ABSTRACT
Objective@#To establish a mouse model of osteoarthritis (OA) and study the bone microarchitecture and bone metabolism of tibial subchondral bone in early stage of OA.@*Methods@#The mouse model of post-traumatic osteoarthritis (PTOA) with anterior cruciate ligament (ACLT) was established by using c57 mice. The Sham operation group served as the control group. All mice were fed with conventional diet. All mice were sacrificed after 4 weeks. The degeneration of knee joint was observed by HE staining and Safranin O-Fast Green staining. The number of osteoclasts was counted by TRAP staining. Micro CT was used to analyze the quantitative parameters of the microstructure of tibia subchondral bone in mice. Serum levels of bone resorption biomarker CTX I and cartilage degeneration marker CTX II were determined.@*Results@#After ACLT 4 weeks, the average score of OARSI in ACLT group was 3.2, which was higher than that in Sham group, and the joint degeneration occurred in mice, presenting the pathological characteristics of early OA. Compared with the sham operation phase, the total subchondral bone volume (TV) of ACLT group was 4.72 mm3, increased by 13.6%; the bone trabecular resolution (Tb.Sp) was 0.130 and 0.154 mm, respectively, and the ACLT group also increased by 18.8%; the bone volume/tissue volume (BV/TV) was 0.470 and 0.294, respectively, and the ACLT group decreased by 48.9%; the bone trabecular thickness (Tb.Th) was 0.162 and 0.083 mm groups, ACLT decreased by 37.5%. Trap staining showed that the number of osteoclasts per unit volume in ACLT group was 72, which was significantly higher than that in sham operation group. The CTX I of mice in the sham operated ACLT group and sham operated group were 20.9 ng/ml and 18.29 ng/ml, with an increase of 48.9% in the ACLT group; the CTX II of mice in the ACLT group and sham operated group were 35.5 ng/ml and 28.6 ng/ml, with an increase of 24.1% in the ACLT group.@*Conclusion@#ACLT Mouse model can successfully construct early OA, which confirms the early loss of osteochondral bone and the pathological changes of osteoclast activation in OA, and provides a new specific target for the treatment of OA.
ABSTRACT
Results : The reactive oxygen species expression in group B was obviously higher than in the other groups, in group C than in groups A, D, and E, and in groups D, E than in group A, all showing significant differences between groups ( P0.05). The oil red O staining positive cells in group B were obviously more than the other groups, and groups C, D, E, and A decreased sequentially, the absorbance ( A) values had significant differences between groups ( P0.05). Real-time fluorescence quantitative PCR detection showed that the relative expressions of PPAR-γ and C/EBP mRNA in group B were significantly higher than those in the other groups, while in group C than in groups A, D, and E, and in groups D, E than in group A ( P0.05). The relative expressions of Runx2 and ALP mRNA in group B were significantly lower than those in the other groups, while in group C than in groups A, D, and E, and in groups D, E than in group A ( P0.05). Western blot detection showed that the relative expression of PPAR-γ and C/EBP protein in group B was significantly higher than those in the other groups, and groups C, D, E, and A decreased sequentially, all showing significant differences between groups ( P<0.05). The relative expression of Runx2 and ALP protein in group B was significantly lower than those in the other groups, and groups C, D, E, and A increased sequentially, all showing significant differences between groups ( P<0.05).
ABSTRACT
MicroRNAs (miRNAs) have recently been recognized to have a role in human orthopedic disorders. The objective of our study was to explore the expression profile and biological function of miRNA-17-5p (miR-17-5p), which is well known to be related to cancer cell proliferation and invasion, in osteoblastic differentiation and in cell proliferation. The expression levels of miR-17-5p in the femoral head mesenchymal stem cells of 20 patients with non-traumatic osteonecrosis (ON) and 10 patients with osteoarthritis (OA) were examined by quantitative reverse transcription-PCR (qRT-PCR). Furthermore, the interaction between miR-17-5p and SMAD7 was observed. We found that in non-traumatic ON samples the level of mature miR-17-5p was significantly lower than that of OA samples (P=0.0002). By targeting SMAD7, miR-17-5p promoted nuclear translocation of beta-catenin, enhanced expression of COL1A1 and finally facilitated the proliferation and differentiation of HMSC-bm cells. We also demonstrated that restoring expression of SMAD7 in HMSC-bm cells partially reversed the function of miR-17-5p. Together, our data suggested a theory that dysfunction of a network containing miR-17-5p, SMAD7 and beta-catenin could contribute to ON pathogenesis. The present study prompts the potential clinical value of miR-17-5p in non-traumatic ON.