Search bioRxiv⌕ Search

Biology subjects

Moreno, M. M.

Publications and source records attributed to Moreno, M. M..

6 recordsLinked to original sources

E-Selectin Orchestrates IL-1B-Dependent Neuroinflammation via NLRP3 in Vincristine-Induced Neuropathy

Vincristine-induced peripheral neuropathy (VIPN) is a frequent and dose-limiting complication of cancer therapy, yet the upstream mechanisms coupling vascular activation to neuroinflammation remain poorly defined. Here we identify E-selectin as a critical orchestrator of vincristine-induced neuropathy. Systematic interrogation of endothelial adhesion molecules in a murine model of VIPN revealed that blockade of E-selectin, but not ICAM-1, PECAM-1 or P-selectin, completely prevented mechanical hypersensitivity and markedly reduced F4/80 immune cell accumulation in dorsal root ganglia and peripheral nerves. Genetic deletion of E-selectin conferred equivalent protection, despite the absence of structural loss of intraepidermal or myelinated fibres, indicating a predominantly functional neuroimmune pathology. Spatial transcriptomics demonstrated that vincristine induces a conserved stress and neuroinflammation-associated transcriptional programme in dorsal root ganglia, with immune and stromal populations acting as dominant signalling hubs. Genetic or pharmacological perturbation of E-selectin did not abolish injury-associated pathways but redistributed cell-cell communication networks, reducing immune-cell dominance and reshaping interferon and metabolic signalling states without inducing Sele expression. Mechanistically, E-selectin exerted non-canonical effects beyond endothelial adhesion. Local E-selectin administration was sufficient to induce macrophage-dependent mechanical hypersensitivity that was abolished in Fut4/7-deficient mice and following phagocyte depletion. In macrophages, E-selectin enhanced vincristine-driven NF-{kappa}B activation, NLRP3 inflammasome assembly and IL-1{beta} release. Together, these findings position E-selectin as an upstream regulator of IL-1{beta}-dependent neuroinflammation in VIPN and identify selective targeting of E-selectin-mediated immune-neuron interactions as a therapeutic strategy for chemotherapy-induced neuropathy.

neuroscience↗

The Actin regulator Mena promotes Wnt signalosome endocytosis and Wnt signalling.

Wnt signaling controls embryonic development and tissue maintenance. Endocytosis of Wnt-receptors is required for signalling, yet uptake mechanisms remain poorly understood. Here, we identify the actin regulator and Ena/VASP protein, Mena, as a key mediator. Upon Wnt stimulation, Mena redistributes from focal adhesions to signalosomes, Wnt-receptor clusters. Mena directly binds Wnt-coreceptors LRP5/6 in a phosphorylation-dependent manner increasing Wnt signal transduction. Sequestration of Ena/VASP proteins impedes in vivo Wnt activation driving Xenopus embryonic development. We resolve previous controversies by showing that Wnt3a triggers rapid Clathrin-Mediated and Fast Endophilin-Mediated LRP6 endocytosis at low concentrations sufficient for Wnt activation. This efficient endocytosis requires Ena/VASP proteins and is specifically promoted by Mena. Our results suggest Mena as a crucial mediator of Wnt signalosome endocytosis thus promoting canonical Wnt signalling.

cell biology↗

Spatial transcriptomic profiling of human paravertebral sympathetic chain ganglia reveals diabetes-induced neuroplasticity

The paravertebral sympathetic chain ganglia (SCG) are autonomic ganglia critical for regulating the "fight-or-flight" response. Symptoms of sympathetic dysfunction are prevalent in diabetes, affecting up to 90% of patients. The molecular and cellular composition of the human SCG and its alteration in diabetes remains poorly defined. To address this gap, we performed spatial transcriptomic profiling of lumbar SCGs from diabetic and non-diabetic organ donors. We identified 3 three distinct neuronal populations, two noradrenergic (NA1 and NA2) and one cholinergic (CHO), based on tyrosine hydroxylase (TH) and SLC18A3 expression, respectively. We also characterized 9 non-neuronal populations consisting of Schwann cells, immune cells, fibroblasts, adipocytes, and endothelial cells. In diabetic SCGs, we observed a significant loss of myelinating Schwann cells and a phenotypic shift of cholinergic neurons toward a noradrenergic identity. Additionally, diabetes was associated with a significant reduction in the transcripts of vasodilatory neuropeptides, such as VIP and CALCA, suggesting a mechanism for impaired vascular control. Upstream regulator analysis highlighted altered neurotrophic signaling in diabetes, with enhanced NGF/TRKA and diminished BDNF/TRKB activity, potentially driven by target-derived cues. Comparison between SCG and dorsal root ganglia (DRG) neurons revealed ganglia-specific genes, like SCN3A and NPY (SCG) versus SCN10A and GPX1 (DRG), offering specific therapeutic targets for autonomic dysfunction or pain. Our findings provide a transcriptomic characterization of human SCG, revealing molecular signatures that underlie diabetic autonomic dysfunction. This work lays a foundation for the development of therapies to restore sympathetic function and avoid unintended autonomic effects in the development of analgesics. Significance StatementAutonomic dysfunction affects up to 90% of people with diabetes, yet the human sympathetic nervous system remains poorly molecularly defined. To address this gap, we present a spatial transcriptomic profile of the human sympathetic chain ganglia (SCG), revealing how diabetes affects the human autonomic nervous system. We show that diabetes shifts the cholinergic neuronal population to a noradrenergic phenotype and reduces vasodilation neuropeptide expression, potentially explaining impaired vascular control and thermoregulation. Comparative analysis of sympathetic and sensory ganglia reveals distinct gene profiles that may inform novel therapeutic strategies. These findings offer critical insight into the molecular drivers of diabetic autonomic neuropathy and lay the groundwork for safer, more precise treatments that selectively modulate autonomic or sensory function in chronic disease.

neuroscience↗

Modulating populational variance of methyl-guanine methyl transferase expression through miR-181d degradation: a novel mechanism of temozolomide resistance

Intratumoral heterogeneity plays a pivotal role in cancer evolution, providing the substrate for adaptation to selective pressures, including treatment with chemotherapy. Here, we show that micro-RNA regulation of variance in the expression of the DNA repair protein methyl-guanine methyl transferase (MGMT) contributes to this heterogeneity and acquired therapeutic resistance. In cell lines derived from glioblastomas, the most common form of primary brain tumor, treatment with standard-of-care temozolomide chemotherapy triggers a feed-forward loop between polyribonucleotide nucleotidyltransferase 1 (PNPT1) and miR-181d, an MGMT regulating miRNA, expediting miR-181d degradation. This degradation requires the activation of Ataxia Telangiectasia and Rad3-related (ATR) kinase. The degradation of miR-181d in glioblastoma cells increased both the mean and the variance of MGMT expression in the cell population. Subclone reconstituted cell populations with similar populational mean MGMT levels but with differences in the variance of MGMT expression exhibited differential temozolomide sensitivity, with the higher MGMT variance population showing increased resistance. This resistance is suppressed by exogenously transfected miR-181d. These findings suggest a key role for miRNA in regulating intra-tumoral heterogeneity through modulation of key DNA repair enzymes and provide a compelling rationale for miRNA delivery as a platform for glioblastoma therapy. Significance StatementThis study demonstrates a mechanistic link between a feed-forward loop mediating microRNA degradation and cell-to-cell variance in gene expression, and the contribution of this mechanism to intratumoral heterogeneity and therapeutic resistance. We show that when glioblastoma, the most common form of adult primary brain tumor, is treated with standard-of-care chemotherapy, temozolomide, a feed-forward loop between miR-181d and PNPT1 is initiated, causing rapid degradation of miR-181d. This degradation increases the cell-to-cell variability in methyl-guanine methyl transferase (MGMT) expression, expanding intra-tumoral heterogeneity and contributing to acquired temozolomide resistance. This process can be suppressed by therapeutic delivery of microRNA, providing compelling considerations for clinical translation.

cancer biology↗

Single-cell characterization of the human C2 dorsal root ganglion recovered from C1-2 arthrodesis surgery: implications for neck pain

Neurons in the dorsal root ganglion (DRG) receive and transmit sensory information from the tissues they innervate and from the external environment. Upper cervical (C1-C2) DRGs are functionally unique as they receive input from the neck, head, and occipital cranial dura, the latter two of which are also innervated by the trigeminal ganglion (TG). The C2 DRG also plays an important role in neck pain, a common and disabling disorder that is poorly understood. Advanced transcriptomic approaches have significantly improved our ability to characterize RNA expression patterns at single-cell resolution in the DRG and TG, but no previous studies have characterized the C2 DRG. Our aim was to use single-nucleus and spatial transcriptomic approaches to create a molecular map of C2 DRGs from patients undergoing arthrodesis surgery with ganglionectomy. Patients with acute (<3 months) or chronic ([&ge;]3 months) neck pain were enrolled and completed patient-reported outcomes and quantitative sensory testing prior to surgery. C2 DRGs were characterized with bulk, single nucleus, and spatial RNA sequencing technologies from 22 patients. Through a comparative analysis to published datasets of the lumbar DRG and TG, neuronal clusters identified in both TG and DRG were identified in the C2 DRG. Therefore, our study definitively characterizes the molecular composition of human C2 neurons and establishes their similarity with unique characteristics of subsets of TG neurons. We identified differentially expressed genes in endothelial, fibroblast and myelinating Schwann cells associated with chronic pain, including FGFBP2, C8orf34 and EFNA1 which have been identified in previous genome and transcriptome wide association studies (GWAS/TWAS). Our work establishes an atlas of the human C2 DRG and identifies altered gene expression patterns associated with chronic neck pain. This work establishes a foundation for the exploration of painful disorders in humans affecting the cervical spine.

neuroscience↗

Molecular architecture of human dermal sleeping nociceptors

Human dermal sleeping nociceptors display ongoing activity in neuropathic pain, affecting 10% of the population. Despite advances in rodents, a molecular marker for these mechano-insensitive C-fibers (CMis) in human skin remains elusive, preventing targeted therapy. In this translational Patch-seq study, we combine single-cell transcriptomics following electrophysiological characterization with single-nucleus and spatial transcriptomics from pigs and humans. We functionally identified CMis in pig sensory neurons with patch-clamp using adapted protocols from human microneurography. We identified oncostatin-M-receptor (OSMR) and somatostatin (SST) as marker genes for CMis. Following dermal injection in healthy human volunteers, oncostatin-M, the ligand of OSMR, exclusively modulates CMis. We identified the entire molecular architecture of human dermal sleeping nociceptors, providing new therapeutic targets and the basis for a mechanistic understanding of neuropathic pain. One Sentence SummaryWe identify the molecular architecture and specifically OSMR and SST as molecular markers for human dermal sleeping nociceptors, key players in the generation of neuropathic pain. Short versionIn this Patch-seq study, we identify OSMR and SST as molecular markers for human dermal sleeping nociceptors, key players in the generation of neuropathic pain.

neuroscience↗