LSD1 promotes the egress of hematopoietic stem and progenitor cells into the bloodstream during the endothelial-to-hematopoietic transition.

During embryonic development, primitive and definitive waves of hematopoiesis take place to provide proper blood cells for each developmental stage, with the possible involvement of epigenetic factors. We previously found that lysine-specific demethylase 1 (LSD1/KDM1A) promotes primitive hematopoietic differentiation by shutting down the gene expression program of hemangioblasts in an Etv2/Etsrp-dependent manner. In the present study, we demonstrated that zebrafish LSD1 also plays important roles in definitive hematopoiesis in the development of hematopoietic stem and progenitor cells.

The double-membrane vesicle (DMV): a virus-induced organelle dedicated to the replication of SARS-CoV-2 and other positive-sense single-stranded RNA viruses.

Positive single-strand RNA (+ RNA) viruses can remodel host cell membranes to induce a replication organelle (RO) isolating the replication of their genome from innate immunity mechanisms. Some of these viruses, including severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2), induce double-membrane vesicles (DMVs) for this purpose. Viral non-structural proteins are essential for DMV biogenesis, but they cannot form without an original membrane from a host cell organelle and a significant supply of lipids.

A morphometric analysis of hepatitis B subviral particles shows no correlation of filament proportion and length with clinical stage and genotype.

It was recently suggested that the composition of circulating hepatitis B subviral particles (SVPs) could be used to differentiate the various stages in chronic hepatitis B virus (HBV) infection, with significantly lower proportions of L and M proteins in inactive carriers than in individuals with chronic hepatitis. L protein is abundant in virions and filamentous SVPs but almost absent from spherical SVPs. We, therefore, performed a morphometric analysis of SVPs in these two groups of patients, by conducting a retrospective analysis on sera from 15 inactive carriers and 11 patients with chronic hepatitis infected with various HBV genotypes.

Three-Dimensional Visualization of Blood and Lymphatic Vessels in the Adult Zebrafish Heart by Chemical Clearing.

Unlike humans, the zebrafish can repair and regenerate its heart following injury. Understanding the molecular and physiological mechanisms of heart regeneration is critical in developing pro-regenerative strategies for clinical application. The cardiac lymphatic and non-lymphatic vasculature both respond to injury in zebrafish and are instrumental in driving optimal repair and regeneration.