Change and significance of osteoprotegerin/receptor activator of NF-κB ligand during differentiation of rat arterial smooth muscle cells into the osteoblast-like cells / 中华老年医学杂志

ABSTRACT

Objective To study the change and significance of osteoprotegerin(OPG)/receptor activator of NF κB ligand(RANKL)during the process of rat arterial smooth muscle cells (SMC) to differentiate subgroups7 d (early) subgroup and 14 d (late) subgroup.into osteoblast-like cells.Methods The rat arterial SMCs were divided randomly into the SMC group,atorvastatin group,and osteoblast-like group.Each group was also divided into 2.The osteoblast-like group was given β-glycerophosphate and vitamin C in culture medium,the atorvastatin group was given both β-glycerophosphate,vitamin C and atorvastatin.Von Kossa staining,Ca2+ content assay,ALP activity assay and osteocalcin assayed with Western blot were used to check the level of calcification.Real-time PCR was used to check the mRNA expressions of OPG and RANKL.Results There was high expression of OPG (early 2.71 ±0.08,late 2.69 ±0.02) but no RANKL in the SMC group all the time.The expressions of OPG were increased in the early subgroup and decreased in late subgroup in the atorvastatin group (early 3.52±0.05,late 2.50±0.03) and osteoblast-like group (early 4.18±0.10,late 2.30 ± 0.11).And the expressions of RANKL were both increased in the atorvastatin group and osteoblast-like group dnring the calcification process (from 1.01 ± 0.19 to 2.40 ± 0.10,and from 1.70±0.07 to 3.22±0.11,respectively).Among the three groups,the ratio of OPG/RANKL was decreased with the increasing calcification level (F =52.93,2.33,both P＜0.05).And compared with the early subgroups,the ratio of OPG/RANKL in the late subgroups was also decreased along with the increase of calcification level in each group(F=38.71,1.74,both P＜0.05).Conclusions The ratio of OPG/RANKL has a negative correlation with the level of the osteoblast-like cells differentiation,and atorvastatin could inhibit the calcification.