1.cGAS: Its Canonical and Non-canonical Functions
Wen-Xian ZHENG ; Meng-Jie XIONG ; Shu-Ting JIA ; Ruo-Yu ZHOU
Progress in Biochemistry and Biophysics 2026;53(5):1279-1296
Cyclic GMP-AMP synthase (cGAS), a pivotal molecule in innate immunity, has emerged as a keypoint in interdisciplinary research at the intersection of basic immunology and tumor biology. As a cytosolic nucleic acid sensor, cGAS is primarily characterized by its capacity to recognize double-stranded DNA (dsDNA) in the cytosol. Upon binding to dsDNA, cGAS undergoes a conformational change that promotes its dimerization and subsequent enzymatic activation. Once activated, it catalyzes the synthesis of the second messenger 2',3'-cGAMP from ATP and GTP. cGAMP then binds to the adaptor protein STING, which resides on the endoplasmic reticulum (ER) membrane. The binding process triggers STING to traffic from the ER to the Golgi apparatus, where it is phosphorylated by the kinase TBK1. Phosphorylated STING serves as a docking site for the transcription factor IRF3, facilitating its phosphorylation by TBK1. Once phosphorylated, IRF3 forms dimers and translocates to the nucleus, where it drives the expression of type I interferons and pro-inflammatory cytokines, initiating a potent antimicrobial state. The DNA-sensing mechanism of cGAS is inherently non-selective regarding the origin of its ligand. It readily detects exogenous DNA from invading pathogens, thereby playing an indispensable role in host defense against microbial infections. However, this same mechanism also enables cGAS to recognize self-DNA that leaks from the nucleus or mitochondria into the cytosol under various cellular stress conditions. While critical for immunity, the recognition of self-dsDNA by cGAS can disrupt cellular homeostasis and trigger aberrant inflammatory responses. The loss of self-tolerance can precipitate or exacerbate the pathogenesis of autoimmune disorders such as systemic lupus erythematosus (SLE) and Aicardi-Goutières syndrome (AGS), highlighting the dual role of cGAS as both a sentinel for infection and a potential driver of autoimmune pathology. Notably, the subcellular localization of cGAS is not still. Increasing recent researches have revealed that cGAS is also abundant within the nucleus, challenging the traditional view of it solely as a cytosolic nucleic acid sensor. Within the nucleus, cGAS exhibits non-canonical functions that are distinct from its canonical immunological role. First, cGAS exists in a state of stringent immunological silence in the nucleus, with mechanisms involving its competitive binding to histones and its post-translational modifications which block the activation of cGAS enzymatic activity, thus, effectively preventing it from mounting an autoimmune attack on genomic DNA. Second, cGAS plays a critical role in maintaining genomic stability. Upon DNA damage, cGAS is rapidly recruited to the lesion site and participates in the DNA damage repair process. Moreover, under conditions of DNA replication stress, cGAS contributes to the stabilization of replication forks, preventing the cell from entering a state of uncontrolled hyper-replication. Consequently, in light of the dual role of cGAS in both immune regulation and tumor development, the development of small-molecule drugs targeting cGAS holds significant therapeutic promise. This review summarizes the structural characteristics of cGAS and its canonical function as a pattern recognition receptor in the cytosol, including the types of pathogens it recognizes and the autoimmune responses resulting from erroneous recognition of self-DNA. It then focuses on its emerging non-canonical functions within the nucleus, detailing its nucleocytoplasmic shuttling, the mechanisms underlying its nuclear immune quiescence, and its role in mediating DNA damage repair and replication fork stabilization. Finally, the review discusses the progress and application prospects of small-molecule drugs targeting cGAS for the treatment of autoimmune diseases and cancer.
2.cGAS: Its Canonical and Non-canonical Functions
Wen-Xian ZHENG ; Meng-Jie XIONG ; Shu-Ting JIA ; Ruo-Yu ZHOU
Progress in Biochemistry and Biophysics 2026;53(5):1279-1296
Cyclic GMP-AMP synthase (cGAS), a pivotal molecule in innate immunity, has emerged as a keypoint in interdisciplinary research at the intersection of basic immunology and tumor biology. As a cytosolic nucleic acid sensor, cGAS is primarily characterized by its capacity to recognize double-stranded DNA (dsDNA) in the cytosol. Upon binding to dsDNA, cGAS undergoes a conformational change that promotes its dimerization and subsequent enzymatic activation. Once activated, it catalyzes the synthesis of the second messenger 2',3'-cGAMP from ATP and GTP. cGAMP then binds to the adaptor protein STING, which resides on the endoplasmic reticulum (ER) membrane. The binding process triggers STING to traffic from the ER to the Golgi apparatus, where it is phosphorylated by the kinase TBK1. Phosphorylated STING serves as a docking site for the transcription factor IRF3, facilitating its phosphorylation by TBK1. Once phosphorylated, IRF3 forms dimers and translocates to the nucleus, where it drives the expression of type I interferons and pro-inflammatory cytokines, initiating a potent antimicrobial state. The DNA-sensing mechanism of cGAS is inherently non-selective regarding the origin of its ligand. It readily detects exogenous DNA from invading pathogens, thereby playing an indispensable role in host defense against microbial infections. However, this same mechanism also enables cGAS to recognize self-DNA that leaks from the nucleus or mitochondria into the cytosol under various cellular stress conditions. While critical for immunity, the recognition of self-dsDNA by cGAS can disrupt cellular homeostasis and trigger aberrant inflammatory responses. The loss of self-tolerance can precipitate or exacerbate the pathogenesis of autoimmune disorders such as systemic lupus erythematosus (SLE) and Aicardi-Goutières syndrome (AGS), highlighting the dual role of cGAS as both a sentinel for infection and a potential driver of autoimmune pathology. Notably, the subcellular localization of cGAS is not still. Increasing recent researches have revealed that cGAS is also abundant within the nucleus, challenging the traditional view of it solely as a cytosolic nucleic acid sensor. Within the nucleus, cGAS exhibits non-canonical functions that are distinct from its canonical immunological role. First, cGAS exists in a state of stringent immunological silence in the nucleus, with mechanisms involving its competitive binding to histones and its post-translational modifications which block the activation of cGAS enzymatic activity, thus, effectively preventing it from mounting an autoimmune attack on genomic DNA. Second, cGAS plays a critical role in maintaining genomic stability. Upon DNA damage, cGAS is rapidly recruited to the lesion site and participates in the DNA damage repair process. Moreover, under conditions of DNA replication stress, cGAS contributes to the stabilization of replication forks, preventing the cell from entering a state of uncontrolled hyper-replication. Consequently, in light of the dual role of cGAS in both immune regulation and tumor development, the development of small-molecule drugs targeting cGAS holds significant therapeutic promise. This review summarizes the structural characteristics of cGAS and its canonical function as a pattern recognition receptor in the cytosol, including the types of pathogens it recognizes and the autoimmune responses resulting from erroneous recognition of self-DNA. It then focuses on its emerging non-canonical functions within the nucleus, detailing its nucleocytoplasmic shuttling, the mechanisms underlying its nuclear immune quiescence, and its role in mediating DNA damage repair and replication fork stabilization. Finally, the review discusses the progress and application prospects of small-molecule drugs targeting cGAS for the treatment of autoimmune diseases and cancer.
3.Association and potential toxicity analysis of butyl benzyl phthalate with pulmonary fibrosis
Xinbei ZHOU ; Ningjuan LIANG ; Ting WU ; Dandan YU ; Xiaohan JIANG ; Jingjing TENG
China Modern Doctor 2025;63(19):6-11
Objective To explore the significance of the toxicity mechanism of butyl benzyl phthalate(BBP)in prevention and treatment of pulmonary fibrosis.Methods In this study,we used network toxicology combined with molecular docking technology to screen the targets of BBP and those related to pulmonary fibrosis through PubChem,GeneCards and other databases,and analyzed the intersecting genes by using a Wayne diagram.Protein-protein interaction networks were constructed to screen the core targets,and the pathway mechanisms were revealed by Gene Ontology and Kyoto Encyclopedia of Genes and Genomes.Finally,molecular docking using AutoDock was performed to verify the binding patterns of core targets and BBP.Results A total of 91 potential targets of BBP-induced lung fibrosis were screened,among which PTGS2 and CYP3A4 were the core targets(binding energies of-1.84 kcal/mol and-1.68 kcal/mol,respectively).Enrichment analysis showed that BBP regulated the fibrosis process through G protein-coupled receptor signaling pathway,calcium signaling pathway and cyclic adenosine monophosphate signaling pathway.Molecular docking confirmed that BBP was stably bound to the core target through hydrogen bonding and hydrophobic interaction.Conclusion This study provides preliminary insights into the molecular mechanism of BBP-induced pulmonary fibrosis through network toxicology,and PTGS2 and CYP3A4 may play key roles in BBP-induced pulmonary fibrosis,which provides a novel reference for the exploration of the mechanism of toxicant-disease association.
4.In vivo production of anti-CD19 CAR-T cells with T cell-targeted engineered exosomes to evaluate cytotoxicity against lymphoma cells
Dong TING ; Zhou YING ; Yu BOYU ; Xia XUEJIAO ; Ma YIGE ; Ma YAN ; Gao YANG ; Zhou MENGYING ; Wang CHANGJUN ; Li QIUYI ; Gu CHAOJIANG
Chinese Journal of Clinical Oncology 2025;52(6):279-286
Objective:Chimeric antigen receptor T-cell(CAR-T)immunotherapy has made major breakthroughs in the treatment of blood tu-mors.However,current CAR-T therapies face several limitations:they require autologous cells,involve a lengthy and costly production pro-cess,and use lentiviral transduction that carry risk of insertional carcinogenesis due to random integration.Therefore,there is an urgent need to develop a universal cost-effective cancer immunotherapy method generating CAR-T cells for in vivo cancer immunotherapy.Meth-ods:This study successfully established an exosome-mediated,T-cell targeted delivery system,demonstrating both precise design and func-tional efficacy for biomedical applications.To optimize CAR-T cell generation the transfection dose was adjusted,and the kinetics of CAR-T cell percentage were recorded.The cytotoxicity of the resulting CAR-T cells was evaluated in vitro by calcein-AM release.To test the tumor-killing in vivo of engineered exosomes,human PBMCs were injected into NPG mice via the tail vein to establish humanized mice,followed by intravenous injection of tumor cells to induce cancer.Results:To overcome the limitations of conditional autologous CAR-T cells,we de-veloped a T cell-targeted exosome system capable of specifically targeting human CD3+,CD4+,and CD8+T cells.CAR-T production was dose-dependent,with transfection efficiency reaching upto 97.8%at 106 particles/cell.Both in vitro cytotoxicity assays and in vivo animal experi-ments demonstrated that exosome-incubated CAR-T cells effectively eliminated CD19-positive Raji cells,highlighting their specificity and therapeutic potential in antigen-directed applications.Conclusions:We successfully established a CD8-targeting exosome delivery system for CAR-T cell production capable of transforming CD8+T cells into functional CAR-T cells,which showed significant tumor-killing ability in vitro and in mice.Compared with the traditional lentiviral vector for the preparation of CAR-T cells in vitro,in vivo-reprogrammed CAR-T cells us-ing our CD8-targeted exosome delivery system,with higher transfection efficiency,shorter production period,lower cost,and eliminated the risk of insertion carcinogenesis.This strategy promises to bring a new era of universal CAR-T medicine,which can improve cancer immuno-therapy and may hold promise as a therapeutic platform to treat various diseases.
5.Study on the correlation between urinary calcium levels and severity and prognosis of chronic kidney disease
Qiongjing YUAN ; Yanyun XIE ; Jinwei WANG ; Zhangzhe PENG ; Pan YU ; Ting MENG ; Ling HUANG ; Wei WANG ; Xiaozhao LI ; Hanwei HUANG ; Fang WANG ; Bixia GAO ; Minghui ZHAO ; Qiaoling ZHOU ; Luxia ZHANG ; Hui XU
Chinese Journal of Epidemiology 2025;46(2):264-272
Objective:To analyze the relationship between 24-hour urinary calcium (24 h UCa) level and the risk of end-stage kidney disease (ESKD), cardiovascular disease (CVD), and all-cause mortality.Methods:In the Chinese Cohort Study of Chronic Kidney Disease, we examined 3 375 patients aged 18-74 years with CKD stages 1-4. Kaplan-Meier survival and Cox proportional hazard regression models were used to test a time-to-event association between levels of 24 h UCa and incidence of ESKD, CVD, and all-cause mortality.Results:During a follow-up of 4.17 (3.37, 5.20) years, 179, 145, 104 and 38 ESKD events occurred in <0.60, 0.60-, 1.20-, ≥2.32 mmol 24 h UCa groups. Higher levels of 24 h UCa (1.20-,≥2.32 mmol) were independently associated with a lower incidence of ESKD events in patients with CKD, with HR (95% CI) of 0.71 (0.54-0.93) and 0.43 (0.29-0.64), respectively. No significant associations with CVD and all-cause mortality endpoints were detected. Conclusion:Among patients with CKD, levels of 24 h UCa displayed an association with the risk of ESKD among patients with CKD stages 1-4.
6.Effects of evidence-based nursing combined with multi-dimensional health education on negative emotions and postoperative rehabilitation of patients undergoing elective surgery for choleystolithiasis
Ting YU ; Zhen WU ; Wenjing GAO ; Ye HE ; Zhigang ZHOU
Journal of Navy Medicine 2025;46(10):1052-1057
Objective To explore the effects of evidence-based nursing combined with multi-dimensional health education on negative emotions and postoperative rehabilitation of patients undergoing elective surgery for cholecystolithiasis.Methods A total of 100 patients with cholecystolithiasis who underwent elective surgery in Yixing Traditional Chinese Hospital Medicine from September 2023 to August 2024 were selected.The patients were assigned to control group and observation group by PEMS3.1 for Windows completely random(two groups and multiple groups)program,with 50 cases in each group.The control group received routine nursing,and the observation group received evidence-based nursing combined with multidimensional health education on the basis of routine nursing.The intervention duration of the two groups was 7 days.Visual analogue scale(VAS)scores,negative emotions(self-rating anxiety scale[SAS]and self-rating depression scale[SDS]),postoperative complications,and postoperative rehabilitation were compared between the two groups.Results The VAS scores at 24 h and 72 h after surgery were lower than those at 6 h after surgery in both groups,especially in the observation group(P<0.05).The scores of SAS and SDS in both groups after intervention were significantly decreased compared with those before intervention,and the scores of negative emotions in the observation group after intervention were significantly lower than those in the control group(P<0.05).The total incidence of gastrointestinal discomfort,biliary fistula and wound infection/bleeding in the observation group was significantly lower than that in the control group(4.00%vs.18.00%,P<0.05).The time of getting out of bed,the time of anal exhaust,the time of resuming normal diet and the time of hospitalization in the observation group were significantly lower than those in the control group(P<0.05).Conclusion The combination of evidence-based nursing and multi-dimensional health education during perioperative period of cholecystolithiasis surgery can reduce postoperative pain,improve the positive attitude of treatment,reduce complications,and promote the recovery of the disease.
7.Construction and preliminary validation of machine learning predictive models for cervical cancer screening based on human DNA methylation
Yuan YANG ; Hang ZHOU ; Yakun WANG ; Yu DAI ; Ruoji PI ; Hua ZHANG ; Ziyue HUANG ; Ting WU ; Jinghong YANG ; Wen CHEN
Chinese Journal of Oncology 2025;47(2):193-200
Objective:Using methylation characteristics of human genes to construct machine learning predictive models for screening cervical cancer and precancerous lesions.Methods:Human DNA methylation detection was performed on 224 cervical exfoliated cell specimens from the Cancer Hospital of the Chinese Academy of Medical Sciences, Tianjin Central Hospital of Gynecology Obstetrics, Xinmi Maternal and Child Health Hospital of Henan Province, West China Second Affiliated Hospital of Sichuan University, and Heping Hospital Affiliated to Changzhi Medical College collected during April 2014 and March 2015. The hypermethylated gene fragments related to cervical cancer were selected by high-density, high-association, and hypermethylated gene fragment screening and the LASSO regression algorithm. Taking cervical intraepithelial neoplasia grade 2 (CIN2) or more severe lesions as the research outcome, machine learning predictive models based on the random forest (RF), naive Bayes (NB), and support vector machine (SVM) algorithm, respectively, were constructed. A total of 144 outpatient specimens were used as the training set and 80 cervical exfoliated cell specimens from women participating in the cervical cancer screening program were used as the test set to verify the predictive models. Using histological diagnosis results as the gold standard, the detection efficacy for CIN2 or more severe lesions of the three machine learning predictive models were compared with that of the human papilloma virus (HPV) detection and cytological diagnosis.Results:In the training set of 144 cases, there were 34 cases of HPV positivity, with a positive rate of 23.61%. Cytologically, there were 37 cases diagnosed as no intraepithelial lesion or malignancy (NILM), and 107 cases diagnosed as atypical squamous cells of undetermined significance (ASC-US) or above. Histologically, there were 28 cases without cervical intraepithelial neoplasia or benign cervical lesions, 31 cases of CIN1, 18 cases of CIN2, 31 cases of CIN3, and 36 cases of squamous cell carcinoma. Seven hypermethylated gene fragments were selected from 45 genes, and three machine learning prediction models based on the RF, NB, and SVM algorithm, respectively, were constructed. In the validation set of 80 cases, there were 28 cases of HPV positivity, with a positive rate of 35.00%. Cytologically, there were 65 cases diagnosed as NILM and 15 cases as ASC-US or above. Histologically, there were 39 cases without cervical intraepithelial neoplasia or benign cervical lesions, 10 cases of CIN1, 10 cases of CIN2, 11 cases of CIN3, and 10 cases of squamous cell carcinoma. In the validation set, the area under the curve (AUC) values of the RF model, NB model, SVM model, HPV detection, and cytological diagnosis of CIN2 or above were 0.90, 0.88, 0.82, 0.68, and 0.45, respectively. The DeLong test showed that there was no statistically significant difference in the AUC values between the RF, NB, and SVM models (all P>0.05), and the AUC values of the RF and NB models were higher than that of HPV detection (both P<0.01), and the AUC values of the RF, NB, and SVM models were higher than that of cytological diagnosis (all P<0.01). Compared with the NB model, the sensitivity of the RF model was similar (80.65% vs. 77.42%), but the specificity of the NB model was much higher than that of the RF model (93.88% vs. 73.47%). Conclusion:Among the machine learning prediction models for cervical cancer and precancerous lesions constructed based on human DNA methylation, the NB model has good predictive performance for CIN2 and above lesions, and may be used for screening of cervical cancer and precancerous lesions.
8.Construction of a recombinant adenovirus for Mycobacterium tuberculosis c-di-AMP phosphodiesterase expression and induction of humoral immunity
Jia-hao HU ; Huan-huan NING ; Meng-juan DONG ; Yan-zhi LU ; Ting DAI ; Cong-yue ZHANG ; Zi-qing XU ; Shu-yu WANG ; Zheng-yan ZHOU ; Yin-lan BAI
Chinese Journal of Zoonoses 2025;41(4):364-369
A recombinant adenovirus(rAd)for expression of Mycobacterium tuberculosis(M.tb)c-di-AMP phosphodiesterase CnpB was constructed,and its induced humoral immune response was detected.The codon-optimized gene of M.tb CnpB was cloned into the adenoviral plasmid pcADV.The recombinant plasmid pcADV-CnpB was transfected into HEK293T cells,and expression was detected with Western blot.The recombinant plasmid pcADV-CnpB and the backbone plasmid were co-transfected into HEK293T cells to obtain the recombinant adenovirus rAd-CnpB.rAd-CnpB was amplified in HEK293T cells,and the target protein expression of rAd-CnpB was detected with Western blot and immunofluorescence.Mice were immunized with rAd-CnpB intranasally,and their sera and bronchoalveolar lavage fluid(BALF)were collected.ELISA was used to detect levels of antigen-specific antibodies.Restriction enzyme digestion and sequencing indicated that the recombinant plasmid pcADV-CnpB was successfully constructed and led to protein expression in eukaryotic cells.rAd-CnpB was packaged and produced in HEK293T cells.After amplification and purification,rAd-CnpB with a titer of 5.53×1010 PFU/mL was obtained.rAd-CnpB led to CnpB expression in HEK293T cells.Intranasal immunization with rAd-CnpB increased levels of IgG and secretory IgA in BALF and led to high levels of IgG in sera.rAd-CnpB,the recombinant adenovirus for expression of c-di-AMP phosphodiesterase CnpB was successfully constructed,and was found to induce antigen-specific humoral and mucosal immune responses through mucosal immunization.Thus,rAd-CnpB may be used in further research on new TB vaccine strategies.
9.Mechanism of silibinin derivative Sil-1 modulating MAPK signaling pathway to inhibit acute myocardial infarction in rats
Yi-fan LIU ; Meng LI ; De-yu CUI ; Xiao-yan LU ; Ting-bo NING ; Chun-xiu XU ; Jing-chun YAO ; Ji-dong ZHOU ; Zhong LIU
Chinese Pharmacological Bulletin 2025;41(8):1453-1462
Aim To study the protective effect of the silibinin derivative Sil-1 on acute myocardial ischemia in SD rats and its mechanism of action.Methods Af-ter 18 hours of oxygen-glucose deprivation and treat-ment of H9c2 cells,the protective effect of Sil-1 on rat cardiomyocytes was examined.SD rats were treated 30 minutes before surgery,followed by 24 h ligation of the left anterior descending coronary artery.The cardiopro-tective effects of Sil-1 and its mechanisms for improving myocardial ischemic injury were investigated using pro-teomics technology.Results In vitro,compared with the control group,the activity of H9c2 cells in the mod-el group showed reduced cell viability,increased dead cells,elevated ROS and higher levels of LDH and in-flammatory cytokines TNF-α,IL-1β and IL-6 in the culture medium.Sil-1 could improve the above condi-tions to different degrees.In vivo,compared with the control group,rats in the model group showed signifi-cantly higher T waves on electrocardiogram,significant ischemic areas in the heart section,disorganized ar-rangement of cardiomyocytes,increased inflammatory factor infiltration and elevated CK,CK-MB,LDH and inflammatory factors TNF-α,IL-6 and IL-1β.Besides,NF-κB phosphorylation levels in myocardial tissue in-creased.Sil-1 improved the above conditions to varying degrees.The results of proteomics showed that 90 pro-teins were found between the control vs model group and the Sil-1 vs model group,and KEGG enrichment a-nalysis showed that MAPK,chemokines,VEGF and other signaling pathways were abundant.Western blot results showed that Sil-1 blocked the phosphorylation of ERK,JNK and p38 MAPK.Conclusions Sil-1 inhib-its the MAPK pathway by blocking the phosphorylation of JNK,ERK,and p38 MAPK,and achieves a protec-tive effect on rats with acute myocardial infarction.
10.Study on the correlation between urinary calcium levels and severity and prognosis of chronic kidney disease
Qiongjing YUAN ; Yanyun XIE ; Jinwei WANG ; Zhangzhe PENG ; Pan YU ; Ting MENG ; Ling HUANG ; Wei WANG ; Xiaozhao LI ; Hanwei HUANG ; Fang WANG ; Bixia GAO ; Minghui ZHAO ; Qiaoling ZHOU ; Luxia ZHANG ; Hui XU
Chinese Journal of Epidemiology 2025;46(2):264-272
Objective:To analyze the relationship between 24-hour urinary calcium (24 h UCa) level and the risk of end-stage kidney disease (ESKD), cardiovascular disease (CVD), and all-cause mortality.Methods:In the Chinese Cohort Study of Chronic Kidney Disease, we examined 3 375 patients aged 18-74 years with CKD stages 1-4. Kaplan-Meier survival and Cox proportional hazard regression models were used to test a time-to-event association between levels of 24 h UCa and incidence of ESKD, CVD, and all-cause mortality.Results:During a follow-up of 4.17 (3.37, 5.20) years, 179, 145, 104 and 38 ESKD events occurred in <0.60, 0.60-, 1.20-, ≥2.32 mmol 24 h UCa groups. Higher levels of 24 h UCa (1.20-,≥2.32 mmol) were independently associated with a lower incidence of ESKD events in patients with CKD, with HR (95% CI) of 0.71 (0.54-0.93) and 0.43 (0.29-0.64), respectively. No significant associations with CVD and all-cause mortality endpoints were detected. Conclusion:Among patients with CKD, levels of 24 h UCa displayed an association with the risk of ESKD among patients with CKD stages 1-4.

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