Biology subjects

Garcia-Diaz, A.

Publications and source records attributed to Garcia-Diaz, A..

3 recordsLinked to original sources

bioRxiv2025

Derivation and analysis of human somatic sensory neuron subtypes facilitated through fluorescent hPSC reporters

Peripheral sensory neuropathy (PSN) is associated with several devastating neurological conditions, yet effective strategies to prevent or alleviate the consequences of PSN are nearly non-existent. A major challenge in the development of better therapeutic interventions is the lack of appropriate human model systems. Human induced pluripotent stem cell (hiPSC)-derived somatosensory neurons present a promising strategy to overcome this issue but remain of limited translational utility, in part due to the low efficiency and lack of sensory subtype selectivity of the existing sensory neuron derivation protocols. To improve upon iPSC-based somatosensory disease models, we here describe the generation and validation of a genetic toolset to fluorescently label all or distinct (nociceptor, low threshold mechanoreceptor, and proprioceptor) somatosensory subtypes. These new resources will be transformative for hPSC-based approaches in PSN disease modeling - a critical step towards translating new findings into clinically relevant therapeutic strategies.

neuroscience↗

bioRxiv2021

The C. elegans Notch proteins LIN-12 and GLP-1 are tuned to lower force thresholds for activation than Drosophila Notch

The conserved transmembrane receptor Notch mediates cell fate decisions in all animals. In the absence of ligand, a Negative Regulatory Region (NRR) in the Notch ectodomain adopts an autoinhibited confirmation, masking an ADAM protease cleavage site [1, 2]; ligand binding makes the cleavage site accessible, leading to shedding of the Notch ectodomain as the first step of signal transduction [3, 4]. In Drosophila and vertebrates, the ligands are all single-pass transmembrane Delta/Serrate/LAG-2 (DSL) proteins; the endocytic adaptor Epsin binds to the ubiquitinated intracellular domain, and the resulting Clathrin-mediated endocytosis exerts a "pulling force" that exposes the cleavage site in the NRR [4-6]. However, in C. elegans, the presence of natural secreted DSL proteins [7] and other observations suggested that Epsin-mediated endocytosis may not be required to activate the Notch proteins LIN-12 and GLP-1. Here, we confirm that neither Epsin nor the cytosolic domains of DSL proteins are required for Notch signaling in C. elegans. Furthermore, we provide evidence that the NRRs of LIN-12 and GLP-1 are tuned to a lower force level than the NRR of Drosophila Notch. Finally, we show that adding a Leucine "plug" that occludes the cleavage site in vertebrate and Drosophila Notch proteins but is absent in the C. elegans Notch proteins [1, 2] renders the LIN-12 and GLP-1 NRRs dependent on Epsin-mediated ligand endocytosis, indicating that greater force is now required to expose the cleavage site. Thus, the NRRs of LIN-12 and GLP-1 appear to be tuned to a lower force threshold, accounting for the different requirements for signaling in C. elegans.

developmental biology↗

bioRxiv2019

VE-PTP participates in vasculogenic mimicry by preventing autophagic degradation of VE-cadherin

Aberrant extra-vascular expression of VE-cadherin has been observed in metastasis associated with Vasculogenic Mimicry (VM); we have recently shown that in VM prone (VM+) tumor cells VE-cadherin is mainly in the form of pVE-cadherin in Y658 allowing an increased plasticity that potentiates VM development. As excessive VE-cadherin phosphorylation is regulated by the phosphatase VEPTP in endothelial cells in the current study we analysed its role in this aberrant phenotype in malignant tumor cells. We show that human malignant melanoma cells VM+, also express VE-PTP although at lower levels than endothelial cells. The complex VE-PTP/VE-Cadherin/p120-catenin act as a safeguard to prevent VE-cadherin degradation by autophagy. Indeed, silencing of VE-PTP results in complete degradation of VE-cadherin with the features of autophagy and increases the global p120 tyrosine phosphorylation status. In summary, we show that VE-PTP is involved in VM formation and disruption of VE-PTP/VE-Cadherin/p120 complex results in enhanced autophagy in aggressive VM+ cells.

cancer biology↗