Biology subjects

Price, K. L.

Publications and source records attributed to Price, K. L..

11 recordsLinked to original sources

bioRxiv2025

Genetic lineage tracing identifies intermediate mesoderm as a novel contributor to mammalian kidney lymphatics

The lymphatic vasculature is essential for fluid homeostasis, immune regulation and possesses diverse organ-specific functions. During development, lymphatic endothelial cells (LEC) arise from multiple progenitor sources that form organ-specific lymphatic networks. While the origins of LECs in the heart, skin, and mesentery have been studied, those in the kidney remain unresolved. Here, we combined genetic lineage tracing in mouse embryos with optical clearing and high-resolution three-dimensional imaging to identify two distinct progenitor sources of kidney lymphatics. The majority of kidney LECs originate from a Tie2 endothelial lineage previously linked to venous or capillary vessels. Approximately 15% derive from Osr1 intermediate mesoderm, a lineage that generates kidney nephrons and stroma. Osr1-derived LECs were absent from the heart, mesentery, and skin, indicating a kidney-specific contribution, and arose independently of nephron and stromal lineages. Both Tie2 and Osr1 lineages contributed to vessel sprouting and de novo formation of lymphatic clusters. Revealing a novel cellular origin of LECs and identifying a dual origin for kidney lymphatics, we demonstrate that de novo lymphatic formation can occur from both shared and organ-specific progenitors. This work advances our understanding of how lymphatics assemble during development and provides a framework for targeting kidney lymphatics in disease.

developmental biology↗

bioRxiv2025

Examination of germline and somatic intercellular bridges in Hydra vulgaris reveals insights into the evolutionarily conserved mechanism of intercellular bridge formation

Incomplete cytokinesis results in the formation of stable intercellular bridges that have been extensively studied in bilaterians, where they play essential roles in cell-cell communication and coordination of differentiation. However, little is known about their structure and molecular composition in non-bilaterian animals. This study characterizes germline and somatic intercellular bridges in the cnidarian Hydra vulgaris, providing insights into their evolutionary origins and functional significance. We identified key conserved components, including KIF23, F-actin, and phosphotyrosine. Notably, we observed microtubule localization within Hydra ring canals, suggesting previously unrecognized functions for this cytoskeletal component in intercellular bridge formation. Bioinformatic analyses confirmed the conserved expression of Kif23 and suggested its role as a molecular marker for identifying ring canal-associated components. EdU incorporation during DNA replication demonstrated that cells connected by ring canals exhibit synchronized cell cycles, which may be critical for the coordination of division and differentiation. Our findings reveal that the molecular and structural features of intercellular bridges in Hydra are conserved across evolutionary lineages, highlighting their ancient origins and functional significance in cellular connectivity. The presence of synchronized cell cycles in ring canal-connected cells underscores their role in promoting coordinated cellular behaviors, processes fundamental to multicellular organization. This study provides new perspectives on the evolution of incomplete cytokinesis and establishes a framework for comparative investigations into the diversity and conservation of intercellular bridge mechanisms across metazoans.

cell biology↗

bioRxiv2024

Vincristine treatment reverses podocyte damage in focal segmental glomerulosclerosis

IntroductionFocal segmental glomerulosclerosis (FSGS) is a significant cause of chronic kidney disease and triggered by podocyte damage which can result in cytoskeletal alterations leading to foot process effacement. Vincristine is a chemoprotective drug which alters cytoskeletal microtubules and has been used clinically to reverse FSGS. However, the mechanisms underlying the beneficial effect of vincristine are not understood. MethodsWe exposed immortalised human podocytes to serum obtained from an FSGS patient before, during, and after vincristine treatment. Using RNA-sequencing we determined the effect on the podocyte transcriptome alongside impacts on cytoskeletal structure and filtration barrier integrity using a glomerulus-on-a-chip model. ResultsWe describe an adult index FSGS patient successfully treated on multiple occasions by vincristine. Podocytes exposed to serum obtained during or after vincristine treatment contained lower levels of genes associated with microtubule function compared with cells stimulated with serum collected before treatment during disease presentation. Presentation serum altered the patterning of two key podocyte cytoskeletal components, tubulin and F-actin and increased albumin permeability, changes prevented by vincristine treatment. Immunoglobulin depletion experiments revealed that the podocyte damage initiated by the presentation serum was not due to circulating autoantibodies. Defects in tubulin patterning were observed when podocytes were exposed to serum from other FSGS patients, suggestive of a common disease mechanism. ConclusionVincristine therapy produces a milieu that protects against pathological changes induced by FSGS serum, associated with preservation of tubulin and F-actin organisation. The functional role of vincristine warrants further investigation, to advance our understanding of this alternative FSGS therapeutic.

cell biology↗

bioRxiv2024

Reversal of elevated Gli3 in Autosomal Recessive Polycystic Kidney Disease does not alter cystogenesis

Polycystic kidney diseases (PKD) are genetic disorders characterised by the formation of fluid-filled cysts, which disrupt kidney architecture and function. Autosomal recessive PKD (ARPKD) is a rare form of PKD, caused by mutations in PKHD1, and clinically more severe than the more common autosomal dominant PKD (ADPKD). Prior studies have implicated the ciliary-located Hedgehog (Hh) pathway in ADPKD, with increased levels of Hh components in experimental ADPKD models, and reduced cystogenesis following pharmacological Hh inhibition. In contrast, the role of the Hh pathway in ARPKD is poorly understood. We hypothesised that Hh pathway activity would be elevated during ARPKD pathogenesis, and its modulation may inhibit cystogenesis, akin to prior findings in ADPKD. To test this, we utilised Cpk mice, a model which replicates the pathophysiology of ARPKD, and generated a human cellular ARPKD 3-dimensional cystogenesis model by mutating PKHD1 in human collecting duct cells through CRISPR-Cas9 technology. We found significantly elevated levels of the Hh transcriptional effector Gli3 in the Cpk mouse, a finding replicated in our human cellular ARPKD model. In the Cpk mouse, we also observed an increase in total GLI3 and GLI3 repressor protein levels. However, reduction of increased Gli3 levels via genetic deletion in the Cpk mouse did not affect cyst formation. Similarly, lowering GLI3 transcript to wildtype levels, did not influence cyst size in our human cellular ARPKD model. Collectively, these data show that elevated Gli3 does not modulate cyst progression in the context of ARPKD, highlighting the complexity of the Hh pathway in PKD. New and NoteworthyThe role of the Hedgehog pathway in autosomal recessive polycystic kidney disease (ARPKD) is poorly understood. Here, we describe elevated levels of Gli3, the Hedgehog transcriptional effector, in murine and human ARPKD models. However, reversal of the increase in Gli3 did not significantly affect cystogenesis in a human cell model of ARPKD or disease progression in a mouse model which replicates ARPKD pathophysiology. Collectively, our data indicates that Gli3 does not modulate ARPKD progression.

physiology↗

bioRxiv2024

A unique subset of pericystic endothelium associates with aberrant microvascular remodelling and impaired blood perfusion early in polycystic kidney disease

Hallmarks of autosomal dominant polycystic kidney disease (ADPKD), the most common hereditary kidney anomaly, include expanding fluid-filled epithelial cysts, inflammation, and fibrosis. Despite previous work showing the potential of vascular-based therapies, renal microvascular alterations in ADPKD, and their timing, are poorly understood. Using single-cell transcriptomics of human kidney microvasculature, we identify a population of endothelial cells adjacent to cysts in ADPKD. This pericystic endothelium, distinguishable by its expression of osteopontin (SPP1), has a distinct molecular profile compared to the common endothelial cell injury signature in other kidney diseases. SPP1+ pericystic endothelium was also present in an orthologous mouse model of ADPKD before overt kidney functional decline. By interrogating geometric, topological and fractal properties from three-dimensional imaging of early ADPKD mouse kidneys, we show that pericystic endothelium associates with disorganisation and non-uniformity of the renal cortical microvasculature. Concurrently, we detected region-specific reductions in cortical blood flow within ADPKD murine kidneys using arterial spin labelling. We conclude that ADPKD kidneys contain a unique subset of endothelium manifesting with aberrant remodelling and impaired blood perfusion. Its detection, prior to renal functional decline, advocates the vasculature as a therapeutic target to modulate or preserve renal function in early ADPKD.

pathology↗

bioRxiv2022

Three-dimensional imaging and single-cell transcriptomics of the human kidney implicate perturbation of lymphatics in alloimmunity

Studies of the structural and molecular features of the lymphatic vasculature, which clears fluid, macromolecules and leukocytes from the tissue microenvironment, have largely relied on animal models, with limited information in human organs beyond traditional immunohistochemical assessment. Here, we use three-dimensional imaging and single-cell RNA-sequencing to study lymphatics in the human kidney. We found a hierarchical arrangement of lymphatic vessels within human kidneys, initiating along specialised nephron epithelium in the renal cortex and displaying a distinct, kidney-specific transcriptional profile. In chronic transplant rejection we found kidney allograft lymphatic expansion alongside a loss of structural hierarchy, with human leukocyte antigen-expressing lymphatic vessels infiltrating the medulla, presenting a putative target for alloreactive antibodies. This occurred concurrently with lymphatic vessels invading and interconnecting tertiary lymphoid structures at early stages of lymphocyte colonisation. Analysis of intercellular signalling revealed upregulation of co-inhibitory molecule-mediated CD4+ T cell-lymphatic crosstalk in rejecting kidneys, potentially acting to limit local alloimmune responses. Overall, we delineate novel structural and molecular features of human kidney lymphatics and reveal perturbations to their phenotype and transcriptome in the context of alloimmunity. SUMMARYLymphatics regulate fluid balance and immune cell accumulation but are under-studied in human organs such as the kidney. Jafree and colleagues profiled human kidney lymphatics using three-dimensional imaging and single-cell RNA-sequencing, revealing structural and transcriptional perturbations in rejecting kidney transplants.

immunology↗

bioRxiv2022

The DEPDC1 protein LET-99 is required for cortical stability and antagonizes branched actin formation to promote robust cytokinesis

During cytokinesis, signals from the central spindle stimulate the accumulation of active RhoA-GTPase and thus contractile ring components at the equator, while the astral microtubules inhibit such components at the polar cortex. The DEPDC1 family protein LET-99 is required for furrow ingression in the absence of the central spindle signal, and for timely onset of furrowing even in the presence of the central spindle signal. Here we show that LET-99 works downstream or independently of RhoA-GTP and antagonizes branched F-actin and the Rac protein CED-10 to promote furrow initiation. This interaction with CED-10 is separable from LET-99s function in spindle positioning. We also characterize a new role for LET-99 in regulating cortical stability, where LET-99 acts in parallel with the actomyosin scaffolding protein anillin, but LET-99 does not antagonize CED-10 in this case. We propose that LET-99 acts in a pathway that inhibits the Rac CED-10 to promote the proper balance of branched versus linear F-actin for cytokinesis, and that LET-99 also regulates another factor that contributes to cortical stability.

cell biology↗

bioRxiv2022

Evolutionarily conserved midbody reorganization precedes ring canal formation during gametogenesis

How canonical cytokinesis is altered during germ cell division to produce stable intercellular bridges called ring canals is poorly under-stood. Here, using time-lapse imaging in Drosophila, we observe that ring canal formation occurs via reorganization of the germline mid-body, a structure classically associated with its function in recruiting abscission-regulating proteins in complete cytokinesis. Germline midbodies reorganize from a focus into a ring rather than being discarded, and this transition is accompanied by changes in centralspindlin dynamics. The midbody-to-ring canal transformation is conserved in the Drosophila male and female germlines and during mouse and Hydra spermatogenesis. In Drosophila, ring canal formation depends on Citron kinase function in stark contrast to its role in abscission during somatic cell cytokinesis. Our results challenge existing models of ring canal formation, and provide important insights into broader functions of incomplete cytokinesis events across biological systems, such as those observed during development and disease states.

developmental biology↗

bioRxiv2020

The intrinsically disordered protein SPE-18 promotes localized assembly of the major sperm protein in C. elegans spermatocytes

Many specialized cells use unconventional strategies of cytoskeletal control. Nematode spermatocytes discard their actin and tubulin following meiosis, and instead employ the regulated assembly/disassembly of the Major Sperm Protein (MSP) to drive sperm motility. However prior to the meiotic divisions, MSP is effectively sequestered as it exclusively assembles into paracrystalline structures called fibrous bodies (FBs). The accessory proteins that direct this sequestration process have remained mysterious. This study reveals SPE-18 as an intrinsically disordered protein that that is essential for MSP assembly within FBs. In spe-18 mutant spermatocytes, MSP remains cytosolic, and the cells arrest in meiosis. In wildtype spermatocytes, SPE-18 localizes to pre-FB complexes and functions with the kinase SPE-6 to recruit MSP. Changing patterns of SPE-18 localization revealed unappreciated complexities in FB maturation. Later, within newly individualized spermatids, SPE -18 is rapidly lost, yet SPE-18 loss alone is insufficient for MSP disassembly. Our findings reveal an alternative strategy for sequestering cytoskeletal elements, not as monomers but in localized, bundled polymers. Additionally, these studies provide an important example of disordered proteins promoting ordered cellular structures. Summary StatementIntrinsically disordered proteins are increasingly recognized as key regulators of localized cytoskeletal assembly. Expanding that paradigm, SPE-18 localizes MSP assembly within C. elegans spermatocytes.

developmental biology↗

bioRxiv2019

A functionally conserved mechanism of modulation via a vestibule site in pentameric ligand-gated ion channels

Pentameric ligand-gated ion channels (pLGICs) belong to a class of ion channels involved in fast synaptic signaling in the central and peripheral nervous systems. Molecules acting as allosteric modulators target binding sites that are remote from the neurotransmitter binding site, but functionally affect coupling of ligand binding to channel opening. Here, we investigated an allosteric binding site in the ion channel vestibule, which has converged from a series of studies on prokaryote and eukaryote channel homologs. We discovered single domain antibodies, called nanobodies, which are functionally active as allosteric modulators, and solved co-crystal structures of the prokaryote channel ELIC bound either to a positive (PAM) or a negative (NAM) allosteric modulator. We extrapolate the functional importance of the vestibule binding site to eukaryote ion channels, suggesting a conserved mechanism of allosteric modulation. This work identifies key elements of allosteric binding sites and extends drug design possibilities in pLGICs using nanobodies.

neuroscience↗

bioRxiv2019

Ring canals permit extensive cytoplasm sharing among germline cells independent of fusomes in Drosophila testes

Intercellular bridges, also called ring canals (RCs), connect germline cells during gametogenesis in males and females. They form as a consequence of incomplete cytokinesis during cell division leaving groups of daughter cells connected in syncytia. In Drosophila females, RCs are required for oocyte growth but little is known about the role of RCs during spermatogenesis. Using live imaging, we document extensive intercellular movement of GFP and a subset of endogenous proteins through RCs during spermatogenesis from two-cell diploid spermatogonia to clusters of 64 post-meiotic haploid spermatids. Loss of the fusome, a large cytoplasmic structure extending through RCs that is known to be important during oogenesis, has minimal impact on RC development or intercellular protein movement during spermatogenesis. Our results reveal that male germline RCs remain persistently open and mediate extensive sharing of cytoplasmic information, supporting multiple roles for RCs throughout sperm development.

developmental biology↗