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Faniyan TS, Zhang X, Morgan DA, Robles J, Bathina S, Brookes PS, Rahmouni K, Perry RJ, Chhabra KH. A kidney-hypothalamus axis promotes compensatory glucose production in response to glycosuria. eLife 2024; 12:RP91540. [PMID: 39082939 PMCID: PMC11290820 DOI: 10.7554/elife.91540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/02/2024] Open
Abstract
The kidneys facilitate energy conservation through reabsorption of nutrients including glucose. Almost all the filtered blood glucose is reabsorbed by the kidneys. Loss of glucose in urine (glycosuria) is offset by an increase in endogenous glucose production to maintain normal energy supply in the body. How the body senses this glucose loss and consequently enhances glucose production is unclear. Using renal Slc2a2 (also known as Glut2) knockout mice, we demonstrate that elevated glycosuria activates the hypothalamic-pituitary-adrenal axis, which in turn drives endogenous glucose production. This phenotype was attenuated by selective afferent renal denervation, indicating the involvement of the afferent nerves in promoting the compensatory increase in glucose production. In addition, through plasma proteomics analyses we observed that acute phase proteins - which are usually involved in the body's defense mechanisms against a threat - were the top candidates which were either upregulated or downregulated in renal Slc2a2 KO mice. Overall, afferent renal nerves contribute to promoting endogenous glucose production in response to elevated glycosuria and loss of glucose in urine is sensed as a biological threat in mice. These findings may be useful in improving the efficiency of drugs like SGLT2 inhibitors that are intended to treat hyperglycemia by enhancing glycosuria but are met with a compensatory increase in endogenous glucose production.
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Affiliation(s)
- Tumininu S Faniyan
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Rochester Medical CenterRochesterUnited States
| | - Xinyi Zhang
- Department of Cellular and Molecular Physiology, Yale UniversityNew HavenUnited States
| | - Donald A Morgan
- Department of Neuroscience and Pharmacology, University of Iowa Carver College of MedicineIowa CityUnited States
| | - Jorge Robles
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Rochester Medical CenterRochesterUnited States
| | - Siresha Bathina
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Rochester Medical CenterRochesterUnited States
| | - Paul S Brookes
- Department of Anesthesiology, University of Rochester Medical CenterRochesterUnited States
| | - Kamal Rahmouni
- Department of Neuroscience and Pharmacology, University of Iowa Carver College of MedicineIowa CityUnited States
| | - Rachel J Perry
- Department of Cellular and Molecular Physiology, Yale UniversityNew HavenUnited States
| | - Kavaljit H Chhabra
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Rochester Medical CenterRochesterUnited States
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Hasanian-Langroudi F, Ghasemi A, Hedayati M, Siadat SD, Tohidi M. Novel Insight into the Effect of Probiotics in the Regulation of the Most Important Pathways Involved in the Pathogenesis of Type 2 Diabetes Mellitus. Probiotics Antimicrob Proteins 2024; 16:829-844. [PMID: 37162668 DOI: 10.1007/s12602-023-10056-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/02/2023] [Indexed: 05/11/2023]
Abstract
Type 2 diabetes mellitus (T2DM) is considered one of the most common disorders worldwide. Although several treatment modalities have been developed, the existing interventions have not yielded the desired results. Therefore, researchers have focused on finding treatment choices with low toxicity and few adverse effects that could control T2DM efficiently. Various types of research on the role of gut microbiota in developing T2DM and its related complications have led to the growing interest in probiotic supplementation. Several properties make these organisms unique in terms of human health, including their low cost, high reliability, and good safety profile. Emerging evidence has demonstrated that three of the most important signaling pathways, including nuclear factor kappa B (NF-κB), phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt), and nuclear factor erythroid 2-related factor 2 (Nrf2), which involved in the pathogenesis of T2DM, play key functions in the effects of probiotics on this disease. Hence, we will focus on the clinical applications of probiotics in the management of T2DM. Then, we will also discuss the roles of the involvement of various probiotics in the regulation of the most important signaling pathways (NF-κB, PI3K/Akt, and Nrf2) involved in the pathogenesis of T2DM.
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Affiliation(s)
- Farzaneh Hasanian-Langroudi
- Prevention of Metabolic Disorders Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, P.O. Box, Tehran, 19395-4763, Iran
| | - Asghar Ghasemi
- Endocrine Physiology Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mehdi Hedayati
- Cellular and Molecular Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Seyed Davar Siadat
- Department of Mycobacteriology and Pulmonary Research, Pasteur Institute of Iran, Tehran, Iran.
- Microbiology Research Center, Pasteur Institute of Iran, Tehran, Iran.
| | - Maryam Tohidi
- Prevention of Metabolic Disorders Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, P.O. Box, Tehran, 19395-4763, Iran.
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3
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Faniyan TS, Zhang X, Morgan DA, Robles J, Bathina S, Brookes PS, Rahmouni K, Perry RJ, Chhabra KH. A kidney-hypothalamus axis promotes compensatory glucose production in response to glycosuria. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.09.01.555894. [PMID: 37790458 PMCID: PMC10542134 DOI: 10.1101/2023.09.01.555894] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/05/2023]
Abstract
The kidneys facilitate energy conservation through reabsorption of nutrients including glucose. Almost all the filtered blood glucose is reabsorbed by the kidneys. Loss of glucose in urine (glycosuria) is offset by an increase in endogenous glucose production to maintain normal energy supply in the body. How the body senses this glucose loss and consequently enhances glucose production is unclear. Using renal Glut2 knockout mice, we demonstrate that elevated glycosuria activates the hypothalamic-pituitary-adrenal axis, which in turn drives endogenous glucose production. This phenotype was attenuated by selective afferent renal denervation, indicating the involvement of the afferent nerves in promoting the compensatory increase in glucose production. In addition, through plasma proteomics analyses we observed that acute phase proteins - which are usually involved in body's defense mechanisms against a threat - were the top candidates which were either upregulated or downregulated in renal Glut2 KO mice. Overall, afferent renal nerves contribute to promoting endogenous glucose production in response to elevated glycosuria and loss of glucose in urine is sensed as a biological threat in mice. These findings may be useful in improving efficiency of drugs like SGLT2 inhibitors that are intended to treat hyperglycemia by enhancing glycosuria but are met with a compensatory increase in endogenous glucose production.
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4
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Yang G, Su F, Han BX, Su HX, Guo CH, Yu SH, Guan QL, Hou XM. HNF1A induces glioblastoma by upregulating EPS8 and activating PI3K/AKT signaling pathway. Biochem Pharmacol 2024; 223:116133. [PMID: 38494066 DOI: 10.1016/j.bcp.2024.116133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Revised: 01/04/2024] [Accepted: 03/14/2024] [Indexed: 03/19/2024]
Abstract
Despite the exact biological role of HNF1 homolog A (HNF1A) in the regulatory mechanism of glioblastoma (GBM), the molecular mechanism, especially the downstream regulation as a transcription factor, remains to be further elucidated. Immunohistochemistry was used to detect the expression and clinical relevance of HNF1A in GBM patients. CCK8, TUNEL, and subcutaneous tumor formation in nude mice were used to evaluate the effect of HNF1A on GBM in vitro and in vivo. The correction between HNF1A and epidermal growth factor receptor pathway substrate 8 (EPS8) was illustrated by bioinformatics analysis and luciferase assay. Further mechanism was explored that the transcription factor HNF1A regulated the expression of EPS8 and downstream signaling pathways by directly binding to the promoter region of EPS8. Our comprehensive analysis of clinical samples in this study showed that upregulated expression of HNF1A was associated with poor survival in GBM patients. Further, we found that knockdown of HNF1A markedly suppressed the malignant phenotype of GBM cells in vivo and in vitro as well as promoted apoptosis of tumor cells, which was reversed by upregulation of HNF1A. Mechanistically, HNF1A could significantly activate PI3K/AKT signaling pathway by specifically binding to the promoter regions of EPS8. Moreover, overexpression of EPS8 was able to reverse the apoptosis of tumor cells caused by HNF1A knockdown, thereby exacerbating the GBM progression. Correctively, our study has clarified the explicit mechanism by which HNF1A promotes GBM malignancy and provides a new therapeutic target for further clinical application.
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Affiliation(s)
- Gang Yang
- The First Clinical Medical College of Lanzhou University, Lanzhou, Gansu 730000, PR China; Department of Neurosurgery, The First Hospital of Lanzhou University, Lanzhou, Gansu 730000, PR China
| | - Fei Su
- The First Clinical Medical College of Lanzhou University, Lanzhou, Gansu 730000, PR China; Department of Oncology, The First Hospital of Lanzhou University, Lanzhou, Gansu 730000, PR China
| | - Bin-Xiao Han
- Gansu Institute of Medical Information, Institute of Gansu Medical Science Research, Lanzhou, Gansu 730000, PR China
| | - Hong-Xin Su
- Department of Oncology, The First Hospital of Lanzhou University, Lanzhou, Gansu 730000, PR China
| | - Chen-Hao Guo
- The First Clinical Medical College of Lanzhou University, Lanzhou, Gansu 730000, PR China; Department of Oncology, The First Hospital of Lanzhou University, Lanzhou, Gansu 730000, PR China
| | - Shao-Hua Yu
- The First Clinical Medical College of Lanzhou University, Lanzhou, Gansu 730000, PR China; Department of Oncology, The First Hospital of Lanzhou University, Lanzhou, Gansu 730000, PR China
| | - Quan-Lin Guan
- The First Clinical Medical College of Lanzhou University, Lanzhou, Gansu 730000, PR China; Department of Oncology Surgery, The First Hospital of Lanzhou University, Lanzhou, Gansu 730000, PR China.
| | - Xiao-Ming Hou
- Department of Oncology, The First Hospital of Lanzhou University, Lanzhou, Gansu 730000, PR China.
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Shen Z, Hou Y, Zhao G, Tan L, Chen J, Dong Z, Ni C, Pei L. Physiological functions of glucose transporter-2: From cell physiology to links with diabetes mellitus. Heliyon 2024; 10:e25459. [PMID: 38333863 PMCID: PMC10850595 DOI: 10.1016/j.heliyon.2024.e25459] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Revised: 01/26/2024] [Accepted: 01/26/2024] [Indexed: 02/10/2024] Open
Abstract
Glucose is a sugar crucial for human health since it participates in many biochemical reactions. It produces adenosine 5'-triphosphate (ATP) and nucleosides through glucose metabolic and pentose phosphate pathways. These processes require many transporter proteins to assist in transferring glucose across cells, and the most notable ones are glucose transporter-2 (GLUT-2) and sodium/glucose cotransporter 1 (SGLT1). Glucose enters small intestinal epithelial cells from the intestinal lumen by crossing the brush boundary membrane via the SGLT1 cotransporter. It exits the cells by traversing the basolateral membrane through the activity of the GLUT-2 transporter, supplying energy throughout the body. Dysregulation of these glucose transporters is involved in the pathogenesis of several metabolic diseases, such as diabetes. Natural loss of GLUT-2 or its downregulation causes abnormal blood glucose concentrations in the body, such as fasting hypoglycemia and glucose tolerance. Therefore, understanding GLUT-2 physiology is necessary for exploring the mechanisms of diabetes and targeted treatment development. This article reviews how the apical GLUT-2 transporter maintains normal physiological functions of the human body and the adaptive changes this transporter produces under pathological conditions such as diabetes.
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Affiliation(s)
- Zhean Shen
- Xinjiang Institute of Technology, Aksu, China
| | - Yingze Hou
- Sanquan College of Xinxiang Medical University, Xinxiang, China
| | - Guo Zhao
- National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Libi Tan
- School of Laboratory Medicine and Biotechnology, Southern Medical University, China
| | - Jili Chen
- Department of Nutrition and Food Hygiene School of Public Health, Zhejiang University School of Medicine, Hangzhou, China
| | - Ziqi Dong
- School of Public Health, Peking University Health Science Center, Beijing 100021, China
| | - Chunxiao Ni
- Hangzhou Lin ‘an District Center for Disease Control and Prevention, Hangzhou, China
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Chhabra KH, Bathina S, Faniyan TS, Samuel DJ, Raza MU, de Souza Cordeiro LM, Viana Di Prisco G, Atwood BK, Robles J, Bainbridge L, Davis A. ADGRL1 is a glucose receptor involved in mediating energy and glucose homeostasis. Diabetologia 2024; 67:170-189. [PMID: 37712955 PMCID: PMC10709246 DOI: 10.1007/s00125-023-06010-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Accepted: 08/07/2023] [Indexed: 09/16/2023]
Abstract
AIMS/HYPOTHESIS The brain is a major consumer of glucose as an energy source and regulates systemic glucose as well as energy balance. Although glucose transporters such as GLUT2 and sodium-glucose cotransporter 2 (SGLT2) are known to regulate glucose homeostasis and metabolism, the identity of a receptor that binds glucose to activate glucose signalling pathways in the brain is unknown. In this study, we aimed to discover a glucose receptor in the mouse hypothalamus. METHODS Here we used a high molecular mass glucose-biotin polymer to enrich glucose-bound mouse hypothalamic neurons through cell-based affinity chromatography. We then subjected the enriched neurons to proteomic analyses and identified adhesion G-protein coupled receptor 1 (ADGRL1) as a top candidate for a glucose receptor. We validated glucose-ADGRL1 interactions using CHO cells stably expressing human ADGRL1 and ligand-receptor binding assays. We generated and determined the phenotype of global Adgrl1-knockout mice and hypothalamus-specific Adgrl1-deficient mice. We measured the variables related to glucose and energy homeostasis in these mice. We also generated an Adgrl1Cre mouse model to investigate the role of ADGRL1 in sensing glucose using electrophysiology. RESULTS Adgrl1 is highly expressed in the ventromedial nucleus of the hypothalamus (VMH) in mice. Lack of Adgrl1 in the VMH in mice caused fasting hyperinsulinaemia, enhanced glucose-stimulated insulin secretion and insulin resistance. In addition, the Adgrl1-deficient mice had impaired feeding responses to glucose and fasting coupled with abnormal glucose sensing and decreased physical activity before development of obesity and hyperglycaemia. In female mice, ovariectomy was necessary to reveal the contribution of ADGRL1 to energy and glucose homeostasis. CONCLUSIONS/INTERPRETATION Altogether, our findings demonstrate that ADGRL1 binds glucose and is involved in energy as well as glucose homeostasis in a sex-dependent manner. Targeting ADGRL1 may introduce a new class of drugs for the treatment of type 2 diabetes and obesity.
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Affiliation(s)
- Kavaljit H Chhabra
- Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA.
- Department of Pharmacology and Physiology, University of Rochester Medical Center, Rochester, NY, USA.
| | - Siresha Bathina
- Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
| | - Tumininu S Faniyan
- Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
| | - Dennis J Samuel
- Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
| | - Muhammad Ummear Raza
- Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
| | - Leticia Maria de Souza Cordeiro
- Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
| | - Gonzalo Viana Di Prisco
- Department of Pharmacology & Toxicology, Indiana University School of Medicine, Indianapolis, IN, USA
- Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Brady K Atwood
- Department of Pharmacology & Toxicology, Indiana University School of Medicine, Indianapolis, IN, USA
- Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Jorge Robles
- Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
| | - Lauren Bainbridge
- Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
| | - Autumn Davis
- Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
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7
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Xi L, Zhai G, Liu Y, Gong Y, Lu Q, Zhang Z, Liu H, Jin J, Zhu X, Yin Z, Xie S, Han D. Attenuated glucose uptake promotes catabolic metabolism through activated AMPK signaling and impaired insulin signaling in zebrafish. Front Nutr 2023; 10:1187283. [PMID: 37305084 PMCID: PMC10250679 DOI: 10.3389/fnut.2023.1187283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Accepted: 05/04/2023] [Indexed: 06/13/2023] Open
Abstract
Glucose metabolism in fish remains a controversial area of research as many fish species are traditionally considered glucose-intolerant. Although energy homeostasis remodeling has been observed in fish with inhibited fatty acid β-oxidation (FAO), the effects and mechanism of the remodeling caused by blocked glucose uptake remain poorly understood. In this study, we blocked glucose uptake by knocking out glut2 in zebrafish. Intriguingly, the complete lethality, found in Glut2-null mice, was not observed in glut2-/- zebrafish. Approxiamately 30% of glut2-/- fish survived to adulthood and could reproduce. The maternal zygotic mutant glut2 (MZglut2) fish exhibited growth retardation, decreased blood and tissue glucose levels, and low locomotion activity. The decreased pancreatic β-cell numbers and insulin expression, as well as liver insulin receptor a (insra), fatty acid synthesis (chrebp, srebf1, fasn, fads2, and scd), triglyceride synthesis (dgat1a), and muscle mechanistic target of rapamycin kinase (mtor) of MZglut2 zebrafish, suggest impaired insulin-dependent anabolic metabolism. Upregulated expression of lipolysis (atgl and lpl) and FAO genes (cpt1aa and cpt1ab) in the liver and proteolysis genes (bckdk, glud1b, and murf1a) in muscle were observed in the MZglut2 zebrafish, as well as elevated levels of P-AMPK proteins in both the liver and muscle, indicating enhanced catabolic metabolism associated with AMPK signaling. In addition, decreased amino acids and elevated carnitines of the MZglut2 zebrafish supported the decreased protein and lipid content of the whole fish. In summary, we found that blocked glucose uptake impaired insulin signaling-mediated anabolism via β-cell loss, while AMPK signaling-mediated catabolism was enhanced. These findings reveal the mechanism of energy homeostasis remodeling caused by blocked glucose uptake, which may be a potential strategy for adapting to low glucose levels.
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Affiliation(s)
- Longwei Xi
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
- College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Gang Zhai
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
- College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Yulong Liu
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
- College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Yulong Gong
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
| | - Qisheng Lu
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
- College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Zhimin Zhang
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
| | - Haokun Liu
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
- College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Junyan Jin
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
- College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Xiaoming Zhu
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
- College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Zhan Yin
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
- College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing, China
- Hubei Hongshan Laboratory, Huazhong Agriculture University, Wuhan, China
- The Innovative Academy of Seed Design, Chinese Academy of Sciences, Wuhan, China
| | - Shouqi Xie
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
- College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing, China
- The Innovative Academy of Seed Design, Chinese Academy of Sciences, Wuhan, China
| | - Dong Han
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
- College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing, China
- Hubei Hongshan Laboratory, Huazhong Agriculture University, Wuhan, China
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Fujino M, Morito N, Hayashi T, Ojima M, Ishibashi S, Kuno A, Koshiba S, Yamagata K, Takahashi S. Transcription factor c-Maf deletion improves streptozotocin-induced diabetic nephropathy by directly regulating Sglt2 and Glut2. JCI Insight 2023; 8:163306. [PMID: 36787192 PMCID: PMC10070115 DOI: 10.1172/jci.insight.163306] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Accepted: 02/01/2023] [Indexed: 02/15/2023] Open
Abstract
The transcription factor c-Maf has been widely studied and has been reported to play a critical role in embryonic kidney development; however, the postnatal functions of c-Maf in adult kidneys remain unknown as c-Maf-null C57BL/6J mice exhibit embryonic lethality. In this study, we investigated the role of c-Maf in adult mouse kidneys by comparing the phenotypes of tamoxifen-inducible (TAM-inducible) c-Maf-knockout mice (c-Maffl/fl; CAG-Cre-ERTM mice named "c-MafΔTAM") with those of c-Maffl/fl control mice, 10 days after TAM injection [TAM(10d)]. In addition, we examined the effects of c-Maf deletion on diabetic conditions by injecting the mice with streptozotocin, 4 weeks before TAM injection. c-MafΔTAM mice displayed primary glycosuria caused by sodium-glucose cotransporter 2 (Sglt2) and glucose transporter 2 (Glut2) downregulation in the kidneys without diabetes, as well as morphological changes and life-threatening injuries in the kidneys on TAM(10d). Under diabetic conditions, c-Maf deletion promoted recovery from hyperglycemia and suppressed albuminuria and diabetic nephropathy by causing similar effects as did Sglt2 knockout and SGLT2 inhibitors. In addition to demonstrating the potentially unique gene regulation of c-Maf, these findings highlight the renoprotective effects of c-Maf deficiency under diabetic conditions and suggest that c-Maf could be a novel therapeutic target gene for treating diabetic nephropathy.
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Affiliation(s)
- Mitsunori Fujino
- Department of Anatomy and Embryology, Faculty of Medicine
- PhD Program in Human Biology, School of Integrative and Global Majors
| | - Naoki Morito
- Department of Nephrology, Faculty of Medicine; and
| | - Takuto Hayashi
- Department of Anatomy and Embryology, Faculty of Medicine
- Doctoral Program in Biomedical Sciences, Graduate School of Comprehensive Human Sciences, University of Tsukuba, Ibaraki, Japan
| | - Masami Ojima
- Department of Anatomy and Embryology, Faculty of Medicine
| | - Shun Ishibashi
- Department of Anatomy and Embryology, Faculty of Medicine
- Doctoral Program in Biomedical Sciences, Graduate School of Comprehensive Human Sciences, University of Tsukuba, Ibaraki, Japan
| | - Akihiro Kuno
- Department of Anatomy and Embryology, Faculty of Medicine
| | - Seizo Koshiba
- Tohoku Medical Megabank Organization and
- Advanced Research Center for Innovations in Next-Generation Medicine (INGEM), Tohoku University, Sendai, Japan
| | | | - Satoru Takahashi
- Department of Anatomy and Embryology, Faculty of Medicine
- Laboratory Animal Resource Center
- Life Science Center for Survival Dynamics, Tsukuba Advanced Research Alliance (TARA)
- International Institute for Integrative Sleep Medicine (WPI-IIIS), and
- Transborder Medical Research Center, Faculty of Medicine, University of Tsukuba, Ibaraki, Japan
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9
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Normal β-Cell Glut2 Expression Is not Required for Regulating Glucose-Stimulated Insulin Secretion and Systemic Glucose Homeostasis in Mice. Biomolecules 2023; 13:biom13030540. [PMID: 36979475 PMCID: PMC10046365 DOI: 10.3390/biom13030540] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Revised: 03/09/2023] [Accepted: 03/11/2023] [Indexed: 03/19/2023] Open
Abstract
Objective: Glucose transporter 2 (GLUT2) is expressed in the pancreatic β-cell, intestine, liver, and kidney in mice. Although GLUT2 is considered as a major regulator of insulin secretion, in vivo contribution of β-cell Glut2 to glucose-stimulated insulin secretion and systemic glucose homeostasis is undefined. Therefore, the main objective of this study is to determine the role of β-cell Glut2 in regulating insulin secretion and blood glucose levels in mice. Methods: We produced mice in which we can knock down Glut2 at a desired time specifically in β-cells (β-Glut2 KD) by crossing Glut2LoxP/LoxP mice with Ins1CreERT2 mouse strain and using the Cre-Lox recombination technique. We measured fasting blood glucose levels, glucose tolerance, and glucose-stimulated insulin secretion in the β-Glut2 KD mice. We used qRT-PCR and immunofluorescence to validate the deficiency of β-cell Glut2 in β-Glut2 KD mice. Results: We report that both male and female β-Glut2 KD mice have normal glucose-stimulated insulin secretion. Moreover, the β-Glut2 KD mice exhibit normal fasting blood glucose levels and glucose tolerance. The β-Glut2 KD mice have upregulated GLUT1 in islets. Conclusions: Our findings demonstrate that normal β-cell Glut2 expression is not essential for regulating glucose-stimulated insulin secretion and systemic glucose homeostasis in mice. Therefore, the currently assumed role of β-cell GLUT2 in regulating insulin secretion and blood glucose levels needs to be recalibrated. This will allow an opportunity to determine the contribution of other β-cell glucose transporters or factors whose normal expression may be necessary for mediating glucose stimulated insulin secretion.
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10
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Naik AS, Brosius FC. Cannabinoid Signaling in the Diabetic Proximal Tubule: Of Mice and Men. Am J Kidney Dis 2023; 81:110-113. [PMID: 36126758 PMCID: PMC9780186 DOI: 10.1053/j.ajkd.2022.09.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Accepted: 09/11/2022] [Indexed: 12/25/2022]
Affiliation(s)
- Abhijit S Naik
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan.
| | - Frank C Brosius
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan; Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, Michigan; Department of Medicine, University of Arizona, Tucson, Arizona.
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11
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Ahmad M, Abramovich I, Agranovich B, Nemirovski A, Gottlieb E, Hinden L, Tam J. Kidney Proximal Tubule GLUT2-More than Meets the Eye. Cells 2022; 12:cells12010094. [PMID: 36611887 PMCID: PMC9818791 DOI: 10.3390/cells12010094] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 12/06/2022] [Accepted: 12/23/2022] [Indexed: 12/28/2022] Open
Abstract
Tubulopathy plays a central role in the pathophysiology of diabetic kidney disease (DKD). Under diabetic conditions, the kidney proximal tubule cells (KPTCs) are exposed to an extensive amount of nutrients, most notably glucose; these nutrients deteriorate KPTCs function and promote the development and progression of DKD. Recently, the facilitative glucose transporter 2 (GLUT2) in KPTCs has emerged as a central regulator in the pathogenesis of DKD. This has been demonstrated by identifying its specific role in enhancing glucose reabsorption and glucotoxicity, and by deciphering its effect in regulating the expression of the sodium-glucose transporter 2 (SGLT2) in KPTCs. Moreover, reduction/deletion of KPTC-GLUT2 has been recently found to ameliorate DKD, raising the plausible idea of considering it as a therapeutic target against DKD. However, the underlying molecular mechanisms by which GLUT2 exerts its deleterious effects in KPTCs remain vague. Herein, we review the current findings on the proximal tubule GLUT2 biology and function under physiologic conditions, and its involvement in the pathophysiology of DKD. Furthermore, we shed new light on its cellular regulation during diabetic conditions.
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Affiliation(s)
- Majdoleen Ahmad
- Obesity and Metabolism Laboratory, Faculty of Medicine, The Institute for Drug Research, School of Pharmacy, The Hebrew University of Jerusalem, Jerusalem 9112001, Israel
| | - Ifat Abramovich
- Rappaport Faculty of Medicine and Research Institute, Technion, Haifa 3525422, Israel
| | - Bella Agranovich
- Rappaport Faculty of Medicine and Research Institute, Technion, Haifa 3525422, Israel
| | - Alina Nemirovski
- Obesity and Metabolism Laboratory, Faculty of Medicine, The Institute for Drug Research, School of Pharmacy, The Hebrew University of Jerusalem, Jerusalem 9112001, Israel
| | - Eyal Gottlieb
- Rappaport Faculty of Medicine and Research Institute, Technion, Haifa 3525422, Israel
| | - Liad Hinden
- Obesity and Metabolism Laboratory, Faculty of Medicine, The Institute for Drug Research, School of Pharmacy, The Hebrew University of Jerusalem, Jerusalem 9112001, Israel
- Correspondence: (L.H.); (J.T.); Tel.: +972-2-675-7650 (L.H.); +972-2-675-7645 (J.T.)
| | - Joseph Tam
- Obesity and Metabolism Laboratory, Faculty of Medicine, The Institute for Drug Research, School of Pharmacy, The Hebrew University of Jerusalem, Jerusalem 9112001, Israel
- Correspondence: (L.H.); (J.T.); Tel.: +972-2-675-7650 (L.H.); +972-2-675-7645 (J.T.)
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Genetic and Pharmacological Inhibition of GCN2 Ameliorates Hyperglycemia and Insulin Resistance in Type 2 Diabetic Mice. Antioxidants (Basel) 2022; 11:antiox11081584. [PMID: 36009303 PMCID: PMC9404927 DOI: 10.3390/antiox11081584] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Revised: 08/10/2022] [Accepted: 08/15/2022] [Indexed: 01/13/2023] Open
Abstract
It is well recognized that there is a strong and complex association between nonalcoholic fatty liver disease (NAFLD) and type 2 diabetes (T2D). We previously demonstrated that genetic knockout or pharmacological inhibition of general control nondepressible kinase 2 (GCN2), a well-known amino acid sensor, alleviated hepatic steatosis and insulin resistance in obese mice. However, whether GCN2 affects the development of T2D remains unclear. After a high-fat diet (HFD) plus low-dose streptozotocin (STZ) treatments, Gcn2−/− mice developed less hyperglycemia, insulin resistance, hepatic steatosis, and oxidative stress than wild-type (WT) mice. Inhibition of GCN2 by intraperitoneal injection of 3 mg/kg GCN2iB (a specific inhibitor of GCN2) every other day for 6 weeks also ameliorated hyperglycemia, insulin resistance, hepatic steatosis, and oxidative stress in HFD/STZ- and leptin receptor deletion (db/db)-induced T2D mice. Moreover, depletion of hepatic GCN2 in db/db mice by tail vein injection of an AAV8-shGcn2 vector resulted in similar improvement in those metabolic disorders. The protective mechanism of GCN2 inhibition in T2D mice was associated with regulation of the glucose metabolic pathway, repression of lipogenesis genes, and activation of the Nrf2 pathway. Together, our data provide evidence that strategies to inhibit hepatic GCN2 activity may be novel approaches for T2D therapy.
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