Rho kinase inhibition protects kidneys from diabetic nephropathy without reducing blood pressure

• Published in: Kidney international Vol. 79; no. 4; pp. 432 - 442
• Main Authors: Komers, Radko, Oyama, Terry T., Beard, Douglas R., Tikellis, Chris, Xu, Bei, Lotspeich, Daniel F., Anderson, Sharon
• Format: Journal Article
• Language: English
• Published: Basingstoke Elsevier Inc 01.02.2011; Nature Publishing Group; Elsevier Limited
• Subjects: 1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine - analogs & derivatives; 1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine - pharmacology; Angiotensin II Type 1 Receptor Blockers - pharmacology; Animals; Associated diseases and complications; Biological and medical sciences; Blood Pressure - drug effects; connective tissue growth factor; Diabetes Mellitus, Experimental - drug therapy; Diabetes Mellitus, Experimental - enzymology; Diabetes. Impaired glucose tolerance; Diabetic Nephropathies - enzymology; Diabetic Nephropathies - pathology; Diabetic Nephropathies - physiopathology; Diabetic Nephropathies - prevention & control; diabetic nephropathy; Endocrine pancreas. Apud cells (diseases); Endocrinopathies; Epithelial-Mesenchymal Transition - drug effects; fasudil; Gene Expression - drug effects; glomerulosclerosis; Kidney - drug effects; Kidney - enzymology; Kidney - pathology; Kidneys; Losartan - pharmacology; Male; Medical sciences; Membrane Proteins - genetics; Membrane Proteins - metabolism; Nephrectomy; Nephrology. Urinary tract diseases; Protein Kinase Inhibitors - pharmacology; Rats; Rats, Sprague-Dawley; Rho-associated kinases (ROCK); rho-Associated Kinases - antagonists & inhibitors; transforming growth factor-β; Urinary system involvement in other diseases. Miscellaneous; Vascular Endothelial Growth Factor A - metabolism; connective tissue growth factor; Rho-associated kinases (ROCK); glomerulosclerosis; transforming growth factor-β; fasudil; diabetic nephropathy; Endocrinopathy; Glomerulonephritis; Kidney disease; Glomerulosclerosis; Nephrology; Urinary system disease; Vasodilator agent; Transforming growth factor β; Diabetes mellitus; Connective tissue growth factor; Kidney; Urology; Fasudil; Concomitant disease; Urinary system; Diabetic nephropathy; Arterial pressure; Inhibitor; Blood pressure; Hemodynamics; Inhibition
• ISSN: 0085-2538; 1523-1755
• DOI: 10.1038/ki.2010.428

Rho-associated kinases (ROCK) are activated in the kidney as well as in cultured cells of diabetic models and have been implicated in renal pathophysiology. To explore whether inhibition of ROCK is protective, we studied its role in a model of accelerated diabetic nephropathy where uninephrectomized rats were made diabetic by streptozotocin. After establishing diabetes, rats were treated with the ROCK inhibitor fasudil continuously or for the final 6 weeks of an 18-week experimental period. The results were compared to similar rats given losartan, an established treatment of clinical and experimental diabetic nephropathy, or a combination of both agents. Vehicle-treated diabetic and non-diabetic uninephrectomized rats served as controls. Diabetes resulted in a rapid development of albuminuria, higher glomerulosclerosis and interstitial fibrosis scores, lower glomerular filtration rates, and increased expression of several molecular markers of diabetic nephropathy. Eighteen weeks of fasudil treatment reduced renal ROCK activity, and ameliorated diabetes-induced structural changes in the kidney and expression of the molecular markers in association with a modest anti-proteinuric effect but no change in blood pressure. Late intervention with fasudil reduced glomerulosclerosis, but did not influence proteinuria. Most effects of fasudil were comparable to those of losartan, although losartan lowered blood pressure and further lowered proteinuria. The combination of both treatments was no different than losartan alone. Thus, ROCK inhibition protected the kidney from diabetic nephropathy even though it did not reduce the blood pressure.