Lymphotoxin-ß promotes breast cancer bone metastasis colonization and osteolytic outgrowth.

Bone metastasis is a lethal consequence of breast cancer. Here we used single-cell transcriptomics to investigate the molecular mechanisms underlying bone metastasis colonization-the rate-limiting step in the metastatic cascade. We identified that lymphotoxin-ß (LTß) is highly expressed in tumour cells within the bone microenvironment and this expression is associated with poor bone metastasis-free survival. LTß promotes tumour cell colonization and outgrowth in multiple breast cancer models. Mechanistically, tumour-derived LTß activates osteoblasts through nuclear factor-κB2 signalling to secrete CCL2/5, which facilitates tumour cell adhesion to osteoblasts and accelerates osteoclastogenesis, leading to bone metastasis progression. Blocking LTß signalling with a decoy receptor significantly suppressed bone metastasis in vivo, whereas clinical sample analysis revealed significantly higher LTß expression in bone metastases than in primary tumours. Our findings highlight LTß as a bone niche-induced factor that promotes tumour cell colonization and osteolytic outgrowth and underscore its potential as a therapeutic target for patients with bone metastatic disease.

The bidirectional influence between emotional language and inhibitory control in Chinese: An ERP study.

The bidirectional influence between emotional language and inhibitory processes has been studied in alphabetic languages, highlighting the need for additional investigation in nonalphabetic languages to explore potential cross-linguistic differences. The present ERP study investigated the bidirectional influence in the context of Mandarin, a language with unique linguistic features and neural substrates. In Experiment 1, emotional adjectives preceded the Go/NoGo cue. The ERPs revealed that negative emotional language facilitated inhibitory control. In Experiment 2, with a Go/NoGo cue preceding the emotional language, the study confirmed that inhibitory control facilitated the semantic integration of negative language in Chinese, whereas the inhibited state may not affect deeper refinement of the emotional content. However, no interaction was observed in positive emotional language processing. These results suggest an interaction between inhibitory control and negative emotional language processing in Chinese, supporting the integrative emotion-cognition view.

Structural analysis of the human C5a-C5aR1 complex using cryo-electron microscopy.

The complement system is a complex network of proteins that plays a crucial role in the innate immune response. One important component of this system is the C5a-C5aR1 complex, which is critical in the recruitment and activation of immune cells. In-depth investigation of the activation mechanism as well as biased signaling of the C5a-C5aR1 system will facilitate the elucidation of C5a-mediated pathophysiology. In this study, we determined the structure of C5a-C5aR1-Gi complex at a high resolution of 3 Šusing cryo-electron microscopy (Cryo-EM). Our results revealed the binding site of C5a, which consists of a polar recognition region on the extracellular side and an amphipathic pocket within the transmembrane domain. Furthermore, we found that C5a binding induces conformational changes of C5aR1, which subsequently leads to the activation of G protein signaling pathways. Notably, a key residue (M265) located on transmembrane helix 6 (TM6) was identified to play a crucial role in regulating the recruitment of ß-arrestin driven by C5a. This study provides more information about the structure and function of the human C5a-C5aR1 complex, which is essential for the proper functioning of the complement system. The findings of this study can also provide a foundation for the design of new pharmaceuticals targeting this receptor with bias or specificity.

Occurrence of Maize Leaf Spot Disease Caused by Leptosphaerulina australis in Yunnan, China.

Maize (Zea mays) is vital as a staple food and livestock feed crop. Yunnan is one of the main maize-producing provinces in China (National Bureau of Statistics, 2022). While corn production in Yunnan is lower than the national average, the development of drought-tolerant varieties has contributed to improving productivity. In August 2021, a new leaf spot disease on maize was observed in Lancang, Yunnan (22°26'38.11"N to 22°48'38.68"N, 99°48'15.13"E to 99°59'20.03"E), causing serious damages to maize production with incidence up to 76.19 %. Initially, small light yellow lesions were seen scattered on diseased maize leaves, round or polygon, measuring 0.3 to 2.0 cm in diameter. In the intermediate phase, these lesions sank, ruptured, and turned white with dark brown borders. In severe cases, they merged into large irregular patches, reaching up to 10 cm, leading to complete leaf necrosis. Small black ascomata were seen on the lesions. Tissue sections reveal perithecium embedded in leaves, measuring 94~145 µm in diameter. Symptomatic tissues were sterilized in 1.5% NaClO for 60s, and washed twice withsterile purified water, then plated on potato dextrose agar (PDA) at 25℃, 90% relative humidity (RH), and a 12-hour light cycle. 6 isolates were obtained from 2 diseased maize cultivars. In 20 days, the colony reached the edge of the PDA plate, the center darkening from white, featuring white aerial mycelium on top and black on the reverse side. Brown ascomata, solitary or clustered, measured 80.1~176.7 × 55.57~138.9 µm. The ellipsoid to oblong ascospores were 17.9~39.7 × 10.9~14.1 µm, and the bitunicate, thick-walled asci were 90.1~133.3 × 26.6~33.5 µm. The genomic DNA was extracted using the Chelex-100 method (Möller et al. 1992). For molecular identification, the ITS, LSU, and ß-tubulin (Tub2) genes were amplified using primer pairs ITS1/ITS4 (White et al. 1990), LR0R/LR5 (Vilgalys et al. 1990) and Btub2Fd/Btub4Rd (Woudenberg et al. 2009), respectively. Sequencing was performed by Sangon Biotech (Shanghai) Co., Ltd. The sequenced loci (GenBank accession nos.: LSU, OL687348-53; ITS, OL617009-10, and OL664058-61; Tub2, OL741678-83) of the isolates exhibited 100%/ 99%/ 100% similarities with L. australis genes: LSU, MH868885; ITS, KF381084; Tub2, GU237541, respectively. Using MEGA 11.0, phylogenetic trees were constructed using the maximum-likelihood algorithm on concatenated sequences of LSU, ITS, and Tub2 for isolates LCMB1 to 6. The isolates clustered with two L. australis strains with 100 % bootstrap support (1,000 replicates). The results were consistent with the Bayesian Inference tree. The pathogenicity test used strain LCMB4 on six healthy maize plants during the heading period under natural conditions. Three leaves pre-plant were wounded with sterile sandpaper and sprayed with conidial suspension (106 spores ml-1, diluted in sterilized water) in the greenhouse at 28℃, 90% RH, and a 12-hour light cycle, with sterilized distilled water used for control. Inoculated leaves developed symptoms consistent with the described after 10 days, while control leaves remained symptomless. The same pathogen was re-isolated from the infected leaves, fulfilling Koch's postulates. Previously, L. australis has been isolated from turfgrass (Mitkowski et al. 2004), Alfalfa (Zhang et al. 2021), soil (Li et al. 2018), and Paris polyphylla var. chinensis (Fu et al. 2019), but not from maize. This is the first report of L. australis causing leaf spot on maize globally.

Development and validation of a predictive model assessing the risk of sarcopenia in rheumatoid arthritis patients.

Background: Sarcopenia is linked to an unfavorable prognosis in individuals with rheumatoid arthritis (RA). Early identification and treatment of sarcopenia are clinically significant. This study aimed to create and validate a nomogram for predicting sarcopenia risk in RA patients, providing clinicians with a reliable tool for the early identification of high-risk patients. Methods: Patients with RA diagnosed between August 2022 and January 2024 were included and randomized into training and validation sets in a 7:3 ratio. Least Absolute Shrinkage and Selection Operator (LASSO) regression analysis and multifactorial logistic regression analysis were used to screen the risk variables for RA-associated muscle loss and to create an RA sarcopenia risk score. The predictive performance and clinical utility of the risk model were evaluated by plotting the receiver operating characteristic curve and calculating the area under the curve (AUC), along with the calibration curve and clinical decision curve (DCA). Results: A total of 480 patients with RA were included in the study (90% female, with the largest number in the 45-59 age group, about 50%). In this study, four variables (body mass index, disease duration, hemoglobin, and grip strength) were included to construct a nomogram for predicting RA sarcopenia. The training and validation set AUCs were 0.915 (95% CI: 0.8795-0.9498) and 0.907 (95% CI: 0.8552-0.9597), respectively, proving that the predictive model was well discriminated. The calibration curve showed that the predicted values of the model were basically in line with the actual values, demonstrating good calibration. The DCA indicated that almost the entire range of patients with RA can benefit from this novel prediction model, suggesting good clinical utility. Conclusion: This study developed and validated a nomogram prediction model to predict the risk of sarcopenia in RA patients. The model can assist clinicians in enhancing their ability to screen for RA sarcopenia, assess patient prognosis, make early decisions, and improve the quality of life for RA patients.

Combination therapy consisting of transarterial chemoembolization, lenvatinib, and programmed cell death protein 1 blockade for hepatocellular carcinoma with inferior vena cava tumor thrombus: a case series study and literature review.

INTRODUCTION: Patients with hepatocellular carcinoma (HCC) and inferior vena cava carcinoma tumor thrombus (IVCTT) have poor prognosis. Combination therapy involving blockade of programmed cell death protein 1 (PD-1) and tyrosine kinase inhibitors (TKIs) is an efficient treatment strategy for advanced HCC. However, surgical treatment after a combination of systemic therapy and transarterial chemoembolization (TACE) for HCC with IVCTT has not been widely reported, and the efficacy and safety of this treatment have not been studied. METHODS: In the 21 cases reported herein, the patients were treated with TACE, lenvatinib, and PD-1 blockade. The treatment responses, progression-free survival (PFS), overall survival (OS), disease control rate, and toxicities were evaluated, and the related literature was reviewed. RESULTS: The overall response and disease control rates were 66.7% and 85.7%, respectively. The median PFS time was 16.0 months, with a 1-year PFS rate of 55.60%. The median OS was not reached, with a 1-year OS rate of 66.70%. Four patients underwent hepatectomy without serious complications and survived for 29.1, 24.7, 14.2, and 13.8 months. Three patients survived tumor-free, and one patient experienced intrahepatic recurrence. Pathological complete response and major pathological responses were observed in one and three patients, respectively. Treatment-related adverse events of any grade occurred in of 8/9 patients (88.9%), and grade 3 treatment-related adverse events occurred in one patient. CONCLUSION: The combination of TACE, lenvatinib, and PD-1 is effective for HCC with IVCTT and has acceptable adverse effects.

Coordination Desymmetrization of Copper Single-Atom Catalyst for Efficient Nitrate Reduction.

Coordination engineering strategy for optimizing the catalytic performance of single-atom catalysts (SACs) has been rapidly developed over the last decade. However, previous reports on copper SACs for nitrate reduction reactions (NO3RR) have mostly focused on symmetric coordination configurations such as Cu-N4 and Cu-N3. In addition, the mechanism in terms of the regulation of coordination environment and catalytic properties of SACs has not been well demonstrated. Herein, we disrupted the local symmetric structure of copper atoms by introducing unsaturated heteroatomic coordination of Cu-O and Cu-N to achieve the coordination desymmetrization of Cu-N1O2 SACs. The Cu-N1O2 SACs exhibit an efficient nitrate-to-ammonia conversion with a high FE of ~96.5 % and a yield rate of 3120 µg NH3 h-1 cm-2 at -0.60 V vs RHE. As indicated by in situ Raman spectra, the catalysts facilitate the accumulation of NO3 - and the selective adsorption of *NO2, which were further confirmed by the theoretical study of surface dipole moment and orbital hybridization. Our work illustrated the correlation between the coordination desymmetrization and the catalytic performance of copper SACs for NO3RR.

Electrochemical sensing technology based on a ligation-initiated LAMP-assisted CRISPR/Cas12a system for high-specificity detection of EGFR E746-A750 deletion mutation.

Epidermal growth factor receptor (EGFR) mutation status is pivotal in predicting the efficacy of tyrosine kinase inhibitor treatments against tumors. Among EGFR mutations, the E746-A750 deletion is particularly common and accurately quantifying it can guide targeted therapies. This study introduces a novel visual sensing technology using the clustered regularly interspaced short palindromic repeats (CRISPR)/Cas12a system guided by ligation-initiated loop-mediated isothermal amplification (LAMP) to detect the del E746-A750 mutation in EGFR. Conventional LAMP primers were simplified by designing a pair of target-specific stem-loop DNA probes, enabling selective amplification of the target DNA. The CRISPR/Cas12a system was employed to identify the target nucleic acid and activate Cas12a trans-cleavage activity, thereby enhancing the specificity of the assay. Furthermore, the biosensor utilized high-performance nanomaterials such as triangular gold nanoparticles and graphdiyne, known for their large specific surface area, to enhance sensitivity effectively as a sensing platform. The proposed biosensor demonstrated outstanding specificity, achieving a low detection limit of 17 fM (S/N = 3). Consequently, this innovative strategy not only expands the application scope of CRISPR/Cas12a technology but also introduces a promising approach for clinical diagnostics in modern medicine.

Silvaticusins A-D: ent-kaurane diterpenoids and a cyclobutane-containing ent-kaurane dimer from Isodon silvaticus.

Three new ent-kaurane diterpenoids, silvaticusins A-C (1-3), along with a new ent-kaurane dimer silvaticusin D (4) were isolated from the aerial parts of Isodon silvaticus. The structures of these new compounds were established mainly by comprehensive analysis of their NMR and MS data. The absolute configuration of compounds 1 and 4 were determined using a single-crystal X-ray diffraction and computational methods, respectively. Compounds 2 and 3 were found to exhibit remarkable cytotoxic effects against five human tumor cell lines (HL-60, A-549, SMMC-7721, MDA-MB-231, and SW-480), with IC50 values spanning from 1.27 ± 0.08 to 7.52 ± 0.33 µM.

Reading disability is characterized by reduced print-speech convergence.

Reading disability (RD) may be characterized by reduced print-speech convergence, which is the extent to which neurocognitive processes for reading and hearing words overlap. We examined how print-speech convergence changes from children (mean age: 11.07+0.48) to adults (mean age: 21.33+1.80) in 86 readers with or without RD. The participants were recruited in elementary schools and associate degree colleges in China (from 2020 to 2021). Three patterns of abnormalities were revealed: (1) persistent reduction of print-speech convergence in the left inferior parietal cortex in both children and adults with RD, suggesting a neural signature of RD; (2) reduction of print-speech convergence in the left inferior frontal gyrus only evident in children but not adults with RD, suggesting a developmental delay; and (3) increased print-speech convergence in adults with RD than typical adults in the bilateral cerebella/fusiform, suggesting compensations. It provides insights into developmental differences in brain functional abnormalities in RD.

Nomogram models predicting prognosis for patients with t(8;21) acute myeloid leukemia: a SEER-based study.

BACKGROUND: Acute myeloid leukemia (AML) with t(8;21) manifests as a diverse hematological malignancy. Although it was categorized into a favorable subtype, 30-40% of patients experience relapse. The objective of this research was to devise a nomogram for the accurate anticipation of both overall survival (OS) and cancer-specific survival (CSS) in t(8;21) AML. METHODS: From the Surveillance, Epidemiology, and End Results (SEER) database, individuals diagnosed with t(8;21) AML from 2000 to 2018 were selected. Prognostic factors for t(8;21) AML were identified using Cox regression analysis and Akaike Information Criterion (AIC), forming the basis for constructing prognostic nomograms. RESULTS: Key variables, including first primary tumor, age group, race, and chemotherapy, were identified and integrated into the nomogram. The C-index values for the nomograms predicting OS and CSS were 0.753 (validation: 0.765) and 0.764 (validation: 0.757), respectively. Ultimately, based on nomogram scores, patients were stratified into high-risk and low-risk groups, revealing significant disparities in both OS and CSS between these groups (P < 0.001). CONCLUSION: This study innovatively crafted nomograms, incorporating clinical and therapeutic variables, to forecast the 1-, 3-, and 5-year survival rates for individuals with t(8;21) AML.

Development and validation of a machine learning-based interpretable model for predicting sepsis by complete blood cell parameters.

Background: Sepsis, a severe infectious disease, carries a high mortality rate. Early detection and prompt treatment are crucial for reducing mortality and improving prognosis. The aim of this research is to develop a clinical prediction model using machine learning algorithms, leveraging complete blood cell (CBC) parameters, to detect sepsis at an early stage. Methods: The study involved 572 patients admitted to West China Hospital of Sichuan University between July 2020 and September 2021. Among them, 215 were diagnosed with sepsis, while 357 had local infections. Demographic information was collected, and 57 CBC parameters were analyzed to identify potential predictors using techniques such as the Least Absolute Shrinkage and Selection Operator (LASSO), Random Forest (RF), Support Vector Machine (SVM), and eXtreme Gradient Boosting (XGBoost). The prediction model was built using Logistic Regression and evaluated for diagnostic specificity, discrimination, and clinical applicability including metrics such as the area under the curve (AUC), calibration curve, clinical impact curve, and clinical decision curve. Additionally, the model's diagnostic performance was assessed on a separate validation cohort. Shapley's additive explanations (SHAP), and breakdown (BD) profiles were used to explain the contribution of each variable in predicting the outcome. Results: Among all the machine learning methods' prediction models, the LASSO-based model (λ = min) demonstrated the highest diagnostic performance in both the discovery cohort (AUC = 0.9446, P < 0.001) and the validation cohort (AUC = 0.9001, P < 0.001). Furthermore, upon local analysis and interpretation of the model, we demonstrated that LY-Z, MO-Z, and PLT-I had the most significant impact on the outcome. Conclusions: The predictive model based on CBC parameters can be utilized as an effective approach for the early detection of sepsis.

A Facile Approach to Construct Novel Polyesters as Soft Midblock for Thermoplastic Elastomers.

The development of innovative synthetic strategies to create functional polycaprolactones is highly demanded for advanced material applications. In this contribution, we reported a facile synthetic strategy to prepare a class of CL-based monomers (R-TO) derived from epoxides. They readily polymerize via well-controlled ring-opening polymerization (ROP) to afford a series of polyesters P(R-TO) with high molecular weight (Mn up to 350 kDa). Sequential addition copolymerization of MTO and L-lactide (L-LA) allowed to access of a series of ABA triblock copolymers with composition-dependent mechanical properties. Notably, P(L-LA)100-b-P(MTO)500-b-P(L-LA)100 containing the amorphous P(MTO) segment as a soft midblock and crystalline P(L-LA) domain as hard end block behaved as an excellent thermoplastic elastomer (TPE) with high elongation at break (1438 ± 204%), tensile strength (23.5 ± 1.7 MPa), and outstanding elastic recovery (>88%).

Correction: Duhuo Jisheng Decoction regulates intracellular zinc homeostasis by enhancing autophagy via PTEN/Akt/mTOR pathway to improve knee cartilage degeneration.

[This corrects the article DOI: 10.1371/journal.pone.0290925.].

Optimal management options for esophageal gastrointestinal stromal tumors (E-GIST).

OBJECTIVE: To explore the different treatment modalities for esophageal gastrointestinal stromal tumors (E-GIST) and their respective applicability and clinical outcomes. METHODS: This is a retrospective study in which consecutive patients diagnosed with E-GIST at our hospital from January 2017 to August 2023 were included. The clinical characteristics of all the patients as well as long-term quality of life were recorded and analyzed. RESULTS: A total of 23 (12 males, 11 females) E-GIST patients with a mean age of 56.7 ± 12.0 years were included in this study. Common symptoms, including upper abdominal pain, acid reflux, and heartburn, accounted for over 60 % of cases. Fifteen patients underwent endoscopic resection, five patients underwent surgical resection, two patients underwent surgical resection after receiving preoperative imatinib therapy, and one patient received conservative management. CONCLUSION: Different treatment strategies may be applied to the patients with E-GIST depending on the their clinical features. Our study provides insights into precise treatment for different patients. However, due to the rarity of the disease, it is challenging to collect a large sample size from a single center, necessitating more multicenter prospective large-scale studies.

Metabolic reprograming mediated by tumor cell-intrinsic type I IFN signaling is required for CD47-SIRPα blockade efficacy.

Type I interferons have been well recognized for their roles in various types of immune cells during tumor immunotherapy. However, their direct effects on tumor cells are less understood. Oxidative phosphorylation is typically latent in tumor cells. Whether oxidative phosphorylation can be targeted for immunotherapy remains unclear. Here, we find that tumor cell responsiveness to type I, but not type II interferons, is essential for CD47-SIRPα blockade immunotherapy in female mice. Mechanistically, type I interferons directly reprogram tumor cell metabolism by activating oxidative phosphorylation for ATP production in an ISG15-dependent manner. ATP extracellular release is also promoted by type I interferons due to enhanced secretory autophagy. Functionally, tumor cells with genetic deficiency in oxidative phosphorylation or autophagy are resistant to CD47-SIRPα blockade. ATP released upon CD47-SIRPα blockade is required for antitumor T cell response induction via P2X7 receptor-mediated dendritic cell activation. Based on this mechanism, combinations with inhibitors of ATP-degrading ectoenzymes, CD39 and CD73, are designed and show synergistic antitumor effects with CD47-SIRPα blockade. Together, these data reveal an important role of type I interferons on tumor cell metabolic reprograming for tumor immunotherapy and provide rational strategies harnessing this mechanism for enhanced efficacy of CD47-SIRPα blockade.

Visual Analytics of Multivariate Networks with Representation Learning and Composite Variable Construction.

Multivariate networks are commonly found in realworld data-driven applications. Uncovering and understanding the relations of interest in multivariate networks is not a trivial task. This paper presents a visual analytics workflow for studying multivariate networks to extract associations between different structural and semantic characteristics of the networks (e.g., what are the combinations of attributes largely relating to the density of a social network?). The workflow consists of a neuralnetwork- based learning phase to classify the data based on the chosen input and output attributes, a dimensionality reduction and optimization phase to produce a simplified set of results for examination, and finally an interpreting phase conducted by the user through an interactive visualization interface. A key part of our design is a composite variable construction step that remodels nonlinear features obtained by neural networks into linear features that are intuitive to interpret. We demonstrate the capabilities of this workflow with multiple case studies on networks derived from social media usage and also evaluate the workflow with qualitative feedback from experts.

Enhancing prostate cancer diagnosis and reducing unnecessary biopsies with [18F]DCFPyL PET/CT imaging in PI-RADS 3/4 patients.

For patients presenting with prostate imaging reporting and data system (PI-RADS) 3/4 findings on magnetic resonance imaging (MRI) examinations, the standard recommendation typically involves undergoing a biopsy for pathological assessment to ascertain the nature of the lesion. This course of action, though essential for accurate diagnosis, invariably amplifies the psychological distress experienced by patients and introduces a host of potential complications associated with the biopsy procedure. However, [18F]DCFPyL PET/CT imaging emerges as a promising alternative, demonstrating considerable diagnostic efficacy in discerning benign prostate lesions from malignant ones. This study aims to explore the diagnostic value of [18F]DCFPyL PET/CT imaging for prostate cancer in patients with PI-RADS 3/4 lesions, assisting in clinical decision-making to avoid unnecessary biopsies. 30 patients diagnosed with PI-RADS 3/4 lesions through mpMRI underwent [18F]DCFPyL PET/CT imaging, with final biopsy pathology results as the "reference standard". Diagnostic performance was assessed through receiver operating characteristic (ROC) analysis, evaluating the diagnostic efficacy of molecular imaging PSMA (miPSMA) visual analysis and semi-quantitative analysis in [18F]DCFPyL PET/CT imaging. Lesions were assigned miPSMA scores according to the prostate cancer molecular imaging standardized evaluation criteria. Among the 30 patients, 13 were pathologically confirmed to have prostate cancer. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of visual analysis in [18F]DCFPyL PET/CT imaging for diagnosing PI-RADS 3/4 lesions were 61.5%, 88.2%, 80.0%, 75.0%, and 76.5%, respectively. Using SUVmax 4.17 as the optimal threshold, the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy for diagnosis were 92.3%, 88.2%, 85.7%, 93.8%, and 90.0%, respectively. The area under the ROC curve (AUC) for semi-quantitative analysis was 0.94, significantly higher than visual analysis at 0.80. [18F]DCFPyL PET/CT imaging accurately diagnosed benign lesions in 15 (50%) of the PI-RADS 3/4 patients. For patients with PI-RADS 4 lesions, the positive predictive value of [18F]DCFPyL PET/CT imaging reached 100%. [18F]DCFPyL PET/CT imaging provides potential preoperative prediction of lesion nature in mpMRI PI-RADS 3/4 patients, which may aid in treatment decision-making and reducing unnecessary biopsies.

Exploring the destructive synergy between IL-33 and Suilysin hemolysis on blood-brain barrier stability.

Streptococcus suis type 2 (SS2) is a zoonotic pathogen capable of eliciting meningitis, presenting significant challenges to both the swine industry and public health. Suilysin (Sly), one of SS2 most potent virulence determinants, releases a surfeit of inflammatory agents following red blood cell lysis. Notably, while current research on Sly role in SS2-induced meningitis predominantly centers on its interaction with the blood-brain barrier (BBB), the repercussions of Sly hemolytic products on BBB function have largely been sidestepped. In this vein, our study delves into the ramifications of Sly-induced hemolysis on BBB integrity. We discern that Sly hemolytic derivatives exacerbate the permeability of Sly-induced in vitro BBB models. Within these Sly hemolytic products, Interleukin-33 (IL-33) disrupts the expression and distribution of Claudin-5 in brain microvascular endothelial cells, facilitating the release of Interleukin-6 (IL-6) and Interleukin-8 (IL-8), thereby amplifying BBB permeability. Preliminary mechanistic insights suggest that IL-33-driven expression of IL-6 and IL-8 is orchestrated by the p38-mitogen-activated protein kinase signaling, whereas matrix metalloproteinase 9 mediates IL-33-induced suppression of Claudin-5. To validate these in vitro findings, an SS2-infected mouse model was established, and upon intravenous administration of growth stimulation expressed gene 2 (ST2) antibodies, in vivo results further underscored the pivotal role of the IL-33/ST2 axis during SS2 cerebral invasion. In summation, this study pioneerly illuminates the involvement of Sly hemolytic products in SS2-mediated BBB compromise and spotlights the instrumental role and primary mechanism of IL-33 therein. These insights enrich our comprehension of SS2 meningitis pathogenesis, laying pivotal groundwork for therapeutic advancements against SS2-induced meningitis.IMPORTANCEThe treatment of meningitis caused by Streptococcus suis type 2 (SS2) has always been a clinical challenge. Elucidating the molecular mechanisms by which SS2 breaches the blood-brain barrier (BBB) is crucial for the development of meningitis therapeutics. Suilysin (Sly) is one of the most important virulence factors of SS2, which can quickly lyse red blood cells and release large amounts of damage-associated molecular patterns, such as hemoglobin, IL-33, cyclophilin A, and so on. However, the impact of these hemolytic products on the function of BBB is unknown and ignored. This study is the first to investigate the effect of Sly hemolytic products on BBB function. The data are crucial for the study of the pathogenesis of SS2 meningitis and can provide an important reference for the development of meningitis therapeutics.