trichostatin-a and largazole

Selective inhibition of KDAC isoforms while maintaining potency remains a challenge. Using the largazole macrocyclic depsipeptide structure as a starting point for developing new KDACIs with increased selectivity, a combination of four different simplified largazole analogue (SLA) scaffolds with diverse zinc-binding groups (for a total of 60 compounds) were designed, synthesized, and evaluated against class I KDACs 1, 3, and 8, and class II KDAC6. Experimental evidence as well as molecular docking poses converged to establish the cyclic tetrapeptides (CTPs) as the primary determinant of both potency and selectivity by influencing the correct alignment of the zinc-binding group in the KDAC active site, providing a further basis for developing new KDACIs of higher isoform selectivity and potency.

Topics: Depsipeptides; Histone Deacetylase Inhibitors; Histone Deacetylases; Humans; Molecular Docking Simulation; Protein Isoforms; Structure-Activity Relationship; Thiazoles

Mesenchymal stem cells (MSCs) are self-renewing cells that exhibit differentiation capacity and immune regulation ability. These versatile cells have a wide range of potential applications. However, the spontaneous differentiation and aging of MSCs during long-term culturing restrict the amount of cells available for therapies and tissue engineering. Thus, maintaining the biological characteristics of MSCs during long-term culturing is crucial. Chromatic modification via epigenetic regulatory mechanisms (e.g., histone acetylation, deacetylation, and methylation) is crucial in stem cell pluripotency. We investigated the effects of largazole or trichostatin A (TSA), a novel histone deacetylase inhibitor (HDACi), against human umbilical cord (hUC)-MSCs aging. Results show that low concentrations of largazole or TSA can significantly improve hUC-MSCs proliferation and delay hUC-MSCs aging. Largazole can better improve MSCs proliferation than TSA. HDAC is modulate histone H3 acetylation and methylation in the telomerase reverse-transcriptase, octamer-binding transcription factor 4, Nanog, C-X-C chemokine receptor 4, alkaline phosphatase, and osteopontin genes. HDACis can promote hUC-MSCs proliferation and suppress hUC-MSCs spontaneous osteogenic differentiation. HDACis can affect histone H3 lysine 9 or 14 acetylation and histone H3 lysine 4 dimethylation, thus increasing the mRNA expression of pluripotent and proliferative genes and suppressing the spontaneous differentiation of hUC-MSCs.

Topics: Apoptosis; Cell Proliferation; Cells, Cultured; Cellular Senescence; Chromatin Immunoprecipitation; Depsipeptides; Histone Deacetylase Inhibitors; Humans; Hydroxamic Acids; Mesenchymal Stem Cells; Real-Time Polymerase Chain Reaction; Thiazoles; Umbilical Cord