The role of SARS-CoV-2 target ACE2 in cardiovascular diseases

The correlation between corona virus disease 2019 and alopecia areata: a literature review

Corona virus disease 2019(COVID-19) is one of the most serious respiratory pandemic diseases threatening human health for centuries. Alopecia areata (AA) is a sudden patchy hair loss, an autoimmune disease, which seriously affects the image and mental health of patients. Evidence shows that the risk of autoimmune diseases significantly increases after COVID-19, and is positively correlated with the severity, with a significant increase in the risk of alopecia in those over 40 years old. The relationship between COVID-19 and AA has become a hot topic of current research. Strengthening the research on the correlation between COVID-19 and AA can help to identify and protect susceptible populations at an early stage. This article reviews the research progress on the epidemiological background of COVID-19 and AA, the situation and possible mechanisms of AA induced by COVID-19 or COVID-19 vaccination, and potential treatment methods.

ACE2 activation alleviates sepsis-induced cardiomyopathy by promoting MasR-Sirt1-mediated mitochondrial biogenesis

Sepsis-induced cardiomyopathy (SIC), caused by a dysregulated host response to infection, is a major contributor to high mortality. Angiotensin-converting enzyme 2 (ACE2), a crucial component of the renin-angiotensin system (RAS), has protective effects against several cardiovascular diseases, such as myocardial infarction and heart failure. However, the role of ACE2 in the pathogenesis of SIC and underlying mechanisms remain unknown. The present study was designed to examine the effects of ACE2 activation or inhibition on SIC in C57BL/6 mice. The ACE2 activator diminazene aceturate (DIZE) and ACE2 inhibitor MLN-4760 were applied for treatment. Myocardial function, inflammatory response, oxidative stress, apoptosis and mitochondrial biogenesis were investigated. Major assays were echocardiography, H&E staining, immunofluorescence staining, DHE staining, TUNEL staining, Western blot, qPCR analysis, ELISA and corresponding kits. We confirmed that ACE2 was markedly downregulated in septic heart tissues. Pharmacological activation of ACE2 by DIZE ameliorated cecal ligation puncture (CLP)-induced mortality, cardiac dysfunction, inflammatory response, oxidative stress and the cardiomyocyte apoptosis by promoting MasR-Sirt1-mediated mitochondrial biogenesis. In contrast, SIC was aggravated via inhibiting MasR-Sirt1-mediated mitochondrial biogenesis by the use of ACE2 inhibitor MLN-4760. Consequently, activation of ACE2 may protect against SIC by promoting MasR-Sirt1-mediated mitochondrial biogenesis.

Myocardial Angiotensin-Converting Enzyme 2 Protein Expression in Ischemic Heart Failure

The angiotensin-converting enzyme 2 (ACE2)-angiotensin-(1-7)-Mas receptor axis plays a significant role in regulating myocardial remodeling and the development of heart failure (HF), with ACE2 being the primary focus. However, contemporary understanding of the membrane-bound form of the human ACE2 protein remains insufficient. The purpose of this study was to determine the expression of ACE2 protein in different cells of the left ventricular myocardium in non-diseased hearts and at various stages of ischemic HF. A total of 103 myocardial tissue samples from the left ventricle underwent quantitative and semi-quantitative immunohistochemical analysis. Upon assessing ACE2 immunostaining in all myocardial cells through unselective digital image analysis, there was no change in the stage A HF group. Nevertheless, the expression of ACE2 membrane protein in cardiomyocytes showed a tendency to increase, while non-cardiomyocyte ACE2 expression decreased significantly (p < 0.001). In the stage B HF group, the intensity of ACE2 immunostaining continued to increase with rising cardiomyocyte ACE2 expression (p < 0.001). Non-cardiomyocyte expression, in contrast, remained similar to that observed in the stage A HF group. In the stages C/D HF group, ACE2 expression reached its highest level in cardiomyocytes (p < 0.001), while ACE2 expression in non-cardiomyocytes was the lowest (p < 0.001). These changes in ACE2 protein levels are associated with left ventricular remodeling in ischemic HF.

COVID-19 and Multiorgan Response: The Long-Term Impact

In late December 2019, severe acute respiratory syndrome coronavirus type-2 (SARS-CoV-2) was discovered following a cluster of pneumonia cases in Wuhan, China. During the early stages of the COVID-19 pandemic in 2020, it was unclear how this virus would manifest into a multiorgan impacting disease. After over 750 million cases worldwide, it has become increasingly evident that SARS-CoV-2 is a complex multifaceted disease we continue to develop our understanding of the pathophysiology of COVID-19 and how it affects these systems has many theories, ranging from direct viral infection via ACE2 receptor binding, to indirect coagulation dysfunction, cytokine storm, and pathological activation of the complement system. Since the onset of the pandemic, disease presentation, management, and manifestation have changed significantly. This paper intends to expand on the long-term impacts of COVID-19 on the cardiovascular, respiratory, urinary, gastrointestinal, and vascular systems of the body and the changes in clinical management. It is evident that the pharmacological, nonpharmacological and psychological management of COVID-19 patients require clearer guidelines to improve the survival odds and long-term clinical outcomes of those presenting with severe disease.

Acute Kidney Injury Associated with Severe SARS-CoV-2 Infection: Risk Factors for Morbidity and Mortality and a Potential Benefit of Combined Therapy with Tocilizumab and Corticosteroids

Background: Acute kidney injury (AKI) is a common complication in patients with severe COVID-19. Methods: We retrospectively reviewed 249 patients admitted to an intensive care unit (ICU) during the first wave of the pandemic to determine risk factors for AKI. Demographics, comorbidities, and clinical and outcome variables were obtained from electronic medical records. Results: Univariate analysis revealed older age, higher admission serum creatinine, elevated Sequential Organ Failure Assessment (SOFA) score, elevated admission D-Dimer, elevated CRP on day 2, mechanical ventilation, vasopressor requirement, and azithromycin usage as significant risk factors for AKI. Multivariate analysis demonstrated that higher admission creatinine (p = 0.0001, OR = 2.41, 95% CI = 1.56–3.70), vasopressor requirement (p = 0.0001, OR = 3.20, 95% CI = 1.69–5.98), elevated admission D-Dimer (p = 0.008, OR = 1.0001, 95% CI = 1.000–1.001), and elevated C-reactive protein (CRP) on day 2 (p = 0.033, OR = 1.0001, 95% CI = 1.004–1.009) were independent risk factors. Conversely, the combined use of Tocilizumab and corticosteroids was independently associated with reduced AKI risk (p = 0.0009, OR = 0.437, 95% CI = 0.23–0.81). Conclusion: This study confirms the high rate of AKI and associated mortality among COVID-19 patients admitted to ICUs and suggests a role for inflammation and/or coagulopathy in AKI development. One should consider the possibility that early administration of anti-inflammatory agents, as is now routinely conducted in the management of COVID-19-associated acute respiratory distress syndrome, may improve clinical outcomes in patients with AKI.

Influenza A virus modulates ACE2 expression and SARS-CoV-2 infectivity in human cardiomyocytes

Influenza A virus (IAV) and SARS-CoV-2 virus are both acute respiratory viruses currently circulating in the human population. This study aims to determine the impact of IAV infection on SARS-CoV-2 pathogenesis and cardiomyocyte function. Infection of human bronchial epithelial cells (HBEC), A549 cells, lung fibroblasts (HLF), monocyte derived macrophages (MDMs), cardiac fibroblasts (HCF) and hiPSC-derived cardiomyocytes with IAV enhanced the expression of ACE2, the SARS-CoV-2 receptor. Similarly, IAV infection increased levels of ACE2 in the lungs of mice and humans. Of interest, we detected heavily glycosylated form of ACE2 in hiPSC-CMs and poorly glycosylated ACE2 in other cell types. Also, prior IAV infection enhances SARS-CoV-2 spike protein binding and viral entry in all cell types. However, efficient SARS-CoV-2 replication was uniquely inhibited in cardiomyocytes. Glycosylation of ACE2 correlated with enzymatic conversion of its substrate Ang II, induction of eNOS and nitric oxide production, may provide a potential mechanism for the restricted SARS-CoV-2 replication in cardiomyocytes.

An unexpected cause of chest pain, dyspnea and palpitations in a young patient during a post-COVID syndrome

A 31-year-old male presented with sudden onset of chest pain and dyspnea after a COVID-19 infection. Initially labeled as a myopericarditis related to COVID-19, because of the young age and low risk profile, after a multiparametric evaluation was possible to diagnose and treat an unstable lesion on an intermediate branch of left coronary.

Age and gender differences in ACE2 and TMPRSS2 expressions in oral epithelial cells

Background

SARS-CoV-2, which has brought a huge negative impact on the world since the end of 2019, is reported to invade cells using the spike (S) protein to bind to angiotensin-converting enzyme II (ACE2) receptors on human cells while the transmembrane protease serine 2 (TMPRSS2) is the key protease that activates the S protein, which greatly facilitates the entry of SARS-CoV-2 into target cells. In our previous study, it was observed that the positive rate of SARS-CoV-2 nucleic acids in saliva was higher in male and the elderly COVID-19 patients, suggesting that the susceptibility of oral tissues to SARS-CoV-2 may be related to gender and age. This research aimed to further investigate the SARS-CoV-2 susceptibility in oral tissues and influencing factors from the perspective of ACE2 and TMPRSS2, which were two proteins closely associated with SARS-CoV-2 infection.

Methods

Immunofluorescence was used to find the localization of ACE2 and TMPRSS2 in oral mucosal tissues. Transcriptomic sequencing data of several datasets were then collected to analysis the relationship between the expressions of ACE2 and TMPRSS2 with the age and gender of patients. Furthermore, oral tissues from patients with different ages and genders were collected. Immunohistochemistry staining, qRT-PCR and western blot were performed to explore the relationship between expression levels of ACE2 and TMPRSS2 and patient age as well as gender.

Results

The results showed that the two proteins were able to be co-expressed in the epithelial cells of oral tissues, and their expression levels were higher in the relatively elderly group than those in relatively younger group. Male oral epithelial cells exhibited higher level of TMPRSS2.

Conclusions

Our findings comprehensively confirmed the existence of ACE2 and TMPRSS2 in oral tissues and clarify the relationship between the expression levels with human age and gender for the first time, providing evidence for possible entry routes of SARS-CoV-2 and the influencing factors of SARS-CoV-2 colonization in oral cavity. Thus, the oral mucosa might be at potential risk of infection by SARS-CoV-2, especially in male or elderly patients. Using saliva to detect the nucleic acids of SARS-CoV-2 may be more accurate for elder male COVID-19 patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-021-03037-4.

The Impact of Angiotensin-Converting Enzyme 2 (ACE2) Expression on the Incidence and Severity of COVID-19 Infection

The novel coronavirus disease 2019 (COVID-19) pandemic has led to an unprecedented threat to the international community and raised major concerns in terms of public health safety. Although our current understanding of the complexity of COVID-19 pathogenesis remains limited, the infection is largely mediated by the interaction of viral spike protein and angiotensin-converting enzyme 2 (ACE2). The functional importance of ACE2 in different demographic and comorbid conditions may explain the significant variation in incidence and mortality of COVID-19 in vulnerable groups, and highlights its candidacy as a potential therapeutic target. We provide evidence supporting the idea that differences in incidence and severity of COVID-19 infection may be related to ACE2. Emerging data based on the prevalence and severity of COVID-19 among those with established high levels of ACE2 expression strongly support our hypothesis. Considering the burden of COVID-19 infection in these vulnerable groups and the impact of the potential therapeutic and preventive measures that would result from adopting ACE2-driven anti-viral strategies, our hypothesis may expedite global efforts to control the current COVID-19 pandemic.

The role of SARS-CoV-2 target ACE2 in cardiovascular diseases

SARS-CoV-2, the virus responsible for the global coronavirus disease (COVID-19) pandemic, attacks multiple organs of the human body by binding to angiotensin-converting enzyme 2 (ACE2) to enter cells. More than 20 million people have already been infected by the virus. ACE2 is not only a functional receptor of COVID-19 but also an important endogenous antagonist of the renin-angiotensin system (RAS). A large number of studies have shown that ACE2 can reverse myocardial injury in various cardiovascular diseases (CVDs) as well as is exert anti-inflammatory, antioxidant, anti-apoptotic and anticardiomyocyte fibrosis effects by regulating transforming growth factor beta, mitogen-activated protein kinases, calcium ions in cells and other major pathways. The ACE2/angiotensin-(1-7)/Mas receptor axis plays a decisive role in the cardiovascular system to combat the negative effects of the ACE/angiotensin II/angiotensin II type 1 receptor axis. However, the underlying mechanism of ACE2 in cardiac protection remains unclear. Some approaches for enhancing ACE2 expression in CVDs have been suggested, which may provide targets for the development of novel clinical therapies. In this review, we aimed to identify and summarize the role of ACE2 in CVDs.