CCL2 and sarcopenia: Similarly, increased expression levels of chemokine (C-C motif) ligand 2 (CCL2) were detected in C2C12 myoblasts with senescence induced by oleic acid treatment [20], whereas increased expression of matrix metallopeptidase 3 (MMP3) was detected in muscle fibers overexpressing p16 and p21 from mice with sarcopenia induced by 1,25-dihydroxycholecalciferol deficiency [21].