Event Title
In Vitro Skeletal Myofiber Disassembly and Recovery with Cardiotoxin
Location
Philadelphia Campus
Start Date
7-5-2014 1:00 PM
Description
Injury to skeletal and cardiac muscle myofibers In Vivo has been effected experimentally by injection of cobra venom cardiotoxin. This cardiotoxin has been shown to specifically disassemble myofibers in muscle while leaving the surrounding tissues unaffected. To determine if cardiotoxin would similarly affect skeletal muscle In Vitro, primary embryonic chick skeletal muscle cultures were exposed to low doses of cardiotoxin from Naja mossambica mossambica. Cells at 4 days in culture were exposed to toxin for 48 hours. Toxin was washed out after the treatment period. Cultures were fed daily, fixed on days 1-3 after wash out and immunofluorescently labeled for muscle specific proteins. Immediately after wash-out it was observed that myofibers had disassembled in the majority of myocytes. Preliminary data indicated that nuclear counts between treated and untreated cultures remained relatively constant suggesting limited cell death in treated cultures. Compared to control cultures, length and girth of treated myocytes as well as number of nuclei per myotube were negatively impacted by toxin exposure. After wash-out toxin treated cultures exhibited thin, unstriated myofibers in mononucleated myocytes by day 2 of recovery. By day 3 of recovery myotubes with 2-3 nuclei, slightly increased girth and small numbers of myofibers with alpha-actinin striations were detected.
In Vitro Skeletal Myofiber Disassembly and Recovery with Cardiotoxin
Philadelphia Campus
Injury to skeletal and cardiac muscle myofibers In Vivo has been effected experimentally by injection of cobra venom cardiotoxin. This cardiotoxin has been shown to specifically disassemble myofibers in muscle while leaving the surrounding tissues unaffected. To determine if cardiotoxin would similarly affect skeletal muscle In Vitro, primary embryonic chick skeletal muscle cultures were exposed to low doses of cardiotoxin from Naja mossambica mossambica. Cells at 4 days in culture were exposed to toxin for 48 hours. Toxin was washed out after the treatment period. Cultures were fed daily, fixed on days 1-3 after wash out and immunofluorescently labeled for muscle specific proteins. Immediately after wash-out it was observed that myofibers had disassembled in the majority of myocytes. Preliminary data indicated that nuclear counts between treated and untreated cultures remained relatively constant suggesting limited cell death in treated cultures. Compared to control cultures, length and girth of treated myocytes as well as number of nuclei per myotube were negatively impacted by toxin exposure. After wash-out toxin treated cultures exhibited thin, unstriated myofibers in mononucleated myocytes by day 2 of recovery. By day 3 of recovery myotubes with 2-3 nuclei, slightly increased girth and small numbers of myofibers with alpha-actinin striations were detected.