title: [Lycopene protects against hypoxia/reoxygenation injury in mouse cardiomyocytes by inhibiting endoplasmic reticulum stress induced apoptosis].
abstract: OBJECTIVE
  To investigate the effects of lycopene on primary cultured neonatal mouse cardiomyocytes with hypoxia/reoxgenation (H/R) injury and explore related mechanism.
  
  
  METHODS
  Primary cultured neonatal mouse cardiomyocytes were randomly divided to control group (control); lycopene group (5 μmol/L, lyc); H/R group (4 hours hypoxia followed by 6 hours reoxgenation); lycopene+ H/R group (lyc+ H/R, the cardiomyocytes were incubated with 5 μmol/L lycopene for 4 hours before H/R treatment). The cell viability of cardiomyocytes was assessed by CCK-8 assay. The apoptotic rate of cardiomyocytes was evaluated by flow cytometry using AnnexinV-PI double staining. Western blot was used to determine the GRP78, CHOP, Bax and Bcl-2 protein expression in cardiomyocytes. The mRNA expressions of ATF6、eIF2α and sXbp-1 were detected by real-time PCR. The fluorescence intensity for reactive oxygen species (ROS) in cardiomyocytes was measured with Olympus fluorescence microscope.
  
  
  RESULTS
  Compared to control group, the cell viability of cardiomyocytes was significantly reduced ((64.28±6.12)% vs. (100.00±4.98)%, P<0.01), the apoptotic rate ((24.42±1.76)% vs. (5.16±1.31)%, P<0.01) and ratio of Bax/Bcl-2 (2.33±0.20 vs. 1.00±0.09, P<0.01) significantly increased, the ATF6, eIF2α and sXbp-1 mRNA expression, the CHOP and GRP78 protein expression (1.98±0.15 vs. 1.00±0.12, 2.09±0.11 vs. 1.00±0.09) as well as fluorescence intensity for ROS ((262.13±22.03)% vs. (100.00±12.35)%) were markedly increased in H/R group (all P<0.01). Compared to the H/R group, pretreatment with lycopene markedly improved the cell viability of cardiomyocytes ((81.75±6.85)%, P<0.01), significantly decreased the apoptotic rate ((17.24±2.02)%, P<0.01) and ratio of Bax/Bcl-2(1.64±0.13, P<0.01), significantly down-regulated the mRNA expression levels of ATF6, eIF2α and sXbp-1, and the protein expression levels of CHOP (1.54±0.12) and GRP78 (1.53±0.12), significantly reduced the fluorescence intensity for ROS ((171.18±19.09)%, all P<0.01).
  
  
  CONCLUSIONS
  Lycopene could attenuate hypoxia/reoxygenation-injury in primary cultured neonatal mouse cardiomyocytes, possibly through inhibiting the ER stress and alleviating the ER stress-induced apoptosis.
authors.affiliation: Department of Anesthesiology, North Sichuan Medical College Affiliated Hospital, Nanchong 637000, China.
authors.forename: J Q
authors.initials: JQ
authors.lastname: Xu
authors.forename: B
authors.initials: B
authors.lastname: Chen
authors.forename: H X
authors.initials: HX
authors.lastname: Hu
authors.forename: R C
authors.initials: RC
authors.lastname: Yue
authors.forename: S
authors.initials: S
authors.lastname: Zhang
authors.forename: L
authors.initials: L
authors.lastname: Xu
authors.forename: H
authors.initials: H
authors.lastname: Wang
authors.forename: Q
authors.initials: Q
authors.lastname: Li
authors.forename: C Y
authors.initials: CY
authors.lastname: Tan
authors.forename: H Y
authors.initials: HY
authors.lastname: Chen
authors.forename: R Y
authors.initials: RY
authors.lastname: Zhang
mesh_terms: D051702:Activating Transcription Factor 6 / Q000378:metabolism; D000818:Animals; D017209:Apoptosis; D002338:Carotenoids / Q000494:pharmacology*; D015687:Cell Hypoxia; D002470:Cell Survival; D002478:Cells, Cultured; D000091342:Endoplasmic Reticulum Chaperone BiP; D059865:Endoplasmic Reticulum Stress; D015852:Eukaryotic Initiation Factor-2 / Q000378:metabolism; D006360:Heat-Shock Proteins / Q000378:metabolism; D000077276:Lycopene; D051379:Mice; D032383:Myocytes, Cardiac / Q000187:drug effects*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D011897:Random Allocation; D017382:Reactive Oxygen Species / Q000378:metabolism; D051742:Transcription Factor CHOP / Q000378:metabolism; D000071717:X-Box Binding Protein 1 / Q000378:metabolism; D051028:bcl-2-Associated X Protein / Q000378:metabolism
chemical_list: D051702:Activating Transcription Factor 6; C497112:Atf6 protein, mouse; C494827:Bax protein, mouse; C497250:Ddit3 protein, mouse; D000091342:Endoplasmic Reticulum Chaperone BiP; D015852:Eukaryotic Initiation Factor-2; D006360:Heat-Shock Proteins; C000717248:Hspa5 protein, mouse; D019253:Proto-Oncogene Proteins c-bcl-2; D017382:Reactive Oxygen Species; D000071717:X-Box Binding Protein 1; C000605544:Xbp1 protein, mouse; D051028:bcl-2-Associated X Protein; C052617:Bcl2 protein, mouse; D051742:Transcription Factor CHOP; D002338:Carotenoids; D000077276:Lycopene