The Controversy of Renin-Angiotensin-System Blocker Facilitation Versus Countering COVID-19 Infection

SARS-CoV-2 mechanisms of cell tropism in various organs considering host factors

A critical step in the drug design for SARS-CoV-2 is to discover its molecular targets. This study comprehensively reviewed the molecular mechanisms of SARS-CoV-2, exploring host cell tropism and interaction targets crucial for cell entry. The findings revealed that beyond ACE2 as the primary entry receptor, alternative receptors, co-receptors, and several proteases such as TMPRSS2, Furin, Cathepsin L, and ADAM play critical roles in virus entry and subsequent pathogenesis. Additionally, SARS-CoV-2 displays tropism in various human organs due to its diverse receptors. This review delves into the intricate details of receptors, host proteases, and the involvement of each organ. Polymorphisms in the ACE2 receptor and mutations in the spike or its RBD region contribute to the emergence of variants like Alpha, Beta, Gamma, Delta, and Omicron, impacting the pathogenicity of SARS-CoV-2. The challenge posed by mutations raises questions about the effectiveness of existing vaccines and drugs, necessitating consideration for updates in their formulations. In the urgency of these critical situations, repurposed drugs such as Camostat Mesylate and Nafamostat Mesylate emerge as viable pharmaceutical options. Numerous drugs are involved in inhibiting receptors and host factors crucial for SARS-CoV-2 entry, with most discussed in this review. In conclusion, this study may provide valuable insights to inform decisions in therapeutic approaches.

A comprehensive review of the literature on CD10: its function, clinical application, and prospects

CD10, a zinc-dependent metalloprotease found on the cell surface, plays a pivotal role in an array of physiological and pathological processes including cardiovascular regulation, immune function, fetal development, pain response, oncogenesis, and aging. Recognized as a biomarker for hematopoietic and tissue stem cells, CD10 has garnered attention for its prognostic potential in the progression of leukemia and various solid tumors. Recent studies underscore its regulatory significance and therapeutic promise in combating Alzheimer's disease (AD), and it is noted for its protective role in preventing heart failure (HF), obesity, and type-2 diabetes. Furthermore, CD10/substance P interaction has also been shown to contribute to the pain signaling regulation and immunomodulation in diseases such as complex regional pain syndrome (CRPS) and osteoarthritis (OA). The emergence of COVID-19 has sparked interest in CD10's involvement in the disease's pathogenesis. Given its association with multiple disease states, CD10 is a prime therapeutic target; inhibitors targeting CD10 are now being advanced as therapeutic agents. This review compiles recent and earlier literature on CD10, elucidating its physicochemical attributes, tissue-specific expression, and molecular functions. Furthermore, it details the association of CD10 with various diseases and the clinical advancements of its inhibitors, providing a comprehensive overview of its growing significance in medical research.

Low serum albumin: A neglected predictor in patients with cardiovascular disease

Albumin, the most abundant circulating protein in blood, is an essential protein which binds and transports various drugs and substances, maintains the oncotic pressure of blood and influences the physiological function of the circulatory system. Albumin also has anti-inflammatory, antioxidant, and antithrombotic properties. Evidence supports albumin's role as a strong predictor of cardiovascular (CV) risk in several patient groups. Its protective role extends to those with coronary artery disease, heart failure, hypertension, atrial fibrillation, peripheral artery disease or ischemic stroke, as well as those undergoing revascularization procedures or with aortic stenosis undergoing transcatheter aortic valve replacement, and patients with congenital heart disease and/or endocarditis. Hypoalbuminemia is a strong prognosticator of increased all-cause and CV mortality according to several cohort studies and meta-analyses in hospitalized and non-hospitalized patients with or without comorbidities. Normalization of albumin levels before discharge lowers mortality risk, compared with hypoalbuminemia before discharge. Modified forms of albumin, such as ischemia modified albumin, also has prognostic value in patients with coronary or peripheral artery disease. When albumin is combined with other risk factors, such as uric acid or C-reactive protein, the prognostic value is enhanced. Although albumin supplementation may be a plausible approach, its efficacy has not been established and in patients with hypoalbuminemia, priority is focused on diagnosing and managing the underlying condition. The CV effects of hypoalbuminemia and relevant issues are considered in this review. Large cohort studies and meta-analyses are tabulated and the physiologic effects of albumin and the deleterious effects of low albumin are pictorially illustrated.

COVID-19 infection and body weight: A deleterious liaison in a J-curve relationship

During the course of the COVID-19 pandemic, obesity has been shown to be an independent risk factor for high morbidity and mortality. Obesity confers poor outcomes in younger (<60 years) patients, an age-group considered low-risk for complications, a privilege that is negated by obesity. Findings are consistent, the higher the body mass index (BMI) the worse the outcomes. Ectopic (visceral) obesity also promotes proinflammatory, prothrombotic, and vasoconstrictive states, thus enhancing the deleterious effects of COVID-19 disease. Less, albeit robust, evidence also exists for a higher risk of COVID-19 infection incurred with underweight. Thus, the relationship of COVID-19 and BMI has a J-curve pattern, where patients with both overweight/obesity and underweight are more susceptible to the ailments of COVID-19. The pathophysiology underlying this link is multifactorial, mostly relating to the inflammatory state characterizing obesity, the impaired immune response to infectious agents coupled with increased viral load, the overexpression in adipose tissue of the receptors and proteases for viral entry, an increased sympathetic activity, limited cardiorespiratory reserve, a prothrombotic milieu, and the associated comorbidities. All these issues are herein reviewed, the results of large studies and meta-analyses are tabulated and the pathogenetic mechanisms and the BMI relationship with COVID-19 are pictorially illustrated.

Comparison of the clinical course of COVID-19 infection in sickle cell disease patients with healthcare professionals

It is highly expected that COVID-19 infection will have devastating consequences in sickle cell disease (SCD) patients due to endothelial activation and decreased tissue and organ reserve as a result of microvascular ischemia and continuous inflammation. In this study, we aimed to compare the clinical course of COVID-19 in adult SCD patients under the organ injury mitigation and clinical care improvement program (BASCARE) with healthcare professionals without significant comorbid conditions. The study was planned as a retrospective, multicenter and cross-sectional study. Thirty-nine SCD patients, ages 18 to 64 years, and 121 healthcare professionals, ages 21 to 53, were included in the study. The data were collected from the Electronic Health Recording System of PRANA, where SCD patients under the BASCARE program had been registered. The data of other patients were collected from the Electronic Hospital Data Recording System and patient files. In the SCD group, the crude incidence of COVID-19 was 9%, while in healthcare professionals at the same period was 23%. Among the symptoms, besides fever, loss of smell and taste were more prominent in the SCD group than in healthcare professionals. There was a significant difference between the two groups in terms of development of pneumonia, hospitalization, and need for intubation (43 vs 5%, P < 0.00001; 26 vs 7%, P = 0.002; and 10 vs 1%, P = 0.002, respectively). Prophylactic low molecular weight heparin and salicylate were used more in the SCD group than in healthcare professionals group (41 vs 9% and 28 vs 1%; P < 0.0001 for both). The 3-month mortality rate was demonstrated as 5% in the SCD group, while 0 in the healthcare professionals group. One patient in the SCD group became continously dependent on respiratory support. The cause of death was acute chest syndrome in the first case, hepatic necrosis and multi-organ failure in the second case. In conclusion, these observations supported the expectation that the course of COVID-19 in SCD patients will get worse. The BASCARE program applied in SCD patients could not change the poor outcome.

Genetics of symptom remission in outpatients with COVID-19

We conducted a genome-wide association study of time to remission of COVID-19 symptoms in 1723 outpatients with at least one risk factor for disease severity from the COLCORONA clinical trial. We found a significant association at 5p13.3 (rs1173773; P = 4.94 × 10^-8) near the natriuretic peptide receptor 3 gene (NPR3). By day 15 of the study, 44%, 54% and 59% of participants with 0, 1, or 2 copies of the effect allele respectively, had symptom remission. In 851 participants not treated with colchicine (placebo), there was a significant association at 9q33.1 (rs62575331; P = 2.95 × 10^-8) in interaction with colchicine (P = 1.19 × 10^-5) without impact on risk of hospitalisations, highlighting a possibly shared mechanistic pathway. By day 15 of the study, 46%, 62% and 64% of those with 0, 1, or 2 copies of the effect allele respectively, had symptom remission. The findings need to be replicated and could contribute to the biological understanding of COVID-19 symptom remission.

COVID-19 and Acute Myocardial Injury and Infarction: Related Mechanisms and Emerging Challenges

In the era of the coronavirus disease 2019 (COVID-19) pandemic, acute cardiac injury (ACI), as reflected by elevated cardiac troponin above the 99th percentile, has been observed in 8%-62% of patients with COVID-19 infection with highest incidence and mortality recorded in patients with severe infection. Apart from the clinically and electrocardiographically discernible causes of ACI, such as acute myocardial infarction (MI), other cardiac causes need to be considered such as myocarditis, Takotsubo syndrome, and direct injury from COVID-19, together with noncardiac conditions, such as pulmonary embolism, critical illness, and sepsis. Acute coronary syndromes (ACS) with normal or near-normal coronary arteries (ACS-NNOCA) appear to have a higher prevalence in both COVID-19 positive and negative patients in the pandemic compared to the pre-pandemic era. Echocardiography, coronary angiography, chest computed tomography and/or cardiac magnetic resonance imaging may render a correct diagnosis, obviating the need for endomyocardial biopsy. Importantly, a significant delay has been recorded in patients with ACS seeking advice for their symptoms, while their routine care has been sharply disrupted with fewer urgent coronary angiographies and/or primary percutaneous coronary interventions performed in the case of ST-elevation MI (STEMI) with an inappropriate shift toward thrombolysis, all contributing to a higher complication rate in these patients. Thus, new challenges have emerged in rendering a diagnosis and delivering treatment in patients with ACI/ACS in the pandemic era. These issues, the various mechanisms involved in the development of ACI/ACS, and relevant current guidelines are herein reviewed.

Mortality in Patients with COVID-19 on Renin Angiotensin System Inhibitor Long-Term Treatment: An Observational Study Showing that Things Are Not Always as They Seem

Introduction

At the beginning of the coronavirus disease 2019 (COVID-19) pandemic, controversial data were reported concerning angiotensin-converting enzyme (ACE) inhibitors and angiotensin II receptor blockers (ARBs) that induced a number of physicians to stop using them in patients with COVID-19. Although large-scale studies have ruled out this concern, it is common experience that patients with COVID-19 taking ACE inhibitors or ARBs are at increased risk of death. The aim of this study was to investigate the reasons for this apparently high mortality rate.

Methods

During the first wave of the pandemic, we conducted a field study of 427 consecutive patients with COVID-19 upon their admission to the emergency department of a hospital in one of the most severely hit cities in northern Italy, and 30 days later. The disease was defined as being mild, moderate or severe on the basis of clinical, laboratory and imaging data, and a multivariate model was used to analyse the determinants of mortality.

Results

Within 30 days of admission, 31.6% of the patients treated with ACE inhibitors or ARBs and 15.2% of those not treated with these drugs had died. Multivariate analysis showed that the determinants of mortality were age (p = 0.0001), hypertension (p = 0.0120) and diabetes (p = 0.0129), whereas ACE inhibitors or ARBs had no effect on mortality. There was no significant difference between the patients treated with ACE inhibitors and those treated with ARBs.

Conclusion

The apparently increased mortality of patients with COVID-19 receiving long-term treatment with ACE inhibitors or ARBs is not due to the drugs themselves, but to the conditions associated with their use.

Cardiovascular implications and complications of the coronavirus disease-2019 pandemic: a world upside down

PURPOSE OF REVIEW

The new pandemic of coronavirus disease-2019 (COVID-19) has produced a global tumult and has overburdened national health systems. We herein discuss the cardiovascular implications and complications of this pandemic analyzing the most recent data clustered over the last several months.

RECENT FINDINGS

COVID-19 afflicts the cardiovascular system producing acute cardiac injury in 10-20% of cases with mild disease but in greater than 50-60% in severe cases, contributing to patients' demise. Other cardiovascular complications include arrhythmias, heart failure, pulmonary embolism and shock. Off-label therapies are being trialed with their own inherent cardiovascular risks, while supportive therapies currently dominate, until more specific and effective antiviral therapies and vaccinations become available. A controversial issue relates to the safety of drugs blocking the renin--angiotensin system as an angiotensin-converting enzyme (ACE) homologue, ACE2, serves as the receptor for viral entry into host cells. However, to-date, no harm has been proven for these drugs.

SUMMARY

In the cardiovascular system, COVID-19 can induce acute cardiac injury, arrhythmias, heart failure, pulmonary embolism, shock and death, whereas anti-COVID therapies also confer serious cardiovascular side-effects. Ongoing extensive efforts focus on specific vaccines and antivirals. Meanwhile, cardiovascular risk factors and diseases should be jointly controlled according to current evidence-based guidelines.

COVID-19 Infection: Viral Macro- and Micro-Vascular Coagulopathy and Thromboembolism/Prophylactic and Therapeutic Management

Coronavirus-2019 (COVID-19) predisposes patients to arterial and venous thrombosis commonly complicating the clinical course of hospitalized patients and attributed to the inflammatory state, endothelial dysfunction, platelet activation and blood stasis. This viral coagulopathy may occur despite thromboprophylaxis and raises mortality; the risk appears highest among critically ill inpatients monitored in the intensive care unit. The prevalence of venous thromboembolism in COVID-19 patients has been reported to reach ∼10-35%, while autopsies raise it to nearly 60%. The most common thrombotic complication is pulmonary embolism, which though may occur in the absence of a recognizable deep venous thrombosis and may be due to pulmonary arterial thrombosis rather than embolism, resulting in thrombotic occlusion of small- to mid-sized pulmonary arteries and subsequent infarction of lung parenchyma. This micro-thrombotic pattern seems more specific for COVID-19 and is associated with an intense immuno-inflammatory reaction that results in diffuse occlusive thrombotic micro-angiopathy with alveolar damage and vascular angiogenesis. Furthermore, thrombosis has also been observed in various arterial sites, including coronary, cerebral and peripheral arteries. Biomarkers related to coagulation, platelet activation and inflammation have been suggested as useful diagnostic and prognostic tools for COVID-19-associated coagulopathy; among them, D-dimer remains a key biomarker employed in clinical practice. Various medical societies have issued guidelines or consensus statements regarding thromboprophylaxis and treatment of these thrombotic complications specifically adapted to COVID-19 patients. All these issues are detailed in this review, data from meta-analyses and current guidelines are tabulated, while the relevant mechanisms of this virus-associated coagulopathy are pictorially illustrated.

Neprilysin expression and functions in development, ageing and disease

Neprilysin (NEP) is an integral membrane-bound metallopeptidase with a wide spectrum of substrates and physiological functions. It plays an important role in proteolytic processes in the kidney, cardiovascular regulation, immune response, cell proliferation, foetal development etc. It is an important neuropeptidase and amyloid-degrading enzyme which makes NEP a therapeutic target in Alzheimer's disease (AD). Moreover, it plays a preventive role in development of cancer, obesity and type-2 diabetes. Recently a role of NEP in COVID-19 pathogenesis has also been suggested. Despite intensive research into NEP structure and functions in different organisms, changes in its expression and regulation during brain development and ageing, especially in age-related pathologies, is still not fully understood. This prevents development of pharmacological treatments from various diseases in which NEP is implicated although recently a dual-acting drug sacubitril-valsartan (LCZ696) combining a NEP inhibitor and angiotensin receptor blocker has been approved for treatment of heart failure. Also, various natural compounds capable of upregulating NEP expression, including green tea (EGCG), have been proposed as a preventive medicine in prostate cancer and AD. This review summarizes the existing literature and our own research on the expression and activity of NEP in normal brain development, ageing and under pathological conditions.

Immune Dysfunction and Multiple Treatment Modalities for the SARS-CoV-2 Pandemic: Races of Uncontrolled Running Sweat?

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) caused a global pandemic threat with more than 11.8 million confirmed cases and more than 0.5 million deaths as of 3 July 2020. Given the lack of definitive pharmaceutical interventions against SARS-CoV-2, multiple therapeutic strategies and personal protective applications are being used to reduce the risk of high mortality and community spread of this infection. Currently, more than a hundred vaccines and/or alternative therapeutic regimens are in clinical trials, and some of them have shown promising results in improving the immune cell environment and controlling the infection. In this review, we discussed high-performance multi-directory strategies describing the uncontrolled deregulation of the host immune landscape associated with coronavirus disease (COVID-19) and treatment strategies using an anti-neoplastic regimen. We also followed selected current treatment plans and the most important on-going clinical trials and their respective outcomes for blocking SARS-CoV-2 pathogenesis through regenerative medicine, such as stem cell therapy, chimeric antigen receptors, natural killer (NK) cells, extracellular vesicular-based therapy, and others including immunomodulatory regimens, anti-neoplastic therapy, and current clinical vaccine therapy.