Genetic variations in GABA metabolism and epilepsy.

Epilepsy is a paroxysmal brain disorder that results from an imbalance between neuronal excitation and inhibition. Gamma-aminobutyric acid (GABA) is the most important inhibitory neurotransmitter in the brain and plays an important role in the occurrence and development of epilepsy. Abnormalities in all aspects of GABA metabolism, including GABA synthesis, transport, genes encoding GABA receptors, and GABA inactivation, may lead to epilepsy. GABRA1, GABRA2, GABRA5, GABRB1, GABRB2, GABRB3, GABRG2 and GABBR2 are genes that encode GABA receptors and are commonly associated with epilepsy. Mutations of these genes lead to a variety of epilepsy syndromes with different clinical phenotypes, primarily by down regulating receptor expression and reducing the amplitude of GABA-evoked potentials. GABA is metabolized by GABA transaminase and succinate semi aldehyde dehydrogenase, which are encoded by the ABAT and ALDH5A1 genes, respectively. Mutations of these genes result in symptoms related to deficiency of GABA transaminase and succinate semi aldehyde dehydrogenase, such as epilepsy and cognitive impairment. Most of the variation in genes associated with GABA metabolism are accompanied by developmental disorders. This review focuses on advances in understanding the relationship between genetic variation in GABA metabolism and epilepsy to establish a basis for the accurate diagnosis and treatment of epilepsy.

Molecular typing of familial temporal lobe epilepsy.

The pathogenesis of temporal lobe epilepsy (TLE) was originally considered to be acquired. However, some reports showed that TLE was clustered in some families, indicating a genetic etiology. With the popularity of genetic testing technology, eleven different types of familial TLE (FTLE), including ETL1-ETL11, have been reported, of which ETL9-ETL11 had not yet been included in the OMIM database. These types of FTLE were caused by different genes/Loci and had distinct characteristics. ETL1, ETL7 and ETL10 were characterized by auditory, visual and aphasia seizures, leading to the diagnosis of familial lateral TLE. ETL2, ETL3 and ETL6 showed prominent autonomic symptom and automatism with or without hippocampal abnormalities, indicating a mesial temporal origin. Febrile seizures were common in FTLEs such as ETL2, ETL5, ETL6 and ETL11. ETL4 was diagnosed as occipitotemporal lobe epilepsy with a high incidence of migraine and visual aura. Considering the diversity and complexity of the symptoms of TLE, neurologists enquiring about the family history of epilepsy should ask whether the relatives of the proband had experienced unnoticeable seizures and whether there is a family history of other neurological diseases carefully. Most FTLE patients had a good prognosis with or without anti-seizure medication treatment, with the exception of patients with heterozygous mutations of the CPA6 gene. The pathogenic mechanism was diverse among these genes and spans disturbances of neuron development, differentiation and synaptic signaling. In this article, we describe the research progress on eleven different types of FTLE. The precise molecular typing of FTLE would facilitate the diagnosis and treatment of FTLE and genetic counseling for this disorder.

[New variants in FLNA gene cause periventricular nodular heterotopia and epileptic seizure in three cases].

OBJECTIVE: To explore the genetic bases of 3 patients with periventricular nodular heterotopia and epileptic seizure. METHODS: The clinical data of three patients presenting with periventricular nodular ectopic with epileptic seizure were analyzed. Whole exome sequencing (WES) was performed on the patients, and Sanger sequencing was used to validate the suspected variants. RESULTS: In three female patients, head MRI showed nodular gray matter ectopic in the bilateral ventricle. WES identified the heterozygous c.2720del T(p.Leu907Argfs*39) variant of FLNA gene in case 1 and her mother (case 2), and heterozygous c.1387_1390del GTGC(p.Val463Profs*34) of FLNA gene in case 3. According to the American College of Medical Genetics and Genomics standards and guidelines, the c.2720delT(p.Leu907Argfs*39) and c.1387_1390del GTGC (p.Val463Profs*34) variants of FLNA gene were predicted to be pathogenic (PVS1+PM2+PP1) and likely pathogenic(PVS1+PM2), respectively. CONCLUSION: The c.2720delT(p.Leu907Argfs*39) and c.1387_1390del GTGC(p.Val463Profs*34) variants of FLNA gene may be the genetic cause of the three patients.

The prognosis of epilepsy patients with CACNA1H missense variants: A longitudinal cohort study.

OBJECTIVE: CACNA1H is regarded as a gene conferring susceptibility to generalised epilepsy. However, the prognosis of epilepsy patients carrying the CACNA1H missense variants of uncertain significance (VUS) is unknown. A prospective cohort was generated to determine the deleterious effects of these variants and to check whether the presence of these variants affects the prognosis of epilepsy patients. METHOD: This study was conducted at Xijing Hospital in Xian, China. All patients were followed up for at least 1 year. Previous reports were searched for previously reported variants. Ensembl database was searched for variants in the general population. Combined Annotation Dependent Depletion (CADD) was used to evaluate the deleterious effect of variants. Logistic regression and Cox regression were used for data analysis. RESULTS: The study included 176 epilepsy patients with or without CACNA1H variants. In epilepsy patients with missense variants, we found 35 different variants, including 33 variants with uncertain significance and 2 likely benign variants. No significant difference was observed between the distribution of CADD scores of the variants from this cohort, of the general population, and of those found in previous reports. Among epilepsy patients with missense variants, the number of antiepileptic drugs (AEDs) administered to the patients, a first-degree family history of epilepsy, and possibly the presence of abnormalities in brain radiology findings were correlated with the poorer prognosis. Among the entire cohort, the type of epilepsy, number of AEDs administered, and presence of abnormalities in brain radiology findings were associated with the prognosis of these patients. The deleterious effect of CACNA1H missense variants or their presence was not related to the prognosis of epilepsy patients. CONCLUSION: The results of our study suggest that CACNA1H variants are related to multiple epilepsy syndromes. However, there is no strong evidence of the correlation between CACNA1H missense variants and a certain type of epilepsy. In our study cohort, both the deleterious effects and the presence of CACNA1H variants were found to be unrelated to the prognosis of patients with epilepsy. These findings suggest that CACNA1H missense variants that are classified as VUS might not influence the outcome of epilepsy.

Exploration on the Interaction Ability of Antitumor Compound Bis-[2,6-difluoro-N-(hydroxyl-<κ>O)benzamidato-<κ>O]dibutylitin(IV) with Human Peroxisome Proliferator-Activated Receptor hPPARγ.

Diorganotin(IV) antitumor compound bis-[2,6-difluoro-N-(hydroxyl-<κ>O)benzamidato-<κ>O] (DBDF2,6T) was one of the novel patent organotin compounds with high antitumor activity and relatively low toxicity. In this study, several methods were used to study the interaction between DBDF2,6T and hPPARγ protein, including fluorescence quenching, three-dimensional (3D) fluorescence, drug affinity responsive target stability (DARTS), ultrafiltration-LC, and molecular docking. According to the experimental results, the quenching process of the hPPARγ protein was induced by static quenching mode to form a nonradiative ground-state complex with DBDF2,6T spontaneously, mainly through the hydrophobic force. DBDF2,6T could bind to the hPPARγ protein directly and give the protein the ability of antienzymatic hydrolysis. And the binding mode of DBDF2,6T into hPPARγ protein appeared to have an orientation towards residues of SER342 and GLY284. In conclusion, these methods could comprehensively reveal the interaction details of DBDF2,6T and the hPPARγ protein and established a feasible way to preliminarily identify the agonist compounds for the hPPARγ protein.

Effect of Dibutyltin Dilaurate on Triglyceride Metabolism through the Inhibition of the mTOR Pathway in Human HL7702 Liver Cells.

Dibutyltin dilaurate (DBTD) has multiple applications in daily life. However, DBTD is easily deposited in the liver and affects liver functions. This study was designed to explore the effects of DBTD on triglyceride metabolism in human normal hepatocyte HL7702 cells. Our results showed that the intracellular fat contents were dose-dependently decreased by DBTD. The expression of lipolysis genes and proteins were elevated while the lipogenesis genes and proteins were diminished by DBTD. The phosphorylation levels of ribosomal S6 kinase 1 were reduced by both rapamycin and DBTD, indicating that the mTOR pathway was suppressed possibly. The decreased sterol regulatory element-binding protein 1C (SREBP1C) transcription levels, as well as the increased peroxisome proliferator-activated receptor alpha (PPARα) transcription levels, caused by rapamycin and DBTD corresponded to the inactive mTOR pathway. In conclusion, it was possible that DBTD reduced the intracellular triglyceride through depressing the mTOR pathway and affecting its downstream transcription factors.

Resistin does not down-regulate the transcription of insulin receptor promoter.

OBJECTIVE: To detect the effect of resistin on the transcription of insulin receptor promoter. METHODS: Luciferase reporter gene was fused downstream of human insulin receptor promoter and the enzymatic activity of luciferase was determined in the presence or absence of resistin. The resistin expressed with plasmid was stained with antibody against Myc tag which was in frame fused with resistin coding sequence, and then imaged with confocal microscopy. RESULTS: The treatment of pIRP-LUC transfected cells with recombinant resistin did not result in significant difference in the enzymatic activity of luciferase compared to the untreated cells. Cell staining showed that green fluorescence could be observed in the cytoplasm, but not in the nucleus. CONCLUSION: The results suggest that the endogenous resistin may functionally locate in the cytoplasm, but does not enter the nucleus and not down-regulate the transcription of insulin receptor promoter.

[Assembly of full-length human resistin gene in vitro and construction of its eukaryotic expression vector].

OBJECTIVE: To assemble the full-length of human resistin gene in vitro by using oligonucleotides and to construct its eukaryotic expression vector. METHODS: According to the gene sequence of resistin (GenBank: AF323081), 10 oligonucleotides were designed and synthesized, followed by a touch down PCR to assemble the full-length gene. The PCR products were cloned into pSecTag2B vector and confirmed by sequencing. RESULTS: The band of PCR products and gene sequencing showed the insert fragment in pSecTag2B vector was identical to that as designed. CONCLUSION: The full-length of human resistin coding sequence was successfully assembled and amplified by touch down PCR, and a resistin-expressing eukaryotic vector was constructed.

Relationship between resistin level in serum and acute coronary syndrome or stable angina pectoris.

OBJECTIVE: To investigate the relationship between serum resistin level and acute coronary syndrome (ACS) or stable angina pectoris (SAP). METHODS: Sixty-five patients, with coronary artery disease, were enrolled and divided into three subgroups: acute myocardial infarction (AMI), unstable angina pectoris (UAP) and SAP, and 26 healthy people were recruited as controls in the cross-sectional study. Serum resistin levels were determined by ELISA (enzyme-linked immunosorbent assay), and WBC (white blood cell count), hsCRP (high sensitive C-reaction protein), CK(max) (maximum of creatinkinase), CK-MB(max) (maximum of isozyme of creatinkinase) and cTnI(max) (maximum of troponin) were measured by standard laboratory methods. RESULTS: The serum resistin levels were 4 folds higher in AMI patients, 2.43 folds in UAP patients and 1.12 folds in SAP patients than in the healthy controls (P<0.05). The resistin levels were also significantly different between AMI [(8.16+/-0.79) ng/ml], UAP [(5.59+/-0.75) ng/ml] and SAP [(3.45+/-0.56) ng/ml] groups (P<0.01); WBC, hsCRP, CK(max), CK-MB(max) and cTnI(max) were significantly increased in AMI patients over UAP and SAP patients. Spearman analysis showed that serum resistin levels were positively correlated with WBC (r=0.412, P=0.046), hsCRP (r=0.427, P=0.037), CK(max), CK-MB(max) and cTnI(max) (r=0.731, 0.678, 0.656; P<0.01). CONCLUSION: Serum resistin levels increased with inflammatory factors and myocardial impairment. The results suggest that human resistin might play an important role in the pathogenesis of atherosclerosis and AMI as an inflammatory factor.