Biology subjects

Hurley, E.

Publications and source records attributed to Hurley, E..

7 recordsLinked to original sources

bioRxiv2025

Robotic Handling Preserves Induced Pluripotent Stem Cell Derived Vascular Smooth Muscle Cells Differentiation using a Weekend-free, Automatable, Low-variability, Low-cost (WALL) Protocol

Vascular disease modeling and tissue engineering require scalable, efficient, and reproducible methods for differentiating cells, however no studies have validated whether automation, essential for scale-up, preserves differentiation quality in cells. Here, we developed a differentiation protocol for induced pluripotent stem cell (iPSC)-derived vascular smooth muscle cells (iVSMCs) that is applicable to both manual, and automated robotic culture. iPSC lines generated from male and female donors across various ages were used to optimize the generation of iVSMCs. iVSMCs had consistent morphology and protein expression was largely similar to primary VSMCs, including expression of myosin heavy chain-11 (MYH11), -smooth muscle actin (-SMA), transgelin (TAGLN) and calponin (CNN1). Functionally, these iVSMCs could respond to the vasoconstrictor carbachol. Coupling this protocol with an automated Hamilton liquid-handling robotics system allowed the generation of iVSMCs in large quantities, morphologically similar to manually differentiated iVSMCs. Comparative proteomic analysis confirmed protein expression did not differ between automated and manual differentiation methods. Automation markedly reduced manual labor and facilitated increased production without sacrificing cell quality. This study demonstrates the feasibility of automating iVSMC differentiation, marking a significant step towards scalable VSMC manufacturing for three-dimensional applications, and for the ever-growing demands of organoid and tissue engineering applications. Statement of significanceThe rapidly expanding fields of tissue engineering and high-throughput disease modeling require large quantities of viable cells, making automation essential. Robotic liquid handling systems are increasingly employed for generating large quantities of induced pluripotent stem cell (iPSC)-derived cells, requiring the development of scalable protocols. No studies have yet evaluated whether the use of robotic liquid handling alters the differentiation of cells compared to traditional manual handling. Here, we report a scalable differentiation protocol that robustly generates iPSC-derived VSMCs (iVSMCs) from a cohort of female and male donors of varying age (n=5 lines). We demonstrate for the first time that iVSMCs, differentiated through an automated robotic pipeline, had no significant differences in morphological or proteomic phenotype compared to manual differentiation. The ability to automate this protocol facilitates robust and reproducible differentiation of large quantities of iVSMC, setting a precedent for the application of automation in generating iPSC-derived cells. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=57 SRC="FIGDIR/small/690512v1_ufig1.gif" ALT="Figure 1000"> View larger version (18K): org.highwire.dtl.DTLVardef@673d61org.highwire.dtl.DTLVardef@1eead89org.highwire.dtl.DTLVardef@c3089eorg.highwire.dtl.DTLVardef@6af2cd_HPS_FORMAT_FIGEXP M_FIG C_FIG

developmental biology↗

bioRxiv2024

The STRIPAK complex is required for radial sorting and laminin receptor expression in Schwann cells

During peripheral nervous system development, Schwann cells undergo Rac1-dependent cytoskeletal reorganization as they insert cytoplasmic extensions into axon bundles to radially sort, ensheath, and myelinate individual axons. However, our understanding of the direct effectors targeted by Rac1 is limited. Here, we demonstrate that striatin-3 and MOB4 are novel Rac1 interactors. We show that, similar to Rac1-null Schwann cells, Schwann cell specific ablation of striatin-3 causes defects in lamellipodia formation. In addition, conditional Schwann cell knockout of multiple striatin proteins presents a severe delay in radial sorting. Finally, we demonstrate here that deletion of Rac1 or striatin-1/3 in Schwann cells causes defects in Hippo pathway regulation, phosphorylation of the Hippo pathway effectors YAP and TAZ, and expression of genes co-regulated by YAP and TAZ, such as extracellular matrix receptors. In summary, our results indicate that striatin-3 is a novel Rac1 interactor, show that striatin proteins are required for peripheral nervous system development, and reveal a role for Rac1 in regulation of the Hippo pathway in Schwann cells.

neuroscience↗

bioRxiv2024

Emergent glutamate & dopamine dysfunction in VPS35(D620N) knock-in mice and rapid reversal by LRRK2 inhibition

The D620N variant in Vacuolar Protein Sorting 35 (VPS35) causes autosomal-dominant, late- onset Parkinsons disease. VPS35 is a core subunit of the retromer complex that canonically recycles transmembrane cargo from sorting endosomes. Although retromer cargoes include many synaptic proteins, VPS35s neuronal functions are poorly understood. To investigate the consequences of the Parkinsons mutation, striatal neurotransmission was assessed in 1-, 3- & 6-month-old VPS35 D620N knock-in (VKI) mice. Spontaneous and optogenetically- evoked corticostriatal glutamate transmission was increased in VKI striatal spiny projection neurons by 6 months, when total striatal glutamate release, quantified by iGluSnFR imaging, showed similarities to wild-type. dLight imaging revealed robust increases in VKI striatal dopamine release by 6 months, which were reversed with acute ex vivo leucine-rich repeat kinase 2 (LRRK2) inhibition. We conclude that increased glutamate and dopamine transmission in VKI mice progressively emerges in young-adulthood, and that dopamine dysfunction is likely the result of sustained, rapidly-reversible, LRRK2 hyperactivity.

neuroscience↗

bioRxiv2024

Loss of prohibitin 2 in Schwann cells dysregulates key transcription factors controlling developmental myelination

Schwann cells are critical for the proper development and function of the peripheral nervous system, where they form a mutually beneficial relationship with axons. Past studies have highlighted that a pair of proteins called the prohibitins play major roles in Schwann cell biology. Prohibitins are ubiquitously expressed and versatile proteins. We have previously shown that while prohibitins play a crucial role in Schwann cell mitochondria for long-term myelin maintenance and axon health, they may also be present at the Schwann cell-axon interface during development. Here, we expand on this work, showing that drug-mediated modulation of prohibitins in vitro disrupts myelination and confirming that Schwann cell-specific ablation of prohibitin 2 (Phb2) in vivo results in early and severe defects in peripheral nerve development. Using a proteomic approach in vitro, we identify a pool of candidate PHB2 interactors that change their interaction with PHB2 depending on the presence of axonal signals. Furthermore, we show in vivo that loss of Phb2 in mouse Schwann cells causes ineffective proliferation and dysregulation of transcription factors EGR2 (KROX20), POU3F1 (OCT6) and POU3F2 (BRN2) that are necessary for proper Schwann cell maturation. Schwann cell-specific deletion of Jun, a transcription factor associated with negative regulation of myelination, confers partial rescue of the development defect seen in mice lacking Schwann cell Phb2. This work develops our understanding of Schwann cell biology, revealing that Phb2 may directly or indirectly modulate the timely expression of transcription factors necessary for proper peripheral nervous system development, and proposing candidates that may play a role in PHB2-mediated integration of axon signals in the Schwann cell.

neuroscience↗

bioRxiv2022

MPZ-T124M mouse model replicates human axonopathy and suggest alteration in axo-glia communication

Myelin is essential for rapid nerve impulse propagation and axon protection. Accordingly, defects in myelination or myelin maintenance lead to secondary axonal damage and subsequent degeneration. Studies utilizing genetic (CNPase-, MAG-, and PLP-null mice) and naturally occurring neuropathy models suggest that myelinating glia also support axons independently from myelin. Myelin protein zero (MPZ or P0), which is expressed only by Schwann cells, is critical for myelin formation and maintenance in the peripheral nervous system. Many mutations in MPZ are associated with demyelinating neuropathies (Charcot-Marie-Tooth disease type 1B [CMT1B]). Surprisingly, the substitution of threonine by methionine at position 124 of P0 (P0T124M) causes axonal neuropathy (CMT2J) with little to no myelin damage. This disease provides an excellent paradigm to understand how myelinating glia support axons independently from myelin. To study this, we generated targeted knock-in P0T124M mutant mice, a genetically authentic model of T124M-CMT2J neuropathy. Similar to patients, these mice develop axonopathy between 2 and 12 months of age, characterized by impaired motor performance, normal nerve conduction velocities but reduced compound motor action potential amplitudes, and axonal damage with only minor compact myelin modifications. Mechanistically, we detected metabolic changes that could lead to axonal degeneration, and prominent alterations in non-compact myelin domains such as paranodes, Schmidt-Lanterman incisures, and gap junctions, implicated in Schwann cell-axon communication and axonal metabolic support. Finally, we document perturbed mitochondrial size and distribution along P0T124M axons suggesting altered axonal transport. Our data suggest that Schwann cells in P0T124M mutant mice cannot provide axons with sufficient trophic support, leading to reduced ATP biosynthesis and axonopathy. In conclusion, the P0T124M mouse model faithfully reproduces the human neuropathy and represents a unique tool for identifying the molecular basis for glial support of axons.

neuroscience↗

bioRxiv2021

β-Catenin-NFκB-CFTR interactions in cholangiocytes regulate inflammation and fibrosis during ductular reaction

Expansion of biliary epithelial cells (BECs) during ductular reaction (DR) is observed in liver diseases including cystic fibrosis (CF), and associated with inflammation and fibrosis, albeit without complete understanding of underlying mechanism. Using two different genetic knockouts of {beta}-catenin, one with {beta}-catenin loss is hepatocytes and BECs (KO1), and another with loss in only hepatocytes (KO2), we demonstrate disparate long-term repair after an initial injury by 2-week choline-deficient ethionine- supplemented diet. KO2 show gradual liver repopulation with BEC-derived {beta}-catenin- positive hepatocytes, and resolution of injury. KO1 showed persistent loss of {beta}-catenin, NF-{kappa}B activation in BECs, progressive DR and fibrosis, reminiscent of CF histology. We identify interactions of {beta}-catenin, NF{kappa}B and CF transmembranous conductance regulator (CFTR) in BECs. Loss of CFTR or {beta}-catenin led to NF-{kappa}B activation, DR and inflammation. Thus, we report a novel {beta}-catenin-NF{kappa}B-CFTR interactome in BECs, and its disruption may contribute to hepatic pathology of CF.

pathology↗

bioRxiv2020

mTORC1 and JUN are activated after deletion of Prohibitin 1 in Schwann cells and may link mitochondrial dysfunction to demyelination

Schwann cell (SC) mitochondria are quickly emerging as an important regulator of myelin maintenance in the peripheral nervous system (PNS). However, the mechanisms underlying demyelination in the context of mitochondrial dysfunction in the PNS are incompletely understood. We recently showed that conditional ablation of the mitochondrial protein Prohibitin 1 (Phb1) in SCs causes a severe and fast progressing demyelinating peripheral neuropathy, but the mechanism that causes failure of myelin maintenance remained unknown. Here, we report that mTORC1 and JUN are continuously activated in the absence of Phb1, likely due to mitochondrial damage. Moreover, we demonstrate that these pathways are involved in the demyelination process, and that inhibition of mTORC1 using rapamycin partially rescues the demyelinating pathology. Therefore, we propose that mTORC1 and JUN may play a critical role as executioners of demyelination in the context of perturbations to SC mitochondria.

neuroscience↗