Genome-wide profiling of DNA/RNA hybrids (R-loops) in psoriasis disease

DNA/RNA hybrids (R-loops) are RNA-mediated epigenetic element involved in the molecular mechanismof human diseases. R-loops are three-stranded structure made up a DNA/RNA hybrid and the displacedsingle-stranded DNA. Recently proposed independent-antibody method of our group leads to detect thesestructures in different type of cells started from germ cells to currently somatic cells. One physiologicalinstance of such structure present at our chromosomes ends (telomeres) as a lncRNA named TERRA(TElomeric Repeat-containing RNA; constitutive of hexameric repeats (TTAGGG/CCCTAA)n. UsingTERRA as a privilege model system to study R-loops helps us to understand DNA/RNA hybrids areaccumulated at the telomeres of different chromosomes in psoriasis patient samples (lesional and nonlesioanlskin samples vs. healthy controls) as previously observed in germ cells. It is reported that shorttelomeres are associated with higher TERRA levels in aging research. TERRA/DNA hybrids opens newstartegies to study psoriasis genome instability. Distribution of different non-coding RNA besides TERRAthroughout the genome of psoriasis-derived skin cells revealed the unresolved DNA/RNA hybrids mayfacilitate skin lesions formation and may play an important role in epigenome shaping.