title: Transient Receptor Potential Melastatin 4 (TRPM4) Contributes to High Salt Diet-Mediated Early-Stage Endothelial Injury.
abstract: OBJECTIVE
  The present study investigated whether the transient receptor potential melastatin 4 (TRPM4) channel plays a role in high salt diet (HSD)-induced endothelial injuries.
  
  
  METHODS
  Western blotting and immunofluorescence were used to examine TRPM4 expression in the mesenteric endothelium of Dahl salt-sensitive (SS) rats fed a HSD. The MTT, TUNEL, and transwell assays were used to evaluate the cell viability, cell apoptosis, and cell migration, respectively, of human umbilical vein endothelial cells (HUVECs). Enzyme-linked immunosorbent assays were used to determine the concentrations of intercellular adhesion molecule 1 (ICAM-1), vascular cell adhesion protein 1 (VCAM-1), and E-selectin. Carboxy-H2DCFDA, a membrane-permeable reactive oxygen species (ROS)-sensitive fluorescent probe, was used to detect intracellular ROS levels.
  
  
  RESULTS
  TRPM4 was mainly expressed near the plasma membrane of mesenteric artery endothelial cells, and its expression level increased in SS hypertensive rats fed a HSD. Its protein expression was significantly upregulated upon treatment with exogenous hydrogen peroxide (H2O2) and aldosterone in cultured HUVECs. Cell viability decreased upon treatment with both agents in a concentration-dependent manner, which could be partially reversed by 9-phenanthrol, a specific TRPM4 inhibitor. Exogenous H2O2 induced apoptosis, enhanced cell migration, and increased the release of adhesion molecules, including ICAM-1, VCAM-1, and E-selectin, all of which were significantly attenuated upon treatment with 9-phenanthrol. Aldosterone and H2O2 induced the accumulation of intracellular ROS, which was significantly inhibited by 9-phenanthrol, suggesting that oxidative stress is one of the mechanisms underlying aldosterone-induced endothelial injury.
  
  
  CONCLUSIONS
  Given the fact that oxidative stress and high levels of circulating aldosterone are present in hypertensive patients, we suggest that the upregulation of TRPM4 in the vascular endothelium may be involved in endothelial injuries caused by these stimuli.
authors.forename: Xiao-Qing
authors.initials: XQ
authors.lastname: Ding
authors.forename: Tao
authors.initials: T
authors.lastname: Ban
authors.forename: Zeng-Yan
authors.initials: ZY
authors.lastname: Liu
authors.forename: Jie
authors.initials: J
authors.lastname: Lou
authors.forename: Liang-Liang
authors.initials: LL
authors.lastname: Tang
authors.forename: Jia-Xin
authors.initials: JX
authors.lastname: Wang
authors.forename: Wen-Feng
authors.initials: WF
authors.lastname: Chu
authors.forename: Dan
authors.initials: D
authors.lastname: Zhao
authors.forename: Bin-Lin
authors.initials: BL
authors.lastname: Song
authors.forename: Zhi-Ren
authors.initials: ZR
authors.lastname: Zhang
mesh_terms: D000450:Aldosterone / Q000633:toxicity; D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D002465:Cell Movement / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D004032:Diet; D019040:E-Selectin / Q000032:analysis; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D061307:Human Umbilical Vein Endothelial Cells; D006801:Humans; D006861:Hydrogen Peroxide / Q000633:toxicity; D008297:Male; D008638:Mesenteric Arteries / Q000166:cytology; D018384:Oxidative Stress / Q000187:drug effects; D010616:Phenanthrenes / Q000494:pharmacology; D034741:RNA, Small Interfering / Q000378:metabolism; D051381:Rats; D020303:Rats, Inbred Dahl; D012965:Sodium Chloride / Q000494:pharmacology; D050053:TRPM Cation Channels / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D015854:Up-Regulation / Q000187:drug effects
chemical_list: D019040:E-Selectin; D010616:Phenanthrenes; D034741:RNA, Small Interfering; D050053:TRPM Cation Channels; C500239:TRPM4 protein, rat; D012965:Sodium Chloride; D000450:Aldosterone; C091375:9-phenanthrol; D006861:Hydrogen Peroxide
keywords: 9-phenanthrol; Aldosterone; Hydrogen peroxide; Hypertension; Salt-sensitive; TRPM4