Objective To observe expression of Caspase-3 and apoptosis around the prosthesis and explore the relationship of the expression and the apoptosis with the periimplant osteolysis. Methods From April 2001 to August 2006, 16 patients (10 males, 6 females) underwent the revision total hip arthroplasty surgery, who had the primary total hip arthroplasty at the ages of 45-67 years and had the revision total hip arthroplasty at the ages of 55-78 years, with the implantation duration of 7-13 years. According to their preoperative X-ray films andthe findings during the operation, the patients were divided into two groups: theloose/osteolytic group (n=8) and the loose/non-osteolytic group (n=8). The interface tissues were obtained from the peri-implant region in the patients. The synovial samples were taken from another 6 patients (2 males, 4 females; age, 54-68years; illness course, 9-15 years), who underwent the primary total hip arthroplasty for osteoarthritis. These 6 patients were used as controls. The tissues were prepared for the immunohistochemical assays to determine the expression of Caspase-3. The TUNEL assays were performed to quantify the apoptotic cells. The quantitative analysis on the positive cells and the correlation with the presence of the particulate wear debris and the severity of osteolysis were also performed. Results The level of the expression for Caspase-3 and the apoptosis index inthe loose/osteolytic group were significantly increased when compared with those in the loose/non-osteolytic group and the control group (P＜0.01). The polyethylene particles were surrounded by more positive cells than the metal particles. The positive cells were present at a higher level in the tissue sections where the high-wear status was present when compared with the areas where the low-wear status was present (P＜0.05). Conclusion There is a statistical correlation of the Caspase-3 expression to the apoptosis index and to the presence of the particulate wear debris and the severity of osteolysis, which may be one of the key points for the bone reconstruction inhibition and the bone resorption at the boneimplant interface under the stimulation of the wear debris. The apoptosis is involved in the pathogenesis of the aseptic loosening, which is closely related to the signal transportation of Caspase-3.
Objective To observe the effect of pilose antler polypeptides(PAP)on the apoptosis of rabbit marrow mesenchymal stem cells (MSCs) differentiated into chondrogenic phenotype by interleukin 1β (IL-1β) so as to optimize the seeding cells in cartilage tissue engineering. Methods The MSCs were separated from the nucleated cells fraction of autologus bone marrow by density gradient centrifuge and cultured in vitro. The MSCs were induced into chondrogenic phenotype by transforming growth factor β1(TGF-β1) and basic fibroblast growth factor(bFGF). According to different medias, the MSCs were randomly divided into four groups: group A as black control group, group B(100 ng IL-1β)，group C(10 μg/ml PAP+100 ng IL-1β) and group D(100 ng/ml TGF-β1 +100 ng IL-1β). The samples were harvested and observed by morphology, flow cytometry analysis, RT-PCR and ELISA at 24, 48 and 72 hours. Results The intranuclear chromatin agglutinated into lump and located under nulear membranes which changed into irregular shapeat 24 hours. The intranuclear chromatin agglutinated intensifily at 48 hours. Then the nucear fragments agglutinated into apoptosic corpuscles at 72 hours in group B. The structure change of cells in groups C and D was later than that in group B, and the number of cells changed shape was fewer than that in group B. The structure change of cells in group A was not significant. The apoptosic rate of cells, the mRNA expression of Caspase-3 and the enzymatic activity of Caspase-3 gradually increased in group B, and there were significant differences compared with groups A,C and D(Plt;0.01). Conclusion Caspase-3 is involved in aoptosis of the MSCs differentiated into chondrogenic phenotype cultured in vitro. PAP could prevent from or reverse apoptosis of these MSCs by decreasing the expression of Caspase-3 and inhibiting the activity of Caspase-3.
Objective To observe the biological characters of chondrocytes in articular loose body and to find out seeding cells for cartilage tissue engineering. Methods Samples from 5 loose body cartilages, 2 normal articular cartilages and 6 osteoarthritis articular cartilages were collected. Part of each sample’s cartilage was histologically studied to observe the chondrocytes distribution the morphologic changes by toluidine-blue staining, chondrocytes’ apoptosis by terminal deoxynucleotidyl transferase mediated deoxyuridine triphosphate-biotin nick end-labeling (TUNEL). The rest of each cartilage was digested and isolated by 0.25% trypsin and 0.2% collagenase Ⅱ, and then were cultivated in 10%DMEM. Their morphologic changes were observed 24h later.Comparison was made btween three cartilages. Results Compared with normal cartilage and osteoarthritis articular cartilage, the cells density was higher, their lacunars were larger, cells distribution was irregular, and apoptosis was more apparent in loose body cartilage. Conclusion The characters of chondrocytes from loose body is more like fibroblasts so they can not serve as seeding cells directly for cartilage tissue engineering.
