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.

ObjectiveTo establish steroid-induced osteonecrosis of the femoral head （SANFH） cell model by using dexamethasone （DEX）-induced bone marrow mesenchymal stem cells （BMSCs） and demonstrate that Gushing Granules （GSNs） exert an improving effect by activating the phosphatidylinositol-3-kinase/protein kinase B/B-lymphoma-2 gene related promoter （PI3K/Akt/Bad） signalling pathway. MethodsFirstly， SD rats were orally administered with drugs at a dose of 0.9 g·kg^-1 to prepare GSN-containing serum， and CCK-8 screening was used to determine the optimal dosage and duration of action. Then， BMSCs were cultured and treated with 1×10^-6 mol·L^-1 DEX， 10% GSN-containing serum， and inhibitor LY294002 of PI3K/Akt signalling pathway for 24 hours to model and group SANFH cells. Cell viability and proliferation were detected by using CCK-8 assay kit and EdU staining kit. Flow cytometry was used to detect cell apoptosis. An alkaline phosphatase （ALP） assay kit was employed to detect ALP expression. In order to detect the PI3K/Akt/Bad signalling pathway and protein and mRNA expression of apoptosis-related proteins such as apoptosis regulatory factors B-cell lymphoma-2 gene （Bcl-2）， and Bcl-2-associated X protein （Bax）， osteocalcin （OCN）， and Collagen Ⅰ， we used Western blot and Real-time fluorescence quantitative polymerase chain reaction （Real-time PCR）. ResultsThe CCK-8 assay kit determined that the optimal dosage for GSN-containing serum is 10%， and the duration of action is 48 hours. After modelling and grouping the cells in each group， the detection results showed that the SANFH model group had significantly lower cell viability， cell proliferation， and ALP expression， as well as protein and mRNA expressions of PI3K， Akt， Bad， Bcl-2， OCN， and Collagen I compared to the blank group. The nucleic acid and protein levels of the Bax index and the cell apoptosis rate detected by flow cytometry significantly increased （P<0.05，P<0.01）. After treatment with GSN-containing serum， cell viability， cell proliferation， and ALP expression， as well as expressions of PI3K， Akt， Bad， Bcl-2， OCN， and Collagen Ⅰ nucleic acids and proteins were significantly increased， while the nucleic acid and protein levels of the Bax index and the cell apoptosis rate detected by flow cytometry significantly decreased（P<0.05，P<0.01）. Compared with the GSN drug-containing serum group， the simultaneous treatment with the inhibitor LY294002 and GSN drug-containing serum reversed the improvement effect of GSN. Specifically， the cell viability， cell proliferation， ALP expression， and the nucleic acid and protein levels of PI3K， Akt， Bad， Bcl-2， OCN， and Collagen Ⅰ were all significantly decreased， while the nucleic acid and protein levels of the Bax index and the cell apoptosis rate detected by flow cytometry were significantly increased （P<0.05， P<0.01）. ConclusionGSNs antagonize DEX-induced apoptosis of BMSCs by activating the PI3K/Akt/Bad signalling pathway， providing a scientific theoretical basis for the clinical treatment of SANFH with GSNs.

Objective:To evaluate the role of NOD-like receptor protein 3 (NLRP3) inflammasome-mediated microglia activation in myocardial ischaemia-reperfusion-induced brain injury in mice.Methods:Fifty-two SPF healthy male wild-type C57BL/6 mice and 52 NLRP3 -/- mice, aged 8-10 weeks, were divided into 4 groups ( n=26 each) using a random number table method: wild type sham operation group (W-S group), wild type myocardial ischemia-reperfusion group (W-IR group), NLRP3 -/- sham operation group (NLRP3 -/--S group), and NLRP3 -/- myocardial ischemia-reperfusion group (NLRP3 -/--IR group). The myocardial ischemia-reperfusion-induced brain injury model was established by ligating the left anterior descending coronary artery for 45 min followed by 24 h of reperfusion in anesthetized mice. The cognitive function was evaluated using the modified Morris water maze test at 24 h of reperfusion. The mice were sacrificed after blood specimens were collected, and brain tissues were obtained for measurement of the blood-brain barrier permeability and water content, for microscopic examination of the pathological changes of brain tissues, and for determination of serum S-100β protein and neuron-specific enolase (NSE) concentrations, contents of interleukin-1 beta (IL-1β), IL-6 and tumor necrosis factor-alpha (TNF-α) in hippocampal tissues (by enzyme-linked immunosorbent assay), expression of NLRP3, apoptosis-associated speck-like protein (ASC), cleaved cysteine aspartate protease 1 (cleaved-caspase-1), gasdermin D (GSDMD), ionized calcium-binding adapter molecule 1 (Iba-1), and occludin in hippocampal tissues (by immunofluorescence and/or Western blot). The apoptosis rate of neurons and density of dendritic spine were calculated. Results:Compared with sham operation group, the escape latency was significantly prolonged, the number of crossing the original platform was decreased, and the time spent in the target quadrant was shortened, the concentrations of serum S-100β protein and NSE were increased, the blood-brain barrier permeability and brain water content were increased, the dendritic spine density in the hippocampal CA1 area was decreased, the contents of IL-1β, IL-6 and TNF-α were increased, the expression of NLRP3, ASC, cleaved-caspase-1, GSDMD and Iba-1 was up-regulated, and the expression of occludin was down-regulated ( P<0.05), and the pathological injury to brain tissues was found in ischemia-reperfusion group. Compared with W-IR group, the escape latency was significantly shortened, the number of crossing the original platform was increased, and the time spent in the target quadrant was prolonged, the concentrations of serum S-100β protein and NSE were decreased, the blood-brain barrier permeability and brain water content were decreased, the dendritic spine density in the hippocampal CA1 area was increased, the contents of IL-1β, IL-6 and TNF-α were decreased, the expression of NLRP3, ASC, cleaved-caspase-1, GSDMD and Iba-1 was down-regulated, and the expression of occludin was up-regulated ( P<0.05), and the pathological injury to brain tissues was alleviated in NLRP3 -/--IR group. Conclusions:NLRP3 inflammasome-mediated microglia activation is involved in myocardial ischaemia-reperfusion-induced brain injury in mice.

Inflammatory diseases (IDs) are a general term of diseases characterized by chronic inflammation as the primary pathogenetic mechanism, which seriously affect the quality of patient′s life and cause significant social and medical burden. Current drugs for IDs include nonsteroidal anti-inflammatory drugs, corticosteroids, immunomodulators, biologics, and antioxidants, but these drugs may cause gastrointestinal side effects, induce or worsen infections, and cause non-response or intolerance. Given the outstanding performance of metal polyphenol network (MPN) in the fields of drug delivery, biomedical imaging, and catalytic therapy, its application in the diagnosis and treatment of IDs has attracted much attention and significant progress has been made. In this paper, we first provide an overview of the types of IDs and their generating mechanisms, then sort out and summarize the different forms of MPN in recent years, and finally discuss in detail the characteristics of MPN and their latest research progress in the diagnosis and treatment of IDs. This research may provide useful references for scientific research and clinical practice in the related fields.

Objective To observe the effects of Bushen Huoxue Prescription on the pathway related to necroptosis of nucleus pulposus cells in a model rabbit of intervertebral disc degeneration;To explore its mechanisms in delaying intervertebral disc degeneration.Methods A intervertebral disc degeneration rabbit model was established using the spinal instability method.Totally 40 model rabbits were randomly divided into model group,ibuprofen group and Bushen Huoxue Prescription low-,medium-and high-dosage groups.Additionally,a normal control group and a sham-operation group were set up,with 8 rabbits in each group.Each treatment groups received the corresponding drugs via gavage for two consecutive weeks.HE staining was used to observe morphology of nucleus pulposus tissue,transmission electron microscopy was used to observe ultrastructure in nucleus pulposus cells,immunohistochemical staining was used to assess the expressions of Aggrecan and Collagen Ⅱ in nucleus pulposus tissue,Western blot was used to detect the expressions of p-RIPK1,p-RIPK3 and p-MLKL protein in nucleus pulposus tissue.Results Compared with the sham-operation group,the model group showed a significant decrease in nucleus pulposus cells,disordered cell arrangement,reduced extracellular matrix,interrupted cell membrane continuity under transmission electron microscopy,organelle swelling,nuclear membrane disruption,partial chromatin loss,and positive expression of Aggrecan and Collagen Ⅱ in nucleus pulposus tissue decreased(P<0.01),while the expressions of p-RIPK1,p-RIPK3 and p-MLKL protein significantly increased(P<0.01).Compared with the model group,the treatment groups showed an increased number of nucleus pulposus cells with orderly arrangement and more extracellular matrix,the ultrastructural damage of the cell membrane,organelle and nucleus in nucleus pulposus cells was partially restored under transmission electron microscopy,the positive expressions of Aggrecan and Collagen Ⅱ significantly increased in Bushen Huoxue Prescription medium-and high-dosage groups and the ibuprofen group(P<0.05,P<0.01),while the expressions of p-RIPK1,p-RIPK3 and p-MLKL protein significantly decreased(P<0.05,P<0.01).Conclusion Bushen Huoxue Prescription may delay intervertebral disc degeneration of the model rabbit by inhibiting the expressions of p-RIPK1,p-RIPK3 and p-MLKL protein in nucleus pulposus cells,and promoting the generation of extracellular matrix components Aggrecan and Collagen Ⅱ.

Objective To observe the effects of Bushen Huoxue Prescription on pressure-induced necroptosis in human nucleus pulposus cells and the expressions of RIPK1/RIPK3/MLKL pathway;To explore its potential mechanism in delaying intervertebral disc degeneration.Methods Human primary nucleus pulposus cells were cultured in vitro,and a model of nucleus pulposus cell degeneration was established using continuous load pressure method.After modeling,the nucleus pulposus cells were divided into model group,Bushen Huoxue Prescription group and inhibitor group,blank serum,Bushen Huoxue Prescription containing serum and necroptotic apoptosis inhibitor(Nec-1)intervention were administered,respectively.Normal group nucleus pulposus cells were cultured routinely.AO/EB fluorescence dual staining method was used for detecting cell apoptosis,flow cytometry was used to detect the necroptosis rate of nucleus pulposus cells,Western blot was used to detect the protein expressions of p-receptor interacting protein kinase(RIPK)1,p-RIPK3 and p-mixed lineage kinase domain like protein(MLKL),RT-qPCR was used to detect the mRNA expressions of RIPK1,RIPK3 and MLKL.Results Compared with the normal group,the model group showed more red fluorescence under AO/EB staining of nucleus pulposus cells,which were round and condensed,the necroptosis rate of nucleus pulposus cells increased(P<0.05),the protein expressions of p-RIPK1,p-RIPK3 and p-MLKL increased(P<0.05,P<0.01),while there was no significant difference in RIPK1 mRNA expression(P>0.05),and RIPK3 and MLKL mRNA expression increased(P<0.01).Compared with the model group,Bushen Huoxue Prescription group and the inhibitor group had less red condensed chromatin in the nucleus pulposus cells,Bushen Huoxue Prescription group had a lower rate of necroptosis(P<0.05),while the inhibitor group showed a decreasing trend in necroptosis rate(P>0.05),the protein expressions of p-RIPK1,p-RIPK3 and p-MLKL decreased in Bushen Huoxue Prescription group and the inhibitor group(P<0.05,P<0.01),while there was no significant difference in RIPK1 mRNA expression(P>0.05),and RIPK3 and MLKL mRNA expressions decreased(P<0.01).Conclusion Bushen Huoxue Prescription can alleviate pressure-induced damage to nucleus pulposus cells and inhibit necroptosis,thereby slowing the progression of intervertebral disc degeneration.Its mechanism may be related to the RIPK1/RIPK3/MLKL pathway mediated necroptosis.

Objective To investigate the correlation between dual-energy computed tomography angiography(CTA)parameters of carotid plaques and acute stroke events.Methods A retrospective analysis was conducted on the clinical and imaging data of patients who underwent dual-energy head and neck CTA and brain MRI scans.Utilizing the Siemens workstation(Syngo.Via VB40B),region of interest(ROI)were placed on the thickest slice of the carotid plaque in the axial plane to obtain parameters such as fat fraction(FF),virtual non-contrast(VNC)value,iodine concentration(IC),electron density(Rho),effective atomic number(Zeff),dual energy index(DEI),spectral curve,and corresponding CT values at 40 keV(40 keVHU)and 90 keV(90 keVHU).The slope of the energy spectrum curve(λ)was calculated within the 40 keV-90 keV range.Patients with acute cerebral infarction(ACI)in the ipsilateral anterior circulation territory were classified into the ACI group,while those without were classified into the non-acute cerebral infarction(NACI)(NACI group).Qualitative data were analyzed using the x2 test,and quantitative data were analyzed using the t-test.The predictive performance was assessed using the area under the curve(AUC)of the receiver operating characteristic(ROC)curve,and the differences between different ROC curves were compared using the DeLong test.Results A total of 72 patients were included,with 21 in the ACI group and 51 in the NACI group.The mean values of FF,Zeff,and 40 keVHU in the ACI group were greater than those in the NACI group.Statistically significant differences were observed between the groups for Zeff,DEI,40 keVHU,and λ(P＜0.05).40 keVHU demonstrated the highest predictive performance,and the AUC,sensitivity,and specificity was 0.789,81.0％,and 74.5％,respectively.A combined variable constructed through logistic regression analysis yielded an AUC,sensitivity,and specificity of 0.796,85.7％,and 70.6％,respectively,with no significant statistical differences compared to single factor variables.Conclusion Dual-energy CTA parameters of carotid plaques may aid in predicting intraplaque hemorrhage(IPH)and the occurrence of acute stroke events.

As global greenhouse gases continue rising, the urgency of more ambitious action is clearer than ever before. China is the world's biggest emitter of greenhouse gases and one of the countries affected most by climate change. The evidence about the impacts of climate change on the environment and human health may encourage China to take more decisive action to mitigate greenhouse gas emissions and adapt to climate impacts. This article aimed to review the evidence of environmental damages and health risks posed by climate change and to provide a new science-based perspective for the delivery of sustainable development goals. Over recent decades, China has experienced a strong warming pattern with a growing frequency of extreme weather events, and the impacts of climate change on China's environment and human health have been consistently observed, with increasing O ₃ air pollution, decreases in water resources and availability, land degradation, and increased risks for both communicable and non-communicable diseases. Therefore, China's climate policy should target the key factors driving climate change and scale up strategic measures to curb carbon emissions and adapt to inevitable increasing climate impacts. It provides new insights for not only China but also other countries, particularly developing and emerging economies, to ensure climate and environmental sustainability whilst pursuing economic growth.
Climate Change ; China ; Humans ; Greenhouse Gases ; Air Pollution ; Sustainable Development ; Environment

L-citrulline is a nonprotein amino acid that plays an important role in human health and has great market demand. Although microbial cell factories have been widely used for biosynthesis, there are still challenges such as genetic instability and low efficiency in the biosynthesis of L-citrulline. In this study, an efficient, plasmid-free, non-inducible L-citrulline-producing strain of Escherichia coli BL21(DE3) was engineered by combined strategies. Firstly, a chassis strain capable of synthesizing L-citrulline was constructed by block of L-citrulline degradation and removal of feedback inhibition, with the L-citrulline titer of 0.43 g/L. Secondly, a push-pull-restrain strategy was employed to enhance the L-citrulline biosynthesis, which realized the L-citrulline titer of 6.0 g/L. Thirdly, the NADPH synthesis and L-citrulline transport were strengthened to promote the synthesis efficiency, which achieved the L-citrulline titer of 11.6 g/L. Finally, fed-batch fermentation was performed with the engineered strain in a 3 L fermenter, in which the L-citrulline titer reached 44.9 g/L. This study lays the foundation for the industrial production of L-citrulline and provides insights for the modification of other amino acid metabolic networks.
Citrulline/biosynthesis* ; Escherichia coli/genetics* ; Metabolic Engineering/methods* ; Fermentation ; NADP/biosynthesis*

PURPOSE: The rate of complications among patients undergoing surgery has increased due to infection with SARS-CoV-2 and other variants of concern. However, Omicron has shown decreased pathogenicity, raising questions about the risk of postoperative complications among patients who are infected with this variant. This study aimed to investigate complications and related factors among patients with recent Omicron infection prior to undergoing orthopedic surgery. METHODS: A historical control study was conducted. Data were collected from all patients who underwent surgery during 2 distinct periods: (1) between Dec 12, 2022 and Jan 31, 2023 (COVID-19 positive group), (2) between Dec 12, 2021 and Jan 31, 2022 (COVID-19 negative control group). The patients were at least 18 years old. Patients who received conservative treatment after admission or had high-risk diseases or special circumstances (use of anticoagulants before surgery) were excluded from the study. The study outcomes were the total complication rate and related factors. Binary logistic regression analysis was used to identify related factors, and odds ratio (OR) and 95% confidence interval (CI) were calculated to assess the impact of COVID-19 infection on complications. RESULTS: In the analysis, a total of 847 patients who underwent surgery were included, with 275 of these patients testing positive for COVID-19 and 572 testing negative. The COVID-19-positive group had a significantly higher rate of total complications (11.27%) than the control group (4.90%, p < 0.001). After adjusting for relevant factors, the OR was 3.08 (95% CI: 1.45-6.53). Patients who were diagnosed with COVID-19 at 3-4 weeks (OR = 0.20 (95% CI: 0.06-0.59), p = 0.005), 5-6 weeks (OR = 0.16 (95% CI: 0.04-0.59), p = 0.010), or ≥7 weeks (OR = 0.26 (95% CI: 0.06-1.02), p = 0.069) prior to surgery had a lower risk of complications than those who were diagnosed at 0-2 weeks prior to surgery. Seven factors (age, indications for surgery, time of operation, time of COVID-19 diagnosis prior to surgery, C-reactive protein levels, alanine transaminase levels, and aspartate aminotransferase levels) were found to be associated with complications; thus, these factors were used to create a nomogram. CONCLUSION Omicron continues to be a significant factor in the incidence of postoperative complications among patients undergoing orthopedic surgery. By identifying the factors associated with these complications, we can determine the optimal surgical timing, provide more accurate prognostic information, and offer appropriate consultation for orthopedic surgery patients who have been infected with Omicron.
Humans ; COVID-19/complications* ; Male ; Female ; Middle Aged ; Postoperative Complications/epidemiology* ; SARS-CoV-2 ; Orthopedic Procedures/adverse effects* ; Aged ; Nomograms ; Adult ; Retrospective Studies ; Risk Factors