Suchergebnisse

Mammals optimize their physiology to the light–dark cycle by synchronization of the master circadian clock in the brain with peripheral clocks in the rest of the tissues of the body. Circadian oscillations rely on a negative feedback loop exerted by the molecular clock that is composed by transcriptional activators Bmal1 and Clock, and their negative regulators Period and Cryptochrome. Components of the molecular clock are expressed during early development, but onset of robust circadian oscillations is only detected later during embryogenesis. Here, we have used na¨ıve pluripotent mouse embryonic stem cells (mESCs) to study the role of Bmal1 during early development. We found that, compared to wild-type cells, Bmal12/2 mESCs express higher levels of Nanog protein and altered expression of pluripotencyassociated signalling pathways. Importantly, Bmal12/2 mESCs display deficient multi-lineage cell differentiation capacity during the formation of teratomas and gastrula-like organoids. Overall, we reveal that Bmal1 regulates pluripotent cell differentiation and propose that the molecular clock is an hitherto unrecognized regulator of mammalian development. ; Ramon y Cajal grant of the Spanish ministry of economy and competitiveness RYC2012-10019 ; Spanish ministry of economy and competitiveness BFU2016-75233-P ; Andalusian regional government PC-0246-2017 ; Fundacion Progreso y Salud (FPS) ; Instituto de Salud Carlos III European Union (EU) CPII17/00032 PI17/01574 ; University of Granada

Multipotent mesenchymal stromal cells (MSCs) have emerged as a promising cell therapy in regenerative medicine and for autoimmune/inflammatory diseases. However, a main hurdle for MSCs-based therapies is the loss of their proliferative potential in vitro. Here we report that glycoprotein A repetitions predominant (GARP) is required for the proliferation and survival of adipose-derived MSCs (ASCs) via its regulation of transforming growth factor-β (TGF-β) activation. Silencing of GARP in human ASCs increased their activation of TGF-β which augmented the levels of mitochondrial reactive oxygen species (mtROS), resulting in DNA damage, a block in proliferation and apoptosis. Inhibition of TGF-β signaling reduced the levels of mtROS and DNA damage and restored the ability of GARP-/low ASCs to proliferate. In contrast, overexpression of GARP in ASCs increased their proliferative capacity and rendered them more resistant to etoposide-induced DNA damage and apoptosis, in a TGF-β-dependent manner. In summary, our data show that the presence or absence of GARP on ASCs gives rise to distinct TGF-β responses with diametrically opposing effects on ASC proliferation and survival. ; This work has been financed by the Instituto de Salud Carlos III, Spain (www.isciii.es) and Fondo Europeo de Desarrollo Regional (FEDER), from the European Union, through the research grants PI15/00794, PI18/00826, and the contract CPII15/00032 (P.A), PI15/02015, PI18/00337, and ISCIII Red de Terapia Celular (RD12/0019/0006) (F.M.). P.A. is supported by the Consejería de Salud - Junta de Andalucía through the contract "Nicolás Monardes (C-0013-2018). F.M. is supported by the Fundación Progreso y Salud (Consejería de Salud—Junta de Andalucía). A.B.C.-G. is supported by the Ministerio de Ciencia y Tecnología, through the contract PEJ-2014-A-46314. V.A. is funded by the L'Oréal-UNESCO For Women In Science Program. V.R.-M. is supported by a Miguel Servet II contract FIS/FEDER (CPII17/00032) and ISCIII/FEDER PI17/01574. S.G-P. is supported by a Miguel Servet I contract FIS/FEDER (CP14/00197). P.M. is supported by the Fundación Andaluza Progreso y Salud (Consejería de Salud—Junta de Andalucía). ; Yes