title: MicroRNA-199a-5p Regulates the Proliferation of Pulmonary Microvascular Endothelial Cells in Hepatopulmonary Syndrome.
abstract: OBJECTIVE
  Pulmonary microvascular endothelial cell (PMVEC) proliferation and angiogenesis contribute to the development of hepatopulmonary syndrome (HPS). MicroRNA-199a-5p (miR-199a-5p) has emerged as a potent regulator of angiogenesis, and its expression levels significantly decrease in the serum of patients with hepatopathy. However, it has not been reported about whether miR-199a-5p might control PMVEC proliferation. Here, we described the miR-199a-5p governing PMVEC proliferation in HPS.
  
  
  METHODS
  PMVECs were treated with rat serum from common bile duct ligation (CBDL) or sham. MiR-199a-5p mimic or inhibitor was used to change the miR-199a-5p expression. Knockdown of caveolin-1 (Cav-1) was performed using siRNA. NSC-23766 was used to inhibit Rac1 activity. Gene and protein expressions were quantified by qRT-PCR and western blot. Cell proliferation was analyzed by 3H-TdR incorporation and CCK-8 assays. Stress fibers were detected by immunofluorescence.
  
  
  RESULTS
  CBDL rat serum induced the down-regulation of miR-199a-5p. Delivery of miR-199a-5p suppressed the CBDL rat serum-induced PMVEC proliferation whereas knockdown of miR-199a-5p promoted PMVEC proliferation. This was accompanied by a decrease and an increase in Cav-1 expression, respectively. Cav-1 siRNA abolished the enhancement of PMVEC proliferation induced by the miR-199a-5p inhibition. Although stress fibers were disrupted in Cav-1 deficient cells, NSC-23766 increased stress fibers and contributed to cell proliferation.
  
  
  CONCLUSIONS
  CBDL rat serum induced down-regulation of miR-199a-5p in PMVECs, which led to an increase of Cav-1 gene expression. Increased Cav-1 expression, by inhibiting Rac1 activity, led to the formation of stress fibers, which contribute to PMVEC proliferation and thus the pathogenesis of HPS.
authors.forename: Jing
authors.initials: J
authors.lastname: Zeng
authors.forename: Lin
authors.initials: L
authors.lastname: Chen
authors.forename: Bing
authors.initials: B
authors.lastname: Chen
authors.forename: Kaizhi
authors.initials: K
authors.lastname: Lu
authors.forename: Karine
authors.initials: K
authors.lastname: Belguise
authors.forename: Xiaobo
authors.initials: X
authors.lastname: Wang
authors.forename: Bin
authors.initials: B
authors.lastname: Yi
mesh_terms: D000634:Aminoquinolines / Q000494:pharmacology; D000818:Animals; D051242:Caveolin 1 / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D049109:Cell Proliferation; D002478:Cells, Cultured; D015536:Down-Regulation; D042783:Endothelial Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D020065:Hepatopulmonary Syndrome / Q000378:metabolism / Q000473:pathology; D008168:Lung / Q000166:cytology; D008297:Male; D035683:MicroRNAs / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D016376:Oligonucleotides, Antisense / Q000378:metabolism; D011743:Pyrimidines / Q000494:pharmacology; D034622:RNA Interference; D012333:RNA, Messenger / Q000378:metabolism; D034741:RNA, Small Interfering / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D060888:Real-Time Polymerase Chain Reaction; D020830:rac1 GTP-Binding Protein / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism
chemical_list: D000634:Aminoquinolines; D051242:Caveolin 1; C552425:MIRN199 microRNA, rat; D035683:MicroRNAs; C487513:NSC 23766; D016376:Oligonucleotides, Antisense; D011743:Pyrimidines; D012333:RNA, Messenger; D034741:RNA, Small Interfering; C499134:Rac1 protein, rat; D020830:rac1 GTP-Binding Protein