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Zamolodchikova TS, Tolpygo SM, Kotov AV. Insulin in the regulation of the renin-angiotensin system: a new perspective on the mechanism of insulin resistance and diabetic complications. Front Endocrinol (Lausanne) 2024; 15:1293221. [PMID: 38323106 PMCID: PMC10844507 DOI: 10.3389/fendo.2024.1293221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Accepted: 01/08/2024] [Indexed: 02/08/2024] Open
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Navarro J, Sanchez A, Ba Aqeel SH, Ye M, Rehman MZ, Wysocki J, Rademaker A, Molitch ME, Batlle D. Urinary Angiotensinogen in Patients With Type 1 Diabetes With Microalbuminuria: Gender Differences and Effect of Intensive Insulin Therapy. Kidney Int Rep 2022; 7:2657-2667. [PMID: 36506234 PMCID: PMC9727532 DOI: 10.1016/j.ekir.2022.09.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Revised: 08/25/2022] [Accepted: 09/12/2022] [Indexed: 12/15/2022] Open
Abstract
Introduction Angiotensinogen (AOG) is the precursor of peptides of the renin angiotensin system (RAS). Because insulin up-regulates transcriptional factors that normally repress kidney AOG synthesis, we evaluated urinary AOG (uAOG) in patients with type 1 diabetes (T1D) and microalbuminuria who are receiving either intensive or conventional insulin therapy. Methods Urine samples from participants of the Diabetes Control and Complications Trial (DCCT) were used for the following: (i) uAOG/creatinine measurements in 103 patients with microalbuminuria and 103 patients with normoalbuminuria, matched for age, gender, disease duration, and allocation to insulin therapy; and (ii) uAOG/creatinine measurements from patients with microalbuminuria allocated to intensive insulin therapy (n = 58) or conventional insulin therapy (n = 41) after 3 years on each modality. Results uAOG was higher in patients who started with microalbuminuria than in those with normoalbuminuria (6.65 vs. 4.0 ng/mg creatinine, P < 0.01). uAOG was higher in females than in males with microalbuminuria (11.7 vs. 5.4 ng/mg creatinine, P = 0.015). uAOG was lower in patients with microalbuminuria allocated to intensive insulin therapy than in conventional insulin therapy (3.98 vs. 7.42 ng/mg creatinine, P < 0.01). These differences in uAOG were observed though albumin excretion rate (AER) was not significantly different. Conclusion In patients with T1D and microalbuminuria, uAOG is increased and varies with gender and the type of insulin therapy independently of AER. This suggests that AOG production is increased in females and it is decreased by intensive insulin therapy. The reduction in uAOG with intensive insulin therapy, by kidney RAS downregulation, may contribute to the known renoprotective action associated with intensive insulin and improved glycemic control.
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Affiliation(s)
- Jessica Navarro
- Division of Nephrology and Hypertension, Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Alejandro Sanchez
- Division of Nephrology and Hypertension, Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Sheeba H. Ba Aqeel
- Division of Nephrology and Hypertension, Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Minghao Ye
- Division of Nephrology and Hypertension, Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Mohammed Z. Rehman
- Division of Nephrology and Hypertension, Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Jan Wysocki
- Division of Nephrology and Hypertension, Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Alfred Rademaker
- Division of Preventive Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Mark E. Molitch
- Division of Endocrinology, Metabolism and Molecular Medicine, Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Daniel Batlle
- Division of Nephrology and Hypertension, Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA,Correspondence: Daniel Batlle, Division of Nephrology and Hypertension, Department of Medicine, The Feinberg School of Medicine, Northwestern University, 320 E Superior, Chicago, Illinois 60611, USA.
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Vehicle emissions-exposure alters expression of systemic and tissue-specific components of the renin-angiotensin system and promotes outcomes associated with cardiovascular disease and obesity in wild-type C57BL/6 male mice. Toxicol Rep 2021; 8:846-862. [PMID: 33948438 PMCID: PMC8080412 DOI: 10.1016/j.toxrep.2021.04.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Revised: 04/03/2021] [Accepted: 04/09/2021] [Indexed: 12/24/2022] Open
Abstract
Vehicle emission-exposure increases systemic and adipose renin-angiotensin signaling. Emission-exposure promotes renal, vascular, and adipocyte AT1 receptor expression. Diet and emission-exposure are associated with adipocyte hypertrophy and weight gain. Emission-exposure promotes expression of adipokines and adipose inflammatory factors. High-fat diet promotes an obese adipose phenotype, exacerbated by emission-exposure.
Exposure to air pollution from traffic-generated sources is known to contribute to the etiology of inflammatory diseases, including cardiovascular disease (CVD) and obesity; however, the signaling pathways involved are still under investigation. Dysregulation of the renin-angiotensin system (RAS) can contribute to CVD and alter lipid storage and inflammation in adipose tissue. Our previous exposure studies revealed that traffic-generated emissions increase RAS signaling, further exacerbated by a high-fat diet. Thus, we investigated the hypothesis that exposure to engine emissions increases systemic and local adipocyte RAS signaling, promoting the expression of factors involved in CVD and obesity. Male C57BL/6 mice (6–8 wk old) were fed either a high-fat (HF, n = 16) or low-fat (LF, n = 16) diet, beginning 30d prior to exposures, and then exposed via inhalation to either filtered air (FA, controls) or a mixture of diesel engine + gasoline engine vehicle emissions (MVE: 100 μg PM/m3) via whole-body inhalation for 6 h/d, 7 d/wk, 30d. Endpoints were assessed via immunofluorescence and RT-qPCR. MVE-exposure promoted vascular adhesion factors (VCAM-1, ICAM-1) expression, monocyte/macrophage sequestration, and oxidative stress in the vasculature, associated with increased angiotensin II receptor type 1 (AT1) expression. In the kidney, MVE-exposure promoted the expression of renin, AT1, and AT2 receptors. In adipose tissue, both HF-diet and MVE-exposure mediated increased epididymal fat pad weight and adipocyte hypertrophy, associated with increased angiotensinogen and AT1 receptor expression; however, these outcomes were further exacerbated in the MVE + HF group. MVE-exposure also induced inflammation, monocyte chemoattractant protein (MCP)-1, and leptin, while reducing insulin receptor and glucose transporter, GLUT4, expression in adipose tissue. Our results indicate that MVE-exposure promotes systemic and local adipose RAS signaling, associated with increased expression of factors contributing to CVD and obesity, further exacerbated by HF diet consumption.
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Key Words
- ACE, angiotensin converting enzyme
- AGT, angiotensinogen
- AT1, angiotensin II receptor subtype 1
- AT2, angiotensin II receptor subtype 2
- Adipose
- Air pollution
- Ang II, angiotensin II
- CVD
- CVD, cardiovascular disease
- DHE, dihydroethidium
- FA, filtered air (controls)
- GLUT-4, glucose transporter type 4
- HF, high-fat diet
- ICAM-1, intracellular adhesion molecule-1
- IL-6, interleukin-6
- IL-β, interleukin beta
- IR, insulin receptor
- LDL, low density lipoprotein
- LF, low-fat diet
- LOX-1, lectin-like oxidized low-density lipoprotein receptor
- MCP-1, monocyte chemoattractant protein-1
- MOMA-2, anti-monocyte + macrophage antibody
- MVE, mixed gasoline and diesel vehicle emissions
- Obesity
- PM, particulate matter
- RAS, renin-angiotensin system
- ROS, reactive oxygen species
- Renin-angiotensin system
- T2D, type 2 diabetes
- TNF-α, tumor necrosis factor alpha
- VCAM-1, vascular cell adhesion molecule-1
- vWF, Von Willebrand factor
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Suwannasrisuk P, Boonchaya-Anant P, Houngngam N, Udomsawaengsup S, Sunthornyothin S. Changes in plasma aldosterone level after weight loss by bariatric surgery in morbidly obese patients. BMC Endocr Disord 2020; 20:45. [PMID: 32252748 PMCID: PMC7132890 DOI: 10.1186/s12902-020-0527-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/17/2019] [Accepted: 03/24/2020] [Indexed: 01/10/2023] Open
Abstract
BACKGROUND Overactivation of renin-aldosterone-angiotensin system (RAS) is part of the pathogenesis of obesity-associated hypertension. Evidences have shown that weight loss can result in reduction in blood pressure and RAS. This study was aim to investigate changes of plasma aldosterone concentration (PAC) after bariatric surgery. METHODS A prospective study was done in 14 morbidly obese patients undergoing bariatric surgery. Patients who were taking medications that can interfere with PAC and renin levels were excluded. Collection of blood samples were done at baseline and at 3 and 6-month post-bariatric surgery. RESULTS Four out of 14 patients had hypertension at baseline. Mean body mass index (BMI) was 56.7 ± 13.5 kg/m2. PAC were significantly decreased at 3-and 6-month post-bariatric surgery from 14.3 ± 8.0 to 7.5 ± 5.5 [reduction of 36% from baseline (P < 0.01)] and 8.0 ± 6.6 ng/dl [reduction of 32% from baseline (P < 0.05)] respectively. The reduction of PAC at 3-month post-surgery was correlated with the reduction of body weight (r = 0.46, P < 0.05), waist circumference (r = 0.73, P < 0.05) and percent of body fat (r = 0.58, P < 0.05). CONCLUSIONS Maximal reduction of PAC in obese patients underwent bariatric surgery occurred during the first 3 months after bariatric surgery. The reduction of PAC was associated with the reduction of body weight, waist circumference and percent of body fat suggesting the link between RAS and obesity-mediated hypertension.
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Affiliation(s)
- Preaw Suwannasrisuk
- Division of Endocrinology and Metabolism, Department of Medicine, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand.
- Department of Medicine, Faculty of Medicine, Naresuan University, Phitsanulok, Thailand.
| | - Patchaya Boonchaya-Anant
- Division of Endocrinology and Metabolism, Department of Medicine, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
- Excellence Center in Diabetes, Hormones and Metabolism, King Chulalongkorn Memorial Hospital, Thai Red Cross Society, Bangkok, Thailand
| | - Natnicha Houngngam
- Division of Endocrinology and Metabolism, Department of Medicine, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
- Excellence Center in Diabetes, Hormones and Metabolism, King Chulalongkorn Memorial Hospital, Thai Red Cross Society, Bangkok, Thailand
| | - Suthep Udomsawaengsup
- Department of Surgery, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
| | - Sarat Sunthornyothin
- Division of Endocrinology and Metabolism, Department of Medicine, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
- Excellence Center in Diabetes, Hormones and Metabolism, King Chulalongkorn Memorial Hospital, Thai Red Cross Society, Bangkok, Thailand
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Miyata KN, Zhao S, Wu CH, Lo CS, Ghosh A, Chenier I, Filep JG, Ingelfinger JR, Zhang SL, Chan JSD. Comparison of the effects of insulin and SGLT2 inhibitor on the Renal Renin-Angiotensin system in type 1 diabetes mice. Diabetes Res Clin Pract 2020; 162:108107. [PMID: 32173417 DOI: 10.1016/j.diabres.2020.108107] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Revised: 02/19/2020] [Accepted: 02/25/2020] [Indexed: 01/22/2023]
Abstract
AIMS SGLT2 inhibitors have been proposed as an adjunct to insulin therapy for glycemic control in type 1 diabetes (T1D) patients. However, concern has been raised due to an increase in renin-angiotensin-system (RAS) activity reported in a clinical trial in which an SGLT2 inhibitor was added while insulin dose was reduced in T1D patients. We previously reported that insulin inhibits intrarenal angiotensinogen (Agt) gene transcription and RAS activation. We hypothesized that insulin, rather than SGLT2 inhibition might regulate the intrarenal RAS. METHODS We compared RAS activity in non-diabetic wild type mice, Akita mice (T1D model) and Akita mice treated with insulin or the SGLT2 inhibitor canagliflozin. RESULTS Treatment of Akita mice with insulin or canagliflozin produced similar reductions in blood glucose, whereas insulin, but not canagliflozin, reduced elevated systolic blood pressure. Akita mice exhibited increased renal Agt mRNA/protein expression, which was attenuated by insulin, but not by canagliflozin. Furthermore, insulin was more effective than canagliflozin in lowering kidney weight and albuminuria. CONCLUSIONS Insulin, but not canagliflozin, lowers intrarenal RAS activity in Akita mice. Our findings can be of potential clinical importance, especially for T1D patients who are not on RAS inhibitors at the time of adding SGLT2 inhibitors.
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Affiliation(s)
- Kana N Miyata
- Département de Médecine, Université de Montréal, Centre de recherche du Centre hospitalier de l'Université de Montréal (CRCHUM), Tour Viger-Pavillon R, 900 Saint Denis Street, Montréal, Quebec H2X 0A9, Canada
| | - Shuiling Zhao
- Département de Médecine, Université de Montréal, Centre de recherche du Centre hospitalier de l'Université de Montréal (CRCHUM), Tour Viger-Pavillon R, 900 Saint Denis Street, Montréal, Quebec H2X 0A9, Canada
| | - Chin-Han Wu
- Département de Médecine, Université de Montréal, Centre de recherche du Centre hospitalier de l'Université de Montréal (CRCHUM), Tour Viger-Pavillon R, 900 Saint Denis Street, Montréal, Quebec H2X 0A9, Canada
| | - Chao-Sheng Lo
- Département de Médecine, Université de Montréal, Centre de recherche du Centre hospitalier de l'Université de Montréal (CRCHUM), Tour Viger-Pavillon R, 900 Saint Denis Street, Montréal, Quebec H2X 0A9, Canada
| | - Anindya Ghosh
- Département de Médecine, Université de Montréal, Centre de recherche du Centre hospitalier de l'Université de Montréal (CRCHUM), Tour Viger-Pavillon R, 900 Saint Denis Street, Montréal, Quebec H2X 0A9, Canada
| | - Isabelle Chenier
- Département de Médecine, Université de Montréal, Centre de recherche du Centre hospitalier de l'Université de Montréal (CRCHUM), Tour Viger-Pavillon R, 900 Saint Denis Street, Montréal, Quebec H2X 0A9, Canada
| | - Janos G Filep
- Université de Montréal, Centre de recherche de l'Hopital Maisonneuve-Rosemont, 5415 boul. l'Assomption, Montréal, Quebec H1T 2M4, Canada
| | - Julie R Ingelfinger
- Harvard Medical School, Pediatric Nephrology Unit, Massachusetts General Hospital, 15 Parkman Street, WAC 709, Boston, MA 02114-3117, USA
| | - Shao-Ling Zhang
- Département de Médecine, Université de Montréal, Centre de recherche du Centre hospitalier de l'Université de Montréal (CRCHUM), Tour Viger-Pavillon R, 900 Saint Denis Street, Montréal, Quebec H2X 0A9, Canada.
| | - John S D Chan
- Département de Médecine, Université de Montréal, Centre de recherche du Centre hospitalier de l'Université de Montréal (CRCHUM), Tour Viger-Pavillon R, 900 Saint Denis Street, Montréal, Quebec H2X 0A9, Canada.
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Tubular Deficiency of Heterogeneous Nuclear Ribonucleoprotein F Elevates Systolic Blood Pressure and Induces Glycosuria in Mice. Sci Rep 2019; 9:15765. [PMID: 31673025 PMCID: PMC6823451 DOI: 10.1038/s41598-019-52323-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Accepted: 10/11/2019] [Indexed: 12/31/2022] Open
Abstract
We reported previously that overexpression of heterogeneous nuclear ribonucleoprotein F (Hnrnpf) in renal proximal tubular cells (RPTCs) suppresses angiotensinogen (Agt) expression, and attenuates systemic hypertension and renal injury in diabetic Hnrnpf-transgenic (Tg) mice. We thus hypothesized that deletion of Hnrnpf in the renal proximal tubules (RPT) of mice would worsen systemic hypertension and kidney injury, perhaps revealing novel mechanism(s). Tubule-specific Hnrnpf knockout (KO) mice were generated by crossbreeding Pax8-Cre mice with floxed Hnrnpf mice on a C57BL/6 background. Both male and female KO mice exhibited elevated systolic blood pressure, increased urinary albumin/creatinine ratio, tubulo-interstitial fibrosis and glycosuria without changes in blood glucose or glomerular filtration rate compared with control littermates. However, glycosuria disappeared in male KO mice at the age of 12 weeks, while female KO mice had persistent glycosuria. Agt expression was elevated, whereas sodium-glucose co-transporter 2 (Sglt2) expression was down-regulated in RPTs of both male and female KO mice as compared to control littermates. In vitro, KO of HNRNPF in human RPTCs (HK-2) by CRISPR gRNA up-regulated AGT and down-regulated SGLT2 expression. The Sglt2 inhibitor canagliflozin treatment had no effect on Agt and Sglt2 expression in HK-2 and in RPTCs of wild-type mice but induced glycosuria. Our results demonstrate that Hnrnpf plays a role in the development of hypertension and glycosuria through modulation of renal Agt and Sglt2 expression in mice, respectively.
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Ghosh A, Zhao S, Lo CS, Maachi H, Chenier I, Lateef MA, Abdo S, Filep JG, Ingelfinger JR, Zhang SL, Chan JSD. Heterogeneous Nuclear Ribonucleoprotein F Mediates Insulin Inhibition of Bcl2-Modifying Factor Expression and Tubulopathy in Diabetic Kidney. Sci Rep 2019; 9:6687. [PMID: 31040360 PMCID: PMC6491582 DOI: 10.1038/s41598-019-43218-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Accepted: 02/04/2019] [Indexed: 11/25/2022] Open
Abstract
We investigated the molecular mechanism(s) by which insulin prevents Bcl2-modifying factor (Bmf)-induced renal proximal tubular cell (RPTC) apoptosis and loss in diabetic mice. Transgenic mice (Tg) mice specifically overexpressing human BMF in RPTCs and non-Tg littermates were studied at 10 to 20 weeks of age. Non-diabetic littermates, diabetic Akita mice +/− insulin implant, Akita Tg mice specifically overexpressing heterogeneous nuclear ribonucleoprotein F (hnRNP F) in their RPTCs and immortalized rat renal proximal tubular cells (IRPTCs) were also studied. BMF-Tg mice exhibited higher systolic blood pressure, urinary albumin/creatinine ratio, RPTC apoptosis and urinary RPTCs than non-Tg mice. Insulin treatment in Akita mice and Akita mice overexpressing hnRNP F suppressed Bmf expression and RPTC apoptosis. In hyperinsulinemic-euglycemic wild type mice, renal Bmf expression was down-regulated with up-regulation of hnRNP F. In vitro, insulin inhibited high glucose-stimulation of Bmf expression, predominantly via p44/42 mitogen-activated protein kinase (MAPK) signaling. Transfection of p44/42 MAPK or hnRNP F small interfering RNA (siRNA) prevented insulin inhibition of Bmf expression. HnRNP F inhibited Bmf transcription via hnRNP F-responsive element in the Bmf promoter. Our results demonstrate that hnRNP F suppression of Bmf transcription is an important mechanism by which insulin protects RPTCs from apoptosis in diabetes.
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Affiliation(s)
- Anindya Ghosh
- Département de medecine, Université de Montréal, Centre de recherche du Centre hospitalier de l'Université de Montréal (CRCHUM), 900 Saint Denis Street, Montréal, QC, H2X 0A9, Canada
| | - Shuiling Zhao
- Département de medecine, Université de Montréal, Centre de recherche du Centre hospitalier de l'Université de Montréal (CRCHUM), 900 Saint Denis Street, Montréal, QC, H2X 0A9, Canada
| | - Chao-Sheng Lo
- Département de medecine, Université de Montréal, Centre de recherche du Centre hospitalier de l'Université de Montréal (CRCHUM), 900 Saint Denis Street, Montréal, QC, H2X 0A9, Canada
| | - Hasna Maachi
- Département de medecine, Université de Montréal, Centre de recherche du Centre hospitalier de l'Université de Montréal (CRCHUM), 900 Saint Denis Street, Montréal, QC, H2X 0A9, Canada
| | - Isabelle Chenier
- Département de medecine, Université de Montréal, Centre de recherche du Centre hospitalier de l'Université de Montréal (CRCHUM), 900 Saint Denis Street, Montréal, QC, H2X 0A9, Canada
| | - Muhammad Abdul Lateef
- Département de medecine, Université de Montréal, Centre de recherche du Centre hospitalier de l'Université de Montréal (CRCHUM), 900 Saint Denis Street, Montréal, QC, H2X 0A9, Canada
| | - Shaaban Abdo
- Département de medecine, Université de Montréal, Centre de recherche du Centre hospitalier de l'Université de Montréal (CRCHUM), 900 Saint Denis Street, Montréal, QC, H2X 0A9, Canada
| | - Janos G Filep
- Département de pathologie et biologie cellulaire, Université de Montréal, Centre de recherche, Hôpital Maisonneuve-Rosemont, 5415 boul. de l'Assomption, Montréal, QC, H1T 2M4, Canada
| | - Julie R Ingelfinger
- Harvard Medical School, Pediatric Nephrology Unit, Massachusetts General Hospital, 15 Parkman Street, WAC 709, Boston, MA, 02114-3117, USA
| | - Shao-Ling Zhang
- Département de medecine, Université de Montréal, Centre de recherche du Centre hospitalier de l'Université de Montréal (CRCHUM), 900 Saint Denis Street, Montréal, QC, H2X 0A9, Canada.
| | - John S D Chan
- Département de medecine, Université de Montréal, Centre de recherche du Centre hospitalier de l'Université de Montréal (CRCHUM), 900 Saint Denis Street, Montréal, QC, H2X 0A9, Canada.
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Lo CS, Shi Y, Chenier I, Ghosh A, Wu CH, Cailhier JF, Ethier J, Lattouf JB, Filep JG, Ingelfinger JR, Zhang SL, Chan JSD. Heterogeneous Nuclear Ribonucleoprotein F Stimulates Sirtuin-1 Gene Expression and Attenuates Nephropathy Progression in Diabetic Mice. Diabetes 2017; 66:1964-1978. [PMID: 28424160 PMCID: PMC5482081 DOI: 10.2337/db16-1588] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Accepted: 04/10/2017] [Indexed: 12/19/2022]
Abstract
We investigated the mechanism of heterogeneous nuclear ribonucleoprotein F (hnRNP F) renoprotective action in a type 2 diabetes (T2D) mouse model (db/db). Immortalized rat renal proximal tubular cells (IRPTCs) and kidneys from humans with T2D were also studied. The db/db mice developed hyperglycemia, oxidative stress, and nephropathy at age 20 weeks compared with their db/m littermates. These abnormalities, with the exception of hyperglycemia, were attenuated in db/dbhnRNP F-transgenic (Tg) mice specifically overexpressing hnRNP F in their RPTCs. Sirtuin-1, Foxo3α, and catalase expression were significantly decreased in RPTCs from db/db mice and normalized in db/dbhnRNP F-Tg mice. In vitro, hnRNP F overexpression stimulated Sirtuin-1 and Foxo3α with downregulation of acetylated p53 expression and prevented downregulation of Sirtuin-1 and Foxo3α expression in IRPTCs by high glucose plus palmitate. Transfection of Sirtuin-1 small interfering RNA prevented hnRNP F stimulation of Foxo3α and downregulation of acetylated p53 expression. hnRNP F stimulated Sirtuin-1 transcription via hnRNP F-responsive element in the Sirtuin-1 promoter. Human T2D kidneys exhibited more RPTC apoptosis and lower expression of hnRNP F, SIRTUIN-1, and FOXO3α than nondiabetic kidneys. Our results demonstrate that hnRNP F protects kidneys against oxidative stress and nephropathy via stimulation of Sirtuin-1 expression and signaling in diabetes.
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MESH Headings
- Acetylation
- Aged
- Animals
- Apoptosis
- Blotting, Western
- Case-Control Studies
- Cells, Cultured
- Diabetes Mellitus, Experimental/complications
- Diabetes Mellitus, Experimental/genetics
- Diabetes Mellitus, Experimental/metabolism
- Diabetes Mellitus, Type 2/complications
- Diabetes Mellitus, Type 2/genetics
- Diabetes Mellitus, Type 2/metabolism
- Diabetic Nephropathies/etiology
- Diabetic Nephropathies/genetics
- Diabetic Nephropathies/metabolism
- Disease Models, Animal
- Disease Progression
- Female
- Fibrosis
- Forkhead Box Protein O3
- Gene Expression Regulation/genetics
- Heterogeneous-Nuclear Ribonucleoprotein Group F-H/genetics
- Heterogeneous-Nuclear Ribonucleoprotein Group F-H/metabolism
- Humans
- Immunohistochemistry
- In Situ Nick-End Labeling
- In Vitro Techniques
- Kidney/metabolism
- Kidney/pathology
- Kidney Tubules, Proximal/metabolism
- Male
- Mice
- Mice, Knockout
- Mice, Transgenic
- Middle Aged
- Oxidative Stress
- Rats
- Real-Time Polymerase Chain Reaction
- Receptors, Leptin/genetics
- Sirtuin 1/genetics
- Sirtuin 1/metabolism
- Tumor Suppressor Protein p53/metabolism
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Affiliation(s)
- Chao-Sheng Lo
- Centre de recherche, Centre hospitalier de l'Université de Montréal (CRCHUM) and Département de médecine, Université de Montréal, Montreal, QC, Canada
| | - Yixuan Shi
- Centre de recherche, Centre hospitalier de l'Université de Montréal (CRCHUM) and Département de médecine, Université de Montréal, Montreal, QC, Canada
| | - Isabelle Chenier
- Centre de recherche, Centre hospitalier de l'Université de Montréal (CRCHUM) and Département de médecine, Université de Montréal, Montreal, QC, Canada
| | - Anindya Ghosh
- Centre de recherche, Centre hospitalier de l'Université de Montréal (CRCHUM) and Département de médecine, Université de Montréal, Montreal, QC, Canada
| | - Chin-Han Wu
- Centre de recherche, Centre hospitalier de l'Université de Montréal (CRCHUM) and Département de médecine, Université de Montréal, Montreal, QC, Canada
| | - Jean-Francois Cailhier
- Centre de recherche, Centre hospitalier de l'Université de Montréal (CRCHUM) and Département de médecine, Université de Montréal, Montreal, QC, Canada
| | - Jean Ethier
- Centre de recherche, Centre hospitalier de l'Université de Montréal (CRCHUM) and Département de médecine, Université de Montréal, Montreal, QC, Canada
| | - Jean-Baptiste Lattouf
- Centre de recherche, Centre hospitalier de l'Université de Montréal (CRCHUM) and Département de médecine, Université de Montréal, Montreal, QC, Canada
| | - Janos G Filep
- Centre de recherche, Hôpital Maisonneuve-Rosemont and Department of Pathology and Cell Biology, Université de Montréal, Montreal, QC, Canada
| | - Julie R Ingelfinger
- Pediatric Nephrology Unit, Massachusetts General Hospital, Harvard Medical School, Boston, MA
| | - Shao-Ling Zhang
- Centre de recherche, Centre hospitalier de l'Université de Montréal (CRCHUM) and Département de médecine, Université de Montréal, Montreal, QC, Canada
| | - John S D Chan
- Centre de recherche, Centre hospitalier de l'Université de Montréal (CRCHUM) and Département de médecine, Université de Montréal, Montreal, QC, Canada
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Ghosh A, Abdo S, Zhao S, Wu CH, Shi Y, Lo CS, Chenier I, Alquier T, Filep JG, Ingelfinger JR, Zhang SL, Chan JSD. Insulin Inhibits Nrf2 Gene Expression via Heterogeneous Nuclear Ribonucleoprotein F/K in Diabetic Mice. Endocrinology 2017; 158:903-919. [PMID: 28324005 PMCID: PMC5460794 DOI: 10.1210/en.2016-1576] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/11/2016] [Accepted: 01/17/2017] [Indexed: 11/19/2022]
Abstract
Oxidative stress induces endogenous antioxidants via nuclear factor erythroid 2-related factor 2 (Nrf2), potentially preventing tissue injury. We investigated whether insulin affects renal Nrf2 expression in type 1 diabetes (T1D) and studied its underlying mechanism. Insulin normalized hyperglycemia, hypertension, oxidative stress, and renal injury; inhibited renal Nrf2 and angiotensinogen (Agt) gene expression; and upregulated heterogeneous nuclear ribonucleoprotein F and K (hnRNP F and hnRNP K) expression in Akita mice with T1D. In immortalized rat renal proximal tubular cells, insulin suppressed Nrf2 and Agt but stimulated hnRNP F and hnRNP K gene transcription in high glucose via p44/42 mitogen-activated protein kinase signaling. Transfection with small interfering RNAs of p44/42 MAPK, hnRNP F, or hnRNP K blocked insulin inhibition of Nrf2 gene transcription. Insulin curbed Nrf2 promoter activity via a specific DNA-responsive element that binds hnRNP F/K, and hnRNP F/K overexpression curtailed Nrf2 promoter activity. In hyperinsulinemic-euglycemic mice, renal Nrf2 and Agt expression was downregulated, whereas hnRNP F/K expression was upregulated. Thus, the beneficial actions of insulin in diabetic nephropathy appear to be mediated, in part, by suppressing renal Nrf2 and Agt gene transcription and preventing Nrf2 stimulation of Agt expression via hnRNP F/K. These findings identify hnRNP F/K and Nrf2 as potential therapeutic targets in diabetes.
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Affiliation(s)
- Anindya Ghosh
- Department of Medicine, Université de Montréal and Centre de recherche du Centre hospitalier de l'Université de Montréal (CRCHUM), Montreal, Quebec, Canada
| | - Shaaban Abdo
- Department of Medicine, Université de Montréal and Centre de recherche du Centre hospitalier de l'Université de Montréal (CRCHUM), Montreal, Quebec, Canada
| | - Shuiling Zhao
- Department of Medicine, Université de Montréal and Centre de recherche du Centre hospitalier de l'Université de Montréal (CRCHUM), Montreal, Quebec, Canada
| | - Chin-Han Wu
- Department of Medicine, Université de Montréal and Centre de recherche du Centre hospitalier de l'Université de Montréal (CRCHUM), Montreal, Quebec, Canada
| | - Yixuan Shi
- Department of Medicine, Université de Montréal and Centre de recherche du Centre hospitalier de l'Université de Montréal (CRCHUM), Montreal, Quebec, Canada
| | - Chao-Sheng Lo
- Department of Medicine, Université de Montréal and Centre de recherche du Centre hospitalier de l'Université de Montréal (CRCHUM), Montreal, Quebec, Canada
| | - Isabelle Chenier
- Department of Medicine, Université de Montréal and Centre de recherche du Centre hospitalier de l'Université de Montréal (CRCHUM), Montreal, Quebec, Canada
| | - Thierry Alquier
- Department of Medicine, Université de Montréal and Centre de recherche du Centre hospitalier de l'Université de Montréal (CRCHUM), Montreal, Quebec, Canada
| | - Janos G Filep
- Department of Pathology and Cell Biology, Université de Montréal and Centre de recherche, Hôpital Maisonneuve-Rosemont, Montreal, Quebec, Canada
| | - Julie R Ingelfinger
- Pediatric Nephrology Unit, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Shao-Ling Zhang
- Department of Medicine, Université de Montréal and Centre de recherche du Centre hospitalier de l'Université de Montréal (CRCHUM), Montreal, Quebec, Canada
| | - John S D Chan
- Department of Medicine, Université de Montréal and Centre de recherche du Centre hospitalier de l'Université de Montréal (CRCHUM), Montreal, Quebec, Canada
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10
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Lo CS, Shi Y, Chang SY, Abdo S, Chenier I, Filep JG, Ingelfinger JR, Zhang SL, Chan JSD. Overexpression of heterogeneous nuclear ribonucleoprotein F stimulates renal Ace-2 gene expression and prevents TGF-β1-induced kidney injury in a mouse model of diabetes. Diabetologia 2015; 58:2443-54. [PMID: 26232095 PMCID: PMC4572079 DOI: 10.1007/s00125-015-3700-y] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/05/2015] [Accepted: 06/26/2015] [Indexed: 01/09/2023]
Abstract
AIMS/HYPOTHESIS We investigated whether heterogeneous nuclear ribonucleoprotein F (hnRNP F) stimulates renal ACE-2 expression and prevents TGF-β1 signalling, TGF-β1 inhibition of Ace-2 gene expression and induction of tubulo-fibrosis in an Akita mouse model of type 1 diabetes. METHODS Adult male Akita transgenic (Tg) mice overexpressing specifically hnRNP F in their renal proximal tubular cells (RPTCs) were studied. Non-Akita littermates and Akita mice served as controls. Immortalised rat RPTCs stably transfected with plasmid containing either rat Hnrnpf cDNA or rat Ace-2 gene promoter were also studied. RESULTS Overexpression of hnRNP F attenuated systemic hypertension, glomerular filtration rate, albumin/creatinine ratio, urinary angiotensinogen (AGT) and angiotensin (Ang) II levels, renal fibrosis and profibrotic gene (Agt, Tgf-β1, TGF-β receptor II [Tgf-βrII]) expression, stimulated anti-profibrotic gene (Ace-2 and Ang 1-7 receptor [MasR]) expression, and normalised urinary Ang 1-7 level in Akita Hnrnpf-Tg mice as compared with Akita mice. In vitro, hnRNP F overexpression stimulated Ace-2 gene promoter activity, mRNA and protein expression, and attenuated Agt, Tgf-β1 and Tgf-βrII gene expression. Furthermore, hnRNP F overexpression prevented TGF-β1 signalling and TGF-β1 inhibition of Ace-2 gene expression. CONCLUSIONS/INTERPRETATION These data demonstrate that hnRNP F stimulates Ace-2 gene transcription, prevents TGF-β1 inhibition of Ace-2 gene transcription and induction of kidney injury in diabetes. HnRNP F may be a potential target for treating hypertension and renal fibrosis in diabetes.
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Affiliation(s)
- Chao-Sheng Lo
- Centre de recherche, Centre hospitalier de l'Université de Montréal (CRCHUM) - Tour Viger Pavillon R, Université de Montréal, 900 Saint-Denis Street, Montreal, QC, H2X 0A9, Canada
| | - Yixuan Shi
- Centre de recherche, Centre hospitalier de l'Université de Montréal (CRCHUM) - Tour Viger Pavillon R, Université de Montréal, 900 Saint-Denis Street, Montreal, QC, H2X 0A9, Canada
| | - Shiao-Ying Chang
- Centre de recherche, Centre hospitalier de l'Université de Montréal (CRCHUM) - Tour Viger Pavillon R, Université de Montréal, 900 Saint-Denis Street, Montreal, QC, H2X 0A9, Canada
| | - Shaaban Abdo
- Centre de recherche, Centre hospitalier de l'Université de Montréal (CRCHUM) - Tour Viger Pavillon R, Université de Montréal, 900 Saint-Denis Street, Montreal, QC, H2X 0A9, Canada
| | - Isabelle Chenier
- Centre de recherche, Centre hospitalier de l'Université de Montréal (CRCHUM) - Tour Viger Pavillon R, Université de Montréal, 900 Saint-Denis Street, Montreal, QC, H2X 0A9, Canada
| | - Janos G Filep
- Research Centre, Maisonneuve-Rosemont Hospital, Université de Montréal, Montreal, QC, Canada
| | - Julie R Ingelfinger
- Pediatric Nephrology Unit, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Shao-Ling Zhang
- Centre de recherche, Centre hospitalier de l'Université de Montréal (CRCHUM) - Tour Viger Pavillon R, Université de Montréal, 900 Saint-Denis Street, Montreal, QC, H2X 0A9, Canada.
| | - John S D Chan
- Centre de recherche, Centre hospitalier de l'Université de Montréal (CRCHUM) - Tour Viger Pavillon R, Université de Montréal, 900 Saint-Denis Street, Montreal, QC, H2X 0A9, Canada.
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11
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Abdo S, Shi Y, Otoukesh A, Ghosh A, Lo CS, Chenier I, Filep JG, Ingelfinger JR, Zhang SL, Chan JSD. Catalase overexpression prevents nuclear factor erythroid 2-related factor 2 stimulation of renal angiotensinogen gene expression, hypertension, and kidney injury in diabetic mice. Diabetes 2014; 63:3483-96. [PMID: 24812425 PMCID: PMC4171660 DOI: 10.2337/db13-1830] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
This study investigated the impact of catalase (Cat) overexpression in renal proximal tubule cells (RPTCs) on nuclear factor erythroid 2-related factor 2 (Nrf2) stimulation of angiotensinogen (Agt) gene expression and the development of hypertension and renal injury in diabetic Akita transgenic mice. Additionally, adult male mice were treated with the Nrf2 activator oltipraz with or without the inhibitor trigonelline. Rat RPTCs, stably transfected with plasmid containing either rat Agt or Nrf2 gene promoter, were also studied. Cat overexpression normalized systolic BP, attenuated renal injury, and inhibited RPTC Nrf2, Agt, and heme oxygenase-1 (HO-1) gene expression in Akita Cat transgenic mice compared with Akita mice. In vitro, high glucose level, hydrogen peroxide, and oltipraz stimulated Nrf2 and Agt gene expression; these changes were blocked by trigonelline, small interfering RNAs of Nrf2, antioxidants, or pharmacological inhibitors of nuclear factor-κB and p38 mitogen-activated protein kinase. The deletion of Nrf2-responsive elements in the rat Agt gene promoter abolished the stimulatory effect of oltipraz. Oltipraz administration also augmented Agt, HO-1, and Nrf2 gene expression in mouse RPTCs and was reversed by trigonelline. These data identify a novel mechanism, Nrf2-mediated stimulation of intrarenal Agt gene expression and activation of the renin-angiotensin system, by which hyperglycemia induces hypertension and renal injury in diabetic mice.
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Affiliation(s)
- Shaaban Abdo
- Research Centre, Centre Hospitalier de l'Université de Montréal, Université de Montréal, Montréal, Québec, Canada
| | - Yixuan Shi
- Research Centre, Centre Hospitalier de l'Université de Montréal, Université de Montréal, Montréal, Québec, Canada
| | - Abouzar Otoukesh
- Research Centre, Centre Hospitalier de l'Université de Montréal, Université de Montréal, Montréal, Québec, Canada
| | - Anindya Ghosh
- Research Centre, Centre Hospitalier de l'Université de Montréal, Université de Montréal, Montréal, Québec, Canada
| | - Chao-Sheng Lo
- Research Centre, Centre Hospitalier de l'Université de Montréal, Université de Montréal, Montréal, Québec, Canada
| | - Isabelle Chenier
- Research Centre, Centre Hospitalier de l'Université de Montréal, Université de Montréal, Montréal, Québec, Canada
| | - Janos G Filep
- Research Centre, Hôpital Maisonneuve-Rosemont, Université de Montréal, Montréal, Québec, Canada
| | - Julie R Ingelfinger
- Pediatric Nephrology Unit, Massachusetts General Hospital, Harvard Medical School, Boston, MA
| | - Shao Ling Zhang
- Research Centre, Centre Hospitalier de l'Université de Montréal, Université de Montréal, Montréal, Québec, Canada
| | - John S D Chan
- Research Centre, Centre Hospitalier de l'Université de Montréal, Université de Montréal, Montréal, Québec, Canada
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Qi Y, Zhang K, Wu Y, Xu Z, Yong QC, Kumar R, Baker KM, Zhu Q, Chen S, Guo S. Novel mechanism of blood pressure regulation by forkhead box class O1-mediated transcriptional control of hepatic angiotensinogen. Hypertension 2014; 64:1131-40. [PMID: 25069665 DOI: 10.1161/hypertensionaha.114.03970] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The renin-angiotensin system is a major determinant of blood pressure regulation. It consists of a cascade of enzymatic reactions involving 3 components: angiotensinogen, renin, and angiotensin-converting enzyme, which generate angiotensin II as a biologically active product. Angiotensinogen is largely produced in the liver, acting as a major determinant of the circulating renin-angiotensin system, which exerts acute hemodynamic effects on blood pressure regulation. How the expression of angiotensinogen is regulated is not completely understood. Here, we hypothesize that angiotensinogen is regulated by forkhead transcription factor forkhead box class O1 (Foxo1), an insulin-suppressed transcription factor, and thereby controls blood pressure in mice. We generated liver-specific Foxo1 knockout mice, which exhibited a reduction in plasma angiotensinogen and angiotensin II levels and a significant decrease in blood pressure. Using hepatocyte cultures, we demonstrated that overexpression of Foxo1 increased angiotensinogen expression, whereas hepatocytes lacking Foxo1 demonstrated a reduction of angiotensinogen gene expression and partially impaired insulin inhibition on angiotensinogen gene expression. Furthermore, mouse angiotensinogen prompter analysis demonstrated that the angiotensinogen promoter region contains a functional Foxo1-binding site, which is responsible for both Foxo1 stimulation and insulin suppression on the promoter activity. Together, these data demonstrate that Foxo1 regulates hepatic angiotensinogen gene expression and controls plasma angiotensinogen and angiotensin II levels, modulating blood pressure control in mice.
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Affiliation(s)
- Yajuan Qi
- From the Division of Molecular Cardiology, Department of Medicine, College of Medicine, Texas A&M University Health Science Center, Balyor Scott & White Health, Temple (Y.Q., K.Z., Y.W., Z.X., Q.C.Y., R.K., K.M.B., Q.Z., S.C., S.G.); and Central Texas Veterans Health Care System, Temple (Y.Q., K.Z., Y.W., Z.X., Q.C.Y., R.K., K.M.B., Q.Z., S.C., S.G.)
| | - Kebin Zhang
- From the Division of Molecular Cardiology, Department of Medicine, College of Medicine, Texas A&M University Health Science Center, Balyor Scott & White Health, Temple (Y.Q., K.Z., Y.W., Z.X., Q.C.Y., R.K., K.M.B., Q.Z., S.C., S.G.); and Central Texas Veterans Health Care System, Temple (Y.Q., K.Z., Y.W., Z.X., Q.C.Y., R.K., K.M.B., Q.Z., S.C., S.G.)
| | - Yuxin Wu
- From the Division of Molecular Cardiology, Department of Medicine, College of Medicine, Texas A&M University Health Science Center, Balyor Scott & White Health, Temple (Y.Q., K.Z., Y.W., Z.X., Q.C.Y., R.K., K.M.B., Q.Z., S.C., S.G.); and Central Texas Veterans Health Care System, Temple (Y.Q., K.Z., Y.W., Z.X., Q.C.Y., R.K., K.M.B., Q.Z., S.C., S.G.)
| | - Zihui Xu
- From the Division of Molecular Cardiology, Department of Medicine, College of Medicine, Texas A&M University Health Science Center, Balyor Scott & White Health, Temple (Y.Q., K.Z., Y.W., Z.X., Q.C.Y., R.K., K.M.B., Q.Z., S.C., S.G.); and Central Texas Veterans Health Care System, Temple (Y.Q., K.Z., Y.W., Z.X., Q.C.Y., R.K., K.M.B., Q.Z., S.C., S.G.)
| | - Qian Chen Yong
- From the Division of Molecular Cardiology, Department of Medicine, College of Medicine, Texas A&M University Health Science Center, Balyor Scott & White Health, Temple (Y.Q., K.Z., Y.W., Z.X., Q.C.Y., R.K., K.M.B., Q.Z., S.C., S.G.); and Central Texas Veterans Health Care System, Temple (Y.Q., K.Z., Y.W., Z.X., Q.C.Y., R.K., K.M.B., Q.Z., S.C., S.G.)
| | - Rajesh Kumar
- From the Division of Molecular Cardiology, Department of Medicine, College of Medicine, Texas A&M University Health Science Center, Balyor Scott & White Health, Temple (Y.Q., K.Z., Y.W., Z.X., Q.C.Y., R.K., K.M.B., Q.Z., S.C., S.G.); and Central Texas Veterans Health Care System, Temple (Y.Q., K.Z., Y.W., Z.X., Q.C.Y., R.K., K.M.B., Q.Z., S.C., S.G.)
| | - Kenneth M Baker
- From the Division of Molecular Cardiology, Department of Medicine, College of Medicine, Texas A&M University Health Science Center, Balyor Scott & White Health, Temple (Y.Q., K.Z., Y.W., Z.X., Q.C.Y., R.K., K.M.B., Q.Z., S.C., S.G.); and Central Texas Veterans Health Care System, Temple (Y.Q., K.Z., Y.W., Z.X., Q.C.Y., R.K., K.M.B., Q.Z., S.C., S.G.)
| | - Qinglei Zhu
- From the Division of Molecular Cardiology, Department of Medicine, College of Medicine, Texas A&M University Health Science Center, Balyor Scott & White Health, Temple (Y.Q., K.Z., Y.W., Z.X., Q.C.Y., R.K., K.M.B., Q.Z., S.C., S.G.); and Central Texas Veterans Health Care System, Temple (Y.Q., K.Z., Y.W., Z.X., Q.C.Y., R.K., K.M.B., Q.Z., S.C., S.G.)
| | - Shouwen Chen
- From the Division of Molecular Cardiology, Department of Medicine, College of Medicine, Texas A&M University Health Science Center, Balyor Scott & White Health, Temple (Y.Q., K.Z., Y.W., Z.X., Q.C.Y., R.K., K.M.B., Q.Z., S.C., S.G.); and Central Texas Veterans Health Care System, Temple (Y.Q., K.Z., Y.W., Z.X., Q.C.Y., R.K., K.M.B., Q.Z., S.C., S.G.)
| | - Shaodong Guo
- From the Division of Molecular Cardiology, Department of Medicine, College of Medicine, Texas A&M University Health Science Center, Balyor Scott & White Health, Temple (Y.Q., K.Z., Y.W., Z.X., Q.C.Y., R.K., K.M.B., Q.Z., S.C., S.G.); and Central Texas Veterans Health Care System, Temple (Y.Q., K.Z., Y.W., Z.X., Q.C.Y., R.K., K.M.B., Q.Z., S.C., S.G.).
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13
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Kamiyama M, Urushihara M, Morikawa T, Konishi Y, Imanishi M, Nishiyama A, Kobori H. Oxidative stress/angiotensinogen/renin-angiotensin system axis in patients with diabetic nephropathy. Int J Mol Sci 2013; 14:23045-62. [PMID: 24284398 PMCID: PMC3856105 DOI: 10.3390/ijms141123045] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2013] [Revised: 11/07/2013] [Accepted: 11/07/2013] [Indexed: 01/22/2023] Open
Abstract
Although recent studies have proven that renin-angiotensin system (RAS) blockades retard the progression of diabetic nephropathy, the detailed mechanisms of their reno-protective effects on the development of diabetic nephropathy remain uncertain. In rodent models, it has been reported that reactive oxygen species (ROS) are important for intrarenal angiotensinogen (AGT) augmentation in the progression of diabetic nephropathy. However, no direct evidence is available to demonstrate that AGT expression is enhanced in the kidneys of patients with diabetes. To examine whether the expression levels of ROS- and RAS-related factors in kidneys are increased with the progression of diabetic nephropathy, biopsied samples from 8 controls and 27 patients with type 2 diabetes were used. After the biopsy, these patients were diagnosed with minor glomerular abnormality or diabetes mellitus by clinical and pathological findings. The intensities of AGT, angiotensin II (Ang II), 4-hydroxy-2-nonenal (4-HNE), and heme oxygenase-1 (HO-1) were examined by fluorescence in situ hybridization and/or immunohistochemistry. Expression levels were greater in patients with diabetes than in control subjects. Moreover, the augmented intrarenal AGT mRNA expression paralleled renal dysfunction in patients with diabetes. These data suggest the importance of the activated oxidative stress/AGT/RAS axis in the pathogenesis of diabetic nephropathy.
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Affiliation(s)
- Masumi Kamiyama
- Department of Physiology, Tulane University Health Sciences Center, 1430 Tulane Avenue, New Orleans, LA 70112, USA; E-Mails: (M.K.); (M.U.)
- Hypertension and Renal Center of Excellence, Tulane University Health Sciences Center, 1430 Tulane Avenue, New Orleans, LA 70112, USA
| | - Maki Urushihara
- Department of Physiology, Tulane University Health Sciences Center, 1430 Tulane Avenue, New Orleans, LA 70112, USA; E-Mails: (M.K.); (M.U.)
- Hypertension and Renal Center of Excellence, Tulane University Health Sciences Center, 1430 Tulane Avenue, New Orleans, LA 70112, USA
| | - Takashi Morikawa
- Department of Nephrology and Hypertension, Osaka City General Hospital, 2-13-22 Miyakojima-Hondori, Miyakojima-ku, Osaka 534-0021, Japan; E-Mails: (T.M.); (Y.K.); (M.I.)
| | - Yoshio Konishi
- Department of Nephrology and Hypertension, Osaka City General Hospital, 2-13-22 Miyakojima-Hondori, Miyakojima-ku, Osaka 534-0021, Japan; E-Mails: (T.M.); (Y.K.); (M.I.)
| | - Masahito Imanishi
- Department of Nephrology and Hypertension, Osaka City General Hospital, 2-13-22 Miyakojima-Hondori, Miyakojima-ku, Osaka 534-0021, Japan; E-Mails: (T.M.); (Y.K.); (M.I.)
| | - Akira Nishiyama
- Department of Pharmacology, Kagawa University Medical School, Miki, 1750-1 Ikenobe, Miki, Kagawa 761-0793, Japan; E-Mail:
| | - Hiroyuki Kobori
- Department of Physiology, Tulane University Health Sciences Center, 1430 Tulane Avenue, New Orleans, LA 70112, USA; E-Mails: (M.K.); (M.U.)
- Hypertension and Renal Center of Excellence, Tulane University Health Sciences Center, 1430 Tulane Avenue, New Orleans, LA 70112, USA
- Department of Pharmacology, Kagawa University Medical School, Miki, 1750-1 Ikenobe, Miki, Kagawa 761-0793, Japan; E-Mail:
- Department of Medicine, Tulane University Health Sciences Center, 1430 Tulane Avenue, New Orleans, LA 70112, USA
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +1-504-988-2591; Fax: +1-504-988-0911
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14
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Lo CS, Chang SY, Chenier I, Filep JG, Ingelfinger JR, Zhang SL, Chan JS. Heterogeneous nuclear ribonucleoprotein F suppresses angiotensinogen gene expression and attenuates hypertension and kidney injury in diabetic mice. Diabetes 2012; 61:2597-608. [PMID: 22664958 PMCID: PMC3447919 DOI: 10.2337/db11-1349] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
We investigated the impact of heterogeneous nuclear ribonucleoprotein F (hnRNP F) overexpression on angiotensinogen (Agt) gene expression, hypertension, and renal proximal tubular cell (RPTC) injury in high-glucose milieu both in vivo and in vitro. Diabetic Akita transgenic (Tg) mice specifically overexpressing hnRNP F in their RPTCs were created, and the effects on systemic hypertension, Agt gene expression, renal hypertrophy, and interstitial fibrosis were studied. We also examined immortalized rat RPTCs stably transfected with control plasmid or plasmid containing hnRNP F cDNA in vitro. The results showed that hnRNP F overexpression attenuated systemic hypertension, suppressed Agt and transforming growth factor-β1 (TGF-β1) gene expression, and reduced urinary Agt and angiotensin II levels, renal hypertrophy, and glomerulotubular fibrosis in Akita hnRNP F-Tg mice. In vitro, hnRNP F overexpression prevented the high-glucose stimulation of Agt and TGF-β1 mRNA expression and cellular hypertrophy in RPTCs. These data suggest that hnRNP F plays a modulatory role and can ameliorate hypertension, renal hypertrophy, and interstitial fibrosis in diabetes. The underlying mechanism is mediated, at least in part, via the suppression of intrarenal Agt gene expression in vivo. hnRNP F may be a potential target in the treatment of hypertension and kidney injury in diabetes.
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Affiliation(s)
- Chao-Sheng Lo
- Centre de Recherche du Centre Hospitalier de l’Université de Montréal, Université de Montréal, Hôtel-Dieu Hospital, Montreal, Quebec, Canada
| | - Shiao-Ying Chang
- Centre de Recherche du Centre Hospitalier de l’Université de Montréal, Université de Montréal, Hôtel-Dieu Hospital, Montreal, Quebec, Canada
| | - Isabelle Chenier
- Centre de Recherche du Centre Hospitalier de l’Université de Montréal, Université de Montréal, Hôtel-Dieu Hospital, Montreal, Quebec, Canada
| | - Janos G. Filep
- Research Centre, Maisonneuve-Rosemont Hospital, Montreal, Quebec, Canada
| | - Julie R. Ingelfinger
- Pediatric Nephrology Unit, Massachusetts General Hospital, Boston, Massachusetts
| | - Shao Ling Zhang
- Centre de Recherche du Centre Hospitalier de l’Université de Montréal, Université de Montréal, Hôtel-Dieu Hospital, Montreal, Quebec, Canada
| | - John S.D. Chan
- Centre de Recherche du Centre Hospitalier de l’Université de Montréal, Université de Montréal, Hôtel-Dieu Hospital, Montreal, Quebec, Canada
- Corresponding author: John S.D. Chan,
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Putnam K, Shoemaker R, Yiannikouris F, Cassis LA. The renin-angiotensin system: a target of and contributor to dyslipidemias, altered glucose homeostasis, and hypertension of the metabolic syndrome. Am J Physiol Heart Circ Physiol 2012; 302:H1219-30. [PMID: 22227126 DOI: 10.1152/ajpheart.00796.2011] [Citation(s) in RCA: 159] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The renin-angiotensin system (RAS) is an important therapeutic target in the treatment of hypertension. Obesity has emerged as a primary contributor to essential hypertension in the United States and clusters with other metabolic disorders (hyperglycemia, hypertension, high triglycerides, low HDL cholesterol) defined within the metabolic syndrome. In addition to hypertension, RAS blockade may also serve as an effective treatment strategy to control impaired glucose and insulin tolerance and dyslipidemias in patients with the metabolic syndrome. Hyperglycemia, insulin resistance, and/or specific cholesterol metabolites have been demonstrated to activate components required for the synthesis [angiotensinogen, renin, angiotensin-converting enzyme (ACE)], degradation (ACE2), or responsiveness (angiotensin II type 1 receptors, Mas receptors) to angiotensin peptides in cell types (e.g., pancreatic islet cells, adipocytes, macrophages) that mediate specific disorders of the metabolic syndrome. An activated local RAS in these cell types may contribute to dysregulated function by promoting oxidative stress, apoptosis, and inflammation. This review will discuss data demonstrating the regulation of components of the RAS by cholesterol and its metabolites, glucose, and/or insulin in cell types implicated in disorders of the metabolic syndrome. In addition, we discuss data supporting a role for an activated local RAS in dyslipidemias and glucose intolerance/insulin resistance and the development of hypertension in the metabolic syndrome. Identification of an activated RAS as a common thread contributing to several disorders of the metabolic syndrome makes the use of angiotensin receptor blockers and ACE inhibitors an intriguing and novel option for multisymptom treatment.
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Affiliation(s)
- Kelly Putnam
- Graduate Center for Nutritional Sciences, University of Kentucky, Lexington, 40536-0200, USA
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Jiang D, Jia Y, Zhou Y, Jarrett HW. Two-dimensional southwestern blotting and characterization of transcription factors on-blot. J Proteome Res 2009; 8:3693-701. [PMID: 19388704 DOI: 10.1021/pr900214p] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Two-dimensional Southwestern blotting (2D-SW) described here combines several steps. Proteins are separated by two-dimensional gel electrophoresis and transferred to nitrocellulose (NC) or polyvinylidene fluoride (PVDF) membrane. The blotted proteins are then partially renatured and probed with a specific radiolabeled oligonucleotide for Southwestern blotting (SW) analysis. The detected proteins are then processed by on-blot digestion and identified by LC-MS/MS analysis. A transcription factor, bound by a specific radiolabeled element, is thus characterized without aligning with protein spots on a gel. In this study, we systematically optimize conditions for 2D-SW and on-blot digestion. By quantifying the SW signal using a scintillation counter, the optimal conditions for SW were determined to be PVDF membrane, 0.5% PVP40 for membrane blocking, serial dilution of guanidine HCl for denaturing and renaturing proteins on the blot, and an SDS stripping buffer to remove radiation from the blot. By the quantification of the peptide yields using nano-ESI-MS analysis, the optimized conditions for on-blot digestions were found to be 0.5% Zwittergent 3-16 and 30% acetonitrile in trypsin digestion buffer. With the use of the optimized 2D-SW technique and on-blot digestion combined with HPLC-nano-ESI-MS/MS, a GFP-C/EBP model protein was successfully characterized from a bacterial extract, and native C/EBP beta was identified from 100 microg of HEK293 nuclear extract without any previous purification.
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Affiliation(s)
- Daifeng Jiang
- Department of Chemistry, University of Texas San Antonio, San Antonio, Texas 78249, USA
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Tran S, Chen YW, Chenier I, Chan JSD, Quaggin S, Hébert MJ, Ingelfinger JR, Zhang SL. Maternal diabetes modulates renal morphogenesis in offspring. J Am Soc Nephrol 2008; 19:943-52. [PMID: 18305124 DOI: 10.1681/asn.2007080864] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Maternal diabetes leads to an adverse in utero environment, but whether maternal diabetes impairs nephrogenesis is unknown. Diabetes was induced with streptozotocin in pregnant Hoxb7-green fluorescence protein mice at embryonic day 13, and the offspring were examined at several time points after birth. Compared with offspring of nondiabetic controls, offspring of diabetic mice had lower body weight, body size, kidney weight, and nephron number. The observed renal dysmorphogenesis may be the result of increased apoptosis, because immunohistochemical analysis revealed significantly more apoptotic podocytes as well as increased active caspase-3 immunostaining in the renal tubules compared with control mice. Regarding potential mediators of these differences, offspring of diabetic mice had increased expression of intrarenal angiotensinogen and renin mRNA, upregulation of NF-kappaB isoforms p50 and p65, and activation of the NF-kappaB pathway. In conclusion, maternal diabetes impairs nephrogenesis, possibly via enhanced intrarenal activation of the renin-angiotensin system and NF-kappaB signaling.
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Affiliation(s)
- Stella Tran
- University of Montreal, Centre Hospitalier de l'Université de Montréal-Hôtel-Dieu, Research Centre, Montreal, Quebec, Canada
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Sarafidis PA, Bakris GL. The antinatriuretic effect of insulin: an unappreciated mechanism for hypertension associated with insulin resistance? Am J Nephrol 2007; 27:44-54. [PMID: 17245074 DOI: 10.1159/000098955] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2006] [Accepted: 12/13/2006] [Indexed: 12/24/2022]
Abstract
Insulin resistance is proposed to be causally related to the metabolic syndrome disorders, but a direct cause-and-effect relationship between insulin resistance and hypertension was not originally obvious. Previous data suggested that insulin promotes sodium retention from the kidney, and thus research efforts focused on this action among several other possible pathways connecting insulin resistance and hyperinsulinemia with hypertension. A review of numerous studies provides evidence that this antinatriuretic effect of insulin is preserved in states of metabolic insulin resistance, representing a major mechanism for blood pressure elevation. More recent experimental and clinical studies have added data about the exact tubular sites of this insulin action, its relation with the respective insulin action on potassium handling, its possible role in the development of salt sensitivity in essential hypertension, as well as the involvement of oxidant stress in these associations. This review summarizes the current state of knowledge in this area and attempts to highlight an important but rather overlooked pathway for hypertension development in the metabolic syndrome, the influence of high insulin levels leading to volume expansion.
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Affiliation(s)
- Pantelis A Sarafidis
- First Department of Medicine, AHEPA University Hospital, Aristotle University, Thessaloniki, Greece.
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Wei CC, Zhang SL, Chen YW, Guo DF, Ingelfinger JR, Bomsztyk K, Chan JSD. Heterogeneous Nuclear Ribonucleoprotein K Modulates Angiotensinogen Gene Expression in Kidney Cells. J Biol Chem 2006; 281:25344-55. [PMID: 16837467 DOI: 10.1074/jbc.m601945200] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The present studies aimed to identify the 70-kDa nuclear protein that binds to an insulin-responsive element in the rat angiotensinogen gene promoter and to define its action on angiotensinogen gene expression. Nuclear proteins were isolated from rat kidney proximal tubular cells and subjected to two-dimensional electrophoresis. The 70-kDa nuclear protein was detected by Southwestern blotting and subsequently identified by mass spectrometry, which revealed that it was identical to 65-kDa heterogeneous nuclear ribonucleoprotein K (hnRNP K). hnRNP K bound to the insulin-responsive element of the rat angiotensinogen gene was revealed by a gel mobility shift assay and chromatin immunoprecipitation assay. hnRNP K inhibited angiotensinogen mRNA expression and promoter activity. In contrast, hnRNP K down-expression by small interference RNA enhanced angiotensinogen mRNA expression. Moreover, hnRNP K interacted with hnRNP F in pulldown and co-immunoprecipitation assays. Co-transfection of hnRNP K and hnRNP F further suppressed angiotensinogen mRNA expression. Finally, in vitro and in vivo studies demonstrated that high glucose increases and insulin inhibits hnRNP K expression in rat kidney proximal tubular cells. In conclusion, our experiments revealed that hnRNP K is a nuclear protein that binds to the insulin-responsive element of the rat angiotensinogen gene promoter and modulates angiotensinogen gene transcription in the kidney.
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Affiliation(s)
- Chih-Chang Wei
- Centre de Recherche, Centre Hospitalier de l'Université de Montréal-Hôtel-Dieu, Montreal, Quebec H2W 1T8, Canada
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20
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Sarafidis PA, Ruilope LM. Insulin resistance, hyperinsulinemia, and renal injury: mechanisms and implications. Am J Nephrol 2006; 26:232-44. [PMID: 16733348 DOI: 10.1159/000093632] [Citation(s) in RCA: 182] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2006] [Accepted: 04/24/2006] [Indexed: 12/11/2022]
Abstract
Most of the basic components of the metabolic syndrome, namely type 2 diabetes mellitus, hypertension, obesity, or low high-density lipoprotein cholesterol levels, apart from being major risk factors for cardiovascular disease have been also associated with an increased risk of chronic kidney disease. However, several epidemiologic studies conducted over the past years suggest that the central component of the syndrome, insulin resistance, as well as compensatory hyperinsulinemia are independently associated with an increased prevalence of chronic kidney disease. In addition, background studies support the existence of several pathways linking insulin resistance and hyperinsulinemia with kidney damage. Insulin per se promotes the proliferation of renal cells and stimulates the production of other important growth factors such as insulin-like growth factor-1 and transforming growth factor beta. Insulin also upregulates the expression of angiotensin II type 1 receptor in mesangial cells, thus enhancing the deleterious effects of angiotensin II in the kidney, and stimulates production and renal action of endothelin-1. Moreover, insulin resistance and hyperinsulinemia are associated with decreased endothelial production of nitric oxide and increased oxidative stress which have been also implicated in the progression of diabetic nephropathy. This review analyzes the above and other potential mechanisms, through which insulin resistance and hyperinsulinemia can contribute to renal injury.
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Affiliation(s)
- Pantelis A Sarafidis
- Hypertension/Clinical Research Center, Department of Preventive Medicine, Rush University Medical Center, Chicago, IL 60612, USA.
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Hsieh TJ, Fustier P, Zhang SL, Filep JG, Tang SS, Ingelfinger JR, Fantus IG, Hamet P, Chan JSD. High glucose stimulates angiotensinogen gene expression and cell hypertrophy via activation of the hexosamine biosynthesis pathway in rat kidney proximal tubular cells. Endocrinology 2003; 144:4338-49. [PMID: 12960040 DOI: 10.1210/en.2003-0220] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The present study investigated whether activation of the hexosamine biosynthesis pathway might mediate at least in part the high glucose effect on angiotensinogen (ANG) gene expression and immortalized renal proximal tubular cell (IRPTC) hypertrophy. IRPTC were cultured in monolayer. ANG, renin, and beta-actin mRNA expression were determined by specific RT-PCR assays. Phosphorylation of p38 MAPK, activating transcription factor-2 (ATF-2), and cAMP-responsive element-binding protein (CREB) was determined by Western blot analysis. Cell hypertrophy was assessed by flow cytometry, intracellular p27kip1 protein levels, and [3H]leucine incorporation into proteins. Glucosamine stimulated ANG and renin mRNA expression and enhanced p38 MAPK, ATF-2, and CREB phosphorylation in normal glucose (5 mm) medium. Azaserine and 6-diazo-5-oxo-l-norleucine (inhibitors of glutamine: fructose-6-phosphate amino transferase enzyme) blocked the stimulatory effect of high glucose, but not that of glucosamine, on ANG gene expression in IRPTCs. SB 203580 (a specific p38 MAPK inhibitor) attenuated glucosamine action on ANG gene expression as well as p38 MAPK and ATF-2 phosphorylation, but not that of CREB. GF 109203X and calphostin C (inhibitors of protein kinase C) blocked the effect of glucosamine on ANG gene expression and CREB phosphorylation, but had no impact on p38 MAPK and ATF-2 phosphorylation. Finally, both glucosamine and high glucose induced IRPTC hypertrophy. The hypertrophic effect of glucosamine was blocked in the presence of GF 109203X, but not azaserine and SB 203580. In contrast, the hypertrophic effect of high glucose was blocked in the presence of azaserine and GF 109203X, but not SB203580. Our studies demonstrate that the stimulatory effect of high glucose on ANG gene expression and IRPTC hypertrophy may be mediated at least in part via activation of hexosamine biosynthesis pathway signaling.
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Affiliation(s)
- Tusty-Jiuan Hsieh
- Université de Montréal Centre Hospitalier de l'Université de Montréal-Hôtel Dieu, Centre de Recherche Pavillon Masson, Montréal, Québec, Canada H2W 1T8
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Zhang SL, Chen X, Wei CC, Filep JG, Tang SS, Ingelfinger JR, Chan JSD. Insulin inhibits dexamethasone effect on angiotensinogen gene expression and induction of hypertrophy in rat kidney proximal tubular cells in high glucose. Endocrinology 2002; 143:4627-35. [PMID: 12446590 DOI: 10.1210/en.2002-220408] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The present studies investigated whether insulin inhibits the stimulatory effect of dexamethasone (DEX) on angiotensinogen (ANG) gene expression and induction of hypertrophy in rat immortalized renal proximal tubular cells (IRPTCs) in a high-glucose milieu. Rat IRPTCs were cultured in monolayer. ANG and ANG mRNA expression in IRPTCs were quantified by a specific RIA for rat ANG and by RT-PCR assay, respectively. A fusion gene containing the full length of the 5'-flanking region of the rat ANG gene linked to a chloramphenicol acetyl transferase reporter gene was introduced into IRPTCs. The level of fusion gene expression was determined by cellular chloramphenicol acetyl transferase enzymatic activity. Cellular hypertrophy was assessed by flow cytometry, cellular p27(Kip1) protein expression, and protein assay. Our results showed that high glucose (i.e. 25 mM) and DEX (10(-7) M) additively stimulated ANG gene expression and induced IRPTC hypertrophy. Insulin inhibited the effect of high glucose and DEX on these parameters. The inhibitory effect of insulin was reversed by PD 98059 (a MAPK inhibitor) but not by wortmannin (a phosphatidylinositol-3-kinase inhibitor). These results demonstrate that insulin is effective in blocking the stimulatory action of high glucose and DEX on ANG gene expression and induction of IRPTC hypertrophy, suggesting its important role in preventing local intrarenal renin-angiotensin system activation and renal proximal tubular cell hypertrophy induced by hyperglycemia and glucocorticoids in vivo.
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Affiliation(s)
- Shao-Ling Zhang
- Université de Montréal, Centre Hospitalier de l'Université de Montréal, Hôtel-Dieu Hospital, Research Center, Montréal, Québec H2W 1T8 Canada
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