The gender-specific association of CXCL16 A181V gene polymorphism with susceptibility to multiple sclerosis, and its effects on PBMC mRNA and plasma soluble CXCL16 levels: preliminary findings

A Functional Variant of CXCL16 Is Associated With Predisposition to Sepsis and MODS in Trauma Patients: Genetic Association Studies

PURPOSE

CXC chemokines are mediators which mediate immune cells migration to sites of inflammation and injury. Chemokine C-X-C motif ligand 16 (CXCL16) plays an important role in the occurrence and development of sepsis through leukocyte chemotaxis, leukocyte adhesion and endotoxin clearance. In this study, we selected a set of tagging single nucleotide polymorphisms (tag SNPs) in the CXCL16 gene and investigated their clinical relevance to the development of sepsis and multiple organ dysfunction syndrome (MODS) in patients with major trauma in three independent Chinese Han populations.

METHODS

A total of 1,620 major trauma patients were enrolled in this study. Among these patients, 920 came from Chongqing in western China, 350 came from Zhejiang Province in eastern China, and 350 came from Guizhou Province in southwestern China. The improved multiplex ligation detection reaction (iMLDR) method was employed in the genotyping and genetic association analyses to determine the associations between CXCL16 haplotypes and sepsis morbidity rate and higher MOD scores in three cohorts.

RESULTS

Only CXCL16 T123V181 haplotype was associated with an increased risk for sepsis morbidity and higher MOD scores in the three cohorts (OR = 1.89, P = 0.001 for the Chongqing cohort; OR = 1.76, P = 0.004 for the Zhejiang cohort; OR = 1.55, P = 0.012 for the Guizhou cohort). The effect of T123V181 haplotype on the chemotaxis, migration and endotoxin clearance of immune cells were further observed. Protein modeling analysis showed that T123 and V181 might alter the structure of the CXCL16 active center. Thus it enhanced the chemotaxis and adhesion ability of immunocytes.

CONCLUSION

We demonstrate the mechanism of CXCL16 T123V181 haplotype which regulates the sepsis morbidity rate and thus provide a new biomarker for early diagnosis of sepsis and MODS.

CLINICAL TRIAL REGISTRATION

www.ClinicalTrials.gov, identifier NCT01713205 (https://www.clinicaltrials.gov/ct2/results?cond=&term=+NCT01713205&cntry=&state=&city=&dist=).

ZFAT gene variant association with multiple sclerosis in the Arabian Gulf population: A genetic basis for gender-associated susceptibility

Single nucleotide polymorphisms (SNPs) are useful genetic markers to investigate the onset of multiple sclerosis (MS). A genome wide association study identified 7 SNPs associated with interferon‑β therapy response, however, not with MS risk in a Spanish population. To investigate these findings in a different cohort, the 7 SNPs were investigated in an Arabian Gulf population. The SNPs were analyzed in 268 subjects (156 patients and 112 healthy volunteers) from the Arabian Gulf region using restriction fragment length polymorphism-polymerase chain reaction (PCR) and KBioscience Competitive Allele Specific PCR genotyping methods. Associations between the SNPs and MS were investigated using logistic regression. The present study observed, for the first time, that in an Arabian Gulf population, the ZFAT rs733254 polymorphism (T>G) is a gender‑specific risk marker for MS. ZFAT was associated with MS in women but not in men. The G variant was highly associated with the risk of MS [odds ratio (OR)=2.38 and 95% confidence interval (CI), 1.45‑3.91); P=0.0014]. Whereas variant T was a significantly protective factor [OR=0.420 (95% CI, 0.25‑0.69); P=0.0014, recessive model]. The findings of the present study provide a genetic basis for the gender‑associated susceptibility to MS. In addition, this MS-associated rs733254 SNP may predict MS onset in females from the Arabian Gulf population.

GWAS-identified multiple sclerosis risk loci involved in immune response: validation in Russians

Multiple sclerosis (MS) is a chronic neuro-inflammatory disease of complex etiology. The results of GWAS, a high-throughput method to discover genetic architecture of MS, require replication in independent ethnic groups. We performed a replication study of nine GWAS-identified SNPs in immune response in Russians. Associations of CLEC16A and IL2RA with MS were validated. Besides, we observed the associations of CLEC16A and IRF8 in women, and IL7RA and CD58 in men. With multi-locus association analysis two protective biallelic combinations: (TNFRSF1A*T+CLEC16A*A) and (TNFRSF1A*T+IRF8*A) were identified in women. Associations of CLEC16A*G/G and both biallelic combinations in women with MS survived the permutation test.