AIM: To analyze the effect of sentrin-specific protease 3 ( SENP3 ) on the activity of telomerase and the length of telomere of rat osteoblasts. METHODS:The rat osteoblasts was treated with 0. 2 mmol/L H2 O2 . The ex-pression of SENP3 and specificity protein 1 (Sp1) was detected by Western blotting. The rat osteoblasts were transfected with pcDNA3. 0-SENP3. The viability of the osteoblasts was evaluated by MTT assay. The concentrations of alkaline phos-phatase ( ALP) and osteopontin ( OPN) were measured by ELISA. Osteocalcin ( OCN) was measured by RIA. The expres-sion of Sp1 and telomerase reverse transcriptase ( TERT) were determined by Western blotting. The activity of telomerase was analyzed by PCR-TRAP method. The length of telomere was detected by PCR. pcDNA3. 0-SENP3 and siRNA-Sp1 were co-transfected into osteoblasts, and the above indicators were measured. RESULTS:After the osteoblasts were trea-ted with H2 O2 , the expression of SENP3 and Sp1 was significantly increased. After pcDNA3. 0-SENP3 was transfected into the osteoblasts, the expression of Sp1 and TERT, the cell viability, and the concentrations of ALP, OCN and OPN were all dramatically increased. The activity of telomerase and the length of telomere were significantly enhanced. However, once pcDNA3. 0-SENP3 and siRNA-Sp1 were co-transfected into the osteoblasts, no significantly change of above indicators was observed. CONCLUSION:SENP3 increases the expression of TERT through increasing the expression of Sp1, leading to the increase in the activity of telomerase and the length of telomere, finally enhances the viability of osteoblasts.%目的：：研究sentrin特异性蛋白酶3( SENP3)对大鼠成骨细胞端粒酶活性及端粒长度的影响。方法：首先0．2 mmol/L H2 O2处理体外培养的大鼠成骨细胞后,Western blotting法检测SENP3及特异性蛋白1( Sp1)的表达。 pcDNA3．0-SENP3转染成骨细胞,分别于24 h、48 h、72 h后采用四甲基偶氮唑蓝( MTT)法检测细胞活力的变化。转染48 h后,Western blotting法检测Sp1和端粒酶逆转录酶( TERT)的表达,PCR-TRAP法及PCR法检测端粒酶活性及端粒长度；ELISA检测上清中碱性磷酸酶( ALP)和骨桥蛋白( OPN)的含量；放射免疫法( RIA)检测骨钙蛋白( OCN)的含量。最后将pcDNA3．0-SENP3与siRNA-Sp1共转染成骨细胞,并检测以上指标。结果： H2 O2处理成骨细胞后,SENP3和Sp1的表达显著上升。 pcDNA3．0-SENP3转染成骨细胞后,Sp1和TERT的表达显著上升,细胞活力、ALP、OPN及OCN含量也都显著上升；端粒酶活性显著增加及端粒长度缩短显著延缓。而当pcDNA3．0-SENP3与siRNA-Sp1共转染成骨细胞后,细胞活力,ALP、OPN及OCN含量,端粒酶活性及端粒长度均未发生显著变化。结论：SENP1通过上调Sp1的表达促进TERT的表达,增加端粒酶活性上升及延缓端粒长度缩短,从而增强成骨细胞增殖能力。
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