Interaction of the NRF2 and p63 transcription factors promotes keratinocyte proliferation in the epidermis

Epigenetic regulation of cell and tissue function requires the coordinated action of transcription factors. However, their combinatorial activities during regeneration remain largely unexplored. Here, we discover an unexpected interaction between the cytoprotective transcription factor NRF2 and p63-a key player in epithelial morphogenesis. Chromatin immunoprecipitation combined with sequencing and reporter assays identifies enhancers and promoters that are simultaneously activated by NRF2 and p63 in human keratinocytes. Modeling of p63 and NRF2 binding to nucleosomal DNA suggests their chromatin-assisted interaction. Pharmacological and genetic activation of NRF2 increases NRF2-p63 binding to enhancers and promotes keratinocyte proliferation, which involves the common NRF2-p63 target cyclin-dependent kinase 12. These results unravel a collaborative function of NRF2 and p63 in the control of epidermal renewal and suggest their combined activation as a strategy to promote repair of human skin and other stratified epithelia

C6-ceramide synergistically potentiates the anti-tumor effects of histone deacetylase inhibitors via AKT dephosphorylation and α-tubulin hyperacetylation both in vitro and in vivo

Histone deacetylase inhibitors (HDACIs) have shown promising anti-tumor effects for a variety of malignancies, however, many tumors are reportedly resistant to them. In this study, we made a novel discovery that co-administration of HDACIs (Trichostatin A (TSA) and others) and exogenous cell-permeable short-chain ceramide (C6) results in striking increase in cancer cell death and apoptosis in multiple cancer cells. These events are associated with perturbations in diverse cell signaling pathways, including inactivation of Akt/mTOR and increase in α-tubulin acetylation (both in vivo and in vitro). TSA interacts in a highly synergistic manner with C6-ceramide to disrupt HDAC6/protein phosphatase 1 (PP1)/tubulin complex, to induce α-tubulin hyperacetylation, and to release and activate PP1, which then leads to AKT dephosphorylation and eventually causes cancer cell death. Interestingly, TSA itself results in short-term ceramide accumulation, which as a result of metabolic (glycosylation) removal, does not result in evident increase of cancer cell death. However, adding C6-ceramide led to a very pronounced increase in ceramide level and marked increase in cell death. Importantly, the effective synergistic anti-tumor activity of TSA plus C6-ceramide is also seen in in vivo mice xenograft pancreatic and ovarian cancer models, indicating that this regimen (HDACI plus C6-ceramide) may represent a more effective form of therapy against pancreatic and ovarian carcinoma

Epigenetic Transcriptional Regulation of the Growth Arrest-Specific gene 1 (Gas1) in Hepatic Cell Proliferation at Mononucleosomal Resolution

BACKGROUND: Gas1 (growth arrest-specific 1) gene is known to inhibit cell proliferation in a variety of models, but its possible implication in regulating quiescence in adult tissues has not been examined to date. The knowledge of how Gas1 is regulated in quiescence may contribute to understand the deregulation occurring in neoplastic diseases. METHODOLOGY/PRINCIPAL FINDINGS: Gas1 expression has been studied in quiescent murine liver and during the naturally synchronized cell proliferation after partial hepatectomy. Chromatin immunoprecipitation at nucleosomal resolution (Nuc-ChIP) has been used to carry out the study preserving the in vivo conditions. Transcription has been assessed at real time by quantifying the presence of RNA polymerase II in coding regions (RNApol-ChIP). It has been found that Gas1 is expressed not only in quiescent liver but also at the cell cycle G(1)/S transition. The latter expression peak had not been previously reported. Two nucleosomes, flanking a nucleosome-free region, are positioned close to the transcription start site. Both nucleosomes slide in going from the active to the inactive state and vice versa. Nuc-ChIP analysis of the acquisition of histone epigenetic marks show distinctive features in both active states: H3K9ac and H3K4me2 are characteristic of transcription in G(0) and H4R3me2 in G(1)/S transition. Sequential-ChIP analysis revealed that the "repressing" mark H3K9me2 colocalize with several "activating" marks at nucleosome N-1 when Gas1 is actively transcribed suggesting a greater plasticity of epigenetic marks than proposed until now. The recruitment of chromatin-remodeling or modifying complexes also displayed distinct characteristics in quiescence and the G(1)/S transition. CONCLUSIONS/SIGNIFICANCE: The finding that Gas1 is transcribed at the G(1)/S transition suggests that the gene may exert a novel function during cell proliferation. Transcription of this gene is modulated by specific "activating" and "repressing" epigenetic marks, and by chromatin remodeling and histone modifying complexes recruitment, at specific nucleosomes in Gas1 promoter

Синтез та алкілування аміду, отриманого на основі N-фталоілгліцину та гідразиду ендикової кислоти

Himic acid hydrazide derivatives are promising in terms of practical use compounds due to their wide range of biological effects (primarily neurotropic activity) and their synthetic potential. Earlier investigated in detail the methods of synthesis of hydrazones, urea, amide and imide derivatives of himic acid hydrazide. Also known diverse biological action of N-Phthaloylglycine, which could serve as an effective protection for the amino group of glycine and has interesting structural features that contribute to the formation of supramolecular complexes. The methodology of synthesis of 2-(Phthalimidoyl)-N-benzyl-N-(4-azatricyclo[5.2.1.02-endo,6-endo]dec-8-ene-3,5-dione-4-yl)acetamide, including obtaining of 2-(Phthalimidoyl)-N-(4-azatricyclo[5.2.1.02-endo,6-endo]dec-8-ene-3,5-dione-4-yl)acetamide based on himic acid hydrazide acid and Phthalylglycyl chloride and alkylation of obtained product. Found that acceptable yield is observed during the alkylation reaction in boiling solution of anhydrous acetone in the presence of excess calcined potassium carbonate. The structure of obtained products was confirmed by analyzing the 1H NMR spectrum.Предложен метод получения 2-(фталимидоил)-N-бензил-N-(4-азатрицикло[5.2.1.02-эндо,6-эндо]дец-8-ен-3,5-дион-4-ил)ацетамида на основе продукта взаимодействия N-фталоилглицина и гидразида эндиковой кислоты.На основі продукту взаємодії N-фталоїлгліцину з гідразидом ендикової кислоти запропоновано метод синтезу 2-(фталімідоїл)-N-бензил-N-(4-азатрицикло[5.2.1.02-ендо,6-ендо]дец-8-ен-3,5-діон-4-іл)ацетаміду

Synthesis and alkylation of amide obtained by N-Phthaloylglycine and himic acid hydrazide

Himic acid hydrazide derivatives are promising in terms of practical use compounds due to their wide range of biological effects (primarily neurotropic activity) and their synthetic potential. Earlier investigated in detail the methods of synthesis of hydrazones, urea, amide and imide derivatives of himic acid hydrazide. Also known diverse biological action of N-Phthaloylglycine, which could serve as an effective protection for the amino group of glycine and has interesting structural features that contribute to the formation of supramolecular complexes. The methodology of synthesis of 2-(Phthalimidoyl)-N-benzyl-N-(4-azatricyclo[5.2.1.02-endo,6-endo]dec-8-ene-3,5-dione-4-yl)acetamide, including obtaining of 2-(Phthalimidoyl)-N-(4-azatricyclo[5.2.1.02-endo,6-endo]dec-8-ene-3,5-dione-4-yl)acetamide based on himic acid hydrazide acid and Phthalylglycyl chloride and alkylation of obtained product. Found that acceptable yield is observed during the alkylation reaction in boiling solution of anhydrous acetone in the presence of excess calcined potassium carbonate. The structure of obtained products was confirmed by analyzing the 1H NMR spectrum