中文摘要：

目的探讨高血压条件下异常升高的周期性张应变刺激对血管平滑肌细胞（vascular smooth muscle cells,VSMCs）增殖活性的影响以及VSMCs中一种长链非编码RNA（long non-coding RNA,lncRNA）XR007793在其中可能的作用。方法应用体外周期性张应变加载系统Flexcell-4000对VSMCs分别施加5%生理性张应变和15%病理性高张应变,加载频率为1.25 Hz,加载时间24 h。荧光实时定量PCR检测XR007793及其共表达基因：信号转导与转录激活因子2（STAT2）、细胞分裂相关蛋白8（CDCA8）、原癌基因LMO2和干扰素调节因子（IRF7）的表达变化,Western bloting方法检测增殖细胞核抗原（proliferating cell nuclear antigen,PCNA）表达变化,RNA干扰技术抑制VSMCs的XR007793表达,静态条件下流式细胞术检测VSMCs周期变化,牵拉条件下Brdu检测VSMCs增值变化情况。结果与5%生理性张应变组相比,15%病理性高张应变显著下调XR007793表达水平,促进VSMCs增值活性并上调STAT2和CDCA8的表达水平。静态条件下干扰XR-007793,VSMC增殖水平显著上升。高周期性张应变条件下干扰XR-007793,VSMC增殖水平上升,CDCA8表达水平上升。结论病理性高张应变可能通过降低XR007793表达来影响CDCA8表达变化,进而调控VSMCs增殖功能变化过程。研究结果为阐明高血压条件下血管重建机制和药物治疗靶标的研究提供新的实验依据。

英文摘要：

Objective To investigate the effect of pathologically elevated-cyclic strain induced by hypertension on proliferation of vascular smooth muscle cells（ VSMCs） and the role of long non-coding RNA（ IncRNA）-XR007793 during this process. Methods Flexcell-4000 tension system was used to apply physiologically（ 5%magnitude） and pathologically（ 15% magnitude） cyclic strain with frequency of 1. 25 Hz on VSMCs for 24 h respectively. qRT-PCR was used to detect the expression of XR007793 and 4 co-expressed genes： signal transducer and activator of transcription 2（ STAT2）,cell division cycle associated 8（ CDCA8）,proto-oncogene LMO2 and interferon regulatory factor（ IRF7）. Western blot was used to detect the proliferating cell nuclear antigen（ PCNA） level in VSMCs. RNA inference was used to inhibit XR007793 expression. The cell cycle of VSMCs was measured by flow cytometry in static condition and the cell proliferation was detected by Brdu-Elisa in cyclic strain loading condition. Results Compared with 5% cyclic strain,15% cyclic strain remarkably decreased the XR007793 level and increased the proliferation of VSMCs,along with the increasing expression of STAT2 and CDCA8. XR007793 specific siRNA transfection under static condition decreased the expression of XR007793 and increased the VSMC proliferation. Under 15% cyclic strain,XR007793 specific siRNA transfection also increased the VSMC proliferation and the expression of CDCA8 compared with the non-specific siRNA control.Conclusions Pathologically elevated-cyclic strain decreases the XR007793 expression level and increases the CDCA8 expression level to modulate VSMC proliferation. These results provide new experimental evidence for the study of mechanobiological mechanism during hypertension and potential targets for hypertension therapy.