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.Prediction and verification of the mechanism of action of Jiawei qifang weitong granule in ameliorating precancerous lesions of gastric cancer
Wenlong CHEN ; Meiwen TANG ; Yeping YU ; Xinyuan CHEN ; Long PANG ; Changzhou XIONG ; Yingye LIANG ; Ting WANG
China Pharmacy 2026;37(15):1948-1953
OBJECTIVE To predict and verify the mechanism of Jiawei qifang weitong granule in ameliorating precancerous lesions of gastric cancer (PLGC). METHODS Transcriptomic data of PLGC-related were obtained from the GEO database to screen differentially expressed genes and conduct functional enrichment analysis. Targets related to gastric mucosal injury repair were screened via the GeneCards database. The active ingredient targets of Jiawei qifang weitong granule were predicted using the TCMSP and other databases. The intersection of differentially expressed genes, gastric mucosal repair targets and active ingredient targets was extracted. A protein-protein interaction network was constructed based on the STRING database, and the top 6 hub target genes with the highest connectivity were screened. A PLGC rat model was established by combining 1-methyl-3-nitro-1-nitrosoguanidine with alternating fasting and full feeding. Model rats were divided into model group, weifuchun group (positive control, 0.40 g/kg), low-, medium- and high-dose Jiawei qifang weitong granule groups (9.73, 19.44, 38.90 g/kg), with 10 rats in each group. Another 10 unmodeled rats were set as control group. Rats in each group were intragastrically administered corresponding liquid medicine or normal saline once a day for 30 consecutive days. After the last administration, pathological morphological changes of rat gastric tissues were observed, and the mRNA expression levels of hub target genes as well as partial protein expression levels in gastric tissues were detected. RESULTS Transcriptomics and network pharmacology analyses revealed that the top 6 hub target genes ranked by connectivity included MMP9 (matrix metalloproteinase 9), BCL2(B-cell lymphoma 2), IL10(interleukin 10),ICAM1(intercellular adhesion molecule 1), PTGS2 (prostaglandin-endoperoxide synthase 2), and HIF1A (hypoxia-inducible factor 1α subunit). Animal experiments showed that compared with the model group, gastric mucosal pathological injury was significantly alleviated in medium- and high-dose Jiawei qifang weitong granule groups and weifuchun group. The pathological injury score of gastric mucosa, the mRNA expression levels of MMP9, PTGS2, ICAM1, BCL2 and HIF1A, as well as the protein expression levels of PTGS2 and BCL2 in gastric tissues were significantly decreased (P<0.05), while the mRNA expression level of IL10 was significantly increased (P<0.05). CONCLUSIONS Jiawei qifang weitong granule may ameliorate PLGC by targeted down-regulating the mRNA expression of MMP9, PTGS2, ICAM1, BCL2 and HIF1A, up-regulating IL10 mRNA expression, and regulating the imbalance between gastric mucosal inflammatory response and injury repair.
4.Key influencing factors and improvement strategies of prognosis in lung transplant recipients
Mengting ZHANG ; Xiaoshan LI ; Ting QIAN ; Lin MAN ; Min XIONG ; Shiqiang XUE ; Yetian QIAO ; Lin ZHU ; Jingyu CHEN ; Bo WU
Organ Transplantation 2026;17(5):875-882
In recent years, remarkable advances have been made in lung transplantation regarding donor evaluation, perioperative support, and immune regulation, laying a foundation for improving the long-term survival of recipients. The rational application of extended criteria donor lungs and the popularization of ex vivo lung perfusion technology have enhanced the utilization efficiency and safety of marginal donor lungs. Refined assessment of risk factors such as donors’ smoking history and infectious status has reduced the incidence of primary graft dysfunction and postoperative infection. In terms of recipient management, individualized assessment systems have been gradually optimized. The standardized application of intraoperative extracorporeal membrane oxygenation and the development of minimally invasive surgical techniques have effectively alleviated perioperative injuries. The optimization of postoperative immunosuppressive regimens and advances in rejection monitoring technologies have further improved the long-term survival of grafts. Nevertheless, chronic graft dysfunction and recurrent or refractory infections remain the major bottlenecks restricting long-term prognosis. Future research should focus on expanding donor sources, improving the repair quality of marginal donor lungs, promoting precise immunosuppression and anti-infection strategies, and comprehensively enhancing the long-term survival rate and quality of life of lung transplant recipients.
5.Artificial intelligence-based digital technology:progress and applications in gastrointestinal oncology surgery
He TING ; Wei JIANMING ; Li XIONG ; Di DAWEI ; Wang JUNFU
Chinese Journal of Clinical Oncology 2025;52(13):683-687
With the rise of the digital era,various digital technologies,including three-dimensional printing,reconstruction,and visualization,have been widely applied in medicine,particularly in surgery,advancing medical development and innovation.Digital technology and preci-sion medicine have advanced with the development and application of artificial intelligence(AI),leading to diverse innovations in the field of surgery.Digital technology has also facilitated new approaches in precision medicine,enabling the precise localization of lesions before sur-gery,real-time intraoperative navigation,and the establishment of predictive models for postoperative outcomes.These advancements have thus driven the comprehensive transformation of surgical practice toward greater personalization,precision,and intelligence.This study provides a comprehensive review of the application of digital technologies in gastrointestinal tumor management,encompassing preoperat-ive planning,intraoperative navigation,and postoperative recovery.The evolution of digital technologies is described,and an in-depth sum-mary is provided of the development and clinical value of digital technology in gastrointestinal tumor surgery.Additionally,the study pro-poses future directions for digital medicine in this field.
6.Chemical constituents from the stems and barks of Maytenus variabilis
Ting HE ; Bing-qian LIU ; Jian-feng CHEN ; Xiao-qin YU ; Cheng-xiong LIU ; Kun ZOU ; Fan CHENG
Chinese Traditional Patent Medicine 2025;47(5):1539-1547
AIM To study the chemical constituents from the stems and barks of Maytenus variabilis(Hemsl.)C.Y.Cheng.METHODS The 95%ethanol extract from the stems and barks of M.variabilis was isolated and purified by silica gel,Sephadex LH-20 and semi preparative HPLC,then the structures of obtained compounds were identified by physicochemical properties and spectral data.RESULTS Twenty-three compounds were isolated and identified as β-amyrin(1),3β-acetoxyolean-12-en-11-one(2),ursa-12-ene-11-one-3-ol octocosate(3),friedelin(4),canophyllol(5),pinoresinol(6),medioresinol(7),isolariciresinol(8),dihydrodehydrodiconiferyl alcohol(9),vanillic acid(10),7R,8S-5-methoxydihydrodehydroconiferyl alcohol(11),β-hydroxypropiovanillone(12),triptregeline B(13),triptregeline E(14),(+)-evofolin B(15),2,5-dimethoxybenzoquinone(16),olean-12-ene-3,11-dione(17),β-sitosterol(18),(-)-(7R,7'R,7"S,8S,8'S,8"S)-4',4"-dihydroxy-3,3',3",5-tetramethoxy-7,9',7',9-diepoxy-4,8"-oxy-8,8'-sesquineolignan-7",9"-diol(19),phyllostadimer B(20),rayalinol(21),lyoniresinol(22),dihydrobuddlenol B(23).CONCLUSION Compounds 3,9-11,13-14,16,19-21,23 are isolated from genus Maytenus for the first time,and compounds 2,4-5,7-8,12,15,17,22 are first found from this plant.
7.CURRENT DISTRIBUTION OF AEDES AEGYPTI IN LEIZHOU PENINSULA,ZHANJIANG CITY,GUANGDONG PROVINCE
Rui-Peng LU ; Jin-Hua DUAN ; Yu-Wen ZHONG ; Hui DENG ; Jun WU ; Li-Ping LIU ; Wei-Xiong YIN ; Feng XING ; Hui HUANG ; Chang-Jie FU ; Zong-Jing CHEN ; Ming-Ji CHENG ; Sheng-Jun HU ; Ya-Ting CHEN ; Wen-Ting GUO ; Li-Feng LIN
Acta Parasitologica et Medica Entomologica Sinica 2025;32(1):16-21
Objective To investigate the status of population dynamics and distribution changes of Aedes aegypti in Guangdong Province.Methods Continuous monitoring was conducted from May 2018 to July 2024 in Wushi Town and Qishui Town,Leizhou City,Zhanjiang City,Guangdong Province.Additionally,a survey of the distribution of Ae.aegypti along the Leizhou Peninsula coast was carried out.Results The density of Ae.aegypti in Zhanjiang showed a gradual decline from 2018 to 2024.The last detection of adult Ae.aegypti in Wushi Town was in September 2021,and the last larva was found in October 2023.No Ae.aegypti was detected in Qishui Town during surveys from 2021 to 2024.A survey of 18 coastal villages in the Leizhou Peninsula revealed no detections of Ae.aegypti.Conclusions This study provides a basis for understanding the distribution and population density fluctuations of Ae.aegypti,assessing its invasion risk,and scientifically conducting relevant prevention and control efforts.
8.Therapeutic effect of metallic stent implantation on the treatment of central airway malacia after lung transplantation
Hang YANG ; Min XIONG ; Jingyu CHEN ; Ting JIANG ; Bo WU
Chinese Journal of Organ Transplantation 2025;46(4):300-305
Objective:To investigate the efficacy and safety of metallic stent implantation for the treatment of central airway malacia following lung transplantation.Methods:Clinical data of 14 recipients who underwent metallic stent implantation for central airway malacia after lung transplantation at Wuxi People's Hospital Affiliated to Nanjing Medical University from January 2023 to June 2024 were retrospectively analyzed. Clinical symptoms, modified Medical Research Council (mMRC) dyspnea scale scores, Karnofsky Performance Status (KPS) scores, and pulmonary function were evaluated before and 2 weeks after stent implantation. The incidence of post-implantation complications was recorded during follow-up.Results:Among the 14 recipients, 13 were male and 1 was female, with a mean age of (57.29±10.93) years (range: 27-71 years). All patients successfully underwent metallic stent placement in a single attempt, with no serious intraoperative complications. Clinical symptoms such as dyspnea improved significantly after stent implantation. Compared with pre-treatment values, mMRC scores decreased [3.00 (2.00, 4.00) vs 1.00 (1.00, 2.00), P<0.001], KPS scores increased [30.00 (10.00, 32.50) vs 80.00 (60.00, 90.00), P=0.001], and forced expiratory volume in one second (FEV 1) improved [(1.25±0.42) L vs (1.74±0.38) L, P=0.006]. Postoperative complications included granulation tissue formation (7 cases), epithelialization within the stent (3 cases), and mucus plugging (4 cases). As of the last follow-up in September 2024, eight patients had their stents successfully removed, and one patient had died due to cytomegalovirus infection. Conclusions:Metallic stent implantation can significantly relieve clinical symptoms of central airway malacia after lung transplantation, improve quality of life, and shows a favorable safety profile.
9.Evaluation of host nucleic acid removal and pathogen enrichment methods in animal tissue samples
Xuezhi HUANG ; Zuming ZHANG ; Hao ZHOU ; Ting ZHAO ; Zirui XIONG ; Guangqian PEI ; Yunfei WANG ; Mengnan CUI ; Yan GUO ; Haifeng PAN ; Yujun CUI ; Hang FAN
Chinese Journal of Zoonoses 2025;41(7):682-690
This study was aimed at investigating the effectiveness of various host nucleic acid removal and non-specific amplifica-tion techniques in animal tissue samples,to increase the accuracy of pathogen identification in tissue samples.Simulated samples were prepared with a mixture of mouse lung tissue homogenates and Klebsiella pneumoniae fluids,and processed with six host nucleic acid removal kits and three non-specific amplification techniques.The effectiveness of each method in removing host DNA and enriching nucleic acids of pathogenic microorganisms was evaluated through real-time fluorescence quantitative PCR and high-throughput se-quencing.For host nucleic acid removal techniques,the method of selective cleavage and quantitative degradation of host DNA(Com-plete5 kit)effectively decreased the host nucleic acid content in tissue samples and increased the relative abundance of pathogen nucleic acids.In contrast,the magnetic bead method for host DNA removal(Next microbiome DNA enrichment Kit kit)was less effec-tive.At lower pathogen concentrations(77 CFU/mL),the Vazyme kit was more effective than the other kits in removing host nucleic acids.Non-specific amplification techniques(MALBAC whole genome amplification,MDA isothermal amplification,and random primer amplification)were not applicable to tissue samples and were not effective in increasing the relative abundance of pathogen nucleic acids.Selective lysis and quantitative degradation of host DNA were suitable for processing tissue samples with high host back-ground and low pathogenic microorganism levels,whereas non-specific amplification methods were not applicable to tissue samples for pre-processing of macro-genome high-throughput sequencing.
10.Isolation,identification,and biological characterization of enterotoxigenic Escherichia coli from a South China tiger
Jing-ru XU ; Zhi-hao ZHU ; Yu-qi LI ; Si-si FAN ; Ya-li KANG ; Yu-bin ZHUO ; Ling-shan HUANG ; Shu-qi QIU ; XUE-YUXI ; Xiao-ping WU ; Yu-ting LIAO ; Wei-ye LIN ; Xiao-ziyi XIAO ; Xue-jin LI ; Teng-teng CHEN ; Xi-pan LIN ; Kai-xiong LIN ; Ke-wei FAN
Chinese Journal of Zoonoses 2025;41(6):567-573
This study was aimed at identifying the pathogenic bacteria responsible for the death of a young tiger at the Fujian Meihua Mountain South China Tiger Breeding Research Institute.Tissue samples from the lungs,liver,and intestines of the deceased tiger were collected,and the bacteria were cultured inasterile environment.The bacterial strains were characterized according to their morphological and molecular biological properties,including assessment of virulence genes and antibiotic resistance genes,mouse lethality tests,and antibiotic susceptibility evaluations.A predominant bacterial strain isolated from the liver of the deceased tiger was identified as enterotoxigenic Escherichia coli(ETEC)strain Tiger22513F.Phylogenetic analysis of the 16S rRNA gene revealed that the Tiger22513F strain exhibited close genetic similarity to the reference strain ETEC(MF919609.1),with 99.9%nucleotide similarity,and resided on the same evolutionary branch.The Tiger22513F strain contained 11 antibiotic resistance genes(tetA,sul1,sul3,cmlA,floR,blaTEM,blaSHV,blaCMY-2,qnrA,qnrS,and qnrD)along with five virulence genes(VT1,fyuA,tsh,iucD,and ST).Mouse lethality tests indicated significant pathogenicity toward mice,affecting primarily the lungs,liver,and intestines.Antibiotic susceptibility testing demonstrated that this strain exhibited resistance to various classes of beta-lactam antibiotics,as well as quinolones and aminoglycosides.This investigation successfully isolated a multi-drug resistant enterotoxigenic Escherichia coli strain with pronounced pathogenicity from the liver of a deceased tiger;thus providing valuable scientific insights for clinical diagnosis,as well as prevention and control measures,against ETEC infections in South China tigers.

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