Effect of Angiotensin-Converting-Enzyme Inhibitor and Angiotensin II Receptor Antagonist Treatment on ACE2 Expression and SARS-CoV-2 Replication in Primary Airway Epithelial Cells

SARS-CoV-2 spike protein-ACE2 interaction increases carbohydrate sulfotransferases and reduces N-acetylgalactosamine-4-sulfatase by p38 MAPK

Immunostaining in lungs of patients who died with COVID-19 infection showed increased intensity and distribution of chondroitin sulfate and decline in N-acetylgalactostamine-4-sulfatase (Arylsulfatase B; ARSB). To explain these findings, human small airway epithelial cells were exposed to the SARS-CoV-2 spike protein receptor binding domain (SPRBD) and transcriptional mechanisms were investigated. Phospho-p38 MAPK and phospho-SMAD3 increased following exposure to the SPRBD, and their inhibition suppressed the promoter activation of the carbohydrate sulfotransferases CHST15 and CHST11, which contributed to chondroitin sulfate biosynthesis. Decline in ARSB was mediated by phospho-38 MAPK-induced N-terminal Rb phosphorylation and an associated increase in Rb-E2F1 binding and decline in E2F1 binding to the ARSB promoter. The increases in chondroitin sulfotransferases were inhibited when treated with phospho-p38-MAPK inhibitors, SMAD3 (SIS3) inhibitors, as well as antihistamine desloratadine and antibiotic monensin. In the mouse model of carrageenan-induced systemic inflammation, increases in phospho-p38 MAPK and expression of CHST15 and CHST11 and declines in DNA-E2F binding and ARSB expression occurred in the lung, similar to the observed effects in this SPRBD model of COVID-19 infection. Since accumulation of chondroitin sulfates is associated with fibrotic lung conditions and diffuse alveolar damage, increased attention to p38-MAPK inhibition may be beneficial in ameliorating Covid-19 infections.

The role of autoimmunity and autoinflammation in giant cell arteritis: A systematic literature review

Giant cell arteritis is the most common form of large vessel vasculitis and preferentially involves large and medium-sized arteries in patients over the age of 50. Aggressive wall inflammation, neoangiogenesis and consecutive remodeling processes are the hallmark of the disease. Though etiology is unknown, cellular and humoral immunopathological processes are well understood. Matrix metalloproteinase-9 mediated tissue infiltration occurs through lysis of basal membranes in adventitial vessels. CD4+ cells attain residency in immunoprotected niches, differentiate into vasculitogenic effector cells and enforce further leukotaxis. Signaling pathways involve the NOTCH1-Jagged1 pathway opening vessel infiltration, CD28 mediated T-cell overstimulation, lost PD-1/PD-L1 co-inhibition and JAK/STAT signaling in interferon dependent responses. From a humoral perspective, IL-6 represents a classical cytokine and potential Th-cell differentiator whereas interferon-γ (IFN- γ) has been shown to induce chemokine ligands. Current therapies involve glucocorticoids, tocilizumab and methotrexate application. However, new agents, most notably JAK/STAT inhibitors, PD-1 agonists and MMP-9 blocking substances, are being evaluated in ongoing clinical trials.

Relation Between Renin–Angiotensin–Aldosterone System Inhibitors and COVID-19 Severity

Background: Angiotensin-converting enzyme 2 (ACE2) receptor serves as a receptor for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus causing COVID-19, to enter the lungs. Angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) may increase the expression of ACE2, resulting in concerns that patients with COVID-19 who are receiving these agents may be at increased risk of severe disease. This study was conducted to further investigate the effects of ACEIs and ARBs on the severity of COVID-19 in hospitalized hypertensive patients.

Methods: The study was a retrospective observational study. The medical records of all adult hypertensive patients who were hospitalized at Dammam Medical Complex (DMC) between March 1, 2020, and December 31, 2020, due to COVID-19 were reviewed. The hypertensive patients who were receiving ACEIs or ARBs were compared with the other hypertensive patients who were not on ACEIs or ARBs.

Results: A total of 148 hypertensive patients were included in the analysis. They consisted of 106 male and 42 female patients (72% and 28%, respectively). Nearly half of the patients were Saudi (75 patients, 50%). A total of 81 patients were in the ACEI/ARB group, and 67 patients were in the control group. There were no differences between the two groups in age, diabetic status, history of chronic kidney disease, initial blood pressure measurements, and initial oxygen requirements, but the control group contained fewer female patients (18% versus 37%) and Saudi patients (36% versus 63%) than the ACEI/ARB group (p-values = 0.017 and 0.002, respectively). The use of ACEIs or ARBs was associated with significant reductions in ICU admission (9% versus 31%, p-value = 0.001), need for intubation (7% versus 28%, p-value = 0.002), and death (2% versus 24%, p-value = 0.000). A significant negative association between the use ACEIs or ARBs and mortality was also observed in the multivariate analysis after the adjustment for the possible confounders, with an odds ratio (OR) of 0.087 and a 95% confidence interval (CI) of 0.017-0.449.

Conclusions: ACEIs and ARBs have no adverse effects on the clinical prognosis of COVID-19 patients with hypertension. Their use might be even beneficial and protective, but future larger studies are needed to confirm these effects. In the meanwhile, they should be continued in COVID-19 hypertensive patients unless their use is contraindicated for other reasons (e.g., hypotension, hyperkalemia, or acute kidney injury (AKI)).