Biology subjects

Zong, W.

Publications and source records attributed to Zong, W..

24 records · Page 2Linked to original sources

bioRxiv2021

Controllable drug release of pH-sensitive liposomes encapsulating artificial cytosol system

The fabrication of cell model containing artificial cytosol is challenging. Herein we constructed an artificial cytosol contained cell model by electroformation method. Agarose was selected as the main component of the artificial cytosol. Sucrose was added into agarose to regulate the sol viscosity and phase transition temperature (Tm). The viscosity of the sol with the mass ratio (agarose-sucrose) 1:9 was closest to the natural cytosolic. DSPC/20 mol% Chol was used to form large unilamellar vesicle (LUV) as cell model compartment. The rhodamine release experiment confirmed that the release of rhodamine from LUVs containing artificial cytosol took more time than that from LUVs containing pure water. The unique release profile makes agarose-sucrose@LUVs suitable as a drug carrier. Doxorubicin (DOX) is loaded in the agarose-sucrose@LUVs, and their half maximum inhibition concentration on HeLa cells is 0.015 mol L-1, which means 31.7 times increase in inhibition efficiency over free DOX.

biochemistry↗

bioRxiv2020

Transcriptional alterations in opioid use disorder reveal an interplay between neuroinflammation and synaptic remodeling

BackgroundPrevalence rates of opioid use disorder (OUD) have increased dramatically, accompanied by a surge of overdose deaths. While opioid dependence has been extensively studied in preclinical models, an understanding of the biological alterations that occur in the brains of people who chronically use opioids and who are diagnosed with OUD remains limited. To address this limitation, RNA-sequencing (RNA-seq) was conducted on the dorsolateral prefrontal cortex (DLPFC) and nucleus accumbens (NAc), regions heavily implicated in OUD, from postmortem brains in subjects with OUD. MethodsWe performed RNA-seq on the DLPFC and NAc from unaffected comparison subjects (n=20) and subjects diagnosed with OUD (n=20). Our transcriptomic analyses identified differentially expressed (DE) transcripts and investigated the transcriptional coherence between brain regions using rank-rank hypergeometric ordering (RRHO). Weighted gene co-expression analyses (WGCNA) also identified OUD-specific modules and gene networks. Integrative analyses between DE transcripts and GWAS datasets using linkage disequilibrium score (LDSC) assessed the genetic liability psychiatric-related phenotypes. ResultsRRHO analyses revealed extensive overlap in transcripts between DLPFC and NAc in OUD, primarily relating to synaptic remodeling and neuroinflammation. Identified transcripts were enriched for factors that control pro-inflammatory cytokine-mediated, chondroitin sulfate, and extracellular matrix signaling. Cell-type deconvolution implicated a role for microglia as a critical driver for opioid-induced neuroplasticity. Using LDSC, we discovered genetic liabilities for risky behavior, attention deficit hyperactivity disorder, and depression. ConclusionsOverall, our findings reveal new connections between the brains immune system and opioid dependence in the human brain.

neuroscience↗

bioRxiv2020

Prospective representations in rat orbitofrontal ensembles

The orbitofrontal cortex (OFC) has been proposed to encode expected outcomes, which is thought to be important for outcome-directed behavior. However, such neural encoding can also often be explained by the recall of information about the recent past. To dissociate the retrospective and prospective aspects of encoding in the OFC, we designed a non-spatial, continuous, alternating odor-sequence task that mimicked a continuous T-maze. The task consisted of two alternating sequences of four odor-guided trials (2 sequences x 4 positions). In each trial, rats were asked to make a "go" or "no-go" action based on a fixed odor-reward contingency. Odors at both the first and last positions were distinct across the two sequences, such that they resembled unique paths in the past and future, respectively; odors at positions in between were the same and thus resembled a common path. We trained classifiers using neural activity to distinguish between either sequences or positions and asked whether the neural activity patterns in the common path were more like the ones in the past or the future. We found a proximal prospective code for sequence information as well as a distal prospective code for positional information, the latter of which was closely associated with rats ability to predict future outcomes. This study demonstrates a prospective behaviorally-relevant predictive code in rat OFC.

neuroscience↗

bioRxiv2020

Light-Sheet Fluorescence Imaging Charts the Gastrula Origin of Vascular Endothelial Cells in Early Zebrafish Embryos

It remains challenging to construct a complete cell lineage map of the origin of vascular endothelial cells in any vertebrate embryo. Here, we report the application of in toto light-sheet fluorescence imaging of embryos to tracing the origin of vascular endothelial cells (ECs) at single-cell resolution in zebrafish. We first adapted a previously-reported method to mount embryos and light-sheet imaging, created an alignment, fusion, and extraction all-in-one software (AFEIO) for processing big data, and performed quantitative analysis of cell lineage relationships using commercially-available Imaris software. Our data revealed that vascular ECs originated from broad regions of the gastrula along the dorsal-ventral and anterior-posterior axes, of which the dorsal-anterior cells contributed to cerebral ECs, the dorsal-lateral cells to anterior trunk ECs, and the ventral-lateral cells to posterior trunk and tail ECs. Therefore, this work, to our knowledge, charts the first comprehensive map of the gastrula origin of vascular ECs in zebrafish, and has potential applications for studying the origin of any embryonic organs in zebrafish and other model organisms.

developmental biology↗

bioRxiv2020

VIL1, a Polycomb-associated protein, modulates high ambient temperature response via H3K27me3 and H2A.Z in Arabidopsis thaliana

Adapting to the everchanging environment is key to a successful life for an organism. Eukaryotes reprogram their transcriptome in order to adapt to an unfavorable environment. To achieve this reprogramming, plants and animals employ multiple responses including epigenetic regulation. In the search for mutations compromised in high ambient temperature response, we found that VIL1, a PHD finger protein displays aberrant development at high temperature. RNA-seq analysis shows that vil1 fails to downregulate heat suppressed genes. H2A.Z ChIP-seq showed that unlike wild type, vil1 fails to evict H2A.Z from heat responsive genes. We also found that vil1 suppresses constitutive thermo-morphogenic phenotype of arp6. Supporting this phenotype, RNA-seq analysis revealed that constitutive heat responsive transcriptome of arp6 reverted back to the wild-type levels in arp6vil1. This observation suggests an antagonistic relationship between VIL1 and ARP6. We found that this antagonism can be explained in part by interaction between H3K27me3 and H2A.Z.

plant biology↗

bioRxiv2017

In vivo Imaging β-cell Function Reveals Two Waves of β-cell Maturation

The insulin-secreting cells generated from stem cells in vitro are less glucose responsive than primary {beta}-cells. To search for the missing ingredients that are needed for {beta}-cell maturation, we have longitudinally monitored function of every {beta}-cell in Tg (ins:Rcamp1.07) zebrafish embryos with a newly-invented two-photon light-sheet microscope. We have shown that {beta}-cell maturation begins from the islet mantle and propagates to the islet core during the hatching period, coordinated by the islet vascularization. Lower concentration of glucose is optimal to initiate {beta}-cell maturation, while increased glucose delivery to every cell through microcirculation is required for functional boosting of the {beta}-cells. Both the initiation and the boosting of {beta}-cell maturation demands activation of calcineurin/NFAT by glucose. Calcineurin activator combined with glucose promotes mouse neonatal {beta}-cells cultured in vitro to mature to a functional state similar to adult {beta}-cells, suggesting a new strategy for improving stem cell-derived {beta}-like cell function in vitro.

developmental biology↗