Identification of molecular mechanisms underlying frailty and successful aging in centenarians

259 p.El envejecimiento es un proceso sistémico, multifactorial y degenerativo caracterizado por el declive y la pérdida de capacidades físicas y mentales. La esperanza media de vida ha aumentado considerablemente en el último siglo, incrementando así el número de personas mayores en la población y, por tanto, las limitaciones funcionales y las enfermedades relacionadas con la edad. En este sentido, la fragilidad representa un nuevo síndrome geriátrico que se caracteriza por una pérdida de la capacidad funcional y una disminución de la capacidad de respuesta al estrés fisiológico, lo que resulta en una mayor vulnerabilidad del individuo y en resultados negativos para la salud. Se trata de una afección dinámica que se está convirtiendo en un importante problema de salud que es necesario detectar e intervenir. Se sabe relativamente poco sobre la fisiopatología de este síndrome y los mecanismos moleculares subyacentes a la fragilidad siguen siendo poco conocidos. Con el fin de abordar esta cuestión, se analizó el perfil transcriptómico de un conjunto de individuos robustos y frágiles residentes en el País Vasco, y se encontraron 35 genes expresados diferencialmente que se asociaron con el estado e fragilidad. Éstos incluían genes asociados a inflamación, respuesta inmune o miRNAs, procesos previamente relacionados con la fragilidad. Entre ellos, 7 candidatos fueron validados en cohortes independientes y también mostraron un patrón de expresión similar en mioblastos y fibroblastos primarios humanos mantenidos en cultivo. Su expresión fue parcialmente restaurada tras diferentes programas de intervención en individuos frágiles. Análisis adicionales revelaron la expresión de un conjunto mínimo de 3 genes (aumento de EGR1 y disminución de DDX11L1 y miR454) fuertemente asociados con el estado de fragilidad y las características clínicas vinculadas a la fragilidad como la multimorbilidad y la polifarmacia. Además, descubrimos su papel en el envejecimiento celular e identificamos su actividad como mediadores de vías asociadas a la senescencia, convirtiéndose en potenciales actores en la fisiopatología de este síndrome geriátrico. En conjunto, nuestros resultados revelan un vínculo entre fragilidad y senescencia.El envejecimiento cerebral consiste en una pérdida progresiva de las capacidades funcionales que se asocia a un deterioro cognitivo progresivo y puede conducir a enfermedades neurodegenerativas.Aunque se han utilizado diferentes enfoques para identificar biomarcadores y vías moleculares subyacentes al envejecimiento cerebral, se mantienen en gran medida desconocidos. Los centenarios,muestran una longevidad extrema que se acompaña de una mejor función cognitiva, menos comorbilidades y una mayor calidad de vida y, por lo tanto, se han propuesto como modelo de envejecimiento saludable. En nuestro estudio, realizamos análisis transcriptómicos en muestras de hipocampo humano de individuos de diferentes edades, incluyendo individuos jóvenes, ancianos y centenarios, con el fin de abordar los mecanismos moleculares subyacentes al envejecimiento cerebral.Identificamos un patrón de expresión génica diferencial en muestras cerebrales de centenarios en comparación con los otros dos grupos. En particular, varios miembros de la familia de genes de las metalotioneínas (MTs) se expresaron en gran medida en el hipocampo de los centenarios. Estos hallazgos se validaron en dos cohortes adicionales e independientes. En particular, las MTs fueron expresadas principalmente por los astrocitos y estudios funcionales in vitro describieron el papel de las MTs en su viabilidad y actividad. De hecho, el silenciamiento de MT1 o MT3 en astrocitos humanos primarios provocó una disminución de la proliferación, un aumento de la apoptosis y la senescencia, junto con un incremento de la expresión de genes inflamatorios. En general, estos resultados muestran que el hipocampo de los centenarios presenta altos niveles de MTs, que se expresan principalmente en los astrocitos convirtiéndose en un mecanismo defensivo que podría proporcionar neuroprotección en el cerebro durante el envejecimiento. Otros análisis adicionales, revelaron un subconjunto de 6 genes cuya expresión se correlacionaba con el envejecimiento cronológico en el hipocampo humano. Entre ellos, el descenso de RAD23B mostró las mayores diferencias a nivel estadístico tanto en humanos como enratones. La validación en cohortes adicionales confirmó la disminución de los niveles de RAD23B con la edad, también a nivel proteico, que se agravaban en condiciones patológicas, ya que sus niveles eran más bajos o totalmente ausentes en pacientes con enfermedad de Alzheimer. Además, experimentos de silenciamiento en cultivos celulares in vitro demostraron que estaba implicado en la viabilidad y actividad de los astrocitos, lo que indica que es un biomarcador putativo y regulador del envejecimiento celular en el cerebro

Targeting Myotonic Dystrophy Type 1 with Metformin

Myotonic dystrophy type 1 (DM1) is a multisystemic disorder of genetic origin. Progressive muscular weakness, atrophy and myotonia are its most prominent neuromuscular features, while additional clinical manifestations in multiple organs are also common. Overall, DM1 features resemble accelerated aging. There is currently no cure or specific treatment for myotonic dystrophy patients. However, in recent years a great effort has been made to identify potential new therapeutic strategies for DM1 patients. Metformin is a biguanide antidiabetic drug, with potential to delay aging at cellular and organismal levels. In DM1, different studies revealed that metformin rescues multiple phenotypes of the disease. This review provides an overview of recent findings describing metformin as a novel therapy to combat DM1 and their link with aging.M.G.-P. and A.S.-A. are recipient of predoctoral fellowships from the University of the Basque Country (PIF 15/245) and Carlos III Institute (FI17/00250), respectively. This work is supported by grants from the Carlos III Institute and FEDER funds (PI17/01841, DTS18/00181, PI19/01355, PI21/00557), Health Department from Basque Country (2017222021, 2018222021, 2020333008) and CIBERNED funds

Myotonic Dystrophy type 1 cells display impaired metabolism and mitochondrial dysfunction that are reversed by metformin

Myotonic dystrophy type 1 (DM1; MIM #160900) is an autosomal dominant disorder, clinically characterized by progressive muscular weakness and multisystem degeneration. The broad phenotypes observed in patients with DM1 resemble the appearance of a multisystem accelerated aging process. However, the molecular mechanisms underlying these phenotypes remain largely unknown. In this study, we characterized the impact of metabolism and mitochondria on fibroblasts and peripheral blood mononuclear cells (PBMCs) derived from patients with DM1 and healthy individuals. Our results revealed a decrease in oxidative phosphorylation system (OXPHOS) activity, oxygen consumption rate (OCR), ATP production, energy metabolism, and mitochondria! dynamics in DM1 fibroblasts, as well as increased accumulation of reactive oxygen species (ROS). PBMCs of DM1 patients also displayed reduced mitochondria! dynamics and energy metabolism. Moreover, treatment with metformin reversed the metabolic and mitochondria! defects as well as additional accelerated aging phenotypes, such as impaired proliferation, in DM1-derived fibroblasts. Our results identify impaired cell metabolism and mitochondria! dysfunction as important drivers of DM1 pathophysiology and, therefore, reveal the efficacy of metformin treatment in a pre-clinical setting.This work was supported by grants from the Instituto Salud Carlos III and FEDER funds (CP16/00039, PI16/01580, PI17/01841) and Health department from Basque Country (2017 and 2018-2017222021)

Senescence plays a role in myotonic dystrophy type 1 br

Myotonic dystrophy type 1 (DM1; MIM #160900) is an autosomal dominant disorder, clinically characterized by progressive muscular weakness and multisystem degeneration. The broad phenotypes observed in patients with DM1 resemble the appearance of an accelerated aging process. However, the molecular mechanisms underlying these phenotypes remain largely unknown. Transcriptomic analysis of fibroblasts derived from patients with DM1 and healthy individuals revealed a decrease in cell cycle activity, cell division, and DNA damage response in DM1, all of which related to the accumulation of cellular senescence. The data from transcriptome analyses were corroborated in human myoblasts and blood samples, as well as in mouse and Drosophila models of the disease. Serial passage studies in vitro confirmed the accelerated increase in senescence and the acquisition of a senescence-associated secretory phenotype in DM1 fibroblasts, whereas the DM1 Drosophila model showed reduced longevity and impaired locomotor activity. Moreover, functional studies highlighted the impact of BMI1 and downstream p16INK4A/ RB and ARF/p53/p21CIP pathways in DM1-associated cellular phenotypes. Importantly, treatment with the senolytic compounds Quercetin, Dasatinib, or Navitoclax reversed the accelerated aging phenotypes in both DM1 fibroblasts in vitro and in Drosophila in vivo. Our results identify the accumulation of senescence as part of DM1 pathophysiology and, therefore, demonstrate the efficacy of senolytic compounds in the preclinical setting.MGP and ASA are recipient of predoctoral fellowships from the University of the Basque Country (PIF 15/245) and Carlos III Institute (FI17/00250), respectively. We thank the methodological support service of Biodonostia Institute for help with statistical analysis. This work is supported by grants from the Instituto Salud Carlos III and FEDER funds (PI16/01580, PI17/01841, DTS18/00181, PI19/01355, CPII19/00021, and DTS20/00179), La Caixa, and Health department from Basque Country (2017222021, 2018222021, and 2020333008)

High SOX9 Maintains Glioma Stem Cell Activity through a Regulatory Loop Involving STAT3 and PML

Glioma stem cells (GSCs) are critical targets for glioma therapy. SOX9 is a transcription factor with critical roles during neurodevelopment, particularly within neural stem cells. Previous studies showed that high levels of SOX9 are associated with poor glioma patient survival. SOX9 knockdown impairs GSCs proliferation, confirming its potential as a target for glioma therapy. In this study, we characterized the function of SOX9 directly in patient-derived glioma stem cells. Notably, transcriptome analysis of GSCs with SOX9 knockdown revealed STAT3 and PML as downstream targets. Functional studies demonstrated that SOX9, STAT3, and PML form a regulatory loop that is key for GSC activity and self-renewal. Analysis of glioma clinical biopsies confirmed a positive correlation between SOX9/STAT3/PML and poor patient survival among the cases with the highest SOX9 expression levels. Importantly, direct STAT3 or PML inhibitors reduced the expression of SOX9, STAT3, and PML proteins, which significantly reduced GSCs tumorigenicity. In summary, our study reveals a novel role for SOX9 upstream of STAT3, as a GSC pathway regulator, and presents pharmacological inhibitors of the signaling cascade.P.A. and A.S.-A. were recipients of predoctoral fellowships from the AECC foundation and Carlos III Institute (ISCIII), respectively. M.a.-S. holds a Sara Borrell postdoctoral contract from the ISCIII (CD19/00154). E.C.-G. was a recipient of a Stop Fuga de Cerebros postdoctoral fellowship and holds a Miguel Servet contract from the ISCIII (CP19/00085). We thank the Histology Platform of the Biodonostia Health Research Institute, The Neuro-Oncology Committee of Donostia University Hospital, and Basque Biobank for their help. This research was supported by grants from ISCIII and FEDER Funds (CP16/00039, DTS16/00184, PI16/01580, DTS18/00181, PI18/01612, CP19/00085), and the Industry and Health Departments of the Basque Country

PR-LncRNA Signature Regulates Glioma Cell Activity Through Expression of SOX Factors

Long non-coding RNAs (LncRNAs) have emerged as a relevant class of genome regulators involved in a broad range of biological processes and with important roles in tumor initiation and malignant progression. We have previously identified a p53-regulated tumor suppressor signature of LncRNAs (PR-LncRNAs) in colorectal cancer. Our aim was to identify the expression and function of this signature in gliomas. We found that the expression of the four PR-LncRNAs tested was high in human low-grade glioma samples and diminished with increasing grade of disease, being the lowest in glioblastoma samples. Functional assays demonstrated that PR-LncRNA silencing increased glioma cell proliferation and oncosphere formation. Mechanistically, we found an inverse correlation between PR-LncRNA expression and SOX1, SOX2 and SOX9 stem cell factors in human glioma biopsies and in glioma cells in vitro. Moreover, knock-down of SOX activity abolished the effect of PR-LncRNA silencing in glioma cell activity. In conclusion, our results demonstrate that the expression and function of PR-LncRNAs are significantly altered in gliomagenesis and that their activity is mediated by SOX factors. These results may provide important insights into the mechanisms responsible for glioblastoma pathogenesis.PA, JA-I and AS-A were recipients of a predoctoral fellowship from the Spanish Association Against Cancer (AECC Gipuzkoa), Basque Government and Instituto Salud Carlos III. This work was supported by grants from the Carlos III Institute of Health and the European Regional Development Fund (PI13/02277, CP16/00039, DTS16/084, and PI16/01580) and Industry and Health Departments of the Basque Country