HeLa E-Box Binding Protein, HEB, Inhibits Promoter Activity of the Lysophosphatidic Acid Receptor Gene Lpar1 in Neocortical Neuroblast Cells.

Lysophosphatidic acid (LPA) is an endogenous lysophospholipid with signaling properties outside of the cell and it signals through specific G protein-coupled receptors, known as LPA1-6. For one of its receptors, LPA1 (gene name Lpar1), details on the cis-acting elements for transcriptional control have not been defined. Using 5'RACE analysis, we report the identification of an alternative transcription start site of mouse Lpar1 and characterize approximately 3,500 bp of non-coding flanking sequence 5' of mouse Lpar1 gene for promoter activity. Transient transfection of cells derived from mouse neocortical neuroblasts with constructs from the 5' regions of mouse Lpar1 gene revealed the region between -248 to +225 serving as the basal promoter for Lpar1. This region also lacks a TATA box. For the region between -761 to -248, a negative regulatory element affected the basal expression of Lpar1. This region has three E-box sequences and mutagenesis of these E-boxes, followed by transient expression, demonstrated that two of the E-boxes act as negative modulators of Lpar1. One of these E-box sequences bound the HeLa E-box binding protein (HEB), and modulation of HEB levels in the transfected cells regulated the transcription of the reporter gene. Based on our data, we propose that HEB may be required for a proper regulation of Lpar1 expression in the embryonic neocortical neuroblast cells and to affect its function in both normal brain development and disease settings.

Sleep-Dependent Directional Coupling of Cardiorespiratory System in Patients With Obstructive Sleep Apnea.

OBJECTIVE: Cardiorespiratory interactions have been widely investigated in different physiological states and conditions. Various types of coupling characteristics have been observed in the cardiorespiratory system; however, it is difficult to identify and quantify details of their interaction. In this study, we investigate directional coupling of the cardiorespiratory system in different physiological states (sleep stages) and conditions, i.e., severity of obstructive sleep apnea (OSA). METHODS: Directionality analysis is performed using the evolution map approach with heartbeats acquired from electrocardiogram and abdominal respiratory effort measured from the polysomnographic data of 39 healthy individuals and 24 mild, 21 moderate, and 23 severe patients with OSA. The mean phase coherence is used to confirm the weak and strong coupling of cardiorespiratory system. RESULTS: We find that unidirectional coupling from the respiratory to the cardiac system increases during wakefulness (average value of -0.61) and rapid eye movement sleep (-0.55). Furthermore, unidirectional coupling between the two systems significantly decreases during light (-0.52) and deep sleep, which is further decreased in deep sleep (-0.46), approaching bidirectional coupling. In addition, unidirectional coupling from the respiratory to the cardiac system also significantly increases according to the severity of OSA. CONCLUSION: These coupling characteristics in different states and conditions are believed to be linked with autonomic nervous modulation. SIGNIFICANCE: Our approach could provide an opportunity to understand how integrated systems cooperate for physiological functions under internal and external environmental changes, and how abnormality in one physiological system could develop to increase the risk of other systemic dysfunctions and/or disorders.

Real-time apnea-hypopnea event detection during sleep by convolutional neural networks.

Sleep apnea-hypopnea event detection has been widely studied using various biosignals and algorithms. However, most minute-by-minute analysis techniques have difficulty detecting accurate event start/end positions. Furthermore, they require hand-engineered feature extraction and selection processes. In this paper, we propose a new approach for real-time apnea-hypopnea event detection using convolutional neural networks and a single-channel nasal pressure signal. From 179 polysomnographic recordings, 50 were used for training, 25 for validation, and 104 for testing. Nasal pressure signals were adaptively normalized, and then segmented by sliding a 10-s window at 1-s intervals. The convolutional neural networks were trained with the data, which consisted of class-balanced segments, and were then tested to evaluate their event detection performance. According to a segment-by-segment analysis, the proposed method exhibited performance results with a Cohen's kappa coefficient of 0.82, a sensitivity of 81.1%, a specificity of 98.5%, and an accuracy of 96.6%. In addition, the Pearson's correlation coefficient between estimated apnea-hypopnea index (AHI) and reference AHI was 0.99, and the average accuracy of sleep apnea and hypopnea syndrome (SAHS) diagnosis was 94.9% for AHI cutoff values of ≥5, 15, and 30 events/h. Our approach could potentially be used as a supportive method to reduce event detection time in sleep laboratories. In addition, it can be applied to screen SAHS severity before polysomnography.

Antiproliferative and cytotoxic effects of resveratrol in mitochondria-mediated apoptosis in rat b103 neuroblastoma cells.

Resveratrol, a natural compound, has been shown to possess anti-cancer, anti-aging, anti-inflammatory, anti-microbial, and neuroprotective activities. In this study, we examined the antiproliferative and cytotoxicity properties of resveratrol in Rat B103 neuroblastoma cells; although it's molecular mechanisms for the biological effects are not fully defined. Here, we examined the cellular cytotoxicity of resveratrol by cell viability assay, antiproliferation by BrdU assay, DNA fragmentation by DNA ladder assay, activation of caspases and Bcl-2 family proteins were detected by western blot analyses. The results of our investigation suggest that resveratrol increased cellular cytotoxicity of Rat B103 neuroblastoma cells in a dose-and time-dependent manner with IC(50) of 17.86 µM at 48 h. On the other hand, incubation of neuroblastoma cells with resveratrol resulted in S-phase cell cycle arrests which dose-dependently and significantly reduced BrdU positive cells through the downregulation of cyclin D1 protein. In addition, resveratrol dose-dependently and significantly downregulated the expression of anti-apoptotic protein includes Bcl-2, Bcl-xL and Mcl-1 and also activates cleavage caspase-9 and-3 via the downregulation of procaspase-9 and -3 in a dose-dependent manner which indicates that involvement of intrinsic mitochondria-mediated apoptotic pathway. In conclusion, resveratrol increases cellular cytotoxicity and inhibits the proliferation of B103 neuroblastoma cells by inducing mitochondria-mediated intrinsic caspase dependent pathway which suggests this natural compound could be used as therapeutic purposes for neuroblastoma malignancies.