title: Ets-1 targeted by microrna-221 regulates angiotensin II-induced renal fibroblast activation and fibrosis.
abstract: BACKGROUND
  Fibroblast activation is one of the most important mechanisms for Angiotensin II (Ang II) in promoting renal fibrosis. Transcription factor Ets-1 is recognized to play a key role in kidney diseases. However, the role and mechanisms of Ets-1 in Ang-II induced fibroblast activation and kidney fibrosis are not fully understood.
  
  
  METHODS
  Mice were treated with Ang II via osmotic mini-pumps or Ang II expression plasmid (pAng II). Cultured normal rat kidney interstitial fibroblast (NRK-49F) cells were incubated with Ang II. Role of Ets-1 in renal fibrosis and fibroblast activation were assessed by Western blot, Immunohistochemical staining'MTT, Boyden chamber and Immunofluorescence staining. Effects of miR-221 on Ets-1 and fibroblast activation were investigated by MTT, Boyden chamber, Western blot and Q-PCR.
  
  
  RESULTS
  We found that Ets-1 was up-regulated in fibrotic kidneys. Similarly, Ang II could activate NRK-49F cells as demonstrated by up-regulated α-SMA and fibronectin(FN) expression and enhanced cell proliferation and migration. Ang II also induced Ets-1 expression in NRK-49F cells in a dose and time dependent manner. Knock-down of Ets-1 by RNA interference attenuated Ang II-induced activation of NRK-49F cells. Ets-1 was previously reported as a target of microRNA-221 (miR-221). In Ang II-induced fibrotic kidney, miR-221 was down-regulated. Similar results were observed in Ang II treated NRK-49F cells. Ectopic expression of miR-221 mimic attenuated the up-regulation of Ets-1 by Ang II in NRK-49F cells, which further prevented the activation of NRK-49F cells. However, the inhibitor of miR-221 aggravated Ang II induced Ets-1 expression and NRK-49F cells activation.
  
  
  CONCLUSIONS
  Our study suggests that miR-221/Ets-1 axis takes an important role in mediating AngII induced interstitial fibroblast activation and renal fibrosis.
authors.affiliation: Center for Kidney Disease, 2 Affiliated Hospital, Nanjing Medical University, Nanjing, China.
authors.forename: Jia
authors.initials: J
authors.lastname: Di
authors.forename: Lei
authors.initials: L
authors.lastname: Jiang
authors.forename: Yang
authors.initials: Y
authors.lastname: Zhou
authors.forename: Hongdi
authors.initials: H
authors.lastname: Cao
authors.forename: Li
authors.initials: L
authors.lastname: Fang
authors.forename: Ping
authors.initials: P
authors.lastname: Wen
authors.forename: Xiurong
authors.initials: X
authors.lastname: Li
authors.forename: Chunsun
authors.initials: C
authors.lastname: Dai
authors.forename: Junwei
authors.initials: J
authors.lastname: Yang
mesh_terms: D000804:Angiotensin II / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D002460:Cell Line; D049109:Cell Proliferation / Q000235:genetics; D015536:Down-Regulation / Q000235:genetics; D005260:Female; D005347:Fibroblasts / Q000378:metabolism*; D005353:Fibronectins / Q000378:metabolism; D005355:Fibrosis / Q000235:genetics / Q000378:metabolism*; D015870:Gene Expression / Q000235:genetics; D007668:Kidney / Q000378:metabolism*; D007674:Kidney Diseases / Q000235:genetics / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D050784:Proto-Oncogene Protein c-ets-1 / Q000235:genetics / Q000378:metabolism*; D051381:Rats; D015854:Up-Regulation / Q000235:genetics
chemical_list: D005353:Fibronectins; D035683:MicroRNAs; D050784:Proto-Oncogene Protein c-ets-1; D000804:Angiotensin II