Biology subjects

Sevilla-Montero, J.

Publications and source records attributed to Sevilla-Montero, J..

4 recordsLinked to original sources

bioRxiv2026

Mast cell desensitization induces a distinct IgE-dependent transcriptional program associated with immune regulation

Allergen-driven IgE-mast cell (MC) activation is a central feature of allergic diseases, whose prevalence continues to increase worldwide. Allergen immunotherapy (AIT) is currently the only disease-modifying treatment and induces a state of MC hyporesponsiveness termed desensitization; however, its underlying molecular mechanisms remain incompletely understood and whether this state reflects passive signal attenuation or active cellular reprogramming remains unresolved. Here, we define the molecular landscape of MC desensitization using a human polyclonal platform that captures the physiological diversity of allergen-specific IgE. Desensitization reduced degranulation in an allergen-specific manner and induced progressive internalization of allergen-specific IgE. Although early steps were associated with LAT phosphorylation, subsequent allergen challenge failed to propagate activation to distal IgE/Fc{varepsilon}RI effectors, revealing selective signaling uncoupling. Transcriptomic profiling uncovered a distinct transcriptional program comprising 168 upregulated genes enriched in immunoregulatory pathways and largely non-overlapping with classical activation signatures. This reprogramming occurred despite minimal alterations in mitochondrial respiration and selective impairment of allergen-induced glycolysis. Functionally, desensitized MCs enhanced allergen-driven proliferation of memory CD4 T cells. Together, these findings demonstrate that MC desensitization is not merely passive hyporesponsiveness but involves time-dependent allergen-specific IgE internalization, selective signal propagation, and a unique immunoregulatory transcriptional imprint that may contribute to tolerance during AIT.

immunology↗

bioRxiv2022

Cigarette smoke induces pulmonary arterial dysfunction through an imbalance in the guanylyl cyclase redox status.

Chronic obstructive pulmonary disease (COPD), whose main risk factor is cigarette smoking (CS), is one of the most common diseases globally. Many COPD patients also develop pulmonary hypertension (PH), a severe complication that leads to premature death. Evidence suggests reactive oxygen species (ROS) involvement in COPD and PH, especially regarding pulmonary artery smooth muscle cells (PASMC) dysfunction. However, the effects of CS on the pulmonary vasculature are not completely understood. Herein we provide evidence on the effects of CS extract (CSE) exposure on PASMC regarding ROS production, antioxidant response and its consequences on vascular tone dysregulation. Our results indicate that CSE exposure promotes mitochondrial fission, mitochondrial membrane depolarization and increased mitochondrial superoxide levels. However, the increase in superoxide did not parallel a counterbalancing antioxidant response in human pulmonary artery (PA) cells. Interestingly, the mitochondrial superoxide chelator mitoTEMPO reduced mitochondrial fission and membrane potential depolarization caused by CSE. As we have previously shown, CSE reduces PA vasoconstriction and vasodilation. In this respect, mitoTEMPO prevented the impaired nitric oxide-mediated vasodilation, while vasoconstriction remained reduced. Finally, we observed a CSE-driven downregulation of the Cyb5R3 enzyme, which prevents soluble guanylyl cyclase oxidation in PASMC. This might explain the CSE-mediated decrease in PA vasodilation. These results provide evidence that there might be a connection between mitochondrial ROS and altered vasodilation responses in PH secondary to COPD, and strongly support the potential of antioxidant strategies specifically targeting mitochondria as a new therapy for these diseases. Graphical abstract O_FIG_DISPLAY_L [Figure 1] M_FIG_DISPLAY C_FIG_DISPLAY

cell biology↗

bioRxiv2020

Time-dependent dual effect of NLRP3 inflammasome in brain ischemia

Background and purposePost-ischemic inflammation contributes to worsening of ischemic brain injury and in this process, the inflammasomes play a key role. Inflammasomes are cytosolic multiprotein complexes which upon assembly activate the maturation and secretion of the inflammatory cytokines IL-1{beta} and IL-18. However, participation of the NLRP3 inflammasome in ischemic stroke remains controversial. Our aims were to determine the role of NLRP3 in ischemia and to explore the mechanism involved in the potential protective effect of the neurovascular unit. MethodsWT and NLRP3 knock-out mice were subjected to ischemia by middle cerebral artery occlusion (60 minutes) with or without treatment with MCC950 at different time points post-stroke. Brain injury was measured histologically with 2,3,5-triphenyltetrazolium chloride (TTC) staining. ResultsWe identified a time-dependent dual effect of NLRP3. While neither the pre-treatment with MCC950 nor the genetic approach (NLRP3 KO) proved to be neuroprotective, post-reperfusion treatment with MCC950 significantly reduced the infarct volume in a dose-dependent manner. Importantly, MCC950 improved the neuro-motor function and reduced the expression of different pro-inflammatory cytokines (IL-1{beta}, TNF-), NLRP3 inflammasome components (NLRP3, pro-caspase-1), protease expression (MMP9) and endothelial adhesion molecules (ICAM, VCAM). We observed a marked protection of the blood-brain barrier (BBB), which was also reflected in the recovery of the tight junctions proteins (ZO-1, Claudin-5). Additionally, MCC950 produced a reduction of the CCL2 chemokine in blood serum and in brain tissue, which lead to a reduction in the immune cell infiltration. ConclusionsThese findings suggest that post-reperfusion NLRP3 inhibition may be an effective acute therapy for protecting the blood-brain barrier in cerebral ischemia with potential clinical translation.

neuroscience↗

bioRxiv2019

Direct Effects of Cigarette Smoke in Pulmonary Arterial Cells alter Vascular Tone through Arterial Remodeling and Kv7.4 Channel Dysregulation.

Chronic obstructive pulmonary disease (COPD) is a widespread disease, with no curative therapies nowadays. Exposure to cigarette smoking is considered the chief leading cause of COPD. Current drugs therapies improve patient quality of life, however they do not revert the progression of the disease. Therefore, a deeper study of the cellular and molecular mechanisms that underlie this pathology is required to be able to carry out targeted and effective treatments. Although the effects of cigarette smoke in the progressive deterioration of the airway have been extensively studied in COPD patients, its effects on pulmonary vasculature have been unexplored, due to the classic conception that vascular damage is a consequence of alveolar hypoxia and loss of capillary bed. In this paper, we aimed to study the effects of cigarette smoke extract (CSE) in regulating pulmonary arterial cells phenotypic modulation, in particular the effects in fibroblasts (hPAFib) and smooth muscle cells (hPASMC), and in murine pulmonary arteries. Our results demonstrated that CSE exposure had direct effects on hPAFib and hPASMC, promoting a senescent phenotype that in turn contributed, through the secretion of inflammatory molecules, to increase the proliferative potential of non-exposed cells. CSE also increased total ROS levels in hPAFib and hPASMC, and upregulated NADPH oxidase subunits NOX1 and p22phox. Most importantly, CSE affected cell contractility and dysregulated the expression and activity of voltage-gated K+ channel Kv7.4. This contributed to limit vascular responses impairing vasoconstriction and endothelium-dependent and independent relaxation.

cell biology↗