Background
NRXN1 deletions are identified as one of major rare risk factors for autism spectrum disorder (ASD) and other neurodevelopmental disorders. ASD has 30% co-morbidity with epilepsy, and the latter is associated with excessive neuronal firing. NRXN1 encodes hundreds of presynaptic neuro-adhesion proteins categorized as NRXN1α/β/γ. Previous studies on cultured cells show that the short NRXN1β primarily exerts excitation effect, whereas the long NRXN1α which is more commonly deleted in patients involves in both excitation and inhibition. However, patient-derived models are essential for understanding functional consequences of NRXN1α deletions in human neurons. We recently derived induced pluripotent stem cells (iPSCs) from five controls and three ASD patients carrying NRXN1α+/- and showed increased calcium transients in patient neurons.
Methods
In this study we investigated the electrophysiological properties of iPSC-derived cortical neurons in control and ASD patients carrying NRXN1α+/- using patch clamping. Whole genome RNA sequencing was carried out to further understand the potential underlying molecular mechanism.
Results
NRXN1α+/- cortical neurons were shown to display larger sodium currents, higher AP amplitude and accelerated depolarization time. RNASeq analyses revealed transcriptomic changes with significant upregulation glutamatergic synapse and ion channels/transporter activity including voltage-gated potassium channels (GRIN1, GRIN3B, SLC17A6, CACNG3, CACNA1A, SHANK1), which are likely to couple with the increased excitability in NRXN1α+/- cortical neurons.
Conclusions
Together with recent evidence of increased calcium transients, our results showed that human NRXN1α+/- isoform deletions altered neuronal excitability and non-synaptic function, and NRXN1α+/- patient iPSCs may be used as an ASD model for therapeutic development with calcium transients and excitability as readouts.
IntroductionApproximately 5%–20% of reproductive women suffer from polycystic ovary syndrome (PCOS). Auricular points acupressure (AA) may serve as alternative management for PCOS for its benefits in both physical and psychological well-being. However, the effects of AA for insulin resistance (IR) in overweight/obese PCOS women have not been confirmed.Methods and analysisThe present study is designed as a randomised, placebo-controlled pilot trial to evaluate the effectiveness and safety of AA in treating IR in women with PCOS. A total of 60 eligible PCOS subjects will be randomised into an intervention group (AA group) and a control group (sham AA group) in a ratio of 1:1. Magnetic beads will be taped to the auricular points by the same senior acupuncture specialist from the First Affiliated Hospital, Heilongjiang University of Chinese Medicine. The treatment will last for 12 weeks. Primary outcome measure will be changes in homeostasis model assessment of IR between baseline and after 3 months of AA/sham AA treatment. Secondary outcomes include hormonal profile, weight, waist/hip circumference, body mass index, blood pressure, Ferriman-Gallwey score, acne and the assessment of health-related quality of life. Outcome measures are collected at baseline and the end of treatment visit.Ethics and disseminationThe protocol has been approved by the ethics committee of the First Affiliated Hospital of Heilongjiang University of Chinese Medicine (HZYLLKY201800301). Written informed consent will be obtained from all participants. The results will be disseminated through peer-reviewed journals for publications.Trial registration numberNCT03546595; Pre-results.
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