ABSTRACT
Objective:To investigate the role of long non-coding RNA nuclear paraspeckle assembly transcript 1 (Neat1) in pyroptosis of ultraviolet B (UVB)-induced human lens epithelial cells (LECs) and to explore the possible mechanism.Methods:The human lens epithelial cell line HLE-B3 was cultured in vitro, and cells at log phase were exposed to ultraviolet B for 0, 2, 4 and 8 hours, respectively.The expression of cysteine aspartic acid-specific protease-1 (caspase-1), a protein related to pyroptosis, was detected by Western blot.The relative expression level of Neat1 in cells after different irradiation durations was determined by real-time quantitative PCR.Cell viability was determined by the cell counting kit-8 (CCK-8) method to screen the optimal irradiation duration for UVB-induced LECs pyroptosis, which was finally determined to be 4 hours.HLE-B3 cells were divided into negative siRNA transfection group, siRNA Neat1 transfection group, negative siRNA transfection+ irradiation group and siRNA Neat1 transfection+ irradiation group, and were transfected with corresponding reagents for 24 hours.The negative siRNA transfection+ irradiation group and siRNA Neat1 transfection+ irradiation group were irradiated with UVB for 4 hours after transfection.The cell viability was detected by the CCK-8 method.The pyroptosis rate was detected by flow cytometry.The expression levels of caspase-1, gasdermin D (GSDMD) and nod-like receptor protein 3 (NLRP3) proteins were detected by Western blot.The concentration of interleukin (IL)-1β was detected by enzyme-linked immunosorbent assay (ELISA). Ultrastructural changes in HLE-B3 cells were observed under a transmission electron microscope. Results:The grayscale of caspase-1 protein bands increased with the extension of irradiation duration.The relative expression levels of caspase-1 protein at 0, 2, 4 and 8 hours of irradiation were 0.05±0.01, 0.25±0.07, 0.51±0.04 and 0.74±0.02, respectively, with a statistically significant overall difference ( F=168.223, P<0.001), and significant differences were found in paired comparisons (all at P<0.05). With prolonged irradiation, the relative expression level of Neat1 mRNA increased and the cell viability decreased, with statistically significant differences in paired comparisons (all at P<0.05). Compared with negative siRNA transfection group, the cell viability was increased in siRNA Neat1 transfection group and decreased in negative siRNA transfection+ irradiation group, with statistically significant differences (both at P<0.01). Compared with negative siRNA transfection+ irradiation group, the cell viability was increased in siRNA Neat1 transfection+ irradiation group, showing a statistically significant difference ( P<0.05). The pyroptosis rate was significantly lower in negative siRNA transfection group and siRNA Neat1 transfection+ irradiation group than in negative siRNA transfection+ irradiation group, and the differences were statistically significant (both at P<0.01). The relative expression levels of caspase-1, NLRP3 and GSDMD proteins in negative siRNA transfection+ irradiation group were higher than those in negative siRNA transfection group and siRNA Neat1 transfection+ irradiation group and the differences were statistically significant (all at P<0.01). The concentration of IL-1β was significantly higher in negative siRNA transfection+ irradiation group than in negative siRNA transfection group and siRNA Neat1 transfection+ irradiation group, and the differences were statistically significant (all at P<0.05). Cell swelling, formed cell membrane pores, vacuolated cells and fuzzy mitochondrial cristae were seen in negative siRNA transfection+ irradiation group and siRNA Neat1 transfection+ irradiation group by transmission electron microscopy.Compared with negative siRNA transfection+ irradiation group, slighter cell swelling, fewer cell membrane pores and lighter mitochondrial swelling were seen in siRNA Neat1 transfection+ irradiation group. Conclusions:Neat1 is involved in human LECs pyroptosis induced by UVB through the classic pyroptosis pathway mediated by caspase-1.Knockdown of Neat1 can inhibit the pyroptosis of human LECs.
ABSTRACT
Objective To analyze the dynamic relation between preoperative and postoperative subjective symptoms with the ocular surface and objective detection indexes of tear film structure and function in the patients with diabetic cataract phacoemulsification.Methods Thirty cases (30 eyes) with diabetic cataract were selected as the group A.Thirty cases (30 eyes) of age-related cataract were selected as group B.The two groups conducted the questionnaire survey of ocular surface disease index(OSDI) on preoperative 1 d,postoperative 1 week,i,3 months.The Keratograph 5M ocular surface analyzer was used to detect the tear river height,average tear film breakup time(TBUT),nasal conjunctival congestion score and nasal ciliary congestion score.The tear insulin and MUC5AC levels were detected by ELISA.Results The OSDI score at various time periods in the group A was higher than that in the group B (P＜0.05);The scores at postoperative 1 week in the two groups was increased compared with before operation(P＜0.05);the central lacrimal river height at postoperative 1 week in the two groups was decreased compared with before operation(P＜0.05).Average TBUT at postoperative 3 months in the group A approached the level before surgery,while which at postoperative 1 month in the group B closed to that before operation.The nasal conjunctival and ciliary congestion scores in the group A were higher than those in the group B(P＜0.05).The tear insulin and MUCSAC levels in the group A were lower than those in the group B,the differences were statistically significant (P＜0.05).The tear insulin level at postoperative 3 months gradually closed to the preoperative level,while the tear MUCSAC level still had obvious difference compared with preoperative level.Conclusion The changes of subjective symptoms and objective indexes of ocular surface and tear film after phacoemulsification in diabetic cataract patients are more obvious and the recovery time is more longer;the Keratograph 5M ocular surface comprehensive analyzer can serve as the routine method for observing the ocular surface and tear film function before and after cataract surgery in the patients with diabetes.
ABSTRACT
Background Human LECs can express telomerase activity,which participates in the formation of cataract.It is reported that estrogen can increase the expression of telomerase activity in human endometrial cancer and breast cancer cells and play an important role in promoting proliferation and anti-apoptosis,but whether estrogen exerts its role on human LECs is still unclear.Objective This study aimed to investigate whether β-estradiol (β-E2) can increase the telomerase activity of human LECs and the influence of β-E2 on proliferation and apoptosis of human LECs.Method Human LECs line was cultured and passaged in vitro,and 1×10-6 mol/L β-E2 was added in the medium for 0,6,12,24 and 48 hours,and reverse transcription PCR was used to determine the optimal time of the expression of human telomerase reverse transcriptase (hTERT) mRNA in the cells.Cultured cells were divided into five groups.The cells in the blank contol group were cultured in the routin medium.Ethanol of 0.1％ was added in the solvent control group,and 1 × 10-8,1 × 10-7 or 1 × 10-6 mol/L β-E2 was added in the medium in different contents of β-E2 groups,respectively.The relative expression level of hTERT mRNA in different groups was detected by reverse transcription PCR.Telomere repeat amplification protocol (TRAP)-ELISA was employed to determine the telomerase activity.The proliferative value of the cells was assayed by cell counting kit-8,and the apoptosis rate of the cells was examined by Hoechst33258 staining.Results The optimal time of β-E2 to rise the expression of hTERT mRNA (absorbance) was at 24 hours under the 1×10-6 mol/L.The relative expression levels of hTERT mRNA in the cells were 0.477±0.015,0.712±0.013 and 0.914±0.031 in the 1 ×10-8,1 ×10-7 and 1 ×10-6 mol/L β-E2 group,which were signifincatly higher than 0.428±0.010 in the blank control group and 0.426±0.010 in the solvent control group (all at P＜0.05).The telomerase activity values (absorbance) were 0.711 ±0.015,0.941±0.010 and 1.249±0.047 in the 1×10-8,1×10-7and 1×10-6 mol/L β-E2 group,which were higher than 0.535±0.013 in the blank control group and 0.543 ±0.013 in the solvent control group (all at P =0.000).The proliferantive values of the cells (absorbance) were significantly raised in the 1 × 10-8 mol/L β-E2 group compared with l × 10-7 and 1 × 10-6 mol/L β-E2 group (both at P =0.000),and no significnant difference was found in the proliferetive values between the blank control group and the solvent control group (P =0.718,0.856).The apoptosis rates of the cells in the 1 × 10-8,1 × 10-7 and 1 × 10-6 mol/L β-E2 group were lower than those in the the blank control group and the solvent control group (all at P=0.000),and there was no significant difference between the blank control group and the solvent control group (P =0.777).No obvious correlation was found between the HLECs preliferative values and hTERT mRNA expression levels or telomerase activity values (r=-0.299,P=0.278;r=-0.157,P=0.576).However,significantly negative correlations were seen between apoptosis rates and hTERT mRNA expression levels or telomerase activity values (r =-0.975,P=0.000;r=-0.981,P=0.000).Conclusions β-E2can increase the activity of telomerase in human LECs,and high dose of β-E2can inhibit apoptosis,but it dose not promote proliferation.