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Liu H, Han Z, Chen L, Zhang J, Zhang Z, Chen Y, Liu F, Wang K, Liu J, Sai N, Zhou X, Zhou C, Hu S, Wen Q, Ma L. ZNFX1 promotes AMPK-mediated autophagy against Mycobacterium tuberculosis by stabilizing Prkaa2 mRNA. JCI Insight 2024; 9:e171850. [PMID: 38016036 PMCID: PMC10906457 DOI: 10.1172/jci.insight.171850] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Accepted: 11/14/2023] [Indexed: 11/30/2023] Open
Abstract
Tuberculosis has the highest mortality rate worldwide for a chronic infectious disease caused by a single pathogen. RNA-binding proteins (RBPs) are involved in autophagy - a key defense mechanism against Mycobacterium tuberculosis (M. tuberculosis) infection - by modulating RNA stability and forming intricate regulatory networks. However, the functions of host RBPs during M. tuberculosis infection remain relatively unexplored. Zinc finger NFX1-type containing 1 (ZNFX1), a conserved RBP critically involved in immune deficiency diseases and mycobacterial infections, is significantly upregulated in M. tuberculosis-infected macrophages. Here, we aimed to explore the immunoregulatory functions of ZNFX1 during M. tuberculosis infection. We observed that Znfx1 knockout markedly compromised the multifaceted immune responses mediated by macrophages. This compromise resulted in reduced phagocytosis, suppressed macrophage activation, increased M. tuberculosis burden, progressive lung tissue injury, and chronic inflammation in M. tuberculosis-infected mice. Mechanistic investigations revealed that the absence of ZNFX1 inhibited autophagy, consequently mediating immune suppression. ZNFX1 critically maintained AMPK-regulated autophagic flux by stabilizing protein kinase AMP-activated catalytic subunit alpha 2 mRNA, which encodes a key catalytic α subunit of AMPK, through its zinc finger region. This process contributed to M. tuberculosis growth suppression. These findings reveal a function of ZNFX1 in establishing anti-M. tuberculosis immune responses, enhancing our understanding of the roles of RBPs in tuberculosis immunity and providing a promising approach to bolster antituberculosis immunotherapy.
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Singh PR, Dadireddy V, Udupa S, Kalladi SM, Shee S, Khosla S, Rajmani RS, Singh A, Ramakumar S, Nagaraja V. The Mycobacterium tuberculosis methyltransferase Rv2067c manipulates host epigenetic programming to promote its own survival. Nat Commun 2023; 14:8497. [PMID: 38129415 PMCID: PMC10739865 DOI: 10.1038/s41467-023-43940-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Accepted: 11/24/2023] [Indexed: 12/23/2023] Open
Abstract
Mycobacterium tuberculosis has evolved several mechanisms to counter host defense arsenals for its proliferation. Here we report that M. tuberculosis employs a multi-pronged approach to modify host epigenetic machinery for its survival. It secretes methyltransferase (MTase) Rv2067c into macrophages, trimethylating histone H3K79 in a non-nucleosomal context. Rv2067c downregulates host MTase DOT1L, decreasing DOT1L-mediated nucleosomally added H3K79me3 mark on pro-inflammatory response genes. Consequent inhibition of caspase-8-dependent apoptosis and enhancement of RIPK3-mediated necrosis results in increased pathogenesis. In parallel, Rv2067c enhances the expression of SESTRIN3, NLRC3, and TMTC1, enabling the pathogen to overcome host inflammatory and oxidative responses. We provide the structural basis for differential methylation of H3K79 by Rv2067c and DOT1L. The structures of Rv2067c and DOT1L explain how their action on H3K79 is spatially and temporally separated, enabling Rv2067c to effectively intercept the host epigenetic circuit and downstream signaling.
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Affiliation(s)
- Prakruti R Singh
- Department of Microbiology & Cell Biology, Indian Institute of Science (IISc), Bengaluru, India
- Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR), Bengaluru, India
| | | | - Shubha Udupa
- Department of Microbiology & Cell Biology, Indian Institute of Science (IISc), Bengaluru, India
| | - Shashwath Malli Kalladi
- Department of Microbiology & Cell Biology, Indian Institute of Science (IISc), Bengaluru, India
| | - Somnath Shee
- Centre for Infectious Disease Research (CIDR), Department of Microbiology and Cell Biology, Indian Institute of Science (IISc), Bengaluru, India
| | - Sanjeev Khosla
- Council of Scientific and Industrial Research-Institute of Microbial Technology, Chandigarh (CSIR -IMTech), Chandigarh, India
| | - Raju S Rajmani
- Centre for Infectious Disease Research (CIDR), Department of Microbiology and Cell Biology, Indian Institute of Science (IISc), Bengaluru, India
| | - Amit Singh
- Centre for Infectious Disease Research (CIDR), Department of Microbiology and Cell Biology, Indian Institute of Science (IISc), Bengaluru, India
| | | | - Valakunja Nagaraja
- Department of Microbiology & Cell Biology, Indian Institute of Science (IISc), Bengaluru, India.
- Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR), Bengaluru, India.
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Abstract
Tuberculosis (TB) remains the leading cause of bacterial disease-related death and is among the top 10 overall causes of death worldwide. The complex nature of this infectious lung disease has proven difficult to treat, and significant research efforts are now evaluating the feasibility of host-directed, adjunctive therapies. An attractive approach in host-directed therapy targets host epigenetics, or gene regulation, to redirect the immune response in a host-beneficial manner. Substantial evidence exists demonstrating that host epigenetics are dysregulated during TB and that epigenetic-based therapies may be highly effective to treat TB. However, the caveat is that much of the knowledge that exists on the modulation of the host epigenome during TB has been gained using in vitro, small-animal, or blood-derived cell models, which do not accurately reflect the pulmonary nature of the disease. In humans, the first and major target cells of Mycobacterium tuberculosis are alveolar macrophages (AM). As such, their response to infection and treatment is clinically relevant and ultimately drives the outcome of disease. In this review, we compare the fundamental differences between AM and circulating monocyte-derived macrophages in the context of TB and summarize the recent advances in elucidating the epigenomes of these cells, including changes to the transcriptome, DNA methylome, and chromatin architecture. We will also discuss trained immunity in AM as a new and emerging field in TB research and provide some perspectives for the translational potential of targeting host epigenetics as an alternative TB therapy.
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Chen Y, Zhai W, Zhang K, Liu H, Zhu T, Su L, Bermudez L, Chen H, Guo A. Small RNA Profiling in Mycobacterium Provides Insights Into Stress Adaptability. Front Microbiol 2021; 12:752537. [PMID: 34803973 PMCID: PMC8600241 DOI: 10.3389/fmicb.2021.752537] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Accepted: 10/01/2021] [Indexed: 11/29/2022] Open
Abstract
Mycobacteria encounter a number of environmental changes during infection and respond using different mechanisms. Small RNA (sRNA) is a post-transcriptionally regulatory system for gene functions and has been investigated in many other bacteria. This study used Mycobacterium tuberculosis and Mycobacterium bovis Bacillus Calmette-Guérin (BCG) infection models and sequenced whole bacterial RNAs before and after host cell infection. A comparison of differentially expressed sRNAs using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) and target prediction was carried out. Six pathogenically relevant stress conditions, growth rate, and morphology were used to screen and identify sRNAs. From these data, a subset of sRNAs was differentially expressed in multiple infection groups and stress conditions. Many were found associated with lipid metabolism. Among them, ncBCG427 was significantly downregulated when BCG entered into macrophages and was associated with increased biofilm formation. The reduction of virulence possibility depends on regulating lipid metabolism.
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Affiliation(s)
- Yingyu Chen
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,National Animal Tuberculosis Para-Reference Laboratory (Wuhan) of Ministry of Agriculture and Rural Affairs, Huazhong Agricultural University, Wuhan, China
| | - Wenjun Zhai
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,National Animal Tuberculosis Para-Reference Laboratory (Wuhan) of Ministry of Agriculture and Rural Affairs, Huazhong Agricultural University, Wuhan, China
| | - Kailun Zhang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,National Animal Tuberculosis Para-Reference Laboratory (Wuhan) of Ministry of Agriculture and Rural Affairs, Huazhong Agricultural University, Wuhan, China
| | - Han Liu
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,National Animal Tuberculosis Para-Reference Laboratory (Wuhan) of Ministry of Agriculture and Rural Affairs, Huazhong Agricultural University, Wuhan, China
| | - Tingting Zhu
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,National Animal Tuberculosis Para-Reference Laboratory (Wuhan) of Ministry of Agriculture and Rural Affairs, Huazhong Agricultural University, Wuhan, China
| | - Li Su
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,National Animal Tuberculosis Para-Reference Laboratory (Wuhan) of Ministry of Agriculture and Rural Affairs, Huazhong Agricultural University, Wuhan, China
| | - Luiz Bermudez
- Department of Biomedical Sciences, College of Veterinary Medicine, Oregon State University, Corvallis, OR, United States
| | - Huanchun Chen
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,National Animal Tuberculosis Para-Reference Laboratory (Wuhan) of Ministry of Agriculture and Rural Affairs, Huazhong Agricultural University, Wuhan, China
| | - Aizhen Guo
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,National Animal Tuberculosis Para-Reference Laboratory (Wuhan) of Ministry of Agriculture and Rural Affairs, Huazhong Agricultural University, Wuhan, China
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