Growth/differentiation Factor-5 Induces Osteogenic Differentiation of Human Ligamentum Flavum Cells through Activation of ERK1/2 and p38 MAPK

Cellular Physiology and Biochemistry

关键词: Growth/differentiation factor-5;    Ligamentum flavum;    Ossification;    Osteogenic differentiation;    Mitogen-activated protein kinases;   

DOI  :  10.1159/000320526

学科分类：分子生物学，细胞生物学和基因

来源: S Karger AG

【 摘 要 】

Ossification of ligamentum flavum (OLF) is a pathological ectopic ossification in the spinal ligament, leading to spinal canal stenosis, but little was known about its pathogenesis. A previous study has found growth/differentiation factor (GDF)-5 expression at ossified sites of the ligaments from OLF patients. This study aimed to investigate the osteogenic effects of GDF-5 on cultured human ligamentum flavum cells (LFCs). LFCs were isolated from human spinal ligamentum flavum, and treated with or without recombinant human (rh) GDF-5. Alkaline phosphatase (ALP) activity was measured. Expression of osteocalcin was assessed by reverse transcriptase-PCR, Western blotting and immunofluorescence. Matrix mineralization was assessed by alizarin red staining. Activation of mitogen-activated protein kinases (MAPK) ERK1/2, p38 and JNK were detected by Western blotting. We found that rhGDF-5 treatment increased ALP activity and osteocalcin expression in a time- and dose-dependent manner, and induced mineralized nodule form. In addition, rhGDF-5 challenge mediated the ERK1/2 and p38 activation but not JNK. Inhibiting this activation pharmacologically, using U0126, a ERK1/2 inhibitor, or SB203580, a p38 inhibitor, resulted in significantly lower ALP activity and osteocalcin protein expression. The present study shows that rhGDF-5 induces osteogenic differentiation of human LFCs through activation of ERK1/2 and p38 MAPK. These findings give some new insight into the pathogenesis of OLF.

【 授权许可】

CC BY-NC-ND