title: Calreticulin protects rat microvascular endothelial cells against microwave radiation-induced injury by attenuating endoplasmic reticulum stress.
abstract: OBJECTIVE
  This study was designed to evaluate whether exogenous CRT was beneficial for alleviating MR-induced injury by suppressing ER stress in rat MMECs.
  
  
  METHODS
  MMECs were pretreated with CRT (25 pg/mL) for 12 hours, followed by the exposure to 2.856 GHz radiation at a mean power density of 30 mW/cm(2) for six minutes. MR-induced injury in MMECs was evaluated by LDH leakage, apoptosis, and cell viability analysis. The expression of GRP78, CRT, CHOP, Bcl-2, and Bax were examined by Western blot analysis to reflect ER stress response and ER stress-related apoptosis.
  
  
  RESULTS
  MR induced marked MMECs injury, as shown by increased LDH leakage and apoptosis rate and decreased cell viability. MR also induced excessive ER stress, characterized by increased expression of GRP78 and CRT, and ER stress-related apoptotic signaling as well, as shown by the upregulation of CHOP and Bax and the downregulation of Bcl-2. Exogenous CRT pretreatment remarkably attenuated MR-induced cell apoptosis and LDH leakage, ER stress, and activation of the ER stress-related apoptotic signaling.
  
  
  CONCLUSIONS
  Exogenous CRT attenuates MR-induced ER stress-related apoptosis by suppressing CHOP-mediated apoptotic signaling pathways in MMECs.
authors.affiliation: Department of Pathophysiology, Chinese PLA General Hospital, Beijing, China; Department of Pathophysiology, College of Basic Medical Sciences, Taishan Medical University, Taian, China; State Key Laboratory of Kidney Disease (Chinese PLA General Hospital 2011DAV00088), Beijing, China.
authors.forename: Wei-Hong
authors.initials: WH
authors.lastname: Li
authors.forename: Yu-Zhen
authors.initials: YZ
authors.lastname: Li
authors.forename: Dan-Dan
authors.initials: DD
authors.lastname: Song
authors.forename: Xiao-Reng
authors.initials: XR
authors.lastname: Wang
authors.forename: Mi
authors.initials: M
authors.lastname: Liu
authors.forename: Xu-Dong
authors.initials: XD
authors.lastname: Wu
authors.forename: Xiu-Hua
authors.initials: XH
authors.lastname: Liu
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000528:radiation effects; D064032:Calbindin 2 / Q000378:metabolism*; D002199:Capillary Permeability / Q000528:radiation effects*; D059865:Endoplasmic Reticulum Stress / Q000528:radiation effects*; D042783:Endothelial Cells / Q000378:metabolism* / Q000473:pathology; D005260:Female; D006360:Heat-Shock Proteins / Q000378:metabolism; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D008297:Male; D055806:Microvessels / Q000378:metabolism* / Q000473:pathology; D008872:Microwaves / Q000009:adverse effects*; D051381:Rats; D017207:Rats, Sprague-Dawley; D015398:Signal Transduction / Q000528:radiation effects; D051028:bcl-2-Associated X Protein / Q000378:metabolism; D000091342:Endoplasmic Reticulum Chaperone BiP
chemical_list: D064032:Calbindin 2; D006360:Heat-Shock Proteins; D007770:L-Lactate Dehydrogenase; D051028:bcl-2-Associated X Protein; C494828:Bax protein, rat; C576512:Calb2 protein, rat; C051684:GRP78 protein, rat; D000091342:Endoplasmic Reticulum Chaperone BiP
keywords: apoptosis; calreticulin; endoplasmic reticulum stress; endothelial cells; microwave radiation