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.

BACKGROUND:Preliminary clinical observations found that Jiawei Chunze Decoction is an effective formula for clinical treatment of urinary retention after spinal cord injury.Animal experiments have found that the phosphatidylinositol 3-kinase/protein kinase B(PI3K/Akt)signaling pathway is closely related to the degree of bladder dysfunction. OBJECTIVE:To further investigate the effects of Jiawei Chunze Decoction on bladder function and PI3K/Akt signaling pathway in rats with urinary retention. METHODS:Sixty female Sprague-Dawley rats were randomly divided into sham operation group,model group,Jiawei Chunze Decoction low-dose group,Jiawei Chunze Decoction high-dose group and agonist group.In the sham operation group,the spinal cord was exposed but not transected.In the other groups,the modified Hassan Shaker spinal cord transection method was used to prepare the model of sacral medullary injury.At 24 hours after modeling,the sham operation group and model group were intragastrically given equal volume of normal saline,Jiawei Chunze Decoction low-dose and high-dose groups were given Jiawei Chunze Decoction granules containing 14.4 and 28.8 g/kg,respectively,via intragastric administration for 4 weeks,and the agonist group was treated with an intraperitoneal injection of PI3K/Akt signaling pathway agonist 740Y-P at a dose of 0.02 mg/kg.After 4 weeks of treatment,the maximum bladder capacity,leakage point pressure and bladder compliance of rats in each group were detected by urine flow dynamics.The minimum bladder contraction tension and frequency of rats in each group were detected by detrusor pull test.The pathological changes of the rat bladder in each group were observed by hematoxylin-eosin staining.The concentrations of GRP78,CHOP and Caspase-12 in serum were detected by ELISA,and the mRNA and protein expressions of PI3K,Akt,GRP78,CHOP and Caspase-12 in bladder tissues were detected by RT-PCR and western blot,respectively. RESULTS AND CONCLUSION:Compared with the sham operation group,the maximum bladder volume,bladder compliance and minimum systolic tension of rats in the model group were increased(P<0.05),and the leakage point pressure and bladder contraction frequency were decreased(P<0.05);serum GRP78,CHOP,and Caspase-12 levels were also increased(P<0.05).The arrangement of bladder epithelial cells in the model group was disordered,and there was monocyte infiltration between cells,tissue edema,and detrusor tract atrophy.The mRNA and protein expressions of PI3K and Akt in bladder tissues were significantly decreased in the model group compared with the sham operation group,while those of GRP78,CHOP and Caspase-12 were increased(P<0.05).Compared with the model group,the maximum bladder volume,bladder compliance and minimum systolic tension of rats were decreased in the Jiawei Chunze Decoction low-dose,high-dose and agonist groups after 4 weeks of intervention(P<0.05),while the leakage point pressure and bladder contraction frequency were increased(P<0.05);serum GRP78,CHOP,Caspase-12 levels were decreased(P<0.05).The bladder epithelial cells in the three intervention groups were distributed evenly,arranged neatly,with less inflammatory cell infiltration and fuller detrusor muscle bundle.Compared with the model group,the mRNA and protein expressions of PI3K and Akt were increased in the three intervention groups,while those of GRP78,CHOP and Caspase-12 were decreased(P<0.05).The Jiawei Chunze Decoction high-dose group was better than the Jiawei Chunze Decoction low-dose group and shared the similar results with the agonist group.To conclude,Jiawei Chunze Decoction can improve the bladder function of rats with urinary retention after spinal cord injury,and the mechanism may be related to reducing the occurrence of endoplasmic reticulum stress in bladder tissue through the PI3K/Akt signaling pathway,and then alleviating apoptosis.

BACKGROUND:Research has demonstrated a close association between ferroptosis and vascular dementia.Tongmai Kaiqiao Pill has a certain effect on improving the cognitive function of vascular dementia patients,but its mechanism is unclear. OBJECTIVE:To explore the interventional effects and molecular mechanisms of Tongmai Kaiqiao Pill for vascular dementia based on the regulation of ferroptosis by the nuclear factor erythroid-2-related factor 2(Nrf2)/heme oxygenase-1(HO-1)/glutathione peroxidase 4(GPX4)signaling pathway. METHODS:Among eighty-four SD male rats,12 rats were used as the sham-operated group,and the rest of them were prepared as a model of vascular dementia by the modified 2-VO method,and then randomly divided into the model group,the Tongmai Kaiqiao Pills high-,moderate-,and low-dosage(27.6,13.8,and 6.9 g/kg)groups,the combined group(Tongmai Kaiqiao Pill high-dosage+ML385,20 mg/kg),and the donepezil hydrochloride group(0.45 mg/kg).The drug was given once a day by intragastric administration.The combined group was also intraperitoneally injected Nrf2 inhibitor ML385,once a day,for 4 weeks.Morris water maze was used to detect the learning memory ability of rats.Hematoxylin-eosin staining was used to observe the histopathological changes in the hippocampus of rats in each group.Colorimetric assay was used to detect the content of reduced glutathione,ferrous ion(Fe2+),and malondialdehyde in the serum of rats.Prussian blue staining was used to detect the iron deposition in the hippocampal tissue of rats.Transmission electron microscopy was used to observe the ultrastructural changes of mitochondria in rat hippocampal tissues.Western blot assay was used to detect the protein expression levels of Nrf2,HO-1,GPX4,XCT,and ferritin heavy chain 1(FTH1)in rat hippocampal tissues. RESULTS AND CONCLUSION:(1)In comparison to the sham operation,rats in the model group exhibited a significantly prolonged latency period(P<0.05)and a reduced number of platform crossings(P<0.05).Additionally,the hippocampal tissues of these rats displayed loosely organized structure,deeply stained cell nuclei,and solidified or lysed chromatin.Ferri ions aggregated in CA1 region.There were atrophied mitochondria with dissolved cristae and thickened mitochondrial membranes.Fe2+,malondialdehyde,and reduced glutathione levels in rat serum were found to be elevated(P<0.05).A significant reduction in the expression of GPX4,HO-1,XCT,Nrf2,and FTH1 proteins was detected in the hippocampus(P<0.05).(2)Compared to the model group,the average escape latency of the rats was significantly reduced following intervention with Tongmai Kaiqiao Pills and donepezil hydrochloride(P<0.05),with an increased number of platform crossings(P<0.05).Hippocampal neurons showed significant recovery.Notably,iron aggregation in the CA1 region was significantly reduced,and mitochondrial structure and function were improved.There were significant reductions in Fe2+and malondialdehyde levels,while the levels of GPX4,HO-1,XCT,Nrf2,and FTH1 in rat hippocampal tissues,and reduced glutathione in serum were significantly increased(P<0.05).(3)The high-dose Tongmai Kaiqiao Pills exhibited a treatment effect comparable to that of donepezil hydrochloride(P>0.05),with a significant prolongation of water maze escape latency(P<0.05),a reduced number of platform crossings(P<0.05),and insignificant neuronal pathological changes in the CA1 area.However,the combined group showed increased iron deposition,elevated malondialdehyde and Fe2+levels in blood serum(P<0.05),reduced glutathione content(P<0.05),hippocampal tissue mitochondrial atrophy,and reduced expression of Nrf2,XCT,HO-1,GPX4,and FTH1 proteins(P<0.05).Within a certain range,higher doses of Tongmai Kaiqiao Pills demonstrated a more pronounced effect,comparable to the efficacy of high-dose donepezil hydrochloride.(4)It is concluded that Tongmai Kaiqiao Pills have been shown to mitigate histopathological changes in the rat hippocampus and enhance cognitive function in rats with vascular dementia.The mechanism of action is likely associated with the suppression of ferroptosis through the activation of the Nrf2/HO-1/GPX4 signaling pathway.

BACKGROUND:Primary osteoporosis has a high incidence,but the pathogenesis is not fully understood.Currently,there is a lack of effective early screening indicators and treatment programs. OBJECTIVE:To further explore the mechanism of primary osteoporosis through comprehensive bioinformatics analysis. METHODS:The primary osteoporosis data were obtained from the gene expression omnibus(GEO)database,and the differentially expressed genes were screened for Gene Ontology(GO)function and Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway enrichment analysis.In addition,the differentially expressed genes were subjected to protein-protein interaction network to determine the core genes related to primary osteoporosis,and the least absolute shrinkage and selection operator algorithm was used to identify and verify the primary osteoporosis-related biomarkers.Immune cell correlation analysis,gene enrichment analysis and drug target network analysis were performed.Finally,the biomarkers were validated using qPCR assay. RESULTS AND CONCLUSION:A total of 126 differentially expressed genes and 5 biomarkers including prostaglandins,epidermal growth factor receptor,mitogen-activated protein kinase 3,transforming growth factor B1,and retinoblastoma gene 1 were obtained in this study.GO analysis showed that differentially expressed genes were mainly concentrated in the cellular response to oxidative stress and the regulation of autophagy.KEGG analysis showed that autophagy and senescence pathways were mainly involved.Immunoassay of biomarkers showed that prostaglandins,retinoblastoma gene 1,and mitogen-activated protein kinase 3 were closely related to immune cells.Gene enrichment analysis showed that biomarkers were associated with immune-related pathways.Drug target network analysis showed that the five biomarkers were associated with primary osteoporosis drugs.The results of qPCR showed that the expression of prostaglandins,epidermal growth factor receptor,mitogen-activated protein kinase 3,and transforming growth factor B1 in the primary osteoporosis sample was significantly increased compared with the control sample(P<0.001),while the expression of retinoblastoma gene 1 in the primary osteoporosis sample was significantly decreased compared with the control sample(P<0.001).Overall,the study screened and validated five potential biomarkers of primary osteoporosis,providing a reference basis for further in-depth investigation of the pathogenesis,early screening and diagnosis,and targeted treatment of primary osteoporosis.

Objective To explore the value of high-frequency ultrasound in the detection of metastatic hepatocellular carcinoma and displaying lesion characteristics. Methods A total of 38 paitients with hepatocellular carcinoma satellite lesions within 40 mm of subcutaneous tissue were underwent low-frequency (1-5 MHz) and high-frequency (6-9 MHz) ultrasound. Detection rates and ultrasonic features were compared. Results High-frequency grayscale ultrasound had a higher detection rate (71.1% vs. 36.8%, P＜0.001). Subgroup analysis showed higher detection rates with chemotherapy history (88.9% vs. 33.3%, P＝0.002), fatty liver (71.9% vs 31.3%, P＜0.001) or superficial lesion (within 20 mm, 76.5% vs 41.2%, P＝0.031). High-frequency ultrasound also showed clearer margins (P＝0.004) and more arterial-phase rim enhancement (P＝0.007). Conclusions 6-9 MHz ultrasound detects metastatic hepatocellular carcinoma, especially superficial lesions, more effectively than 1-5 MHz ultrasound and better visualizes characteristics.

Objective To explore the effects of sigma-1 receptor(Sig-1R)on brain function in rats after cardiopulmo-nary resuscitation and its protective role in brain injury.Methods Rats were randomly assigned to four groups with 20 in each:sham-operated control(sham group),6-hour post-resuscitation(PR 6 h group),12-hour post-resuscitation(PR 12 h group)and 24-hour post-resuscitation(PR 24 h group).In the latter three groups,cardiac arrest was induced by as-phyxiation,and cardiopulmonary resuscitation was performed 6 minutes after cardiac arrest.The rats were scored for neu-rological deficits at 6,12 and 24 hrs after resuscitation,respectively;after that,the rats were executed,and the expres-sion of Sig-1R protein,mitochondrial function index,and endoplasmic reticulum stress index apoptosis index were detec-ted by Western blot and immunohistochemistry.The correlation between Sig-1R and mitochondrial,endoplasmic reticulum stress and apoptosis indexes was evaluated.Results Compared with the sham-operated group,the rats in test group showed a gradual decrease in neurological deficit scores,Sig-1R protein expression,brain tissue adenosine triphos-phate(ATP)concentration and mitochondrial membrane potential(MMP)levels at 6,12,and 24 hrs of PR(P＜0.05);CHOP protein,activated cleaved caspase-12 and cleaved caspase-3 protein expression were consistently elevated(P＜0.05).In addition,Sig-1R was negatively correlated with brain tissue endoplasmic reticulum stress and apoptosis(P＜0.05)but positively correlated with mitochondrial membrane potential level(P＜0.05).Conclusions Sig-1R ex-pression in rat brain tissue correlates with brain injury after cardiopulmonary resuscitation and potential mechanism seems to be neuronal protection through modulating mitochondrial function and endoplasmic reticulum stress.

OBJECTIVE: To investigate the anti-inflammatory effect of rutaecarpine (RUT) on monosodium urate crystal (MSU)-induced murine peritonitis in mice and further explored the underlying mechanism of RUT in lipopolysaccharide (LPS)/MSU-induced gout model in vitro. METHODS: In MSU-induced mice, 36 male C57BL/6 mice were randomly divided into 6 groups of 8 mice each group, including the control group, model group, RUT low-, medium-, and high-doses groups, and prednisone acetate group. The mice in each group were orally administered the corresponding drugs or vehicle once a day for 7 consecutive days. The gout inflammation model was established by intraperitoneal injection of MSU to evaluate the anti-gout inflammatory effects of RUT. Then the proinflammatory cytokines were measured by enzyme-linked immunosorbent assay (ELISA) and the proportions of infiltrating neutrophils cytokines were detected by flow cytometry. In LPS/MSU-treated or untreated THP-1 macrophages, cell viability was observed by cell counting kit 8 and proinflammatory cytokines were measured by ELISA. The percentage of pyroptotic cells were detected by flow cytometry. Respectively, the mRNA and protein levels were measured by real-time quantitative polymerase chain reaction (qRT-PCR) and Western blot, the nuclear translocation of nuclear factor κB (NF-κB) p65 was observed by laser confocal imaging. Additionally, surface plasmon resonance (SPR) and molecular docking were applied to validate the binding ability of RUT components to tumor necrosis factor α (TNF-α) targets. RESULTS: RUT reduced the levels of infiltrating neutrophils and monocytes and decreased the levels of the proinflammatory cytokines interleukin 1β (IL-1β) and interleukin 6 (IL-6, all P<0.01). In vitro, RUT reduced the production of IL-1β, IL-6 and TNF-α. In addition, RT-PCR revealed the inhibitory effects of RUT on the mRNA levels of IL-1β, IL-6, cyclooxygenase-2 and TNF-α (P<0.05 or P<0.01). Mechanistically, RUT markedly reduced protein expressions of tumor necrosis factor receptor (TNFR), phospho-mitogen-activated protein kinase (p-MAPK), phospho-extracellular signal-regulated kinase, phospho-c-Jun N-terminal kinase, phospho-NF-κB, phospho-kinase α/β, NOD-like receptor thermal protein domain associated protein 3 (NLRPS), cleaved-cysteinyl aspartate specific proteinase-1 and cleaved-gasdermin D in macrophages (P<0.05 or P<0.01). Molecularly, SPR revealed that RUT bound to TNF-α with a calculated equilibrium dissociation constant of 31.7 µmol/L. Molecular docking further confirmed that RUT could interact directly with the TNF-α protein via hydrogen bonding, van der Waals interactions, and carbon-hydrogen bonding. CONCLUSION RUT alleviated MSU-induced peritonitis and inhibited the TNFR1-MAPK/NF-κB and NLRP3 inflammasome signaling pathway to attenuate gouty inflammation induced by LPS/MSU in THP-1 macrophages, suggesting that RUT could be a potential therapeutic candidate for gout.
Animals ; NF-kappa B/metabolism* ; Male ; Indole Alkaloids/therapeutic use* ; Signal Transduction/drug effects* ; Mice, Inbred C57BL ; Inflammation/complications* ; Uric Acid ; Quinazolines/therapeutic use* ; NLR Family, Pyrin Domain-Containing 3 Protein/metabolism* ; Humans ; Gout/chemically induced* ; Inflammasomes/metabolism* ; Cytokines/metabolism* ; THP-1 Cells ; Mitogen-Activated Protein Kinases/metabolism* ; Mice ; Molecular Docking Simulation ; Lipopolysaccharides ; Quinazolinones

Bone repair remains an important target in tissue engineering, making the development of bioactive scaffolds for effective bone defect repair a critical objective. In this study, β-tricalcium phosphate (β-TCP) scaffolds incorporated with processed pyritum decoction (PPD) were fabricated using three-dimensional (3D) printing-assisted freeze-casting. The produced composite scaffolds were evaluated for their mechanical strength, physicochemical properties, biocompatibility, in vitro pro-angiogenic activity, and in vivo efficacy in repairing rabbit femoral defects. They not only demonstrated excellent physicochemical properties, enhanced mechanical strength, and good biosafety but also significantly promoted the proliferation, migration, and aggregation of pro-angiogenic human umbilical vein endothelial cells (HUVECs). In vivo studies revealed that all scaffold groups facilitated osteogenesis at the bone defect site, with the β-TCP scaffolds loaded with PPD markedly enhancing the expression of neurogenic locus Notch homolog protein 1 (Notch1), vascular endothelial growth factor (VEGF), bone morphogenetic protein-2 (BMP-2), and osteopontin (OPN). Overall, the scaffolds developed in this study exhibited strong angiogenic and osteogenic capabilities both in vitro and in vivo. The incorporation of PPD notably promoted the angiogenic-osteogenic coupling, thereby accelerating bone repair, which suggests that PPD is a promising material for bone repair and that the PPD/β-TCP scaffolds hold great potential as a bone graft alternative.
Calcium Phosphates/chemistry* ; Animals ; Bone Regeneration ; Rabbits ; Tissue Scaffolds ; Printing, Three-Dimensional ; Humans ; Human Umbilical Vein Endothelial Cells ; Neovascularization, Physiologic ; Osteogenesis ; Tissue Engineering/methods* ; Biomimetic Materials ; Cell Proliferation ; Angiogenesis

Temporomandibular joint osteoarthritis (TMJ-OA) is a common disease often accompanied by pain, seriously affecting physical and mental health of patients. Abnormal innervation at the osteochondral junction has been considered as a predominant origin of arthralgia, while the specific mechanism mediating pain remains unclear. To investigate the underlying mechanism of TMJ-OA pain, an abnormal joint loading model was used to induce TMJ-OA pain. We found that during the development of TMJ-OA, the increased innervation of sympathetic nerve of subchondral bone precedes that of sensory nerves. Furthermore, these two types of nerves are spatially closely associated. Additionally, it was discovered that activation of sympathetic neural signals promotes osteoarthritic pain in mice, whereas blocking these signals effectively alleviates pain. In vitro experiments also confirmed that norepinephrine released by sympathetic neurons promotes the activation and axonal growth of sensory neurons. Moreover, we also discovered that through releasing norepinephrine, regional sympathetic nerves of subchondral bone were found to regulate growth and activation of local sensory nerves synergistically with other pain regulators. This study identified the role of regional sympathetic nerves in mediating pain in TMJ-OA. It sheds light on a new mechanism of abnormal innervation at the osteochondral junction and the regional crosstalk between peripheral nerves, providing a potential target for treating TMJ-OA pain.
Animals ; Osteoarthritis/physiopathology* ; Mice ; Sympathetic Nervous System/physiopathology* ; Temporomandibular Joint Disorders/physiopathology* ; Arthralgia ; Sensory Receptor Cells ; Disease Models, Animal ; Norepinephrine ; Male ; Temporomandibular Joint/physiopathology* ; Pain Measurement