Dietary modulation of Paneth cells

摘要 正如我们最近所展示的那样，肥胖症被低估的影响之一是对肠道天然免疫的抑制。 在超重/肥胖患者中，使用潘氏细胞表型(作为潘氏细胞功能的替代)作为证据- 概念上的。用西方饮食(WD)喂养的野生型小鼠也出现了潘氏细胞缺陷。我们进一步展示了 WD的摄入会导致微生物群介导的脱氧胆酸(一种次级胆汁酸)的增加， 激活回肠中的FXR通路。肠上皮中FXR的激活，以及FXR- 介导的I型干扰素在髓系细胞中的激活，共同触发潘氏细胞缺陷。关键人物 在将这些发现转化为临床之前，需要解决的问题包括个人饮食 影响潘氏细胞功能的成分，以及长期服用WD导致潘氏细胞缺陷 单独改变饮食习惯是不可逆的。我们的长期目标是剖析细胞和分子机制 WD消费如何影响肠道干细胞(ISC)和潘氏细胞生物学。这些发现将 促进为患有肠道天然免疫功能障碍的肥胖患者设计试验。这项提议的目的是 是为了确定WD消费是如何导致Paneth细胞异常的。中心假设是，从长期来看 饮食中果糖的摄入导致潘氏细胞能力下降导致潘氏细胞缺陷 补充(潘氏细胞本身和/或肠道干细胞[ISC])。我们的理由是这种认同 (S)恢复潘氏细胞功能的机制的研究将为许多患者提供新的治疗机会， 如炎症性肠病和移植物抗宿主病，潘氏细胞在这些疾病中发挥作用 在发病机制中起关键作用。我们的初步数据表明，仅饮食中的果糖摄入量就足够了。 触发潘氏细胞缺陷，以及长期(≥12个月)WD消费后潘氏细胞缺陷是 改用标准饮食不可逆。我们的具体目标将检验以下假设：(Aim1)如何 饮食中的果糖直接导致潘氏细胞缺陷；(目标2)长期摄入WD会损害 Paneth细胞以及ISCs修复和补充有缺陷Paneth细胞的能力。总而言之，我们 将了解饮食中果糖在调节潘氏细胞和ISC功能中的作用。这一贡献是 意义重大，因为它将建立肠上皮果糖分解代谢和相关基因作为治疗 目标。这项拟议的研究是创新的，因为我们调查了长期接触不良饮食对 肠道先天免疫，这是一个迄今未被研究过的过程。我们还使用最先进的ISC文化系统和 ScRNA-seq和scATAC-seq技术用于识别影响Paneth细胞和 ISC功能。确定饮食如何调节与疾病相关的关键细胞表型的机制将 提供对其他炎症性疾病的洞察。

ABSTRACT One of the underappreciated effect of obesity is the repression of gut innate immunity, as we recently showed in overweight/obese patients, using Paneth cell phenotype (as a surrogate for Paneth cell function) as a proof- of-concept. Wild type mice fed with western diet (WD) also developed Paneth cell defects. We further showed that WD consumption results in microbiota-mediated increase in deoxycholic acid (a secondary bile acid), which activates the FXR pathway in the ileum. FXR activation in the intestinal epithelium, as well as FXR- mediated type I interferon activation in myeloid cells, collectively trigger Paneth cell defects. The critical questions that need to be addressed before translating these findings to clinic include how individual dietary components that impact Paneth cell function, and if long-term WD consumption renders Paneth cell defects irreversible to dietary switch alone. Our long-term goal is to dissect the cellular and molecular mechanisms of how WD consumption affect the intestinal stem cell (ISC) and Paneth cell biology. These discoveries will facilitate design of trials for obese patients with gut innate immunity dysfunction. The objective of this proposal is to determine how WD consumption induces Paneth cell abnormality. The central hypothesis is that long-term consumption of dietary fructose result in Paneth cell defect due to diminished capacity of Paneth cell replenishment (by Paneth cells themselves and/or intestinal stem cells [ISC]). Our rationale is that identification of the mechanism(s) to restore Paneth cell function will offer new therapeutic opportunities for many patients, such as those with inflammatory bowel disease and graft versus host disease, of which Paneth cells play a critical role in pathogenesis. Our preliminary data suggest that dietary fructose consumption alone is sufficient to trigger Paneth cell defects, and that Paneth cell defects after long-term (≥12 months) WD consumption are not reversible by switching to standard diet. Our specific aims will test the following hypotheses: (Aim1) How dietary fructose directly induces Paneth cell defects; (Aim 2) Long-term WD consumption will impair the capacity of Paneth cells as well as ISCs to repair and replenish defective Paneth cells. Upon conclusion, we will understand the role for dietary fructose in modulating Paneth cell and ISC function. This contribution is significant since it will establish intestinal epithelial fructose catabolism and associated genes as therapeutic targets. The proposed research is innovative because we investigate how long-term exposure to poor diet on gut innate immunity, a heretofore-unexamined process. We also use state-of-the-art ISC culture system and scRNA-seq and scATAC-seq techniques to identify molecular and cellular targets that affect Paneth cell and ISC functions. Identifying the mechanisms of how diets regulate a key disease-relevant cellular phenotype will provide insight into other inflammatory disorders.