1.The Structure and Function of The YopJ Family Effectors in The Bacterial Type III Secretion System
Ao-Ning LI ; Wen-Bo LI ; Yu-Ying LU ; Min-Hui ZHU ; Yu-Long QIN ; Yong ZHAO ; Zhao-Huan ZHANG
Progress in Biochemistry and Biophysics 2026;53(3):516-533
The Type III Secretion System (T3SS) serves as a pivotal virulence apparatus for numerous Gram-negative bacterial pathogens, enabling them to infect both animal and plant hosts. Functioning as a molecular syringe, the T3SS directly translocates bacterial effector proteins from the bacterial cytoplasm into the interior of eukaryotic host cells. These effectors are central weapons that precisely manipulate a wide spectrum of host cellular physiological processes, ranging from cytoskeletal dynamics to immune signaling, to establish a favorable niche for bacterial survival and proliferation. Among the diverse arsenal of T3SS effectors, the YopJ family constitutes a critical group of virulence factors. Members of this family are characterized by a conserved catalytic triad structure—a hallmark of the CE clan of cysteine proteases that has been evolutionarily repurposed to confer acetyltransferase activity. A defining and intriguing feature of these enzymes is their stringent dependence on a host-derived eukaryotic cofactor, inositol hexakisphosphate (IP6), for allosteric activation. This requirement acts as a sophisticated molecular safeguard, ensuring enzymatic activity only within the appropriate host environment, thereby preventing detrimental effects on the bacterium itself. While seminal studies on individual members such as Yersinia’s YopJ and Salmonella’s AvrA have provided deep mechanistic insights, a systematic and integrative understanding of the structure-function relationships across the entire family remains fragmented. Key questions persist regarding how a conserved catalytic core has diverged to recognize distinct host substrates in different kingdoms of life. To address this gap, this article provides a systematic review of the YopJ family, focusing on three interconnected aspects: their structural features, their catalytic mechanism, and their divergent immunosuppressive strategies in animal versus plant hosts. By conducting a comparative analysis of the sequences and resolved three-dimensional structures of three representative members (e.g., HopZ1a, PopP2, AvrA), we elucidate regions of significant variation embedded within the conserved core catalytic architecture. These variable regions, often involving surface loops and substrate-binding interfaces, are crucial determinants of target specificity and functional specialization. The functional divergence of this effector family is most apparent when comparing their modes of action in different hosts. In animal hosts, YopJ-family effectors primarily sabotage innate immune signaling pathways. They achieve this by acetylating key serine and threonine residues within the activation loops of critical kinases in the MAPK and NF‑κB pathways. This post-translational modification blocks the phosphorylation and subsequent activation of these kinases, leading to potent suppression of inflammatory cytokine production. Conversely, in plant hosts, the strategy broadens to dismantle the two-tiered plant immune system. YopJ homologs target a more diverse set of substrates, including immune-associated receptor-like cytoplasmic kinases (RLCKs), microtubule networks via tubulin acetylation (which disrupts cellular trafficking and signaling), and transcription factors central to defense gene regulation. This multi-target approach effectively suppresses both Pattern-Triggered Immunity (PTI) and Effector-Triggered Immunity (ETI). In conclusion, this synthesis aims to deepen the mechanistic understanding of YopJ family-mediated pathogenesis by integrating structural biology with cellular function across host kingdoms. Elucidating the precise molecular basis for substrate selection—how conserved platforms achieve target diversity—is a major frontier. Furthermore, this knowledge provides a vital theoretical foundation for developing novel anti-virulence strategies. Targeting the conserved IP6-binding pocket or the catalytic acetyltransferase activity itself represents a promising avenue for designing broad-spectrum inhibitors that could disarm this critical family of bacterial effectors, potentially offering new therapeutic approaches against a range of pathogenic bacteria.
2.The Regulatory Effects and Mechanisms of Piezo1 Channel on Chondrocytes and Bone Metabolic Dysregulation in Osteoarthritis
Yan LI ; Tao LIU ; Yu-Biao GU ; Hui-Qing TIAN ; Lei ZHANG ; Bi-Hui BAI ; Zhi-Jun HE ; Wen CHEN ; Jin-Peng LI ; Fei LI
Progress in Biochemistry and Biophysics 2026;53(3):564-576
Osteoarthritis (OA), a highly prevalent degenerative joint disease worldwide, is defined by articular cartilage degradation, abnormal bone remodeling, and persistent chronic inflammation. It severely compromises patients’ quality of life, and currently, there is no radical cure. Abnormal mechanical stress is widely regarded as a core driver of OA pathogenesis, and the exploration of mechanical signal perception and transduction mechanisms has become crucial for deciphering OA’s pathophysiological processes. Piezo1, a key mechanosensitive cation channel belonging to the Piezo protein family, has recently gained significant attention due to its pivotal role in mediating cellular responses to mechanical stimuli in joint tissues. This review systematically examines Piezo1’s expression patterns, regulatory mechanisms, and pathological functions in OA, with a particular focus on its dual roles in modulating chondrocyte homeostasis and bone metabolism disorders, while also delving into the underlying molecular signaling pathways and potential therapeutic implications. Piezo1, consisting of approximately 2 500 amino acids and forming a unique trimeric propeller-like structure, is widely expressed in chondrocytes, osteocytes, mesenchymal stem cells, and synovial cells. It exhibits permeability to cations such as Ca2+, K+, and Na+, and directly responds to membrane tension changes induced by mechanical stimuli like fluid shear stress and mechanical overload. In OA patients and animal models, Piezo1 expression is significantly upregulated, especially in cartilage regions subjected to abnormal mechanical stress (e.g., human temporomandibular joint cartilage). This overexpression is closely associated with aggravated cartilage degeneration, increased chondrocyte apoptosis, accelerated cellular senescence, and intensified inflammatory responses. Mechanical overload and pro-inflammatory cytokines (e.g., IL-1β) are key inducers of Piezo1 upregulation: IL-1β activates the PI3K/AKT/mTOR signaling pathway to enhance Piezo1 expression, forming a pathogenic positive feedback loop that inhibits chondrocyte autophagy, promotes apoptosis, and further accelerates joint degeneration. Mechanistically, Piezo1 mediates OA progression through multiple interconnected pathways. When activated by mechanical stress, Piezo1 triggers excessive Ca2+ influx, leading to endoplasmic reticulum stress (ERS) and mitochondrial dysfunction, which directly induce chondrocyte apoptosis. This process involves the activation of downstream signaling cascades such as cGAS-STING and YAP-MMP13/ADAMTS5. YAP, a transcriptional regulator, upregulates the expression of matrix metalloproteinase 13 (MMP13) and aggrecanase (ADAMTS5), thereby accelerating cartilage matrix degradation. Additionally, Piezo1-driven Ca2+ overload promotes the accumulation of reactive oxygen species (ROS) and upregulates senescence markers (p16 and p21), accelerating chondrocyte senescence via the p38MAPK and NF-κB pathways. Senescent chondrocytes secrete senescence-associated secretory phenotype (SASP) factors (e.g., IL-6, IL-1β), further amplifying joint inflammation. In terms of bone metabolism, Piezo1 maintains joint homeostasis by promoting the differentiation of fibrocartilage stem cells into chondrocytes and balancing bone formation and resorption through regulating the FoxC1/YAP axis and RANKL/OPG ratio. Therapeutically, targeting Piezo1 shows promising potential. Preclinical studies have demonstrated that Piezo1 inhibitors (e.g., GsMTx4) can reduce joint damage and alleviate pain in OA mice. Simultaneously, siRNA-mediated co-silencing of Piezo1 and TRPV4 (another mechanosensitive channel) decreases intracellular Ca2+ concentration, inhibits chondrocyte apoptosis, and promotes cartilage repair. Conditional knockout of Piezo1 using Gdf5-Cre transgenic mice alleviates cartilage degeneration in post-traumatic OA models by downregulating MMP13 and ADAMTS5 expression. Despite existing challenges, such as off-target effects of inhibitors, inefficient local drug delivery, and interindividual genetic variability, strategies like developing selective Piezo1 antagonists, optimizing targeted nanocarriers, and combining Piezo1-targeted therapy with physical therapy provide viable avenues for clinical translation. The authors propose that Piezo1 serves as a critical therapeutic target for OA, and future research should focus on deciphering its context-dependent regulatory networks, developing tissue-specific intervention strategies, and validating their efficacy and safety in clinical trials to address the unmet medical needs of OA patients.
3.The first record of Anopheles messeae (Diptera: Culicidae) parasitized by water mites in China
Xue-ru CHEN ; Wen-zhen YAO ; Yu-hao LI ; Gui-chang LI ; Tao MENG ; Qun-ling FENG ; Xin-hui LIU ; Li-hong QIAO ; Xiang-ting WU ; Xue-feng ZHANG ; Cheng-lin LI ; Xue-cheng DONG ; Da-wei WANG ; Xiao-yan SI ; Yu-hong GUO
Acta Parasitologica et Medica Entomologica Sinica 2026;33(1):53-57
Objective This study reports on the obligatory parasitism of water mites Arrenurus sp. on Anopheles messeae at the Manzhouli Port, Inner Mongolia, China. Methods Duing July 2024, a survey on the mosquito diversity was conducted at the Manzhouli Port. Captured mosquitoes and their ectoparasites were identified to species level. Results A total of 1840 adult mosquitoes were collected, representing species from three genera: Culex(Cx. modestus, Cx. pipiens pallens), Aedes(Ae. dorsalis, Ae. flavidorsalis, Ae. flavescens), and Anopheles (An. messeae). Among all the mosqutioes specimens,3 out of 150 captured An. messeae were found to carry ectoparasitic mites, with number of 2,4,27 mites separately. Morphological and molecular identification reached the same result as water mites(Hydrachnidiae, Hydracrina). COI gene sequence showed 94% similarity with the closest species Arrenurus truncatellus. Conlusions Literature review suggests water mites are host-specific parasitism of mosquito species and herein with the first record of Arrenurus sp. parasiting on An. Messeae in the most high-latitude region globally.
4.Inhibition of HDAC3 Promotes Psoriasis Development in Mice Through Regulating Th17
Fan XU ; Xin-Rui ZHANG ; Yang-Chen XIA ; Wen-Ting LI ; Hao CHEN ; An-Qi QIN ; Ai-Hong ZHANG ; Yi-Ran ZHU ; Feng TIAN ; Quan-Hui ZHENG
Progress in Biochemistry and Biophysics 2025;52(4):1008-1017
ObjectiveTo investigate the influence of histone deacetylase 3 (HDAC3) on the occurrence, development of psoriasis-like inflammation in mice, and the relative immune mechanisms. MethodsHealthy C57BL/6 mice aged 6-8 weeks were selected and randomly divided into 3 groups: control group (Control), psoriasis model group (IMQ), and HDAC3 inhibitor RGFP966-treated psoriasis model group (IMQ+RGFP966). One day prior to the experiment, the back hair of the mice was shaved. After a one-day stabilization period, the mice in Control group was treated with an equal amount of vaseline, while the mice in IMQ group was treated with imiquimod (62.5 mg/d) applied topically on the back to establish a psoriasis-like inflammation model. The mice in IMQ+RGFP966 group received intervention with a high dose of the HDAC3-selective inhibitor RGFP966 (30 mg/kg) based on the psoriasis-like model. All groups were treated continuously for 5 d, during which psoriasis-like inflammation symptoms (scaling, erythema, skin thickness), body weight, and mental status were observed and recorded, with photographs taken for documentation. After euthanasia, hematoxylin-eosin (HE) staining was used to assess the effect of RGFP966 on the skin tissue structure of the mice, and skin thickness was measured. The mRNA and protein expression levels of HDAC3 in skin tissues were detected using reverse transcription real-time quantitative polymerase chain reaction (RT-qPCR) and Western blot (WB), respectively. Flow cytometry was employed to analyze neutrophils in peripheral blood and lymph nodes, CD4+ T lymphocytes, CD8+ T lymphocytes in peripheral blood, and IL-17A secretion by peripheral blood CD4+ T lymphocytes. Additionally, spleen CD4+ T lymphocyte expression of HDAC3, CCR6, CCR8, and IL-17A secretion levels were analyzed. Immunohistochemistry was used to detect the localization and expression levels of HDAC3, IL-17A, and IL-10 in skin tissues. ResultsCompared with the Control group, the IMQ group exhibited significant psoriasis-like inflammation, characterized by erythema, scaling, and skin wrinkling. Compared with the IMQ group, RGFP966 exacerbated psoriasis-like inflammatory symptoms, leading to increased hyperkeratosis. The psoriasis area and severity index (PASI) skin symptom scores were higher in the IMQ group than those in the Control group, and the scores were further elevated in the IMQ+RGFP966 group compared to the IMQ group. Skin thickness measurements showed a trend of IMQ+RGFP966>IMQ>Control. The numbers of neutrophils in the blood and lymph nodes increased sequentially in the Control, IMQ, and IMQ+RGFP966 groups, with a similar trend observed for CD4+ and CD8+ T lymphocytes in the blood. In skin tissues, compared with the Control group, the mRNA and protein levels of HDAC3 decreased in the IMQ group, but RGFP966 did not further reduce these expressions. HDAC3 was primarily located in the nucleus. Compared with the Control group, the nuclear HDAC3 content decreased in the skin tissues of the IMQ group, and RGFP966 further reduced nuclear HDAC3. Compared with the Control and IMQ groups, RGFP966 treatment decreased HDAC3 expression in splenic CD4+ and CD8+ T cells. RGFP966 treatment increased the expression of CCR6 and CCR8 in splenic CD4+ T cells and enhanced IL-17A secretion by peripheral blood and splenic CD4+ T lymphocytes. Additionally, compared with the IMQ group, RGFP966 reduced IL-10 protein levels and upregulated IL-17A expression in skin tissues. ConclusionRGFP966 exacerbates psoriatic-like inflammatory responses by inhibiting HDAC3, increasing the secretion of the cytokine IL-17A, and upregulating the expression of chemokines CCR8 and CCR6.
5.Bioactive metabolites: A clue to the link between MASLD and CKD?
Wen-Ying CHEN ; Jia-Hui ZHANG ; Li-Li CHEN ; Christopher D. BYRNE ; Giovanni TARGHER ; Liang LUO ; Yan NI ; Ming-Hua ZHENG ; Dan-Qin SUN
Clinical and Molecular Hepatology 2025;31(1):56-73
Metabolites produced as intermediaries or end-products of microbial metabolism provide crucial signals for health and diseases, such as metabolic dysfunction-associated steatotic liver disease (MASLD). These metabolites include products of the bacterial metabolism of dietary substrates, modification of host molecules (such as bile acids [BAs], trimethylamine-N-oxide, and short-chain fatty acids), or products directly derived from bacteria. Recent studies have provided new insights into the association between MASLD and the risk of developing chronic kidney disease (CKD). Furthermore, alterations in microbiota composition and metabolite profiles, notably altered BAs, have been described in studies investigating the association between MASLD and the risk of CKD. This narrative review discusses alterations of specific classes of metabolites, BAs, fructose, vitamin D, and microbiota composition that may be implicated in the link between MASLD and CKD.
6.Bioactive metabolites: A clue to the link between MASLD and CKD?
Wen-Ying CHEN ; Jia-Hui ZHANG ; Li-Li CHEN ; Christopher D. BYRNE ; Giovanni TARGHER ; Liang LUO ; Yan NI ; Ming-Hua ZHENG ; Dan-Qin SUN
Clinical and Molecular Hepatology 2025;31(1):56-73
Metabolites produced as intermediaries or end-products of microbial metabolism provide crucial signals for health and diseases, such as metabolic dysfunction-associated steatotic liver disease (MASLD). These metabolites include products of the bacterial metabolism of dietary substrates, modification of host molecules (such as bile acids [BAs], trimethylamine-N-oxide, and short-chain fatty acids), or products directly derived from bacteria. Recent studies have provided new insights into the association between MASLD and the risk of developing chronic kidney disease (CKD). Furthermore, alterations in microbiota composition and metabolite profiles, notably altered BAs, have been described in studies investigating the association between MASLD and the risk of CKD. This narrative review discusses alterations of specific classes of metabolites, BAs, fructose, vitamin D, and microbiota composition that may be implicated in the link between MASLD and CKD.
7.The Xenomitochondrion Provides Extensive Supply for Mitochondrial Transplantation
Zhen YANG ; Wen-Peng LI ; Tian NIU ; Hui-Wen XUE ; Si-Xi ZHAO ; Xing-Bo ZHAO
Chinese Journal of Biochemistry and Molecular Biology 2025;41(2):273-283
Mitochondria are organelles in eukaryotic cells that play a crucial role in cellular energy me-tabolism,oxidative stress,heat production,and signal transduction.Mitochondrial transplantation(MT)is currently one of the most advanced techniques for treating mitochondrial dysfunction and anti-aging re-search.This study aimed to explore the feasibility and effectiveness of xenogeneic MT by transplanting mitochondria from yak(Bos grunniens),domestic cattle(Bos taurus),and horse(Equus caballus)into mice(Mus musculus).The results demonstrated that mitochondria from yak,domestic cattle,and horse could be successfully transplanted into mice and maintained in various tissues and organs of the mice for at least 14 days,as confirmed by confocal imaging,digital PCR,and DNA sequencing.MT mice exhibi-ted positive biological effects,including increased ATP content and mitochondrial DNA copy number(P<0.05),with the maximum effect observed on day 7,which was sustained until day 14.Reactive oxygen species(ROS)levels in MT mice significantly increased at 2 hours post-injection(P<0.05),then grad-ually decreased towards baseline levels by day 7 and day 14(P>0.05).These findings support the effec-tiveness of xenogeneic MT and suggest that the effects can be maintained for up to 14 days.This study provides scientific evidence for future clinical applications.
8.Analysis on the disease burden trend and attributable risk factors of common gynecological cancers in China from 1990 to 2021
Xiao-hui ZHOU ; Yi-xin ZOU ; Zhuo-ying LI ; Yu-xuan XIAO ; Dan-dan TANG ; Yu-xin ZHOU ; Pei-wen LU ; Qun XU ; Yong-bing XIANG
Fudan University Journal of Medical Sciences 2025;52(6):783-793
Objective To describe and analyze the current status,changing trend and influencing factors of the disease burden of cervical,endometrial and ovarian cancer in China from 1990 to 2021.Methods Data on incidence,mortality,disability-adjusted life year(DALY),and other indicators for cervical,endometrial and ovarian cancer were collected from the 2021 Global Burden of Disease database.Joinpoint regression models were used to analyze time trends,and age-period-cohort(APC)models assessed their impact on incidence and mortality.Spearman correlation analysis was performed to evaluate the relationship between the sociodemographic index(SDI)and the cancer indicators.Finally,the attributable risk factors for the disease burden were analyzed.Results From 1990 to 2021,age-standardized incidence rates of cervical and endometrial cancers in China significantly increased,while ovarian cancer showed no significant change.Age-standardized mortality,DALY,and years of life lost due to premature death(YLL)decreased significantly.The disease burden was heavier in middle-aged and older groups.APC model indicated an increase in cervical cancer incidence and a decrease in mortality over time.Furthermore,the incidence risks of cervical and endometrial cancers were elevated in successive birth cohorts,whereas a lower risk was observed for ovarian cancer.Correlation analysis showed significant associations between cancer incidence and mortality with SDI.Obesity has significantly contributed to the disease burden of common gynecologic cancers in China.Conclusion Mortality rates of cervical,endometrial and ovarian cancer have declined,while the incidence of cervical and endometrial cancers has significantly increased.The trends in incidence and mortality are influenced by age,period and cohort effects.Future efforts should focus on controlling risk factors like obesity to reduce the disease burden.
9.Cross-sectional survey of healthcare-associated infection in 5 736 medical institutions across China in 2024
Cui ZENG ; Wuqiang GAO ; Fu QIAO ; Hui ZHAO ; Xu FANG ; Linping LI ; Xiuwen CHEN ; Jiansen CHEN ; Dan LI ; Yuan ZHOU ; Lingli YU ; Qinglan MENG ; Xia MOU ; Lijuan XIONG ; Weiguang LI ; Ding LIU ; Jiaqing XIAO ; Limei OU ; Baozhen LI ; Jun YIN ; Haojun ZHANG ; Qiang FU ; Qun LU ; Biao WU ; Ya-wei XING ; Shumei SUN ; Shuncai WANG ; Longmin DU ; Jingping ZHANG ; Wen-ying HE ; Gui CHENG ; Nan REN ; Xun HUANG ; Anhua WU
Chinese Journal of Infection Control 2025;24(11):1572-1583
Objective To understand the current situation of healthcare-associated infection(HAI)in China,pro-vide data support and decision-making basis for formulating scientific and effective strategies for HAI prevention and control.Methods A nationwide cross-sectional survey on HAI was conducted among various types and levels of medical institutions in China according to a unified protocol of bedside surveys and case investigations.Results In 2024,a total of 5 736 medical institutions and 2 751 765 patients were surveyed.Among them,34 889 HAI cases were identified,with a prevalence rate of 1.27%.The number of HAI episodes was 38 032,and case prevalence rate was 1.38%.The prevalence rate of HAI in medical institutions in different regions of China ranged from 0.66%to 2.35%.Among medical institutions of different scales,those with a bed capacity of ≥900 had the high-est incidence of HAI,reaching 1.65%.The most common infection site was the lower respiratory tract(44.66%),followed by the urinary tract(12.94%),surgical site(9.32%),upper respiratory tract(7.02%),and bloodstream infection(5.78%).The top 3 departments with the highest HAI rates were the general intensive care unit(10.02%),department of neurosurgery(5.51%),and department(group)of hematology(5.34%).A total of 23 238 strains of HAI pathogens were detected,with 10 714 strains(46.10%)from lower respiratory tract speci-mens.The top 5 detected strains were Klebsiella pneumoniae(14.76%),Pseudomonas aeruginosa(13.33%),Escherichia coli(12.79%),Acinetobacter baumannii(9.23%),and Staphylococcus aureus(7.88%).231 944 pa-tients underwent class Ⅰ incision surgery were monitored,with 1 647 cases experienced surgical site infection,and the prevalence rate of surgical site infection was 0.71%.The number of patients who should undergo pathogen de-tection(patients receiving therapeutic and therapeutic combined prophylactic antimicrobial agents)was 715 179,while the actual number was 480 492,with a pathogen detection rate of 67.18%.425 225 patients received patho-genic detection before treatment,with a detection rate of 59.46%.Conclusion The overall HAI prevalence in Chi-na is lower,showing disparities among medical institutions of different regions and scales.Therefore,precise imple-mentation of measures is necessary for HAI prevention and control,with a focus on high-risk institutions and high-risk departments,key areas,and critical procedures.All levels of medical institutions should continuously reduce the incidence of HAI by strengthening monitoring,standardizing the use of antimicrobial agents,and reinforcing basic HAI prevention and control measures.
10.Mechanistic Study of ATO and MET Synergistically Promoting Apoptosis in Leukemia Cells
Meng LIU ; Li-Wen-Hui HUANG ; Xiao-Hui SI ; Xin-Qing NIU
Journal of Experimental Hematology 2025;33(6):1609-1616
Objective:To study the mechanism of arsenic trioxide(ATO)combined with metformin(MET)in promoting apoptosis of leukemia cells.Methods:CCK-8 method was used to detect the viability of leukemia cell line KG1a,K562,and THP1 cells treated by ATO monotherapy,MET monotherapy,and ATO combined with MET.Flow cytometry was used to detect cell cycle and apoptosis.RT-qPCR was used to detect the mRNA expression of PI3K/Akt and LKB1/AMPK pathway-related genes.Western blot was used to detect the expression of PI3K/Akt and LKB1/AMPK pathway-related proteins and autophagy-related protein LC3B and P62.Results:Compared with the ATO monotherapy group,ATO combined with MET significantly inhibited the growth of KG1a,K562 and THP1 cells,and the difference in KG1a cells was more statistically significant.The combination of the two drugs induced KG1a cell cycle arrest,promoted apoptosis,increased the expression of autophagy-related protein LC3B and P62,up-regulated the mRNA expression levels of PI3K/Akt pathway and LKB1/AMPK pathway-related genes,as well as the expression of LKB1/AMPK pathway-related proteins,and down-regulated the expression of PI3K/Akt pathway-related proteins.Conclusion:ATO combined with MET promotes apoptosis by up-regulating LKB1/AMPK and down-regulating PI3K/Akt signaling pathway to regulate the autophagy of leukemia cells.


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