AIM: To investigate the expression features of PDCD5 (programmed cell death 5 protein) in osteoarthritic and normal human cartilage, and speculate on its potential functions in the pathogenesis of osteoarthritis (OA). METHODS: Articular cartilage specimens were obtained from 30 patients with OA and 16 healthy patients at the time os arthroplasty. Expression of PDCD5 was detected by flow cytometry, immunofluorescence, RT-PCR and immunohistochemical analysis. RESULTS: Enhanced expression and nuclear accumulation of PDCD5 in OA chondrocytes were found. PDCD5-positive chondrocytes were mainly distributed in the superficial and deep zones of OA tissue sections, as opposed to, in the superficial and middle regions of normal healthy tissue sections.CONCLUSION: Since apoptotic chondrocyte death occurs more frequently in OA cartilage than in normal healthy cartilage and PDCD5 is an apoptosis-related protein, the different expression patterns of PDCD5 in OA cartilage from that in normal healthy cartilage indicate that PDCD5 is involved in the pathogenesis of OA.

To study the effects of hydroxyurea and etoposide transduction of human marrkow mesenchymal and progenitor stem cells by adeno-associated virus (AAV). METHODS: Isolated human bone marrow mesenchymal stem and progenitor cells (hMSCs) were cultured in DMEM containing 10% FBS or 5% FBS and dexamethasone 1umol/L respectively. After being trated with hydroxyurea dn etoposide. hMSCs which indirectly reflected the relative trnasduction efficiency of different groups, and virus DNA was isolated by Hirt extracion for Southemhybridization. RESULTS: Transduction luciferase activity and transduction efficeiency in culture treadeted with hydroxyuread and etoposide were significantly higher than that in control cultures. Diveiding cells had about 20-fold hagher transduction efficeity compared with eontrol cells. Transduction efficeiency in stratinary cells was about 50 time higher than that in control cells. Southern analysis showed that hydroxyurea and etoposide enhanced second-trand DNA synthesis by rAAV. CONCUSION: Hydroxyurea and etoposide could increase trnadsuction efficiency of hMSCs by AAV vectors and stationalry cells were more sensitive to these than dividing cells.

Objective. To demonstratie the roles of p16INK4a in the senescence of human chondrocytes and the progerssion of osteoarthritis (OA). Methods. Immunohistochemistry and reverse transcriptase polymerase chain reaction (RT-PCR) were performed p16INK4a expression in fetal, normal age-matched and OA cartilage, and Western blot was used in primary cultured chondrocytes from diffenent origins. To explored a functional p16INK4a knockdown in OA chondrocytes, the primary cultured cells were treated with p16INK4a-specific small interfering ribonucleic acids (siRNAs). Expression of p16INK4a, p14ARF and p53 was observed by Western blot and RT-PCR. The phosphorylation status of pRb, enescence-associated β- galactosidease (SA-β-gal), cell G1/S transition and cell proliferation were studied by Western blot, histoogical staining, 3H-thymidine incorporation and cell counts respectively. Expression of the collagen Ⅰ, collagen Ⅱ and aggrecan genes was measured by semiquantitative RT-PCR. To establish the response of chondrocytes to cytokines, cells were treated with transfroming growth factor-β1(TGF-β1) or interleukin-1α (IL-1α) and examined for incorporation of 3H-hymidine, 3H-proline and 35S-sulphate respectively. Results. A significant incresase of p16INK4a was detected in OA chondrocytes compared with normal age-matched and fetal chondrocytes (P<0.01) in vivo and in vitro. Treated with p16INK4a-specific siRNAs, OA chondrocytes displayed a significant dectrease in p16INK4a expression with an increase of phosphorylated pRb, but no alteration of p14ARF and p53 expression, followed by decreases of senescent features and increases in the expression of some chondrocyte-specific genes and overall repair capacity. Conclusions. p16INK4a is instrumentsal in the senescence of human articular chondrocytes or OA. The reduction of p16INK4a by RNA interference RNAi) contributed to the recovery of osteoarthritic chondrocytes, suggesting that p16INK4a may be a viable future therapeutic candidate.

关于软骨损伤后自我修复能务有限，不能形成正常透明软骨。人闪希望用细胞移植的方法修复软骨。本文介绍移植修复所涉及的细胞选择。载体系统选择，基质干细胞、载体材料的研究进展。