smallRNA 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依据其所处的（微）血管床位置，行使各异的功能。这类功能差异大概率源于差异化的微小RNA（microRNA）与信使RNA（mRNA）转录模式，但目前此类分子的具体种类尚未被充分探明。我们通过在开展（小）RNA测序分析前对微血管进行激光显微切割，聚焦于小鼠肾皮质微血管区域的内皮细胞。借此手段，我们对小动脉、肾小球、肾小管周围毛细血管以及毛细血管后静脉的微小RNA和信使RNA转录谱进行了系统表征。本研究采用实时定量聚合酶链式反应（RT-qPCR）、原位杂交与免疫组织化学技术对测序结果进行了验证。结果显示，所有微血管区域均存在独特的微小RNA与信使RNA转录谱，专属的标记性微小RNA和信使RNA仅在单一微血管区域呈现富集转录。原位杂交实验验证了mmu-miR-140-3p在小动脉中的定位、mmu-miR-322-3p在肾小球中的定位，以及mmu-miR-451a在毛细血管后静脉中的定位。免疫组织化学染色结果表明，血管性血友病因子（von Willebrand Factor）蛋白主要在小动脉与毛细血管后静脉中表达；GABRB1的表达在肾小球中富集，而IGF1的表达则集中于毛细血管后静脉。本研究证实，小鼠肾脏微血管内皮异质性由差异表达的微小RNA与信使RNA共同介导。本研究鉴定得到的转录谱可为未来探索健康与疾病状态下微血管参与机制的相关研究提供关键的分子参考依据。