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.Analysis of T7 RNA Polymerase: From Structure-function Relationship to dsRNA Challenge and Biotechnological Applications
Wei-Chen NING ; Yu HUA ; Hui-Ling YOU ; Qiu-Shi LI ; Yao WU ; Yun-Long LIU ; Zhen-Xin HU
Progress in Biochemistry and Biophysics 2025;52(9):2280-2294
T7 RNA polymerase (T7 RNAP) is one of the simplest known RNA polymerases. Its unique structural features make it a critical model for studying the mechanisms of RNA synthesis. This review systematically examines the static crystal structure of T7 RNAP, beginning with an in-depth examination of its characteristic “thumb”, “palm”, and “finger” domains, which form the classic “right-hand-like” architecture. By detailing these structural elements, this review establishes a foundation for understanding the overall organization of T7 RNAP. This review systematically maps the functional roles of secondary structural elements and their subdomains in transcriptional catalysis, progressively elucidating the fundamental relationships between structure and function. Further, the intrinsic flexibility of T7 RNAP and its applications in research are also discussed. Additionally, the review presents the structural diagrams of the enzyme at different stages of the transcription process, and through these diagrams, it provides a detailed description of the complete transcription process of T7 RNAP. By integrating structural dynamics and kinetics analyses, the review constructs a comprehensive framework that bridges static structure to dynamic processes. Despite its advantages, T7 RNAP has a notable limitation: it generates double-stranded RNA (dsRNA) as a byproduct. The presence of dsRNA not only compromises the purity of mRNA products but also elicits nonspecific immune responses, which pose significant challenges for biotechnological and therapeutic applications. The review provides a detailed exploration of the mechanisms underlying dsRNA formation during T7 RNAP catalysis, reviews current strategies to mitigate this issue, and highlights recent progress in the field. A key focus is the semi-rational design of T7 RNAP mutants engineered to minimize dsRNA generation and enhance catalytic performance. Beyond its role in transcription, T7 RNAP exhibits rapid development and extensive application in fields, including gene editing, biosensing, and mRNA vaccines. This review systematically examines the structure-function relationships of T7 RNAP, elucidates the mechanisms of dsRNA formation, and discusses engineering strategies to optimize its performance. It further explores the engineering optimization and functional expansion of T7 RNAP. Furthermore, this review also addresses the pressing issues that currently need resolution, discusses the major challenges in the practical application of T7 RNAP, and provides an outlook on potential future research directions. In summary, this review provides a comprehensive analysis of T7 RNAP, ranging from its structural architecture to cutting-edge applications. We systematically examine: (1) the characteristic right-hand domains (thumb, palm, fingers) that define its minimalistic structure; (2) the structure-function relationships underlying transcriptional catalysis; and (3) the dynamic transitions during the complete transcription cycle. While highlighting T7 RNAP’s versatility in gene editing, biosensing, and mRNA vaccine production, we critically address its major limitation—dsRNA byproduct formation—and evaluate engineering solutions including semi-rationally designed mutants. By synthesizing current knowledge and identifying key challenges, this work aims to provide novel insights for the development and application of T7 RNAP and to foster further thought and progress in related fields.
3.Preparation and intestinal absorption mechanism of herpetrione and Herpetospermum caudigerum polysaccharides based self-assembled nanoparticles.
Xiang DENG ; Yu-Wen ZHU ; Ji-Xing ZHENG ; Rui SONG ; Jian-Tao NING ; Ling-Yu HANG ; Zhi-Hui YANG ; Hai-Long YUAN
China Journal of Chinese Materia Medica 2025;50(2):404-412
In this experiment, self-assembled nanoparticles(SANs) were prepared by the pH-driven method, and Her-HCP SAN was constructed by using herpetrione(Her) and Herpetospermum caudigerum polysaccharides(HCPs). The average particle size and polydispersity index(PDI) were used as evaluation indexes for process optimization, and the quality of the final formulation was evaluated in terms of particle size, PDI, Zeta potential, and microstructure. The proposed Her-HCP SAN showed a spheroid structure and uniform morphology, with an average particle size of(244.58±16.84) nm, a PDI of 0.147 1±0.014 8, and a Zeta potential of(-38.52±2.11) mV. Her-HCP SAN significantly increased the saturation solubility of Her by 2.69 times, with a cumulative release of 90.18% within eight hours. The results of in vivo unidirectional intestinal perfusion reveal that Her active pharmaceutical ingredient(API) is most effectively absorbed in the jejunum, where both K_a and P_(app) are significantly higher compared to the ileum(P<0.001). However, the addition of HCP leads to a significant reduction in the P_(app) of Her in the jejunum(P<0.05). Furthermore, the formation of the Her-HCP SAN results in a notably lower P_(app) in the jejunum compared to Her API alone(P<0.001), while both K_a and P_(app) in the ileum are significantly increased(P<0.001, P<0.05). The absorption of Her-HCP SAN at different concentrations in the ileum shows no significant differences, and the pH has no significant effect on the absorption of Her-HCP SAN in the ileum. The addition of the transporter protein inhibitors(indomethacin and rifampicin) significantly increases the absorption parameters K_a and P_(app) of Her-HCP SAN in the ileum(P<0.05,P<0.01), whereas the addition of verapamil has no significant effect on the intestinal absorption parameters of Her-HCP SAN, suggesting that Her may be a substrate for multidrug resistance-associated protein 2 and breast cancer resistance proteins but not a substrate of P-glycoprotein.
Nanoparticles/metabolism*
;
Polysaccharides/pharmacokinetics*
;
Intestinal Absorption/drug effects*
;
Animals
;
Rats
;
Particle Size
;
Drugs, Chinese Herbal/pharmacokinetics*
;
Male
;
Rats, Sprague-Dawley
;
Drug Carriers/chemistry*
;
Drug Compounding
;
Cucurbitaceae/chemistry*
4.Pharmacokinetics study of Dayuanyin in normal and febrile rats.
Yu-Jie HOU ; Kang-Ning XIAO ; Jian-Yun BI ; Xin-Jun ZHANG ; Xin-Rui LI ; Yu-Qing WANG ; Ming SU ; Xin-Ru SUN ; Hui ZHANG ; Bo-Yang WANG ; Li-Jie WANG ; Shan-Xin LIU
China Journal of Chinese Materia Medica 2025;50(2):527-533
Based on the pharmacokinetics theory, this study investigated the pharmacokinetic characteristics of albiflorin, paeoniflorin, wogonoside, and wogonin in normal and febrile rats and summarized absorption and elimination rules of Dayuanyin in them to provide reference for further development and clinical application of Dayuanyin. Blood samples were taken from the fundus venous plexus of normal and model rats after intragastric administration of Dayuanyin at different time points. The concentration of each substance in blood was determined by ultra performance liquid chromatography-triple quadrupole mass spectrometry(UPLC-MS/MS) technique at different time points. DAS 2.0, a piece of pharmacokinetics software, was used to calculate the pharmacokinetic parameters of each component. The results show that the 4 components had good linear relationship in their respective ranges, and the results of methodological investigation met the requirements. The pharmacokinetic parameters of C_(max), T_(max), t_(1/2), AUC_(0-t), AUC_(0-∞), and MRT_(0-t) were calculated by the DAS 2.0 non-compartmental model. Compared with those in the normal group, C_(max) and AUC_(0-t) of the 4 components in the model group were significantly increased. There were significant differences in the pharmacokinetic characteristics between the normal and model groups, suggesting that the absorption and elimination of Dayuanyin may be affected by the changes of internal environment of the body in different physiological states.
Animals
;
Rats
;
Drugs, Chinese Herbal/administration & dosage*
;
Male
;
Rats, Sprague-Dawley
;
Fever/metabolism*
;
Tandem Mass Spectrometry
;
Chromatography, High Pressure Liquid
;
Glucosides/pharmacokinetics*
;
Monoterpenes
5.Molecular mechanism of programmed cell death in lung cancer and progress in traditional Chinese medicine intervention.
Cheng LUO ; Bo NING ; Xin-Yue ZHANG ; Yu-Zhi HUO ; Xin-Hui WU ; Yuan-Hang YE ; Fei WANG
China Journal of Chinese Materia Medica 2025;50(3):632-643
Lung cancer is one of the most common and deadliest cancers globally, with its incidence and mortality rates rising each year. Therefore, finding new, safe, and effective alternative therapies poses a significant research challenge in this field. Programmed cell death refers to the process by which cells actively self-destruct in response to specific stimuli, regulated by genetic mechanisms. Modern research indicates that dysregulation of programmed cell death is widespread in the occurrence and progression of lung cancer, allowing cancer cells to evade death while continuing to proliferate and metastasize. Thus, inducing the death of lung cancer cells can be considered a novel therapeutic strategy for treating the disease. In recent years, research on traditional Chinese medicine(TCM) in the field of oncology has gained widespread attention, becoming a focal point. An increasing number of studies have demonstrated that TCM can inhibit the progression of lung cancer and exert anti-cancer effects by inducing apoptosis, necroptosis, pyroptosis, autophagy, and ferroptosis. This paper provided a comprehensive review of the molecular mechanisms of programmed cell death in lung cancer, along with the potential mechanisms and research advancements related to the regulation of these processes by TCM, so as to establish a theoretical foundation and direction for future basic and clinical research on lung cancer.
Humans
;
Lung Neoplasms/pathology*
;
Medicine, Chinese Traditional
;
Drugs, Chinese Herbal/therapeutic use*
;
Apoptosis/drug effects*
;
Animals
;
Autophagy/drug effects*
6.Identification of tissue distribution components and mechanism of antipyretic effect of famous classical formula Dayuanyin.
Yu-Jie HOU ; Kang-Ning XIAO ; Jian-Yun BI ; Xin-Rui LI ; Ming SU ; Li-Jie WANG ; Yu-Qing WANG ; Dan-Dan SUN ; Hui ZHANG ; Xin-Jun ZHANG ; Shan-Xin LIU
China Journal of Chinese Materia Medica 2025;50(10):2810-2824
Based on the ultra performance liquid chromatography-quadrupole Exactive Orbitrap mass spectrometry(UPLC-Q-Exactive Orbitrap-MS) technology, combined with related literature, databases, and reference material information, this study qualitatively analyzed the components of Dayuanyin in the tissue of rats after gavage and employed molecular docking technology to predict the rationality of the mechanism behind the antipyretic effect of the in vivo components in Dayuanyin. A total of 21, 26, 20, 21, 14, and 31 prototype components and 3, 16, 3, 7, 5, and 24 metabolites were identified from the heart, liver, spleen, lung, kidney, and hypothalamus of the rats, respectively, and the binding ability of key components and targets was further verified by molecular docking. The results showed that all components had good binding ability with targets. The established UPLC-Q-Exactive Orbitrap-MS could effectively and quickly identify the Dayuanyin components distributed in tissue and preliminarily identify their metabolites. Many components were identified in the hypothalamus, which suggested that the components delivered to the brain should be focused on in the study on Dayuanyin in the treatment of febrile diseases. The molecular docking technology was used to predict the rationality of the mechanism behind its antipyretic effect, which lays the foundation for the clarification of the material basis and action mechanism of Dayuanyin, the development of new preparations, and the prediction of quality markers.
Animals
;
Drugs, Chinese Herbal/administration & dosage*
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Rats
;
Molecular Docking Simulation
;
Male
;
Antipyretics/metabolism*
;
Rats, Sprague-Dawley
;
Tissue Distribution
;
Mass Spectrometry
;
Chromatography, High Pressure Liquid
;
Hypothalamus/metabolism*
7.Injectable agents for the induction of Peyronie's disease in model rats: a comparative study.
Guang-Jun DU ; Si-Yan XING ; Ning WU ; Tong WANG ; Yue-Hui JIANG ; Tao SONG ; Bai-Bing YANG ; Yu-Tian DAI
Asian Journal of Andrology 2025;27(1):96-100
Peyronie's disease (PD) is a disorder characterized by fibrous plaque formation in the penile tissue that leads to curvature and complications in advanced stages. In this study, we aimed to compare four injectable induction agents for the establishment of a robust rat model of PD: transforming growth factor-β1 (TGF-β1), fibrin, sodium tetradecyl sulfate (STS) combined with TGF-β1, and polidocanol (POL) combined with TGF-β1. The results showed that injection of TGF-β1 or fibrin into the tunica albuginea induced pathological endpoints without causing penile curvature. The STS + TGF-β1 combination resulted in both histological and morphological alterations, but with a high incidence of localized necrosis that led to animal death. The POL + TGF-β1 combination produced pathological changes and curvature comparable to STS + TGF-β1 and led to fewer complications. In conclusion, fibrin, STS + TGF-β1, and POL + TGF-β1 all induced PD with a certain degree of penile curvature and histological fibrosis in rats. The POL + TGF-β1 combination offered comparatively greater safety and clinical relevance and may have the greatest potential for PD research using model rats.
Animals
;
Male
;
Penile Induration/drug therapy*
;
Rats
;
Transforming Growth Factor beta1/metabolism*
;
Disease Models, Animal
;
Fibrin
;
Penis/drug effects*
;
Polidocanol/administration & dosage*
;
Rats, Sprague-Dawley
;
Polyethylene Glycols/administration & dosage*
;
Injections
8.Novel biallelic MCMDC2 variants were associated with meiotic arrest and nonobstructive azoospermia.
Hao-Wei BAI ; Na LI ; Yu-Xiang ZHANG ; Jia-Qiang LUO ; Ru-Hui TIAN ; Peng LI ; Yu-Hua HUANG ; Fu-Rong BAI ; Cun-Zhong DENG ; Fu-Jun ZHAO ; Ren MO ; Ning CHI ; Yu-Chuan ZHOU ; Zheng LI ; Chen-Cheng YAO ; Er-Lei ZHI
Asian Journal of Andrology 2025;27(2):268-275
Nonobstructive azoospermia (NOA), one of the most severe types of male infertility, etiology often remains unclear in most cases. Therefore, this study aimed to detect four biallelic detrimental variants (0.5%) in the minichromosome maintenance domain containing 2 ( MCMDC2 ) genes in 768 NOA patients by whole-exome sequencing (WES). Hematoxylin and eosin (H&E) demonstrated that MCMDC2 deleterious variants caused meiotic arrest in three patients (c.1360G>T, c.1956G>T, and c.685C>T) and hypospermatogenesis in one patient (c.94G>T), as further confirmed through immunofluorescence (IF) staining. The single-cell RNA sequencing data indicated that MCMDC2 was substantially expressed during spermatogenesis. The variants were confirmed as deleterious and responsible for patient infertility through bioinformatics and in vitro experimental analyses. The results revealed four MCMDC2 variants related to NOA, which contributes to the current perception of the function of MCMDC2 in male fertility and presents new perspectives on the genetic etiology of NOA.
Humans
;
Male
;
Azoospermia/genetics*
;
Meiosis/genetics*
;
Spermatogenesis/genetics*
;
Adult
;
Exome Sequencing
;
Microtubule-Associated Proteins/genetics*
;
Alleles
;
Infertility, Male/genetics*
9.Regulation of testosterone synthesis by circadian clock genes and its research progress in male diseases.
Gang NING ; Bo-Nan LI ; Hui WU ; Ruo-Bing SHI ; A-Jian PENG ; Hao-Yu WANG ; Xing ZHOU
Asian Journal of Andrology 2025;27(5):564-573
The circadian clock is an important internal time regulatory system for a range of physiological and behavioral rhythms within living organisms. Testosterone, as one of the most critical sex hormones, is essential for the development of the reproductive system, maintenance of reproductive function, and the overall health of males. The secretion of testosterone in mammals is characterized by distinct circadian rhythms and is closely associated with the regulation of circadian clock genes. Here we review the central and peripheral regulatory mechanisms underlying the influence of circadian clock genes upon testosterone synthesis. We also examined the specific effects of these genes on the occurrence, development, and treatment of common male diseases, including late-onset hypogonadism, erectile dysfunction, male infertility, and prostate cancer.
Testosterone/metabolism*
;
Humans
;
Male
;
Circadian Clocks/genetics*
;
Circadian Rhythm Signaling Peptides and Proteins/metabolism*
;
Circadian Rhythm/physiology*
;
Hypogonadism/metabolism*
;
Erectile Dysfunction/metabolism*
;
Infertility, Male/metabolism*
;
Prostatic Neoplasms/metabolism*
;
Men's Health
10.Multi-modal magnetic resonance imaging assessment and mechanism exploration of preterm white matter injury in neonatal rats.
Xiao-Tian GAO ; Hai-Mo ZHANG ; Xiao-Zu ZHANG ; Yi-Jing WANG ; Hui-Ning BI ; Miao YU ; Yan LI ; Xiao-Li WANG
Chinese Journal of Contemporary Pediatrics 2025;27(3):366-372
OBJECTIVES:
To evaluate preterm white matter injury (PWMI) in neonatal rats using multimodal magnetic resonance imaging (MRI) combined with histological assessments and to explore its underlying mechanisms.
METHODS:
Healthy 3-day-old Sprague-Dawley neonatal rats were randomly divided into a sham operation group and a PWMI group (n=12 in each group). A PWMI model was established in neonatal rats through hypoxia-ischemia. Laser speckle imaging was used to observe changes in cerebral oxygen saturation and blood flow at different time points post-modeling. Multimodal MRI was employed to assess the condition of white matter injury, while hematoxylin-eosin staining was utilized to observe morphological changes in the striatal area on the injured side. Immunofluorescence staining was performed to detect the proliferation and differentiation of oligodendrocyte precursor cells.
RESULTS:
At 0, 6, 12, 24, and 72 hours post-modeling, the relative blood flow and relative oxygen saturation on the injured side in the PWMI group were significantly lower than those in the sham operation group (P<0.05). At 24 hours post-modeling, T2-weighted imaging showed high signals in the white matter of the injured side in the PWMI group, with relative apparent diffusion coefficient values and Lorenz differential values being lower than those in the sham operation group (P<0.001); additionally, the arrangement of nerve cells in the PWMI group was disordered, and the number of EdU+PDGFR-α+ cells was higher than that in the sham operation group (P<0.001). At 28 days post-modeling, the relative fractional anisotropy values, the number of EdU+Olig2+ cells, and the fluorescence intensity of myelin basic protein and neurofilament protein 200 in the white matter region of the PWMI group were all lower than those in the sham operation group (P<0.001).
CONCLUSIONS
Multimodal MRI can evaluate early and long-term changes in PWMI in neonatal rat models in vivo, providing both imaging and pathological evidence for the diagnosis and treatment of PWMI in neonates. Hypoxia-ischemia inhibits the proliferation and differentiation of oligodendrocyte precursor cells in neonatal rats, leading to PWMI.
Animals
;
Rats, Sprague-Dawley
;
Magnetic Resonance Imaging/methods*
;
Rats
;
White Matter/injuries*
;
Animals, Newborn
;
Female
;
Multimodal Imaging
;
Male
;
Hypoxia-Ischemia, Brain/pathology*

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