Polymorphisms of interleukin-1 and interleukin-6 genes on the risk of ischemic stroke in a meta-analysis

Association of IL-6 rs1800795, but not TNF-α rs1800629, and IL-1β rs16944 polymorphisms' genotypes with recovery of ischemic stroke patients following thrombolysis

OBJECTIVES

Inflammatory cytokines like tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, and IL-6 can cause brain injury, slow recovery, and adverse effects (ADEs) in ischemic stroke (IS) patients treated with recombinant tissue plasminogen activator (rtPA). We explored the relationship between selected polymorphisms within TNF-α, IL-1β and IL-6 genes, and post-IS outcome and ADEs in patients treated with rtPA.

METHODS

One hundred and sixty-six patients with IS treated with rtPA were included in this study. The modified Rankin Scale (mRS) was used to assess functional recovery 3 months after IS likewise thrombolytic therapy efficacy. Patients were classified into groups with favorable (0-1) or poor recovery based on their mRS score at the ninetieth day post-IS. During hospitalization, ADEs following rtPA were monitored. TNF-α-308 G/A (rs1800629), IL-1β-511 G/A (rs16944), and IL-6-174 G/C (rs1800795) polymorphisms were genotyped using Real-Time PCR. SPSS software version 22.0 was used for statistical analyses.

RESULTS

Patients with the TNF-α-308 G/A GG genotype had a higher mean NIHSS value at admission (12.75 ± 5.176) than those carrying A-allele (10.56 ± 3.979;p = 0.016). Individuals with the CC genotype of the IL-6-174 G/C polymorphism had significantly lower NIHSS scores (8.79 ± 5.053) than those with G-allele (12.06 ± 6.562) 24 hours after rtPA (p = 0.050). Patients with the GG genotype of the IL-6-174 G/C polymorphism had a significantly poorer outcome (p = 0.024; OR = 2.339; 95%CI 1.121-4.880), while patients who were G-allele carriers of the Il-6-174 G/C polymorphism and had the AA genotype of the IL-1β-511 G/A polymorphism were statistically significantly more likely to experience hemorrhagic transformation (p = 0.046; OR = 2.7273; 95%CI 1.0414-7.1426).

CONCLUSION

GG genotype of the IL-6-174 G/C polymorphism is associated with poor recovery after IS treated with rtPA therapy.

Shared genetic risk factors for depression and stroke

BACKGROUND

The comorbidity of major depressive disorder (MDD) and stroke are common in clinic. There is a growing body of evidence suggesting a bi-directional relationship between stroke and depression. However, the mechanisms underlying the relationship between MDD and stroke are poorly investigated. Considering that both MDD and stroke can be heritable and are influenced by multiple risk genes, shared genetic risk factors between MDD and stroke may exist.

OBJECTIVE

The objective is to review the existing evidence for common genetic risk factors for both MDD and stroke and to outline the possible pathophysiological mechanisms mediating this association.

METHODS

A systematic review and meta-analysis was performed. Gene association studies regarding stroke and depression were searched in the database PubMed, CNKI, and Chinese Biomedical Literature Database before December 2018. Statistical analysis was performed using the software Revman 5.3.

RESULTS

Genetic polymorphisms of 4 genes, methylenetetrahydrofolate reductase (MTHFR) and apolipoprotein E (ApoE) have been demonstrated to associate with the increased risk for both MDD and stroke, while the association between identified polymorphisms in angiotensin converting enzyme (ACE) and serum paraoxonase (PON1) with depression is still under debate, for the existing studies are insufficient in sample size. These results suggest the possible pathophysiological mechanisms that are common to these two disorders, including immune-inflammatory imbalance, increased oxidative and nitrative stress, dysregulation of lipoprotein and lipid metabolism, and changes of cerebrovascular morphology and function. Other associated genes with few or conflicting results have also been included, and a few studies have investigated the effects of the described polymorphisms on MDD and stroke comorbidity, such as post stroke depression.

CONCLUSION

These findings suggest that shared genetic pathways may contribute to the comorbidity of MDD and stroke. Studies to evaluate the shared genetic variations between MDD and stroke may provide insights into the molecular mechanisms that trigger disease progression.

A meta-analysis on associations of IL-6 and IL-10 polymorphisms with susceptibility to ischemic stroke

BACKGROUND

Some previous studies already explored associations of interleukin-6 (IL-6) and interleukin-10 (IL-10) polymorphisms with ischemic stroke (IS). However, the results were conflicting. In this meta-analysis, we aimed to better analyze the relationship between IL-6/IL-10 polymorphisms and IS in a larger pooled population.

METHODS

We performed a systematic search of PubMed, Web of Science, Embase and CNKI. We calculated pooled odds ratios (ORs) and 95% confidence intervals (CIs) to estimate associations between IL-6/IL-10 polymorphisms and IS.

RESULTS

Totally 37 studies were included for analyses. A significant association with IS was observed for IL-10 rs1800896 polymorphism in AA versus GG + GA (recessive model, p = .001, OR = 1.42, 95%CI 1.15-1.75) in overall population. Further subgroup analyses showed that IL-6 rs1800795 was significantly associated with IS in Asians in GG versus GC + CC (dominant model, p = .0005, OR = 0.74, 95%CI 0.62-0.88), CC versus GG + GC (recessive model, p = .003, OR = 1.61, 95%CI 1.17-2.21) and G versus C (allele model, p = .01, OR = 0.74, 95%CI 0.58-0.93), whereas IL-10 rs1800896 polymorphism was significantly associated with cerebral infarction (CI) in GG versus GA + AA (dominant model, p = .02, OR = 2.04, 95%CI 1.14-3.64), GA versus GG + AA (overdominant model, p = .03, OR = 0.50, 95%CI 0.27-0.93) and G versus A (allele model, p = .01, OR = 1.92, 95%CI 1.16-3.17).

CONCLUSIONS

Our findings indicated that IL-6 rs1800795 polymorphism was significantly associated with individual susceptibility to IS in Asians, but not in Caucasians. In addition, IL-10 rs1800896 polymorphism was also significantly associated with individual susceptibility to IS, especially for CI.

Genome-Wide Expression Profiles for Ischemic Stroke: A Meta-Analysis

BACKGROUND

Genome-wide expression studies (GWES), using microarray platforms, have allowed a deeper understanding of the molecular factors involved in the pathophysiology of ischemic stroke (IS), one of the main global causes of mortality and disability.

METHODS

In the current work, we carried out a meta-analysis of available GWES for IS. Bioinformatics and computational biology analyses were applied to identify enriched functional categories and convergence with other genomic datasets for IS.

RESULTS

Three primary datasets were included and in the meta-analyses for GWES and IS, 41 differentially expressed (DE) genes were identified using a random effects model. Thirteen of these genes were downregulated and 28 were upregulated. An analysis of functional categories found a significant enrichment for the Gene Ontology Term "Inflammatory Response" and for binding sites for the PAX2 transcription factor.

CONCLUSIONS

The list of DE genes identified in this meta-analysis of GWES for IS is useful for future genetic and molecular studies, which would allow the identification of novel mechanisms involved in the pathophysiology of IS. Several of the DE genes found in this meta-analysis have known functional roles related to mechanisms involved in the pathophysiology of IS. It is recognized the role of the inflammatory response in the pathophysiology of IS.

Functional polymorphism rs3783553 in the 3'-untranslated region of IL-1A increased the risk of ischemic stroke: A case-control study

Accumulating evidence indicates interleukin-1 (IL-1) is a critical mediator of inflammatory responses in ischemic stroke (IS). The aim of this study was to investigate whether rs3783553 in the 3'-untranslated region of IL-1A was associated with the risk of IS. In this hospital-based case-control study, we genotyped the rs3783553 using polymerase chain reaction in 316 patients with IS and 332 age, sex, and ethnicity-matched controls. Plasma level of IL-1α was measured by enzyme-linked immunosorbent assay. The relative luciferase activities were measured by the Dual Luciferase assay system. The presence of ins/ins genotype was associated with higher odds ratios (ORs) of IS compared with del/del genotype (ins/ins vs del/del: adjusted OR 1.77, 95% confidence interval [CI] 1.06-2.98; recessive model: adjusted OR 1.69, 95% CI 1.06-2.70). The higher risk of IS was also observed in allele comparison (adjusted OR 1.29, 95% CI 1.00-1.65). Multivariate logistic regression analysis showed that age, hypertension, total cholesterol, triglyceride, low-density lipoprotein, and rs3783553ins/ins genotypes were independent risk factors for IS. Plasma level of IL-1α was higher among IS patients compared with controls (P = .03). Notably, IS patients with the TTCA/TTCA genotype had a higher level of IL-1α compared with those with the del/del genotype (P = .01). Luciferase reporter assay showed that the vector containing the TTCA del allele exhibited a reduced transcriptional activity in the presence of miR-122 and miR-378. These findings indicate that IL-1A rs3783553 ins/ins genotype may increase the susceptibility to IS, possibly by interrupting the binding site of miR-122 and miR-378.

Association between genetic polymorphisms of interleukins and cerebral infarction risk: a meta-analysis

Interleukins (ILs) are the most typical inflammatory and immunoregulatory cytokines. Evidences have shown that polymorphisms in ILs are associated with cerebral infarction risk. However, the results remain inconclusive. The present study was to evaluate the role of ILs polymorphisms in cerebral infarction susceptibility. Relevant case-control studies published between January 2000 and December 2015 were searched and retrieved from the electronic databases of Web of Science, PubMed, Embase and the Chinese Biomedical Database. The odds ratio (OR) with its 95% confidence interval (CI) were employed to calculate the strength of association. A total of 55 articles including 12619 cerebral infarction patients and 14436 controls were screened out. Four ILs (IL-1, IL-6, IL-10 and IL-18) contained nine single nucleotide polymorphisms (SNPs; IL-1α -899C/T, IL-1β -511C/T and IL-1β +3953C/T; IL-6 -174G/C and -572C/G; IL-10 -819C/T and -1082A/G; IL-18 -607C/A and -137G/C). Our result showed that IL-1α -899C/T and IL-18 -607C/A (under all the genetic models), and IL-6 -572C/G (under the allelic model, heterogeneity model and dominant model) were associated with increased the risk of cerebral infarction (P<0.05). Subgroup analysis by ethnicity showed that IL-6 -174G/C polymorphism (under all the five models) and IL-10 -1082A/G polymorphism (under the allelic model and heterologous model) were significantly associated with increased the cerebral infarction risk in Asians. Other genetic polymorphisms were not related with cerebral infarction susceptibility under any genetic models. In conclusion, IL-1α -899C/T, IL-6 -572C/G and IL-18 -607C/A might be risk factors for cerebral infarction development. Further studies with well-designed and large sample size are still required.

Genetic association between inflammatory genes (IL-1α, CD14, LGALS2, PSMA6) and risk of ischemic stroke: A meta-analysis

BACKGROUND

Sequence variations in genes involved in inflammatory system are known to contribute to the risk of cerebrovascular diseases (CVD) including stroke. Very few number of studies have been published in the context of the association between Interleukin-1α(IL-1α), CD14 cell surface glycoprotein (CD14), Galectin-2-encoding gene (LGALS2)and proteasome subunit type 6 (PSMA6) gene polymorphisms with susceptibility to ischemic stroke (IS).

OBJECTIVE

The present meta-analysis aimed to provide a comprehensive account of the association between IL-1α (-C889T and -C511T), CD14 (-C159T), LGALS2 (-C3279T) and PSMA6 (-C8G) gene polymorphisms and susceptibility to IS.

METHODS

A literature search for eligible genetic studies published before August 31, 2015 was conducted in the PubMed, Medline, EMBASE, OVID, and Google Scholar databases. Fixed or random effects models were used to estimate the Pooled Odds ratio (OR) and 95% confidence interval (CI) using RevMan 5.3 software.

RESULTS

Total 21 studies were included in our meta-analysis. No significant association was observed between IL-1α (-C889T) [OR = 1.18, 95% CI: 0.67-2.08, P = 0.58], IL-1α (-C511T) [OR = 0.95, 95% CI: 0.66-1.37, P = 0.77], LGALS2(-C2379T) [OR = 0.29, 95% CI: 0.02-4.26, P = 0.37] and CD14 (-C260T) [OR = 0.93, 95% CI: 0.77-1.11, P = 0. 42] gene polymorphisms and risk of IS. However, protective level of association was observed between PSMA6 (-C8G) gene polymorphism and susceptibility to IS under the recessive model [OR = 0.25, 95% CI: 0.08-0.72, P = 0.01].

CONCLUSION

Our meta-analysis shows that IL-1α (-C889T and -C511T), CD14 (-C159T), LGALS2 (-C3279T) and gene polymorphisms are not significantly associated with the risk of IS while PSMA6 (-C8G) gene polymorphism may play a protective role with the susceptibility of IS. Further prospective large epidemiological studies are needed to confirm these findings in different populations.

The association between three promoter polymorphisms of IL-1 and stroke: a meta-analysis

AIM

The association between Interleukin-1 (IL-1) gene polymorphism and stroke remains controversial. The present study was designed to clarify this relationship through a pooled analysis of the numerous epidemiological studies focusing on this association.

METHODS

Published data addressing the association between polymorphism of the IL-1 gene and stroke were selected from electronic databases. A total of 21 studies from 19 publications including 5280 stroke patients and 5699 controls were included in this meta-analysis which detect whether IL-1α-889C/T, IL-1β-511C/T and IL-1 RN polymorphism were associated with stroke susceptibility.

RESULT

The combined results of overall analysis revealed that there was a significant association between IL-1α-889C/T polymorphism and stroke (allele model: OR = 1.39, 95% CI = 1.14-1.68, P < 0.001; recessive model: OR = 1.56, 95% CI = 1.27-1.90, P < 0.001; dominant model: OR = 1.45, 95% CI = 1.13-1.87, P = 0.004; additive model: OR = 1.70, 95% CI = 1.37-2.10, P < 0.001). On a subgroup analysis by ethnicity of study population, significant association was found in Asians (allele model: OR = 1.25 95% CI = 1.12-1.39, P < 0.001; recessive model: OR = 1.36, 95% CI = 1.09-1.69, P = 0.007; dominant model: OR = 1.29, 95% CI = 1.12-1.48, P < 0.001; additive model: OR = 1.42, 95% CI = 1.13-1.80, P = 0.003). There are no associations of IL-1β-511C/T and IL-RN polymorphisms on stroke risk were identified.

CONCLUSION

In conclusion, our results suggested that IL-1α-889C/T polymorphism is associated with stroke risk, especially in Asians. However, no associations of IL-1β-511C/T and IL-RN polymorphisms on stroke risk in overall analysis or subgroup analysis.

PPARγ and IL-6 - 174G>C gene variants in Croatian patients with ischemic stroke

AIM

Etiology of ischemic stroke (IS) is multifactorial and includes interaction of genetic and environmental factors. Different genes, their polymorphisms, host susceptibility, and inflammation processes play a role in IS development. The aim of this study was to evaluate the effect of PPAR-γ and IL-6 gene variants on IS onset.

MATERIAL AND METHODS

A total of 301 subjects (144 males, 157 females) participated in the study, 114 patients with IS and 187 healthy controls.

RESULTS

Statistically significant predictors of IS were male gender (OR 7.13, 95% CI 2.92-17.39, p<0.001), hypertension (OR 7.82. 95% CI 2.53-24.19, p<0.001), lowered HDL cholesterol (OR 8.20, 95% CI 2.41-27.94, p=0.001), elevated C-reactive protein (OR 5.26, 95% CI 1.92-14.41) and IL-6 -174 GC (OR 2.44 95% CI 1.01-5.91, p=0.0048) genotype. Males, compared to females, had 7 times higher odds for stroke. IL6 -174G/C genotype increased the odds for IS for 2.4 times. PPARγ was not statistically significantly associated with stroke.

CONCLUSION

We can point to the IL-6 -174G>C polymorphisms as candidate gene marker and risk factor for the prediction of ischemic stroke.

Influence of interleukin-6 gene -174G>C polymorphism on development of atherosclerosis: a meta-analysis of 50 studies involving 33,514 subjects

Increasing epidemiological studies have focused on the associations between interleukin-6 (IL-6) gene -174G>C polymorphism and atherosclerotic diseases, but the results are still controversial. This meta-analysis was designed to identify whether this association exists. PubMed, Embase, Web of Science, Cochrane database, Clinicaltrials.gov and Current Controlled Trials, Chinese Clinical Trial Registry, CBMdisc, CNKI and Google Scholar were searched to get the genetic association studies. The crude odds ratios (ORs) and their corresponding 95% confidence intervals (CIs) were used to estimate the association between the IL-6 gene -174G>C polymorphism and atherosclerosis ( AS ) risk. The subgroup analyses were made on the following: ethnicity, atherosclerotic diseases and source of controls. Finally, 50 studies (15,029 cases and 18,485 controls) were included in this meta-analysis. Overall, no significant association was found between the IL-6 gene -174G>C polymorphism and AS risk (for C allele vs. G allele: OR=1.02, 95% CI=0.94-1.11, p=0.64; for C/C vs. G/G: OR=1.01, 95% CI=0.85-1.21, p=0.88; for C/C vs. C/G+G/G: OR=0.97, 95% CI=0.84-1.12, p=0.68; for C/C+C/G vs. G/G: OR=1.07, 95% CI=0.97-1.17, p=0.18). In the subgroup analyses, significant associations were found between the IL-6 gene -174G>C polymorphism and AS in non-Caucasian group (for CC+CG vs. GG: OR=1.22, 95% CI=1.06-1.41, p=0.005), other atherosclerotic diseases group (for C allele vs. G allele: OR =0.75, 95% CI=0.61-0.93, p=0.008; for C/C vs. G/G: OR=0.56, 95% CI=0.38-0.81, p=0.002; for C/C vs. C/G+G/G: OR=0.60, 95% CI=0.45-0.79, p=0.0004) and population-based group (for C allele vs. G allele: OR=1.09, 95% CI=1.00-1.18, p=0.04; for CC+CG vs. GG: OR=1.15, 95% CI=1.04-1.27, p=0.005). In summary, the present meta-analysis suggests that the IL-6 gene -174G C polymorphism is associated with the susceptibility to AS. However, due to the high heterogeneity in the meta-analysis, the results should be interpreted with caution.

Associations between interleukin-1 gene polymorphisms and coronary heart disease risk: a meta-analysis

Objective

A great number of studies regarding the associations between IL-1B-511, IL-1B+3954 and IL-1RN VNTR polymorphisms within the IL-1gene cluster and coronary heart disease (CHD) have been published. However, results have been inconsistent. In this study, a meta-analysis was performed to investigate the associations.

Methods

Published literature from PubMed and Embase databases were searched for eligible publications. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using random- or fixed- effect model.

Results

Thirteen studies (3,219 cases/2,445 controls) for IL-1B-511 polymorphism, nine studies (1,828 cases/1,818 controls) for IL-1B+3954 polymorphism and twelve studies (2,987 cases/ 2,208 controls) for IL-1RN VNTR polymorphism were included in this meta analysis. The results indicated that both IL-1B-511 and IL-1B+3954 polymorphisms were not associated with CHD risk (IL-1B-511 T vs. C: OR = 0.98, 95%CI 0.87–1.09; IL-1B+3954 T vs. C: OR = 1.06, 95%CI 0.95–1.19). Similarly, there was no association between IL-1RN VNTR polymorphism and CHD risk (*2 vs. L: OR = 1.00, 95%CI 0.85–1.17).

Conclusions

This meta-analysis suggested that there were no associations between IL-1 gene cluster polymorphisms and CHD.