Margaroli, C. | Search bioRxiv

bioRxiv2026

Plasma regulates homeostatic pulmonary endothelial signaling to mitigate vascular leak following polytrauma and hemorrhagic shock

IntroductionIn hemorrhagic shock, plasma resuscitation preserves vascular integrity and protects against trauma-induced coagulopathy and organ injury. Despite demonstrated clinical benefit, the endothelial mechanisms underlying plasma resuscitation remain incompletely defined. This study investigated endothelial-specific responses to plasma resuscitation to identify targetable pathways that promote vascular repair after traumatic injury. MethodsA murine model of severe polytrauma-hemorrhagic shock (PT/HS) with demonstrable vascular endotheliopathy by 24 hours was used to compare pulmonary vascular endothelial cell (EC) responses to resuscitation with lactated Ringers (LR) relative to fresh frozen plasma (FFP). Whole blood was collected for inflammatory biomarker analysis, and pulmonary vascular leak was quantified by dextran extravasation. Pulmonary EC glycocalyx (eGC) structure was assessed by transmission electron microscopy and immunofluorescence. Spatial transcriptomic profiling of pulmonary ECs was performed using a GeoMx Digital Spatial Profiler. Key transcriptomic findings related to mitochondrial biogenesis were validated by immunostaining and by treating primary human lung EC with FFP or LR. ResultsAt 24 hours after injury, FFP reduced systemic inflammatory cytokines, pulmonary innate immune cell infiltration, and PT/HS-induced vascular leak compared to LR. Plasma levels of syndecan-1, syndecan-4, and hyaluronan were decreased, consistent with enhanced pulmonary eGC expression. Although few differences in eGC-related genes were detected, pathway analysis revealed enrichment of cellular bioenergetics and metabolic recovery pathways in ECs after FFP, whereas LR was associated with oxidative stress and inflammatory signaling. FFP enhanced mitochondrial content in pulmonary EC after PT/HS and in treated human EC compared to LR-treated controls. ConclusionsFFP resuscitation after PT/HS reduces systemic inflammation and preserves pulmonary vascular barrier function, potentially through promotion of mitochondrial signaling, metabolic recovery, and endothelial stress regulation.

cell biology↗

bioRxiv2025

Aging increases ovarian cancer growth, metastasis and immunosuppression that can be alleviated by inhibiting hedgehog signaling

Ovarian cancer incidence and mortality increase with age, yet how aging shapes tumor progression and the immune microenvironment remains poorly defined. Using orthotopic syngeneic models of distinct cellular origins (ovarian surface epithelial and fallopian tube-derived) in young versus aged mice, we show that aged hosts exhibit higher tumor burden, metastasis and ascites. Follicle depletion in young mice did not recapitulate these effects, indicating contributions beyond hormonal decline. Spatial transcriptomics revealed distinct age dependent intratumoral heterogeneity, with Hedgehog signaling enrichment in CD45+ cells from aged tumors, alongside elevated CD206+ tumor-associated macrophages and FoxP3+ regulatory T cells. Pharmacologic Hedgehog inhibition in aged mice suppressed tumor growth, reduced metastasis, and decreased CD206+ macrophages and FoxP3+ T cells while preserving CD8+T cells. In human ovarian cancer, Hedgehog activation correlated with immunosuppressive and immune checkpoint resistance signatures. We propose Hedgehog inhibition as an immunomodulatory strategy for Hedgehog activated or post menopausal ovarian cancer.

cancer biology↗

bioRxiv2022

Spatial transcriptomic profiling of coronary endothelial cells in SARS-CoV-2 myocarditis

ObjectivesOur objective was to examine coronary endothelial and myocardial programming in patients with severe COVID-19 utilizing digital spatial transcriptomics. BackgroundSevere acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has well-established links to thrombotic and cardiovascular events. Endothelial cell infection was initially proposed to initiate vascular events; however, this paradigm has sparked growing controversy. The significance of myocardial infection also remains unclear. MethodsAutopsy-derived cardiac tissue from control (n = 4) and COVID-19 (n = 8) patients underwent spatial transcriptomic profiling to assess differential expression patterns in myocardial and coronary vascular tissue. Our approach enabled transcriptional profiling in situ with preserved anatomy and unaltered local SARS-CoV-2 expression. In so doing, we examined the paracrine effect of SARS-CoV-2 infection in cardiac tissue. ResultsWe observed heterogeneous myocardial infection that tended to colocalize with CD31 positive cells within coronary capillaries. Despite these differences, COVID-19 patients displayed a uniform and unique myocardial transcriptional profile independent of local viral burden. Segmentation of tissues directly infected with SARS-CoV-2 showed unique, pro-inflammatory expression profiles including upregulated mediators of viral antigen presentation and immune regulation. Infected cell types appeared to primarily be capillary endothelial cells as differentially expressed genes included endothelial cell markers. However, there was limited differential expression within the endothelium of larger coronary vessels. ConclusionsOur results highlight altered myocardial programming during severe COVID-19 that may in part be associated with capillary endothelial cells. However, similar patterns were not observed in larger vessels, diminishing endotheliitis and endothelial activation as key drivers of cardiovascular events during COVID-19. Condensed AbstractSARS-CoV-2 is linked to thrombotic and cardiovascular events; however, the mechanism remains uncertain. Our objective was to examine coronary endothelial and myocardial programming in patients with severe COVID-19 utilizing digital spatial transcriptomics. Autopsy-derived coronary arterial and cardiac tissues from control and COVID-19 patients underwent spatial transcriptomic profiling. Our approach enabled transcriptional profiling in situ with preserved anatomy and unaltered local SARS-CoV-2 expression. We observed unique, pro-inflammatory expression profiles among all COVID-19 patients. While heterogeneous viral expression was noted within the tissue, SARS-CoV-2 tended to colocalize with CD31 positive cells within coronary capillaries and was associated with unique expression profiles. Similar patterns were not observed in larger coronary vessels. Our results highlight altered myocardial programming during severe COVID-19 that may in part be associated with capillary endothelial cells. Such results diminish coronary arterial endotheliitis and endothelial activation as key drivers of cardiovascular events during COVID-19 infection. LIST OF HIGHLIGHTSO_LISARS-CoV-2 has variable expression patterns within the myocardium of COVID-19 patients C_LIO_LISARS-CoV-2 infection induces a unique myocardial transcriptional programming independent of local viral burden C_LIO_LISARS-CoV-2 myocarditis is predominantly associated with capillaritis, and tissues directly infected with SARS-CoV-2 have unique, pro-inflammatory expression profiles C_LIO_LIDiffuse endothelial activation of larger coronary vessels was absent, diminishing large artery endotheliitis as a significant contributor to cardiovascular events during COVID-19 infection. C_LI

pathology↗