ObjectiveTo lay a theoretical foundation for the research of regulation of Hyperpolarization activated cyclic nucleotide gated channel 1 (HCN1) gene expression and its involvement in the pathogenesis of Mesio-temporal lobe epilepsy (MTLE) and other related diseases, the bioinformatics methods were used to analyze sequence characteristic, transcription factors and their binding sites in the promoter region of human HCN1 gene, and the physicochemical properties, signal peptides, hydrophobicity, transmembrane regions, protein structure, interacting proteins and functions of HCN1 proteins.MethodBiological software and website, such as Protparam, Protscale, MHMM, SignalP 5.0, NetPhos 3.1, Swiss-Model, Promoter 2.0, AliBaba2.1 and EMBOSS were used to analyze and predict physicochemical properties, structural functions, localized expression, phylogenetic relationships and protein interactions with human HCN1 protein, and promoter, CpG island and transcription factor characteristics of HCN1 gene.ResultsThe evolutionary analysis of HCN1 protein showed that the genetic distance between human and Pongo abelii was the smallest, indicating the closest genetic relationship between human and Pongo abelii. Human HCN1 protein was an unstable hydrophilic protein located on the plasma membrane, which contained two transmembrane structure. However, the predicted results showed that there was no signal peptide and nuclear localization sequence in this protein. The secondary structure of HCN1 protein was mostly random coil and alpha helix, and it contained multiple potential phosphorylation sites. The ontology analysis results of HCN1 protein were showed as follows. The cellular component of HCN1 protein was located in the plasma membrane (GO:0005886); the molecular functionof HCN1 protein were cyclic adenosine monophosphate binding (GO:0030552) and voltage-gated ion channel activity (GO:0005244); the biological process of this protein were reacting to cAMP (GO:0071320) and transmembrane transport of potassium (GO:0071805). The analysis results of String database showed that the proteins that had close interaction with human HCN1 protein mainly included the ten proteins (HCN2, HCN4, PEX5L, MARCH7, KCTD3, GNAT3, SHKBP1, KCNQ2, FLNA and NEDD4L). These proteins were mainly involved in regulation of ion transport and transmembrane transport of potassium (GO:0071805). The HCN1 gene was located at 5p12 and contained 8 exons and 7 introns.There were at least three promoter regions in the nucleotide sequence of 2 000 bp from the upstream of the HCN1 gene to the 5 'flanks, and contained a 158 bp CpG island in the promoter region and one TATA boxes and one CAAT boxes in the 5' regulation region ofHCN1 gene; niceteen transcription factors, including NF-κB, NF-1, AP-1, TBP, IRF-1, c-Ets-1, Elf-1, HNF-3, HNF-1, YY1, GATA-1, RXR-α, GR, AP-2αA, ENKTF-1, C/EBPβ, C/EBPα, c-Fos and c-Jun, binding in the promoter region of the HCN1 gene were predicted by both softwares (AliBaba2.1 and PROMO2).ConclusionThe analysis results provide important information for further studies on the role of HCN1. Bioinformatics analysis of the promoter region can improve the research efficiency of gene promoters, and provide theoretical basis for subsequent experiments to construct expression vectors of HCN1 gene promoters and identify their functions.
ObjectiveTo investigate the effect of valproic acid (VPA) coadministred with lamotrigine (LTG) on epileptic patients' ammonia and evaluate the influencing factors of elevated blood ammonia in epileptic patients.MethodsA retrospective analysis of clinical data from 146 patients with epilepsy (including newly diagnosed epilepsy patients) who were admitted to the Seventh Affiliated Hospital of Sun Yat-Sen University from May 2018 to April 2020 was performed. The patients were divided into no antiepileptic drug group (group A), VPA group only (group B) and VPA combined LTG group (group C), and the concentration of the blood ammonia of the patients were analyzed.ResultThe average ammonia levels in groups A, B and C were (18.14±1.19), (25.89±0.87) and (36.60±4.34) μmol/L, and the incidence of blood ammonia higher than normal were 2.77%, 8.89% and 20.0%, respectively.The difference between group B and group A and group C were statistically significant (P<0.05), the difference between group C and group A was statistically significant (P<0.05).ConclusionPatients with epilepsy who use VPA were at increased risk of blood ammonia and LTG can increase ammonia in epileptic patients who were treated with VPA. So when VPA was combined with LTG, more attention should be paid to ammonia of patient to avoid adverse reactions.