“Protection from MRSA lethality by inhibiting LXRα phosphorylation”

项目摘要 该提案旨在确定LXRα在丝氨酸196（S196）的磷酸化是否是LXR α的可能靶点。 MRSA的治疗干预。我们以前发表的研究表明，在培养的细胞和小鼠 LXRα S196 A的非磷酸化形式重新编程LXRα S196 A的心脏代谢疾病模型， 调节转录组并产生更强的抗炎反应。我们假设减少 髓样细胞和内皮细胞中的LXRα磷酸化可通过对MRSA的耐药性减少MRSA的病理 通过增强的外泌体释放的毒素介导的杀伤。 为了验证这一点，我们将开发一种小鼠模型，该模型携带髓样或内皮细胞特异性LXRα S196 A 敲入小鼠，并将MRSA感染后血液中的死亡率和外泌体丰度与WT进行比较 LXRα小鼠和全局LXRα S196 A小鼠。我们还将产生原代巨噬细胞和内皮细胞， 野生型和LXRα S196 A小鼠，并测量MRSA感染后对基因表达的影响，以揭示 通过LXRα S196磷酸化调节的基因和途径，可用于预防和 治疗目的。我们还将测试是否药物干预，促进非- 野生型LXRα的磷酸化形式可以保护野生型小鼠和人PBMC免受致死性MRSA的侵害 感染这些目标的成功完成将决定LXRα磷酸化是否代表一种易处理的 作为治疗MRSA的靶点，由于其能够减少炎症基因表达。

PROJECT SUMMARY This proposal aims to determine whether LXRα phosphorylation at serine 196 (S196) is a possible target for therapeutic intervention in MRSA. Our previous published studies demonstrated in cultured cells and mouse models of cardiometabolic diseases that the non-phosphorylated form of LXRα S196A reprograms the LXR- modulated transcriptome and produces a more robust anti-inflammatory response. We hypothesize that reducing LXRα phosphorylation in myeloid and endothelial cells would reduce MRSA pathology via resistance to MRSA toxin-mediated killing via enhanced exosome release. To test this, we will develop a mouse model that harbors either myeloid or endothelial cell-specific LXRα S196A knock-in mice and compare the mortality and exosome abundance in the blood upon MRSA infection to that of WT LXRα mice and global LXRα S196A mice. We will also generate primary macrophages and endothelial cells from wild-type and LXRα S196A mice and measure effects on gene expression upon infection with MRSA to reveal genes and pathways modulated by LXRα S196 phosphorylation that can be manipulated for preventive and therapeutic purposes. We will also test whether pharmacological interventions that promote the non- phosphorylated form of the wild-type LXRα can protect wild-type mice and human PBMCs from lethal MRSA infection. Successful completion of the aims will determine whether LXRα phosphorylation represents a tractable target for treating MRSA due to its ability to reduce inflammatory gene expression.