Biology subjects

Moss, J. J.

Publications and source records attributed to Moss, J. J..

6 recordsLinked to original sources

bioRxiv2026

NSAIDs impair fracture healing by disrupting neutrophil-mediated repair

Neutrophils are among the first immune cells recruited to fractures, yet their contribution to bone repair remains poorly understood. Using live imaging and neutrophil perturbation in adult zebrafish, we show that neutrophils establish the early fracture microenvironment. Neutrophils rapidly accumulated at fractures, underwent NETosis, and exhibited transcriptional programmes associated with matrix remodelling. Compromising neutrophil recruitment, via ibuprofen treatment or orthogonal perturbations, increased fracture non-union, delayed osteoblast differentiation, impaired mineralisation, and altered callus architecture. Mechanistically, neutrophils actively interacted with extracellular matrix proteins, including laminin, fibronectin, and collagen I, through uptake, trafficking and secretion-associated pathways. Together, our findings reveal that neutrophils establish a provisional emergency fracture matrix that templates subsequent bone repair, providing a mechanistic link between early non-steroidal anti-inflammatory drug (NSAID) exposure and impaired skeletal regeneration.

immunology↗

bioRxiv2026

Nanovibrational stimulation preferentially enhances osteogenic responses in zebrafish

Mechanical cues are key regulators of bone formation, yet their potential as therapeutic stimuli remains incompletely explored in vivo. Nanovibrational stimulation, which delivers low-amplitude, high-frequency mechanical input, has been shown to promote osteogenic differentiation in vitro, and rodent studies have similarly demonstrated osteogenic effects. However, its impact on other cellular systems at the whole-organism level remains poorly understood. Here, we demonstrate that nanovibrational stimulation enhances myogenic differentiation in vitro before investigating its effects on skeletal development and tissue specificity in zebrafish. Larval zebrafish exposed to nanovibrational stimulation exhibited increased osteoblast numbers and enhanced bone formation relative to controls. In adult zebrafish, nanovibration increased the osteoblast response to a fracture-like injury, indicating enhanced osteogenic activity during repair. To assess tissue specificity, we examined additional cell types and systems relevant to skeletal regeneration, including cartilage, muscle, vasculature and innate immune cells. Although nanovibrational stimulation promoted myogenic differentiation of C2C12 cells in vitro, its effects on muscle and other non-skeletal tissues in zebrafish larvae were comparatively limited. These findings suggest that nanovibrational stimulation exerts a preferential effect on osteogenic processes in vivo. These findings demonstrate that nanovibrational stimulation preferentially enhances osteoblast-mediated bone formation and skeletal injury responses in zebrafish, without causing significant perturbations in other tissues. Our results establish zebrafish as a tractable in vivo model for investigating vibration-induced mechanobiological processes, providing a more physiologically relevant representation of tissue-level mechanotransduction than conventional two-dimensional culture systems. Furthermore, these findings highlight the potential of nanovibrational stimulation as a non-invasive strategy to promote bone regeneration and fracture repair.

physiology↗

bioRxiv2026

Loss of lmx1ba drives premature osteoarthritis through disruption of skeletal homeostasis

Osteoarthritis is increasingly recognised as a disease of failed integration across the whole joint unit; however, the mechanisms that co-ordinate tissue integrity from development through to adult homeostasis remain largely unresolved. The LIM-homeodomain transcription factor LMX1B is a key determinant of embryonic skeletal patterning, but how it functions to regulate skeletal integrity in the mature skeleton is unknown. Recently, LMX1B was identified as a key driver of osteoarthritis. Here we show that loss of lmx1ba in zebrafish causes premature and progressive severe osteoarthritic pathology in adult spines and jaws, despite largely normal early skeletal patterning, revealing a conserved and continuous requirement for lmx1ba in joint maintenance beyond development. At a cellular level, loss of lmx1ba decouples osteoblast and osteoclast-mediated remodelling leading to bone overgrowth, heterogeneity of bone properties causing increased incidence of spontaneous fractures, and progressive abnormalities in spine morphology. In parallel, we observe degeneration of the intervertebral disc and dysregulation of the proteome and glycosaminoglycans indicative of disrupted extracellular matrix and a breakdown of the coordinated regulation of hard and soft tissue interfaces, which at the organismal level leads to altered joint performance. Notably, degeneration is restricted to mobile joints, and is not observed in cranial sutures, demonstrating a selective requirement for lmx1ba in mechanically active tissues. These changes are consistent with a model of spatially disrupted matrix properties that, under cyclic loading, promote progressive tissue damage. Our findings support a model in which continued expression of LMX1B in adulthood is required to maintain joint structures throughout life.

physiology↗

bioRxiv2025

Characterisation of lmx1b paralogues in zebrafish reveals divergent roles in skeletal, kidney, and muscle development

LMX1B, a LIM-homeodomain family transcription factor, plays critical roles in the development of multiple tissues, including limbs, eyes, kidneys, brain, and spinal cord. Mutations in the human LMX1B gene cause the rare autosomal-dominant disorder, Nail-patella syndrome which affects development of limbs, eyes, brain, and kidneys. In zebrafish, lmx1b has two paralogues: lmx1ba and lmx1bb. While lmx1b morpholino data exists, stable mutants were previously lacking. Here we describe the characterisation of lmx1b stable mutant lines, with a focus on development of tissues which are affected in Nail-patella syndrome. We demonstrate that the lmx1b paralogues have divergent developmental roles in zebrafish, with lmx1ba affecting skeletal and neuronal development, and lmx1bb affecting renal development. The double mutant, representing loss of both paralogues (lmx1b dKO) showed a stronger phenotype which included additional defects to trunk muscle patterning, and a failure to fully inflate the notochord leading to a dramatic reduction in body length. Overall, these mutant lines demonstrate the utility of zebrafish for modelling Nail- patella syndrome and describe a previously undescribed role for lmx1b in notochord cell inflation. SUMMARY STATEMENTZebrafish lmx1ba and lmx1bb knockout lines exhibit paralogue-specific roles in cartilage, renal, muscle, and notochord development, establishing zebrafish as a viable model for dissecting LMX1B- related pathologies such as Nail-patella syndrome.

developmental biology↗

bioRxiv2024

Defining mononuclear phagocyte distribution and behaviour in the zebrafish heart

Mononuclear phagocytes (MNPs) are recognised as highly plastic, multifunctional cells that influence multiple physiological and pathophysiological states. In the heart, they support homeostatic functions, contribute to disease progression and play multiple roles in reparative and regenerative processes following tissue damage. Understanding the heterogeneous populations of cells that contribute to these diverse functions is crucial to facilitating beneficial, and limiting adverse, cardiac outcomes. However, characterisation of precise populations of cardiac immune cells remains incomplete in vertebrate models capable of endogenous regeneration, such as adult zebrafish. Here, we use a combination of transgenic lines to identify distinct MNPs in the zebrafish heart. We show that larval macrophage populations have different origins and a sub-population of csf1ra expressing cells are maintained on the surface of the adult heart. MNPs are differently distributed in the myocardium, exhibit different behaviours and are distinguished via expression level of csf1ra and mpeg1.1. Following injury, tissue resident macrophages rapidly proliferate potentially contributing to reduced scarring. The adult zebrafish heart contains multiple populations of MNPs that can be defined by existing tools. This new understanding of innate immune cell populations in the heart of adult zebrafish sheds light on the composition of a pro-regenerative cardiac microenvironment.

immunology↗

bioRxiv2021

Autophagy coordinates chondrocyte development and early joint formation in zebrafish

Autophagy is a catabolic process responsible for the removal of waste and damaged cellular components by lysosomal degradation. It plays a key role in fundamental cell processes, including ER stress mitigation, control of cell metabolism, and cell differentiation and proliferation, all of which are essential for cartilage cell (chondrocyte) development and survival, and for the formation of cartilage. Correspondingly, autophagy dysregulation has been implicated in several skeletal disorders such as osteoarthritis and osteoporosis. To test the requirement for autophagy during skeletal development in zebrafish, we generated an atg13 CRISPR knockout zebrafish line. This line showed a complete loss of atg13 expression, and restricted autophagic activity in vivo. In the absence of autophagy, chondrocyte maturation was accelerated, with chondrocytes exhibiting signs of premature hypertrophy. Focussing on the jaw element, autophagy disruption affected joint articulation causing restricted mouth opening. This gross behavioural phenotype corresponded with a failure to thrive, and death in homozygote atg13 nulls within 17 days. Taken together, our results are consistent with autophagy contributing to the timely regulation of chondrocyte maturation and for extracellular matrix formation.

developmental biology↗