Introduction of DNA enzyme for Egr-1 into tubulointerstitial fibroblasts by electroporation reduced interstitial alpha-smooth muscle actin expression and fibrosis in unilateral ureteral obstruction (UUO) rats.
The phenotypic alteration of interstitial fibroblasts into 'myofibroblasts', acquiring characteristics of both fibroblasts and smooth muscle cells is a key event in the formation of tubulointerstitial fibrosis. The up-regulation of the early growth response gene 1 (Egr-1) preceded the increased interstitial expression of alpha-smooth muscle actin (alphaSMA), a marker of phenotypic changes, in obstructed kidney, a model of interstitial fibrosis. To target Egr-1 expression in the interstitium of obstructed kidneys, we introduced a DNA enzyme for Egr-1 (ED5) or scrambled DNA (SCR) into interstitial fibroblasts by electroporation-mediated gene transfer. Northern blot analysis confirmed an increase in the cortical mRNA expression of Egr-1 in the obstructed kidneys from untreated or SCR-treated rats, while ED5 transfection blocked Egr-1 expression with a concomitant reduction in TGF-beta, alphaSMA and type I collagen mRNA expression. Consequently, ED5 inhibited interstitial fibrosis. In conclusion, electroporation-mediated retrograde gene transfer can be an ideal vehicle into interstitial fibroblasts, and molecular intervention of Egr-1 in the interstitium may become a new therapeutic strategy for interstitial fibrosis.
Nakamura
H
H
Department of Internal Medicine and Therapeutics, Osaka University Graduate School of Medicine, Suita, Japan.
Isaka
Y
Y
Tsujie
M
M
Rupprecht
H D
HD
Akagi
Y
Y
Ueda
N
N
Imai
E
E
Hori
M
M
D000199:Actins / Q000235:genetics; D000818:Animals; D002460:Cell Line; D024042:Collagen Type I / Q000235:genetics; D004277:DNA, Single-Stranded / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000235:genetics*; D051766:Early Growth Response Protein 1; D018274:Electroporation; D005355:Fibrosis; D015870:Gene Expression; D015316:Genetic Therapy / Q000379:methods*; D017874:Immediate-Early Proteins; D007668:Kidney / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D014157:Transcription Factors / Q000235:genetics*; D016212:Transforming Growth Factor beta / Q000235:genetics; D014517:Ureteral Obstruction / Q000628:therapy*
D000199:Actins; D024042:Collagen Type I; C400152:DNA enzyme ED5; D004277:DNA, Single-Stranded; D004268:DNA-Binding Proteins; D051766:Early Growth Response Protein 1; C486110:Egr1 protein, rat; D017874:Immediate-Early Proteins; D012333:RNA, Messenger; D014157:Transcription Factors; D016212:Transforming Growth Factor beta