Stability and Ecological Effects of Main Plant Communities in Minqin Desert Area

[ Objective ] To elucidate the change trend in stability and ecological effects of plant communities in desert along with global wanning. [ Method ] The data of site-specific observation on five main plant communities at ten plots in Minqin desert area were used to analyze the stability and ecological effects of desert plant communities by using two indicators vegetation coverage and projective cover degree. [ Results ] The vegetation coverage of Artemisia arenaria and Ephedra przewalskii, and the projective cover degree of A. arenaria and man-made Haloxylon ammodendron forest decreased remarkably; and the vegetation coverage of Ni- traria tangutorum was also decreased to some extent. [ Conduslon] （1） The plant communities with poor vegetation coverage gives a relatively strong stability, while that with high vegetation coverage has a relatively poor stability; （2） the yearly precipitation is the determinant of vegetation coverage and projective cover deglee; （3） the ecological function is found to be most remarkable in per unit area N. tangutorum, followed by E. przewalskii and N. tangutorum ＋H. ammodendron, and least in per unit area A. Arenaria. The vegetation is sparse in desert and plant branches does not distribute regularly, thus the crown-based vegetation coverage can not reflect the actual surface coverage.

lncRNA CRNDE调控miR-29a-3p对LPS诱导的人脐静脉内皮细胞增殖与凋亡影响的分子机制研究

目的:探讨长链非编码RNA(lncRNA)结直肠肿瘤差异表达基因(CRNDE)对脂多糖(LPS)诱导的人脐静脉内皮细胞(HUVECs)增殖和凋亡的影响及其可能的作用机制。方法:将HUVECs分为对照组(细胞正常培养)、LPS组(细胞用1.0μg·ml^(-1)的LPS诱导24 h)、si-NC+LPS组(用1.0μg·ml^(-1)LPS诱导转染siNC的细胞24 h)、si-CRNDE+LPS组(用1.0μg·ml^(-1)LPS诱导转染si-CRNDE的细胞24 h)、miR-NC+LPS组(用1.0μg·ml^(-1)LPS诱导转染miR-NC的细胞24 h)、miR-29a-3p+LPS组(用1.0μg·ml^(-1)LPS诱导转染miR-29a-3p mimics的细胞24 h)、anti-miR-NC+si-CRNDE+LPS组(用1.0μg·ml^(-1)LPS诱导共转染anti-miR-NC与si-CRNDE的细胞24 h)和anti-miR-29a-3p+si-CRNDE+LPS组(用1.0μg·ml^(-1)LPS诱导共转染anti-miR-29a-3p与si-CRNDE的细胞24 h)。实时定量聚合酶链反应(RT-qPCR)检测细胞中CRNDE和miR-29a-3p表达,细胞计数试剂盒-8(CCK-8)、流式细胞仪和蛋白质印迹法分别检测细胞增殖、凋亡及细胞中细胞周期蛋白D1(CyclinD1)和活化的半胱氨酸天冬氨酸蛋白酶-3(Cleaved-caspase-3)表达。双荧光素酶报告基因实验验证CRNDE与miR-29a-3p调控关系。结果:与对照组比较,LPS组HUVECs中CRNDE表达升高(P<0.05),而miR-29a-3p表达降低(P<0.05)。与si-NC+LPS组比较,si-CRNDE+LPS组HUVECs存活率和CyclinD1表达升高(P<0.05),细胞凋亡率和Cleaved-caspase-3表达降低(P<0.05)。与miR-NC+LPS组比较,miR-29a-3p+LPS组HUVECs存活率和CyclinD1表达升高(P<0.05),细胞凋亡率和Cleaved-caspase-3表达降低(P<0.05)。CRNDE靶向负调控miR-29a-3p。与anti-miR-NC+si-CRNDE+LPS组比较,anti-miR-29a-3p+si-CRNDE+LPS组HUVECs存活率和CyclinD1表达降低(P<0.05),细胞凋亡率和Cleaved-caspase-3表达升高(P<0.05)。结论:低表达CRNDE可抑制LPS处理的内皮细胞增殖,并诱导细胞凋亡,其作用机制与负调控miR-29a-3p表达有关。