While meibomian gland dysfunction (MGD) is widely recognized as a major cause of evaporative dry eye disease, little is known about normal gland differentiation and lipid synthesis or the mechanism underlying gland atrophy and abnormal lipid secretion. The purpose of this study was to use single-cell and spatial transcriptomics to probe changes in cell composition, differentiation, and gene expression associated with two murine models of MGD: age-related gland atrophy in wild-type mice and altered meibum quality in acyl-CoA wax alcohol acyltransferase 2 () knockout (KO) mice. Methods: Young (6 month) and old (22 month) wild type, C57Bl/6 mice and young (3 month) and old (13 month) Awat2 KO mice were used in these studies. For single-cell analysis, the tarsal plate was dissected from the upper and lower eyelids, and single cells isolated and submitted to the UCI Genomic Core, while for the spatial analysis frozen tissue sections were shipped to Resolve Biosciences on dry ice and sections probed in duplicate using a meibomian gland specific, 100 gene Molecular Chartography panel. Analysis of gene expression patterns identified the stratified expression of lipogenic genes during meibocyte differentiation, which may control the progressive synthesis of meibum lipids; an age-related decrease in meibocytes; and increased immune cell infiltration. Additionally, we detected unique immune cell populations in the KO mouse suggesting activation of psoriasis-like, inflammatory pathways perhaps caused by ductal dilation and hyperplasia. Together these findings support novel mechanism controlling gland function and dysfunction.

中文翻译：

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年龄和功能障碍对睑板腺种群动态的影响


虽然睑板腺功能障碍（MGD）被广泛认为是蒸发性干眼病的主要原因，但人们对正常腺体分化和脂质合成或腺体萎缩和异常脂质分泌的机制知之甚少。本研究的目的是利用单细胞和空间转录组学来探讨与两种 MGD 小鼠模型相关的细胞组成、分化和基因表达的变化：野生型小鼠中与年龄相关的腺体萎缩和酰基中睑脂质量的改变-CoA蜡醇酰基转移酶2()敲除(KO)小鼠。方法：在这些研究中使用年轻（6个月）和年老（22个月）野生型、C57Bl/6小鼠以及年轻（3个月）和年老（13个月）Awat2 KO小鼠。对于单细胞分析，从上眼睑和下眼睑切下睑板，分离单细胞并提交给 UCI 基因组核心，而对于空间分析，将冷冻组织切片运送到干冰上的 Resolve Biosciences，并在使用睑板腺特异性 100 基因分子图谱面板重复。基因表达模式分析确定了睑板细胞分化过程中脂肪生成基因的分层表达，这可能控制睑脂脂质的逐步合成；与年龄相关的睑板细胞减少；并增加免疫细胞浸润。此外，我们在 KO 小鼠中检测到独特的免疫细胞群，表明银屑病样炎症途径的激活可能是由导管扩张和增生引起的。这些发现共同支持了控制腺体功能和功能障碍的新机制。