Biology subjects

WANG, Z.

Publications and source records attributed to WANG, Z..

3 recordsLinked to original sources

bioRxiv2023

Circulating Microparticles: Optimization and Standardization of Isolation Protocols and Reassessment of Their Characteristics and Functions

Microparticles (MPs) are convenient for clinical diagnosis, and have functional roles in signal transduction. Although the importance of MPs is being increasingly recognized, the diversity of isolated protocols for MPs results in a heterogeneous population of their unknown origins, even expands to uncertain functions. Here we systematically studied the composition of MPs at different centrifugal speed intervals, and found that 3000g was a critical centrifugation speed in determining new MPs composition. The platelet-derived particles accounted for more than 80% under 3000g, while only about 20% in MPs obtained over 3000g. Furthermore, we found that the function of new MPs was significantly different from that of traditional ones, such as procoagulation activity, anti-inflammation and clinical diagnosis etc. Thus, our work optimized the method of MPs isolation, clarified some characteristics and physiological functions that should belong to platelets rather than MPs, which will derive new conceptual MPs for its composition and function.

cell biology↗

bioRxiv2022

H3K4 di- and trimethylation modulate the stability of RNA polymerase II pausing

Modifications of histones are intricately linked with the regulation of gene expression, with demonstrated roles in various physiological processes and disease pathogenesis. Methylation of histone H3 lysine 4 (H3K4), implemented by the COMPASS family, is enriched at promoters and associated cis-regulatory elements, with H3K4 trimethylation (H3K4me3) considered a hallmark of active gene promoters. However, the relative roles of deposition and removal of H3K4 methylation, as well as the extent to which these events contribute to transcriptional regulation have so far remained unclear. Here, through rapid depletion of the transcription regulator SPT5 or either of two shared subunits of COMPASS family members, we reveal a dynamic turnover of H3K4me3 mediated by the KDM5 family of histone demethylases. Loss of H3K4me3 following COMPASS disruption does not impair the recruitment of TFIID and initiating RNA polymerase II (Pol II). Instead, H3K4me3 loss leads to reductions in the paused form of Pol II on chromatin while inducing the relative enrichment of the Integrator-PP2A (INTAC) termination complex, leading to reduced levels of elongating polymerases, thus revealing how H3K4me3 dynamics can regulate Pol II pausing to sustain or attenuate transcription.

molecular biology↗

bioRxiv2022

Spatial cell fate manipulation of human pluripotent stem cells by controlling microenvironment using photocurable hydrogel

Human pluripotent stem cells (hPSCs) dynamically respond to their chemical and physical microenvironment, dictating their behavior. However, conventional in vitro studies predominantly employ plastic culture wares, which offer a simplified representation of the in vivo microenvironment. Emerging evidence underscores the pivotal role of mechanical and topological cues in hPSC differentiation and maintenance. In this study, we cultured hPSCs on hydrogel substrates with spatially controlled stiffness. The use of culture substrates that enable precise manipulation of spatial mechanical properties holds promise for better mimicking in vivo conditions and advancing tissue engineering techniques. We designed a photocurable polyethylene glycol-polyvinyl alcohol (PVA-PEG) hydrogel, allowing for spatial control of surface stiffness and geometry at a micrometer scale. This versatile hydrogel can be functionalized with various extracellular matrix (ECM) proteins. Laminin 511-functionalized PVA-PEG gel effectively supports the growth and differentiation of hPSCs. Moreover, by spatially modulating the stiffness of the patterned gel, we achieved spatially selective cell differentiation, resulting in the generation of intricate, patterned structures. Summary statementA new hydrogel substrate enables spatial control of surface stiffness at the micrometer level, enabling local differentiation of hPSC and facilitating complex pattern formation.

bioengineering↗