hsa-let-7b-5p facilitates Mycobacterium tuberculosis survival in THP-1 human macrophages by Fas downregulation

The MiR-139-5p and CXCR4 axis may play a role in high glucose-induced inflammation by regulating monocyte migration

MicroRNAs, a class of small non-coding RNA molecules that regulate gene expression post-transcriptionally, are implicated in various pathological conditions including diabetes mellitus (DM). DM has been increasingly recognized as an inflammatory disease and monocytes play a key role in propagating inflammation under hyperglycemic conditions. We hypothesize that high glucose dysregulates microRNAs to promote monocyte inflammatory activity, which may contribute to the pathogenesis of DM. THP-1 monocytes were cultured in normal (5 mM) and high (25 mM) glucose conditions. RT-qPCR and Western blotting were performed to assay microRNAs and proteins, respectively. Monocytes were transfected with microRNA mimics using Lipofectamine RNAiMAX reagent. THP-1 monocyte growth was assessed using Calcein-AM dye and a Boyden chamber assay was applied to measure monocyte migration. The results showed that high glucose downregulated miR-139-5p associated with increased protein expression of CXCR4, an experimentally validated target of miR-139-5p. Correspondingly, treatment with high glucose resulted in a significant increase in THP-1 cell migration towards SDF-1, a cognate ligand for CXCR4. MiR-139-5p overexpression inhibited high glucose-induced CXCR4 expression, leading to reduced cell migration towards SDF-1. High glucose did not affect THP-1 monocyte growth. In conclusion, the miR-139-5p-CXCR4 axis may play a role in high glucose-induced inflammation by regulating monocyte migration.

The critical role of miRNA in bacterial zoonosis

The public's health and the financial sustainability of international societies remain threatened by bacterial zoonoses, with limited reliable diagnostic and therapeutic options available for bacterial diseases. Bacterial infections influence mammalian miRNA expression in host-pathogen interactions. In order to counteract bacterial infections, miRNAs participate in gene-specific expression and play important regulatory roles that rely on translational inhibition and target gene degradation by binding to the 3' non-coding region of target genes. Intriguingly, according to current studies, that exogenous miRNAs derived from plants could potentially serve as effective medicinal components sourced from traditional Chinese medicine plants. These exogenous miRNAs exhibit stable functionality in mammals and mimic the regulatory roles of endogenous miRNAs, illuminating the molecular processes behind the therapeutic effects of plants. This review details the immune defense mechanisms of inflammation, apoptosis, autophagy and cell cycle disturbance caused by some typical bacterial infections, summarizes the role of some mammalian miRNAs in regulating these mechanisms, and introduces the cGAS-STING signaling pathway in detail. Evidence suggests that this newly discovered immune defense mechanism in mammalian cells can also be affected by miRNAs. Meanwhile, some examples of transboundary regulation of mammalian mRNA and even bacterial diseases by exogenous miRNAs from plants are also summarized. This viewpoint provides fresh understanding of microbial tactics and host mechanisms in the management of bacterial illnesses.

Lung Inflammation Signature in Post-COVID-19 TB Patients

Tuberculosis (TB) remains a leading cause of infectious disease mortality worldwide, despite the COVID-19 pandemic. The mechanisms by which SARS-CoV-2 affects tuberculosis progression have not yet been established. Here, we compared the level of inflammation in the wall of the tuberculoma and in the parenchymal lung tissue of 30 patients diagnosed with tuberculoma without a history of COVID-19 and 30 patients diagnosed with tuberculoma 3 months after COVID-19. We also characterized TB activity in these patients using a panel of TB-associated miRNAs. Histopathological changes were examined in the resection material, and the expression level of cytokine/chemokine genes was determined by qRT-PCR. In patients with a history of COVID-19, the histological data obtained suggested activation of tuberculosis. In the same group of patients, as opposed to those without a history of COVID-19, equally high levels of pro-inflammatory cytokines/chemokines were expressed both in the tuberculoma wall and in the periphery of the resected specimen. A full set of miRNAs (miR-191, miR-193a, miR-222, miR-223, miR-155, miR-26a, and miR-150) were downregulated in the sera of patients with TB and active COVID-19 co-infection compared to controls. Our observations indicate signs of tuberculosis activation resulting from COVID-19 infection.

Mycobacterium tuberculosis sRNA MTS2823 regulates the growth of the multidrug-resistant strain in macrophages

Tuberculosis (TB), caused by Mycobacterium tuberculosis (MTB), is a serious contagious disease. MTB-encoded small regulatory RNA (sRNA) MTS2823 was reported to be upregulated in the plasma of TB patients. Nevertheless, whether MTS2823 is implicated in MTB drug resistance is unclear. Human macrophage cell line THP-1 was infected with the drug-susceptible strain H37Rv or the multidrug-resistant (MDR) strain 8462. Colony-forming unit assay was implemented for evaluating intracellular growth of the MTB strains. Enzyme-linked immunosorbent assay was used for measurement of inflammatory cytokines. Real-time quantitative polymerase chain reaction was utilized to assess MTS2823 and recombinase A (recA) expression in strains 8462 and H37Rv. Nitric oxide (NO) production in the MDR strain-infected THP-1 cells was measured. In this study, MTS2823 was found to display a low level in the MDR strain. Overexpressing MTS2823 promoted intracellular growth of the MDR strain and inhibited inflammatory cytokine and NO production in infected THP-1 cells. RecA might be a target of MTS2823 in the MDR strain. Overall, MTB-encoded sRNA MTS2823 displays a low level and regulates the growth of the MDR strain in THP-1 cells by modulating recA.

Immune regulation and emerging roles of noncoding RNAs in Mycobacterium tuberculosis infection

Tuberculosis, caused by Mycobacterium tuberculosis, engenders an onerous burden on public hygiene. Congenital and adaptive immunity in the human body act as robust defenses against the pathogens. However, in coevolution with humans, this microbe has gained multiple lines of mechanisms to circumvent the immune response to sustain its intracellular persistence and long-term survival inside a host. Moreover, emerging evidence has revealed that this stealthy bacterium can alter the expression of demic noncoding RNAs (ncRNAs), leading to dysregulated biological processes subsequently, which may be the rationale behind the pathogenesis of tuberculosis. Meanwhile, the differential accumulation in clinical samples endows them with the capacity to be indicators in the time of tuberculosis suffering. In this article, we reviewed the nearest insights into the impact of ncRNAs during Mycobacterium tuberculosis infection as realized via immune response modulation and their potential as biomarkers for the diagnosis, drug resistance identification, treatment evaluation, and adverse drug reaction prediction of tuberculosis, aiming to inspire novel and precise therapy development to combat this pathogen in the future.

Network-Based Data Analysis Reveals Ion Channel-Related Gene Features in COVID-19: A Bioinformatic Approach

Coronavirus disease 2019 (COVID-19) seriously threatens human health and has been disseminated worldwide. Although there are several treatments for COVID-19, its control is currently suboptimal. Therefore, the development of novel strategies to treat COVID-19 is necessary. Ion channels are located on the membranes of all excitable cells and many intracellular organelles and are key components involved in various biological processes. They are a target of interest when searching for drug targets. This study aimed to reveal the relevant molecular features of ion channel genes in COVID-19 based on bioinformatic analyses. The RNA-sequencing data of patients with COVID-19 and healthy subjects (GSE152418 and GSE171110 datasets) were obtained from the Gene Expression Omnibus (GEO) database. Ion channel genes were selected from the Hugo Gene Nomenclature Committee (HGNC) database. The RStudio software was used to process the data based on the corresponding R language package to identify ion channel-associated differentially expressed genes (DEGs). Based on the DEGs, Gene Ontology (GO) functional and pathway enrichment analyses were performed using the Enrichr web tool. The STRING database was used to generate a protein-protein interaction (PPI) network, and the Cytoscape software was used to screen for hub genes in the PPI network based on the cytoHubba plug-in. Transcription factors (TF)-DEG, DEG-microRNA (miRNA) and DEG-disease association networks were constructed using the NetworkAnalyst web tool. Finally, the screened hub genes as drug targets were subjected to enrichment analysis based on the DSigDB using the Enrichr web tool to identify potential therapeutic agents for COVID-19. A total of 29 ion channel-associated DEGs were identified. GO functional analysis showed that the DEGs were integral components of the plasma membrane and were mainly involved in inorganic cation transmembrane transport and ion channel activity functions. Pathway analysis showed that the DEGs were mainly involved in nicotine addiction, calcium regulation in the cardiac cell and neuronal system pathways. The top 10 hub genes screened based on the PPI network included KCNA2, KCNJ4, CACNA1A, CACNA1E, NALCN, KCNA5, CACNA2D1, TRPC1, TRPM3 and KCNN3. The TF-DEG and DEG-miRNA networks revealed significant TFs (FOXC1, GATA2, HINFP, USF2, JUN and NFKB1) and miRNAs (hsa-mir-146a-5p, hsa-mir-27a-3p, hsa-mir-335-5p, hsa-let-7b-5p and hsa-mir-129-2-3p). Gene-disease association network analysis revealed that the DEGs were closely associated with intellectual disability and cerebellar ataxia. Drug-target enrichment analysis showed that the relevant drugs targeting the hub genes CACNA2D1, CACNA1A, CACNA1E, KCNA2 and KCNA5 were gabapentin, gabapentin enacarbil, pregabalin, guanidine hydrochloride and 4-aminopyridine. The results of this study provide a valuable basis for exploring the mechanisms of ion channel genes in COVID-19 and clues for developing therapeutic strategies for COVID-19.

MicroRNAs as Regulators of Phagocytosis

MicroRNAs (miRNAs) are short non-coding RNAs that regulate gene expression and thus act as important regulators of cellular phenotype and function. As their expression may be dysregulated in numerous diseases, they are of interest as biomarkers. What is more, attempts of modulation of some microRNAs for therapeutic reasons have been undertaken. In this review, we discuss the current knowledge regarding the influence of microRNAs on phagocytosis, which may be exerted on different levels, such as through macrophages polarization, phagosome maturation, reactive oxygen species production and cytokines synthesis. This phenomenon plays an important role in numerous pathological conditions.

MicroRNA hsa-let-7a facilitates staphylococcal small colony variants survival in the THP-1 macrophages by reshaping inflammatory responses

Recent studies have provided emerging evidence of the critical involvement of microRNAs in host immune defence against bacterial infection and that likewise the expression of the miRNAs is profoundly impacted by a variety of pathogens to subvert the immune response. Here, we report the role of hsa-let-7a miRNA in response to Staphylococcus epidermidis Small Colony Variants infection. We also assessed whether the expression levels of inflammatory cytokines associated with the hsa-let-7a are manipulated by the pathogen and the effect of the IFN-γ priming on the expression of hsa-let-7a and the fate of SCVs/WTs in infected macrophages. A striking observation was the downregulation of the let-7a miRNA upon challenge of the THP-1 activated cells with the SCV isolates while no significant changes in expression were noticed after the infection of macrophages with their WT counterparts. Staphylococcus epidermidis WT and SCV strains were found to invade and survive in macrophages. A significant reduction in bacterial load for both phenotypes was observed in macrophages treated with let-7a mimic compared to untreated ones. Survival of WTs was augmented in cells treated with the inhibitor in 4 out of 5 strains as compared to the number of bacteria recovered from non-transfected cells. At the same time, let-7a inhibitor did not influence on the survival of SCVs in macrophages as their number was comparable to number recovered from non-transfected cells. When the ratio of both let-7a cytokine targets was compared, anti-inflammatory IL-10 cytokine was induced by SCVs predominantly, while the macrophage challenge with WTs was characterized by the inflammatory cytokine profile with high IL-6 and low IL-10 production. Moreover, the balance between pro-inflammatory and anti-inflammatory cytokines has been expectedly retrieved when macrophages were transfected with let-7a mimic before infection with WT or SCV strains. The results also show that IFN-γ likely regulates the macrophage environment contributing to the inflammatory response and elimination of bacteria from intracellular milieu by augmenting the synthesis of pro-inflammatory cytokines and supressing the anti-inflammatory IL-10. Our work has shown that SCVs have the potential to regulate the let-7a miRNA to balance the pro-inflammatory IL-6 with anti-inflammatory IL-10 and this mechanism is one of the ways in a complex regulatory network adopted by SCVs to promote their survival.

Integrated Analysis of miRNA-mRNA Regulatory Networks Associated with Osteonecrosis of the Femoral Head

Osteonecrosis of the femoral head (ONFH) accounts for as many as 18% of total hip arthroplasties. Knowledge of genetic changes and molecular abnormalities could help identify individuals considered to be at a higher risk of developing ONFH. In this study, we sought to identify differentially expressed miRNAs (DEmiRs) and genes (DEGs) associated with ONFH by integrated bioinformatics analyses as well as to construct the miRNA-mRNA regulatory network involving in the pathogenesis of ONFH. We performed differential expression analysis using a gene expression profile GSE123568 and a miRNA expression profile GSE89587 deposited in the Gene Expression Omnibus and identified 47 DEmiRs (24 upregulated miRNAs and 23 downregulated miRNAs) and 529 DEGs (218 upregulated genes and 311 downregulated genes). Gene Ontology enrichment analyses of DEGs suggested that DEGs were significantly enriched in neutrophil activation, cytosol, and ubiquitin-protein transferase activity. Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses of DEGs revealed that DEGs were significantly enriched in transcriptional misregulation in cancer. DEGs-based miRNA-mRNA regulatory networks were obtained by searching miRNA-mRNA prediction databases, TargetScan, miTarBase, miRMap, miRDB, and miRanda databases. Then, overlapped miRNAs were selected between these putative miRNAs and DEmiRs between ONFH and non-ONFH, and pairs of the DEmiR-DEG regulatory network were finally depicted. There were 12 nodes and 64 interactions for upDEmiR-downDEG regulatory networks and 6 nodes and 16 interactions for downDEmiR-upDEG regulatory networks. Using the STRING database, we established a protein-protein interaction network based on the overlapped DEGs between ONFH and non-ONFH. C5AR1, CDC27, CDC34, KAT2B, CPPED1, TFDP1, and MX2 were identified as the hub genes. The present study characterizes the miRNA profile, gene profile, and miRNA-mRNA regulatory network in ONFH, which may contribute to the interpretation of the pathogenesis of ONFH and the identification of novel biomarkers and therapeutic targets for ONFH.

Monocyte and Macrophage miRNA: Potent Biomarker and Target for Host-Directed Therapy for Tuberculosis

The end TB strategy reinforces the essentiality of readily accessible biomarkers for early tuberculosis diagnosis. Exploration of microRNA (miRNA) and pathway analysis opens an avenue for the discovery of possible therapeutic targets. miRNA is a small, non-coding oligonucleotide characterized by the mechanism of gene regulation, transcription, and immunomodulation. Studies on miRNA define their importance as an immune marker for active disease progression and as an immunomodulator for innate mechanisms, such as apoptosis and autophagy. Monocyte research is highly advancing toward TB pathogenesis and biomarker efficiency because of its innate and adaptive response connectivity. The combination of monocytes/macrophages and their relative miRNA expression furnish newer insight on the unresolved mechanism for Mycobacterium survival, exploitation of host defense, latent infection, and disease resistance. This review deals with miRNA from monocytes, their relative expression in different disease stages of TB, multiple gene regulating mechanisms in shaping immunity against tuberculosis, and their functionality as biomarker and host-mediated therapeutics. Future collaborative efforts involving multidisciplinary approach in various ethnic population with multiple factors (age, gender, mycobacterial strain, disease stage, other chronic lung infections, and inflammatory disease criteria) on these short miRNAs from body fluids and cells could predict the valuable miRNA biosignature network as a potent tool for biomarkers and host-directed therapy.

The Role of microRNAs and Long Non-Coding RNAs in the Regulation of the Immune Response to Mycobacterium tuberculosis Infection

Non-coding RNAs have emerged as critical regulators of the immune response to infection. MicroRNAs (miRNAs) are small non-coding RNAs which regulate host defense mechanisms against viruses, bacteria and fungi. They are involved in the delicate interplay between Mycobacterium tuberculosis, the causative agent of tuberculosis (TB), and its host, which dictates the course of infection. Differential expression of miRNAs upon infection with M. tuberculosis, regulates host signaling pathways linked to inflammation, autophagy, apoptosis and polarization of macrophages. Experimental evidence suggests that virulent M. tuberculosis often utilize host miRNAs to promote pathogenicity by restricting host-mediated antibacterial signaling pathways. At the same time, host- induced miRNAs augment antibacterial processes such as autophagy, to limit bacterial proliferation. Targeting miRNAs is an emerging option for host-directed therapies. Recent studies have explored the role of long non-coding RNA (lncRNAs) in the regulation of the host response to mycobacterial infection. Among other functions, lncRNAs interact with chromatin remodelers to regulate gene expression and also function as miRNA sponges. In this review we attempt to summarize recent literature on how miRNAs and lncRNAs are differentially expressed during the course of M. tuberculosis infection, and how they influence the outcome of infection. We also discuss the potential use of non-coding RNAs as biomarkers of active and latent tuberculosis. Comprehensive understanding of the role of these non-coding RNAs is the first step towards developing RNA-based therapeutics and diagnostic tools for the treatment of TB.

MicroRNA expression profiles analysis of apheresis platelets treated with vitamin B2 and ultraviolet-B during storage

Whether platelet (PLT) microRNA (miRNA) profiles are affected by pathogen reduction technology (PRT) using vitamin B₂ and ultraviolet-B (VB₂-PRT) remains unclear. Samples from VB₂-PRT-treated (experimental group, E_) and untreated (control group, C_) apheresis PLTs were taken on days 1, 3 and 5 of storage, designated as E_1, E_3, E_5, C_1, C_3 and C_5, respectively. The miRNA expression profiles were assessed by DNA Nano Ball (DNB) sequencing technology, and verified by quantitive real-time fluorescence quantitative PCR (qRT-PCR). Compared with the expression profiles of PLT miRNAs, 3895 miRNAs were identified in the E_ groups while 4106 were in the C_ groups. There were 487 significant differentially expressed miRNAs in E_1 vs C_1 group, including 220 upregulated and 287 downregulated, such as miR-146a-5p and let-7b-5p. There were 908 significant differentially expressed miRNAs in E_3 vs C_3 group, including 297 upregulated and 611 downregulated, such as miR-142-5p and miR-7-5p. There were 229 significant differentially expressed miRNAs in E_5 vs C_5 group, including 80 upregulated and 149 downregulated, such as miR-3529-3p and miR-451a. These differentially expressed miRNAs had been suggested to have functional roles in energy homeostasis, cell communication, proliferation, migration and apoptosis. GO analysis showed a significant enrichmen in relevant biological process categories as receptor activity, signal transduction, cell transport, motility and chemotaxis. The significantly enriched KEGG pathway of predicted target genes was Glycosaminoglycan biosynthesis in E_ vs C_ groups. These new observation could provide insights on the understanding of change of miRNA profiles of PLT treated with VB₂-PRT.

The role of non-coding RNA on macrophage modification in tuberculosis infection

Tuberculosis (TB), a serious disease caused by Mycobacterium tuberculosis (Mtb), remains the world's top infectious killer. It is well-established that TB can circumvent the host's immune response for long-term survival. Macrophages serve as the major host cells for TB growth and persistence and their altered functions are critical for the response of the host defense against TB exposure (elimination, latency, reactivation, and bacillary dissemination). Noncoding RNAs are crucial posttranscriptional regulators of macrophage discrimination. Therefore, this review highlights the regulatory mechanism underlying the relationship between noncoding RNAs and macrophages in TB infection, which may facilitate the identification of potential therapeutic targets and effective diagnosis biomarkers for TB disease.

Intelligent Mechanisms of Macrophage Apoptosis Subversion by Mycobacterium

Macrophages are one of the first innate defense barriers and play an indispensable role in communication between innate and adaptive immune responses, leading to restricted Mycobacterium tuberculosis (Mtb) infection. The macrophages can undergo programmed cell death (apoptosis), which is a crucial step to limit the intracellular growth of bacilli by liberating them into extracellular milieu in the form of apoptotic bodies. These bodies can be taken up by the macrophages for the further degradation of bacilli or by the dendritic cells, thereby leading to the activation of T lymphocytes. However, Mtb has the ability to interplay with complex signaling networks to subvert macrophage apoptosis. Here, we describe the intelligent strategies of Mtb inhibition of macrophages apoptosis. This review provides a platform for the future study of unrevealed Mtb anti-apoptotic mechanisms and the design of therapeutic interventions.

microRNAs in Mycobacterial Infection: Modulation of Host Immune Response and Apoptotic Pathways

Our current knowledge of mycobacterial infections in humans has progressively increased over the past few decades. The infection of Mycobacterium tuberculosis causes tuberculosis (TB) disease, which has reasoned for excessive morbidity and mortality worldwide, and has become a foremost issue of health problem globally. Mycobacterium leprae, another member of the family Mycobacteriaceae, is responsible for causing a chronic disease known as leprosy that mainly affects mucosa of the upper respiratory tract, skin, peripheral nerves, and eyes. Ample amount of existing data suggests that pathogenic mycobacteria have skilled in utilizing different mechanisms to escape or offset the host immune responses. They hijack the machinery of immune cells through the modulation of microRNAs (miRs), which regulate gene expression and immune responses of the host. Evidence shows that miRs have now gained considerable attention in the research, owing to their involvement in a broad range of inflammatory processes that are further implicated in the pathogenesis of several diseases. However, the knowledge of functions of miRs during mycobacterial infections remains limited. This review summarises recent findings of differential expression of miRs, which are used to good advantage by mycobacteria in offsetting host immune responses generated against them.