RT Journal Article
SR Electronic
T1 Impaired myogenesis in the quadriceps muscle of cachectic COPD patients
JF European Respiratory Journal
JO Eur Respir J
FD European Respiratory Society
SP 4433
VO 44
IS Suppl 58
A1 Carme Casadevall
A1 Sergi Pascual
A1 Simón García
A1 Pilar Ausín
A1 Xavier Trepat
A1 Esther Barreiro
A1 Joaquim Gea
YR 2014
UL http://erj.ersjournals.com/content/44/Suppl_58/4433.abstract
AB Although muscle mass loss is frequently observed in COPD patients, its etiology remains to be fully elucidated. Preliminary reports have suggested that there is a defect in the number or function of satellite cells resulting in an inefficient myonuclear turnover, which would involve a decrease in protein synthesis in the corresponding cytosolic domains. Aim: To test this hypothesis we have studied the myogenic process in the quadriceps muscle of cachectic COPD patients. Methods: Muscle biopsies from 15 cachectic and 15 non-cachectic severe COPD patients and 10 healthy subjects were obtained. Fibers and satellite cells were evaluated using immunohistochemistry and morphometric techniques, whereas the expression of the main myogenic factors was studied by real-time PCR. In addition, myocytes obtained from biopsies were cultured and their proliferation and differentiation phases were also analyzed. Main Results: The quadriceps of cachectic COPD patients showed smaller fibers and only slight signs of muscle injury. Surprisingly, the number of satellite cells was increased in this population, despite that muscles showed a concomitant downregulation of the late-stages markers of myogenesis. Proliferation and differentiation of myocytes in primary cultures did not show differences between cachectic patients and controls. Conclusions: Our results suggest that in cachectic COPD patients, the “in vivo” myogenic process is defective, and such impairment seems to be the result of the interaction of local factors with myogenic events in those patients.Funded by SAF 2011-26908, FIS 11/02029 & 12/02534, SEPAR 761, FUCAP 2009 and CIBERES.