Publications by authors named "Francois Redelsperger"
Article Synopsis
- The text discusses envelope genes of retroviral origin that are important for placentation and cell fusion, specifically in forming a layer of the placenta in mice.
- Researchers used mice lacking a particular gene (SynB mice) to explore its role in the fusion of certain immune cells into larger multinucleated cells, like osteoclasts in bones and giant cells in soft tissues.
- Results showed that the absence of this gene reduced the number of multinucleated cells early in formation, but did not affect their function, indicating its key role during initial stages of cell fusion rather than ongoing cell activity.
Background & Aims: Hepatitis B virus (HBV) RNA can undergo alternative splicing, but the relevance of this post-transcriptional regulation remains elusive. The mechanism of HBV alternative splicing regulation and its impact on liver pathogenesis were investigated.
Methods: HBV RNA-interacting proteins were identified by RNA pull-down, combined with mass spectrometry analysis.
Article Synopsis
- Syncytins, originally from endogenous retroviruses, play a key role in cell-cell fusion during placentation and muscle formation, forming syncytia like the syncytiotrophoblast in placental mammals.
- Mice lacking syncytins showed over a 20% decrease in muscle mass and fiber size, particularly in males, suggesting a male-specific impact on muscle development and characteristics.
- Experimental results indicate syncytins are crucial for myoblast fusion and muscle repair, with similar effects observed in human and other animal myoblasts, pointing to their role in muscle growth differences between sexes in placental mammals.
Hepatitis B splicing-regulated protein (HBSP) of the hepatitis B virus (HBV) was uncovered a few years ago but its function remains unknown. HBSP expression occurs from a spliced viral transcript that increases during the course of liver disease. This study aimed at characterizing the impact of HBSP on cellular signaling pathways in vitro and on liver pathogenesis in transgenic (Tg) mice.
View Article and Find Full Text PDFSyncytins are fusogenic envelope (env) genes of retroviral origin that have been captured for a function in placentation. Multiple independent events of syncytin gene capture were found to have occurred in primates, rodents, lagomorphs, carnivores, and ruminants. In the mouse, two syncytin-A and -B genes are present, which trigger the formation of the two-layered placental syncytiotrophoblast at the maternal-fetal interface, a structure classified as hemotrichorial.
View Article and Find Full Text PDFArticle Synopsis
- Syncytin genes are proteins derived from retroviruses that play a crucial role in placenta formation, with two already found in the mouse lineage.
- Researchers explored the squirrel-related rodent clade and discovered a new syncytin gene, named syncytin-Mar1, through genomic analysis of ground squirrels.
- This gene exhibits specific expression in the placenta and is crucial for cell fusion processes, indicating its significant role in placentation evolution, dating back at least 25 million years.
Defective hepatitis B virus (dHBV) generated from spliced RNA is detected in the sera of HBV-chronic carriers. Our study was designed to determine whether the proportion of dHBV changed during the course of infection, and to investigate whether dHBV might interfere with HBV replication. To achieve this, HBV wild-type and dHBV levels were determined by Q-PCR in sera from 56 untreated chronic patients and 23 acute patients, in sequential samples from 4 treated-patients and from liver-humanized mice after HBV infection.
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