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Taylor AJ, Panzhinskiy E, Orban PC, Lynn FC, Schaeffer DF, Johnson JD, Kopp JL, Verchere CB. Islet amyloid polypeptide does not suppress pancreatic cancer. Mol Metab 2023; 68:101667. [PMID: 36621763 PMCID: PMC9938314 DOI: 10.1016/j.molmet.2023.101667] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Revised: 12/24/2022] [Accepted: 01/02/2023] [Indexed: 01/06/2023] Open
Abstract
OBJECTIVES Pancreatic cancer risk is elevated approximately two-fold in type 1 and type 2 diabetes. Islet amyloid polypeptide (IAPP) is an abundant beta-cell peptide hormone that declines with diabetes progression. IAPP has been reported to act as a tumour-suppressor in p53-deficient cancers capable of regressing tumour volumes. Given the decline of IAPP during diabetes development, we investigated the actions of IAPP in pancreatic ductal adenocarcinoma (PDAC; the most common form of pancreatic cancer) to determine if IAPP loss in diabetes may increase the risk of pancreatic cancer. METHODS PANC-1, MIA PaCa-2, and H1299 cells were treated with rodent IAPP, and the IAPP analogs pramlintide and davalintide, and assayed for changes in proliferation, death, and glycolysis. An IAPP-deficient mouse model of PDAC (Iapp-/-; Kras+/LSL-G12D; Trp53flox/flox; Ptf1a+/CreER) was generated for survival analysis. RESULTS IAPP did not impact glycolysis in MIA PaCa-2 cells, and did not impact cell death, proliferation, or glycolysis in PANC-1 cells or in H1299 cells, which were previously reported as IAPP-sensitive. Iapp deletion in Kras+/LSL-G12D; Trp53flox/flox; Ptf1a+/CreER mice had no effect on survival time to lethal tumour burden. CONCLUSIONS In contrast to previous reports, we find that IAPP does not function as a tumour suppressor. This suggests that loss of IAPP signalling likely does not increase the risk of pancreatic cancer in individuals with diabetes.
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Affiliation(s)
- Austin J Taylor
- BC Children's Hospital Research Institute, Vancouver, BC, Canada; Centre for Molecular Medicine and Therapeutics, Vancouver, BC, Canada; Department of Pathology and Laboratory Medicine, University of British Columbia, BC, Canada
| | - Evgeniy Panzhinskiy
- Life Sciences Institute, University of British Columbia, BC, Canada; Department of Biochemistry, University of British Columbia, BC, Canada
| | - Paul C Orban
- BC Children's Hospital Research Institute, Vancouver, BC, Canada; Centre for Molecular Medicine and Therapeutics, Vancouver, BC, Canada; Department of Surgery, University of British Columbia, BC, Canada
| | - Francis C Lynn
- BC Children's Hospital Research Institute, Vancouver, BC, Canada; Department of Surgery, University of British Columbia, BC, Canada; Department of Cellular and Physiological Sciences, University of British Columbia, BC, Canada
| | - David F Schaeffer
- Department of Pathology and Laboratory Medicine, University of British Columbia, BC, Canada; Pancreas Centre BC, Vancouver, BC, Canada
| | - James D Johnson
- Life Sciences Institute, University of British Columbia, BC, Canada; Department of Cellular and Physiological Sciences, University of British Columbia, BC, Canada
| | - Janel L Kopp
- Life Sciences Institute, University of British Columbia, BC, Canada; Department of Cellular and Physiological Sciences, University of British Columbia, BC, Canada
| | - C Bruce Verchere
- BC Children's Hospital Research Institute, Vancouver, BC, Canada; Centre for Molecular Medicine and Therapeutics, Vancouver, BC, Canada; Department of Pathology and Laboratory Medicine, University of British Columbia, BC, Canada; Department of Surgery, University of British Columbia, BC, Canada.
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2
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Brownrigg GP, Xia YH, Chu CMJ, Wang S, Chao C, Zhang JA, Skovsø S, Panzhinskiy E, Hu X, Johnson JD, Rideout EJ. Sex differences in islet stress responses support female β cell resilience. Mol Metab 2023; 69:101678. [PMID: 36690328 PMCID: PMC9971554 DOI: 10.1016/j.molmet.2023.101678] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Revised: 01/07/2023] [Accepted: 01/17/2023] [Indexed: 01/21/2023] Open
Abstract
OBJECTIVE Pancreatic β cells play a key role in maintaining glucose homeostasis; dysfunction of this critical cell type causes type 2 diabetes (T2D). Emerging evidence points to sex differences in β cells, but few studies have examined male-female differences in β cell stress responses and resilience across multiple contexts, including diabetes. Here, we address the need for high-quality information on sex differences in β cell and islet gene expression and function using both human and rodent samples. METHODS In humans, we compared β cell gene expression and insulin secretion in donors with T2D to non-diabetic donors in both males and females. In mice, we generated a well-powered islet RNAseq dataset from 20-week-old male and female siblings with similar insulin sensitivity. Our unbiased gene expression analysis pointed to a sex difference in the endoplasmic reticulum (ER) stress response. Based on this analysis, we hypothesized female islets would be more resilient to ER stress than male islets. To test this, we subjected islets isolated from age-matched male and female mice to thapsigargin treatment and monitored protein synthesis, cell death, and β cell insulin production and secretion. Transcriptomic and proteomic analyses were used to characterize sex differences in islet responses to ER stress. RESULTS Our single-cell analysis of human β cells revealed sex-specific changes to gene expression and function in T2D, correlating with more robust insulin secretion in human islets isolated from female donors with T2D compared to male donors with T2D. In mice, RNA sequencing revealed differential enrichment of unfolded protein response pathway-associated genes, where female islets showed higher expression of genes linked with protein synthesis, folding, and processing. This differential expression was physiologically significant, as islets isolated from female mice were more resilient to ER stress induction with thapsigargin. Specifically, female islets showed a greater ability to maintain glucose-stimulated insulin production and secretion during ER stress compared with males. CONCLUSIONS Our data demonstrate sex differences in β cell gene expression in both humans and mice, and that female β cells show a greater ability to maintain glucose-stimulated insulin secretion across multiple physiological and pathological contexts.
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Affiliation(s)
- George P Brownrigg
- Department of Cellular and Physiological Sciences, Life Sciences Institute, The University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC, V6T 1Z3, Canada
| | - Yi Han Xia
- Department of Cellular and Physiological Sciences, Life Sciences Institute, The University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC, V6T 1Z3, Canada
| | - Chieh Min Jamie Chu
- Department of Cellular and Physiological Sciences, Life Sciences Institute, The University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC, V6T 1Z3, Canada
| | - Su Wang
- Department of Cellular and Physiological Sciences, Life Sciences Institute, The University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC, V6T 1Z3, Canada
| | - Charlotte Chao
- Department of Cellular and Physiological Sciences, Life Sciences Institute, The University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC, V6T 1Z3, Canada
| | - Jiashuo Aaron Zhang
- Department of Cellular and Physiological Sciences, Life Sciences Institute, The University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC, V6T 1Z3, Canada
| | - Søs Skovsø
- Department of Cellular and Physiological Sciences, Life Sciences Institute, The University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC, V6T 1Z3, Canada
| | - Evgeniy Panzhinskiy
- Department of Cellular and Physiological Sciences, Life Sciences Institute, The University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC, V6T 1Z3, Canada
| | - Xiaoke Hu
- Department of Cellular and Physiological Sciences, Life Sciences Institute, The University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC, V6T 1Z3, Canada
| | - James D Johnson
- Department of Cellular and Physiological Sciences, Life Sciences Institute, The University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC, V6T 1Z3, Canada.
| | - Elizabeth J Rideout
- Department of Cellular and Physiological Sciences, Life Sciences Institute, The University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC, V6T 1Z3, Canada.
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3
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Chu CMJ, Modi H, Ellis C, Krentz NAJ, Skovsø S, Zhao YB, Cen H, Noursadeghi N, Panzhinskiy E, Hu X, Dionne DA, Xia YH, Xuan S, Huising MO, Kieffer TJ, Lynn FC, Johnson JD. Dynamic Ins2 Gene Activity Defines β-Cell Maturity States. Diabetes 2022; 71:2612-2631. [PMID: 36170671 DOI: 10.2337/db21-1065] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Accepted: 09/20/2022] [Indexed: 01/11/2023]
Abstract
Transcriptional and functional cellular specialization has been described for insulin-secreting β-cells of the endocrine pancreas. However, it is not clear whether β-cell heterogeneity is stable or reflects dynamic cellular states. We investigated the temporal kinetics of endogenous insulin gene activity using live cell imaging, with complementary experiments using FACS and single-cell RNA sequencing, in β-cells from Ins2GFP knockin mice. In vivo staining and FACS analysis of islets from Ins2GFP mice confirmed that at a given moment, ∼25% of β-cells exhibited significantly higher activity at the evolutionarily conserved insulin gene, Ins2. Live cell imaging over days captured Ins2 gene activity dynamics in single β-cells. Autocorrelation analysis revealed a subset of oscillating cells, with mean oscillation periods of 17 h. Increased glucose concentrations stimulated more cells to oscillate and resulted in higher average Ins2 gene activity per cell. Single-cell RNA sequencing showed that Ins2(GFP)HIGH β-cells were enriched for markers of β-cell maturity. Ins2(GFP)HIGH β-cells were also significantly less viable at all glucose concentrations and in the context of endoplasmic reticulum stress. Collectively, our results demonstrate that the heterogeneity of insulin production, observed in mouse and human β-cells, can be accounted for by dynamic states of insulin gene activity.
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Affiliation(s)
- Chieh Min Jamie Chu
- Diabetes Focus Team, Life Sciences Institute, Departments of Cellular and Physiological Sciences and Surgery, University of British Columbia, Vancouver, Canada
| | - Honey Modi
- Diabetes Focus Team, Life Sciences Institute, Departments of Cellular and Physiological Sciences and Surgery, University of British Columbia, Vancouver, Canada
| | - Cara Ellis
- Diabetes Focus Team, Life Sciences Institute, Departments of Cellular and Physiological Sciences and Surgery, University of British Columbia, Vancouver, Canada
| | - Nicole A J Krentz
- BC Children's Hospital Research Institute, Department of Surgery, University of British Columbia, Vancouver, Canada
| | - Søs Skovsø
- Diabetes Focus Team, Life Sciences Institute, Departments of Cellular and Physiological Sciences and Surgery, University of British Columbia, Vancouver, Canada
| | - Yiwei Bernie Zhao
- Biomedical Research Centre, Departments of Cellular and Physiological Sciences and Surgery, University of British Columbia, Vancouver, Canada
| | - Haoning Cen
- Diabetes Focus Team, Life Sciences Institute, Departments of Cellular and Physiological Sciences and Surgery, University of British Columbia, Vancouver, Canada
| | - Nilou Noursadeghi
- Diabetes Focus Team, Life Sciences Institute, Departments of Cellular and Physiological Sciences and Surgery, University of British Columbia, Vancouver, Canada
| | - Evgeniy Panzhinskiy
- Diabetes Focus Team, Life Sciences Institute, Departments of Cellular and Physiological Sciences and Surgery, University of British Columbia, Vancouver, Canada
| | - Xiaoke Hu
- Diabetes Focus Team, Life Sciences Institute, Departments of Cellular and Physiological Sciences and Surgery, University of British Columbia, Vancouver, Canada
| | - Derek A Dionne
- Diabetes Focus Team, Life Sciences Institute, Departments of Cellular and Physiological Sciences and Surgery, University of British Columbia, Vancouver, Canada
| | - Yi Han Xia
- Diabetes Focus Team, Life Sciences Institute, Departments of Cellular and Physiological Sciences and Surgery, University of British Columbia, Vancouver, Canada
| | - Shouhong Xuan
- Division of Hematology/Oncology, Department of Medicine, Columbia University Medical Center, New York, NY
| | - Mark O Huising
- Department of Neurobiology, Physiology and Behavior, University of California, Davis, Davis, CA
- Department of Physiology and Membrane Biology, University of California, Davis, Davis, CA
| | - Timothy J Kieffer
- Diabetes Focus Team, Life Sciences Institute, Departments of Cellular and Physiological Sciences and Surgery, University of British Columbia, Vancouver, Canada
| | - Francis C Lynn
- BC Children's Hospital Research Institute, Department of Surgery, University of British Columbia, Vancouver, Canada
| | - James D Johnson
- Diabetes Focus Team, Life Sciences Institute, Departments of Cellular and Physiological Sciences and Surgery, University of British Columbia, Vancouver, Canada
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4
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Skovsø S, Panzhinskiy E, Kolic J, Cen HH, Dionne DA, Dai XQ, Sharma RB, Elghazi L, Ellis CE, Faulkner K, Marcil SAM, Overby P, Noursadeghi N, Hutchinson D, Hu X, Li H, Modi H, Wildi JS, Botezelli JD, Noh HL, Suk S, Gablaski B, Bautista A, Kim R, Cras-Méneur C, Flibotte S, Sinha S, Luciani DS, Nislow C, Rideout EJ, Cytrynbaum EN, Kim JK, Bernal-Mizrachi E, Alonso LC, MacDonald PE, Johnson JD. Beta-cell specific Insr deletion promotes insulin hypersecretion and improves glucose tolerance prior to global insulin resistance. Nat Commun 2022; 13:735. [PMID: 35136059 PMCID: PMC8826929 DOI: 10.1038/s41467-022-28039-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Accepted: 01/05/2022] [Indexed: 01/23/2023] Open
Abstract
Insulin receptor (Insr) protein is present at higher levels in pancreatic β-cells than in most other tissues, but the consequences of β-cell insulin resistance remain enigmatic. Here, we use an Ins1cre knock-in allele to delete Insr specifically in β-cells of both female and male mice. We compare experimental mice to Ins1cre-containing littermate controls at multiple ages and on multiple diets. RNA-seq of purified recombined β-cells reveals transcriptomic consequences of Insr loss, which differ between female and male mice. Action potential and calcium oscillation frequencies are increased in Insr knockout β-cells from female, but not male mice, whereas only male βInsrKO islets have reduced ATP-coupled oxygen consumption rate and reduced expression of genes involved in ATP synthesis. Female βInsrKO and βInsrHET mice exhibit elevated insulin release in ex vivo perifusion experiments, during hyperglycemic clamps, and following i.p. glucose challenge. Deletion of Insr does not alter β-cell area up to 9 months of age, nor does it impair hyperglycemia-induced proliferation. Based on our data, we adapt a mathematical model to include β-cell insulin resistance, which predicts that β-cell Insr knockout improves glucose tolerance depending on the degree of whole-body insulin resistance. Indeed, glucose tolerance is significantly improved in female βInsrKO and βInsrHET mice compared to controls at 9, 21 and 39 weeks, and also in insulin-sensitive 4-week old males. We observe no improved glucose tolerance in older male mice or in high fat diet-fed mice, corroborating the prediction that global insulin resistance obscures the effects of β-cell specific insulin resistance. The propensity for hyperinsulinemia is associated with mildly reduced fasting glucose and increased body weight. We further validate our main in vivo findings using an Ins1-CreERT transgenic line and find that male mice have improved glucose tolerance 4 weeks after tamoxifen-mediated Insr deletion. Collectively, our data show that β-cell insulin resistance in the form of reduced β-cell Insr contributes to hyperinsulinemia in the context of glucose stimulation, thereby improving glucose homeostasis in otherwise insulin sensitive sex, dietary and age contexts.
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Affiliation(s)
- Søs Skovsø
- Diabetes Research Group, Life Sciences Institute, and Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, BC, Canada
| | - Evgeniy Panzhinskiy
- Diabetes Research Group, Life Sciences Institute, and Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, BC, Canada
| | - Jelena Kolic
- Diabetes Research Group, Life Sciences Institute, and Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, BC, Canada
| | - Haoning Howard Cen
- Diabetes Research Group, Life Sciences Institute, and Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, BC, Canada
| | - Derek A Dionne
- Diabetes Research Group, Life Sciences Institute, and Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, BC, Canada
| | - Xiao-Qing Dai
- Alberta Diabetes Institute and Department of Pharmacology, University of Alberta, Edmonton, Canada
| | - Rohit B Sharma
- Division of Endocrinology, Diabetes and Metabolism and the Weill Center for Metabolic Health, Weill Cornell Medicine, New York, NY, USA
| | - Lynda Elghazi
- Department of Ophthalmology and Visual Sciences, University of Michigan Kellogg Eye Center, Ann Arbor, MI, USA
| | - Cara E Ellis
- Diabetes Research Group, Life Sciences Institute, and Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, BC, Canada
| | - Katharine Faulkner
- Department of Mathematics, University of British Columbia, Vancouver, BC, Canada
| | - Stephanie A M Marcil
- Diabetes Research Group, Life Sciences Institute, and Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, BC, Canada
| | - Peter Overby
- Diabetes Research Group, Life Sciences Institute, and Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, BC, Canada
| | - Nilou Noursadeghi
- Diabetes Research Group, Life Sciences Institute, and Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, BC, Canada
| | - Daria Hutchinson
- Diabetes Research Group, Life Sciences Institute, and Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, BC, Canada
| | - Xiaoke Hu
- Diabetes Research Group, Life Sciences Institute, and Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, BC, Canada
| | - Hong Li
- Diabetes Research Group, Life Sciences Institute, and Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, BC, Canada
| | - Honey Modi
- Diabetes Research Group, Life Sciences Institute, and Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, BC, Canada
| | - Jennifer S Wildi
- Diabetes Research Group, Life Sciences Institute, and Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, BC, Canada
| | - J Diego Botezelli
- Diabetes Research Group, Life Sciences Institute, and Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, BC, Canada
| | - Hye Lim Noh
- Program in Molecular Medicine University of Massachusetts Medical School, Worcester, MA, USA
- Charles River Laboratories, Shrewsbury, MA, USA
| | - Sujin Suk
- Program in Molecular Medicine University of Massachusetts Medical School, Worcester, MA, USA
| | - Brian Gablaski
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Massachusetts Medical School, Worcester, MA, USA
- Charles River Laboratories, Shrewsbury, MA, USA
| | - Austin Bautista
- Alberta Diabetes Institute and Department of Pharmacology, University of Alberta, Edmonton, Canada
| | - Ryekjang Kim
- Alberta Diabetes Institute and Department of Pharmacology, University of Alberta, Edmonton, Canada
| | - Corentin Cras-Méneur
- Department of Internal Medicine, Division of Metabolism, Endocrinology and Diabetes, University of Michigan, Ann Arbor, MI, USA
| | - Stephane Flibotte
- UBC Life Sciences Institute Bioinformatics Facility, University of British Columbia, Vancouver, BC, Canada
| | - Sunita Sinha
- UBC Sequencing and Bioinformatics Consortium, Pharmaceutical Sciences, University of British Columbia, Vancouver, BC, Canada
| | - Dan S Luciani
- BC Children's Hospital Research Institute, Department of Surgery, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Corey Nislow
- UBC Sequencing and Bioinformatics Consortium, Pharmaceutical Sciences, University of British Columbia, Vancouver, BC, Canada
| | - Elizabeth J Rideout
- Diabetes Research Group, Life Sciences Institute, and Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, BC, Canada
| | - Eric N Cytrynbaum
- Department of Mathematics, University of British Columbia, Vancouver, BC, Canada
| | - Jason K Kim
- Program in Molecular Medicine University of Massachusetts Medical School, Worcester, MA, USA
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Massachusetts Medical School, Worcester, MA, USA
| | - Ernesto Bernal-Mizrachi
- Division of Endocrinology, Diabetes and Metabolism, University of Miami Miller School of Medicine and Miami VA Health Care System, Miami, FL, USA
| | - Laura C Alonso
- Division of Endocrinology, Diabetes and Metabolism and the Weill Center for Metabolic Health, Weill Cornell Medicine, New York, NY, USA
| | - Patrick E MacDonald
- Alberta Diabetes Institute and Department of Pharmacology, University of Alberta, Edmonton, Canada
| | - James D Johnson
- Diabetes Research Group, Life Sciences Institute, and Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, BC, Canada.
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5
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Kolic J, Beet L, Overby P, Cen HH, Panzhinskiy E, Ure DR, Cross JL, Huizinga RB, Johnson JD. Differential Effects of Voclosporin and Tacrolimus on Insulin Secretion From Human Islets. Endocrinology 2020; 161:5902465. [PMID: 32894758 PMCID: PMC7567406 DOI: 10.1210/endocr/bqaa162] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Accepted: 09/02/2020] [Indexed: 12/16/2022]
Abstract
The incidence of new onset diabetes after transplant (NODAT) has increased over the past decade, likely due to calcineurin inhibitor-based immunosuppressants, including tacrolimus (TAC) and cyclosporin. Voclosporin (VCS), a next-generation calcineurin inhibitor, is reported to cause fewer incidences of NODAT but the reason is unclear. While calcineurin signaling plays important roles in pancreatic β-cell survival, proliferation, and function, its effects on human β-cells remain understudied. In particular, we do not understand why some calcineurin inhibitors have more profound effects on the incidence of NODAT. We compared the effects of TAC and VCS on the dynamics of insulin secretory function, programmed cell death rate, and the transcriptomic profile of human islets. We studied 2 clinically relevant doses of TAC (10 ng/mL, 30 ng/mL) and VCS (20 ng/mL, 60 ng/mL), meant to approximate the clinical trough and peak concentrations. TAC, but not VCS, caused a significant impairment of 15 mM glucose-stimulated and 30 mM KCl-stimulated insulin secretion. This points to molecular defects in the distal stages of exocytosis after voltage-gated Ca2+ entry. No significant effects on islet cell survival or total insulin content were identified. RNA sequencing showed that TAC significantly decreased the expression of 17 genes, including direct and indirect regulators of exocytosis (SYT16, TBC1D30, PCK1, SMOC1, SYT5, PDK4, and CREM), whereas VCS has less broad, and milder, effects on gene expression. Clinically relevant doses of TAC, but not VCS, directly inhibit insulin secretion from human islets, likely via transcriptional control of exocytosis machinery.
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Affiliation(s)
- Jelena Kolic
- Diabetes Research Group, Life Sciences Institute, Department of Cellular and Physiological Sciences & Department of Surgery, University of British Columbia, Vancouver, Canada
| | - Leanne Beet
- Diabetes Research Group, Life Sciences Institute, Department of Cellular and Physiological Sciences & Department of Surgery, University of British Columbia, Vancouver, Canada
| | - Peter Overby
- Diabetes Research Group, Life Sciences Institute, Department of Cellular and Physiological Sciences & Department of Surgery, University of British Columbia, Vancouver, Canada
| | - Haoning Howard Cen
- Diabetes Research Group, Life Sciences Institute, Department of Cellular and Physiological Sciences & Department of Surgery, University of British Columbia, Vancouver, Canada
| | - Evgeniy Panzhinskiy
- Diabetes Research Group, Life Sciences Institute, Department of Cellular and Physiological Sciences & Department of Surgery, University of British Columbia, Vancouver, Canada
| | - Daren R Ure
- Hepion Pharmaceuticals, Edmonton, Alberta, Canada
| | | | | | - James D Johnson
- Correspondence: Professor James D. Johnson, PhD, Faculty of Medicine, Department of Cellular and Physiological Sciences & Department of Surgery, The University of British Columbia, Life Sciences Institute, 5358 – 2350 Health Sciences Mall, Vancouver, British Columbia, Canada, V6T 1Z3. E-mail: ; Twitter: @JimJohnsonSci
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Panzhinskiy E, Huang H, Macdonald K, Johnson J, Lynn FC. 20 - CRISPR-Cas9 Optogenetic System for Insulin Expression in Human Embryonic Stem Cell-Derived β-Like Cells. Can J Diabetes 2020. [DOI: 10.1016/j.jcjd.2020.08.024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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7
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Kolic J, Beet L, Overby P, Cen HH, Cross J, Huizinga R, Johnson J, Panzhinskiy E. 79 - Differential Effects of Voclosporin and Tacrolimus on Insulin Secretion From Human Islets. Can J Diabetes 2020. [DOI: 10.1016/j.jcjd.2020.08.085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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8
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Panzhinskiy E, Bashir R, Bagchi D, Nair S. Effect of Curcumin and α-Lipoic Acid in Attenuating Weight Gain and Adiposity. J Am Coll Nutr 2019; 38:493-498. [PMID: 30620684 DOI: 10.1080/07315724.2018.1557572] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2018] [Revised: 11/29/2018] [Accepted: 12/05/2018] [Indexed: 12/31/2022]
Abstract
Objective: Obesity is growing at epidemic proportions worldwide. Natural compounds curcumin and α-lipoic acid have been shown to reduce body-weight gain in both preclinical and clinical studies. This study examined the effect of a combination of curcumin and α-lipoic acid on weight gain and adiposity in high-fat-diet (HFD)-fed mice. Methods: C57BL6 mice (7 weeks old) were randomly assigned to receive either HFD (60% fat) or a normal diet (ND, 10% fat) for a 12-week period, following which the mice receiving HFD were further assigned to supplemental curcumin (0.07%), α-lipoic acid (0.2%), or a combination of curcumin and α-lipoic acid formulated into the HFD for a further 12 weeks. Food intake and body mass were determined on a weekly basis. Body fat composition was determined by dual energy X-ray absorptiometry. Results: Treatment with both curcumin and α-lipoic acid significantly reduced body weight gain in HFD-treated mice, and the combination was more effective in attenuating body weight compared to the individual agents. Food intake and caloric intake were significantly lower in the mice that received α-lipoic acid. Percentage body fat and fat mass and lean body mass, which were increased following HFD feeding, were attenuated in the mice receiving curcumin and the combination. Lean mass was also elevated in the mice that were subjected to an HFD, which was unaltered by curcumin or the combination. Conclusions: Taken together, the combination of curcumin and α-lipoic acid exhibits an additive effect in reducing weight gain and adiposity in response to high-fat feeding.
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Affiliation(s)
- Evgeniy Panzhinskiy
- a Division of Pharmaceutical Sciences, School of Pharmacy, College of Health Sciences, University of Wyoming, College of Health Sciences , Laramie , Wyoming , USA
- b Diabetes Research Group, University of British Columbia, Life Sciences Institute , Vancouver , British Columbia , Canada
| | - Raza Bashir
- c Iovate Health Sciences International Inc ., Oakville , Ontario , Canada
| | - Debasis Bagchi
- d College of Pharmacy, University of Houston , Houston , Texas , USA
| | - Sreejayan Nair
- a Division of Pharmaceutical Sciences, School of Pharmacy, College of Health Sciences, University of Wyoming, College of Health Sciences , Laramie , Wyoming , USA
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9
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Panzhinskiy E, Johnson JD. Unique ER Stress Mechanisms in β Cells Limit the Translation Potential of Therapies Targeting eIF2α. Endocrinology 2017; 158:1564-1566. [PMID: 28575435 DOI: 10.1210/en.2017-00256] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Accepted: 03/17/2017] [Indexed: 11/19/2022]
Affiliation(s)
- Evgeniy Panzhinskiy
- Department of Cellular and Physiological Sciences, Diabetes Research Group, Life Sciences Institute, University of British Columbia, Vancouver, BC V6T1Z3, Canada
| | - James D Johnson
- Department of Cellular and Physiological Sciences, Diabetes Research Group, Life Sciences Institute, University of British Columbia, Vancouver, BC V6T1Z3, Canada
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10
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Panzhinskiy E, Taghizadeh F, Chu KY, Yang YH, Jan E, Johnson J. Eukaryotic Translation Initiation Factor 2A (eIF2A) Protects Pancreatic Beta Cells During ER Stress-Induced ApoptosisImage 6. Can J Diabetes 2016. [DOI: 10.1016/j.jcjd.2016.08.038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Arakawa H, Kandadi MR, Panzhinskiy E, Belmore K, Deng G, Love E, Robertson PM, Commodore JJ, Cassady CJ, Nair S, Vincent JB. Spectroscopic and biological activity studies of the chromium-binding peptide EEEEGDD. J Biol Inorg Chem 2016; 21:369-81. [DOI: 10.1007/s00775-016-1347-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Accepted: 02/16/2016] [Indexed: 10/22/2022]
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Szabat M, Page MM, Panzhinskiy E, Skovsø S, Mojibian M, Fernandez-Tajes J, Bruin JE, Bround MJ, Lee JTC, Xu EE, Taghizadeh F, O'Dwyer S, van de Bunt M, Moon KM, Sinha S, Han J, Fan Y, Lynn FC, Trucco M, Borchers CH, Foster LJ, Nislow C, Kieffer TJ, Johnson JD. Reduced Insulin Production Relieves Endoplasmic Reticulum Stress and Induces β Cell Proliferation. Cell Metab 2016; 23:179-93. [PMID: 26626461 DOI: 10.1016/j.cmet.2015.10.016] [Citation(s) in RCA: 132] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Revised: 09/13/2015] [Accepted: 10/25/2015] [Indexed: 11/25/2022]
Abstract
Pancreatic β cells are mostly post-mitotic, but it is unclear what locks them in this state. Perturbations including uncontrolled hyperglycemia can drive β cells into more pliable states with reduced cellular insulin levels, increased β cell proliferation, and hormone mis-expression, but it is unknown whether reduced insulin production itself plays a role. Here, we define the effects of ∼50% reduced insulin production in Ins1(-/-):Ins2(f/f):Pdx1Cre(ERT):mTmG mice prior to robust hyperglycemia. Transcriptome, proteome, and network analysis revealed alleviation of chronic endoplasmic reticulum (ER) stress, indicated by reduced Ddit3, Trib3, and Atf4 expression; reduced Xbp1 splicing; and reduced phospho-eIF2α. This state was associated with hyper-phosphorylation of Akt, which is negatively regulated by Trib3, and with cyclinD1 upregulation. Remarkably, β cell proliferation was increased 2-fold after reduced insulin production independently of hyperglycemia. Eventually, recombined cells mis-expressed glucagon in the hyperglycemic state. We conclude that the normally high rate of insulin production suppresses β cell proliferation in a cell-autonomous manner.
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Affiliation(s)
- Marta Szabat
- Department of Cellular and Physiological Sciences, Diabetes Research Group, Life Sciences Institute, University of British Columbia, BC V6T1Z3, Canada
| | - Melissa M Page
- Department of Cellular and Physiological Sciences, Diabetes Research Group, Life Sciences Institute, University of British Columbia, BC V6T1Z3, Canada
| | - Evgeniy Panzhinskiy
- Department of Cellular and Physiological Sciences, Diabetes Research Group, Life Sciences Institute, University of British Columbia, BC V6T1Z3, Canada
| | - Søs Skovsø
- Department of Cellular and Physiological Sciences, Diabetes Research Group, Life Sciences Institute, University of British Columbia, BC V6T1Z3, Canada
| | - Majid Mojibian
- Department of Cellular and Physiological Sciences, Diabetes Research Group, Life Sciences Institute, University of British Columbia, BC V6T1Z3, Canada
| | - Juan Fernandez-Tajes
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK
| | - Jennifer E Bruin
- Department of Cellular and Physiological Sciences, Diabetes Research Group, Life Sciences Institute, University of British Columbia, BC V6T1Z3, Canada
| | - Michael J Bround
- Department of Cellular and Physiological Sciences, Diabetes Research Group, Life Sciences Institute, University of British Columbia, BC V6T1Z3, Canada
| | - Jason T C Lee
- Department of Cellular and Physiological Sciences, Diabetes Research Group, Life Sciences Institute, University of British Columbia, BC V6T1Z3, Canada
| | - Eric E Xu
- Child and Family Research Institute, University of British Columbia, BC V5Z 4H4, Canada
| | - Farnaz Taghizadeh
- Department of Cellular and Physiological Sciences, Diabetes Research Group, Life Sciences Institute, University of British Columbia, BC V6T1Z3, Canada
| | - Shannon O'Dwyer
- Department of Cellular and Physiological Sciences, Diabetes Research Group, Life Sciences Institute, University of British Columbia, BC V6T1Z3, Canada
| | - Martijn van de Bunt
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK
| | - Kyung-Mee Moon
- Centre for High-Throughput Biology, University of British Columbia, BC V6T 1Z3, Canada
| | - Sunita Sinha
- Faculty of Pharmaceutical Sciences, University of British Columbia, BC V6T 1Z3, Canada
| | - Jun Han
- UVic-Genome BC Proteomics Centre, University of Victoria, BC V8Z 7X8, Canada
| | - Yong Fan
- Institute of Cellular Therapeutics, Allegheny Health Network, Pittsburgh, PA 15212-4772, USA
| | - Francis C Lynn
- Child and Family Research Institute, University of British Columbia, BC V5Z 4H4, Canada
| | - Massimo Trucco
- Institute of Cellular Therapeutics, Allegheny Health Network, Pittsburgh, PA 15212-4772, USA
| | | | - Leonard J Foster
- Centre for High-Throughput Biology, University of British Columbia, BC V6T 1Z3, Canada
| | - Corey Nislow
- Faculty of Pharmaceutical Sciences, University of British Columbia, BC V6T 1Z3, Canada
| | - Timothy J Kieffer
- Department of Cellular and Physiological Sciences, Diabetes Research Group, Life Sciences Institute, University of British Columbia, BC V6T1Z3, Canada
| | - James D Johnson
- Department of Cellular and Physiological Sciences, Diabetes Research Group, Life Sciences Institute, University of British Columbia, BC V6T1Z3, Canada.
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Kandadi MR, Panzhinskiy E, Roe ND, Nair S, Hu D, Sun A. Deletion of protein tyrosine phosphatase 1B rescues against myocardial anomalies in high fat diet-induced obesity: Role of AMPK-dependent autophagy. Biochim Biophys Acta Mol Basis Dis 2015; 1852:299-309. [DOI: 10.1016/j.bbadis.2014.07.004] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2014] [Revised: 06/20/2014] [Accepted: 07/03/2014] [Indexed: 01/11/2023]
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Zhang H, Okamoto M, Panzhinskiy E, Zawada WM, Das M. PKCδ/midkine pathway drives hypoxia-induced proliferation and differentiation of human lung epithelial cells. Am J Physiol Cell Physiol 2014; 306:C648-58. [PMID: 24500281 PMCID: PMC3962599 DOI: 10.1152/ajpcell.00351.2013] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2013] [Accepted: 01/30/2014] [Indexed: 12/13/2022]
Abstract
Epithelial cells are key players in the pathobiology of numerous hypoxia-induced lung diseases. The mechanisms mediating such hypoxic responses of epithelial cells are not well characterized. Earlier studies reported that hypoxia stimulates protein kinase C (PKC)δ activation in renal cancer cells and an increase in expression of a heparin-binding growth factor, midkine (MK), in lung alveolar epithelial cells. We reasoned that hypoxia might regulate MK levels via a PKCδ-dependent pathway and hypothesized that PKCδ-driven MK expression is required for hypoxia-induced lung epithelial cell proliferation and differentiation. Replication of human lung epithelial cells (A549) was significantly increased by chronic hypoxia (1% O2) and was dependent on expression of PKCδ. Hypoxia-induced proliferation of epithelial cells was accompanied by translocation of PKCδ from Golgi into the nuclei. Marked attenuation in MK protein levels by rottlerin, a pharmacological antagonist of PKC, and by small interfering RNA-targeting PKCδ, revealed that PKCδ is required for MK expression in both normoxic and hypoxic lung epithelial cells. Sequestering MK secreted into the culture media with a neutralizing antibody reduced hypoxia-induced proliferation demonstrating that an increase in MK release from cells is linked with epithelial cell division under hypoxia. In addition, recombinant MK accelerated transition of hypoxic epithelial cells to cells of mesenchymal phenotype characterized by elongated morphology and increased expression of mesenchymal markers, α-smooth muscle actin, and vimentin. We conclude that PKCδ/MK axis mediates hypoxic proliferation and differentiation of lung epithelial cells. Manipulation of PKCδ and MK activity in epithelial cells might be beneficial for the treatment of hypoxia-mediated lung diseases.
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Affiliation(s)
- Hanying Zhang
- Department of Animal Sciences, University of Wyoming, Laramie, Wyoming
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Panzhinskiy E, Hua Y, Lapchak PA, Topchiy E, Lehmann TE, Ren J, Nair S. Novel curcumin derivative CNB-001 mitigates obesity-associated insulin resistance. J Pharmacol Exp Ther 2014; 349:248-57. [PMID: 24549372 DOI: 10.1124/jpet.113.208728] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Type 2 diabetes is growing at epidemic proportions, and pharmacological interventions are being actively sought. This study examined the effect of a novel neuroprotective curcuminoid, CNB-001 [4-((1E)-2-(5-(4-hydroxy-3-methoxystyryl-)-1-phenyl-1H-pyrazoyl-3-yl)vinyl)-2-methoxy-phenol], on glucose intolerance and insulin signaling in high-fat diet (HFD)-fed mice. C57BL6 mice (5-6 weeks old) were randomly assigned to receive either a HFD (45% fat) or a low-fat diet (LFD, 10% fat) for 24 weeks, together with CNB-001 (40 mg/kg i.p. per day). Glucose tolerance test revealed that the area under the curve of postchallenge glucose concentration was elevated on HF-feeding, which was attenuated by CNB-001. CNB-001 attenuated body weight gain, serum triglycerides, and IL-6, and augmented insulin signaling [elevated phosphoprotein kinase B (p-Akt), and phosphoinsulin receptor (p-IR)β, lowered endoplasmic reticulum (ER) stress, protein-tyrosine phosphatase 1B (PTP1B)] and glucose uptake in gastrocnemius muscle of HFD-fed mice. Respiratory quotient, measured using a metabolic chamber, was elevated in HFD-fed mice, which was unaltered by CNB-001, although CNB-001 treatment resulted in higher energy expenditure. In cultured myotubes, CNB-001 reversed palmitate-induced impairment of insulin signaling and glucose uptake. Docking studies suggest a potential interaction between CNB-001 and PTP1B. Taken together, CNB-001 alleviates obesity-induced glucose intolerance and represents a potential candidate for further development as an antidiabetic agent.
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Affiliation(s)
- Evgeniy Panzhinskiy
- Division of Pharmaceutical Sciences and Center for Cardiovascular Research and Alternative Medicine, University of Wyoming, College of Health Sciences, Laramie, Wyoming (E.P., Y.H., J.R., S.N.); Cedars-Sinai Medical Center, Department of Neurology and Neurosurgery, Burns and Allen Research Institute, Los Angeles, California (P.A.L.); and Chemistry Department, University of Wyoming, Laramie, Wyoming (E.T., T.E.L.)
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Panzhinskiy E, Ren J, Nair S. Protein tyrosine phosphatase 1B and insulin resistance: role of endoplasmic reticulum stress/reactive oxygen species/nuclear factor kappa B axis. PLoS One 2013; 8:e77228. [PMID: 24204775 PMCID: PMC3799617 DOI: 10.1371/journal.pone.0077228] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2013] [Accepted: 09/01/2013] [Indexed: 12/24/2022] Open
Abstract
Obesity-induced endoplasmic reticulum (ER) stress has been proposed as an important pathway in the development of insulin resistance. Protein-tyrosine phosphatase 1B (PTP1B) is a negative regulator of insulin signaling and is tethered to the ER-membrane. The aim of the study was to determine the mechanisms involved in the crosstalk between ER-stress and PTP1B. PTP1B whole body knockout and C57BL/6J mice were subjected to a high-fat or normal chow-diet for 20 weeks. High-fat diet feeding induced body weight gain, increased adiposity, systemic glucose intolerance, and hepatic steatosis were attenuated by PTP1B deletion. High-fat diet- fed PTP1B knockout mice also exhibited improved glucose uptake measured using [(3)H]-2-deoxy-glucose incorporation assay and Akt phosphorylation in the skeletal muscle tissue, compared to their wild-type control mice which received similar diet. High-fat diet-induced upregulation of glucose-regulated protein-78, phosphorylation of eukaryotic initiation factor 2α and c-Jun NH2-terminal kinase-2 were significantly attenuated in the PTP1B knockout mice. Mice lacking PTP1B showed decreased expression of the autophagy related protein p62 and the unfolded protein response adaptor protein NCK1 (non-catalytic region of tyrosine kinase). Treatment of C2C12 myotubes with the ER-stressor tunicamycin resulted in the accumulation of reactive oxygen species (ROS), leading to the activation of protein expression of PTP1B. Furthermore, tunicamycin-induced ROS production activated nuclear translocation of NFκB p65 and was required for ER stress-mediated expression of PTP1B. Our data suggest that PTP1B is induced by ER stress via the activation of the ROS-NFκB axis which is causes unfolded protein response and mediates insulin resistance in the skeletal muscle under obese condition.
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Affiliation(s)
- Evgeniy Panzhinskiy
- School of Pharmacy & Center for Cardiovascular Research and Alternative Medicine, University of Wyoming College of Health Sciences, Laramie, Wyoming, United States of America
| | - Jun Ren
- School of Pharmacy & Center for Cardiovascular Research and Alternative Medicine, University of Wyoming College of Health Sciences, Laramie, Wyoming, United States of America
| | - Sreejayan Nair
- School of Pharmacy & Center for Cardiovascular Research and Alternative Medicine, University of Wyoming College of Health Sciences, Laramie, Wyoming, United States of America
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Topchiy E, Panzhinskiy E, Griffin WST, Barger SW, Das M, Zawada WM. Nox4-generated superoxide drives angiotensin II-induced neural stem cell proliferation. Dev Neurosci 2013; 35:293-305. [PMID: 23751520 DOI: 10.1159/000350502] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2012] [Accepted: 03/05/2013] [Indexed: 01/16/2023] Open
Abstract
Reactive oxygen species (ROS) have been reported to affect neural stem cell self-renewal and therefore may be important for normal development and may influence neurodegenerative processes when ROS activity is elevated. To determine if increasing production of superoxide, via activation of NADPH oxidase (Nox), increases neural stem cell proliferation, 100 nM angiotensin II (Ang II) - a strong stimulator of Nox - was applied to cultures of a murine neural stem cell line, C17.2. Twelve hours following a single treatment with Ang II, there was a doubling of the number of neural stem cells. This increase in neural stem cell numbers was preceded by a gradual elevation of superoxide levels (detected by dihydroethidium fluorescence) from the steady state at 0, 5, and 30 min and gradually increasing from 1 h to the maximum at 12 h, and returning to baseline at 24 h. Ang II-dependent proliferation was blocked by the antioxidant N-acetyl-L-cysteine. Confocal microscopy revealed the presence of two sources of intracellular ROS in C17.2 cells: (i) mitochondrial and (ii) extramitochondrial; the latter indicative of the involvement of one or more specific isoforms of Nox. Of the Nox family, mRNA expression for one member, Nox4, is abundant in neural stem cell cultures, and Ang II treatment resulted in elevation of the relative levels of Nox4 protein. SiRNA targeting of Nox4 mRNA reduced both the constitutive and Ang II-induced Nox4 protein levels and attenuated Ang II-driven increases in superoxide levels and stem cell proliferation. Our findings are consistent with our hypothesis that Ang II-induced proliferation of neural stem cells occurs via Nox4-generated superoxide, suggesting that an Ang II/Nox4 axis is an important regulator of neural stem cell self-renewal and as such may fine-tune normal, stress- or disease-modifying neurogenesis.
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Affiliation(s)
- Elena Topchiy
- Department of Behavioral Neuroscience, Oregon Health and Sciences University, 3181 SW Sam Jackson Park Rd., mail code L470, Portland, OR 97239, USA.
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Panzhinskiy E, Ren J, Nair S. Pharmacological Inhibition of Protein Tyrosine Phosphatase 1B: A Promising Strategy for the Treatment of Obesity and Type 2 Diabetes Mellitus. Curr Med Chem 2013; 20:2609-25. [DOI: 10.2174/0929867311320210001] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2012] [Revised: 02/27/2013] [Accepted: 04/08/2013] [Indexed: 11/22/2022]
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Abstract
AIMS/HYPOTHESIS Endoplasmic reticulum (ER) stress has been recognised as a common pathway in the development of obesity-associated insulin resistance. Protein tyrosine phosphatase 1B (PTP1B) is a negative regulator of insulin signalling and is localised on the ER membrane. The aim of the study was to investigate the cross-talk between ER stress and PTP1B. METHODS Leptin-deficient obese (ob/ob), Ptp1b (also known as Ptpn1) knockout and C57BL/6J mice were subjected to a high-fat or normal-chow diet for 20 weeks. ER stress was induced in cultured myotubes by treatment with tunicamycin. Immunohistochemistry and western blotting were used to assess proteins involved in the ER stress response. Myotube glucose uptake was determined by measuring 2-deoxy[(3)H]glucose incorporation. RESULTS A high-fat diet induced ER stress and PTP1B expression in the muscle tissue of mice and these responses were attenuated by treatment with the ER chaperone tauroursodeoxycholic acid (TUDCA). Cultured myotubes exhibited increased levels of PTP1B in response to tunicamycin treatment. Silencing of Ptp1b with small interfering RNA (siRNA) or overexpression of Ptp1b with adenovirus construct failed to alter the levels of ER stress. Ptp1b knockout mice did not differ from the wild-type mice in the extent of tunicamycin-induced upregulation of glucose-regulated protein-78. However, tunicamycin-induced phosphorylation of eukaryotic initiation factor 2α and c-Jun NH(2)-terminal kinase-2 were significantly attenuated in the Ptp1b knockout mice. Treatment with TUDCA or silencing of PTP1B reversed tunicamycin-induced blunted myotube glucose uptake. CONCLUSIONS/INTERPRETATION Our data suggest that PTP1B is activated by ER stress and is required for full-range activation of ER stress pathways in mediating insulin resistance in the skeletal muscle.
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Affiliation(s)
- E. Panzhinskiy
- School of Pharmacy, University of Wyoming, College of Health Sciences, Laramie, WY 82071, USA. Center for Cardiovascular Research and Alternative Medicine, University of Wyoming, Laramie, WY, USA
| | - Y. Hua
- School of Pharmacy, University of Wyoming, College of Health Sciences, Laramie, WY 82071, USA. Center for Cardiovascular Research and Alternative Medicine, University of Wyoming, Laramie, WY, USA
| | - B. Culver
- School of Pharmacy, University of Wyoming, College of Health Sciences, Laramie, WY 82071, USA. Center for Cardiovascular Research and Alternative Medicine, University of Wyoming, Laramie, WY, USA
| | - J. Ren
- School of Pharmacy, University of Wyoming, College of Health Sciences, Laramie, WY 82071, USA. Center for Cardiovascular Research and Alternative Medicine, University of Wyoming, Laramie, WY, USA
| | - S. Nair
- School of Pharmacy, University of Wyoming, College of Health Sciences, Laramie, WY 82071, USA. Center for Cardiovascular Research and Alternative Medicine, University of Wyoming, Laramie, WY, USA
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Panzhinskiy E, Zawada WM, Stenmark KR, Das M. Hypoxia induces unique proliferative response in adventitial fibroblasts by activating PDGFβ receptor-JNK1 signalling. Cardiovasc Res 2012; 95:356-65. [PMID: 22735370 DOI: 10.1093/cvr/cvs194] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
AIMS Pulmonary hypertension (PH) is a devastating condition for which no disease-modifying therapies exist. PH is recognized as proliferative disease of the pulmonary artery (PA). In the experimental newborn calf model of hypoxia-induced PH, adventitial fibroblasts in the PA wall exhibit a heightened replication index. Because elevated platelet-derived growth factor β receptor (PDGFβ-R) signalling is associated with PH, we tested the hypothesis that the activation of PDGFβ-R contributes to fibroblast proliferation and adventitial remodelling in PH. METHODS AND RESULTS Newborn calves were exposed to either ambient air (P(B) = 640 mmHg) (Neo-C) or high altitude (P(B) = 445 mm Hg) (Neo-PH) for 2 weeks. PDGFβ-R phosphorylation was markedly elevated in PA adventitia of Neo-PH calves as well as in cultured PA fibroblasts isolated from Neo-PH animals. PDGFβ-R activation with PDGF-BB stimulated higher replication in Neo-PH cells compared with that of control fibroblasts. PDGF-BB-induced proliferation was dependent on reactive oxygen species generation and extracellular signal-regulated kinase1/2 activation in both cell populations; however, only Neo-PH cell division via PDGFβ-R activation displayed a unique dependence on c-Jun N-terminal kinase1 (JNK1) stimulation as the blockade of JNK1 with SP600125, a pharmacological antagonist of the JNK pathway, and JNK1-targeted siRNA selectively blunted Neo-PH cell proliferation. CONCLUSIONS Our data strongly suggest that hypoxia-induced modified cells engage the PDGFβ-R-JNK1 axis to confer distinctively heightened proliferation and adventitial remodelling in PH.
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Affiliation(s)
- Evgeniy Panzhinskiy
- Department of Pharmaceutical Sciences, University of Wyoming, Laramie, WY, USA
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Panzhinskiy E, Lapchak PA, Ren J, Sreejayan N. A novel neuroprotective curcuminoid alleviates glucose intolerance and improves insulin signaling. FASEB J 2012. [DOI: 10.1096/fasebj.26.1_supplement.672.7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | - Paul A Lapchak
- Department of NeurologyCedars-Sinai Medical CenterLos AngelesCA
| | - Jun Ren
- School of PharmacyUniversity of WyomingLaramieWY
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Topchiy E, Panzhinskiy E, Das M, Zawada M. Angiotensin II stimulates neural stem cell proliferation through Nox4‐generated superoxide. FASEB J 2011. [DOI: 10.1096/fasebj.25.1_supplement.lb521] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Elena Topchiy
- Department of GeriatricsUniversity of Arkansas for Medical SciencesLittle RockAR
- School of PharmacyUniversity of WyomingLaramieWY
| | | | - Mita Das
- School of PharmacyUniversity of WyomingLaramieWY
| | - Michael Zawada
- Department of GeriatricsUniversity of Arkansas for Medical SciencesLittle RockAR
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Panzhinskiy E, Shields K, Zawada M, Stenmark K, Das M. Pulmonary artery adventitial fibroblasts acquire JNK1‐mediated proliferative responses upon exposure to chronic hypoxia. FASEB J 2011. [DOI: 10.1096/fasebj.25.1_supplement.1034.19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Panzhinskiy E, Shields K, Zawada M, Stenmark K, Das M. PDGF‐BB signaling in adventitial fibroblasts during hypoxia‐induced pulmonary hypertension. FASEB J 2010. [DOI: 10.1096/fasebj.24.1_supplement.1023.22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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