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，已有3030万美国人被诊断为糖尿病(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风险因素。在所有形式的糖尿病中，无法维持 正常血糖水平是由进行性功能障碍和最终失去的胰岛素分泌b细胞造成的。 胰腺。由于标准治疗的治疗失败率很高，开发新的治疗方法 保留甚至增强B细胞的功能是当务之急。此外，男性之间的新陈代谢差异 而女性在健康老龄化和疾病期间受到赞赏，但对此了解甚少。 胰腺b细胞需要几个关键因素才能适当地分泌胰岛素。一个这样的因素是Mafa，一个 转录因子是成熟b细胞功能的基础。人MafA(MAFA)在B细胞中的早期丢失 2型糖尿病患者强调了它对人类b细胞健康的重要性。此外，一种自然发生的， 最近发现MAFA(S64F MAFA)基因突变可使携带者易患家族性、成人型和非家族性遗传病。 出现糖尿病或低血糖(低血糖)。奇怪的是，与S64F MAFA相关的糖尿病 在男性中更为常见，而女性则倾向于出现低血糖。为了更好地理解性行为- 这种变异的依赖效应，我们产生了一个含有这种突变的小鼠模型。此模型显示了 在人类身上可以看到预期的性别依赖效应，这表明老鼠和人类的机制相似。 雄性S64F MAFA小鼠由于普遍的b细胞过早衰老和衰老而出现高血糖，而 雌性S64F MAFA小鼠具有降血糖作用，其机制尚不清楚。然而，我们的 初步研究表明，S64F MAFA在女性体内会产生不同的b细胞亚型，其中之一是 机能亢进。综上所述，这些结果表明，S64F MAFA可以引起不同的b细胞反应 产生与性别有关的疾病：糖尿病(b细胞功能低下)和低血糖(b细胞功能亢进)。 这项研究将鉴定和比较男性和男性对S64F MAFA的不同分子反应 跨越小鼠和人类的女性b细胞，以了解人类特有的性别依赖的b细胞反应 B细胞。我们将首先使用渗透性的、原理验证的S64F MAFA小鼠模型，它模仿了几个 用单细胞转录组分鉴定人类疾病的不同b细胞群。例如, 过早衰老特征的多样性将与衰老的男性S64F MAFA的功能障碍有关 B细胞。然后我们将研究对S64F MAFA蛋白的分子和功能反应 利用新的伪胰岛技术识别靶点的转基因、男性和女性人类b细胞 是人类B细胞功能所独有的。总而言之，我们的工作将促进对性别依赖的基本理解 人类的B细胞反应。男性相对脆弱和女性抵抗的机制 这种模式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.