osama Sabri
- University of Leipzig, IFB Adiposity Diseases, Leipzig, Germany.,Department of Nuclear Medicine, University Hospital, Leipzig, Germany
| | - Swen Hesse
- University of Leipzig, IFB Adiposity Diseases, Leipzig, Germany.,Department of Nuclear Medicine, University Hospital, Leipzig, Germany
| | - Peter Brust
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Research Site Leipzig, Department of Neuroradiopharmaceuticals, Leipzig, Germany
| | - Anke Tönjes
- Department of Endocrinology and Nephrology, University Hospital, Leipzig, Germany
| | - Kerstin Krause
- Department of Endocrinology and Nephrology, University Hospital, Leipzig, Germany
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Kunath A, Hesselbarth N, Gericke M, Kern M, Dommel S, Kovacs P, Stumvoll M, Blüher M, Klöting N. Repin1 deficiency improves insulin sensitivity and glucose metabolism in db/db mice by reducing adipose tissue mass and inflammation. Biochem Biophys Res Commun 2016; 478:398-402. [DOI: 10.1016/j.bbrc.2016.07.038] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Accepted: 07/07/2016] [Indexed: 11/26/2022]
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Novel genes on rat chromosome 10 are linked to body fat mass, preadipocyte number and adipocyte size. Int J Obes (Lond) 2016; 40:1832-1840. [PMID: 27460604 DOI: 10.1038/ijo.2016.127] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Revised: 05/10/2016] [Accepted: 06/12/2016] [Indexed: 01/23/2023]
Abstract
BACKGROUND The genetic architecture of obesity is multifactorial. We have previously identified a quantitative trait locus (QTL) on rat chromosome 10 in a F2 cross of Wistar Ottawa Karlsburg (WOKW) and Dark Agouti (DA) rats responsible for obesity-related traits. The QTL was confirmed in congenic DA.WOKW10 rats. To pinpoint the region carrying causal genes, we established two new subcongenic lines, L1 and L2, with smaller refined segments of chromosome 10 to identify novel candidate genes. METHODS All lines were extensively characterized under different diet conditions. We employed transcriptome analysis in visceral adipose tissue (VAT) by RNA-Seq technology to identify potential underlying genes in the segregating regions. Three candidate genes were measured in human paired samples of VAT and subcutaneous (SC) AT (SAT) (N=304) individuals with a wide range of body weight and glucose homeostasis parameters. RESULTS DA.WOKW and L1 subcongenic lines were protected against body fat gain under high-fat diet (HFD), whereas L2 and DA had significantly more body fat after high-fat feeding. Interestingly, adipocyte size distribution in SAT and epigonadal AT of L1 subcongenic rats did not undergo typical ballooning under HFD and the number of preadipocytes in AT was significantly elevated in L2 compared with L1 and parental rats. Transcriptome analysis identified three candidate genes in VAT on rat chromosome 10. In humans, these candidate genes were differentially expressed between SAT and VAT. Moreover, HID1 mRNA significantly correlates with parameters of obesity and glucose metabolism. CONCLUSIONS Our data suggest novel candidate genes for obesity that map on rat chromosome 10 in an interval 102.2-104.7 Mb and are strongly associated with body fat mass regulation, preadipocyte number and adipocyte size in rats. Among those genes, AT head involution defective (HID1) mRNA expression may be relevant for human fat distribution and glucose homeostasis.
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14
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Krause K, Weiner J, Hönes S, Klöting N, Rijntjes E, Heiker JT, Gebhardt C, Köhrle J, Führer D, Steinhoff K, Hesse S, Moeller LC, Tönjes A. The Effects of Thyroid Hormones on Gene Expression of Acyl-Coenzyme A Thioesterases in Adipose Tissue and Liver of Mice. Eur Thyroid J 2015; 4:59-66. [PMID: 26601074 PMCID: PMC4640296 DOI: 10.1159/000437304] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Revised: 06/29/2015] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Thyroid hormones (TH) exert pleiotropic effects on glucose and lipid homeostasis. However, it is as yet unclear how TH regulate lipid storage and utilization in order to adapt to metabolic needs. Acyl-CoA thioesterases (ACOTs) have been proposed to play a regulatory role in the metabolism of fatty acids. OBJECTIVES We investigated the interaction between thyroid dysfunction and Acot expression in adipose tissues and livers of thyrotoxic and hypothyroid mice. METHODS Ten-week-old female C57BL/6NTac mice (n = 10/group) were made hyperthyroid by the application of L-thyroxine (2 µg/ml in drinking water) for 4 weeks. Hypothyroidism was induced in 10-week-old mice by feeding an iodine-free chow supplemented with 0.15% PTU for 4 weeks. We measured mRNA expression levels of Acot8, 11 and 13 in the liver and epididymal and inguinal white and brown adipose tissues (BAT). Furthermore, we investigated hepatic Acot gene expression in TRα- and TRβ-deficient mice. RESULTS We showed that the expression of Acot8, 11 and 13 is predominantly stimulated by a thyrotoxic state in the epididymal white adipose tissue. In contrast, hypothyroidism predominantly induces the expression of Acot8 in BAT in comparison with BAT of thyrotoxic and euthyroid mice (p < 0.01). However, no significant changes in Acot expression were observed in inguinal white adipose tissue. In liver, Acot gene expression is collectively elicited by a thyrotoxic state. CONCLUSIONS These data suggest that ACOTs are targets of TH and are likely to influence 3,5,3'-triiodo-L-thyronine-orchestrated mechanisms of lipid uptake, storage and utilization to adapt the regulation of metabolic demands.
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Affiliation(s)
- Kerstin Krause
- Division of Endocrinology and Nephrology, Department of Medicine, Leipzig, Germany
- *Kerstin Krause, Division of Endocrinology and Nephrology, Department of Medicine, University of Leipzig, Liebigstrasse 21, DE-04103 Leipzig (Germany), E-Mail
| | - Juliane Weiner
- Division of Endocrinology and Nephrology, Department of Medicine, Leipzig, Germany
| | - Sebastian Hönes
- Department of Endocrinology and Metabolism, University of Duisburg-Essen, Essen, Germany
| | - Nora Klöting
- Division of Endocrinology and Nephrology, Department of Medicine, Leipzig, Germany
- IFB Adiposity Diseases, Leipzig University Medical Centre, Leipzig, Germany
| | - Eddy Rijntjes
- Institute for Experimental Endocrinology, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - John T. Heiker
- Division of Endocrinology and Nephrology, Department of Medicine, Leipzig, Germany
| | - Claudia Gebhardt
- Division of Endocrinology and Nephrology, Department of Medicine, Leipzig, Germany
| | - Josef Köhrle
- Institute for Experimental Endocrinology, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Dagmar Führer
- Department of Endocrinology and Metabolism, University of Duisburg-Essen, Essen, Germany
| | - Karen Steinhoff
- Department of Nuclear Medicine, University of Leipzig, Leipzig, Germany
| | - Swen Hesse
- Department of Nuclear Medicine, University of Leipzig, Leipzig, Germany
- IFB Adiposity Diseases, Leipzig University Medical Centre, Leipzig, Germany
| | - Lars C. Moeller
- Department of Endocrinology and Metabolism, University of Duisburg-Essen, Essen, Germany
| | - Anke Tönjes
- Division of Endocrinology and Nephrology, Department of Medicine, Leipzig, Germany
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15
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Andrade FDO, de Assis S, Jin L, Fontelles CC, Barbisan LF, Purgatto E, Hilakivi-Clarke L, Ong TP. Lipidomic fatty acid profile and global gene expression pattern in mammary gland of rats that were exposed to lard-based high fat diet during fetal and lactation periods associated to breast cancer risk in adulthood. Chem Biol Interact 2015; 239:118-28. [PMID: 26115784 DOI: 10.1016/j.cbi.2015.06.035] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2014] [Revised: 06/05/2015] [Accepted: 06/23/2015] [Indexed: 02/07/2023]
Abstract
The persistent effects of animal fat consumption during pregnancy and nursing on the programming of breast cancer risk among female offspring were studied here. We have previously found that female offspring of rat dams that consumed a lard-based high-fat (HF) diet (60% fat-derived energy) during pregnancy, or during pregnancy and lactation, were at a reduced risk of developing mammary cancer. To better understand the unexpected protective effects of early life lard exposure, we have applied lipidomics and nutrigenomics approaches to investigate the fatty acid profile and global gene expression patterns in the mammary tissue of the female offspring. Consumption of this HF diet during gestation had few effects on the mammary tissue fatty acids profile of young adult offspring, while exposure from gestation throughout nursing promoted significant alterations in the fatty acids profile. Major differences were related to decreases in saturated fatty acids (SFA) and increases in omega-6 polyunsaturated fatty acids (PUFAs), monounsaturated fatty acids (MUFAs) and conjugated linolenic acid (CLA) concentrations. In addition several differences in gene expression patterns by microarray analysis between the control and in utero or in utero and during lactation HF exposed offspring were identified. Differential dependency network (DDN) analysis indicated that many of the genes exhibited unique connections to other genes only in the HF offspring. These unique connections included Hrh1-Ythdf1 and Repin1-Elavl2 in the in utero HF offspring, and Rnf213-Htr3b and Klf5-Chrna4 in the in utero and lactation HF offspring, compared with the control offspring. We conclude that an exposure to a lard-based HF diet during early life changes the fatty acid profile and transcriptional network in mammary gland in young adult rats, and these changes appear to be consistent with reduced mammary cancer risk observed in our previous study.
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Affiliation(s)
- Fábia de Oliveira Andrade
- Departament of Food and Experimental Nutrition, Faculty of Pharmaceutical Sciences, University of São Paulo, Av. Prof. Lineu Prestes 580, Bloco 14, 05508-900 São Paulo, SP, Brazil
| | - Sonia de Assis
- Department of Oncology, Georgetown University Lombardi Comprehensive Cancer Center, Research Building, Room E407, Georgetown University School of Medicine, 3970 Reservoir Road NW, Washington, DC 20007, USA
| | - Lu Jin
- Department of Oncology, Georgetown University Lombardi Comprehensive Cancer Center, Research Building, Room E407, Georgetown University School of Medicine, 3970 Reservoir Road NW, Washington, DC 20007, USA
| | - Camile Castilho Fontelles
- Departament of Food and Experimental Nutrition, Faculty of Pharmaceutical Sciences, University of São Paulo, Av. Prof. Lineu Prestes 580, Bloco 14, 05508-900 São Paulo, SP, Brazil
| | - Luís Fernando Barbisan
- Department of Morphology, Botucatu Bioscience Institute, State University of São Paulo Botucatu, Distrito de Rubião Júnior, s/n. Rubião Júnior, 18618000 Botucatu, SP, Brazil
| | - Eduardo Purgatto
- Departament of Food and Experimental Nutrition, Faculty of Pharmaceutical Sciences, University of São Paulo, Av. Prof. Lineu Prestes 580, Bloco 14, 05508-900 São Paulo, SP, Brazil
| | - Leena Hilakivi-Clarke
- Department of Oncology, Georgetown University Lombardi Comprehensive Cancer Center, Research Building, Room E407, Georgetown University School of Medicine, 3970 Reservoir Road NW, Washington, DC 20007, USA
| | - Thomas Prates Ong
- Departament of Food and Experimental Nutrition, Faculty of Pharmaceutical Sciences, University of São Paulo, Av. Prof. Lineu Prestes 580, Bloco 14, 05508-900 São Paulo, SP, Brazil; Food Research Center (NAPAN), Av. Prof. Lineu Prestes 580, Bloco 14, 05508-900 São Paulo, SP, Brazil.
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16
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Kern M, Kosacka J, Hesselbarth N, Brückner J, Heiker JT, Flehmig G, Klöting I, Kovacs P, Matz-Soja M, Gebhardt R, Krohn K, Sales S, Abshagen K, Shevchenko A, Stumvoll M, Blüher M, Klöting N. Liver-restricted Repin1 deficiency improves whole-body insulin sensitivity, alters lipid metabolism, and causes secondary changes in adipose tissue in mice. Diabetes 2014; 63:3295-309. [PMID: 24760138 DOI: 10.2337/db13-0933] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Replication initiator 1 (Repin1) is a zinc finger protein highly expressed in liver and adipose tissue and maps within a quantitative trait locus (QTL) for body weight and triglyceride (TG) levels in the rat. The QTL has further been supported as a susceptibility locus for dyslipidemia and related metabolic disorders in congenic and subcongenic rat strains. Here, we elucidated the role of Repin1 in lipid metabolism in vivo. We generated a liver-specific Repin1 knockout mouse (LRep1(-/-)) and systematically characterized the consequences of Repin1 deficiency in the liver on body weight, glucose and lipid metabolism, liver lipid patterns, and protein/mRNA expression. Hyperinsulinemic-euglycemic clamp studies revealed significantly improved whole-body insulin sensitivity in LRep1(-/-) mice, which may be due to significantly lower TG content in the liver. Repin1 deficiency causes significant changes in potential downstream target molecules including Cd36, Pparγ, Glut2 protein, Akt phosphorylation, and lipocalin2, Vamp4, and Snap23 mRNA expression. Mice with hepatic deletion of Repin1 display secondary changes in adipose tissue function, which may be mediated by altered hepatic expression of lipocalin2 or chemerin. Our findings indicate that Repin1 plays a role in insulin sensitivity and lipid metabolism by regulating key genes of glucose and lipid metabolism.
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Affiliation(s)
- Matthias Kern
- Department of Medicine, University of Leipzig, Leipzig, Germany
| | - Joanna Kosacka
- Department of Medicine, University of Leipzig, Leipzig, Germany
| | | | - Julia Brückner
- Department of Medicine, University of Leipzig, Leipzig, Germany
| | - John T Heiker
- Department of Medicine, University of Leipzig, Leipzig, Germany
| | - Gesine Flehmig
- IFB AdiposityDiseases, University of Leipzig, Leipzig, Germany
| | - Ingrid Klöting
- Department of Laboratory Animal Science, University of Greifswald, Karlsburg, Germany
| | - Peter Kovacs
- IFB AdiposityDiseases, University of Leipzig, Leipzig, Germany
| | - Madlen Matz-Soja
- Institute of Biochemistry, Medical Faculty, University of Leipzig, Leipzig, Germany
| | - Rolf Gebhardt
- Institute of Biochemistry, Medical Faculty, University of Leipzig, Leipzig, Germany
| | - Knut Krohn
- Interdisciplinary Center for Clinical Research, Core Unit DNA Technologies, University of Leipzig, Leipzig, Germany
| | - Susanne Sales
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Kerstin Abshagen
- Institute for Experimental Surgery, Rostock University Medical School, Rostock, Germany
| | - Andrej Shevchenko
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Michael Stumvoll
- Department of Medicine, University of Leipzig, Leipzig, Germany IFB AdiposityDiseases, University of Leipzig, Leipzig, Germany
| | - Matthias Blüher
- Department of Medicine, University of Leipzig, Leipzig, Germany IFB AdiposityDiseases, University of Leipzig, Leipzig, Germany
| | - Nora Klöting
- Department of Medicine, University of Leipzig, Leipzig, Germany IFB AdiposityDiseases, University of Leipzig, Leipzig, Germany
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Heiker JT, Klöting N. Replication initiator 1 in adipose tissue function and human obesity. VITAMINS AND HORMONES 2013; 91:97-105. [PMID: 23374714 DOI: 10.1016/b978-0-12-407766-9.00005-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Replication initiator 1 (Repin1) was discovered as the replication initiation-region protein 60kDa (RIP60) and characterized as a zinc finger protein involved in DNA binding and bending during initiation of DNA replication. As with many members of the zinc finger family, physiological functions and regulations of Repin1 as well as the underlying molecular mechanisms have remained elusive since its discovery in 1990. However, recent results have revealed interesting new insights into Repin1 function. Repin1 is highly expressed in liver and adipose tissue and it has been suggested as a candidate gene for obesity and related metabolic disorders in congenic and subcongenic rat strains. Repin1 seems to participate in the regulation of genes involved in adipogenesis, lipid droplet formation and fusion, as well as glucose and fatty acid transport in adipocytes. Given the observation that Repin1 expression in human adipose tissue significantly correlates with total body fat mass and adipocyte size, therapeutic strategies to reduce Repin1 action in adipose tissue may be a potential approach to tackle adipose tissue dysfunction in obesity. Thus, human and in vitro data suggest a role of Repin1 in adipocyte function and could therefore emerge as an interesting therapeutic target in human obesity.
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Affiliation(s)
- John T Heiker
- Department of Medicine, Endocrinology and Diabetes, Universität Leipzig, Leipzig, Germany.
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18
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Abstract
The factors that influence preadipocyte determination remain poorly understood. In the present paper, we report that CREBL2 [CREB (cAMP-response-element-binding protein)-like 2], a novel bZIP_1 protein, is up-regulated during MDI-induced preadipocyte differentiation. During both overexpression and under physiological conditions, CREBL2 interacted and was entirely co-localized with CREB. Overexpression of CREBL2 was sufficient to promote adipogenesis via up-regulating the expression of PPARγ (peroxisome-proliferator-activated receptor γ) and C/EBPα (CCAAT/enhancer-binding protein α) and accelerate lipogenesis accompanied with increased GLUT (glucose transporter) 1 and GLUT4. CREBL2 knockdown restrained adipogenic conversion and lipogenesis. Additionally, depletion of CREB could completely block the effects of overexpressed CREBL2, whereas an increase in CREB could not drive adipogenesis in the absence of CREBL2, indicating that the roles for CREBL2 on adipogenesis were CREB-dependent. Furthermore, siCREBL2 [siRNA (short interfering RNA) against CREBL2] could down-regulate CREB transcriptional activity and suppress CREB phosphorylation. CREB knockdown decreased the CREBL2 protein levels and vice versa. Collectively, the results of the present study indicate that CREBL2 plays a critical role in adipogenesis and lipogenesis via interaction with CREB.
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Semirale AA, Zhang XW, Wiren KM. Body composition changes and inhibition of fat development in vivo implicates androgen in regulation of stem cell lineage allocation. J Cell Biochem 2011; 112:1773-86. [PMID: 21381083 DOI: 10.1002/jcb.23098] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Androgens regulate body composition in youth and declining testosterone that occurs with aging is associated with muscle wasting, increased fat mass and osteopenia. Transgenic mice with targeted androgen receptor (AR) over-expression in mesenchymal stem cells (MSC) were generated to explore the role of androgen signaling in the regulation of body composition. Transgenic males, but not females, were shorter and have reduced body weight and visceral fat accumulation. Dual-energy X-ray absorptiometry (DXA) revealed significant reductions in fat mass with a reciprocal increase in lean mass, yet no difference in food consumption or locomotor activity was observed. Adipose tissue weight was normal in brown fat but reduced in both gonadal and perirenal depots, and reduced hyperplasia was observed with smaller adipocyte size in visceral and subcutaneous white adipose tissue. Although serum leptin, adiponectin, triglyceride, and insulin levels were no different between the genotypes, intraperitoneal glucose tolerance testing (IPGTT) showed improved glucose clearance in transgenic males. High levels of the AR transgene are detected in MSCs but not in mature fat tissue. Reduced fibroblast colony forming units indicate fewer progenitor cells resident in the marrow in vivo. Precocious expression of glucose transporter 4 (GLUT4), peroxisome proliferator-activated receptor γ (PPARγ), and CCAAT enhancer-binding protein α (C/EBPα) was observed in proliferating precursor cultures from transgenic mice compared to controls. In more mature cultures, there was little difference between the genotypes. We propose a mechanism where enhanced androgen sensitivity can alter lineage commitment in vivo to reduce progenitor number and fat development, while increasing the expression of key factors to promote smaller adipocytes with improved glucose clearance.
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Affiliation(s)
- Anthony A Semirale
- Research Service, Veterans Affairs Medical Center, Portland, Oregon 97239, USA
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20
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Bahr J, Klöting N, Klöting I, Follak N. Gene expression profiling supports the role of Repin1 in the pathophysiology of metabolic syndrome. Endocrine 2011; 40:310-4. [PMID: 21701954 DOI: 10.1007/s12020-011-9497-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2011] [Accepted: 05/30/2011] [Indexed: 01/09/2023]
Abstract
Congenic BB rat strains carrying a SHR segment (D4Got41-Tacr1; 60.5-122.8 Mb; BB.4S) or a WOKW segment (D4Got41-Fabp1; 60.5-104.6 Mb; BB.4W) of chromosome 4 within the BB/OK background develop facets of the metabolic syndrome when compared with their parental BB/OK rats. To narrow down potential genes involved in the pathophysiology of metabolic syndrome, gene expression studies in adipose tissues of BB/OK, BB.4S, and BB.4W rats were initiated. Total RNA of subcutaneous and epididymal adipose tissue of BB/OK (n=10), congenic BB.4S (n=8), and BB.4W (n=9) males at an age of 4 weeks was isolated. The mRNA expression of 92 genes involved in obesity, insulin resistance and other metabolic traits was measured by RT-PCR. Significant differences in gene expression were only found in Repin1 in both adipose tissues. Congenic BB.4W showed significantly lower gene expression than did BB.4S and BB/OK. Our findings and newly published findings of Repin1 in 3T3-L1 adipocytes support the hypothesis that Repin1 may affect the development of facets of the metabolic syndrome.
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Bahr J, Klöting N, Wilke B, Klöting I, Follak N. High-fat diet protects BB/OK rats from developing type 1 diabetes. Diabetes Metab Res Rev 2011; 27:552-6. [PMID: 21523881 DOI: 10.1002/dmrr.1207] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
BACKGROUND It is well known that lipid metabolism plays an important role in the early stages of type 1 diabetes (T1D). For that reason, we examined factors that influence lipid metabolism of BioBreeding/Ottawa Kalsburg (BB/OK) rats that spontaneously develop an insulin-dependent T1D. METHODS BB/OK female rats were fed a high-fat diet during pregnancy (Ssniff R-Z + 10% tallow) and their progeny were also given this diet up to an age of 30 weeks (n = 55) or 4 weeks (n = 14) to study gene expression of Pparg, Fasn, Lep, Adipoq, Repin1, Rarres 2, and Glut4 in adipose tissue. Forty-two BB/OK rats fed the normal diet (Ssniff R-Z) during pregnancy and the observation period served as controls. RESULTS The high-fat diet significantly decreased diabetes frequency in BB/OK rats when compared with control rats (71 versus 95%, p = 0.002). Although this difference was also reflected in the male rats (68 versus 100%, p = 0.003), no significant variation was observed in female rats (73 versus 90%, p = 0.23). The high-fat diet resulted in significantly reduced mRNA expression of examined genes in subcutaneous adipose tissue, but not in visceral adipose tissue, except for Fasn and Repin1 expression. CONCLUSIONS A high-fat diet seems to protect BB/OK rats from T1D in a sex-specific manner. The data suggest that a high-fat diet might influence fat accumulation and/or fat metabolism and prevent T1D development in male rats, which is supported by changes in adipose tissue gene expression.
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Affiliation(s)
- Jeanette Bahr
- Department of Laboratory Animal Science, Medical Faculty, University of Greifswald, Karlsburg, Germany
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