Biology subjects

Sandler, J.

Publications and source records attributed to Sandler, J..

2 recordsLinked to original sources

bioRxiv2025

prdm1a drives a fate switch between hair cells of different mechanosensory organs

Vertebrate mechanosensory hair cells (HCs) in the ear detect sound and gravitational forces. Additionally, fish have homologous lateral line HCs in the skin that detect water vibrations for orientation and predator avoidance. HCs in fish and other non-mammalian vertebrates regenerate to restore function after damage, but mammalian HCs lack this ability, causing deafness and vestibular defects. Experimental attempts at regeneration in mice result in incomplete differentiation of immature HCs. Despite differences in regeneration, the gene regulatory networks (GRNs) driving HC maturation are highly similar across vertebrates. Here, we show that the transcription factor prdm1a plays a key role in the HC fate GRN in the zebrafish lateral line. Mutating prdm1a respecifies lateral line HCs into ear HCs, altering morphology and transcriptome. Understanding how transcription factors control diverse HC fates in zebrafish is crucial for understanding the yet unsolved regeneration of diverse HCs in mammalian ears to restore hearing and balance.

developmental biology↗

bioRxiv2022

Mechanobiology of Fibroblast Activation in Skin Grafting

Mechanical stretching of living tissues can activate long-lived changes in tissue cells such as fibroblasts, increasing their contractility and initiating phenotypic transformations. Increased mechanical stimulus typically leads to monotonically increasing activation of fibroblasts cultured in 2D, but activation levels are difficult to predict for cells in 3D fibrous tissues, leading to variable outcomes in procedures such as skin grafting. Here we report that the source of this variation is cell-extracellular matrix (ECM) interactions and their variation with the duration and magnitude of applied stretch, and present a model that can predict the degree to which stretch will either increase or decrease long-term activation levels of fibroblasts cultured within a stretched, three-dimensional collagen matrix. Combining experimental and mathematical approaches across multiple scales, we show that the viscoplasticity of the ECM regulates this nonmonotonic, long-term cell activation. Results demonstrate that feedback between cell and ECM determines how cells retain memory of mechanical stretch.

biophysics↗