Matrix metalloproteinase-9 gene polymorphisms and their interaction with environment on subarachnoid hemorrhage risk

Levels of Matrix Metalloproteinase 9 Are Elevated in Persons With Schizophrenia or Bipolar Disorder: The Role of Modifiable Factors

Background

Matrix metalloproteinases (MMPs) are a diverse set of enzymes associated with inflammation. MMP-9 is of particular interest because it has been associated with autoimmune and cardiopulmonary disorders, tobacco smoking, and obesity, prevalent in psychiatric populations.

Methods

Sensitive enzyme immunoassays measured MMP-9 in blood samples from 1121 individuals (mean age = 35.6 [SD = 13.0] years; 47.7% male; 440 with schizophrenia, 399 with bipolar disorder, and 282 without a psychiatric disorder). We estimated the odds of diagnosis associated with MMP-9, demographic variables, tobacco smoking, and obesity, and also the partial explained variance using regression methods. We also determined the association between psychiatric medications and MMP-9 levels.

Results

Individuals with elevated MMP-9 levels had higher odds of schizophrenia or bipolar disorder compared with the nonpsychiatric group adjusted for demographic variables. Partial correlation analyses indicated the demographic-adjusted variance associated with MMP-9, smoking, obesity, and their interaction explained 59.6% for schizophrenia and 39.9% for bipolar disorder. Levels of MMP-9 were substantially lower in individuals receiving valproate, particularly relatively high doses.

Conclusions

Individuals with higher levels of MMP-9 have significantly higher odds of schizophrenia or bipolar disorder. Individuals receiving valproate had substantially lower levels of MMP-9, possibly related to its ability to inhibit histone deacetylation. A substantial portion of the variance in clinical disorders associated with MMP-9 can be attributed to smoking or obesity. Interventions to reduce smoking and obesity might reduce the morbidity and mortality associated with elevated MMP-9 levels and improve the health outcomes of individuals with these disorders.

Inflammation and Oxidative Stress: Potential Targets for Improving Prognosis After Subarachnoid Hemorrhage

Subarachnoid hemorrhage (SAH) has a high mortality rate and causes long-term disability in many patients, often associated with cognitive impairment. However, the pathogenesis of delayed brain dysfunction after SAH is not fully understood. A growing body of evidence suggests that neuroinflammation and oxidative stress play a negative role in neurofunctional deficits. Red blood cells and hemoglobin, immune cells, proinflammatory cytokines, and peroxidases are directly or indirectly involved in the regulation of neuroinflammation and oxidative stress in the central nervous system after SAH. This review explores the role of various cellular and acellular components in secondary inflammation and oxidative stress after SAH, and aims to provide new ideas for clinical treatment to improve the prognosis of SAH.

Interleukin-1 and Interleukin-6 Polymorphisms Might Influence Predisposition to Hemorrhagic Cerebral Vascular Diseases: A Meta-Analysis

BACKGROUND

Interleukin-1 (IL-1) and IL-6 polymorphisms might influence predisposition to hemorrhagic cerebral vascular diseases, but the results of already published studies regarding relationship between IL-1/IL-6 polymorphisms and hemorrhagic cerebral vascular diseases were still controversial and ambiguous.

OBJECTIVES

The authors designed this meta-analysis to more precisely estimate the relationship between IL-1/IL-6 polymorphisms and hemorrhagic cerebral vascular diseases by pooling the results of already published related studies.

METHODS

The authors searched PubMed, EMBASE, Web of Science, and CNKI for already published studies. Eighteen already published studies were pooled analyzed in this meta-analysis.

RESULTS

The pooled meta-analyses' results showed that distributions of IL-1A rs1800587, IL-1B rs16944, and IL-6 rs1800796 polymorphisms among patients and controls differed significantly. Moreover, distribution of the IL-6 rs1800795 polymorphism among patients and controls from Asians also differed significantly. Further analyses showed similar findings for IL-1A rs1800587, IL-1B rs16944, and IL-6 rs1800796 polymorphisms in aneurysmal subarachnoid hemorrhage (aSAH) subgroup.

CONCLUSIONS

This meta-analysis suggested that IL-1A rs1800587, IL-1B rs16944, and IL-6 rs1800796 polymorphisms might influence susceptibility to hemorrhagic cerebral vascular diseases, especially for aSAH. Moreover, IL-6 rs1800795 might influence susceptibility to hemorrhagic cerebral vascular diseases in Asians.

MMP9 rs17576 Is Simultaneously Correlated with Symptomatic Intracranial Atherosclerotic Stenosis and White Matter Hyperintensities in Chinese Population

PURPOSE

The aim of this study was screening for single nucleotide polymorphisms (SNPs) associated with white matter hyperintensities (WMHs) in symptomatic intracranial atherosclerotic stenosis (sICAS) patients and exploring a possible connection in the genetic background between macrovascular disease and small vessel disease.

METHODS

There were 400 sICAS patients enrolled in the study. Fazekas scores were applied to WMH classification. Healthy controls were referred to 1,000 Genome Project and GeneSky company who provided 1,007 Chinese healthy controls. Fast target sequencing technology was used to select the SNPs of 102 genes related to the pathogenesis of sICAS in the sICAS patients.

RESULTS

The allele frequencies of 88 SNPs were significantly different between the sICAS group and the healthy controls (p < 0.05). The allele frequencies of 53 SNPs were significantly different between the sICAS patients with and without WMHs (p < 0.05). Further analysis found that matrix metalloproteinase 9 (MMP9) rs17576 was simultaneously related to sICAS and WMHs. The frequency of the rs17576 A allele was significantly lower in sICAS patients when compared to the normal controls (p = 0.03, OR [95% CI] = 0.75 [0.625-0.91]). Also, the frequency of the rs17576 genotypes was significantly different under codominant (p = 0.009), dominant (p = 0.014), and recessive (p= 0.023) models. The frequency of the rs17576 A allele was significantly higher in sICAS with WMH patients, compared to those without WMHs (p = 0.022, OR [95% CI] = 1.54 [1.06-2.22]); the frequency of the rs17576 genotypes was significantly different under codominant (p = 0.019) and recessive (p = 0.032) models. Logistic regression analysis showed that age, hypertension, and MMP9 rs17576 AA genotype were independent risk factors for sICAS with WMHs.

CONCLUSION

MMP9 rs17576 may be simultaneously associated with the risk of sICAS and WMHs.

Disturbed balance in the expression of MMP9 and TIMP3 in cerebral amyloid angiopathy-related intracerebral haemorrhage

Cerebral amyloid angiopathy (CAA) is characterized by the deposition of the amyloid β (Aβ) protein in the cerebral vasculature and poses a major risk factor for the development of intracerebral haemorrhages (ICH). However, only a minority of patients with CAA develops ICH (CAA-ICH), and to date it is unclear which mechanisms determine why some patients with CAA are more susceptible to haemorrhage than others. We hypothesized that an imbalance between matrix metalloproteinases (MMPs) and their inhibitors (TIMPs) contributes to vessel wall weakening. MMP9 plays a role in the degradation of various components of the extracellular matrix as well as of Aβ and increased MMP9 expression has been previously associated with CAA. TIMP3 is an inhibitor of MMP9 and increased TIMP3 expression in cerebral vessels has also been associated with CAA. In this study, we investigated the expression of MMP9 and TIMP3 in occipital brain tissue of CAA-ICH cases (n = 11) by immunohistochemistry and compared this to the expression in brain tissue of CAA cases without ICH (CAA-non-haemorrhagic, CAA-NH, n = 18). We showed that MMP9 expression is increased in CAA-ICH cases compared to CAA-NH cases. Furthermore, we showed that TIMP3 expression is increased in CAA cases compared to controls without CAA, and that TIMP3 expression is reduced in a subset of CAA-ICH cases compared to CAA-NH cases. In conclusion, in patients with CAA, a disbalance in cerebrovascular MMP9 and TIMP3 expression is associated with CAA-related ICH.

eNOS rs2070744 polymorphism might influence predisposition to hemorrhagic cerebral vascular diseases in East Asians: A meta-analysis

INTRODUCTION

Endothelial nitric oxide synthase (eNOS) polymorphisms might influence predisposition to hemorrhagic cerebral vascular diseases, but the results of already published studies regarding relationship between eNOS polymorphisms and hemorrhagic cerebral vascular diseases were still controversial.

METHODS

The authors performed this meta-analysis to estimate relationship between eNOS polymorphisms and hemorrhagic cerebral vascular diseases in a larger pooled population by combing the results of already published related studies. The authors searched Pubmed, Embase, Web of Science, and CNKI for already published studies.

RESULTS

Eighteen already published studies were pooled analyzed in this meta-analysis. The pooled meta-analyses results showed that eNOS rs2070744 polymorphism was significantly associated with predisposition to hemorrhagic cerebral vascular diseases in East Asians (dominant comparison: OR = 0.77, p = .01; overdominant comparison: OR = 1.24, p = .04; allele comparison: OR = 0.78, p = .006) Nevertheless, the pooled meta-analyses did not reveal any positive results for eNOS rs1799983 and rs869109213 polymorphisms.

CONCLUSIONS

This meta-analysis suggested that eNOS rs2070744 polymorphism, but not rs1799983 and rs869109213 polymorphisms, might influence predisposition to hemorrhagic cerebral vascular diseases in East Asians.