Az endokannabinoid rendszer genetikai asszociációs vizsgálatai szorongással összefüggésben = Genetic association analyses of the endocannabinoid system on anxious phenotype

Bevezetés: A stresszválasz és az érzelmi élet szabályozásában betöltött szerepéről egyre több adat gyűlt össze az endokannabinoid rendszerrel (ECS) kapcsolatban és komoly farmakológiai targetté vált elsősorban a szorongásoldás területén. Amellett, hogy az állatkísérletes vizsgálatok meggyőző, az anxiolítikus hatást megalapozó eredményekkelszolgálnak, a vonatkozó humán genetikai adatok meglepően hiányosak az irodalomban. Saját vizsgálatunkban az ECS-hez tartozó cannabinoid receptor 1 (CB1R) és a zsírsavamid hidroláz (fatty acid amide hydrolase, FAAH) gén polimorfizmusokat vizsgálatuk különböző interakciós modellekben a szorongással összefüggésben. Módszerek: Vizsgálatsorozatunkba kb. 900 önkéntes, átlagpopulációt reprezentáló résztvevőt vontunk be. A fenotípus méréséhez a Rövid Tünet Skála Szorongás alskáláját, valamint a STAI kérdőívet használtuk. A gyermekkori trauma előfordulását a Gyermekkori Adverzitás Kérdőív segítségével tártuk fel. A genetikai vizsgálatok elvégzéséhez szájnyálkahártya mintából izoláltunk DNS-t, majd MassArray Sequenom technikával történt a genotipizálás. A statisztikai elemzéshez generalizált lineáris regressziót, illetve post hoc teszteket végeztünk. Eredmények: Az egyes SNP-k önálló hatása nem bizonyult szignifikánsnak a fenotípusvarianciák tekintetében. Ezzel szemben az interakciós elemzések markáns összefüggéseket tárt fel. A CB1R gén promoterében elhelyezkedő rs2180619 polimorfizmus GG genotípus az 5-HTTLPR SS genotípussal együtt szignifikánsan magasabb STAI-T pontszámmal járt együtt (p=0.0006) összehasonlítva az ellenpárokkal. A GG és SS genotípus egyidejű hordozása majdnem 5-szörös rizikót jelentett a magas szorongáspontszámmal járó fenotípusra, mint az A és L allél hordozás (OR=4.64, 95% CI: 1.7-12.71). A FAAH gén C385A polimorfizmusát tekintve az A allél járt együtt magasabb BSI-ANX és a STAI-T pontszámmal abban az esetben, ha többszörös gyermekkori trauma szerepelt az anamnézisben ,szemben a C allél hordozókkal (pinteract=0.00002; pinteract=0.0023). Konklúzió: Vizsgálatunkban újabb megerősítést nyertek az ECS patogenikus szerepét igazoló korábbi adatok a szorongásra vonatkozóan. Eredményeink szerint a CB1R és a FAAH gén komplex módon, a szerotonintranszporter-génnel és a gyermekkori traumákkal interakcióban vesz részt a felnőttkori, humán szorongásos fenotípus kialakulásában

Financial Stress Interacts With CLOCK Gene to Affect Migraine.

Previous studies suggested that both maladaptive stress response and circadian dysregulation might have a role in the background of migraine. However, effects of circadian genes on migraine have not been tested yet. In the present study, we investigated the main effect of rs10462028 of the circadian locomotor output cycles kaput (CLOCK) gene and its interaction with different stress factors on migraine. In our cross-sectional study 2,157 subjects recruited from Manchester and Budapest completed the ID-Migraine questionnaire to detect migraine type headaches (migraineID). Additional stress factors were assessed by a shortened version of the Childhood Trauma Questionnaire, the List of Threatening Experiences questionnaire, and a validated questionnaire to identify financial difficulties. Rs10462028 showed no main genetic effect on migraineID. However, chronic stress indexed by financial difficulties showed a significant interaction effect with rs10462028 (p = 0.006 in recessive model) on migraineID. This result remained significant after correction for lifetime bipolar and unipolar depression and was replicated in both subsamples, although only a trend effect was reached after Bonferroni-correction, which is the strictest correction not considering interdependences. Childhood adversity (CHA) and Recent negative life events (RLE) showed no significant gene × stress interaction with rs10462028. In addition, in silico analysis demonstrated that the genetic region tagged by rs10462028 alters the binding of several miRNAs. Our exploratory study suggests that variations in the CLOCK gene, with moderating effect on gene function through miRNA binding, in interaction with financial difficulties might influence the risk of migraine-type headaches. Thus, financial hardship as a chronic stress factor may affect migraine through altering circadian rhythms

Variants in the CNR1 gene predispose to headache with nausea in the presence of life stress

One of the main effects of the endocannabinoid system in the brain is stress adaptation with presynaptic endocannabinoid receptor 1 (CB1 receptors) playing a major role. In the present study, we investigated whether the effect of the CB1 receptor coding CNR1 gene on migraine and its symptoms is conditional on life stress. In a cross-sectional European population (n = 2426), recruited from Manchester and Budapest, we used the ID-Migraine questionnaire for migraine screening, the Life Threatening Experiences questionnaire to measure recent negative life events (RLE), and covered the CNR1 gene with 11 SNPs. The main genetic effects and the CNR1 × RLE interaction with age and sex as covariates were tested. None of the SNPs showed main genetic effects on possible migraine or its symptoms, but 5 SNPs showed nominally significant interaction with RLE on headache with nausea using logistic regression models. The effect of rs806366 remained significant after correction for multiple testing and replicated in the subpopulations. This effect was independent from depression- and anxiety-related phenotypes. In addition, a Bayesian systems-based analysis demonstrated that in the development of headache with nausea all SNPs were more relevant with higher a posteriori probability in those who experienced recent life stress. In summary, the CNR1 gene in interaction with life stress increased the risk of headache with nausea suggesting a specific pathological mechanism to develop migraine, and indicating that a subgroup of migraine patients, who suffer from life stress triggered migraine with frequent nausea, may benefit from therapies that increase the endocannabinoid tone

Effects of IL1B single nucleotide polymorphisms on depressive and anxiety symptoms are determined by severity and type of life stress

Interleukin-1b is one of the main mediators in the cross-talk between the immune system and the central nervous system. Higher interleukin-1b levels are found in mood spectrum disorders, and the stressinduced expression rate of the interleukin-1b gene (IL1B) is altered by polymorphisms in the region. Therefore we examined the effects of rs16944 and rs1143643 single nucleotide polymorphisms (SNPs) within the IL1B gene on depressive and anxiety symptoms, as measured by the Brief Symptom Inventory, in a Hungarian population sample of 1053 persons. Distal and proximal environmental stress factors were also included in our analysis, namely childhood adversity and recent negative life-events. We found that rs16944 minor (A) allele specifically interacted with childhood adversity increasing depressive and anxiety symptoms, while rs1143643’s minor (A) allele showed protective effect against depressive symptoms after recent life stress. The genetic main effects of the two SNPs were not significant in the main analysis, but the interaction effects remained significant after correction for multiple testing. In addition, the effect of rs16944 A allele was reversed in a subsample with low-exposure to life stress, suggesting a protective effect against depressive symptoms, in the post hoc analysis. In summary, both of the two IL1B SNPs showed specific environmental stressor-dependent effects on mood disorder symptoms. We also demonstrated that the presence of exposure to childhood adversity changed the direction of the rs16944 effect on depression phenotype. Therefore our results suggest that it is advisable to include environmental factors in genetic association studies when examining the effect of the IL1B gene

Significance of risk polymorphisms for depression depends on stress exposure

Depression is a polygenic and multifactorial disorder where environmental effects exert a significant impact, yet most genetic studies do not consider the effect of stressors which may be one reason for the lack of replicable results in candidate gene studies, GWAS and between human studies and animal models. Relevance of functional polymorphisms in seven candidate genes previously implicated in animal and human studies on a depression-related phenotype given various recent stress exposure levels was assessed with Bayesian relevance analysis in 1682 subjects. This Bayesian analysis indicated a gene-environment interaction whose significance was also tested with a traditional multivariate analysis using general linear models. The investigated genetic factors were only relevant in the moderate and/or high stress exposure groups. Rank order of genes was GALR2 > BDNF > P2RX7 > HTR1A > SLC6A4 > CB1 > HTR2A, with strong relevance for the first four. Robust gene-gene-environment interaction was found between BDNF and HTR1A. Gene-environment interaction effect was confirmed, namely no main effect of genes, but a significant modulatory effect on environment-induced development of depression were found. Our data support the strong causative role of the environment modified by genetic factors, similar to animal models. Gene-environment interactions point to epigenetic factors associated with risk SNPs. Galanin-2 receptor, BDNF and X-type purin-7 receptor could be drug targets for new antidepressants