A novel epigenetic marker, Ten-eleven translocation family member 2 (TET2), is identified in the intractable epileptic brain and regulates ATP binding cassette subfamily B member 1 (ABCB1) in the blood-brain barrier

Drug-resistant epilepsy (DRE) is a chronic condition derived from spontaneous changes and regulatory effects in the epileptic brain. As demethylation factors, ten-eleven translocation (TET) family members have become a focus in recent studies of neurological disorders. Here, we quantified and localized TET1, TET2 and 5-hydroxymethylcytosine (5-hmC) in the temporal lobe cortex of DRE patients (n = 27) and traumatic brain hemorrhage controls (n = 10) by immunochemical staining. TET2 and ATP binding cassette subfamily B member 1 (ABCB1) expression patterns were determined in the isolated brain capillaries of DRE patients. TET2 expression was significantly increased in the temporal cortical tissue of DRE patients with or without hippocampal sclerosis (HS) compared to control patients, while TET1 and 5-hmC showed no differences in expression. We also found that a particularly strong expression of TET2 in the vascular tissue of DRE patients. ABCB1 and TET2 have evidently higher expression in the vascular endothelium from the neocortex of DRE patients. In blood–brain barrier (BBB) model, TET2 depletion can cause attenuated expression and function of ABCB1. Data from a cohort study and experiments in a BBB model suggest that TET2 has a specific regulatory effect on ABCB1, which may serve as a potential mechanism and target in DRE.

Association of xenobiotic receptor polymorphisms with carbamazepine response in epilepsy patients

PURPOSE

Drug-resistant epilepsy is a problem worldwide. Xenobiotic receptors may play a significant role in the establishment of resistance to antiepileptic agents. Previous studies have confirmed that the metabolism and efficacy of carbamazepine (CBZ) can be influenced by xenobiotic receptors, especially pregnane X receptor (PXR), constitutive androstane receptor (CAR), and aryl hydrocarbon receptor (AHR). Therefore, this study intends to elucidate the pharmacogenomic associations of polymorphisms of these xenobiotic receptors with the CBZ response in epilepsy patients, and these genetic data may be useful for the treatment of clinical prophylaxis and individualized treatment of intractable epilepsy.

METHODS

Adult patients with epilepsy who were on CBZ-based monotherapy and combination therapy (n = 257) were genotyped, and the patients were divided into drug-responsive and drug-resistant groups according to the International League Against Epilepsy criteria. We sought to tag single-nucleotide polymorphisms (SNPs) of PXR, CAR and AHR that principally represent alleles associated with drug resistance risk; in addition, a gene interaction analysis reference panel was constructed for SNP-based imputation.

RESULTS

No significant effects of PXR or AHR polymorphisms were observed. However, an interaction between the CAR rs2502815 variant and CBZ response was observed: in CBZ-based monotherapy and combination therapy patients, the GG genotype of the CAR rs2502815 variant (vs. wild-type homozygous) was independently associated with CBZ response after adjusting for variables [odds ratio (OR) = 0.389, 95% confidence interval (CI) 0.203-0.743, p = 0.004]. The results of the haplotype and gene interaction case-control analyses of the CBZ response were negative. Our results provide clinical data regarding the genetic possibilities of drug responses related to CAR variation in epilepsy patients.

CONCLUSION

This study is the first to indicate a potentially relevant interaction between the CAR rs2502815 polymorphism and the CBZ response in epilepsy patients.

Urinary incontinence following deep brain stimulation of the globus pallidus internus: case report

Deep brain stimulation (DBS) is a well-established therapy for patients with advanced Parkinson's disease (PD), dystonia, and other movement disorders. In contrast to the strong positive effects that have been documented for motor symptoms, the effects of DBS on nonmotor symptoms have not been fully elucidated. Some reports suggest that stimulation of the subthalamic nucleus may improve lower urinary tract symptoms in patients with PD; however, reports of the effects of globus pallidus internus (GPi) DBS on urinary symptoms are limited. The authors present the case of a 49-year-old woman with PD who developed severe urinary incontinence after 27 months of GPi DBS. The urinary incontinence disappeared when stimulation was turned off, and reemerged after it was turned on again. After activation of a more dorsal contact in the left electrode, the patient's urinary dynamics returned to normal.

History of Chinese stereotactic and functional neurosurgery

Chinese stereotactic and functional neurosurgery started in 1963. Dr. Jian-Ping Xu did stereotactic surgery for Parkinson's disease with a small Cartesian coordinate stereotactic device which he designed. In 1983, the first Chinese Institute of Stereotactic and Functional Neurosurgery was established by Dr. Jian-Ping Xu and Dr. Ye-Han Wang in the Anhui Provincial Hospital in the city of Hefei. Since then, the Institute has hosted an annual National Workshop on Stereotactic and Functional Neurosurgery, where more than 80% of the functional neurosurgeons now practicing in China have been trained. In 1986, the Chinese Society of Stereotactic and Functional Neurosurgery was established, and the first issue of the Chinese Journal of Stereotactic and Functional Neurosurgery was published. With more than 35 years of development, stereotactic and functional neurosurgery has become a very important branch of surgery in China. More than 5,000 functional neurosurgery procedures and more than 8,000 stereotactic radiosurgery procedures are now performed annually.