A comprehensive guide to the pharmacologic regulation of angiotensin converting enzyme 2 (ACE2), the SARS-CoV-2 entry receptor

Role of angiotensin converting enzyme in pathogenesis associated with immunity in cardiovascular diseases

Angiotensin converting enzyme (ACE) is not only a critical component in the renin-angiotensin system (RAS), but also suggested as an important mediator for immune response and activity, such as immune cell mobilization, metabolism, biogenesis of immunoregulatory molecules, etc. The chronic duration of cardiovascular diseases (CVD) has been increasingly considered to be triggered by uncontrolled pathologic immune reactions from myeloid cells and lymphocytes. Considering the potential anti-inflammatory effect of the traditional antihypertensive ACE inhibitor (ACEi), we attempt to elucidate whether ACE and its catalytically relevant substances as well as signaling pathways play a role in the immunity-related pathogenesis of common CVD, such as arterial hypertension, atherosclerosis and arrythmias. ACEi was also reported to benefit the prognoses of COVID-19-positive patients with CVD, and COVID-19 disease with preexisting CVD or subsequent cardiovascular damage is featured by a significant influx of immune cells and proinflammatory molecules, suggesting that ACE may also participate in COVID-19 induced cardiovascular injury, because COVID-19 disease basically triggers an overactive pathologic immune response. Hopefully, the ACE inhibition and manipulation of those associated bioactive signals could supplement the current medicinal management of various CVD and bring greater benefit to patients' cardiovascular health.

Marine Sponge-Derived Secondary Metabolites Modulate SARS-CoV-2 Entry Mechanisms

The emergence of SARS-CoV 2 caused the COVID-19 pandemic, resulting in numerous global infections and deaths. In particular, people with metabolic diseases display an increased risk of severe COVID 19 and a fatal outcome. Treatment options for severe cases are limited, and the appearance of new virus variants complicates the development of novel therapies. To better manage viral infections like COVID 19, new therapeutic approaches are needed. Marine sponges offer a natural and renewable source of unique bioactive agents. These sponges produce secondary metabolites with various effects, including anti-viral, anti-inflammatory, and anti-tumorigenic properties. In the current study, we investigated the effect of five different marine sponge-derived secondary metabolites (four bromotyrosines and one sesquiterpenoid hydroquinone). Two of these, Avarol and Acetyl-dibromoverongiaquinol reduced the expression of ACE2, the main receptor for SARS-CoV 2, and the alternative receptor NRP1. Moreover, these substances derived from sponges demonstrated the ability to diminish the virus titer in SARS-CoV 2-infected cells, especially concerning the Omicron lineage. However, the reduction was not substantial enough to expect a significant impact on infected humans. Consequently, the investigated sponge-derived secondary metabolites are not likely to be effective to treat COVID 19 as a stand-alone therapy.

Proteomics-based mass spectrometry profiling of SARS-CoV-2 infection from human nasopharyngeal samples

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the cause of the on-going global pandemic of coronavirus disease 2019 (COVID-19) that continues to pose a significant threat to public health worldwide. SARS-CoV-2 encodes four structural proteins namely membrane, nucleocapsid, spike, and envelope proteins that play essential roles in viral entry, fusion, and attachment to the host cell. Extensively glycosylated spike protein efficiently binds to the host angiotensin-converting enzyme 2 initiating viral entry and pathogenesis. Reverse transcriptase polymerase chain reaction on nasopharyngeal swab is the preferred method of sample collection and viral detection because it is a rapid, specific, and high-throughput technique. Alternate strategies such as proteomics and glycoproteomics-based mass spectrometry enable a more detailed and holistic view of the viral proteins and host-pathogen interactions and help in detection of potential disease markers. In this review, we highlight the use of mass spectrometry methods to profile the SARS-CoV-2 proteome from clinical nasopharyngeal swab samples. We also highlight the necessity for a comprehensive glycoproteomics mapping of SARS-CoV-2 from biological complex matrices to identify potential COVID-19 markers.

SARS-CoV-2 infection and its effects on the endocrine system

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causing corona virus disease 2019 (COVID-19) can infect multiple tissues, including endocrine organs, such as the pancreas, adrenal, thyroid, and adipose tissue. The main receptor for SARS-CoV-2, ACE2, is ubiquitously expressed in the cells of the endocrine organs and accordingly, the virus has been detected in various amounts in all endocrine tissues in post-mortem samples from COVID-19 patients. The infection with SARS-CoV-2 may directly lead to organ damage or dysfunction, such as hyperglycaemia or in rare cases, new-onset diabetes. Furthermore, an infection with SARS-CoV-2 may have indirect effects affecting the endocrine system. The exact mechanisms are not yet completely understood and have to be further investigated. Conversely, endocrine diseases may affect the severity of COVID-19 and emphasis has to be laid on reducing the prevalence, or enhance the treatment, of these often non-communicable diseases in the future.

COVID-19 presenting as acute epiglottitis: A case report and literature review

Coronavirus disease 2019 (COVID-19) occasionally causes acute laryngitis, requiring emergency treatment. Understanding the characteristic laryngeal findings can help diagnose COVID-19 earlier, prevent worsening infection, and properly manage airway obstruction. Herein, we report the case of a 44-year-old male with acute epiglottitis likely caused by COVID-19. On presentation, chest computed tomography (CT) showed no signs of pneumonia. However, the larynx had extensive necrotic-like erosive lesions resembling those of tuberculous laryngitis. COVID-19 was diagnosed by reverse-transcription polymerase chain reaction, and secondary bacterial superinfections were suspected after blood testing. The symptoms improved after administration of antibiotics (sulbactam sodium/ampicillin sodium), steroids (dexamethasone), and favipiravir. The patient developed a high fever on the sixth day of hospitalization, and pneumonia was identified on CT. Various culture tests, including tuberculosis, were negative. Thus, remdesivir was administered for COVID-19-induced pneumonia. The patient gradually recovered, was transferred to another hospital, and was discharged on the 35th day of hospitalization. Six previous case reports of COVID-19-induced acute epiglottitis suggested that acute epiglottitis preceded the onset of pneumonia. The laryngeal findings from this report may be useful for diagnosing COVID-19 that does not cause pneumonia and for bringing attention to pneumonia after a COVID-19 diagnosis.

Long Chain N3-PUFA Decreases ACE2 Protein Levels and Prevents SARS-CoV-2 Cell Entry

Angiotensin-converting enzyme 2 (ACE2) is a target of interest for both COVID-19 and cardiovascular disease management. Even though lower ACE2 levels may be beneficial in SARS-CoV-2 infectivity, maintaining the ACE1/ACE2 balance is also crucial for cardiovascular health. So far, reports describing conditions capable of altering ACE2 protein levels, especially via dietary components, are limited. In this study, the effects of omega-3 polyunsaturated fatty acids (n3-PUFA) on the protein levels of ACE1 and ACE2 in rodent tissues, human endothelial and kidney cell lines, and human plasma were examined. The ability of n3-PUFA to affect the entry of the SARS-CoV-2 pseudovirus into cells was also tested. Docosahexaenoic acid (DHA), and in some cases eicosapentaenoic acid (EPA), but not α-linoleic acid (ALA), reduced both ACE1 and ACE2 (non-glycosylated p100 and glycosylated p130 forms) in the heart, aorta, and kidneys of obese rats, as well as in human EA.hy926 endothelial and HEK293 kidney cells. Dietary supplementation with either DHA or ALA had no effect on plasma soluble ACE2 levels in humans. However, treatment of HEK293 cells with 80 and 125 µM DHA for 16 h inhibited the entry of the SARS-CoV-2 pseudovirus. These results strongly suggest that DHA treatment may reduce the ability of SARS-CoV-2 to infect cells via a mechanism involving a decrease in the absolute level of ACE2 protein as well as its glycosylation. Our findings warrant further evaluation of long-chain n3-PUFA supplements as a novel option for restricting SARS-CoV-2 infectivity in the general population.

Small molecule angiotensin converting enzyme inhibitors: A medicinal chemistry perspective

Angiotensin-converting enzyme (ACE), a zinc metalloprotein, is a central component of the renin-angiotensin system (RAS). It degrades bradykinin and other vasoactive peptides. Angiotensin-converting-enzyme inhibitors (ACE inhibitors, ACEIs) decrease the formation of angiotensin II and increase the level of bradykinin, thus relaxing blood vessels as well as reducing blood volume, lowering blood pressure and reducing oxygen consumption by the heart, which can be used to prevent and treat cardiovascular diseases and kidney diseases. Nevertheless, ACEIs are associated with a range of adverse effects such as renal insufficiency, which limits their use. In recent years, researchers have attempted to reduce the adverse effects of ACEIs by improving the selectivity of ACEIs for structural domains based on conformational relationships, and have developed a series of novel ACEIs. In this review, we have summarized the research advances of ACE inhibitors, focusing on the development sources, design strategies and analysis of structure-activity relationships and the biological activities of ACE inhibitors.

Use of natural cysteine protease inhibitors in limiting SARS-Co-2 fusion into human respiratory cells

Specific antibodies that humans acquire as a result of disease or after vaccination are needed to effectively suppress infection with a specific variant of SARS CoV-2 virus. The S protein of the D614G variant of coronavirus is used as an antigen in known vaccines to date. It is known that COVID-19 disease resulting from infection with this coronavirus can often be very dangerous to the health and lives of patients. In contrast, vaccines produce antibodies against an older version of the protein S-D614G (January 2020) and therefore have difficulty recognizing new variants of the virus. In our project we propose to obtain specific and precise antibodies by means of so-called controlled infection against specific infectious variants of the SARS-CoV-2 virus “here and now”. Currently, several variants of this pathogen have already emerged that threaten the health and lives of patients. We propose to reduce this threat by partially, but not completely, blocking the fusion mechanism of the SARS-CoV-2 virus into human respiratory cells. According to our plan, this can be achieved by inhibiting cathepsin L activity in respiratory cells, after introducing natural and non-toxic cysteine protease inhibitors into this area. We obtain these inhibitors by our own method from natural, “human body friendly” natural resources. We hypothesize that blocking cathepsin L will reduce the number of infecting viruses in cells to such an extent that COVID-19 developing in infected individuals will not threaten their health and life. At the same time, the number of viruses will be sufficient for the body's own immune system to produce precise antibodies against a specific version of this pathogen.

Molecular imaging on ACE2-dependent transocular infection of coronavirus

A transocular infection has been proved as one of the main approaches that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) invades the body, and angiotensin-converting enzyme 2 (ACE2) plays a key role in this procedure. Dynamic and quantitative details on virus distribution are lacking for virus prevention and drug design. In this study, a radiotraceable pseudovirus packed with an enhanced green fluorescent protein (EGFP) gene, 125 I-CoV, was prepared and inoculated in the unilateral eye of humanized ACE2 (hACE2) mice or ACE2-knockout (ACE2-KO) mice. Single-photon emission computed tomography/computed tomography images were acquired at multiple time points to exhibit ACE2-dependent procedures from invasion to clearance. Positron emission tomography (PET) and western blot were performed to quantify ACE2 expression and verify the factors affecting transocular infection. For the transocular infection of coronavirus (CoV), the renin-angiotensin-aldosterone system (RAAS), lungs, intestines, and genital glands were the main targeted organs. Due to the specific anchor to ACE2-expressed host cells, virus concentrations in genital glands, liver, and lungs ranked the top three most and stabilized at 3.75 ± 0.55, 3.30 ± 0.25, and 2.10 ± 0.55% inoculated dose (ID)/mL at 48 h post treatment. Meanwhile, ACE2-KO mice had already completed the in vivo clearance. In consideration of organ volumes, lungs (14.50 ± 3.75%ID) and liver (10.94 ± 0.71%ID) were the main in-store reservoirs of CoV. However, the inoculated eye (5.52 ± 1.85%ID for hACE2, 5.24 ± 1.45%ID for ACE2-KO, p > 0.05) and the adjacent brain exhibited ACE2-independent virus infection at the end of 72 h observation, and absolute amount of virus played a key role in host cell infection. These observations on CoV infection were further manifested by infection-driven intracellular EGFP expression. ACE2 PET revealed an infection-related systematic upregulation of ACE2 expression in the organs involved in RAAS (e.g., brain, lung, heart, liver, and kidney) and the organ that was of own local renin-angiotensin system (e.g., eye). Transocular infection of CoV is ACE2-dependent and constitutes the cause of disturbed ACE2 expression in the host. The brain, genital glands, and intestines were of the highest unit uptake, potentially accounting for the sequelae. Lungs and liver were of the highest absolute amount, closely related to the respiratory diffusion and in vivo duplication. ACE2 expression was upregulated in the short term after infection with CoV. These visual and quantitative results are helpful to fully understanding the transocular path of SARS-CoV-2 and other CoVs.

Lack of Correlation Between Soluble Angiotensin-Converting Enzyme 2 and Inflammatory Markers in Hospitalized COVID-19 Patients with Hypertension

Purpose

This study aimed to investigate the correlation of plasma soluble angiotensin-converting enzyme 2, sACE2, and several inflammatory markers in COVID-19 patients requiring hospitalization with hypertension. Additionally, we analyzed the effects of renin-angiotensin-aldosterone-system, RAAS, inhibitors on the levels of sACE2 and inflammatory marker levels in patients with COVID-19.

Patients and Methods

This cross-sectional study involved patients with COVID-19 who required hospitalization on a stable dose of antihypertensive drugs. The study included three hospitals in Jakarta and Tangerang, Indonesia, between December 2020 and June 2021. We classified eligible subjects into two groups: patients with COVID-19 treated with antihypertensive RAAS inhibitors or non-RAAS inhibitors.

Results

We found no correlation between sACE2 and all the inflammatory and coagulation markers studied (high-sensitivity C-reactive protein, IL-6, IL-10, IL6/IL10, tumor necrosis factor-α, neutrophil-to-lymphocyte ratio, and D-dimer) in COVID-19 patients with hypertension. Further analysis showed lower sACE2 concentrations and IL-6/IL-10 ratio in patients treated with RAAS inhibitors vs those treated with non-RAAS inhibitors.

Conclusion

We found no correlation between ACE2 and inflammatory markers. Using RAAS inhibitors resulted in a lower sACE2 and IL-6/IL-10 ratio. The type of antihypertensive treatments has a neutral effect on disease severity and outcome in COVID-19 patients with hypertension. However, to firmly-established these effects, our findings should be confirmed in a much larger population.

Folic acid restricts SARS-CoV-2 invasion by methylating ACE2

The current COVID-19 pandemic is motivating us to elucidate the molecular mechanism of SARS-CoV-2 invasion and find methods for decreasing its transmissibility. We found that SARS-CoV-2 could increase the protein level of ACE2 in mice. Folic acid and 5-10-methylenetetrahydrofolate reductase (MTHFR) could promote the methylation of the ACE2 promoter and inhibit ACE2 expression. Folic acid treatment decreased the binding ability of Spike protein, pseudovirus and inactivated authentic SARS-CoV-2 to host cells. Thus, folic acid treatment could decrease SARS-CoV-2 invasion and SARS-CoV-2-neutralizing antibody production in mice. These data suggest that increased intake of folic acid may inhibit ACE2 expression and reduce the transmissibility of SARS-CoV-2. Folic acid could play an important role in SARS-CoV-2 infection prevention and control.

Managing SARS-CoV2 Infections Through Resolution of Inflammation by Eicosanoids: A Review

Severe Corona Virus Disease is characterized by angiocentric inflammation of lungs and cytokine storm leading to potentially fatal multiple organ failure. Several studies have shown the high levels of pro-inflammatory cytokines, indicative of a poor prognosis in COVID-19. Eicosanoids play an important role in the induction of inflammation and cytokine production, while anti-inflammatory and pro-resolving properties of some eicosanoic acid derivatives enable inflamed tissues to return to homeostasis through the resolution of inflammation by aiding the clearance of cell debris and downregulation of pro-inflammatory stimulants. This review attempts to provide an overall insight on the eicosanoids synthesis and their role in the resolution of inflammation in the context of Corona Virus infection.

Diabetes and COVID-19: Short- and Long-Term Consequences

When the corona pandemic commenced more than two years ago, it was quickly recognized that people with metabolic diseases show an augmented risk of severe COVID-19 and an increased mortality compared to people without these comorbidities. Furthermore, an infection with SARS-CoV-2 has been shown to lead to an aggravation of metabolic diseases and in single cases to new-onset metabolic disorders. In addition to the increased risk for people with diabetes in the acute phase of COVID-19, this patient group also seems to be more often affected by long-COVID and to experience more long-term consequences than people without diabetes. The mechanisms behind these discrepancies between people with and without diabetes in relation to COVID-19 are not completely understood yet and will require further research and follow-up studies during the following years. In the current review, we discuss why patients with diabetes have this higher risk of developing severe COVID-19 symptoms not only in the acute phase of the disease but also in relation to long-COVID, vaccine breakthrough infections and re-infections. Furthermore, we discuss the effects of lockdown on glycemic control.

Obesity and COVID-19: What are the Consequences?

Obesity is an increasing health problem all over the world. In combination with the current COVID-19 pandemic, this has turned into a massive challenge as individuals with overweight and obesity at all ages show a significant increase in their risk of getting severe COVID-19. Around 20% of all patients that were hospitalized for COVID-19 suffered from obesity alone, whereas obesity in combination with other metabolic comorbidities, such as type 2 diabetes and hypertension, account for up to 60% of all hospitalizations in relation to COVID-19. Therefore, it is of immense importance to put the spotlight on the high incidence of obesity present already in childhood both by changing the individual minds and by encouraging politicians and the whole society to commence preventive interventions for achieving a better nutrition for all social classes all over the world. In the current review, we aim to explain the different pathways and mechanisms that are responsible for the increased risk of severe COVID-19 in people with overweight and obesity. Furthermore, we discuss how the pandemic has led to weight gains in many people during lockdown. At the end, we discuss the importance of preventing such an interface between a non-communicable disease like obesity and a communicable disease like COVID-19 in the future.

Neuromodulation by selective angiotensin-converting enzyme 2 inhibitors

Here, neuromodulatory effects of selective angiotensin-converting enzyme 2 (ACE2) inhibitors were investigated. Two different types of small molecule ligands for ACE2 inhibition were selected using chemical genetic approach, they were synthesized using developed chemical method and tested using presynaptic rat brain nerve terminals (synaptosomes). EBC-36032 (1 µM) increased in a dose-dependent manner spontaneous and stimulated ROS generation in nerve terminals that was of non-mitochondrial origin. Another inhibitor EBC-36033 (MLN-4760) was inert regarding modulation of ROS generation. EBC-36032 and EBC-36033 (100 µM) did not modulate the exocytotic release of L-[¹⁴C]glutamate, whereas both inhibitors decreased the initial rate of uptake, but not accumulation (10 min) of L-[¹⁴C]glutamate by nerve terminals. EBC-36032 (100 µM) decreased the exocytotic release as well as the initial rate and accumulation of [³H]GABA by nerve terminals. EBC-36032 and EBC-36033 did not change the extracellular levels and transporter-mediated release of [³H]GABA and L-[¹⁴C]glutamate, and tonic leakage of [³H]GABA from nerve terminals. Therefore, synthesized selective ACE2 inhibitors decreased uptake of glutamate and GABA as well as exocytosis of GABA at the presynaptic level. The initial rate of glutamate uptake was the only parameter that was mitigated by both ACE2 inhibitors despite stereochemistry issues. In terms of ACE2-targeted antiviral/anti-SARS-CoV-2 and other therapies, novel ACE2 inhibitors should be checked on the subject of possible renin-angiotensin system (RAS)-independent neurological side effects.

The effect of various compounds on the COVID mechanisms, from chemical to molecular aspects

The novel coronavirus that caused COVID-19 pandemic is SARS-CoV-2. Although various vaccines are currently being used to prevent the disease's severe consequences, there is still a need for medications for those who become infected. The SARS-CoV-2 has a variety of proteins that have been studied extensively since the virus's advent. In this review article, we looked at chemical to molecular aspects of the various structures studied that have pharmaceutical activity and attempted to find a link between drug activity and compound structure. For example, designing of the compounds which bind to the allosteric site and modify hydrogen bonds or the salt bridges can disrupt SARS-CoV2 RBD–ACE2 complex. It seems that quaternary ammonium moiety and quinolin-1-ium structure could act as a negative allosteric modulator to reduce the tendency between spike-ACE2. Pharmaceutical structures with amino heads and hydrophobic tails can block envelope protein to prevent making mature SARS-CoV-2. Also, structures based on naphthalene pharmacophores or isosteres can form a strong bond with the PLpro and form a π-π and the Mpro's active site can be occupied by octapeptide compounds or linear compounds with a similar fitting ability to octapeptide compounds. And for protein RdRp, it is critical to consider pH and pKa so that pKa regulation of compounds to comply with patients is very effective, thus, the presence of tetrazole, phenylpyrazole groups, and analogs of pyrophosphate in the designed drugs increase the likelihood of the RdRp active site inhibition. Finally, it can be deduced that designing hybrid drug molecules along with considering the aforementioned characteristics would be a suitable approach for developing medicines in order to accurate targeting and complete inhibition this virus.

The Influence of Sex, Gender, and Age on COVID-19 Data in the Piedmont Region (Northwest Italy): The Virus Prefers Men

Several important sex and gender differences in the clinical manifestation of diseases have been known for a long time but are still underestimated. The infectious Coronavirus 2019 disease pandemic has provided evidence of the importance of a sex and gender-based approach; it mainly affected men with worse symptomatology due to a different immune system, which is stronger in women, and to the Angiotensin-converting enzyme 2 and Transmembrane protease serine 2 roles which are differently expressed among the sexes. Additionally, women are more inclined to maintain social distance and smoke less. Analysis of data on the infectious Coronavirus 2019 disease testing from people admitted to the Amedeo di Savoia Hospital, a regional referral center for infectious diseases, has been applied to the whole of 2020 data (254,640 records). A high percentage of data in the dataset was not suitable due to a lack of information or entering errors. Among the suitable samples, records have been analyzed for positive/negative outcomes, matching records for unique subjects (N = 123,542), to evaluate individual recurrence of testing. Data are presented in age and sex-disaggregated ways. Analyses of the suitable sample also concerned the relation between testing and hospital admission motivation and symptoms. Our analysis indicated that a sex and gender-based approach is mandatory for patients and the National Health System’s sustainability.

Screening of potential spike glycoprotein / ACE2 dual antagonists against COVID-19 in silico molecular docking

The novel coronavirus disease has spread rapidly and caused sustained pressure on economic and medical resources to many countries. Vaccines and effective drugs are needed to fight against the epidemic. Traditional Chinese Medicine (TCM) plays an important and effective role in the treatment of COVID-19. Therefore, the active components of TCM are potential structural basis for the discovery of antiviral drugs. Through screening by molecular docking, Oleanolic acid, Tryptanthrin, Chrysophanol and Rhein were found to have better spike protein and ACE2 inhibitory activity, which could block the invasion and recognition of SARS-CoV-2 at the same time, should be investigated as antiviral candidates.

Progress in the Synthesis of Heterocyclic Compounds Catalyzed by Lipases

Heterocyclic compounds are representative of a larger class of organic compounds, and worthy of attention for many reasons, chief of which is the participation of heterocyclic scaffolds in the skeleton structure of many drugs. Lipases are enzymes with catalytic versatility, and play a key role in catalyzing the reaction of carbon–carbon bond formation, allowing the production of different compounds. This article reviewed the lipase-catalyzed aldol reaction, Knoevenagel reaction, Michael reaction, Mannich reaction, etc., in the synthesis of several classes of heterocyclic compounds with important physiological and pharmacological activities, and also prospected the research focus in lipase-catalyzed chemistry transformations in the future.

Antiviral strategies targeting host factors and mechanisms obliging +ssRNA viral pathogens

The ongoing COVID-19 pandemic, periodic recurrence of viral infections, and the emergence of challenging variants has created an urgent need of alternative therapeutic approaches to combat the spread of viral infections, failing to which may pose a greater risk to mankind in future. Resilience against antiviral drugs or fast evolutionary rate of viruses is stressing the scientific community to identify new therapeutic approaches for timely control of disease. Host metabolic pathways are exquisite reservoir of energy to viruses and contribute a diverse array of functions for successful replication and pathogenesis of virus. Targeting the host factors rather than viral enzymes to cease viral infection, has emerged as an alternative antiviral strategy. This approach offers advantage in terms of increased threshold to viral resistance and can provide broad-spectrum antiviral action against different viruses. The article here provides substantial review of literature illuminating the host factors and molecular mechanisms involved in innate/adaptive responses to viral infection, hijacking of signalling pathways by viruses and the intracellular metabolic pathways required for viral replication. Host-targeted drugs acting on the pathways usurped by viruses are also addressed in this study. Host-directed antiviral therapeutics might prove to be a rewarding approach in controlling the unprecedented spread of viral infection, however the probability of cellular side effects or cytotoxicity on host cell should not be ignored at the time of clinical investigations.

COVID-19-related cardiac complications from clinical evidences to basic mechanisms: opinion paper of the ESC Working Group on Cellular Biology of the Heart

The pandemic of coronavirus disease (COVID)-19 is a global threat, causing high mortality, especially in the elderly. The main symptoms and the primary cause of death are related to interstitial pneumonia. Viral entry also into myocardial cells mainly via the angiotensin converting enzyme type 2 (ACE2) receptor and excessive production of pro-inflammatory cytokines, however, also make the heart susceptible to injury. In addition to the immediate damage caused by the acute inflammatory response, the heart may also suffer from long-term consequences of COVID-19, potentially causing a post-pandemic increase in cardiac complications. Although the main cause of cardiac damage in COVID-19 remains coagulopathy with micro- (and to a lesser extent macro-) vascular occlusion, open questions remain about other possible modalities of cardiac dysfunction, such as direct infection of myocardial cells, effects of cytokines storm, and mechanisms related to enhanced coagulopathy. In this opinion paper, we focus on these lesser appreciated possibilities and propose experimental approaches that could provide a more comprehensive understanding of the cellular and molecular bases of cardiac injury in COVID-19 patients. We first discuss approaches to characterize cardiac damage caused by possible direct viral infection of cardiac cells, followed by formulating hypotheses on how to reproduce and investigate the hyperinflammatory and pro-thrombotic conditions observed in the heart of COVID-19 patients using experimental in vitro systems. Finally, we elaborate on strategies to discover novel pathology biomarkers using omics platforms.

Management of Inflammatory Bowel Disease during Coronavirus Disease 2019 Pandemic

Inflammatory bowel disease (IBD) is a chronic inflammation consisted of ulcerative colitis and Crohn’s disease. IBD is a global disease with heavy economic burden. Coronavirus disease-2019 (COVID-19) is a novel disease which spread rapidly and becomes a pandemic. This pandemic situation affects the management of IBD. Severe acute respiratory syndrome coronavirus-2 as the etiology of COVID-19 requires angiotensin-converting enzyme (ACE2) as its receptor. ACE2 is found to be abundant in the gastrointestinal tract, particularly the small intestine and colon. This causes the presence of gastrointestinal symptoms in COVID-19 and interacts with gastrointestinal diseases including IBD. The diagnosis of IBD in patients with COVID-19 is similar with general population with precautions regarding endoscopic procedure. IBD does not increase the risk for contracting COVID-19 nor worsen the outcome of COVID-19. The first step in managing patients with IBD during pandemic is by implicating strict health protocol. There is still a controversy regarding surgery for IBD during pandemic. Medications for IBD are safe during pandemic except systemic corticosteroids. IBD patients without COVID-19 should continue their medications until the goal of disease remission is achieved. If asymptomatic COVID-19 is present, corticosteroid dose should be lowered, tapered, and stopped if available. Anti-tumor necrosis factor (TNF) administration should be postponed for 2 weeks. If COVID-19 manifestations exist, systemic corticosteroid, thiopurine, methotrexate, and anti-TNF should be discontinued. Supporting treatment for COVID-19 can be administered safely. In case of relapsing, the treatment of IBD must be started with the limitation of systemic corticosteroid.

The classical and potential novel healthy functions of rice bran protein and its hydrolysates

Rice bran protein (RBP) is a plant protein obtained from rice bran, a byproduct produced during rice milling process. It has been proved to be a high quality protein due to containing all of the essential amino acids and the content closing to the FAO/WHO recommended ideal pattern. Recent studies indicated that RBP and rice bran protein hydrolysates (RBPH) served variety biological functions. In this review, we summarized the classical functions of RBP and RBPH mediating antioxidant activity, chronic diseases prevention (such as antihypertensive effect, anti-diabetic effect, cholesterol-lowering activity), and anti-cancer effect. We also proposed their potential novel functions on anti-obesity effect, attenuating sarcopenia, promoting wound healing. Furthermore, the potential benefit to coronavirus disease 2019 (COVID-19) patients was put forward, which might provide new strategy for development and utilization of RBP and RBPH.

Heart Failure and Coronavirus Disease-19

Globally, 4.2% population suffer from heart failure. The condition has a mortality rate between 56% and 78%. Coronavirus disease-2019 (COVID-19) was first reported in December 2019 and became a pandemic since March 11, 2020. As COVID-19 emerges, cardiovascular disorders including, heart failure, become one of the most common comorbidity that increase the risk for contracting the disease. Heart failure and COVID-19 have reciprocal relationship. Patients with heart failure are at higher risk for COVID-19 with more unfavorable outcome. COVID-19 itself may deteriorate pre-existing heart failure in the subject. This situation is mediated by the presence of angiotensin converting enzyme-2 (ACE-2) in cardiac myocytes and pericytes, direct effect of viral invasion to myocytes and pericytes, downregulation of ACE-2 which hampers cardiovascular function, and uncontrolled inflammation known as cytokine storm. Prudent management, including implementation of telemedicine, continuation of ACE inhibitor and angiotensin receptor blocker, and medications’ side effects monitoring, is important in managing patients with coexisting heart failure and COVID-19.

Case report: Epiglottitis in the setting of COVID-19

Epiglottitis is an uncommon, potentially fatal infection of the epiglottis that can lead to complete upper airway obstruction. Isolated pathogens are usually nasopharyngeal bacteria, most commonly Haemophilus influenzae type b (Hib). While the incidence of epiglottitis has diminished significantly over the years due to widespread vaccination against Hib, the proportion of epiglottitis caused by other pathogens has increased. In this report, we introduce an unseen presentation of acute epiglottitis associated with severe acute respiratory distress syndrome--coronavirus2 (SARS-CoV-2), who presented to the emergency department with throat pain and odynophagia that quickly resulted in respiratory distress. Clinicians should be aware of airway edema's concomitant presence in patients with acute epiglottitis and COVID-19 and maintain a low threshold for intubation. The rapidly progressive nature of COVID-19 and its complications may preclude intubation later on in the patient’s clinical course, potentially necessitating an emergent surgical airway.

Multifunctional angiotensin converting enzyme 2, the SARS-CoV-2 entry receptor, and critical appraisal of its role in acute lung injury

The recent emergence of coronavirus disease-2019 (COVID-19) as a pandemic affecting millions of individuals has raised great concern throughout the world, and the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) was identified as the causative agent for COVID-19. The multifunctional protein angiotensin converting enzyme 2 (ACE2) is accepted as its primary target for entry into host cells. In its enzymatic function, ACE2, like its homologue ACE, regulates the renin-angiotensin system (RAS) critical for cardiovascular and renal homeostasis in mammals. Unlike ACE, however, ACE2 drives an alternative RAS pathway by degrading Ang-II and thus operates to balance RAS homeostasis in the context of hypertension, heart failure, and cardiovascular as well as renal complications of diabetes. Outside the RAS, ACE2 hydrolyzes key peptides, such as amyloid-β, apelin, and [des-Arg9]-bradykinin. In addition to its enzymatic functions, ACE2 is found to regulate intestinal amino acid homeostasis and the gut microbiome. Although the non-enzymatic function of ACE2 as the entry receptor for SARS-CoV-2 has been well established, the contribution of enzymatic functions of ACE2 to the pathogenesis of COVID-19-related lung injury has been a matter of debate. A complete understanding of this central enzyme may begin to explain the various symptoms and pathologies seen in SARS-CoV-2 infected individuals, and may aid in the development of novel treatments for COVID-19.

Colonic Epithelial Angiotensin-Converting Enzyme 2 (ACE2) Expression in Blacks and Whites: Potential Implications for Pathogenesis Covid-19 Racial Disparities

Background

Covid-19 toll is disproportionate in Blacks although the mechanisms remain incompletely understood. From a biological perspective, several host proteins have received most attention as logical susceptibility targets. Specifically, angiotensin-converting enzyme 2 (ACE2) serves as the epithelial cell receptor and acts in concert with transmembrane protease serine 2 (TMPRSS2). Intriguingly, ACE2 can also suppress the inflammatory response and therefore may impact the severity of Covid-19 infections (from the exuberant immune response a.k.a. “cytokine storm”). We, therefore, assessed expression of ACE2 and TMPRSS2 in Blacks versus Whites.

Methods

Archived mucosal biopsies from colonoscopic biopsies of visually normal rectal mucosa without concurrent neoplasia or inflammation were used for this study. Total mRNA was isolated and subjected to real-time polymerase chain reaction for ACE2, and TMPRSS2 was assessed from non-Hispanic Blacks (n = 45) and non-Hispanic Whites (n = 38). GAPDH and beta-actin were used for normalization. Multivariable analysis was performed using Analyse-IT software.

Results

ACE2 and TMPRSS2 levels were not altered by gender, BMI, or age. ACE2 levels were lower in Blacks than Whites achieving statistical significance in multivariable (0.51-fold, p = 0.03) but not quite in univariable (p = 0.07) analysis. This downregulation was mirrored in TMRPSS2 in both univariable (p = 0.03) and multivariable analyses (0.41-fold, p = 0.02). Moreover, there was a strong correlation between ACE2 and TMPRSS2 levels (r-squared = 0.78).

Conclusions

To our knowledge, this is the first report on racial differences inACE2 and TMPRSS2 mucosal expression. This may provide potential biological underpinnings for the disproportionately higher mortality of Covid-19 in Blacks and should spur future studies.

Current Updates on Naturally Occurring Compounds Recognizing SARS-CoV-2 Druggable Targets

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been identified in China as the etiologic agent of the recent COVID-19 pandemic outbreak. Due to its high transmissibility, this virus quickly spread throughout the world, causing considerable health issues. The scientific community exerted noteworthy efforts to obtain therapeutic solutions for COVID-19, and new scientific networks were constituted. No certified drugs to efficiently inhibit the virus were identified, and the development of de-novo medicines requires approximately ten years of research. Therefore, the repurposing of natural products could be an effective strategy to handle SARS-CoV-2 infection. This review aims to update on current status of the natural occurring compounds recognizing SARS-CoV-2 druggable targets. Among the clinical trials actually recruited, some natural compounds are ongoing to examine their potential role to prevent and to treat the COVID-19 infection. Many natural scaffolds, including alkaloids, terpenes, flavonoids, and benzoquinones, were investigated by in-silico, in-vitro, and in-vivo approaches. Despite the large data set obtained by a computational approach, experimental evidences in most cases are not available. To fill this gap, further efforts to validate these results are required. We believe that an accurate investigation of naturally occurring compounds may provide insights for the potential treatment of COVID-19 patients.