Abstract：
Urolithin A (UroA), a dietary phytochemical, is produced by gut bacteria from fruits rich in natural polyphenols ellagitannins (ETs). The efficiency of ETs metabolism to UroA in humans depends on gut microbiota. UroA has shown a variety of pharmacological activities. In this study we investigated the effects of UroA on atherosclerotic lesion development and stability. Apolipoprotein E-deficient (ApoE-/-) mice were fed a high-fat and high-cholesterol diet for 3 months to establish atherosclerosis model. Meanwhile the mice were administered UroA (50 mg·kg-1·d-1, i.g.). We showed that UroA administration significantly decreased diet-induced atherosclerotic lesions in brachiocephalic arteries, macrophage content in plaques, expression of endothelial adhesion molecules, intraplaque hemorrhage and size of necrotic core, while increased the expression of smooth muscle actin and the thickness of fibrous cap, implying features of plaque stabilization. The underlying mechanisms were elucidated using TNF-α-stimulated human endothelial cells. Pretreatment with UroA (10, 25, 50 μM) dose-dependently inhibited TNF-α-induced endothelial cell activation and monocyte adhesion. However, the anti-inflammatory effects of UroA in TNF-α-stimulated human umbilical vein endothelial cells (HUVECs) were independent of NF-κB p65 pathway. We conducted RNA-sequencing profiling analysis to identify the differential expression of genes (DEGs) associated with vascular function, inflammatory responses, cell adhesion and thrombosis in UroA-pretreated HUVECs. Human disease enrichment analysis revealed that the DEGs were significantly correlated with cardiovascular diseases. We demonstrated that UroA pretreatment mitigated endothelial inflammation by promoting NO production and decreasing YAP/TAZ protein expression and TEAD transcriptional activity in TNF-α-stimulated HUVECs. On the other hand, we found that UroA administration modulated the transcription and cleavage of lipogenic transcription factors SREBP1/2 in the liver to ameliorate cholesterol metabolism in ApoE-/- mice. This study provides an experimental basis for new dietary therapeutic option to prevent atherosclerosis.
摘要：
尿磷脂A(UroA),一种膳食植物化学物质，由富含天然多酚的水果的肠道细菌产生。人体内ET代谢为UroA的效率取决于肠道微生物群。UroA已显示出多种药理活性。在这项研究中，我们研究了UroA对动脉粥样硬化病变发展和稳定性的影响。采用高脂高胆固醇饮食喂养载脂蛋白E缺陷(ApoE-/-)小鼠3个月建立动脉粥样硬化模型。同时给予小鼠UroA(50mg·kg-1·d-1,i.g.)。我们显示UroA给药显著减少了饮食诱导的头臂动脉粥样硬化病变，斑块中的巨噬细胞含量，内皮粘附分子的表达，斑块内出血和坏死核心的大小，同时增加了平滑肌肌动蛋白的表达和纤维帽的厚度，暗示斑块稳定的特征。使用TNF-α刺激的人内皮细胞阐明了潜在的机制。UroA（10、25、50μM）预处理剂量依赖性地抑制TNF-α诱导的内皮细胞活化和单核细胞粘附。然而,UroA对TNF-α刺激的人脐静脉内皮细胞（HUVECs）的抗炎作用与NF-κBp65通路无关。我们进行了RNA测序谱分析，以确定与血管功能相关的基因（DEG）的差异表达，炎症反应，UroA预处理的HUVECs中的细胞粘附和血栓形成。人类疾病富集分析表明，DEGs与心血管疾病显着相关。我们证明UroA预处理通过促进NO产生和降低TNF-α刺激的HUVECs中YAP/TAZ蛋白表达和TEAD转录活性来减轻内皮炎症。另一方面,我们发现UroA在ApoE-/-小鼠肝脏中调节脂肪转录因子SREBP1/2的转录和裂解，从而改善胆固醇代谢。本研究为预防动脉粥样硬化的新饮食治疗方案提供了实验依据。
