| In vitro Measurement of Membrane Attack Complex in RPE Cells
|
|
Author:
Date:
2021-02-20
[Abstract] Initiation of the complement system results in the formation of a multiprotein pore termed the membrane attack complex (MAC, C5b-C9). MAC pores accumulate on a cell surface and can result in cell lysis. The retinal pigment epithelium (RPE) is a single monolayer of pigmented epithelial cells located at the posterior poll of the eye that forms the outer blood retinal barrier. RPE cells are highly polarized with apical microvilli and basolateral contact with Bruch’s membrane. In order to obtain biologically relevant polarized RPE cultures in vitro, RPE cells are seeded onto the apical side of a transwell filter and cultured for 4 weeks in low serum media. MAC formation on RPE cells has been reported to be sub-lytic. MAC formation can be achieved in vitro by introduction of normal human ...
[摘要] [摘要]补体系统的启动导致形成称为膜攻击复合物(MAC,C5b-C9)的多蛋白孔。MAC孔积聚在细胞表面,可导致细胞裂解。视网膜色素上皮细胞(RPE)是位于眼那种形式的后轮询色素上皮细胞的单个单层š外血视网膜屏障。RPE细胞高度极化,顶端微绒毛和与Bruch膜的基底外侧接触。为了在体外获得生物学上相关的极化RPE培养物,将RPE细胞接种到Transwell滤膜的顶端,并在低血清培养基中培养4周。MAC形成Ò Ñ据报道,RPE细胞是亚裂解的。通过在血清饥饿24小时后向培养基中引入正常人血清(NHS),可以在体外实现MAC的形成。NHS包含启动补体激活和MAC形成所需的所有血清补体蛋白。我们结合了体外RPE极化和补体激活,以利用共聚焦显微镜在体外可视化MAC形成,从而实现了高分辨率MAC成像。
[背景]补体系统是一种进化保守的先天免疫途径。补体激活存在三种主要的独立但重叠的途径,它们在C3转化酶,经典途径,凝集素途径和替代途径中收敛。在经典途径中,免疫复合物(抗原-抗体复合物)通过C1q亚成分结合C1,然后C1s蛋白酶亚基裂解补体因子C4和C2。这些片段(C4bC2b)形成酶复合物“ ...
|
|
|
| Molecular and Phenotypic Characterization Following RNAi Mediated Knockdown in Drosophila
|
|
Author:
Date:
2021-02-20
[Abstract] Loss of function studies shed significant light on the involvement of a gene or gene product in different cellular processes. Short hairpin RNA (shRNA) mediated RNA interference (RNAi) is a classical yet straightforward technique frequently used to knock down a gene for assessing its function. Similar perturbations in gene expression can be achieved by siRNA, microRNA, or CRISPR-Cas9 methods also. In Drosophila genetics, the UAS-GAL4 system is utilized to express RNAi and make ubiquitous and tissue-specific knockdowns possible. The UAS-GAL4 system borrows genetic components of S. cerevisiae, hence rule out the possibility of accidental expression of the system. In particular, this technique uses a target-specific shRNA, and the expression of the same is governed by the upstream activating ...
[摘要] [摘要]功能丧失的研究为基因或基因产物在不同细胞过程中的参与提供了重要启示。短发夹RNA(shRNA)介导的RNA干扰(RNAi)是一种经典而直接的技术,经常用于敲低基因以评估其功能。也可以通过siRNA,microRNA或CRISPR-Cas9方法实现类似的基因表达扰动。在果蝇遗传学中,UAS-GAL4系统用于表达RNAi,并使遍在和组织特异性的基因敲除成为可能。UAS-GAL4系统借鉴了酿酒酵母的遗传成分,因此排除了系统意外表达的可能性。特别地,该技术使用靶标特异性shRNA,并且其表达受上游激活序列(UAS)支配。由特定启动子调节的GAL4受控表达可以普遍或以组织特异性方式驱动干扰RNA的表达。通过RNA分离和半定量RT-PCR反应,然后进行琼脂糖凝胶电泳来测量敲低效率。我们还采用了免疫染色程序来评估击倒效率。
RNAi为研究人员提供了降低基因产物水平(相当于亚同型条件)并研究结果的选择。基于UAS-GAL4的RNAi方法提供了基因表达的时空调节,还有助于推断早期发育阶段所需的基因功能。
[背景]果蝇果蝇(果蝇)是在研究实验室经常使用的一种通用模式生物。果蝇易于处理,繁殖和维护。而且,精心制作却寿命短,繁殖力高的果蝇具有更多的优势。果蝇遗传学工具的易用性有助于发展对基因功能的全面了解。由于果蝇基因中有60%与人类基因同源,并且具有前面提到的其他优点,因此果蝇是研究体内基因功能的显而易见的模型生物。 ...
|
|
|
| Estimation of the Minimum Number of Replication Origins Per Chromosome in any Organism
|
|
Author:
Date:
2020-10-20
[Abstract] Eukaryote nuclear genomes predominantly replicate through multiple replication origins. The number of replication origins activated per chromosome during the S-phase duration may vary according to many factors, but the predominant one is replication stress. Several studies have applied different approaches to estimate the number and map the positions of the replication origins in various organisms. However, without a parameter to restrict the minimum of necessary origins, less sensitive techniques may suggest conflicting results. The estimation of the minimum number of replication origins (MO) per chromosome is an innovative method that allows the establishment of a threshold, which serves as a parameter for genomic approaches that map origins. For this, the MO can be easily ...
[摘要] [摘要] 比率可能因多种因素而变化,但最主要的因素是复制应力。一些研究应用了不同的方法来估计复制源在不同生物体中的数量和位置。然而,如果没有一个参数来限制必要起源的最小值,那么不太敏感的技术可能会产生相互矛盾的结果。估计每个染色体的最小复制源数量(MO)是一种创新的方法,它允许建立一个阈值,作为绘制起源的基因组方法的参数。为此,MO可以很容易地通过一个公式得到,这个公式需要作为参数:染色体大小、S期持续时间和复制率。在基因组数据库(如NCBI)中可以获得任何生物体的染色体大小,通过监测DNA复制来估计S期的持续时间,并通过DNA组合方法获得复制率。 提供了一种简单、快速的估算MO的方法一个新的方法学框架来协助研究任何有机体。 关键词: DNA复制,复制来源,复制率,S期持续时间,染色体大小 [背景] ...
|
|
|