Changes in the Adaptive Cellular Repertoire after Infection with Different SARS-CoV-2 VOCs in a Cohort of Vaccinated Healthcare Workers.

BACKGROUND: Currently approved vaccines are highly effective in protecting against hospitalization and severe COVID-19 infections. How pre-existing immunity responds to new variants with mutated antigens is crucial information for elucidating the functional interplay between antibodies and B and T cell responses during infection with new SARS-CoV-2 variants. METHODS: In this study, we monitored the dynamics and persistence of the immune response versus different SARS-CoV-2 variants of concern that emerged during the pandemic period (2021-2022) in a cohort of vaccinated healthcare workers, who experienced breakthrough infection in the Pre-Delta, Delta, and Omicron waves. We evaluated both the humoral and cell-mediated responses after infection. We also evaluated the anti-SARS-CoV-2 antibodies levels produced by infection in comparison with those produced after vaccination. RESULTS: Our results highlighted that the immune response against the Delta VOC mainly involved an adaptive humoral and switched memory B cells component, even 3 months after the last vaccine dose, conversely showing a high percentage of depleted adaptive T cells. Omicron infections triggered a consistent production of non-vaccine-associated anti-N antibodies, probably to balance the spike epitope immune escape mechanisms. CONCLUSION: Our results suggest a direct dependence between the VOC and different humoral and B and T cell balances in the post-infection period, despite the administration of a different number of vaccine doses and the elapsed time since the last vaccination.

Evaluation of the SsIR/NIE recombinant antigen ELISA for the follow up of patients infected by Strongyloides stercoralis: a diagnostic study.

Some serology assays demonstrated useful for post-treatment monitoring of Strongyloides stercoralis infection. Serology frequently has low specificity, which might be improved by the use of recombinant antigens. The Strongy Detect ELISA is based on 2 recombinant antigens (SsIR and NIE) and proved good accuracy. Aim of this study was to evaluate the performance of this test for the post-treatment monitoring of strongyloidiasis. We tested 38 paired sera, with matched fecal tests results, stored in our biobank and originating from a randomized controlled trial. At baseline, all patients tested positive for at least 1 fecal assay among PCR, direct stool microscopy and agar plate culture. Patients were re-tested with both serology and fecal assays 12 months after treatment. Primary outcome was the relative reduction in optical density (OD) between baseline and follow up. We observed that about 95% samples showed a reduction between pre and post-treatment OD, with a median relative reduction of 93.9% (IQR 77.3%­98.1%). In conclusion, the test proved reliable for post-treatment monitoring. However, some technical issues, including that the threshold for positivity has not be predefined, and that a substantial number of samples showed overflow signals, need to be fixed to permit use in routine practice.

SARS-CoV-2 infection risk is higher in vaccinated patients with inflammatory autoimmune diseases or liver transplantation treated with mycophenolate due to an impaired antiviral immune response: results of the extended follow up of the RIVALSA prospective cohort.

Background: A relevant proportion of immunocompromised patients did not reach a detectable seroconversion after a full primary vaccination cycle against SARS-CoV-2. The effect of different immunosuppressants and the potential risks for SARS-CoV-2 infection in these subjects is largely unknown. Methods: Patients from the Rivalsa prospective, observational cohort study with planned anti SARS-CoV-2 third dose mRNA vaccination between October and December 2021 were asked to participate to this follow-up study. Patients were asked about eventual confirmed positivity to SARS-CoV-2 infection within 6 months from the third dose and to undergo a blood draw to evaluate seroconversion status after the additional vaccine shot. Results: 19 out of 114 patients taking part in the survey developed a confirmed SARS-CoV-2 infection; we identified mycophenolate treatment as an independent predictor of an increased risk of infection even after the third vaccine dose (OR: 5.20, 95% CI: 1.70-20.00, p=0.0053). This result is in agreement with the in vitro evidence that MMF impairs both B and T lymphocytes driven immune responses (reduction both in memory B cells producing anti-spike antibodies and in proliferating CD4+ and CD8+ T cells). Conclusions: Immunocompromised patients need an additional vaccine administration to reach a detectable seroconversion, thus fostering a more personalized approach to their clinical management. Moreover, patients undergoing mycophenolate treatment show a specific increased infection risk, with respect to other immunosuppressants thus supporting a closer monitoring of their health status.

Lentilactobacillus kefiri SGL 13 and Andrographis paniculata alleviate dextran sulfate sodium induced colitis in mice.

Introduction: Inflammatory bowel diseases (IBD) are chronic inflammatory conditions that typically involve diarrhea, abdominal pain, fatigue, and weight loss, with a dramatic impact on patients' quality of life. Standard medications are often associated with adverse side effects. Thus, alternative treatments such as probiotics are of great interest. The purpose of the present study was to evaluate the effects of oral administration of Lentilactobacillus kefiri (basonym: Lactobacillus kefiri) SGL 13 and Andrographis paniculata, namely, Paniculin 13™, on dextran sodium sulfate (DSS)- treated C57BL/6J mice. Methods: Colitis was induced by administering 1.5% DSS in drinking water for 9 days. Forty male mice were divided into four groups, receiving PBS (control), 1.5% DSS, Paniculin 13™ and 1.5% DSS + Paniculin 13™. Results: The results showed that body weight loss and Disease Activity Index (DAI) score were improved by Paniculin 13™. Moreover, Paniculin 13™ ameliorated DSS-induced dysbiosis, by modulating the gut microbiota composition. The gene expression of MPO, TNFα and iNOS in colon tissue was reduced and these data matched with the histological results, supporting the efficacy of Paniculin 13™ in reducing the inflammatory response. No adverse effects were associated to Paniculin 13™ administration. Discussion: In conclusion, Paniculin 13™ could be an effective add-on approach to conventional therapies for IBD.

Humoral Effect of SARS-CoV-2 mRNA vaccination with booster dose in solid tumor patients with different anticancer treatments.

Introduction: Cancer patients are at risk for serious complications in case of SARS-CoV-2 infection. In these patients SARS-CoV-2 vaccination is strongly recommended, with the preferential use of mRNA vaccines. The antibody response in cancer patients is variable, depending on the type of cancer and antitumoral treatment. In solid tumor patients an antibody response similar to healthy subjects has been confirmed after the second dose. Only few studies explored the duration of immunization after the two doses and the effect of the third dose. Methods: In our study we explored a cohort of 273 solid tumor patients at different stages and treated with different anticancer therapies. Results and Discussion: Our analysis demonstrated that the persistence of the neutralizing antibody and the humoral response after the booster dose of vaccine was not dependent on either the tumor type, the stage or type of anticancer treatment.

Effect of Lactoferrin on Clinical Outcomes of Hospitalized Patients with COVID-19: The LAC Randomized Clinical Trial.

As lactoferrin is a nutritional supplement with proven antiviral and immunomodulatory abilities, it may be used to improve the clinical course of COVID-19. The clinical efficacy and safety of bovine lactoferrin were evaluated in the LAC randomized double-blind placebo-controlled trial. A total of 218 hospitalized adult patients with moderate-to-severe COVID-19 were randomized to receive 800 mg/die oral bovine lactoferrin (n = 113) or placebo (n = 105), both given in combination with standard COVID-19 therapy. No differences in lactoferrin vs. placebo were observed in the primary outcomes: the proportion of death or intensive care unit admission (risk ratio of 1.06 (95% CI 0.63-1.79)) or proportion of discharge or National Early Warning Score 2 (NEWS2) ≤ 2 within 14 days from enrollment (RR of 0.85 (95% CI 0.70-1.04)). Lactoferrin showed an excellent safety and tolerability profile. Even though bovine lactoferrin is safe and tolerable, our results do not support its use in hospitalized patients with moderate-to-severe COVID-19.

Baseline Plasma Osteopontin Protein Elevation Predicts Adverse Outcomes in Hospitalized COVID-19 Patients.

More than three years have passed since the first case, and COVID-19 is still a health concern, with several open issues such as the lack of reliable predictors of a patient's outcome. Osteopontin (OPN) is involved in inflammatory response to infection and in thrombosis driven by chronic inflammation, thus being a potential biomarker for COVID-19. The aim of the study was to evaluate OPN for predicting negative (death or need of ICU admission) or positive (discharge and/or clinical resolution within the first 14 days of hospitalization) outcome. We enrolled 133 hospitalized, moderate-to-severe COVID-19 patients in a prospective observational study between January and May 2021. Circulating OPN levels were measured by ELISA at admission and at day 7. The results showed a significant correlation between higher plasma concentrations of OPN at hospital admission and a worsening clinical condition. At multivariate analysis, after correction for demographic (age and gender) and variables of disease severity (NEWS2 and PiO2/FiO2), OPN measured at baseline predicted an adverse prognosis with an odds ratio of 1.01 (C.I. 1.0-1.01). At ROC curve analysis, baseline OPN levels higher than 437 ng/mL predicted a severe disease evolution with 53% sensitivity and 83% specificity (area under the curve 0.649, p = 0.011, likelihood ratio of 1.76, (95% confidence interval (CI): 1.35-2.28)). Our data show that OPN levels determined at the admission to hospital wards might represent a promising biomarker for early stratification of patients' COVID-19 severity. Taken together, these results highlight the involvement of OPN in COVID-19 evolution, especially in dysregulated immune response conditions, and the possible use of OPN measurements as a prognostic tool in COVID-19.

CGRP Plasma Levels Correlate with the Clinical Evolution and Prognosis of Hospitalized Acute COVID-19 Patients.

SARS-CoV-2 is the etiological agent of COVID-19, an extremely heterogenous disease that can cause severe respiratory failure and critical illness. To date, reliable biomarkers allowing for early patient stratification according to disease severity are still lacking. Calcitonin gene-related peptide (CGRP) is a vasoactive neuropeptide involved in lung pathophysiology and immune modulation and is poorly investigated in the COVID-19 context. In this observational, prospective cohort study, we investigated the correlation between CGRP and clinical disease evolution in hospitalized moderate to severe COVID-19 patients. Between January and May 2021 (Italian third pandemic wave), 135 consecutive SARS-CoV-2 patients were diagnosed as being eligible for the study. Plasma CGRP level evaluation and routine laboratory tests were performed on blood samples collected at baseline and after 7 days of hospitalization. At baseline, the majority our patients had a moderate to severe clinical presentation, and higher plasma CGRP levels predicted a higher risk of in-hospital negative evolution (odds-ratio OR 2.84 [IQR 1.07-7.51]) and were correlated with pulmonary intravascular coagulopathy (OR 2.92 [IQR 1.19-7.17]). Finally, plasma CGRP levels were also correlated with plasma IP10 levels. Our data support a possible crosstalk between the lung and the neuroimmune axis, highlighting a crucial role for plasma CGRP in sustaining COVID-19-related hyperinflammation.

Ongoing Mycophenolate Treatment Impairs Anti-SARS-CoV-2 Vaccination Response in Patients Affected by Chronic Inflammatory Autoimmune Diseases or Liver Transplantation Recipients: Results of the RIVALSA Prospective Cohort.

Vaccines are the most effective means to prevent the potentially deadly effects of SARS-CoV-2 infection, but not all vaccinated individuals gain the same degree of protection. Patients undergoing chronic immunosuppressive therapy due to autoimmune diseases or liver transplants, for example, may show impaired anti-SARS-CoV-2 antibody response after vaccination. We performed a prospective observational study with parallel arms, aiming to (a) evaluate seroconversion after anti-SARS-CoV-2 mRNA vaccine administration in different subgroups of patients receiving immunosuppressive treatment for rheumatological or autoimmune diseases or to prevent organ rejection after liver transplantation and (b) identify negative predictors of IgG anti-SARS-CoV-2 development. Out of 437 eligible patients, 183 individuals were enrolled at the Rheumatology and Hepatology Tertiary Units of "Maggiore della Carità" University Hospital in Novara: of those, 52 were healthy subjects, while among the remaining 131 patients, 30 had a diagnosis of spondyloarthritis, 25 had autoimmune hepatitis, 10 were liver transplantation recipients, 23 suffered from connective tissue diseases (including 10 cases that overlapped with other diseases), 40 were treated for rheumatoid arthritis, and 5 had vasculitis. Moreover, all patients were receiving chronic immunosuppressive therapy. The immunogenicity of mRNA COVID-19 vaccines was evaluated by measuring IgG anti-SARS-CoV-2 antibody titers before vaccination and after 10, 30, and 90 days since the first dose administration. Of the selected cohort of patients, 24.0% did not develop any detectable anti-SARS-CoV-2 IgG after a complete mRNA-based two doses primary vaccination cycle. At univariate analysis, independent predictors of an absent antibody response to vaccine were a history of liver transplantation (OR 11.5, 95% CI 2.5−53.7, p = 0.0018), the presence of a comorbid active neoplasia (OR 26.4, 95% CI 2.8−252.4, p = 0.0045), and an ongoing immunosuppressive treatment with mycophenolate (MMF) (OR 14.0, 95% CI 3.6−54.9, p = 0.0002) or with calcineurin inhibitors (OR 17.5, 95% CI 3.1−99.0, p = 0.0012). At multivariate analysis, only treatment with MMF (OR 24.8, 95% CI 5.9−103.2, p < 0.0001) and active neoplasia (OR 33.2, 95% CI 5.4−204.1, p = 0.0002) were independent predictors of seroconversion failure. These findings suggest that MMF dose reduction or suspension may be required to optimize vaccine response in these patients.

Baseline plasma SARS-CoV-2 RNA detection predicts an adverse COVID-19 evolution in moderate to severe hospitalized patients.

BACKGROUND: SARS-CoV-2 is a single-stranded RNA virus, known to be the causative agent of COVID-19. As the resulting disease shows a very heterogeneous range of clinical manifestations, the identification of early biomarkers allowing patients stratification according to the expected disease severity is still an unmet clinical need. METHODS: In this observational prospective cohort study, 137 consecutive patients, testing positive for SARS-CoV-2 infection by nasopharyngeal swab RT-PCR or antigenic test, were enrolled to evaluate their plasma viral load at the time of hospitalization. RESULTS: Even if all of them had a molecular diagnosis of COVID-19, only 29 patients showed a detectable plasma SARS-CoV-2 RNAemia. Such viremic patients also showed other clinical and laboratory finding alterations (increased troponin I, IL-6, RDW-CV, and creatinine levels along with decreased platelet count and glomerular filtration rate). A plasma detectable RNA viral load predicted in hospital death or ICU admission with an odds ratio of 3.53 (CI: 1.44-8.64, P=0.0058), while the lack of a detectable viral load was associated with a faster recovery, with an odds ratio of 4.06 (CI: 1.72-9.59, P=0.0014). These findings were confirmed in multivariate models including age, sex and baseline National Early Warning Score 2 and arterial oxygen tension over inspired oxygen fraction ratio. CONCLUSIONS: Our data thus suggest that plasma viral RNA load at the time of hospital admission could represent a useful independent biomarker allowing early patients' stratification according to the expected disease evolution, and driving clinical decisions tailored on the specific needs of the individual patient.

Baseline Plasma Gas6 Protein Elevation Predicts Adverse Outcomes in Hospitalized COVID-19 Patients.

Reliable biomarkers allowing early patients' stratification for the risk of adverse outcomes in COVID-19 are lacking. Gas6, together with its tyrosine kinase receptors named TAM, is involved in the regulation of immune homeostasis, fibrosis, and thrombosis. Our aim was to evaluate whether Gas6, sAxl, and sMerTK could represent early predictors of disease evolution either towards a negative (death or need of ICU admission) or a positive (discharge and/or clinical resolution within the first 14 days of hospitalization) outcome. To this purpose, between January and May 2021 (corresponding to third pandemic wave in Italy), 139 consecutive SARS-CoV-2 positive patients were enrolled in a prospective observational study. Plasma levels of these molecules were measured by ELISA at the time of hospitalization and after 7 and 14 days. We observed that higher plasma Gas6 concentrations at hospital admission were associated with a worsening in clinical conditions while lower sMerTK concentrations at baseline and after 7 days of hospitalization were associated with a more favorable outcome. At multivariate analysis, after correction for demographic and COVID-19 severity variables (NEWS2 and PiO2/FiO2), only Gas6 measured at baseline predicted an adverse prognosis with an odds ratio of 1.03 (C.I. 1.01-10.5). At ROC curve analysis, baseline Gas6 levels higher than 58.0 ng/ml predicted a severe disease evolution with 53.3% sensitivity and 77.6% specificity (area under the curve 0.653, p = 0.01, likelihood ratio of 2.38, IQR: 1.46-3.87). Taken together, these results support the hypothesis that a dysregulation in the Gas6/TAM axis could play a relevant role in modulating the course of COVID-19 and suggest that plasma Gas6 may represent a promising prognostic laboratory parameter for this condition.

The accuracy of a recombinant antigen immunochromatographic test for the detection of Strongyloides stercoralis infection in migrants from sub-Saharan Africa.

BACKGROUND: Strongyloidiasis, a nematode infection which is mainly caused by Strongyloides stercoralis in humans, can lead to a fatal syndrome in immunocompromised individuals. Its diagnosis is challenging due to the absence of a diagnostic gold standard. The infection is highly prevalent in migrants from endemic countries in tropical and subtropical areas, and a rapid diagnostic test would be helpful for screening purposes. The aim of this study was to estimate the accuracy of a novel immunochromatographic test (ICT) for the diagnosis of S. stercoralis infection. METHODS: A single-centre diagnostic accuracy study was undertaken using well-characterized frozen sera available from the biobank of a referral hospital for parasitic diseases in Italy. The included sera were from migrants from sub-Saharan Africa, and matching results were available for agar plate culture and/or polymerase chain reaction for S. stercoralis; moreover, the results of both a commercial enzyme-linked immunosorbent assay test and an in-house immunofluorescence test for strongyloidiasis were made available. Laboratory staff who read the ICT results were blinded as regards the results of the other tests. Two readers independently read the ICT, and a third one was involved when results were discrepant. The accuracy of the ICT was assessed both against the results of the panel of faecal tests and by latent class analysis (LCA). RESULTS: Agreement between the readers was excellent [Cohen's κ = 92.7%, 95% confidence interval (CI) 88.3-97.1%]. When assessed against the results of the faecal tests, the sensitivity and specificity of the ICT were 82.4% (95% CI 75.7-89.0%) and 73.8% (95% CI 66.8-80.9%), respectively. According to the LCA, the sensitivity and specificity were 86.3% (95% CI 80.1-92.5%) and 73.9% (95% CI 67.0-80.8%), respectively. CONCLUSIONS: The results of the ICT demonstrated ease of interpretation. The accuracy proved good, though the sensitivity might be further improved for screening purposes.

Prognostic Markers in Hospitalized COVID-19 Patients: The Role of IP-10 and C-Reactive Protein.

BACKGROUND: SARS-CoV-2 is responsible for COVID-19, a clinically heterogeneous disease, ranging from being completely asymptomatic to life-threating manifestations. An unmet clinical need is the identification at disease onset or during its course of reliable biomarkers allowing patients' stratification according to disease severity. In this observational prospective cohort study, patients' immunologic and laboratory signatures were analyzed to identify independent predictors of unfavorable (either death or intensive care unit admission need) or favorable (discharge and/or clinical resolution within the first 14 days of hospitalization) outcome. METHODS: Between January and May 2021 (third wave of the pandemic), we enrolled 139 consecutive SARS-CoV-2 positive patients hospitalized in Northern Italy to study their immunological and laboratory signatures. Multiplex cytokine, chemokine, and growth factor analysis, along with routine laboratory tests, were performed at baseline and after 7 days of hospital stay. RESULTS: According to their baseline characteristics, the majority of our patients experienced a moderate to severe illness. At multivariate analysis, the only independent predictors of disease evolution were the serum concentrations of IP-10 (at baseline) and of C-reactive protein (CRP) after 7 days of hospitalization. Receiver-operating characteristic (ROC) curve analysis confirmed that baseline IP - 10 > 4271 pg/mL and CRP > 2.3 mg/dL at 7 days predict a worsening in clinical conditions (87% sensitivity, 66% specificity, area under the curve (AUC) 0.772, p < 0.001 and 83% sensitivity, 73% specificity, AUC 0.826, p < 0.001, respectively). CONCLUSIONS: According to our results, baseline IP-10 and CRP after 7 days of hospitalization could be useful in driving clinical decisions tailored to the expected disease trajectory in hospitalized COVID-19 patients.

Association Between Sex Hormone Levels and Clinical Outcomes in Patients With COVID-19 Admitted to Hospital: An Observational, Retrospective, Cohort Study.

Understanding the cause of sex disparities in COVID-19 outcomes is a major challenge. We investigate sex hormone levels and their association with outcomes in COVID-19 patients, stratified by sex and age. This observational, retrospective, cohort study included 138 patients aged 18 years or older with COVID-19, hospitalized in Italy between February 1 and May 30, 2020. The association between sex hormones (testosterone, estradiol, progesterone, dehydroepiandrosterone) and outcomes (ARDS, severe COVID-19, in-hospital mortality) was explored in 120 patients aged 50 years and over. STROBE checklist was followed. The median age was 73.5 years [IQR 61, 82]; 55.8% were male. In older males, testosterone was lower if ARDS and severe COVID-19 were reported than if not (3.6 vs. 5.3 nmol/L, p =0.0378 and 3.7 vs. 8.5 nmol/L, p =0.0011, respectively). Deceased males had lower testosterone (2.4 vs. 4.8 nmol/L, p =0.0536) and higher estradiol than survivors (40 vs. 24 pg/mL, p = 0.0006). Testosterone was negatively associated with ARDS (OR 0.849 [95% CI 0.734, 0.982]), severe COVID-19 (OR 0.691 [95% CI 0.546, 0.874]), and in-hospital mortality (OR 0.742 [95% CI 0.566, 0.972]), regardless of potential confounders, though confirmed only in the regression model on males. Higher estradiol was associated with a higher probability of death (OR 1.051 [95% CI 1.018, 1.084]), confirmed in both sex models. In males, higher testosterone seems to be protective against any considered outcome. Higher estradiol was associated with a higher probability of death in both sexes.

A Triple Culture Cell System Modeling the Human Blood-Brain Barrier.

The delivery of drugs to the brain remains a challenge due to the blood-brain barrier's (BBB) highly specific and restrictive properties, which controls and restrict access to the brain parenchyma. However, with the development of nanotechnologies, large panels of new nanomaterials were developed to improve drug delivery, highlighting the need for reliable in vitro microsystems to predict brain penetration in the frame of preclinical assays. Here is a straightforward method to set up a microphysiological system to model the BBB using solely human cells. In its configuration, the model consists of a triple culture including brain-like endothelial cells (BLECs), pericytes, and astrocytes, the three main BBB cellular actors necessary to induce and regulate the BBB properties in a more physiological manner without the requirement of tightening compounds. The model developed in a 12-well plate format, ready after 6 days of triple culture, is characterized in physical properties, gene, and protein expressions and used for polymeric nanogel transport measurement. The model can be used for an extensive range of experiments in healthy and pathological conditions and represents a valuable tool for preclinical assessments of molecule and particle transport, as well as inter-and intracellular trafficking.

Secretome of endothelial progenitor cells from stroke patients promotes endothelial barrier tightness and protects against hypoxia-induced vascular leakage.

BACKGROUND: Cell-based therapeutic strategies have been proposed as an alternative for brain repair after stroke, but their clinical application has been hampered by potential adverse effects in the long term. The present study was designed to test the effect of the secretome of endothelial progenitor cells (EPCs) from stroke patients (scCM) on in vitro human models of angiogenesis and vascular barrier. METHODS: Two different scCM batches were analysed by mass spectrometry and a proteome profiler. Human primary CD34+-derived endothelial cells (CD34+-ECs) were used for designing angiogenesis studies (proliferation, migration, and tubulogenesis) or in vitro models of EC monolayer (confluent monolayer ECs-CMECs) and blood-brain barrier (BBB; brain-like ECs-BLECs). Cells were treated with scCM (5 µg/mL) or protein-free endothelial basal medium (scEBM-control). CMECs or BLECs were exposed (6 h) to oxygen-glucose deprivation (OGD) conditions (1% oxygen and glucose-free medium) or normoxia (control-5% oxygen, 1 g/L of glucose) and treated with scCM or scEBM during reoxygenation (24 h). RESULTS: The analysis of different scCM batches showed a good reproducibility in terms of protein yield and composition. scCM increased CD34+-EC proliferation, tubulogenesis, and migration compared to the control (scEBM). The proteomic analysis of scCM revealed the presence of growth factors and molecules modulating cell metabolism and inflammatory pathways. Further, scCM decreased the permeability of CMECs and upregulated the expression of the junctional proteins such as occludin, VE-cadherin, and ZO-1. Such effects were possibly mediated through the activation of the interferon pathway and a moderate downregulation of Wnt signalling. Furthermore, OGD increased the permeability of both CMECs and BLECs, while scCM prevented the OGD-induced vascular leakage in both models. These effects were possibly mediated through the upregulation of junctional proteins and the regulation of MAPK/VEGFR2 activity. CONCLUSION: Our results suggest that scCM promotes angiogenesis and the maturation of newly formed vessels while restoring the BBB function in ischemic conditions. In conclusion, our results highlight the possibility of using EPC-secretome as a therapeutic alternative to promote brain angiogenesis and protect from ischemia-induced vascular leakage.

Miniaturization and Automation of a Human In Vitro Blood-Brain Barrier Model for the High-Throughput Screening of Compounds in the Early Stage of Drug Discovery.

Central nervous system (CNS) diseases are one of the top causes of death worldwide. As there is a difficulty of drug penetration into the brain due to the blood-brain barrier (BBB), many CNS drugs treatments fail in clinical trials. Hence, there is a need to develop effective CNS drugs following strategies for delivery to the brain by better selecting them as early as possible during the drug discovery process. The use of in vitro BBB models has proved useful to evaluate the impact of drugs/compounds toxicity, BBB permeation rates and molecular transport mechanisms within the brain cells in academic research and early-stage drug discovery. However, these studies that require biological material (animal brain or human cells) are time-consuming and involve costly amounts of materials and plastic wastes due to the format of the models. Hence, to adapt to the high yields needed in early-stage drug discoveries for compound screenings, a patented well-established human in vitro BBB model was miniaturized and automated into a 96-well format. This replicate met all the BBB model reliability criteria to get predictive results, allowing a significant reduction in biological materials, waste and a higher screening capacity for being extensively used during early-stage drug discovery studies.

Understanding protection from SARS-CoV-2 using metabolomics.

The COVID-19 pandemic is still raging in most countries. Although the recent mass vaccination campaign has opened a new chapter in the battle against SARS-CoV-2, the world is still far from herd immunity. There is an urgent need to identify healthy people at high risk of contracting COVID-19, as well as supplements and nutraceuticals that can reduce the risk of infection or mitigate symptoms. In the present study, a metabolic phenotype that could protect individuals from SARS-CoV-2 infection or predispose them to developing COVID-19 was investigated. Untargeted metabolomics was performed on serum samples collected from 51 healthcare workers who were in good health at the beginning of the COVID-19 outbreak in Italy, and who were later exposed to the same risk of developing COVID-19. Half of them developed COVID-19 within three weeks of the blood collection. Our results demonstrate the presence of a specific signature associated with protection from SARS-CoV-2. Circulating monolaurin, which has well-known antiviral and antibacterial properties, was higher in protected subjects, suggesting a potential defensive role against SARS-CoV-2 infection; thus, dietary supplements could boost the immune system against this infection. In addition, our data demonstrate that people with higher levels of cholesterol are at higher risk of developing COVID-19. The present study demonstrates that metabolomics can be of great help for developing personalized medicine and for supporting public healthcare strategies. Studies with larger cohorts of subjects are necessary to confirm our findings.