Oral Lisinopril Raises Tissue Levels of ACE2, the SARS-CoV-2 Receptor, in Healthy Male and Female Mice

Novel benzimidazole angiotensin receptor blockers with anti-SARS-CoV-2 activity equipotent to that of nirmatrelvir: computational and enzymatic studies

BACKGROUND

Pre-existing hypertensive pathologies are linked to worsened outcomes in patients infected with severe-acute respiratory syndrome (SARS-CoV-2). Sartans, a family of anti-hypertensive angiotensin receptor blockers (ARBs), reduce morbidity and mortality in coronavirus 2019 patients by aeffecting angiotensin-converting enzyme-2 (ACE2). The purpose of this study was to determine the anti-SARS-CoV-2viral and antihypertensive abilities of nirmatrelvir, and commercially available (e.g. candesartan, losartan, and losartan carboxylic (Exp3174))) and newly synthesized sartans (e.g. benzimidazole-N-biphenyl carboxyl (ACC519C), and benzimidazole-N-biphenyl tetrazole (ACC519T)), compared to nirmatrelvir, the antiviral component of paxlovid.

RESEARCH DESIGN AND METHODS

Surface plasmon resonance-binding (SPR) and enzymatic studies were used to determine drug effect on ACE2, antiviral abilities were evaluated using Vero E6 cells infected with SARS-CoV-2 and antihypertensive effects were investigated using rabbit iliac arteries contracted to angiotensin II-dose response.

RESULTS

The antiviral activity of benzimidazole-based candesartan and ACC519C were equipotent with nirmatrelvir (95% inhibition), while the imidazole-based losartan and E×p3174and ACC519T were less potent (75-80 and 50%, respectively%) and E×p3174was the least effective (50%). Furthermore, SPR analysis revealed a high binding affinity of sartans for ACE2 protein. Moreover, candesartan and nirmatrelvir exhibited the greatest inhibitory and cytopathic effect (3.96%) when given in combination rather than individually (6.10% and 5.08%, respectively). In addition,The ACE2 enzymatic activity assays demonstrated enhancement or inhibition properties of novel sartans toward ACE2 enzyme. Lastly, ACC519T potently reduced angiotensin II-mediated contraction while nirmatrelvir and ACC519T(2) had no effect.

CONCLUSION

This study describes the discovery of a new class of benzimidazole-based sartans that drastically inhibit SARS-CoV-2, which could be attributed, at least in part, to their interaction with ACE2.

Kidney organoids reveal redundancy in viral entry pathways during ACE2-dependent SARS-CoV-2 infection

With a high incidence of acute kidney injury among hospitalized COVID-19 patients, considerable attention has been focussed on whether SARS-CoV-2 specifically targets kidney cells to directly impact renal function, or whether renal damage is primarily an indirect outcome. To date, several studies have utilized kidney organoids to understand the pathogenesis of COVID-19, revealing the ability for SARS-CoV-2 to predominantly infect cells of the proximal tubule (PT), with reduced infectivity following administration of soluble ACE2. However, the immaturity of standard human kidney organoids represents a significant hurdle, leaving the preferred SARS-CoV-2 processing pathway, existence of alternate viral receptors, and the effect of common hypertensive medications on the expression of ACE2 in the context of SARS-CoV-2 exposure incompletely understood. Utilizing a novel kidney organoid model with enhanced PT maturity, genetic- and drug-mediated inhibition of viral entry and processing factors confirmed the requirement for ACE2 for SARS-CoV-2 entry but showed that the virus can utilize dual viral spike protein processing pathways downstream of ACE2 receptor binding. These include TMPRSS- and CTSL/CTSB-mediated non-endosomal and endocytic pathways, with TMPRSS10 likely playing a more significant role in the non-endosomal pathway in renal cells than TMPRSS2. Finally, treatment with the antihypertensive ACE inhibitor, lisinopril, showed negligible impact on receptor expression or susceptibility of renal cells to infection. This study represents the first in-depth characterization of viral entry in stem cell-derived human kidney organoids with enhanced PTs, providing deeper insight into the renal implications of the ongoing COVID-19 pandemic.

IMPORTANCE

Utilizing a human iPSC-derived kidney organoid model with improved proximal tubule (PT) maturity, we identified the mechanism of SARS-CoV-2 entry in renal cells, confirming ACE2 as the sole receptor and revealing redundancy in downstream cell surface TMPRSS- and endocytic Cathepsin-mediated pathways. In addition, these data address the implications of SARS-CoV-2 exposure in the setting of the commonly prescribed ACE-inhibitor, lisinopril, confirming its negligible impact on infection of kidney cells. Taken together, these results provide valuable insight into the mechanism of viral infection in the human kidney.

Overreactive macrophages in SARS-CoV-2 infection: The effects of ACEI

Among various factors influencing the course of SARS-CoV-2 infection in humans, macrophage overactivation is considered the main cause of the cytokine storm that leads to severe complications of COVID-19. Moreover, the increased expression of angiotensin converting enzyme 2 (ACE2), an obligatory entry receptor of the coronavirus, caused by treatment with ACE inhibitors (ACEI) lowered overall confidence in the safety of these drugs. However, analysis of the course of coronavirus infection in patients treated with ACEI does not support these concerns. Instead, the beneficial effect of ACEI on macrophages has increasingly been emphasized. This includes their anti-inflammatory activation and the consequent reduction in the risk of severe disease and life-threatening complications. Herein, we summarize the current knowledge and understanding of the dual role of macrophages in SARS-CoV-2 infection, with a special focus on the postulated mechanisms underlying the beneficial effects of macrophage targeting by ACEI. These seem to involve the stimulation of macrophage angiotensin II type 2 and Mas receptors by angiotensin 1-7, intensively produced due to the up-regulation of ACE2 expression on macrophages, as well as the direct inhibition of macrophage hyper-responsiveness by ACEI. The impact of ACEI on macrophages may also lead to the activation of an effective antiviral response due to the increased expression of ACE2.

Determinants of Post-COVID-19 Conditions among SARS-CoV-2-Infected Patients in Saudi Arabia: A Web-Based Cross-Sectional Study

Background: Large numbers of people infected with COVID-19 developed acute symptoms. Post-COVID-19 conditions have been reported after recovery or discharge from the hospital. However, little is known about the prevalence and possible risk factors of post-COVID-19 conditions in the Saudi community. Here, we describe the incidence of post-COVID-19 conditions among the general population of Saudi Arabia. Methods: We conducted a cross-sectional, nationwide study using an online survey in Saudi Arabia from 1 September 2021 to 28 February 2022. The survey was distributed using social media platforms, such as Twitter, WhatsApp, and Facebook. Patients with SARS-CoV-2 infection were included in the questionnaire adapted from published studies. Result: The study enrolled 7520 individuals who were previously infected with SARS-CoV-2. Most patients in our study were symptomatic and their acute symptoms may persist for more than six days. On the other hand, long-term complications may develop and continue for an extended period (post-COVID-19 conditions). Most of these complications are respiratory, neurological, psychological, or skin related. The proportion of long-term complications reported in this study is 36% among SARS-CoV-2-infected individuals. In addition, being female, old age, number of chronic complications, long-term medication, length of stay in hospital and intensive care unit, and duration of acute symptoms may be significant predictors of post-COVID-19 symptoms. Conclusion: In conclusion, the incidence of post-COVID-19 conditions among the Saudi population was high, which urges further investigation into the risk factors associated with post-COVID-19 symptoms.

I’ve looked at gut from both sides now: Gastrointestinal tract involvement in the pathogenesis of SARS-CoV-2 and HIV/SIV infections

The lumen of the gastrointestinal (GI) tract contains an incredibly diverse and extensive collection of microorganisms that can directly stimulate the immune system. There are significant data to demonstrate that the spatial localization of the microbiome can impact viral disease pathogenesis. Here we discuss recent studies that have investigated causes and consequences of GI tract pathologies in HIV, SIV, and SARS-CoV-2 infections with HIV and SIV initiating GI pathology from the basal side and SARS-CoV-2 from the luminal side. Both these infections result in alterations of the intestinal barrier, leading to microbial translocation, persistent inflammation, and T-cell immune activation. GI tract damage is one of the major contributors to multisystem inflammatory syndrome in SARS-CoV-2-infected individuals and to the incomplete immune restoration in HIV-infected subjects, even in those with robust viral control with antiretroviral therapy. While the causes of GI tract pathologies differ between these virus families, therapeutic interventions to reduce microbial translocation-induced inflammation and improve the integrity of the GI tract may improve the prognoses of infected individuals.

Angiotensin-(1-9) in hypertension

Angiotensin-(1-9) [Ang-(1-9)] is a peptide of the non-canonical renin-angiotensin system (RAS) synthesized from angiotensin I by the monopeptidase angiotensin-converting enzyme type 2 (ACE2). Using osmotic minipumps, infusion of Ang-(1-9) consistently reduces blood pressure in several rat hypertension models. In these animals, hypertension-induced end-organ damage is also decreased. Several pieces of evidence suggest that Ang-(1-9) is the endogenous ligand that binds and activates the type-2 angiotensin II receptor (AT2R). Activation of AT2R triggers different tissue-specific signaling pathways. This phenomenon could be explained by the ability of AT2R to form different heterodimers with other G protein-coupled receptors. Because of the antihypertensive and protective effects of AT2R activation by Ang-(1-9), associated with a short half-life of RAS peptides, several synthetic AT2R agonists have been synthesized and assayed. Some of them, particularly CGP42112, C21 and novokinin, have demonstrated antihypertensive properties. Only two synthetic AT2R agonists, C21 and LP2-3, have been tested in clinical trials, but none of them like an antihypertensive. Therefore, Ang-(1-9) is a promising antihypertensive drug that reduces hypertension-induced end-organ damage. However, further research is required to translate this finding successfully to the clinic.