Inhibition of connective tissue growth factor by small interfering RNA prevents renal fibrosis in rats undergoing chronic allograft nephropathy.
OBJECTIVE
Connective tissue growth factor (CTGF) is a highly profibrogenic molecule implicated in renal fibrogenesis. Small interfering RNA (siRNA) is an effective tool to silence gene expression. This study determined whether caudal vein injection of siRNA targeting CTGF inhibited its expression in rat kidneys in vivo, and furthermore whether it protected the kidney from renal fibrosis in chronic allograft nephropathy (CAN).


METHODS
Male inbred Fischer (F344, RT1(lv1)) rat renal grafts were orthotopically transplanted into Lewis (LEW, RT1(1)) rats following the procedure of Kamada with our modification. At 6 weeks, recipients were divided into siRNA, normal saline (NS), and control siRNA groups, using daily siRNA-targeting CTGF (0.1 mg/kg), or NS, or a control siRNA via caudal vein injection for 14 days. At 4, 6, and 8 weeks, we observed the pathologic changes, expression of CTGF, E-cadherin, collagen I and IV, and anti-smooth muscle actin (alpha-SMA).


RESULTS
Serum creatinine level, Banff score, and the expression of CTGF were significantly lower among the siRNA than the NS or the control siRNA groups at 8 weeks (P < .05). The expressions of collagen I and IV, and alpha-SMA were also significantly downregulated and E-cadherin was lost in the siRNA versus the NS and control siRNA groups at 8 weeks.


CONCLUSIONS
This study showed that delivery of CTGF siRNA via the caudal vein significantly inhibited expression of CTGF in rat kidneys, effectively preventing fibrosis in CAN. The results suggest that siRNA-targeting of CTGF has the potential to be a novel strategy for amelioration of CAN.
Luo
G H
GH
Transplantation Institute, West China Hospital, Sichuan University, Chengdu, China.
Lu
Y P
YP
Song
J
J
Yang
L
L
Shi
Y J
YJ
Li
Y P
YP
D000818:Animals; D055513:Connective Tissue Growth Factor; D004195:Disease Models, Animal; D005355:Fibrosis; D017874:Immediate-Early Proteins / Q000037:antagonists & inhibitors / Q000235:genetics*; D036341:Intercellular Signaling Peptides and Proteins / Q000235:genetics*; D007668:Kidney / Q000473:pathology*; D016030:Kidney Transplantation / Q000473:pathology*; D008297:Male; D034741:RNA, Small Interfering / Q000235:genetics*; D051381:Rats; D011916:Rats, Inbred F344; D011917:Rats, Inbred Lew; D014184:Transplantation, Homologous / Q000473:pathology
C526316:CCN2 protein, rat; D017874:Immediate-Early Proteins; D036341:Intercellular Signaling Peptides and Proteins; D034741:RNA, Small Interfering; D055513:Connective Tissue Growth Factor