mRNA data - Unique miRNome and Transcriptome Profiles Underlie Microvascular Heterogeneity in Mouse Kidney

Endothelial cells in the blood vessels in the kidney exert different functions depending on the (micro)vascular bed they are located in. These functional differences are likely a result of differential microRNA and mRNA transcription patterns, yet the identity of these molecules is not well known. We zoomed in on the endothelial cells of microvascular compartments in mouse renal cortex by laser microdissecting the microvessels prior to (small) RNA sequencing analyses. By these means, we characterised microRNA and mRNA transcription profiles of arterioles, glomeruli, peritubular capillaries, and post-capillary venules. RT-qPCR, in situ hybridisation, and immunohistochemistry were used to validate sequencing results. Unique microRNA and mRNA transcription profiles were found in all microvascular compartments, with dedicated marker microRNAs and mRNAs showing enriched transcription in a single microvascular compartment. In situ hybridisation validated localisation of microRNAs mmu-miR-140-3p in arterioles, of mmu-miR-322-3p in glomeruli, and of mmu-miR-451a in post-capillary venules. Immunohistochemical staining showed that von Willebrand Factor protein was mainly expressed in arterioles and post-capillary venules, while GABRB1 expression was enriched in glomeruli and IGF1 in post-capillary venules. Our study shows that microvascular endothelial heterogeneity in mouse kidney is a result of a combination of differentially expressed microRNAs and mRNAs. The identified profiles provide important molecular information to take into account for future studies into microvascular engagement in health and disease.肾脏血管内的内皮细胞（endothelial cells）依据其所处的微血管床（microvascular bed）类型发挥不同的功能。这类功能差异大概率源于微小RNA（microRNA）与信使RNA（mRNA）的差异化转录模式，但目前此类分子的具体种类尚不明确。本研究通过在进行小RNA测序（small RNA sequencing）分析前，利用激光显微切割（laser microdissection）技术分离小鼠肾皮质微血管室的内皮细胞，对小动脉（arterioles）、肾小球（glomeruli）、肾小管周围毛细血管（peritubular capillaries）以及毛细血管后静脉（post-capillary venules）的微小RNA与信使RNA转录谱进行了表征。本研究采用实时定量聚合酶链反应（RT-qPCR）、原位杂交（in situ hybridisation）以及免疫组织化学（immunohistochemistry）对测序结果进行了验证。研究发现，所有微血管室均存在独特的微小RNA与信使RNA转录谱，且存在特异性标记分子：部分微小RNA与信使RNA仅在单一微血管室中呈现转录富集现象。原位杂交实验证实，微小RNA mmu-miR-140-3p定位于小动脉，mmu-miR-322-3p定位于肾小球，mmu-miR-451a定位于毛细血管后静脉。免疫组织化学染色结果显示，血管性血友病因子（von Willebrand Factor）主要在小动脉与毛细血管后静脉中表达，而γ-氨基丁酸A型受体β1亚基（GABRB1）在肾小球中富集，胰岛素样生长因子1（IGF1）则在毛细血管后静脉中高表达。本研究表明，小鼠肾脏微血管内皮异质性由差异化表达的微小RNA与信使RNA共同介导。本研究鉴定得到的转录谱可为未来针对健康与疾病状态下微血管参与机制的相关研究提供重要的分子参考依据。