1.Advancements in Gas-releasing Micro/Nanoplatforms for Overcoming MDR Bacterial Infections in Diabetic Wounds
Ruo-Can LIU ; Yu-Qian WANG ; Shuai ZHANG ; Shao-Zhi ZUO ; Yun-Di WU ; Xi-Long WU
Progress in Biochemistry and Biophysics 2026;53(5):1356-1375
Chronic diabetic wounds, severely complicated by multidrug-resistant (MDR) bacterial infections, represent a profound and escalating global health crisis. The intrinsically hostile microenvironment of diabetic wounds, characterized by localized hypoxia, persistent oxidative stress, and poor vascularization, creates an ideal niche for opportunistic pathogens such as Staphylococcus aureus and Pseudomonas aeruginosa. These bacteria readily construct dense extracellular polymeric substance (EPS) biofilms, which not only physically shield the microbes from host immune responses but also actively trap the wound in a state of chronic, unresolved inflammation. Consequently, conventional systemic and topical antibiotic therapies are becoming increasingly futile, as poor perfusion at the wound site restricts drug bioavailability, while the rapid genetic evolution of bacteria and the impenetrable nature of biofilms lead to catastrophic treatment failures, often culminating in severe tissue necrosis and lower-extremity amputations. To circumvent the limitations of traditional antimicrobials, therapeutic gas delivery has emerged as a highly promising, paradigm-shifting strategy. Gaseous signaling molecules, particularly nitric oxide (NO), carbon monoxide (CO), hydrogen sulfide (H2S), and hydrogen (H2), possess unique physicochemical properties that allow them to seamlessly penetrate dense biofilm matrices and cellular membranes. Once inside, these gases operate via multi-targeted mechanisms that are incredibly difficult for bacteria to develop resistance against; for instance, NO induces severe lipid peroxidation and DNA cleavage in bacteria, CO downregulates pro-inflammatory cytokines, H2S significantly accelerates endothelial cell migration for neovascularization, and H2 acts as a powerful selective antioxidant to neutralize tissue-damaging reactive oxygen species (ROS). Together, these therapeutic gases not only exert broad-spectrum bactericidal effects but also actively reprogram the wound bed by promoting the critical M1-to-M2 macrophage polarization and stimulating angiogenesis. Despite their immense biological potential, the direct clinical translation of gas therapies is severely hindered by inherent physicochemical drawbacks, including extreme volatility, short physiological half-lives, poor aqueous solubility, and the high risk of off-target systemic toxicity, if applied indiscriminately. To conquer these immense pharmacokinetic barriers, cutting-edge advancements in materials science have driven the development of gas-releasing micro- and nanoplatforms. Utilizing sophisticated carriers such as metal-organic frameworks (MOFs), mesoporous silica, polymeric nanoparticles, liposomes, and injectable hydrogels, researchers can now encapsulate gas-donor molecules to achieve sustained, localized delivery. More importantly, these advanced nanoplatforms are ingeniously engineered to be stimuli-responsive. By exploiting the pathological hallmarks of the diabetic wound environment, such as elevated glucose concentrations, acidic pH, and overexpressed ROS, or by utilizing external triggers like near-infrared (NIR) light irradiation and ultrasound, these intelligent platforms ensure on-demand, precise spatio-temporal gas release. This often allows for powerful synergistic combinations, such as photothermal or photodynamic therapy coupled with gas release, thereby obliterating biofilms while sparing healthy tissue. While the therapeutic outcomes of these smart delivery systems in eradicating MDR infections and accelerating tissue repair are unprecedented, several critical challenges remain before widespread clinical adoption, as long-term biosafety profiles of the carrier nanomaterials, complexities in large-scale good manufacturing practice (GMP) production, and stringent regulatory hurdles must be rigorously addressed. Looking forward, the next frontier lies in the realm of precision medicine and theranostics, where future research must focus on the seamless integration of these gas-releasing platforms with flexible, wearable biosensors capable of continuously monitoring wound biomarkers (e.g., pH, temperature, uric acid) in real-time. Coupled with artificial intelligence algorithms to govern automated, closed-loop adaptive dosing, these next-generation smart dressings hold the ultimate potential to comprehensively transform the clinical management of complex, infected diabetic wounds.
2.Advancements in Gas-releasing Micro/Nanoplatforms for Overcoming MDR Bacterial Infections in Diabetic Wounds
Ruo-Can LIU ; Yu-Qian WANG ; Shuai ZHANG ; Shao-Zhi ZUO ; Yun-Di WU ; Xi-Long WU
Progress in Biochemistry and Biophysics 2026;53(5):1356-1375
Chronic diabetic wounds, severely complicated by multidrug-resistant (MDR) bacterial infections, represent a profound and escalating global health crisis. The intrinsically hostile microenvironment of diabetic wounds, characterized by localized hypoxia, persistent oxidative stress, and poor vascularization, creates an ideal niche for opportunistic pathogens such as Staphylococcus aureus and Pseudomonas aeruginosa. These bacteria readily construct dense extracellular polymeric substance (EPS) biofilms, which not only physically shield the microbes from host immune responses but also actively trap the wound in a state of chronic, unresolved inflammation. Consequently, conventional systemic and topical antibiotic therapies are becoming increasingly futile, as poor perfusion at the wound site restricts drug bioavailability, while the rapid genetic evolution of bacteria and the impenetrable nature of biofilms lead to catastrophic treatment failures, often culminating in severe tissue necrosis and lower-extremity amputations. To circumvent the limitations of traditional antimicrobials, therapeutic gas delivery has emerged as a highly promising, paradigm-shifting strategy. Gaseous signaling molecules, particularly nitric oxide (NO), carbon monoxide (CO), hydrogen sulfide (H2S), and hydrogen (H2), possess unique physicochemical properties that allow them to seamlessly penetrate dense biofilm matrices and cellular membranes. Once inside, these gases operate via multi-targeted mechanisms that are incredibly difficult for bacteria to develop resistance against; for instance, NO induces severe lipid peroxidation and DNA cleavage in bacteria, CO downregulates pro-inflammatory cytokines, H2S significantly accelerates endothelial cell migration for neovascularization, and H2 acts as a powerful selective antioxidant to neutralize tissue-damaging reactive oxygen species (ROS). Together, these therapeutic gases not only exert broad-spectrum bactericidal effects but also actively reprogram the wound bed by promoting the critical M1-to-M2 macrophage polarization and stimulating angiogenesis. Despite their immense biological potential, the direct clinical translation of gas therapies is severely hindered by inherent physicochemical drawbacks, including extreme volatility, short physiological half-lives, poor aqueous solubility, and the high risk of off-target systemic toxicity, if applied indiscriminately. To conquer these immense pharmacokinetic barriers, cutting-edge advancements in materials science have driven the development of gas-releasing micro- and nanoplatforms. Utilizing sophisticated carriers such as metal-organic frameworks (MOFs), mesoporous silica, polymeric nanoparticles, liposomes, and injectable hydrogels, researchers can now encapsulate gas-donor molecules to achieve sustained, localized delivery. More importantly, these advanced nanoplatforms are ingeniously engineered to be stimuli-responsive. By exploiting the pathological hallmarks of the diabetic wound environment, such as elevated glucose concentrations, acidic pH, and overexpressed ROS, or by utilizing external triggers like near-infrared (NIR) light irradiation and ultrasound, these intelligent platforms ensure on-demand, precise spatio-temporal gas release. This often allows for powerful synergistic combinations, such as photothermal or photodynamic therapy coupled with gas release, thereby obliterating biofilms while sparing healthy tissue. While the therapeutic outcomes of these smart delivery systems in eradicating MDR infections and accelerating tissue repair are unprecedented, several critical challenges remain before widespread clinical adoption, as long-term biosafety profiles of the carrier nanomaterials, complexities in large-scale good manufacturing practice (GMP) production, and stringent regulatory hurdles must be rigorously addressed. Looking forward, the next frontier lies in the realm of precision medicine and theranostics, where future research must focus on the seamless integration of these gas-releasing platforms with flexible, wearable biosensors capable of continuously monitoring wound biomarkers (e.g., pH, temperature, uric acid) in real-time. Coupled with artificial intelligence algorithms to govern automated, closed-loop adaptive dosing, these next-generation smart dressings hold the ultimate potential to comprehensively transform the clinical management of complex, infected diabetic wounds.
3.Integrated molecular characterization of sarcomatoid hepatocellular carcinoma
Rong-Qi SUN ; Yu-Hang YE ; Ye XU ; Bo WANG ; Si-Yuan PAN ; Ning LI ; Long CHEN ; Jing-Yue PAN ; Zhi-Qiang HU ; Jia FAN ; Zheng-Jun ZHOU ; Jian ZHOU ; Cheng-Li SONG ; Shao-Lai ZHOU
Clinical and Molecular Hepatology 2025;31(2):426-444
Background:
s/Aims: Sarcomatoid hepatocellular carcinoma (HCC) is a rare histological subtype of HCC characterized by extremely poor prognosis; however, its molecular characterization has not been elucidated.
Methods:
In this study, we conducted an integrated multiomics study of whole-exome sequencing, RNA-seq, spatial transcriptome, and immunohistochemical analyses of 28 paired sarcomatoid tumor components and conventional HCC components from 10 patients with sarcomatoid HCC, in order to identify frequently altered genes, infer the tumor subclonal architectures, track the genomic evolution, and delineate the transcriptional characteristics of sarcomatoid HCCs.
Results:
Our results showed that the sarcomatoid HCCs had poor prognosis. The sarcomatoid tumor components and the conventional HCC components were derived from common ancestors, mostly accessing similar mutational processes. Clonal phylogenies demonstrated branched tumor evolution during sarcomatoid HCC development and progression. TP53 mutation commonly occurred at tumor initiation, whereas ARID2 mutation often occurred later. Transcriptome analyses revealed the epithelial–mesenchymal transition (EMT) and hypoxic phenotype in sarcomatoid tumor components, which were confirmed by immunohistochemical staining. Moreover, we identified ARID2 mutations in 70% (7/10) of patients with sarcomatoid HCC but only 1–5% of patients with non-sarcomatoid HCC. Biofunctional investigations revealed that inactivating mutation of ARID2 contributes to HCC growth and metastasis and induces EMT in a hypoxic microenvironment.
Conclusions
We offer a comprehensive description of the molecular basis for sarcomatoid HCC, and identify genomic alteration (ARID2 mutation) together with the tumor microenvironment (hypoxic microenvironment), that may contribute to the formation of the sarcomatoid tumor component through EMT, leading to sarcomatoid HCC development and progression.
4.Analysis of current status and influencing factors of knowledge, attitude, and practice of post-intensive care syndrome
Wenhao WU ; Yun RAO ; Zhi WANG ; Pingang LI ; Yanmei TONG ; Guiping ZHANG ; Yanxia SHAO ; Boshan TONG ; Wei SUN
Chinese Journal of Digestive Surgery 2025;24(10):1326-1332
Objective:To investigate the current status of knowledge, attitude, and practice (KAP) of intensive care unit (ICU) medical staff for post-intensive care syndrome (PICS) and explore its influencing factors.Methods:The cross-sectional investigation study with stratified sampling was conducted. From June to September 2024, ICU medical staff from general hospitals in 5 regions (Chongqing, Beijing, Shaanxi, Jiangsu, and Gansu) were selected as the research subjects. The KAP of PICS questionnaire was distributed in the form of an electronic questionnaire. Observation indicators: (1) results of the questionnaire survey; (2) general information of ICU medical staff; (3) KAP scores of PICS and the correlation among various dimensions; (4) analysis of influencing factors for KAP of PICS. Comparison of measurement data with normal distribution between groups was conducted using the independent samples t test. One-way analysis of variance (ANOVA) was applied for com-parison among multiple groups, and post-hoc LSD test was used for pairwise comparison. Comparison of count data between groups was conducted using the chi-square test. Pearson correlation analysis was adopted for correlation analysis. Multiple linear regression analysis was used for univariate and multivariate analyses. Results:(1) Results of questionnaire survey. A total of 410 questionnaires were distributed and retrieved, among which 408 were valid, with an effective rate of 99.512%(408/410). (2) General information of ICU medical staff. Among the 408 ICU medical staff, there were 79 males and 329 females. Eight cases were under 25 years old, 248 cases were 25-35 years old, 132 cases were 36-40 years old, and 20 cases were over 40 years old. In terms of professional title, there were 10 junior nurses, 130 junior nurse practitioners, 228 intermediate nurse practitioners, and 40 senior nurse practitioners. About the educational background, 34 cases had a junior college degree, 347 cases had a bachelor's degree, and 27 cases had a master's degree or above. Regarding the hospital level, 25 nurses worked in secondary hospitals and 383 cases in tertiary hospitals. In terms of ICU type, 181 cases were from specialized ICU and 227 cases from general ICU. About working experience in ICU, 41 nurses had less than 5 years, 207 cases had 5-10 years, and 160 cases had more than 10 years. (3) KAP scores of PICS and the correlation among various dimensions. The total KAP score of PICS among the 408 ICU medical staff was 88.7±14.2, with 40.2±9.2 for the knowledge dimension, 22.0±5.6 for the attitude dimension, and 26.5±6.3 for the practice dimension. Pearson correlation analysis showed that the knowledge dimension of PICS among ICU medical staff was significantly positively correlated with both the attitude dimension and the practice dimension ( r=0.15, 0.69, P<0.05); the attitude dimension was positively correlated with the practice dimension ( r=0.23, P<0.05).(4) Analysis of influencing factors for KAP of PICS. Results of multivariate analysis showed that age (25-35 years old, 36-40 years old, over 40 years old), educational background and hospital level were independent influencing factors for the KAP of PICS among ICU medical staff ( t=2.23, 1.97, 2.84, 0.15, 2.04, P<0.05). Conclusions:The KAP of PICS among ICU medical staff is relatively good, while their practical ability still needs to be improved. Age, educational background, and hospital level are independent influencing factors for the KAP of PICS among ICU medical staff.
5.The Evolutionary Trace and Structure-Function Relationship of the Cholera Toxin
Chinese Journal of Biochemistry and Molecular Biology 2025;41(10):1432-1444
The bacterial ADP-ribosylating exotoxins are produced by bacteria and infect different human body tissues.Herein,we investigated the molecular evolution of AB5-type bacterial toxins expressed by Vibrio cholerae and other bacteria with similar invasion mechanisms to interpret the co-evolutionary history of V.cholerae cholera toxin(CT)and their hosts,aiming to reveal the causes of its transdermal immuno-genicity.We elaborated on the intracellular toxicity mechanisms of CT,including ganglioside receptor-mediated endocytosis and hyperactivation of the cAMP pathway,as well as the behavioral traces of related bacteriophages within the genomes of these bacteria.Models such as the relatively decoupled evolution of A and B subunits of CT and the evolutionary coupling of transdermal and mucosal immunity were summa-rized.Furthermore,we described mechanisms including phage-mediated horizontal gene transfer(exem-plified by Vibrio phage CTXΦ),toxin targeting variation,expansion of molecular recognition domains,and functional adaptive evolution of the toxins.In this research,we employed bioinformatic tools to con-struct phylogenetic trees and analyze genetic variations in the amino acid sequences of toxin A/B subunits and proteins of secretion systems.Tajima's test was utilized to quantify genetic distance,diversity,and neutral selection pressure.Key findings include:(1)a"decoupled evolution"mode for the A and B subunits of CT,with the B subunit under stronger negative selection;(2)horizontal gene transfer media-ted by CTXΦ and other phages drives the cross-species spread of toxin genes;(3)the interaction be-tween the toxin co-regulated pilus(TCP)and the TLR-5(Toll-like receptor 5)promotes the transdermal immunogenicity of the CT B subunit.These findings suggest the role of"toxin-host arm race"co-evolu-tion,and are consistent with the hypothesis of intergenerational transmission of immune memory in CT e-volution,thereby providing theoretical support for further research into the biological mechanisms and co-evolutionary history of AB5-type bacterial toxins.
6.Advacnes in right ventricular function in pulmonary hypertension:focus on the 7th World Symposium on Pulmonary Hypertension
Shao-fei LIU ; Rui-qi WANG ; Zhi-fu GUO ; Ni ZHU
Chinese Journal of Interventional Cardiology 2025;33(10):574-580
Since 1973,the World Symposium on Pulmonary Hypertension(WSPH)has served as a pivotal platform for the advancing research in pulmonary hypertension(PH).At the 6th WSPH in 2018,the WSPH expert group refined the definitions related to cardiopulmonary physiology and right ventricular(RV)failure,thereby underscoring the critical role of RV dysfunction in the progression of PH.With ongoing advances in the field,RV failure associated with PH has received increasing attention and is now recognized as an important determinant of the prognosis of PH.The 7th WSPH,held in Barcelona,Spain,in 2024,presented the latest perspectives on the RV pathophysiology and its interaction with the pulmonary vasculature.The symposium emphasized new insights into the pathology of RV failure,RV phenotypes across different PH subgroups,and progress in therapeutic approaches targeting RV dysfunction.Additionally,the WSPH expert group delineated prospective research directions and identified unresolved issues.This article will review the RV function-related updates from the 7th WSPH and summarize recent findings,providing a systematic review of the evolution and breakthroughs in RV function research within the context of PH.
7.Effects of Jisuishang Formula on neurological function and ferroptosis in a rat model of cervical spondylotic myelopathy
Han-li YANG ; Ming SHI ; Chun-zhi LIU ; Shao-hu LIN ; Ming-gao HU ; Xian-zhong BU ; Yuan-ming ZHONG ; Wei XU
Chinese Traditional Patent Medicine 2025;47(10):3233-3241
AIM To investigate the effects of Jisuishang Formula on neurological function and ferroptosis in a rat model of cervical spondylotic myelopathy(CSM).METHODS The CSM rat models were established and randomly assigned to the model group,the Fer-1 group(2 g/kg Ferrostatin-1 via intraperitoneal injection),the low-dose(9.7 g/kg,intragastrically),medium-dose(19.4 g/kg,intragastrically)and high-dose(38.8 g/kg,intragastrically)Jisuishang Formula groups,and the sham operation group,with 6 rats in each group.Following 4 weeks of treatment administration,BBB locomotor scores and oblique plate test result were recorded to assess their neurological function in rats.Histopathological evaluation utilized HE staining for spinal cord tissue pathology,Nissl staining for Nissl body visualization,and Prussian blue staining for iron ion deposition analysis.Protein expressions of Nrf2,SLC7A11,GPX4,HO-1,TFRC and Cox2 in spinal cord tissues was detected by immunofluorescence and Western blot,while mRNA expressions were quantified using RT-qPCR.RESULTS Compared to the sham group,the CSM model group exhibited significantly reduced BBB locomotor scores and inclined plane test performance at 1,2 and 4 weeks post-operation(P<0.05);obvious tissue cavitation,cellular edema and Prussian blue positive iron deposition in spinal cord tissues;downregulated protein and mRNA expressions of Nrf2,SLC7A11,GPX4,HO-1(P<0.05);and upregulated protein and mRNA expressions of TFRC and Cox2(P<0.05).Compared to the model group,the Jisuishang Formula and Fer-1 intervention groups showed significantly improved BBB scores and inclined plane test result at 1,2 and 4 weeks post-operation(P<0.05);reduced tissue cavitation,attenuated cellular edema and decreased Prussian blue positive iron deposition in spinal cord tissues;upregulated protein and mRNA expression of Nrf2,SLC7A11,GPX4 and HO-1 in spinal cord tissues(P<0.05);and downregulated protein and mRNA expressions of TFRC and Cox2(P<0.05).CONCLUSION Targeting the Nrf2/SLC7A11/GPX4 signaling pathway,Jisuishang Formula potentially suppresses ferroptosis and alleviates iron accumulation in spinal cord neurons,thereby improving neurological recovery in CSM rats.
8.Role of cell communication between cancer-associated fibroblasts and tumor-associated macrophages in tumor development
Qi-hui SHAO ; Zhi-yan ZHAN ; Li HONG
Chinese Pharmacological Bulletin 2025;41(12):2226-2230
Cancer-associated fibroblasts(CAFs)and tumor-asso-ciated macrophages(TAMs)play crucial roles in the tumor microenvironment,and their interaction exerts a significant influ-ence on tumorigenesis and development.With the rapid develop-ment of research techniques,we have acquired novel understand-ings of the cell communication between TAMs and CAFs at the single-cell level.The cell communication between the two is of-ten related to the polarization of TAMs and remodeling of the mi-croenvironmental matrix by CAFs,thereby mediating mechanisms such as immunosuppression or tumor invasion and metastasis.Specific subsets of CAFs and TAMs have also been discovered to play a role in suppressing tumor progression.Nutrient metabo-lites may also participate in the interaction between CAFs and TAMs and have the potential to become new therapeutic targets for tumors.This review explores the research progress in the cell communication between TAMs and CAFs,expounds on the com-plexity of their interaction,and is expected to provide new per-spectives for the treatment and prevention of cancer and tumors.
9.Single-cell sequencing reveals heterogeneity of B cells in osteoporosis patients and their interactions with osteoblasts
Zhi TANG ; Yang SHAO ; Shaoshuo LI ; Shubin QI ; Hengyang LU ; Mao WU ; Junfeng YANG ; Jianwei WANG
Chinese Journal of Tissue Engineering Research 2025;29(26):5501-5510
BACKGROUND:The pathogenesis of osteoporosis is closely related to the immune system.A comprehensive and in-depth study of the relationship between immunity and osteoporosis is crucial for understanding and treating the disease.OBJECTIVE:To investigate the role of immune cells in osteoporosis using single-cell sequencing technology.METHODS:Femoral head tissue samples from osteoporosis and non-osteoporosis patients were downloaded from GEO database and analyzed using single-cell sequencing.Data analysis,including cell clustering,functional enrichment,pseudotime trajectory,and cell interaction analyses,was performed using R4.3.0 and software packages such as Seurat v.4.3,monocle(2.28.0),and CellChat.The femoral head tissues of patients with femoral neck fracture who underwent artificial hip replacement surgery were obtained,including two cases of osteoporosis patients and two cases of non-osteoporosis patients.Immunohistochemical staining was used to detect the protein expression of CCL13 and CCL18.qPCR was used to detect the immunoglobulin heavy constant γ-4,immunoglobulin λ constant 3,human class Ⅱ major histocompatibility complex DRβ1,and CD83 mRNA expression.Western blot was used to detect the protein expression of receptor-type tyrosine protein phosphatase C,CD22,and CD99.RESULTS AND CONCLUSION:Transcriptomic analysis identified 10 cell clusters,including osteoclasts,myeloid cells,T cells,osteoblasts,macrophages,monocytes,erythrocytes,B cells,bone marrow mesenchymal stem cells,and mast cells.There was an increase in the ratio of osteoclasts to T cells and a decrease in the ratio of osteoblasts to B cells in the femoral head tissue of the osteoporosis group.Among the B-cell subpopulations,the proportion of B-cells of taxa 1,3(BC1,BC3)in the femoral head tissue of the osteoporosis group was higher than that of the non-osteoporosis group,and the proportion of B-cells of taxa 2(BC2)was less than that of the non-osteoporosis group.BC1 was enriched significantly for labels such as regulation of adaptive immune response,somatic recombination of immune receptors,and modulation of lymphocyte-mediated immunity,while BC3 was enriched significantly for labels such as regulation of immunoglobulin production,response to type Ⅱ interferon,apoptotic processes involving cysteine endopeptidases,and cytotoxicity.The communication intensity between B-cell subtype BC1 and osteoblasts in the femoral head tissue of the osteoporosis group was higher than that of the non-osteoporosis group,while the communication intensity between BC3 and BC1 was also increased.The communication between BC3 and BC1 was significantly enriched in the CD22-receptor-type tyrosine protein phosphatase C pathway;the communication between BC1 and osteoblasts was mainly enriched in the CD99-CD99 pathway;and the communication between BC3 and osteoblasts was also highly enriched in the CD99-CD99 pathway.Protein expression of CCL13,CCL18,receptor-type tyrosine protein phosphatase C,CD22,CD99,immunoglobulin heavy constant γ-4,immunoglobulin λ constant 3,human class Ⅱ major histocompatibility complex DRβ1,and CD83 mRNA were higher in femoral tissues of the osteoporosis group than those of the non-osteoporosis group(P<0.05).To conclude,specific B cell subpopulations can influence the differentiation and apoptosis of osteoblasts in the femoral tissue of osteoporosis patients.
10.The Evolutionary Trace and Structure-Function Relationship of the Cholera Toxin
Chinese Journal of Biochemistry and Molecular Biology 2025;41(10):1432-1444
The bacterial ADP-ribosylating exotoxins are produced by bacteria and infect different human body tissues.Herein,we investigated the molecular evolution of AB5-type bacterial toxins expressed by Vibrio cholerae and other bacteria with similar invasion mechanisms to interpret the co-evolutionary history of V.cholerae cholera toxin(CT)and their hosts,aiming to reveal the causes of its transdermal immuno-genicity.We elaborated on the intracellular toxicity mechanisms of CT,including ganglioside receptor-mediated endocytosis and hyperactivation of the cAMP pathway,as well as the behavioral traces of related bacteriophages within the genomes of these bacteria.Models such as the relatively decoupled evolution of A and B subunits of CT and the evolutionary coupling of transdermal and mucosal immunity were summa-rized.Furthermore,we described mechanisms including phage-mediated horizontal gene transfer(exem-plified by Vibrio phage CTXΦ),toxin targeting variation,expansion of molecular recognition domains,and functional adaptive evolution of the toxins.In this research,we employed bioinformatic tools to con-struct phylogenetic trees and analyze genetic variations in the amino acid sequences of toxin A/B subunits and proteins of secretion systems.Tajima's test was utilized to quantify genetic distance,diversity,and neutral selection pressure.Key findings include:(1)a"decoupled evolution"mode for the A and B subunits of CT,with the B subunit under stronger negative selection;(2)horizontal gene transfer media-ted by CTXΦ and other phages drives the cross-species spread of toxin genes;(3)the interaction be-tween the toxin co-regulated pilus(TCP)and the TLR-5(Toll-like receptor 5)promotes the transdermal immunogenicity of the CT B subunit.These findings suggest the role of"toxin-host arm race"co-evolu-tion,and are consistent with the hypothesis of intergenerational transmission of immune memory in CT e-volution,thereby providing theoretical support for further research into the biological mechanisms and co-evolutionary history of AB5-type bacterial toxins.

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