Adenovirus-mediated osteoprotegerin ameliorates cartilage destruction by inhibiting proteoglycan loss and chondrocyte apoptosis in rats with collagen-induced arthritis.

Our aim is to elucidate the effects of osteoproteogerin (OPG) on cartilage destruction in rats as a model of collagen-induced arthritis (CIA). To establish the CIA model, Sprague Dawley rats were injected with bovine type II collagen solution subcutaneously via the tails. Adenovirus-mediated OPG (Ad-OPG) was then injected intra-articularly either at the beginning of CIA (early OPG treatment) or one week after CIA establishment (late OPG treatment); vehicle or Ad-green fluorescent protein were injected as controls. The rats were killed 4 weeks after treatment. Ankle-joint sections were obtained for histology. Serum samples were collected for enzyme-linked immunosorbent assay. Safranin O staining showed that proteoglycan loss was inhibited in the early and late Ad-OPG groups. Terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling staining revealed that both early and late Ad-OPG treatments significantly prevented chondrocyte apoptosis in CIA rats. Furthermore, disintegrin and metalloproteinase with thrombospondin motif-5 expression decreased remarkably in the early and late OPG treatment groups. However, the cartilage destruction score, cartilage oligomeric matrix protein level and caspase-3 expression were only decreased in the early Ad-OPG treatment group. Additionally, ankle-joint swelling and the interleukin-1ß expression level in CIA rats were not notably altered by Ad-OPG treatment. Taken together, our results suggest that early Ad-OPG treatment has potent protective effects against cartilage destruction during rheumatoid arthritis progression, mainly by reducing proteoglycan loss and chondrocyte apoptosis.

[Early total care pattern for intertrochanteric fracture of femur in the elderly].

OBJECTIVE: To evaluate clinical results of early total care (ETC) treatment for elderly patients with intertrochanteric femur fractures. METHODS: Clinical data of 106 elderly patients with intertrochanteric fracture treated from January 2012 and February 2015 were retrospectively studied. According to whether receiving the early total care mode, the patients were divided into 2 groups, 34 cases were diagnosed and treated with early total care pattern (ETC group), including 14 males and 20 females with an average age of (74.88 ± 4.38) years old ranging from 70 to 86. According to Evans types, 4 cases were type I, 5 cases were type II, 13 cases were type III, 11 cases were type IV, 1 case was type V. Seventy-two patients were treated with conventional trauma method (conventional group), including 35 males and 37 females with an average age of (74.46 ± 3.63) years old ranging from 70 to 85. According to Evans type, 8 cases were type I ,13 cases were type II, 25 cases were type III, 25 cases were type IV, and 1 case was type V. All fractures were treated with proximal femoral nails anti-rotation (PFNA). Operative time, hospital stays, leaving bed time, complications, cases of death at 1 year after operation, postoperative Harris score at 12 months were observed and compared. RESULTS: All patients were followed up, the time of ETC group ranged from 9 to 18 months with an average of 13.29 ± 1.51, and the time in conventional group ranged from 12 to 16 months with an average 12.93 ± 1.15, while there was no significant difference between two groups in time of following-up (t = 1.368, P = 0.174). There was no significant meaning in cases of death between ETC group (2 cases) and conventional group (8 cases). Three cases occurred complications in ETC group, and 20 cases in conventional group,there was obvious meaning between two groups (χ² = 0.739, P = 0.318). Operative time,hospital stays,leaving bed time in ETC group respectively was (2.03 ± 0.67) d, (15.41 ± 2.87) d and (3.62 ± 0.74) d; while in conventional group respectively was (4.17 ± 1.59) d, (20.11 ± 4.24) d and (5.35 ± 1.22) d; there were significant differences between two groups in operative time, hospital stays, leaving bed time. Postoperative Harris scores at 12 months in ETC group was (82.32 ± 4.56), and (79.24 ± 5.52) in conventional group, there was obvious meaning between two groups (t = 2.833, P = 0.006). CONCLUSION: ETC pattern is a novel method for diagnosis and treatment of intertrochanteric femur fractures in elderly, it could shorten operative time, hospital stays, leaving bed time, decrease complications and promote recovery of function.

Osteoprotegerin promotes the proliferation of chondrocytes and affects the expression of ADAMTS-5 and TIMP-4 through MEK/ERK signaling.

The involvement of osteoprotegerin (OPG) in bone metabolism has previously been established; however, whether OPG regulates chondrocytes directly and exerts precise cellular and molecular effects on chondrocytes remains to be determined. Thus, the present study aimed to investigate the direct effect of OPG on the viability, proliferation and functional consequences of chondrocytes. Primary chondrocytes were isolated from the knee of Sprague-Dawley rats. Passage 1 chondrocytes were identified by toluidine blue staining and used in the experiments. The cell proliferation induced by OPG at various concentrations was measured by a Cell Counting kit-8 (CCK-8) assay. Following pretreatment with mitogen-activated/extracellular signal-regulated kinase kinase (MEK) inhibitor U0126, extracellular signal-regulated kinase (ERK) inhibitor PD098059, and P38 mitogen-activated protein kinase (P38MAPK) inhibitor SB203580 for 30 min, chondrocytes were treated with OPG, and CCK-8 was performed. The cellular signals of MAPKs, including ERK, P38MAPK and c-Jun N-terminal protein kinase (JNK), were investigated by western blot analysis following treatment with OPG. The functional consequences following treatment with soluble OPG were analyzed by qPCR and western blot analysis. OPG increased chondrocyte proliferation with maximal effect at 10 ng/ml, and induced the phosphorylation of MEK and ERK but not P38MAPK or JNK. Suppression of ERK activity via PD098095 inhibited OPG-induced chondrocyte proliferation. Administration of OPG significantly downregulated ADAMTS­5 and upregulated tissue inhibitor of metalloproteinase (TIMP)-4 production, but had no effect on the expression of TIMP-1, -2 and -3, insulin-like growth factor I, transforming growth factor-ß, basic fibroblast growth factor, bone morphogenetic protein-2, collagen II, aggrecan and ADAMTS-4. Suppression of ERK activity via PD098095 inhibited the alteration of ADAMTS-5 and TIMP-4 expression induced by OPG. OPG therefore regulated the proliferation of chondrocytes via MEK/ERK signaling, and directly affected chondrocytes by influencing the expression profile of ADAMTS-5 and TIMP-4.