Exosomal miR-145 and miR-885 regulate thrombosis in COVID-19.

We hypothesized that exosomal microRNAs (miRNAs) could be implied in the pathogenesis of thromboembolic complications in COVID-19. We isolated circulating exosomes from COVID-19 patients and then we divided our population in two arms based on the D-dimer level on hospital admission. We observed that exosomal miR-145 and miR-885 significantly correlate with D-Dimer levels. Moreover, we demonstrate that human endothelial cells express the main cofactors needed for SARS-CoV-2 internalization, including ACE2, TMPRSS2, and CD-147. Interestingly, human endothelial cells treated with serum from COVID-19 patients release significantly less miR-145 and miR-885, exhibit increased apoptosis, and display significantly impaired angiogenetic properties compared to cells treated with non-COVID-19 serum. Taken together, our data indicate that exosomal miR-145 and miR-885 are essential in modulating thromboembolic events in COVID-19. Significance Statement In this work, we demonstrate for the first time that two specific microRNA (namely miR-145 and miR-885) contained in circulating exosomes are functionally involved in thromboembolic events in COVID-19. Our findings are especially relevant to the general audience when considering the emerging prominence of post-acute sequelae of COVID-19 systemic manifestations known as Long-COVID.

miR-142 Targets TIM-1 in Human Endothelial Cells: Potential Implications for Stroke, COVID-19, Zika, Ebola, Dengue, and Other Viral Infections.

T-cell immunoglobulin and mucin domain 1 (TIM-1) has been recently identified as one of the factors involved in the internalization of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in human cells, in addition to angiotensin-converting enzyme 2 (ACE2), transmembrane serine protease 2 (TMPRSS2), neuropilin-1, and others. We hypothesized that specific microRNAs could target TIM-1, with potential implications for the management of patients suffering from coronavirus disease 2019 (COVID-19). By combining bioinformatic analyses and functional assays, we identified miR-142 as a specific regulator of TIM-1 transcription. Since TIM-1 has been implicated in the regulation of endothelial function at the level of the blood-brain barrier (BBB) and its levels have been shown to be associated with stroke and cerebral ischemia-reperfusion injury, we validated miR-142 as a functional modulator of TIM-1 in human brain microvascular endothelial cells (hBMECs). Taken together, our results indicate that miR-142 targets TIM-1, representing a novel strategy against cerebrovascular disorders, as well as systemic complications of SARS-CoV-2 and other viral infections.

Combining L-Arginine with vitamin C improves long-COVID symptoms: The LINCOLN Survey.

INTRODUCTION: Recent evidence suggests that oxidative stress and endothelial dysfunction play critical roles in the pathophysiology of COVID-19 and Long-COVID. We hypothesized that a supplementation combining L-Arginine (to improve endothelial function) and Vitamin C (to reduce oxidation) could have favorable effects on Long-COVID symptoms. METHODS: We designed a survey (LINCOLN: L-Arginine and Vitamin C improves Long-COVID), assessing several symptoms that have been associated with Long-COVID to be administered nationwide to COVID-19 survivors; the survey also included effort perception, measured using the Borg scale. Patients receiving the survey were divided in two groups, with a 2:1 ratio: the first group included patients that received L-Arginine + Vitamin C, whereas the second group received a multivitamin combination (alternative treatment). RESULTS: 1390 patients successfully completed the survey. Following a 30-day treatment in both groups, the survey revealed that patients in the L-Arginine + Vitamin C treatment arm had significantly lower scores compared to patients who had received the multivitamin combination. There were no other significant differences between the two groups. When examining effort perception, we observed a significantly lower value (p < 0.0001) in patients receiving L-Arginine + Vitamin C compared to the alternative-treatment arm. CONCLUSIONS: Our survey indicates that the supplementation with L-Arginine + Vitamin C has beneficial effects in Long-COVID, in terms of attenuating its typical symptoms and improving effort perception.

Physical decline and cognitive impairment in frail hypertensive elders during COVID-19.

BACKGROUND: Hypertension is common in older adults and its incidence increases with age. We investigated the correlation between physical and cognitive impairment in older adults with frailty and hypertension. METHODS: We recruited frail hypertensive older adults during the COVID-19 pandemic, between March 2021 and December 2021. Global cognitive function was assessed through the Montreal Cognitive Assessment (MoCA), physical frailty assessment was performed following the Fried criteria, and all patients underwent physical evaluation through 5-meter gait speed test. RESULTS: We enrolled 203 frail hypertensive older adults and we found a significant correlation between MoCA score and gait speed test (r: 0.495; p<0.001) in our population. To evaluate the impact of comorbidities and other factors on our results, we applied a linear regression analysis with MoCA score as a dependent variable, observing a significant association with age, diabetes, chronic obstructive pulmonary disease (COPD), and gait speed test. CONCLUSIONS: Our study revealed for the first time a significant correlation between physical and cognitive impairment in frail hypertensive elderly subjects.

L-Arginine Enhances the Effects of Cardiac Rehabilitation on Physical Performance: New Insights for Managing Cardiovascular Patients During the COVID-19 Pandemic.

Cardiac rehabilitation (CR) following acute myocardial infarction (AMI) improves physical capacities and decreases hospitalizations and cardiovascular mortality. L-arginine is the substrate used by nitric oxide (NO) synthase to generate NO and it has been shown to exert its beneficial effects on endothelium driving vasodilatation, reducing inflammation, and ameliorating physical function. We hypothesized that L-arginine could enhance physical capacities in patients who underwent CR after AMI. We designed a study aimed to assess the effects of L-arginine administration on the physical capacity of patients who underwent coronary revascularization after AMI. The trial was carried out amid the COVID-19 pandemic. Patients were assigned, with a 2:1 ratio, to add to their standard therapy one bottle containing 1.66 g of L-arginine or one bottle of identical aspect apart from not containing L-arginine, twice a day orally for 3 weeks. Patients performed a 6-minute walking test (6MWT), and their Borg modified 0-10 rating of perceived exertion (BRPE) was assessed before starting and at the end of the treatment. Seventy-five patients receiving L-arginine, and 35 receiving placebo successfully completed the study. The 6MWT distance increased significantly in the L-arginine group compared with both baseline and placebo (P < 0.0001). Additionally, we observed a significant improvement in the BRPE in patients treated with L-arginine but not in the placebo group. Taken together, our data indicate that L-arginine potentiates the response to CR independently of age, sex, baseline functional capacity, and comorbid conditions. SIGNIFICANCE STATEMENT: This study shows for the first time that oral supplementation of L-arginine potentiates the response to cardiac rehabilitation after myocardial infarction and cardiac revascularization. Indeed, we observed a significant improvement in two fundamental parameters, namely, the 6-minute walking test and the Borg modified 0-10 rating of perceived exertion. Strikingly, the beneficial effects of L-arginine were independent of age, sex, comorbid conditions, and baseline functional capacity.

l-Arginine and COVID-19: An Update.

l-Arginine is involved in many different biological processes and recent reports indicate that it could also play a crucial role in the coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Herein, we present an updated systematic overview of the current evidence on the functional contribution of L-Arginine in COVID-19, describing its actions on endothelial cells and the immune system and discussing its potential as a therapeutic tool, emerged from recent clinical experimentations.

miR-24 Targets the Transmembrane Glycoprotein Neuropilin-1 in Human Brain Microvascular Endothelial Cells.

Neuropilin-1 is a transmembrane glycoprotein that has been implicated in several processes including angiogenesis and immunity. Recent evidence has also shown that it is implied in the cellular internalization of the severe acute respiratory syndrome coronavirus (SARS-CoV-2), which causes the coronavirus disease 2019 (COVID-19). We hypothesized that specific microRNAs can target Neuropilin-1. By combining bioinformatic and functional approaches, we identified miR-24 as a regulator of Neuropilin-1 transcription. Since Neuropilin-1 has been shown to play a key role in the endothelium-mediated regulation of the blood-brain barrier, we validated miR-24 as a functional modulator of Neuropilin-1 in human brain microvascular endothelial cells (hBMECs), which are the most suitable cell line for an in vitro blood-brain barrier model.