Biology subjects

de la Villa, P.

Publications and source records attributed to de la Villa, P..

6 recordsLinked to original sources

bioRxiv2024

Topical administration of novel FKBP12 ligand MP-004 improves retinal function and structure in retinitis pigmentosa models.

PurposeThis study evaluates the therapeutic potential of MP-004, a novel FKBP12 ligand, in the treatment of inherited retinal dystrophies (IRDs). MP-004 targets FKBP12/RyR interaction, which is disrupted in several neurological disorders with underlying oxidative stress. MethodsThe toxicity and efficacy of MP-004 were examined in vitro in 661W cells. Efficacy was evaluated in phototoxic and H2O2-induced damage using impedance assays, calcium igaing and in situ PLA. In vivo, MP-004 efficacy was evaluated in the rd10 mouse model of retinitis pigmenetosa (RP) by topical ocular instillation. Retinal function was assessed by electroretinography (ERG), visual acuity was measured using a water maze test, and retinal structure was analyzed morphometrically. ResultsMP-004 exhibited low toxicity (LD50: 1.22 mM) and effectively protected 661W cells from phototoxicity (EC50: 30.6 nM). Under oxidative stress conditions, MP-004 preserved FKBP12.6/RyR2 interaction, partially restored endoplasmic reticulum calcium stores and prevented cell death. In vivo, MP-004 significantly preserved retinal function in rd10 mice, with ERG wave amplitude increases of up to 50% in scotopic and 71% in photopic conditions, corresponding to rod and cone functions, respectively. Additionally, MP-004 improved visual acuity for low spatial frequency patterns, and preserved retinal structure with a 23% increase in outer nuclear layer thickness, and preservation in the number of rods and cones and their segment length. ConclusionsMP-004 shows promise as a therapeutic agent for RP, preserving retinal structure and function, likely through modulation of FKBP12.6/RyR2 interaction. Further studies are needed to explore its pharmacokinetics and efficacy in other IRD models.

neuroscience↗

bioRxiv2023

Human Placenta-Derived Mesenchymal Stem Cells Stimulate Neuronal Regeneration By Promoting Axon Growth And Restoring Neuronal Activity

Cell therapy is a cutting-edge medical approach that involves the use of cells to treat various diseases and conditions. It harnesses the remarkable regenerative and reparative abilities of cells to restore or replace damaged tissues and promote healing. In the last decades, mesenchymal stem cells (MSCs) have become the cornerstone of cellular therapy due to their unique characteristics. Specifically human placenta-derived mesenchymal stem cells (hPMSCs) are highlighted for their unique features, including ease to isolate, non-invasive techniques for large scale cell production, significant immunomodulatory capacity, and a high ability to migrate to injuries. Researchers are exploring innovative techniques to overcome the low regenerative capacity of Central Nervous System (CNS) neurons, with one promising avenue being the development of tailored mesenchymal stem cell therapies capable of promoting neural repair and recovery. In this context, we have evaluated hPMSCs as candidate for CNS lesion regeneration using a skillful co-culture model system. Indeed, we have demonstrated the hPMSCs ability to stimulate damaged rat-retina neurons regeneration by promoting axon growth and restoring neuronal activity both under normoxia and hypoxia conditions. With our model we have obtained neuronal regeneration values of 10-12% and axonal length per neuron rates of 19.99{+/-}0.77, m/neuron. To assess whether the regenerative capabilities of hPMSCs are contact-dependent effects or it is mediated through paracrine mechanisms, we carried out transwell co-culture and conditioned medium experiments confirming the role of secreted factors in axonal regeneration. It was found that hPMSCs produce brain derived, nerve growth factors (BDNF, NGF) and Neurotrophin-3, involved in the process of neuronal regeneration and restoration of their physiological activity of neurons. The capability to access axonal physiology is crucial for studying information processing among neurons in healthy and diseased states. We confirm the success of our treatment using the patch clamp technique to study ionic currents in individual isolated living cells, confirming that in our model the regenerated neurons are electrophysiologically active.

cell biology↗

bioRxiv2023

Retinal affectation in Huntington's disease mouse models concurs with a local innate immune response

Huntingtons disease (HD) is a devastating disorder caused by aberrant expansion of CAG repeats in the HTT gene. Striatal dysfunction has been widely studied in HD mouse models. However, cumulative evidence indicates that the retina can also be functionally altered with consequences for visual function and circadian rhythms. The retina is the most exposed part of the central nervous system that can be used for monitoring the health status of patients using noninvasive techniques. To establish the retina as an appropriate tissue for HD studies, we linked the retinal alterations with those in the inner brain. We confirmed the malfunction of the R6/1 retinas, which underwent a rearrangement of their transcriptome as extensive as in the striatum, indicating a profound retinal affectation in HD. Tissue-enriched genes were downregulated in both areas, but a neuroinflammation signature was specifically induced in the R6/1 retina due to glial activation that was reminiscent of the situation in HD patients brains. These phenomena were confirmed in the zQ175 strain, and were accompanied by a differential impairment of the autophagy system between both tissues. Overall, these results demonstrated the suitability of the mouse retina as a research model for HD.

neuroscience↗

bioRxiv2022

Ambra1 haploinsufficiency results in metabolic alterations and exacerbates age-associated retinal degeneration

Autophagy is a key process in the maintenance of cellular homeostasis. The age-dependent decline in retinal autophagy has been associated with photoreceptor degeneration. Retinal dysfunction can also result from damage to the retinal pigment epithelium (RPE), as the RPE-retina constitutes an important metabolic ecosystem that must be finely tuned to preserve visual function. While studies of mice lacking essential autophagy genes have revealed a predisposition to retinal degeneration, the consequences of a moderate reduction in autophagy, similar to that which occurs during physiological aging, remain unclear. Here, we describe a retinal phenotype consistent with accelerated aging in mice carrying a haploinsufficiency for Ambra1, a pro-autophagic gene. These mice show protein aggregation in the retina and RPE, metabolic underperformance, and premature vision loss. Moreover, Ambra1+/gt mice are more prone to retinal degeneration after RPE stress. These findings indicate that autophagy provides crucial support to RPE-retinal metabolism and protects the retina against stress and physiological aging.

cell biology↗

bioRxiv2020

Nr2e3 functional domain ablation by CRISPR-Cas9D10A identifies a new isoform and generates Retinitis Pigmentosa and Enhanced S-cone Syndrome models

Mutations in NR2E3 cause retinitis pigmentosa (RP) and enhanced S-cone syndrome (ESCS) in humans. This gene produces a large isoform encoded in 8 exons and a previously unreported shorter isoform of 7 exons, whose function is unknown. We generated two mouse models by targeting exon 8 of Nr2e3 using CRISPR/Cas9-D10A nickase. Allele {Delta}27 is an in-frame deletion of 27 bp that ablates the dimerization domain, whereas allele {Delta}E8 (full deletion of exon 8), produces only the short isoform that lacks the dimerization and repressor domains. The {Delta}27 mutant shows developmental alterations and a non-progressive electrophysiological dysfunction that resembles the ESCS phenotype. The {Delta}E8 mutant exhibits progressive retinal degeneration, as occurs in human RP patients. Interestingly, the mutant retinas show invaginations similar to fovea-like pits. Our mutants suggest a role of Nr2e3 as a cone-patterning regulator and provide valuable models for studying mechanisms of NR2E3-associated retinal dystrophies and evaluating potential therapies. O_FIG O_LINKSMALLFIG WIDTH=186 HEIGHT=200 SRC="FIGDIR/small/147785v1_ufig1.gif" ALT="Figure 1"> View larger version (43K): org.highwire.dtl.DTLVardef@1f5916forg.highwire.dtl.DTLVardef@11f1384org.highwire.dtl.DTLVardef@13a6cd2org.highwire.dtl.DTLVardef@be52b3_HPS_FORMAT_FIGEXP M_FIG C_FIG Highlights- Nr2e3 mouse models were generated by exon 8 deletion using CRISPR/Cas9 D10A nickase. - New Nr2e3 mRNA retaining intron 7 encodes a short protein expressed in adult retina. - Deletion of 9 aa of the NR2E3 dimerization domain causes enhanced S-cone syndrome. - Deletion of exon 8 produces a phenotype similar to Retinitis Pigmentosa in mouse.

genetics↗

bioRxiv2020

Insulin receptor activation by proinsulin preserves synapses and vision in retinitis pigmentosa

Synaptic loss, neuronal death, and circuit remodeling are common features of central nervous system neurodegenerative disorders. Retinitis pigmentosa (RP), the leading cause of inherited blindness, is a group of retinal dystrophies characterized by photoreceptor dysfunction and death. The insulin receptor, a key controller of metabolism, also regulates neuronal survival and synaptic formation, maintenance, and activity. Indeed, deficient insulin receptor signaling has been implicated in several brain neurodegenerative pathologies. We present evidence linking impaired insulin receptor signaling with RP. We describe a selective decrease in the levels of the insulin receptor and its downstream effector phospho-S6 in retinal horizontal cell axons in the rd10 mouse model of RP, as well as aberrant synapses between rod photoreceptors and the postsynaptic terminals of horizontal and bipolar cells. A gene therapy strategy to induce sustained proinsulin production restored retinal insulin receptor signaling, by increasing S6 phosphorylation, without peripheral metabolic consequences. Moreover, proinsulin preserved photoreceptor synaptic connectivity and prolonged visual function in electroretinogram and optomotor tests. These findings support the therapeutic potential of proinsulin in RP.

neuroscience↗