The cyclic guanosine monophosphate-adenosine monophosphate synthase-stimulator of interferon genes (cGAS-STING) pathway is a cornerstone of host innate immunity, playing a central role in detecting cytosolic double-stranded DNA of both endogenous and exogenous origins. Upon activation, cGAS synthesizes the second messenger 2'3'-cyclic GMP-AMP (cGAMP), which binds and activates STING to trigger downstream immune responses, including the production of type I interferons and proinflammatory cytokines. Emerging studies highlight the cGAS-STING pathway as a promising therapeutic target for preventing and treating diverse pathologies, with particularly transformative potential in anticancer therapies. In this review, we dissect the key findings, functions, and associated components of the cGAS-STING pathway. In addition, we emphasize the factors that upregulate or downregulate the pathway, as well as the role of the cGAS-STING pathway in health and disease. By integrating mechanistic insights with clinical perspectives, this review aims to bridge fundamental discoveries with therapeutic applications of cGAS-STING biology.
Humans ; Nucleotidyltransferases/metabolism* ; Membrane Proteins/metabolism* ; Animals ; Immunity, Innate/physiology* ; Signal Transduction/physiology* ; Neoplasms/metabolism*

This study aims to explore the effects of Buzhong Yiqi Decoction(BYD) on the cyclic guanosine monophosphate-adenosine monophosphate synthase(cGAS)-stimulator of interferon genes(STING) signaling pathway in the mouse model of autoimmune thyroiditis(AIT) and the mechanism of BYD in alleviating the immune injury. Forty-eight NOD.H-2~(h4) mice were assigned into normal, model, low-, medium-, and high-dose BYD, and selenium yeast tablets groups(n=8). Mice of 8 weeks old were treated with 0.05% sodium iodide solution for 8 weeks for the modeling of AIT and then administrated with corresponding drugs by gavage for 8 weeks before sampling. High performance liquid chromatography was employed to measure the astragaloside Ⅳ content in BYD. Hematoxylin-eosin staining was employed to observe the pathological changes in the mouse thyroid tissue. Enzyme-linked immunosorbent assay was employed to measure the serum levels of thyroid peroxidase antibody(TPO-Ab), thyroglobulin antibody(TgAb), and interferon-γ(IFN-γ). Flow cytometry was employed to detect the distribution of T cell subsets in the spleen. The immunohistochemical method was used to detect the expression of cGAS, STING, TANK-binding kinase 1(TBK1), and interferon regulatory factor 3(IRF3). Real-time PCR and Western blot were employed to determine the mRNA and protein levels, respectively, of markers related to the cGAS-STING signaling pathway in the thyroid tissue. The results showed that the content of astragaloside Ⅳ in BYD was(7.06±0.08) mg·mL~(-1). Compared with the normal group, the model group showed disrupted structures of thyroid follicular epithelial cells, massive infiltration of lymphocytes, and elevated levels of TgAb and TPO-Ab. Compared with the model group, the four treatment groups showed intact epithelial cells, reduced lymphocyte infiltration, and lowered levels of TgAb and TPO-Ab. Compared with the normal group, the model group showed increases in the proportions of Th1 and Th17 cells, a decrease in the proportion of Th2 cells, and an increase in the IFN-γ level. Compared with the model group, the four treatment groups presented decreased proportions of Th1 and Th17 cells and lowered levels of IFN-γ, and the medium-dose BYD group showed an increase in the proportion of Th2 cells. Compared with the normal group, the modeling up-regulated the mRNA levels of cGAS, STING, TBK1, and IRF3 and the protein levels of cGAS, p-STING, p-TBK1, and p-IRF3. Compared with the model group, the four treatment groups showed reduced levels of cGAS, STING, TBK1, and IRF3-positive products, down-regulated mRNA levels of cGAS, STING, and TBK1, and down-regulated protein levels of cGAS and p-STING. The high-dose BYD group showed down-regulations in the mRNA level of IRF3 and the protein levels of p-TBK1 and p-IRF3. The above results indicate that BYD can repair the imbalance of T cell subsets, alleviate immune injury, and reduce thyroid lymphocyte infiltration in AIT mice by inhibiting the cGAS-STING signaling pathway.
Animals ; Drugs, Chinese Herbal/administration & dosage* ; Signal Transduction/drug effects* ; Thyroiditis, Autoimmune/metabolism* ; Mice ; Membrane Proteins/metabolism* ; Mice, Inbred NOD ; Humans ; Female ; Nucleotidyltransferases/metabolism* ; Male ; Disease Models, Animal

Objective To investigate the effects of cucurbitacin B (CucB) on alleviating skin lesions and inflammation in psoriasis mice via the cGAS-STING signaling pathway. Methods The expression of genes associated with the cGAS-STING signaling pathway in psoriatic lesions and non-lesional skin was analyzed, and hallmark gene set enrichment analysis was performed. The cytotoxicity of CucB on BMDMs was evaluated using the CCK-8 assay. The expression levels of genes and proteins related to the cGAS-STING signaling pathway, along with the secretion of inflammatory cytokines, were measured at different concentrations of CucB using quantitative PCR, Western blotting, and ELISA. Imiquimod-induced psoriasis BALB/c mice were divided into four groups: normal group, model group, low-dose CucB group [0.1 mg/ (kg.d)], and high-dose CucB group [0.4 mg/ (kg.d)], with five mice per group. PASI scoring was performed to assess the severity of psoriasis after 6 days of treatment, and HE staining was conducted to observe pathological damage. Meanwhile, the mRNA levels of inflammatory cytokines and their secretion were detected by qPCR and ELISA. Results Most cGAS-STING signaling-related genes were upregulated in lesional skin of psoriasis patients, and the hallmark gene set enrichment analysis revealed that the most significantly upregulated genes were primarily associated with immune response signaling pathways. CucB inhibited dsDNA-induced phosphorylation of interferon regulatory factor 3 (IRF3) and STING proteins in both bone-marrow derived macrophages(BMDMs) and THP-1 cells. CucB also suppressed dsDNA-induced mRNA expression of IFNB1, TNF, IFIT1, CXCL10, ISG15, and reduced the secretion of cytokines such as IFN-β, IL-1β, and TNF-α in THP-1 cells. In the imiquimod-induced psoriasis mouse model, CucB treatment reduced psoriatic symptoms, alleviated skin lesions, and attenuated inflammation. ELISA and qPCR results showed that CucB significantly reduced serum secretion levels of IL-6, TNF-α, and IL-1β, as well as the mRNA levels of IL23A, IL1B, IL6, TNF, and IFNB1. Conclusion CucB inhibits cytoplasmic DNA-induced activationc of the GAS-STING pathway. CucB significantly attenuates skin lesions and inflammation in IMQ-induced psoriatic mice, and the potential molecular mechanism may be related to the down-regulation of the cGAS-STING pathway.
Animals ; Psoriasis/pathology* ; Signal Transduction/drug effects* ; Membrane Proteins/genetics* ; Mice ; Nucleotidyltransferases/genetics* ; Disease Models, Animal ; Mice, Inbred BALB C ; Skin/metabolism* ; Triterpenes/therapeutic use* ; Humans ; Cytokines/metabolism* ; Inflammation/drug therapy* ; Male

Virus-induced senescence (VIS) is a significant biological phenomenon, which is associated with declining immune function, accelerating aging process and causing aging-related diseases. A variety of common viruses, including RNA viruses (such as SARS-CoV-2), DNA viruses (such as herpesviruses and hepatitis B virus), and prions can cause VIS in host cells. The primary mechanisms include abnormal activation of the cGAS-STING signaling pathway, DNA damage response, and potential correlations with the integrated stress response due to intracellular phase separation. Viral infection and cellular senescence influence each other: cellular senescence serves as a defense to restrict viral replication and transmission, while some viruses exploit cellular senescence to enhance their infectivity and replication. Understanding the mechanisms of VIS is conducive to the development of therapeutic strategies for viral infections and promotion of healthy aging. However, there is lack of research on therapeutic targets and drug development in this field so far. Although senolytics may be effective for anti-senescent cells therapy, their efficacy for VIS needs evidence from further clinical trials. This article reviews the research progress on the connection between viral infection and cellular senescence, to provide insights for the prevention and treatment of aging related diseases.
Humans ; Cellular Senescence/physiology* ; Virus Diseases/physiopathology* ; Signal Transduction ; Nucleotidyltransferases/metabolism* ; DNA Damage ; Virus Replication ; COVID-19 ; Membrane Proteins/metabolism* ; SARS-CoV-2

Although cisplatin is a widely used chemotherapeutic agent, it is severely toxic and causes irreversible hearing loss, restricting its application in clinical settings. This study aimed to determine the molecular mechanism underlying cisplatin-induced ototoxicity. Here, we established in vitro and in vivo ototoxicity models of cisplatin-induced hair cell loss, and our results showed that reducing STING levels decreased inflammatory factor expression and hair cell death. In addition, we found that cisplatin-induced mitochondrial dysfunction was accompanied by cytosolic DNA, which may act as a critical linker between the cyclic GMP-AMP synthesis-stimulator of interferon genes (cGAS-STING) pathway and the pathogenesis of cisplatin-induced hearing loss. H-151, a specific inhibitor of STING, reduced hair cell damage and ameliorated the hearing loss caused by cisplatin in vivo. This study underscores the role of cGAS-STING in cisplatin ototoxicity and presents H-151 as a promising therapeutic for hearing loss.
Cisplatin/toxicity* ; Animals ; Nucleotidyltransferases/antagonists & inhibitors* ; Membrane Proteins/antagonists & inhibitors* ; Signal Transduction/drug effects* ; Mice ; Hair Cells, Auditory, Inner/pathology* ; Antineoplastic Agents/toxicity* ; Mice, Inbred C57BL ; Hearing Loss/metabolism* ; Male ; Ototoxicity/metabolism*

OBJECTIVE: To investigate the role and mechanism of the cyclic guanosine monophosphate-adenosine monophosphate synthase/stimulator of interferon gene (cGAS/STING) pathway in oleic acid-induced acute lung injury (ALI) in mice. METHODS: Male wild-type C57BL/6J mice were randomly divided into five groups (each n = 10): normal control group, ALI model group, and 5, 50, 500 μg/kg inhibitor pretreatment groups. The ALI model was established by tail vein injection of oleic acid (7 mL/kg), while the normal control group received no intervention. The inhibitor pretreatment groups were intraperitoneally injected with the corresponding doses of cGAS inhibitor RU.521 respectively 1 hour before modeling. At 24 hours post-modeling, blood was collected, and mice were sacrificed. Lung tissue pathological changes were observed under light microscopy after hematoxylin-eosin (HE) staining, and pathological scores were assessed. Western blotting was used to detect the protein expressions of cGAS, STING, phosphorylated TANK-binding kinase 1 (p-TBK1), phosphorylated interferon regulatory factor 3 (p-IRF3), and phosphorylated nuclear factor-κB p65 (p-NF-κB p65) in lung tissue. Immunohistochemistry was performed to observe STING and p-NF-κB positive expressions in lung tissue. Serum interferon-β (IFN-β) levels were measured by enzyme-linked immunosorbent assay (ELISA). RESULTS: Compared with the normal control group, the ALI model group exhibited significant focal alveolar thickening, intra-alveolar hemorrhage, pulmonary capillary congestion, and neutrophil infiltration in the pulmonary interstitium and alveoli, along with markedly increased pathological scores (10.33±0.58 vs. 1.33±0.58, P < 0.05). Protein expressions of cGAS, STING, p-TBK1, p-IRF3, and p-NF-κB p65 in lung tissue significantly increased [cGAS protein (cGAS/β-actin): 1.24±0.02 vs. 0.56±0.02, STING protein (STING/β-actin): 1.27±0.01 vs. 0.55±0.01, p-TBK1 protin (p-TBK1/β-actin): 1.34±0.03 vs. 0.22±0.01, p-IRF3 protein (p-IRF3/β-actin): 1.23±0.02 vs. 0.36±0.01, p-NF-κB p65 protein (p-NF-κB p65/β-actin): 1.30±0.02 vs. 0.53±0.02, all P < 0.05], positive expressions of STING and p-NF-κB in lung tissue were significantly elevated [STING (A value): 0.51±0.03 vs. 0.30±0.07, p-NF-κB (A value): 0.57±0.05 vs. 0.31±0.03, both P < 0.05], and serum IFN-β levels were also significantly higher (ng/L: 256.02±3.84 vs. 64.15±1.17, P < 0.05). The cGAS inhibitor pretreatment groups showed restored alveolar structural integrity, reduced inflammatory cell infiltration, and decreased hemorrhage area, along with dose-dependent lower pathological scores as well as the protein expressions of cGAS, STING, p-TBK1, p-IRF3 and p-NF-κB p65 in lung tissue, with significant differences between the 500 μg/kg inhibitor group and ALI model group [pathological score: 2.67±0.58 vs. 10.33±0.58, cGAS protein (cGAS/β-actin): 0.56±0.03 vs. 1.24±0.02, STING protein (STING/β-actin): 0.67±0.03 vs. 1.27±0.01, p-TBK1 protein (p-TBK1/β-actin): 0.28±0.01 vs. 1.34±0.03, p-IRF3 protein (p-IRF3/β-actin): 0.32±0.01 vs. 1.23±0.02, p-NF-κB p65 protein (p-NF-κB p65/β-actin): 0.63±0.01 vs. 1.30±0.02, all P < 0.05]. Compared with the ALI model group, positive expressions of STING and p-NF-κB in lung tissue were significantly reduced in the 500 μg/kg inhibitor group [STING (A value): 0.40±0.01 vs. 0.51±0.03, p-NF-κB (A value): 0.43±0.02 vs. 0.57±0.05, both P < 0.05], and serum IFN-β levels were also markedly reduced (ng/L: 150.03±6.19 vs. 256.02±3.84, P < 0.05). CONCLUSIONS The cGAS/STING pathway is activated in oleic acid-induced ALI, leading to exacerbated inflammatory responses and increased lung damage. RU.521 can inhibit cGAS, thereby down-regulating the expression of pathway proteins and cytokines, and providing protection to lung tissue.
Animals ; Acute Lung Injury/chemically induced* ; Male ; Nucleotidyltransferases/metabolism* ; Mice ; Signal Transduction ; Mice, Inbred C57BL ; Membrane Proteins/metabolism* ; Oleic Acid/adverse effects* ; Transcription Factor RelA/metabolism* ; Lung/pathology* ; Interferon Regulatory Factor-3/metabolism* ; Disease Models, Animal

OBJECTIVES: This study aims to explore the potential relationships of cell-free DNA (cfDNA) in gingival crevicular fluid (GCF) with periodontal clinical indicators and the expression of DNA receptor pathway cyclic guanosine phosphate-adenosine phosphate synthase (cGAS)-stimulator of interferon genes (STING) in gingival tissues and human gingival fibroblasts (HGFs). METHODS: GCF and gingival tissue samples were collected from periodontally healthy individuals and patients diagnosed with periodontitis. Periodontal clinical indicators were recorded, including plaque index (PLT), bleeding index (BI), probing depth (PD), and clinical attachment level (CAL). The concentration of cfDNA in GCF was quantified, and the correlation between GCF and periodontal clinical indicators was analyzed. Immunofluorescence and reverse transcription-quantitative polymerase chain reaction (RT-qPCR) were used to assess the distribution of cGAS, STING, and p-STING in gingival tissues. Additionally, the mRNA expression levels of the key components of the cGAS-STING signaling pathway, namely, cGAS, STING, inhibitory of kappa-B kinase (IKK), nuclear factor kappa-B p65 (NF-κB p65), interleukin (IL)-1β, IL-6, and tumor necrosis factor-α (TNF-α), were measured. Furthermore, cfDNA extracted from GCF was employed to stimulate HGFs in the healthy control and periodontitis groups, and the mRNA expression levels of the key molecules of cGAS-STING signaling pathway were detected through Western blot and RT-qPCR. RESULTS: The concentration of cfDNA in GCF was found to be significantly elevated in the periodontitis group compared with the control group. Moreover, cfDNA concentration demonstrated a strong positive correlation with the periodontal clinical indicators. Immunofluorescence analysis revealed considerably increased percentage of fluorescence co-localization of cGAS, STING, and p-STING with the gingival fibroblast FSP-1 marker in the gingival tissues of the periodontitis group. The mRNA expression levels of cGAS, STING, IKK, NF-κB p65, IL-1β, IL-6,and TNF-α were significantly higher in the periodontitis group. In vitro stimulation of HGFs with GCF-derived cfDNA resulted in increased protein expression of cGAS and p-STING and considerably upregulated the mRNA expression levels of cGAS, STING, IKK, NF-κB p65, IL-1β, IL-6, and TNF-α in the healthy and periodontitis groups compared with the blank group. Correlation analysis showed that the concentration of cfDNA at the sampling site was positively correlated with the mRNA expression levels of cGAS, STING, NF-κB p65, and IL-6 in gingival tissues. CONCLUSIONS cfDNA concentrations in the GCF of patients with periodontitis are considerably elevated, and are associated with the activation of the cGAS-STING signaling pathway in HGFs. These findings suggest that cfDNA contributes to the progression of periodontitis.
Humans ; Gingival Crevicular Fluid/metabolism* ; Signal Transduction ; Gingiva/cytology* ; Nucleotidyltransferases/genetics* ; Membrane Proteins/genetics* ; Cell-Free Nucleic Acids/analysis* ; Fibroblasts/metabolism* ; Tumor Necrosis Factor-alpha/metabolism* ; Periodontitis/metabolism* ; Interleukin-1beta/metabolism* ; Interleukin-6/metabolism* ; Adult ; RNA, Messenger/metabolism* ; Male ; Female

OBJECTIVES: To explore the role of the cGAS-STING signaling pathway in the therapeutic mechanism of Liangxue Jiedu Huayu Formula (LXJDHYF) for acute-on-chronic liver failure (ACLF) in mice. METHODS: Thirty C57BL/6 mice were randomly divided into blank control group, model group, low- and high-dose LXJDHYF groups, and H151 (a specific cGAS-STING pathway inhibitor) group (n=6). In all but the control group, the mice were treated with CCl₄ to induce liver cirrhosis followed by intraperitoneal injections of lipopolysaccharide and D-amino galactose to establish mouse models of ACLF. After the treatments, the mouse livers were collected for HE and TUNEL staining, and serum levels of ALT, AST and TBil were determined. In bone marrow-derived macrophages (BMDMs) and liver tissues of ACLF mice, the expressions of cGAS-STING signaling pathway-related mRNAs including IFN‑β, ISG15, IL-6 and TNF-α were determined with RT-qPCR, and the phosphorylation levels of IRF3 and STING proteins were investigated using Western blotting. RESULTS: Compared with the mice in the model group, the LXJDHYF-treated mice exhibited milder hepatocyte necrosis and inflammatory cell infiltration in the liver with significantly reduced hepatocyte apoptosis. LXJDHYF treatment also significantly lowered serum levels of ALT, AST, TBil, IL-6 and TNF-α in ACLF mice and effectively suppressed the expressions of cGAS-STING signaling pathway-related mRNA in both the BMDMs and the liver tissues and the phosphorylation of IRF3 and STING proteins in the BMDMs. CONCLUSIONS LXJDHYF can significantly improve liver function and attenuate inflammation in ACLF mice possibly by inhibiting excessive activation of the cGAS-STING signaling pathway.
Animals ; Signal Transduction/drug effects* ; Mice ; Nucleotidyltransferases/metabolism* ; Mice, Inbred C57BL ; Acute-On-Chronic Liver Failure/etiology* ; Membrane Proteins/metabolism* ; Drugs, Chinese Herbal/therapeutic use* ; Liver/metabolism* ; Disease Models, Animal ; Interferon Regulatory Factor-3/metabolism* ; Interleukin-6/metabolism* ; Male

This study aimed to explore the mechanism of how African swine fever virus (ASFV) I226R protein inhibits the cGAS-STING signaling pathway. We observed that I226R protein (pI226R) significantly inhibited the cGAS-STING-mediated type Ⅰ interferons and the interferon-stimulated genes production by dual-luciferase reporter assay system and real-time quantitative PCR. The results of co-immunoprecipitation assay and confocal microscopy showed that pI226R interacted with cGAS. Furthermore, pI226R promoted cGAS degradation through autophagy-lysosome pathway. Moreover, we found that pI226R decreased the binding of cGAS to E3 ligase tripartite motif protein 56 (TRIM56), resulting in the weakened monoubiquitination of cGAS, thus inhibiting the activation of cGAS and cGAS-STING signaling. In conclusion, ASFV pI226R suppresses the antiviral innate immune response by antagonizing cGAS, which contributes to an in-depth understanding of the immune escape mechanism of ASFV and provides a theoretical basis for the development of vaccines.
Animals ; Swine ; African Swine Fever Virus/metabolism* ; Membrane Proteins/metabolism* ; Immunity, Innate ; Nucleotidyltransferases/metabolism* ; Signal Transduction/genetics*

As a DNA receptor in the cytoplasm,cyclic GMP-AMP synthase (cGAS) can recognize abnormal DNA in the cytoplasm and activate stimulator of interferon genes (STING) to regulate the immune response. The recent studies have demonstrated that this pathway plays a role in non-infectious inflammatory diseases by promoting the expression of type Ⅰ interferon and interferon-stimulated gene.This article reviews the activation and regulation of cGAS-STING pathway in multiple systems and the effect of this pathway on the occurrence and progression of non-infectious inflammatory diseases,providing theoretical reference for future application of cGAS-STING pathway-related drugs in non-infectious inflammatory diseases.
Humans ; Interferons ; Membrane Proteins/metabolism* ; Noncommunicable Diseases ; Nucleotides, Cyclic ; Nucleotidyltransferases/metabolism* ; Signal Transduction