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1.
Nat Chem Biol ; 2024 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-38773328

RESUMO

A timely inflammatory response is crucial for early viral defense, but uncontrolled inflammation harms the host. Retinoic acid-inducible gene I (RIG-I) has a pivotal role in detecting RNA viruses, yet the regulatory mechanisms governing its sensitivity remain elusive. Here we identify PTENα, an N-terminally extended form of PTEN, as an RNA-binding protein with a preference for the CAUC(G/U)UCAU motif. Using both in vivo and in vitro viral infection assays, we demonstrated that PTENα restricted the host innate immune response, relying on its RNA-binding capacity and phosphatase activity. Mechanistically, PTENα directly bound to viral RNA and enzymatically converted its 5'-triphosphate to 5'-monophosphate, thereby reducing RIG-I sensitivity. Physiologically, brain-intrinsic PTENα exerted protective effects against viral inflammation, while peripheral PTENα restricted host antiviral immunity and, to some extent, promoted viral replication. Collectively, our findings underscore the significance of PTENα in modulating viral RNA- and RIG-I-mediated immune recognition, offering potential therapeutic implications for infectious diseases.

2.
Ecotoxicol Environ Saf ; 277: 116326, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38640800

RESUMO

The available information regarding the impact of antimony (Sb), a novel environmental pollutant, on the intestinal microbiota and host health is limited. In this study, we conducted physiological characterizations to investigate the response of adult zebrafish to different environmental concentrations (0, 30, 300, and 3000 µg/L) of Sb over a period of 14 days. Biochemical and pathological changes demonstrated that Sb effectively compromised the integrity of the intestinal physical barrier and induced inflammatory responses as well as oxidative stress. Analysis of both intestinal microbial community and metabolome revealed that exposure to 0 and 30 µg/L of Sb resulted in similar microbiota structures; however, exposure to 300 µg/L altered microbial communities' composition (e.g., a decline in genus Cetobacterium and an increase in Vibrio). Furthermore, exposure to 300 µg/L significantly decreased levels of bile acids and glycerophospholipids while triggering intestinal inflammation but activating self-protective mechanisms such as antibiotic presence. Notably, even exposure to 30 µg/L of Sb can trigger dysbiosis of intestinal microbiota and metabolites, potentially impacting fish health through the "microbiota-intestine-brain axis" and contributing to disease initiation. This study provides valuable insights into toxicity-related information concerning environmental impacts of Sb on aquatic organisms with significant implications for developing management strategies.


Assuntos
Antimônio , Microbioma Gastrointestinal , Poluentes Químicos da Água , Peixe-Zebra , Animais , Microbioma Gastrointestinal/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Antimônio/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Metaboloma/efeitos dos fármacos , Metabolômica
3.
Adv Sci (Weinh) ; 11(16): e2304501, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38386350

RESUMO

CD8+ T cells are critical for host antitumor responses, whereas persistent antigenic stimulation and excessive inflammatory signals lead to T cell dysfunction or exhaustion. Increasing early memory T cells can improve T cell persistence and empower T cell-mediated tumor eradication, especially for adoptive cancer immunotherapy. Here, it is reported that tumor-associated monocytes (TAMos) are highly correlated with the accumulation of CD8+ memory T cells in human cancers. Further analysis identifies that TAMos selectively reprogram CD8+ T cells into T central memory-like (TCM-like) cells with enhanced recall responses. L-NMMA, a pan nitric oxide synthase inhibitor, can mitigate TAMo-mediated inhibition of T cell proliferation without affecting TCM-like cell generation. Moreover, the modified T cells by TAMo exposure and L-NMMA treatment exhibit long-term persistence and elicit superior antitumor effects in vivo. Mechanistically, the transmembrane protein CD300LG is involved in TAMo-mediated TCM-like cell polarization in a cell-cell contact-dependent manner. Thus, the terminally differentiated TAMo subset (CD300LGhighACElow) mainly contributes to TCM-like cell development. Taken together, these findings establish the significance of TAMos in boosting T-cell antitumor immunity.


Assuntos
Linfócitos T CD8-Positivos , Monócitos , Linfócitos T CD8-Positivos/imunologia , Camundongos , Animais , Monócitos/imunologia , Humanos , Células T de Memória/imunologia , Memória Imunológica/imunologia , Modelos Animais de Doenças , Neoplasias/imunologia , Neoplasias/terapia , Camundongos Endogâmicos C57BL , Linhagem Celular Tumoral , Imunoterapia Adotiva/métodos
5.
iScience ; 26(8): 107367, 2023 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-37520707

RESUMO

Immune checkpoint blockade has become an effective approach to reverse the immune tolerance of tumor cells. Indoleamine 2,3-dioxygenase 1 (IDO1) is frequently upregulated in many types of cancers and contributes to the establishment of an immunosuppressive cancer microenvironment, which has been thought to be a potential target for cancer therapy. However, the development of IDO1 inhibitors for clinical application is still limited. Here, we isolated a DNA aptamer with a strong affinity and inhibitory activity against IDO1, designated as IDO-APT. By conjugating with nanoparticles, in situ injection of IDO-APT to CT26 tumor-bearing mice significantly suppresses the activity of regulatory T cells and promotes the function of CD8+ T cells, leading to tumor suppression and prolonged survival. Therefore, this functional IDO1-specific aptamer with potent anti-tumor effects may serve as a potential therapeutic strategy in cancer immunotherapy. Our data provide an alternative way to target IDO1 in addition to small molecule inhibitors.

6.
Analyst ; 148(11): 2616-2625, 2023 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-37191022

RESUMO

Aptamers associated with cancer targeting therapy are commonly focused on cell membrane proteins; however, the study of intracellular, particularly, nuclear proteins is limited. The nuclear phosphatase PAC1 has been reported to be a potential T cell-related immunotherapeutic target. Here, we identified an aptamer, designated as PA5, with high affinity and specificity for PAC1 through the systematic evolution of ligands by exponential enrichment (SELEX) procedure. We then developed a dual-module aptamer PAC1-AS consisting of a cell-internalizing module and a targeting module, which can recognize PAC1 in the nucleus under physiological conditions. This modularized aptamer raises the possibility of manipulating endosomes and provides insights into the exploration and development of an efficient cancer immunotherapy approach.


Assuntos
Aptâmeros de Nucleotídeos , Aptâmeros de Nucleotídeos/metabolismo , Técnica de Seleção de Aptâmeros/métodos , Ligantes , Proteínas Nucleares , Linfócitos T
7.
Materials (Basel) ; 16(6)2023 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-36984289

RESUMO

In recent years, waste material recycling and reuse have attracted great interest as environmentally friendly modifiers to improve asphalt pavement performance. In this study, anhydrous calcium sulfate whiskers (ACSW), synthesized using phosphogypsum waste, and waste cooking oil (WCO), one of the most prevalent waste oils, were used together as modifiers to create an environmentally friendly asphalt mixture. In particular, WCO was used to compensate for the negative effects of ACSW on asphalt mixture performance at low temperatures. A variety of ACSW and WCO compound-modified asphalt mixtures were fabricated. High-temperature stability, medium-temperature fatigue, low-temperature anti-cracking, moisture susceptibility, repeated freeze-thaw, and long-term aging tests were conducted to comprehensively evaluate the pavement performance. Compared to the base asphalt mixture, the compound-modified asphalt mixtures were demonstrated to have better high- and low-temperature, moisture susceptibility, fatigue, anti-freezing, and anti-aging properties, especially for the 6%ACSW and 2%WCO compound-modified asphalt mixture. Therefore, the 6%ACSW and 2%WCO compound-modified asphalt mixture was ultimately selected for use in construction, as this mixture can meet the requirements for regions with cold winters and hot summers.

8.
Nat Immunol ; 21(3): 287-297, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31932812

RESUMO

Cancer cells subvert immune surveillance through inhibition of T cell effector function. Elucidation of the mechanism of T cell dysfunction is therefore central to cancer immunotherapy. Here, we report that dual specificity phosphatase 2 (DUSP2; also known as phosphatase of activated cells 1, PAC1) acts as an immune checkpoint in T cell antitumor immunity. PAC1 is selectively upregulated in exhausted tumor-infiltrating lymphocytes and is associated with poor prognosis of patients with cancer. PAC1hi effector T cells lose their proliferative and effector capacities and convert into exhausted T cells. Deletion of PAC1 enhances immune responses and reduces cancer susceptibility in mice. Through activation of EGR1, excessive reactive oxygen species in the tumor microenvironment induce expression of PAC1, which recruits the Mi-2ß nucleosome-remodeling and histone-deacetylase complex, eventually leading to chromatin remodeling of effector T cells. Our study demonstrates that PAC1 is an epigenetic immune regulator and highlights the importance of targeting PAC1 in cancer immunotherapy.


Assuntos
Fosfatase 2 de Especificidade Dupla/imunologia , Neoplasias/imunologia , Linfócitos T/imunologia , Animais , Cromatina/genética , Cromatina/metabolismo , Fosfatase 2 de Especificidade Dupla/deficiência , Fosfatase 2 de Especificidade Dupla/genética , Proteína 1 de Resposta de Crescimento Precoce/metabolismo , Feminino , Humanos , Ativação Linfocitária , Linfócitos do Interstício Tumoral/imunologia , Masculino , Complexo Mi-2 de Remodelação de Nucleossomo e Desacetilase/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos NOD , Camundongos Knockout , Camundongos SCID , Neoplasias/genética , Neoplasias/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Microambiente Tumoral/genética , Microambiente Tumoral/imunologia , Regulação para Cima
9.
ChemSusChem ; 12(10): 2294-2301, 2019 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-30806010

RESUMO

Layered lithium-rich cathode materials are one of the most promising cathode materials owing to their higher mass energy density than the commercial counterparts. A series of trace Yb-doped lithium-rich cathode materials Li1.2 Mn0.54 Ni0.13 Co0.13-x Ybx O2 (0≤x≤0.050) were synthesized and the effects were investigated by XRD, X-ray photoelectron spectroscopy, and high-resolution TEM. The participation of Yb ions in electrochemical reactions and the larger binding energy of Yb-O than M-O (M=Mn, Ni, Co), which expands the lithium layer spacing and stabilizes the oxygen stacking, resulted in excellent performance of materials doped with a limited Yb content (x≤0.005). However, higher doping amounts (x>0.005) significantly increased the charge-transfer impedance and led to a sharp deterioration in electrochemical performance. The reason lies in the large difference in ionic radius between the transition metals (Mn, Co, and Ni) and Yb. There is an upper limit to the amount of Yb ions in the lattice. If the amount of Yb is higher than the limit, excess Yb ions enter the Li layers instead of staying in the transition-metal layers or even segregate on the surface and form electrochemically inert oxides.

10.
J Med Microbiol ; 60(Pt 12): 1827-1834, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21852522

RESUMO

The objective of this study was to screen for novel quorum-sensing inhibitors (QSIs) from traditional Chinese medicines (TCMs) that inhibit bacterial biofilm formation. Six of 46 active components found in TCMs were identified as putative QSIs based on molecular docking studies. Of these, three compounds inhibited biofilm formation by Pseudomonas aeruginosa and Stenotrophomonas maltophilia at a concentration of 200 µM. A fourth compound (emodin) significantly inhibited biofilm formation at 20 µM and induced proteolysis of the quorum-sensing signal receptor TraR in Escherichia coli at a concentration of 3-30 mM. Emodin also increased the activity of ampicillin against P. aeruginosa. Therefore, emodin might be suitable for development into an antivirulence and antibacterial agent.


Assuntos
Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Medicamentos de Ervas Chinesas/farmacologia , Emodina/farmacologia , Pseudomonas aeruginosa/efeitos dos fármacos , Percepção de Quorum/efeitos dos fármacos , Antraquinonas/farmacologia , Cumarínicos/farmacologia , Escherichia coli/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Naftoquinonas/farmacologia , Pseudomonas aeruginosa/crescimento & desenvolvimento , Pseudomonas aeruginosa/patogenicidade , Stenotrophomonas maltophilia/efeitos dos fármacos
11.
J Agric Food Chem ; 57(20): 9764-8, 2009 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-20560630

RESUMO

Monascus products are used as both natural colorants and food additives all over the world. However, its safety is really an issue because of the presence of citrinin, which is considered to be hepatotoxic and nephrotoxic. Therefore, the objective of the present study was to develop an approach for using a fragment of pigment-related gene pks1 to replace citrinin-activator gene ctnA. The character of citrinin antibacterial activity to Bacillus subtilis was used for primary screening of transformants based on the foundation that the inhibition zone formed around the mutant colonies with low citrinin products will become smaller. The selected mutants were then further confirmed by polymerase chain reaction and high-performance liquid chromatography methods. During all of the processes, antibiotic markers and vectors were avoided. The results showed that the citrinin products of mutants were reduced to 42%, while the pigment products were improved to 33.9%, respectively, over those of the wild-type strains.


Assuntos
Citrinina/biossíntese , Proteínas Fúngicas/genética , Engenharia Genética/métodos , Vetores Genéticos/genética , Monascus/genética , Mutação , Pigmentos Biológicos/biossíntese , Antibacterianos/farmacologia , Proteínas Fúngicas/metabolismo , Vetores Genéticos/metabolismo , Monascus/efeitos dos fármacos , Monascus/metabolismo
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