Kawasaki disease patients homozygous for the rs12252-C variant of interferon-induced transmembrane protein-3 are significantly more likely to develop coronary artery lesions

Genome-Wide Association Study Identifies Novel Susceptibility Genes Associated with Coronary Artery Aneurysm Formation in Kawasaki Disease

Kawasaki disease (KD) or Kawasaki syndrome is known as a vasculitis of small to medium-sized vessels, and coronary arteries are predominantly involved in childhood. Generally, 20–25% of untreated with IVIG and 3–5% of treated KD patients have been developed coronary artery lesions (CALs), such as dilatation and aneurysm. Understanding how coronary artery aneurysms (CAAs) are established and maintained in KD patients is therefore of great importance. Upon our previous genotyping data of 157 valid KD subjects, a genome-wide association study (GWAS) has been conducted among 11 (7%) CAA-developed KD patients to reveal five significant genetic variants passed pre-defined thresholds and resulted in two novel susceptibility protein-coding genes, which are NEBL (rs16921209 (P = 7.44 × 10⁻⁹; OR = 32.22) and rs7922552 (P = 8.43 × 10⁻⁹; OR = 32.0)) and TUBA3C (rs17076896 (P = 8.04 × 10⁻⁹; OR = 21.03)). Their known functions have been reported to associate with cardiac muscle and tubulin, respectively. As a result, this might imply their putative roles of establishing CAAs during KD progression. Additionally, various model analyses have been utilized to determine dominant and recessive inheritance patterns of identified susceptibility mutations. Finally, all susceptibility genes hit by significant genetic variants were further investigated and the top three representative gene-ontology (GO) clusters were regulation of cell projection organization, neuron recognition, and peptidyl-threonine phosphorylation. Our results help to depict the potential routes of the pathogenesis of CAAs in KD patients and will facilitate researchers to improve the diagnosis and prognosis of KD in personalized medicine.

Age-related onset of obesity corresponds with metabolic dysregulation and altered microglia morphology in mice deficient for Ifitm proteins

The IfitmDel mouse lacks all five of the Ifitm genes via LoxP deletion. This animal breeds normally with no obvious defect in development. The IfitmDel animals exhibit a steady and significantly enhanced weight gain relative to wild-type controls beginning about three months of age and under normal feeding conditions. The increased weight corresponds with elevated fat mass, and in tolerance tests they are hyporesponsive to insulin but respond normally to glucose. Both young (4 mo) and older (12 mo) IfitmDel mice have enhanced levels of serum leptin suggesting a defect in leptin/leptin receptor signaling. Analysis of the gene expression profiles in the hypothalamus of IfitmDel animals, compared to WT, demonstrated an altered ratio of Pomc and Npy neuropeptide expression, which likely impairs the satiation response of the IfitmDel animal leading to an increased eating behavior. Also elevated in hypothalamus of IfitmDel mice were pro-inflammatory cytokine expression and reduced IL-10. Anatomical analysis of the hypothalamus using immunohistochemistry revealed that microglia exhibit an abnormal morphology in IfitmDel animals and respond abnormally to Poly:IC challenge. These abnormalities extend the phenotype of the IfitmDel mouse beyond abnormal responses to viral challenge to include a metabolic phenotype and weight gain. Further, this novel phenotype for the IfitmDel mouse could be related to abnormal neuropeptide production, inflammatory status and microglia status in the hypothalamus.

IFITM3 rs12252 T>C polymorphism is associated with the risk of severe influenza: a meta-analysis

The interferon-inducible transmembrane protein 3 (IFITM3), as one of the key genes involved in the interferon pathway, is critical for defending the host against influenza virus, and the rs12252 T>C variant in IFITM3 might be associated with susceptibility to severe influenza. Owing to contradictory and inconclusive results, we performed a meta-analysis to assess the association between rs12252 T>C polymorphism and severe influenza risk. A comprehensive literature search up to 1 August 2014 was conducted in EMBASE, Pubmed, Web of Science, VIP, Wanfang and CNKI databases. Four eligible studies with a total of 445 influenza patients and 3396 controls were included in this meta-analysis. Overall, our results demonstrated a significant association between the IFITM3 rs12252 T>C polymorphism and influenza risk [C vs. T: odds ratio (OR) 1·68, 95% confidence interval (CI) 1·32–2·13; CC vs. CT+TT: OR 2·38, 95% CI 1·52–3·73; CC+CT vs. TT: OR 1·62, 95% CI 1·18–2·22]. Stratification by ethnicity indicated that the variant C allele was associated with an 88% increased risk of influenza in Asians (C vs. T: OR 1·88, 95% CI 1·34–2·62). Moreover, subjects carrying the variant C allele had an increased risk of developing severe illness upon influenza infection (C vs. T: OR 2·70, 95% CI 1·86–3·94). However, no significant association was observed in patients with mild infection (C vs. T: OR 1·26, 95% CI 0·93–1·71). Our meta-analysis suggests that IFITM3 rs12252 T>C polymorphism is significantly associated with increased risk of severe influenza but not with the chance of initial virus infection.