Biology subjects

Jones, M. H.

Publications and source records attributed to Jones, M. H..

5 recordsLinked to original sources

bioRxiv2026

Fibroblasts neurotrophin signaling sustains pathological vascular maturation in rheumatoid arthritis.

Treatment failures in rheumatoid arthritis (RA) leads to undesirable morbidity associated with immunosuppression. Recent studies of synovial tissue from refractory RA patients highlight the role of synovial fibroblasts and vascular endothelium in driving treatment failure. Utilizing high-dimensional spatial transcriptomics, we uncovered a crucial role for neurotrophin signaling in driving abnormal vascular maturation in RA synovia. Neurotrophins, including nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), and neurotrophin-3 (NT3), induce differentiation of synovial fibroblasts into mural cells - pericytes and vascular smooth muscle cells. Mechanistically, NOTCH3 signaling activates a cascade of neurotrophin signaling through transcriptional induction of NGFR, a co-receptor for NGF. In RA synovial tissue explants, stimulation with NGF, BDNF, or NT3 leads to a dramatic increase in maturation of synovial tissue vasculature. Conversely, pharmacologic inhibition with neurotrophin inhibitors drastically abolished maturation of vascularization in RA synovial explants. Notably, the FDA-approved tropomyosin receptor kinase (TRK) inhibitors larotrectinib and entrectinib effectively reverse synovial vascular maturation in human RA tissue explants.Our findings suggest that fibroblast-derived neurotrophin signaling is a critical pathway in sustaining mature blood vessels in RA synovia, and that neurotrophin inhibitors reverse abnormal vascular maturation in RA. One Sentence SummaryIn rheumatoid arthritis, fibroblast neurotrophin signaling drives abnormal vascular maturation by inducing differentiation of fibroblasts into vascular mural cells.

molecular biology↗

bioRxiv2025

Fibroblasts sense spatial proximity via an EGFR CREB5 axis to restore quiescent synovial lining in remission rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic inflammatory disease where the synovial lining membrane undergoes pathological changes resulting in joint destruction. In healthy joints, the synovial lining is essential for joint homeostasis, forming a selective barrier and secreting lubricating molecules, yet the mechanisms that restores homeostatic synovial lining during RA remission remains poorly understood. Here, we applied spatial transcriptomics to examine biopsies of RA patients in remission to identify a mechanism that orchestrates a phenotypic switch specifying synovial quiescent lining fibroblast differentiation. Spatial transcriptomics revealed a proximity-sensing program where at low cell-density, fibroblasts adopt proliferative and fibrotic transcriptional state characterized by expression of MKI67, COL1A2 and COL6A2, whereas at high cell-density, fibroblasts induce a quiescent lining fibroblast transcriptional program characterized by PRG4, CLU and PDPN. Mechanistically, fibroblasts sense spatial proximity through HB-EGF-EGFR signaling, which leads to phosphorylation of transcription factor CREB5. Perturbation of the EGFR-CREB5 axis abolishes fibroblast proximity-sensing and blocks synovial lining fibroblast differentiation. Conversely, EGFR activation by the ligand HB-EGF or pharmacologic activation of CREB5 is sufficient to induce synovial lining fibroblast differentiation. Together, our findings define a novel spatial proximity-sensing pathway underlying a return to homoeostatic fibroblast function during RA remission. By sensing their spatial proximity to neighboring fibroblasts, synovial fibroblasts translate these positional cues into signals that lead to restoration of normal, steady-state synovial lining membrane.

genomics↗

bioRxiv2023

Distinct regions of the kinesin-5 C-terminal tail are essential for mitotic spindle midzone localization and sliding force

Kinesin-5 motor proteins play essential roles during mitosis in most organisms. Their tetrameric structure and plus-end-directed motility allow them to bind to and move along antiparallel microtubules, thereby pushing spindle poles apart to assemble a bipolar spindle. Recent work has shown that the C-terminal tail is particularly important to kinesin-5 function: the tail affects motor domain structure, ATP hydrolysis, motility, clustering, and sliding force measured for purified motors, as well as motility, clustering, and spindle assembly in cells. Because previous work has focused on presence or absence of the entire tail, the functionally important regions of the tail remain to be identified. We have therefore characterized a series of kinesin-5/Cut7 tail truncation alleles in fission yeast. Partial truncation causes mitotic defects and temperature-sensitive growth, while further truncation that removes the conserved BimC motif is lethal. We compared the sliding force generated by cut7 mutants using a kinesin-14 mutant background in which some microtubules detach from the spindle poles and are pushed into the nuclear envelope. These Cut7-driven protrusions decreased as more of the tail was truncated, and the most severe truncations produced no observable protrusions. Our observations suggest that the C-terminal tail of Cut7p contributes to both sliding force and midzone localization. In the context of sequential tail truncation, the BimC motif and adjacent C-terminal amino acids are particularly important for sliding force. In addition, moderate tail truncation increases midzone localization, but further truncation of residues N-terminal to the BimC motif decreases midzone localization.

cell biology↗

bioRxiv2023

Low-dose cytokine immunotherapy of solid cancers enabled by phagocytic-competent protein co-crystals

Protein therapeutics are often compromised by sub-optimal biodistribution contributing to poor efficacy and adverse events. Drug delivery mechanisms better able to target protein drugs to the disease site and provide localized, sustained release have the potential to transform therapeutic standards. PODS(R) crystals (PODS) are natural-mimetic, micron-scale protein co-crystals engineered to incorporate a protein cargo that can be sustainably released under the action of resident proteases. PODS are efficiently taken up by phagocytic cells with the cargo protein subsequently released in a bioactive form. Since blood-circulating phagocytic cells, including monocytes, are actively recruited into diseased and inflamed tissue, such as the tumour microenvironment, we postulated that monocyte/macrophage-mediated PODS delivery could be used as a molecular "Trojan horse" to efficiently deliver therapeutic proteins to target cells. This could improve the pharmacodynamics and pharmacokinetics of protein drug delivery to treat systemic and disseminated diseases. Interleukin-2 (IL-2) is notoriously toxic at the high doses required for therapeutic efficacy. Here, we demonstrate the therapeutic efficacy and tolerability of low doses of PODS containing IL-2 cargo (PODS-IL-2) administered intravenously in a mouse model of melanoma. We further demonstrate the therapeutic benefit of PODS delivering IL-2, interleukin-15 (IL-15) and interferon gamma (IFN-{gamma}) in a mouse model of renal cell carcinoma at two doses. Efficacy was seen in both doses with the higher dose generating rapid and complete rejection of the tumour in some of the mice treated with each cytokine. This study provides proof-of-concept for the utility of intravenously administered PODS to provide a generalised and widely applicable mechanism to effectively deliver protein drugs for the therapy of cancer and potentially other diseases.

cancer biology↗

bioRxiv2022

Kinesin-5/Cut7 moves bidirectionally on fission-yeast spindles with activity that increases in anaphase

Kinesin-5 motors are essential to separate mitotic spindle poles and assemble a bipolar spindle in many organisms. These tetrameric motors crosslink and slide apart antiparallel microtubules via microtubule plus-end-directed motility. However, kinesin-5s typically accumulate more at spindle poles than in the center of the spindle where antiparallel microtubule overlaps are most numerous. While the relevance of this localization has remained unclear, increasing evidence suggests that it occurs due to bidirectional motility or trafficking of kinesin-5 motors. The kinesin-5 motor Cut7p from fission yeast has been shown to move bidirectionally in reconstituted systems. However, bidirectional movement has not been shown in cells and the funtion of the minus-end-directed movement remains unclear. Here, we characterized the motility of kinesin-5/Cut7 on bipolar and monopolar spindles in fission yeast and observed movement both toward plus and minus ends of microtubules. Notably, we found that the activity of the motor increases at the onset on anaphase B. Perturbations to microtubule dynamics did not significantly change the observed Cut7p movement, while Cut7p mutation reduced or abolished observable movement. These results suggest that the directed movement of Cut7p was due to the motility of the motor itself. Mutations of Cut7p that decreased plus-end-directed motility enhanced its spindle-pole localization. In contrast, abolishing Cut7 motility or replacing it with plus-end-directed human Eg5 eliminates the pole localization. Our results suggest a new hypothesis for the function of minus-end-directed motility and spindle-pole localization of kinesin-5s in spindle assembly.

cell biology↗