Gene Expression Profile of Hypertrophic Chondrocytes Treated with HO: A Preliminary Investigation / 中国医学科学杂志(英文版)

Objective To identify the osteogenesis genes whose expression is altered in hypertrophic chondrocytes treated with HO. Methods Murine chondrogenitor cells (ATDC5) were differentiated into hypertrophic chondrocytes by Insulin-Transferrin-Selenium (ITS) treatment, and then treated with HO. Suitable conditions (concentration, time) were determined by using the MTT assay. After total RNA isolation and cDNA synthesis, the levels of 84 genes were determined using the PCR array, whereas quantitative RT-PCR was carried out to validate the PCR array data. Result We identified 9 up-regulated genes and 12 down-regulated genes, encoding proteins with various functions, such as collagen proteins, transcription factors, proteins involved in skeletal development and bone mineral metabolism, as well as cell adhesion molecules. Quantitative RT-PCR confirmed the altered expression of 5 down-regulated genes (Smad2, Smad4, transforming growth factor $\beta$ receptor 1, transforming growth factor $\beta$ receptor 3, and matrix metalloproteinase 10). Conclusions HO significantly changed the expression of several genes involved in a variety of biological functions. Because of the link between oxidative damage and Kashin-Beck disease, these genes may also be involved in the deep-zone necrosis of the cartilage observed in Kashin-Beck disease.

Expression of Proteus mirabilis polyphosphate kinase and preparation of its polyclonal antibodies / 南方医科大学学报

<p><b>OBJECTIVE</b>To express and purify polyphosphate kinase (PPK) from Proteus mirabilis and prepare the polyclonal antibody against PPK.</p><p><b>METHODS</b>The antigenicity and hydrophobicity of PPK were analyzed using software. The N-terminal conservative sequence containing 309 amino acids was selected as the target peptide, and its corresponding gene sequence with modification based on prokaryotic cells-preferred codon was synthesized and inserted into plasmid pET28b(+). The constructed recombinant plasmid was transformed into Escherichia coli BL21 (DE3) and induced with IPTG. The expressed fusion protein was purified using Ni-affinity chromatography. The purified protein was injected along with adjuvant in rabbits to prepare the polyclonal antibodies against PPK.</p><p><b>RESULTS AND CONCLUSION</b>PPK fusion protein expressed by E. coli was purified successfully using Ni-affinity chromatography. ELISA result demonstrated that the harvested rabbit anti-sera against PPK had a high titer of 1:512 000, and Western blotting showed a good specificity of the antibody, which can be used further study of the role of PPK in the pathogenesis of Proteus mirabilis infection.</p>

Increased Chondrocyte Apoptosis in Kashin-Beck Disease and Rats Induced by T-2 Toxin and Selenium Deficiency / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To investigate chondrocyte apoptosis and the expression of biochemical markers associated with apoptosis in Kashin-Beck disease (KBD) and in an established T-2 toxin- and selenium (Se) deficiency-induced rat model.</p><p><b>METHODS</b>Cartilages were collected from the hand phalanges of five patients with KBD and five healthy children. Sprague-Dawley rats were administered a selenium-deficient diet for 4 weeks prior to T-2 toxin exposure. The apoptotic chondrocytes were observed by terminal deoxynucleotidyl transferase dUTP nick end labeling staining. Caspase-3, p53, Bcl-2, and Bax proteins in the cartilages were visualized by immunohistochemistry, their protein levels were determined by Western blotting, and mRNA levels were determined by real-time reverse transcription polymerase chain reaction.</p><p><b>RESULTS</b>Increased chondrocyte apoptosis was observed in the cartilages of children with KBD. Increased apoptotic and caspase-3-stained cells were observed in the cartilages of rats fed with normal and Se-deficient diets plus T-2 toxin exposure compared to those in rats fed with normal and Se-deficient diets. Caspase-3, p53, and Bax proteins and mRNA levels were higher, whereas Bcl-2 levels were lower in rats fed with normal or Se-deficiency diets supplemented with T-2 toxin than the corresponding levels in rats fed with normal diet.</p><p><b>CONCLUSION</b>T-2 toxin under a selenium-deficient nutritional status induces chondrocyte death, which emphasizes the role of chondrocyte apoptosis in cartilage damage and progression of KBD.</p>

Role of JNK signaling pathway in chondrocyte apoptosis induced by nitric oxide / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To study the role of c-jun N-terminal kinase (JNK) signaling pathway in chondrocyte apoptosis induced by nitric oxide (NO) using NO donor sodium nitroprusside (SNP) and JNK inhibitor SP600125.</p><p><b>METHODS</b>Articular chondrocytes were separated from New Zealand rabbits aged 3 weeks by mechanical digestion and enzyme digestion and identified by toluidine blue staining, and then the chondrocytes were treated with SNP and SP600125 for 24 h. The cell apoptosis was evaluated by Annexin V-fluorescein isothiocyanate (FITC)/propidium iodide (PI) flow cytometry and terminal deoxynucleotidyl transferase (TdT)-mediated dUTP-biotin nick end labeling (TUNEL), and the expression levels of nuclear factor-kappa B (NF-κB) p65 and p53 were measured by western blot.</p><p><b>RESULTS</b>Compared with those in control group, the early apoptotic rate of SNP-treated chondrocytes increased as the concentration of SNProse, exhibiting a concentration dependency (P < 0.05), and the expression levels of NF-κB p65 and p53 also increased (P < 0.05); JNK inhibitor SP600125 inhibited these increases (P < 0.05).</p><p><b>CONCLUSION</b>JNK signaling pathway plays an important role in NO-induced chondrocyte apoptosis. JNK inhibitor SP600125 can reduce NO-induced apoptosis and expression of NF-κB p65 and p53 in articular chondrocytes of rabbits in a concentration-dependent manner.</p>

Effects of T-2 toxin and selenium on expression of aggrecanase in human chondrocyte / 中国地方病学杂志

Objective To determine effects of T-2 toxin and selenium on expression of aggrecanase in human chondrocyte.Methods Human chondrocytes were treated with T-2 toxin(0,1,10,20 μg/L),and/or sodium selenite(final concentration of selenium 0,0.1 mg/L) for 5 days.Aggrecan expression was determined by Western blotting,aggrecanase-1 and aggrecanase-2 mRNA levels were measured by RT-PCR.ResultsSelenium and T-2 toxin had effects on both aggrecan protein levels and its aggrecanases(include aggrecanase-1 and aggrecanase-2 ) mRNA levels(F =0.294,27.71 for aggrecan,F =107.45,362.25 for aggrecanase-l,F =34.68,22.26 for aggrecanase-2,respectively,all P ＜ 0.05),and there was interaction between selenium and T-2 toxin on aggrecan,aggrecanase-1 and aggrecanase-2 expression(F =79.99,230.76,388.33,all P ＜ 0.05).Furthermore,selenium presented significant antagonism to T-2 toxin on aggrecan,aggrecanase-1 and aggrecanase-2 expression.Aggrecan expression levels(0.278 ± 0.015,0.235 ± 0.029,0.195 ± 0.028,0.399 ± 0.028,0.299 ± 0.020,0.263 ±0.019) induced by both 1,10,20 μg/L T-2 toxin and 0,0.1 mg/L selenium were significantly decreased than the levels(0.472 ± 0.0358,0.197 ± 0.018,all P ＜ 0.05) in control group(0 mg/L toxin).Selenium partially blocked the effects induced by 1,10,and 20 μg/L T-2 toxin(all P＜ 0.05).One,10,20 μg/L T-2 toxin and 0,0.1 mg/L selenium increased both aggrecanase-1 mRNA levels(0.535 ± 0.033,1.071 ± 0.043,1.454 ± 0.058,1.057 ±0.048,0.555 ± 0.036,0.902 ± 0.045) and aggrecanase-2 mRNA levels(0.596 ± 0.038,0.656 ± 0.033,0.949 ±0.049,0.600 ± 0.040,0.453 ± 0.031,0.164 ± 0.011),when compared with control(0.481 ± 0.023,0.346 ±0.020 for aggrecanase-1 and 0.387 ± 0.020,1.021 ± 0.046 for aggrecanase-2,respectively,all P ＜ 0.05).Selenium partially blocked 10,20 μg/L T-2 toxins induced upregulation of aggrecanase-1 (all P ＜ 0.05) and aggrecanase-2 (all P ＜ 0.05 ).Conclusions These data suggest a possible molecular mechanism that T-2 toxin could induce cartilage matrix degradation through the upregulation of aggrecanases expression and enzyme activities.Trace element selenium has some protective effect on cartilage proteoglycan degradation induced by T-2 toxins.

Serum malondialdehyde level and activities of antioxidant enzymes of children from Kaschin-Beck disease areas of Xinghai county in Qinhai province / 中国地方病学杂志

Objective To observe the activities of serum peroxidase capacity,and lipid peroxidation of children from Kaschin-Beck disease (KBD) areas of Xinghai county in Qinhai province,and to explore the relationship between antioxidant capacity and KBD.Methods Sixty four KBD and forty six health subjects without KBD were chosen from KBD endemic areas,which included primary schools of Tangnaihai,Xialujuan and Qushian of Xinghai county in Qinghai province,and fifty nine age-matched healthy control subjects without KBD were from a non-KBD endemic area,Nanfan primary school of Chang'an county in Shaanxi province.Twenty patients with KBD and twenty control subjects from KBD areas and non-KBD area were extracted by simple random sampling method.2,3-DAN fluorescence technique was used to test the hair and blood selenium.The biochemical techniques were used to test the indicators of oxidative stress including malondialdehyde(MDA),antioxidant enzyme activities,total antioxidant capacity(T-AOC),serum superoxide dismutase(SOD),catalase(CAT) and glutathione peroxidase(GSHPx).ResultsAll patients with KBD had significantly lower serum GSH-Px activities[ (59.53 ± 25.23)kU/L] and selenium levels in hair[ (67.64 ± 17.28)μg/L] and blood[(36.27 ± 13.29)μg/L],respectively,than that of control subjects from KBD areas [ ( 91.88 ± 22.99 ) kU/L,( 153.32 ± 24.31 ) μg/L,( 63.06 ± 13.66) μg/L ] and nonKBD areas[ ( 122.68 ± 41.74)kU/L,(242.35 ± 38.56)μg/L,(98.93 ± 17.18)μg/L,all P ＜ 0.05].Serum MDA levels in KBD patients[ (4.64 ± 1.11 )μmol/L] were significantly higher than that in control subjects from KBD [(3.31 ± 1.22)μmol/L] and non-KBD areas[ (3.43 ± 1.29)μmol/L,all P ＜ 0.05].On the other hand,T-AOC,SOD and CAT activities were significantly higher in both KBD[(19.80 ± 6.64),(55.80 ± 8.14),(16.45 ± 5.61 ) kU/L] and control subjects[ (21.71 ± 8.82),(57.45 ± 6.96),(15.63 ± 9.18)kU/L] from KBD areas than that of control subjects from non-KBD area[ (13.56 ± 5.38),(42.79 ± 8.10),(6.05 ± 2.71 )kU/L,all P ＜ 0.05 ].Hair selenium levels,blood selenium levels and GSH-Px activity of control subjects from KBD areas were,respectively,significantly lower than that in control subjects from non-KBD area(all P ＜ 0.05).Conclusions These findings strongly confirm the evidence that KBD patients are susceptible to oxidative stress.The results also show the increase in antioxidant enzymes,which could probably be due to adaptive response to pro-oxidant in KBD state.Hence,there seems to be an imbalance between oxidant and antioxidant systems in KBD patients.

Sodium valproate induces mitochondria-dependent apoptosis in human hepatoblastoma cells / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Sodium valproate inhibits proliferation in neuroblastoma and glioma cells, and inhibits proliferation and induces apoptosis in hepatoblastoma cells. Information describing the molecular pathways of the antitumor effects of sodium valproate is limited; therefore, we explored the mechanisms of action of sodium valproate in the human hepatoblastoma cell line, HepG2.</p><p><b>METHODS</b>The effects of sodium valproate on the proliferation of HepG2 cells were evaluated by the Walsh-schema transform and colony formation assays. Sodium valproate-induced apoptosis in HepG2 cells was investigated with fluorescence microscopy to detect morphological changes; by flow cytometry to calculate DNA ploidy and apoptotic cell percentages; with Western blotting analyses to determine c-Jun N-terminal kinases (JNK), p-JNK, Bcl-2, Bax, and caspase-3 and -9 protein expression levels; and using JC-1 fluorescence microscopy to detect the membrane potential of mitochondria. Statistical analyses were performed using one-way analysis of variance by SPSS 13.0 software.</p><p><b>RESULTS</b>Our results indicated that sodium valproate treatment inhibited the proliferation of HepG2 cells in a dose-dependent manner. Sodium valproate induced apoptosis in HepG2 cells as it: caused morphologic changes associated with apoptosis, including condensed and fragmented chromatin; increased the percentage of hypodiploid cells in a dose-dependent manner; increased the percentage of annexin V-positive/propidium iodide-negative cells from 9.52% to 74.87%; decreased JNK and increased phosphate-JNK protein expression levels; reduced the membrane potential of mitochondria; decreased the ratio of Bcl-2/Bax; and activated caspases-3 and -9.</p><p><b>CONCLUSION</b>Sodium valproate inhibited the proliferation of HepG2 cells, triggered mitochondria-dependent HepG2 cell apoptosis and activated JNK.</p>

Expressions of nucleoside diphosphate kinase (nm23) in tumor tissues are related with metastasis and length of survival of patients with hepatocellular carcinoma / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To evaluate the relationship of expressions of nucleoside diphosphate kinase (nm23) and proliferating cell nuclear antigen (PCNA), as well as apoptosis, with the prognosis of HCC patients by analyzing their pathological and clinical data.</p><p><b>METHODS</b>The expressions of nm23 and PCNA were analyzed by immunohistochemistry and the apoptotic phenomena were detected by TUNEL technique in the liver samples from 43 HCC tissues, 39 para-neoplastic tissues, and 10 normal tissues. The mean apoptosis index (AI) and proliferative index (PI) in individual sample were calculated.</p><p><b>RESULTS</b>As shown by the detection, 32.6% of carcinomas had negative nm23 signal in tumor tissues, whereas all para-neoplastic and normal tissues had positive nm23. The AI in nm23 positive HCC was significantly higher than that in nm23 negative one, with statistical difference (P<0.05). Furthermore, the expressions of nm23, and the values of AI and PI were contrastively analyzed with some main pathological and clinical data of HCC. It revealed that HCC with extrahepatic metastasis showed remarkable correlation with the negative nm23 (P=0.013) and higher PI values of HCC (P=0.015). The disease-free survival in HCC patients with negative nm23 expression was significantly poorer than that in patients with positive nm23 expression.</p><p><b>CONCLUSIONS</b>These data suggest that expressions of nm23 protein in tumor tissues are correlated with occurrences of metastasis and length of survival of the HCC patients, which may be an indicator for their prognosis.</p>

Effect of Tanshinone II A on expression of EGF and EGFR in hepatocellular carcinoma cell line SMMC-7721 / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To observe the effect of Tanshinone II A on the expression of epidermal growth facter (EGF) and epidermal growth facter recepter (EGFR) in human hepatocellular carcinoma cell line SMMC-7721.</p><p><b>METHODS</b>The human hepatocellular carcinoma SMMC-7721 cells cultured in vitro was treated with different concentrations of Tanshinone II A. The proliferation of the cells was measured by MTT assay, and the apoptosis of the cells was investigated by flow cytometry and cytochemical staining with Hoechst 33342. The expression of EGF and EGFR was detected by immunocytochemistry method. The levels of EGF in medium were measured by radioimmunoassay.</p><p><b>RESULT</b>Tanshinone II A inhibited the growth of SMMC-7721 cells remarkably in a dose-dependent manner. The inhibitory rate reached the peak (72.5%) after 0.5 microg/ml Tanshinone II A was used for 48 h, which was significantly higher than that in the controls (P<0.05). FCM analysis showed that when SMMC-7721 cells were treated with 0.5 microg/ml Tanshinone II A, the apoptosis rates for 24 h, 48 h and 72 h were (4.06+/-0.27)%, (7.58+/-0.56)% and (5.23+/-0.13)%, respectively which were markedly higher than those in the controls (all P<0.01). SMMC-7721 cell apoptosis with cell shrinkage, nuclear chromatin concentration and fragmentation as well as the formation of apoptotic bodies were observed by cytochemical staining when treated with Tanshinone II A. The immunocytochemistry showed that the expressions of EGF and EGFR were down regulated while the concentration of Tanshinone II A was increasing. The high expression rates for EGF and EGFR were 10%, 20%, respectively, and the gray scale was 181.52+/-1.63, 179.37+/-1.59, which were markedly higher than those in the controls (all P<0.05). The levels of EGF in medium measured by radioimmunoassay were decreased significantly after Tanshinone II A treatment.</p><p><b>CONCLUSION</b>Tanshinone II A can inhibit cell proliferation and induce apoptosis in hepatocellular carcinoma cell line SMMC-7721, which may be related to the down-regulation of EGF and EGFR protein expression.</p>

Construction of tissue-engineered cartilage by seeding chondrocytes on allogeneic cancellous bone matrix gelatin / 南方医科大学学报

<p><b>OBJECTIVE</b>To evaluate the use of cancellous bone matrix gelatin (BMG) combined with chondrocytes in constructing tissue-engineered cartilage by observing the growth, proliferation and differentiation of chondrocytes on allogeneic cancellous BMG.</p><p><b>METHODS</b>The articular chondrocytes isolated from a 1-month-old rabbit were multiplied to a monolayer and seeded onto cancellous BMG to construct tissue-engineered cartilage in vitro during a period of 6 weeks. Samples were taken from the construct after 1, 2, 4, and 6 weeks of culture and evaluated by histology, immunohistochemistry and transmission electron microscopy (TEM).</p><p><b>RESULTS</b>The chondrocytes excreted matrix proteoglycan and collagen on cancellous BMG. With the prolongation of the culture time, the cells proliferated in the construct and the cells in the lacunae increased. Numerous chondrocytes were present the central region of the cancellous BMG and surrounded by extracellular matrix. By 6 weeks of culture, the BMG was covered with 15-20 layers of chondrocytes and cartilaginous tissue occurred in the pores throughout the cancellous BMG. Immunohistochemical staining showed rich and evenly distributed type II collagen around the chondrocytes, and TEM revealed an ultrastructure of the chondrocyte similar to that of native chondroctyes, with abundant extracellular matrix produced around the cells.</p><p><b>CONCLUSION</b>Tissue-engineered cartilage can be constructed in vitro using allogeneic cancellous BMG combined with chondrocytes. Allogeneic cancellous BMG serves as a good scaffold material for tissue-engineered cartilage to promote the growth and proliferation of the seeded chondrocytes and allows maintenance of the differentiation phenotype of the cells.</p>

T-2 toxin-induced apoptosis involving Fas, p53, Bcl-xL, Bcl-2, Bax and caspase-3 signaling pathways in human chondrocytes / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

<p><b>OBJECTIVE</b>To investigate the effects of T-2 toxin on expressions of Fas, p53, Bcl-xL, Bcl-2, Bax and caspase-3 on human chondrocytes.</p><p><b>METHODS</b>Human chondrocytes were treated with T-2 toxin (1-20 ng/ml) for 5 d. Fas, p53 and other apoptosis-related proteins such as Bax, Bcl-2, Bcl-xL, caspase-3 were determined by Western blot analysis and their mRNA expressions were determined by reverse transcriptase-polymerase chain reaction (RT-PCR).</p><p><b>RESULTS</b>Increases in Fas, p53 and the pro-apoptotic factor Bax protein and mRNA expressions and a decrease of the anti-apoptotic factor Bcl-xL were observed in a dose-dependent manner after exposures to 1-20 ng/ml T-2 toxin, while the expression of the anti-apoptotic factor Bcl-2 was unchanged. Meanwhile, T-2 toxin could also up-regulate the expressions of both pro-caspase-3 and caspase-3 in a dose-dependent manner.</p><p><b>CONCLUSION</b>These data suggest a possible underlying molecular mechanism for T-2 toxin to induce the apoptosis signaling pathway in human chondrocytes by regulation of apoptosis-related proteins.</p>

Promotion of the articular cartilage proteoglycan degradation by T-2 toxin and selenium protective effect / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

<p><b>OBJECTIVE</b>To identify the relationship between T-2 toxin and Kashin-Beck disease (KBD), the effects of T-2 toxin on aggrecan metabolism in human chondrocytes and cartilage were investigated in vitro.</p><p><b>METHODS</b>Chondrocytes were isolated from human articular cartilage and cultured in vitro. Hyaluronic acid (HA), soluble CD44 (sCD44), IL-1beta and TNF-alpha levels in supernatants were measured by enzyme-linked immunosorbent assay (ELISA). CD44 content in chondrocyte membrane was determined by flow cytometry (FCM). CD44, hyaluronic acid synthetase-2 (HAS-2) and aggrecanases mRNA levels in chondrocytes were determined using reverse transcription polymerase chain reaction (RT-PCR). Immunocytochemical method was used to investigate expressions of BC-13, 3-B-3(-) and 2-B-6 epitopes in the cartilage reconstructed in vitro.</p><p><b>RESULTS</b>T-2 toxin inhibited CD44, HAS-2, and aggrecan mRNA expressions, but promoted aggrecanase-2 mRNA expression. Meanwhile, CD44 expression was found to be the lowest in the chondrocytes cultured with T-2 toxin and the highest in control plus selenium group. In addition, ELISA results indicated that there were higher sCD44, IL-1beta and TNF-alpha levels in T-2 toxin group. Similarly, higher HA levels were also observed in T-2 toxin group using radioimmunoprecipitation assay (RIPA). Furthermore, using monoclonal antibodies BC-13, 3-B-3 and 2-B-6, strong positive immunostaining was found in the reconstructed cartilage cultured with T-2 toxin, whereas no positive staining or very weak staining was observed in the cartilage cultured without T-2 toxin. Selenium could partly inhibit the effects of T-2 toxin above.</p><p><b>CONCLUSION</b>T-2 toxin could inhibit aggrecan synthesis, promote aggrecanases and pro-inflammatory cytokines production, and consequently induce aggrecan degradation in chondrocytes. These will perturb metabolism balance between aggrecan synthesis and degradation in cartilage, inducing aggrecan loss in the end, which may be the initiation of the cartilage degradation.</p>

Protective effect of selenium against T-2 toxin-induced inhibition of chondrocyte aggrecan and collagen II synthesis / 南方医科大学学报

<p><b>OBJECTIVE</b>To study the inhibitory effect of T-2 toxin on the expression of aggrecan and collagen II in chondrocytes and the protection of selenium against this effect.</p><p><b>METHODS</b>Human chondrocytes cultured in vitro were treated with T-2 toxin at different concentrations for varied time periods (1-5 days), and the cell viability was measured by MTT assay. Aggrecan expression was detected by toluidine blue staining and collagen II expression by immunostaining using monoclonal antibody of collagen. Aggrecan and collagen II mRNA expressions were measured by semiquantitative RT-PCR.</p><p><b>RESULTS</b>T-2 toxin dose- and time-dependently affected chondrocyte viability within the concentration range of 0.001-2 mg/L, the prolonged treatment time further enhanced the dose dependence of the inhibitory effect. T-2 toxin lowered aggrecan and collagen II synthesis in the chondrocytes and reduced their mRNA expressions. Selenium could partly attenuate the inhibitory effects of T-2 toxin on aggrecan mRNA expression, but showed no such effect against T-2-induced collagen II expression.</p><p><b>CONCLUSION</b>T-2 toxin can obviously inhibit aggrecan and collagen II synthesis in human chondrocytes, and selenium can partly antagonize the inhibitory effects of T-2 toxin on aggrecan.</p>

Mechanism of chondrocyte apoptosis in Kashin-Beck disease and primary osteoarthritis: a comparative study / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate chondrocyte apoptosis and the expressions of Bcl-2, Bax, Fas and iNOS in the articular cartilage between Kashin-Beck disease (KBD) and primary osteoarthritis (OA) and explore the difference in pathogenesis between the two diseases.</p><p><b>METHODS</b>The articular cartilage specimens were collected from 15 normal human subjects, 15 adult patients with KBD and 15 with OA. Chondrocyte apoptosis was detected by TUNEL method, and the expressions of Bcl-2, Bax, Fas and iNOS in articular cartilage were examined with B-SA immunohistochemistry.</p><p><b>RESULTS</b>The percentages of apoptotic chondrocytes positive for TUNEL staining in the articular cartilage were significantly higher in patients with KBD and OA than in normal control subjects (F=20.90-53.16, df=42, P<0.01), and the erosive areas of the articular cartilage contained greater percentage of apoptotic chondrocytes than the non-erosive areas in the same patient with KBD (t=4.154, df=28, P<0.01) or OA (t=6.004, df=28, P<0.01). No significant difference was noted in the positive apoptotic chondrocytes between KBD and OA (t=1.329-1.362, df=28, P>0.05). The percentage of chondrocytes positive for Bcl-2, Bax, Fas and iNOS were significantly higher in KBD and OA patients than in the control subjects (F=25.46-215.31, df=42, P<0.01), and significant differences were observed in Bcl-2, Bax, Fas and iNOS expressions between the erosed areas and non-erosed areas in articular cartilage in patients with KBD (t=2.608-7.77, df=28, P<0.05) and OA (t=2.278-5.413, df=28, P<0.05), but their expressions showed no significant difference between the two diseases (t=0.284-1.590, df=28, P>0.05).</p><p><b>CONCLUSION</b>There was no significant difference in apoptotic chondrocytes and Bcl-2, Bax, Fas and iNOS expressions in the cartilage between adult patients with KBD and OA.</p>