Recent progress on cGAS-STING pathway in tumor radiotherapy / 中华放射肿瘤学杂志

Radiotherapy is widely used in the treatment of primary and metastatic malignant tumors. It is traditionally believed that the killing effect of radiotherapy on tumor is based on the direct or indirect damage of ionizing radiation to DNA. In recent years, the anti-tumor role and mechanism of anti-tumor immune response induced by ionizing radiation have captivated widespread attention and achieved significant progress. Among them, Cyclic GMP-AMP synthase (cGAS)-stimulator of interference genes (STING) pathway is considered to be one of the key regulatory hubs. cGAS is a cytoplasmic DNA receptor that can bind to tumor-derived double-stranded DNA and activate the downstream STING, thereby activating anti-tumor immune response of the host. In view of the latest progress in this field, the important role and potential mechanism of cGAS-STING pathway in radiotherapy immune effect were mainly summarized, and the application prospect of targeting cGAS-STING pathway in radiotherapy sensitization was explored.

Tetrahydroxy stilbene glycoside ameliorates neuroin-flammation for Alzheimer's disease via cGAS-STING / 中国药理学与毒理学杂志

OBJECTIVE Alzheimer's disease(AD)is the most common neurodegenerative disease worldwide.Neuroinflammation is a potential target for the patients with AD.It is attributed to activated microglia and the release of various inflammatory mediators from infec-tion,ischemia and toxin accumulation.Accumulating evi-dence has indicated that the cGAS-STING pathway driven neuroinflammation in neurological disease.TSG is a main natural active ingredient that derived from polyg-onum multiflorum.Previous research from our group found that TSG has beneficial effects of anti-aging,anti-inflammatory action and improving memory function in APP/PS1 transgenic AD mice.Here,we investigated the effects of TSG on cognitive impairment and neuroinflam-mation in APP/PS1-AD mice and explore the underly-ing mechanism by which TSG ameliorates memory func-tion in the cGAS-STING-mediated inflammatory response.METHODS The Morris water mace test and the novel object recognition test were performed to test the effects of TSG on spatial learning and cognitive and memory abil-ity in APP/PS1 double transgenic AD mice model.In addi-tion,real-time quantitative PCR,Western blotting,ELISA analysis,and flow cytometry to examine gene and pro-tein expression of cGAS-STING related pro-inflammatory cytokines and chemokines.Statistical analyses were ana-lyzed using the SPSS 25.0 package by analysis of vari-ance(ANOVA).Neuman-Keuls or Tukey's multiple-com-parisons test were conducted as ANOVA justified post hoc comparisons between group means.RESULTS We demonstrated that AD transgenic mice exhibited cognitive deficits accompanied by the elevated serum and brain inflammation.The expressions of serum inflammatory cytokines and the activation of microglia in cerebral cor-tex and hippocampus were suppressed after TSG treat-ment,which was probably attributable to the decrease of cyclic GMP-AMP synthase(cGAS)and stimulator of interferon genes(STING)triggered immune response.Additionally,the data showed that TSG treatment reduced the expression level of inflammatory cytokines(IL-1β,TNF-α,IFN-β,IFN-α)in microglial cells BV2 primed with LPS and IFN-γ.CONCLUSION TSG implicated the health benefits in preventing cognitive disorders by inhib-iting neuroinflammation via cGAS-STING signalling path-way in AD.

Phase separation in cGAS-STING signaling / 医学前沿

Biomolecular condensates formed by phase separation are widespread and play critical roles in many physiological and pathological processes. cGAS-STING signaling functions to detect aberrant DNA signals to initiate anti-infection defense and antitumor immunity. At the same time, cGAS-STING signaling must be carefully regulated to maintain immune homeostasis. Interestingly, exciting recent studies have reported that biomolecular phase separation exists and plays important roles in different steps of cGAS-STING signaling, including cGAS condensates, STING condensates, and IRF3 condensates. In addition, several intracellular and extracellular factors have been proposed to modulate the condensates in cGAS-STING signaling. These studies reveal novel activation and regulation mechanisms of cGAS-STING signaling and provide new opportunities for drug discovery. Here, we summarize recent advances in the phase separation of cGAS-STING signaling and the development of potential drugs targeting these innate immune condensates.

Prospective insight into the role of benzyl propylene glycoside as a modulator of the cGAS-STING signaling pathway in the management of nonalcoholic fatty pancreas animal model

BACKGROUND: Nonalcoholic fatty pancreatitis (NAFP) is one of the metabolic syndrome manifestations that need further studies to determine its molecular determinants and find effective medications. We aimed to investigate the potential effect of benzyl propylene glycoside on NAFP management via targeting the pancreatic cGAS-STING pathway-related genes (DDX58, NFκB1 & CHUK) and their upstream regulator miRNA (miR-1976) that were retrieved from bioinformatics analysis. METHODS: The rats were fed either normal chow or a high-fat high-sucrose diet (HFHS), as a nutritional model for NAFP. After 8 weeks, the HFHS-fed rats were subdivided randomly into 4 groups; untreated HFHS group (NAFP model group) and three treated groups which received 3 doses of benzyl propylene glycoside (10, 20, and 30 mg/kg) daily for 4 weeks, parallel with HFHS feeding. RESULTS: The molecular analysis revealed that benzyl propylene glycoside could modulate the expression of the pancreatic cGAS-STING pathway-related through the downregulation of the expression of DDX58, NFκB1, and CHUK mRNAs and upregulation of miR-1976 expression. Moreover, the applied treatment reversed insulin resistance, inflammation, and fibrosis observed in the untreated NAFP group, as evidenced by improved lipid panel, decreased body weight and the serum level of lipase and amylase, reduced protein levels of NFκB1 and caspase-3 with a significant reduction in area % of collagen fibers in the pancreatic sections of treated animals. CONCLUSION: benzyl propylene glycoside showed a potential ability to attenuate NAFP development, inhibit pancreatic inflammation and fibrosis and reduce the pathological and metabolic disturbances monitored in the applied NAFP animal model. The detected effect was correlated with modulation of the expression of pancreatic (DDX58, NFκB1, and CHUK mRNAs and miR-1976) panel.

Research progress of novel drug delivery system for STING agonist / 中国药理学通报

Stimulator of interferon genes(STING)is a key protein in cGAS-STING signaling pathway and plays an important role in immune response mediated by the exogenous or endogenous DNA.This review describes the biological function of STING, the process of cGAS-STING pathway, the classification and administration of STING agonists, and summarizes the currently reported drug delivery systems.The delivery of STING agonists through appropriate drug carriers can overcome the lack of difficult entry, easy enzymatic hydrolysis, short half-life and poor targeting, improve the body's innate and adaptive immunity, and enhance the therapeutic effect of drugs.In conclusion, this paper mainly reviews the research progress of drug delivery system for STING agonists to provide basis for the development of drug delivery system and promote the clinical transformation and application of STING agonists.

Research advances on stimulator of interferon genes (STING) and its agonists / 药学学报

As a key signal transduction molecule involved in the innate immune response, stimulator of interferon genes (STING) is triggered by cytosolic DNA from pathogen and host origins, and plays an important role in inducing the secretion of type I interferons and proinflammatory cytokines, thereby defending against viral and intracellular bacterial infections and regulating the production of spontaneous antitumor immune responses in vivo. Thus, STING agonists have shown useful therapeutic effects for pathogen infection and cancer. In the past decade research on STING and its agonists has progressed rapidly. Here, we summarize recent advances in the structure and activation of STING and the mechanism of the cGAS-STING pathway. In particular, we review research advances of STING agonists, analyze the crystal structure of STING in complex with its agonists and the structure-activity relationship of STING agonists, and summarize the strong challenges of developing STING agonists.

cGAS-STING signaling pathway and diseases / 国际生物医学工程杂志

The cGAS-STING pathway plays a significant role in host defense against viral and bacterial infection.In the process,the cytoplasmic free DNA,considered as a danger signal,is recognized by nucleotidyl transferase cGAS.cGAS is activated by double-stranded DNA (dsDNA) and catalyzes the synthesis of a noncanonical cyclic dinucleotide 2'5'-cGAMP from adenosine triphosphate (ATP) and guanosine triphosphate (GTP).cGAMP serve as an endogenous second messenger to stimulate the induction of type Ⅰ interferons via STING.In addition to the exogenous bacterial or viral DNA,abnormal deposition of host DNA in cytosol also activates the cGAS-STING signaling pathway cascade,resulting in inflammation and autoimmune diseases.Subsequent studies found that this pathway also plays an important role in tumor's responsiveness to radio-therapy and chemo-therapy.Activation of cGAS-STING pathway produces or enhances the therapeutic efficacy.These findings suggest that specifically interfering with cGAS-STING activation may hold therapeutic value for the treatment of cancer,infection and inflammatory diseases.In this paper,the activation mechanism of cGAS-STING pathway and its relationship with the treatment of diseases were summarized,and the regulation of cGAS-STING pathway was introduced in detail.