title: Urotensin II inhibits doxorubicin-induced human umbilical vein endothelial cell death by modulating ATF expression and via the ERK and Akt pathway.
abstract: OBJECTIVE
  Regulation of the homeostasis of vascular endothelium is critical for the processes of vascular remodeling and angiogenesis under physiological and pathological conditions. Urotensin II (U-II), a potent vasoactive peptide, participates in vascular and myocardial remodeling after injury. We investigated the protective effect of U-II on doxorubicin (DOX)-induced apoptosis in cultured human umbilical vein endothelial cells (HUVECs) and the potential mechanisms involved in this process.
  
  
  METHODS
  Cultured HUVECs were treated with vehicle, DOX (1 µM), U-II, or U-II plus DOX. Apoptosis was evaluated by DNA strand break level with TdT-mediated dUTP nick-end labeling (TUNEL) staining. Western blot analysis was employed to determine the related protein expression and flow cytometry assay was used to determine the TUNEL positive cells.
  
  
  RESULTS
  U-II reduced the quantity of cleaved caspase-3 and cytosol cytochrome c and increased Bcl-2 expression, which results in protecting HUVECs from DOX-induced apoptosis. U-II induced Activating transcription factor 3 (ATF3) at both mRNA and protein levels in U-II-treated cells. Knockdown of ATF3 with ATF3 siRNA significantly reduced ATF3 protein levels and U-II protective effect under DOX-treated condition. U-II downregulated p53 expression in DOX-induced HUVECs apoptosis, and it rapidly activated extracellular signal-regulated protein kinase (ERK) and Akt. The DOX induced change of p53 was not affected by U-II antagonist (urantide) under ATF-3 knockdown. The inhibitory effect of U-II on DOX-increased apoptosis was attenuated by inhibitors of ERK (U0126) and PI3K/Akt (LY294002).
  
  
  CONCLUSIONS
  Our observations provide evidence that U-II protects HUVECs from DOX-induced apoptosis. ERK-Akt phosphorylation, ATF3 activation, and p53 downregulation may play a signal-transduction role in this process.
authors.affiliation: Graduate Institute of Medical Sciences, National Defense Medical Center, Taipei, Taiwan, Republic of China.
authors.forename: Yen-Ling
authors.initials: YL
authors.lastname: Chen
authors.affiliation: Graduate Institute of Medical Sciences, National Defense Medical Center, Taipei, Taiwan, Republic of China; Division of Cardiovascular Surgery, Department of Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan, Republic of China.
authors.forename: Yi-Ting
authors.initials: YT
authors.lastname: Tsai
authors.affiliation: Division of Cardiovascular Surgery, Department of Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan, Republic of China.
authors.forename: Chung-Yi
authors.initials: CY
authors.lastname: Lee
authors.affiliation: Department of Nursing, Min-Hwei College of Health Care Management, Tainan, Taiwan, Republic of China.
authors.forename: Chien-Hsing
authors.initials: CH
authors.lastname: Lee
authors.affiliation: School of Medical and Health Sciences, Fooyin University, Kaohsiung, Taiwan, Republic of China.
authors.forename: Chung-Yi
authors.initials: CY
authors.lastname: Chen
authors.affiliation: School of Medical and Health Sciences, Fooyin University, Kaohsiung, Taiwan, Republic of China.
authors.forename: Chi-Ming
authors.initials: CM
authors.lastname: Liu
authors.affiliation: Division of Cardiology, Department of Internal Medicine and Graduate Institute of Clinical Medical Science, China Medical University, Taichung, Taiwan, Republic of China; Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan, Republic of China; Division of Cardiology, Department of Internal Medicine, China Medical University Hospital, Taichung, Taiwan, Republic of China.
authors.forename: Jin-Jer
authors.initials: JJ
authors.lastname: Chen
authors.affiliation: Graduate Institute of Medical Sciences, National Defense Medical Center, Taipei, Taiwan, Republic of China; Department of Pharmacology, National Defense Medical Center, Taipei, Taiwan, Republic of China.
authors.forename: Shih-Hurng
authors.initials: SH
authors.lastname: Loh
authors.affiliation: Graduate Institute of Medical Sciences, National Defense Medical Center, Taipei, Taiwan, Republic of China; Division of Cardiovascular Surgery, Department of Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan, Republic of China.
authors.forename: Chien-Sung
authors.initials: CS
authors.lastname: Tsai
mesh_terms: D051700:Activating Transcription Factor 3 / Q000235:genetics / Q000378:metabolism*; D000903:Antibiotics, Antineoplastic / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D004317:Doxorubicin / Q000494:pharmacology*; D015870:Gene Expression / Q000187:drug effects; D061307:Human Umbilical Vein Endothelial Cells / Q000502:physiology*; D006801:Humans; D020935:MAP Kinase Signaling System; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism; D014579:Urotensins / Q000502:physiology*
chemical_list: C490449:ATF3 protein, human; D051700:Activating Transcription Factor 3; D000903:Antibiotics, Antineoplastic; C495901:TP53 protein, human; D016159:Tumor Suppressor Protein p53; D014579:Urotensins; D004317:Doxorubicin; C029677:urotensin II; D019869:Phosphatidylinositol 3-Kinases; D051057:Proto-Oncogene Proteins c-akt