Examining how the novel S64F MAFA variant produces glucose intolerance or hypoglycemia in a sex-dependent manner

项目摘要 截至2018年，有3030万美国人被诊断患有糖尿病（占美国人口的10%）。 男性性别偏见）。它与许多慢性疾病密切相关，如心脏病发作、中风和癌症， 使糖尿病成为发病率和死亡率的主要危险因素。在所有形式的糖尿病中， 正常的葡萄糖水平是由进行性的功能障碍和最终丧失产生胰岛素的B细胞引起的。 胰腺标准治疗的治疗失败率很高，开发新的治疗方法， 保持甚至增强B细胞功能是优先考虑的。此外，男性之间的新陈代谢差异 和妇女在健康的老龄化和疾病的赞赏，但很少了解。 胰腺b细胞需要几个关键因素来适当分泌胰岛素。其中一个因素是MafA， 成熟B细胞功能的基础转录因子。人MafA（MAFA）在B细胞中的早期丢失， 患有2型糖尿病的患者突出了其对人类B细胞健康的重要性。此外，一种天然存在的， MAFA基因突变（S64 F MAFA）最近被确定为使携带者易患家族性、成人- 发病糖尿病或低血糖（低血糖）。奇怪的是，S64 F MAFA相关的糖尿病 在男性中更普遍，而女性倾向于出现低血糖。为了更好地了解性- 由于该变体的依赖性效应，我们产生了携带该突变的小鼠模型。该模型显示了 在人类中观察到的预期性别依赖性效应，表明小鼠和人类之间存在类似的机制。 雄性S64 F MAFA小鼠由于广泛的、过早的b细胞老化和衰老而高血糖，而 雌性S64 F MAFA小鼠通过一种尚未明确定义的机制而降低血糖。但我们的 初步研究表明，S64 F MAFA在女性中产生不同的b细胞亚型，其中之一是 机能亢进总之，这些结果表明，S64 F MAFA可以引起不同的b细胞应答， 产生依赖性疾病：糖尿病（b细胞功能减退）和低血糖症（b细胞功能亢进）。 本研究将鉴定和比较男性和女性对S64 F MAFA的不同分子反应， 小鼠和人类的雌性b细胞，以了解人类特有的性别依赖性b细胞反应。 B细胞我们将首先使用渗透剂、原理验证S64 F MAFA小鼠模型，该模型模拟了几种 人类疾病的各个方面，通过单细胞转录组学鉴定不同的B细胞群体。比如说， 过早衰老特征的多样性将与衰老的男性S64 F MAFA中观察到的功能障碍有关 B细胞然后，我们将研究S64 F MAFA蛋白在细胞中的分子和功能反应。 使用新型假胰岛技术鉴定靶点的遗传修饰的男性和女性人类B细胞 是人类B细胞功能所独有的总之，我们的工作将促进对性别依赖性的基本理解。 人类的B细胞反应。男性相对脆弱和女性抵抗的机制 在这个模型中的糖尿病可以被利用来开发针对个人的治疗方法。

PROJECT ABSTRACT As of 2018, 30.3 million Americans have been diagnosed with diabetes (10% of the U.S. population with a male sex bias). Its close associations with many chronic diseases, such as heart attacks, strokes, and cancers, make diabetes a leading risk factor for morbidity and mortality. In all forms of diabetes, the inability to maintain normal glucose levels results from progressive dysfunction and eventual loss of insulin-producing b-cells in the pancreas. With high rates of treatment failure on standard therapy, developing new therapeutic approaches to preserve or even enhance b-cell function is a priority. Furthermore, differences in metabolism between men and women during healthy aging and disease are appreciated but poorly understood. Pancreatic b-cells require several key factors to appropriately secrete insulin. One such factor is MafA, a transcription factor fundamental to mature b-cell function. The early loss of human MafA (MAFA) in b-cells in patients with type 2 diabetes highlights its importance to human b-cell health. In addition, a naturally occurring, genetic mutation in MAFA (S64F MAFA) was recently identified to predispose carriers to either familial, adult- onset diabetes or hypoglycemia (low blood glucose). Curiously, S64F MAFA-associated diabetes is much more prevalent in men while women tend to present with hypoglycemia. To better understand the sex- dependent effects of this variant, we generated a mouse model harboring this mutation. This model shows the expected sex-dependent effects seen in humans, suggesting similar mechanisms between mice and humans. Male S64F MAFA mice were hyperglycemic due to widespread, premature b-cell aging and senescence, while female S64F MAFA mice were hypoglycemic by a mechanism which is not yet clearly defined. However, our preliminary studies suggest that S64F MAFA creates different b-cell subtypes in females, one of which is hyperfunctional. Taken together, these results suggest that S64F MAFA can incur diverse b-cell responses to produce sex-dependent diseases: diabetes (b-cell hypofunction) and hypoglycemia (b-cell hyperfunction). This investigation will identify and compare the diverse molecular responses to S64F MAFA in male and female b-cells across mice and humans to understand the sex-dependent, b-cell responses unique to human b-cells. We will first use the penetrant, proof-of-principle S64F MAFA mouse model which mimics several aspects of human disease to identify the diverse b-cell populations by single cell transcriptomics. For example, diversity in premature aging signatures will be related to the dysfunction seen in senescent, male S64F MAFA b-cells. We will then investigate the molecular and functional responses to the S64F MAFA protein in genetically modified, male and female human b-cells using novel pseudoislet technology to identify targets unique to human b-cell function. In sum, our work will advance fundamental understanding of sex-dependent b-cell responses in humans. Mechanisms underlying a relative male vulnerability and female resistance to diabetes in this model can be harnessed to develop therapies tailored to the individual.