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。

Objective To assess whether interleukin-10 (IL-10) is chondropotective in vitro. Methods Chonrocytes Ⅱ. The first passage cells were grown in 24-well plates with DMEM, supplemented with 10% fetal bovine serum, for 2-4 days. The cells were then cultured in 0.1% fetal bovine serum DMEM medium, and given respecitvly interleukin-1 (IL-1) 100μ/ml, IL-1 100μ/ml +recombinant murine interleukin-10 (mnIL-10) 20ng/ml, mmIL-10 20ng/ml, and cultured for 48 hours. Scanning electron morphology and immunohistochemical study of nitric oxide synthease 2 and matric metalloproteinase 3 mRNA in situ hybridization were performed. Cell proliferation and morphology were observed under inverted microscope from the beginning of cell culture for three weeks. Results IL-1 stimulated granule production in the cytoplasma of chondrocytes, and the cells died in the second third weeks of culture. IL-10 antagonized IL-1, protected the cells from death and maintained chondrocyte proliferation. scanning electron morphology showed that IL-1 stimulated the formation of mumerous microvilli on the cell surface, while thin and less numerous microvilli were found in culturre with IL-10. Immunohistochemical study and in situ hybridization showed that IL-10 inhibited NOS2 and MMP3 expression. Conclusion IL-10 not only inhibits the synthesis of inflammatiory cytokines, but also directly protects chondrocytes by antagonizing IL-1.

目的 骨骼基质细胞体外培养条件下是否分化为骨细胞；探索多孔聚乳酸作为组织工程载体吸附培养骨髓基质细胞的可行性。方法 取兔骨髓细胞经培养得到骨髓基质细胞，以地塞米松、维生素C、β-磷酸甘油诱导细胞分化，以原位杂交检测骨桥素和骨连接素mRNA，Von Kossa钙染色检测矿化结节。以生物可降解材料——聚乳酸吸附培养骨髓基质细胞，扫描电镜和组织学苏木精-伊红染色观察细胞的生长情况，并对载体中培养第4～12天细胞计数。结果 骨髓基质细胞经诱导第2周表达骨桥素，第3周表达骨桥素、骨连接素和形成矿化结节。细胞可以进入多孔聚乳酸内部生长，12d细胞密度可以达2.6×107/cm3。结论 骨髓基质细胞含有成骨干细胞；多孔聚乳酸可以吸附骨髓基质细胞生长，因此可能作为骨组织工程材料。

目的 研究骨髓基质细胞修复兔关节软骨的可能性。方法 取自体骨髓基质细胞体外培养扩增，聚乳酸吸附骨髓基质细胞值入兔膝关节软骨负重（内髁）和非负重区（外髁）缺损内，观察4、8、12周后软骨缺损的修复情况，并对组织切片评分。结果 8、12周后，骨髓基质细胞在负重区缺损内可以形成透明软骨，组织评分接近正常软骨优于对照，非负重区内没有形成透明软骨。结论 骨髓基质细胞可以修复关节软骨缺损，摩擦和压应力是成软骨的重要条件。

Bone marrow-derived mesencbymal progenitor cells are capable of chondrogenesis, making them a possible source of cells for carrtilano tisssee engineering. Because of this, we studied the effect of human transforming growth factor β2 (TGF-β2) on mesenehymal progenitor cell chondrogenesis in monolayer culture using gene transfecion technology. A recombinant pcDNA3.1 (+)/TGF-β2 construct containing a full-length TGF-β2 from a human placental cDNA library was created through gone cloning and DNA recombination. The construct was then lipofected into mesenchymal progenitor cells isolated from human bone marrow. RT-PCR, Western bthrtth, and immunohistochemistry analyses were performed to idemify the expression of TGF-β2 and earilage-associated genes and proteins. The results showed that TGF-β2 was expressed throughout the culture period. The transfected progenitor cells expressed and produced collagen type Ⅱ and aggrecan 48h after transfection, and the expression and synthesis were upregulated after 4 weeks. In contrast, the tested genes and proteins were not detected in non-transfected cells, This shows that transfection of pcDNA3.1(+)/TGF.β2 into mesenchymal progenitor cells is able to provide transient and peristent expression of cartilage-specific genes and proteins, and suggests that the differentiation of human marrow-derived mesenchymal progenitor cell into chondrocytes in monolayer culture is feasible and mky be induced by TGF-β2.