Objective Corticosteroids can destroy the cartilage. To investigate the effect of dexamethasone (Dexa) on the apoptosis and expression of Fas/FasL of human articular chondrocytes (HACs) in vitro so as to explore the mechanism ofpro-apoptotic role of Dexa on HACs. Methods Following full agreement of patients, the cartilage specimens were collectedfrom the patients with osteoarthritis undergoing knee replacement. The second passage HACs were incubated in cell culture media containing 0.125, 1.25, 12.5, 25, and 50 μg/mL Dexa for 48 hours respectively to determine the optimal concentration of Dexa by MTT. The apoptosis was assessed by TMRE/Hoechst/Annexin V-FITC/7-AAD quadruple staining after culture for 0, 24, and 48 hours. The mRNA expressions of Fas and FasL were determined by real-time quantitative PCR after culture for 48 hours. The protein expressions of Fas and FasL were determined by immunohistochemistry staining analysis after culture for 24 hours and 48 hours. Results The cell inhibitory rate of 25 μg/mL Dexa was significantly higher than that of 50 μg/mL Dexa (P lt; 0.05), and there were significant differences when compared with that at other concentrations of Dexa (P lt; 0.05), so 25 μg/mL Dexa was appropriately selected as an optimal concentration of Dexa. The apoptotic rates of HACs were 5.8% ± 0.3%, 27.0% ± 2.6%, and 36.0% ± 3.1% at 0, 24, and 48 hours, respectively, in a time dependent manner (P lt; 0.05). The expressions of Fas mRNA were (8.93 ± 1.12) × 10—3 in the experimental group and (3.31 ± 0.37) × 10—3 in the control group, showing significant difference (P lt; 0.05). The expressions of FasL mRNA were (5.92 ± 0.66) × 10—3 in the experimental group and (2.31 ± 0.35) × 10—3in the control group, showing significant difference (P lt; 0.05). The expressions of Fas and FasL proteins showed an increasing tendency with time in the experimental group and the expressions were significantly higher than those in the control group after culture for 24 hours and 48 hours (P lt; 0.05). Conclusion Dexa can induce the apoptosis and significantly upregulate the apoptotic gene expression of Fas/FasL, which can provide the experimental evidence to further investigate the role of Fas/FasL signaling pathway in Dexa-induced HACs apoptosis.
Objective To study the expressions of phosphatese and tensin homolog deletedin chromosom ten （PTEN）, Fas/FasL system and matrix metalloproteinnases-2 （MMP-2） in human gastric cancer. Methods Seventy-five cases of gastric carcinoma were selected from paraffin wax embodied specimens with full clinicopathological data, and another 15 cases of normal gastric mucosa specimens were selected as the control group. SP immunohistochemistry was used to measure the expressions of PTEN， Fas/FasL and MMP-2 in them. The data was statistically analyzed by χ2 test and relative analysis. Results The expressions of PTEN, Fas/FasL and MMP-2 were correlated with the lymphatic metastasis, degree of infiltration, clinical TMN stage and pathological histological differentiated degree of gastric cancer (Plt;0.05). PTEN was positive correlated with Fas/FasL (r=0.401, Plt;0.001). MMP-2 was negative correlated with Fas/FasL (r=－0.720， Plt;0.001). MMP-2 was negative correlated with PTEN (r=－0.336， Plt;0.001). Conclusion There is guidance meaning in testing the expressions of PTEN, Fas/FasL and MMP-2 in gastric cancer to estimate the prevention, diagnoses, therapy and prognosis of gastric cancer.
Objective
To investigate the effects of gamma;-interferon (IFN-gamma; on the expression of costimulatory molecules B7-1 (CD80) and B7-2 (CD86) and Fas/FasL in human retina.
Methods
Nine human eyes were obtained from the eye-bank of Zhongshan Ophthalmic Center. Six eyes were used for making retinal wholemounts, and 12 retinal wholemounts from each eye were put into the 24-hole culture board which had 2ml DMEM/F12 culture medium in each hole. The wholemounts were divided into 3 groups whose concentration of IFN-gamma; was 0, 200, and 1000 U/ml respectively. After cultured in 37℃ culture box (95%O 2，5%CO 2) for 24 hours, the expressions of B7-1 (CD80), B7-2 (CD86), and Fas/FasL on these retinal wholemounts were detected by immunohistochemical method. The retinal wholemounts from 3 healthy people were detected by immunohistochemical method as the control.
Results
Expression of FasL but not B7-1, B7-2 or Fas was found in the control group, while the expression of B7-1, B7-2 and Fas and increased expression of FasL were found after cultured with IFN-gamma;.
Conclusion
IFN-gamma; may be involved in the occurrence of ocular immune response and induction of apoptosis via the stimulation of expression of costimulatory molecules and Fas/FasL, which plays an important role in the activation of T lymphocytes.
(Chin J Ocul Fundus Dis, 2006, 22: 117-119)
