Suchergebnisse

© 2021 García-Casas, Alvarez-Illera, Gómez-Orte, Cabello, Fonteriz, Montero and Alvarez. ; We have reported recently that the mitochondrial Na+/Ca2+ exchanger inhibitor CGP37157 extends lifespan in Caenorhabditis elegans by a mechanism involving mitochondria, the TOR pathway and the insulin/IGF1 pathway. Here we show that CGP37157 significantly improved the evolution with age of the sarcomeric regular structure, delaying development of sarcopenia in C. elegans body wall muscle and increasing the average and maximum speed of the worms. Similarly, CGP37157 favored the maintenance of a regular mitochondrial structure during aging. We have also investigated further the mechanism of the effect of CGP37157 by studying its effect in mutants of aak-1;aak-2/AMP-activated kinase, sir-2.1/sirtuin, rsks-1/S6 kinase and daf-16/FOXO. We found that this compound was still effective increasing lifespan in all these mutants, indicating that these pathways are not involved in the effect. We have then monitored pharynx cytosolic and mitochondrial Ca2+ signalling and our results suggest that CGP37157 is probably inhibiting not only the mitochondrial Na+/Ca2+ exchanger, but also Ca2+ entry through the plasma membrane. Finally, a transcriptomic study detected that CGP37157 induced changes in lipid metabolism enzymes and a four-fold increase in the expression of ncx-6, one of the C. elegans mitochondrial Na+/Ca2+ exchangers. In summary, CGP37157 increases both lifespan and healthspan by a mechanism involving changes in cytosolic and mitochondrial Ca2+ homeostasis. Thus, Ca2+ signalling could be a promising target to act on aging. ; This work was supported by a grant from the Spanish Ministerio de Economía, Industria y Competitividad (BFU2017-83509-R) to JA and MM, project co-financed by the European Union through the European Regional Development Fund, and by grants from the Spanish Ministerio de Ciencia, Innovación y Universidades (PGC 2018–094276-B-I00) and the Rioja Salud Foundation (FEDER funds) to JC. PG-C had a FPI fellowship from Ministerio de Economía y Competitividad. Financial support from Programa Estratégico Instituto de Biología y Genética Molecular (IBGM), Escalera de Excelencia, Junta de Castilla y León (Ref. CLU-2019-02) is gratefully acknowledged. Some C. elegans strains were provided by the Caenorhabditis Genetics Center (CGC), which is funded by NIH Office of Research Infrastructure Programs (P40 OD010440).

In view of the proven link between adult hippocampal neurogenesis (AHN) and learning and memory impairment, we generated a straightforward adult neurogenesis in vitro model to recapitulate DNA methylation marks in the context of Alzheimer's disease (AD). Neural progenitor cells (NPCs) were differentiated for 29 days and Aβ peptide 1–42 was added. mRNA expression of Neuronal Differentiation 1 (NEUROD1), Neural Cell Adhesion Molecule 1 (NCAM1), Tubulin Beta 3 Class III (TUBB3), RNA Binding Fox-1 Homolog 3 (RBFOX3), Calbindin 1 (CALB1), and Glial Fibrillary Acidic Protein (GFAP) was determined by RT-qPCR to characterize the culture and framed within the multistep process of AHN. Hippocampal DNA methylation marks previously identified in Contactin-Associated Protein 1 (CNTNAP1), SEPT5-GP1BB Readthrough (SEPT5-GP1BB), T-Box Transcription Factor 5 (TBX5), and Nucleoredoxin (NXN) genes were profiled by bisulfite pyrosequencing or bisulfite cloning sequencing; mRNA expression was also measured. NXN outlined a peak of DNA methylation overlapping type 3 neuroblasts. Aβ-treated NPCs showed transient decreases of mRNA expression for SEPT5-GP1BB and NXN on day 9 or 19 and an increase in DNA methylation on day 29 for NXN. NXN and SEPT5-GP1BB may reflect alterations detected in the brain of AD human patients, broadening our understanding of this disease. ; This research was funded by the Spanish Government through a grant from the Institute of Health Carlos III (FIS PI17/02218), jointly funded by the European Regional Development Fund (ERDF), European Union, A way of shaping Europe; the Trans-Pyrenean Biomedical Research Network (REFBIO II-MOMENEU project) and the Government of Navarra through two grants from the Department of Industry of the Government of Navarra (PI058 iBEAS-Plus and PI055 iBEAS-Plus). AUC received a grant Doctorandos industriales 2018-2020 and a Predoctoral grant (2019) founded by the Department of Industry and Health of the Government of Navarra. MM received a grant Programa de ...

[Aim]: Functional in vivo studies on the mitochondrial thioredoxin system are hampered by the embryonic or larval lethal phenotypes displayed by murine or Drosophila knock-out models. Thus, the access to alternative metazoan knock-out models for the mitochondrial thioredoxin system is of critical importance. [Results]: We report here the characterization of the mitochondrial thioredoxin system of Caenorhabditis elegans that is composed of the genes trx-2 and trxr-2. We demonstrate that the proteins thioredoxin 2 (TRX-2) and thioredoxin reductase 2 (TRXR-2) localize to the mitochondria of several cells and tissues of the nematode and that trx-2 and trxr-2 are upregulated upon induction of the mitochondrial unfolded protein response. Surprisingly, C. elegans trx-2 (lof ) and trxr-2 (null) single and double mutants are viable and display similar growth rates as wild-type controls. Moreover, the lack of the mitochondrial thioredoxin system does not affect longevity, reactive oxygen species production or the apoptotic program. Interestingly, we found a protective role of TRXR-2 in a transgenic nematode model of Alzheimer's disease (AD) that expresses human β-amyloid peptide and causes an age-dependent progressive paralysis. Hence, trxr-2 downregulation enhanced the paralysis phenotype, while a strong decrease of β-amyloid peptide and amyloid deposits occurred when TRXR-2 was overexpressed. [Innovation]: C. elegans provides the first viable metazoan knock-out model for the mitochondrial thioredoxin system and identifies a novel role of this system in β-amyloid peptide toxicity and AD. [Conclusion]: The nematode strains characterized in this work make C. elegans an ideal model organism to study the pathophysiology of the mitochondrial thioredoxin system at the level of a complete organism. ; A.M.-V. was supported by the Instituto de Salud Carlos III [Projects PI050065 and PI080557, co-financed by the Fondo Social Europeo, FEDER] and Junta de Andalucía [Projects P07-CVI-02697 and P08-CVI-03629], Spain. B.C.-V. was supported by a fellowship from the Consejo Nacional de Ciencia y Tecnología (CONACYT) from the Government of Mexico. P.N. was supported by the Instituto de Salud Carlos III [project PI080500, co-financed by the Fondo Social Europeo, FEDER], and Junta de Andalucía [project P08-CTS-03988]. Work in the laboratory of P.S., a member of the NordForsk Nordic C. elegans network, was supported by a grant from the Swedish Research Council. J.C. was supported by the Spanish Ministry of Education and Science Grant BFU2010-21794 and the RiojaSalud Foundation. ; Peer reviewed

Glutathione is the most abundant thiol in the vast majority of organisms and is maintained in its reduced form by the flavoenzyme glutathione reductase. In this work, we describe the genetic and functional analysis of the Caenorhabditis elegans gsr-1 gene that encodes the only glutathione reductase protein in this model organism. By using green fluorescent protein reporters we demonstrate that gsr-1 produces two GSR-1 isoforms, one located in the cytoplasm and one in the mitochondria. gsr-1 loss of function mutants display a fully penetrant embryonic lethal phenotype characterized by a progressive and robust cell division delay accompanied by an aberrant distribution of interphasic chromatin in the periphery of the cell nucleus. Maternally expressed GSR-1 is sufficient to support embryonic development but these animals are short-lived, sensitized to chemical stress and have increased mitochondrial fragmentation and lower mitochondrial DNA content. Furthermore, the embryonic lethality of gsr-1 worms is prevented by restoring GSR-1 activity in the cytoplasm but not in mitochondria. Given the fact that the thioredoxin redox systems are dispensable in C. elegans, our data support a prominent role of the glutathione reductase/glutathione pathway in maintaining redox homeostasis in the nematode. ; Some strains were provided by the CGC, which is funded by NIH Office of Research Infrastructure Programs (P40 OD010440) and by the Japanese National Bioresource Project. We thank Cristina Cecchi, Amir Shapir, Paul Sternberg, Bart Braeckman, Chris Link, Simon Tuck, Keith Blackwell, José López-Barneo and LivOn Labs for strains and chemicals, Katie McCallum and Danielle Garsin for their help with skn-1 experiments and Elizabeth Veal and Michel Toledano for critical reading of the manuscript. Prof. Rafael Fernández-Chacón is deeply acknowledged for his continuous support. AMV was supported by grants from the Spanish Ministry of Economy and Competitiveness (BFU2015-64408-P) and the Instituto de Salud Carlos III (PI11/00072, cofinanced by the Fondo Social Europeo) and is a member of the GENIE and EU-ROS Cost Action of the European Union. NJS was supported by a grant from the US National Institutes of Health National Institute for Arthritis and Musculoskeletal and Skin Diseases (AR-054342). CJG was funded by a Doctoral Training Studentship provided by the University of Nottingham. PA was supported by the Spanish Ministry of Economy and Competitiveness (BFU2013-42709P). JC is a member of the GENIE Cost action and was funded by Rioja Salud Foundation (Onco-2-2015). ; Peer Reviewed

¿Quiénes son los nuevos Pepes en Alemania, esos chicos y chicas españolas que dejaron su país durante la crisis económica de los últimos años para buscarse un futuro en tierras teutonas? En verdad, poco tienen ellos que ver con el Pepe de la famosa película y de la realidad de hace 50 años. Las de hoy son personas altamente formadas y con un mayor conocimiento de idiomas que ninguna generación anterior. Provienen muchas veces de un nivel cultural medio y tienen un perfil más internacional, más europeo. Para que los conozcan mejor, los Pepes y las Pepas actuales cuentan en este libro sus propias experiencias con la migración y con la vida en Alemania. Cada uno y cada una de ellos ofrece algo distinto, curioso y original. Pero en su conjunto, dibujan con sus reflexiones un panorama amplio de un fenómeno tan polifacético como es la migración.

In the presence of aggregation-prone proteins, the cytosol and endoplasmic reticulum (ER) undergo a dramatic shift in their respective redox status, with the cytosol becoming more oxidized and the ER more reducing. However, whether and how changes in the cellular redox status may affect protein aggregation is unknown. Here, we show that C. elegans loss-of-function mutants for the glutathione reductase gsr-1 gene enhance the deleterious phenotypes of heterologous human, as well as endogenous worm aggregation-prone proteins. These effects are phenocopied by the GSH-depleting agent diethyl maleate. Additionally, gsr-1 mutants abolish the nuclear translocation of HLH-30/TFEB transcription factor, a key inducer of autophagy, and strongly impair the degradation of the autophagy substrate p62/SQST-1::GFP, revealing glutathione reductase may have a role in the clearance of protein aggregates by autophagy. Blocking autophagy in gsr-1 worms expressing aggregation-prone proteins results in strong synthetic developmental phenotypes and lethality, supporting the physiological importance of glutathione reductase in the regulation of misfolded protein clearance. Furthermore, impairing redox homeostasis in both yeast and mammalian cells induces toxicity phenotypes associated with protein aggregation. Together, our data reveal that glutathione redox homeostasis may be central to proteostasis maintenance through autophagy regulation. ; . The Spanish Ministry of Economy and Competitiveness supported EF-S and VG (BFU2016–78265-P), PA (BFU2016– 79313-P and MDM-2016–0687), and AM-V (BFU2015–64408-P). AM-V was also supported by the Instituto de Salud Carlos III (PI11/ 00072) and RPV-M (CPII16/00004, PI14/00949 and PI17/00011). All projects were cofinanced by the Fondo Social Europeo (FEDER). AM-V is a member of the GENIE and EU-ROS Cost Actions of the European Union and RPV-M is a Marie Curie Fellow (CIG322034, EU).