Laboratory Medicine Center, Department of Clinical Laboratory, Zhejiang Provincial People's Hospital, Affiliated People's Hospital, Hangzhou Medical College, Hangzhou, Zhejiang, China.
Department of Laboratory Medicine, Third Affiliated Hospital of Zhejiang Chinese Medical University, Hangzhou, Zhejiang, China.
PLoS One. 2022 Nov 21;17(11):e0278059. doi: 10.1371/journal.pone.0278059. eCollection 2022.
MicroRNA-146a (miRNA-146a) is a nuclear factor κB (NF-κB)-inducible and inflammation-sensitive miRNA, while papain elicits anti-inflammatory effects by inhibiting monocyte-platelet aggregate (MPA)-mediated NF-κB pathway activation in monocytes. This study aimed to demonstrate the underlying effects of papain on MPA formation-initiated miRNA-146a expression and subsequent action in monocytes.
THP-1 cells were exposed to papain, miRNA-146a mimic and inhibitor, NF-κB inhibitor (BAY11-7082), and platelets. Flow cytometry was used to measure the MPA formation-initiated monocyte activation. Levels of miRNA-146a, cyclooxygenase 2 (COX-2) mRNA and protein, and monocyte chemoattractant protein 1 (MCP-1) were analyzed in monocytes by RT-PCR, western blot, and ELISA.
The NF-κB inhibitor and miRNA-146a mimics upregulated miRNA-146a expression but suppressed subsequent monocyte activation and expression of COX-2 and MCP-1. Following exposure to papain, the enhanced miRNA-146a transcription induced by MPA-formation was found along with significant inhibition of monocyte activation in a dose-dependent manner. However, the inhibitory tendency was significantly reversed by miRNA-146a inhibitors. Expression of COX-2 mRNA and protein, as well as MCP-1, was inhibited in monocytes by papain, whereas miRNA-146a inhibitors promoted COX-2 and MCP-1 expression.
Our findings suggest that papain can inhibit MPA formation-mediated expression of inflammatory mediators in activated monocytes by upregulating miRNA-146a transcription.
微小 RNA-146a（miRNA-146a）是一种核因子 κB（NF-κB）诱导和炎症敏感的 miRNA，而木瓜凝乳蛋白酶通过抑制单核细胞-血小板聚集（MPA）介导的 NF-κB 通路激活来发挥抗炎作用。本研究旨在证明木瓜凝乳蛋白酶对 MPA 形成起始的 miRNA-146a 表达及其在单核细胞中的后续作用的潜在影响。
THP-1 细胞暴露于木瓜凝乳蛋白酶、miRNA-146a 模拟物和抑制剂、NF-κB 抑制剂（BAY11-7082）和血小板。流式细胞术用于测量 MPA 形成起始的单核细胞激活。通过 RT-PCR、western blot 和 ELISA 分析单核细胞中 miRNA-146a、环氧化酶 2（COX-2）mRNA 和蛋白以及单核细胞趋化蛋白 1（MCP-1）的水平。
NF-κB 抑制剂和 miRNA-146a 模拟物上调了 miRNA-146a 的表达，但抑制了随后的单核细胞激活和 COX-2 和 MCP-1 的表达。暴露于木瓜凝乳蛋白酶后，发现 MPA 形成诱导的 miRNA-146a 转录增强与单核细胞激活呈剂量依赖性抑制。然而，miRNA-146a 抑制剂显著逆转了抑制趋势。木瓜凝乳蛋白酶抑制了单核细胞中 COX-2 mRNA 和蛋白以及 MCP-1 的表达，而 miRNA-146a 抑制剂促进了 COX-2 和 MCP-1 的表达。
我们的研究结果表明，木瓜凝乳蛋白酶通过上调 miRNA-146a 转录来抑制 MPA 形成介导的激活单核细胞中炎症介质的表达。
