The regulation of meibomian gland dysfunction by growth hormone and insulin-like

摘要 眉板腺功能障碍(MGD)被认为是干眼的主要原因。 疾病，它影响着美国数百万人的生活质量。MGD的特点是 终末排泄管梗阻，导管上皮过度角化 腮腺黏度和汗腺萎缩/脱落。目前，MGD的作用机制是 不知道。危险因素包括高龄、雄激素缺乏和接触13-顺式维甲酸 酸(RA)。鉴于类风湿关节炎导致典型的MGD，我建议研究MGD的机制 使用人类眉毛腺细胞培养和暴露于RA的小鼠模型。我假设 RA通过影响特异性抗原抑制眉板腺细胞的增殖并诱导细胞死亡 细胞内途径和上调特定的死亡诱导蛋白。此外，我 假设类风湿关节炎通过特定的角化相关因素促进眉板腺角化 蛋白质。 为了对抗RA诱导的MGD，我建议使用两种激素，生长激素(GH) 和胰岛素样生长因子-1(IGF-1)。众所周知，GH/IGF-1促进细胞增殖和 细胞存活，并在其他类型皮脂腺的增殖和分化中发挥作用 腺体细胞。我假设GH/IGF-1信号与RA诱导的信号通路相交 并对抗与细胞增殖、细胞死亡和角质化有关的蛋白质变化。至 测试我的假设，我将使用包括人体细胞在内的各种实验程序 培养，免疫分析，酶分析，qRT-PCR，RNA沉默，荧光显微镜， 流式细胞术、小鼠模型、组织学和激素治疗。 我的具体目标是：1)确定13-顺式维甲酸诱导细胞的机制 永生化人睑板腺上皮细胞周期停滞、细胞死亡和角化 2)阐明GH/IGF-1如何阻断13-cis RA诱导的这些细胞的产生 后遗症；3)检查生长激素信号改变的小鼠的眉肌腺组织学；4) 测定13-顺式维甲酸对包括腺体萎缩和导管在内的MGD的影响 野生型(WT)小鼠的过度角化；5)确定局部治疗的效果 GH/IGF-1对13-顺式维甲酸诱导的WT小鼠MGD的影响我的长期目标是更好地 了解MGD的机制，并将这些信息转化为潜在的治疗方法 为了MGD。

ABSTRACT Meibomian gland dysfunction (MGD) is believed to be the leading cause of dry eye disease, which affects the quality of life of millions of people in the US. MGD is characterized by terminal excretory duct obstruction, hyperkeratinization of the ductal epithelium, increased viscosity of meibum and meibomian gland atrophy/dropout. Currently the mechanism of MGD is not known. Risk factors include old age, androgen deficiency and exposure to 13-cis retinoic acid (RA). Given that RA causes prototypical MGD, I propose to study the mechanism of MGD using human meibomian gland cell cultures and mouse models exposed to RA. I hypothesize that RA inhibits meibomian gland cell proliferation and induces cell death by affecting specific intracellular pathways and upregulating specific death-inducing proteins. In addition, I hypothesize that RA promotes meibomian gland keratinization via specific keratinization-related proteins. To counteract RA-induced MGD, I propose to use two hormones, growth hormone (GH) and insulin-like growth factor-1 (IGF-1). GH/IGF-1 is well-known to promote cell proliferation and cell survival, and plays roles in the proliferation and differentiation of other types of sebaceous gland cells. I hypothesize that GH/IGF-1 signaling intersects the RA-induced signaling pathways and antagonizes the protein changes involved in proliferation, cell death and keratinization. To test my hypotheses, I will use a variety of experimental procedures, including human cell cultures, immunoassays, enzyme assays, qRT-PCR, RNA silencing, fluorescence microscopy, flow cytometry, mouse models, histology and hormone treatments. My specific aims are to: 1) determine the mechanism by which 13-cis RA induces cell cycle arrest, cell death and keratinization in immortalized human meibomian gland epithelial cells; 2) elucidate how GH/IGF-1 interrupts the generation of these 13-cis RA-induced cellular sequelae; 3) examine the meibomian gland histology in mice with altered GH signaling; 4) determine the effect of 13-cis RA on inducing MGD including gland atrophy and ductal hyperkeratinization in wild type (WT) mice; and 5) determine the effect of topical treatment with GH/IGF-1 on 13-cis RA induced MGD in WT mice. My long-term objective is to better understand the mechanism of MGD and to translate this information into a potential treatment for MGD.