184. Regulating Mitochondrial Biogenesis Transducers NRF1 To Inhibit Renal Interstitial Fibrosis

Abstract

Mitochondrial dysfunction is a newly established risk factor for the development of renal fibrosis. Cell survival and injury repair is facilitated by mitochondrial biogenesis. NRF-1 is a key transcription factor regulating the function of mitochondria.However, the role of this process in renal fibrosis is unknown. Thus, we hereby discuss the correlations of NRF-1 and renal interstitial fibrosis. Materials and Methods: NRK-49F (Normal Rat kidney fibroblast) cells were used. In vitro fibrosis model was established by treatment with transforming growth factor-b1 (TGF-b1). The fibrogenic marker (e.q. fibronectin) and fibrogenic signal proteins (e.q. pSmad2/3,Smad2/3,Smad7) were investigated. Here, we used that two distinct mechanisms regulate NRF1 activition and degradation of NRF1. NRF-1 was transfect by NRF-1 overexpression gene to evaluate NRF-1 activity of the therapeutic effect in renal fibrosis. In addition, NRF-1 was silenced by NRF-1 shRNA to evaluate the significance of NRF-1. ELISA was used to evaluate the secreted fibronectin. Western blot was used to examine the intracellular fibrogenic signal proteins (e.q. pSmad2/3,Smad2/3,Smad7). Immunofluorescence staining was used to assay the in situ expression of proteins (e.g. fibronectin). Results: Our study demonstrated that expression of NRF-1 is significantly decreased in renal fibrosis. However, transfection with pcDNA-NRF-1 (2mg/mL) expression vector did dramatically reverse TGF-b1-induced cellular fibrosis concomitantly with the suppression of fibronectin (both intracellular and extracellular fibronectin) and fibrogenic signal protein. Intriguingly, NRF-1 shRNA dramatically increased TGF-b1-induced cellular fibrosis. Collectively, these finding suggest that NRF-1 plays a pivotal role on renal cellular fibrosis. Moreover, NRF-1 might act as a novel renal fibrosis antagonist by down-regulating fibrosis signaling in renal fibroblast cells.