title: Antifibrotic effects of Smad4 small interfering RNAs in injured skeletal muscle after acute contusion.
abstract: Muscle injuries are common musculoskeletal problems encountered in sports medicine clinics. In this study, we examined the effect of lentivirus-mediated small interfering RNA (siRNA) targeting Smad4 on the suppression of the fibrosis in injured skeletal muscles. We found that Smad4-siRNA could efficiently knock down the expression of Smad4 in the C2C12 myoblast cells and in the contunded mice gastrocnemius muscle. The expression of mRNA level of Smad4 decreased to 11% and 49% compared to the control group, respectively, and the expression of protein level decreased to 13% and 57% respectively. Moreover, the lentivirus-mediated siRNA was stably transfected only into the skeletal muscle and not into the liver of the animals. In contunded mice gastrocnemius, the collagenous and vimentin-positive area in the Smad4 siRNA group reduced to 36% and 37% compared to the control group, respectively. Furthermore, compared to the scrambled Smad4 siRNA-injected mice and PBS control-injected mice, the muscle function of the mice injected with lentivirus-mediated Smad4 siRNA improved in terms of both fast-twitch and tetanic strength (P<0.05). The results suggest that the gene therapy of inhibiting Smad4 by lentivirus-mediated siRNA could be a useful approach to prevent scar tissue formation and improve the function of injured skeletal muscle.
authors.affiliation: Sports Medicine Center of Fudan University, Department of Sports Medicine, Huashan Hospital, Shanghai, China.
authors.forename: H
authors.initials: H
authors.lastname: Li
authors.forename: J
authors.initials: J
authors.lastname: Chen
authors.forename: S
authors.initials: S
authors.lastname: Chen
authors.forename: Q
authors.initials: Q
authors.lastname: Zhang
authors.forename: S
authors.initials: S
authors.lastname: Chen
mesh_terms: D000818:Animals; D001265:Athletic Injuries / Q000473:pathology / Q000628:therapy; D002460:Cell Line; D003288:Contusions / Q000473:pathology / Q000628:therapy*; D005260:Female; D005355:Fibrosis / Q000209:etiology / Q000517:prevention & control; D015316:Genetic Therapy / Q000379:methods; D005822:Genetic Vectors; D016086:Lentivirus / Q000235:genetics; D051379:Mice; D008810:Mice, Inbred C57BL; D018482:Muscle, Skeletal / Q000293:injuries*; D032446:Myoblasts / Q000473:pathology; D041681:NIH 3T3 Cells; D012333:RNA, Messenger / Q000378:metabolism; D034741:RNA, Small Interfering / Q000008:administration & dosage*; D051901:Smad4 Protein / Q000235:genetics*
chemical_list: D012333:RNA, Messenger; D034741:RNA, Small Interfering; D051901:Smad4 Protein; C490810:Smad4 protein, mouse