Association Of STX1B And BCL11A Gene Single Nucleotide Polymorphisms With The Risk And Drug Resistance Of Epilepsy

BackgroundThe STX1B gene is located on chromosome 16,and its encoded STX1B protein is the core component of the release mechanism of presynaptic vesicles.The BCL11A gene is located on chromosome 2,and its encoded zinc finger protein is highly expressed in hematopoietic tissues and the brain.Abnormal expression of BCL11A gene can lead to synaptic dysplasia.Studies abroad have reported that some epilepsy patients have STX1B and BCL11A gene mutations,but the association between these two gene mutations and epilepsy diagnosis and treatment is unclear,and there is a lack of suffficient evidence that STX1B and BCL11A gene single nucleotide polymorphisms are associated with the risk of epilepsy and the efficacy of antiepileptic drug treatment.ObjectivesTo explore the association of STX1B and BCL11A single nucleotide polymorphisms with the risk of epilepsy and the efficacy of antiepileptic drug treatment in Han Chinese from Southwest China and the possible mechanism.MethodsIn this study,after obtaining the approval of the ethics committee and the informed consent of the patients,we collected peripheral venous blood samples of Han epilepsy patients who were treated and diagnosed and gender-age-matched healthy controls in the First Affiliated Hospital of Kunming Medical University and Chenggong Branch of the First Affiliated Hospital of Kunming Medical University from February 2019 to December 2020,and temporal lobe tissue samples from the Neurosurgery Department of the First Affiliated Hospital of Kunming Medical University and the Neurosurgery Brain Bank of the Xinqiao Hospital of Army Military Medical University from drug-resistant epilepsy patients and gender-age matched temporal lobe tissue samples from traumatic brain injury without a history of epilepsy.We first used the 1000 Genomes Project database to screen out the SNPs data of the STX1B gene and BCL11A gene in the Han population in southern China,and then used the Haploview software to screen out the tagSNPs of the two genes with r2>0.8 and the minor allele frequency greater than 0.05,and then use the universal fluorescent probe method to genotype the STX1B and BCL11A gene tagSNPs in all blood samples and brain tissues of patients with drug-resistant epilepsy,and qPCR was used to detect the mRNA expression levels of STX1B and BCL11A genes in the temporal lobe brain tissue of patients with drug-resistant epilepsy and the control group.The expression quantitative trait loci(EQTL)were analyzed using STX1B and BCL11A tagSNPs genotyping data,STX1B and BCL11A expression data in brain tissues of 16 patients with drug-resistant epilepsy,and data from GTEX and BrainCloud;Brain tissue data provided by Kang et al were used for gene co-expression analysis,Cytoscape database for protein-protein interaction analysis,Metascape database for enrichment analysis.Finally,gene interaction analysis was carried out to explore the association of STX1B and BCL11A interaction with the risk of epilepsy and the efficacy of antiepileptic drug treatment.ResultsA total of 984 blood samples(434 patients with epilepsy and 550 healthy controls)and 25 temporal lobe tissues(16 patients with drug-resistant epilepsy and 9 patients with brain trauma without epilepsy)were included.The expression level of STX1B in the temporal lobe brain tissue of patients with drug-resistant epilepsy was significantly lower than that in the temporal lobe brain tissue of control group,and the difference was statistically significant(P=0.016).After Bonferroni correction,the distribution of alleles of STX1Brs140820592 was statistically different between the epilepsy group and the normal control group(P=0.002).After adjusting the age and gender and Bonferroni correction,we found that rs140820592 reduced the risks of epilepsy,GTCS and antiepileptic drug resistance in Han Chinese from Southwest China(OR=0.542,95%CI=0.358-0.819,P=0.004;OR=0.394,95%CI=0.209-0.742,P=0.004;OR=0.260,95%CI=0.103-0.653,P=0.004).EQTL analysis showed that rs140820592 regulates the expression level of STX1B in human brain tissue(P=0.012;P=0.000023214).Gene co-expression analysis showed that the function of STX1B is correlated with the function of target genes of approved antiepileptic drugs in human brain tissue.Protein-protein interaction analysis revealed that the STX1B gene-encoded protein has a direct interaction with multiple approved antiepileptic drug targets.Enrichment analysis showed that STX1B influences epilepsy risk through multiple biological pathways;The BCL11A expression level in the temporal lobe brain tissue of patients with drug-resistant epilepsy was significantly lower than that in the temporal lobe brain tissue of control group,and the difference was statistically significant(P=0.022).After Bonferroni correction,the distribution of the rs2556375 allele of the BCL11A gene was statistically different between the drug-resistant epilepsy group and the drug-responsive epilepsy group(P=0.000).After adjusting the gender and age and Bonferroni correction,we found that rs2556375 increased the risks of epilepsy and GTCS and antiepileptic drug resistance in Han Chinese from Southwest China(OR=2.774,95%CI=1.420-5.417,P=0.003,OR=2.984,95%CI=1.401-6.356,P=0.005,OR=2.700,95%CI=1.366-5.338,P=0.004;OR=5.970,95%CI=1.751-20.348,P=0.004,OR=6.977,95%CI=1.922-25.327,P=0.003;OR=21.336,95%CI=2.489-183.402,P=0.005).EQTL analysis showed that rs2556375 regulates the expression level of BCL11A in human brain tissue(P=0.0096;P=0.033).Gene co-expression analysis showed that the function of BCL11A in human brain tissue is correlated with the function of target genes of approved antiepileptic drugs.Protein-protein interaction analysis revealed that the BCL11A gene-encoded protein has a direct interaction with multiple approved antiepileptic drug targets.Enrichment analysis found that BCL11A influences epilepsy risk through multiple biological pathways;Gene-gene interaction analysis showed that STX1B and BCL11A have no obvious interaction in the risk of epilepsy and GTCS and the resistance of antiepileptic drugs.ConclusionsSTX1B and BCL11A may be new targets for the diagnosis and treatment of epilepsy in Han Chinese from Southwest China.In the brain tissue of patients with epilepsy,rs 140820592 may reduce the risks of epilepsy,GTCS and antiepileptic drug resistance by upregulating the expression level of STX1B in Han Chinese from Southwest China;rs2556375 may increase the risks of epilepsy,GTCS and antiepileptic drug resistance by downregulating the expression level of BCL11A in Han Chinese from Southwest China;STX1B and BCL11A have no obvious interaction in the risks of epilepsy and GTCS and antiepileptic drug resistance.