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Janssen AWF, Katiraei S, Bartosinska B, Eberhard D, Willems van Dijk K, Kersten S. Loss of angiopoietin-like 4 (ANGPTL4) in mice with diet-induced obesity uncouples visceral obesity from glucose intolerance partly via the gut microbiota. Diabetologia 2018; 61:1447-1458. [PMID: 29502266 PMCID: PMC6449003 DOI: 10.1007/s00125-018-4583-5] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2017] [Accepted: 01/22/2018] [Indexed: 02/07/2023]
Abstract
AIMS/HYPOTHESIS Angiopoietin-like 4 (ANGPTL4) is an important regulator of triacylglycerol metabolism, carrying out this role by inhibiting the enzymes lipoprotein lipase and pancreatic lipase. ANGPTL4 is a potential target for ameliorating cardiometabolic diseases. Although ANGPTL4 has been implicated in obesity, the study of the direct role of ANGPTL4 in diet-induced obesity and related metabolic dysfunction is hampered by the massive acute-phase response and development of lethal chylous ascites and peritonitis in Angptl4-/- mice fed a standard high-fat diet. The aim of this study was to better characterise the role of ANGPTL4 in glucose homeostasis and metabolic dysfunction during obesity. METHODS We chronically fed wild-type (WT) and Angptl4-/- mice a diet rich in unsaturated fatty acids and cholesterol, combined with fructose in drinking water, and studied metabolic function. The role of the gut microbiota was investigated by orally administering a mixture of antibiotics (ampicillin, neomycin, metronidazole). Glucose homeostasis was assessed via i.p. glucose and insulin tolerance tests. RESULTS Mice lacking ANGPTL4 displayed an increase in body weight gain, visceral adipose tissue mass, visceral adipose tissue lipoprotein lipase activity and visceral adipose tissue inflammation compared with WT mice. However, they also unexpectedly had markedly improved glucose tolerance, which was accompanied by elevated insulin levels. Loss of ANGPTL4 did not affect glucose-stimulated insulin secretion in isolated pancreatic islets. Since the gut microbiota have been suggested to influence insulin secretion, and because ANGPTL4 has been proposed to link the gut microbiota to host metabolism, we hypothesised a potential role of the gut microbiota. Gut microbiota composition was significantly different between Angptl4-/- mice and WT mice. Interestingly, suppression of the gut microbiota using antibiotics largely abolished the differences in glucose tolerance and insulin levels between WT and Angptl4-/- mice. CONCLUSIONS/INTERPRETATION Despite increasing visceral fat mass, inactivation of ANGPTL4 improves glucose tolerance, at least partly via a gut microbiota-dependent mechanism.
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Affiliation(s)
- Aafke W F Janssen
- Nutrition, Metabolism and Genomics Group, Division of Human Nutrition and Health, Wageningen University, Stippeneng 4, 6708 WE, Wageningen, the Netherlands
| | - Saeed Katiraei
- Department of Human Genetics, Leiden University Medical Center, Leiden, the Netherlands
- Einthoven Laboratory for Experimental Vascular Medicine, Leiden University Medical Center, Leiden, the Netherlands
| | - Barbara Bartosinska
- Institute of Metabolic Physiology, Department of Biology, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
- Institute for Beta Cell Biology, German Diabetes Center, Leibniz Center for Diabetes Research, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
- German Center for Diabetes Research (DZD), München Neuherberg, Germany
| | - Daniel Eberhard
- Institute of Metabolic Physiology, Department of Biology, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
- Institute for Beta Cell Biology, German Diabetes Center, Leibniz Center for Diabetes Research, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
- German Center for Diabetes Research (DZD), München Neuherberg, Germany
| | - Ko Willems van Dijk
- Department of Human Genetics, Leiden University Medical Center, Leiden, the Netherlands
- Einthoven Laboratory for Experimental Vascular Medicine, Leiden University Medical Center, Leiden, the Netherlands
- Division of Endocrinology, Department of Medicine, Leiden University Medical Center, Leiden, the Netherlands
| | - Sander Kersten
- Nutrition, Metabolism and Genomics Group, Division of Human Nutrition and Health, Wageningen University, Stippeneng 4, 6708 WE, Wageningen, the Netherlands.
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52
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Acosta-Montaño P, García-González V. Effects of Dietary Fatty Acids in Pancreatic Beta Cell Metabolism, Implications in Homeostasis. Nutrients 2018; 10:nu10040393. [PMID: 29565831 PMCID: PMC5946178 DOI: 10.3390/nu10040393] [Citation(s) in RCA: 76] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Revised: 03/02/2018] [Accepted: 03/13/2018] [Indexed: 12/26/2022] Open
Abstract
Fatty acids are involved in several metabolic processes, including the development of metabolic and cardiovascular diseases. In recent years a disease that has received escalated interest is type 2 diabetes (T2D). Many contributing factors including a high-caloric diet rich in dietary saturated fats have been broadly characterized as triggers of T2D. Insulin resistance resulting from a high saturated fat diet leads to alterations in lipid cellular intake and accumulation which generate lipotoxic conditions, a key phenomenon in the metabolism of β-cells. Alternatively, unsaturated fatty acids have been described to show opposite effects in pancreatic β-cells. The purpose of this work is to perform a critical analysis of the complex role of saturated and unsaturated fatty acids in β-cell metabolism. We discuss the diverse effects main dietary fatty acids have upon pancreatic β-cell metabolism as a key factor to maintain homeostasis by focusing in the cellular and molecular mechanisms involved in the development and progression of T2D. For instance, modifications in protein homeostasis as well as the intracellular management of lipid metabolism which are associated with inflammatory pathways. These conditions initiate critical metabolic rearrangements, that in turn have repercussions on insulin β-cell metabolism. This review allows an integral and broad understanding of different functions of fatty acids inside β-cells, being important metabolites for novel therapeutic targets in T2D treatment.
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Affiliation(s)
- Paloma Acosta-Montaño
- Departamento de Bioquímica, Facultad de Medicina Mexicali, Universidad Autónoma de Baja California, Mexicali 21000, Mexico.
| | - Víctor García-González
- Departamento de Bioquímica, Facultad de Medicina Mexicali, Universidad Autónoma de Baja California, Mexicali 21000, Mexico.
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53
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He W, Yuan T, Choezom D, Hunkler H, Annamalai K, Lupse B, Maedler K. Ageing potentiates diet-induced glucose intolerance, β-cell failure and tissue inflammation through TLR4. Sci Rep 2018; 8:2767. [PMID: 29426925 PMCID: PMC5807311 DOI: 10.1038/s41598-018-20909-w] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Accepted: 01/25/2018] [Indexed: 12/25/2022] Open
Abstract
Ageing and obesity are two major risk factors for the development of type 2 diabetes (T2D). A chronic, low-grade, sterile inflammation contributes to insulin resistance and β-cell failure. Toll-like receptor-4 (TLR4) is a major pro-inflammatory pathway; its ligands as well as downstream signals are increased systemically in patients with T2D and at-risk individuals. In the present study we investigated the combined effects of high fat/high sucrose diet (HFD) feeding, ageing and TLR4-deficiency on tissue inflammation, insulin resistance and β-cell failure. In young mice, a short-term HFD resulted in a mildly impaired glucose tolerance and reduced insulin secretion, together with a β-cell mass compensation. In older mice, HFD further deteriorated insulin secretion and induced a significantly impaired glucose tolerance and augmented tissue inflammation in adipose, liver and pancreatic islets, all of which was attenuated by TLR4 deficiency. Our results show that ageing exacerbates HFD-induced impairment of glucose homeostasis and pancreatic β-cell function and survival, and deteriorates HFD-induced induction of mRNA expression of inflammatory cytokines and pro-inflammatory macrophage markers. TLR4-deficiency protects against these combined deleterious effects of a high fat diet and ageing through a reduced expression of inflammatory products in both insulin sensitive tissues and pancreatic islets.
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Affiliation(s)
- Wei He
- Centre for Biomolecular Interactions, University of Bremen, Bremen, Germany.
| | - Ting Yuan
- Centre for Biomolecular Interactions, University of Bremen, Bremen, Germany
| | - Dolma Choezom
- Centre for Biomolecular Interactions, University of Bremen, Bremen, Germany
| | - Hannah Hunkler
- Centre for Biomolecular Interactions, University of Bremen, Bremen, Germany
| | - Karthika Annamalai
- Centre for Biomolecular Interactions, University of Bremen, Bremen, Germany
| | - Blaz Lupse
- Centre for Biomolecular Interactions, University of Bremen, Bremen, Germany
| | - Kathrin Maedler
- Centre for Biomolecular Interactions, University of Bremen, Bremen, Germany.
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54
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Gut Microbiota-Immune System Crosstalk and Pancreatic Disorders. Mediators Inflamm 2018; 2018:7946431. [PMID: 29563853 PMCID: PMC5833470 DOI: 10.1155/2018/7946431] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Revised: 12/05/2017] [Accepted: 12/18/2017] [Indexed: 12/15/2022] Open
Abstract
Gut microbiota is key to the development and modulation of the mucosal immune system. It plays a central role in several physiological functions, in the modulation of inflammatory signaling and in the protection against infections. In healthy states, there is a perfect balance between commensal and pathogens, and microbiota and the immune system interact to maintain gut homeostasis. The alteration of such balance, called dysbiosis, determines an intestinal bacterial overgrowth which leads to the disruption of the intestinal barrier with systemic translocation of pathogens. The pancreas does not possess its own microbiota, and it is believed that inflammatory and neoplastic processes affecting the gland may be linked to intestinal dysbiosis. Increasing research evidence testifies a correlation between intestinal dysbiosis and various pancreatic disorders, but it remains unclear whether dysbiosis is the cause or an effect. The analysis of specific alterations in the microbiome profile may permit to develop novel tools for the early detection of several pancreatic disorders, utilizing samples, such as blood, saliva, and stools. Future studies will have to elucidate the mechanisms by which gut microbiota is modulated and how it tunes the immune system, in order to be able to develop innovative treatment strategies for pancreatic disorders.
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55
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Kreznar JH, Keller MP, Traeger LL, Rabaglia ME, Schueler KL, Stapleton DS, Zhao W, Vivas EI, Yandell BS, Broman AT, Hagenbuch B, Attie AD, Rey FE. Host Genotype and Gut Microbiome Modulate Insulin Secretion and Diet-Induced Metabolic Phenotypes. Cell Rep 2017; 18:1739-1750. [PMID: 28199845 DOI: 10.1016/j.celrep.2017.01.062] [Citation(s) in RCA: 121] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Revised: 12/09/2016] [Accepted: 01/24/2017] [Indexed: 12/14/2022] Open
Abstract
Genetic variation drives phenotypic diversity and influences the predisposition to metabolic disease. Here, we characterize the metabolic phenotypes of eight genetically distinct inbred mouse strains in response to a high-fat/high-sucrose diet. We found significant variation in diabetes-related phenotypes and gut microbiota composition among the different mouse strains in response to the dietary challenge and identified taxa associated with these traits. Follow-up microbiota transplant experiments showed that altering the composition of the gut microbiota modifies strain-specific susceptibility to diet-induced metabolic disease. Animals harboring microbial communities with enhanced capacity for processing dietary sugars and for generating hydrophobic bile acids showed increased susceptibility to metabolic disease. Notably, differences in glucose-stimulated insulin secretion between different mouse strains were partially recapitulated via gut microbiota transfer. Our results suggest that the gut microbiome contributes to the genetic and phenotypic diversity observed among mouse strains and provide a link between the gut microbiome and insulin secretion.
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Affiliation(s)
- Julia H Kreznar
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Mark P Keller
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Lindsay L Traeger
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Mary E Rabaglia
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Kathryn L Schueler
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Donald S Stapleton
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Wen Zhao
- Department of Biostatistics and Medical Informatics, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Eugenio I Vivas
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Brian S Yandell
- Department of Statistics, University of Wisconsin-Madison, Madison, WI 53706, USA; Department of Horticulture, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Aimee Teo Broman
- Department of Biostatistics and Medical Informatics, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Bruno Hagenbuch
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas, Kansas City, KS 66160, USA
| | - Alan D Attie
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA.
| | - Federico E Rey
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI 53706, USA.
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56
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Huang XT, Yue SJ, Li C, Huang YH, Cheng QM, Li XH, Hao CX, Wang LZ, Xu JP, Ji M, Chen C, Feng DD, Luo ZQ. A Sustained Activation of Pancreatic NMDARs Is a Novel Factor of β-Cell Apoptosis and Dysfunction. Endocrinology 2017; 158:3900-3913. [PMID: 28938426 DOI: 10.1210/en.2017-00366] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Accepted: 08/30/2017] [Indexed: 02/07/2023]
Abstract
Type 2 diabetes, which features β-cell failure, is caused by the decrease of β-cell mass and insulin secretory function. Current treatments fail to halt the decrease of functional β-cell mass. Strategies to prevent β-cell apoptosis and dysfunction are highly desirable. Recently, our group and others have reported that blockade of N-methyl-d-aspartate receptors (NMDARs) in the islets has been proposed to prevent the progress of type 2 diabetes through improving β-cell function. It suggests that a sustained activation of the NMDARs may exhibit deleterious effect on β-cells. However, the exact functional impact and mechanism of the sustained NMDAR stimulation on islet β-cells remains unclear. Here, we identify a sustained activation of pancreatic NMDARs as a novel factor of apoptotic β-cell death and function. The sustained treatment with NMDA results in an increase of intracellular [Ca2+] and reactive oxygen species, subsequently induces mitochondrial membrane potential depolarization and a decrease of oxidative phosphorylation expression, and then impairs the mitochondrial function of β-cells. NMDA specifically induces the mitochondrial-dependent pathway of apoptosis in β-cells through upregulation of the proapoptotic Bim and Bax, and downregulation of antiapoptotic Bcl-2. Furthermore, a sustained stimulation of NMDARs impairs β-cell insulin secretion through decrease of pancreatic duodenal homeobox-1 (Pdx-1) and adenosine triphosphate synthesis. The activation of nuclear factor-κB partly contributes to the reduction of Pdx-1 expression induced by overstimulation of NMDARs. In conclusion, we show that the sustained stimulation of NMDARs is a novel mediator of apoptotic signaling and β-cell dysfunction, providing a mechanistic insight into the pathological role of NMDARs activation in diabetes.
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Affiliation(s)
- Xiao-Ting Huang
- Department of Physiology, Xiangya School of Medicine, Central South University, Changsha, Hunan 410078, China
| | - Shao-Jie Yue
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, Hunan 410078, China
| | - Chen Li
- Department of Physiology, Changzhi Medical College, Changzhi, Shanxi 046000, China
| | - Yan-Hong Huang
- Department of Physiology, Xiangya School of Medicine, Central South University, Changsha, Hunan 410078, China
| | - Qing-Mei Cheng
- Department of Physiology, Xiangya School of Medicine, Central South University, Changsha, Hunan 410078, China
| | - Xiao-Hong Li
- Department of Physiology, Xiangya School of Medicine, Central South University, Changsha, Hunan 410078, China
| | - Cai-Xia Hao
- Department of Physiology, Xiangya School of Medicine, Central South University, Changsha, Hunan 410078, China
| | - Ling-Zhi Wang
- Department of Physiology, Xiangya School of Medicine, Central South University, Changsha, Hunan 410078, China
| | - Jian-Ping Xu
- Department of Physiology, Xiangya School of Medicine, Central South University, Changsha, Hunan 410078, China
| | - Ming Ji
- Department of Physiology, Xiangya School of Medicine, Central South University, Changsha, Hunan 410078, China
| | - Chen Chen
- School of Biomedical Sciences, the University of Queensland, Brisbane 999029, Australia
| | - Dan-Dan Feng
- Department of Physiology, Xiangya School of Medicine, Central South University, Changsha, Hunan 410078, China
| | - Zi-Qiang Luo
- Department of Physiology, Xiangya School of Medicine, Central South University, Changsha, Hunan 410078, China
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57
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Jouvet N, Estall JL. The pancreas: Bandmaster of glucose homeostasis. Exp Cell Res 2017; 360:19-23. [DOI: 10.1016/j.yexcr.2017.03.050] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2017] [Revised: 03/21/2017] [Accepted: 03/23/2017] [Indexed: 01/02/2023]
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58
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Gond DP, Singh S, Agrawal NK. Testing an association between TLR4 and CXCR1 gene polymorphisms with susceptibility to urinary tract infection in type 2 diabetes in north Indian population. Gene 2017; 641:196-202. [PMID: 29066305 DOI: 10.1016/j.gene.2017.10.060] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2017] [Revised: 10/18/2017] [Accepted: 10/20/2017] [Indexed: 12/21/2022]
Abstract
BACKGROUND Genetic variations of Toll like receptor 4 (TLR4) and CXC-chemokine receptor type1 (CXCR1), the key elements of innate immune system and their association with urinary tract infection (UTI) were studied in general population. In present study we investigate genetic variation of these genes in diabetic patients (3 to 4 times higher prevalence of UTI in comparison to general population). METHODS A total 1100 subjects (318 diabetic patients with UTI, 324 diabetic patients without UTI, 200 non-diabetic UTI patients and 260 age matched healthy control) were enrolled in the study. SNPs of TLR4 rs4986790, rs4986791 and CXCR1 rs2234671 was assessed by PCR-RFLP and PCR-SSP respectively. RESULTS Statistical analysis revealed that A/G genotype and G allele of TLR4 rs4986790 are significantly associated with UTI in both diabetics and nondiabetic patients in comparison to healthy control. Similarly CT genotype and T allele of TLR4 rs4986791 are also significantly associated with UTI in both groups. We also found that prevalence of A/G genotype of TLR4 rs4986790 and CT genotype of TLR4 rs4986791 are significantly higher in patients of diabetes with UTI in comparison to diabetic patients without UTI. We did not find any association of CXCR1 rs2234671 polymorphism with UTI by comparing with any group. CONCLUSION We found that TLR4 rs4986790 and rs4986791 gene polymorphism is a risk for UTI development in both diabetic and nondiabetic patients in north Indian population.
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Affiliation(s)
- Dinesh Prasad Gond
- Department of Endocrinology and Metabolism, Institute of Medical Sciences, Banaras Hindu University, Varanasi, India
| | - Shivendra Singh
- Department of Nephrology, Institute of Medical Sciences, Banaras Hindu University, Varanasi, India
| | - N K Agrawal
- Department of Endocrinology and Metabolism, Institute of Medical Sciences, Banaras Hindu University, Varanasi, India.
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59
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Subramanian VS, Sabui S, Moradi H, Marchant JS, Said HM. Inhibition of intestinal ascorbic acid uptake by lipopolysaccharide is mediated via transcriptional mechanisms. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2017; 1860:556-565. [PMID: 29030247 DOI: 10.1016/j.bbamem.2017.10.010] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Revised: 09/14/2017] [Accepted: 10/08/2017] [Indexed: 12/28/2022]
Abstract
Ascorbic acid (AA) accumulation in intestinal epithelial cells is an active transport process mainly mediated by two sodium-dependent vitamin C transporters (SVCT-1 and SVCT-2). To date, little is known about the effect of gut microbiota generated lipopolysaccharide (LPS) on intestinal absorption of water-soluble vitamins. Therefore, the objective of this study was to investigate the effects of bacterially-derived LPS on AA homeostasis in enterocytes using Caco-2 cells, mouse intestine and intestinal enteroids models. Pre-treating Caco-2 cells and mice with LPS led to a significant decrease in carrier-mediated AA uptake. This inhibition was associated with a significant reduction in SVCT-1 and SVCT-2 protein, mRNA, and hnRNA expression. Furthermore, pre-treating enteroids with LPS also led to a marked decrease in SVCT-1 and SVCT-2 protein and mRNA expression. Inhibition of SVCT-1 and SVCT-2 occurred at least in part at the transcriptional level as promoter activity of SLC23A1 and SLC23A2 was attenuated following LPS treatment. Subsequently, we examined the protein and mRNA expression levels of HNF1α and Sp1 transcription factors, which are needed for basal SLC23A1 and SLC23A2 promoter activity, and found that they were significantly decreased in the LPS treated Caco-2 cells and mouse jejunum; this was reflected on level of the observed reduction in the interaction of these transcription factors with their respective promoters in Caco-2 cells treated with LPS. Our findings indicate that LPS inhibits intestinal carrier- mediated AA uptake by down regulating the expression of both vitamin C transporters and transcriptional regulation of SLC23A1 and SLC23A2 genes.
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Affiliation(s)
- Veedamali S Subramanian
- Departments of Medicine, Physiology and Biophysics, University of California, Irvine, CA 92697, United States; Department of Veterans Affairs Medical Center, Long Beach, CA 90822, United States.
| | - Subrata Sabui
- Departments of Medicine, Physiology and Biophysics, University of California, Irvine, CA 92697, United States; Department of Veterans Affairs Medical Center, Long Beach, CA 90822, United States
| | - Hamid Moradi
- Departments of Medicine, Physiology and Biophysics, University of California, Irvine, CA 92697, United States; Department of Veterans Affairs Medical Center, Long Beach, CA 90822, United States
| | - Jonathan S Marchant
- Department of Pharmacology, University of Minnesota Medical School, MN 55455, United States
| | - Hamid M Said
- Departments of Medicine, Physiology and Biophysics, University of California, Irvine, CA 92697, United States; Department of Veterans Affairs Medical Center, Long Beach, CA 90822, United States
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60
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Levet S, Medina J, Joanou J, Demolder A, Queruel N, Réant K, Normand M, Seffals M, Dimier J, Germi R, Piofczyk T, Portoukalian J, Touraine JL, Perron H. An ancestral retroviral protein identified as a therapeutic target in type-1 diabetes. JCI Insight 2017; 2:94387. [PMID: 28878130 DOI: 10.1172/jci.insight.94387] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2017] [Accepted: 07/25/2017] [Indexed: 12/16/2022] Open
Abstract
Human endogenous retroviruses (HERVs), remnants of ancestral viral genomic insertions, are known to represent 8% of the human genome and are associated with several pathologies. In particular, the envelope protein of HERV-W family (HERV-W-Env) has been involved in multiple sclerosis pathogenesis. Investigations to detect HERV-W-Env in a few other autoimmune diseases were negative, except in type-1 diabetes (T1D). In patients suffering from T1D, HERV-W-Env protein was detected in 70% of sera, and its corresponding RNA was detected in 57% of peripheral blood mononuclear cells. While studies on human Langerhans islets evidenced the inhibition of insulin secretion by HERV-W-Env, this endogenous protein was found to be expressed by acinar cells in 75% of human T1D pancreata. An extensive immunohistological analysis further revealed a significant correlation between HERV-W-Env expression and macrophage infiltrates in the exocrine part of human pancreata. Such findings were corroborated by in vivo studies on transgenic mice expressing HERV-W-env gene, which displayed hyperglycemia and decreased levels of insulin, along with immune cell infiltrates in their pancreas. Altogether, these results strongly suggest an involvement of HERV-W-Env in T1D pathogenesis. They also provide potentially novel therapeutic perspectives, since unveiling a pathogenic target in T1D.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Julie Dimier
- IBS, UMR 5075 CEA-CNRS-Université Grenoble-Alpes, Grenoble, France
| | - Raphaële Germi
- IBS, UMR 5075 CEA-CNRS-Université Grenoble-Alpes, Grenoble, France.,Department of Virology, Grenoble University Hospital, Grenoble, France
| | | | | | | | - Hervé Perron
- GeNeuro Innovation, Lyon, France.,Laboratoire des déficits immunitaires, University of Lyon, France.,GeNeuro SA, Plan-les-Ouates, Geneva, Switzerland
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61
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Abstract
BACKGROUND Environmental and lifestyle changes, in addition to the ageing of populations, are generally believed to account for the rapid global increase in type 2 diabetes prevalence and incidence in recent decades. DISCUSSION In this review, we present a comprehensive overview of factors contributing to diabetes risk, including aspects of diet quality and quantity, little physical activity, increased monitor viewing time or sitting in general, exposure to noise or fine dust, short or disturbed sleep, smoking, stress and depression, and a low socioeconomic status. In general, these factors promote an increase in body mass index. Since loss of β-cell function is the ultimate cause of developing overt type 2 diabetes, environmental and lifestyle changes must have resulted in a higher risk of β-cell damage in those at genetic risk. Multiple mechanistic pathways may come into play. CONCLUSIONS Strategies of diabetes prevention should aim at promoting a 'diabetes-protective lifestyle' whilst simultaneously enhancing the resistance of the human organism to pro-diabetic environmental and lifestyle factors. More research on diabetes-protective mechanisms seems warranted.
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62
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Kolb H, Martin S. Environmental/lifestyle factors in the pathogenesis and prevention of type 2 diabetes. BMC Med 2017; 15:131. [PMID: 28720102 PMCID: PMC5516328 DOI: 10.1186/s12916-017-0901-x] [Citation(s) in RCA: 352] [Impact Index Per Article: 50.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Accepted: 06/23/2017] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Environmental and lifestyle changes, in addition to the ageing of populations, are generally believed to account for the rapid global increase in type 2 diabetes prevalence and incidence in recent decades. DISCUSSION In this review, we present a comprehensive overview of factors contributing to diabetes risk, including aspects of diet quality and quantity, little physical activity, increased monitor viewing time or sitting in general, exposure to noise or fine dust, short or disturbed sleep, smoking, stress and depression, and a low socioeconomic status. In general, these factors promote an increase in body mass index. Since loss of β-cell function is the ultimate cause of developing overt type 2 diabetes, environmental and lifestyle changes must have resulted in a higher risk of β-cell damage in those at genetic risk. Multiple mechanistic pathways may come into play. CONCLUSIONS Strategies of diabetes prevention should aim at promoting a 'diabetes-protective lifestyle' whilst simultaneously enhancing the resistance of the human organism to pro-diabetic environmental and lifestyle factors. More research on diabetes-protective mechanisms seems warranted.
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Affiliation(s)
- Hubert Kolb
- Faculty of Medicine, University of Duesseldorf, Duesseldorf, Germany. .,West-German Centre of Diabetes and Health, Duesseldorf Catholic Hospital Group, Hohensandweg 37, 40591, Duesseldorf, Germany.
| | - Stephan Martin
- Faculty of Medicine, University of Duesseldorf, Duesseldorf, Germany.,West-German Centre of Diabetes and Health, Duesseldorf Catholic Hospital Group, Hohensandweg 37, 40591, Duesseldorf, Germany
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63
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Crovesy L, Ostrowski M, Ferreira DMTP, Rosado EL, Soares-Mota M. Effect of Lactobacillus on body weight and body fat in overweight subjects: a systematic review of randomized controlled clinical trials. Int J Obes (Lond) 2017; 41:1607-1614. [PMID: 28792488 DOI: 10.1038/ijo.2017.161] [Citation(s) in RCA: 130] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Revised: 06/01/2017] [Accepted: 06/25/2017] [Indexed: 12/14/2022]
Abstract
Gut microbiota is important for maintaining body weight. Modulation of gut microbiota by probiotics may result in weight loss and thus help in obesity treatment. The aim of this systematic review was to evaluate the effects of Lactobacillus on weight loss and/or fat mass in overweight adults. A search was performed on the Medline (PubMed) and Scopus electronic databases using the search terms: 'probiotics', 'Lactobacillus, 'obesity', 'body weight changes', 'weight loss', 'overweight', 'abdominal obesity', 'body composition', 'body weight', 'body fat' and 'fat mass'. In the total were found 1567 articles, but only 14 were included in this systematic review. Of these nine showed decreased body weight and/or body fat, three did not find effect and two showed weight gain. Results suggest that the beneficial effects are strain dependent. It can highlight that Lactobacillus plantarum and Lactobacillus rhamnosus when combined with a hypocaloric diet, L. plantarum with Lactobacillus curvatus, Lactobacillus gasseri, Lactobacillus amylovorus, Lactobacillus acidophilus and Lactobacillus casei with phenolic compounds, and multiple species of Lactobacillus.
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Affiliation(s)
- L Crovesy
- Institute of Nutrition Josué de Castro, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - M Ostrowski
- Institute of Nutrition Josué de Castro, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - D M T P Ferreira
- Library of Health Sciences Center, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - E L Rosado
- Institute of Nutrition Josué de Castro, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - M Soares-Mota
- Institute of Nutrition Josué de Castro, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
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64
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Zou R, Xue J, Huang Q, Dai Z, Xu Y. Involvement of receptor-interacting protein 140 in palmitate-stimulated macrophage infiltration of pancreatic beta cells. Exp Ther Med 2017; 14:483-494. [PMID: 28672957 PMCID: PMC5488400 DOI: 10.3892/etm.2017.4544] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Accepted: 01/06/2017] [Indexed: 02/06/2023] Open
Abstract
Receptor-interacting protein 140 (RIP140) in macrophages stimulates the nuclear factor-κB subunit RelA to activate tumor necrosis factor (TNF)-α and interleukin (IL)-6 transcription. However, under lipotoxic conditions, the involvement of RIP140 in the infiltration of beta cells by macrophages remains unknown. In the present study, murine RAW264.7 macrophages were transfected with a RIP140 overexpression plasmid or siRNA prior to macrophage activation with 500 µM palmitate. Palmitate-free conditioned media was then collected and added to murine insulinoma MIN6 cells. Significant decreases were observed in cell viability (P<0.01), glucose-stimulated insulin secretion (P<0.01) and levels of peroxisome proliferator-activated receptor-γ coactivator-1α (P<0.05), phosphoenolpyruvate carboxykinase and proliferating cell nuclear antigen mRNA (P<0.01) in MIN6 cells. In addition, conditioned media from palmitate-treated and RIP140-upregulated macrophages significantly increased the levels of uncoupling protein-2 (P<0.01), inducible nitric oxide synthase 1 (P<0.01) and pancreatic and duodenal homeobox 1 (P<0.05) mRNA and levels of activated Jun N-terminal kinase (JNK) (P<0.01) and extracellular signal-regulated kinase (ERK) 1/2 (P<0.01). In turn, the conditioned media was found to be significantly enriched in TNF-α and IL-6 (both P<0.05). These results were the opposite of those obtained from MIN6 cells treated with conditioned media from palmitate-treated and RIP140-knockdown macrophages. MIN6 cells were transfected with RIP140 overexpression plasmid or siRNA prior to treatment with 500 µM palmitate and supernatant was collected for use in macrophage chemotaxis assays. In the palmitate-activated and RIP140-overexpressing MIN6 cells, TNF-α and IL-6 secretion increased significantly (both P<0.05) and macrophage chemotaxis towards MIN6 cells was enhanced. By contrast, downregulating RIP140 in MIN6 cells had the opposite effect. These data suggest that RIP140 in macrophages mediates the transcription of inflammatory cytokines when concentration of palmitate is high. Macrophage RIP140 may also impair beta cell function by activating the JNK and ERK1/2 signaling pathways and promoting specific gene transcription. Furthermore, expression of RIP140 in pancreatic beta cells may stimulate macrophage chemotaxis, thus triggering local low-grade inflammation.
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Affiliation(s)
- Runmei Zou
- Department of Endocrinology, Zhongnan Hospital of Wuhan University, Wuhan, Hubei 430071, P.R. China.,Children's Medical Center, The Second Xiangya Hospital of Central South University, Changsha, Hunan 410011, P.R. China
| | - Junli Xue
- Department of Endocrinology, Zhongnan Hospital of Wuhan University, Wuhan, Hubei 430071, P.R. China
| | - Qi Huang
- Department of Endocrinology, Zhongnan Hospital of Wuhan University, Wuhan, Hubei 430071, P.R. China
| | - Zhe Dai
- Department of Endocrinology, Zhongnan Hospital of Wuhan University, Wuhan, Hubei 430071, P.R. China
| | - Yancheng Xu
- Department of Endocrinology, Zhongnan Hospital of Wuhan University, Wuhan, Hubei 430071, P.R. China
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65
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Jandhyala SM, Madhulika A, Deepika G, Rao GV, Reddy DN, Subramanyam C, Sasikala M, Talukdar R. Altered intestinal microbiota in patients with chronic pancreatitis: implications in diabetes and metabolic abnormalities. Sci Rep 2017; 7:43640. [PMID: 28255158 PMCID: PMC5334648 DOI: 10.1038/srep43640] [Citation(s) in RCA: 76] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Accepted: 01/26/2017] [Indexed: 11/09/2022] Open
Abstract
Intestinal dysbiosis and its functional implications in chronic pancreatitis (CP) have not been elaborately studied. We evaluated the taxonomic and functional alterations in intestinal microbiota in 30 well-characterised patients with CP (16 without, 14 with diabetes) and 10 healthy controls. The patients with CP and diabetes had significantly longer disease duration and greater degree of malnutrition. There was increase in plasma endotoxin concentrations from controls to CP non-diabetics to CP diabetics. We observed significant differences in richness and alpha diversity between the groups. We also observed increase in the Firmicutes:Bacteroidetes ratio in CP patients without and with diabetes. There was reduction in abundance of Faecalibacterium prausnitzii and Ruminococcus bromii from controls to CP non-diabetics to CP diabetics. On the other hand, there was increase in LPS (endotoxin) synthetic pathways (KEGG orthology) in the groups. Faecalibacterium prausnitzii abundance correlated negatively with plasma endotoxin and glycemic status; while plasma endotoxin correlated positively with blood glucose and negatively with plasma insulin. Our results have important implications for future studies exploring mechanistic insights on secondary diabetes in CP.
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Affiliation(s)
| | - A Madhulika
- Dept. of Clinical Nutrition, Asian Institute of Gastroenterology, Hyderabad, India
| | - G Deepika
- Dept. of Biochemistry, Asian Institute of Gastroenterology, Hyderabad, India
| | - G Venkat Rao
- Dept. of Surgical Gastroenterology, Asian Institute of Gastroenterology, Hyderabad, India
| | - D Nageshwar Reddy
- Dept. of Medical Gastroenterology, Asian Institute of Gastroenterology, Hyderabad, India
| | | | - Mitnala Sasikala
- Division of Basic Sciences, Asian Healthcare Foundation, Hyderabad, India
| | - Rupjyoti Talukdar
- Division of Basic Sciences, Asian Healthcare Foundation, Hyderabad, India.,Dept. of Medical Gastroenterology, Asian Institute of Gastroenterology, Hyderabad, India
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66
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Wang X, Ge QM, Bian F, Dong Y, Huang CM. Inhibition of TLR4 protects rat islets against lipopolysaccharide-induced dysfunction. Mol Med Rep 2016; 15:805-812. [PMID: 28101570 DOI: 10.3892/mmr.2016.6097] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2015] [Accepted: 10/07/2016] [Indexed: 11/06/2022] Open
Abstract
Oxidative stress leads to dysfunction in pancreatic cells, causing a reduction in insulin secretion following exposure to glucose. Toll-like receptor 4 (TLR4) may be activated by exposure to lipopolysaccharide (LPS) stress. TLR4 may mediate the initiation of inflammatory and immune defense responses; however, the importance of the LPS/TLR4 interaction in apoptosis induced by oxidative stress in pancreatic β cells remains to be elucidated. The present study aimed to investigate the importance of TLR4 during LPS‑induced oxidative stress, apoptosis and dysfunction of insulin secretion in isolated islets of rats. LPS‑induced stimulation of TLR4 increased the production of reactive oxygen species and promoted apoptosis by upregulating the expression levels of caspase‑3, poly ADP ribose polymerase and altering the expression ratio of B‑cell lymphoma‑2 (Bcl‑2)/Bcl‑2 associated X protein. Additionally, the insulin secretion of islets cells was reduced. Anti‑TLR4 antibody and a knockdown of TLR4 by TLR4‑short hairpin RNA were used to inhibit TLR4 activity, which may reverse LPS‑induced events. The present study determined that in islets exposed to LPS oxidative stress, dysfunction may be partly mediated via the TLR4 pathway. Inhibition of TLR4 may prevent dysfunction of rat islets due to oxidative stress. The present study revealed that targeting the LPS/TLR4 signaling pathway and antioxidant therapy may be a novel treatment for the severely septic patients with hyperglycemia stress.
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Affiliation(s)
- Xiao Wang
- Department of Emergency, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200092, P.R. China
| | - Qin Min Ge
- Department of Emergency, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200092, P.R. China
| | - Fan Bian
- Department of Nephrology, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200092, P.R. China
| | - Yan Dong
- Department of Endocrinology, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200092, P.R. China
| | - Chun Mei Huang
- Department of Emergency, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200092, P.R. China
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67
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Sekar S, Crawford R, Xiao Y, Prasadam I. Dietary Fats and Osteoarthritis: Insights, Evidences, and New Horizons. J Cell Biochem 2016; 118:453-463. [DOI: 10.1002/jcb.25758] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2016] [Accepted: 10/10/2016] [Indexed: 12/11/2022]
Affiliation(s)
- Sunderajhan Sekar
- Institute of Health and Biomedical Innovation; Queensland University of Technology; Brisbane Australia
| | - Ross Crawford
- Institute of Health and Biomedical Innovation; Queensland University of Technology; Brisbane Australia
- The Prince Charles Hospital; Orthopedic Department; Brisbane Australia
| | - Yin Xiao
- Institute of Health and Biomedical Innovation; Queensland University of Technology; Brisbane Australia
| | - Indira Prasadam
- Institute of Health and Biomedical Innovation; Queensland University of Technology; Brisbane Australia
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68
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Yin JJ, Xie G, Zhang N, Li Y. Inhibiting autophagy promotes endoplasmic reticulum stress and the ROS‑induced nod‑like receptor 3‑dependent proinflammatory response in HepG2 cells. Mol Med Rep 2016; 14:3999-4007. [PMID: 27600251 DOI: 10.3892/mmr.2016.5708] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2015] [Accepted: 08/09/2016] [Indexed: 11/06/2022] Open
Abstract
Inflammation and endoplasmic reticulum (ER) stress are key contributors to insulin resistance and metabolic disease, and interleukin (IL)‑1β is involved in insulin resistance. The present study aimed to investigated the role of autophagy in LPS‑induced ER stress and inflammation, which may provide evidence for controlling metabolic disease associated with inflammation. Lipopolysaccharide (LPS) induced the activation of ER stress and the nod‑like receptor 3‑dependent expression of IL‑1β and caspase‑1, as shown by western blotting, which contributed to HepG2 cell death. This also involved the generation of mitochondrial reactive oxygen species and the autophagy signaling response, which are derived from the ER stress pathway. The percentage of apoptotic cells was measured by flow cytometry with fluorescein isothiocyanate/propidium iodide staining. Reactive oxygen species formation was detected by flow cytometry using the peroxide sensitive fluorescent probe 2',7'‑dichlorofluorescin diacetate. Autophagy activation was measured by western blotting and confirmed using transmission electron microscopy. Furthermore, inhibiting autophagy promoted ER stress and the proinflammatory response in addition to cell death. These findings provide insights into the protective role of autophagy in LPS‑induced cell death and ER stress, and further identified the association of autophagy, ER stress and inflammation in HepG2 cells.
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Affiliation(s)
- Jia-Jing Yin
- Department of Endocrinology, First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang 150001, P.R. China
| | - Guangying Xie
- Department of Endocrinology, First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang 150001, P.R. China
| | - Ning Zhang
- Department of Endocrinology, First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang 150001, P.R. China
| | - Yanbo Li
- Department of Endocrinology, First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang 150001, P.R. China
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69
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Baothman OA, Zamzami MA, Taher I, Abubaker J, Abu-Farha M. The role of Gut Microbiota in the development of obesity and Diabetes. Lipids Health Dis 2016; 15:108. [PMID: 27317359 PMCID: PMC4912704 DOI: 10.1186/s12944-016-0278-4] [Citation(s) in RCA: 300] [Impact Index Per Article: 37.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Accepted: 06/15/2016] [Indexed: 02/08/2023] Open
Abstract
Obesity and its associated complications like type 2 diabetes (T2D) are reaching epidemic stages. Increased food intake and lack of exercise are two main contributing factors. Recent work has been highlighting an increasingly more important role of gut microbiota in metabolic disorders. It’s well known that gut microbiota plays a major role in the development of food absorption and low grade inflammation, two key processes in obesity and diabetes. This review summarizes key discoveries during the past decade that established the role of gut microbiota in the development of obesity and diabetes. It will look at the role of key metabolites mainly the short chain fatty acids (SCFA) that are produced by gut microbiota and how they impact key metabolic pathways such as insulin signalling, incretin production as well as inflammation. It will further look at the possible ways to harness the beneficial aspects of the gut microbiota to combat these metabolic disorders and reduce their impact.
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Affiliation(s)
- Othman A Baothman
- Department of Biochemistry, King Abdul Aziz University, Jeddah, Saudi Arabia
| | - Mazin A Zamzami
- Department of Biochemistry, King Abdul Aziz University, Jeddah, Saudi Arabia
| | - Ibrahim Taher
- Faculty of Medicine, Aljouf University, Aljouf, Saudi Arabia
| | - Jehad Abubaker
- Biochemistry and Molecular Biology Unit, Dasman Diabetes Institute, Dasman, P.O. Box 1180, 15462, Kuwait City, Kuwait.
| | - Mohamed Abu-Farha
- Biochemistry and Molecular Biology Unit, Dasman Diabetes Institute, Dasman, P.O. Box 1180, 15462, Kuwait City, Kuwait.
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70
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He K, Hu Y, Ma H, Zou Z, Xiao Y, Yang Y, Feng M, Li X, Ye X. Rhizoma Coptidis alkaloids alleviate hyperlipidemia in B6 mice by modulating gut microbiota and bile acid pathways. Biochim Biophys Acta Mol Basis Dis 2016; 1862:1696-709. [PMID: 27287254 DOI: 10.1016/j.bbadis.2016.06.006] [Citation(s) in RCA: 101] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Revised: 05/25/2016] [Accepted: 06/06/2016] [Indexed: 12/13/2022]
Abstract
It is hypothesized that Rhizoma Coptidis (RC) alkaloids exert their hypolipidemic effects primarily by targeting the gastrointestinal tract and liver. Thus, this study was conducted to evaluate the antihyperlipidemic mechanisms of RC alkaloids (at a daily dose of 140mg/kg for 35days) in high-fat and high-cholesterol induced hyperlipidemic B6 mice. After treatment, serum lipid parameters were determined, the expression of lipid metabolism related genes and pathways such as the sterol regulatory element binding proteins (SREBPs) and bile acid signaling in mice were also investigated. Meanwhile, Illumina sequencing was used to investigate the differences in gut microbiota of B6 mice. The results indicated that RC alkaloids reduced the body weight gain and serum total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), total bile acids (TBA) and lipopolysaccharide of B6 mice. Liver fat deposition and epididymal adipose cell size were also deceased in therapy group. RC alkaloids feeding significantly promoted the abundance of Sporobacter termitidis, Alcaligenes faecalis, Akkermansia muciniphila in the gut of mice, whereas, the abundance of Escherichia coli, Desulfovibrio C21_c20, Parabacteroides distasonis was suppressed. The observed antihyperlipidemic effects of RC alkaloids can also be attributed to their action as agonists of FXR and TGR5, activators for SREBP2, LDLR, UCP2 and CYP7A1, inhibitors of HMGCR, TXNIP, TLR4 and JNK. Therefore, this study expands current knowledge on hypolipidemic mechanisms of RC alkaloids and presents new evidence supporting a key role for RC alkaloids as regulators of lipid homeostasis by modulation gut microbiota and hepatic lipid metabolism.
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Affiliation(s)
- Kai He
- Chongqing Productivity Promotion Center for the Modernization of Chinese Traditional Medicine, School of Pharmaceutical Sciences, Southwest University, Chongqing 400716, China; Department of Clinical Laboratory, Hunan University of Medicine, Hunan 418000, China
| | - Yinran Hu
- Chongqing Productivity Promotion Center for the Modernization of Chinese Traditional Medicine, School of Pharmaceutical Sciences, Southwest University, Chongqing 400716, China
| | - Hang Ma
- Chongqing Productivity Promotion Center for the Modernization of Chinese Traditional Medicine, School of Pharmaceutical Sciences, Southwest University, Chongqing 400716, China
| | - Zongyao Zou
- Chongqing Productivity Promotion Center for the Modernization of Chinese Traditional Medicine, School of Pharmaceutical Sciences, Southwest University, Chongqing 400716, China
| | - Yubo Xiao
- Chongqing Productivity Promotion Center for the Modernization of Chinese Traditional Medicine, School of Pharmaceutical Sciences, Southwest University, Chongqing 400716, China
| | - Yong Yang
- Department of Clinical Laboratory, Hunan University of Medicine, Hunan 418000, China
| | - Min Feng
- Chongqing Productivity Promotion Center for the Modernization of Chinese Traditional Medicine, School of Pharmaceutical Sciences, Southwest University, Chongqing 400716, China
| | - Xuegang Li
- Chongqing Productivity Promotion Center for the Modernization of Chinese Traditional Medicine, School of Pharmaceutical Sciences, Southwest University, Chongqing 400716, China.
| | - Xiaoli Ye
- School of Life Sciences, Southwest University, Chongqing 400715, China.
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71
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Li C, Li X, Han H, Cui H, Peng M, Wang G, Wang Z. Effect of probiotics on metabolic profiles in type 2 diabetes mellitus: A meta-analysis of randomized, controlled trials. Medicine (Baltimore) 2016; 95:e4088. [PMID: 27368052 PMCID: PMC4937966 DOI: 10.1097/md.0000000000004088] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Type 2 diabetes mellitus (T2DM) is a prevalent metabolic disease which is imposing heavy burden on global health and economy. Recent studies indicate gut microbiota play important role on the pathogenesis and metabolic disturbance of T2DM. As an effective mean of regulating gut microbiota, probiotics are live micro-organisms that are believed to provide a specific health benefit on the host. Whether probiotic supplementation could improve metabolic profiles by modifying gut microbiota in T2DM or not is still in controversy.The aim of the study is to assess the effect of probiotic supplementation on metabolic profiles in T2DM.We searched PubMed, EMBASE, and Cochrane Library up to 12 April 2016. Two review authors independently assessed study eligibility, extracted data, and evaluated risk of bias of included studies. Data were pooled by using the random-effect model and expressed as standardized mean difference (SMD) with 95% confidence interval (CI). Heterogeneity was assessed and quantified (I).A total of 12 randomized controlled trials (RCTs) were included. Lipid profiles (n = 508) and fasting blood glucose (FBG) (n = 520) were reported in 9 trials; the homeostasis model of assessment for insulin resistance index (HOMA-IR) (n = 368) and glycosylated hemoglobin (HbA1c) (n = 380) were reported in 6 trials. Probiotics could alleviate FBG (SMD -0.61 mmol/L, 95% CI [-0.92, -0.30], P = 0.0001). Probiotics could increase high-density lipoprotein-cholesterol (HDL-C) (SMD 0.42 mmol/L, 95% CI [0.08, 0.76], P = 0.01). There were no significant differences in low-density lipoprotein-cholesterol (LDL-C), total cholesterol (TC), triglyceride (TG), HbA1c and HOMA-IR between the treatment group and the control group.Probiotics may improve glycemic control and lipid metabolism in T2DM. Application of probiotic agents might become a new method for glucose management in T2DM.
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Affiliation(s)
| | - Xin Li
- Department of Cardiothoracic Surgery
| | - Hongqiu Han
- Department of General Surgery, Tianjin Medical University General Hospital, Tianjin, China
- Correspondence: Zhiqiang Wang, Hongqiu Han, Heping District, Tianjin, China (e-mail: ; )
| | | | | | | | - Zhiqiang Wang
- Intensive Care Unit
- Correspondence: Zhiqiang Wang, Hongqiu Han, Heping District, Tianjin, China (e-mail: ; )
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72
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Navarro E, Funtikova AN, Fíto M, Schröder H. Can metabolically healthy obesity be explained by diet, genetics, and inflammation? Mol Nutr Food Res 2015; 59:75-93. [PMID: 25418549 DOI: 10.1002/mnfr.201400521] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Revised: 11/18/2014] [Accepted: 11/18/2014] [Indexed: 12/20/2022]
Abstract
A substantial proportion of obese individuals do not present cardiometabolic complications such as diabetes, hypertension, or dyslipidemia. Some, but not all, prospective studies observe similar risk of cardiovascular events and all-cause mortality among individuals with this so-called "metabolically healthy obese" (MHO) phenotype, compared to the metabolically healthy normal weight or metabolically healthy non-obese phenotypes. Compared to the metabolically unhealthy obese (MUO) phenotype, MHO is often characterized by a more favorable inflammatory profile, less visceral fat, less infiltration of macrophages into adipose tissue, and smaller adipocyte cell size. Tipping the inflammation balance in adipose tissue might be particularly important for metabolic health in the obese. While the potential role of genetic predisposition or lifestyle factors such as diet in the MHO phenotype is yet to be clarified, it is well known that diet affects inflammation profile and contributes to the functionality of adipose tissue. This review will discuss genetic predisposition and the molecular mechanisms underlying the potential effect of food on the development of the metabolic phenotype characteristic of obesity.
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73
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Bandsma RHJ, Ackerley C, Koulajian K, Zhang L, van Zutphen T, van Dijk TH, Xiao C, Giacca A, Lewis GF. A low-protein diet combined with low-dose endotoxin leads to changes in glucose homeostasis in weanling rats. Am J Physiol Endocrinol Metab 2015; 309:E466-73. [PMID: 26152763 DOI: 10.1152/ajpendo.00090.2015] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/24/2015] [Accepted: 07/01/2015] [Indexed: 12/23/2022]
Abstract
Severe malnutrition is a leading cause of global childhood mortality, and infection and hypoglycemia or hyperglycemia are commonly present. The etiology behind the changes in glucose homeostasis is poorly understood. Here, we generated an animal model of severe malnutrition with and without low-grade inflammation to investigate the effects on glucose homeostasis. Immediately after weaning, rats were fed diets containing 5 [low-protein diet (LP)] or 20% protein [control diet (CTRL)], with or without repeated low-dose intraperitoneal lipopolysaccharide (LPS; 2 mg/kg), to mimic inflammation resulting from infections. After 4 wk on the diets, hyperglycemic clamps or euglycemic hyperinsulinemic clamps were performed with infusion of [U-(13)C6]glucose and [2-(13)C]glycerol to assess insulin secretion, action, and hepatic glucose metabolism. In separate studies, pancreatic islets were isolated for further analyses of insulin secretion and islet morphometry. Glucose clearance was reduced significantly by LP feeding alone (16%) and by LP feeding with LPS administration (43.8%) compared with control during the hyperglycemic clamps. This was associated with a strongly reduced insulin secretion in LP-fed rats in vivo as well as ex vivo in islets but signficantly enhanced whole body insulin sensitivity. Gluconeogenesis rates were unaffected by LP feeding, but glycogenolysis was higher after LP feeding. A protein-deficient diet in young rats leads to a susceptibility to low-dose endotoxin-induced impairment in glucose clearance with a decrease in the islet insulin secretory pathway. A protein-deficient diet is associated with enhanced peripheral insulin sensitivity but impaired insulin-mediated suppression of hepatic glycogenolysis.
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Affiliation(s)
- Robert H J Bandsma
- Division of Gastroenterology, Hepatology, and Nutrition, The Hospital for Sick Children, Toronto, Ontario, Canada; Physiology and Experimental Medicine Program, Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada; Department of Pediatrics, Center for Liver, Digestive, and Metabolic Diseases, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands;
| | - Cameron Ackerley
- Department of Paediatric Laboratory Medicine, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Khajag Koulajian
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada; Division of Endocrinology and Metabolism, Department of Medicine, University of Toronto, Toronto, Ontario, Canada; and
| | - Ling Zhang
- Physiology and Experimental Medicine Program, Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Tim van Zutphen
- Department of Pediatrics, Center for Liver, Digestive, and Metabolic Diseases, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Theo H van Dijk
- Department of Pediatrics, Center for Liver, Digestive, and Metabolic Diseases, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Changting Xiao
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada; Division of Endocrinology and Metabolism, Department of Medicine, University of Toronto, Toronto, Ontario, Canada; and Banting and Best Diabetes Centre, University of Toronto, Toronto, Ontario, Canada
| | - Adria Giacca
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada; Division of Endocrinology and Metabolism, Department of Medicine, University of Toronto, Toronto, Ontario, Canada; and Banting and Best Diabetes Centre, University of Toronto, Toronto, Ontario, Canada
| | - Gary F Lewis
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada; Division of Endocrinology and Metabolism, Department of Medicine, University of Toronto, Toronto, Ontario, Canada; and Banting and Best Diabetes Centre, University of Toronto, Toronto, Ontario, Canada
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74
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Tran CD, Grice DM, Wade B, Kerr CA, Bauer DC, Li D, Hannan GN. Gut permeability, its interaction with gut microflora and effects on metabolic health are mediated by the lymphatics system, liver and bile acid. Future Microbiol 2015; 10:1339-53. [DOI: 10.2217/fmb.15.54] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
There is evidence to link obesity (and metabolic syndrome) with alterations in gut permeability and microbiota. The underlying mechanisms have been questioned and have prompted this review. We propose that the gut barrier function is a primary driver in maintaining metabolic health with poor health being linked to ‘gut leakiness'. This review will highlight changes in intestinal permeability and how it may change gut microflora and subsequently affect metabolic health by influencing the functioning of major bodily organs/organ systems: the lymphatic system, liver and pancreas. We also discuss the likelihood that metabolic syndrome undergoes a cyclic worsening facilitated by an increase in intestinal permeability leading to gut dysbiosis, culminating in ongoing poor health leading to further exacerbated gut leakiness.
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Affiliation(s)
- Cuong D Tran
- CSIRO Food & Nutrition Flagship, Adelaide, SA 5000, Australia
| | - Desma M Grice
- CSIRO Food & Nutrition Flagship, North Ryde, NSW 2113, Australia
| | - Ben Wade
- CSIRO Biosecurity Flagship, Geelong, VIC 3219, Australia
| | - Caroline A Kerr
- CSIRO Food & Nutrition Flagship, North Ryde, NSW 2113, Australia
| | - Denis C Bauer
- CSIRO Digital Productivity & Services Flagship, North Ryde, NSW 1670, Australia
| | - Dongmei Li
- CSIRO Food & Nutrition Flagship, North Ryde, NSW 2113, Australia
| | - Garry N Hannan
- CSIRO Food & Nutrition Flagship, North Ryde, NSW 2113, Australia
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Peng D, Jiang F, Zhang R, Tang S, Chen M, Yan J, Sun X, Luo Y, Hu C, Jia W. Association of Toll-like Receptor 4 Gene polymorphisms with susceptibility to type 2 diabetes mellitus in the Chinese population. J Diabetes 2015; 7:485-92. [PMID: 25104099 DOI: 10.1111/1753-0407.12206] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/14/2014] [Revised: 07/05/2014] [Accepted: 07/30/2014] [Indexed: 01/17/2023] Open
Abstract
BACKGROUND Toll-like receptor 4 (TLR4) plays an important role in innate immunity. Activation of innate immune response and subsequent chronic low-grade inflammation are thought to be involved in the pathogenesis of type 2 diabetes. In this study, we aimed to investigate the association of TLR4 variants with type 2 diabetes in the Chinese population. METHODS Seven tag single nucleotide polymorphisms (SNPs) of TLR4 based on HapMap Chinese data were genotyped in the Shanghai Chinese, including 3404 type 2 diabetes patients and 3401 controls. The controls were extensively phenotyped for the traits related to glucose metabolism and insulin secretion. RESULTS In total participants, we identified that rs10759932 and rs1927911 were associated with type 2 diabetes (odds ratio 1.106, P = 0.009 for rs10759532, odds ratio 1.092, P = 0.013 for rs1927911). rs11536889 showed a trend association with type 2 diabetes (odds ratio 0.957, P = 0.057). This SNP was also associated with 2-h plasma glucose (P = 0.033) and high-density lipoprotein-cholesterol (P = 0.031). In female participants, rs10759932, rs1927911 and rs11536889 were associated with type 2 diabetes (odds ratio 1.176, P = 0.002 for rs10759932, odds ratio 1.136, P = 0.009 for rs1927911, odds ratio 0.882, P = 0.024 for rs11536889). Besides, rs11536889 was significantly associated with 2-h plasma glucose (P = 0.050) and HOMA-B (P = 0.046) with adjusting for age and body mass index in female normal subjects. CONCLUSIONS We conclude that genetic variants of TLR4 are associated with type 2 diabetes in the Chinese population, especially in female subjects.
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Affiliation(s)
- Danfeng Peng
- Shanghai Diabetes Institute, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Clinical Center for Diabetes, Shanghai Key Clinic Center for Metabolic Diseases, Department of Endocrinology and Metabolism, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China
| | - Feng Jiang
- Shanghai Diabetes Institute, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Clinical Center for Diabetes, Shanghai Key Clinic Center for Metabolic Diseases, Department of Endocrinology and Metabolism, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China
| | - Rong Zhang
- Shanghai Diabetes Institute, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Clinical Center for Diabetes, Shanghai Key Clinic Center for Metabolic Diseases, Department of Endocrinology and Metabolism, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China
| | - Shanshan Tang
- Shanghai Diabetes Institute, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Clinical Center for Diabetes, Shanghai Key Clinic Center for Metabolic Diseases, Department of Endocrinology and Metabolism, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China
| | - Miao Chen
- Shanghai Diabetes Institute, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Clinical Center for Diabetes, Shanghai Key Clinic Center for Metabolic Diseases, Department of Endocrinology and Metabolism, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China
| | - Jing Yan
- Shanghai Diabetes Institute, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Clinical Center for Diabetes, Shanghai Key Clinic Center for Metabolic Diseases, Department of Endocrinology and Metabolism, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China
| | - Xue Sun
- Shanghai Diabetes Institute, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Clinical Center for Diabetes, Shanghai Key Clinic Center for Metabolic Diseases, Department of Endocrinology and Metabolism, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China
| | - Yi Luo
- Shanghai Diabetes Institute, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Clinical Center for Diabetes, Shanghai Key Clinic Center for Metabolic Diseases, Department of Endocrinology and Metabolism, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China
| | - Cheng Hu
- Shanghai Diabetes Institute, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Clinical Center for Diabetes, Shanghai Key Clinic Center for Metabolic Diseases, Department of Endocrinology and Metabolism, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China
| | - Weiping Jia
- Shanghai Diabetes Institute, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Clinical Center for Diabetes, Shanghai Key Clinic Center for Metabolic Diseases, Department of Endocrinology and Metabolism, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China
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76
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Leal-Lopes C, Velloso FJ, Campopiano JC, Sogayar MC, Correa RG. Roles of Commensal Microbiota in Pancreas Homeostasis and Pancreatic Pathologies. J Diabetes Res 2015; 2015:284680. [PMID: 26347203 PMCID: PMC4544440 DOI: 10.1155/2015/284680] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/28/2015] [Accepted: 07/09/2015] [Indexed: 12/12/2022] Open
Abstract
The pancreas plays a central role in metabolism, allowing ingested food to be converted and used as fuel by the cells throughout the body. On the other hand, the pancreas may be affected by devastating diseases, such as pancreatitis, pancreatic adenocarcinoma (PAC), and diabetes mellitus (DM), which generally results in a wide metabolic imbalance. The causes for the development and progression of these diseases are still controversial; therefore it is essential to better understand the underlying mechanisms which compromise the pancreatic homeostasis. The interest in the study of the commensal microbiome increased extensively in recent years, when many discoveries have illustrated its central role in both human physiology and maintenance of homeostasis. Further understanding of the involvement of the microbiome during the development of pathological conditions is critical for the improvement of new diagnostic and therapeutic approaches. In the present review, we discuss recent findings on the behavior and functions played by the microbiota in major pancreatic diseases and provide further insights into its potential roles in the maintenance of pancreatic steady-state activities.
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Affiliation(s)
- Camila Leal-Lopes
- Department of Biochemistry, Chemistry Institute, University of São Paulo, 05508-000 São Paulo, SP, Brazil
- Cell and Molecular Therapy Center (NUCEL-NETCEM), School of Medicine, University of São Paulo, 05360-130 São Paulo, SP, Brazil
| | - Fernando J. Velloso
- Cell and Molecular Therapy Center (NUCEL-NETCEM), School of Medicine, University of São Paulo, 05360-130 São Paulo, SP, Brazil
| | - Julia C. Campopiano
- Cell and Molecular Therapy Center (NUCEL-NETCEM), School of Medicine, University of São Paulo, 05360-130 São Paulo, SP, Brazil
| | - Mari C. Sogayar
- Department of Biochemistry, Chemistry Institute, University of São Paulo, 05508-000 São Paulo, SP, Brazil
- Cell and Molecular Therapy Center (NUCEL-NETCEM), School of Medicine, University of São Paulo, 05360-130 São Paulo, SP, Brazil
| | - Ricardo G. Correa
- Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
- *Ricardo G. Correa:
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77
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Han JL, Lin HL. Intestinal microbiota and type 2 diabetes: From mechanism insights to therapeutic perspective. World J Gastroenterol 2014; 20:17737-17745. [PMID: 25548472 PMCID: PMC4273124 DOI: 10.3748/wjg.v20.i47.17737] [Citation(s) in RCA: 105] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2014] [Revised: 09/26/2014] [Accepted: 11/19/2014] [Indexed: 02/06/2023] Open
Abstract
The incidence of type 2 diabetes (T2DM) is rapidly increasing worldwide. However, the pathogenesis of T2DM has not yet been well explained. Recent evidence suggests that the intestinal microbiota composition is associated with obesity and T2DM. In this review, we provide an overview about the mechanisms underlying the role of intestinal microbiota in the pathogenesis of T2DM. There is clear evidence that the intestinal microbiota influences the host through its effect on body weight, bile acid metabolism, proinflammatory activity and insulin resistance, and modulation of gut hormones. Modulating gut microbiota with the use of probiotics, prebiotics, antibiotics, and fecal microbiota transplantation may have benefits for improvement in glucose metabolism and insulin resistance in the host. Further studies are required to increase our understanding of the complex interplay between intestinal microbiota and the host with T2DM. Further studies may be able to boost the development of new effective therapeutic approaches for T2DM.
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78
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Pepin E, Higa A, Schuster-Klein C, Bernard C, Sulpice T, Guardiola B, Chevet E, Alquier T. Deletion of apoptosis signal-regulating kinase 1 (ASK1) protects pancreatic beta-cells from stress-induced death but not from glucose homeostasis alterations under pro-inflammatory conditions. PLoS One 2014; 9:e112714. [PMID: 25383781 PMCID: PMC4226582 DOI: 10.1371/journal.pone.0112714] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Accepted: 10/14/2014] [Indexed: 01/22/2023] Open
Abstract
BACKGROUND Type 2 diabetes is characterized by pancreatic beta-cell dysfunction and is associated with low-grade inflammation. Recent observations suggest that apoptosis signal-regulating kinase 1 (ASK1) is involved in beta-cell death in response to different stressors. In this study, we tested whether ASK1 deficiency protects beta-cells from glucolipotoxic conditions and cytokines treatment or from glucose homeostasis alteration induced by endotoxemia. METHODOLOGY/PRINCIPAL FINDINGS Insulin secretion was neither affected upon shRNA-mediated downregulation of ASK1 in MIN6 cells nor in islets from ASK1-deficient mice. ASK1 silencing in MIN6 cells and deletion in islets did not prevent the deleterious effect of glucolipotoxic conditions or cytokines on insulin secretion. However, it protected MIN6 cells from death induced by ER stress or palmitate and islets from short term caspase activation in response to cytokines. Moreover, endotoxemia induced by LPS infusion increased insulin secretion during hyperglycemic clamps but the response was similar in wild-type and ASK1-deficient mice. Finally, insulin sensitivity in the presence of LPS was not affected by ASK1-deficiency. CONCLUSIONS/SIGNIFICANCE Our study demonstrates that ASK1 is not involved in beta-cell function and dysfunction but controls stress-induced beta-cell death.
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Affiliation(s)
| | - Arisa Higa
- Inserm U1053, Team Endoplasmic Reticulum Stress and Cancer, Université de Bordeaux, Bordeaux, France, 33076
| | | | | | - Thierry Sulpice
- Betagenex Inc, Laval, QC, Canada, H7V5B7
- Physiogenex SAS, Labège, France, 31670
| | | | - Eric Chevet
- Inserm U1053, Team Endoplasmic Reticulum Stress and Cancer, Université de Bordeaux, Bordeaux, France, 33076
| | - Thierry Alquier
- Montreal Diabetes Research Center, Centre de Recherche du Centre Hospitalier de l’Université de Montréal (CRCHUM), and Departments of Medicine, Biochemistry and Cell Biology and Pathology, Université de Montréal, Montréal, QC, Canada, H3T 1J4
- * E-mail:
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79
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Agrawal NK, Kant S. Targeting inflammation in diabetes: Newer therapeutic options. World J Diabetes 2014; 5:697-710. [PMID: 25317247 PMCID: PMC4138593 DOI: 10.4239/wjd.v5.i5.697] [Citation(s) in RCA: 131] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/27/2013] [Revised: 04/24/2014] [Accepted: 05/29/2014] [Indexed: 02/05/2023] Open
Abstract
Inflammation has been recognised to both decrease beta cell insulin secretion and increase insulin resistance. Circulating cytokines can affect beta cell function directly leading to secretory dysfunction and increased apoptosis. These cytokines can also indirectly affect beta cell function by increasing adipocyte inflammation.The resulting glucotoxicity and lipotoxicity further enhance the inflammatory process resulting in a vicious cycle. Weight reduction and drugs such as metformin have been shown to decrease the levels of C-Reactive Protein by 31% and 13%, respectively. Pioglitazone, insulin and statins have anti-inflammatory effects. Interleukin 1 and tumor necrosis factor-α antagonists are in trials and NSAIDs such as salsalate have shown an improvement in insulin sensitivity. Inhibition of 12-lipo-oxygenase, histone de-acetylases, and activation of sirtuin-1 are upcoming molecular targets to reduce inflammation. These therapies have also been shown to decrease the conversion of pre-diabetes state to diabetes. Drugs like glicazide, troglitazone, N-acetylcysteine and selective COX-2 inhibitors have shown benefit in diabetic neuropathy by decreasing inflammatory markers. Retinopathy drugs are used to target vascular endothelial growth factor, angiopoietin-2, various proteinases and chemokines. Drugs targeting the proteinases and various chemokines are pentoxifylline, inhibitors of nuclear factor-kappa B and mammalian target of rapamycin and are in clinical trials for diabetic nephropathy. Commonly used drugs such as insulin, metformin, peroxisome proliferator-activated receptors, glucagon like peptide-1 agonists and dipeptidyl peptidase-4 inhibitors also decrease inflammation. Anti-inflammatory therapies represent a potential approach for the therapy of diabetes and its complications.
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80
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Nackiewicz D, Dan M, He W, Kim R, Salmi A, Rütti S, Westwell-Roper C, Cunningham A, Speck M, Schuster-Klein C, Guardiola B, Maedler K, Ehses JA. TLR2/6 and TLR4-activated macrophages contribute to islet inflammation and impair beta cell insulin gene expression via IL-1 and IL-6. Diabetologia 2014; 57:1645-54. [PMID: 24816367 DOI: 10.1007/s00125-014-3249-1] [Citation(s) in RCA: 82] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/28/2013] [Accepted: 04/08/2014] [Indexed: 01/08/2023]
Abstract
AIMS/HYPOTHESIS Inflammation contributes to pancreatic beta cell dysfunction in type 2 diabetes. Toll-like receptor (TLR)-2 and -4 ligands are increased systemically in recently diagnosed type 2 diabetes patients, and TLR2- and TLR4-deficient mice are protected from the metabolic consequences of a high-fat diet. Here we investigated the role of macrophages in TLR2/6- and TLR4-mediated effects on islet inflammation and beta cell function. METHODS Genetic and pharmacological approaches were used to determine the effects of TLR2/6 and TLR4 ligands on mouse islets, human islets and purified rat beta cells. Islet macrophages were depleted and sorted by flow cytometry and the effects of TLR2/6- and TLR4-activated bone-marrow-derived macrophages (BMDMs) on beta cell function were assessed. RESULTS Macrophages contributed to TLR2/6- and TLR4-induced islet Il1a/IL1A and Il1b/IL1B mRNA expression in mouse and human islets and IL-1β secretion from human islets. TLR2/6 and TLR4 ligands also reduced insulin gene expression; however, this occurred in a non-beta cell autonomous manner. TLR2/6- and TLR4-activated BMDMs reduced beta cell insulin secretion partly via reducing Ins1, Ins2, and Pdx1 mRNA expression. Antagonism of the IL-1 receptor and neutralisation of IL-6 completely reversed the effects of activated macrophages on beta cell gene expression. CONCLUSIONS/INTERPRETATION We conclude that islet macrophages are major contributors to islet IL-1β secretion in response to TLR2/6 and TLR4 ligands. BMDMs stimulated with TLR2/6 and TLR4 ligands reduce insulin secretion from pancreatic beta cells, partly via IL-1β- and IL-6-mediated decreased insulin gene expression.
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Affiliation(s)
- Dominika Nackiewicz
- Department of Surgery, Faculty of Medicine, The University of British Columbia, Child and Family Research Institute, 950 W 28th Ave, Vancouver, BC, Canada, V5Z 4H4
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81
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Ghosal A, Sekar TV, Said HM. Biotin uptake by mouse and human pancreatic beta cells/islets: a regulated, lipopolysaccharide-sensitive carrier-mediated process. Am J Physiol Gastrointest Liver Physiol 2014; 307:G365-73. [PMID: 24904078 PMCID: PMC4121639 DOI: 10.1152/ajpgi.00157.2014] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Biotin is essential for the normal function of pancreatic beta cells. These cells obtain biotin from their surroundings via transport across their cell membrane. Little is known about the uptake mechanism involved, how it is regulated, and how it is affected by internal and external factors. We addressed these issues using the mouse-derived pancreatic beta-TC-6 cells and freshly isolated mouse and human primary pancreatic beta cells as models. The results showed biotin uptake by pancreatic beta-TC-6 cells occurs via a Na(+)-dependent, carrier-mediated process, that is sensitive to desthiobiotin, as well as to pantothenic acid and lipoate; the process is also saturable as a function of concentration (apparent Km = 22.24 ± 5.5 μM). These cells express the sodium-dependent multivitamin transporter (SMVT), whose knockdown (with doxycycline-inducible shRNA) led to a sever inhibition in biotin uptake. Similarly, uptake of biotin by mouse and human primary pancreatic islets is Na(+)-dependent and carrier-mediated, and both cell types express SMVT. Biotin uptake by pancreatic beta-TC-6 cells is also adaptively regulated (via transcriptional mechanism) by extracellular substrate level. Chronic treatment of pancreatic beta-TC-6 cells with bacterial lipopolysaccharides (LPS) leads to inhibition in biotin uptake. This inhibition is mediated via a Toll-Like receptor 4-mediated process and involves a decrease in membrane expression of SMVT. These findings show, for the first time, that pancreatic beta cells/islets take up biotin via a specific and regulated carrier-mediated process, and that the process is sensitive to the effect of LPS.
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Affiliation(s)
- Abhisek Ghosal
- Departments of Medicine and Physiology/Biophysics, University of California, Irvine, California; and Department of Veterans Affairs Medical Center, Long Beach, California
| | - Thillai V. Sekar
- Departments of Medicine and Physiology/Biophysics, University of California, Irvine, California; and Department of Veterans Affairs Medical Center, Long Beach, California
| | - Hamid M. Said
- Departments of Medicine and Physiology/Biophysics, University of California, Irvine, California; and Department of Veterans Affairs Medical Center, Long Beach, California
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Abstract
Free fatty acids (FFAs) exert both positive and negative effects on beta cell survival and insulin secretory function, depending on concentration, duration, and glucose abundance. Lipid signals are mediated not only through metabolic pathways, but also through cell surface and nuclear receptors. Toxicity is modulated by positive signals arising from circulating factors such as hormones, growth factors and incretins, as well as negative signals such as inflammatory mediators and cytokines. Intracellular mechanisms of lipotoxicity include metabolic interference and cellular stress responses such as oxidative stress, endoplasmic reticulum (ER) stress, and possibly autophagy. New findings strengthen an old hypothesis that lipids may also impair compensatory beta cell proliferation. Clinical observations continue to support a role for lipid biology in the risk and progression of both type 1 (T1D) and type 2 diabetes (T2D). This review summarizes recent work in this important, rapidly evolving field.
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Affiliation(s)
- Rohit B Sharma
- Diabetes Center of Excellence, University of Massachusetts Medical School, 368 Plantation Street, Worcester, MA, 01605, USA
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Balistreri CR, Bonfigli AR, Boemi M, Olivieri F, Ceriello A, Genovese S, Franceschi C, Spazzafumo L, Fabietti P, Candore G, Caruso C, Lio D, Testa R. Evidences of +896 A/G TLR4 polymorphism as an indicative of prevalence of complications in T2DM patients. Mediators Inflamm 2014; 2014:973139. [PMID: 24803744 PMCID: PMC3996297 DOI: 10.1155/2014/973139] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2014] [Accepted: 03/06/2014] [Indexed: 01/08/2023] Open
Abstract
T2DM is today considered as world-wide health problem, with complications responsible of an enhanced mortality and morbidity. Thus, new strategies for its prevention and therapy are necessary. For this reason, the research interest has focused its attention on TLR4 and its polymorphisms, particularly the rs4986790. However, no conclusive findings have been reported until now about the role of this polymorphism in development of T2DM and its complications, even if a recent meta-analysis showed its T2DM association in Caucasians. In this study, we sought to evaluate the weight of rs4986790 polymorphism in the risk of the major T2DM complications, including 367 T2DM patients complicated for the 55.6%. Patients with A/A and A/G TLR4 genotypes showed significant differences in complication's prevalence. In particular, AG carriers had higher risk prevalence for neuropathy (P = 0.026), lower limb arteriopathy (P = 0.013), and the major cardiovascular pathologies (P = 0.017). Their cumulative risk was significant (P = 0.01), with a threefold risk to develop neuropathy, lower limb arteriopathy, and major cardiovascular events in AG cases compared to AA cases. The adjusted OR for the confounding variables was 3.788 (95% CI: 1.642-8.741). Thus, the rs4986790 polymorphism may be an indicative of prevalence of complications in T2DM patients.
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Affiliation(s)
- Carmela Rita Balistreri
- Department of Pathobiology and Medical and Forensic Biotechnologies, University of Palermo, Tukory's Street 211, 90134 Palermo, Italy
| | - Anna Rita Bonfigli
- Metabolic Diseases and Diabetology Unit, Italian National Research Center on Aging (INRCA), Ancona, Italy
| | - Massimo Boemi
- Metabolic Diseases and Diabetology Unit, Italian National Research Center on Aging (INRCA), Ancona, Italy
| | - Fabiola Olivieri
- Department of Clinical and Molecular Sciences, Università Politecnica delle Marche, Ancona, Italy
- Center of Clinical Pathology and Innovative Therapy, Italian National Research Center on Aging (INRCA), Ancona, Italy
| | - Antonio Ceriello
- Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Barcelona, Spain
| | - Stefano Genovese
- Department of Cardiovascular and Metabolic Diseases, IRCCS Gruppo Multimedica, Sesto San Giovanni (MI), Italy
| | - Claudio Franceschi
- Department of Experimental, Diagnostic and Specialty Medicine (DIMES), University of Bologna, CNR-ISOF and IRCCS Neuroscience, Bologna, Italy
| | - Liana Spazzafumo
- Biostatistical Center, Italian National Research Center on Aging (INRCA), Ancona, Italy
| | - Paolo Fabietti
- Biostatistical Center, Italian National Research Center on Aging (INRCA), Ancona, Italy
| | - Giuseppina Candore
- Department of Pathobiology and Medical and Forensic Biotechnologies, University of Palermo, Tukory's Street 211, 90134 Palermo, Italy
| | - Calogero Caruso
- Department of Pathobiology and Medical and Forensic Biotechnologies, University of Palermo, Tukory's Street 211, 90134 Palermo, Italy
| | - Domenico Lio
- Department of Pathobiology and Medical and Forensic Biotechnologies, University of Palermo, Tukory's Street 211, 90134 Palermo, Italy
| | - Roberto Testa
- Experimental Models in Clinical Pathology, Italian National Research Center on Aging (INRCA), Ancona, Italy
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Lack of association between TLR4 genetic polymorphisms and diabetic nephropathy in a Chinese population. BIOMED RESEARCH INTERNATIONAL 2014; 2014:704167. [PMID: 24779014 PMCID: PMC3980983 DOI: 10.1155/2014/704167] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/26/2014] [Accepted: 02/28/2014] [Indexed: 12/02/2022]
Abstract
Objective. Toll-like receptor 4 (TLR4) plays a central role in innate immunity. Activation of innate immune response and subsequent chronic low-grade inflammation are thought to be involved in the pathogenesis of diabetic nephropathy. In this study, we aimed to investigate whether TLR4 variants are associated with diabetic nephropathy in the Chinese population. Methods. Seven tagging single nucleotide polymorphisms (SNPs) of TLR4 based on HapMap Chinese data were genotyped in 1,455 Chinese type 2 diabetic patients. Of these patients, 622 were diagnosed with diabetic nephropathy and 833 were patients with diabetes for over 5 years but without diabetic nephropathy. Results. None of the SNPs and haplotypes showed significant association to diabetic nephropathy in our study. No association between the SNPs and quantitative traits was observed either. Conclusion. We concluded that common variants within TLR4 genes were not associated with diabetic nephropathy in the Chinese type 2 diabetes patients.
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Cucak H, Mayer C, Tonnesen M, Thomsen LH, Grunnet LG, Rosendahl A. Macrophage contact dependent and independent TLR4 mechanisms induce β-cell dysfunction and apoptosis in a mouse model of type 2 diabetes. PLoS One 2014; 9:e90685. [PMID: 24594974 PMCID: PMC3940939 DOI: 10.1371/journal.pone.0090685] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2013] [Accepted: 02/03/2014] [Indexed: 12/21/2022] Open
Abstract
Type 2 diabetes (T2D) is evolving into a global disease and patients have a systemic low-grade inflammation, yet the role of this inflammation is still not established. One plausible mechanism is enhanced expression and activity of the innate immune system. Therefore, we evaluated the expression and the function of the toll-like receptor 4 (TLR4) on pancreatic β-cells in primary mouse islets and on the murine β-cell line MIN6 in the presence or absence of macrophages. Diabetic islets have 40% fewer TLR4 positive β-cells, but twice the number of TLR4 positive macrophages as compared to healthy islets. Healthy and diabetic islets respond to a TLR4 challenge with enhanced production of cytokines (5–10-fold), while the TLR4 negative β-cell line MIN6 fails to produce cytokines. TLR4 stimulation induces β-cell dysfunction in mouse islets, measured as reduced glucose stimulated insulin secretion. Diabetic macrophages from 4-months old mice have acquired a transient enhanced capacity to produce cytokines when stimulated with LPS. Interestingly, this is lost in 6-months old diabetic mice. TLR4 activation alone does not induce apoptosis in islets or MIN-6 cells. In contrast, macrophages mediate TLR4-dependent cell-contact dependent (3-fold) as well as cell-contact independent (2-fold) apoptosis of both islets and MIN-6 cells. Importantly, diabetic macrophages have a significantly enhanced capacity to induce β-cell apoptosis compared to healthy macrophages. Taken together, the TLR4 responsiveness is elevated in the diabetic islets and mainly mediated by newly recruited macrophages. The TLR4 positive macrophages, in both a cell-contact dependent and independent manner, induce apoptosis of β-cells in a TLR4 dependent fashion and TLR4 activation directly induces β-cell dysfunction. Thus, targeting either the TLR4 pathway or the macrophages provides a novel attractive treatment regime for T2D.
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Affiliation(s)
- Helena Cucak
- Hagedorn Research Institute, Department of Diabetic Complication Biology, Måløv, Denmark
| | - Christopher Mayer
- Hagedorn Research Institute, Department of Diabetic Complication Biology, Måløv, Denmark
| | - Morten Tonnesen
- Hagedorn Research Institute, Department of Diabetic Complication Biology, Måløv, Denmark
| | - Lise Høj Thomsen
- Hagedorn Research Institute, Department of Diabetic Complication Biology, Måløv, Denmark
| | | | - Alexander Rosendahl
- Hagedorn Research Institute, Department of Diabetic Complication Biology, Måløv, Denmark
- * E-mail:
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86
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Toll-like receptors and NLRP3 as central regulators of pancreatic islet inflammation in type 2 diabetes. Immunol Cell Biol 2014; 92:314-23. [PMID: 24492799 DOI: 10.1038/icb.2014.4] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2013] [Revised: 01/03/2014] [Accepted: 01/06/2014] [Indexed: 12/17/2022]
Abstract
The global health and economic burden of type 2 diabetes (T2D) has reached staggering proportions. Current projections estimate that 592 million people will have diabetes by 2035. T2D-which comprises 90% of cases-is a complex disease, in most cases resulting from a combination of predisposing genes and an unhealthy environment. Clinical onset of the disease occurs when pancreatic β cells fail in the face of insulin resistance. It has long been appreciated that chronic activation of the innate immune system is associated with T2D, and many organs critical to the regulation of glucose homeostasis show signs of a chronic inflammatory process, including the pancreatic islets of Langerhans. Recent clinical trials using IL-1-targeting agents have confirmed that inflammation contributes to β-cell failure in humans with T2D. However, little is known about the nature of the pro-inflammatory response within the islet, and there is considerable debate about the triggers for islet inflammation, which may be systemically derived and/or tissue-specific. In this review, we present evidence that Toll-like receptors 2 and 4 and the NLRP3 (Nucleotide-binding oligomerization domain, Leucine-rich Repeat and Pyrin domain containing 3) inflammasome are triggers for islet inflammation in T2D and propose that the activation of macrophages by these triggers mediates islet endocrine cell dysfunction. Therapeutically targeting these receptors may improve hyperglycemia and protect the β cell in T2D.
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87
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Teng KT, Chang CY, Chang LF, Nesaretnam K. Modulation of obesity-induced inflammation by dietary fats: mechanisms and clinical evidence. Nutr J 2014; 13:12. [PMID: 24476102 PMCID: PMC3922162 DOI: 10.1186/1475-2891-13-12] [Citation(s) in RCA: 103] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2013] [Accepted: 01/13/2014] [Indexed: 01/16/2023] Open
Abstract
Obesity plays a pivotal role in the development of low-grade inflammation. Dietary fatty acids are important modulators of inflammatory responses. Saturated fatty acids (SFA) and n-6 polyunsaturated fatty acids (PUFA) have been reported to exert pro-inflammatory effects. n-3 PUFA in particular, possess anti-inflammatory properties. Numerous clinical studies have been conducted over decades to investigate the impact of dietary fatty acids on inflammatory response in obese individuals, however the findings remained uncertain. High fat meals have been reported to increase pro-inflammatory responses, however there is limited evidence to support the role of individual dietary fatty acids in a postprandial state. Evidence in chronic studies is contradictory, the effects of individual dietary fatty acids deserves further attention. Weight loss rather than n-3 PUFA supplementation may play a more prominent role in alleviating low grade inflammation. In this context, the present review provides an update on the mechanistic insight and the influence of dietary fats on low grade inflammation, based on clinical evidence from acute and chronic clinical studies in obese and overweight individuals.
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Affiliation(s)
- Kim-Tiu Teng
- Product Development and Advisory Services, Malaysian Palm Oil Board (MPOB), 6 Persiaran Institusi, Bandar Baru Bangi, 43000 Kajang, Selangor, Malaysia.
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88
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Semache M, Ghislain J, Zarrouki B, Tremblay C, Poitout V. Pancreatic and duodenal homeobox-1 nuclear localization is regulated by glucose in dispersed rat islets but not in insulin-secreting cell lines. Islets 2014; 6:e982376. [PMID: 25437380 PMCID: PMC4588559 DOI: 10.4161/19382014.2014.982376] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
The transcription factor Pancreatic and Duodenal Homeobox-1 (PDX-1) plays a major role in the development and function of pancreatic β-cells and its mutation results in diabetes. In adult β-cells, glucose stimulates transcription of the insulin gene in part by regulating PDX-1 expression, stability and activity. Glucose is also thought to modulate PDX-1 nuclear translocation but in vitro studies examining nucleo-cytoplasmic shuttling of endogenous or ectopically expressed PDX-1 in insulin-secreting cell lines have led to conflicting results. Here we show that endogenous PDX-1 undergoes translocation from the cytoplasm to the nucleus in response to glucose in dispersed rat islets but not in insulin-secreting MIN6, HIT-T15, or INS832/13 cells. Interestingly, however, we found that a PDX-1-GFP fusion protein can shuttle from the cytoplasm to the nucleus in response to glucose stimulation in HIT-T15 cells. Our results suggest that the regulation of endogenous PDX-1 sub-cellular localization by glucose is observed in primary islets and that care should be taken when interpreting data from insulin-secreting cell lines.
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Key Words
- ANOVA, analysis of variance
- BSA, bovine serum albumin
- DAPI, 4′, 6-diamidino-2-phenylindole
- DMEM, dulbecco's modified eagle medium
- EDTA, ethylenediaminetetraacetic acid
- GFP, green fluorescent protein
- HDAC, histone deacetylase
- HIT-T15
- INS832/13
- KRBH, krebs ringer bicarbonate hepes
- MIN6
- MODY, maturity-onset diabetes of the young
- PDX-1
- PDX-1, pancreatic and duodenal homeobox-1
- SEM, standard error of the mean
- SUMO, small ubiquitin-like modifier
- T2D, type 2 diabetes
- ZDF, zucker diabetic fatty
- glucose
- glucose-stimulated insulin secretion
- nucleo-cytoplasmic shuttling
- pancreatic β cells
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Affiliation(s)
- Meriem Semache
- Montreal Diabetes Research Center; CRCHUM; Montreal, QC, Canada
- Department of Biochemistry; University of Montreal; QC, Canada
| | - Julien Ghislain
- Montreal Diabetes Research Center; CRCHUM; Montreal, QC, Canada
| | - Bader Zarrouki
- Montreal Diabetes Research Center; CRCHUM; Montreal, QC, Canada
- Department of Medicine; University of Montreal; QC, Canada
| | | | - Vincent Poitout
- Montreal Diabetes Research Center; CRCHUM; Montreal, QC, Canada
- Department of Biochemistry; University of Montreal; QC, Canada
- Department of Medicine; University of Montreal; QC, Canada
- Correspondence to: Vincent Poitout;
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89
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Constantinescu AA, Gleizes C, Alhosin M, Yala E, Zobairi F, Leclercq A, Stoian G, Mitrea IL, Prévost G, Toti F, Kessler L. Exocrine cell-derived microparticles in response to lipopolysaccharide promote endocrine dysfunction in cystic fibrosis. J Cyst Fibros 2013; 13:219-26. [PMID: 24095207 DOI: 10.1016/j.jcf.2013.08.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2013] [Revised: 08/26/2013] [Accepted: 08/30/2013] [Indexed: 10/26/2022]
Abstract
BACKGROUND Diabetes in cystic fibrosis (CF) is a result of exocrine pancreas alteration followed by endocrine dysfunction at a later stage. Microparticles (MPs) are plasma membrane fragments shed from stimulated or damaged cells that act as cellular effectors. Our aim was to identify a new form of interaction between exocrine and endocrine pancreatic cells mediated by exocrine MPs, in the context of recurrent infection in CF. METHODS MPs from either human exocrine CFTRΔF508-mutated (CFPAC-1) cells or exocrine normal pancreatic (PANC-1) cells were collected after treatment by LPS from Pseudomonas aeruginosa and applied to rat endocrine normal insulin-secreting RIN-m5F cells. MP membrane integration in target cells was established by confocal microscopy and flow cytometry using PKH26 lipid probe. Apoptosis, lysosomal activity, insulin secretion were measured after 18 h. MP-mediated NF-κB activation was measured in HEK-Blue reporter cells by SEAP reporter gene system and in RIN-m5F cells by Western blot. In endocrine normal cells, CFTR inhibition was achieved using Inhibitor-172. RESULTS Compared to PANC-1, MPs from CFPAC-1 significantly reduced insulin secretion and lysosomal activity in RIN-m5F. MPs induced NF-κB activation by increasing the level of IκB phosphorylation. Moreover, the inhibition of NF-κB activation using specific inhibitors was associated with a restored insulin secretion. Interestingly, CFTR inhibition in normal RIN-m5F cells promoted apoptosis and decreased insulin secretion. CONCLUSIONS During recurrent infections associated with CF, exocrine MPs may contribute to endocrine cell dysfunction via NF-κB pathways. Membrane CFTR dysfunction is associated with decreased insulin secretion.
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Affiliation(s)
- Andrei Alexandru Constantinescu
- EA7293, Vascular and Tissular Stress in Transplantation, Federation of Translational Medicine of Strasbourg, Faculty of Medicine, University of Strasbourg, 74 route du Rhin, F-67401 Illkirch, Strasbourg, France; Department of Parasitology and Parasitic Diseases and Animal Biology, Faculty of Veterinary Medicine, University of Agronomical Sciences and Veterinary Medicine, 105 spl. Independentei, sector 5, 050097 Bucharest, Romania
| | - Céline Gleizes
- EA7293, Vascular and Tissular Stress in Transplantation, Federation of Translational Medicine of Strasbourg, Faculty of Medicine, University of Strasbourg, 74 route du Rhin, F-67401 Illkirch, Strasbourg, France
| | - Mahmoud Alhosin
- UMR7213 CNRS, Laboratory of Biophotonics and Pharmacology, 74 route du Rhin, F-67401 Illkirch, France
| | - Elhassan Yala
- EA7293, Vascular and Tissular Stress in Transplantation, Federation of Translational Medicine of Strasbourg, Faculty of Medicine, University of Strasbourg, 74 route du Rhin, F-67401 Illkirch, Strasbourg, France
| | - Fatiha Zobairi
- EA7293, Vascular and Tissular Stress in Transplantation, Federation of Translational Medicine of Strasbourg, Faculty of Medicine, University of Strasbourg, 74 route du Rhin, F-67401 Illkirch, Strasbourg, France
| | - Alexandre Leclercq
- Department of Pneumology, University Hospital, 1 place de L'hôpital, CHU de Strasbourg, BP426, 67091 Strasbourg Cedex, France
| | - Gheorghe Stoian
- Department of Biochemistry and Molecular Biology, Faculty of Biology, University of Bucharest, 91-95 spl. Independentei, sector 5, 050095 Bucharest, Romania
| | - Ioan Liviu Mitrea
- Department of Parasitology and Parasitic Diseases and Animal Biology, Faculty of Veterinary Medicine, University of Agronomical Sciences and Veterinary Medicine, 105 spl. Independentei, sector 5, 050097 Bucharest, Romania
| | - Gilles Prévost
- EA7290 Early Bacterial Virulence, Faculty of Medicine, University of Strasbourg, 3 rue Koeberlé, F-67000 Strasbourg, France
| | - Florence Toti
- UMR7213 CNRS, Laboratory of Biophotonics and Pharmacology, 74 route du Rhin, F-67401 Illkirch, France; Faculty of Pharmacy, University of Strasbourg, 74 route du Rhin, F-67401 Illkirch, France
| | - Laurence Kessler
- EA7293, Vascular and Tissular Stress in Transplantation, Federation of Translational Medicine of Strasbourg, Faculty of Medicine, University of Strasbourg, 74 route du Rhin, F-67401 Illkirch, Strasbourg, France; Department of Diabetology, University Hospital, 1 place de l'Hôpital, CHU de Strasbourg, BP421, 67091 Strasbourg Cedex, France.
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90
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Semache M, Zarrouki B, Fontés G, Fogarty S, Kikani C, Chawki MB, Rutter J, Poitout V. Per-Arnt-Sim kinase regulates pancreatic duodenal homeobox-1 protein stability via phosphorylation of glycogen synthase kinase 3β in pancreatic β-cells. J Biol Chem 2013; 288:24825-33. [PMID: 23853095 DOI: 10.1074/jbc.m113.495945] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
In pancreatic β-cells, glucose induces the binding of the transcription factor pancreatic duodenal homeobox-1 (PDX-1) to the insulin gene promoter to activate insulin gene transcription. At low glucose levels, glycogen synthase kinase 3β (GSK3β) is known to phosphorylate PDX-1 on C-terminal serine residues, which triggers PDX-1 proteasomal degradation. We previously showed that the serine/threonine Per-Arnt-Sim domain-containing kinase (PASK) regulates insulin gene transcription via PDX-1. However, the mechanisms underlying this regulation are unknown. In this study, we aimed to identify the role of PASK in the regulation of PDX-1 phosphorylation, protein expression, and stability in insulin-secreting cells and isolated rodent islets of Langerhans. We observed that glucose induces a decrease in overall PDX-1 serine phosphorylation and that overexpression of WT PASK mimics this effect. In vitro, PASK directly phosphorylates GSK3β on its inactivating phosphorylation site Ser(9). Overexpression of a kinase-dead (KD), dominant negative version of PASK blocks glucose-induced Ser(9) phosphorylation of GSK3β. Accordingly, GSK3β Ser(9) phosphorylation is reduced in islets from pask-null mice. Overexpression of WT PASK or KD GSK3β protects PDX-1 from degradation and results in increased PDX-1 protein abundance. Conversely, overexpression of KD PASK blocks glucose-induction of PDX-1 protein. We conclude that PASK phosphorylates and inactivates GSK3β, thereby preventing PDX-1 serine phosphorylation and alleviating GSK3β-mediated PDX-1 protein degradation in pancreatic β-cells.
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Affiliation(s)
- Meriem Semache
- Montreal Diabetes Research Center, CRCHUM, Quebec City H1W4A4, Canada
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91
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Imai Y, Dobrian AD, Morris MA, Nadler JL. Islet inflammation: a unifying target for diabetes treatment? Trends Endocrinol Metab 2013; 24:351-60. [PMID: 23484621 PMCID: PMC3686848 DOI: 10.1016/j.tem.2013.01.007] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2012] [Revised: 01/22/2013] [Accepted: 01/23/2013] [Indexed: 12/12/2022]
Abstract
In the past decade, islet inflammation has emerged as a contributor to the loss of functional β cell mass in both type 1 (T1D) and type 2 diabetes (T2D). Evidence supports the idea that overnutrition and insulin resistance result in the production of proinflammatory mediators by β cells. In addition to compromising β cell function and survival, cytokines may recruit macrophages into islets, thus augmenting inflammation. Limited but intriguing data imply a role of adaptive immune response in islet dysfunction in T2D. Clinical trials have validated anti-inflammatory therapies in T2D, whereas immune therapy for T1D remains challenging. Further research is required to improve our understanding of islet inflammatory pathways and to identify more effective therapeutic targets for T1D and T2D.
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Affiliation(s)
- Yumi Imai
- Department of Internal Medicine, Strelitz Diabetes Center, Eastern Virginia Medical School, Norfolk, VA 23507, USA.
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92
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Lucas K, Maes M. Role of the Toll Like receptor (TLR) radical cycle in chronic inflammation: possible treatments targeting the TLR4 pathway. Mol Neurobiol 2013; 48:190-204. [PMID: 23436141 PMCID: PMC7091222 DOI: 10.1007/s12035-013-8425-7] [Citation(s) in RCA: 338] [Impact Index Per Article: 30.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2012] [Accepted: 02/05/2013] [Indexed: 12/11/2022]
Abstract
Activation of the Toll-like receptor 4 (TLR4) complex, a receptor of the innate immune system, may underpin the pathophysiology of many human diseases, including asthma, cardiovascular disorder, diabetes, obesity, metabolic syndrome, autoimmune disorders, neuroinflammatory disorders, schizophrenia, bipolar disorder, autism, clinical depression, chronic fatigue syndrome, alcohol abuse, and toluene inhalation. TLRs are pattern recognition receptors that recognize damage-associated molecular patterns and pathogen-associated molecular patterns, including lipopolysaccharide (LPS) from gram-negative bacteria. Here we focus on the environmental factors, which are known to trigger TLR4, e.g., ozone, atmosphere particulate matter, long-lived reactive oxygen intermediate, pentachlorophenol, ionizing radiation, and toluene. Activation of the TLR4 pathways may cause chronic inflammation and increased production of reactive oxygen and nitrogen species (ROS/RNS) and oxidative and nitrosative stress and therefore TLR-related diseases. This implies that drugs or substances that modify these pathways may prevent or improve the abovementioned diseases. Here we review some of the most promising drugs and agents that have the potential to attenuate TLR-mediated inflammation, e.g., anti-LPS strategies that aim to neutralize LPS (synthetic anti-LPS peptides and recombinant factor C) and TLR4/MyD88 antagonists, including eritoran, CyP, EM-163, epigallocatechin-3-gallate, 6-shogaol, cinnamon extract, N-acetylcysteine, melatonin, and molecular hydrogen. The authors posit that activation of the TLR radical (ROS/RNS) cycle is a common pathway underpinning many "civilization" disorders and that targeting the TLR radical cycle may be an effective method to treat many inflammatory disorders.
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Affiliation(s)
- Kurt Lucas
- Sportzenkoppel 54, 22359, Hamburg, Germany
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93
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Panwar H, Rashmi HM, Batish VK, Grover S. Probiotics as potential biotherapeutics in the management of type 2 diabetes - prospects and perspectives. Diabetes Metab Res Rev 2013; 29:103-12. [PMID: 23225499 DOI: 10.1002/dmrr.2376] [Citation(s) in RCA: 101] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2012] [Revised: 07/12/2012] [Accepted: 11/03/2012] [Indexed: 12/23/2022]
Abstract
Diabetes mellitus is a looming epidemic worldwide, affecting almost all major sections of society, creating burdens on global health and economy. A large number of studies have identified a series of multiple risk factors such as genetic predisposition, epigenetic changes, unhealthy lifestyle, and altered gut microbiota that cause increased adiposity, β-cell dysfunction, hyperglycemia, hypercholesterolemia, adiposity, dyslipidaemia, metabolic endotoxemia, systemic inflammation, intestinal permeability (leaky gut), defective secretion of incretins and oxidative stress associated with type 2 diabetes (T2D). Recent studies have proposed multifactorial interventions including dietary manipulation in the management of T2D. The same interventions have also been recommended by many national and international diabetes associations. These studies are aimed at deciphering the gut microbial influence on health and disease. Interestingly, results from several genomic, metagenomic and metabolomic studies have provided substantial information to target gut microbiota by dietary interventions for the management of T2D. Probiotics particularly lactobacilli and bifidobacteria have recently emerged as the prospective biotherapeutics with proven efficacy demonstrated in various in vitro and in vivo animal models adequately supported with their established multifunctional roles and mechanism of action for the prevention and disease treatment. The dietary interventions in conjunction with probiotics - a novel multifactorial strategy to abrogate progression and development of diabetes - hold considerable promise through improving the altered gut microbial composition and by targeting all the possible risk factors. This review will highlight the new developments in probiotic interventions and future prospects for exploring probiotic therapy in the prevention and control of lifestyle diseases like T2D.
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Affiliation(s)
- Harsh Panwar
- Molecular Biology Unit, Dairy Microbiology Division, National Dairy Research Institute, Karnal, Haryana, India
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94
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Williams KH, Shackel NA, Gorrell MD, McLennan SV, Twigg SM. Diabetes and nonalcoholic Fatty liver disease: a pathogenic duo. Endocr Rev 2013; 34:84-129. [PMID: 23238855 DOI: 10.1210/er.2012-1009] [Citation(s) in RCA: 168] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Recent data increasingly support a complex interplay between the metabolic condition diabetes mellitus and the pathologically defined nonalcoholic fatty liver disease (NAFLD). NAFLD predicts the development of type 2 diabetes and vice versa, and each condition may serve as a progression factor for the other. Although the association of diabetes and NAFLD is likely to be partly the result of a "common soil," it is also probable that diabetes interacts with NAFLD through specific pathogenic mechanisms. In particular, through interrelated metabolic pathways currently only partly understood, diabetes appears to accelerate the progression of NAFLD to nonalcoholic steatohepatitis, defined by the presence of necroinflammation, with varying degrees of liver fibrosis. In the research setting, obstacles that have made the identification of clinically significant NAFLD, and particularly nonalcoholic steatohepatitis, difficult are being addressed with the use of new imaging techniques combined with risk algorithms derived from peripheral blood profiling. These techniques are likely to be used in the diabetes population in the near future. This review examines the pathogenic links between NAFLD and diabetes by exploring the epidemiological evidence in humans and also through newer animal models. Emerging technology to help screen noninvasively for differing pathological forms of NAFLD and the potential role of preventive and therapeutic approaches for NAFLD in the setting of diabetes are also examined.
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Affiliation(s)
- K H Williams
- Sydney Medical School and the Bosch Institute, The University of Sydney, Sydney, New South Wales 2006, Australia
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