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1.
J Neurosci ; 2024 Sep 03.
Article in English | MEDLINE | ID: mdl-39227159

ABSTRACT

Targeting altered expression and/or activity of GABA transporters (GATs) provide therapeutic benefit for age-related impairments, including cognitive dysfunction. However, the mechanisms underlying the transcriptional regulation of GATs are unknown. In the present study, we demonstrated that the stimulator of interferon genes (STING) upregulates GAT1 and GAT3 expression in the brain which resulted in cognitive dysfunction. Genetic and pharmacological intervention of STING suppressed the expression of both GAT1 and GAT3, increased the ambient GABA concentration, and therefore, enhanced tonic GABAA inhibition of principal hippocampal neurons, resulting in spatial learning and working memory deficits in mice in a type I interferon (IFN I)-independent manner. Stimulation of the STING-GAT pathway efficiently restored cognitive dysfunction in STING-deficient mice models. Our study uncovered for the first time that the STING signaling pathway regulates GATs expression in a cell autonomous manner and therefore could be a novel target for GABAergic cognitive deficits.Significance Statement GABA concentration in extracellular space is maintained by GABA release and clearance of GABA back to brain cells for degradation. GABA clearance from the synaptic cleft predominantly depends on level and activity of GABA transporters (GATs) in the brain. Insufficient GABA clearance resulted to an aberrant tonic GABAA inhibition in brain. In this study, we have identified an unusually high GABA content in brain of STING-deficient mice, resulting in cognitive impairment. Our results show that STING regulates GATs expression through STING-TBK1-IRF3 pathway and thus regulates GABAergic tone. This is the first study that indicates that the STING-TBK1-IRF3 signaling pathway maintains GABA homeostasis in brain, which may offer a novel therapeutic target for modulating GABAergic tone in cases of cognitive dysfunction.

2.
Biomed Pharmacother ; 179: 117313, 2024 Oct.
Article in English | MEDLINE | ID: mdl-39167844

ABSTRACT

Mycobacteroides abscessus (Mabc) is a rapidly growing nontuberculous mycobacterium that poses a considerable challenge as a multidrug-resistant pathogen causing chronic human infection. Effective therapeutics that enhance protective immune responses to Mabc are urgently needed. This study introduces trans-3,5,4'-trimethoxystilbene (V46), a novel resveratrol analogue with autophagy-activating properties and antimicrobial activity against Mabc infection, including multidrug-resistant strains. Among the resveratrol analogues tested, V46 significantly inhibited the growth of both rough and smooth Mabc strains, including multidrug-resistant strains, in macrophages and in the lungs of mice infected with Mabc. Additionally, V46 substantially reduced Mabc-induced levels of pro-inflammatory cytokines and chemokines in both macrophages and during in vivo infection. Mechanistic analysis showed that V46 suppressed the activation of the protein kinase B/Akt-mammalian target of rapamycin signaling pathway and enhanced adenosine monophosphate-activated protein kinase signaling in Mabc-infected cells. Notably, V46 activated autophagy and the nuclear translocation of transcription factor EB, which is crucial for antimicrobial host defenses against Mabc. Furthermore, V46 upregulated genes associated with autophagy and lysosomal biogenesis in Mabc-infected bone marrow-derived macrophages. The combination of V46 and rifabutin exerted a synergistic antimicrobial effect. These findings identify V46 as a candidate host-directed therapeutic for Mabc infection that activates autophagy and lysosomal function via transcription factor EB.


Subject(s)
Autophagy , Basic Helix-Loop-Helix Leucine Zipper Transcription Factors , Mycobacterium abscessus , Autophagy/drug effects , Animals , Mycobacterium abscessus/drug effects , Mice , Basic Helix-Loop-Helix Leucine Zipper Transcription Factors/metabolism , Macrophages/drug effects , Macrophages/metabolism , Mycobacterium Infections, Nontuberculous/drug therapy , Mycobacterium Infections, Nontuberculous/microbiology , Stilbenes/pharmacology , Humans , RAW 264.7 Cells , Signal Transduction/drug effects , Anti-Bacterial Agents/pharmacology , Mice, Inbred C57BL , Female , Cytokines/metabolism , Mice, Inbred BALB C
3.
Immune Netw ; 24(1): e4, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38455468

ABSTRACT

TNF, a pleiotropic proinflammatory cytokine, is important for protective immunity and immunopathology during Mycobacterium tuberculosis (Mtb) infection, which causes tuberculosis (TB) in humans. TNF is produced primarily by phagocytes in the lungs during the early stages of Mtb infection and performs diverse physiological and pathological functions by binding to its receptors in a context-dependent manner. TNF is essential for granuloma formation, chronic infection prevention, and macrophage recruitment to and activation at the site of infection. In animal models, TNF, in cooperation with chemokines, contributes to the initiation, maintenance, and clearance of mycobacteria in granulomas. Although anti-TNF therapy is effective against immune diseases such as rheumatoid arthritis, it carries the risk of reactivating TB. Furthermore, TNF-associated inflammation contributes to cachexia in patients with TB. This review focuses on the multifaceted role of TNF in the pathogenesis and prevention of TB and underscores the importance of investigating the functions of TNF and its receptors in the establishment of protective immunity against and in the pathology of TB. Such investigations will facilitate the development of therapeutic strategies that target TNF signaling, which makes beneficial and detrimental contributions to the pathogenesis of TB.

4.
Mitochondrion ; 75: 101852, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38360196

ABSTRACT

Mycobacteria, including Mycobacterium tuberculosis (Mtb) and non-tuberculous mycobacteria (NTM), pose challenges in treatment due to their increased resistance to antibiotics. Following infection, mycobacteria and their components trigger robust innate and inflammatory immune responses intricately associated with the modulation of mitochondrial functions, including oxidative phosphorylation (OXPHOS) and metabolism. Certainly, mitochondrial reactive oxygen species (mtROS) are an inevitable by-product of OXPHOS and function as a bactericidal weapon; however, an excessive accumulation of mtROS are linked to pathological inflammation and necroptotic cell death during mycobacterial infection. Despite previous studies outlining various host pathways involved in regulating mtROS levels during antimicrobial responses in mycobacterial infection, our understanding of the precise mechanisms orchestrating the fine regulation of this response remains limited. Emerging evidence suggests that mycobacterial proteins play a role in targeting the mitochondria of the host, indicating the potential influence of microbial factors on mitochondrial functions within host cells. In this review, we provide an overview of how both host and Mtb factors influence mtROS generation during infection. A comprehensive study of host and microbial factors that target mtROS will shed light on innovative approaches for effectively managing drug-resistant mycobacterial infections.


Subject(s)
Mycobacterium tuberculosis , Humans , Reactive Oxygen Species/metabolism , Anti-Bacterial Agents , Inflammation/metabolism , Mitochondria/metabolism
6.
Int Immunopharmacol ; 121: 110461, 2023 Aug.
Article in English | MEDLINE | ID: mdl-37331298

ABSTRACT

Ginsenosides are steroid glycosides derived from ginseng plants such as Panax ginseng, Panax quinquefolium, and Panax notoginseng. Advances in recent studies have identified numerous physiological functions of each type of ginsenoside, i.e., immunomodulatory, antioxidative, and anti-inflammatory functions, in the context of inflammatory diseases. Accumulating evidence has revealed the molecular mechanisms by which the single or combined ginsenoside(s) exhibit anti-inflammatory effects, although it remains largely unclear. It is well known that excessive production of reactive oxygen species (ROS) is associated with pathological inflammation and cell death in a variety of cells, and that inhibition of ROS generation ameliorates the local and systemic inflammatory responses. The mechanisms by which ginsenosides attenuate inflammation are largely unknown; however, targeting ROS is suggested as one of the crucial mechanisms for the ginsenosides to control the pathological inflammation in the immune and non-immune cells. This review will summarize the latest progress in ginsenoside studies, particularly in the context of antioxidant mechanisms for its anti-inflammatory effects. A better understanding of the distinct types and the combined action of ginsenosides will pave the way for developing potential preventive and therapeutic modalities in treating various inflammation-related diseases.


Subject(s)
Ginsenosides , Panax notoginseng , Ginsenosides/therapeutic use , Reactive Oxygen Species/metabolism , Oxidative Stress , Antioxidants/metabolism , Inflammation/drug therapy
7.
Front Immunol ; 14: 1203756, 2023.
Article in English | MEDLINE | ID: mdl-37261340

ABSTRACT

Itaconate is a crucial anti-infective and anti-inflammatory immunometabolite that accumulates upon disruption of the Krebs cycle in effector macrophages undergoing inflammatory stress. Esterified derivatives of itaconate (4-octyl itaconate and dimethyl itaconate) and its isomers (mesaconate and citraconate) are promising candidate drugs for inflammation and infection. Several itaconate family members participate in host defense, immune and metabolic modulation, and amelioration of infection, although opposite effects have also been reported. However, the precise mechanisms by which itaconate and its family members exert its effects are not fully understood. In addition, contradictory results in different experimental settings and a lack of clinical data make it difficult to draw definitive conclusions about the therapeutic potential of itaconate. Here we review how the immune response gene 1-itaconate pathway is activated during infection and its role in host defense and pathogenesis in a context-dependent manner. Certain pathogens can use itaconate to establish infections. Finally, we briefly discuss the major mechanisms by which itaconate family members exert antimicrobial effects. To thoroughly comprehend how itaconate exerts its anti-inflammatory and antimicrobial effects, additional research on the actual mechanism of action is necessary. This review examines the current state of itaconate research in infection and identifies the key challenges and opportunities for future research in this field.


Subject(s)
Anti-Inflammatory Agents , Inflammation , Humans , Anti-Inflammatory Agents/therapeutic use , Inflammation/metabolism
8.
Anticancer Res ; 43(5): 1943-1957, 2023 May.
Article in English | MEDLINE | ID: mdl-37097701

ABSTRACT

BACKGROUND/AIM: Autophagy-related genes (ATGs) are involved in autophagy activation, which has a pleiotropic role in cancer development. However, the potential value of ATG expression levels in colon adenocarcinoma (COAD) is unclear. This study aimed to examine the modulation of ATG expression levels and their association with clinical and molecular aspects of COAD. MATERIALS AND METHODS: We used the clinical and molecular phenotypes and RNA sequencing datasets of the cancer genome atlas (TCGA)-COAD project using TCGAbiolinks and cBioPortal. Comparisons of ATG expression levels between tumor and normal tissues were performed using DESeq2 within R. Gene expression and immune cell infiltration levels were analyzed by TIMER. RESULTS: ATG9B had the highest expression levels among ATGs in COAD tissues compared to normal tissues and was related to advanced stage and poor prognosis in COAD. In addition, ATG9B expression was positively associated with the consensus molecular subtype 4 and chromosomal instability but negatively correlated with tumor mutation burden. Furthermore, high ATG9B expression levels were associated with low immune cell infiltration and decreased expression of natural killer cell activation genes. CONCLUSION: ATG9B is a poor prognostic biomarker driving immune evasion of COAD through negative correlation with immune cell infiltration.


Subject(s)
Adenocarcinoma , Autophagy-Related Proteins , Colonic Neoplasms , Tumor Escape , Biomarkers, Tumor , Colonic Neoplasms/diagnosis , Adenocarcinoma/diagnosis , Humans , Autophagy-Related Proteins/genetics , Membrane Proteins/genetics , Prognosis , Male , Female , Adult , Middle Aged , Aged , Aged, 80 and over
9.
Cell Biosci ; 13(1): 49, 2023 Mar 08.
Article in English | MEDLINE | ID: mdl-36882813

ABSTRACT

BACKGROUND: Itaconate, a crucial immunometabolite, plays a critical role in linking immune and metabolic functions to influence host defense and inflammation. Due to its polar structure, the esterified cell-permeable derivatives of itaconate are being developed to provide therapeutic opportunities in infectious and inflammatory diseases. Yet, it remains largely uncharacterized whether itaconate derivatives have potentials in promoting host-directed therapeutics (HDT) against mycobacterial infections. Here, we report dimethyl itaconate (DMI) as the promising candidate for HDT against both Mycobacterium tuberculosis (Mtb) and nontuberculous mycobacteria by orchestrating multiple innate immune programs. RESULTS: DMI per se has low bactericidal activity against Mtb, M. bovis Bacillus Calmette-Guérin (BCG), and M. avium (Mav). However, DMI robustly activated intracellular elimination of multiple mycobacterial strains (Mtb, BCG, Mav, and even to multidrug-resistant Mtb) in macrophages and in vivo. DMI significantly suppressed the production of interleukin-6 and -10, whereas it enhanced autophagy and phagosomal maturation, during Mtb infection. DMI-mediated autophagy partly contributed to antimicrobial host defenses in macrophages. Moreover, DMI significantly downregulated the activation of signal transducer and activator of transcription 3 signaling during infection with Mtb, BCG, and Mav. CONCLUSION: Together, DMI has potent anti-mycobacterial activities in macrophages and in vivo through promoting multifaceted ways for innate host defenses. DMI may bring light to new candidate for HDT against Mtb and nontuberculous mycobacteria, both of which infections are often intractable with antibiotic resistance.

10.
Cells ; 12(4)2023 02 17.
Article in English | MEDLINE | ID: mdl-36831317

ABSTRACT

Peroxisome proliferator-activated receptors (PPARs) α, ß, and γ are nuclear receptors that orchestrate the transcriptional regulation of genes involved in a variety of biological responses, such as energy metabolism and homeostasis, regulation of inflammation, cellular development, and differentiation. The many roles played by the PPAR signaling pathways indicate that PPARs may be useful targets for various human diseases, including metabolic and inflammatory conditions and tumors. Accumulating evidence suggests that each PPAR plays prominent but different roles in viral, bacterial, and parasitic infectious disease development. In this review, we discuss recent PPAR research works that are focused on how PPARs control various infections and immune responses. In addition, we describe the current and potential therapeutic uses of PPAR agonists/antagonists in the context of infectious diseases. A more comprehensive understanding of the roles played by PPARs in terms of host-pathogen interactions will yield potential adjunctive personalized therapies employing PPAR-modulating agents.


Subject(s)
Communicable Diseases , Receptors, Cytoplasmic and Nuclear , Humans , Gene Expression Regulation , PPAR alpha , Inflammation
11.
Exp Mol Med ; 55(2): 333-346, 2023 02.
Article in English | MEDLINE | ID: mdl-36720915

ABSTRACT

The Arg/N-degron pathway, which is involved in the degradation of proteins bearing an N-terminal signal peptide, is connected to p62/SQSTM1-mediated autophagy. However, the impact of the molecular link between the N-degron and autophagy pathways is largely unknown in the context of systemic inflammation. Here, we show that chemical mimetics of the N-degron Nt-Arg pathway (p62 ligands) decreased mortality in sepsis and inhibited pathological inflammation by activating mitophagy and immunometabolic remodeling. The p62 ligands alleviated systemic inflammation in a mouse model of lipopolysaccharide (LPS)-induced septic shock and in the cecal ligation and puncture model of sepsis. In macrophages, the p62 ligand attenuated the production of proinflammatory cytokines and chemokines in response to various innate immune stimuli. Mechanistically, the p62 ligand augmented LPS-induced mitophagy and inhibited the production of mitochondrial reactive oxygen species in macrophages. The p62 ligand-mediated anti-inflammatory, antioxidative, and mitophagy-activating effects depended on p62. In parallel, the p62 ligand significantly downregulated the LPS-induced upregulation of aerobic glycolysis and lactate production. Together, our findings demonstrate that p62 ligands play a critical role in the regulation of inflammatory responses by orchestrating mitophagy and immunometabolic remodeling.


Subject(s)
Mitophagy , Sepsis , Animals , Mice , Ligands , Lipopolysaccharides/pharmacology , Autophagy , Inflammation/drug therapy , Sepsis/drug therapy
12.
Sci Rep ; 12(1): 21227, 2022 12 08.
Article in English | MEDLINE | ID: mdl-36481664

ABSTRACT

Although nearly a fifth of symptomatic COVID-19 patients suffers from severe pulmonary inflammation, the mechanism of developing severe illness is not yet fully understood. To identify significantly altered genes in severe COVID-19, we generated messenger RNA and micro-RNA profiling data of peripheral blood mononuclear cells (PBMCs) from five COVID-19 patients (2 severe and 3 mild patients) and three healthy controls (HC). For further evaluation, two publicly available RNA-Seq datasets (GSE157103 and GSE152418) and one single-cell RNA-Seq dataset (GSE174072) were employed. Based on RNA-Seq datasets, thrombospondin 1 (THBS1) and interleukin-17 receptor A (IL17RA) were significantly upregulated in severe COVID-19 patients' blood. From single-cell RNA-sequencing data, IL17RA level is increased in monocytes and neutrophils, whereas THBS1 level is mainly increased in the platelets. Moreover, we identified three differentially expressed microRNAs in severe COVID-19 using micro-RNA sequencings. Intriguingly, hsa-miR-29a-3p significantly downregulated in severe COVID-19 was predicted to bind the 3'-untranslated regions of both IL17RA and THBS1 mRNAs. Further validation analysis of our cohort (8 HC, 7 severe and 8 mild patients) showed that THBS1, but not IL17RA, was significantly upregulated, whereas hsa-miR-29a-3p was downregulated, in PBMCs from severe patients. These findings strongly suggest that dysregulated expression of THBS1, IL17RA, and hsa-miR-29a-3p involves severe COVID-19.


Subject(s)
COVID-19 , MicroRNAs , Humans , Thrombospondin 1/genetics , COVID-19/genetics , Leukocytes, Mononuclear , MicroRNAs/genetics
13.
Int J Mol Sci ; 23(21)2022 Nov 05.
Article in English | MEDLINE | ID: mdl-36362370

ABSTRACT

Sirtuin 1 (SIRT1) regulates cellular processes by deacetylating non-histone targets, including transcription factors and intracellular signalling mediators; thus, its abnormal activation is closely linked to the pathophysiology of several diseases. However, its function in Toxoplasma gondii infection is unclear. We found that SIRT1 contributes to autophagy activation via the AMP-activated protein kinase (AMPK) and PI3K/AKT signalling pathways, promoting anti-Toxoplasma responses. Myeloid-specific Sirt1-/- mice exhibited an increased cyst burden in brain tissue compared to wild-type mice following infection with the avirulent ME49 strain. Consistently, the intracellular survival of T. gondii was markedly increased in Sirt1-deficient bone-marrow-derived macrophages (BMDMs). In contrast, the activation of SIRT1 by resveratrol resulted in not only the induction of autophagy but also a significantly increased anti-Toxoplasma effect. Notably, SIRT1 regulates the FoxO-autophagy axis in several human diseases. Importantly, the T. gondii-induced phosphorylation, acetylation, and cytosolic translocation of FoxO1 was enhanced in Sirt1-deficient BMDMs and the pharmacological inhibition of PI3K/AKT signalling reduced the cytosolic translocation of FoxO1 in BMDMs infected with T. gondii. Further, the CaMKK2-dependent AMPK signalling pathway is responsible for the effect of SIRT1 on the FoxO3a-autophagy axis and for its anti-Toxoplasma activity. Collectively, our findings reveal a previously unappreciated role for SIRT1 in Toxoplasma infection.


Subject(s)
Toxoplasma , Animals , Humans , Mice , AMP-Activated Protein Kinases/metabolism , Autophagy , Calcium-Calmodulin-Dependent Protein Kinase Kinase , Phosphatidylinositol 3-Kinases/metabolism , Proto-Oncogene Proteins c-akt/metabolism , Sirtuin 1/genetics , Toxoplasma/metabolism , Forkhead Transcription Factors/metabolism
14.
PLoS One ; 17(11): e0277670, 2022.
Article in English | MEDLINE | ID: mdl-36395154

ABSTRACT

The ability of Mycobacterium tuberculosis (Mtb) to persist in its host may enable an evolutionary advantage for drug resistant variants to emerge. A potential strategy to prevent persistence and gain drug efficacy is to directly target the activity of enzymes that are crucial for persistence. We present a method for expedited discovery and structure-based design of lead compounds by targeting the hypoxia-associated enzyme L-alanine dehydrogenase (AlaDH). Biochemical and structural analyses of AlaDH confirmed binding of nucleoside derivatives and showed a site adjacent to the nucleoside binding pocket that can confer specificity to putative inhibitors. Using a combination of dye-ligand affinity chromatography, enzyme kinetics and protein crystallographic studies, we show the development and validation of drug prototypes. Crystal structures of AlaDH-inhibitor complexes with variations at the N6 position of the adenyl-moiety of the inhibitor provide insight into the molecular basis for the specificity of these compounds. We describe a drug-designing pipeline that aims to block Mtb to proliferate upon re-oxygenation by specifically blocking NAD accessibility to AlaDH. The collective approach to drug discovery was further evaluated through in silico analyses providing additional insight into an efficient drug development strategy that can be further assessed with the incorporation of in vivo studies.


Subject(s)
Alanine Dehydrogenase , Mycobacterium tuberculosis , Alanine Dehydrogenase/metabolism , Mycobacterium tuberculosis/metabolism , Nucleosides , Enzyme Inhibitors/pharmacology , Enzyme Inhibitors/chemistry , Drug Discovery
15.
Front Immunol ; 13: 946929, 2022.
Article in English | MEDLINE | ID: mdl-36248815

ABSTRACT

Mycobacterial acyl carrier protein (AcpM; Rv2244), a key protein involved in Mycobacterium tuberculosis (Mtb) mycolic acid production, has been shown to suppress host cell death during mycobacterial infection. This study reports that mycobacterial AcpM works as an effector to subvert host defense and promote bacterial growth by increasing microRNA (miRNA)-155-5p expression. In murine bone marrow-derived macrophages (BMDMs), AcpM protein prevented transcription factor EB (TFEB) from translocating to the nucleus in BMDMs, which likely inhibited transcriptional activation of several autophagy and lysosomal genes. Although AcpM did not suppress autophagic flux in BMDMs, AcpM reduced Mtb and LAMP1 co-localization indicating that AcpM inhibits phagolysosomal fusion during Mtb infection. Mechanistically, AcpM boosted the Akt-mTOR pathway in BMDMs by upregulating miRNA-155-5p, a SHIP1-targeting miRNA. When miRNA-155-5p expression was inhibited in BMDMs, AcpM-induced increased intracellular survival of Mtb was suppressed. In addition, AcpM overexpression significantly reduced mycobacterial clearance in C3HeB/FeJ mice infected with recombinant M. smegmatis strains. Collectively, our findings point to AcpM as a novel mycobacterial effector to regulate antimicrobial host defense and a potential new therapeutic target for Mtb infection.


Subject(s)
Basic Helix-Loop-Helix Leucine Zipper Transcription Factors/metabolism , MicroRNAs , Mycobacterium tuberculosis , Acyl Carrier Protein , Animals , Mice , MicroRNAs/genetics , MicroRNAs/metabolism , Mycobacterium tuberculosis/physiology , Mycolic Acids , Proto-Oncogene Proteins c-akt/metabolism , TOR Serine-Threonine Kinases/metabolism
16.
J Hematol Oncol ; 15(1): 156, 2022 10 26.
Article in English | MEDLINE | ID: mdl-36289517

ABSTRACT

Acute myeloid leukemia (AML) is an aggressive blood cancer with poor clinical outcomes. Emerging data suggest that mitochondrial oxidative phosphorylation (mtOXPHOS) plays a significant role in AML tumorigenesis, progression, and resistance to chemotherapies. However, how the mtOXPHOS is regulated in AML cells is not well understood. In this study, we investigated the oncogenic functions of ERRα in AML by combining in silico, in vitro, and in vivo analyses and showed ERRα is a key regulator of mtOXPHOS in AML cells. The increased ERRα level was associated with worse clinical outcomes of AML patients. Single cell RNA-Seq analysis of human primary AML cells indicated that ERRα-expressing cancer cells had significantly higher mtOXPHOS enrichment scores. Blockade of ERRα by pharmacologic inhibitor (XCT-790) or gene silencing suppressed mtOXPHOS and increased anti-leukemic effects in vitro and in xenograft mouse models.


Subject(s)
Antineoplastic Agents , Leukemia, Myeloid, Acute , Humans , Mice , Animals , Oxidative Phosphorylation , Apoptosis , Mitochondria/metabolism , Leukemia, Myeloid, Acute/genetics , Antineoplastic Agents/pharmacology , Antineoplastic Agents/therapeutic use , Cell Line, Tumor , Cell Proliferation , ERRalpha Estrogen-Related Receptor
17.
Virulence ; 13(1): 1966-1984, 2022 Dec.
Article in English | MEDLINE | ID: mdl-36271707

ABSTRACT

Ohmyungsamycin A (OMS) is a newly identified cyclic peptide that exerts antimicrobial effects against Mycobacterium tuberculosis. However, its role in nontuberculous mycobacteria (NTMs) infections has not been clarified. Mycobacteroides abscessus (Mabc) is a rapidly growing NTM that has emerged as a human pathogen in both immunocompetent and immunosuppressed individuals. In this study, we demonstrated that OMS had significant antimicrobial effects against Mabc infection in both immunocompetent and immunodeficient mice, and in macrophages. OMS treatment amplified Mabc-induced expression of M1-related proinflammatory cytokines and inducible nitric oxide synthase, and significantly downregulated arginase-1 expression in murine macrophages. In addition, OMS augmented Mabc-mediated production of mitochondrial reactive oxygen species (mtROS), which promoted M1-like proinflammatory responses in Mabc-infected macrophages. OMS-induced production of mtROS and nitric oxide was critical for OMS-mediated antimicrobial responses during Mabc infections. Notably, the combination of OMS and rifabutin had a synergistic effect on the antimicrobial responses against Mabc infections in vitro, in murine macrophages, and in zebrafish models in vivo. Collectively, these data strongly suggest that OMS may be an effective M1-like adjunctive therapeutic against Mabc infections, either alone or in combination with antibiotics.


Subject(s)
Mycobacterium Infections, Nontuberculous , Mycobacterium abscessus , Humans , Mice , Animals , Zebrafish , Mycobacterium Infections, Nontuberculous/metabolism , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/therapeutic use , Anti-Bacterial Agents/metabolism , Macrophages/microbiology
18.
Cells ; 11(18)2022 09 19.
Article in English | MEDLINE | ID: mdl-36139497

ABSTRACT

Sirtuins (SIRTs) are members of the class III histone deacetylase family and epigenetically control multiple target genes to modulate diverse biological responses in cells. Among the SIRTs, SIRT1 is the most well-studied, with a role in the modulation of immune and inflammatory responses following infection. The functions of SIRT1 include orchestrating immune, inflammatory, metabolic, and autophagic responses, all of which are required in establishing and controlling host defenses during infection. In this review, we summarize recent information on the roles of SIRT1 and its regulatory mechanisms during bacterial, viral, and parasitic infections. We also discuss several SIRT1 modulators, as potential antimicrobial treatments. Understanding the function of SIRT1 in balancing immune homeostasis will contribute to the development of new therapeutics for the treatment of infection and inflammatory disease.


Subject(s)
Sirtuin 1 , Sirtuins , Autophagy , Sirtuin 1/metabolism , Sirtuins/metabolism
19.
Gut Microbes ; 14(1): 2073132, 2022.
Article in English | MEDLINE | ID: mdl-35579969

ABSTRACT

Nontuberculous mycobacterial pulmonary diseases (NTM-PDs) are emerging as global health threats with issues of antibiotic resistance. Accumulating evidence suggests that the gut-lung axis may provide novel candidates for host-directed therapeutics against various infectious diseases. However, little is known about the gut-lung axis in the context of host protective immunity to identify new therapeutics for NTM-PDs. This study was performed to identify gut microbes and metabolites capable of conferring pulmonary immunity to NTM-PDs. Using metabolomics analysis of sera from NTM-PD patients and mouse models, we showed that the levels of l-arginine were decreased in sera from NTM-PD patients and NTM-infected mice. Oral administration of l-arginine significantly enhanced pulmonary antimicrobial activities with the expansion of IFN-γ-producing effector T cells and a shift to microbicidal (M1) macrophages in the lungs of NTM-PD model mice. Mice that received fecal microbiota transplants from l-arginine-treated mice showed increased protective host defense in the lungs against NTM-PD, whereas l-arginine-induced pulmonary host defense was attenuated in mice treated with antibiotics. Using 16S rRNA sequencing, we further showed that l-arginine administration resulted in enrichment of the gut microbiota composition with Bifidobacterium species. Notably, oral treatment with either Bifidobacterium pseudolongum or inosine enhanced antimicrobial pulmonary immune defense against NTM infection, even with multidrug-resistant clinical NTM strains. Our findings indicate that l-arginine-induced gut microbiota remodeling with enrichment of B. pseudolongum boosts pulmonary immune defense against NTM infection by driving the protective gut-lung axis in vivo.


Subject(s)
Gastrointestinal Microbiome , Mycobacterium Infections, Nontuberculous , Animals , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/therapeutic use , Arginine , Humans , Lung , Mice , Mycobacterium Infections, Nontuberculous/drug therapy , Mycobacterium Infections, Nontuberculous/microbiology , RNA, Ribosomal, 16S
20.
J Hematol Oncol ; 15(1): 51, 2022 05 07.
Article in English | MEDLINE | ID: mdl-35526025

ABSTRACT

Acute myeloid leukemia (AML) is a severe hematologic malignancy prevalent in older patients, and the identification of potential therapeutic targets for AML is problematic. Autophagy is a lysosome-dependent catabolic pathway involved in the tumorigenesis and/or treatment of various cancers. Mounting evidence has suggested that autophagy plays a critical role in the initiation and progression of AML and anticancer responses. In this review, we describe recent updates on the multifaceted functions of autophagy linking to genetic alterations of AML. We also summarize the latest evidence for autophagy-related genes as potential prognostic predictors and drivers of AML tumorigenesis. We then discuss the crosstalk between autophagy and tumor cell metabolism into the impact on both AML progression and anti-leukemic treatment. Moreover, a series of autophagy regulators, i.e., the inhibitors and activators, are described as potential therapeutics for AML. Finally, we describe the translation of autophagy-modulating therapeutics into clinical practice. Autophagy in AML is a double-edged sword, necessitating a deeper understanding of how autophagy influences dual functions in AML tumorigenesis and anti-leukemic responses.


Subject(s)
Apoptosis , Leukemia, Myeloid, Acute , Aged , Autophagy , Carcinogenesis , Humans , Leukemia, Myeloid, Acute/genetics , Signal Transduction
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