Letter: the therapeutic potential of targeting CCL25/CCR9 in colonic inflammatory bowel disease - reading between the lines

Genetically Predicted Association of 91 Circulating Inflammatory Proteins with Multiple Sclerosis: A Mendelian Randomization Study

Previous studies have validated a close association between inflammatory factors and multiple sclerosis (MS), but their causal relationship is not fully profiled yet. This study used Mendelian randomization (MR) to investigate the causal effect of circulating inflammatory proteins on MS. Data from a large-scale genome-wide association study (GWAS) were analyzed using a two-sample MR method to explore the relationship between 91 circulating inflammatory proteins and MS. The inverse-variance-weighted (IVW) analysis was employed as the main method for evaluating exposures and outcomes. Furthermore, series of the methods of MR Egger, weighted median, simple mode, and weighted mode were used to fortify the final results. The results of the IVW method were corrected with Bonferroni (bon) and false discovery rate (fdr) for validating the robustness of results and ensuring the absence of heterogeneity and horizontal pleiotropy. The sensitivity analysis was also performed. The results of the forward MR analysis showed that higher levels of CCL25 were found to be associated with an increased risk of MS according to IVW results, OR: 1.085, 95% CI (1.011, 1.165), p = 2.42 × 10-2, adjusted p_adj_bon = 1, p_adj_fdr = 0.307. Similarly, higher levels of CXCL10 were found to be associated with an increased risk of MS, OR: 1.231, 95% CI (1.057, 1.433), p = 7.49 × 10-3, adjusted p_adj_bon = 0.682, p_adj_fdr = 0.227. In contrast, elevated levels of neurturin (NRTN) were associated with a decreased risk of MS, OR: 0.815, 95% CI (0.689, 0.964), p = 1.68 × 10-2, adjusted p_adj_bon = 1, p_adj_fdr = 0.307. Reverse MR analysis showed no causal relationship between MS and the identified circulating inflammatory cytokines. The effects of heterogeneity and level pleiotropy were further excluded by sensitivity analysis. This study provides new insights into the relationship between circulating inflammatory proteins and MS and brings up a new possibility of using these cytokines as potential biomarkers and therapeutic targets. The data in this study show that there are only weak associations between inflammatory molecules and MS risk, which did not survive bon and fdr correction, and the obtained p-values are quite low. Therefore, further studies on larger samples are needed.

Aflatoxin B1 exposure exacerbates chemokine receptor expression in the BTBR T+ Itpr3tf/J Mouse Model, unveiling insights into autism spectrum disorder: A focus on brain and spleen

OBJECTIVE

Autism spectrum disorder (ASD) is a neurodevelopmental condition characterized by significant difficulties in social interaction, communication, and repeated stereotypic behaviour. Aflatoxin B1 (AFB1) is the most potent and well-known mycotoxin in various food sources. Despite its propensity to generate significant biochemical and structural changes in human and animal tissues, the influence of AFB1 on ASD has yet to be thoroughly studied. Mounting evidence indicates that chemokine receptors play a crucial function in the central nervous system and are implicated in developing several neuroinflammatory disorders. Chemokine receptors in individuals with ASD were elevated in the anterior cingulate gyrus astrocytes, cerebellum, and brain.

METHODS

The BTBR T+Itpr3tf/J (BTBR) mice are inbred strains that exhibit strong and consistently observed deficits in social interactions, characterized by excessive self-grooming and limited vocalization in social contexts. We examined the impact of AFB1 on CCR3-, CCR7-, CCR9-, CXCR3-, CXCR4-, and CXCR6-expressing I-A/I-E+ cells in the spleen of the BTBR mouse model of autism. We evaluated the mRNA levels of CCR3, CCR7, CCR9, CXCR3, CXCR4, and CXCR6 chemokine receptors in the brain.

RESULTS

The exposure to AFB1 in BTBR mice resulted in a significant rise in the number of I-A/I-E+CCR3+, I-A/I-E+CCR7+, I-A/I-E+CCR9+, I-A/I-E+CXCR3+, I-A/I-E+CXCR4+, and I-A/I-E+CXCR6+ cells. Furthermore, exposure to AFB1 increased mRNA expression levels of CCR3, CCR7, CCR9, CXCR3, CXCR4, and CXCR6 in the brain.

CONCLUSIONS

These findings highlight that AFB1 exposure increases the expression of chemokine receptors in BTBR mice, indicating the necessity for further research into AFB1's role in the development of ASD.

Toll-Like Receptor 4 Promotes Th17 Lymphocyte Infiltration Via CCL25/CCR9 in Pathogenesis of Experimental Autoimmune Encephalomyelitis

Toll-like receptor 4 (TLR4) is a key component in innate immunity and has been linked to central nervous system (CNS) inflammation diseases, such as multiple sclerosis (MS), an inflammatory disorder induced by autoreactive Th17 cells. In our study, we found that TLR4 deficient (TLR4^-/-) mice were inadequate to induce experimental autoimmune encephalomyelitis (EAE), characterized by low clinic score and weight loss, alleviative demyelinating, as well as decreased inflammatory cell infiltration in the spinal cord. In the lesion area of EAE mice, loss of TLR4 down-regulated the secretion of inflammatory cytokines and chemokine CCL25. Furthermore, the expression of CCR9 was decreased and chemotactic migration was attenuated in TLR4^-/- Th17 cells. Our results demonstrate that TLR4 may mediate Th17 infiltration through CCL25/CCR9 signal during pathogenesis of EAE. Graphical Abstract Immunofluorescent staining of RORγt (green) and CCR9 (red) in spinal cords. TLR4 deficiency down-regulates CCR9 expression in infiltrating lymphocytes.