Recordings from neuron–HEK cell cocultures reveal the determinants of miniature excitatory postsynaptic currents

Spontaneous exocytosis of single synaptic vesicles generates miniature synaptic currents, which provide a window into the dynamic control of synaptic transmission. To resolve the impact of different factors on the dynamics and variability of synaptic transmission, we recorded miniature excitatory postsynaptic currents (mEPSCs) from cocultures of mouse hippocampal neurons with HEK cells expressing the postsynaptic proteins GluA2, neuroligin 1, PSD-95, and stargazin. Synapses between neurons and these heterologous cells have a molecularly defined postsynaptic apparatus, while the compact morphology of HEK cells eliminates the distorting effect of dendritic filtering. HEK cells in coculture produced mEPSCs with a higher frequency, larger amplitude, and more rapid rise and decay than neurons from the same culture. However, mEPSC area indicated that nerve terminals in synapses with both neurons and HEK cells release similar populations of vesicles. Modulation by the glutamate receptor ligand aniracetam revealed receptor contributions to mEPSC shape. Dendritic cable effects account for the slower mEPSC rise in neurons, whereas the slower decay also depends on other factors. Lastly, expression of synaptobrevin transmembrane domain mutants in neurons slowed the rise of HEK cell mEPSCs, thus revealing the impact of synaptic fusion pores. In summary, we show that cocultures of neurons with heterologous cells provide a geometrically simplified and molecularly defined system to investigate the time course of synaptic transmission and to resolve the contribution of vesicles, fusion pores, dendrites, and receptors to this process.     

Current Status of Human Papillomavirus-Related Head and Neck Cancer: From Viral Genome to Patient Care

Virologica Sinica - Human papillomavirus (HPV) infection identified as a definitive human carcinogen is increasingly being recognized for its role in carcinogenesis of human cancers. Up to...     

蛹虫草组学研究进展

作为虫草属的模式种,蛹虫草是目前虫草类真菌中研究和应用最为广泛的物种之一。随着基因组序列的公布,蛹虫草组学水平的研究近年来取得了明显的进展。本文从基因组、线粒体基因组、甲基化组、转录组、蛋白质组、代谢网络等角度对蛹虫草组学水平的研究现状进行综述,期望对进一步推动蛹虫草的深入研究提供帮助。     

Leptin gene-targeted editing in ob/ob mouse adipose tissue based on the CRISPR/Cas9 system

Gene therapy has become the most effective treatment for monogenic diseases. Congenital LEPTIN deficiency is a rare autosomal recessive monogenic obesity syndrome caused by mutations in the Leptin gene. Ob/ob mouse is a monogenic obesity model, which carries a homozygous point mutation of C to T in Exon 2 of the Leptin gene. Here, we attempted to edit the mutated Leptin gene in ob/ob mice preadipocytes and inguinal adipose tissues using CRISPR/Cas9 to correct the C to T mutation and restore the production of LEPTIN protein by adipocytes. The edited preadipocytes exhibit a correction of 5.5% of Leptin alleles and produce normal LEPTIN protein when differentiated into mature adipocytes. The ob/ob mice display correction of 1.67% of Leptin alleles, which is sufficient to restore the production and physiological functions of LEPTIN protein, such as suppressing appetite and alleviating insulin resistance. Our study suggests CRISPR/Cas9-mediated in situ genome editing as a feasible therapeutic strategy for human monogenic diseases, and paves the way for further research on efficient delivery system in potential future clinical application.     

Dissolvable Gelatin-Based Microcarriers Generated through Droplet Microfluidics for Expansion and Culture of Mesenchymal Stromal Cells

Microcarriers are synthetic particles used in bioreactor-based cell manufacturing of anchorage-dependent cells to promote proliferation at efficient physical volumes, mainly by increasing the surface area-to-volume ratio. Mesenchymal stromal cells (MSCs) are adherent cells that are used for numerous clinical trials of autologous and allogeneic cell therapy, thus requiring avenues for large-scale cell production at efficiently low volumes and cost. Here, a dissolvable gelatin-based microcarrier is developed for MSC expansion. This novel microcarrier shows comparable cell attachment efficiency and proliferation rate when compared to several commercial microcarriers, but with higher harvesting yield due to the direct dissolution of microcarrier particles and thus reduced cell loss at the cell harvesting step. Furthermore, gene expression and in vitro differentiation suggest that MSCs cultured on gelatin microcarriers maintain trilineage differentiation with similar adipogenic differentiation efficiency and higher chondrogenic and osteogenic differentiation efficiency when compared to MSCs cultured on 2D planar polystyrene tissue culture flask; on the contrary, MSCs cultured on conventional microcarriers appear to be bipotent along osteochondral lineages whereby adipogenic differentiation potential is impeded. These results suggest that these gelatin microcarriers are suitable for MSC culture and expansion, and can also potentially be extended for other types of anchorage-dependent cells.     

Stage-dependent plasticity in biomass allocation and allometry in response to population density in Abutilon theophrasti: a step forward to understanding the nature of phenotypic plasticity

Plant Ecology - How plants respond to density via modular plasticity is obscure, probably because relevant studies using covariance analysis (ANCOVA) and allometric analysis rarely focus on...     

Effect of leaf water extracts of four Asteraceae alien invasive plants on germination performance of Lactuca sativa L. under acid deposition

Plant Ecology - Allelopathy of alien invasive plants (AIP) on plant germination performance is essential for their successful invasion. However, the allelopathy of AIP may be reformed or even...     

Resonance of Different Waveguide Structures with Various Vertical Indirect Coupled Cavities

In the paper, resonances of different waveguide structures with various vertical indirect coupled cavities were investigated by FDTD (finite difference-time domain). In the silicon cavity, Fano resonance could be observed at about 1430 nm. The coupling distance for the gold cavity/air cavity had less effect on the transmittance of the main waveguide but had a great influence on the transmission for water cavity in the visible region, which showed that water cavity could adjust resonance of waveguide structures. In addition, with the increment of refractive index n, the resonance peak at about 850 nm moved to the long wavelength (redshift). Dispersion rate about 2 × 10^–3/nm indicated that the transparent dielectric selectively absorbed the surface plasmon polariton wave and the sensitivity of the waveguide structure designed in this paper has high stability for the refractive index of the main waveguide cavity. Obvious Fano resonance could be observed with the increase of refractive index for silicon cavity. Among the four dielectrics, silicon and water are suitable for studying Fano resonance and filter dielectrics.

     

Clinical relevance of oncogenic driver mutations identified in endometrial carcinoma

PurposeEndometrial carcinoma (EC) is a clinically heterogeneous disease characterized by a number of different histological subtypes, and its heterogeneity may be involved in the accumulation of multiple genetic alterations. The aim of this work was to investigate the comprehensive mutational profile of EC tumors, and examine the associations between somatic mutations and clinicopathological features or survival in EC patients.MethodsA total of 100 surgical tumors were obtained from EC patients who had previously undergone surgery. Genomic DNA samples extracted from fresh-frozen tissues were analyzed using the Ion AmpliSeq Cancer Hotspot Panel v2 Kit, covering 50 tumor-related genes.ResultsValidated mutations were detected in 91 of the 100 tumors (91%) and identified in eight of the most frequently mutated genes, namely PTEN (57%), PIK3CA (51%), TP53 (30%), KRAS (23%), CTNNB1 (21%), FBFR2 (13%), FBXW7(10%) and RB1 (9%). PTEN mutations were found to associated with young age (< 60), early-stage, endometrioid histology, non-recurrence and better overall survival (OS). CTNNB1 mutations were associated with young age, endometrioid histology and better OS. On the other hands, TP53 mutations were associated with late-stage, non-endometrioid histology, high-grade, recurrence and worse OS. FBWX7 mutations were associated with late-stage, vascular invasion and lymph node metastasis. FGFR2 mutations correlated with deep (≥ 1/2) myometrial invasion.ConclusionOur comprehensive mutational profile will be useful for understanding and evaluating the molecular characteristics of EC tumors, and may lead to the establishment of novel treatment strategies that improve the survival of patients with EC in the future.