TRPC1通道影响血管平滑肌细胞功能的作用及机制

背景:血管平滑肌细胞功能的正常与否与血管疾病的发生密切相关,TRPC1通道能够调控血管平滑肌细胞的功能。目的:总结搜索到的文献中得到的TRPC1通道对血管平滑肌细功能的影响,讨论TRPC1通道影响血管平滑肌细胞功能可能的机制。方法:应用计算机检索北京航空航天大学图书馆、中国知网、百度学术和PubMed Central Medline数据库1969至2017年收录的与血管平滑肌细胞和TRPC1通道相关的文献。英文检索词为"vascular smooth muscle cells,TRPC1 channel,vascular smooth muscle cells function",中文检索词为"血管平滑肌细胞,经典瞬时受体电位通道,血管平滑肌细胞功能",最后纳入1篇中文文献和44篇英文文献进行综述。结果与结论:(1)TRPC1通道是非选择性阳离子通道超家族TRP中的一种,在血管平滑肌上广泛表达,调控血管平滑肌细胞功能的多个方面;(2)TRPC1通道自发现以来,因其对钙库驱动的钙内流的贡献,被认为是细胞上钙库驱动的钙通道的一种。多年以来,人们用基因敲除,RNAi,mRNA阻断和特异性阻断抗体等研究方法,得到了大量关于TRPC1通道影响血管平滑肌细胞功能的研究成果。(3)文章对目前得到的关于TRPC1通道对血管平滑肌细胞影响的研究结果进行了总结,并且探讨了TRPC1通道影响血管平滑肌细胞可能的机制。

固体火箭发动机单室双推力装药设计

以某型火箭弹为研究背景,从推进剂种类选择、推进剂药型分类探讨及火箭弹内弹道计算依次展开,借助Matlab软件编制程序研究单室双推力火箭发动机装药设计的影响因素。经过反复迭代计算,多组结果进行比较,最终确定装药几何结构参数。结果表明:所得到的内弹道计算曲线满足总体要求,与试验数据吻合较好,设计过程中得到的调整经验总结对固体火箭发动机的研制具有一定的参考价值。

Effect of Electrical Stimulation on the Growth of Endothelial Cell

Exogenous electrical stimulation plays an important role on endothelial cells and vessels. Study on the effect of electrical stimulation on endothelial cells might be helpful to regulate cell metabolism on a certain extent, or provide new ideas for vascular tissue engineering. A bioreactor that can apply electrical stimulation was designed on the basis of parallel-plate chamber. To investigate the possible effect of electrical stimulation on human umbilical vein endothelial cells (HUVECs), the different levels and duration′s electrical stimulations were applied to HUVECs in culture. The cell morphology was observed by microscopy and the levels of endothelial nitric oxide synthase (eNOS) gene were measured by RT-PCR. Different levels and durations of electrical stimulation produce different effects on eNOS gene expression. The eNOS gene expressions of the experimental group cells under the voltage of 50 mV, 100 mV,150 mV and 200 mV were significantly lower than that of the control group after 3-hour electrical stimulation, while the eNOS gene levels of the experimental group cells in 6-hour electrical stimulation were higher than those of the control group under all tested voltages. After 12-hour stimulation, the eNOS gene levels of HUVECs decreased under 50 mV, and then gradually increased until 200 mV. The low voltage of 6-hour electrical stimulation is more appropriate for HUVECs growth.

次氯酸钠氧化脱除化学镀镍废水中的氨氮

针对化学镀镍废水氨氮浓度高、去除难度较大等特点,以预处理后的实际化学镀镍废水为试验对象,采用次氯酸钠氧化法脱除废水中的剩余氨氮。分别研究NaClO溶液投加量、反应时间、初始pH值及反应温度对氨氮去除效果的影响,得到较适宜的反应条件为:NaClO溶液投加量为1800 mg/L,反应时间为30 min,初始pH值为6.0～7.0,反应温度为10～30℃。在此条件下,废水氨氮去除率达到91%以上,剩余氨氮浓度低于15 mg/L,满足GB 21900—2008《电镀污染物排放标准》表2中对氨氮的排放限值。结果表明:次氯酸钠氧化作为深度处理方式脱除化学镀镍废水中氨氮是高效可行的。

Irrelevance of BK_(Ca) Channel Expression to VSMCs Phenotype under Shear Stress

Large conductance Ca^(2+)-activated K^+ (BK_(Ca)) channel exhibits a phenotype-dependent expression on vascular smooth muscle cells(VSMCs), which prefers to contractile phenotype. Meanwhile, shear stress definitely influences VSMCs proliferation and contraction. Thereby, a hypothesis was raised, would shear stress change the BK_(Ca)expression and correlate with VSMC phenotype? In order to investigate it, VSMCs were exposed to shear stress in a parallel-plate flow chamber with 12 dynes/cm^2 for 12 h. Subsequently, the effect of shear stress on VSMC proliferation, BK_(Ca)channel expression and contractile phenotype marker, α-smooth muscle cell actin(α-SMA) and smooth muscle myosin heavy chain(SMMHC), was determined by immunofluorescence microscopy, flow cytometery as well as reverse transcriptionpolymerase chain reaction(RT-PCR), respectively. Data show that shear stress enhanced the expression of BK_(Ca)channel while inhibiting VSMC proliferation.Paralleled to those phenomena, the expression of both α-SMA and SM-MHC were decreased significantly. These results demonstrated that upregulation of BK_(Ca)channel was irrelevant to the maintenance VSMC of contractile phenotype under shear stress.This finding provides a new insight into understanding the correlation of BK_(Ca)channel and VSMC phenotype.

Trichostatin A and Shear Stress in Regulating Endothelium Differentiation of Bone Marrow Mesenchymal Stem Cells

Differentiation of bone marrow mesenchymal stem cells (MSCs) into endothelial cells (EC) is characterized by the expression of specific endothelial marker genes. Mechanical stimulations play potential effects in EC oriented differentiation of MSCs. However, molecular mechanisms of endothelial differentiation from MSCs have not been defined.Histone acetylations play important roles in regulating gene expression. Histone acetylation status is maintained by histone acetyltransferase (HAT) and histone deacetylases (HDACs). Our previous work described that VEGF and laminar shear stress (SS) work together in determining EC oriented differentiation of MSC. Trichostatin A (TSA) is one of the lustone deacetylase inhibitor. In this study, we found that both TSA and SS could induce EC oriented differentiation of MSCs. And TSA combined with SS showed more powerful influence on the EC oriented differentiation of MSCs.

Effects of Tensile Stimulation and Electrical Stimulation on the Connexion-43 m RNA Levels of Cardiomyocytes in vitro

The heart is regulated by excitation-contraction mechanism and electrical stimulation, so both cardiac tissues and myocytes in vivo are affected by the mechanical and electrical factors at the same time. The device that can supply both tensile stimulation and electrical stimulation was produced. Cardiomyocytes were isolated by trypsin and collagenase Ⅱ combined digestion. After 72 h's culture, different electrical stimulations(0.5 V/cm, 1 V/cm, 2 V/cm;1 Hz;2 ms;30 min) and mechanical stretching force(tensile 10%, 6 h) were used to stimulate cultured cardiomyocytes respectively. Then the combinative stimulation of mechanical and electrical stimulation with 0.5 V/cm was used to apply to cardiomyocytes simultaneously. After stimulation,Connexin-43(Cx-43) mRNA level was detected by RT-PCR. The stimulation by electrical pulse of 0.5 V/cm resulted in obvious enhancement of Cx-43 m RNA level compared to the control group and the Cx-43 mRNA levels at 0.5 V/cm were higher significantly than those under both 1.0 V/cm and 2.0 V/cm. After 10% of tensile stimulation for 6 h, expressions of Cx-43 mRNA were also significantly promoted. The combinative effect of mechanical and electrical stimulation on the expression of Cx-43 mRNA is higher than that under unique tensile stimulation or electrical stimulation,which is more beneficial to the development and connection of cardiomyocytes.