Biology subjects

Meng, Y.

Publications and source records attributed to Meng, Y..

4 recordsLinked to original sources

bioRxiv2018

Fast, volumetric live-cell imaging using high-resolution light-field microscopy

Visualizing diverse anatomical and functional traits that span many spatial scales with high spatio-temporal resolution provides insights into the fundamentals of living organisms. Light-field microscopy (LFM) has recently emerged as a scanning-free, scalable method that allows for high-speed, volumetric functional brain imaging. Given those promising applications at the tissue level, at its other extreme, this highly-scalable approach holds great potential for observing structures and dynamics in single-cell specimens. However, the challenge remains for current LFM to achieve subcellular level, near-diffraction-limited 3D spatial resolution. Here, we report high-resolution LFM (HR-LFM) for live-cell imaging with a resolution of 300-700 nm in all three dimensions, an imaging depth of several micrometers, and a volume acquisition time of milliseconds. We demonstrate the technique by imaging various cellular dynamics and structures and tracking single particles. The method may advance LFM as a particularly useful tool for understanding biological systems at multiple spatio-temporal levels.

bioengineering↗

bioRxiv2018

Visual intensity ratio modulates operant learning responses in larval zebrafish

Larval zebrafish is a promising vertebrate model for understanding neural mechanisms underlying learning and memory. Here, we report on a high-throughput operant learning system for zebrafish larvae and demonstrate that lower visual intensity ratio of the conditioned stimulus to the background can enhance learning ability, highlighted by several behavioral metrics. We further characterize the learning curves as well as memory extinction for each conditioned pattern. Finally, we show how this learning process developed from 7 days old to 10 days old zebrafish.\n\nHighlightsO_LIConditioned visual patterns with lower intensity ratio to the background elicited stronger operant learning responses\nC_LIO_LIMemory extinction was modulated by the visual intensity ratio of the conditioned stimulus to the background\nC_LIO_LIA high-throughput automated system for acquiring and analyzing behavioral data\nC_LI

animal behavior and cognition↗

bioRxiv2018

Efficient differentiation of vascular endothelial cells from dermal-derived mesenchymal stem cells induced by endothelial cell lines conditioned medium

ObjectiveTo directionally-differentiate dermis-derived mesenchymal stem cells (DMSCs) into vascular endothelial cells (VECs) in vitro, providing an experimental basis for studies on the pathogenesis and treatment of vascular diseases.\n\nMethodsAfter separation by adherent culture, VEC line supernatant, vascular endothelial growth factor (VEGF), bone morphogenetic protein-4 and hypoxia were used for the differentiation of VECs from DMSCs. The cell type was authenticated by flow cytometry, matrigel angiogenesis assay in vitro, and immunofluorescent staining during differentiation. The VEGF concentration was investigated by enzyme-linked immunosorbent assay.\n\nResultsAfter 28 days of differentiation, the cell surface marker CD31 was significantly positive (80%-90%) by flow cytometry in the VEC line-conditioned culture, which was significantly higher than in the other groups. Differentiated DMSCs had the ability to ingest Dil-ac-LDL and vascularize in the conditioned culture, but not in the other groups. In the VEC line supernatant, the concentration of VEGF was very low. The VEGF concentration changed along with the differentiation into VECs in the medium of the conditioned culture group.\n\nConclusionVEC line supernatant can induce the differentiation of DMSCs into VECs, possibly through the pathway except VEGF.

cell biology↗

bioRxiv2018

FRMD8 promotes inflammatory and growth factor signalling by stabilising the iRhom/ADAM17 sheddase complex

Many intercellular signals are synthesised as transmembrane precursors that are released by proteolytic cleavage ( shedding) from the cell surface. ADAM17, a membrane-tethered metalloprotease, is the primary shedding enzyme responsible for the release of the inflammatory cytokine TNF and several EGF receptor ligands. ADAM17 exists in complex with the rhomboid-like iRhom proteins, which act as cofactors that regulate ADAM17 substrate shedding. Here we report that the poorly characterised FERM domain-containing protein FRMD8 is a new component of iRhom2/ADAM17 sheddase complex. FRMD8 binds to the cytoplasmic N-terminus of iRhoms, and is necessary to stabilise the iRhoms and ADAM17 beyond the Golgi. In the absence of FRMD8, iRhom2 and ADAM17 are degraded via the endolysosomal pathway, resulting in the reduction of ADAM17-mediated shedding. We have confirmed the pathophysiological significance of FRMD8 in iPSC-derived human macrophages and mouse tissues, thus demonstrating its role in the regulated release of multiple cytokine and growth factor signals.

biochemistry↗