Biology subjects

Sola, P.

Publications and source records attributed to Sola, P..

4 recordsLinked to original sources

bioRxiv2025

BMAL1 and YAP cooperate to hijack enhancers and promote inflammation in the aged epidermis

Ageing is characterised by persistent low-grade inflammation that is linked to impaired tissue homeostasis and functionality. However, the molecular mechanisms driving age-associated inflammation remain poorly understood. The mammalian skin is a clinically relevant target of age-driven inflammation associated with compromised barrier function, inefficient wound healing, elevated oxidative stress, and DNA damage accumulation. Here, we show that upon ageing a previously uncharacterised BMAL1-YAP transcriptional complex is hijacked from chromatin regions associated with homeostatic genes in adult epidermis and redirected to inflammation-related enhancers, amplifying the transcription of their target genes. Independently of its known role as a core circadian clock component, BMAL1 partners with the mechanosensitive transcriptional cofactor YAP at enhancer regions to regulate epidermal identity genes. In contrast, in aged skin, BMAL1-YAP complexes bind to enhancers of inflammation-related genes, co-regulated by NF-KB. Interestingly, aged pro-inflammatory signals from the IL-17 pathway activate YAP in a Hippo-independent manner. These findings unveil a transcriptional mechanism underlying epidermal ageing, linking chromatin dynamics to inflammatory transcriptional programs through BMAL1-YAP-bound enhancer rewiring. By elucidating how ageing reprograms transcriptional networks, our work highlights potential strategies to counteract chronic inflammation and restore tissue homeostasis across age-related loss of functionality.

molecular biology↗

bioRxiv2022

Mechanisms of vascular maturation and maintenance captured by longitudinal imaging of live mouse skin

A functional network of blood vessels is essential for organ growth and homeostasis. Yet, how the vasculature matures and maintains adult homeostasis remains elusive in live mice. By longitudinally tracking the same neonatal endothelial cells (ECs) over days to weeks, we found that capillary plexus expansion is driven by network-wide vessel regression and transient angiogenesis. A fixed number of neonatal ECs rearrange their positions to evenly distribute throughout the developing plexus and become positionally stable in adulthood. Upon injury, while neonatal ECs are predisposed to die, adult ECs survive through a plasmalemmal self-repair response. Furthermore, adult neighboring ECs reactivate migration to assist vessel repair. Lastly, neonatal vessel regression and adult vascular maintenance are orchestrated by temporally restricted VEGFR2 dependent signaling. Our work sheds light on fundamental cellular mechanisms that underlie both vascular maturation and adult homeostasis in vivo.

developmental biology↗

bioRxiv2022

Local IL-17 orchestrates skin aging

Skin aging is characterized by structural and functional changes that lead to slower wound healing and higher rate of infections, which contribute to age-associated frailty. This likely depends on synergy between alterations in the local microenvironment and stem cell-intrinsic changes, underscored by pro-inflammatory microenvironments that drive pleotropic changes. To date, little is known about the precise nature and origin of the proposed age-associated inflammatory cues, or how they affect different tissue resident cell types. Based on deep single-cell RNA-sequencing of the entire dermal compartment, we now provide a comprehensive understanding of the age-associated changes in all skin cell types. We show a previously unreported skew towards an IL-17-expressing phenotype of Th cells, {gamma}{delta} T cells and innate lymphoid cells in aged skin. Aberrant IL-17 signaling is common to many autoimmune (e.g., rheumatoid arthritis and psoriasis) and chronic inflammatory diseases. Importantly, in vivo blockade of IL-17-triggered signaling during the aging process reduces the pro-inflammatory state by affecting immune and non-immune skin cells of both dermis and epidermis. Strikingly, IL-17 neutralization significantly delays the appearance of age-related traits, such as decreased epidermal thickness, increased cornified layer thickness and ameliorated hair follicle stem cell activation and hair shaft regeneration. Our results indicate that the aged skin shows chronic and persistent signs of inflammation, and that age-associated increased IL-17 signaling could be targeted as a strategy to prevent age-associated skin ailments in elderly.

cell biology↗

bioRxiv2019

Immunotherapy prevents long-term disability in relapsing multiple sclerosis over 15 years

ObjectiveWhether immunotherapy improves long-term disability in multiple sclerosis has not been satisfactorily demonstrated. This study examined the effect of immunotherapy on long-term disability outcomes in relapsing-remitting multiple sclerosis.\n\nMethodsWe studied patients from MSBase followed for [≥]1 year, with [≥]3 visits, [≥]1 visit per year and exposed to a multiple sclerosis therapy, and a subset of patients with [≥]15-year follow-up. Marginal structural models were used to compare the hazard of 12-month confirmed increase and decrease in disability, EDSS step 6 and the incidence of relapses between treated and untreated periods. Marginal structural models were continuously re-adjusted for patient age, sex, pregnancy, date, disease course, time from first symptom, prior relapse history, disability and MRI activity.\n\nResults14,717 patients were studied. During the treated periods, patients were less likely to experience relapses (hazard ratio 0.60, 95% confidence interval 0.43-0.82, p=0.0016), worsening of disability (0.56, 0.38-0.82, p=0.0026) and progress to EDSS step 6 (0.33, 0.19-0.59, p=0.00019). Among 1085 patients with [≥]15-year follow-up, the treated patients were less likely to experience relapses (0.59, 0.50-0.70, p=10-9) and worsening of disability (0.81, 0.67-0.99, p=0.043).\n\nConclusionsContinued treatment with multiple sclerosis immunotherapies reduces disability accrual (by 19-44%), the risk of need of a walking aid by 67% and the frequency of relapses (by 40-41%) over 15 years. A proof of long-term effect of immunomodulation on disability outcomes is the key to establishing its disease modifying properties.

neuroscience↗