title: Elucidation of the therapeutic role of mitochondrial biogenesis transducers NRF-1 in the regulation of renal fibrosis.
abstract: BACKGROUND
  Mitochondrial dysfunction is a newly established risk factor for the development of renal fibrosis. Cell survival and injury repair is facilitated by mitochondrial biogenesis. Nuclear respiratory factor 1 (NRF-1) is a transcriptional regulation factor that plays a central role in the regulation of mitochondrial biogenesis. However, the transcription factor of this process in renal fibrosis is unknown. Thus, we hereby discussed the correlations of NRF-1 and renal interstitial fibrosis.
  
  
  METHODS
  In vitro fibrosis model was established by treatment with transforming growth factor-β1 (TGF-β1) in NRK-49F (Normal Rat kidney fibroblast). We investigated the ROS production, mitochondrial biogenesis and fibrogenic marker (e.q. fibronectin) during the progression of renal fibrosis by kit and Western blotting assay. Here, we used that two distinct mechanisms regulate NRF-1 activation and degradation of NRF-1. NRF-1 was transfect by pcDNA-NRF-1 overexpression gene to evaluate the NRF-1 activity of the therapeutic effect in renal fibrosis. In addition, NRF-1 was silenced by shRNA-NRF-1 to evaluate the significance of NRF-1. ELISA was used to evaluate the secreted fibronectin. Immunofluorescence staining was used to assay the in situ expression of proteins (e.g. fibronectin, NRF-1).
  
  
  RESULTS
  Under renal fibrosis conditions, TGF-β1 (5ng/ml) increased ROS. Simultaneously, TGF-β1-induced extracellular fibronectin by ELISA assay. In addition, TGF-β1 decreased expression of mitochondrial biogenesis. This is the first time to demonstrate that expression of NRF-1 is significantly decreased in renal fibrosis. However, NRK49F was a transfection with pcDNA-NRF-1 (2μg/ml) expression vector dramatically reverse TGF-β1-induced cellular fibrosis concomitantly with the suppression of fibronectin (both intracellular and extracellular fibronectin). More importantly, transfection with shRNA-NRF-1 (2μg/ml) significantly increased the expression of fibronectin of both intercellular and extracellular origins in NRK-49F cells.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Graduate Institute of Biomedical Science, National Sun Yat-Sen University, Kaohsiung, Taiwan; Graduate Institute of Medical Laboratory Science and Biotechnology, Chung Hwa University of Medical Technology, Tainan, Taiwan.
authors.forename: Pei-Fang
authors.initials: PF
authors.lastname: Hsieh
authors.affiliation: Department of Internal Medicine, Kaohsiung Medical University Chung-Ho Memorial Hospital, Kaohsiung, Taiwan.
authors.forename: Shu-Fen
authors.initials: SF
authors.lastname: Liu
authors.affiliation: Graduate Institute of Biomedical Science, Chung Hwa University of Medical Technology, Tainan, Taiwan.
authors.forename: Tsung-Jen
authors.initials: TJ
authors.lastname: Hung
authors.affiliation: Department of Food Nutrition, Chung Hwa University of Medical Technology, Tainan, Taiwan.
authors.forename: Chien-Ya
authors.initials: CY
authors.lastname: Hung
authors.affiliation: Graduate Institute of Medical Laboratory Science and Biotechnology, Chung Hwa University of Medical Technology, Tainan, Taiwan.
authors.forename: Guo-Zheng
authors.initials: GZ
authors.lastname: Liu
authors.affiliation: Department of Biochemistry, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors.forename: Lea-Yea
authors.initials: LY
authors.lastname: Chuang
authors.affiliation: Department of Acupressure Technology, Chung Hwa University of Medical Technology, Tainan, Taiwan.
authors.forename: Mei-Fen
authors.initials: MF
authors.lastname: Chen
authors.affiliation: Department of Physical Medicine and Rehabilitation, Kaohsiung Veterans General Hospital, Taiwan.
authors.forename: Jue-Long
authors.initials: JL
authors.lastname: Wang
authors.affiliation: Graduate Institute of Medical Laboratory Science and Biotechnology, Chung Hwa University of Medical Technology, Tainan, Taiwan; Department of Medical Technology, Kaohsiung Veterans General Hospital Tainan Branch, Tainan, Taiwan.
authors.forename: Ming-Der
authors.initials: MD
authors.lastname: Shi
authors.affiliation: Department of Biological Science and Technology, Chung Hwa University of Medical Technology, Tainan, Taiwan.
authors.forename: Chen Hung
authors.initials: CH
authors.lastname: Hsu
authors.affiliation: Graduate Institute of Biomedical Science, National Sun Yat-Sen University, Kaohsiung, Taiwan. Electronic address: shiue.shirley@gmail.com.
authors.forename: Yow-Ling
authors.initials: YL
authors.lastname: Shiue
authors.affiliation: Graduate Institute of Medical Laboratory Science and Biotechnology, Chung Hwa University of Medical Technology, Tainan, Taiwan; Graduate Institute of Biomedical Science, Chung Hwa University of Medical Technology, Tainan, Taiwan. Electronic address: Call0955443221@gmail.com.
authors.forename: Yu-Lin
authors.initials: YL
authors.lastname: Yang
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D002460:Cell Line; D005353:Fibronectins / Q000378:metabolism; D005355:Fibrosis; D007674:Kidney Diseases / Q000378:metabolism* / Q000473:pathology*; D008954:Models, Biological; D051266:Nuclear Respiratory Factor 1 / Q000378:metabolism*; D001678:Organelle Biogenesis; D034741:RNA, Small Interfering / Q000378:metabolism; D051381:Rats; D017382:Reactive Oxygen Species / Q000378:metabolism; D014162:Transfection; D016212:Transforming Growth Factor beta / Q000494:pharmacology
chemical_list: D015415:Biomarkers; D005353:Fibronectins; D051266:Nuclear Respiratory Factor 1; D034741:RNA, Small Interfering; D017382:Reactive Oxygen Species; D016212:Transforming Growth Factor beta
keywords: NRF-1; Renal fibrosis