siRNA-Based Therapy Ameliorates Glomerulonephritis

Abstract

RNA interference by short interfering RNAs (siRNAs) holds promise as a therapeutic strategy, but use of siRNAs in vivo remains limited. Here, we developed a system to target delivery of siRNAs to glomeruli via poly(ethylene glycol)-poly(L-lysine)-based vehicles. The siRNA/nanocarrier complex was approximately 10 to 20 nm in diameter, a size that would allow it to move across the fenestrated endothelium to access to the mesangium. After intraperitoneal injection of fluorescence-labeled siRNA/nanocarrier complexes, we detected siRNAs in the blood circulation for a prolonged time. Repeated intraperitoneal administration of a mitogen-activated protein kinase 1 (MAPK1) siRNA/nanocarrier complex suppressed glomerular MAPK1 mRNA and protein expression in a mouse model of glomerulonephritis; this improved kidney function, reduced proteinuria, and ameliorated glomerular sclerosis. Furthermore, this therapy reduced the expression of the profibrotic markers TGF-␤1, plasminogen activator inhibitor-1, and fibronectin. In conclusion, we successfully silenced intraglomerular genes with siRNA using nanocarriers. This technique could aid the investigation of molecular mechanisms of renal disease and has potential as a molecular therapy of glomerular diseases.

Impairment of hepatic nuclear factor-4α binding to theStim1promoter contributes to high glucose-induced upregulation of STIM1 expression in glomerular mesangial cells

“…Further examination showed a good colocalization of HNF4␣ signals with staining of OX-7, which is an antibody recognizing Thy1.1, a MC-specific antigen (Fig. 1, C and D) (9,40,46,47), suggesting MC localization of HNF4␣. These data indicate that HNF4␣ is present in glomerular MCs.…”

“…After 30 min of incubation with blocking buffer, sections were incubated with HNF4␣ and CD90/Thy 1.1 (OX-7) antibodies at 1:50 and 1:100, respectively, in PBS plus 10% donkey serum and 0.2% Triton X-100 at 4°C overnight. OX-7 is an antibody to Thy1.1, a MC-specific antigen, and was used to label MCs (9,40,46,47). After three washes with PBS, sections were then incubated with donkey anti-goat secondary antibodies conjugated with Alexa fluor 568 (for HNF4␣) or with donkey anti-rabbit fluor 488 (for OX-7) (Invitrogen) at a concentration of 1:500 for 1 h at room temperature.…”

Delivery Methods to Target RNAs in the Kidney

“…PEI (-PEG) complex uptake proved to be composition dependent. In an other application of PEG-PLL glomerulonephritis was ameliorated by MAPK1 siRNA in lupus nephritis mouse model (Shimizu et al, 2010). PEG-PLL complexed siRNA transfected glomeruli successfully, unlike the naked siRNA.…”

“…An extensive research in polymer therapeutics led to new generations of polymers improving safety, biocompatibility, and efficiency. One novel approach aims at glomerular protein knockdown using poly-(ethylene-glycol)-poly-(L-lysine) (PEG-PLL) copolymer-based nanocarriers while avoiding size-selective restraints of the glomerular filter (Shimizu et al, 2010). These polymer nanocarriers have enhanced delivery and retention in the kidney compared to naked siRNA following intraperitoneal administration, more specifically to cells of the glomerulus.…”

Oxidative Stress in Multiple Organ Damage in Hypertension, Diabetes and CKD, Mechanisms and New Therapeutic Possibilities

“…In recent years, a few reports about new drug delivery system using nanotechnology have been released (Muro et al, 2006;Kajita et al, 2007;Shimizu et al, 2010). Among them platinum nanoparticles as both superoxide dismutase (SOD) mimetic and catalase mimetic (Kajita et al, 2007;Watanabe et al, 2009).…”