Flavia M. Gonçalves

Increased circulating levels of matrix metalloproteinase (MMP)-8, MMP-9, and pro-inflammatory markers in patients with metabolic syndrome

BACKGROUND Metabolic syndrome (MetS) predisposes to cardiovascular complications. Increased concentrations of pro-inflammatory mediators and imbalanced concentrations of matrix metalloproteinases (MMPs) and their inhibitors (TIMPs) may reflect the pathophysiology of MetS. We compared the circulating levels of MMPs, TIMPs, and inflammatory mediators in MetS patients with those found in healthy controls. METHODS We studied 25 healthy subjects and 25 MetS patients. The plasma levels of pro-MMP-2 and pro-MMP-9 were determined by gelatin zymography. The plasma concentrations of MMP-8, MMP-3, TIMP-1, TIMP-2, monocyte chemoattractant protein-1 (MCP-1), interleukin-6 (IL-6), intercellular adhesion molecule (sICAM-1), and sP-selectin were measured by ELISA kits. RESULTS We found higher sP-selectin, sICAM-1, MCP-1, and IL-6 (all P<0.05) concentrations in MetS patients compared with healthy controls. No differences in pro-MMP-2, MMP-3, and TIMP-2 levels were found (all P>0.05). However, we found higher pro-MMP-9, MMP-8, and TIMP-1 levels in MetS patients compared with healthy controls (all P<0.05). CONCLUSIONS Patients with MetS have increased circulating concentrations of pro-MMP-9, MMP-8, and TIMP-1 that are associated with increased concentrations of pro-inflammatory mediators and adhesion molecules. These findings suggest that MMPs may have a role in the increased cardiovascular risk of MetS patients. Pharmacological interventions targeting MMPs, especially MMP-9 and MMP-8 deserve further investigation in MetS patients.

Different circulating metalloproteinases profiles in women with migraine with and without aura.

BACKGROUND We compared the circulating levels of matrix metalloproteinase (MMP)-2, MMP-9, tissue inhibitors of metalloproteinase (TIMP)-1, TIMP-2, and MMP-9/TIMP-1 and MMP-2/TIMP-2 ratios in migraine patients without aura (MWA) and in migraine patients with aura (MA) with those found in healthy subjects (controls). METHODS We studied 80 migraine (40 MWA and 40 MA) women and 40 controls. Pro-MMP-2 levels were determined by zymography and MMP-9, TIMP-1, and TIMP-2 levels were determined by ELISA. RESULTS While we found similar TIMP-2 levels, higher plasma pro-MMP-2 and pro-MMP-2/TIMP-2 ratios were found in MWA and MA patients compared with controls (P<0.05). Higher TIMP-1 levels and lower MMP-9/TIMP-1 ratios were found in MA, but not in MWA, patients compared with controls (P<0.05). We found no significant differences when patients without headache attack were compared with patients having a headache attack (all P<0.05). CONCLUSIONS We showed an increased net MMP-2 activity in MWA and MA. The increased MMP-9/TIMP-1 ratios in MWA patients contrast with the lower MMP-9/TIMP-1 ratios in MA patients and may reflect pathophysiological differences between these conditions.

Matrix metalloproteinase (MMP)-2 gene polymorphisms affect circulating MMP-2 levels in patients with migraine with aura.

Matrix metalloproteinases (MMP) are involved in the disruption of blood-brain barrier (BBB) during migraine attacks. In the present study, we hypothesized that two functional polymorphisms (C(-1306)T and C(-735)T) in MMP-2 gene and MMP-2 haplotypes are associated with migraine and modify MMP-2 and tissue inhibitor of MMP (TIMP)-2 levels in migraine. Genotypes for MMP-2 polymorphisms were determined by real time-PCR using Taqman allele discrimination assays. Haplotypes were inferred using the PHASE program. Plasma MMP-2 and TIMP-2 concentrations were measured by gelatin zymography and ELISA, respectively, in 148 healthy women without history of migraine and in 204 women with migraine (153 without aura; MWA, and 51 with aura; MA). Patients with MA had higher plasma MMP-2 concentrations and MMP-2/TIMP-2 ratios than patients with MWA and controls (P<0.05). While MMP-2 genotype and haplotype distributions for the polymorphisms were similar among the groups (P>0.05), we found that the CC genotype for C(-735)T polymorphism and the CC haplotype were associated with higher plasma MMP-2 concentrations in MA group (P<0.05). Our findings may help to understand the role of MMP-2 and its genetic variants in the pathophysiology of migraine and to identify a particular group of migraine patients with increased MMP-2 levels that would benefit from the use of MMP inhibitors.

Vascular Endothelial Growth Factor Genetic Polymorphisms and Haplotypes in Women with Migraine

Vascular endothelial growth factor (VEGF) production is regulated by growth factors and inflammatory cytokines, and VEGF plays a role in migraine. We examined for the first time whether three functional polymorphisms in the promoter region of VEGF gene (C(-2578)A, G(-1154)A, and G(-634)C) and VEGF haplotypes are associated with migraine. We studied 114 healthy women without migraine and 175 women with migraine (129 without aura, and 46 with aura). We found no differences in the distributions of VEGF genotypes and alleles (p > 0.05). However, the CAC haplotype was more frequent in controls than in migraine patients, and the AGC haplotype was more frequent in patients with migraine with aura than in controls (both p < 0.05). These findings suggest that VEGF haplotypes affect susceptibility to migraine.

Gene-Gene Interactions Implicated in Vascular Endothelial Function in Migraine

In a previous article in Headache, Sutherland and Griffiths reviewed the genetics of migraine with focus on the molecular basis of both monogenic and common polygenic migraine. Notably, the susceptibility loci identified from recent genome-wide association studies (GWAS) for common migraine have been implicated in vascular function and diseases, and regulation of vascular tone. We would like to comment on the role of gene-gene interactions for migraine genetics and provide an example of interaction among genetic polymorphisms implicated in vascular function in migraine. GWAS findings have provided insights that suggest the need for a renewed focus on vascular function in common migraine. Importantly, novel approaches are required to detect complex genetic effects from multiple minor impact genes and genegene interactions within pathways relevant to the pathophysiology of common migraine. Therefore, gene-gene interaction analysis involving the loci identified in GWAS and implicated in vascular function could be performed to further clarify the potential role of vascular pathways to the pathophysiology of common migraine. Findings from GWAS for common migraine also implicated other important pathways, such as nitric oxide (NO) signaling and oxidative stress. Indeed, there is evidence that NO is an important mediator involved in the pathophysiology of migraine. Excessive NO amounts contributing to migraine are probably derived from inducible NO synthase (iNOS, or NOS2). Moreover, vascular endothelial growth factor (VEGF) induces vasodilation and enhances vascular permeability, thus increasing the risk of migraine attacks, and it is possible that this results of VEGF-induced activation of endothelial NO synthase (eNOS, or NOS3) and enhanced NO formation. Given their role on vascular endothelial function, candidate gene studies have examined the association of polymorphisms of the NOS2, NOS3, and VEGF genes with migraine susceptibility, as well as the combination of their alleles into haplotypes. Importantly, interactions among the polymorphisms of these genes were characterized in 150 women with migraine (107 with migraine without aura and 43 with migraine with aura) diagnosed according to the International Classification of Headache Disorders criteria, and compared to 99 healthy women without migraine. Notably, an interaction between the polymorphisms G2087A (rs2297518) of NOS2 gene and rs743506 of NOS3 gene was found to be associated with migraine, suggesting that this gene-gene interaction may affect the susceptibility to migraine. Noteworthy, these associations must be replicated in independent populations. Moreover, functional studies are needed to determine the molecular mechanisms underlying the observed interactions. However, NO has been suggested as an important mediator in migraine pathophysiology and targeting NOS is a possible approach in the therapy of migraine. These findings implicating the interaction among genes in the NO signaling are relevant because they may help to identify patients at increased risk for migraine. Conflict of Interest: None.