| 1 | Rom J Intern Med 2009 -1 47: 9-18 |
|---|---|
| PMID | 19886064 |
| Title | The implication of CNR1 gene's polymorphisms in the modulation of endocannabinoid system effects. |
| Abstract | The endocannabinoid system (ECS) represents one of the most important physiologic systems involved in organism homeostasis, having various implications upon individual behavior and metabolic phenotype. It is composed of cannabinoid receptors CB1 and CB2, and their genes (CNR1 and CNR2), their endogenous ligands and the enzymes which mediate endogenous ligands' biosynthesis and degradation. Anandamide and 2-arachidonoylglycerol are two endogenous agonists of the cannabinoid receptors. It is considered that ECS connects physical and emotional response to stress with appetite and energy balance, functioning like an after stress recovery system which remains inactive in repose physiologic conditions. It is involved in several physiologic processes like nociception, motor control, memory, learning, appetite, food intake and energy balance. This review analyzes the implication of 11 polymorphisms of CNR1 gene in the modulation of the ECS metabolic and central effects. A lot of studies show that rs12720071, rs1049353, rs806381, rs10485170, rs6454674, rs2023239 polymorphisms are associated with metabolic effects. From them rs12720071, rs104935, rs6454674, rs2023239 polymorphisms are also associated with central effects of ECS (substance addiction, impulsivity, resistance to antidepressive treatment). Other studies indicate that rs806368, rs1535255, (AAT)9,(AAT)12 and (AAT)n are correlated only with central effects (schizophrenia, substance addiction, impulsivity, Parkinson syndrome). The discovery of ECS and its signaling pathways opens a door towards the understanding of several important physiologic processes regarding appetite, food intake, metabolism, weight gain, motor control, memory, learning, drug addiction and nociception. The detailed analysis and validation of the ECS functioning can bring us very close to the discovery of new diagnosis and treatment methods for obesity, drugs abuse and numerous psychic diseases. |
| SCZ Keywords | schizophrenia |
| 2 | Biol. Psychiatry 2010 May 67: 974-82 |
| PMID | 19931854 |
| Title | Brain cannabinoid CB2 receptor in schizophrenia. |
| Abstract | Neural endocannabinoid function appears to be involved in schizophrenia. Two endocannabinoid receptors, CB1 and CB2, are found in the brain and elsewhere in the body. We investigated roles of CB2 in schizophrenia. An association study was performed between tag single nucleotide polymorphisms (SNPs) in the CNR2 gene encoding the CB2 receptor and schizophrenia in two independent case-control populations. Allelic differences of associated SNPs were analyzed in human postmortem brain tissues and in cultured cells. Prepulse inhibition and locomotor activity in C57BL/6JJmsSlc mice with CB2 receptor antagonist AM630 administration was examined. The analysis in the first population revealed nominally significant associations between schizophrenia and two SNPs, and the associations were replicated in the second population. The R63 allele of rs2501432 (R63Q) (p = .001), the C allele of rs12744386 (p = .005) and the haplotype of the R63-C allele (p = 5 x 10(-6)) were significantly increased among 1920 patients with schizophrenia compared with 1920 control subjects in the combined population. A significantly lower response to CB2 ligands in cultured CHO cells transfected with the R63 allele compared with those with Q63, and significantly lower CB2 receptor mRNA and protein levels found in human brain with the CC and CT genotypes of rs12744386 compared with TT genotype were observed. AM630 exacerbated MK-801- or methamphetamine-induced disturbance of prepulse inhibition and hyperactivity in C57BL/6JJmsSlc mice. These findings indicate an increased risk of schizophrenia for people with low CB2 receptor function. |
| SCZ Keywords | schizophrenia |
| 3 | J Affect Disord 2011 Nov 134: 427-30 |
| PMID | 21658778 |
| Title | Genetic association between bipolar disorder and 524A>C (Leu133Ile) polymorphism of CNR2 gene, encoding for CB2 cannabinoid receptor. |
| Abstract | Several studies provided evidence that the endocannabinoid system (ECS) is involved in psychiatric diseases, like major depression, schizophrenia and bipolar disorder (BD), mainly focusing on CB1 cannabinoid receptor, and FAAH, the fatty acid amide hydrolase involved in endocannabinoid metabolism. In this study we investigated the possible association of BD with three missense SNPs, of the gene CNR2, encoding for CB2 cannabinoid receptor. The possible association between BD and three CNR2 missense SNPs, namely rs2501432 (315A>G; Arg63Gln), rs41311993 (524C>A; Leu133Ile) and rs2229579 (1073C>T; Tyr316His), was investigated through a case-control study. Eighty patients and one hundred and sixty healthy subjects were recruited. Allele Specific Oligonucleotide (ASO)-PCR and restriction fragment length polymorphism (RFLP) methods were used for genotyping. A statistically significant association was found between BD and the CNR2 524C>A; Leu133Ile (P(?(2)) = 0.001; OR = 4.74; 95% C.I. = 2.52-10.50) while no statistically significant difference between BD and control group was observed for the other two SNPs. Though further investigations are necessary to confirm this data, our results suggest that CB2 cannabinoid receptor may play a role in BD. |
| SCZ Keywords | schizophrenia |
| 4 | J. Mol. Neurosci. 2013 Oct 51: 454-60 |
| PMID | 23846977 |
| Title | Association of single-nucleotide polymorphisms in the cannabinoid receptor 2 gene with schizophrenia in the Han Chinese population. |
| Abstract | Cannabinoid receptor 2 (CNR2) is a major receptor in the endogenous cannabinoid system. In recent years, many studies have shown that the receptor is closely associated with schizophrenia. This study examined the relationship between CNR2 gene polymorphisms (rs2501432C/T, rs2229579C/T, rs2501401G/A) and schizophrenia. Three hundred sixteen schizophrenia patients and 334 healthy subjects were recruited as case and control groups, respectively. For rs2501432, the CT/TT genotype frequencies in the dominant model, TT genotype frequencies in the additive model, and T allele frequencies of the case group were lower than the control (P < 0.05), and the CT and TT genotypes and T allele frequencies of the male case group were significantly lower than the control (P < 0.05). For rs2229579, the T allele frequencies of the case group were higher than the control (P < 0.05). The T-C-G haplotype in the case group had a significantly lower frequency compared with the controls, but the T-T-A haplotype frequencies were higher in the case group than in the controls (P < 0.05). Our results suggest that the T allele of rs2501432 may be a protective factor, particularly in males, but the T allele of rs2229579 may be a risk factor for schizophrenia. T-C-G may be a protective haplotype for schizophrenia, but not the T-T-A haplotype. |
| SCZ Keywords | schizophrenia |
| 5 | Psychiatr. Genet. 2014 Oct 24: 225-9 |
| PMID | 25014618 |
| Title | Genetic association analysis of CNR1 and CNR2 polymorphisms with schizophrenia in a Korean population. |
| Abstract | Located on 6q15 and 1p36.11, cannabinoid receptor 1 (CNR1) and cannabinoid receptor 2 (CNR2) genes are considered to be a positional and functional candidate gene for the development of mental disorders such as schizophrenia because CNR1 is known as a regulator of dopamine signaling in the hippocampus and the cerebral cortex. However, few genetic studies have been carried out to investigate an association of CNR1 and CNR2 polymorphisms and the risk of schizophrenia. In this study, although the result indicates that CNR1 and CNR2 variations are unlikely to influence schizophrenia susceptibility in a Korean population, the findings would provide meaningful information for further genetic studies. |
| SCZ Keywords | schizophrenia |