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Palygin O, Klemens CA, Isaeva E, Levchenko V, Spires DR, Dissanayake LV, Nikolaienko O, Ilatovskaya DV, Staruschenko A. Characterization of purinergic receptor 2 signaling in podocytes from diabetic kidneys. iScience 2021; 24:102528. [PMID: 34142040 PMCID: PMC8188476 DOI: 10.1016/j.isci.2021.102528] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 04/12/2021] [Accepted: 05/08/2021] [Indexed: 02/08/2023] Open
Abstract
Growing evidence suggests that renal purinergic signaling undergoes significant remodeling during pathophysiological conditions such as diabetes. This study examined the renal P2 receptor profile and ATP-mediated calcium response from podocytes in glomeruli from kidneys with type 1 or type 2 diabetic kidney disease (DKD), using type 2 diabetic nephropathy (T2DN) rats and streptozotocin-injected Dahl salt-sensitive (type 1 diabetes) rats. A dramatic increase in the ATP-mediated intracellular calcium flux in podocytes was observed in both models. Pharmacological inhibition established that P2X4 and P2X7 are the major receptors contributing to the augmented ATP-mediated intracellular calcium signaling in diabetic podocytes. The transition in purinergic receptor composition from metabotropic to ionotropic may disrupt intracellular calcium homeostasis in podocytes resulting in their dysfunction and potentially further aggravating DKD progression. Diabetic podocytes have sustained intracellular Ca2+ signaling in response to ATP Podocyte purinergic receptor signaling is predominantly ionotropic in diabetes Both type 1 and 2 diabetic podocytes have similar purinergic receptor remodeling
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Affiliation(s)
- Oleg Palygin
- Department of Physiology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA.,Cardiovascular Center, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Christine A Klemens
- Department of Physiology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA.,Cardiovascular Center, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Elena Isaeva
- Department of Physiology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA
| | - Vladislav Levchenko
- Department of Physiology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA
| | - Denisha R Spires
- Department of Physiology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA
| | - Lashodya V Dissanayake
- Department of Physiology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA
| | - Oksana Nikolaienko
- Department of Physiology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA
| | - Daria V Ilatovskaya
- Department of Physiology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA.,Division of Nephrology, Department of Medicine, Medical University of South Carolina, Charleston, SC, USA
| | - Alexander Staruschenko
- Department of Physiology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA.,Cardiovascular Center, Medical College of Wisconsin, Milwaukee, WI, USA.,Clement J. Zablocki Veterans Affairs Medical Center, Milwaukee, WI, USA
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Ge Y, Fan F, Didion SP, Roman RJ. Impaired myogenic response of the afferent arteriole contributes to the increased susceptibility to renal disease in Milan normotensive rats. Physiol Rep 2018; 5:5/3/e13089. [PMID: 28193784 PMCID: PMC5309574 DOI: 10.14814/phy2.13089] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Revised: 11/25/2016] [Accepted: 12/01/2016] [Indexed: 12/23/2022] Open
Abstract
Milan normotensive (MNS) rats are more susceptible to the development of renal disease than Milan hypertensive (MHS) rats, but the genes and pathways involved are unknown. This study compared the myogenic response of isolated perfused afferent arterioles (Af‐Art) and autoregulation of renal blood flow (RBF) and glomerular capillary pressure (Pgc) in 6–9‐week‐old MNS and MHS rats. The diameter of the Af‐Art of MHS rats decreased significantly from 14.3 ± 0.5 to 11.5 ± 0.6 μm when perfusion pressure was elevated from 60 to 120 mmHg. In contrast, the diameter of Af‐Art of MNS rats did not decrease. RBF was well autoregulated in MHS rats, but it increased by 26% in MNS rats. Pgc rose by 11 mmHg when renal perfusion pressure (RPP) was increased from 100 to 140 mmHg in MNS but not in MHS rats. Protein excretion increased from 10 ± 1 to 245 ± 36 mg/day in MNS rats as they aged from 3 to 11 months but it did not increase in MHS rats. We also compared the development of proteinuria in MNS and MHS rats following the induction of diabetes with streptozotocin. Protein excretion rose from 16 ± 3 to 234 ± 43 mg/day in MNS rats, but it remained unaltered in MHS rats. These data indicate that the myogenic response of the Af‐art is impaired in MNS rats and increased transmission of pressure to the glomerulus may contribute to renal injury in MNS rats similar to what is seen in fawn‐hooded hypertensive and Dahl salt‐sensitive rats.
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Affiliation(s)
- Ying Ge
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, Mississippi
| | - Fan Fan
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, Mississippi
| | - Sean P Didion
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, Mississippi
| | - Richard J Roman
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, Mississippi
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Spires D, Ilatovskaya DV, Levchenko V, North PE, Geurts AM, Palygin O, Staruschenko A. Protective role of Trpc6 knockout in the progression of diabetic kidney disease. Am J Physiol Renal Physiol 2018; 315:F1091-F1097. [PMID: 29923767 DOI: 10.1152/ajprenal.00155.2018] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Diabetic kidney disease (DKD) is a chronic kidney pathology that leads to end-stage renal disease. Previous studies from our laboratory indicate that there is an association between the development of DKD and the transient receptor potential canonical 6 (TRPC6) channel. Trpc6 expression and activity were increased in the streptozotocin (STZ)-treated Dahl Salt-sensitive (Dahl SS) rat, an established model of type 1 diabetes. Here, using a Trpc6 knockout created on the Dahl SS rat background (SSTrpc6-/-), we test the hypothesis that the absence of Trpc6 will protect podocytes and kidney function during the development of DKD. Four groups of animals (control SSWT, SSTrpc6-/-, STZ-treated SSWT, and STZ-SSTrpc6-/-) were utilized in this study. Diabetes development was monitored for 11 wk after STZ injection with periodic weight, glucose, and urinary output measurements. There was an increase in albuminuria and glomerular injury following STZ treatment, which was not different between Dahl SS and SSTrpc6-/- groups. Western blot analysis revealed elevated levels of nephrin in urine samples of STZ-SSWT rats, which was higher compared with STZ-SSTrpc6-/- rats. Furthermore, pathological increases in basal [Ca2+]i levels and foot process damage of podocytes during the development of DKD was attenuated in the STZ-SSTrpc6-/- compared with STZ-SSWT rats. Overall, our data indicate that TRPC6 channel inhibition may have at least partial renoprotective effects, which could lead to the development of new pharmacological tools to treat or prevent the progression of DKD.
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Affiliation(s)
- Denisha Spires
- Department of Physiology, Medical College of Wisconsin , Milwaukee, Wisconsin
| | - Daria V Ilatovskaya
- Department of Physiology, Medical College of Wisconsin , Milwaukee, Wisconsin.,Medical University of South Carolina, Department of Medicine, Charleston, South Carolina
| | - Vladislav Levchenko
- Department of Physiology, Medical College of Wisconsin , Milwaukee, Wisconsin
| | - Paula E North
- Department of Pathology, Medical College of Wisconsin , Milwaukee, Wisconsin
| | - Aron M Geurts
- Department of Physiology, Medical College of Wisconsin , Milwaukee, Wisconsin
| | - Oleg Palygin
- Department of Physiology, Medical College of Wisconsin , Milwaukee, Wisconsin
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Kitada M, Ogura Y, Koya D. Rodent models of diabetic nephropathy: their utility and limitations. Int J Nephrol Renovasc Dis 2016; 9:279-290. [PMID: 27881924 PMCID: PMC5115690 DOI: 10.2147/ijnrd.s103784] [Citation(s) in RCA: 166] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Diabetic nephropathy is the most common cause of end-stage renal disease. Therefore, novel therapies for the suppression of diabetic nephropathy must be developed. Rodent models are useful for elucidating the pathogenesis of diseases and testing novel therapies, and many type 1 and type 2 diabetic rodent models have been established for the study of diabetes and diabetic complications. Streptozotocin (STZ)-induced diabetic animals are widely used as a model of type 1 diabetes. Akita diabetic mice that have an Ins2+/C96Y mutation and OVE26 mice that overexpress calmodulin in pancreatic β-cells serve as a genetic model of type 1 diabetes. In addition, db/db mice, KK-Ay mice, Zucker diabetic fatty rats, Wistar fatty rats, Otsuka Long-Evans Tokushima Fatty rats and Goto-Kakizaki rats serve as rodent models of type 2 diabetes. An animal model of diabetic nephropathy should exhibit progressive albuminuria and a decrease in renal function, as well as the characteristic histological changes in the glomeruli and the tubulointerstitial lesions that are observed in cases of human diabetic nephropathy. A rodent model that strongly exhibits all these features of human diabetic nephropathy has not yet been developed. However, the currently available rodent models of diabetes can be useful in the study of diabetic nephropathy by increasing our understanding of the features of each diabetic rodent model. Furthermore, the genetic background and strain of each mouse model result in differences in susceptibility to diabetic nephropathy with albuminuria and the development of glomerular and tubulointerstitial lesions. Therefore, the validation of an animal model reproducing human diabetic nephropathy will significantly facilitate our understanding of the underlying genetic mechanisms that contribute to the development of diabetic nephropathy. In this review, we focus on rodent models of diabetes and discuss the utility and limitations of these models for the study of diabetic nephropathy.
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Affiliation(s)
- Munehiro Kitada
- Division of Anticipatory Molecular Food Science and Technology, Medical Research Institute; Department of Diabetology and Endocrinology, Kanazawa Medical University, Uchinada, Ishikawa, Japan
| | - Yoshio Ogura
- Department of Diabetology and Endocrinology, Kanazawa Medical University, Uchinada, Ishikawa, Japan
| | - Daisuke Koya
- Division of Anticipatory Molecular Food Science and Technology, Medical Research Institute; Department of Diabetology and Endocrinology, Kanazawa Medical University, Uchinada, Ishikawa, Japan
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Slaughter TN, Paige A, Spires D, Kojima N, Kyle PB, Garrett MR, Roman RJ, Williams JM. Characterization of the development of renal injury in Type-1 diabetic Dahl salt-sensitive rats. Am J Physiol Regul Integr Comp Physiol 2013; 305:R727-34. [PMID: 23926133 DOI: 10.1152/ajpregu.00382.2012] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The present study compared the progression of renal injury in Sprague-Dawley (SD) and Dahl salt-sensitive (SS) treated with streptozotocin (STZ). The rats received an injection of STZ (50 mg/kg ip) and an insulin pellet (2 U/day sc) to maintain the blood glucose levels between 400 and 600 mg/dl. Twelve weeks later, arterial pressure (143 ± 6 vs. 107 ± 8 mmHg) and proteinuria (557 ± 85 vs. 81 ± 6 mg/day) were significantly elevated in STZ-SS rats compared with the values observed in STZ-SD rats, respectively. The kidneys from STZ-SS rats exhibited thickening of glomerular basement membrane, mesangial expansion, severe glomerulosclerosis, renal interstitial fibrosis, and occasional glomerular nodule formation. In additional studies, treatment with a therapeutic dose of insulin (4 U/day sc) attenuated the development of proteinuria (212 ± 32 mg/day) and renal injury independent of changes in arterial pressure in STZ-SS rats. Since STZ-SS rats developed severe renal injury, we characterized the time course of changes in renal hemodynamics during the progression of renal injury. Nine weeks after diabetes onset, there was a 42% increase in glomerular filtration rate in STZ-SS rats vs. time-control SS rats with reduced renal blood flow. These results indicate that SS rats treated with STZ develop hyperfiltration and progressive proteinuria and display renal histological lesions characteristic of those seen in patients with diabetic nephropathy. Overall, this model may be useful to study signaling pathways and mechanisms that play a role in the progression of diabetes-induced renal disease and the development of new therapies to slow the progression of diabetic nephropathy.
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Affiliation(s)
- Tiffani N Slaughter
- Departments of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, Mississippi; and
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Lopes de Faria JB, Silva KC, Lopes de Faria JM. The contribution of hypertension to diabetic nephropathy and retinopathy: the role of inflammation and oxidative stress. Hypertens Res 2011; 34:413-22. [PMID: 21228783 DOI: 10.1038/hr.2010.263] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Diabetes and hypertension frequently coexist and constitute the most notorious combination for the pathogenesis of diabetic nephropathy and retinopathy. Large clinical trials have clearly demonstrated that tight control of glycemia and/or blood pressure significantly reduces the incidence and progression of diabetic retinopathy (DR) and nephropathy. However, the mechanism by which hypertension interacts with diabetes to induce and/or exacerbate nephropathy and retinopathy is very unclear. Substantial evidence implicates the involvement of chronic inflammation and oxidative stress in the pathogenesis of DR and nephropathy. In addition, hypertension causes oxidative stress and inflammation in the kidney and retina. In the present review, we summarized data obtained from our research along with those from other groups to better understand the role of hypertension in the pathogenesis of diabetic nephropathy and retinopathy. It is suggested that oxidative stress and inflammation may be common denominators of kidney and retinal damage in the concomitant presence of diabetes and hypertension.
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Affiliation(s)
- José Butori Lopes de Faria
- Department of Internal Medicine, Renal Pathophysiology Laboratory, Investigation in Diabetes Complications, Faculty of Medical Sciences, University of Campinas (Unicamp), Campinas, São Paulo, Brazil.
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Rosenthal T, Younis F, Alter A. Combating Combination of Hypertension and Diabetes in Different Rat Models. Pharmaceuticals (Basel) 2010; 3:916-939. [PMID: 27713282 PMCID: PMC4034014 DOI: 10.3390/ph3040916] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2010] [Revised: 03/04/2010] [Accepted: 03/18/2010] [Indexed: 12/18/2022] Open
Abstract
Rat experimental models are used extensively for studying physiological mechanisms and treatments of hypertension and diabetes co-existence. Each one of these conditions is a major risk factor for cardiovascular disease (CVD), and the combination of the two conditions is a potent enhancer of CVD. Five major animal models that advanced our understanding of the mechanisms and therapeutic approaches in humans are discussed in this review: Zucker, Goto-Kakizaki, SHROB, SHR/NDmcr-cp and Cohen Rosenthal diabetic hypertensive (CRDH) rats. The use of various drugs, such as angiotensin-converting enzyme (ACE) inhibitors (ACEIs), various angiotensin receptor blockers (ARBs), and calcium channel blockers (CCBs), to combat the effects of concomitant pathologies on the combination of diabetes and hypertension, as well as the non-pharmacological approach are reviewed in detail for each rat model. Results from experiments on these models indicate that classical factors contributing to the pathology of hypertension and diabetes combination—Including hypertension, hyperglycemia, hyperinsulinemia and hyperlipidemia—can now be treated, although these treatments do not completely prevent renal complications. Animal studies have focused on several mechanisms involved in hypertension/diabetes that remain to be translated into clinical medicine, including hypoxia, oxidative stress, and advanced glycation. Several target molecules have been identified that need to be incorporated into a treatment modality. The challenge continues to be the identification and interpretation of the clinical evidence from the animal models and their application to human treatment.
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Affiliation(s)
- Talma Rosenthal
- Department of Physiology and Pharmacology, Sackler School of Medicine, Tel Aviv University, Israel.
| | - Firas Younis
- Department of Physiology and Pharmacology, Sackler School of Medicine, Tel Aviv University, Israel.
| | - Ariela Alter
- Department of Physiology and Pharmacology, Sackler School of Medicine, Tel Aviv University, Israel.
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Emonnot L, Cohen R, Lo M. Neonatal streptozotocin-induced glucose intolerance: different consequences in Lyon normotensive and hypertensive rats. J Hypertens 2007; 25:429-38. [PMID: 17211251 DOI: 10.1097/hjh.0b013e3280115bd2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND Lyon hypertensive (LH) rats exhibit a mild hypertension associated with excessive body weight, spontaneous hyperlipidemia, elevated insulin/glucose ratio and exaggerated urinary protein excretion. AIMS We aimed to develop, in LH rats and their normotensive control (LL) rats, a moderate non-insulin-dependent diabetic model to study the different consequences on metabolic and renal functions. METHODS Non-insulin-dependent diabetes was induced by intraperitoneal injection of streptozotocin (STZ) at 2 days of age (50, 75 or 100 mg/kg for LH and 75, 100 or 125 mg/kg for LL rats). The evolution, with age, of glycemia, glucose tolerance (glucose 2 g/kg by gavage), blood pressure, plasma lipids and urinary protein and albumin excretions were studied in control and STZ-treated LH and LL rats. RESULTS Although fasting glycemia was not significantly changed, the neonatal administration of STZ increased non-fasting glycemia and induced a marked glucose intolerance that were comparable between LH rats receiving 75 mg/kg and LL rats receiving 100 mg/kg of STZ. Interestingly, in treated LH rats only, the impaired glucose tolerance was accompanied by further metabolic and renal dysfunctions characterized by additional increases in plasma cholesterol (+28%) and triglycerides (+105%) and accelerated progression of proteinuria (+36%) and albuminuria (+48%). CONCLUSIONS These observations indicate that susceptibility to diabetic metabolic disorders and renal diseases may be linked to the genetic predisposition to hypertension. This new model offers a reasonable reflection of the human situation, where hypertension and non-insulin-dependent diabetes often coincide, suitable for molecular, biochemical and pharmacological investigations.
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Affiliation(s)
- Léa Emonnot
- Département de Physiologie et Pharmacologie Clinique - EA3995, Université Lyon 1, France
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Pugliese G, Pricci F, Barsotti P, Iacobini C, Ricci C, Oddi G, Romeo G, Leto G, Marano G, Sorcini M, Sabbatini M, Fuiano G, Di Mario U, Pugliese F. Development of diabetic nephropathy in the Milan normotensive strain, but not in the Milan hypertensive strain: possible permissive role of hemodynamics. Kidney Int 2005; 67:1440-52. [PMID: 15780096 DOI: 10.1111/j.1523-1755.2005.00221.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND Rats of the Milan normotensive strain develop spontaneous glomerulosclerosis, whereas those of the Milan hypertensive strain are resistant to renal disease, possibly due to intrarenal artery hypertrophy protecting from systemic hypertension. To assess the role of hemodynamic versus metabolic factors in diabetic nephropathy, we investigated whether streptozotocin-induced diabetes accelerates glomerulosclerosis in Milan normotensive and/or removes (the hemodynamic) protection in Milan hypertensive rats by reducing preglomerular vascular resistance. METHODS Diabetic and nondiabetic Milan normotensive, hypertensive, and progenitor Wistar rats were followed for 6 months for the assessment of renal function and structure. RESULTS Proteinuria increased in nondiabetic and diabetic normotensive and, to a lesser extent, in diabetic Wistar, but not hypertensive rats. Serum creatinine increased and creatinine clearance decreased in nondiabetic and diabetic normotensive rats at 6 months. At 1.5 months, diabetic normotensive, but not hypertensive rats showed increased glomerular filtration rate and filtration fraction, suggesting glomerular hypertension. Diabetic nephropathy was detected in diabetic normotensive and Wistar, but not hypertensive rats. Glomerular extracellular matrix and TGF-beta mRNA levels increased with diabetes (and age) in normotensive, but not hypertensive rats. Arterioles and interlobular arteries showed increased media thickness in hypertensive versus normotensive rats, with diabetes reducing it only in the normotensive. CONCLUSION These data show that Milan hypertensive rats are not susceptible to diabetic nephropathy, at variance with glomerulosclerosis-prone Milan normotensive rats, thus indicating the importance of genetic background. Our study suggests that the nature of this (genetic) protection might be hemodynamic, with intrarenal artery hypertrophy preventing diabetes-induced loss of autoregulation.
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Affiliation(s)
- Giuseppe Pugliese
- Department of Clinical Sciences and Department of Experimental Medicine and Pathology, "La Sapienza" University, Rome, Italy.
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Hartner A, Veelken R, Wittmann M, Cordasic N, Hilgers KF. Effects of diabetes and hypertension on macrophage infiltration and matrix expansion in the rat kidney. BMC Nephrol 2005; 6:6. [PMID: 15918915 PMCID: PMC1175090 DOI: 10.1186/1471-2369-6-6] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2004] [Accepted: 05/27/2005] [Indexed: 11/10/2022] Open
Abstract
Background In experimental models of diabetes mellitus, aggravation of renal injury by concomitant hypertension has been described. Inflammatory mechanisms contribute to renal damage in both diseases. We investigated whether hypertension and diabetes mellitus act synergistically to induce macrophage infiltration and matrix expansion in the kidney. Methods Insulin-dependent diabetes mellitus was induced by streptozotocin injections to hypertensive mRen2-transgenic rats (TGR) and normotensive Sprague-Dawley control rats. Quantitative immunohistochemical examination of kidney tissue sections was used to measure macrophage infiltration and matrix expansion. The expression of MCP-1, Osteopontin, RANTES, ICAM-1 and VCAM-1 was evaluated by real-time RT-PCR. The localization of MCP-1 was studied by immunohistochemistry. Results Macrophage infiltration was present in the kidney of normotensive diabetic rats. Hypertensive rats exhibited a more marked infiltration of macrophages, regardless of whether diabetes was present or not. Gene expression of ICAM-1, VCAM-1 and RANTES was unaltered whereas Osteopontin and MCP-1 were induced by hypertension. Immunoreactive MCP-1 was slightly increased in diabetic rat kidney podocytes, and more markedly increased in hypertensive animals. Glomerular matrix accumulation was induced by diabetes and hypertension to a similar degree, and was highest in hypertensive, diabetic animals. Conclusion Diabetes mellitus caused a mild, and angiotensin-dependent hypertension a more marked infiltration of macrophages in the kidney. Combination of both diseases led to additive effects on matrix expansion but not on inflammation. Hypertension appears to be a much stronger stimulus for inflammation of the kidney than STZ diabetes, at least in mRen2-transgenic rats.
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Affiliation(s)
- Andrea Hartner
- Children and Youth Hospital, University of Erlangen-Nuremberg, Loschgestrasse 15, D-91054 Erlangen, Germany
| | - Roland Veelken
- Nephrology and Hypertension, University of Erlangen-Nuremberg, Loschgestrasse 8, D-91054 Erlangen, Germany
| | - Michael Wittmann
- Medicine II, Augsburg City Hospital, Stenglinstrasse 2, D-86156 Augsburg, Germany
| | - Nada Cordasic
- Children and Youth Hospital, University of Erlangen-Nuremberg, Loschgestrasse 15, D-91054 Erlangen, Germany
- Nephrology and Hypertension, University of Erlangen-Nuremberg, Loschgestrasse 8, D-91054 Erlangen, Germany
| | - Karl F Hilgers
- Nephrology and Hypertension, University of Erlangen-Nuremberg, Loschgestrasse 8, D-91054 Erlangen, Germany
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Imai G, Satoh T, Kumai T, Murao M, Tsuchida H, Shima Y, Ogimoto G, Fujino T, Kobayashi S, Kimura K. Hypertension accelerates diabetic nephropathy in Wistar fatty rats, a model of type 2 diabetes mellitus, via mitogen-activated protein kinase cascades and transforming growth factor-beta1. Hypertens Res 2003; 26:339-47. [PMID: 12733703 DOI: 10.1291/hypres.26.339] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Although it is known that diabetic nephropathy is accelerated by hypertension, the mechanisms involved in this process are not clear. In this study we aimed to clarify these mechanisms using male Wistar fatty rats (WFR) as a type 2 diabetic model and male Wistar lean rats (WLR) as a control. Each group was fed a normal or high sodium diet from the age of 6 to 14 weeks. We determined the blood pressure and urinary albumin excretion (UAE). At the end of the study, the expressions of mitogen-activated protein kinases (MAPK) and transforming growth factor-beta1 (TGF-beta1) were examined in the isolated glomeruli by Western blot analysis, and the number of glomerular lesions was determined by conventional histology. High sodium load caused hypertension and a marked increase in UAE in the WFR but not in the WLR. Glomerular volume was increased in the hypertensive WFR. There was no difference among the four groups in the expression of c-Jun-NH2-terminal kinase (JNK). In contrast, the expressions of extracellular signal-regulated kinase 1/2 (ERK1/2) and its upstream regulator, MAPK/ERK kinase 1 (MEK1), were augmented in the hypertensive WFR. Expression of p38 MAPK was increased in the normotensive WFR, and further enhanced in the hypertensive WFR. Moreover, administration of high sodium load to WFR augmented the expression of TGF-beta1. In conclusion, systemic hypertension in WFR accelerates the diabetic nephropathy in type 2 diabetes via MEK-ERK and p38 MAPK cascades. TGF-beta1 is also involved in this mechanism.
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Affiliation(s)
- Goro Imai
- Division of Nephrology and Hypertension, Department of Internal Medicine, St. Marianna University School of Medicine, Kawasaki, Japan
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