title: Specific down-regulation of connective tissue growth factor attenuates progression of nephropathy in mouse models of type 1 and type 2 diabetes.
abstract: Diabetic nephropathy (DN) remains a major complication in both type 1 and type 2 diabetes. Systemic administration of antitransforming growth factor-beta (TGF-beta) antibody has shown some promise in mouse models of DN. However, chronic blockade of the multifunctional TGB-beta could be problematic. Several downstream effects of TGF-beta are mediated by connective tissue growth factor (CTGF), which is up-regulated in several renal cells and secreted in the urine in the diabetic state. Using murine models of DN (type 1 and type 2) and a CTGF antisense oligonucleotide (ASO) of novel chimeric chemistry, we evaluated the specific role of this target in DN. In the type 1 model of DN, C57BL6 mice were made diabetic using streptozotocin injections and hyperglycemic animals were treated with CTGF ASOs (20 mg/kg/2 qw) for 4 months. ASO, but not mismatch control oligonucleotide, -treated animals showed significant reduction in target CTGF expression in the kidney with a concomitant decrease in proteinuria and albuminuria. Treatment with the CTGF ASO for 8 wk reduced serum creatinine and attenuated urinary albuminuria and proteinuria in diabetic db/db mice, a model of type 2 DN. The ASO also reduced expression of genes involved in matrix expansion such as fibronectin and collagen (I and IV) and an inhibitor of matrix degradation, PAI-1, in the renal cortex, contributing to significant reversal of mesangial expansion in both models of DN. Pathway analyses demonstrated that diabetes-induced phosphorylation of p38 MAPK and its downstream target CREB was also inhibited by the ASO. Our results strongly suggest that blocking CTGF using a chimeric ASO holds substantial promise for the treatment of DN.
authors.affiliation: Department of Pharmacology (Metabolic Diseases), Kalypsys Inc., 10420 Wateridge Circle, San Diego, CA 92121, USA. mguha@kalypsys.com
authors.forename: Mausumee
authors.initials: M
authors.lastname: Guha
authors.forename: Zhong-Gao
authors.initials: ZG
authors.lastname: Xu
authors.forename: David
authors.initials: D
authors.lastname: Tung
authors.forename: Linda
authors.initials: L
authors.lastname: Lanting
authors.forename: Rama
authors.initials: R
authors.lastname: Natarajan
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D002478:Cells, Cultured; D055513:Connective Tissue Growth Factor; D003921:Diabetes Mellitus, Experimental; D003922:Diabetes Mellitus, Type 1 / Q000150:complications / Q000378:metabolism / Q000473:pathology; D003924:Diabetes Mellitus, Type 2 / Q000150:complications / Q000378:metabolism / Q000473:pathology; D003928:Diabetic Nephropathies / Q000378:metabolism / Q000473:pathology; D004195:Disease Models, Animal; D018450:Disease Progression; D015536:Down-Regulation; D016326:Extracellular Matrix Proteins / Q000235:genetics / Q000378:metabolism; D006801:Humans; D017874:Immediate-Early Proteins / Q000235:genetics / Q000378:metabolism*; D036341:Intercellular Signaling Peptides and Proteins / Q000235:genetics / Q000378:metabolism*; D007668:Kidney / Q000166:cytology / Q000378:metabolism / Q000473:pathology; D051379:Mice; D008810:Mice, Inbred C57BL; D008820:Mice, Obese; D016376:Oligonucleotides, Antisense / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D015415:Biomarkers; C526317:CCN2 protein, human; C526318:CCN2 protein, mouse; C526316:CCN2 protein, rat; D016326:Extracellular Matrix Proteins; D017874:Immediate-Early Proteins; D036341:Intercellular Signaling Peptides and Proteins; D016376:Oligonucleotides, Antisense; D011993:Recombinant Fusion Proteins; D055513:Connective Tissue Growth Factor