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Phenomics (Cham, Switzerland) Apr 2024ADP-ribosylation is a reversible and dynamic post-translational modification mediated by ADP-ribosyltransferases (ARTs). Poly(ADP-ribose) polymerases (PARPs) are an...
UNLABELLED
ADP-ribosylation is a reversible and dynamic post-translational modification mediated by ADP-ribosyltransferases (ARTs). Poly(ADP-ribose) polymerases (PARPs) are an important family of human ARTs. ADP-ribosylation and PARPs have crucial functions in host-pathogen interaction, especially in viral infections. However, the functions and potential molecular mechanisms of ADP-ribosylation and PARPs in infection remain unknown. In this study, bioinformatics analysis revealed significantly changed expression levels of several PARPs in tuberculosis patients compared to healthy individuals. Moreover, the expression levels of these PARPs returned to normal following tuberculosis treatment. Then, the changes in the expression levels of PARPs during infection were validated in Tohoku Hospital Pediatrics-1 (THP1)-induced differentiated macrophages infected with model strains bacillus Calmette-Guérin (BCG) and in human lung adenocarcinoma A549 cells infected with (Ms), respectively. The mRNA levels of PARP9, PARP10, PARP12, and PARP14 were most significantly increased during infection, with corresponding increases in protein levels, indicating the possible biological functions of these PARPs during infection. In addition, the biological function of host PARP9 in infection was further studied. PARP9 deficiency significantly increased the infection efficiency and intracellular proliferation ability of Ms, which was reversed by the reconstruction of PARP9. Collectively, this study updates the understanding of changes in PARP expression during infection and provides evidence supporting PARP9 as a potent suppressor for infection.
SUPPLEMENTARY INFORMATION
The online version contains supplementary material available at 10.1007/s43657-023-00112-2.
PubMed: 38884060
DOI: 10.1007/s43657-023-00112-2 -
Small Methods Jun 2024DL-Lactic acid and D-glucose are important human health indicators. Their aberrant levels in body fluids may indicate a variety of human pathological conditions,...
DL-Lactic acid and D-glucose are important human health indicators. Their aberrant levels in body fluids may indicate a variety of human pathological conditions, suggesting an urgent need of daily monitoring. However, simultaneous and rapid analysis of DL-lactic acid and D-glucose using a sole but simple sensing system has never been reported. Here, an engineered Mycobacterium smegmatis porin A (MspA) nanopore is used to simultaneously identify DL-lactic acid and D-glucose. Highly distinguishable nanopore event features are reported. Assisted with a custom machine learning algorithm, direct identification of DL-lactic acid and D-glucose is performed with human serum, demonstrating its sensing reliability against complex and heterogeneous samples. This sensing strategy is further applied in the analysis of different animal serum samples, according to which gluconic acid is further identified. The serum samples from different animals report distinguishable levels of DL-lactic acid, D-glucose and gluconic acid, suggesting its potential applications in agricultural science and breeding industry. This sensing strategy is generally direct, rapid, economic and requires only ≈µL of input serum, suitable for point of care testing (POCT) applications.
PubMed: 38864527
DOI: 10.1002/smtd.202400664 -
Microbiology Resource Announcements Jun 2024, a member of the family and species , is an F1 cluster phage that infects mc²155. The Maravista genome has 61.3% GC content, is 60,140 bp in length, and encodes 104...
, a member of the family and species , is an F1 cluster phage that infects mc²155. The Maravista genome has 61.3% GC content, is 60,140 bp in length, and encodes 104 putative genes. Maravista encodes two putative glycosyltransferases, suggesting glycosylation of its capsid protein.
PubMed: 38860805
DOI: 10.1128/mra.00502-24 -
Microbiology Spectrum Jul 2024Iron scavenging is required for full virulence of mycobacterial pathogens. During infection, the host immune response restricts mycobacterial access to iron, which is...
Iron scavenging is required for full virulence of mycobacterial pathogens. During infection, the host immune response restricts mycobacterial access to iron, which is essential for bacterial respiration and DNA synthesis. The iron-dependent regulator (IdeR) responds to changes in iron accessibility by repressing iron-uptake genes when iron is available. In contrast, iron-uptake gene transcription is induced when iron is depleted. The gene is essential in and is required for bacterial growth. To further study how iron regulates transcription, wee developed an iron responsive reporter system that relies on an IdeR-regulated promoter to drive Cre and mediated recombination in . Recombination leads to the expression of an antibiotic resistance gene so that mutations that activate the IdeR-regulated promoter can be selected. A transposon library in the background of this reporter system was exposed to media containing iron and hemin, and this resulted in the selection of mutants in the antioxidant mycothiol synthesis pathway. We validated that inactivation of the mycothiol synthesis gene results in increased recombination and increased IdeR-regulated promoter activity in the reporter system. Further, we show that vitamin C, which has been shown to oxidize iron through the Fenton reaction, can decrease promoter activity in the mutant. We conclude that the intracellular redox state balanced by mycothiol can alter IdeR activity in the presence of iron.IMPORTANCE is a tractable organism to study mycobacterial gene regulation. We used to construct a novel recombination-based reporter system that allows for the selection of mutations that deregulate a promoter of interest. Transposon mutagenesis and insertion sequencing (TnSeq) in the recombination reporter strain identified genes that impact iron regulated promoter activity in mycobacteria. We found that the mycothiol synthesis gene is required for IdeR mediated transcriptional regulation by maintaining intracellular redox balance. By affecting the oxidative state of the intracellular environment, mycothiol can modulate iron-dependent transcriptional activity. Taken more broadly, this novel reporter system can be used in combination with transposon mutagenesis to identify genes that are required by to overcome temporary or local changes in iron availability during infection.
Topics: Iron; Mycobacterium smegmatis; Oxidation-Reduction; Gene Expression Regulation, Bacterial; Bacterial Proteins; Inositol; Genes, Reporter; Glycopeptides; Promoter Regions, Genetic; Cysteine; Mycobacterium tuberculosis; DNA Transposable Elements; Repressor Proteins
PubMed: 38860795
DOI: 10.1128/spectrum.00487-24 -
Diagnostic Microbiology and Infectious... May 2024We present a patient who suffered an agricultural rollover trauma and developed a fracture-associated tissue infection caused by Mycobacterium smegmatis. Since cases are...
We present a patient who suffered an agricultural rollover trauma and developed a fracture-associated tissue infection caused by Mycobacterium smegmatis. Since cases are rare, treatment of infections with M. smegmatis requires an interprofessional approach and the combination of surgery and adjunctive antimicrobial treatment.
PubMed: 38850688
DOI: 10.1016/j.diagmicrobio.2024.116379 -
MLife Mar 2024Insertion sequences (ISs) exist widely in bacterial genomes, but their roles in the evolution of bacterial antiphage defense remain to be clarified. Here, we report...
Insertion sequences (ISs) exist widely in bacterial genomes, but their roles in the evolution of bacterial antiphage defense remain to be clarified. Here, we report that, under the pressure of phage infection, the IS transposition of into the gene can occur at high frequencies, which endows the mutant mycobacterium with a broad-spectrum antiphage ability. Lsr2 functions as a negative regulator and directly silences expression of a gene island composed of 11 lipid metabolism-related genes. The complete or partial loss of the gene island leads to a significant decrease of bacteriophage adsorption to the mycobacterium, thus defending against phage infection. Strikingly, a phage that has evolved mutations in two tail-filament genes can re-escape from the inactivation-triggered host defense. This study uncovered a new signaling pathway for activating antimycobacteriophage immunity by IS transposition and provided insight into the natural evolution of bacterial antiphage defense.
PubMed: 38827510
DOI: 10.1002/mlf2.12106 -
International Journal of Biological... Jun 2024Due to the uniqueness and essentiality of MEP pathway for the synthesis of crucial metabolites- isoprenoids, hopanoids, menaquinone etc. in mycobacterium, enzymes of...
Due to the uniqueness and essentiality of MEP pathway for the synthesis of crucial metabolites- isoprenoids, hopanoids, menaquinone etc. in mycobacterium, enzymes of this pathway are considered promising anti-tubercular drug targets. In the present study we seek to understand the consequences of downregulation of three of the essential genes- DXS, IspD, and IspF of MEP pathway using CRISPRi approach combined with transcriptomics in Mycobacterium smegmatis. Conditional knock down of either DXS or IspD or IspF gene showed strong bactericidal effect and a profound change in colony morphology. Impaired MEP pathway due to downregulation of these genes increased the susceptibility to frontline anti-tubercular drugs. Further, reduced EtBr accumulation in all the knock down strains in the presence and absence of efflux inhibitor indicated altered cell wall topology. Subsequently, transcriptional analysis validated by qRT-PCR of +154DXS, +128IspD, +104IspF strains showed that modifying the expression of these MEP pathway enzymes affects the regulation of mycobacterial core components. Among the DEGs, expression of small and large ribosomal binding proteins (rpsL, rpsJ, rplN, rplX, rplM, rplS, etc), essential protein translocases (secE, secY and infA, infC), transcriptional regulator (CarD and SigB) and metabolic enzymes (acpP, hydA, ald and fabD) were significantly depleted causing the bactericidal effect. However, mycobacteria survived under these damaging conditions by upregulating mostly the genes needed for the repair of DNA damage (DNA polymerase IV, dinB), synthesis of essential metabolites (serB, LeuA, atpD) and those strengthening the cell wall integrity (otsA, murA, D-alanyl-D-alanine dipeptidase etc.).
Topics: Bacterial Proteins; Mycobacterium smegmatis; Gene Expression Regulation, Bacterial; Antitubercular Agents; Microbial Viability; Metabolic Networks and Pathways
PubMed: 38823743
DOI: 10.1016/j.ijbiomac.2024.132727 -
Journal of Biomedical Research May 2024Tumor vaccines are a promising avenue in cancer immunotherapy. Despite the progress in targeting specific immune epitopes, tumor cells lacking them can evade treatment....
Tumor vaccines are a promising avenue in cancer immunotherapy. Despite the progress in targeting specific immune epitopes, tumor cells lacking them can evade treatment. Here, we aimed to construct an efficient tumor vaccine Vac-SM, utilizing shikonin (SKN) to induce immunogenic cell death (ICD) and ( ) as an immune adjuvant to enhance tumor vaccine efficacy. SKN demonstrated a dose-dependent and time-dependent cytotoxic effect on the tumor cell line as seen using the CCK-8 assay and induced ICD in tumor cells by detecting the expression of relevant indicators respectively. Compared to that in the control groups, Vac-SM injection in mouse subcutaneous metastatic tumors significantly inhibited tumor growth and distant tumor growth and improved survival rates. effectively induced bone marrow-derived dendritic cells (DC) maturation and activation and tumor-draining lymph nodes showed increased maturation of DC and a higher proportion of effector memory T-cell subsets with Vac-SM treatment, based on flow cytometry analysis results.Collectively, Vac-SM vaccine effectively induces ICD, improves antigen presentation by DC, activates a specific systemic antitumor T-cell immune response, exhibits favorable safety profile, and holds promise for clinical translation for local tumor immunotherapy.
PubMed: 38807377
DOI: 10.7555/JBR.38.20240049 -
Frontiers in Microbiology 2024() genome encompasses 4,173 genes, about a quarter of which remain uncharacterized and hypothetical. Considering the current limitations associated with the diagnosis...
() genome encompasses 4,173 genes, about a quarter of which remain uncharacterized and hypothetical. Considering the current limitations associated with the diagnosis and treatment of tuberculosis, it is imperative to comprehend the pathomechanism of the disease and host-pathogen interactions to identify new drug targets for intervention strategies. Using comparative genome analysis, we identified one of the genes, Rv1509, as a signature protein exclusively present in . To explore the role of Rv1509, a likely methyl transferase, we constructed a knock-in () constitutively expressing Rv1509 (Ms_Rv1509). The Ms_Rv1509 led to differential expression of many transcriptional regulator genes as assessed by RNA-seq analysis. Further, and studies demonstrated an enhanced survival of Ms_Rv1509 inside the host macrophages. Ms_Rv1509 also promoted phagolysosomal escape inside macrophages to boost bacterial replication and dissemination. infection studies revealed that Ms_Rv1509 survives better than BCG and causes pathological manifestations in the pancreas after intraperitoneal infection. Long-time survival of Ms_Rv1509 resulted in lymphocyte migration, increased T regulatory cells, giant cell formation, and likely granuloma formation in the pancreas, pointing toward the role of Rv1509 in pathogenesis.
PubMed: 38803374
DOI: 10.3389/fmicb.2024.1344857 -
Heliyon May 2024The emergence of multidrug-resistant mycobacterial strains is a significant crisis that has led to higher treatment failure rates and more toxic and expensive...
The emergence of multidrug-resistant mycobacterial strains is a significant crisis that has led to higher treatment failure rates and more toxic and expensive medications for tuberculosis (TB). The urgent need to develop novel therapeutics has galvanized research interest towards developing alternative antimicrobials such as silver nanoparticles (AgNPs). The current study focused on the anti-mycobacterial activity of green-synthesized AgNPs and its polyethylene glycol encapsulated derivative (PEG-AgNPs) with improved stability using the leaves extract of . Different characterization methods were used to analyze them. DLS analysis revealed a lower polydispersity index of PEG-AgNPs, suggesting a more uniform size distribution than that of AgNPs. The HR-TEM results revealed that the AgNPs and PEG-AgNPs have predominantly spherical shapes in the size range of 9-35 nm and 15-60 nm, respectively, while positive values of Zeta potential indicate their stability. FTIR-ATR analysis confirmed the presence of functional groups responsible for reducing and capping the bio-reduced AgNPs, whereas the XRD data established its crystalline nature. Impressively, the PEG-AgNPs exhibited maximum inhibitory activity against different Tubercular and Non-Tuberculous species , and , relative to those of AgNPs and Linezolid. The flow cytometry assay showed that the anti-mycobacterial action was mediated by an increase in cell wall permeability. Notably, the results of AFM confirm their ability to inhibit mycobacterial biofilm significantly. We demonstrated the nontoxic nature of these AgNPs, explicated by the absence of hemolytic activity against human RBCs. Overall, the results suggest that PEG-AgNPs could offer a novel therapeutic approach with potential anti-mycobacterial activity and can overcome the limitations of existing TB therapies.
PubMed: 38799742
DOI: 10.1016/j.heliyon.2024.e31116