OBJECTIVES/HYPOTHESIS: To determine whether the myotrophic activity of human insulin-like growth factor (hIGF)-1 promotes restoration of normal myosin heavy chain (MHC) composition after nerve injury, MHC composition was analyzed after hIGF-1 gene transfer in denervated rat laryngeal muscle. STUDY DESIGN: Animal model to study effects of gene transfer on laryngeal paralysis. METHODS: In anesthetized rats, the left recurrent and superior laryngeal nerves are cut and suture ligated. A midline thyrotomy is performed, and the thyroarytenoid muscle is injected with a polyvinyl-based formulation containing a muscle specific expression system and hIGF-1 DNA (treatment group) or saline (control group). After 30 days, animals were killed, and the thyroarytenoid muscle was removed and processed for sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Densitometric measurements were obtained to determine composition of MHCs. RESULTS: As previously described, MHC composition in denervated laryngeal muscle was characterized by a decrease in type IIB and IIL and up-regulation of IIA/IIX. Compared with controls, hIGF-1 treated animals demonstrated a significant increase in expression of type IIB and IIL and a significant decrease in expression of type IIA/X. CONCLUSIONS: These findings suggest that the myotrophic effect of hIGF-1 gene transfer results in normalization of MHC composition in denervated muscle, with suppression of type IIA/X MHC and promotion of type IIL expression.
OBJECTIVES/HYPOTHESIS: To determine whether the myotrophic activity of human insulin-like growth factor (hIGF)-1 promotes restoration of normal myosin heavy chain (MHC) composition after nerve injury, MHC composition was analyzed after hIGF-1 gene transfer in denervated rat laryngeal muscle. STUDY DESIGN: Animal model to study effects of gene transfer on laryngeal paralysis. METHODS: In anesthetized rats, the left recurrent and superior laryngeal nerves are cut and suture ligated. A midline thyrotomy is performed, and the thyroarytenoid muscle is injected with a polyvinyl-based formulation containing a muscle specific expression system and hIGF-1 DNA (treatment group) or saline (control group). After 30 days, animals were killed, and the thyroarytenoid muscle was removed and processed for sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Densitometric measurements were obtained to determine composition of MHCs. RESULTS: As previously described, MHC composition in denervated laryngeal muscle was characterized by a decrease in type IIB and IIL and up-regulation of IIA/IIX. Compared with controls, hIGF-1 treated animals demonstrated a significant increase in expression of type IIB and IIL and a significant decrease in expression of type IIA/X. CONCLUSIONS: These findings suggest that the myotrophic effect of hIGF-1 gene transfer results in normalization of MHC composition in denervated muscle, with suppression of type IIA/X MHC and promotion of type IIL expression.
Authors: Howard W Francis; Ira Papel; Ioan Lina; Wayne Koch; David Tunkel; Paul Fuchs; Sandra Lin; David Kennedy; Robert Ruben; Fred Linthicum; Bernard Marsh; Simon Best; John Carey; Andrew Lane; Patrick Byrne; Paul Flint; David W Eisele Journal: Laryngoscope Date: 2015-08-22 Impact factor: 3.325
Authors: R Andrew Shanely; Kevin A Zwetsloot; Thomas E Childs; Simon J Lees; Richard W Tsika; Frank W Booth Journal: Am J Physiol Cell Physiol Date: 2009-08-05 Impact factor: 4.249
Authors: Benjamin R Slavin; Karim A Sarhane; Nicholas von Guionneau; Phillip J Hanwright; Chenhu Qiu; Hai-Quan Mao; Ahmet Höke; Sami H Tuffaha Journal: Front Bioeng Biotechnol Date: 2021-06-24