The chitinase-like proteins YKL-39 (chitinase 3-like-2) and Chitortriosidase (CHIT-1) are members of the chitinases family. YKL-39 expression has been associated with osteoarthritis, whereas CHIT-1 activity is regarde...The chitinase-like proteins YKL-39 (chitinase 3-like-2) and Chitortriosidase (CHIT-1) are members of the chitinases family. YKL-39 expression has been associated with osteoarthritis, whereas CHIT-1 activity is regarded as a biochemical marker of macrophage activation. So far, the physiological or pathological role of YKL-39 in the inflammation is still poorly understood. We compared YKL-39 and CHIT-1 modulation during monocyte to macrophage transition and polarization. Gene expression analysis was investigated by real-time PCR from mRNA of human monocytes obtained from buffy coat of healthy volunteers, from mRNA of polarized macrophages to classically activated macrophages (or M1), obtained by interferon-γ and lipopolysaccharide exposure, and from mRNA of alternatively activated macrophages (or M2) obtained by interleukin-4 exposure. We demonstrated different variations of YKL-39 and CHIT-1 production during macrophages polarization. CHIT-1 levels gradually increase in the course of the time with a peak of expression between the fifth and the seventh day of culture. In contrast, YKL-39 expression was unaltered in the diverse stage of HMMs differentiation, but increased significantly in M1 polarized macrophages and reverted to base levels in M2 polarized macrophages. These findings indicated that the function of YKL-39 is much more restricted and selective than that exerted by CHIT-1.展开更多
文摘The chitinase-like proteins YKL-39 (chitinase 3-like-2) and Chitortriosidase (CHIT-1) are members of the chitinases family. YKL-39 expression has been associated with osteoarthritis, whereas CHIT-1 activity is regarded as a biochemical marker of macrophage activation. So far, the physiological or pathological role of YKL-39 in the inflammation is still poorly understood. We compared YKL-39 and CHIT-1 modulation during monocyte to macrophage transition and polarization. Gene expression analysis was investigated by real-time PCR from mRNA of human monocytes obtained from buffy coat of healthy volunteers, from mRNA of polarized macrophages to classically activated macrophages (or M1), obtained by interferon-γ and lipopolysaccharide exposure, and from mRNA of alternatively activated macrophages (or M2) obtained by interleukin-4 exposure. We demonstrated different variations of YKL-39 and CHIT-1 production during macrophages polarization. CHIT-1 levels gradually increase in the course of the time with a peak of expression between the fifth and the seventh day of culture. In contrast, YKL-39 expression was unaltered in the diverse stage of HMMs differentiation, but increased significantly in M1 polarized macrophages and reverted to base levels in M2 polarized macrophages. These findings indicated that the function of YKL-39 is much more restricted and selective than that exerted by CHIT-1.
