Biology subjects

Lopez-Otin, C.

Publications and source records attributed to Lopez-Otin, C..

7 recordsLinked to original sources

bioRxiv2026

The aging modulator miR-29 is essential for adult cardiomyocyte function

Aging is the main risk factor for cardiovascular diseases, underscoring the need to identify the molecular regulators that sustain cardiac function during aging. The microRNA miR-29 is a well-established aging-associated regulator as its expression increases with age, and its overexpression promotes premature aging. Here, we define the cardiomyocyte-autonomous role of miR-29 in the adult heart by generating an inducible, cardiomyocyte-specific miR-29-deficient mouse model (Heart-iKO). We show that Heart-iKO mice develop dilated cardiomyopathy (DCM) with reduced ejection fraction that ultimately leads to premature death. Mechanistically, Heart-iKO cardiomyocytes exhibit alterations in mitochondrial structure and function. Transcriptomic profiling of bulk heart tissue and isolated cardiomyocytes revealed a consistent downregulation of genes involved in oxidative phosphorylation and the electron transport chain. We further observed a similar pattern of mitochondrial impairment in miR-29-deficient human cardiomyocytes derived from induced pluripotent stem cells (CM-iPSCs). Together, these findings highlight the context-dependent role of miR-29 in cardiac physiology and aging: although its upregulation promotes premature aging, its basal expression is required to maintain mitochondrial homeostasis and prevent heart failure in the adult myocardium.

physiology↗

bioRxiv2025

Reduced systemic autophagy by simultaneous loss of ATG4B, ATG4C and ATG4D leads to accelerated aging in mice

Autophagy is an essential catabolic pathway that safeguards cellular and tissue homeostasis, yet the systemic consequences of its impairment in mammals remain poorly defined because complete autophagy ablation is embryonic or perinatal lethal. Here, we generate ATG4A-only mice, a model in which ATG4A is the sole remaining ATG4 protease due to combined ATG4B/C/D deletion. Through comprehensive biochemical and cellular analyses, we delineate the in vivo substrate specificity of ATG4A and demonstrate that it sustains only minimal ATG8 priming, uncovering a previously unrecognized functional asymmetry within the mammalian ATG4-ATG8 system. ATG4A-only mice exhibit a profound but incomplete whole-body autophagy deficiency that disrupts multiple organ systems and triggers a premature aging syndrome marked by increased DNA damage, systemic senescence, metabolic dysfunction, and dramatically shortened lifespan. Integrating these findings with comparisons to additional ATG4-deficient models, we show that organismal longevity scales with residual autophagic competence. Together, our work reveals how graded reductions in autophagy integrity influence tissue fitness and aging, establishing autophagic capacity as a key determinant of mammalian lifespan.

cell biology↗

bioRxiv2024

miR-29a-3p, a new myokine orchestrating resistance exercise via coordinated metabolic responses

It remains unclear whether the adaptive response to different exercise models is mediated by EV miRNAs released from skeletal muscle and their functional metabolic role. We sequenced miRNA-loaded plasma EVs obtained from resting mice after 4-weeks endurance or resistance training. Resistance exercise increased the expression of a 11-miRNA profile grouped into two functional clusters. Using both genetically modified animal models and in vitro approaches, we have identified miR-29a-3p as a novel myokine secreted into the bloodstream as EV cargo by contracting skeletal muscle. It is a cornerstone in the adaptation to resistance training by mediating the coordinated expression and secretion of other miRNAs and affecting muscle mass development and energy metabolism in muscle and liver. Taken together, our study suggests a coordinating and determinant role of miR-29a-3p in the response and adaptation to resistance training, possibly due to its role as a myokine through its regulatory role in energy metabolism.

molecular biology↗

bioRxiv2023

Ghrelin delays premature aging in Hutchinson-Gilford progeria syndrome

Hutchinson-Gilford progeria syndrome (HGPS) is a rare and fatal genetic condition arising from a single nucleotide alteration in the LMNA gene, which leads to the production of a defective lamin A protein known as progerin. The buildup of progerin hastens the onset of premature and expedited aging. Patients with HGPS exhibit short stature, low body weight, lipodystrophy, metabolic dysfunction, and skin and musculoskeletal abnormalities and, in most cases, die of cardiovascular disease by their early teenage years. Currently, no effective cure or treatment for the disease highlights the importance of discovering new therapeutic strategies. Herein, we present evidence that the hormone ghrelin, besides promoting autophagy and progerin clearance, rescued several cellular hallmarks of premature aging of human HGPS fibroblasts. Using an HGPS mouse model, LmnaG609G/G609G mice, we also show that ghrelin administration rescued the short-lived mice molecular and histopathological progeroid features, prevented progressive weight loss at later stages, reverted the lipodystrophic phenotype, and extended lifespan. Thus, we disclose that modulation of ghrelin signaling may give rise to new treatment targets and translational approaches that may improve outcomes and the health quality of HGPS patients and natural aging pathologies.

physiology↗

bioRxiv2022

miR-29 is an important driver of aging-related phenotypes

Aging is a consequence of complex molecular changes, but the roles of individual microRNAs (miRNAs) in aging remain unclear. One of the few miRNAs that are upregulated during both normal and premature aging is miR-29. We confirmed this finding in our study in both mouse and monkey models. Follow-up analysis of the transcriptomic changes during normal aging revealed that miR-29 is among the top miRNAs predicted to drive the aging-related gene expression changes. We also showed that partial loss of miR-29 extends the lifespan of Zmpste24-/- mice, an established model of progeria, which indicates that miR-29 is functionally important in this accelerated aging model. To examine whether miR-29 upregulation alone is sufficient to promote aging-related phenotypes in vivo, we generated mice in which miR-29 can be conditionally overexpressed (miR-29TG). We found that miR-29 overexpression in mice is sufficient to drive aging-related phenotypes including alopecia, kyphosis, osteoporosis, senescence, and leads to early lethality. Transcriptomic analysis of both young miR-29TG and old WT mice revealed shared downregulation of genes enriched in extracellular matrix and fatty acid metabolism, and shared upregulation of genes in pathways linked to inflammation. Together, these results highlight the functional importance of miR-29 in controlling a gene expression program that drives agingrelated phenotypes.

physiology↗

bioRxiv2021

OMA1 mediates local and global stress responses against protein misfolding in CHCHD10 mitochondrial myopathy

Mitochondrial stress triggers a response in the cells mitochondria and nucleus, but how these stress responses are coordinated in vivo is poorly understood. Here, we characterize a family with myopathy caused by a dominant p.G58R mutation in the mitochondrial protein CHCHD10. To understand the disease etiology, we developed a novel knock-in mouse model and found that mutant CHCHD10 aggregates in affected tissues, applying a toxic protein stress to the inner mitochondrial membrane. Unexpectedly, survival of CHCHD10 knock-in mice depended on a protective stress response mediated by OMA1. The OMA1 stress response acted both locally within mitochondria, inhibiting mitochondrial fusion, and signaled outside the mitochondria, activating the integrated stress response. We additionally identified an isoform switch in the terminal complex of the electron transport chain as a novel component of this response. Our results demonstrate that OMA1 is essential for neonatal survival conditionally in the setting of inner mitochondrial membrane stress, coordinating local and global stress responses to reshape the mitochondrial network and proteome. Graphical Abtract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=199 SRC="FIGDIR/small/473493v1_ufig1.gif" ALT="Figure 1"> View larger version (38K): org.highwire.dtl.DTLVardef@1ab5990org.highwire.dtl.DTLVardef@85080dorg.highwire.dtl.DTLVardef@1d3a036org.highwire.dtl.DTLVardef@bb4679_HPS_FORMAT_FIGEXP M_FIG C_FIG

cell biology↗

bioRxiv2020

The proliferative history shapes the DNA methylome of B-cell tumors and predicts clinical outcome

We report a systematic analysis of the biological and clinical implications of DNA methylation variability in five categories of B-cell tumors derived from B cells spanning the entire maturation spectrum. We used 2056 primary samples including training and validation series and show that 88% of the human DNA methylome is dynamically modulated under normal and neoplastic conditions. B-cell tumors display both epigenetic imprints of their cellular origin and de novo, disease-specific epigenetic alterations that in part are related to differential transcription factor binding. These differential methylation patterns were used by a machine-learning approach to create a diagnostic algorithm that accurately classifies 14 B-cell tumor entities and subtypes with different clinical management. Beyond this, we identified extensive patient-specific epigenetic variability targeting constitutively silenced chromatin regions, a phenomenon we could relate to the proliferative history of normal and neoplastic B cells. We observed that, depending on the maturation stage of the tumor cell of origin, mitotic activity leaves different imprints into the DNA methylome. Subsequently, we constructed a novel DNA methylation-based mitotic clock called epiCMIT (epigenetically-determined Cumulative MIToses), whose lapse magnitude represents a strong independent prognostic variable within specific B-cell tumor subtypes and is associated with particular driver genetic alterations. Our findings reveal DNA methylation as a holistic tracker of B-cell tumor developmental history, with implications in the differential diagnosis and prediction of the outcome of the patients.

cancer biology↗