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Azouz AA, Tohamy MA, Ali FEM, Mahmoud HM. Enhanced eNOS/nitric oxide production by nebivolol interferes with TGF-β1/Smad3 signaling and collagen I deposition in the kidney after prolonged tacrolimus administration. Life Sci 2024; 355:122995. [PMID: 39159720 DOI: 10.1016/j.lfs.2024.122995] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2024] [Revised: 08/13/2024] [Accepted: 08/15/2024] [Indexed: 08/21/2024]
Abstract
AIMS Tacrolimus is an effective immunosuppressant commonly used post-transplantation and in certain autoimmune diseases. However, its long-term administration is associated with renal fibrosis through transforming growth factor-beta/suppressor of mother against decapentaplegic (TGF-β/Smad) signaling that could be partly attributed to endothelial dysfunction alongside decreased nitric oxide (NO) release. Our study aimed to investigate the prospective renal anti-fibrotic effect of enhanced NO production by nebivolol against tacrolimus-stimulated TGF-β1/Smad3 signaling. MATERIALS AND METHODS To illustrate the proposed mechanism of nebivolol, Nω-nitro-L-arginine methyl ester (L-NAME); nitric oxide synthase inhibitor; was co-administered with nebivolol. Rats were treated for 30 days as control, tacrolimus, tacrolimus/nebivolol, tacrolimus/L-NAME, and tacrolimus/nebivolol/L-NAME groups. KEY FINDINGS Our results revealed that renal NO content was reduced in tacrolimus-treated rats, while treatment with tacrolimus/nebivolol enhanced NO content via up-regulated endothelial nitric oxide synthase (eNOS), but down-regulated inducible nitric oxide synthase (iNOS) expression. That participated in the inhibition of TGF-β1/Smad3 signaling induced by tacrolimus, where the addition of L-NAME abolished the defensive effects of nebivolol. Subsequently, the deposition of collagen I and alpha-smooth muscle actin (α-SMA) was retarded by nebivolol, emphasized by reduced Masson's trichrome staining. In accordance, there was a strong negative correlation between eNOS and both TGF-β1 and collagen I protein expression. The protective effects of nebivolol were further confirmed by the improvement in kidney function biomarkers and histological features. SIGNIFICANCE It can be suggested that treatment with nebivolol along with tacrolimus could effectively suppress renal TGF-β1/Smad3 fibrotic signaling via the enhancement of endothelial NO production, thus curbing renal fibrosis development.
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Affiliation(s)
- Amany A Azouz
- Department of Pharmacology & Toxicology, Faculty of Pharmacy, Beni-Suef University, Beni-Suef 62514, Egypt.
| | - Mohamed A Tohamy
- Department of Biochemistry, Faculty of Pharmacy, Beni-Suef University, Beni-Suef 62514, Egypt
| | - Fares E M Ali
- Department of Pharmacology & Toxicology, Faculty of Pharmacy, Al-Azhar University, Assiut Branch, Assiut 71524, Egypt; Michael Sayegh, Faculty of Pharmacy, Aqaba University of Technology, Aqaba 77110, Jordan
| | - Heba M Mahmoud
- Department of Pharmacology & Toxicology, Faculty of Pharmacy, Beni-Suef University, Beni-Suef 62514, Egypt
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Zeng XC, Tian Y, Liang XM, Wu XB, Yao CM, Chen XM. SGLT2i relieve proteinuria in diabetic nephropathy patients potentially by inhibiting renal oxidative stress rather than through AGEs pathway. Diabetol Metab Syndr 2024; 16:46. [PMID: 38365853 PMCID: PMC10870536 DOI: 10.1186/s13098-024-01280-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2023] [Accepted: 01/31/2024] [Indexed: 02/18/2024] Open
Abstract
AIMS To estimate the effects of the sodium-glucose cotransporter 2 inhibitor (SGLT2i) on proteinuria and oxidative stress expression in type 2 diabetes patients. MATERIALS AND METHODS 68 patients with type 2 diabetes mellitus (T2DM) were divided into three groups according urinary albumin-to-creatinine ratio (UACR), including T2DM with non-albuminuria group (UACR < 30 mg/g), T2DM with microalbuminuria group (30 ≤ UACR ≤ 300 mg/g), T2DM with macroalbuminuria group (UACR>300 mg/g). They all received SGLT2 inhibitors (SGLT2i) treatment for 12 weeks. The expression of advanced glycation end products (AGEs) in plasma and 8-hydroxy-2-deoxyguanosine (8-OHdG) in urine were measured as indications of oxidative stress. The 24-hour urine samples were collected to measure the concentration of proteinuria and 8-OHdG before and after 12 weeks SGLT2i treatment. Plasma renin activity (PRA), angiotensin II (Ang II) and Aldosterone (ALD) were measured to evaluate renin angiotensin aldosterone system (RASS) levels. RESULTS After 12 weeks SGLT2 inhibitors treatment, the median values of 24-hour proteinuria decreased in macroalbuminuria compared to baseline (970 vs. 821 mg/d, P = 0.006). The median values of AGEs and 8-OHdG decreased in microalbuminuria and macroalbuminuria groups when compared to baseline, AGEs (777 vs. 136 ug/ml, P = 0.003) and (755 vs. 210 ug/ml, P = 0.001), 8-OHdG (8.00 vs. 1.88 ng/ml, P = 0.001) and (11.18 vs. 1.90 ng/ml, P < 0.001), respectively. Partial correlations showed that 8-OHdG were relevant to the baseline 24-h proteinuria (r = 0.389, p = 0.001), the reduction of OHdG (Δ8-OHdG) were positively correlated with the decrease of 24-h proteinuria (Δ24-h proteinuria) after 12 weeks of SGLT2i treatment (r = 0.283, P = 0.031). There was no significant correlation between 24-h proteinuria and AGEs in baseline (r = -0.059, p = 0.640) as well as between ΔAGEs and Δ24-h proteinuria (r = 0.022, p = 0.872) after12 weeks of SGLT2i treatment in T2DM patients. CONCLUSIONS SGLT2i may reduce proteinuria in diabetic nephropathy patients, potentially by inhibiting renal oxidative stress, but not through the AGEs pathway and does not induce RAAS activation. TRIAL REGISTRATION This clinical trial was registered on 15/10/2019, in ClinicalTrials.gov, and the registry number is NCT04127084.
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Affiliation(s)
- Xiao-Chun Zeng
- Department of Endocrinology and Metabolism, School of Medicine, Zhongshan Hospital of Xiamen University, Xiamen University, 201-209 Hubin South Road, 361004, Xiamen, P.R. China
- The School of Clinical Medicine, Fujian Medical University, 350004, Fuzhou, P.R. China
| | - Yuan Tian
- Department of Endocrinology and Metabolism, School of Medicine, Zhongshan Hospital of Xiamen University, Xiamen University, 201-209 Hubin South Road, 361004, Xiamen, P.R. China
| | - Xian-Ming Liang
- Center of Clinical Laboratory, School of Medicine, Zhongshan Hospital of Xiamen University, Xiamen University, 201-209 Hubin South Road, 361004, Xiamen, P. R. China
| | - Xiao-Bin Wu
- Department of Endocrinology and Metabolism, School of Medicine, Zhongshan Hospital of Xiamen University, Xiamen University, 201-209 Hubin South Road, 361004, Xiamen, P.R. China
| | - Chun-Meng Yao
- Department of Nephrology, School of Medicine, Zhongshan Hospital of Xiamen University, Xiamen University, 201-209 Hubin South Road, 361004, Xiamen, P. R. China
| | - Xiao-Min Chen
- Department of Endocrinology and Metabolism, School of Medicine, Zhongshan Hospital of Xiamen University, Xiamen University, 201-209 Hubin South Road, 361004, Xiamen, P.R. China.
- The School of Clinical Medicine, Fujian Medical University, 350004, Fuzhou, P.R. China.
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Araújo Encinas JF, Foncesca Peiró CH, Perez MM, Santos Raimundo JR, de Gois KC, Peres MC, Draghi PF, Costas Arcia CG, Simões DP, Murad N, da Costa Aguiar Alves B, Affonso Fonseca FL, Luciano da Veiga G. Does nebivolol have renoprotective action in patients with chronic kidney disease conditions? An integrative review. Eur J Pharmacol 2021; 905:174180. [PMID: 34015319 DOI: 10.1016/j.ejphar.2021.174180] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Revised: 04/28/2021] [Accepted: 05/12/2021] [Indexed: 12/16/2022]
Abstract
Systemic arterial hypertension (SAH) is a chronic disease of multifactorial origin and one of the main risk factors for major adverse cardiovascular events (MACE), which are the leading causes of morbidity and mortality worldwide. The pharmacological treatment of SAH involves five main classes of drugs, and Nebivolol (NEB) is one of those drugs, belonging to the class of third generation β1-adrenoceptors selective blockers. NEB is composed of a racemic mixture of two enantiomers: d-nebivolol, which exerts antagonist effects on β1-adrenoceptors, and l-nebivolol, a vascular β3 receptor agonist. There are several studies that report different actions of NEB, not only for the treatment of SAH, but also as an antioxidant agent or even as a protector of renal damage. The aim of this systematic review was to investigate the available evidence regarding the effects of NEB on kidney diseases, evaluating its possible renoprotective action.
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Affiliation(s)
| | | | - Matheus Moreira Perez
- Laboratório de Análises Clínicas - Centro Universitário Saúde ABC/FMABC, Santo André, Brazil
| | | | | | - Marina Cristina Peres
- Laboratório de Análises Clínicas - Centro Universitário Saúde ABC/FMABC, Santo André, Brazil
| | | | | | - Diogo Pimenta Simões
- Laboratório de Análises Clínicas - Centro Universitário Saúde ABC/FMABC, Santo André, Brazil; Universidade Municipal de São Caetano Do Sul/USCS, São Caetano Do Sul, Brazil
| | - Neif Murad
- Setor de Cardiologia - Centro Universitário Saúde ABC/FMABC, Santo André, Brazil
| | | | - Fernando Luiz Affonso Fonseca
- Laboratório de Análises Clínicas - Centro Universitário Saúde ABC/FMABC, Santo André, Brazil; Departamento de Ciências Farmacêuticas, Universidade Federal de São Paulo, Campus Diadema, Diadema, Brazil
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Basualto-Alarcón C, Llanos P, García-Rivas G, Troncoso MF, Lagos D, Barrientos G, Estrada M. Classic and Novel Sex Hormone Binding Globulin Effects on the Cardiovascular System in Men. Int J Endocrinol 2021; 2021:5527973. [PMID: 34335746 PMCID: PMC8318754 DOI: 10.1155/2021/5527973] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 06/28/2021] [Accepted: 07/05/2021] [Indexed: 12/16/2022] Open
Abstract
In men, 70% of circulating testosterone binds with high affinity to plasma sex hormone binding globulin (SHBG), which determines its bioavailability in their target cells. In recent years, a growing body of evidence has shown that circulating SHBG not only is a passive carrier for steroid hormones but also actively regulates testosterone signaling through putative plasma membrane receptors and by local expression of androgen-binding proteins apparently to reach local elevated testosterone concentrations in specific androgen target tissues. Circulating SHBG levels are influenced by metabolic and hormonal factors, and they are reduced in obesity and insulin resistance, suggesting that SHBG may have a broader clinical utility in assessing the risk for cardiovascular diseases. Importantly, plasma SHBG levels are strongly correlated with testosterone concentrations, and in men, low testosterone levels are associated with an adverse cardiometabolic profile. Although obesity and insulin resistance are associated with an increased incidence of cardiovascular disease, whether they lead to abnormal expression of circulating SHBG or its interaction with androgen signaling remains to be elucidated. SHBG is produced mainly in the liver, but it can also be expressed in several tissues including the brain, fat tissue, and myocardium. Expression of SHBG is controlled by peroxisome proliferator-activated receptor γ (PPARγ) and AMP-activated protein kinase (AMPK). AMPK/PPAR interaction is critical to regulate hepatocyte nuclear factor-4 (HNF4), a prerequisite for SHBG upregulation. In cardiomyocytes, testosterone activates AMPK and PPARs. Therefore, the description of local expression of cardiac SHBG and its circulating levels may shed new light to explain physiological and adverse cardiometabolic roles of androgens in different tissues. According to emerging clinical evidence, here, we will discuss the potential mechanisms with cardioprotective effects and SHBG levels to be used as an early metabolic and cardiovascular biomarker in men.
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Affiliation(s)
- Carla Basualto-Alarcón
- Departamento de Ciencias de la Salud, Universidad de Aysén, Coyhaique 5951537, Chile
- Departamento de Anatomía y Medicina Legal, Facultad de Medicina, Universidad de Chile, Santiago 8389100, Chile
| | - Paola Llanos
- Institute for Research in Dental Sciences, Faculty of Dentistry, Universidad de Chile, Santiago, Chile
| | - Gerardo García-Rivas
- Tecnológico de Monterrey, Hospital Zambrano Hellion, TecSalud, Centro de Medicina Funcional, San Pedro Garza García, Nuevo León 66278, Mexico
| | - Mayarling Francisca Troncoso
- Programa de Fisiología y Biofísica, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago 8389100, Chile
| | - Daniel Lagos
- Programa de Fisiología y Biofísica, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago 8389100, Chile
| | - Genaro Barrientos
- Programa de Fisiología y Biofísica, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago 8389100, Chile
| | - Manuel Estrada
- Programa de Fisiología y Biofísica, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago 8389100, Chile
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Nephroprotective effects of nebivolol in 2K1C rats through regulation of the kidney ROS-ADMA-NO pathway. Pharmacol Rep 2018; 70:917-929. [DOI: 10.1016/j.pharep.2018.04.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Revised: 03/25/2018] [Accepted: 04/12/2018] [Indexed: 01/20/2023]
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Sasser JM, Moningka NC, Tsarova T, Baylis C. Nebivolol does not protect against 5/6 ablation/infarction induced chronic kidney disease in rats - comparison with angiotensin II receptor blockade. Life Sci 2012; 91:54-63. [PMID: 22727796 DOI: 10.1016/j.lfs.2012.06.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2011] [Revised: 05/24/2012] [Accepted: 05/31/2012] [Indexed: 01/31/2023]
Abstract
AIMS Nitric oxide (NO) deficiency contributes to chronic kidney disease progression. Nebivolol, a beta adrenergic receptor antagonist, may enhance endogenous NO. Here, we investigated whether Nebivolol attenuates hypertension and renal injury after 5/6 ablation/infarction (A/I). Efficacy was compared to the AT1 receptor antagonist Olmesartan. MAIN METHODS Kidney disease and hypertension were induced by right kidney ablation and ~2/3 infarction of the left kidney. Rats were treated orally with vehicle (placebo), Nebivolol (5mg/kg b.i.d.), or Olmesartan (2.5mg/kg/day) for 6 weeks after A/I. KEY FINDINGS With placebo, glomerular sclerosis and tubulointersititial fibrosis developed with increased blood pressure and proteinuria, and a fall in NO(x) excretion. Olmesartan prevented these changes, but Nebivolol had no effect on these measures but lowered heart rate. Neither treatment reduced systemic oxidative stress (urinary hydrogen peroxide and TBARS). Compared to controls, renal cortex abundance of nNOSα decreased and nNOSβ increased in rats after 5/6 A/I, with no changes in eNOS. Neither treatment restored nNOSα; however, both reduced nNOSβ. Activity of DDAH was decreased by 5/6 A/I but restored by both treatments despite no increase in DDAH protein abundance. Kidney cortex abundance of manganese SOD fell after 5/6 A/I and was restored by treatment with Olmesartan but not Nebivolol. Extracellular and copper/zinc SOD abundances were not changed. SIGNIFICANCE In conclusion, Nebivolol showed no benefit after 6 weeks in rapidly progressing, ANG II-dependent 5/6 A/I model of chronic kidney disease. This contrasts to the protection seen with 6 month treatment of Nebivolol in the slowly progressing 5/6 ablation model.
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Affiliation(s)
- Jennifer M Sasser
- Departments of Physiology and Functional Genomics, University of Florida, Gainesville, FL, USA.
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Hayden MR, Habibi J, Joginpally T, Karuparthi PR, Sowers JR. Ultrastructure Study of Transgenic Ren2 Rat Aorta - Part 1: Endothelium and Intima. Cardiorenal Med 2012; 2:66-82. [PMID: 22493605 PMCID: PMC3318941 DOI: 10.1159/000335565] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2011] [Accepted: 12/05/2011] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND: The renin-angiotensin-aldosterone system plays an important role in the development and progression of hypertension and accelerated atherosclerosis (atheroscleropathy) associated with the cardiorenal metabolic syndrome and type 2 diabetes mellitus. Additionally, the renin-angiotensin-aldosterone system plays an important role in vascular-endothelial-intimal cellular and extracellular remodeling. METHODS: Thoracic aortas of young male transgenic heterozygous (mRen2)27 (Ren2) rats were utilized for this ultrastructural study. This lean model of hypertension, insulin resistance and oxidative stress harbors the mouse renin gene with increased local tissue (aortic) levels of angiotensin II and angiotensin type 1 receptors and elevated plasma aldosterone levels. RESULTS: The ultrastructural observations included marked endothelial cell retraction, separation, terminal nuclear lifting, adjacent duplication, apoptosis and a suggestion of endothelial progenitor cell attachment. The endothelium demonstrated increased caveolae, microparticles, depletion of Weibel-Palade bodies, loss of cell-cell and basal adhesion hemidesmosome-like structures, platelet adhesion and genesis of subendothelial neointima. CONCLUSION: These observational ultrastructural studies of the transgenic Ren2 vasculature provide an in-depth evaluation of early abnormal remodeling changes within conduit-elastic arteries under conditions of increased local levels of angiotensin II, oxidative stress, insulin resistance and hypertension.
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Affiliation(s)
- Melvin R. Hayden
- Department of Internal Medicine, University of Missouri-Columbia School of Medicine, Columbia, Mo., USA
- Department of Endocrinology Diabetes and Metabolism, University of Missouri-Columbia School of Medicine, Columbia, Mo., USA
- Diabetes and Cardiovascular Disease Center, University of Missouri-Columbia School of Medicine, Columbia, Mo., USA
| | - Javad Habibi
- Department of Internal Medicine, University of Missouri-Columbia School of Medicine, Columbia, Mo., USA
- Department of Endocrinology Diabetes and Metabolism, University of Missouri-Columbia School of Medicine, Columbia, Mo., USA
- Diabetes and Cardiovascular Disease Center, University of Missouri-Columbia School of Medicine, Columbia, Mo., USA
- Harry S. Truman VA Medical Center, Columbia, Mo., USA
| | - Tejaswini Joginpally
- Diabetes and Cardiovascular Disease Center, University of Missouri-Columbia School of Medicine, Columbia, Mo., USA
| | - Poorna R. Karuparthi
- Department of Internal Medicine, University of Missouri-Columbia School of Medicine, Columbia, Mo., USA
- Department of Cardiovascular Disease, University of Missouri-Columbia School of Medicine, Columbia, Mo., USA
| | - James R. Sowers
- Department of Internal Medicine, University of Missouri-Columbia School of Medicine, Columbia, Mo., USA
- Department of Endocrinology Diabetes and Metabolism, University of Missouri-Columbia School of Medicine, Columbia, Mo., USA
- Department of Medical Physiology and Pharmacology, University of Missouri-Columbia School of Medicine, Columbia, Mo., USA
- Diabetes and Cardiovascular Disease Center, University of Missouri-Columbia School of Medicine, Columbia, Mo., USA
- Harry S. Truman VA Medical Center, Columbia, Mo., USA
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Hayden MR, Joginpally T, Salam M, Sowers JR. Childhood and adolescent obesity in cardiorenal metabolic syndrome and Type 2 diabetes: a clinical vignette and ultrastructure study. ACTA ACUST UNITED AC 2011. [DOI: 10.2217/dmt.11.50] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Whaley-Connell A, Habibi J, Panfili Z, Hayden MR, Bagree S, Nistala R, Hyder S, Krueger B, Demarco V, Pulakat L, Ferrario CM, Parrish A, Sowers JR. Angiotensin II activation of mTOR results in tubulointerstitial fibrosis through loss of N-cadherin. Am J Nephrol 2011; 34:115-25. [PMID: 21720156 DOI: 10.1159/000329327] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2011] [Accepted: 05/10/2011] [Indexed: 12/11/2022]
Abstract
BACKGROUND/AIMS Angiotensin (Ang) II contributes to tubulointerstitial fibrosis. Recent data highlight mammalian target of rapamycin (mTOR)/S6 kinase 1 (S6K1) signaling in tubulointerstitial fibrosis; however, the mechanisms remain unclear. Thereby, we investigated the role of Ang II on mTOR/S6K1-dependent proximal tubule (PT) injury, remodeling, and fibrosis. METHODS We utilized young transgenic Ren2 rats (R2-T) and Sprague-Dawley rats (SD-T) treated with the Ang type 1 receptor (AT(1)R) blocker telmisartan (2 mg · kg(-1) · day(-1)) or vehicle (R2-C; SD-C) for 3 weeks to examine PT structure and function. RESULTS Ren2 rats displayed increased systolic blood pressure, proteinuria and increased PT oxidant stress and remodeling. There were parallel increases in kidney injury molecule-1 and reductions in neprilysin and megalin with associated ultrastructural findings of decreased clathrin-coated pits, endosomes, and vacuoles. Ren2 rats displayed increased Serine(2448) phosphorylation of mTOR and downstream S6K1, in concert with ultrastructural basement membrane thickening, tubulointerstitial fibrosis and loss of the adhesion molecule N-cadherin. Telmisartan treatment attenuated proteinuria as well as the biochemical and tubulointerstitial structural abnormalities seen in the Ren2 rats. CONCLUSIONS Our observations suggest that Ang II activation of the AT(1)R contributes to PT brush border injury and remodeling, in part, due to enhanced mTOR/S6K1 signaling which promotes tubulointerstitial fibrosis through loss of N-cadherin.
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Affiliation(s)
- Adam Whaley-Connell
- Harry S. Truman VA Medical Center, and the University of Missouri-Columbia School of Medicine, USA. whaleyconnella @ health.missouri.edu
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Hayden MR, Sowers JR. Childhood-Adolescent Obesity in the Cardiorenal Syndrome: Lessons from Animal Models. Cardiorenal Med 2011; 1:75-86. [PMID: 22294984 DOI: 10.1159/000327022] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2011] [Accepted: 03/02/2011] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND/AIMS Childhood-adolescent overweight and obesity have grown to pandemic proportions during the past decade. The onset of obesity in younger adults will likely be manifested as earlier onset of myocardial and renal end-organ disease in younger adults. For the first time, it is estimated that the current generation may not live to be as old as their parents. Thus, it is important to develop animal models of childhood obesity to understand fundamental pathological organ changes. METHODS In this regard, we utilize transmission electron microscopy evaluation to evaluate early remodeling changes of two adolescent rodent obesity models: the Zucker obese (fa/fa) rat and the db/db mouse models of obesity. We have concentrated on the initial ultrastructural remodeling (obese adipose tissue, skeletal muscle, and islet remodeling) and the associated changes in target end organs (including the myocardium and kidney) in young rodent models of obesity and insulin resistance, collectively manifesting as the cardiorenal metabolic syndrome (CRS). RESULTS Briefly, tissues revealed the following ultrastructural remodeling abnormalities: inflammation, hypertrophy, and early fibrosis in adipose tissue; loss of mitochondria in skeletal muscles, hyperplasia, fibrosis, and depletion of insulin-secretory granules in pancreatic islets; increased intramyocardial lipid accumulation, fibrosis, and mitochondrial deposition in the myocardium, and obesity-related glomerulopathy and tubulopathy in the kidney. CONCLUSION Based on the current knowledge and ultrastructural observations of organ pathology, we propose mechanisms whereby obesity appears to be the driving force behind the development of the CRS.
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Megalin/LRP2 expression is induced by peroxisome proliferator-activated receptor -alpha and -gamma: implications for PPARs' roles in renal function. PLoS One 2011; 6:e16794. [PMID: 21311715 PMCID: PMC3032793 DOI: 10.1371/journal.pone.0016794] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2010] [Accepted: 01/12/2011] [Indexed: 12/13/2022] Open
Abstract
Background Megalin is a large endocytic receptor with relevant functions during development and adult life. It is expressed at the apical surface of several epithelial cell types, including proximal tubule cells (PTCs) in the kidney, where it internalizes apolipoproteins, vitamins and hormones with their corresponding carrier proteins and signaling molecules. Despite the important physiological roles of megalin little is known about the regulation of its expression. By analyzing the human megalin promoter, we found three response elements for the peroxisomal proliferator-activated receptor (PPAR). The objective of this study was to test whether megalin expression is regulated by the PPARs. Methodology/Principal Findings Treatment of epithelial cell lines with PPARα or PPARγ ligands increased megalin mRNA and protein expression. The stimulation of megalin mRNA expression was blocked by the addition of specific PPARα or PPARγ antagonists. Furthermore, PPAR bound to three PPAR response elements located in the megalin promoter, as shown by EMSA, and PPARα and its agonist activated a luciferase construct containing a portion of the megalin promoter and the first response element. Accordingly, the activation of PPARα and PPARγ enhanced megalin expression in mouse kidney. As previously observed, high concentrations of bovine serum albumin (BSA) decreased megalin in PTCs in vitro; however, PTCs pretreated with PPARα and PPARγ agonists avoided this BSA-mediated reduction of megalin expression. Finally, we found that megalin expression was significantly inhibited in the PTCs of rats that were injected with BSA to induce tubulointerstitial damage and proteinuria. Treatment of these rats with PPARγ agonists counteracted the reduction in megalin expression and the proteinuria induced by BSA. Conclusions PPARα/γ and their agonists positively control megalin expression. This regulation could have an important impact on several megalin-mediated physiological processes and on pathophysiologies such as chronic kidney disease associated with diabetes and hypertension, in which megalin expression is impaired.
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Habibi J, Hayden MR, Sowers JR, Pulakat L, Tilmon RD, Manrique C, Lastra G, Demarco VG, Whaley-Connell A. Nebivolol attenuates redox-sensitive glomerular and tubular mediated proteinuria in obese rats. Endocrinology 2011; 152:659-68. [PMID: 21177830 PMCID: PMC3037162 DOI: 10.1210/en.2010-1038] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Obesity and insulin resistance-related proteinuria is associated with oxidative stress and impaired tissue bioavailable nitric oxide. Recent data suggest that nicotinamide adenine dinucleotide phosphate oxidase-mediated oxidative injury to the proximal tubule, like that seen in the glomerulus, contributes to proteinuria in insulin-resistant states. The vasodilator β-blocker nebivolol reduces nicotinamide adenine dinucleotide phosphate oxidase activity, increases bioavailable nitric oxide, and improves insulin sensitivity. To test the hypothesis that a treatment strategy that reduces oxidative stress and attenuates obesity-associated increases in glomerular and proximal tubule derived protein, we treated young Zucker obese (ZO) and age-matched Zucker lean male rats with nebivolol (10 mg · kg(-1) · d(-1)) for 21 d. Compared with Zucker lean, ZO controls exhibited increased proteinuria and γ-glutamyl transpeptidase, reductions in systemic insulin sensitivity in association with increased renal renin, (pro)renin receptor, angiotensin II type 1 receptor, and mineralocorticoid receptor immunostaining, oxidative stress, and glomerular tubular structural abnormalities that were substantially improved with in vivo nebivolol treatment. Nebivolol treatment also led to improvements in glomerular podocyte foot-process effacement and improvement in podocyte-specific proteins (nephrin and synaptopodin) as well as proximal tubule-specific proteins (megalin and lysosomal-associated membrane protein-2) and proximal tubule ultrastructural remodeling in the ZO kidney. Our findings support the notion that obesity and insulin resistance lead to increased glomerulotubular oxidative stress and resultant glomerular and tubular sources of excess urine protein. Furthermore, the results of this study suggest the beneficial effect of nebivolol on proteinuria was derived from improvements in weight and insulin sensitivity and reductions in renal oxidative stress in a state of obesity and insulin resistance.
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Affiliation(s)
- Javad Habibi
- Diabetes and Cardiovascular Center, the University of Missouri-ColumbiaSchool of Medicine, Columbia, Missouri 65211, USA
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Whaley-Connell A, Pulakat L, DeMarco VG, Hayden MR, Habibi J, Henriksen EJ, Sowers JR. Overnutrition and the Cardiorenal Syndrome: Use of a Rodent Model to Examine Mechanisms. Cardiorenal Med 2011; 1:23-30. [PMID: 22258463 DOI: 10.1159/000322827] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Obesity has reached epidemic proportions with far-reaching health care and economic implications. Overnutrition, characterized by excess intake of carbohydrates and fats, has been associated with end-organ damage in several tissues, including the heart and the kidney. Furthermore, overnutrition is one of the most important modifiable and preventable causes of morbidity and mortality associated with cardiovascular and kidney diseases. Insulin resistance and compensatory hyperinsulinemia as well as associated mechanisms, including enhanced renin-angiotensin-aldosterone system activity, inflammation, and oxidative stress, have been implicated in obesity-related cardiorenal injury. In this review, the effect of overnutrition on heart and kidney disease is assessed in a rodent model of overnutrition and obesity, the Zucker obese rat.
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Varagic J, Ahmad S, Brosnihan KB, Habibi J, Tilmon RD, Sowers JR, Ferrario CM. Salt-induced renal injury in spontaneously hypertensive rats: effects of nebivolol. Am J Nephrol 2010; 32:557-66. [PMID: 21042014 DOI: 10.1159/000321471] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2010] [Accepted: 09/25/2010] [Indexed: 12/19/2022]
Abstract
BACKGROUND we investigated renal effects of nebivolol, a selective β(1)-receptor blocker with additional antioxidative ability, in spontaneously hypertensive rats (SHR) where increased salt intake induces oxidative stress and worsens renal function as a result of further activation of the renin-angiotensin and sympathetic nervous systems. METHODS male SHR were given an 8% salt diet (HS; n = 22) for 5 weeks; their age-matched controls (n = 9) received standard chow. Nebivolol was given at a dose of 10 mg/kg/day for 5 weeks in 11 HS rats. RESULTS HS increased blood pressure, plasma renin concentration, urinary protein excretion, and renal nitroxidative stress while decreasing renal blood flow and angiotensin 1-7 receptor (mas) protein expression. There was no change in angiotensin II type 1 receptor expression among the experimental groups. Nebivolol did not alter the salt-induced increase in blood pressure but reduced urinary protein excretion, plasma renin concentration, and nitroxidative stress. Nebivolol also increased neuronal NOS expression while preventing the salt-induced decrease in renal blood flow and mas protein expression. CONCLUSION nebivolol prevented salt-induced kidney injury and associated proteinuria in SHR through a blood pressure-independent mechanism. Its protective effects may be related to reduction in oxidative stress, increases in neuronal NOS and restoration of angiotensin II type 1/mas receptor balance.
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Affiliation(s)
- Jasmina Varagic
- Hypertension and Vascular Research Center, Wake Forest University, Winston-Salem, NC 27157, USA.
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