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Li W, Stevens CM, Pandya AN, Darzynkiewicz Z, Bhattarai P, Tong W, Gonzalez-Juarrero M, North EJ, Zgurskaya HI, Jackson M. Direct Inhibition of MmpL3 by Novel Antitubercular Compounds. ACS Infect Dis 2019; 5:1001-1012. [PMID: 30882198 PMCID: PMC6580365 DOI: 10.1021/acsinfecdis.9b00048] [Citation(s) in RCA: 63] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
MmpL3, an essential transporter involved in the export of mycolic acids, is the proposed target of a number of antimycobacterial inhibitors under development. Whether MmpL3 serves as the direct target of these compounds, however, has been called into question after the discovery that some of them dissipated the proton motive force from which MmpL transporters derive their energy. Using a combination of in vitro and whole-cell-based approaches, we here provide evidence that five structurally distinct MmpL3 inhibitor series, three of which impact proton motive force in Mycobacterium tuberculosis, directly interact with MmpL3. Medium- to high-throughput assays based on these approaches were developed to facilitate the future screening and optimization of MmpL3 inhibitors. The promiscuity of MmpL3 as a drug target and the mechanisms through which missense mutations located in a transmembrane region of this transporter may confer cross-resistance to a variety of chemical scaffolds are discussed in light of the exquisite vulnerability of MmpL3, its apparent mechanisms of interaction with inhibitors, and evidence of conformational changes induced both by the inhibitors and one of the most commonly identified resistance mutations in MmpL3.
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Affiliation(s)
- Wei Li
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, 1682 Campus Delivery, Fort Collins, Colorado 80523, United States
| | - Casey M. Stevens
- Department of Chemistry and Biochemistry, University of Oklahoma, 101 Stephenson Parkway, Norman, Oklahoma 73019, United States
| | - Amitkumar N. Pandya
- School of Pharmacy & Health Professions, Department of Pharmacy Sciences, Creighton University, 2500 California Plaza, Omaha, Nebraska 68178, United States
| | - Zbigniew Darzynkiewicz
- Department of Chemistry and Biochemistry, University of Oklahoma, 101 Stephenson Parkway, Norman, Oklahoma 73019, United States
| | - Pankaj Bhattarai
- School of Pharmacy & Health Professions, Department of Pharmacy Sciences, Creighton University, 2500 California Plaza, Omaha, Nebraska 68178, United States
| | - Weiwei Tong
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, 1682 Campus Delivery, Fort Collins, Colorado 80523, United States
| | - Mercedes Gonzalez-Juarrero
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, 1682 Campus Delivery, Fort Collins, Colorado 80523, United States
| | - E. Jeffrey North
- School of Pharmacy & Health Professions, Department of Pharmacy Sciences, Creighton University, 2500 California Plaza, Omaha, Nebraska 68178, United States
| | - Helen I. Zgurskaya
- Department of Chemistry and Biochemistry, University of Oklahoma, 101 Stephenson Parkway, Norman, Oklahoma 73019, United States
| | - Mary Jackson
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, 1682 Campus Delivery, Fort Collins, Colorado 80523, United States
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The hydrolase LpqI primes mycobacterial peptidoglycan recycling. Nat Commun 2019; 10:2647. [PMID: 31201321 PMCID: PMC6572805 DOI: 10.1038/s41467-019-10586-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Accepted: 05/14/2019] [Indexed: 12/26/2022] Open
Abstract
Growth and division by most bacteria requires remodelling and cleavage of their cell wall. A byproduct of this process is the generation of free peptidoglycan (PG) fragments known as muropeptides, which are recycled in many model organisms. Bacteria and hosts can harness the unique nature of muropeptides as a signal for cell wall damage and infection, respectively. Despite this critical role for muropeptides, it has long been thought that pathogenic mycobacteria such as Mycobacterium tuberculosis do not recycle their PG. Herein we show that M. tuberculosis and Mycobacterium bovis BCG are able to recycle components of their PG. We demonstrate that the core mycobacterial gene lpqI, encodes an authentic NagZ β-N-acetylglucosaminidase and that it is essential for PG-derived amino sugar recycling via an unusual pathway. Together these data provide a critical first step in understanding how mycobacteria recycle their peptidoglycan. Bacterial growth and division require remodelling of the cell wall, which generates free peptidoglycan fragments. Here, Moynihan et al. show that Mycobacterium tuberculosis can recycle components of their peptidoglycan, and characterise a crucial enzyme required for this process.
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Zhang D, Yi Z, Fu Y. Downregulation of miR-20b-5p facilitates Mycobacterium tuberculosis survival in RAW 264.7 macrophages via attenuating the cell apoptosis by Mcl-1 upregulation. J Cell Biochem 2018; 120:5889-5896. [PMID: 30378171 DOI: 10.1002/jcb.27874] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Accepted: 09/20/2018] [Indexed: 12/28/2022]
Abstract
Tuberculosis (TB) is an infectious disease caused by Mycobacterium tuberculosis (Mtb). The interaction between Mtb and macrophages, which is regulated by microRNAs, determines the development of TB. However, the function of microRNA-20b-5p (miR-20b-5p) in RAW 264.7 macrophages against Mtb remains unknown. In this study, we analyzed the expression level of miR-20b-5p in macrophage responses to Mtb infection and exosomes derived from macrophages after Mtb infection. MiR-20b-5p mimics and inhibitor were, respectively, transfected to evaluate the effect of miR-20b-5p on Mtb and macrophages. In addition, the targets of miR-20b-5p were predicted by a bioinformatics analysis. The macrophages were respectively transfected with miR-20b-5p mimics and inhibitor to determine the messenger RNA expression levels of the targets by reverse transcription-polymerase chain reaction assay. The results revealed that the miR-20b-5p expression level was decreased in the infected macrophages at different times. MiR-20b-5p was shown in the exosomes released from macrophages infected with Mtb. Upregulation of the miR-20b-5p level suppressed the survival of Mtb in macrophages, while downregulation of the miR-20b-5p level enhanced the survival of Mtb in macrophages. Overexpression of miR-20b-5p decreased the cell viability and induced apoptosis in Mtb-infected macrophages, while underexpression of miR-20b-5p increased the cell vitality and attenuated apoptosis in Mtb-infected macrophages. The bioinformatics analysis revealed that Mcl-1 was a target of miR-20b-5p. MiR-20b-5p negatively regulated the expression of Mcl-1. Overall, this study is the first to demonstrate the effect of miR-20b-5p on Mtb infection and present miR-20b-5p and exosomes as the potential therapeutic targets of TB.
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Affiliation(s)
- Defeng Zhang
- Department of Laboratory Medicine, Key Laboratory of Clinical Laboratory Diagnostics in Universities of Shandong, Weifang Medical University, Weifang, Shandong, China
| | - Zhengjun Yi
- Department of Laboratory Medicine, Key Laboratory of Clinical Laboratory Diagnostics in Universities of Shandong, Weifang Medical University, Weifang, Shandong, China.,Department of Medical Microbiology, Clinical Medicine College, Weifang Medical University, Weifang, Shandong, China
| | - Yurong Fu
- Department of Laboratory Medicine, Key Laboratory of Clinical Laboratory Diagnostics in Universities of Shandong, Weifang Medical University, Weifang, Shandong, China
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