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Fiorentino TV, De Vito F, Suraci E, Marasco R, Hribal ML, Luzza F, Sesti G. Obesity and overweight are linked to increased sodium-glucose cotransporter 1 and glucose transporter 5 levels in duodenum. Obesity (Silver Spring) 2023; 31:724-731. [PMID: 36746764 DOI: 10.1002/oby.23653] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Revised: 10/03/2022] [Accepted: 10/23/2022] [Indexed: 02/08/2023]
Abstract
OBJECTIVE Prior evidence indicates that individuals with obesity have an accelerated intestinal glucose absorption. This cross-sectional study evaluated whether those with overweight or obesity display higher duodenal protein levels of the glucose carriers sodium-glucose cotransporter 1 (SGLT-1), glucose transporter 2 (GLUT-2), and glucose transporter 5 (GLUT-5). METHODS SGLT-1, GLUT-2, and GLUT-5 protein levels were assessed on duodenal mucosa biopsies of 52 individuals without diabetes categorized on the basis of their BMI as lean, with overweight, or with obesity. RESULTS Individuals with overweight and obesity exhibited progressively increased duodenal protein levels of SGLT-1 and GLUT-5 as compared with the lean group. Conversely, no differences in duodenal GLUT-2 abundance were found among the three groups. Univariate analysis showed that SGLT-1 and GLUT-5 protein levels were positively correlated with BMI, waist circumference, 1-hour post-load glucose, fasting and post-load insulin, and insulin secretion and resistance levels. Furthermore, a positive relationship was detected between intestinal GLUT-5 levels and serum uric acid concentrations, a product of fructose metabolism known to be involved in the pathogenesis of obesity and its complications. CONCLUSIONS Individuals with overweight and obesity display enhanced duodenal SGLT-1 and GLUT-5 abundance, which correlates with increased postprandial glucose concentrations, insulin resistance, and hyperinsulinemia.
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Affiliation(s)
- Teresa Vanessa Fiorentino
- Department of Medical and Surgical Sciences, University Magna Graecia of Catanzaro, Catanzaro, Italy
| | - Francesca De Vito
- Department of Medical and Surgical Sciences, University Magna Graecia of Catanzaro, Catanzaro, Italy
| | - Evelina Suraci
- Department of Health Sciences, University Magna Graecia of Catanzaro, Catanzaro, Italy
| | - Raffaella Marasco
- Department of Health Sciences, University Magna Graecia of Catanzaro, Catanzaro, Italy
| | - Marta Letizia Hribal
- Department of Medical and Surgical Sciences, University Magna Graecia of Catanzaro, Catanzaro, Italy
| | - Francesco Luzza
- Department of Health Sciences, University Magna Graecia of Catanzaro, Catanzaro, Italy
| | - Giorgio Sesti
- Department of Clinical and Molecular Medicine, University of Rome-Sapienza, Rome, Italy
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Chen X, Yan Y, Weng Z, Chen C, Lv M, Lin Q, Du Q, Shen X, Yang L. TAK-875 Mitigates β-Cell Lipotoxicity-Induced Metaflammation Damage through Inhibiting the TLR4-NF- κB Pathway. J Diabetes Res 2019; 2019:5487962. [PMID: 31934590 PMCID: PMC6942802 DOI: 10.1155/2019/5487962] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/05/2019] [Accepted: 09/03/2019] [Indexed: 01/09/2023] Open
Abstract
Metabolic inflammatory damage, characterized by Toll-like receptor 4 (TLR4) signaling activation, is a major mechanism underlying lipotoxicity-induced β-cell damage. The present study is aimed at determining whether G protein-coupled receptor 4 (GPR40) agonist can improve β-cell lipotoxicity-induced damage by inhibiting the TLR4-NF-κB pathway. Lipotoxicity, inflammation-damaged β-cells, obese SD, and TLR4KO rat models were used in the study. In vitro, TAK-875 inhibited the lipotoxicity- and LPS-induced β-cell apoptosis in a concentration-dependent manner, improved the insulin secretion, and inhibited the expression of TLR4 and NF-κB subunit P65. Besides, silencing of TLR4 expression enhanced the protective effects of TAK-875, while TLR4 overexpression attenuated this protective effect. Activation of TLR4 or NF-κB attenuated the antagonism of TAK-875 on PA-induced damage. Moreover, the above process of TAK-875 was partially independent of GPR40 expression. TAK-875 reduced the body weight and inflammatory factors, rebalanced the number and distribution of α or β-cells, inhibited the apoptosis of islet cells, and inhibited the expression of TLR4 and NF-κB subunit P65 in obese rats. Further knockout of the rat TLR4 gene delayed the damage induced by the high-fat diet and synergy with the action of TAK-875. These data suggest that GPR40 agonists antagonized the lipotoxicity β-cell damage by inhibiting the TLR4-NF-κB pathway.
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Affiliation(s)
- Xide Chen
- Endocrinology Department, The First Affiliated Hospital of Fujian Medical University, Fuzhou, 350005 Fujian, China
| | - Yuanli Yan
- Endocrinology Department, The First Affiliated Hospital of Fujian Medical University, Fuzhou, 350005 Fujian, China
| | - Zhiyan Weng
- Endocrinology Department, The First Affiliated Hospital of Fujian Medical University, Fuzhou, 350005 Fujian, China
| | - Chao Chen
- Endocrinology Department, The First Affiliated Hospital of Fujian Medical University, Fuzhou, 350005 Fujian, China
| | - Miaoru Lv
- Endocrinology Department, The First Affiliated Hospital of Fujian Medical University, Fuzhou, 350005 Fujian, China
| | - Qingwen Lin
- Endocrinology Department, The First Affiliated Hospital of Fujian Medical University, Fuzhou, 350005 Fujian, China
| | - Qiuxia Du
- Endocrinology Department, The First Affiliated Hospital of Fujian Medical University, Fuzhou, 350005 Fujian, China
| | - Ximei Shen
- Endocrinology Department, The First Affiliated Hospital of Fujian Medical University, Fuzhou, 350005 Fujian, China
- Diabetes Research Institute of Fujian Province, Fuzhou, 350005 Fujian, China
| | - Liyong Yang
- Endocrinology Department, The First Affiliated Hospital of Fujian Medical University, Fuzhou, 350005 Fujian, China
- Diabetes Research Institute of Fujian Province, Fuzhou, 350005 Fujian, China
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Effect of miglitol on the suppression of nonalcoholic steatohepatitis development and improvement of the gut environment in a rodent model. J Gastroenterol 2017; 52:1180-1191. [PMID: 28349245 PMCID: PMC5666045 DOI: 10.1007/s00535-017-1331-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Accepted: 03/16/2017] [Indexed: 02/07/2023]
Abstract
BACKGROUND The gut environment has been considered to play a role in the development of nonalcoholic steatohepatitis (NASH). α-glucosidase inhibitors (α-GIs) delay carbohydrate absorption and may change the gut environment. We considered that the protective effect of α-GIs against NASH development is related to changes in the gut environment and thus investigated the effects of miglitol, an α-GI, on NASH development and the gut environment. METHODS Mice were divided into three groups and fed a normal chow diet (NCD), a high-fat high-sucrose diet (HFHSD), or HFHSD plus 0.04% miglitol (HFHSD plus M) for 12 weeks. RESULTS Insulin resistance developed more in the HFHSD group than in the NCD group, whereas it was suppressed in the HFHSD plus M group. NASH was evaluated histologically, biochemically, and on the basis of messenger RNA expression levels. Miglitol treatment suppressed HFHSD-induced NASH development with the suppression of hepatic Toll-like receptor 4 expression, increased glucagon-like peptide 1 (GLP-1) concentration, and reduced lipopolysaccharide concentration in portal plasma. Regarding the gut environment, the intestinal transit time was shortened and colon inflammation was suppressed in the HFHSD plus M group compared with the HFHSD group. Regarding the gut microbiota, the abundances of Erysipelotrichaceae and Coriobacteriaceae were increased in the HFHSD group compared with the NCD group, whereas the increase was suppressed in the HFHSD plus M group. CONCLUSIONS We demonstrated that miglitol has a protective effect against HFHSD-induced NASH development. The increased GLP-1 secretion and the suppression of endotoxemia, associated with the changes in the gut environment, including the gut microbiota, could contribute to the underlying mechanisms.
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Shen X, Yang L, Yan S, Zheng H, Liang L, Cai X, Liao M. Fetuin A promotes lipotoxicity in β cells through the TLR4 signaling pathway and the role of pioglitazone in anti-lipotoxicity. Mol Cell Endocrinol 2015; 412:1-11. [PMID: 25986658 DOI: 10.1016/j.mce.2015.05.014] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/28/2014] [Revised: 05/10/2015] [Accepted: 05/12/2015] [Indexed: 01/19/2023]
Abstract
OBJECTIVE Fetuin A (FetA), a secreted glycoprotein, is known to affect inflammation and insulin resistance (IR) in obese humans and animals. Lipotoxicity from chronic hyperlipidemia damages pancreatic β cells, hastening the onset of diabetes. We sought to determine whether FetA promotes lipotoxicity through modulation of the toll-like receptor 4 (TLR4) inflammatory signaling pathway as well as the protective effect of pioglitazone(PIO) on lipotoxicity. METHODS βTC6, a glucose-sensitive mouse pancreatic β cell line, and Sprague-Dawley rats with diet-induced obesity, were used to investigate FetA-mediated lipotoxicity. Protein expression/activation were measured by Western blotting. Small interfering (si)RNAs for TLR4 were used. Cell apoptosis was quantified by TUNEL analysis or flow cytometry, respectively. Insulin release was assessed with an insulin ELISA. RESULTS FetA dose-dependently aggravated palmitic acid (PA)-induced βTC6 cell apoptosis, insulin secretion impairment, and inhibition of the expression of G-protein-coupled receptor 40 (GPR40) and pancreatic duodenal homeobox-1(PDX-1). Combined FetA + PA induced TLR4 expression, and subsequent inhibition of TLR4 signaling or expression was shown to prevent the strengthening effect of FetA on PA-induced lipotoxicity in βTC6 cells. FetA + PA induced p-JNK and nuclear factor-κB (NF-κB) subunit P65 expression, and inhibition of this activity reduced PA+ FetA lipotoxicity in βTC6 cells. PIO could ameliorate PA+ FetA-induced damage to βTC6 cells. Similarly, PIO improved insulin secretion disorder, reduced apoptosis, decreased FetA, TLR4, p-JNK, NF-κB subunit P65 and cleaved caspase 3 expression, and increased GPR40 and PDX-1 expression in islet β cells of diet-induced obese rats. The correlative bivariate analysis showed that increases in Fetuin A were directly proportional to the development of β cell injury. CONCLUSIONS FetA can promote lipotoxicity in β cells through the TLR4-JNK-NF-κB signaling pathway. The protective effects of PIO on lipotoxicity in β cells may involve the inhibition of the activation of the FetA and TLR4 signaling pathway.
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Affiliation(s)
- Ximei Shen
- Endocrinology Department, the First Affiliated Hospital of Fujian Medical University, Fuzhou 350005, Fujian, China
| | - Liyong Yang
- Endocrinology Department, the First Affiliated Hospital of Fujian Medical University, Fuzhou 350005, Fujian, China.
| | - Sunjie Yan
- Endocrinology Department, the First Affiliated Hospital of Fujian Medical University, Fuzhou 350005, Fujian, China
| | - Huanhuan Zheng
- Endocrinology Department, the First Affiliated Hospital of Fujian Medical University, Fuzhou 350005, Fujian, China
| | - Liyu Liang
- Endocrinology Department, the First Affiliated Hospital of Fujian Medical University, Fuzhou 350005, Fujian, China
| | - Xiuhui Cai
- Endocrinology Department, the First Affiliated Hospital of Fujian Medical University, Fuzhou 350005, Fujian, China
| | - Meng Liao
- Endocrinology Department, the First Affiliated Hospital of Fujian Medical University, Fuzhou 350005, Fujian, China
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Wilder-Smith CH, Li X, Ho SS, Leong SM, Wong RK, Koay ES, Ferraris RP. Fructose transporters GLUT5 and GLUT2 expression in adult patients with fructose intolerance. United European Gastroenterol J 2014; 2:14-21. [PMID: 24918004 DOI: 10.1177/2050640613505279] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/29/2013] [Accepted: 08/24/2013] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Gastrointestinal symptoms and malabsorption following fructose ingestion (fructose intolerance) are common in functional gastrointestinal disorders (FGID). The underlying mechanism is unclear, but is hypothesized to be related an abnormality of intestinal fructose transporter proteins. OBJECTIVE To assess the expression of the main intestinal fructose transporter proteins, glucose transport protein 5 (GLUT5) and 2 (GLUT2), in FGID. METHODS The expression of GLUT5 and GLUT2 protein and mRNA in small intestinal biopsy tissue was investigated using real-time reverse-transcription PCR and Western immunoblotting in 11 adults with FGID and fructose intolerance ascertained by breath testing and in 15 controls. RESULTS Median expression levels of GLUT5 mRNA normalized to beta-actin were 0.18 (interquartile range, IQR, 0.13-0.21) in patients and 0.17 (IQR 0.12-0.19) in controls (p > 0.05). Respective levels of GLUT2 mRNA were 0.26 (IQR 0.20-0.31) and 0.26 (IQR 0.19-0.31) (p > 0.05). Median expression levels of GLUT5 protein normalized to alpha-tubulin were 0.95 (IQR 0.52-1.68) in patients and 0.95 (IQR 0.59-1.15) in controls (p > 0.05). Respective protein expression levels for GLUT2 were 1.56 (IQR 1.06-2.14) and 1.35 (IQR 0.96-1.79) (p > 0.05). CONCLUSIONS Human fructose intolerance may not be associated with marked changes in GLUT5 and GLUT2 expression. Replication of these results in a larger subject group, including measures of transporter activation and membrane and subcellular localization, is warranted.
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Affiliation(s)
- Clive H Wilder-Smith
- Brain-Gut Research Group, Bern, Switzerland ; Neurogastroenterology Unit, Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore
| | - Xinhua Li
- Neurogastroenterology Unit, Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore
| | - Sherry Sy Ho
- Molecular Diagnosis Centre, Department of Laboratory Medicine, National University Hospital, Singapore
| | - Sai Mun Leong
- Neurogastroenterology Unit, Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore
| | - Reuben K Wong
- Neurogastroenterology Unit, Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore
| | - Evelyn Sc Koay
- Molecular Diagnosis Centre, Department of Laboratory Medicine, National University Hospital, Singapore ; Department of Pathology, Yong Loo Lin School of Medicine, National University of Singapore
| | - Ronaldo P Ferraris
- Department of Pharmacology & Physiology, UMDNJ - New Jersey Medical School, Newark, USA
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Lee CY. Chronic restraint stress induces intestinal inflammation and alters the expression of hexose and lipid transporters. Clin Exp Pharmacol Physiol 2014; 40:385-91. [PMID: 23586523 DOI: 10.1111/1440-1681.12096] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2013] [Revised: 03/28/2013] [Accepted: 04/10/2013] [Indexed: 11/26/2022]
Abstract
Psychosocial stress is reported to be one of the main causes of obesity. Based on observations in studies that relate stress and gut inflammation to obesity, the present study hypothesized that chronic stress, via inflammation, alters the expression of nutrient transporters and contributes to the development of metabolic syndrome. Rats were exposed to restraint stress for 4 h/day for 5 days/week for eight consecutive weeks. Different segments of rat intestine were then collected and analysed for signs of pathophysiological changes and the expression of Niemann-Pick C1-like-1 (NPC1L1), sodium-dependent glucose transporter-1 (SLC5A1, previously known as SGLT1) and facilitative glucose transporter-2 (SLC2A2, previously known as GLUT2). In a separate experiment, the total anti-oxidant activity (TAA)-time profile of control isolated intestinal segments was measured. Stress decreased the expression of NPC1L1 in the ileum and upregulated SLC5A1 in both the jejunum and ileum and SLC2A2 in the duodenum. Inflammation and morphological changes were observed in the proximal region of the intestine of stressed animals. Compared with jejunal and ileal segments, the rate of increase in TAA was higher in the duodenum, indicating that the segment contained less anti-oxidants; anti-oxidants may function to protect the tissues. In conclusion, stress alters the expression of hexose and lipid transporters in the gut. The site-specific increase in the expression of SLC5A1 and SLC2A2 may be correlated with pathological changes in the intestine. The ileum may be protected, in part, by gut anti-oxidants. Collectively, the data suggest that apart from causing inflammation, chronic stress may promote sugar uptake and contribute to hyperglycaemia.
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Affiliation(s)
- Chooi Yeng Lee
- Discipline of Pharmacy, Monash University Sunway Campus, Selangor, Malaysia.
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Octreotide promotes weight loss via suppression of intestinal MTP and apoB48 expression in diet-induced obesity rats. Nutrition 2013; 29:1259-65. [PMID: 23911221 DOI: 10.1016/j.nut.2013.01.013] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2012] [Revised: 01/11/2013] [Accepted: 01/14/2013] [Indexed: 02/05/2023]
Abstract
OBJECTIVE The goal of this study was to investigate the effect of octreotide on the expression of intestinal fat absorption-associated apolipoproteinB48 (apoB48), microsomal triglyceride transfer protein (MTP) and apolipoproteinAIV (apoAIV) in a high-fat diet-induced obesity rat model. METHODS Sprague-Dawley rats were placed into a control or high-fat diet group. Obese rats from the high-fat diet group were further divided into an obese group and an octreotide-treated group. Rats in the octreotide-treated group were subcutaneously injected with octreotide (40 μg/kg body weight) twice daily for 8 d. Body weight, fasting plasma glucose (FPG), fasting serum insulin, triglyceride (TG), total cholesterol (TC), and high density lipoprotein-cholesterol (HDL-C) were measured. Intestinal MTP, apoB48, and apoAIV expression levels were determined by real-time polymerase chain reaction, Western blot, or enzyme-linked immunosorbent assay analysis. RESULTS We found high-fat diet-induced obesity rats express more apoB, MTP, and apoAIV mRNA as well as apoB48 and MTP protein in the intestine than normal chow-fed rats. This observation occurred along with increased body weight, FPG, TG, TC, fasting serum insulin, and Homeostatic Model Assessment value. Octreotide intervention significantly decreased body weight and blood parameters, and down-regulated expression of apoB mRNA and apoB48 protein, as well as MTP mRNA and proteins. However, apoAIV mRNA was not significantly different between obese and octreotide-treated rats although it was decreased by 47%. CONCLUSION High-fat diet-induced obesity is associated with increased expression of apoB48, MTP, and apoAIV in the intestine. Octreotide intervention inhibited the overexpression of apoB48 and MTP, and consequently brought about reduced fat absorption and weight loss.
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Mace OJ, Schindler M, Patel S. The regulation of K- and L-cell activity by GLUT2 and the calcium-sensing receptor CasR in rat small intestine. J Physiol 2012; 590:2917-36. [PMID: 22495587 DOI: 10.1113/jphysiol.2011.223800] [Citation(s) in RCA: 183] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Intestinal enteroendocrine cells (IECs) secrete gut peptides in response to both nutrients and non-nutrients. Glucose and amino acids both stimulate gut peptide secretion. Our hypothesis was that the facilitative glucose transporter, GLUT2, could act as a glucose sensor and the calcium-sensing receptor, CasR, could detect amino acids in the intestine to modify gut peptide secretion. We used isolated loops of rat small intestine to study the secretion of gluco-insulinotropic peptide (GIP), glucagon-like peptide-1 (GLP-1) and peptide tyrosine tyrosine (PYY) secretion stimulated by luminal perfusion of nutrients or bile acid. Inhibition of the sodium-dependent glucose cotransporter 1 (SGLT1) with phloridzin partially inhibited GIP, GLP-1 and PYY secretion by 45%, suggesting another glucose sensor might be involved in modulating peptide secretion. The response was completely abolished in the presence of the GLUT2 inhibitors phloretin or cytochalasin B. Given that GLUT2 modified gut peptide secretion stimulated by glucose, we investigated whether it was involved in the secretion of gut peptide by other gut peptide secretagogues. Phloretin completely abolished gut peptide secretion stimulated by artificial sweetener (sucralose), dipeptide (glycylsarcosine), lipid (oleoylethanolamine), short chain fatty acid (propionate) and major rat bile acid (taurocholate) indicating a fundamental position for GLUT2 in the gut peptide secretory mechanism. We investigated how GLUT2 was able to influence gut peptide secretion mediated by a diverse range of stimulators and discovered that GLUT2 affected membrane depolarisation through the closure of K+(ATP)-sensitive channels. In the absence of SGLT1 activity (or presence of phloridzin), the secretion of GIP, GLP-1 and PYY was sensitive to K+(ATP)-sensitive channel modulators tolbutamide and diazoxide. L-amino acids phenylalanine (Phe), tryptophan (Trp), asparagine (Asn), arginine (Arg) and glutamine (Gln) also stimulated GIP, GLP-1 and PYY secretion, which was completely abolished when extracellular Ca2+ was absent. The gut peptide response stimulated by the amino acids was also blocked by the CasR inhibitor Calhex 231 and augmented by the CasR agonist NPS-R568. GLUT2 and CasR regulate K- and L-cell activity in response to nutrient and non-nutrient stimuli.
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