bioRxiv Science⌕ Search

bioRxiv · 10.1101/2021.02.22.432353

A G protein-coupled receptor is required in cartilaginous and dense connective tissues to maintain spine alignment

Abstract

Adolescent idiopathic scoliosis (AIS) is the most common spine disorder affecting children worldwide, yet little is known about the pathogenesis of this disorder. Here, we demonstrate that genetic regulation of structural components of the axial skeleton, the intervertebral discs and dense connective tissues (e.g., ligaments and tendons), are essential for maintenance of spinal alignment. We show that the G-coupled protein receptor Adgrg6, previously implicated in human AIS association studies, is required in these tissues to maintain typical spine morphology. We show that Adgrg6 regulates biomechanical properties of tendon and stimulates CREB signaling governing gene expression in cartilaginous tissues of the spine. Treatment with an cAMP agonist was able to mirror aspects of receptor function in culture defining core pathways for regulation of these axial connective tissues. As ADGRG6 is a key gene involved in human AIS, these findings open up novel therapeutic opportunities for human scoliosis. HighlightsO_LIKnockout mice lacking Adgrg6 function in the tendons and ligaments of the spine develop perinatal-onset thoracic scoliosis. C_LIO_LILoss of Adgrg6 function in cartilaginous tissues of the discs contribute to the incidence and severity of scoliosis. C_LIO_LIThe loss of Adgrg6 function in spine tissues provide a model of construct validity for human adolescent idiopathic scoliosis C_LIO_LIFine tuning of the biomechanical properties of dense connective tissues is essential for maintaining spine alignment. C_LI

Source connections

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Liu, Z., Hussien, A. A., Wang, Y., Heckman, T., Gonzalez, R., Karner, C. M., Snedeker, J. G., GRAY, R.. 2021-02-22. A G protein-coupled receptor is required in cartilaginous and dense connective tissues to maintain spine alignment. https://doi.org/10.1101/2021.02.22.432353

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

Dynamic mechanical sorting biases niche occupancy and lineage outcome during development of bilayered glandular epithelia

Tissue compartmentalization into basal and luminal domains is a hallmark of glandular epithelia, yet how fate boundaries are established and stabilized during dynamic morphogenesis remains a major unresolved question. Here, using mouse embryonic explants, organoids, quantitative live imaging and genetic perturbations, we show that basal-luminal compartmentalization is not maintained by fixed boundaries, but through continuous positional corrections. We show that differences in cellular adhesion and actomyosin contractility drive these positional corrections by promoting active cell sorting. We further find that these mechanical differences influence lineage specification by controlling cell positioning rather than directly instructing cell fate. Before commitment, mosaic, but not uniform, perturbation of cell mechanics alters niche occupancy and biases lineage outcome, indicating that relative mechanical properties determine access to fate-instructive niches. Conversely, perturbation of Notch and YAP remodels compartment-specific mechanical properties and cell-positioning dynamics, revealing a reciprocal coupling between lineage state and mechanical sorting. Conservation of this mechanism across four glandular epithelia of distinct origins and functions identifies dynamic mechanical sorting as a general strategy for maintaining robust tissue compartmentalization during the extensive growth and cellular rearrangements of branching morphogenesis.

developmental biology↗

Unbiased lineage tracing across the adipose organ decouples developmental origin from anatomical and transcriptomic identities

The developmental origins of individual adipose depots and whether embryonic lineage dictates adult function remain unresolved. Here, we apply in utero CRISPR-mediated barcoding lineage tracing to construct the first unbiased clonal map of adipose organ development in mice. The developmental hierarchy we uncover challenges several conventions. Remarkably, interscapular brown fat, used as the prototypical brown fat, is the most developmentally isolated brown fat; depots sharing Myf5/Pax3 lineage markers fail to cluster together; mesenteric white fat shares unexpected high clonal ancestry with brown fats despite a radically divergent transcriptome; and subcutaneous white adipose tissues converge transcriptomically despite distant developmental origins. These findings call for a reinterpretation of single-marker lineage tracing data across the adipose organ and propose that adipose depot identity is not solely encoded by embryonic lineage but is substantially shaped by the anatomical niche.

developmental biology↗

Age-dependent mechanical stress underlies unexpected vestibular differentiation and regeneration patterns

Loss of inner-ear sensory hair cells (HCs) is a major cause of hearing and balance disorders. Promoting HC regeneration offers a potential therapeutic strategy, but regenerative capacity is limited in adult mammals and declines rapidly during early postnatal development in mice. HCs can regenerate through trans-differentiation of neighboring supporting cells in a process controlled by Notch mediated lateral inhibition. However, the factors underlying the decrease in regeneration capacity are poorly understood. Here, we combine live imaging with single-HC ablation in mouse vestibular explants to track the dynamics of HC development and regeneration. We reveal unexpected age-dependent deviations from the classical lateral inhibition model, in which new HCs differentiate adjacent to existing HCs. We find that mechanical stress changes with age and that perturbing it alters the observed differentiation patterns. A mathematical model incorporating local mechanical regulation of Notch signaling captures both HC differentiation and regeneration patterns across ages. Together, these findings identify mechanical stress as a crucial regulator of HC differentiation and support an underlying mechanism in which the interplay between local mechanics and Notch signaling shapes regenerative responses. This coupling offers a framework for understanding the age-dependent decline in HC regeneration and motivates investigation of mechanical regulation as a potential therapeutic target.

developmental biology↗