Suppression of Renal Tubulointerstitial Fibrosis by Small Interfering RNA Targeting Heat Shock Protein 47

Abstract

Background/Aim: Unilateral ureteral obstruction (UUO) is a well-established model for tubulointerstitial fibrosis. During the progression of tubulointerstitial fibrosis, upregulation of collagen synthesis and subsequent accumulation of collagen were observed in the tubulointerstitial area. Heat shock protein 47 (HSP47) is a collagen-specific molecular chaperone and plays an essential role in regulating collagen synthesis. We designed small interfering RNA (siRNA) sequences for HSP47 mRNA to examine whether HSP47 is involved in the progression of renal tubulointerstitial fibrosis in a mouse UUO model. Methods: The HSP47 siRNA was injected once via the ureter at the time of UUO preparation. We also applied a new gene delivery system for siRNA using cationized gelatin microspheres. The kidneys were harvested 7 and 14 days after UUO. The HSP47 and type I, III, and IV collagen expression levels were analyzed by immunohistochemistry and Western blotting. Results: Seven days after UUO, the expression levels of HSP47 and type I, III, and IV collagens were markedly upregulated in obstructed kidneys or green fluorescent protein siRNA treated obstructed kidneys. HSP47 siRNA injection significantly reduced the protein expression levels and significantly diminished the accompanying interstitial fibrosis. Moreover, cationized gelatin microspheres as a delivery system enhanced and lengthened the antifibrotic effect of HSP47 siRNA. Conclusions: Our results indicate that HSP47 is a candidate target for the prevention of tubulointerstitial fibrosis and that selective blockade of the HSP47 expression by using siRNA could be a potentially useful therapeutic approach for patients with renal disease.

Inhibition of SET Domain–Containing Lysine Methyltransferase 7/9 Ameliorates Renal Fibrosis

“…Immediately after right ureteral obstruction, 50 mL of SET7/9-siRNA solution (7 mg/kg) was injected retrogradely once into the right kidney via the ureter. 38,39 Sinefungin (Sigma-Aldrich, St Louis, MO) was prepared as a suspension in distilled water and 0.9% NaCl solution, and administered intraperitoneally (0.1 mL per mouse) at a dose of 10 mg/kg per day immediately after UUO. The control group was administered an equal volume of vehicle (0.1 mL of distilled water and 0.9% NaCl solution) intraperitoneally.…”

CLCA Splicing Isoform Associated with Adhesion through β1-Integrin and Its Scaffolding Protein

“…Such incorporated compounds have been reported to be released from the hydrogel after its degradation by endogenous enzymes secreted from the surrounding tissues (23). One week after the injection, the rats were sacrificed, both ears were removed, and 7-m-thick frozen sections were examined in an immunofluorescence study using the same concentrations of antibodies as those shown in the previous section.…”

“…S4). Transfection of an siRNA together with CGM has been reported to have a long-lasting effect on the expression of the target molecule (23). In control (scrambled RNA ϩ CGMtreated) skin, a confocal microscopic study showed that rCLCA-t displayed an intracellular localization.…”

Nano-sized carriers in gene therapy for renal fibrosisin vivo

“…These nanoparticles were shown to inhibit TBR expression and ameliorated fibrotic changes in the fibrotic kidney compared with naked plasmid DNA designed for the expression of TBR siRNA injection [52]. Heat shock protein 47 (HSP47) siRNA with cationized gelatin nanoparticles was shown to knock down HSP47 expression and diminish renal fibrosis in a mouse model of renal fibrosis induced by UUO [53]. Cationic gelatin nanoparticles incorporating plasmid DNA expressing matrix metalloprotease was shown to prevent renal fibrosis in a mouse model of diabetic nephropathy produced by intraperitoneal injection of streptozotocin, which causes damage to the pancreas and results in diabetic nephropathy [54,67].…”