Intravenous Administration of Hepatocyte Growth Factor Gene Ameliorates Diabetic Nephropathy in Mice

Abstract

Abstract. Diabetic nephropathy is characterized by progressive loss of renal function, persistent proteinuria, and relentless accumulation of extracellular matrix leading to glomerulosclerosis and interstitial fibrosis. This study investigated the potential effects of long-term expression of exogenous hepatocyte growth factor (HGF) on normal and diabetic kidneys. Intravenous injection of human HGF gene via naked plasmid vector resulted in abundant HGF protein specifically localized in renal glomeruli, despite an extremely low level of transgene mRNA in the kidney. In uninephrectomized mice made diabetic with streptozotocin, delivery of exogenous HGF gene ameliorated the progression of diabetic nephropathy. HGF attenuated urine albumin and total protein excretion in diabetic mice. Exogenous HGF also mitigated glomerular mesangial expansion, reduced fibronectin and type I collagen deposition, and prevented interstitial myofibroblast activation. In addition, HGF prevented kidney cells from apoptotic death in the glomeruli and tubulointerstitium. Moreover, expression of HGF inhibited renal expression of TGF-␤1 and reduced urine level of TGF-␤1 protein. Therefore, despite the effects of HGF on diabetic nephropathy being controversial, these observations suggest that supplementation of HGF is beneficial in ameliorating diabetic renal insufficiency in mice.Diabetic nephropathy (DN) is the leading cause of chronic kidney diseases (CKD) that ultimately progress to end-stage renal failure (1,2). The number of patients who are afflicted with DN is steadily increasing worldwide, mainly as a result of a growing population of type 2 diabetes. The pathogenesis of DN is characterized by progressive loss of renal function, persistent proteinuria, and accumulation of extracellular matrix (ECM) that leads to glomerulosclerosis and tubulointerstitial fibrosis (3). Current therapy only slows but does not inhibit the progression of diabetic renal insufficiency in clinical settings (4 -6). Therefore, new therapeutic approaches are needed to halt the progressive loss of renal function in patients who have this devastating illness.Hepatocyte growth factor (HGF) has recently emerged as a potent antifibrogenic factor that prevents the onset and progression of a wide variety of CKD, including genetic ICR strainderived glomerulonephritis (7), obstructive nephropathy (8 -10), remnant kidney (11,12), chronic allograft nephropathy (13), and cyclosporin A nephropathy (14). In vitro, HGF specifically antagonizes the profibrotic actions of TGF-␤1 and blocks myofibroblast activation from interstitial fibroblasts and mesenchymal transition from tubular epithelial cells (10,15). In vivo, HGF inhibits renal TGF-␤1 expression and mitigates fibrotic lesions after various chronic injuries (10,12,16,17). Recent studies indicate that the antifibrotic actions of HGF are primarily mediated by specifically interrupting TGF-␤1/Smad signal transduction (15,18,19). In view of a causative role of hyperactive TGF-␤1 signaling in the initiation and development of ...

Characterization of transgene expression and pDNA distribution of the suctioned kidney in mice

“…For clinical use, mounting the tissue suction device to an endoscope can solve the invasiveness of surgery. To date, several factors, such as hepatocyte growth factor and Klotho, have been reported to have a therapeutic potential for renal fibrosis by reducing fibrogenic cytokine production as well as fibronectin and type I collagen deposition (Dai et al, 2004;Satoh et al, 2012). Therefore, using CpG-free plasmids encoding these therapeutic genes could be effective for the treatment of renal fibrosis.…”

Essential Role of Integrin-Linked Kinase in Podocyte Biology

“…Apoptotic cell death was determined by using terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) staining with DeadEnd Fluorometric Apoptosis Detection System (Promega, Madison, WI), as previously reported (26). The slide was double stained with anti-WT-1 antibody (Santa Cruz Biotechnology) for the identification of podocytes.…”

“…Urine albumin was measured by using a mouse Albumin ELISA Quantitation kit, according to the manufacturer's protocol (Bethyl Laboratories, Inc., Montgomery, TX). Serum and urine creatinine was determined by a routine procedure as described previously (26).…”

A Novel Mechanism by which Hepatocyte Growth Factor Blocks Tubular Epithelial to Mesenchymal Transition

“…The ability of HGF to inhibit tissue fibrotic lesions has been attested extensively in a wide variety of organs, including kidney (3)(4)(5)(6). Growing evidence demonstrates that administration of HGF protein or its gene prevents the progressive loss of kidney functions in chronic renal diseases with diverse causes (7)(8)(9)(10)(11). Accordingly, blockade of HGF signaling by a neutralizing antibody markedly exacerbates the progression of renal fibrosis and dysfunctions (12,13).…”