Ascorbic acid induces transient global active chromatin remodelling, providing clues for its anti-cancer effect

In addition to the role of antioxidant, ascorbic acid (reducing Vitamin C) is an important cofactor for Fe2+ and α-ketoglutarate (α-KG) dependent dioxygenases (Fe2+/α-KGDDs) that comprise many diverse enzymes, including collagen prolyl hydroxylases, jmjC (Jumonji C) domain containing histone demethylases, Ten-eleven translocation (TET) 5-methyl cytosine (5mC) dioxygenases, and N6-methyl adenosine (m6A) demethylase FTO and ALKBH5. Ascorbic acid was reported to induce global epigenetic reprogramming. Here we optimized the library construction flow chart of single-stranded DNA profiling method KAS-seq and utilized KAS-seq to profile transient chromatin states changes upon ascorbic acid treatment for 10 min. We identified several critical pathways affected by ascorbic acid treatment, providing some clues for explaining the reported positive impact of anti-cancer, anti-depression, and anti-obesity for taking ascorbic acid. Cells were incubated in completed culture medium at 37 °C, 5% CO2. For vitamin C treatment experiments, cells were treated with/without 0.5 mM vitamin C in the culture medium for 10 min before being subjected to 5 mM N3-kethoxal labeling for another 10 min incubation.