Publications by authors named "Mickael Costallat"
Article Synopsis
- HP1α/CBX5 is linked to multiple sclerosis (MS), and a study found that some MS patients have lower CBX5 levels that relate to worse disease progression and significant changes in gene expression.* -
- The research identified problems with certain RNA species in these patients, suggesting that the Integrator complex, which is important for RNA processing, is less active, potentially raising MS risk.* -
- In experiments with mice lacking Cbx5, similar transcription issues were observed, indicating that HP1α/CBX5 plays a critical role in maintaining proper gene expression and could lead to new ways to categorize MS patients.*
Defects in RNA splicing have been linked to human disorders, but remain poorly explored in inflammatory bowel disease (IBD). Here, we report that expression of the chromatin and alternative splicing regulator HP1γ is reduced in ulcerative colitis (UC). Accordingly, HP1γ gene inactivation in the mouse gut epithelium triggers IBD-like traits, including inflammation and dysbiosis.
View Article and Find Full Text PDFPromoters and enhancers are sites of transcription initiation (TSSs) and carry specific histone modifications, including H3K4me1, H3K4me3, and H3K27ac. Yet, the principles governing the boundaries of such regulatory elements are still poorly characterized. Alu elements are good candidates for a boundary function, being highly abundant in gene-rich regions, while essentially excluded from regulatory elements.
View Article and Find Full Text PDFHP1 proteins are best known as markers of heterochromatin and gene silencing. Yet, they are also RNA-binding proteins and the HP1γ/CBX3 family member is present on transcribed genes together with RNA polymerase II, where it regulates co-transcriptional processes such as alternative splicing. To gain insight in the role of the RNA-binding activity of HP1γ in transcriptionally active chromatin, we have captured and analysed RNAs associated with this protein.
View Article and Find Full Text PDFArticle Synopsis
- The buildup of senescent cells contributes to chronic inflammation as we age, and this process is influenced by cytoplasmic double-stranded RNA, similar to the previously known effects of cytoplasmic DNA.
- Researchers found that various cell types in senescence have high levels of long promoter RNAs and retrotransposon sequences, leading to increased activity of genes responsive to viral double-stranded RNA via the interferon pathway.
- Evidence shows that lower RNA turnover, possibly due to decreased expression of RNA exosome components, exacerbates senescence markers, with oxidative stress also playing a role in this senescence-like RNA accumulation and persistent inflammation.