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The intestinal epithelium is a polarized monolayer of cells, with an apical side facing the lumen and a basal side facing the blood stream. In mice, both proteins and mRNAs have been shown to exhibit global basal-apical polarization; however, polarization in the human intestine has not been systematically explored. Here, we employed laser-capture microdissection to isolate apical and basal epithelial segments from intestinal tissues of 8 individuals and performed RNA sequencing and mass-spectrometry proteomics. We find a substantial polarization of mRNA molecules that largely overlaps polarization patterns observed in mice. This mRNA polarization remains consistent across different zones of the intestinal villi and is generally correlated with the polarization of proteins. Our protein analysis exposes streamlined intracellular nutrient transport and processing and reveals that mitochondria and ribosomes are less polarized in humans compared to mice. Our study provides a resource for understanding human intestinal epithelial biology.

肠上皮（intestinal epithelium）是一层极化的细胞单层，其顶侧（apical side）朝向肠腔，基底侧（basal side）朝向血流。在小鼠中，蛋白质与信使RNA（mRNA）均已被证实存在全局的基底-顶侧极化现象；然而，人类肠道中的极化现象尚未得到系统性探索。本研究采用激光捕获显微切割（laser-capture microdissection）技术，从8名个体的肠道组织中分离出上皮细胞的顶侧与基底侧节段，并开展了RNA测序（RNA sequencing）与质谱蛋白质组学（mass-spectrometry proteomics）分析。我们发现信使RNA（mRNA）分子存在显著极化现象，其极化模式与小鼠中观测到的结果高度重合。这种信使RNA极化现象在肠绒毛的不同区域均保持稳定，且总体上与蛋白质的极化现象相关。我们的蛋白质分析揭示了细胞内营养物质转运与加工过程呈现精简特征，同时发现与小鼠相比，人类的线粒体（mitochondria）与核糖体（ribosomes）的极化程度更低。本研究为解析人类肠上皮生物学特性提供了宝贵的研究资源。