β-catenin-α-catenin and actomyosin signaling differentially regulate growth cone contours and axon undulation and branching of retinal ganglion cells in situ

IntroductionCadherin adhesive and actomyosin signaling are key cytomechanical cues required for neuronal circuit formation, but whether they function together to sculpt developing neurons is not known. Previously, we demonstrated that a β-catenin mutant (β-catNTERM) that disrupts binding of endogeno...

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Main Authors: Valerie Lew, Sukaynah Khetani, Simran Kaur, William Woodward, Sukmin Sandhu, Radhika Rawat, Tamira Elul
Format: Article
Language:English
Published: Frontiers Media S.A. 2025-07-01
Series:Frontiers in Cellular Neuroscience
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Online Access:https://www.frontiersin.org/articles/10.3389/fncel.2025.1572298/full
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author Valerie Lew
Sukaynah Khetani
Simran Kaur
William Woodward
Sukmin Sandhu
Radhika Rawat
Tamira Elul
author_facet Valerie Lew
Sukaynah Khetani
Simran Kaur
William Woodward
Sukmin Sandhu
Radhika Rawat
Tamira Elul
author_sort Valerie Lew
collection DOAJ
description IntroductionCadherin adhesive and actomyosin signaling are key cytomechanical cues required for neuronal circuit formation, but whether they function together to sculpt developing neurons is not known. Previously, we demonstrated that a β-catenin mutant (β-catNTERM) that disrupts binding of endogenous, full length β-catenin to α-catenin in the Cadherin adhesion complex, and a pharmacological inhibitor for actin regulator, non-muscle Myosin II (Blebbistatin), resulted in growth cones with fewer and more filopodia or filopodia-like protrusions than control growth cones of retinal ganglion cells (RGCs) in brains from Xenopus laevis embryos.MethodsHere, we assessed whether perturbation of β-catenin adhesive and Myosin II signaling specifically impacted additional, diverse yet interrelated, parameters of growth cone morphology and axon pathfinding, including two novel measures of growth cone contours.ResultsAmong other findings, we show that growth cones of individual RGCs expressing β-catenin NTERM have less complex contours (lower fractal dimension) and axons that are more undulatory than control growth cones and axons. In contrast, contours of Blebbistatin exposed growth cones are less concave (lower fractional concavity) and their axons extend more branches compared to control RGCs. In additional experiments, an α-catNTERM mutant and ROCK inhibitor phenocopied the specific effects of β-catNTERM and Blebbistatin on complexity and concavity of growth cone contours.DiscussionThis data suggests that β-catenin-α-catenin and actomyosin interactions differentially regulate growth cone contours as well as axonal undulation and branching of RGCs in whole brains. Broadly, our results provide insight into cytomechanical mechanisms of neuronal circuit formation normally, and neuronal connectivity defects in human neurodevelopment disorders associated with mutations in Cadherin and β-catenin.
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publisher Frontiers Media S.A.
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spelling doaj-art-3bedef67347a4bd0a2ecab74bca955ad2025-08-20T02:41:23ZengFrontiers Media S.A.Frontiers in Cellular Neuroscience1662-51022025-07-011910.3389/fncel.2025.15722981572298β-catenin-α-catenin and actomyosin signaling differentially regulate growth cone contours and axon undulation and branching of retinal ganglion cells in situValerie Lew0Sukaynah Khetani1Simran Kaur2William Woodward3Sukmin Sandhu4Radhika Rawat5Tamira Elul6Department of Foundational Biomedical Sciences, College of Osteopathic Medicine, Touro University California, Vallejo, CA, United StatesDepartment of Foundational Biomedical Sciences, College of Osteopathic Medicine, Touro University California, Vallejo, CA, United StatesDepartment of Foundational Biomedical Sciences, College of Osteopathic Medicine, Touro University California, Vallejo, CA, United StatesCollege of Osteopathic Medicine, Touro University Nevada, Henderson, NV, United StatesDepartment of Foundational Biomedical Sciences, College of Osteopathic Medicine, Touro University California, Vallejo, CA, United StatesDepartment of Molecular and Cellular Biology, University of California, Berkeley, Berkeley, CA, United StatesDepartment of Foundational Biomedical Sciences, College of Osteopathic Medicine, Touro University California, Vallejo, CA, United StatesIntroductionCadherin adhesive and actomyosin signaling are key cytomechanical cues required for neuronal circuit formation, but whether they function together to sculpt developing neurons is not known. Previously, we demonstrated that a β-catenin mutant (β-catNTERM) that disrupts binding of endogenous, full length β-catenin to α-catenin in the Cadherin adhesion complex, and a pharmacological inhibitor for actin regulator, non-muscle Myosin II (Blebbistatin), resulted in growth cones with fewer and more filopodia or filopodia-like protrusions than control growth cones of retinal ganglion cells (RGCs) in brains from Xenopus laevis embryos.MethodsHere, we assessed whether perturbation of β-catenin adhesive and Myosin II signaling specifically impacted additional, diverse yet interrelated, parameters of growth cone morphology and axon pathfinding, including two novel measures of growth cone contours.ResultsAmong other findings, we show that growth cones of individual RGCs expressing β-catenin NTERM have less complex contours (lower fractal dimension) and axons that are more undulatory than control growth cones and axons. In contrast, contours of Blebbistatin exposed growth cones are less concave (lower fractional concavity) and their axons extend more branches compared to control RGCs. In additional experiments, an α-catNTERM mutant and ROCK inhibitor phenocopied the specific effects of β-catNTERM and Blebbistatin on complexity and concavity of growth cone contours.DiscussionThis data suggests that β-catenin-α-catenin and actomyosin interactions differentially regulate growth cone contours as well as axonal undulation and branching of RGCs in whole brains. Broadly, our results provide insight into cytomechanical mechanisms of neuronal circuit formation normally, and neuronal connectivity defects in human neurodevelopment disorders associated with mutations in Cadherin and β-catenin.https://www.frontiersin.org/articles/10.3389/fncel.2025.1572298/fullgrowth coneadhesioncytoskeletonaxonXenopusretinal ganglion cells
spellingShingle Valerie Lew
Sukaynah Khetani
Simran Kaur
William Woodward
Sukmin Sandhu
Radhika Rawat
Tamira Elul
β-catenin-α-catenin and actomyosin signaling differentially regulate growth cone contours and axon undulation and branching of retinal ganglion cells in situ
Frontiers in Cellular Neuroscience
growth cone
adhesion
cytoskeleton
axon
Xenopus
retinal ganglion cells
title β-catenin-α-catenin and actomyosin signaling differentially regulate growth cone contours and axon undulation and branching of retinal ganglion cells in situ
title_full β-catenin-α-catenin and actomyosin signaling differentially regulate growth cone contours and axon undulation and branching of retinal ganglion cells in situ
title_fullStr β-catenin-α-catenin and actomyosin signaling differentially regulate growth cone contours and axon undulation and branching of retinal ganglion cells in situ
title_full_unstemmed β-catenin-α-catenin and actomyosin signaling differentially regulate growth cone contours and axon undulation and branching of retinal ganglion cells in situ
title_short β-catenin-α-catenin and actomyosin signaling differentially regulate growth cone contours and axon undulation and branching of retinal ganglion cells in situ
title_sort β catenin α catenin and actomyosin signaling differentially regulate growth cone contours and axon undulation and branching of retinal ganglion cells in situ
topic growth cone
adhesion
cytoskeleton
axon
Xenopus
retinal ganglion cells
url https://www.frontiersin.org/articles/10.3389/fncel.2025.1572298/full
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