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1.
Biochem Biophys Res Commun ; 727: 150326, 2024 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-38968768

RESUMO

The Cyclic GMP-AMP synthase (cGAS) and cGAS/DncV-like nucleotidyltransferase (CD-NTase) enzymes belong to the key components of the innate immune sensor system that generates cyclic dinucleotide molecules in response to danger signals. Recently, it was discovered that CD-NTase in bacteria can undergo conjugation to protein substrates via an E1/E2 enzyme-mediated process, resembling ubiquitin modification system. Subsequently, these CD-NTase conjugated molecules will be hydrolyzed by the Cap3 enzyme in the same gene cluster. However, the experimental structure of bacterial CD-NTase recognized by Cap3 is unknown. Here, we first determined the crystal structure of the Cap3 enzyme in complex with the C-terminal tail of CD-NTase. Our structural and enzymatic analysis revealed that the C-terminal tail of CD-NTase is both necessary and sufficient for the Cap3-mediated hydrolysis of CD-NTase from its substrates. Interestingly, we further observed that after the hydrolysis reaction, the terminal glycine residue of the CD-NTase C-terminal tail was sequentially removed by Cap3, indicating that Cap3 might play a role in quenching the CD-NTase conjugation reaction. Our work provides experimental evidence elucidating the interaction between Cap3 and CD-NTase, and suggests a potential role for Cap3 in the bacterial Cyclic-oligonucleotide-based anti-phage signaling system (CBASS).

2.
Biomed Pharmacother ; 177: 117078, 2024 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-38968795

RESUMO

The eye is one of the most vulnerable parts of the human body. There are many kinds of ophthalmic diseases, which are caused by multiple factors. Generally, ophthalmic diseases have the characteristics of complicated etiology and difficult therapy. With the development of the times, ophthalmic diseases have become a major problem that affects people's lives. Inflammation, a major factor inducing ocular diseases, is one of the most popular research directions. The cGAS/STING pathway is a recently discovered inflammatory signaling pathway, which recognizes double-stranded DNA (dsDNA) as an activation signal to promote the expression of downstream cytokines that promote inflammatory response or autoimmune response. Since most of the current treatments for ophthalmic diseases mainly rely on surgery, it is of positive significance to explore the pathogenesis for the discovery of drug targets. This review summarize the research progress of the cGAS/STING pathway in major ophthalmic diseases by introducing the correlation between classical inflammatory pathway and ophthalmic diseases, in order to predict the research direction and methods targeting the cGAS/STING pathway in the pathogenesis of ophthalmic diseases, and also provide guidance for the mechanism as well as molecular targets of ophthalmic diseases.

3.
Adv Sci (Weinh) ; : e2403158, 2024 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-38953329

RESUMO

In situ cancer vaccination is an attractive strategy that stimulates protective antitumor immunity. Cytotoxic T lymphocytes (CTLs) are major mediators of the adaptive immune defenses, with critical roles in antitumor immune response and establishing immune memory, and are consequently extremely important for in situ vaccines to generate systemic and lasting antitumor efficacy. However, the dense extracellular matrix and hypoxia in solid tumors severely impede the infiltration and function of CTLs, ultimately compromising the efficacy of in situ cancer vaccines. To address this issue, a robust in situ cancer vaccine, Au@MnO2 nanoparticles (AMOPs), based on a gold nanoparticle core coated with a manganese dioxide shell is developed. The AMOPs modulated the unfavorable tumor microenvironment (TME) to restore CTLs infiltration and function and efficiently induced immunogenic cell death. The Mn2+-mediated stimulator of the interferon genes pathway can be activated to further augment the therapeutic efficacy of the AMOPs. Thus, the AMOPs vaccine successfully elicited long-lasting antitumor immunity to considerably inhibit primary, recurrent, and metastatic tumors. This study not only highlights the importance of revitalizing CTLs efficacy against solid tumors but also makes progress toward overcoming TME barriers for sustained antitumor immunity.

4.
Int J Rheum Dis ; 27(7): e15256, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38982864

RESUMO

The cyclic GMP-AMP synthase (cGAS), a prominent intracellular DNA sensor in mammalian cells, controls the innate immune response and the stimulator of interferon genes (STING)-mediated synthesis of pro-inflammatory cytokines, such as type-I interferon (IFN-I). For decades, IFN-I has been hypothesized to be essential in the development of systemic lupus erythematosus (SLE), a chronic multisystem autoimmunity characterized by immune complex (IC) deposition in small vessels. Recent findings revealed that the activation of the cGAS-STING pathway by self-DNA would propagate the autoimmune responses via upregulating IFN-I production in SLE. In this review, we aimed to provide a comprehensive outlook of the role of the cGAS-STING pathway in SLE pathobiology, as well as, a better understanding of current therapeutic opportunities targeting this axis.


Assuntos
Lúpus Eritematoso Sistêmico , Proteínas de Membrana , Nucleotidiltransferases , Transdução de Sinais , Humanos , Lúpus Eritematoso Sistêmico/imunologia , Lúpus Eritematoso Sistêmico/metabolismo , Lúpus Eritematoso Sistêmico/tratamento farmacológico , Nucleotidiltransferases/metabolismo , Proteínas de Membrana/metabolismo , Animais , Autoimunidade , Interferon Tipo I/metabolismo , Interferon Tipo I/imunologia , Terapia de Alvo Molecular , Imunidade Inata
5.
Heliyon ; 10(12): e33093, 2024 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-38988528

RESUMO

The cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) pathway is a critical innate immune pathway primarily due to its vital DNA sensing mechanism in pathogen defence. Recent research advances have shown that excessive activation or damage to the cGAS-STING pathway can exacerbate chronic inflammatory responses, playing a significant role in metabolic dysfunction and aging, leading to the development of related diseases such as obesity, osteoporosis, and neurodegenerative diseases. This article reviews the structure and biological functions of the cGAS-STING signaling pathway and discusses in detail how this pathway regulates the occurrence and development of metabolic and age-related diseases. Additionally, this article introduces potential small molecule drugs targeting cGAS and STING, aiming to provide new research perspectives for studying the pathogenesis and treatment of metabolic-related diseases.

6.
Int Immunopharmacol ; 138: 112652, 2024 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-38986301

RESUMO

Tendinopathy is one of the most prevalent sports injury diseases in orthopedics. However, there is no effective treatment or medicine. Recently, the discovery of tendon stem cells (TSCs) provides a new perspective to find new therapeutic methods for Tendinopathy. Studies have shown that oxidative stress will inevitably cause TSCs injury during tendinopathy, but the mechanism has not been fully elucidated. Here, we report the oxidative damage of TSCs induced by H2O2 via ferroptosis, as well, treatment with H2O2 raised the proportion of mitochondria engulfed by autophagosomes in TSCs. The suppression of mitophagy by Mdivi-1 significantly attenuates the H2O2-induced ferroptosis in TSCs. Mechanically, H2O2 actives the cGAS-STING pathway, which can regulate the level of mitophagy. Interfering with cGAS could impair mitophagy and the classical ferroptotic events. In the rat model of tendinopathy, interference of cGAS could relieve tendon injury by inhibiting ferroptosis. Overall, these results provided novel implications to reveal the molecular mechanism of tendinopathy, by which pointed to cGAS as a potential therapeutic target for the treatment of tendinopathy.

7.
Cell Rep Med ; : 101648, 2024 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-38986624

RESUMO

Low migratory dendritic cell (DC) levels pose a challenge in cancer immune surveillance, yet their impact on tumor immune status and immunotherapy responses remains unclear. We present clinical evidence linking reduced migratory DC levels to immune-cold tumor status, resulting in poor patient outcomes. To address this, we develop an autologous DC-based nanovaccination strategy using patient-derived organoid or cancer cell lysate-pulsed cationic nanoparticles (cNPs) to load immunogenic DC-derived microvesicles (cNPcancer cell@MVDC). This approach transforms immune-cold tumors, increases migratory DCs, activates T cells and natural killer cells, reduces tumor growth, and enhances survival in orthotopic pancreatic and lung cancer models, surpassing conventional methods. In vivo imaging reveals superior cNPcancer cell@MVDC accumulation in tumors and lymph nodes, promoting immune cell infiltration. Mechanistically, cNPs enrich mitochondrial DNA, enhancing cGAS-STING-mediated DC activation and migration. Our strategy shifts cold tumors to a hot state, enhancing antitumor immunity for potential personalized cancer treatments.

8.
Eur J Med Chem ; 275: 116638, 2024 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-38950489

RESUMO

The cGAS (cyclic GMP-AMP synthase)-STING (stimulator of interferon genes) pathway promotes antitumor immune responses by sensing cytosolic DNA fragments leaked from nucleus and mitochondria. Herein, we designed a highly charged ruthenium photosensitizer (Ru1) with a ß-carboline alkaloid derivative as the ligand for photo-activating of the cGAS-STING pathway. Due to the formation of multiple non-covalent intermolecular interactions, Ru1 can self-assemble into carrier-free nanoparticles (NPs). By incorporating the triphenylphosphine substituents, Ru1 can target and photo-damage mitochondrial DNA (mtDNA) to cause the cytoplasmic DNA leakage to activate the cGAS-STING pathway. Finally, Ru1 NPs show potent antitumor effects and elicit intense immune responses in vivo. In conclusion, we report the first self-assembling mtDNA-targeted photosensitizer, which can effectively activate the cGAS-STING pathway, thus providing innovations for the design of new photo-immunotherapeutic agents.


Assuntos
Antineoplásicos , Imunoterapia , Proteínas de Membrana , Nucleotidiltransferases , Fármacos Fotossensibilizantes , Rutênio , Fármacos Fotossensibilizantes/química , Fármacos Fotossensibilizantes/farmacologia , Fármacos Fotossensibilizantes/síntese química , Humanos , Nucleotidiltransferases/metabolismo , Proteínas de Membrana/metabolismo , Animais , Rutênio/química , Rutênio/farmacologia , Camundongos , Antineoplásicos/farmacologia , Antineoplásicos/química , Antineoplásicos/síntese química , Estrutura Molecular , Relação Dose-Resposta a Droga , Nanopartículas/química , Relação Estrutura-Atividade , Ensaios de Seleção de Medicamentos Antitumorais , DNA Mitocondrial/metabolismo , Proliferação de Células/efeitos dos fármacos , Linhagem Celular Tumoral , Neoplasias/tratamento farmacológico , Neoplasias/patologia
9.
Radiother Oncol ; : 110424, 2024 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-38997092

RESUMO

Various genetic and epigenetic changes associated with genomic instability (GI), including DNA damage repair defects, chromosomal instability, and mitochondrial GI, contribute to the development and progression of cancer. These alterations not only result in DNA leakage into the cytoplasm, either directly or through micronuclei, but also trigger downstream inflammatory signals, such as the cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) signaling pathway. Apart from directly inducing DNA damage to eliminate cancer cells, radiotherapy (RT) exerts its antitumor effects through intracellular DNA damage sensing mechanisms, leading to the activation of downstream inflammatory signaling pathways. This not only enables local tumor control but also reshapes the immune microenvironment, triggering systemic immune responses. The combination of RT and immunotherapy has emerged as a captivating avenue to increase the probability of abscopal effects, where distant tumors respond to treatment due to the systemic immunomodulatory effects. This review emphasizes the importance of GI in cancer biology and elucidates the mechanisms by which RT induces GI remodeling of the immune microenvironment. By elucidating the mechanisms of GI and RT-induced immune responses, we aim to emphasize the crucial importance of this approach in modern oncology. Understanding the impact of GI on tumor biological behavior and therapeutic response, as well as the possibility of activating systemic anti-tumor immunity through RT, will pave the way for the development of new treatment strategies and improve prognosis for patients.

10.
FASEB J ; 38(13): e23663, 2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-38958986

RESUMO

This study delves into the unexplored realm of castration-resistant prostate cancer (CRPC) by investigating the role of TRIM28 and its intricate molecular mechanisms using high-throughput single-cell transcriptome sequencing and advanced bioinformatics analysis. Our comprehensive examination unveiled dynamic TRIM28 expression changes, particularly in immune cells such as macrophages and CD8+ T cells within CRPC. Correlation analyses with TCGA data highlighted the connection between TRIM28 and immune checkpoint expression and emphasized its pivotal influence on the quantity and functionality of immune cells. Using TRIM28 knockout mouse models, we identified differentially expressed genes and enriched pathways, unraveling the potential regulatory involvement of TRIM28 in the cGAS-STING pathway. In vitro, experiments further illuminated that TRIM28 knockout in prostate cancer cells induced a notable anti-tumor immune effect by inhibiting M2 macrophage polarization and enhancing CD8+ T cell activity. This impactful discovery was validated in an in situ transplant tumor model, where TRIM28 knockout exhibited a deceleration in tumor growth, reduced proportions of M2 macrophages, and enhanced infiltration of CD8+ T cells. In summary, this study elucidates the hitherto unknown anti-tumor immune role of TRIM28 in CRPC and unravels its potential regulatory mechanism via the cGAS-STING signaling pathway. These findings provide novel insights into the immune landscape of CRPC, offering promising directions for developing innovative therapeutic strategies.


Assuntos
Linfócitos T CD8-Positivos , Proteínas de Membrana , Camundongos Knockout , Neoplasias de Próstata Resistentes à Castração , Proteína 28 com Motivo Tripartido , Proteína 28 com Motivo Tripartido/metabolismo , Proteína 28 com Motivo Tripartido/genética , Animais , Camundongos , Humanos , Masculino , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/metabolismo , Neoplasias de Próstata Resistentes à Castração/genética , Neoplasias de Próstata Resistentes à Castração/metabolismo , Neoplasias de Próstata Resistentes à Castração/imunologia , Neoplasias de Próstata Resistentes à Castração/patologia , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Macrófagos/metabolismo , Macrófagos/imunologia , Nucleotidiltransferases/metabolismo , Nucleotidiltransferases/genética , Regulação Neoplásica da Expressão Gênica , Linhagem Celular Tumoral , Camundongos Endogâmicos C57BL , Transdução de Sinais
11.
Molecules ; 29(13)2024 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-38999073

RESUMO

The cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) pathway is pivotal in immunotherapy. Several agonists and inhibitors of the cGAS-STING pathway have been developed and evaluated for the treatment of various diseases. The agonists aim to activate STING, with cyclic dinucleotides (CDNs) being the most common, while the inhibitors aim to block the enzymatic activity or DNA binding ability of cGAS. Meanwhile, non-CDN compounds and cGAS agonists are also gaining attention. The omnipresence of the cGAS-STING pathway in vivo indicates that its overactivation could lead to undesired inflammatory responses and autoimmune diseases, which underscores the necessity of developing both agonists and inhibitors of the cGAS-STING pathway. This review describes the molecular traits and roles of the cGAS-STING pathway and summarizes the development of cGAS-STING agonists and inhibitors. The information is supposed to be conducive to the design of novel drugs for targeting the cGAS-STING pathway.


Assuntos
Proteínas de Membrana , Nucleotidiltransferases , Transdução de Sinais , Humanos , Nucleotidiltransferases/metabolismo , Nucleotidiltransferases/antagonistas & inibidores , Proteínas de Membrana/metabolismo , Proteínas de Membrana/antagonistas & inibidores , Proteínas de Membrana/agonistas , Transdução de Sinais/efeitos dos fármacos , Animais , Doenças Autoimunes/tratamento farmacológico , Doenças Autoimunes/metabolismo
12.
Adv Sci (Weinh) ; : e2308890, 2024 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-39004913

RESUMO

Interferons (IFNs) activate JAK-STAT pathways to induce downstream effector genes for host defense against invaded pathogens and tumors. Here both type I (ß) and II (γ) IFNs are shown that can activate the transcription factor IRF3 in parallel with STAT1. IRF3-deficiency impairs transcription of a subset of downstream effector genes induced by IFN-ß and IFN-γ. Mechanistically, IFN-induced activation of IRF3 is dependent on the cGAS-STING-TBK1 axis. Both IFN-ß and IFN-γ cause mitochondrial DNA release into the cytosol. In addition, IFNs induce JAK1-mediated tyrosine phosphorylation of cGAS at Y214/Y215, which is essential for its DNA binding activity and signaling. Furthermore, deficiency of cGAS, STING, or IRF3 impairs IFN-ß- or IFN-γ-mediated antiviral and antitumor activities. The findings reveal a novel IRF3 activation pathway parallel with the canonical STAT1/2 activation pathways triggered by IFNs and provide an explanation for the pleiotropic roles of the cGAS-STING-IRF3 axis in host defense.

13.
Sci Total Environ ; : 174674, 2024 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-39002594

RESUMO

Nanoplastics (NPs) are a common type of degraded plastic material associated with adverse health effects such as pulmonary injury. However, the molecular mechanism(s) underlying lung injury as caused by NPs remains uncertain. Thus, we herein investigated the pulmonary toxicity of NPs on RAW264.7 cells and C57BL/6 mice. Our in vitro study indicated that NPs induced oxidative stress, cell death, inflammation, and the activation of the cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING)-signaling pathway. Mice in our in vivo study displayed significant pulmonary fibrosis, inflammation, apoptosis, necrosis, and excessive double-stranded DNA release into serum and bronchoalveolar lavage fluid. Our mechanistic exploration uncovered cGAS-STING-signaling activation as the leading cause of NPs-induced pulmonary fibrosis. The current study opens an avenue toward elucidating the role of the cGAS-STING-signaling pathway in NPs-induced pulmonary injury.

14.
J Biol Chem ; : 107554, 2024 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-39002667

RESUMO

Cyclic GMP-AMP synthase (cGAS), a cytosolic DNA sensor, also exhibits nuclear genomic localization and is involved in DNA damage signaling. In this study, we investigated the impact of cGAS crotonylation on the regulation of the DNA damage response, particularly homologous recombination repair, following exposure to ionizing radiation (IR). Lysine 254 of cGAS is constitutively crotonylated by the CREB-binding protein; however, IR-induced DNA damage triggers SIRT3-mediated decrotonylation. Lysine 254 decrotonylation decreased the DNA-binding affinity of cGAS and inhibited its interaction with PARP1, promoting HR repair. Moreover, SIRT3 suppression led to HR repair inhibition and markedly sensitized cancer cells to IR and DNA-damaging chemicals, highlighting SIRT3 as a potential target for cancer therapy. Overall, this study revealed the crucial role of cGAS crotonylation in the DNA damage response. Furthermore, we propose that modulating cGAS and SIRT3 activities could be potential strategies for cancer therapy.

15.
Bioessays ; : e2400091, 2024 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-38962845

RESUMO

The cGAS-STING signaling pathway plays a pivotal role in sensing cytosolic DNA and initiating innate immune responses against various threats, with disruptions in this pathway being associated with numerous immune-related disorders. Therefore, precise regulation of the cGAS-STING signaling is crucial to ensure appropriate immune responses. Recent research, including ours, underscores the importance of protein condensation in driving the activation and maintenance of innate immune signaling within the cGAS-STING pathway. Consequently, targeting condensation processes in this pathway presents a promising approach for modulating the cGAS-STING signaling and potentially managing associated disorders. In this review, we provide an overview of recent studies elucidating the role and regulatory mechanism of protein condensation in the cGAS-STING signaling pathway while emphasizing its pathological implications. Additionally, we explore the potential of understanding and manipulating condensation dynamics to develop novel strategies for mitigating cGAS-STING-related disorders in the future.

16.
J Inflamm Res ; 17: 4549-4574, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39011416

RESUMO

The prevalence of age-related neurodegenerative diseases, such as Parkinson's disease (PD) and related disorders continues to grow worldwide. Increasing evidence links intracellular inclusions of misfolded alpha-synuclein (α-syn) aggregates, so-called Lewy bodies (LB) and Lewy neuritis, to the progressive pathology of PD and other synucleinopathies. Our previous findings established that α-syn oligomers induce S-nitrosylation and deregulation of the E3-ubiquitin ligase Parkin, leading to mitochondrial disturbances in neuronal cells. The accumulation of damaged mitochondria as a consequence, together with the release of mitochondrial-derived damage-associated molecular patterns (mtDAMPs) could activate the innate immune response and induce neuroinflammation ("mito-inflammation"), eventually accelerating neurodegeneration. However, the molecular pathways that transmit pro-inflammatory signals from damaged mitochondria are not well understood. One of the proposed pathways could be the cyclic GMP-AMP synthase (cGAS) - stimulator of interferon genes (STING) (cGAS-STING) pathway, which plays a pivotal role in modulating the innate immune response. It has recently been suggested that cGAS-STING deregulation may contribute to the development of various pathological conditions. Especially, its excessive engagement may lead to neuroinflammation and appear to be essential for the development of neurodegenerative brain diseases, including PD. However, the precise molecular mechanisms underlying cGAS-STING pathway activation in PD and other synucleinopathies are not fully understood. This review focuses on linking mitochondrial dysfunction to neuroinflammation in these disorders, particularly emphasizing the role of the cGAS-STING signaling. We propose the cGAS-STING pathway as a critical driver of inflammation in α-syn-dependent neurodegeneration and hypothesize that cGAS-STING-driven "mito-inflammation" may be one of the key mechanisms promoting the neurodegeneration in PD. Understanding the molecular mechanisms of α-syn-induced cGAS-STING-associated "mito-inflammation" in PD and related synucleinopathies may contribute to the identification of new targets for the treatment of these disorders.

17.
Diabetes Obes Metab ; 2024 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-38988216

RESUMO

AIM: Post-transcriptional modifications and their specific mechanisms are the focus of research on the regulation of myocardial damage. Stress granules (SGs) can inhibit the inflammatory response by inhibiting the cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) pathway. This study investigated whether alkylation repair homologue protein 5 (ALKBH5) could affect myocardial inflammation and apoptosis during diabetic myocardial ischaemia-reperfusion injury (IRI) through the cGAS-STING pathway via SGs. METHODS: A diabetes ischaemia-reperfusion rat model and a high glucose hypoxia/reoxygenation cell model were established. Adeno-associated virus (AAV) and lentivirus (LV) were used to overexpress ALKBH5, while the SG agonist arsenite (Ars) and the SG inhibitor anisomycin were used as interventions. Then, the levels of apoptosis and related indicators in the cell and rat models were measured. RESULTS: In the in vivo experiment, compared with the normal sham group, the degree of myocardial tissue damage, creatine kinase-MB and cardiac troponin I in serum, and myocardial apoptosis, the infarcted area of myocardium, and the level of B-cell lymphoma 2 associated X protein, cGAS-STING pathway and inflammatory factors in the diabetes ischaemia-reperfusion group were significantly increased. However, the expression of SGs and the levels of ALKBH5, rat sarcoma-GTPase-activating protein-binding protein 1, T-cell intracellular antigen-1 and Bcl2 were significantly decreased. After AAV-ALKBH5 intervention, the degree of myocardial tissue damage, degree of myocardial apoptosis, and extent of myocardial infarction in myocardial tissue were significantly decreased. In the in vitro experiment, compared with those in the normal control group, the levels of lactate dehydrogenase, inflammation and apoptosis were significantly greater, and cell viability and the levels of ALKBH5 and SGs were decreased in the high glucose and hypoxia/reoxygenation groups. In the high glucose hypoxia/reoxygenation cell model, the degree of cell damage, inflammation, and apoptosis was greater than those in the high glucose and hypoxia/reoxygenation models, and the levels of ALKBH5 and SGs were further decreased. LV-ALKBH5 and Ars alleviated the degree of cell damage and inhibited inflammation and cell apoptosis. The inhibition of SGs could partly reverse the protective effect of LV-ALKBH5. The cGAS agonist G140 antagonized the inhibitory effects of the SG agonist Ars on cardiomyocyte apoptosis, inflammation and the cGAS-STING pathway. CONCLUSION: Both ALKBH5 and SGs inhibited myocardial inflammation and apoptosis during diabetic myocardial ischaemia-reperfusion. Mechanistically, ALKBH5 might inhibit the apoptosis of cardiomyocytes by promoting the expression of SGs through the cGAS-STING pathway.

18.
Front Immunol ; 15: 1403070, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39015575

RESUMO

Background: The cGAS-STING axis-mediated type I interferon pathway is a crucial strategy for host defense against DNA virus infection. Numerous evasion strategies developed by the pseudorabies virus (PRV) counteract host antiviral immunity. To what extent PRV-encoded proteins evade the cGAS-STING signaling pathway is unknown. Methods: Using US2 stably expressing cell lines and US2-deficient PRV model, we revealed that the PRV tegument protein US2 reduces STING protein stability and downregulates STING-mediated antiviral signaling. Results: To promote K48-linked ubiquitination and STING degradation, US2 interacts with the LBD structural domain of STING and recruits the E3 ligase TRIM21. TRIM21 deficiency consistently strengthens the host antiviral immune response brought on by PRV infection. Additionally, US2-deficient PRV is less harmful in mice. Conclusions: Our study implies that PRV US2 inhibits IFN signaling by a new mechanism that selectively targets STING while successfully evading the host antiviral response. As a result, the present study reveals a novel strategy by which PRV evades host defense and offers explanations for why the Bartha-K61 classical vaccine strain failed to offer effective defense against PRV variant strains in China, indicating that US2 may be a key target for developing gene-deficient PRV vaccines.


Assuntos
Herpesvirus Suídeo 1 , Imunidade Inata , Proteínas de Membrana , Nucleotidiltransferases , Pseudorraiva , Transdução de Sinais , Animais , Proteínas de Membrana/metabolismo , Proteínas de Membrana/imunologia , Proteínas de Membrana/genética , Transdução de Sinais/imunologia , Herpesvirus Suídeo 1/imunologia , Nucleotidiltransferases/metabolismo , Nucleotidiltransferases/genética , Nucleotidiltransferases/imunologia , Camundongos , Pseudorraiva/imunologia , Pseudorraiva/virologia , Humanos , Ubiquitinação , Ribonucleoproteínas/imunologia , Ribonucleoproteínas/metabolismo , Evasão da Resposta Imune , Interações Hospedeiro-Patógeno/imunologia , Células HEK293
19.
Biomed Pharmacother ; 177: 117134, 2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-39013225

RESUMO

Gastrointestinal cancer is among the most common cancers worldwide. Immune checkpoint inhibitor-based cancer immunotherapy has become an innovative approach in cancer treatment; however, its efficacy in gastrointestinal cancer is limited by the absence of infiltration of immune cells within the tumor microenvironment. Therefore, it is therefore urgent to develop a novel therapeutic drug to enhance immunotherapy. In this study, we describe a previously unreported potentiating effect of Icariside I (ICA I, GH01), the main bioactive compound isolated from the Epimedium species, on anti-tumor immune responses. Mechanistically, molecular docking and SPR assay result show that ICA I binding with TRPV4. ICA I induced intracellular Ca2+ increasing and mitochondrial DNA release by targeting TRPV4, which triggered cytosolic ox-mitoDNA release. Importantly, these intracellular ox-mitoDNA fragments were taken up by immune cells in the tumor microenvironment, which amplified the immune response. Moreover, our study shows the remarkable efficacy of sequential administration of ICA I and anti-α-PD-1 mAb in advanced tumors and provides a strong scientific rationale for recommending such a combination therapy for clinical trials. ICA I enhanced the anti-tumor effects with PD-1 inhibitors by regulating the TRPV4/Ca2+/Ox-mitoDNA/cGAS/STING axis. We expect that these findings will be translated into clinical therapies, which will benefit more patients with cancer in the near future.

20.
Bioact Mater ; 39: 392-405, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38855060

RESUMO

Retinal neovascularization (RNV), a typical pathological manifestation involved in most neovascular diseases, causes retinal detachment, vision loss, and ultimately irreversible blindness. Repeated intravitreal injections of anti-VEGF drugs were developed against RNV, with limitations of incomplete responses and adverse effects. Therefore, a new treatment with a better curative effect and more prolonged dosage is demanding. Here, we induced macrophage polarization to anti-inflammatory M2 phenotype by inhibiting cGAS-STING signaling with an antagonist C176, appreciating the role of cGAS-STING signaling in the retina in pro-inflammatory M1 polarization. C176-loaded and phosphatidylserine-modified dendritic mesoporous silica nanoparticles were constructed and examined by a single intravitreal injection. The biosafe nanoparticles were phagocytosed by retinal macrophages through a phosphatidylserine-mediated "eat me" signal, which persistently release C176 to suppress STING signaling and thereby promote macrophage M2 polarization specifically. A single dosage can effectively alleviate pathological angiogenesis phenotypes in murine oxygen-induced retinopathy models. In conclusion, these C176-loaded nanoparticles with enhanced cell uptake and long-lasting STING inhibition effects might serve as a promising way for treating RNV.

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