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Cheng YW, Huang YC, Chang KF, Huang XF, Sheu GT, Tsai NM. Protective Effect of Curcumin on the Tight Junction Integrity and Cellular Senescence in Human Retinal Pigment Epithelium of Early Diabetic Retinopathy. JOURNAL OF PHYSIOLOGICAL INVESTIGATION 2024; 67:107-117. [PMID: 38857204 DOI: 10.4103/ejpi.ejpi-d-23-00035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Accepted: 05/05/2024] [Indexed: 06/12/2024]
Abstract
Diabetic retinopathy (DR) is a secondary complication of diabetes that can lead to visual impairment and blindness. The retinal pigment epithelium (RPE) is a monolayer of pigment cells that forms the blood-retinal barrier (BRB) via tight junction (TJ) proteins and plays a crucial role in the physiological function of the retina. Hyperglycemia induces RPE death and BRB breakdown, which accelerates the process of DR. Curcumin, an active extract of Curcuma longa , has anti-inflammatory, antioxidant, antiapoptotic, and neuroprotective properties. However, the effect of Curcumin on the BRB under high glucose conditions remains unknown. This study aimed to investigate the protective effects of Curcumin on RPE physiology in vitro and in vivo . Curcumin significantly alleviated cell viability inhibition under high glucose conditions. Moreover, high glucose reduced extracellular signal-regulated kinase and Akt pathways activation to diminish RPE cell growth but reversed by Curcumin treatment. Curcumin protected not only TJ integrity but also retinoid regeneration through TJ proteins and isomerase modulation in diabetic retina. Furthermore, Curcumin decreased the expression of angiogenic factor to inhibit retinal neovascularization. Finally, Curcumin treatment markedly reduced apoptosis during hyperglycemia. In conclusion, Curcumin can alleviate the progression of DR by promoting RPE survival, TJ integrity, retinoid isomerase activity, RPE senescence inhibition, and neovascularization. Therefore, Curcumin exhibits high potential for use as a therapeutic agent for early DR.
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Affiliation(s)
- Yu-Wen Cheng
- Department of Internal Medicine, Lee's General Hospital, Miaoli, Taiwan
| | - Ya-Chih Huang
- Institute of Medicine, Chung Shan Medical University, Taichung, Taiwan
- Department of Medical Laboratory and Biotechnology, Chung Shan Medical University, Taichung, Taiwan
| | - Kai-Fu Chang
- Department of Medical Laboratory and Biotechnology, Chung Shan Medical University, Taichung, Taiwan
| | - Xiao-Fan Huang
- Department of Medical Laboratory and Biotechnology, Chung Shan Medical University, Taichung, Taiwan
| | - Gwo-Tarng Sheu
- Institute of Medicine, Chung Shan Medical University, Taichung, Taiwan
| | - Nu-Man Tsai
- Department of Medical Laboratory and Biotechnology, Chung Shan Medical University, Taichung, Taiwan
- Clinical Laboratory, Chung Shan Medical University Hospital, Taichung, Taiwan
- Department of Life-and-Death Studies, Nanhua University, Chiayi, Taiwan
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Cao R, Tian H, Zhang Y, Liu G, Xu H, Rao G, Tian Y, Fu X. Signaling pathways and intervention for therapy of type 2 diabetes mellitus. MedComm (Beijing) 2023; 4:e283. [PMID: 37303813 PMCID: PMC10248034 DOI: 10.1002/mco2.283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Revised: 04/18/2023] [Accepted: 04/27/2023] [Indexed: 06/13/2023] Open
Abstract
Type 2 diabetes mellitus (T2DM) represents one of the fastest growing epidemic metabolic disorders worldwide and is a strong contributor for a broad range of comorbidities, including vascular, visual, neurological, kidney, and liver diseases. Moreover, recent data suggest a mutual interplay between T2DM and Corona Virus Disease 2019 (COVID-19). T2DM is characterized by insulin resistance (IR) and pancreatic β cell dysfunction. Pioneering discoveries throughout the past few decades have established notable links between signaling pathways and T2DM pathogenesis and therapy. Importantly, a number of signaling pathways substantially control the advancement of core pathological changes in T2DM, including IR and β cell dysfunction, as well as additional pathogenic disturbances. Accordingly, an improved understanding of these signaling pathways sheds light on tractable targets and strategies for developing and repurposing critical therapies to treat T2DM and its complications. In this review, we provide a brief overview of the history of T2DM and signaling pathways, and offer a systematic update on the role and mechanism of key signaling pathways underlying the onset, development, and progression of T2DM. In this content, we also summarize current therapeutic drugs/agents associated with signaling pathways for the treatment of T2DM and its complications, and discuss some implications and directions to the future of this field.
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Affiliation(s)
- Rong Cao
- Department of Endocrinology and MetabolismState Key Laboratory of Biotherapy and Cancer CenterWest China HospitalSichuan University and Collaborative Innovation Center of BiotherapyChengduSichuanChina
| | - Huimin Tian
- Department of Endocrinology and MetabolismState Key Laboratory of Biotherapy and Cancer CenterWest China Medical School, West China HospitalSichuan UniversityChengduSichuanChina
| | - Yu Zhang
- Department of Endocrinology and MetabolismState Key Laboratory of Biotherapy and Cancer CenterWest China Medical School, West China HospitalSichuan UniversityChengduSichuanChina
| | - Geng Liu
- Department of Endocrinology and MetabolismState Key Laboratory of Biotherapy and Cancer CenterWest China HospitalSichuan University and Collaborative Innovation Center of BiotherapyChengduSichuanChina
| | - Haixia Xu
- Department of Endocrinology and MetabolismState Key Laboratory of Biotherapy and Cancer CenterWest China HospitalSichuan University and Collaborative Innovation Center of BiotherapyChengduSichuanChina
| | - Guocheng Rao
- Department of Endocrinology and MetabolismState Key Laboratory of Biotherapy and Cancer CenterWest China Medical School, West China HospitalSichuan UniversityChengduSichuanChina
| | - Yan Tian
- Department of Endocrinology and MetabolismState Key Laboratory of Biotherapy and Cancer CenterWest China HospitalSichuan University and Collaborative Innovation Center of BiotherapyChengduSichuanChina
| | - Xianghui Fu
- Department of Endocrinology and MetabolismState Key Laboratory of Biotherapy and Cancer CenterWest China HospitalSichuan University and Collaborative Innovation Center of BiotherapyChengduSichuanChina
- Department of Endocrinology and MetabolismState Key Laboratory of Biotherapy and Cancer CenterWest China Medical School, West China HospitalSichuan UniversityChengduSichuanChina
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Sidarala V, Kowluru A. The Regulatory Roles of Mitogen-Activated Protein Kinase (MAPK) Pathways in Health and Diabetes: Lessons Learned from the Pancreatic β-Cell. ACTA ACUST UNITED AC 2017; 10:76-84. [PMID: 27779078 DOI: 10.2174/1872214810666161020154905] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Revised: 10/17/2016] [Accepted: 10/17/2016] [Indexed: 01/14/2023]
Abstract
BACKGROUND Glucose-stimulated insulin secretion (GSIS) from the pancreatic β-cell involves several intracellular metabolic events which lead to the translocation of insulin granules towards the membrane for fusion and release. It is well established that loss of β-cell function and decreased GSIS underlie the pathogenesis of diabetes. Evidence from several laboratories, including our own, demonstrated requisite roles of Rac1 and phagocyte-like NADPH oxidase (Nox2)-derived reactive oxygen species (ROS) in optimal function of the pancreatic β-cell, including GSIS. However, it is becoming increasingly clear that prolonged exposure of β-cells to hyperglycemic conditions, leads to sustained activation of Rac1-Nox2 signaling axis culminating in excessive generation of intracellular ROS (oxidative stress) and β-cell dysregulation and demise. Such "cytotoxic" effects of ROS appear to be mediated via the stress-activated protein kinases/mitogen-activated protein kinases (SAPK/MAPK) signaling pathways. OBJECTIVE This review discusses our current understanding of regulation and functions of the conventional MAPKs, namely, ERK1/2, JNK1/2 and p38MAPK. CONCLUSION The MAPK pathways are activated in the presence of various stress stimuli including intracellular ROS, via distinct signaling cascades. Once activated, MAPKs participate in specific intracellular signaling processes via interaction with several downstream kinases including the MAPKactivated protein kinases (MAPKAPKs) and transcription factors including c-jun and p53. We have provided an overview of existing evidence in the islet β-cell on the regulatory roles of these MAPKs in mediating cellular responses to alterations in intracellularly generated ROS, which is mediated by the Rac1-Nox2 signaling module. Additionally, we enlisted recent patents developed to improve β-cell function in diabetes and novel pharmacological agents that target oxidative stress and MAPK pathways.
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Affiliation(s)
- Vaibhav Sidarala
- Beta-Cell Biochemistry Laboratory, John D. Dingell VA Medical Center, Department of Pharmaceutical Sciences, Wayne State University, Detroit, MI 48201. United States
| | - Anjaneyulu Kowluru
- B-4237 Research Service, John D. Dingell VA Medical Center, 4646 John R, Detroit, MI 48201. United States
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Chang HY, Chen SL, Shen MR, Kung ML, Chuang LM, Chen YW. Selective serotonin reuptake inhibitor, fluoxetine, impairs E-cadherin-mediated cell adhesion and alters calcium homeostasis in pancreatic beta cells. Sci Rep 2017; 7:3515. [PMID: 28615694 PMCID: PMC5471211 DOI: 10.1038/s41598-017-03747-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Accepted: 05/05/2017] [Indexed: 12/21/2022] Open
Abstract
Selective serotonin reuptake inhibitors (SSRIs) are the most commonly prescribed drugs for mood disorders. Long term use of SSRIs is associated with an increased risk of diabetes, but the underlying mechanism(s) remains elusive. E-cadherin-mediated cell-cell adhesion and elevated [Ca2+]i are important for insulin release and pancreatic β cell functions. This study aims to investigate whether a SSRI, fluoxetine (Prozac), induces pancreatic β cell dysfunction through affecting E-cadherin and/or [Ca2+]i. Here we show that fluoxetine significantly reduces glucose stimulated insulin secretion (GSIS). MIN6 cells, an established murine immortalized β cell line, form smaller colonies of loosely packed cells with reduced cell-cell contact after fluoxetine treatment. Immunofluorescence staining reveals that fluoxetine increases cytoplasmic accumulation of E-cadherin and reduces the membrane-localized E-cadherin probably due to increase of its endocytosis. Fluoxetine inhibits spreading of β cells on E-cad/Fc coated slides and also disrupts E-cadherin-mediated actin filaments. Additionally, fluoxetine significantly suppresses endoplasmic reticulum (ER) calcium release and store-operated calcium entry (SOCE) activation, probably through reduction of ER calcium storage and inhibition of stromal interaction molecule 1 (STIM1) trafficking. These data suggest that exposure to fluoxetine results in impaired β cell functions, occurring in concert with reduction of E-cadherin-dependent cell adhesion and alterations of calcium homeostasis.
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Affiliation(s)
- Huang-Yu Chang
- Department of Pharmacology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Shu-Ling Chen
- Department of Pharmacology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Meng-Ru Shen
- Department of Pharmacology, College of Medicine, National Cheng Kung University, Tainan, Taiwan.,Department of Obstetrics and Gynecology, College of Medicine, National Cheng Kung University, Tainan, Taiwan.,Advanced Optoelectronic Technology Center, College of Engineering, National Cheng Kung University, Tainan, Taiwan
| | - Mei-Lang Kung
- Department of Chemistry, National Sun Yat-Sen University, Kaohsiung, Taiwan
| | - Lee-Ming Chuang
- Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan.,Department of Medicine, National Taiwan University Medical College, Taipei, Taiwan
| | - Yun-Wen Chen
- Department of Pharmacology, College of Medicine, National Cheng Kung University, Tainan, Taiwan.
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Pratt EPS, Salyer AE, Guerra ML, Hockerman GH. Ca2+ influx through L-type Ca2+ channels and Ca2+-induced Ca2+ release regulate cAMP accumulation and Epac1-dependent ERK 1/2 activation in INS-1 cells. Mol Cell Endocrinol 2016; 419:60-71. [PMID: 26435461 PMCID: PMC4684454 DOI: 10.1016/j.mce.2015.09.034] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Revised: 08/28/2015] [Accepted: 09/29/2015] [Indexed: 02/09/2023]
Abstract
We previously reported that INS-1 cells expressing the intracellular II-III loop of the L-type Ca(2+) channel Cav1.2 (Cav1.2/II-III cells) are deficient in Ca(2+)-induced Ca(2+) release (CICR). Here we show that glucose-stimulated ERK 1/2 phosphorylation (GSEP) is slowed and reduced in Cav1.2/II-III cells compared to INS-1 cells. This parallels a decrease in glucose-stimulated cAMP accumulation (GS-cAMP) in Cav1.2/II-III cells. Influx of Ca(2+) via L-type Ca(2+) channels and CICR play roles in both GSEP and GS-cAMP in INS-1 cells since both are inhibited by nicardipine or ryanodine. Further, the Epac1-selective inhibitor CE3F4 abolishes glucose-stimulated ERK activation in INS-1 cells, as measured using the FRET-based sensor EKAR. The non-selective Epac antagonist ESI-09 but not the Epac2-selective antagonist ESI-05 nor the PKA antagonist Rp-cAMPs inhibits GSEP in both INS-1 and Cav1.2/II-III cells. We conclude that L-type Ca(2+) channel-dependent cAMP accumulation, that's amplified by CICR, activates Epac1 and drives GSEP in INS-1 cells.
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Affiliation(s)
- Evan P S Pratt
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN, USA; Purdue University Life Sciences Graduate Program, Purdue University, West Lafayette, IN, USA
| | - Amy E Salyer
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN, USA
| | - Marcy L Guerra
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN, USA
| | - Gregory H Hockerman
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN, USA.
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Arous C, Halban PA. The skeleton in the closet: actin cytoskeletal remodeling in β-cell function. Am J Physiol Endocrinol Metab 2015; 309:E611-20. [PMID: 26286869 DOI: 10.1152/ajpendo.00268.2015] [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: 06/11/2015] [Accepted: 08/11/2015] [Indexed: 01/13/2023]
Abstract
Over the last few decades, biomedical research has considered not only the function of single cells but also the importance of the physical environment within a whole tissue, including cell-cell and cell-extracellular matrix interactions. Cytoskeleton organization and focal adhesions are crucial sensors for cells that enable them to rapidly communicate with the physical extracellular environment in response to extracellular stimuli, ensuring proper function and adaptation. The involvement of the microtubular-microfilamentous cytoskeleton in secretion mechanisms was proposed almost 50 years ago, since when the evolution of ever more sensitive and sophisticated methods in microscopy and in cell and molecular biology have led us to become aware of the importance of cytoskeleton remodeling for cell shape regulation and its crucial link with signaling pathways leading to β-cell function. Emerging evidence suggests that dysfunction of cytoskeletal components or extracellular matrix modification influences a number of disorders through potential actin cytoskeleton disruption that could be involved in the initiation of multiple cellular functions. Perturbation of β-cell actin cytoskeleton remodeling could arise secondarily to islet inflammation and fibrosis, possibly accounting in part for impaired β-cell function in type 2 diabetes. This review focuses on the role of actin remodeling in insulin secretion mechanisms and its close relationship with focal adhesions and myosin II.
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Affiliation(s)
- Caroline Arous
- Department of Genetic Medicine and Development, University of Geneva Medical Center, Geneva, Switzerland
| | - Philippe A Halban
- Department of Genetic Medicine and Development, University of Geneva Medical Center, Geneva, Switzerland
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Yao XG, Xu X, Wang GH, Lei M, Quan LL, Cheng YH, Wan P, Zhou JP, Chen J, Hu LH, Shen X. BBT improves glucose homeostasis by ameliorating β-cell dysfunction in type 2 diabetic mice. J Endocrinol 2015; 224:327-41. [PMID: 25572265 DOI: 10.1530/joe-14-0721] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Impaired glucose-stimulated insulin secretion (GSIS) and increasing β-cell death are two typical dysfunctions of pancreatic β-cells in individuals that are destined to develop type 2 diabetes, and improvement of β-cell function through GSIS enhancement and/or inhibition of β-cell death is a promising strategy for anti-diabetic therapy. In this study, we discovered that the small molecule, N-(2-benzoylphenyl)-5-bromo-2-thiophenecarboxamide (BBT), was effective in both potentiating GSIS and protecting β-cells from cytokine- or streptozotocin (STZ)-induced cell death. Results of further studies revealed that cAMP/PKA and long-lasting (L-type) voltage-dependent Ca(2) (+) channel/CaMK2 pathways were involved in the action of BBT against GSIS, and that the cAMP/PKA pathway was essential for the protective action of BBT on β-cells. An assay using the model of type 2 diabetic mice induced by high-fat diet combined with STZ (STZ/HFD) demonstrated that BBT administration efficiently restored β-cell functions as indicated by the increased plasma insulin level and decrease in the β-cell loss induced by STZ/HFD. Moreover, the results indicated that BBT treatment decreased fasting blood glucose and HbA1c and improved oral glucose tolerance further highlighting the potential of BBT in anti-hyperglycemia research.
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MESH Headings
- Animals
- Cells, Cultured
- Diabetes Mellitus, Experimental/drug therapy
- Diabetes Mellitus, Experimental/metabolism
- Diabetes Mellitus, Experimental/physiopathology
- Diabetes Mellitus, Type 2/drug therapy
- Diabetes Mellitus, Type 2/metabolism
- Diabetes Mellitus, Type 2/physiopathology
- Diet, High-Fat
- Drug Evaluation, Preclinical
- Glucose/metabolism
- HEK293 Cells
- Homeostasis/drug effects
- Humans
- Hypoglycemic Agents/pharmacology
- Hypoglycemic Agents/therapeutic use
- Insulin-Secreting Cells/drug effects
- Insulin-Secreting Cells/physiology
- Male
- Mice
- Mice, Inbred C57BL
- Streptozocin
- Thiophenes/pharmacology
- Thiophenes/therapeutic use
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Affiliation(s)
- Xin-gang Yao
- Key Laboratory of Receptor ResearchShanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zuchongzhi Road, Shanghai 201203, ChinaCollege of Life and Environmental SciencesShanghai Normal University, 100 Guilin Road, Shanghai 200234, ChinaDepartment of PharmacologyChina Pharmaceutical University, 24 Tongjiaxiang, Nanjing 210009, China
| | - Xin Xu
- Key Laboratory of Receptor ResearchShanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zuchongzhi Road, Shanghai 201203, ChinaCollege of Life and Environmental SciencesShanghai Normal University, 100 Guilin Road, Shanghai 200234, ChinaDepartment of PharmacologyChina Pharmaceutical University, 24 Tongjiaxiang, Nanjing 210009, China
| | - Gai-hong Wang
- Key Laboratory of Receptor ResearchShanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zuchongzhi Road, Shanghai 201203, ChinaCollege of Life and Environmental SciencesShanghai Normal University, 100 Guilin Road, Shanghai 200234, ChinaDepartment of PharmacologyChina Pharmaceutical University, 24 Tongjiaxiang, Nanjing 210009, China
| | - Min Lei
- Key Laboratory of Receptor ResearchShanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zuchongzhi Road, Shanghai 201203, ChinaCollege of Life and Environmental SciencesShanghai Normal University, 100 Guilin Road, Shanghai 200234, ChinaDepartment of PharmacologyChina Pharmaceutical University, 24 Tongjiaxiang, Nanjing 210009, China
| | - Ling-ling Quan
- Key Laboratory of Receptor ResearchShanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zuchongzhi Road, Shanghai 201203, ChinaCollege of Life and Environmental SciencesShanghai Normal University, 100 Guilin Road, Shanghai 200234, ChinaDepartment of PharmacologyChina Pharmaceutical University, 24 Tongjiaxiang, Nanjing 210009, China
| | - Yan-hua Cheng
- Key Laboratory of Receptor ResearchShanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zuchongzhi Road, Shanghai 201203, ChinaCollege of Life and Environmental SciencesShanghai Normal University, 100 Guilin Road, Shanghai 200234, ChinaDepartment of PharmacologyChina Pharmaceutical University, 24 Tongjiaxiang, Nanjing 210009, China
| | - Ping Wan
- Key Laboratory of Receptor ResearchShanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zuchongzhi Road, Shanghai 201203, ChinaCollege of Life and Environmental SciencesShanghai Normal University, 100 Guilin Road, Shanghai 200234, ChinaDepartment of PharmacologyChina Pharmaceutical University, 24 Tongjiaxiang, Nanjing 210009, China
| | - Jin-pei Zhou
- Key Laboratory of Receptor ResearchShanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zuchongzhi Road, Shanghai 201203, ChinaCollege of Life and Environmental SciencesShanghai Normal University, 100 Guilin Road, Shanghai 200234, ChinaDepartment of PharmacologyChina Pharmaceutical University, 24 Tongjiaxiang, Nanjing 210009, China
| | - Jing Chen
- Key Laboratory of Receptor ResearchShanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zuchongzhi Road, Shanghai 201203, ChinaCollege of Life and Environmental SciencesShanghai Normal University, 100 Guilin Road, Shanghai 200234, ChinaDepartment of PharmacologyChina Pharmaceutical University, 24 Tongjiaxiang, Nanjing 210009, China
| | - Li-hong Hu
- Key Laboratory of Receptor ResearchShanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zuchongzhi Road, Shanghai 201203, ChinaCollege of Life and Environmental SciencesShanghai Normal University, 100 Guilin Road, Shanghai 200234, ChinaDepartment of PharmacologyChina Pharmaceutical University, 24 Tongjiaxiang, Nanjing 210009, China
| | - Xu Shen
- Key Laboratory of Receptor ResearchShanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zuchongzhi Road, Shanghai 201203, ChinaCollege of Life and Environmental SciencesShanghai Normal University, 100 Guilin Road, Shanghai 200234, ChinaDepartment of PharmacologyChina Pharmaceutical University, 24 Tongjiaxiang, Nanjing 210009, China
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8
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Lee TY, Lin HH, Chen CL, Hwang SM, Tseng CP. Inhibitory Effect of Excessive Glucose on Its Biochemical Pathway and the Growth of Chinese Hamster Ovary (CHO) Cells. J Carbohydr Chem 2015. [DOI: 10.1080/07328303.2014.977908] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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Pirmoradi L, Mohammadi MT, Safaei A, Mesbah F, Dehghani GA. Does the relief of glucose toxicity act as a mediator in proliferative actions of vanadium on pancreatic islet beta cells in streptozocin diabetic rats? IRANIAN BIOMEDICAL JOURNAL 2015; 18:173-80. [PMID: 24842144 PMCID: PMC4048482 DOI: 10.6091/ibj.1329.2014] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Background: Data shows vanadium protects pancreatic beta cells (BC) from diabetic animals. Whether this effect is direct or through the relief of glucose toxicity is not clear. This study evaluated the potential effect of oral vanadyl sulfate (vanadium) on glycemic status and pancreatic BC of normal and diabetic rats. Methods: Rats were divided into five groups of normal and diabetic. Diabetes was induced with streptozocin (40 mg/kg, i.v.). Normal rats used water (CN) or vanadium (1 mg/ml VOSO4, VTN). Diabetic rats used water (CD), water plus daily neutral protamine Hagedorn insulin injection (80 U/kg, ITD) or vanadium (VTD). Blood samples were taken for blood glucose (BG, mg/dL) and insulin (ng/dL) measurements. After two months, the pancreata of sacrificed rats were prepared for islet staining. Results: Pre-treated normal BG was 88 ± 2, and diabetic BG was 395 ± 9. The final BG in CD, VTD, and ITD was 509 ± 22, 138 ± 14, and 141 ± 14, respectively. Insulin in VTN (0.75 ± 0.01) and VTD (0.78 ± 0.01) was similar, higher than CD (0.51 ± 0.07) but lower than CN (2.51 ± 0.02). VTN islets compared to CN had larger size and denser central core insulin immunoreactivity with plentiful BC. CD and ITD islets were atrophied and had scattered insulin immunoreactivity spots and low BC mass. VTD islets were almost similar to CN. Conclusion: Besides insulin-like activity, vanadium protected pancreatic islet BC, and the relief of glucose toxicity happening with vanadium had a little role in this action.
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Affiliation(s)
- Leila Pirmoradi
- Dept. of Physiology, Nemazi Hospital, Shiraz University of Medical Sciences, Shiraz, Iran
| | | | - Akbar Safaei
- Dept. of Pathology, Nemazi Hospital, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Fakhardin Mesbah
- Dept. of Anatomy, Nemazi Hospital, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Gholam Abbas Dehghani
- Dept. of Physiology, Nemazi Hospital, Shiraz University of Medical Sciences, Shiraz, Iran.,Dept. of Pathology, Nemazi Hospital, Shiraz University of Medical Sciences, Shiraz, Iran
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10
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Tsui S, Dai W, Lu L. CCCTC-binding factor mediates effects of glucose on beta cell survival. Cell Prolif 2013; 47:28-37. [PMID: 24354619 DOI: 10.1111/cpr.12085] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2013] [Accepted: 10/07/2013] [Indexed: 12/17/2022] Open
Abstract
OBJECTIVES Pancreatic islet β-cell survival is paramount for regulation of insulin activity and for maintaining glucose homeostasis. Recently, Pax6 has been shown to be essential for many vital functions in β-cells, although many molecular mechanisms of its homeostasis in β-cells remain unclear. The present study investigates novel effects of glucose- and insulin-induced CCCTC-binding factor (CTCF) activity on Pax6 gene expression as well as for subsequent effects of insulin-activated signalling pathways, on β-cell proliferation. MATERIALS AND METHODS Pancreatic β-TC-1-6 cells were cultured in DMEM and stimulated with high concentrations of glucose (5-125 mm); cell viability was assessed by MTT assay. Effects of CTCF on Pax6 were evaluated in the high glucose-induced environment and CTCF/Erk-suppressed cells, by promoter reporter and western blotting analyses. RESULTS Increases in glucose and insulin concentrations upregulated CTCF and consequently downregulated Pax6 in β-cell survival and proliferation. Knocking-down CTCF directly affected Pax6 transcription through CTCF binding and blocked the response to glucose. Altered Erk activity mediated effects of CTCF on controlling Pax6 expression, which partially regulated β-cell proliferation. CONCLUSIONS CTCF functioned as a molecular mediator between insulin-induced upstream Erk signalling and Pax6 expression in these pancreatic β-cells. This pathway may contribute to regulation of β-cell survival and proliferation.
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Affiliation(s)
- S Tsui
- Department of Medicine, David Geffen School of Medicine University of California Los Angeles, Torrance, CA, 90502, USA
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11
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Zou R, Yang L, Xue J, Ke M, Huang Q, Huang Q, Dai Z, Sun J, Xu Y. WITHDRAWN: RIP140 mediates hyperglycemia-induced glucotoxicity in β-cells via the activation of JNK and ERK1/2 signaling pathways. Diabetes Res Clin Pract 2013:S0168-8227(12)00506-2. [PMID: 23290273 DOI: 10.1016/j.diabres.2012.12.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/20/2012] [Revised: 10/22/2012] [Accepted: 12/13/2012] [Indexed: 10/27/2022]
Abstract
This article has been withdrawn at the request of the author(s) and/or editor. The Publisher apologizes for any inconvenience this may cause. The full Elsevier Policy on Article Withdrawal can be found at http://www.elsevier.com/locate/withdrawalpolicy.
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Affiliation(s)
- Runmei Zou
- Department of Endocrinology, Zhongnan Hospital of Wuhan University, Donghu Road 169#, Wuhan, Hubei 430071, China
| | - Li Yang
- Department of Endocrinology, Zhongnan Hospital of Wuhan University, Donghu Road 169#, Wuhan, Hubei 430071, China
| | - Junli Xue
- Department of Endocrinology, Zhongnan Hospital of Wuhan University, Donghu Road 169#, Wuhan, Hubei 430071, China
| | - Min Ke
- Department of Ophthalmology, Zhongnan Hospital of Wuhan University, Donghu Road 169#, Wuhan, Hubei 430071, China
| | - Qian Huang
- Department of Paediatrics, Zhongnan Hospital of Wuhan University, Donghu Road 169#, Wuhan, Hubei 430071, China
| | - Qi Huang
- Department of Endocrinology, Zhongnan Hospital of Wuhan University, Donghu Road 169#, Wuhan, Hubei 430071, China
| | - Zhe Dai
- Department of Endocrinology, Zhongnan Hospital of Wuhan University, Donghu Road 169#, Wuhan, Hubei 430071, China
| | - Jiazhong Sun
- Department of Endocrinology, Zhongnan Hospital of Wuhan University, Donghu Road 169#, Wuhan, Hubei 430071, China
| | - Yancheng Xu
- Department of Endocrinology, Zhongnan Hospital of Wuhan University, Donghu Road 169#, Wuhan, Hubei 430071, China.
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