Association between interleukin-18 (137G/C and 607C/A) gene polymorphisms and risk of ischemic stroke: a meta-analysis

Interleukin-18 mediated inflammatory brain injury after intracerebral hemorrhage in male mice

Interleukin-18 (IL-18), a pro-inflammatory cytokine, is thought to be associated with inflammation in many neurological diseases such as ischemic stroke and poststroke depression, but the role of IL-18 in inflammatory injury after intracerebral hemorrhage (ICH) remains unclear. In this study, we established the ICH model in male mice and found that IL-18 expression including protein and mRNA levels was significantly increased in brain tissues after ICH. Meanwhile, exogenous IL-18 exacerbated cerebral hematoma and neurological deficits following ICH. In the IL-18 knockout group, the size of hematoma and neurological functions after ICH was decreased compared with the wild-type group, suggesting the critical role of IL-18 on the modulation of brain injury after ICH. Importantly, exogenous IL-18 increased microglial activation in brain tissues after ICH. Furthermore, IL-18 knockout resulted in the reduction of activated microglia after ICH. These results indicated that IL-18 may regulate the inflammatory response after ICH through the activation of microglia. Thus, IL-18 is expected to be a promising therapeutic target for secondary brain injury after ICH.

Polymorphisms of Pro-Inflammatory IL-6 and IL-1β Cytokines in Ascending Aortic Aneurysms as Genetic Modifiers and Predictive and Prognostic Biomarkers

Background: Previous studies have demonstrated that polymorphisms involved in immune genes can affect the risk, pathogenesis, and outcome of thoracic ascending aortic aneurysms (TAAA). Here, we explored the potential associations of five functional promoter polymorphisms in interleukin-6 (IL-6), IL-1B, IL-1A, IL-18, and Tumor necrosis factor (TNF)A genes with TAAA. Methods: 144 TAAA patients and 150 age/gender matched controls were typed using KASPar assays. Effects on telomere length and levels of TAAA related histopathological and serological markers were analyzed. Results: Significant associations with TAAA risk were obtained for IL-6 rs1800795G>C and IL-1B rs16944C>T SNPs. In addition, the combined rs1800795C/rs16944T genotype showed a synergic effect on TAAA pathogenesis and outcome. The combined rs1800795C/rs16944T genotype was significantly associated with: (a) higher serum levels of both cytokines and MMP-9 and -2; (b) a significant CD3+CD4+CD8+ CD68+CD20+ cell infiltration in aorta aneurysm tissues; (c) a significant shorter telomere length and alterations in telomerase activity. Finally, it significantly correlated with TAAA aorta tissue alterations, including elastic fragmentation, medial cell apoptosis, cystic medial changes, and MMP-9 levels. Conclusions: the combined rs1800795C/rs16944T genotype appears to modulate TAAA risk, pathogenesis, and outcome, and consequently can represent a potential predictive and prognostic TAAA biomarker for individual management, implementation of innovative treatments, and selection of the more proper surgical timing and approaches.

Neuroinflammation and fibrosis in stroke: The good, the bad and the ugly

Stroke is the leading cause of death and the main cause of disability in surviving patients. The detrimental interaction between immune cells, glial cells, and matrix components in stroke pathology results in persistent inflammation that progresses to fibrosis. A substantial effort is being directed toward understanding the exact neuroinflammatory events that take place as a result of stroke. The initiation of a potent cytokine response, along with immune cell activation and infiltration in the ischemic core, has massive acute deleterious effects, generally exacerbated by comorbid inflammatory conditions. There is secondary neuroinflammation that promotes further injury, resulting in cell death, but conversely plays a beneficial role, by promoting recovery. This highlights the need for a better understanding of the neuroinflammatory and fibrotic processes, as well as the need to identify new mechanisms and potential modulators. In this review, we summarize several aspects of stroke-induced inflammation, fibrosis, and include a discussion of cytokine inhibitors/inducers, immune cells, and fibro-inflammation signaling inhibitors in order to identify new pharmacological means of intervention.

Investigation of The Relationship Between IL-18 (-607 C/A), IL-18 (-137 G/C) Gene Variations and Ischemic Stroke Disease Development in Thrace Region of Turkey

BACKGROUND

Ischemic stroke is a clinical condition characterized by focal or global cerebral dysfunction resulting from inhibition of brain blood flow. Genetic factors play an important role in the pathogenesis of ischemic stroke. As a result of IL-18 (-607 C/A, -137 G/C) gene variations, it is thought that binding of transcription factors may be affected and IL-18 mRNA expression can be modulated. Therefore, the purpose of our study is to investigate the roles of IL-18 (-607 C/A), IL-18 (-137 G/C) gene variations in the development of ischemic stroke in Trakya Region of Turkey.

METHODS

Our study was performed with 90 ischemic stroke patients and 89 healthy controls. Genotype distributions of IL-18 (-607 C/A, -137 G/C) gene variations were determined using polymerase chain reaction (PCR) method.

RESULTS

GC genotype and CA genotype of IL-18 (-137 G/C) and IL-18 (-607 C/A) gene variations were determined higher significantly in patent group as compared with other genotypes. However, the statistically significant difference was not determined between patients with ischemic stroke and healthy control groups in terms of IL-18 (-137 G/C) and IL-18 (-607 C/A) gene variations (p > 0,05). Allele frequencies of IL-18 (-137 G/C) and IL-18 (-607 C/A) in patient and control groups were significantly different from the Hardy-Weinberg distribution (p < .001 for all).

CONCLUSION

Although these gene variations' genotype distributions were not determined as a genetic risk factor for the development of ischemic stroke, allele frequencies of IL-18 (-137 G/C) and IL-18 (-607 C/A) in patient and control groups were significantly different from the Hardy-Weinberg distribution.

Developmental trajectories of body mass index from childhood into late adolescence and subsequent late adolescence-young adulthood cardiometabolic risk markers

Background

Reports on body mass index (BMI) trajectories from childhood into late adolescence, their determinants, and subsequent cardiometabolic risk markers, particularly among European populations have been few. Moreover, sex-specific investigation is necessary considering the sex difference in BMI, and the sex-specific association between BMI and some cardiometabolic risk markers.

Methods

Using a sample from the DOrtmund Nutritional and Anthropometric Longitudinally Designed study, we explored sex-specific trajectories of the BMI standard deviation score (SDS) from 4 to 18 years of age in 354 males and 335 females by latent (class) growth models. The determinants of trajectory were assessed by logistic regression. We identified cardiometabolic risk markers that were highly associated with BMI SDS trajectory by random forest regression, and finally we used generalized linear models to investigate differences in the identified cardiometabolic risk markers between pairs of trajectories.

Results

We observed four: ‘low-normal weight’, ‘mid-normal weight’, ‘high-normal weight’, and ‘overweight’, and three: ‘‘low-normal weight’, ‘mid-normal weight’, and ‘high-normal weight’ trajectories in males and females, respectively. Higher maternal prepregnancy BMI was associated with the ‘overweight’ trajectory, and with ‘high-normal weight’ trajectory in both sexes. In addition, employed mothers and first-born status were associated with ‘high-normal weight’ trajectory in females. BMI SDS trajectory was associated with high-density lipoprotein-cholesterol and interleukin-18 (IL-18) in males, and diastolic blood pressure and interleukin-6 (IL-6) in females. However, only males following the ‘overweight’ trajectory had significantly higher IL-18 when compared to their ‘low-normal weight’ counterpart.

Conclusions

We identified sex-specific distinct trajectories of BMI SDS from childhood into late adolescence, higher maternal prepregnancy BMI as a common determinant of the ‘high-normal weight’ and ‘overweight’ trajectories, and ‘overweight’ trajectory being associated with elevated IL-18 in late adolescence–young adulthood. This study emphasizes the role of maternal prepregnancy BMI in overweight, and highlights IL-18 as a cardiometabolic signature of overweight across life.

Electronic supplementary material

The online version of this article (10.1186/s12933-019-0813-5) contains supplementary material, which is available to authorized users.