title: Overexpression of Sema3a in myocardial infarction border zone decreases vulnerability of ventricular tachycardia post-myocardial infarction in rats.
abstract: The expression of the chemorepellent Sema3a is inversely related to sympathetic innervation. We investigated whether overexpression of Sema3a in the myocardial infarction (MI) border zone could attenuate sympathetic hyper-innervation and decrease the vulnerability to malignant ventricular tachyarrhythmia (VT) in rats. Survived MI rats were randomized to phosphate buffered saline (PBS, n = 12); mock lentivirus (MLV, n = 13) and lentivirus-mediated overexpression of Sema3a (SLV, n = 13) groups. Sham-operated rats served as control group (CON, n = 20). Cardiac function and electrophysiological study (PES) were performed at 1 week later. Blood and tissue samples were collected for histological analysis, epinephrine (EPI), growth-associated factor 43 (GAP43) and tyrosine hydroxylase (TH) measurements. QTc intervals were significantly shorter in SLV group than in PBS and MLV groups (168.6 ± 7.8 vs. 178.1 ± 9.5 and 180.9 ± 8.2 ms, all P < 0.01). Inducibility of VT by PES was significantly lower in the SLV group [30.8% (4/13)] than in PBS [66.7% (8/12)] and MLV [61.5% (8/13)] groups (P < 0.05). mRNA and protein expressions of Sema3a were significantly higher and the protein expression of GAP43 and TH was significantly lower at 7 days after transduction in SLV group compared with PBS, MLV and CON groups. Myocardial EPI in the border zone was also significantly lower in SLV group than in PBS and MLV group (8.73 ± 1.30 vs. 11.94 ± 1.71 and 12.24 ± 1.54 μg/g protein, P < 0.001). Overexpression of Sema3a in MI border zone could reduce the inducibility of ventricular arrhythmias by reducing sympathetic hyper-reinnervation after infarction.
authors.affiliation: Department of Cardiology, School of Medicine, Xinhua Hospital, Shanghai Jiaotong University, Shanghai, China.
authors.forename: Ren-Hua
authors.initials: RH
authors.lastname: Chen
authors.forename: Yi-Gang
authors.initials: YG
authors.lastname: Li
authors.forename: Kun-Li
authors.initials: KL
authors.lastname: Jiao
authors.forename: Peng-Pai
authors.initials: PP
authors.lastname: Zhang
authors.forename: Yu
authors.initials: Y
authors.lastname: Sun
authors.forename: Li-Ping
authors.initials: LP
authors.lastname: Zhang
authors.forename: Xiang-Fei
authors.initials: XF
authors.lastname: Fong
authors.forename: Wei
authors.initials: W
authors.lastname: Li
authors.forename: Yi
authors.initials: Y
authors.lastname: Yu
mesh_terms: D000818:Animals; D004562:Electrocardiography; D004797:Enzyme-Linked Immunosorbent Assay; D004837:Epinephrine / Q000378:metabolism; D019922:GAP-43 Protein / Q000378:metabolism; D005786:Gene Expression Regulation; D006321:Heart / Q000294:innervation / Q000503:physiopathology; D016086:Lentivirus / Q000235:genetics; D008297:Male; D008845:Microinjections; D009203:Myocardial Infarction / Q000150:complications* / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology; D055495:Neurogenesis; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D040121:Semaphorin-3A / Q000235:genetics / Q000378:metabolism*; D013318:Stroke Volume; D016019:Survival Analysis; D017180:Tachycardia, Ventricular / Q000000981:diagnostic imaging / Q000209:etiology* / Q000235:genetics / Q000503:physiopathology; D014161:Transduction, Genetic; D014463:Ultrasonography
chemical_list: D019922:GAP-43 Protein; D012333:RNA, Messenger; D040121:Semaphorin-3A; D004837:Epinephrine