Biology subjects

Gharbi, A.

Publications and source records attributed to Gharbi, A..

3 recordsLinked to original sources

bioRxiv2024

Immortalized Intestinal Telocytes - A Stem Cell Niche In Vitro

Telocytes, a distinct type of mesenchymal cell, have recently emerged as crucial components of the intestinal stem cell niche, primarily by providing essential Wnt proteins that drive stem cell function. However, their detailed biology and the specific mechanisms by which they regulate stem cell activity remain largely unexplored. Here, we established an immortalized intestinal telocyte cell line that retains the key cellular and molecular characteristics of native telocytes. Remarkably, this cell line, unlike telocyte-depleted immortalized mesenchyme, supports the growth of both mouse and human organoids in co-culture without the need for external factor supplementation. These findings indicate that telocytes are not only essential but are also sufficient to maintain stem cell activity. This immortalized telocyte line provides a valuable source of factors that support stem cell activity in vitro, offering a powerful tool for advancing our understanding of telocyte biology and the reciprocal communication between stem cells and their niche.

cell biology↗

bioRxiv2023

Telocytes are a critical source of Wnts essential for hair follicle regeneration

Self-renewing tissues rely on stem cells (SCs) to regenerate differentiated cells, requiring precise coordination between SCs and their progeny. Here, we investigated how SC activity is regulated across multiple epithelial layers, using the hair follicle (HF) as a model system. We uncovered an extensive, interconnected network of telocytes, specialized mesenchymal cells, that spans all HF layers, including regions previously thought to lack mesenchymal or connective tissue components. These telocyte networks remain in constant contact with SCs and their progeny throughout regeneration, dynamically adapting their structure and molecular profile to provide localized, phase-specific signals. By employing two independent mouse models to ablate telocytes or disrupt their Wnt signaling, we demonstrate that telocyte networks are an essential component of the SC niche. Our findings propose a revised, integrative model of the SC niche, in which telocyte networks and their Wnt production play a central role in adult SC biology and tissue regeneration.

cell biology↗

bioRxiv2022

First Biodegradable Bioactive Glass-based Humidity Sensor

Monitoring changes in edema-associated intracranial pressure that complicates trauma or surgery would lead to improved outcomes. Implantable pressure sensors have been explored, but, these sensors require post-surgical removal leading to risks of injury to brain tissue. Biodegradable implantable sensors would eliminate the risks while providing sensing when needed. Here, we demonstrate a bioactive glass (BaG)-based hydration sensor. A fluorine (CaF2) containing BaG (BaG-F) was produced using a melting manufacturing technique. The structure and electrical properties of the resulting constructs were evaluated to understand the electrical behaviors of this BaG-based sensor. The synthetic process of producing the BaG-F-based sensor was validated by assessing the electrical properties. We demonstrated that this BaG-F chemical composition is highly sensitive to hydration, and that electrical activity (resistive-capacitive) is induced by hydration and reversed by dehydration. These properties make BaG-F suitable for use as a humidity sensor to monitor brain edema and consequently provide an alert for increasing intracranial pressure.

bioengineering↗