22:T4b4,Ubiquitination of proliferating cell nuclear antigen (PCNA) at lysine 164 (K164) activates DNA damage tolerance pathways. Currently, we lack a comprehensive understanding of how PCNA K164 ubiquitination promotes genome stability. To evaluate this, we generated stable cell lines expressing PCNA^K164R from the endogenous PCNA locus. Our data reveal that the inability to ubiquitinate K164 causes perturbations in global DNA replication. Persistent replication stress generates under-replicated regions and is exacerbated by the DNA polymerase inhibitor aphidicolin. We show that these phenotypes are due, in part, to impaired Fanconi anemia group D2 protein (FANCD2)-dependent mitotic DNA synthesis (MiDAS) in PCNA^K164R cells. FANCD2 mono-ubiquitination is significantly reduced in PCNA^K164R mutants, leading to reduced chromatin association and foci formation, both prerequisites for FANCD2-dependent MiDAS. Furthermore, K164 ubiquitination coordinates direct PCNA/FANCD2 colocalization in mitotic nuclei. Here, we show that PCNA K164 ubiquitination maintains human genome stability by promoting FANCD2-dependent MiDAS to prevent the accumulation of under-replicated DNA.23:T4c9,Inflammatory bowel disease alters the gut microbiota, causes defects in mucosal barrier function, and leads to dysregulation of the immune response to microbial stimulation. This study investigated and compared the efficacy of a candidate probiotic strain, Bacillus coagulans BC198, and its heat-killed form in treating dextran sulfate sodium-induced colitis. Both live and heat-killed B. coagulans BC198 increased gut barrier-associated protein expression, reduced neutrophil and M1 macrophage infiltration of colon tissue, and corrected gut microbial dysbiosis induced by colitis. However, only live B. coagulans BC198 could alleviate the general symptoms of colitis, prevent colon shortening, and suppress inflammation and tissue damage. At the molecular level, live B. coagulans BC198 was able to inhibit Th17 cells while promoting Treg cells in mice with colitis, reduce pro-inflammatory MCP-1 production, and increase anti-inflammatory IL-10 expression in the colonic mucosa. The live form of B. coagulans BC198 functioned more effectively than the heat-killed form in ameliorating colitis by enhancing the anti-inflammatory response and promoting Treg cell accumulation in the colon.

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