title: Phosphorylated Myosin Light Chain 2 (p-MLC2) as a Molecular Marker of Antemortem Coronary Artery Spasm.
abstract: BACKGROUND It is not uncommon that only mild coronary artery stenosis is grossly revealed after a system autopsy. While coronary artery spasm (CAS) is the suspected mechanism of these deaths, no specific biomarker has been identified to suggest antemortem CAS. MATERIAL AND METHODS To evaluate the potential of using phosphorylated myosin light chain 2 (p-MLC2) as a diagnostic marker of antemortem CAS, human vascular smooth muscle cells (VSMCs) were cultured and treated with common vasoconstrictors, including prostaglandins F2α (PGF2α), acetylcholine (ACh), and 5-hydroxy tryptamine (5-HT). The p-MLC2 level was examined in the cultured cells using Western blot analysis and in a rat model of spasm provocation tests using immunohistochemistry (IHC). Effects of increased p-MLC2 level on VSMCs contractile activities were assessed in vitro using confocal immunofluorescence assay. Four fatal cases with known antemortem CAS were collected and subject to p-MLC2 detection. RESULTS The p-MLC2 was significantly increased in VSMCs after treatments with vasoconstrictors and in the spasm provocation tests. Myofilament was well-organized and densely stained in VSMCs with high p-MLC2 level, but disarrayed in VSMCs with low p-MLC2 level. Three of the 4 autopsied cases showed strongly positive staining of p-MLC2 at the stenosed coronary segment and the adjacent interstitial small arteries. The fourth case was autopsied at the 6th day after death and showed negative-to-mild positive staining of p-MLC2. CONCLUSIONS p-MLC2 might be a useful marker for diagnosis of antemortem CAS. Autopsy should be performed as soon as possible to collect coronary arteries for detection of p-MLC2.
authors.affiliation: Department of Forensic Medicine, School of Basic Medical Sciences, Fudan University, Shanghai, China (mainland).
authors.forename: Liliang
authors.initials: L
authors.lastname: Li
authors.affiliation: School of Forensic Medicine, Kunming Medical University, Kunming, Yunnan, China (mainland).
authors.forename: Yuhua
authors.initials: Y
authors.lastname: Li
authors.affiliation: Department of Forensic Medicine, School of Basic Medical Sciences, Fudan University, Shanghai, China (mainland).
authors.forename: Junyi
authors.initials: J
authors.lastname: Lin
authors.affiliation: Department of Forensic Medicine, School of Basic Medical Sciences, Fudan University, Shanghai, China (mainland).
authors.forename: Jieqing
authors.initials: J
authors.lastname: Jiang
authors.affiliation: Department of Forensic Medicine, School of Basic Medical Sciences, Fudan University, Shanghai, China (mainland).
authors.forename: Meng
authors.initials: M
authors.lastname: He
authors.affiliation: Forensic Science Center, East China University of Political Science and Law, Shanghai, China (mainland).
authors.forename: Daming
authors.initials: D
authors.lastname: Sun
authors.affiliation: Department of Forensic Medicine, School of Basic Medical Sciences, Fudan University, Shanghai, China (mainland).
authors.forename: Ziqin
authors.initials: Z
authors.lastname: Zhao
authors.affiliation: Department of Forensic Medicine, School of Basic Medical Sciences, Fudan University, Shanghai, China (mainland).
authors.forename: Yiwen
authors.initials: Y
authors.lastname: Shen
authors.affiliation: Department of Forensic Medicine, School of Basic Medical Sciences, Fudan University, Shanghai, China (mainland).
authors.forename: Aimin
authors.initials: A
authors.lastname: Xue
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D001794:Blood Pressure / Q000187:drug effects; D024722:Cardiac Myosins / Q000378:metabolism*; D002478:Cells, Cultured; D017023:Coronary Angiography / Q000379:methods; D023921:Coronary Stenosis / Q000378:metabolism*; D003329:Coronary Vasospasm / Q000378:metabolism*; D003331:Coronary Vessels / Q000378:metabolism; D003933:Diagnosis; D006801:Humans; D008297:Male; D018994:Myosin Light Chains / Q000378:metabolism*; D010766:Phosphorylation; D051381:Rats; D017207:Rats, Sprague-Dawley; D014662:Vasoconstrictor Agents / Q000627:therapeutic use
chemical_list: D015415:Biomarkers; D018994:Myosin Light Chains; D014662:Vasoconstrictor Agents; C107184:myosin light chain 2; D024722:Cardiac Myosins