Angiotensin II Exaggerates SARS-CoV-2 Specific T-Cell Response in Convalescent Individuals following COVID-19.

Dysregulation of renin-angiotensin systems during coronavirus disease 2019 (COVID-19) infection worsens the symptoms and contributes to COVID-19 severity and mortality. This study sought to investigate the effect of exogenous angiotensin II (Ang-II) on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-specific T-cells response in recovered COVID-19 patients. Human peripheral blood mononuclear cells (PBMCs) were treated with Ang II and then stimulated with a SARS-CoV-2 peptide pool. T-cell responses were measured using flow cytometry, while enzyme-linked immunosorbent assay (ELISA) and intracellular cytokine staining (ICS) assays determined functional capability and polarization. Additionally, the relative level of protein phosphorylation was measured using a phosphokinase array. Our results showed that Ang II treatment significantly increased the magnitude of SARS-CoV-2-specific T-cell response in stimulated PBMCs with a SARS-CoV-2 peptide pool. Moreover, the phosphorylation levels of numerous proteins implicated in cardiovascular diseases, inflammation, and viral infection showed significant increases in the presence of Ang II. The mitogenic stimulation of PBMCs after Ang II and SARS-CoV-2 peptide pool stimulation showed functional polarization of T-cells toward Th1/Th17 and Th17 phenotypes, respectively. Meanwhile, ELISA showed increased productions of IL-1ß and IL-6 in Ang II-stimulated PBMCs without affecting the IL-10 level. To our knowledge, this study is the first to demonstrate that Ang II exaggerates SARS-CoV-2-specific T-cells response. Therefore, during COVID-19 infection, Ang II may aggravate the inflammatory response and change the immune response toward a more inflammatory profile against SARS-CoV-2 infection.

The Effect of Local Renin Angiotensin System in the Common Types of Cancer.

The Renin Angiotensin System (RAS) is a hormonal system that is responsible for blood pressure hemostasis and electrolyte balance. It is implicated in cancer hallmarks because it is expressed locally in almost all of the body's tissues. In this review, current knowledge on the effect of local RAS in the common types of cancer such as breast, lung, liver, prostate and skin cancer is summarised. The mechanisms by which RAS components could increase or decrease cancer activity are also discussed. In addition to the former, this review explores how the administration of AT1R blockers and ACE inhibitors drugs intervene with cancer therapy and contribute to the outcomes of cancer.

Classical and Counter-Regulatory Renin-Angiotensin System: Potential Key Roles in COVID-19 Pathophysiology.

In the current COVID-19 pandemic, severe acute respiratory syndrome coronavirus 2 uses angiotensin-converting enzyme-2 (ACE-2) receptors for cell entry, leading to ACE-2 dysfunction and downregulation, which disturb the balance between the classical and counter-regulatory renin-angiotensin system (RAS) in favor of the classical RAS. RAS dysregulation is one of the major characteristics of several cardiovascular diseases; thus, adjustment of this system is the main therapeutic target. RAS inhibitors-particularly angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin II type 1 receptor blockers (ARBs)-are commonly used for treatment of hypertension and cardiovascular disease. Patients with cardiovascular diseases are the group most commonly seen among those with COVID-19 comorbidity. At the beginning of this pandemic, a dilemma occurred regarding the use of ACEIs and ARBs, potentially aggravating cardiovascular and pulmonary dysfunction in COVID-19 patients. Urgent clinical trials from different countries and hospitals reported that there is no association between RAS inhibitor treatment and COVID-19 infection or comorbidity complication. Nevertheless, the disturbance of the RAS that is associated with COVID-19 infection and the potential treatment targeting this area have yet to be resolved. In this review, the link between the dysregulation of classical RAS and counter-regulatory RAS activities in COVID-19 patients with cardiovascular metabolic diseases is investigated. In addition, the latest findings based on ACEI and ARB administration and ACE-2 availability in relation to COVID-19, which may provide a better understanding of the RAS contribution to COVID-19 pathology, are discussed, as they are of the utmost importance amid the current pandemic.

Dans l'actuelle pandémie de la COVID-19, le coronavirus du syndrome respiratoire aigu sévère 2 (SRAS-CoV-2) utilise les récepteurs de l'enzyme de conversion de l'angiotensine 2 (ECA-2) pour entrer dans les cellules, s'ensuit le dysfonctionnement et la régulation à la baisse de l'ECA-2, qui perturbent l'équilibre entre le système rénine-angiotensine (SRA) traditionnel et le SRA contre-régulateur en faveur du SRA traditionnel. La dysrégulation du SRA est l'une des caractéristiques principales des maladies cardiovasculaires. Par conséquent, l'ajustement de ce système est l'objectif thérapeutique principal. Les inhibiteurs du SRA, particulièrement les inhibiteurs de l'ECA (IECA) et les antagonistes des récepteurs de type 1 de l'angiotensine II (ARA), sont communément utilisés pour traiter l'hypertension et les maladies cardiovasculaires. Les patients atteints de maladies cardiovasculaires représentent le groupe le plus fréquemment observé parmi les patients atteints de comorbidités associées à la COVID-19. Au début de la pandémie, un dilemme à propos de l'utilisation des IECA et des ARA s'est posé, puisqu'ils aggravaient potentiellement la dysfonction cardiovasculaire et pulmonaire chez les patients atteints de la COVID-19. Des essais cliniques urgents issus de différents pays et hôpitaux ont montré qu'il n'y avait pas d'association entre le traitement par inhibiteurs du SRA et les complications liées à l'infection par la COVID-19 ou aux comorbidités. Néanmoins, la perturbation du SRA qui est associée à l'infection par la COVID-19 et le traitement potentiel dans ce champ restent à résoudre. Dans la présente revue, le lien entre la dysrégulation du SRA traditionnel et les activités contre-régulatrices du SRA chez les patients atteints de la COVID-19 qui ont des maladies cardiovasculaires métaboliques est étudié. De plus, nous nous penchons sur les plus récentes conclusions fondées sur l'administration des IECA et des ARA et la disponibilité de l'ECA2 en relation avec la COVID-19 pour offrir une meilleure compréhension de la contribution du SRA à la pathologie de la COVID-19, puisqu'ils sont de la plus haute importance dans le contexte de l'actuelle pandémie.

Therapeutic Potential of Vitamin D and Curcumin in an In Vitro Model of Alzheimer Disease.

BACKGROUND: Alzheimer disease is a progressive neurodegenerative disease, affecting a very high proportion of the aging population. Several studies have demonstrated that one of the main contributors to this disease is oxidative stress (OS), which causes peroxidation of protein, lipids, and DNA resulting in the formation of advanced glycosylated end products (AGE) in the brain tissues. These AGE are usually associated with the amyloid ß (Aß), which could further aggravate its toxicity and its clearance. Antioxidants counteract the deterioration caused by OS. OBJECTIVE: We aimed to evaluate the effect of vitamin D3 and curcumin on primary cortical neuronal cultures exposed to Aß1-42 toxicity for different time periods. METHODS: Primary cortical neuronal cultures were set up and exposed to Aß1-42 for up to 72 hours. Cell viability was studied by 3[4,5-dimethylthiazole-2-yl]-2,5-dipheyltetrazolium bromide (MTT) and lactate dehydrogenase (LDH) assay. Biochemical assays for OS such as lipid peroxidation, reduced Glutathione(GSH), Glutathione S-transferase (GST), catalase, and superoxide dismutase (SOD) were conducted. Sandwich enzyme-linked immunosorbent assay (ELISA) was used to study the neurotrophic growth factor (NGF) expression. RESULTS: Treatments with Aß1-42 caused an elevation in lipid peroxidation products, which were ameliorated in the presence of vitamin D3 and curcumin. Both enzymatic (GST, catalase, and SOD) and nonenzymatic antioxidants (reduced GSH) were raised significantly in the presence of vitamin D3 and curcumin, which resulted in the better recovery of neuronal cells from Aß1-42 treatment. Treatment with vitamin D3 and curcumin also resulted in the upregulation of NGF levels. CONCLUSIONS: This study suggests that vitamin D3 and curcumin can be a promising natural therapy for the treatment of Alzheimer disease.