Yin Yang 1 expression and localisation in quadriceps muscle in COPD.

Introduction: Yin Yang 1 (YY1) is a transcriptional repressor that inhibits muscle gene expression and myogenesis. YY1 has not previously been investigated in the skeletal muscle of patients with COPD. The aims of this study were to investigate YY1 expression and localisation in the quadriceps muscle of COPD patients compared to healthy age-matched controls, and examine the relationship between YY1 expression and localisation and quadriceps muscle fibre cross-sectional area (CSA) in COPD patients.