Department of Laboratory Animal Medicine, College of Veterinary Medicine, Jeonbuk National University, Iksan 54596, Republic of Korea.
Int J Mol Sci. 2023 Feb 8;24(4):3439. doi: 10.3390/ijms24043439.
Risk signals are characteristic of many common inflammatory diseases and can function to activate nucleotide-binding oligomerization (NLR) family pyrin domain-containing 3 (NLRP3), the innate immune signal receptor in cytoplasm. The NLRP3 inflammasome plays an important role in the development of liver fibrosis. Activated NLRP3 nucleates the assembly of inflammasomes, leading to the secretion of interleukin (IL)-1β and IL-18, the activation of caspase-1, and the initiation of the inflammatory process. Therefore, it is essential to inhibit the activation of the NLRP3 inflammasome, which plays a vital role in the immune response and in initiating inflammation. RAW 264.7 and LX-2 cells were primed with lipopolysaccharide (LPS) for 4 h and subsequently stimulated for 30 min with 5 mM of adenosine 5'-triphosphate (ATP) to activate the NLRP3 inflammasome. Thymosin beta 4 (Tβ4) was supplemented to RAW264.7 and LX-2 cells 30 min before ATP was added. As a result, we investigated the effects of Tβ4 on the NLRP3 inflammasome. Tβ4 prevented LPS-induced NLRP3 priming by inhibiting NF-kB and JNK/p38 MAPK expression and the LPS and ATP-induced production of reactive oxygen species. Moreover, Tβ4 induced autophagy by controlling autophagy markers (LC3A/B and p62) through the inhibition of the PI3K/AKT/mTOR pathway. LPS combined with ATP significantly increased thee protein expression of inflammatory mediators and NLRP3 inflammasome markers. These events were remarkably suppressed by Tβ4. In conclusion, Tβ4 attenuated NLRP3 inflammasomes by inhibiting NLRP3 inflammasome-related proteins (NLRP3, ASC, IL-1β, and caspase-1). Our results indicate that Tβ4 attenuated the NLRP3 inflammasome through multiple signaling pathway regulations in macrophage and hepatic stellate cells. Therefore, based on the above findings, it is hypothesized that Tβ4 could be a potential inflammatory therapeutic agent targeting the NLRP3 inflammasome in hepatic fibrosis regulation.
风险信号是许多常见炎症性疾病的特征，可激活细胞质中的核苷酸结合寡聚化结构域（NLR）家族富含半胱氨酸的蛋白 3（NLRP3），即先天免疫信号受体。NLRP3 炎性小体在肝纤维化的发展中起着重要作用。激活的 NLRP3 核小体形成炎性小体，导致白细胞介素（IL）-1β和 IL-18 的分泌、半胱天冬酶-1 的激活以及炎症过程的启动。因此，抑制 NLRP3 炎性小体的激活至关重要，因为它在免疫反应和炎症启动中起着至关重要的作用。RAW264.7 和 LX-2 细胞用脂多糖（LPS）预刺激 4 小时，然后用 5mM 三磷酸腺苷（ATP）刺激 30 分钟以激活 NLRP3 炎性小体。在加入 ATP 之前 30 分钟向 RAW264.7 和 LX-2 细胞中添加胸腺素β 4（Tβ4）。结果，我们研究了 Tβ4 对 NLRP3 炎性小体的影响。Tβ4 通过抑制 NF-κB 和 JNK/p38 MAPK 表达以及 LPS 和 ATP 诱导的活性氧产生来阻止 LPS 诱导的 NLRP3 引发。此外，Tβ4 通过控制自噬标志物（LC3A/B 和 p62）来诱导自噬，通过抑制 PI3K/AKT/mTOR 途径。LPS 联合 ATP 显著增加了炎症介质和 NLRP3 炎性小体标志物的蛋白表达。这些事件被 Tβ4 显著抑制。总之，Tβ4 通过抑制 NLRP3 炎性小体相关蛋白（NLRP3、ASC、IL-1β 和半胱天冬酶-1）来减轻 NLRP3 炎性小体。我们的结果表明，Tβ4 通过在巨噬细胞和肝星状细胞中调节多种信号通路来减轻 NLRP3 炎性小体。因此，基于上述发现，假设 Tβ4 可以成为针对肝纤维化调节中 NLRP3 炎性小体的潜在炎症治疗剂。
