Purpose

We discovered that dihydrotestosterone (DHT) decreases the ability of lipopolysaccharide, a bacterial toxin, to stimulate the secretion of leukotriene B4, a potent proinflammatory mediator, by immortalized human meibomian gland epithelial cells (IHMGECs). We hypothesize that this hormone action reflects an androgen suppression of proinflammatory gene activity in these cells. Our goal was to test this hypothesis. For comparison, we also examined whether DHT treatment elicits the same effect in immortalized human corneal (IHC) and conjunctival (IHConj) ECs.

Methods

Differentiated cells were cultured in media containing vehicle or 10 nM DHT. Cells (n = 3 wells/treatment group) were then processed for RNA isolation and the analysis of gene expression by using Illumina BeadChips, background subtraction, cubic spline normalization and Geospiza software.

Results

Our results demonstrate that DHT significantly suppressed the expression of numerous immune-related genes in HMGECs, such as those associated with antigen processing and presentation, innate and adaptive immune responses, chemotaxis, and cytokine production. DHT also enhanced the expression of genes for defensin β1, IL-1 receptor antagonist, and the anti-inflammatory serine peptidase inhibitor, Kazal type 5. In contrast, DHT had no effect on proinflammatory gene expression in HCECs, and significantly increased 33 gene ontologies linked to the immune system in HConjECs.

Conclusions

Our findings support our hypothesis that androgens suppress proinflammatory gene expression in IHMGECs. This hormone effect may contribute to the typical absence of inflammation within the human meibomian gland.

中文翻译：

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二氢睾酮抑制人睑板腺上皮细胞中促炎基因表达。

目的

我们发现二氢睾丸激素（DHT）通过永生化的人类睑板腺上皮细胞（IHMGEC）降低了细菌毒素脂多糖刺激白细胞三烯B4（一种有效的促炎介质）的分泌的能力。我们假设这种激素作用反映了这些细胞中促炎基因活性的雄激素抑制。我们的目标是检验这个假设。为了进行比较，我们还检查了DHT治疗在永生化的人角膜（IHC）和结膜（IHConj）EC中是否引起相同的效果。

方法

将分化的细胞在含有媒介物或10nM DHT的培养基中培养。然后处理细胞（n = 3孔/处理组）以进行RNA分离，并使用Illumina BeadChips，背景扣除，三次样条标准化和Geospiza软件分析基因表达。

结果

我们的结果表明，DHT显着抑制了HMGEC中许多免疫相关基因的表达，例如与抗原加工和呈递，先天性和适应性免疫反应，趋化性和细胞因子产生相关的那些基因。DHT还增强了防御素β1，IL-1受体拮抗剂和抗炎性丝氨酸肽酶抑制剂Kazal 5型的基因表达。相比之下，DHT对HCEC中的促炎基因表达没有影响，并且显着增加了33种基因本体与HConjECs的免疫系统有关。

结论

我们的发现支持我们的假设，即雄激素抑制IHMGEC中的促炎基因表达。这种激素作用可能有助于人类睑板腺内典型的炎症消失。