Probiotic-derived nano-particles in alcoholic liver disease

益生菌已用于预防/治疗酒精性肝病(ALD)。活的益生菌需要在肠道中定居 发挥他们的作用。不幸的是，潜在的疾病状态为益生菌提供了一个不利的环境。 肠道细菌定植，这削弱了益生菌的功能。在过去的几年里，我们展示了LGG 培养上清液(不含活菌)对实验性ALD有预防作用 对小鼠的急性和慢性酒精暴露的影响。然而，LGG上清液是如何发挥其治疗作用的 没有完全理解。胞外体是由细胞内吞作用产生的纳米颗粒，起着递质的作用。 在细胞之间。最近的研究表明，细菌，无论是革兰氏阴性还是革兰氏阳性，都会产生NPs。这个 从“坏”细菌中提取的NPS已被证明是致病的。然而，“好的”细菌-- 益生菌衍生的NPs还没有被研究过。我们的初步研究表明，服用LGG衍生的 Exosome-like NPs(LDNPs)有效地逆转了长期酗酒小鼠模型中的ALD， 提示益生菌LGGs可能通过LDNPs在ALD中发挥作用。LDNPs显着给药 增加肠道AhR活性、IL-22和再生胰岛衍生3(Reg3)β和γ的表达，这在 在维持肠道微生物区系动态平衡和防止细菌肠道转胞方面起着关键作用。此外, LDNPs显著增加肠上皮细胞(IEC)紧密连接并减少 循环内毒素浓度与肠道Nrf2信号上调有关，这是已知的 保护肠屏障连接免受酒精引起的氧化应激损伤。代谢组学分析 发现LDNPs含有高水平的色氨酸微生物代谢物，这是AhR配体，表明 LDNPs可能激活肠道AhR信号转导通路。此外，我们还证明了生姜外切体样蛋白 纳米粒(GDNPs)优先被LGG摄取，提示GDNP可能是一种益生素 增强LGG的效果。这些初步研究为我们的中心假设奠定了基础， LDNPs通过激活肠道AhR-Nrf2信号，增加肠道IL-22、Reg3和Tell的表达 连接，并调节肠道微生物区系动态平衡，增强肠道屏障功能，导致 抑制ALD。我们将在以下四个具体目标中检验我们的假设：(1)确定细菌的作用- ALD中衍生的NPs；(2)确定LDNPs在ALD中有益作用的机制；(3)确定 GDNPs处理可增加LDNP的产生和AhR激动剂的浓缩，从而改善 LDNPs抗酒精性肝病；以及(4)评估酒精性肝炎患者治疗后肠道AhR-Nrf2信号的变化。 LGG。这项研究的完成预计将对基于LGG的益生菌的发展产生重大影响 治疗学在酒精相关性肝病治疗中的作用。

Probiotics have been used to prevent/treat alcoholic liver disease (ALD). Live probiotics need to colonize the gut to exert their function. Unfortunately, underlying disease states provide an unfavorable environment for probiotic bacterial gut colonization, which diminishes probiotics’ function. In the last few years, we showed that LGG culture supernatant (LGGs, without live bacteria) was effective in the prevention of ALD in experimental models of acute and chronic alcohol exposure in mice. However, how LGG supernatant exerts its therapeutic effects is not fully understood. Exosomes are nanoparticles (NPs) derived from cell endocytosis which act as transmitters between cells. Recent studies show that bacteria, both Gram-negative and Gram-positive, produce NPs. The NPs derived from “bad” bacteria have been demonstrated to be pathogenic. However, “good” bacteria-, probiotics-derived NPs have not been studied. Our preliminary study showed that administration of LGG-derived exosome-like NPs (LDNPs) effectively reversed ALD in the binge-on-chronic alcohol exposure mouse model, suggesting that probiotic LGGs may exert its function through LDNPs in ALD. Administration of LDNPs markedly increased intestinal AhR activity, IL-22, and regenerating islet-derived 3 (Reg3) β and γ expression, which play a key role in maintaining gut microbiota homeostasis and preventing bacterial intestinal transcytosis. In addition, LDNPs administration significantly increased intestinal epithelial cell (IEC) tight junctions and decreased circulating LPS concentration associated with upregulation of intestinal Nrf2 signaling, which is known for protecting intestinal barrier junctions against oxidative stress-induced damage by alcohol. Metabolomic analysis revealed that LDNPs contain high levels of microbial metabolites of tryptophan, which are AhR ligands, indicating LDNPs may activate intestinal AhR signaling. Furthermore, we demonstrated that ginger exosome-like nanoparticles (GDNPs) are preferentially taken up by LGG, suggesting that GDNP may serve as a prebiotic to enhance the effects of LGG. These preliminary studies provide the groundwork for our central hypothesis that, by activating intestinal AhR-Nrf2 signaling, LDNPs increase intestinal expression of Il-22, Reg3 and tight junctions, and modulate gut microbiota homeostasis and enhance intestinal barrier function, leading to the suppression of ALD. We will test our hypothesis in following four specific aims: (1) Determine the role of bacteria- derived NPs in ALD; (2) Define the mechanisms of the beneficial effects of LDNPs in ALD; (3) Determine whether GDNPs treatment enhances LDNP production and AhR agonist enrichment that lead to improved effects of LDNPs against ALD; and (4) Evaluate the intestinal AhR-Nrf2 signaling in alcoholic hepatitis patients treated with LGG. Completion of this study is expected to significantly impact the development of LGG-based probiotic therapeutics in the treatment of alcohol-associated liver diseases.