Genetics of Lesch's typology of alcoholism

It is widely accepted that dopamine and serotonin (5-HT) neurotransmission can be critically involved in the development of alcohol abuse and alcohol dependence. Lesch's typology of alcoholism has been gaining increasing popularity as it qualitatively differentiates patients into different treatment response subgroups. The aim of the present study was to evaluate a possible genetic background of Lesch's typology with special emphasis placed on dopamine- and serotonin-related genes. 122 alcoholics (the mean age: 35+/-9 years) were investigated. According to Lesch's typology, 58 patients were of type I, 36 patients of type II, 11 patients of type III, and 17 patients of type IV. Alcohol drinking and family history was assessed by means of a structured interview, based on the Semi-Structured Assessment for the Genetics of Alcoholism. 150 control subjects without psychiatric disorders were also recruited. The control group was ethnically-, age- and gender-matched to the patients. The DRD2 TaqIA, exon 8, and promoter -141C ins/del polymorphisms as well as COMT Val158Met, 5HTT 44 bp del in promoter, and DAT 40 bp VNTR polymorphisms were detected by means of PCR. No significant differences were observed when the whole group of alcoholics and the controls were compared. Similarly, there were no differences between either the Lesch type I or type II alcoholics and the control subjects. No significant differences were observed between type I and type II alcoholics. Alleles frequencies were not calculated for the Lesch type III and type IV alcoholics since the number of patients was too small. The present results argue against any major role of the investigated polymorphisms in either Lesch type I or type II alcoholism. More comprehensive studies are needed to define the role of the investigated polymorphisms in Lesch type III and type IV alcoholism.     

Epidemiology of familial amyloid polyneuropathy in Japan: Identification of a novel endemic focus

BACKGROUND: Familial amyloid polyneuropathy (FAP) is distributed worldwide with several endemic foci including two major foci in Japan. OBJECTIVE: To elucidate a nationwide epidemiology of FAP in Japan. DESIGN, SETTING, AND PATIENTS: (i) We analyzed the data of FAP patients registered by the Ministry of Health, Labour, and Welfare, Japan, during 2003-2005. (ii) As Ishikawa prefecture was found to be a novel endemic focus, we examined 27 FAP patients in Ishikawa to characterize their clinical and genetic features in comparison with other endemic foci. RESULTS: (i) The prevalence of familial amyloidosis in Japan was estimated to be 0.87-1.1 per 1,000,000 persons. Nagano prefecture had the highest prevalence (11-15.5), followed by Kumamoto (10.1-10.3), and then Ishikawa (3.5-4.2). (ii) All the FAP patients in Ishikawa had transthyretin (TTR) type FAP; all the families had a TTR Val30Met mutation except one family with a Leu58Arg mutation. FAP with Val30Met mutation in Ishikawa was characterized by late onset, high penetrance, and moderate autonomic dysfunction. CONCLUSIONS: Ishikawa prefecture is the third endemic focus of FAP in Japan. FAP with TTR Val30Met mutation in Japan can be classified to (i) early-onset and endemic (Nagano and Kumamoto), (ii) late-onset and endemic (Ishikawa), and (iii) late-onset and non-endemic types.     

Genetic polymorphism of <Emphasis Type="Italic">XRCC3</Emphasis> Thr<Superscript>241</Superscript>Met and breast cancer risk: case-control study in Korean women and meta-analysis of 12 studies

To evaluate the relationship of genetic polymorphism in XRCC3 Thr²⁴¹Met and the risk of breast cancer, a hospital-based case-control study was conducted in Korea. Histologically confirmed breast cancer cases (n = 574) and controls (n = 502) with no present or previous history of cancer were recruited from several teaching hospitals in Seoul during 1995–2001. Information on demographic characteristics and other information were collected by interviewed questionnaire. Genetic polymorphisms of XRCC3 Thr²⁴¹Met (C > T) was determined by single base extention assay. The frequency of Thr/Thr, Thr/Met, and Met/Met genotype were 89.4, 10.4, 0.2% in cases and 92.3, 7.7, 0.0% in controls, respectively. Genotype distribution in controls fit well to the Hardy–Weinberg equilibrium (P = 0.74). XRCC3 codon 241 Thr/Met or Met/Met genotype moderately increased the risk of breast cancer (OR = 1.4, 95% CI: 0.87–2.33), but not significant in this study. In the results of meta-analysis using twelve reports, however, Thr/Met or Met/Met genotype increased the risk of breast cancer (OR = 1.08, 95%CI: 1.00–1.17). In conclusion, although the genetic polymorphism of XRCC3 Thr²⁴¹Met was unlikely to have a substantial overall association in Korean women, the meta-analysis of studies, including ours, provided that Thr/Met and Met/Met was weakly increased the risk of breast cancer compare to Thr/Thr genotype.     

A new alpha-synuclein missense variant (Thr72Met) in two Turkish families with Parkinson's disease

IntroductionMissense variants and multiplications of the alpha-synuclein gene (SNCA) are established as rare causes of autosomal dominant forms of Parkinson's Disease (PD).MethodsTwo families of Turkish origins with PD were studied; the SNCA coding region was analyzed by Sanger sequencing, and by whole exome sequencing (WES) in the index patient of the first and the second family, respectively. Co-segregation studies and haplotype analysis across the SNCA locus were carried out. Functional studies included in vitro thioflavin-T aggregation assay and in silico structural modelling of the alpha-synuclein (α-syn) protein.ResultsWe identified a novel heterozygous SNCA variant, c.215C > T (p.Thr72Met), segregating with PD in a total of four members in the two families. A shared haplotype across the SNCA locus was found among variant carriers, suggestive of a common ancestor. We next showed that the Thr72Met α-syn displays enhanced aggregation in-vitro, compared to the wild-type species. In silico analysis of a tetrameric α-syn structural model revealed that Threonine 72 lies in the tetrameric interface, and substitution with the much larger methionine residue could potentially destabilize the tetramer.ConclusionWe present clinical, genetic, and functional data supporting a causative role of the SNCA c.215C > T (p.Thr72Met) variant in familial PD. Testing for this variant in patients with PD, especially of Turkish origin, might detect additional carriers. Further functional analyses might offer new insights into the shared biochemical properties of the PD-causing SNCA missense variants, and how they lead to neurodegeneration.     

Mutaciones y variaciones estructurales en el gen catecol-O-metiltransferasa de los pacientes que exhiben dolor quirúrgico persistente crónico

ObjectivesMutations in the exon 4 of the COMT gene are associated with chronic persistent surgical pain (CPSP). Especially COMT mutated allele G472A (Val158Met) associated with CPSP patients is reported in different ethnic population. The purpose of this study is to evaluate the prevalence of genetic mutations and structural variations in exon 4 of COMT that can be related to the appearance of CPSP in patients under sternotomy.Materials and methodsOne hundred patients with American Society of Anesthesiologists (ASA) physical status grades i, ii and iii, who underwent sternotomy procedures, were selected to assess the development and magnitude of the CPSP evaluated with pain questionaries’ at the end of three months after surgery. This was correlated with COMT allele presence. The exon 4 of COMT gene (that contains the G472A allele) was studied. The polymerase chain reaction (PCR) products were sequenced and mutated sequences were deposited in GenBank®. The structural analysis of COMT was performed using ProCheck® and distortions of three-dimensional tertiary structural orientation was evaluated with root-mean-square deviation (RMSD) score.ResultsGenetic analysis carried out through PCR showed 220 bp amplicons. The 25% of patients with CPSP showed a Numeric Rating Scale (NRS) > 4 pain score. The 20% of these patients have known Val158Met mutation, 5% of patients showed novel mutations c.382C>G, c.383G>C, p.(Arg128Ala). The mutations in COMT gene contributed major structural variations in COMT leading to the formation of inactive COMT that correlates with CPSP.ConclusionThe results of the present study showed that both novel and previously reported mutations in COMT gene has strong association with CPSP.     

Kynurenine pathway is altered in BDNF Val66Met knock-in mice: Effect of physical exercise

The Brain-Derived Neurotrophic Factor (BDNF) Val66Met polymorphism has been correlated with increased predisposition to develop cognitive and psychiatric disorders, and with a reduced response to some therapeutic treatments. However, the mechanisms underlying these impairments are currently not completely understood. Remarkably, kynurenine pathway alterations have also been implicated in cognitive and psychiatric disorders. Moreover, recent evidence suggests that physical exercise may promote beneficial effects by controlling kynurenine metabolism in the muscle.The aim of the present study was to assess whether the kynurenine pathway was differentially regulated in sedentary and exercising wild-type (BDNF^Val/Val) and homozygous knock-in BDNF Val66Met (BDNF^Met/Met) mice. We found that plasma and hippocampal levels of kynurenic acid and the hippocampal mRNA levels of IDO1 and KAT2 protein levels were increased in BDNF^Met/Met mice and were not modulated by physical exercise. On the contrary, KAT1 protein levels in the gastrocnemius muscle were reduced, whereas MCP1 mRNA in the gastrocnemius muscle and GFAP protein in the hippocampus were increased in BDNF^Met/Met mice compared to BDNF^Val/Val mice, and reduced by physical exercise. Physical exercise increased plasmatic kynurenine levels only in BDNF^Met/Met mice, and protein levels of KAT1 and KAT4 in the gastrocnemius muscle and hippocampus respectively, regardless of the genotype. Finally, we found that physical exercise was able to enhance the hippocampal-dependent memory only in the BDNF^Val/Val mice. Overall our results showing an overactivation of the kynurenine pathway in the BDNF^Met/Met mice may suggest a possible mechanism underlying the cognitive deficits reported in the BDNF Val66Met carriers.     

裸鼠高转移性胃癌细胞亚系的筛选及其肝细胞生长因子受体表达

目的 筛选具有较高转移能力的胃癌细胞亚系并从该细胞亚系肝脏重要生长因子受体表达变化这一角度初步探讨肝转移能力与肝脏微环境之间的关系。方法 通过复制裸鼠胃移植瘤模型及对该模型所产生的肝转移灶进行原代培养，获取具有较高转移潜能的胃癌细胞亚系，并应用免疫组化方法对母系与亚系细胞中重要肝细胞生长因子受体(bFGFR，TGFβR，c—Met)表达的情况进行检测。结果 通过两轮筛选，从母系SGC-7901中筛选到高转移潜能胃癌细胞亚系SGC-7901LM2。该亚系中c—Met表达同母系相比有显著增高。结论 高转移胃癌细胞亚系的筛选有利于胃癌肝转移的进一步研究，c—Met表达可能有助于SGC-7901LM2肝转移能力的增强。     

Adaptor protein CRK induces epithelial–mesenchymal transition and metastasis of bladder cancer cells through HGF/c‐Met feedback loop

We have previously reported that an adaptor protein CRK, including CRK‐I and CRK‐II, plays essential roles in the malignant potential of various aggressive human cancers, suggesting the validity of targeting CRK in molecular targeted therapy of a wide range of cancers. Nevertheless, the role of CRK in human bladder cancer with marked invasion, characterized by distant metastasis and poor prognosis, remains obscure. In the present study, immunohistochemistry indicated a striking enhancement of CRK‐I/‐II, but not CRK‐like, in human bladder cancer tissues compared to normal urothelium. We established CRK‐knockdown bladder cancer cells using 5637 and UM‐UC‐3, which showed a significant decline in cell migration, invasion, and proliferation. It is noteworthy that an elimination of CRK conferred suppressed phosphorylation of c‐Met and the downstream scaffold protein Gab1 in a hepatocyte growth factor‐dependent and ‐independent manner. In epithelial–mesenchymal transition‐related molecules, E‐cadherin was upregulated by CRK elimination, whereas N‐cadherin, vimentin, and Zeb1 were downregulated. A similar effect was observed following treatment with c‐Met inhibitor SU11274. Depletion of CRK significantly decreased cell proliferation of 5637 and UM‐UC‐3, consistent with reduced activity of ERK. An orthotopic xenograft model with bioluminescent imaging revealed that CRK knockdown significantly attenuated not only tumor volume but also the number of circulating tumor cells, resulted in a complete abrogation of metastasis. Taken together, this evidence uncovered essential roles of CRK in invasive bladder cancer through the hepatocyte growth factor/c‐Met/CRK feedback loop for epithelial–mesenchymal transition induction. Thus, CRK might be a potent molecular target in bladder cancer, particularly for preventing metastasis, leading to the resolution of clinically longstanding critical issues.