The disruption of proteostasis in neurodegenerative diseases

Cells count on surveillance systems to monitor and protect the cellular proteome which, besides being highly heterogeneous, is constantly being challenged by intrinsic and environmental factors. In this context, the proteostasis network (PN) is essential to achieve a stable and functional proteome. Disruption of the PN is associated with aging and can lead to and/or potentiate the occurrence of many neurodegenerative diseases (ND). This not only emphasizes the importance of the PN in health span and aging but also how its modulation can be a potential target for intervention and treatment of human diseases.info:eu-repo/semantics/publishedVersio

Circadian clock regulates hepatic polyploidy by modulating Mkp1-Erk1/2 signaling pathway

肝細胞の分裂に必須の時計遺伝子 --新しい分子機能を解明、肝疾患の予防や治療にも期待--. 京都大学プレスリリース. 2017-12-25.Liver metabolism undergoes robust circadian oscillations in gene expression and enzymatic activity essential for liver homeostasis, but whether the circadian clock controls homeostatic self-renewal of hepatocytes is unknown. Here we show that hepatocyte polyploidization is markedly accelerated around the central vein, the site of permanent cell self-renewal, in mice deficient in circadian Period genes. In these mice, a massive accumulation of hyperpolyploid mononuclear and binuclear hepatocytes occurs due to impaired mitogen-activated protein kinase phosphatase 1 (Mkp1)-mediated circadian modulation of the extracellular signal-regulated kinase (Erk1/2) activity. Time-lapse imaging of hepatocytes suggests that the reduced activity of Erk1/2 in the midbody during cytokinesis results in abscission failure, leading to polyploidization. Manipulation of Mkp1 phosphatase activity is sufficient to change the ploidy level of hepatocytes. These data provide clear evidence that the Period genes not only orchestrate dynamic changes in metabolic activity, but also regulate homeostatic self-renewal of hepatocytes through Mkp1-Erk1/2 signaling pathway

Epigenomic profiling of primate lymphoblastoid cell lines reveals the evolutionary patterns of epigenetic activities in gene regulatory architectures

Changes in the epigenetic regulation of gene expression have a central role in evolution. Here, we extensively profiled a panel of human, chimpanzee, gorilla, orangutan, and macaque lymphoblastoid cell lines (LCLs), using ChIP-seq for five histone marks, ATAC-seq and RNA-seq, further complemented with whole genome sequencing (WGS) and whole genome bisulfite sequencing (WGBS). We annotated regulatory elements (RE) and integrated chromatin contact maps to define gene regulatory architectures, creating the largest catalog of RE in primates to date. We report that epigenetic conservation and its correlation with sequence conservation in primates depends on the activity state of the regulatory element. Our gene regulatory architectures reveal the coordination of different types of components and highlight the role of promoters and intragenic enhancers (gE) in the regulation of gene expression. We observe that most regulatory changes occur in weakly active gE. Remarkably, novel human-specific gE with weak activities are enriched in human-specific nucleotide changes. These elements appear in genes with signals of positive selection and human acceleration, tissue-specific expression, and particular functional enrichments, suggesting that the regulatory evolution of these genes may have contributed to human adaptation.R.G.-P. was supported by a fellowship from MICINN (FPU13/01823). P.E.-C. was supported by a Formació de Personal Investigador fellowship from Generalitat de Catalunya (FI_B00122). M.K. was supported by a Deutsche Forschungsgemeinschaft (DFG) fellowship (KU 3467/1-1) and the Postdoctoral Junior Leader Fellowship Program from “la Caixa” Banking Foundation (LCF/BQ/PR19/11700002). D.J. was supported by a Juan de la Cierva fellowship (FJCI2016-29558) from MICINN. T.M-B. is supported by funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation program (grant agreement EC-H2020-ERC-CoG-ApeGenomeDiversity-864203), BFU2017-86471-P (AEI/FEDER, UE), “Unidad de Excelencia María de Maeztu”, funded by the AEI (CEX2018-000792-M), Howard Hughes International Early Career, NIH 1R01HG010898-01A1, Obra Social “La Caixa” and Secretaria d’Universitats i Recerca and CERCA Program del Departament d’Economia i Coneixement de la Generalitat de Catalunya (GRC 2017 SGR 880). G.M., V.D.C., and L.D.C. were supported by grants from the Spanish of Economy, Industry, and Competitiveness (MEIC) (BFU2016-75008-P) and G.M. was also supported by the “Convocatoria de Ayudas Fundación BBVA a Investigadores, Innovadores y Creadores Culturales”. J.L.G.-S. was supported by the Spanish government (grants BFU2016-74961-P), an institutional grant Unidad de Excelencia María de Maeztu (MDM-2016-0687) and the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement No 740041). A.N. was supported by Fondo Europeo de Desarrollo Regional (FEDER) with project grants BFU2016-77961-P and PGC2018- 101927-B-I00 and by the Spanish National Institute of Bioinformatics (PT17/0009/0020)