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Nishimura Y, Iwashita M, Hayashi M, Shinjo T, Watanabe Y, Zeze T, Yamashita A, Fukuda T, Sanui T, Sano T, Asano T, Nishimura F. XAF1 overexpression exacerbates diabetes by promoting pancreatic β-cell apoptosis. Acta Diabetol 2022; 59:1275-1286. [PMID: 35829914 PMCID: PMC9402739 DOI: 10.1007/s00592-022-01930-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Accepted: 06/22/2022] [Indexed: 11/29/2022]
Abstract
AIMS Pancreatic β-cell apoptosis may be involved in the onset and progression of type 2 diabetes mellitus, although its mechanism remains unclear. We previously demonstrated that macrophage-derived interferon (IFN) β induced X-linked inhibitor of apoptosis-associated factor 1 (XAF1) expression in β-cells and accelerated β-cell apoptosis in vitro. Here, we explored the effects of XAF1 on β-cell function and progression of diabetes in vivo. METHODS Pancreatic β-cell-selective XAF1 overexpressing (Xaf1 Tg) mice were generated. Xaf1 Tg mice and their wild-type (WT) littermates were fed either a normal diet or a 40% or 60% high-fat diet (HFD). The effects of β-cell XAF1 on β-cell apoptosis and exacerbation of diabetes were investigated. RESULTS Palmitic acid induced IFNβ expression in macrophages, and HFD intake promoted macrophage infiltration in pancreatic islets, both of which cooperatively upregulated XAF1 expression in mouse islets. Furthermore, HFD-fed Xaf1 Tg mice demonstrated increased β-cell apoptosis, lowered insulin expression, and impaired glucose tolerance compared with WT mice fed the same diet. These effects were more pronounced in the 60%HFD group than in the 40%HFD group. CONCLUSIONS Pancreatic β-cell XAF1 expression was enhanced via HFD-induced, macrophage-derived IFNβ, which promoted β-cell apoptosis and led to a reduction in insulin secretion and progression of diabetes. To our knowledge, this is the first report to demonstrate an association between pancreatic β-cell XAF1 overexpression and exacerbation of diabetes, thus providing insight into the mechanism of β-cell mass reduction in diabetes.
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Affiliation(s)
- Yuki Nishimura
- Department of Periodontology, Division of Oral Rehabilitation, Faculty of Dental Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan
| | - Misaki Iwashita
- Department of Periodontology, Division of Oral Rehabilitation, Faculty of Dental Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan.
| | - Masato Hayashi
- Department of Periodontology, Division of Oral Rehabilitation, Faculty of Dental Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan
| | - Takanori Shinjo
- Department of Periodontology, Division of Oral Rehabilitation, Faculty of Dental Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan
| | - Yukari Watanabe
- Department of Periodontology, Division of Oral Rehabilitation, Faculty of Dental Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan
| | - Tatsuro Zeze
- Department of Periodontology, Division of Oral Rehabilitation, Faculty of Dental Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan
| | - Akiko Yamashita
- Department of Periodontology, Division of Oral Rehabilitation, Faculty of Dental Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan
| | - Takao Fukuda
- Department of Periodontology, Division of Oral Rehabilitation, Faculty of Dental Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan
| | - Terukazu Sanui
- Department of Periodontology, Division of Oral Rehabilitation, Faculty of Dental Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan
| | - Tomomi Sano
- Department of Cell Biology and Pharmacology, Faculty of Dental Science, Kyushu University, Fukuoka, Japan
| | - Tomoichiro Asano
- Department of Medical Chemistry, Division of Molecular Medical Science, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Fusanori Nishimura
- Department of Periodontology, Division of Oral Rehabilitation, Faculty of Dental Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan
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Cao M, Bu C, Zhang J, Ren Y, Zhou G, Chen C, Han G, Jiang SW, Wen J. Exosomal Circular RNA hsa_circ_0046060 of Umbilical Cord Mesenchymal Stromal Cell Ameliorates Glucose Metabolism and Insulin Resistance in Gestational Diabetes Mellitus via the miR-338-3p/G6PC2 Axis. Int J Endocrinol 2022; 2022:9218113. [PMID: 35726320 PMCID: PMC9206588 DOI: 10.1155/2022/9218113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Revised: 05/13/2022] [Accepted: 05/20/2022] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND Impaired glucose metabolism and insulin sensitivity have been linked to the pathogenesis of gestational diabetes mellitus (GDM). Exosomes secreted by the umbilical cord mesenchymal stromal cells (UMSCs) and circular RNAs (circRNAs) derived from exosomes have been shown to be associated with the progression of GDM-related complications. METHODS UMSCs were isolated from umbilical cords and identified through flow cytometry. Exosomes were isolated from UMSCs and were then characterized. The expression levels of RNA of hsa_circ_0046060, mmu_circ_0002819, and miR-338-3p were determined by quantitative real-time polymerase chain reaction (RT-qPCR). The intracellular glucose intake and glycogen content were measured using a High Sensitivity Glucose Assay Kit and Glycogen Assay Kit, respectively. Bioinformatics analysis and luciferase reporter assay were used to validate interactions among hsa_circ_0046060, miR-338-3p, and G6PC2. The expression of insulin receptor substrate-1 (IRS-1) and its phosphorylated form, (p-IRS-1), as well as G6PC2, was determined through western blotting. RESULTS UMSCs and exosomes were successfully isolated and identified. The upregulation of hsa_circ_0046060 decreased the intracellular glucose content in L-02 cells (43.45 vs. 16.87 pM/mg, P=0.0002), whereas shRNA-mediated downregulation reversed this effect (16.87 vs. 33.16 pM/mg, P=0.0011). Mmu_circ_0002819 in mice aggravated dysregulated glucose metabolism (49.88 vs. 21.69 pM/mg, P=0.0031) and insulin sensitivity (0.20 vs. 0.11 mg/mL, P=0.03) in GDM mice, which was abrogated by the knockdown of mmu_circ_0002819. The results of luciferase reporter assay revealed that miR-338-3p and G6PC2 were the potential targets of has_circ_0046060. Western blotting results showed that the reduced activation of IRS-1 induced by GDM (1.25 vs. 0.54, P=0.0001) could be rescued by the administration of si-circ-G-UMSC-EXOs (0.54 vs. 1.17, P=0.0001). CONCLUSION Taken together, the inhibition of hsa_circ_0046060 expression in exosomes from GDM-derived UMSCs can alleviate GDM by reversing abnormal glucose metabolism and insulin resistance in vivo and in vitro.
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Affiliation(s)
- Minkai Cao
- Department of Gynecology and Obstetrics, The Second Hospital of Nanjing, Nanjing University of Chinese Medicine, Nanjing 210003, China
- Department of Obstetrics and Gynecology, The Affiliated Wuxi Matemity and Child Health Care Hospital of Nanjing Medical University, Wuxi 214002, Jiangsu, China
| | - Chaozhi Bu
- Center of Reproductive Medicine, State Key Laboratory of Reproductive Medicine, Research Institute for Reproductive Health and Genetic Diseases, The Affiliated Wuxi Matemity and Child Health Care Hospital of Nanjing Medical University, Wuxi 214002, Jiangsu, China
| | - Jingjing Zhang
- Department of Obstetrics and Gynecology, Qilu Hospital of Shandong University, Jinan 250012, Shandong, China
| | - Yongwei Ren
- Center of Reproductive Medicine, State Key Laboratory of Reproductive Medicine, Research Institute for Reproductive Health and Genetic Diseases, The Affiliated Wuxi Matemity and Child Health Care Hospital of Nanjing Medical University, Wuxi 214002, Jiangsu, China
| | - Guanlun Zhou
- Department of Gynecology and Obstetrics, The Second Hospital of Nanjing, Nanjing University of Chinese Medicine, Nanjing 210003, China
| | - Chao Chen
- Department of Gynecology and Obstetrics, The Second Hospital of Nanjing, Nanjing University of Chinese Medicine, Nanjing 210003, China
| | - Guorong Han
- Department of Gynecology and Obstetrics, The Second Hospital of Nanjing, Nanjing University of Chinese Medicine, Nanjing 210003, China
| | - Shi-Wen Jiang
- Center of Reproductive Medicine, State Key Laboratory of Reproductive Medicine, Research Institute for Reproductive Health and Genetic Diseases, The Affiliated Wuxi Matemity and Child Health Care Hospital of Nanjing Medical University, Wuxi 214002, Jiangsu, China
| | - Juan Wen
- Nanjing Maternity and Child Health Care Institute, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Nanjing 210004, China
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Song J, He Q, Guo X, Wang L, Wang J, Cui C, Hu H, Yang M, Cui Y, Zang N, Yan F, Liu F, Sun Y, Liang K, Qin J, Zhao R, Wang C, Sun Z, Hou X, Li W, Chen L. Mesenchymal stem cell-conditioned medium alleviates high fat-induced hyperglucagonemia via miR-181a-5p and its target PTEN/AKT signaling. Mol Cell Endocrinol 2021; 537:111445. [PMID: 34464683 DOI: 10.1016/j.mce.2021.111445] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 08/08/2021] [Accepted: 08/25/2021] [Indexed: 12/24/2022]
Abstract
BACKGROUND α-cell dysregulation gives rise to fasting and postprandial hyperglycemia in type 2 diabetes mellitus(T2DM). Administration of Mesenchymal stem cells (MSCs) or their conditioned medium can improve islet function and enhance insulin secretion. However, studies showing the direct effect of MSCs on islet α-cell dysfunction are limited. METHODS In this study, we used high-fat diet (HFD)-induced mice and α-cell line exposure to palmitate (PA) to determine the effects of bone marrow-derived MSC-conditioned medium (bmMSC-CM) on glucagon secretion. Plasma and supernatant glucagon were detected by enzyme-linked immunosorbent assay(ELISA). To investigate the potential signaling pathways, phosphatase and tensin homolog deleted on chromosome 10 (PTEN), AKT and phosphorylated AKT(p-AKT) were assessed by Western blotting. RESULTS In vivo, bmMSC-CM infusion improved the glucose and insulin tolerance and protected against HFD-induced hyperglycemia and hyperglucagonemia. Meanwhile, bmMSC-CM infusion ameliorated HFD-induced islet hypertrophy and decreased α- and β-cell area. Consistently, in vitro, glucagon secretion from α-cells or primary islets was inhibited by bmMSC-CM, accompanied by reduction of intracellular PTEN expression and restoration of AKT signaling. Previous studies and the TargetScan database indicate that miR-181a and its target PTEN play vital roles in ameliorating α-cell dysfunction. We observed that miR-181a-5p was highly expressed in BM-MSCs but prominently lower in αTC1-6 cells. Overexpression or downregulation of miR-181a-5p respectively alleviated or aggravated glucagon secretion in αTC1-6 cells via the PTEN/AKT signaling pathway. CONCLUSIONS Our observations suggest that MSC-derived miR-181a-5p mitigates glucagon secretion of α-cells by regulating PTEN/AKT signaling, which provides novel evidence demonstrating the potential for MSCs in treating T2DM.
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Affiliation(s)
- Jia Song
- Department of Endocrinology, Qilu Hospital of Shandong University, Jinan, 250012, Shandong, China
| | - Qin He
- Department of Endocrinology, Qilu Hospital of Shandong University, Jinan, 250012, Shandong, China
| | - Xinghong Guo
- Department of Endocrinology, Qilu Hospital of Shandong University, Jinan, 250012, Shandong, China
| | - Lingshu Wang
- Department of Endocrinology, Qilu Hospital of Shandong University, Jinan, 250012, Shandong, China
| | - Jinbang Wang
- Department of Endocrinology, Qilu Hospital of Shandong University, Jinan, 250012, Shandong, China
| | - Chen Cui
- Department of Endocrinology, Qilu Hospital of Shandong University, Jinan, 250012, Shandong, China
| | - Huiqing Hu
- Department of Endocrinology, Qilu Hospital of Shandong University, Jinan, 250012, Shandong, China
| | - Mengmeng Yang
- Department of Endocrinology, Qilu Hospital of Shandong University, Jinan, 250012, Shandong, China
| | - Yixin Cui
- Department of Endocrinology, Qilu Hospital of Shandong University, Jinan, 250012, Shandong, China
| | - Nan Zang
- Department of Endocrinology, Qilu Hospital of Shandong University, Jinan, 250012, Shandong, China
| | - Fei Yan
- Department of Endocrinology, Qilu Hospital of Shandong University, Jinan, 250012, Shandong, China
| | - Fuqiang Liu
- Department of Endocrinology, Qilu Hospital of Shandong University, Jinan, 250012, Shandong, China
| | - Yujing Sun
- Department of Endocrinology, Qilu Hospital of Shandong University, Jinan, 250012, Shandong, China
| | - Kai Liang
- Department of Endocrinology, Qilu Hospital of Shandong University, Jinan, 250012, Shandong, China
| | - Jun Qin
- Department of Endocrinology, Qilu Hospital of Shandong University, Jinan, 250012, Shandong, China
| | - Ruxing Zhao
- Department of Endocrinology, Qilu Hospital of Shandong University, Jinan, 250012, Shandong, China
| | - Chuan Wang
- Department of Endocrinology, Qilu Hospital of Shandong University, Jinan, 250012, Shandong, China
| | - Zheng Sun
- Department of Endocrinology, Qilu Hospital of Shandong University, Jinan, 250012, Shandong, China
| | - Xinguo Hou
- Department of Endocrinology, Qilu Hospital of Shandong University, Jinan, 250012, Shandong, China; Institute of Endocrine and Metabolic Diseases of Shandong University, Jinan, 250012, Shandong, China; Key Laboratory of Endocrine and Metabolic Diseases, Shandong Province Medicine & Health, Jinan, 250012, Shandong, China; Jinan Clinical Research Center for Endocrine and Metabolic Disease, Jinan, 250012, Shandong, China
| | - Wenjuan Li
- Department of Endocrinology, Qilu Hospital of Shandong University, Jinan, 250012, Shandong, China; Institute of Endocrine and Metabolic Diseases of Shandong University, Jinan, 250012, Shandong, China; Key Laboratory of Endocrine and Metabolic Diseases, Shandong Province Medicine & Health, Jinan, 250012, Shandong, China; Jinan Clinical Research Center for Endocrine and Metabolic Disease, Jinan, 250012, Shandong, China.
| | - Li Chen
- Department of Endocrinology, Qilu Hospital of Shandong University, Jinan, 250012, Shandong, China; Institute of Endocrine and Metabolic Diseases of Shandong University, Jinan, 250012, Shandong, China; Key Laboratory of Endocrine and Metabolic Diseases, Shandong Province Medicine & Health, Jinan, 250012, Shandong, China; Jinan Clinical Research Center for Endocrine and Metabolic Disease, Jinan, 250012, Shandong, China.
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Li YZ, Di Cristofano A, Woo M. Metabolic Role of PTEN in Insulin Signaling and Resistance. Cold Spring Harb Perspect Med 2020; 10:a036137. [PMID: 31964643 PMCID: PMC7397839 DOI: 10.1101/cshperspect.a036137] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Phosphatase and tensin homolog (PTEN) is most prominently known for its function in tumorigenesis. However, a metabolic role of PTEN is emerging as a result of its altered expression in type 2 diabetes (T2D), which results in impaired insulin signaling and promotion of insulin resistance during the pathogenesis of T2D. PTEN functions in regulating insulin signaling across different organs have been identified. Through the use of a variety of models, such as tissue-specific knockout (KO) mice and in vitro cell cultures, PTEN's role in regulating insulin action has been elucidated across many cell types. Herein, we will review the recent advancements in the understanding of PTEN's metabolic functions in each of the tissues and cell types that contribute to regulating systemic insulin sensitivity and discuss how PTEN may represent a promising therapeutic strategy for treatment or prevention of T2D.
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Affiliation(s)
- Yu Zhe Li
- Toronto General Hospital Research Institute, University Health Network, Toronto, Ontario M5G 2C4, Canada
- Institute of Medical Science, University of Toronto, Toronto, Ontario M5G 2M9, Canada
| | - Antonio Di Cristofano
- Department of Developmental and Molecular Biology and Medicine (Oncology), Albert Einstein College of Medicine and Albert Einstein Cancer Center, Bronx, New York 10461, USA
| | - Minna Woo
- Toronto General Hospital Research Institute, University Health Network, Toronto, Ontario M5G 2C4, Canada
- Institute of Medical Science, University of Toronto, Toronto, Ontario M5G 2M9, Canada
- Department of Immunology, University of Toronto, Toronto, Ontario M5G 2M9, Canada
- Division of Endocrinology and Metabolism, Department of Medicine, University Health Network/Mount Sinai Hospital, University of Toronto, Toronto, Ontario M5G 2C4, Canada
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Weng Q, Zhao M, Zheng J, Yang L, Xu Z, Zhang Z, Wang J, Wang J, Yang B, Richard Lu Q, Ying M, He Q. STAT3 dictates β-cell apoptosis by modulating PTEN in streptozocin-induced hyperglycemia. Cell Death Differ 2019; 27:130-145. [PMID: 31097787 DOI: 10.1038/s41418-019-0344-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Revised: 03/31/2019] [Accepted: 04/19/2019] [Indexed: 02/07/2023] Open
Abstract
Insufficient pancreatic β-cell mass or insulin-producing β-cells are implicated in all forms of diabetes mellitus. However, the molecular mechanisms underlying β-cell destruction are complex and not fully defined. Here we observed that activation of STAT3 is intensely and specifically inhibited in β-cells under hyperglycemic conditions. By knocking out STAT3 specifically in mouse β-cells, we found that the loss of STAT3 sensitized mice to three low doses of STZ stimulation resulting in hyperglycemia. Mechanistically, accumulating PTEN, induced by STAT3 deficiency, directly represses phosphorylation of AKT, which negatively modulates transcription factor activation, dysregulates β-cell function, positively promotes apoptotic signaling, and finally induces β-cell apoptosis. Notably, the defective secretion of insulin and β-cells apoptosis was completely rescued by PTEN ablation in STAT3-null islets or PTEN inhibitor bpv(phen) treatment. Thus our data suggest that STAT3 is a vital modulator of β-cell survival and function, highlighting a critical role for STAT3 in the negative regulation of PTEN-AKT signaling pathway associated with β-cell dysfunction and apoptosis.
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Affiliation(s)
- Qinjie Weng
- Zhejiang Province Key Laboratory of Anti-Cancer Drug Research, College of Pharmaceutical Sciences, Zhejiang University, 310058, Hangzhou, China.,Center for Drug Safety Evaluation and Research of Zhejiang University, 310058, Hangzhou, China
| | - Mengting Zhao
- Zhejiang Province Key Laboratory of Anti-Cancer Drug Research, College of Pharmaceutical Sciences, Zhejiang University, 310058, Hangzhou, China
| | - Jiahuan Zheng
- Zhejiang Province Key Laboratory of Anti-Cancer Drug Research, College of Pharmaceutical Sciences, Zhejiang University, 310058, Hangzhou, China
| | - Lijun Yang
- Zhejiang Province Key Laboratory of Anti-Cancer Drug Research, College of Pharmaceutical Sciences, Zhejiang University, 310058, Hangzhou, China
| | - Zijie Xu
- Zhejiang Province Key Laboratory of Anti-Cancer Drug Research, College of Pharmaceutical Sciences, Zhejiang University, 310058, Hangzhou, China
| | - Zhikang Zhang
- Zhejiang Province Key Laboratory of Anti-Cancer Drug Research, College of Pharmaceutical Sciences, Zhejiang University, 310058, Hangzhou, China
| | - Jincheng Wang
- Zhejiang Province Key Laboratory of Anti-Cancer Drug Research, College of Pharmaceutical Sciences, Zhejiang University, 310058, Hangzhou, China
| | - Jiajia Wang
- Zhejiang Province Key Laboratory of Anti-Cancer Drug Research, College of Pharmaceutical Sciences, Zhejiang University, 310058, Hangzhou, China
| | - Bo Yang
- Zhejiang Province Key Laboratory of Anti-Cancer Drug Research, College of Pharmaceutical Sciences, Zhejiang University, 310058, Hangzhou, China
| | - Q Richard Lu
- Division of Experimental Hematology and Cancer Biology, Brain Tumor Center, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, 45229, USA
| | - Meidan Ying
- Zhejiang Province Key Laboratory of Anti-Cancer Drug Research, College of Pharmaceutical Sciences, Zhejiang University, 310058, Hangzhou, China.
| | - Qiaojun He
- Zhejiang Province Key Laboratory of Anti-Cancer Drug Research, College of Pharmaceutical Sciences, Zhejiang University, 310058, Hangzhou, China. .,Center for Drug Safety Evaluation and Research of Zhejiang University, 310058, Hangzhou, China.
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Huang YW, Chen JH, Rader JS, Aguilera-Barrantes I, Wang LS. Preventive Effects by Black Raspberries of Endometrial Carcinoma Initiation and Promotion Induced by a High-Fat Diet. Mol Nutr Food Res 2019; 63:e1900013. [PMID: 30951235 DOI: 10.1002/mnfr.201900013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Revised: 03/18/2019] [Indexed: 11/11/2022]
Abstract
SCOPE The chemopreventive effects of black raspberries (BRBs) have not been studied in endometrial tumorigenesis. Here, they are examined in a mouse model of endometrial cancer. METHODS AND RESULTS Wild-type and Pten heterozygous (+/-) female mice are weaned at 3 weeks and fed with four AIN-93G diets: 93G; 93G+5% BRBs powder; high-fat (HF); and HF+5% BRBs. Body weight and diet consumption are recorded weekly until the mice are euthanized at 28 weeks of age. Mice fed with HF diets are found to significantly gain body weight over time. BRBs are not found to affect the development of obesity. Mice in the HF+BRBs group consume less food than the HF-only mice. HF+BRBs diets suppress uterine tumor initiation and promotion more than the HF-only diet by inhibiting cell proliferation. It also reduces HF-induced levels of plasma leptin and 17β-estradiol (E2). Urolithin A, a metabolite of BRBs, suppresses cell proliferation induced by leptin and E2. CONCLUSION BRBs are preventive in HF-mediated uterine tumorigenesis because they suppress cell growth and plasma leptin and E2 levels.
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Affiliation(s)
- Yi-Wen Huang
- Department of Obstetrics and Gynecology, Medical College of Wisconsin, Milwaukee, WI, 53226, USA
| | - Jo-Hsin Chen
- Department of Obstetrics and Gynecology, Medical College of Wisconsin, Milwaukee, WI, 53226, USA
| | - Janet S Rader
- Department of Obstetrics and Gynecology, Medical College of Wisconsin, Milwaukee, WI, 53226, USA
| | | | - Li-Shu Wang
- Department of Medicine, Medical College of Wisconsin, Milwaukee, WI, 53226, USA
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Yan H, Jiang L, Zou H, Chen T, Liang H, Tang L. PTEN suppresses the inflammation, viability, and motility of AP-AR42J cells by activating the Wnt/β-catenin pathway. RSC Adv 2019; 9:5460-5469. [PMID: 35515912 PMCID: PMC9060792 DOI: 10.1039/c8ra08998a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Accepted: 01/14/2019] [Indexed: 11/23/2022] Open
Abstract
Acute pancreatitis (AP), a kind of common acute abdominal disease and typical chemical inflammation, is commonly caused by pancreatin digestion of the pancreas and surrounding tissues. The gene for phosphate and tension homology deleted on chromosome ten (PTEN) is a tumor suppressor that regulates numerous cellular processes. In the present study, we have elaborately investigated the effect of PTEN on the alleviating of AP and its underlying mechanisms. Firstly, we demonstrated an up-regulation of PTEN in the pancreatic tissues from AP rats by immunochemistry, qRT-PCR and western-blot assays. Subsequently, cellular experiments exhibited that PTEN has a significant inhibition effect on the proliferation, invasion and migration of AP cells. Further underlying mechanism studies showed that the growth of AP cells was mainly restrained by PTEN in the G1 phase through activation of the Wnt/β-catenin pathway, which can be demonstrated by the down-regulation of various pro-inflammatory cytokines such as IL-6, IL-10, TNF and IL-1β. Taking these results together, we can draw the conclusion that PTEN plays a significant role in suppressing the inflammation, viability and motility of acute pancreatitis and could be a potential target for AP therapies. Acute pancreatitis (AP), a kind of common acute abdominal disease and typical chemical inflammation, is commonly caused by pancreatin digestion of the pancreas and surrounding tissues.![]()
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Affiliation(s)
- Hongtao Yan
- General Surgery Center of PLA, General Hospital of Western Theater Command No. 270 Rong Du Road, Jinniu District Chengdu Sichuan Province 610083 P. R. China +86-028-86570326
| | - Li Jiang
- Cardiac Care Unit of Cardiothoracic Surgery, General Hospital of Western Theater Command Chengdu Sichuan 610083 P. R. China
| | - Hong Zou
- General Surgery Center of PLA, General Hospital of Western Theater Command No. 270 Rong Du Road, Jinniu District Chengdu Sichuan Province 610083 P. R. China +86-028-86570326
| | - Tao Chen
- General Surgery Center of PLA, General Hospital of Western Theater Command No. 270 Rong Du Road, Jinniu District Chengdu Sichuan Province 610083 P. R. China +86-028-86570326
| | - Hongyin Liang
- General Surgery Center of PLA, General Hospital of Western Theater Command No. 270 Rong Du Road, Jinniu District Chengdu Sichuan Province 610083 P. R. China +86-028-86570326
| | - Lijun Tang
- General Surgery Center of PLA, General Hospital of Western Theater Command No. 270 Rong Du Road, Jinniu District Chengdu Sichuan Province 610083 P. R. China +86-028-86570326
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8
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Zhang Y, Thai K, Jin T, Woo M, Gilbert RE. SIRT1 activation attenuates α cell hyperplasia, hyperglucagonaemia and hyperglycaemia in STZ-diabetic mice. Sci Rep 2018; 8:13972. [PMID: 30228292 PMCID: PMC6143559 DOI: 10.1038/s41598-018-32351-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Accepted: 09/04/2018] [Indexed: 12/19/2022] Open
Abstract
The NAD+-dependent lysine deacetylase, Sirtuin 1 (SIRT1), plays a central role in metabolic regulation. With type 1 diabetes a disease that is characterised by metabolic dysregulation, we sought to assess the impact of SIRT1 activation in experimental, streptozotocin (STZ)-induced diabetes. CD1 mice with and without STZ-induced diabetes were randomized to receive the SIRT1 activating compound, SRT3025, or vehicle over 20 weeks. Vehicle treated STZ-CD1 mice developed severe hyperglycaemia with near-absent circulating insulin and widespread beta cell loss in association with hyperglucagonaemia and expanded islet alpha cell mass. Without affecting ß-cell mass or circulating insulin, diabetic mice that received SRT3025 had substantially improved glycaemic control with greatly reduced islet α cell mass and lower plasma glucagon concentrations. Consistent with reduced glucagon abundance, the diabetes-associated overexpression of key gluconeogenic enzymes, glucose-6-phosphatase and PEPCK were also lowered by SRT3025. Incubating cultured α cells with SRT3025 diminished their glucagon secretion and proliferative activity in association with a reduction in the α cell associated transcription factor, Aristaless Related Homeobox (Arx). By reducing the paradoxical increase in glucagon, SIRT1 activation may offer a new, α-cell centric approach to the treatment of type 1 diabetes.
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Affiliation(s)
- Yanling Zhang
- St. Michael's Hospital, Keenan Research Centre, Li Ka Shing Knowledge Institute, Toronto, M5B 1W8, Canada
| | - Kerri Thai
- St. Michael's Hospital, Keenan Research Centre, Li Ka Shing Knowledge Institute, Toronto, M5B 1W8, Canada
| | - Tianru Jin
- Toronto General Hospital Research Institute (TGHRI), Toronto, ON, M5G 2C4, Canada
| | - Minna Woo
- Toronto General Hospital Research Institute (TGHRI), Toronto, ON, M5G 2C4, Canada
| | - Richard E Gilbert
- St. Michael's Hospital, Keenan Research Centre, Li Ka Shing Knowledge Institute, Toronto, M5B 1W8, Canada.
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Guo J, Dou L, Meng X, Chen Z, Yang W, Fang W, Yang C, Huang X, Tang W, Yang J, Li J. Hepatic MiR-291b-3p Mediated Glucose Metabolism by Directly Targeting p65 to Upregulate PTEN Expression. Sci Rep 2017; 7:39899. [PMID: 28054586 PMCID: PMC5214750 DOI: 10.1038/srep39899] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Accepted: 11/29/2016] [Indexed: 12/14/2022] Open
Abstract
Several studies have suggested an important role of miR-291b-3p in the development of embryonic stem cells. In previous study, we found that the expression of miR-291b-3p was significantly upregulated in the liver of db/db mice. However, the role of miR-291b-3p in glucose metabolism and its underlying mechanisms remain unknown. In the present study, we demonstrated that miR-291b-3p was abundantly expressed in the liver. Of note, hepatic miR-291b-3p expression was upregulated in HFD-fed mice and induced by fasting in C57BL/6 J normal mice. Importantly, hepatic inhibition miR-291b-3p expression ameliorated hyperglycemia and insulin resistance in HFD-fed mice, whereas hepatic overexpression of miR-291b-3p led to hyperglycemia and insulin resistance in C57BL/6 J normal mice. Further study revealed that miR-291b-3p suppressed insulin-stimulated AKT/GSK signaling and increased the expression of gluconeogenic genes in hepatocytes. Moreover, we identified that p65, a subunit of nuclear factor-κB (NF-κB), is a target of miR-291b-3p by bioinformatics analysis and luciferase reporter assay. Silencing of p65 significantly augmented the expression of PTEN and impaired AKT activation. In conclusion, we found novel evidence suggesting that hepatic miR-291b-3p mediated glycogen synthesis and gluconeogenesis through targeting p65 to regulate PTEN expression. Our findings indicate the therapeutic potential of miR-291b-3p inhibitor in hyperglycemia and insulin resistance.
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Affiliation(s)
- Jun Guo
- The MOH Key Laboratory of Geriatrics, Beijing Hospital, National Center of Gerontology, Beijing, 100730, P. R. China
| | - Lin Dou
- The MOH Key Laboratory of Geriatrics, Beijing Hospital, National Center of Gerontology, Beijing, 100730, P. R. China
| | - Xiangyu Meng
- The MOH Key Laboratory of Geriatrics, Beijing Hospital, National Center of Gerontology, Beijing, 100730, P. R. China
| | - Zhenzhen Chen
- Department of physiology and pathophysiology, key laboratory of molecular cardiovascular science of the ministry of education, Peking University Health Science Center, Beijing 100191, China
| | - Weili Yang
- Department of physiology and pathophysiology, key laboratory of molecular cardiovascular science of the ministry of education, Peking University Health Science Center, Beijing 100191, China
| | - Weiwei Fang
- The MOH Key Laboratory of Geriatrics, Beijing Hospital, National Center of Gerontology, Beijing, 100730, P. R. China
| | - Chunxiao Yang
- The MOH Key Laboratory of Geriatrics, Beijing Hospital, National Center of Gerontology, Beijing, 100730, P. R. China
| | - Xiuqing Huang
- The MOH Key Laboratory of Geriatrics, Beijing Hospital, National Center of Gerontology, Beijing, 100730, P. R. China
| | - Weiqing Tang
- The MOH Key Laboratory of Geriatrics, Beijing Hospital, National Center of Gerontology, Beijing, 100730, P. R. China
| | - Jichun Yang
- Department of physiology and pathophysiology, key laboratory of molecular cardiovascular science of the ministry of education, Peking University Health Science Center, Beijing 100191, China
| | - Jian Li
- The MOH Key Laboratory of Geriatrics, Beijing Hospital, National Center of Gerontology, Beijing, 100730, P. R. China
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10
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da Costa RM, Neves KB, Mestriner FL, Louzada-Junior P, Bruder-Nascimento T, Tostes RC. TNF-α induces vascular insulin resistance via positive modulation of PTEN and decreased Akt/eNOS/NO signaling in high fat diet-fed mice. Cardiovasc Diabetol 2016; 15:119. [PMID: 27562094 PMCID: PMC5000486 DOI: 10.1186/s12933-016-0443-0] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Accepted: 08/18/2016] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND High fat diet (HFD) induces insulin resistance in various tissues, including the vasculature. HFD also increases plasma levels of TNF-α, a cytokine that contributes to insulin resistance and vascular dysfunction. Considering that the enzyme phosphatase and tension homologue (PTEN), whose expression is increased by TNF-α, reduces Akt signaling and, consequently, nitric oxide (NO) production, we hypothesized that PTEN contributes to TNF-α-mediated vascular resistance to insulin induced by HFD. Mechanisms underlying PTEN effects were determined. METHODS Mesenteric vascular beds were isolated from C57Bl/6J and TNF-α KO mice submitted to control or HFD diet for 18 weeks to assess molecular mechanisms by which TNF-α and PTEN contribute to vascular dysfunction. RESULTS Vasodilation in response to insulin was decreased in HFD-fed mice and in ex vivo control arteries incubated with TNF-α. TNF-α receptors deficiency and TNF-α blockade with infliximab abolished the effects of HFD and TNF-α on insulin-induced vasodilation. PTEN vascular expression (total and phosphorylated isoforms) was increased in HFD-fed mice. Treatment with a PTEN inhibitor improved insulin-induced vasodilation in HFD-fed mice. TNF-α receptor deletion restored PTEN expression/activity and Akt/eNOS/NO signaling in HFD-fed mice. CONCLUSION TNF-α induces vascular insulin resistance by mechanisms that involve positive modulation of PTEN and inhibition of Akt/eNOS/NO signaling. Our findings highlight TNF-α and PTEN as potential targets to limit insulin resistance and vascular complications associated with obesity-related conditions.
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Affiliation(s)
- Rafael Menezes da Costa
- Department of Pharmacology, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto, SP, Brazil.
| | - Karla Bianca Neves
- Department of Pharmacology, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto, SP, Brazil
| | - Fabíola Leslie Mestriner
- Department of Pharmacology, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto, SP, Brazil
| | - Paulo Louzada-Junior
- Division of Clinical Immunology, Department of Clinical Medicine, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto, SP, Brazil
| | - Thiago Bruder-Nascimento
- Department of Pharmacology, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto, SP, Brazil
| | - Rita C Tostes
- Department of Pharmacology, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto, SP, Brazil
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11
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Abstract
As with other complex diseases, unbiased association studies followed by physiological and experimental characterization have for years formed a paradigm for identifying genes or processes of relevance to type 2 diabetes mellitus (T2D). Recent large-scale common and rare variant genome-wide association studies (GWAS) suggest that substantially larger association studies are needed to identify most T2D loci in the population. To hasten clinical translation of genetic discoveries, new paradigms are also required to aid specialized investigation of nascent hypotheses. We argue for an integrated T2D knowledgebase, designed for a worldwide community to access aggregated large-scale genetic data sets, as one paradigm to catalyse convergence of these efforts.
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12
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Wang Y, Han C, Zhu W, Wu Z, Liu Y, Chen L. An optical method to evaluate both mass and functional competence of pancreatic α- and β-cells. J Cell Sci 2016; 129:2462-71. [PMID: 27173492 DOI: 10.1242/jcs.184523] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Accepted: 04/28/2016] [Indexed: 01/09/2023] Open
Abstract
Imbalanced glucagon and insulin release leads to the onset of type 2 diabetes. To pinpoint the underlying primary driving force, here we have developed a fast, non-biased optical method to measure ratios of pancreatic α- and β-cell mass and function simultaneously. We firstly label both primary α- and β-cells with the red fluorescent probe ZinRhodaLactam-1 (ZRL1), and then highlight α-cells by selectively quenching the ZRL1 signal from β-cells. Based on the signals before and after quenching, we calculate the ratio of the α-cell to β-cell mass within live islets, which we found matched the results from immunohistochemistry. From the same islets, glucagon and insulin release capability can be concomitantly measured. Thus, we were able to measure the ratio of α-cell to β-cell mass and their function in wild-type and diabetic Lepr(db)/Lepr(db) (denoted db/db) mice at different ages. We find that the initial glucose intolerance that appears in 10-week-old db/db mice is associated with further expansion of α-cell mass prior to deterioration in functional β-cell mass. Our method is extendable to studies of islet mass and function in other type 2 diabetes animal models, which shall benefit mechanistic studies of imbalanced hormone secretion during type 2 diabetes progression.
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Affiliation(s)
- Yi Wang
- College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China State Key Laboratory of Membrane Biology, Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Institute of Molecular Medicine, Peking University, Beijing 100871, China
| | - Chengsheng Han
- State Key Laboratory of Membrane Biology, Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Institute of Molecular Medicine, Peking University, Beijing 100871, China
| | - Wenzhen Zhu
- State Key Laboratory of Membrane Biology, Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Institute of Molecular Medicine, Peking University, Beijing 100871, China
| | - Zhengxing Wu
- College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Yanmei Liu
- State Key Laboratory of Membrane Biology, Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Institute of Molecular Medicine, Peking University, Beijing 100871, China
| | - Liangyi Chen
- State Key Laboratory of Membrane Biology, Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Institute of Molecular Medicine, Peking University, Beijing 100871, China
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13
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Wang S, Wang L, Dou L, Guo J, Fang W, Li M, Meng X, Man Y, Shen T, Huang X, Li J. MicroRNA 152 regulates hepatic glycogenesis by targeting PTEN. FEBS J 2016; 283:1935-46. [PMID: 26996529 DOI: 10.1111/febs.13713] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Revised: 01/20/2016] [Accepted: 03/15/2016] [Indexed: 12/16/2022]
Abstract
Hepatic insulin resistance, defined as a diminished ability of hepatocytes to respond to the action of insulin, plays an important role in the development of type 2 diabetes and metabolic syndrome. Aberrant expression of mmu-miR-152-3p (miR-152) is related to the pathogenesis of tumors such as hepatitis B virus related hepatocellular carcinoma. However, the role of miR-152 in hepatic insulin resistance remains unknown. In the present study, we identified the potential role of miR-152 in regulating hepatic glycogenesis. The expression of miR-152 and the level of glycogen were significantly downregulated in the liver of db/db mice and mice fed a high fat diet. In vivo and in vitro results suggest that inhibition of miR-152 expression induced impaired glycogenesis in hepatocytes. Interestingly, miR-152 expression, glycogen synthesis and protein kinase B/glycogen synthase kinase (AKT/GSK) pathway activation were significantly decreased in the liver of mice injected with 16 μg·mL(-1) interleukin 6 (IL-6) by pumps for 7 days and in NCTC 1469 cells treated with 10 ng·mL(-1) IL-6 for 24 h. Moreover, hepatic overexpression of miR-152 rescued IL-6-induced impaired glycogenesis. Finally, phosphatase and tensin homolog (PTEN) was identified as a direct target of miR-152 to mediate hepatic glycogen synthesis. Our findings provide mechanistic insight into the effects of miR-152 on the regulation of the AKT/GSK pathway and the synthesis of glycogen in hepatocytes. Downregulated miR-152 induced impaired hepatic glycogenesis by targeting PTEN. PTEN participated in miR-152-mediated glycogenesis in hepatocytes via regulation of the AKT/GSK pathway.
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Affiliation(s)
- Shuyue Wang
- Peking University Fifth School of Clinical Medicine, Beijing, China
| | - Lilin Wang
- Key Laboratory of Geriatrics, Beijing Hospital and Beijing Institute of Geriatrics, Ministry of Health, China.,Department of Medicine, Shenzhen Family Planning Service Center, Guangdong, China
| | - Lin Dou
- Key Laboratory of Geriatrics, Beijing Hospital and Beijing Institute of Geriatrics, Ministry of Health, China
| | - Jun Guo
- Key Laboratory of Geriatrics, Beijing Hospital and Beijing Institute of Geriatrics, Ministry of Health, China
| | - Weiwei Fang
- Key Laboratory of Geriatrics, Beijing Hospital and Beijing Institute of Geriatrics, Ministry of Health, China
| | - Meng Li
- Peking University Fifth School of Clinical Medicine, Beijing, China.,Key Laboratory of Geriatrics, Beijing Hospital and Beijing Institute of Geriatrics, Ministry of Health, China
| | - Xiangyu Meng
- Peking University Fifth School of Clinical Medicine, Beijing, China.,Key Laboratory of Geriatrics, Beijing Hospital and Beijing Institute of Geriatrics, Ministry of Health, China
| | - Yong Man
- Key Laboratory of Geriatrics, Beijing Hospital and Beijing Institute of Geriatrics, Ministry of Health, China
| | - Tao Shen
- Key Laboratory of Geriatrics, Beijing Hospital and Beijing Institute of Geriatrics, Ministry of Health, China
| | - Xiuqing Huang
- Key Laboratory of Geriatrics, Beijing Hospital and Beijing Institute of Geriatrics, Ministry of Health, China
| | - Jian Li
- Peking University Fifth School of Clinical Medicine, Beijing, China.,Key Laboratory of Geriatrics, Beijing Hospital and Beijing Institute of Geriatrics, Ministry of Health, China
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14
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Abstract
PTEN plays an important role in diabetes pathogenesis not only as a key negative regulator of the PI3K/Akt pathway required for insulin action, but also via its role in other cell processes required to maintain metabolic homeostasis. We describe the generation of tissue-specific PTEN knockout mice and models of both type 1 and type 2 diabetes, which we have found useful for the study of diabetes pathogenesis. We also outline common methods suitable for the characterization of glucose homeostasis in rodent models, including techniques to measure beta cell function and insulin sensitivity.
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Affiliation(s)
- Cynthia T Luk
- Toronto General Research Institute, University Health Network, Toronto, ON, Canada, M5G 2C4
- Institute of Medical Science, University of Toronto, Toronto, ON, Canada, M5G 2C4
| | - Stephanie A Schroer
- Toronto General Research Institute, University Health Network, Toronto, ON, Canada, M5G 2C4
| | - Minna Woo
- Toronto General Research Institute, University Health Network, Toronto, ON, Canada, M5G 2C4.
- Institute of Medical Science, University of Toronto, Toronto, ON, Canada, M5G 2C4.
- Division of Endocrinology, Department of Medicine, University Health Network, University of Toronto, Toronto, ON, Canada, M5G 2C4.
- Toronto General Research Institute, 101 College Street, MaRS Centre/TMDT, Room 10-363, Toronto, ON, Canada, M5G 1L7.
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15
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Phosphatase and Tensin Homologue: Novel Regulation by Developmental Signaling. JOURNAL OF SIGNAL TRANSDUCTION 2015; 2015:282567. [PMID: 26339505 PMCID: PMC4539077 DOI: 10.1155/2015/282567] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/06/2015] [Revised: 06/06/2015] [Accepted: 07/01/2015] [Indexed: 11/18/2022]
Abstract
Phosphatase and tensin homologue (PTEN) is a critical cell endogenous inhibitor of phosphoinositide signaling in mammalian cells. PTEN dephosphorylates phosphoinositide trisphosphate (PIP3), and by so doing PTEN has the function of negative regulation of Akt, thereby inhibiting this key intracellular signal transduction pathway. In numerous cell types, PTEN loss-of-function mutations result in unopposed Akt signaling, producing numerous effects on cells. Numerous reports exist regarding mutations in PTEN leading to unregulated Akt and human disease, most notably cancer. However, less is commonly known about nonmutational regulation of PTEN. This review focuses on an emerging literature on the regulation of PTEN at the transcriptional, posttranscriptional, translational, and posttranslational levels. Specifically, a focus is placed on the role developmental signaling pathways play in PTEN regulation; this includes insulin-like growth factor, NOTCH, transforming growth factor, bone morphogenetic protein, wnt, and hedgehog signaling. The regulation of PTEN by developmental mediators affects critical biological processes including neuronal and organ development, stem cell maintenance, cell cycle regulation, inflammation, response to hypoxia, repair and recovery, and cell death and survival. Perturbations of PTEN regulation consequently lead to human diseases such as cancer, chronic inflammatory syndromes, developmental abnormalities, diabetes, and neurodegeneration.
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16
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Abstract
PURPOSE OF REVIEW Autoimmune destruction of the β cells is considered the key abnormality in type 1 diabetes mellitus and insulin replacement the primary therapeutic strategy. However, a lack of insulin is accompanied by disturbances in glucagon release, which is excessive postprandially, but insufficient during hypoglycaemia. In addition, replacing insulin alone appears insufficient for adequate glucose control. This review focuses on the growing body of evidence that glucagon abnormalities contribute significantly to the pathophysiology of diabetes and on recent efforts to target the glucagon axis as adjunctive therapy to insulin replacement. RECENT FINDINGS This review discusses recent (since 2013) advances in abnormalities of glucagon regulation and their link to the pathophysiology of diabetes; new mechanisms of glucagon action and regulation; manipulation of glucagon in diabetes treatment; and analytical and systems biology tools to study glucagon regulation. SUMMARY Recent efforts 'resurrected' glucagon as a key hormone in the pathophysiology of diabetes. New studies target its abnormal regulation and action that is key for improving diabetes treatment. The progress is promising, but major questions remain, including unravelling the mechanism of loss of glucagon counterregulation in type 1 diabetes mellitus and how best to manipulate glucagon to achieve more efficient and safer glycaemic control.
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Affiliation(s)
- Leon S Farhy
- Division of Endocrinology and Metabolism, Department of Medicine and Center for Diabetes Technology, University of Virginia, Charlottesville, Virginia, USA
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