Suchergebnisse

Reduction of caloric intake delays and prevents age-associated diseases and extends the life span in many organisms. It may be that these benefits are due to positive effects of caloric restriction on stem cell function. We use the planarian model Schmidtea mediterranea, an immortal animal that adapts to long periods of starvation by shrinking in size, to investigate the effects of starvation on telomere length. We show that the longest telomeres are a general signature of planarian adult stem cells. We also observe that starvation leads to an enrichment of stem cells with the longest telomeres and that this enrichment is dependent on mTOR signaling. We propose that one important effect of starvation for the rejuvenation of the adult stem cell pool is through increasing the median telomere length in somatic stem cells. Such a mechanism has broad implications for how dietary effects on aging are mediated at the whole-organism level. González-Estévez and colleagues show that long telomeres are a signature of planarian stem cells. They find that in the immortal planarian, starvation leads to an enrichment of stem cells with the longest telomeres dependent on mTOR signaling. They propose that starvation contributes to the rejuvenation of the adult stem cell pool by increasing their telomere length. ; We would also like to thank E. Arza and A.M. Santos from the CNIC Microscopy Unit and also J. Solana, C. Martín-Durán, R. Romero, L. Sastre, E.G. Arias-Salgado, and all past and current members in the C.G.-E. and I.F. labs. C.G.-E. was funded by a Contrato de Investigadores Miguel Servet (CP12/03214) and by the FLI. The FLI is a member of the Leibniz Association and is financially supported by the Federal Government of Germany and the State of Thuringia. O.G.-G. was funded by an LGSA scholarship. R.P. and B.F.-V. were funded by a grant (PI17-01401) from Fondo de Investigaciones Sanitarias (Instituto de Salud Carlos III, Spain) and FEDER funds. I.F. was funded by grants from Ministerio de Ciencia, Innovación y Universidades (SAF2016-80406-R), Comunidad de Madrid (S2017/BMD-3875), and the Red Temática de Investigación Cooperativa en Enfermedades Cardiovasculares (RD12/0042/0045). The CNIC is supported by the Ministerio de Ciencia, Innovación y Universidades and the Pro CNIC Foundation, and is a Severo Ochoa Center of Excellence (SEV-2015-0505). A.A.A. was funded by grants from the BBSRC (BB/K007564/1) and MRC (MR/M000133/1), and S.S. by a University of Oxford Clarendon Fund Scholarship.

© 2021 The Authors. ; Idiopathic pulmonary fibrosis is a lethal lung fibrotic disease, associated with aging with a mean survival of 2-5 years and no curative treatment. The GSE4 peptide is able to rescue cells from senescence, DNA and oxidative damage, inflammation, and induces telomerase activity. Here, we investigated the protective effect of GSE4 expression in vitro in rat alveolar epithelial cells (AECs), and in vivo in a bleomycin model of lung fibrosis. Bleomycin-injured rat AECs, expressing GSE4 or treated with GSE4-PLGA/PEI nanoparticles showed an increase of telomerase activity, decreased DNA damage, and decreased expression of IL6 and cleaved-caspase 3. In addition, these cells showed an inhibition in expression of fibrotic markers induced by TGF-β such as collagen-I and III among others. Furthermore, treatment with GSE4-PLGA/PEI nanoparticles in a rat model of bleomycin-induced fibrosis, increased telomerase activity and decreased DNA damage in proSP-C cells. Both in preventive and therapeutic protocols GSE4-PLGA/PEI nanoparticles prevented and attenuated lung damage monitored by SPECT-CT and inhibited collagen deposition. Lungs of rats treated with bleomycin and GSE4-PLGA/PEI nanoparticles showed reduced expression of α-SMA and pro-inflammatory cytokines, increased number of pro-SPC-multicellular structures and increased DNA synthesis in proSP-C cells, indicating therapeutic efficacy of GSE4-nanoparticles in experimental lung fibrosis and a possible curative treatment for lung fibrotic patients. ; R.P laboratory was funded by grants P17-01401 (Fondo de Investigaciones Sanitarias, Instituto de Salud Carlos III, Spain supported by FEDER funds), CIBER 576/805_ER16PE06P2016 and MINECO from the Spanish Government (INNPACTO, IPT-2012-0674-090000). M.M-M. laboratory was funded by Instituto de Salud Carlos III PI18/00367, supported by FEDER (Fondos Europeos de Desarrollo Regional (a way to build Europe)), JC received funds from MINECO CICYT SAF2014-55322-P, and GG laboratory was funded by grant SAF2015-68073-R (MINECO/FEDER) supported by FEDER funds. C.MG and R G-L are granted by the CIBERER.

The elucidation of mechanisms involved in resistance to therapies is essential to improve the survival of patients with malignant gliomas. A major feature possessed by glioma cells that may aid their ability to survive therapy and reconstitute tumors is the capacity for self-renewal. We show here that glioma stem cells (GSCs) express low levels of MKP1, a dual-specificity phosphatase, which acts as a negative inhibitor of JNK, ERK1/2, and p38 MAPK, while induction of high levels of MKP1 expression are associated with differentiation of GSC. Notably, we find that high levels of MKP1 correlate with a subset of glioblastoma patients with better prognosis and overall increased survival. Gain of expression studies demonstrated that elevated MKP1 impairs self-renewal and induces differentiation of GSCs while reducing tumorigenesis in vivo. Moreover, we identified that MKP1 is epigenetically regulated and that it mediates the anti-tumor activity of histone deacetylase inhibitors (HDACIs) alone or in combination with temozolomide. In summary, this study identifies MKP1 as a key modulator of the interplay between GSC self-renewal and differentiation and provides evidence that the activation of MKP1, through epigenetic regulation, might be a novel therapeutic strategy to overcome therapy resistance in glioblastoma. ; O.A. (BFI_2011_195), L.G.-R. (PRE_2013_1_760), L.M.-C. (PRE_2014_1_92), and J.A.-I. (PRE_2016_1_0375) were each recipient of a predoctoral fellowship from the Department of Education, University and Research of the Basque Government, and P.A. from the Spanish Association Against Cancer (AECC Gipuzkoa). This work was supported by grants from the Instituto de Salud Carlos III and FEDER Funds (PI13/02277, PI14/01495, PI15/00186, CP16/00039, PI16/01580, DTS16/084), European Union (Marie Curie CIG 2012/712404, REFBIO13/BIOD/009, and 011), and AICR/WCR [13–1270]. ; Peer reviewed