IMPACT OF VIRAL-MEDIATED IGF-I GENE TRANSFER ON SKELETAL MUSCLE FOLLOWING

这个子项目是利用资源的许多研究子项目之一。 由NIH/NCRR资助的中心拨款提供。对子项目的主要支持 子项目的首席调查员可能是由其他来源提供的， 包括美国国立卫生研究院的其他来源。为子项目列出的总成本可能 表示该子项目使用的中心基础设施的估计数量， 不是由NCRR赠款提供给次级项目或次级项目工作人员的直接资金。 胰岛素样生长因子I(IGF-I)是一种强有力的生肌因子，在肌肉再生和肌肉肥大中起着关键作用。本研究的目的是评估IGF-I过表达对以快速抽动为主的肌肉进行石膏固定一段时间后，在重新负荷/移位过程中对肌肉大小和功能恢复的影响。此外，我们还研究了IGF-I受体和结合蛋白(BPS)中伴随的分子反应。将IGF-I重组腺相关病毒载体(rAAV-IGF-IA)注射于幼龄(3wk)C57BL6雌性小鼠一侧后肢前室。20wk龄时，双后肢短位固定2wk，解除胫前肌(TA)和指长伸肌(EDL)的负荷。分别于石膏固定2wk、游离笼移位1wk和3wk后摘除双侧TA和EDL肌。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Insulin-like growth factor I (IGF-I) is a potent myogenic factor that plays a critical role in muscle regeneration and muscle hypertrophy. The purpose of this study was to evaluate the effect of IGF-I overexpression on the recovery of muscle size and function during reloading/reambulation after a period of cast immobilization in predominantly fast twitch muscles. In addition, we investigated concomitant molecular responses in IGF-I receptor and binding proteins (BPs). Recombinant adeno-associated virus vector for IGF-I (rAAV-IGF-IA) was injected into the anterior compartment of one of the hindlimbs of young (3 wk) C57BL6 female mice. At 20 wk of age, both hindlimbs were cast immobilized in a shortened position for 2 wk to unload the tibialis anterior (TA) and extensor longus digitorum (EDL) muscles. The TA and EDL muscles were removed bilaterally after 2 wk of cast immobilization and after 1 and 3 wk of free cage reambulation.