CXC Chemokine Research Articles

CXCR6 expression predicts prognosis and immunotherapeutic benefit in muscle-invasive bladder cancer

BackgroundIncreasing evidence suggests that the CXC chemokine receptor 6 (CXCR6) is involved in tumor progression and the regulation of tumor immunity. However, its role in muscle-invasive bladder cancer (MIBC) remains largely unexplored.MethodsData from 391 MIBC patients in the TCGA, 212 patients from GEO, 131 patients from our center, 195 patients in the IMvigor210 cohort, and single-cell RNA sequencing (scRNA-seq) data from 9 bladder cancer patients (GSE222315) were analyzed. Additionally, data from the GEPIA 2, TISCH2, TIMER2.0, and UALCAN platforms were utilized to investigate the prognostic and immunotherapeutic significance of CXCR6 in MIBC.ResultsWe observed that CXCR6 expression was significantly reduced in bladder cancer tumors and correlated with tumor stage and grade. Low CXCR6 expression was associated with poor recurrence-free survival (RFS) and overall survival (OS) in the TCGA cohort, a finding validated in both the meta-GEO dataset and our center’s cohort. Multivariate analysis confirmed that low CXCR6 expression was an independent predictor of poor OS and RFS. A nomogram incorporating CXCR6 expression and other independent prognostic factors was developed to accurately predict 3- and 5-year OS. Gene set enrichment analysis indicated that immune activation-related pathways were significantly enriched in tumors with high CXCR6 expression. CIBERSORT analysis revealed that CXCR6 expression was positively correlated with CD8+ T cells, CD4+ T cells, activated NK cells, M1 macrophages, and activated dendritic cells in TCGA, findings further validated by TIMER2.0. scRNA-seq data showed that CXCR6 was predominantly expressed in T and NK cells and facilitated T/NK-myeloid interaction via the CXCR6-CXCL16 axis. Importantly, CXCL16+ macrophages and dendritic cells recruited CXCR6+ T and NK cells, which exhibited enhanced cytotoxicity, thereby amplifying anti-tumor immunity. Clinically, in the IMvigor210 immunotherapy cohort, higher CXCR6 expression was associated with improved anti-PD-L1 therapeutic outcomes.ConclusionOur findings highlight CXCR6 as a critical biomarker for predicting prognosis and immunotherapeutic response in MIBC.

LncRNA MALAT1 silencing represses CXCL12-induced proliferation, invasion, and homing behavior in multiple myeloma by inhibiting CXCR4

ABSTRACT Background: Long non-coding RNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) has been identified in multiple myeloma (MM); its influence on the homing behavior in MM cells is unclear. This study elucidates the impact and mechanism by which MALAT1 affects the homing behavior in MM cells. Methods: Bone marrow was obtained from patients with MM. MALAT1 and C-X-C motif chemokine receptor 4 (CXCR4) expression in cluster of differentiation 138-purified (CD138) plasma cells were detected by qRT-PCR and Western blotting. MALAT1, CXCR4, and C-X-C motif chemokine ligand 12 (CXCL12) influences on MM cell viability, proliferation, and invasion was monitored by CCK-8, 5-Ethynyl-2'-deoxyuridine, and Transwell assays. qRT-PCR, Western blotting, and ELISA were utilized to detect homing effect-related proteins in MM cells, including intercellular adhesion molecule 1 (ICAM-1) and very late antigen-4 (VLA-4). Results: MALAT1 and CXCR4 were overexpressed in CD138-purified plasma cells from bone marrow of MM patients, associating with bone damage. MALAT1 upregulated CXCR4 in MM cells. MALAT1 overexpression enhanced MM cell viability, proliferation, and invasion, whereas CXCR4 silencing reversed them. CXCR4 silencing attenuated MALAT1 induction on ICAM-1 and VLA-4 expression in MM cells. CXCL12 upregulation intensified MM cell proliferation and invasion and ICAM-1 and VLA-4 expression in MM cells. MALAT1 silencing counteracted the impact of CXCL12. Conclusion: MALAT1 silencing may repress CXCL12 induction on MM cell proliferation, invasion, and homing behavior by inhibiting CXCR4. MALAT1 may be a promising target for MM treatment.

Icariin ameliorates Coxsackievirus B3-induced viral myocarditis by modulating the S100 calcium binding protein A6/β-catenin/c-Myc signaling pathway

BackgroundCoxsackievirus B3 (CVB3) is a leading cause of viral myocarditis and is currently lacking specific pharmacological treatments, highlighting the critical need for therapeutic development. Icariin (ICA), a prenylated flavonol glycoside, was previously found to exhibit several pharmacological effects, but its potential to combat CVB3 remains uninvestigated. PurposeThis study aimed to elucidate the anti-CVB3 efficacy of ICA and elucidate its molecular mechanisms. MethodsCVB3-infected HeLa cells, H9C2 cells and neonate rat ventricular cardiomyocytes (NRVCs) were selected as in vitro models, and were treated with ICA at 1 and 10 μM. Additionally, BALB/c mice that were infected with CVB3 via intraperitoneal injection were chosen as in vivo model and were treated with ICA or ribavirin over 3 days. The effect of ICA against CVB3 was determined by Cell Counting Kit-8 (CCK-8) assay, western blot, real-time fluorescence quantitative PCR (RT–qPCR), terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay, hematoxylin and eosin (H&E) staining, immunohistochemistry (IHC) and flow cytometry. ResultsIn this study, it was found that ICA is capable of reducing CVB3 viral load both in vitro and in vivo. Mechanistic studies suggested that ICA prevents cardiomyocyte apoptosis by attenuating the S100 calcium binding protein A6 (S100A6)/β-catenin/c-Myc signaling pathway. Additionally, ICA inhibits the secretion of proinflammatory cytokines tumor necrosis factor alpha (TNF-α), interleukin-1beta (IL-1β) and CXC motif chemokine ligand 2 (CXCL2) in heart tissue, thereby mitigating CVB3-induced myocarditis. Moreover, ICA also regulates the immune response of CD4+ T, CD8+ T and Treg cells by changing the cells numbers in spleen tissue. Lastly, ICA can reduce the load of other enteroviruses (such as CVA6, CVA16 and EV71) in rhabdomyosarcoma (RD) cells as well. ConclusionOur findings indicate that ICA provides significant protection against CVB3 infection by modulating the S100A6/β-catenin/c-Myc signaling pathway, suggesting its potential use as a novel drug against CVB3 infection in clinical application.

Study on the changes and significance of CXCL10 level in serum of isolated polymyalgia rheumatica.

To investigate the significance of CXC chemokine ligand 10 (CXCL10) in the pathogenesis of isolated polymyalgia rheumatica (PMR). The serum of six PMR patients diagnosed and treated at the First Affiliated Hospital of Wannan Medical College from September 2019 to December 2020 before treatment and after remission was collected, and the serum of six active rheumatoid arthritis (RA) patients and six healthy medical checkups were also collected, and protein microarray technology was used to detect 24 cytokines, including IL-6, IL-4, CXCL10, CXCL8, and CXCL2. Subsequently, serum was collected from other 28 patients with active PMR, 26 patients with PMR in remission, 24 patients with active RA, and 24 healthy medical checkups who were diagnosed and treated at the First Affiliated Hospital of Wannan Medical College from January 2021 to July 2023, and the enzyme-linked immunosorbent assay (ELISA) was used to validate and compare the levels of CXCL10 in each group and analyze the correlation between the levels of serum CXCL10 and the parameters of the clinical activities of PMR. Protein microarray screening revealed significant differences in CXCL10 before and after PMR treatment, and ELISA validation revealed that peripheral serum CXCL10 levels were significantly higher in the PMR-active group than in the remission group (P < 0.001), and also significantly higher than in the RA-active group (P = 0.003) and in the healthy control group (P < 0.001); correlation analysis showed a significant positive correlation between serum CXCL10 levels and serum ferritin in PMR patients (r = 0.450, P = 0.024). In the ROC curve for distinguishing PMR and RA, the area under the curve is 0.741, sensitivity = 0.643, and specificity = 0.792. CXCL10 may play a role in the pathogenesis of isolated PMR and its level might contribute to the differential diagnosis of PMR and RA. Key Points •The concentration of CXCL10 was higher in peripheral blood of isolated PMR patients. •CXCL10 is a potential diagnostic biomarker for isolated PMR patients. •The level of CXCL10 might contribute to the differential diagnosis of PMR and RA.

Epigenetic Regulation of CXC Chemokine Expression by Environmental Electrophiles Through DNA Methyltransferase Inhibition

Ubiquitously distributed environmental electrophiles covalently modify DNA and proteins, potentially leading to adverse health effects. However, the impacts of specific electrophiles on target proteins and their physiological roles remain largely unknown. In the present study, we focused on DNA methylation, which regulates gene expression and physiological responses. A total of 45 environmental electrophiles were screened for inhibitory effects on the activity of DNA methyltransferase 3B (DNMT3B), a key enzyme in DNA methylation, and four compounds were identified. We focused on 1,2-naphthoquinone (1,2-NQ), an air pollutant whose toxicity has been reported previously. Interestingly, we found that 1,2-NQ modified multiple lysine and histidine residues in DNMT3B, one of which was near the active site in DNMT3B. It was found that 1,2-NQ altered gene expression and evoked inflammatory responses in lung adenocarcinoma cell lines. Furthermore, we found that 1,2-NQ upregulated CXCL8 expression through DNA demethylation of the distal enhancer and promoted cancer cell growth. Our study reveals novel mechanisms of epigenetic regulation by environmental electrophiles through the inhibition of DNMT3B activity and suggests their physiological impact.

Transpulmonary proteome gradients identify inflammatory pathways involved in the development of pulmonary vasculopathy in heart failure

Abstract Background Some, but not all, patients with heart failure (HF) develop pulmonary vascular disease (PVD), which contributes to poor prognosis. Mechanisms leading to PVD in HF are poorly understood. Unbiased analysis of transpulmonary gradients may identify not only markers but also mediators of PVD by identifying proteins that may be consumed or elaborated across the lungs. Purpose Examine hemodynamics and transpulmonary proteome gradients in HFrEF and controls. Methods 21 non-HF controls and 160 patients with advanced HFrEF underwent pulmonary artery (PA) catheterization with blood sampling from the PA catheter in the wedged position (02sat &amp;gt; 90%, indicating pulmonary venous blood) and the un-wedged position to obtain transpulmonary proteome gradients. Samples from controls and HF from the highest quartile (Q4, n=40) and lowest quartile (Q1, n=40) of pulmonary vascular resistance (PVR) were analyzed using proteomic PEA assay of 275 proteins (Olink Target 96, panels CVII, CVIII, Inflammation). Pulmonary artery concentrations ("markers") or transpulmonary fold-change gradients (i.e. putative "mediators") of normalized protein expression (NPX) were plotted against significance; Benjamini–Hochberg FDR&amp;lt;0.05 considered as significant. Results Patients displayed typical characteristics of HFrEF (age 56±8y, NYHA 3.0 ±0.6, 87% males, LVEF 24±9.6%), Controls had similar anthropometrics, gender and age. Comparing all HF to Con, 38 markers of HF were identified (NPX fold-change&amp;gt;2), including 33 up (top 5: NTproBNP, BNP, GDF15, FGF23, IL8) and 5 down. HF patients in Q1 had median PVR 1.5 (IQR: 0.3-1.7) WU and those in Q4 had PVR 5.4 (4.3-6.6) WU. Comparison of Q1 and Q4 identified 3 protein markers of high PVR in PA blood from HF: chemokine CCL3, TNFRSF13B and surfactant protein-D (PSP-D). Examination of protein gradients from HF lungs (Figure) showed significant uptake of 14 protein mediators, most of which were associated with inflammatory responses (top 5: OSM, MMP9, CCL19, BNP, TR), and release of 8 mediators (top 4: IL-6, IL33, CCL4, CXCL10). In contrast, protein gradients were negligible in controls. Patients in Q4 PVR group were characterized by the highest pulmonary uptake of OSM (Oncostatin-M), lymphatic chemokine CCL19, BNP, MMP9, and had more significant transpulmonary release of IL6 and IL33. Across all patients, OSM lung uptake was the strongest correlate of transpulmonary pressure gradient (r=-0.3, p&amp;lt;0.001). Conclusions Lungs of patients with HF, and particularly those with high PVR, display abnormal uptake and release of proinflammatory CC and CXC chemokines and cytokines from IL1 and IL6 family, along with increased pulmonary uptake of IL6-type cytokine Oncostatin-M, a known mediator of lung inflammation and fibrosis, that acts via gp130/JAK/STAT, suggesting a novel role in PVD due to HF.Transpulmonary proteome in HF patients

Intrauterine adhesions repair with menstrual blood-derived mesenchymal stem cells via CXCL13-CXCR5 signal axis and its mechanism

BackgroudIntrauterine Adhesions (IUA) is a common gynecological disease which is seriously endangers the reproductive function of women without any ideal treatment. Some researchers found Menstrual Blood-derived Mesenchymal Stem Cells (MenSCs) can repair of damaged endometrium, however, has not been fully clarified. This study aims to evaluate the therapeutic effects of MenSCs in IUA and the repair mechanism in vivo.MethodsThis study is Laboratory-based study. To evaluate the therapeutic effects of MenSCs in IUA, We cultivated MenSCs, established mouse endometrial injury model, observed the uterine morphology and degree of endometrial fibrosis and compared the expression of CXC chemokine ligand-13 (CXCL13)、CXC chemokine receptor-5 (CXCR5)、Plasmin Activating Inhibitor-1(Pai-1), Transforming Growth Faction-β1(TGF- β1) and Matrix Metalloproteinase-9 (Mmp-9) among each groups. GraphPad Prism 8.0 was used for statistical processing. Data were expressed as mean ± SD. Statistical comparisons among groups were performed with one-way ANOVA. P < 0.05 were considered statistically significant.ResultsWe successfully cultured and identified MenSCs and established mice model of uterine adhesion. After treatment with MenSCs, endometrial morphology of mice was partially restored, endometrial thickness was increased, and glands were multipiled. The concentrations of CXCL13 and CXCR5 were significantly increased by immunofluorescence detection compared with the control group. The results of RT-qPCR showed that the expressions of Pai-1 and Mmp-9 were significantly lower than those of the control group.ConclusionsMenSCs may reduce endometrial fibrosis and the down-regulating expression of Pai-1、Mmp-9 and CXCL13-CXCR5 axis were involved in the process of MenSCs repaired IUA.

CXCR4 up-regulation mediated by USP1 deubiquitination promotes the tumorigenesis and immune escape in esophageal squamous-cell carcinoma.

CXC chemokine receptor 4 (CXCR4) and ubiquitin specific protease 1 (USP1) have been reported to involve in the tumorigenesis of esophageal squamous-cell carcinoma (ESCC). Here, we investigated whether USP1 induced CXCR4 deubiquitination in regulating ESCC progression. MTT assay, 5-ethynyl-2'-deoxyuridine assay, flow cytometry, transwell assay and ELISA analysis were used to detect cell oncogenic phenotypes, macrophage phenotypes, inflammatory cytokines production, the cytotoxicity of cytokine-induced killer (CIK) cells and CD8 + T cell apoptosis. Protein interaction was determined by immunoprecipitation assay. Cellular ubiquitination detected the ubiquitination effect on CXCR4. A mouse xenograft model was established for in vivo experiments. CXCR4 was highly expressed in ESCC tissues and cells. Functionally, CXCR4 silencing suppressed ESCC cell proliferation, invasion, and induced cell apoptosis. Moreover, CXCR4 deficiency suppressed cancer cell immune escape by suppressing macrophage M2 polarization, elevating inflammatory cytokines produced by PBMCs, enhancing the cytotoxicity of CIK cells, and suppressing CD8 + T cell apoptosis. A high USP1 expression was observed in ESCC, USP1 interacted with CXCR4 and enhanced its protein stability through deubiquitination. USP1 silencing suppressed ESCC cell proliferation, invasion, and immune escape, which were reversed by CXCR4 overexpression. In vivo assay showed that USP1 deficiency impeded tumor growth by regulating CXCR4. Besides, fused in sarcoma (FUS) was confirmed to bind to USP1 and stabilized its mRNA expression, and could regulate CXCR4 via USP1. In conclusion, USP1 stabilized CXCR4 by removing ubiquitination on CXCR4, thereby promoting ESCC cell proliferation, invasion, and immune escape in vitro, and tumor growth in vivo.

CXC chemokine receptor 4 - mediated immune modulation and tumor microenvironment heterogeneity in gastric cancer: Utilizing multi-omics approaches to identify potential therapeutic targets.

G-protein-coupled receptors (GPRs) are critical regulators of various biological behaviors, and their role in gastric cancer (GC) progression is gaining increasing attention. Among them, the immune regulatory mechanisms mediated by chemokine receptor 4 (CXCR4) remain insufficiently understood. This study aims to explore the immune regulatory functions of CXCR4 and the heterogeneity of the tumor microenvironment (TME) by examining GPR-related gene expression in GC. Through multi-omics approaches, including spatial transcriptomics and single-cell RNA sequencing, we investigated the oncogenic mechanisms of CXCR4, particularly its role in T cell immune exhaustion. In vitro experiments, including ELISA, PCR, CCK8 assays, cell scratch assays, and colony formation assays, were used to validate the role of CXCR4 in the migration and invasion of AGS and SNU-1 cell lines. CXCR4 silencing using siRNA further demonstrated its regulatory effects on these cellular processes. Our results revealed a strong correlation between elevated CXCR4 expression and increased exhaustion of regulatory T cells (Tregs) in the TME. Furthermore, heightened CXCR4 expression was linked to increased TME heterogeneity, driven by oxidative stress and activation of the NF-κB pathway, promoting immune evasion and tumor progression. Silencing CXCR4 significantly inhibited the invasive and proliferative abilities of AGS and SNU-1 cells, while also reducing the expression of pro-inflammatory cytokines IL-1β and interleukin-6, thus alleviating chronic inflammation and improving TME conditions. In conclusion, our comprehensive investigation highlights CXCR4 as a key mediator of TME dynamics and immune modulation in GC. Targeting CXCR4 presents a promising therapeutic strategy to slow tumor progression by reducing Tregs-mediated immune exhaustion and TME heterogeneity, positioning it as a novel therapeutic target in GC treatment.

The exploration of molecular mechanisms involved in the effect of Traditional Chinese Medicine in the treatment of intracerebral hemorrhage

Background: This study aimed to explore the underlying mechanism of the efficacy of Traditional Chinese Medicine (TCM) in alleviating intracerebral hemorrhage (ICH). Methods: Keywords for TCM treatment in ICH were searched in PubMed and CNKI, and relevant literature has been integrated to extract and collect related gene targets. These selected genes were further analyzed by Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG). Protein-protein interaction (PPI) analysis was performed on the target genes in the String database. Results: A total of 491 key genes were identified from 555 references. GO and KEGG analysis of these genes revealed that anti-apoptotic, anti-inflammatory, and anti-oxidative stress-related processes and pathways were significantly enriched. PPI network uncovered the crucial genes involved in these biological functions were phosphatase and tensin homolog (PTEN), signal transducer and activator of transcription 3 (STAT3), the rearranged during transfection (RET) gene, signal transducer and activator of transcription 1 (STAT1), apolipoprotein E (APOE), 5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA), CXC chemokine receptor type 4 (CXCR4), Jun proto-oncogene (JUN), c-fos protein (FOS), and tumor necrosis factor (TNF). Conclusions: This study unveiled that TCM treatment plays an important role in the treatment of ICH via anti-inflammatory, anti-apoptotic, and anti-oxidative stress signaling.

Bone Destruction-Chemotactic Osteoprogenitor Cells Deliver Liposome Nanomedicines for the Treatment of Osteosarcoma and Osteoporosis.

Therapeutic efficacy of skeletal diseases is usually limited by unfavorable drug delivery due to incapable bone targeting and low bone affinity of conventional drug carriers, as well as relatively reduced vascularization and dense structure of bone tissues. Due to CXC chemokine receptor 4 (CXCR4)/CXC chemokine ligand 12 (CXCL12) signal axis-guided recruitment, osteoprogenitor cells (OPCs) can actively migrate to bone disease nidus. Here, drugs-loaded nanoliposomes are prepared and decorated onto OPCs by biotin-streptavidin linkage for precise bone disease targeting and effective drug delivery. In mouse models of tibia defect and orthotopic osteosarcoma, superior targeting property of OPCs-based drug delivery systems toward diseased bone niduses is verified. By encapsulating antitumor and antiosteoporosis drugs into nanoliposomes, OPCs-based drug delivery systems effectively inhibit disease development and restore bone destruction in mouse models of orthotopic osteosarcoma and ovariectomized osteoporosis. This study reveals a cell-based drug delivery system for precise bone disease targeting and highly effective drug delivery, which will find great potential as a universal drug delivery platform for targeting treatment of various bone diseases.

Potential protective association of the AA genotype and a allele of CXCR4 rs2228014 polymorphism with COVID-19 severity in adult egyptians

BackgroundBy the end of December 2019, a new coronavirus, termed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), emerged, and the cause of the disease was named coronavirus disease 2019 (COVID-19). Several genetic factors have been implicated in diverse responses to SARS-CoV-2 infection, such as the C-X-C chemokine receptor 4 (CXCR4) rs2228014 polymorphism, which has been previously studied in various diseases but has not been explored in the context of COVID-19 severity. The current study aimed to assess the association between the rs2228014 polymorphism in the CXCR4 gene and the severity of COVID-19, which has not been previously reported.MethodThis cross-sectional study analyzed 300 adult Egyptian COVID-19 patients (156 with mild or moderate and 144 with severe or critical symptoms) admitted to Assiut University Quarantine Hospital from June to September 2022 during the omicron variant. The rs2228014 polymorphism in the CXCR4 gene was detected using real-time PCR with a TaqMan assay probe. Receiver operating characteristic (ROC) curve analysis was used to determine the best cutoff values for C-reactive protein (CRP) that can be used to estimate the severity of COVID-19. P values less than 0.05 were considered to indicate statistical significance.ResultsNo significant differences in the allelic or genotypic frequencies of CXCR4 rs2228014 were detected between the severity groups. However, the exclusive presence of the AA genotype in mild or moderate cases suggests its potential protective role. Additionally, significant differences in myalgia presentation, leukocyte counts and antibiotic use, were observed among different genotypes. Statistical data showed that the severity of COVID-19 could be predicted at a cutoff value of CRP > 30 mg/L, with a sensitivity of 74.3% and a specificity of 42.9%.ConclusionThe present findings suggest a potential protective role of the AA genotype and A allele of CXCR4 rs2228014 against severe COVID-19. Additionally, factors such as lack of vaccination and comorbidities such as hypertension, renal disease, and diabetes mellitus were associated with increased disease severity.

Inulin-based nanoparticles for targeted siRNA delivery in acute kidney injury

RNA interference has emerged as a promising therapeutic strategy to tackle acute kidney injury (AKI). Development of targeted delivery systems is highly desired for selective renal delivery of RNA and improved therapeutic outcomes in AKI. Inulin is a plant polysaccharide traditionally employed to measure glomerular filtration rate. Here, we describe the synthesis of inulin modified with α-cyclam-p-toluic acid (CPTA) to form a novel renal-targeted polymer, Inulin-CPTA (IC), which is capable of selective siRNA delivery to the injured kidneys. We show that conjugating CPTA to inulin imparts IC with targeting properties for cells that overexpress the C-X-C chemokine receptor 4 (CXCR4). Self-assembled IC/siRNA nanoparticles (polyplexes) demonstrated rapid accumulation in the injured kidneys with selective uptake and prolonged retention in injured renal tubules overexpressing the CXCR4 receptor. Tumor-suppressor protein p53 contributes significantly to the pathogenesis of AKI. siRNA-induced silencing of p53 has shown therapeutic potential in several preclinical studies, making it an important target in the treatment of AKI. Systemically administered nanoparticles formulated using IC and siRNA against p53 selectively accumulated in the injured kidneys and potently silenced p53 expression. Selective p53 knockdown led to positive therapeutic outcomes in mice with cisplatin-induced AKI, as seen by reduced tubular cell death, renal injury, inflammation, and overall improved renal function. These findings indicate that IC is a promising new carrier for renal-targeted delivery of RNA for the treatment of AKI.

Differential expression and significance of cytokines in cerebrospinal fluid of patients with viral encephalitis

To extensively identify cerebrospinal fluid (CSF) cytokine profiles related to the occurrence, development and prognosis of viral encephalitis (VE) patients by using a high-throughput proteomic approach.We measured 80 cytokines in the CSF of acute-phase VE patients (n = 11) using high-throughput protein chip technology, comparing them to controls (n = 6). ELISA validated these findings and assessed additional cytokines from prior literature in a larger cohort (15 VE patients, 15 controls). Correlations between biomarkers and clinical characteristics were also examined.In the initial stage, we identified two differentially expressed cytokines: cathepsin-L (CTSL), which was up-regulated, and Fractalkine, which was down-regulated. Functional enrichment analysis revealed that these proteins are linked to inflammation, apoptosis, autophagy, and blood-brain barrier disruption. In stage2, the elevations of cathepsin-L (CTSL), fractalkine, interleukin-6 (IL-6), IL-1β, macrophage migration inhibitory factor (MIF), tumor necrosis factor-α (TNF-α), insulin-like growth factor Ⅱ (IGF-2) and CXC chemokine ligand 10 (CXCL10) in VE were validated by ELISA. The results of linear regression indicated that these cytokines was positively correlated with CSF reactive lesions (p < 0.05).In this study, some biomarkers related with CSF level changes and prognosis were obtained. Although these cytokines are not specific, they may be related to the occurrence and development of VE. CTSL, MIF, IL-1β, TNF-α and CXCL10 can be used as VE potential biomarkers. These cytokines may participate in the pathogenesis of VE through inflammatory response, cell apoptosis, autophagy, blood-brain barrier disruption and cytokine-cytokine receptor interaction pathway.

Structural insights into KSHV-GPCR constitutive activation and CXCL1 chemokine recognition

Kaposi's sarcoma-associated herpesvirus (KSHV) encodes a viral G protein-coupled receptor, KSHV-GPCR, that contributes to KSHV immune evasion and pathogenesis of Kaposi's sarcoma. KSHV-GPCR shares a high similarity with CXC chemokine receptors CXCR2 and can be activated by selected chemokine ligands. Like other herpesvirus-encoded GPCRs, KSHV-GPCR is characterized by its constitutive activity by coupling to various G proteins. We investigated the structural basis of ligand-dependent and constitutive activation of KSHV-GPCR, obtaining high-resolution cryo-EM structures of KSHV-GPCR-Gi complexes with and without the bound CXCL1 chemokine. Analysis of the apo-KSHV-GPCR-Gi structure (2.81 Å) unraveled the involvement of extracellular loop 2 in constitutive activation of the receptor. In comparison, the CXCL1-bound KSHV-GPCR-Gi structure (3.01 Å) showed a two-site binding mode and provided detailed information of CXCL1 binding to a chemokine receptor. The dual activation mechanism employed by KSHV-GPCR represents an evolutionary adaptation for immune evasion and contributes to the pathogenesis of Kaposi's sarcoma. Together with results from functional assays that confirmed the structural models, these findings may help to develop therapeutic strategies for KSHV infection.

Effect of tocilizumab on endothelial and platelet-derived CXC-chemokines and their association with inflammation and myocardial injury in STEMI patients undergoing primary PCI

BackgroundTocilizumab improves myocardial salvage in ST-elevation myocardial infarction (STEMI) patients when administered before percutaneous coronary intervention (PCI). The mechanisms underlying ischemia-reperfusion injury remain unclear. In this sub-study, we investigated whether endothelial and platelet-derived CXC chemokines are involved, as they represent inflammatory mediators from two cell types relevant to myocardial infarction. Associations between these chemokines and neutrophils, C-reactive protein (CRP), troponin T (TnT), myocardial salvage index (MSI), microvascular obstruction (MVO), and infarct size. MethodsThis is a sub-study of the ASSAIL-MI trial, a double-blind clinical trial that randomized 199 STEMI patients to receive either 280 mg tocilizumab (n = 101) or placebo (n = 98) intravenously before PCI. Blood samples were collected prior to infusion, at day 1–2, 3–7, and at 3 and 6 months. Heparin was administered before baseline in 150 patients, while 49 received it after. We measured CXC-chemokines CXCL4, CXCL5, CXCL6, CXCL7, and CXCL12 using immunoassays. Cardiac MRI was performed in the first week and at 6 months. ResultsTocilizumab did not significantly affect CXC-chemokines levels. Although some correlations were observed between chemokine levels and neutrophil counts and CRP, none of the CXC chemokines were associated with infarct size, MSI, MVO, or TnT levels. Notably, CXCL 12 levels increased in patients who received heparin before baseline, while other CXC-chemokines decreased significantly. ConclusionThis study suggests that the beneficial effects of tocilizumab in STEMI patients are not due to changes in circulating endothelial or platelet-derived CXC-chemokines, compared to placebo. However, heparin significantly influences the levels of these chemokines.

Host cell glycosylation selects for infection with CCR5- versus CXCR4-tropic HIV-1.

Human immunodeficiency virus type 1 (HIV-1) infection involves a selection bottleneck that leads to transmission of one or a few variants. C-C motif chemokine receptor 5 (CCR5) or C-X-C motif chemokine receptor 4 (CXCR4) can act as coreceptors for HIV-1 viral entry. However, initial infection mostly occurs via CCR5, despite abundant expression of CXCR4 on target cells. The host factors that influence HIV-1 susceptibility and selection during transmission are unclear. Here we conduct CRISPR-Cas9 screens and identify SLC35A2 (a transporter of UDP-galactose expressed in target cells in blood and mucosa) as a potent and specific CXCR4-tropic restriction factor in primary target CD4+ T cells. SLC35A2 inactivation, which resulted in truncated glycans, not only increased CXCR4-tropic infection levels but also decreased those of CCR5-tropic strains consistently. Single-cycle infections demonstrated that the effect is cell-intrinsic. These data support a role for a host protein that influences glycan structure in regulating HIV-1 infection. Host cell glycosylation may, therefore, affect HIV-1 selection during transmission in vivo.

CXCR3-CXCL11 Signaling Restricts Angiogenesis and Promotes Pericyte Recruitment.

Endothelial cell (EC)-pericyte interactions are known to remodel in response to hemodynamic forces; yet there is a lack of mechanistic understanding of the signaling pathways that underlie these events. Here, we have identified a novel signaling network regulated by blood flow in ECs-the chemokine receptor CXCR3 (CXC motif chemokine receptor 3) and one of its ligands, CXCL11 (CXC motif chemokine ligand 11)-that delimits EC angiogenic potential and promotes pericyte recruitment to ECs during development. We investigated the role of CXCR3 on vascular development using both 2- and 3-dimensional in vitro assays, to study EC-pericyte interactions and EC behavioral responses to blood flow. Additionally, genetic mutants and pharmacological modulators were used in zebra fish in vivo to study the impacts of CXCR3 loss and gain of function on vascular development. In vitro modeling of EC-pericyte interactions demonstrates that suppression of EC-specific CXCR3 signaling leads to loss of pericyte association with EC tubes. In vivo, phenotypic defects are particularly noted in the cranial vasculature, where we see a loss of pericyte association with ECs and expansion of the vasculature in zebra fish treated with the Cxcr3 inhibitor AMG487 or in homozygous cxcr3.1/3.2/3.3 triple mutants. We also demonstrate that CXCR3-deficient ECs are more elongated, move more slowly, and have impaired EC-EC junctions compared with their control counterparts. Our results suggest that CXCR3 signaling in ECs helps promote vascular stabilization events during development by preventing EC overgrowth and promoting pericyte recruitment.

Mechanism of Huayu Jiedu Decoction in Inhibiting Malignant Biological Characteristics of Multiple Myeloma

To analyze and explore the effects of Huayu Jiedu Decoction on the malignant biological characteristics of multiple myeloma (MM) cells and its molecular mechanism, so as to provide experimental basis and theoretical basis for the alternative therapy of anti-MM in traditional Chinese medicine. Different concentrations of Huayu Jiedu Decoction were used to intervene myeloma U266 cells. The changes of cell proliferation activity were detected by CCK-8 assay, apoptosis was detected by Annexin V/PI double staining flow cytometry, and apoptosis and protein expression of related signaling pathways were detected by Western blot. Real-time quantitative PCR was used to detect mRNA expression changes of high mobility group protein B1 (HMGB1), CXC chemokine receptor 4 (CXCR4) and interleukin-6 (IL-6). Huayu Jiedu Decoction inhibited the proliferative activity of U266 cells and induced their apoptosis in a concentration and time dependent manner ( r =-0.713, r =-0.827). After treatment with Huayu Jiedu Decoction for 48 h, the expressions of anti-apoptotic protein Bcl-2 and survivin were down-regulated, while the expression of pro-apoptotic protein Bax was up-regulated, and the phosphorylation level of TLR4/NF-κB signaling pathway was inhibited. After intervention of Huayu Jiedu decoction, the expressions of HMGB1 and IL-6 mRNA were significantly decreased, while the expression of CXCR4 was not significantly decreased. Huayu Jiedu Decoction can inhibit the proliferative activity of U266 cells and induce programmed death. Its molecular mechanism may be related to regulating the expression of apoptotic proteins, inhibiting the activation of TLR4/NF-κB pathway and down-regulating the expression of HMGB1 and IL-6 mRNA.

An overview of the role of chemokine CX3CL1 (Fractalkine) and CX3C chemokine receptor 1 in systemic sclerosis.

Systemic sclerosis (SSc) is a complex autoimmune disease characterized by fibrosis, vascular damage, and immune dysregulation. Fractalkine or chemokine (C-X3-C motif) ligand 1 (CX3CL1), a chemokine and adhesion molecule, along with its receptor CX3CR1, have been implicated in the inflammatory processes of SSc. CX3CL1 functions as both a chemoattractant and an adhesion molecule, guiding immune cell trafficking. This systematic review examines the role of CX3CL1 and its receptor CX3CR1 in the pathogenesis of SSc, with a focus on pulmonary and vascular complications. A systematic literature search was conducted across databases including PubMed, Scopus, and Web of Science from inception to November 2020. The search focused on studies investigating the CX3CL1/CX3CR1 axis in the context of SSc. The review identified elevated CX3CL1 expression in SSc patients, particularly in the skin and lungs, where CX3CR1 is expressed on infiltrating immune cells. Higher levels of CX3CL1 were correlated with the severity of interstitial lung disease in SSc patients, indicating a potential predictive marker for disease progression. CX3CR1-positive monocytes and NK cells were recruited to inflamed tissues, contributing to fibrosis and tissue damage. Animal studies showed that inhibition of the CX3CL1/CX3CR1 axis reduced fibrosis and improved vascular function. The CX3CL1/CX3CR1 axis plays a key role in immune cell recruitment and fibrosis in SSc. Elevated CX3CL1 levels are associated with lung and vascular complications, making it a potential biomarker for disease progression and a promising therapeutic target.