Silencing miR-125b-5p attenuates inflammatory response and apoptosis inhibition in mycobacterium tuberculosis-infected human macrophages by targeting DNA damage-regulated autophagy modulator 2 (DRAM2)

Abstract

Tuberculosis is one of the most important infectious diseases worldwide and macrophage apoptosis is the major host defense mechanism against TB. We attempted to characterize the role of miRNA (miR)-125b-5p on mycobacterium tuberculosis (Mtb) infection and macrophages behaviors in vitro. According to fluorescence-activated cell separation (FACS), primary monocytes (CD14 + ) in TB patients were accumulated, and apoptotic monocytes were decreased. Peripheral blood mononuclear cells (PBMCs)-derived macrophages (MDMs) and monocytic cells THP-1-derived macrophage-like cells (TDMs) in vitro were used to be infected with H37Rv. After infection, colony-forming units assay revealed the increase of bacterial activity, FACS demonstrated the decrease of apoptosis rate of MDMs and TDMs, as well as promoted levels of IL-6, TNF-α, Bax, and Bim and suppressed levels of IL-10 and Bcl-2, examined by enzyme-linked immunosorbent assay (ELISA) and western blot assay. Expression of miR-125b-5p and DNA damage-regulated autophagy modulator 2 (DRAM2) was examined, and realtime PCR and western blot assay showed that miR-125b-5p was upregulated, whereas DRAM2 was downregulated in primary monocytes and H37Rv-infected macrophages (MDMs and TDMs). Moreover, blocking miR-125b-5p could attenuated H37Rv-induced bacterial activity and inflammatory response of MDMs and TDMs, accompanied with apoptosis inhibition. Whereas these effects of miR-125b-5p knockdown were abolished by downregulating DRAM2. In mechanism, DRAM2 was a downstream target of miR-125b-5p, as evidenced by dual-luciferase reporter assay. Collectively, silencing miR-125b-5p could protect human macrophages against Mtb infection through promoting apoptosis and inhibiting inflammatory response via targeting DRAM2, suggesting a novel target for Mtb eliminating.

Integrative investigation of the TF–miRNA coregulatory network involved in the inhibition of breast cancer cell proliferation by resveratrol

“…We found that resveratrol reduced the expression of hsa-miR-34a-5p, which helped improve patient survival. Hsa-miR-125b-5p inhibits apoptosis by targeting DRAM or TRIAP1 [35,36]. Wei et al confirmed that hsa-miR-181a-5p inhibited the apoptosis and autophagy of MCF-7 cells [37].…”

Shedding Light on Autophagy During Human Tuberculosis. A Long Way to Go

“…Importantly, the authors demonstrated that miR-144* targets DRAM2 (an interactor of Beclin 1 and UVRAG) in human monocytes/macrophages, thus affecting autophagosome formation ( Kim et al., 2017 ). Consequently, DRAM2 levels were decreased in monocytes from TB patients as compared to HD ( Liu G. et al., 2020 ).…”

The Roles of Host Noncoding RNAs in Mycobacterium tuberculosis Infection

“…Downregulation of miR-20a-5p was demonstrated to negatively modulate Bim expression in a JNK2-dependent manner and to promote mycobacterial clearance and reduce survival in macrophages, while JNK2 was shown to be a novel direct target of miR-20a-5p ( 37 ). In addition, a study found that miR-125b-5p was upregulated in patients with TB and in macrophages infected with M. tuberculosis ( 38 ). Inhibition of miR-125b-5p can improve the apoptosis rate of macrophages and the expression of apoptosis-related genes Bax and Bim and reduce the secretion of proinflammatory cytokines IL-6 and TNF-α to protect macrophages from injury induced by M. tuberculosis .…”

“…Inhibition of miR-125b-5p can improve the apoptosis rate of macrophages and the expression of apoptosis-related genes Bax and Bim and reduce the secretion of proinflammatory cytokines IL-6 and TNF-α to protect macrophages from injury induced by M. tuberculosis . In addition, downregulation of miR-125b-5p also attenuated M. tuberculosis infection in human macrophages in vitro by targeting DNA damage-regulated autophagy modulator 2 (DRAM2), promoting apoptosis and inhibiting inflammatory response ( 38 ). Not surprisingly, M. tuberculosis can regulate the host’s miRNAs to inhibit apoptosis, thereby replicating in the cell, conducive to their own survival.…”