ANX A2在抗磷脂抗体诱导THP-1细胞组织因子表达中的作用

目的： 构建针对人膜联蛋白A2（ANX A2）的RNA干扰（RNAi）慢病毒表达载体，转染THP-1细胞，探讨ANX A2在抗磷脂抗体（APL）诱导单核细胞组织因子（TF）表达中的作用。方法：设计4条ANX A2特异性RNAi的寡核苷酸序列,与慢病毒载体pGCSIL-GFP连接，PCR及测序鉴定正确后，Western蛋白印迹法筛选出有效干扰序列。包装293T细胞获得重组慢病毒LV-RNAi-ANX A2，感染单核细胞株THP-1，观察细胞ANX A2 mRNA和蛋白表达下降程度。再用APL/β2GPI复合物刺激干扰后的THP-1细胞，观察TF mRNA表达及TF活性变化。结果：成功构建RNAi慢病毒载体并筛选出有效干扰片段；包装293T细胞后病毒滴度为3×1012TU/L；感染THP-1后细胞ANX A2 mRNA和蛋白均被沉默。APL/β2GPI复合物刺激干扰后的THP-1细胞，其TF表达下降至基础水平。结论：构建的慢病毒表达载体能显著抑制THP-1细胞ANX A2的表达，进而影响APL诱导的TF表达，证明ANX A2在APL诱导的单核细胞表达TF过程中具有重要作用。

Role of ANX A2 in APL-induced expression of tissue factor in THP-1 cells

AIM: To construct a lentiviral vector harboring RNAi sequence targeting human annexin A2 (ANX A2) and to investigate the functions of ANX A2 in antiphospholipid antibody (APL)-induced tissue factor (TF) expression in monocytes. METHODS: Four different short hairpin RNAs (shRNA) targeting ANX A2 gene were constructed and cloned into the pGCSIL-GFP vector. After identification with PCR and sequencing, the effective interference sequence was further determined by Western blotting analysis. The recombinant lentivirus LV-RNAi-ANX A2 harvested from 293T cells was transferred into THP-1 cells and the ANX A2 mRNA and protein expression on THP-1 cells were examined. The transferred-THP-1 cells were stimulated by APL/β_2GPI compound, and the TF mRNA and TF activity was assayed. RESULTS: The RNAi sequences targeting the human ANX A2 gene were successfully inserted into the lentiviral vector and the high-performance RNA interference sequence was sieved out. The recombinant lentivirus was harvested from 293T cells with a viral titer of 3×10~(12) TU/L. THP-1 cells infected with LV-RNAi-ANX A2 showed almost lockout of ANX A2 both at mRNA and protein levels. The TF expression was also significantly decreased in the transferred-THP-1 cells induced by APL/β_2GPI compound. CONCLUSION: The lentiviral vector constructed in the present study blocks the ANX A2 expression in THP-1 cells and further inhibits the TF expression induced by APL/β_2GPI compound, which indicates that ANX A2 do play an important role in APL-induced TF expression on monocytes.