Laboratory for Cardiac and Thoracic Diagnosis, Regeneration and Applied Immunology, Department of Thoracic Surgery, Medical University of Vienna, 1090 Vienna, Austria.
Aposcience AG, 1200 Vienna, Austria.
Int J Mol Sci. 2021 Oct 27;22(21):11631. doi: 10.3390/ijms222111631.
Sebaceous glands are adnexal structures, which critically contribute to skin homeostasis and the establishment of a functional epidermal barrier. Sebocytes, the main cell population found within the sebaceous glands, are highly specialized lipid-producing cells. Sebaceous gland-resembling tissue structures are also found in male rodents in the form of preputial glands. Similar to sebaceous glands, they are composed of lipid-specialized sebocytes. Due to a lack of adequate organ culture models for skin sebaceous glands and the fact that preputial glands are much larger and easier to handle, previous studies used preputial glands as a model for skin sebaceous glands. Here, we compared both types of sebocytes, using a single-cell RNA sequencing approach, to unravel potential similarities and differences between the two sebocyte populations. In spite of common gene expression patterns due to general lipid-producing properties, we found significant differences in the expression levels of genes encoding enzymes involved in the biogenesis of specialized lipid classes. Specifically, genes critically involved in the mevalonate pathway, including squalene synthase, as well as the sphingolipid salvage pathway, such as ceramide synthase, (acid) sphingomyelinase or acid and alkaline ceramidases, were significantly less expressed by preputial gland sebocytes. Together, our data revealed tissue-specific sebocyte populations, indicating major developmental, functional as well as biosynthetic differences between both glands. The use of preputial glands as a surrogate model to study skin sebaceous glands is therefore limited, and major differences between both glands need to be carefully considered before planning an experiment.
皮脂腺是附属结构，对皮肤稳态和功能性表皮屏障的建立至关重要。皮脂腺中的主要细胞群体是高度特化的产脂细胞。在雄性啮齿动物中，也存在类似于皮脂腺的组织结构，即包皮腺。与皮脂腺类似，它们由专门产生脂质的皮脂腺组成。由于缺乏用于皮肤皮脂腺的充分器官培养模型，而且包皮腺更大且更容易处理，因此之前的研究使用包皮腺作为皮肤皮脂腺的模型。在这里，我们使用单细胞 RNA 测序方法比较了这两种皮脂腺，以揭示两种皮脂细胞群体之间的潜在相似性和差异。尽管由于普遍的产脂特性导致常见的基因表达模式，但我们发现参与特殊脂质类生物发生的酶编码基因的表达水平存在显著差异。具体而言，在甲羟戊酸途径中起关键作用的基因，包括鲨烯合酶，以及神经酰胺合成酶、（酸性）神经鞘磷脂酶或酸性和碱性神经酰胺酶等鞘脂补救途径的基因，在包皮腺皮脂腺中的表达水平显著降低。总之，我们的数据揭示了组织特异性的皮脂细胞群体，表明两种腺体之间存在主要的发育、功能和生物合成差异。因此，将包皮腺用作研究皮肤皮脂腺的替代模型是有限的，在计划实验之前需要仔细考虑两种腺体之间的主要差异。
