Phenotyping the Responses to Systemic Corticosteroids in the Management of Asthma Attacks (PRISMA): protocol for an observational and translational pilot study.

INTRODUCTION: Asthma and its associated exacerbation are heterogeneous. Although severe asthma attacks are systematically prescribed corticosteroids and often antibiotics, little is known about the variability of response to these therapies. Blood eosinophils and fractional exhaled nitric oxide (FeNO) are type 2 inflammation biomarkers that have established mechanistic, prognostic and theragnostic values in chronic asthma, but their utility in acute asthma is unclear. We speculate that the clinical and biological response to those treatments varies according to inflammometry and microbiological test results. METHODS AND ANALYSIS: An observational longitudinal pilot study with multimodal clinical and translational assessments will be performed on 50 physician-diagnosed ≥12-year-old asthmatics presenting with an asthma attack and 12 healthy controls, including blood eosinophil count (venous and point-of-care (POC) capillary blood), FeNO and testing for airway infection (sputum cultures and POC nasopharyngeal swabs). People with asthma will be assessed on day 0 and after a 7-day corticosteroid course, with home monitoring performed in between. The primary analysis will be the change in the forced expiratory volume in 1 s according to type 2 inflammatory status (blood eosinophils ≥0.15×109/L and/or FeNO ≥25 ppb) after treatment. Key secondary analyses will compare changes in symptom scores and the proportion of patients achieving a minimal clinically important difference. Exploratory analyses will assess the relationship between clinical, lung function, inflammatory and microbiome parameters; satisfaction plus reliability indices of POC tests; and sex-gender variability in treatment response. Ultimately, this pilot study will serve to plan a larger trial comparing the clinical and biological response to systemic corticosteroids according to inflammatory biomarkers, offering valuable guidance for more personalised therapeutic strategies in asthma attacks. ETHICS AND DISSEMINATION: The protocol has been approved by the Research Ethics Committee of the CIUSSS de l'Estrie-CHUS, Sherbrooke, Quebec, Canada (#2023-4687). Results will be communicated in an international meeting and submitted to a peer-reviewed journal. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov Registry (NCT05870215).

Bases neurobiológicas de vulnerabilidad psiquiátrica a lo largo de las etapas de la vida hormonal de la mujer / Neurobiological bases of psychiatric vulnerability through the female hormonal stages

Women are about twice more likely than men to suffer from depression, it has been hypothesized that reproductive events (i.e., premenstrual, pre and postpartum, menopausal transition) may represent vulnerability periods for depression, in part because of a heightened sensitivity to intense hormonal fluctuations. 1) Most women report physical or emotional symptoms premenstrually, some being severe enough to be diagnosed as premenstrual dysphoric disorder (PMDD); some recent studies suggest that PMDD is biologically different from major depression; 2) While pregnancy does not increase the risk for depression, women with a past history of depression are at risk for recurrent episodes or relapse if antidepressant medications are discontinued; 3) Hormonal changes during the postpartum period may trigger symptoms of postpartum depression; 4) Almost half of perimenopausal women are clinically depressed, and over a third experience their first episode of depression in the perimenopausal period. The increase in major depressive episodes during this period has been linked to erratic gonadal hormonal changes.

Las mujeres poseen alrededor del doble de posibilidades que los hombres de sufrir depresión. Se ha planteado como hipótesis que los eventos reproductivos (ej. premenstrual, pre y postparto, transición menopáusica) pueden representar periodos de vulnerabilidad para la depresión, en parte, debido a la elevada sensibilidad a las intensas fluctuaciones hormonales. 1) La mayoría de las mujeres informan síntomas físicos o emocionales premenstruales, siendo algunos suficientemente severos para ser diagnosticados como trastorno disfórico premenstrual (TDPM); algunos estudios recientes sugieren que el TDPM es biológicamente diferente de la depresión mayor; 2) Mientras que el embarazo no aumenta el riesgo para la depresión, las mujeres con una historia pasada de depresión están en riesgo para episodios recurrentes o recaída si se discontinúan los medicamentos antidepresivos; 3) Los cambios hormonales durante el período del postparto pueden gatillar síntomas de depresión postparto; 4) Casi la mitad de las mujeres perimenopáusicas están clínicamente deprimidas y sobre un tercio experimenta su primer episodio de depresión en el período perimenopáusico. El aumento de los episodios depresivos mayores durante este período se ha relacionado con cambios erráticos de las hormonas gonadales.

Src-mediated phosphorylation of Hsp90 in response to vascular endothelial growth factor (VEGF) is required for VEGF receptor-2 signaling to endothelial NO synthase.

Nitric oxide (NO) release from endothelial cells, via endothelial NO synthase (eNOS) activation, is central to the proangiogenic actions of vascular endothelial growth factor (VEGF). VEGF signaling to eNOS is principally mediated by an Akt-dependent phosphorylation of eNOS and by increased association of eNOS to the molecular chaperone, heat-shock protein 90 kDa (Hsp90). Herein, we report that VEGFR-2 activation induces tyrosine phosphorylation of VEGF receptor 2 (VEGFR-2)-associated Hsp90beta. Tyrosine phosphorylation of Hsp90beta in response to VEGF is dependent on internalization of the VEGFR-2 and on Src kinase activation. Furthermore, we demonstrate that c-Src directly phosphorylates Hsp90 on tyrosine 300 residue and that this event is essential for VEGF-stimulated eNOS association to Hsp90 and thus NO release from endothelial cells. Our work identifies Y300 phosphorylation of Hsp90 as a novel regulated posttranslational modification of the chaperone and demonstrates its importance in the proangiogenic actions of VEGF, namely by regulating NO release from endothelial cells.

Vascular endothelial growth factor-dependent down-regulation of Flk-1/KDR involves Cbl-mediated ubiquitination. Consequences on nitric oxide production from endothelial cells.

Ligand-stimulated degradation of receptor tyrosine kinase (RTK) is an important regulatory step of signal transduction. The vascular endothelial growth factor (VEGF) receptor Flk-1/KDR is responsible for the VEGF-stimulated nitric oxide (NO) production from endothelial cells. Cellular mechanisms mediating the negative regulation of Flk-1 signaling in endothelial cells have not been investigated. Here we show that Flk-1 is rapidly down-regulated following VEGF stimulation of bovine aortic endothelial cells (BAECs). Consequently, VEGF pretreatment of endothelial cells prevents any further stimulation of Flk-1, resulting in decreased NO production from subsequent VEGF challenges. Ubiquitination of RTKs targets them for degradation; we demonstrate that activation of Flk-1 by VEGF leads to its polyubiquitination in BAECs. Furthermore, VEGF stimulation of BAECs or COS-7 cells transiently transfected with Flk-1 results in the phosphorylation of the ubiquitin ligase Cbl, the enhanced association of Cbl with Flk-1, and the relocalization of Cbl to vesicular structures in BAECs. Overexpression of Cbl in COS-7 cells enhances VEGF-induced ubiquitination of Flk-1, whereas a Cbl mutant lacking the ubiquitin ligase RING finger domain, 70Z/3-Cbl, does not. Moreover, expression of Cbl in contrast to 70Z/3-Cbl inhibits the Flk-1-dependent activation of eNOS and, thus, NO release. In BAEC overexpressing Cbl, the degradation of Flk-1 upon VEGF stimulation is accelerated compared with cells transfected with a control vector (green fluorescent protein). Our findings demonstrate that Flk-1 is rapidly down-regulated following sustained VEGF stimulation and identify Cbl as a negative regulator of Flk-1 signaling to eNOS. Cbl thus plays a role in the regulation of VEGF signaling by mediating the stimulated ubiquitination and, consequently, degradation of Flk-1 in endothelial cells.