MiR-625-5p is a potential therapeutic target in sepsis by regulating CXCL16/CXCR6 axis and endothelial barrier.

BACKGROUND: MicroRNA plays an important role in the progression of sepsis. We found a significant increase of in miR-625-5p expression in the blood of patients with sepsis, and lipopolysaccharide (LPS)-stimulated EA.hy926 cells. To date, little is known about the specific biological function of miR-625-5p in sepsis. METHODS: Changes in miR-625-5p expression were verified through quantitative real-time polymerase chain reaction in 45 patients with sepsis or septic shock and 30 healthy subjects. In vitro, EA.hy926 cells were treated with LPS. Transendothelial electrical resistance assay and FITC-dextran were used in evaluating endothelial barrier function. RESULTS: Herein, patients with sepsis or septic shock had significantly higher miR-625-5p expression levels, chemokine (C-X-C motif) ligand 16 (CXCL16) levels, and glycocalyx components than the healthy controls, and miR-625-5p level was positively correlated with disease. Kaplan-Meier analysis demonstrated a strong association between miR-625-5p level and 28-day mortality. Furthermore, the miR-625-5p inhibitor significantly alleviated LPS-induced endothelial barrier injury in vitro. Then, miR-625-5p positively regulated CXCL16 and down-regulated miR-625-5p attenuated CXCL16 transcription and expression in EA.hy926 cells. CXCL16 knockout significantly alleviated vascular barrier dysfunction in the LPS-induced EA.hy926 cells. sCXCL16 treatment in EA.hy926 cells significantly increased endothelial hyperpermeability by disrupting endothelial glycocalyx, tight junction proteins, and adherens junction proteins through the modulation of C-X-C chemokine receptor type 6 (CXCR6). CONCLUSIONS: Increase in miR-625-5p level may be an effective biomarker for predicting 28-day mortality in patients with sepsis/septic shock. miR-625-5p is a critical pathogenic factor for endothelial barrier dysfunction in LPS-induced EA.hy926 cells because it activates the CXCL16/CXCR6 axis.

Silencing CXCL16 alleviate neuroinflammation and M1 microglial polarization in mouse brain hemorrhage model and BV2 cell model through PI3K/AKT pathway.

Neuroinflammation and microglia polarization play pivotal roles in brain injury induced by intracerebral hemorrhage (ICH). Despite the well-established involvement of CXC motif chemokine ligand 16 (CXCL16) in regulating inflammatory responses across various diseases, its specific functions in the context of neuroinflammation and microglial polarization following ICH remain elusive. In this study, we investigated the impact of CXCL16 on neuroinflammation and microglia polarization using both mouse and cell models. Our findings revealed elevated CXCL16 expression in mice following ICH and in BV2 cells after lipopolysaccharide (LPS) stimulation. Specific silencing of CXCL16 using siRNA led to a reduction in the expression of neuroinflammatory factors, including IL-1ß and IL-6, as well as decreased expression of the M1 microglia marker iNOS. Simultaneously, it enhanced the expression of anti-inflammatory factors such as IL-10 and the M2 microglia marker Arg-1. These results were consistent across both mouse and cell models. Intriguingly, co-administration of the PI3K-specific agonist 740 Y-P with siRNA in LPS-stimulated cells reversed the effects of siRNA. In conclusion, silencing CXCL16 can positively alleviate neuroinflammation and M1 microglial polarization in BV2 inflammation models and ICH mice. Furthermore, in BV2 cells, this beneficial effect is mediated through the PI3K/Akt pathway. Inhibition of CXCL16 could be a novel approach for treating and diagnosing cerebral hemorrhage.

Soluble CXCL16 is a prognostic biomarker associated with rapidly progressive interstitial lung disease complicated with dermatomyositis.

OBJECTIVES: Rapidly progressive interstitial lung disease (RPILD) in patients with dermatomyositis (DM) significantly impacts prognosis, leading to high mortality rates. Although several indicators have been demonstrated to strongly correlate with the risk of developing RPILD, their clinical utility still needs to be investigated. The objective of this study was to investigate the clinical significance of soluble CXCL16 (sCXCL16) in DM patients complicated with RPILD. METHODS: Serum sCXCL16 was measured by enzyme-linked immunosorbent assay in 96 patients with DM and 55 matching healthy donors. Correlations between sCXCL16 levels and clinical features, laboratory examinations and the predictive value of baseline sCXCL16 level for RPILD were analysed. RESULTS: The serum sCXCL16 levels were significantly higher in patients with DM (n = 96, 3.264 ± 1.516 ng/mL) compared with healthy donors (n = 55, 1.781 ± 0.318 ng/mL), especially in DM complicated with RPILD (n = 31, 4.441 ± 1.706 ng/mL). The sCXCL16 levels were positively correlated with levels of serum ferritin, C reactive protein, erythrocyte sedimentation rate, lactate dehydrogenase, hydroxybutyrate dehydrogenase, and negatively correlated with peripheral lymphocytes percentage, but showed no correlation with levels of anti-melanoma differentiation-associated gene 5 antibody, Krebs von den Lungen-6 or creatine kinase. Multivariable analysis showed that elevated sCXCL16 was an independent prognostic factor for poor prognosis of RPILD in patients with DM. The 2-year survival rate was significantly lower in patients with high sCXCL16 level than in those with low sCXCL16 level. CONCLUSION: A higher serum sCXCL16 level was identified as a predictive biomarker of RPILD in patients with DM, and closely associated with poor prognosis.

CXCL16-dependent scavenging of oxidized lipids by islet macrophages promotes differentiation of pathogenic CD8+ T cells in diabetic autoimmunity.

The pancreatic islet microenvironment is highly oxidative, rendering ß cells vulnerable to autoinflammatory insults. Here, we examined the role of islet resident macrophages in the autoimmune attack that initiates type 1 diabetes. Islet macrophages highly expressed CXCL16, a chemokine and scavenger receptor for oxidized low-density lipoproteins (OxLDLs), regardless of autoimmune predisposition. Deletion of Cxcl16 in nonobese diabetic (NOD) mice suppressed the development of autoimmune diabetes. Mechanistically, Cxcl16 deficiency impaired clearance of OxLDL by islet macrophages, leading to OxLDL accumulation in pancreatic islets and a substantial reduction in intra-islet transitory (Texint) CD8+ T cells displaying proliferative and effector signatures. Texint cells were vulnerable to oxidative stress and diminished by ferroptosis; PD-1 blockade rescued this population and reversed diabetes resistance in NOD.Cxcl16-/- mice. Thus, OxLDL scavenging in pancreatic islets inadvertently promotes differentiation of pathogenic CD8+ T cells, presenting a paradigm wherein tissue homeostasis processes can facilitate autoimmune pathogenesis in predisposed individuals.

LGR6 is a prognostic biomarker for less differentiated tumors in lymph nodes of colon cancer patients.

Introduction: The aim was to investigate whether the stem cell marker LGR6 has prognostic value in colon cancer, alone or in combination with the prognostic biomarkers CEA and CXCL16. Methods: LGR6 mRNA levels were determined in 370 half lymph nodes of 121 colon cancer patients. Ability to predict relapse after curative surgery was estimated by Kaplan-Meier survival model and Cox regression analyses. Results: Patients with high LGR6 levels [LGR6(+)] had a decreased mean survival time of 11 months at 5-year follow-up and 47 months at 12-year follow-up, respectively, with hazard ratios of 3.2 and 2.8. LGR6 mRNA analysis added prognostic value to CEA and CXCL16 mRNA analysis. In the poor prognosis groups CEA(+) and CXCL16(+), further division was achieved by LGR6 analysis. LGR6(+) patients had a very poor prognosis. LGR6 also identified a small number of CEA(-), TNM stage I patients who relapsed suggesting stem cell origin of these tumors. LGR6 and LGR5 levels correlated strongly in lymph nodes of stage I and IV patients but not in stage II patients, suggesting that these stem cell markers are differentially regulated. Conclusion: This study highlights LGR6 as a useful prognostic biomarker independently and in combination with CEA, CXCL16 or LGR5 identifying different risk groups.

Bortezomib restrains M2 polarization and reduces CXCL16-associated CXCR6+CD4 T cell chemotaxis in bleomycin-induced pulmonary fibrosis.

BACKGROUND: The development of pulmonary fibrosis involves a cascade of events, in which inflammation mediated by immune cells plays a pivotal role. Chemotherapeutic drugs have been shown to have dual effects on fibrosis, with bleomycin exacerbating pulmonary fibrosis and bortezomib alleviating tissue fibrotic processes. Understanding the intricate interplay between chemotherapeutic drugs, immune responses, and pulmonary fibrosis is likely to serve as the foundation for crafting tailored therapeutic strategies. METHODS: A model of bleomycin-induced pulmonary fibrosis was established, followed by treatment with bortezomib. Tissue samples were collected for analysis of immune cell subsets and functional assessment by flow cytometry and in vitro cell experiments. Additionally, multi-omics analysis was conducted to further elucidate the expression of chemokines and chemokine receptors, as well as the characteristics of cell populations. RESULTS: Here, we observed that the expression of CXCL16 and CXCR6 was elevated in the lung tissue of a pulmonary fibrosis model. In the context of pulmonary fibrosis or TGF-ß1 stimulation in vitro, macrophages exhibited an M2-polarized phenotype and secreted more CXCL16 than those of the control group. Moreover, flow cytometry revealed increased expression levels of CD69 and CXCR6 in pulmonary CD4 T cells during fibrosis progression. The administration of bortezomib alleviated bleomycin-induced pulmonary fibrosis, accompanied by reduced ratio of M2-polarized macrophages and decreased accumulation of CD4 T cells expressing CXCR6. CONCLUSIONS: Our findings provide insights into the key immune players involved in bleomycin-induced pulmonary fibrosis and offer preclinical evidence supporting the repurposing strategy and combination approaches to reduce lung fibrosis.

Deletion of the mRNA endonuclease Regnase-1 promotes NK cell anti-tumor activity via OCT2-dependent transcription of Ifng.

Limited infiltration and activity of natural killer (NK) and T cells within the tumor microenvironment (TME) correlate with poor immunotherapy responses. Here, we examined the role of the endonuclease Regnase-1 on NK cell anti-tumor activity. NK cell-specific deletion of Regnase-1 (Reg1ΔNK) augmented cytolytic activity and interferon-gamma (IFN-γ) production in vitro and increased intra-tumoral accumulation of Reg1ΔNK-NK cells in vivo, reducing tumor growth dependent on IFN-γ. Transcriptional changes in Reg1ΔNK-NK cells included elevated IFN-γ expression, cytolytic effectors, and the chemokine receptor CXCR6. IFN-γ induced expression of the CXCR6 ligand CXCL16 on myeloid cells, promoting further recruitment of Reg1ΔNK-NK cells. Mechanistically, Regnase-1 deletion increased its targets, the transcriptional regulators OCT2 and IκBζ, following interleukin (IL)-12 and IL-18 stimulation, and the resulting OCT2-IκBζ-NF-κB complex induced Ifng transcription. Silencing Regnase-1 in human NK cells increased the expression of IFNG and POU2F2. Our findings highlight NK cell dysfunction in the TME and propose that targeting Regnase-1 could augment active NK cell persistence for cancer immunotherapy.

The role of the CXCR6/CXCL16 axis in the pathogenesis of fibrotic disease.

CXC chemokine receptor 6 (CXCR6), a seven-transmembrane domain G-protein-coupled receptor, plays a pivotal regulatory role in inflammation and tissue damage through its interaction with CXC chemokine ligand 16 (CXCL16). This axis is implicated in the pathogenesis of various fibrotic diseases and correlates with clinical parameters that indicate disease severity, activity, and prognosis in organ fibrosis, including afflictions of the liver, kidney, lung, cardiovascular system, skin, and intestines. Soluble CXCL16 (sCXCL16) serves as a chemokine, facilitating the migration and recruitment of CXCR6-expressing cells, while membrane-bound CXCL16 (mCXCL16) functions as a transmembrane protein with adhesion properties, facilitating intercellular interactions by binding to CXCR6. The CXCR6/CXCL16 axis is established to regulate the cycle of damage and repair during chronic inflammation, either through modulating immune cell-mediated intercellular communication or by independently influencing fibroblast homing, proliferation, and activation, with each pathway potentially culminating in the onset and progression of fibrotic diseases. However, clinically exploiting the targeting of the CXCR6/CXCL16 axis requires further elucidation of the intricate chemokine interactions within fibrosis pathogenesis. This review explores the biology of CXCR6/CXCL16, its multifaceted effects contributing to fibrosis in various organs, and the prospective clinical implications of these insights.

Sodium butyrate restricts neutrophils migration and NETs formation through reducing macrophage-derived CXCL16 in calculous cholecystitis.

Background: Neutrophil extracellular traps (NETs) havebeen demonstrated to initiate gallstone formation. Cholecystitis is a common complication of gallstones. As short-chain fatty acids (SCFAs), Butyrate acid has anti-inflammatory effects and alleviates cholesterol gallstones. However, the role of Butyrate acid in NETs of calculous cholecystitis and the molecular mechanism remains unclear. The effect of Sodium butyrate on neutrophil migration and NETs formation involved in macrophages polarization and exosomalCXCL16 in calculous cholecystitis was explored in our study. Methods: The number of neutrophils and NETs, macrophages polarization and exosomal CXCL16 level were analyzed in clinic samples from patients. Exosomes were obtained and verified by gradient centrifugation, transmission electron microscopy, NanoSight analysis and Western blotting. Transwell, immunofluorescence and ELISA were used to detect neutrophil migration and NETs formation. Results: Our results demonstrated that a large number of neutrophils and NETs, as well as M1 macrophages and exosomal CXCL16, were found in the blood of gallstones patients, especially patients with acute calculous cholecystitis. Exosomal CXCL16 was upregulated in plasma of calculous cholecystitis patients or Lipopolysaccharide induced macrophages, and promoted neutrophil cell migration and NETs formation. Sodium butyrate reduced exosomal CXCL16 secretion through the inhibition of M1 macrophage polarization to suppress neutrophils migration and NETs formation. Conclusion: Our study suggested that Sodium butyrate may inhibit neutrophils migration and NETs formation to alleviate calculous cholecystitis by reducing exosomal CXCL16 secretion from macrophage and macrophage polarization. General significance: Our finding may provide a link between exosomes and neutrophils to serve as a potential therapeutic intervention in calculous cholecystitis.

TRPM2-dependent autophagy inhibition exacerbates oxidative stress-induced CXCL16 secretion by keratinocytes in vitiligo.

Vitiligo is a depigmented skin disease due to the destruction of melanocytes. Under oxidative stress, keratinocyte-derived chemokine C-X-C motif ligand 16 (CXCL16) plays a critical role in recruiting CD8+ T cells, which kill melanocytes. Autophagy serves as a protective cell survival mechanism and impairment of autophagy has been linked to increased secretion of the proinflammatory cytokines. However, the role of autophagy in the secretion of CXCL16 under oxidative stress has not been investigated. Herein, we initially found that autophagy was suppressed in both keratinocytes of vitiligo lesions and keratinocytes exposed to oxidative stress in vitro. Autophagy inhibition also promoted CXCL16 secretion. Furthermore, upregulated transient receptor potential cation channel subfamily M member 2 (TRPM2) functioned as an upstream oxidative stress sensor to inhibit autophagy. Moreover, TRPM2-mediated Ca2+ influx activated calpain to shear autophagy related 5 (Atg5) and Atg12-Atg5 conjugate formation was blocked to inhibit autophagy under oxidative stress. More importantly, Atg5 downregulation enhanced the binding of interferon regulatory factor 3 (IRF3) to the CXCL16 promoter region by activating Tank-binding kinase 1 (TBK1), thus promoting CXCL16 secretion. These findings suggested that TRPM2-restrained autophagy promotes CXCL16 secretion via the Atg5-TBK1-IRF3 signaling pathway under oxidative stress. Inhibition of TRPM2 may serve as a potential target for the treatment of vitiligo. © 2024 The Pathological Society of Great Britain and Ireland.

CXCL16 promotes tumor metastasis by regulating angiogenesis in the tumor micro-environment of BRAF V600E mutant colorectal cancer.

Patients of colorectal cancer (CRC) with BRAF V600E mutation obtain poor prognosis. This study aimed to explore the role and mechanism of BRAF V600E mutation in angiogenesis of tumor micro-environment (TME). It has been reported that CXCL16 expression in TME is closely related to BRAF mutation. Clinicopathological features of CRC with BRAF V600E mutant or wild type were collected in this study. Immunohistochemistry (IHC) assays were conducted to test the expressions of vascular endothelial growth factor (VEGF), CD31 and CXCL16. ROC curve was used to determine the optimal cut off values of CXCL16. A total of 680 patients including 141 BRAF V600E type and 679 wild type were included. BRAF V600E mutant tumors were presented with significant worse clinicopathological features and a shorter overall survival (OS) than wild-type. Besides, chemokines CXCL16 was up-regulated in BRAF V600E mutant tissues and was associated with poorer prognosis. In addition, VEGF levels and vascular endothelial cell density was significantly increased in BRAF mutation. At last, CXCL16 was positively correlated with VEGF expression and vascular endothelial cell density. In conclusion, BRAF V600E mutations may promote metastasis of CRC by regulating CXCL16 expression and promoting angiogenesis in the TME.

CXCL16 exacerbates Pseudomonas aeruginosa keratitis by promoting neutrophil activation.

Pseudomonas aeruginosa (PA) keratitis is a major cause of blindness characterized by corneal inflammation. In a murine model of PA keratitis, we assessed the detrimental effects of CXC chemokine ligand 16 (CXCL16). Quantitative PCR (qPCR), western blotting (WB) and immunofluorescence were used to measure the expression and localization of CXCL16 and its receptor, CXC chemokine receptor 6 (CXCR6). Clinical scores, plate counting, and hematoxylin-eosin staining were used to assess infection severity and its exacerbation by CXCL16. Immunofluorescence, myeloperoxidase assays, and flow cytometry were used to detect neutrophil activity and colocalization with CXCR6. WB and immunofluorescence were used to measure levels of reactive oxygen species (ROS) and matrix metalloproteinases (MMPs). These methods also were used to measure the activation of downstream NF-κB signaling and its positive feedback on CXCL16 expression. ELISA, flow cytometry, and qPCR were used to measure the expression of CXCL2 and T helper 17 (Th17) cell-related genes. CXCL16 and CXCR6 expression was increased in infected corneas. Topical application of CXCL16 exacerbated keratitis by increasing corneal bacterial load and promoting neutrophil infiltration, whereas neutralizing antibody against CXCL16 had the opposite effect. CXCL16 also increased ROS and MMP levels. This neutrophil activation may be caused by its positive feedback with the NF-κB pathway and the upregulation of CXCL2 and Th17 cell related-genes. These data suggest that CXCL16 is an attractive therapeutic target for PA keratitis.

Systemic virus infection results in CD8 T cell recruitment to the retina in the absence of local virus infection.

During recent years, evidence has emerged that immune privileged sites such as the CNS and the retina may be more integrated in the systemic response to infection than was previously believed. In line with this, it was recently shown that a systemic acute virus infection leads to infiltration of CD8 T cells in the brains of immunocompetent mice. In this study, we extend these findings to the neurological tissue of the eye, namely the retina. We show that an acute systemic virus infection in mice leads to a transient CD8 T cell infiltration in the retina that is not directed by virus infection inside the retina. CD8 T cells were found throughout the retinal tissue, and had a high expression of CXCR6 and CXCR3, as also reported for tissue residing CD8 T cells in the lung and liver. We also show that the pigment epithelium lining the retina expresses CXCL16 (the ligand for CXCR6) similar to epithelial cells of the lung. Thus, our results suggest that the retina undergoes immune surveillance during a systemic infection, and that this surveillance appears to be directed by mechanisms similar to those described for non-privileged tissues.

Tumor-associated macrophages promote cisplatin resistance in ovarian cancer cells by enhancing WTAP-mediated N6-methyladenosine RNA methylation via the CXCL16/CXCR6 axis.

PURPOSE: Tumor-promotive tumor-associated macrophages (TAMs) and the CXCL16/CXCR6 axis have been reported to be correlated with the limited efficacy of chemotherapy in ovarian cancer (OC). However, the role of TAM-secreted CXCL16 and the mechanism by which it affects the cisplatin (DDP) resistance of OC cells remain elusive. METHODS: We induced human THP-1 monocytes to differentiate into macrophages. Next, SKOV3 and TOV-112D cells were co-cultured with the macrophages, followed by incubation with increasing concentrations of DDP. The effects of CXCL16, CXCR6, and WTAP on the DDP resistance of OC cells were investigated using the CCK-8 assay, colony formation assay, flow cytometry, and TUNEL staining. CXCL16 concentrations were determined by ELISA. Quantitative real-time PCR and western blotting were used to examine related markers. RESULTS: Our results showed that after being co-cultured with TAMs, the DDP resistance of OC cells was significantly enhanced and their CXCL16 levels were elevated. Acquired DDP resistance was characterized by an increased IC50 value for DDP, the formation of cell colonies, and decreased levels of cell apoptosis, which were accompanied by reduced levels of caspase-3 and Bax expression, and increased levels of Bcl-2, PARP1, BRCA1, and BRCA2 expression. Either CXCL16 knockdown in TAMs or CXCR6 knockdown in OC cells suppressed the DDP resistance of OC cells that had been co-cultured with TAMs. Knockdown of CXCL16 affected m6A RNA methylation in OC cells, as reflected by decreased YTHDF1/WTAP expression and increased ALKBH5 expression. WTAP overexpression and knockdown promoted and suppressed the DDP resistance of OC cells, respectively. CONCLUSION: Tumor-associated macrophages promote the cisplatin resistance of OC cells by enhancing WTAP-mediated N6-methyladenosine RNA methylation via the CXCL16/CXCR6 axis.

Role of the CXCR6/CXCL16 axis in autoimmune diseases.

The C-X-C motif ligand 16, or CXCL16, is a chemokine that belongs to the ELR - CXC subfamily. Its function is to bind to the chemokine receptor CXCR6, which is a G protein-coupled receptor with 7 transmembrane domains. The CXCR6/CXCL16 axis has been linked to the development of numerous autoimmune diseases and is connected to clinical parameters that reflect disease severity, activity, and prognosis in conditions such as multiple sclerosis, autoimmune hepatitis, rheumatoid arthritis, Crohn's disease, and psoriasis. CXCL16 is expressed in various immune cells, such as dendritic cells, monocytes, macrophages, and B cells. During autoimmune diseases, CXCL16 can facilitate the adhesion of immune cells like monocytes, T cells, NKT cells, and others to endothelial cells and dendritic cells. Additionally, sCXCL16 can regulate the migration of CXCR6-expressing leukocytes, which includes CD8+ T cells, CD4+ T cells, NK cells, constant natural killer T cells, plasma cells, and monocytes. Further investigation is required to comprehend the intricate interactions between chemokines and the pathogenesis of autoimmune diseases. It remains to be seen whether the CXCR6/CXCL16 axis represents a new target for the treatment of these conditions.

sCXCL16 as a prognostic biomarker for COVID-19 outcome.

As elevated levels of the soluble CXCL16 (sCXCL16) chemokine have been reported in severe coronavirus disease 2019 (COVID-19) patients, this study examined whether sCXCL16 concentration on the first day of hospitalization predicted death in COVID-19 patients. A total of 76 patients with COVID-19 were admitted to the Military Hospital of Tunis, Tunisia, between October 2020 and April 2021, and later classified as survivors or nonsurvivors based on their outcomes. At admission, the groups were matched by age, gender, comorbidities, and the percentage of patients with moderate conditions. On the first day of admission, serum's sCXCL16 concentrations were measured using a magnetic-bead assay. There was an eightfold increase in serum sCXCL16 levels in the nonsurvivors' group (3661.51 ± 2464.87 pg/mL vs. 454.3 ± 338.07 pg/mL, p < 0.0001). For the optimal cutoff value of sCXCL16 at 2095 pg/mL, we found a 94.6% sensitivity and a 97.4% specificity, with an area under curve of 0.981 (p = 5.03E-08; 95% confidence interval [95% CI]: 0.951-1.0114). Considering the risk of death at a concentration above the threshold, the unadjusted odds ratio was 36 (p < 0.0001). The adjusted odd ratio was estimated at 1.003 (p < 0.0001; 95% CI: 1.002-1.004). Finally, there was a significant difference between survival and nonsurvival groups in leukocyte numbers (p = 0.006), lymphocytes (p = 0.001), polymorphonuclear neutrophils (p = 0.001), and C-reactive protein levels (p = 0.007), except for monocytes (p = 0.881). Based on these results, sCXCL16 level could be used for detecting nonsurvival COVID-19 patients. Therefore, we recommend assessing this marker in hospitalized COVID-19 patients.

Upregulation of IL-33, CCL2, and CXCL16 levels in Brazilian pregnant women infected by Toxoplasma gondii.

Congenital toxoplasmosis can cause neurological and eye damage, behavioral alterations, or death in fetuses or babies born to Toxoplasma gondii-infected women. Several pieces of evidence suggest that socioeconomic, environmental, and inflammatory patterns linked to the maternal immune response partly drive the pathogenesis of this disease. However, immunoregulation induced by T. gondii infection during gestation is not completely understood. The aim of this study was to assess the association between T. gondii seropositivity and concentrations of plasma markers (CCL2, CXCL16, IL-17, and IL-33) in Brazilian pregnant women. Inflammatory markers were measured by immunoassays in the plasma of 131 pregnant women (13 to 46 years old). The prevalence of T. gondii infections was 45.8% (n = 60) in this population. The concentrations of CCL2, CXCL16, and IL-33 were higher in T. gondii-seropositive than in seronegative pregnant women, while the opposite was observed for IL-17 levels. In IgG+ women, a strong correlation between IL-17 and IL-33 (r = 0.7508, p = 0.0001) and a moderate correlation between CXCL16/IL-17 (r = 0.7319, p = 0.0001) and CXCL16/CCL2 (r = 0.3519, p = 0.0098) was observed. In uninfected women, a strong correlation was found between IL-17 and CXCL16 (r = 0.6779, p = 0.0001) but moderate between IL-17 and IL-33 (r = 0.4820, p = 0.0001). In summary, our data suggest that plasma upregulation of CCL2, CXCL16, and IL-33 might exert a potential protective role in the mother/fetus/parasite axis and, in addition, multiparous women are more likely to be infected with T. gondii than primiparous women.

Metformin attenuates symptoms of osteoarthritis: role of genetic diversity of Bcl2 and CXCL16 in OA.

OBJECTIVE: This study aimed to evaluate the effectiveness of metformin versus placebo in overweight patients with knee osteoarthritis (OA). In addition, to assess the effects of inflammatory mediators and apoptotic proteins in the pathogenesis of OA, the genetic polymorphisms of two genes, one related to apoptosis (rs2279115 of Bcl-2) and the other related to inflammation (rs2277680 of CXCL-16), were investigated. METHODS: In this double-blind placebo-controlled clinical trial, patients were randomly divided to two groups, one group receiving metformin (n = 44) and the other one receiving an identical inert placebo (n = 44) for 4 consecutive months (starting dose 0.5 g/day for the first week, increase to 1 g/day for the second week, and further increase to 1.5 g/day for the remaining period). Another group of healthy individuals (n = 92) with no history and diagnosis of OA were included in this study in order to evaluate the role of genetics in OA. The outcome of treatment regimen was evaluated using the Knee Injury and Osteoarthritis Outcome Score (KOOS) questionnaire. The frequency of variants of rs2277680 (A181V) and rs2279115 (938C>A) were determined in extracted DNAs using PCR-RFLP method. RESULTS: Our results indicated an increase in scores of pain (P ≤ 0.0001), activity of daily living (ADL) (P ≤ 0.0001), sport and recreation (Sport/Rec) (P ≤ 0.0001), and quality of life (QOL) (P = 0.003) and total scores of the KOOS questionnaire in the metformin group compared to the placebo group. Susceptibility to OA was associated with age, gender, family history, CC genotype of 938C>A (Pa = 0.001; OR = 5.2; 95% CI = 2.0-13.7), and GG+GA genotypes of A181V (Pa = 0.04; OR = 2.1; 95% CI = 1.1-10.5). The C allele of 938C>A (Pa = 0.04; OR = 2.2; 95% CI = 1.1-9.8) and G allele of A181V (Pa = 0.02; OR = 2.2; 95% CI = 1.1-4.8) were also associated with OA. CONCLUSION: Our findings support the possible beneficial effects of metformin on improving pain, ADL, Sport/Rec, and QOL in OA patients. Our findings support the association between the CC genotype of Bcl-2 and GG+GA genotypes of CXCL-16 and OA.

ELK3-CXCL16 axis determines natural killer cell cytotoxicity via the chemotactic activity of CXCL16 in triple negative breast cancer.

Triple-negative breast cancer (TNBC) is the most challenging subtype of breast cancer because of its aggressive behavior and the limited therapeutic strategies available. In the last decade, immunotherapy has become a promising treatment to prolong survival in advanced solid cancers including TNBC. However, the efficacy of immunotherapy in solid cancers remains limited because solid tumors contain few tumor-infiltrating lymphocytes. Here, we show that targeting an ETS transcription factor ELK3 (ELK3) recruits immune cells including natural killer (NK) cells into tumors via the chemotactic activity of chemokine. ELK3 depletion increases CXCL16 expression level and promotes NK cell cytotoxicity through CXCL16-mediated NK cell recruitment in TNBC. In silico analysis showed that ELK3 is negatively correlated with CXCL16 expression in breast cancer patient samples. Low expression of ELK3 and high expression of CXCL16 were associated with a better prognosis. Low expression of ELK3 and high expression of CXCL16 were associated with increased expression of NK cell-related genes. Our findings demonstrate that the ELK3-CXCL16 axis modulates NK cell recruitment to increase NK cell cytotoxicity, suggesting that targeting the ELK3 gene could be an adjuvant strategy for increasing the efficacy of immunotherapy in TNBC.

Neuroserpin: A potential biomarker for early-onset severe preeclampsia.

Preeclampsia is a hypertensive disease of pregnancy associated with intense inflammatory and pro-coagulant responses. Neuroserpin is a serine protease inhibitor that has been involved in neurological and immune processes and has not yet been investigated in preeclampsia. Herein, we evaluated neuroserpin levels in association with other inflammatory mediators (IL-17A, IL-33, and CXCL-16) during severe preeclampsia. The mediators' plasma levels were measured by immunoassays in 24 pregnant women with severe preeclampsia (early preeclampsia: N = 17, late preeclampsia: N = 7), 34 normotensive pregnant women, and 32 non-pregnant women. In general, pregnancy was associated with higher levels of neuroserpin, IL-17A, IL-33, and CXCL-16 than the non-pregnant state. However, this increase was attenuated in pregnancies complicated by severe preeclampsia. Although neuroserpin levels did not differ between normotensive pregnant women and pregnant women with severe preeclampsia, neuroserpin levels tended to be lower in early-onset than in late-onset severe preeclampsia. There were positive correlations between neuroserpin and IL-17A, neuroserpin and CXCL-16, and IL-17A and CXCL-16 levels in women with severe preeclampsia. In addition, although the risk for developing severe preeclampsia was higher in older women in this study, maternal age did not significantly influence the mediators' levels, nor their correlations in the preeclampsia group. In summary, our data suggest that neuroserpin might be a potential biomarker for early-onset severe preeclampsia and, that the imbalance among neuroserpin, IL-17A, IL-33, and CXCL-16 levels may be associated with the pathogenesis of preeclampsia, regardless of the maternal age.