Angiotensin-converting enzyme 2 (ACE2), SARS-CoV-2 and the pathophysiology of coronavirus disease 2019 (COVID-19)

Deep Phenotyping of Headache in Hospitalized COVID-19 Patients via Principal Component Analysis

Objectives: Headache is a common symptom in systemic infections, and one of the symptoms of the novel coronavirus disease 2019 (COVID-19). The objective of this study was to characterize the phenotype of COVID-19 headache via machine learning. Methods: We performed a cross-sectional study nested in a retrospective cohort. Hospitalized patients with COVID-19 confirmed diagnosis who described headache were included in the study. Generalized Linear Models and Principal Component Analysis were employed to detect associations between intensity and self-reported disability caused by headache, quality and topography of headache, migraine features, COVID-19 symptoms, and results from laboratory tests. Results: One hundred and six patients were included in the study, with a mean age of 56.6 ± 11.2, including 68 (64.2%) females. Higher intensity and/or disability caused by headache were associated with female sex, fever, abnormal platelet count and leukocytosis, as well as migraine symptoms such as aggravation by physical activity, pulsating pain, and simultaneous photophobia and phonophobia. Pain in the frontal area (83.0% of the sample), pulsating quality, higher intensity of pain, and presence of nausea were related to lymphopenia. Pressing pain and lack of aggravation by routine physical activity were linked to low C-reactive protein and procalcitonin levels. Conclusion: Intensity and disability caused by headache attributed to COVID-19 are associated with the disease state and symptoms. Two distinct headache phenotypes were observed in relation with COVID-19 status. One phenotype seems to associate migraine symptoms with hematologic and inflammatory biomarkers of severe COVID-19; while another phenotype would link tension-type headache symptoms to milder COVID-19.

COVID-19 and Body Iron: A Survey on Phenomenological and Genetic Correlations

To provide solid information about viral infection, disease, and body iron metabolism, the literature was surveyed for mutual correlations. Gender and age profiles of COVID-19 infection and disease correlate well with the profiles of serum iron and ferritin with correlation coefficients ≥ 0.75. There are further symptomatic hints that the ABO blood group system contributes to these correlations. Remarkably, the susceptibility to both the viral disease and iron dyshomeostasis can be traced back to the same gene loci of the ABO blood group system. The overlapping of susceptible gene loci together with the phenomenological correlations in gender and age are strong indicators for the interrelation of body iron dyshomeostasis with COVID-19 infection and disease.

Unexpected low burden of coronavirus disease 2019 (COVID-19) in sub-Saharan Africa region despite disastrous predictions: reasons and perspectives

The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is responsible for the development of a highly contagious disease called coronavirus disease (COVID-19). Ten months after the onset of the pandemic, America and Europe remain the most affected regions. Initially, experts predicted that Africa, the poorest continent with the most vulnerable population and health system, would be greatly affected by the ongoing outbreak. However, 240days after the first confirmed case, Africa is among the least affected region, with lower than expected incident cases and mortality. In this review, we discuss possible explanations and reasons for this unexpected low burden of COVID-19 in Africa. We focus on the characteristics of the virus, specificities of the sub-Saharan African population and local environment.

Severe Acute Respiratory Syndrome Coronavirus 2: The Importance of Prompt Detection of Cardiovascular Involvement

Increased morbidity and mortality are associated with coronavirus disease 2019 (COVID-19) when there is cardiovascular (CV) involvement. Due to the absence of prospective, well-designed, controlled studies, the exact mechanism responsible for cardiac injury among patients with COVID-19 remains uncertain. However, possible mechanisms described in observational studies can be considered. Non-ischemic events and ischemic myocardial involvement are the two main pathophysiological mechanisms of acute cardiac injury in COVID-19 patients. Non-ischemic myocardial injury is probably predominant and is secondary to multiple pathological mechanisms. Cardiac involvement is relatively common among hospitalized patients with COVID-19 and is associated with a greater risk of in-hospital mortality and ventricular arrhythmias. There was also a high and significantly positive linear correlation between troponin T and plasma high-sensitivity C-reactive protein levels. It is important to promptly detect CV involvement to avoid increased mortality in these patients. These findings highlight the importance of clinical surveillance and laboratory testing of serum troponin levels to ensure appropriate early identification and proceed with appropriate treatment. This should apply to patients with/without prior CV involvement. There are several possible mechanisms of myocardial tissue damage and the exact mechanisms involved need to be explored in well-designed studies.

Corticosteroid therapy is associated with the delay of SARS-CoV-2 clearance in COVID-19 patients

The impact of corticosteroid treatment on virological course of coronavirus disease 2019 (COVID-19) patients remains unclear. This study aimed to explore the association between corticosteroid and viral clearance in COVID-19. The clinical data of COVID-19 patients from 10 hospitals of Jiangsu, China, were retrospectively collected. Cox regression and Kaplan-Meier analysis were used to analyze the adverse factors of virus clearance. Of the 309 COVID-19 patients, eighty-nine (28.8%) patients received corticosteroid treatment during hospitalization. Corticosteroid group showed higher C-reactive protein (median 11.1 vs. 7.0 mg/l, P = 0.018) and lower lymphocytes (median 0.9 vs. 1.4 × 109/l, P < 0.001) on admission. Fever (93.3% vs. 65.0%, P < 0.001) and cough (69.7% vs. 57.3%, P = 0.043) were more common in corticosteroid group. The proportions of patients with severe illness (34.8% vs. 1.8%, P < 0.001), respiratory failure (25.8% vs. 1.4%, P < 0.001), acute respiratory distress syndrome (4.5% vs. 0%, P = 0.002), and admission to ICU (20.2% vs. 0.9%, P < 0.001) were significantly higher in corticosteroid group than non-corticosteroid group. The duration of virus clearance (median 18.0 vs. 16.0 days, P < 0.001) and hospitalization (median 17.0 vs. 15.0 days, P < 0.001) were also significantly longer in corticosteroid group than non-corticosteroid group. Treated with corticosteroid (Hazard ratio [HR], 0.698; 95% confidence interval [CI], 0.512 to 0.951; P = 0.023) was an adverse factor of the clearance of SARS-CoV-2, especially for male patients (HR, 0.620; 95% CI, 0.408 to 0.942; P = 0.025). The cumulative probability of SARS-CoV-2 clearance was lower in corticosteroid group (P < 0.001). Corticosteroid treatment may delay the SARS-CoV-2 clearance of COVID-19 patients and should be used with cautions.

New drug targets for hypertension: A literature review

Hypertension is one of the most prevalent cardiovascular diseases worldwide. However, in the population of resistant hypertension, blood pressure is difficult to control effectively. Moreover, antihypertensive drugs may have adverse effect currently. Hence, new therapeutic targets and treatments are needed to uncovered and exploited to control hypertension and its comorbidities. In the past, classical drug targets, such as the aldosterone receptor, aldosterone synthase, and ACE2/angiotensin 1-7/Mas receptor axis, have been investigated. Recently, vaccines and drugs targeting the gastrointestinal microbiome, which represent drug classes, have also been investigated for the management of blood pressure. In this review, we summarized current knowledge on classical and new drug targets and discussed the potential utility of new drugs in the treatment of hypertension.

Molecular Mechanisms Lead to Sex-Specific COVID-19 Prognosis and Targeted Therapies

Clinical and epidemiological studies have identified male sex as an important risk factor for COVID-19 clinical outcomes and mortality. This raises the question as to how this risk factor can be addressed in the prognosis, clinical management, and the treatment of patients with Coronavirus disease 2019 (COVID-19). Currently, there are no guidelines or protocols to help alter the course of sex-specific COVID-19 prognosis, especially in severe disease presentations. This is partly due to the lack of research studies characterizing the differences in male vs. female host response to the severe acute respiratory syndrome Coronavirus-2 (SARS-CoV-2) infection and a lack of a well-rounded understanding of the molecular mechanisms involved. Here, we discuss three distinct but interconnected molecular-level differences in males and females that likely play an essential role in the COVID-19 prognosis. We review interactions of SARS-CoV-2 with host cell angiotensin-converting enzyme 2 (ACE2) in the viral entry between males vs. females and discuss the differential regulation of the renin-angiotensin system (RAS) between the two sexes. Next, we present immune response disparities and how immune function and endocrine regulation may render males increasingly vulnerable to severe COVID-19. We describe the interconnected roles of these three regulatory systems in males and females in response to SARS-CoV-2 infection. Finally, we highlight the clinical implications of these mechanisms to patients with COVID-19 and propose putative targeted therapies that can help reduce COVID-19 severity in those critically ill.

Novel Molecular Evidence Related to COVID-19 in Patients with Diabetes Mellitus

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has rapidly evolved into a global pandemic. The hyperglycemia in patients with diabetes mellitus (DM) substantially compromises their innate immune system. SARS-CoV-2 uses human angiotensin-converting enzyme 2 (ACE2) receptors to enter the affected cell. Uncontrolled hyperglycemia-induced glycosylation of ACE2 and the S protein of SARS-CoV-2 could facilitate the binding of S protein to ACE2, enabling viral entry. Downregulation of ACE2 activity secondary to SARS-CoV-2 infection, with consequent accumulation of angiotensin II and metabolites, eventually leads to poor outcomes. The altered binding of ACE2 with SARS-CoV-2 and the compromised innate immunity of patients with DM increase their susceptibility to COVID-19; COVID-19 induces pancreatic β-cell injury and poor glycemic control, which further compromises the immune response and aggravates hyperglycemia and COVID-19 progression, forming a vicious cycle. Sequential cleavage of viral S protein by furin and transmembrane serine protease 2 (TMPRSS2) triggers viral entry to release the viral genome into the target cell. Hence, TMPRSS2 and furin are possible drug targets. As type 1 DM exhibits a Th1-driven autoimmune process, the relatively lower mortality of COVID-19 in type 1 DM compared to type 2 DM might be attributed to an imbalance between Th1 and Th2 immunity. The anti-inflammatory effects of dipeptidyl peptidase-4 inhibitor may benefit patients with DM and COVID-19. The potential protective effects of sodium-glucose cotransporter-2 inhibitor (SGLT2i), including reduction in lactate level, prevention of lowering of cytosolic pH and reduction in pro-inflammatory cytokine levels may justify the provision of SGLT2i to patients with DM and mild or asymptomatic COVID-19. For patients with DM and COVID-19 who require hospitalization, insulin-based treatment is recommended with cessation of metformin and SGLT2i. Further evidence from randomized or case-control clinical trials is necessary to elucidate the effectiveness and pitfalls of different types of medication for DM.

Body Localization of ACE-2: On the Trail of the Keyhole of SARS-CoV-2

The explosion of the new coronavirus (SARS-CoV-2) pandemic has brought the role of the angiotensin converting enzyme 2 (ACE2) back into the scientific limelight. Since SARS-CoV-2 must bind the ACE2 for entering the host cells in humans, its expression and body localization are critical to track the potential target organ of this infection and to outline disease progression and clinical outcomes. Here, we mapped the physiological body distribution, expression, and activities of ACE2 and discussed its potential correlations and mutal interactions with the disparate symptoms present in SARS-CoV-2 patients at the level of different organs. We highlighted that despite during SARS-CoV-2 infection ACE2-expressing organs may become direct targets, leading to severe pathological manifestations, and subsequent multiple organ failures, the exact mechanism and the potential interactions through which ACE2 acts in these organs is still heavily debated. Further scientific efforts, also considering a personalized approach aimed to consider specific patient differences in the mutual interactions ACE2-SARS-CoV-2 and the long-term health effects associated with COVID-19 are currently mandatory.

SARS-CoV-2 infection does not induce HIV viral escape in the central nervous system: A case series

We report two cases of HIV positive patients with SARS-CoV-2 infection and a recent diagnosis of opportunistic infections of central nervous system (CNS). We investigated the potential impact of coinfection with SARS-CoV-2 on HIV replication in CNS.

Cell-mediated immunity to SARS-CoV-2

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) viruses spread unscrupulously virtually every corner on the planet in a very quick speed leading to an unprecedented world pandemic of COVID-19 claiming a great many of people's life. Paramount importance has been given to the studies on the virus itself including genomic variation and viron structure, as well as cell entry pathway and tissue residence. Other than that, to learn the main characteristic of host immunity responding to SARS-CoV-2 infection is an eminent task for restraining virus and controlling disease progress. Beside antibody production in response to SARS-CoV-2 infection, host cellular immunity plays an indispensable role in impeding virus replication and expansion at various stages of COVID-19 disease. In this review, we summarized the recent knowledge regarding the aberrant regulation and dysfunction of multiple immune cells during SARS-CoV-2 infection. This includes the dysregulation of immune cell number, Th polarity, cytokine storm they implicated with, as well as cell function exhaustion after chronic virus stimulation. Notwithstanding that many obstacles remain to be overcome, studies on immunotherapy for COVID-19 treatment based on the known features of host immunity in response to SARS-CoV-2 infection offer us tangible benefits and hope for making this SARS-CoV-2 pandemic under control.

The impact of SARS-CoV-2 on skeletal muscles

In 2019-2020, the SARS-CoV-2 pandemic has shocked the world and most health care systems, and a “second wave” of the viral spread is ongoing in Europe and in Italy too. While, at the initial outbreak, the treatment of patients had focused on the respiratory symptoms, many diverse clinical manifestations of the disease have to date been reported. However, the complete course of the disease has not yet been fully clarified. In particular, several reports from the real-world clinical practice have highlighted the noxious effects of SARS-CoV-2 on skeletal muscles. In this brief review, we summarized the main current findings about muscular and neuromuscular damages that may be triggered by the virus or by the drugs used to treat COVID-19. Moreover, we underlined the need of attentive care and vigilance for patients with neuro-muscular disorders, who may be particularly susceptible to infection and at increased risk for severe COVID-19.

Maternal, fetal and neonatal outcomes of large series of SARS-CoV-2 positive pregnancies in peripartum period: A single-center prospective comparative study

OBJECTIVE

To describe the proportions of asymptomatic, mild and severe diseases in infected pregnant women admitted for delivery. To compare maternal, fetal and neonatal outcomes of SARS-CoV-2 infected pregnant women with those of non-infected patients.

STUDY DESIGN

Through an universal PCR testing for SARS-COV-2 at admission (not symptoms-based), this prospective cohort study enrolled all pregnant women admitted for delivery between 16th of June and the 16th of August 2020 in the West French Guiana Hospital Center.

RESULTS

507 pregnant women were included during the study period, of which 137 (27 %) were infected with SARS-COV-2. On admission, only 34/137 (24.8 %) of these patients presented with clinical symptoms. Among asymptomatic women, 16 /103 (15 %) became symptomatic after diagnosis. Throughout the delivery hospitalization and follow-up, 87/137 (63.5 %) remained always asymptomatic, 45/137 (32.8 %) developed a mild COVID-19 and 5/137 (3.6 %) developed a severe infection. SARS-CoV-2 infected patients were more likely to have post-partum hemorrhage >500 mL (14.2 % vs 7.2 %, RR 2.0 [95 %CI 1.1-3.4]), to be transfused (5.5 % vs 1.1 %, RR 4.9 [1.5-16.6]), and to be hospitalized in ICU (3.6 % vs 0.8 %, RR 4.5 [95 %CI 1.1-18.6] than uninfected ones. Intra-uterine fetal demises were more common in infected mothers compared to controls (5.1 % vs 1.1 %, RR 4.7 [95 % CI 1.4-45.9). Among 108 neonates from infected mothers tested at birth, none tested positive (0/108). When tested between 25 and 42 h after delivery, 4/29 (13.7 %) were positive for SARS-CoV-2 RT-PCR on nasopharyngeal swabs and remained asymptomatic.

CONCLUSION

Pregnant women admitted for delivery and diagnosed with a SARS-COV-2 infection through an universal screening were symptomatic in only a quarter of cases. Their risks of post-partum hemorrhage, transfusion and admission to ICU were higher than those of uninfected patients. They also presented a higher risk of intra-uterine fetal demise. There were no other differences in maternal, obstetrical or neonatal outcomes.

COVID-19 and the kidney: what we think we know so far and what we don't

The novel coronavirus disease infection (COVID-19) outbreak that was declared a global pandemic in March 2020 had led to an internationally variable but concerning incidence of COVID-associated acute kidney injury (AKI), with prevalence reported as high as 46% in large cohorts of hospitalized patients. Variability in AKI may be explained by differences in traditional risk factors for AKI, heterogeneity among patient cohorts, and differences in racial and ethnic groups. Further, AKI requiring kidney replacement therapies (KRT) has been associated with increased mortality. Proposed mechanisms of kidney injury include direct viral-induced tubular or glomerular injury, sepsis-associated AKI, and thrombotic disease. Kidney pathology include acute tubular injury, glomerular fibrin thrombi, pigmented tubular casts, and collapsing focal segmental glomerulosclerosis. "Viral-like" particles have been observed in renal samples at electron microscopy and viral RNA has been identified in both glomerular and tubular compartments of kidney specimens, but the link between viral presence and injury remain unclear. Though the link between AKI and poor outcomes is clear, prevalence and outcomes of COVID-19 in patients with chronic kidney disease and end stage kidney disease has not yet been reported. In patients on immunosuppression like those with kidney transplants or glomerular disease, COVID-19 has presented a management dilemma. Herein, we review the existing literature on kidney disease in COVID-19 and discuss what remains to be learned.

Possible silent hypoxemia in a COVID-19 patient: A case report

INTRODUCTION

It has been hypothesized that silent hypoxemia is the cause of rapid progressive respiratory failure with severe hypoxia that occurs in some COVID-19 patients without warning.

PRESENTATION OF CASE

A 60-year-old male presented cough without any breathing difficulty. Vital signs showed blood pressure 130/75 mmHg, pulse 84x/minute, respiratory rate (RR) 21x/minute, body temperature 36.5C, and oxygen saturation (SpO2) 75% on room air. RT-PCR for COVID-19 were positive. On third day, he complained of worsening of breath shortness, but his RR was still normal (22x/minute) with SpO2 of 98% on 3 L/minute oxygen via nasal cannula. On fifth day, he experienced severe shortness of breath with RR 38x/minute. He was then intubated using a synchronized intermittent mandatory ventilation. Blood gas analysis showed pH 7.54, PaO2 58.9 mmHg, PaCO2 31.1 mmHg, HCO3 26.9mEq/L, SaO2 94.7%, FiO2 30%, and P/F ratio 196 mmHg. On eighth day, his condition deteriorated with blood pressure 80/40 mmHg with norepinephrine support, pulse 109x/minute, and SpO2 72% with ventilator. He experienced cardiac arrest and underwent basic life support, then resumed strained breathing with return of spontaneous circulation. Blood gas analysis showed pH 7.07, PaO2 58.1 mmHg, PaCO2 108.9 mmHg, HCO3 32.1mEq/L, SaO2 78.7%, FiO2 90%, and P/F ratio 65 mmHg. Three hours later, he suffered cardiac arrest again and eventually died.

DISCUSSION

Possible mechanisms of silent hypoxemia are V/Q mismatch, intrapulmonary shunting, and intravascular microthrombi.

CONCLUSIONS

Silent hypoxemia might be considered as an early sign of deterioration of COVID-19 patients, thus, physician may be able to intervene early and decrease its morbidity and mortality.

Coronavirus disease 2019-Historical context, virology, pathogenesis, immunotherapy, and vaccine development

The current Coronavirus Disease 2019 (COVID-19) pandemic is causing great alarm around the world. The pathogen for COVID-19 - severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) - is the seventh known coronavirus to cause pneumonia in humans. While much remains unknown about SARS-CoV-2, physicians and researchers have begun to publish relevant findings, and much evidence is available on coronaviruses previously circulating in human and animal populations. In this review, we situate COVID-19 in its context as a transboundary viral disease, and provide a comprehensive discussion focused on the discovery, spread, virology, pathogenesis, and clinical features of this disease, its causative coronaviral pathogen, and approaches to combating the disease through immunotherapies and other treatments and vaccine development. An epidemiological survey revealed a potentially large number of asymptomatic SARS-CoV-2 carriers within the population, which may hamper efforts against COVID-19. Finally, we emphasize that vaccines against SARS-CoV-2, which may be developed by 2021, will be essential for prevention of COVID-19.

COVID-19 in Elderly Adults: Clinical Features, Molecular Mechanisms, and Proposed Strategies

Coronavirus disease 2019 (COVID-19) is causing problems worldwide. Most people are susceptible to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), but elderly populations are more susceptible. Elevated susceptibility and death rates in elderly COVID-19 patients, especially those with age-related complications, are challenges for pandemic prevention and control. In this paper, we review the clinical features of elderly patients with COVID-19 and explore the related molecular mechanisms that are essential for the exploration of preventive and therapeutic strategies in the current pandemic. Furthermore, we analyze the feasibility of currently recommended potential novel methods against COVID-19 among elderly populations.

Controlling Cytokine Storm Is Vital in COVID-19

Corona virus disease 2019 (COVID-19) has caused a global outbreak and severely posed threat to people's health and social stability. Mounting evidence suggests that immunopathological changes, including diminished lymphocytes and elevated cytokines, are important drivers of disease progression and death in coronavirus infections. Cytokine storm not only limits further spread of virus in the body but also induces secondary tissue damage through the secretion of large amounts of active mediators and inflammatory factors. It has been determined that cytokine storm is a major cause of deaths in COVID-19; therefore, in order to reverse the deterioration of severe and critically ill patients from this disease, the cytokine storm has become a key therapeutic target. Although specific mechanisms of the occurrences of cytokine storms in COVID-19 have not been fully illuminated, hyper-activated innate immune responses, and dysregulation of ACE2 (angiotensin converting enzyme 2) expression and its downstream pathways might provide possibilities. Tailored immunoregulatory therapies have been applied to counteract cytokine storms, such as inhibition of cytokines, corticosteroids, blood purification therapy, and mesenchymal stem cell therapy. This review will summarize advances in the research of cytokine storms induced by COVID-19, as well as potential intervention strategies to control cytokine storms.

Challenges and stepwise fit-for-purpose optimization for bioanalyses of remdesivir metabolites nucleotide monophosphate and triphosphate in mouse tissues using LC-MS/MS

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A robust and reliable LC–MS/MS method for the quantification of RMP and RTP was optimized and validated.

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The novel method solved the major challenges of direct determination of RMP and RTP in biological matrix through improvement of LC retention, stability and recovery.

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The method was validated and successfully applied to mouse tissue distribution study.

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This method provides useful information for further study of remdesivir as well as extends the approach for phosphate determination.

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The method solved the major challenges for determining RMP and RTP in biological matrix such as LC retention, stability and recovery.

Remdesivir is a prodrug of the nucleotide analogue and used for COVID-19 treatment. However, the bioanalysis of the active metabolites remdesivir nucleotide triphosphate (RTP) and its precursor remdesivir nucleotide monophosphate (RMP) is very challenging. Herein, we established a novel method to separate RTP and RMP on a BioBasic AX column and quantified them by high-performance liquid chromatography-tandem mass spectrometry in positive electrospray ionization mode. Stepwise, we optimized chromatographic retention on an anion exchange column, improved stability in matrix through the addition of 5,5′-dithiobis-(2nitrobenzoic acid) and PhosSTOP EASYpack, and increased recovery by dissociation of tight protein binding with 2 % formic acid aqueous solution. The method allowed lower limit of quantification of 20 nM for RMP and 10 nM for RTP. Method validation demonstrated acceptable accuracy (93.6%–103% for RMP, 94.5%–107% for RTP) and precision (RSD < 11.9 % for RMP, RSD < 11.4 % for RTP), suggesting that it was sensitive and robust for simultaneous quantification of RMP and RTP. The method was successfully applied to analyze RMP and RTP in mouse tissues. In general, the developed method is suitable to monitor RMP and RTP, and provides a useful approach for exploring more detailed effects of remdesivir in treating diseases.

The potential role of serum angiotensin-converting enzyme in coronavirus disease 2019

BACKGROUND

To explore the clinical significance of serum angiotensin-converting enzyme (ACE) activity in coronavirus disease 2019 (COVID-19).

METHODS

In this retrospective study, a total of 136 consecutive patients with confirmed COVID-19 were recruited. Demographic and clinical data were recorded. The serum ACE activity was measured at baseline and during the recovery phase, and its relationship with clinical condition was analyzed.

RESULTS

Of the 136 patients with confirmed COVID-19, the 16 severe patients were older and had a higher body mass index (BMI) and proportion of hypertension than the 120 nonsevere patients. In comparison to those of normal controls, the baseline serum ACE activities of subjects in the severe group and nonsevere group were decreased, with the lowest level in the severe group. However, the serum ACE activity increased in the recovery phase, and there were no significant differences among the severe group, nonsevere group and normal control group.

CONCLUSION

Serum ACE activity could be used as a marker to reflect the clinical condition of COVID-19 since low activity was associated with the severity of COVID-19 at baseline, and the activity increased with the remission of the disease.

Environmental Nanoparticles, SARS-CoV-2 Brain Involvement, and Potential Acceleration of Alzheimer's and Parkinson's Diseases in Young Urbanites Exposed to Air Pollution

Alzheimer's and Parkinson's diseases (AD, PD) have a pediatric and young adult onset in Metropolitan Mexico City (MMC). The SARS-CoV-2 neurotropic RNA virus is triggering neurological complications and deep concern regarding acceleration of neuroinflammatory and neurodegenerative processes already in progress. This review, based on our MMC experience, will discuss two major issues: 1) why residents chronically exposed to air pollution are likely to be more susceptible to SARS-CoV-2 systemic and brain effects and 2) why young people with AD and PD already in progress will accelerate neurodegenerative processes. Secondary mental consequences of social distancing and isolation, fear, financial insecurity, violence, poor health support, and lack of understanding of the complex crisis are expected in MMC residents infected or free of SARS-CoV-2. MMC residents with pre-SARS-CoV-2 accumulation of misfolded proteins diagnostic of AD and PD and metal-rich, magnetic nanoparticles damaging key neural organelles are an ideal host for neurotropic SARS-CoV-2 RNA virus invading the body through the same portals damaged by nanoparticles: nasal olfactory epithelium, the gastrointestinal tract, and the alveolar-capillary portal. We urgently need MMC multicenter retrospective-prospective neurological and psychiatric population follow-up and intervention strategies in place in case of acceleration of neurodegenerative processes, increased risk of suicide, and mental disease worsening. Identification of vulnerable populations and continuous effort to lower air pollution ought to be critical steps.

SARS-CoV-2 cell receptor gene ACE2 -mediated immunomodulation in breast cancer subtypes

The recent outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has impacted the world severely. The binding of the SARS-CoV-2 virus to the angiotensin-converting enzyme 2 (ACE2) and its intake by the host cell is a necessary step for infection. ACE2 has garnered widespread therapeutic possibility as it is entry/interactive point for SARS-CoV-2, responsible for coronavirus disease 2019 (COVID-19) pandemic and providing a critical regulator for immune modulation in various disease. Patients with suffering from cancer always being on the verge of being immune compromised therefore gaining knowledge about how SARS-CoV-2 viruses affecting immune cells in human cancers will provides us new opportunities for preventing or treating virus-associated cancers. Despite COVID-19 pandemic got center stage at present time, however very little research being explores, which increase our knowledge in context with how SARS-CoV-2 infection affect cancer a cellular level. Therefore, in light of the ACE-2 as an important contributor of COVID-19 global, we analyzed correlation between ACE2 and tumor immune infiltration (TIL) level and the type markers of immune cells were investigated in breast cancer subtypes by using TIMER database. Our findings shed light on the immunomodulatory role of ACE2 in the luminal A subtype which may play crucial role in imparting therapeutic resistance in this cancer subtype.

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The recent outbreak of Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has impacted the world severely.

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The binding of the SARS-CoV-2 virus to the angiotensin-converting enzyme 2 (ACE2) and its intake of this complex by the host cell is a necessary step for infection.

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We reported that the differential gene expression of ACE2 defines its pathological role in each molecular subtype of breast cancer differently.

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Our analysis suggested that the expression of ACE2 gene may relate to immune function in luminal A subtype of breast cancer.

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This study is much significant in context with current pandemic in which ACE2 inhibitors are widely used for the COVD-19 treatment.

The emerging role of neutrophil extracellular traps in severe acute respiratory syndrome coronavirus 2 (COVID-19)

The novel coronavirus SARS-CoV-2 causes COVID-19, a highly pathogenic viral infection threatening millions. The majority of the individuals infected are asymptomatic or mildly symptomatic showing typical clinical signs of common cold. However, approximately 20% of the patients can progress to acute respiratory distress syndrome (ARDS), evolving to death in about 5% of cases. Recently, angiotensin-converting enzyme 2 (ACE2) has been shown to be a functional receptor for virus entry into host target cells. The upregulation of ACE2 in patients with comorbidities may represent a propensity for increased viral load and spreading of infection to extrapulmonary tissues. This systemic infection is associated with higher neutrophil to lymphocyte ratio in infected tissues and high levels of pro-inflammatory cytokines leading to an extensive microthrombus formation with multiorgan failure. Herein we investigated whether SARS-CoV-2 can stimulate extracellular neutrophils traps (NETs) in a process called NETosis. We demonstrated for the first time that SARS-CoV-2 in fact is able to activate NETosis in human neutrophils. Our findings indicated that this process is associated with increased levels of intracellular Reactive Oxygen Species (ROS) in neutrophils. The ROS-NET pathway plays a role in thrombosis formation and our study suggest the importance of this target for therapy approaches against disease.

ACE2: Evidence of role as entry receptor for SARS-CoV-2 and implications in comorbidities

Pandemic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes coronavirus 19 disease (COVID-19) which presents a large spectrum of manifestations with fatal outcomes in vulnerable people over 70-years-old and with hypertension, diabetes, obesity, cardiovascular disease, COPD, and smoking status. Knowledge of the entry receptor is key to understand SARS-CoV-2 tropism, transmission and pathogenesis. Early evidence pointed to angiotensin-converting enzyme 2 (ACE2) as SARS-CoV-2 entry receptor. Here, we provide a critical summary of the current knowledge highlighting the limitations and remaining gaps that need to be addressed to fully characterize ACE2 function in SARS-CoV-2 infection and associated pathogenesis. We also discuss ACE2 expression and potential role in the context of comorbidities associated with poor COVID-19 outcomes. Finally, we discuss the potential co-receptors/attachment factors such as neuropilins, heparan sulfate and sialic acids and the putative alternative receptors, such as CD147 and GRP78.

Potential Therapeutic Effect of Traditional Chinese Medicine on Coronavirus Disease 2019: A Review

The Coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 has been rapidly spreading globally and has caused worldwide social and economic disruption. Currently, no specific antiviral drugs or clinically effective vaccines are available to prevent and treat COVID-19. Traditional Chinese medicine (TCM) can facilitate syndrome differentiation and treatment according to the clinical manifestations of patients and has demonstrated effectiveness in epidemic prevention and control. In China, TCM intervention has helped to control the epidemic; however, TCM has not been fully recognized worldwide. In this review, we summarize the epidemiology and etiological characteristics of severe acute respiratory syndrome coronavirus 2 and the prevention and treatment measures of COVID-19. Additionally, we describe the application of TCM in the treatment of COVID-19 and the identification of small molecules of TCM that demonstrate anti-coronavirus activity. We also analyze the current problems associated with the recognition of TCM. We hope that, through the contribution of TCM, combined with modern technological research and the support of our international counterparts, COVID-19 can be effectively controlled and treated.

A review of vaccine effects on women in light of the COVID-19 pandemic

The pandemic situation triggered by the spread of COVID-19 has caused great harm worldwide. More than six million people have been infected, and more than 360,000 of them have died. This is the worst catastrophe suffered by mankind in recent history. In the face of this severe disaster, people all over the world are frightened of the prospect of facing an outbreak or an annual recurrence. However, the development of a vaccine will help control the impact of COVID-19. Women in particular have been more seriously affected by the pandemic. Since the pressure and physical load they suffer are often greater than what men endure, women are more threatened by COVID-19. Though women have a poorer quality of life and work and face worse economic conditions, they also tend to have better physiological immunity than men, which can ease the effect of COVID-19. The early development of a vaccine against COVID-19 is an important issue that must take into consideration women's better immune response to the virus along with the technique of hormone regulation. Relevant research has been conducted on female-specific vaccines in the past, and women's issues were considered during those clinical trials to ensure that complications and antibody responses were positive and effective in women. National policies should also propose good strategies for women to be vaccinated. This could improve consciousness, give women a better vaccination experience, enhance their willingness to vaccinate, and protect them from COVID-19 infection.

Nutritional status of patients with COVID-19

The relationship between immunity and nutrition is well known and its role in coronavirus disease 2019 (COVID-19) is also being paid great attention. However, the nutritional status of COVID-19 patients is unknown. Vitamin B1, B6, B12, vitamin D (25-hydroxyvitamin D), folate, selenium, and zinc levels were measured in 50 hospitalized patients with COVID-19. Overall, 76% of the patients were vitamin D deficient and 42% were selenium deficient. No significant increase in the incidence of deficiency was found for vitamins B1, B6, and B12, folate, and zinc in patients with COVID-19. The COVID-19 group showed significantly lower vitamin D values than the healthy control group (150 people, matched by age/sex). Severe vitamin D deficiency (based on a cut-off of ≤10 ng/dl) was found in 24.0% of the patients in the COVID-19 group and 7.3% in the control group. Among 12 patients with respiratory distress, 11 (91.7%) were deficient in at least one nutrient. However, patients without respiratory distress showed a deficiency in 30/38 cases (78.9%; p =  0.425). These results suggest that a deficiency of vitamin D or selenium may decrease the immune defenses against COVID-19 and cause progression to severe disease. However, more precise and large-scale studies are needed.

Hypertension is a risk factor for adverse outcomes in patients with coronavirus disease 2019: a cohort study

BACKGROUND

Comorbidities are commonly seen in patients with coronavirus disease 2019 (COVID-19), but the clinical implication is not yet well-delineated. We aim to characterize the prevalence and clinical implications of comorbidities in patients with COVID-19.

METHODS

This is a retrospective multi-centre study involving patients admitted between January 16th and March 10th 2020. The composite endpoint was defined as the presence of at least one of the following, intensive care unit (ICU) admission, or the need for mechanical ventilation, or death.

RESULTS

A total of 472 consecutive cases admitted to 51 certified COVID-19 tertiary care hospitals were enrolled (median age was 43 [32-53.5] years and 53.0% were male). There were 101 (21.4%) patients presented with comorbidities, including hypertension (15.0%), diabetes mellitus (7.8%), coronary artery disease (2.6%), chronic obstructive pulmonary disease (1.3%) and cerebrovascular disease (1.9%). The composite endpoint occurred in 65 (13.8%) patients. Multivariate stepwise logistic regression analysis indicated that older age (odds ratio [OR] 1.39, 95% confidence interval (CI) 1.05-1.85, per 10-year increment), antecedent hypertension (OR 2.82, 95% CI 1.09-7.29), neutrophil counts (OR 1.33, 95% CI 1.14-1.56) and lactate dehydrogenase level (OR 1.01, 95% CI 1.00-1.01) were independently associated with the presence of composite endpoint. Hypertensive patients, compared with controls, had a greater chance of experiencing the composite endpoint (p < .001) and each individual endpoint, i.e. ICU admission (p < .001), mechanical ventilation (p < .001) and death (p = .012). In the stepwise regression analysis of anti-hypertensive medications, none of the therapy predicted the composite endpoint.

CONCLUSIONS

Hypertension is a common comorbidity in patients with COVID-19 and associated with adverse outcomes. KEY MESSAGES Hypertension was identified as the comorbidity associated with the prognosis of COVID-19 in this retrospective cohort. Patients with hypertension could experience an increased risk of the composite endpoint. Anti-hypertensive therapy did not affect patient outcomes.

Male predisposition to severe COVID-19: Review of evidence and potential therapeutic prospects

The severe form of COVID-19 has significant sex disparities, with high fatalities commonly reported among males than females. The incidence of COVID-19 has also been higher in males compared with their female counterparts. This trend could be attributed to a better responsive and robust immune system in females. Cytokine storm is one of the pathophysiological features of severe COVID-19, and it occurs as a result of over-activation of immune cells leading to severe inflammation and tissue damage. Nevertheless, it is well modulated in females compared to their male counterparts. Severe inflammation in males is reported to facilitate progression of mild to severe COVID-19. The sex hormones, estrogens and androgens which exist in varying functional levels respectively in females and males are cited as the underlying cause for the differential immune response to COVID-19. Evidence abounds that estrogen modulate the immune system to protect females from severe inflammation and for that matter severe COVID-19. On the contrary, androgen has been implicated in over-activation of immune cells, cytokine storm and the attendant severe inflammation, which perhaps predispose males to severe COVID-19. In this review efforts are made to expand understanding and explain the possible roles of the immune system, the sex hormones and the angiotensin-converting enzyme (ACE) systems in male bias to severe COVID-19. Also, this review explores possible therapeutic avenues including androgen deprivation therapy (ADT), estrogen-based therapy, and ACE inhibitors for consideration in the fight against COVID-19.

Long-Term Respiratory and Neurological Sequelae of COVID-19

Since the initial reports of coronavirus disease 2019 (COVID-19) in China in late 2019, infections from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have spread rapidly, resulting in a global pandemic that has caused millions of deaths. Initially, the large number of infected people required the direction of global healthcare resources to provide supportive care for the acutely ill population in an attempt to reduce mortality. While clinical trials for safe and effective antiviral agents are ongoing, and vaccine development programs are being accelerated, long-term sequelae of SARS-CoV-2 infection have become increasingly recognized and concerning. Although the upper and lower respiratory tracts are the main sites of entry of SARS-CoV-2 into the body, resulting in COVID-19 pneumonia as the most common presentation, acute lung damage may be followed by pulmonary fibrosis and chronic impairment of lung function, with impaired quality of life. Also, increasing reports have shown that SARS-CoV-2 infection involves the central nervous system (CNS) and the peripheral nervous system (PNS) and directly or indirectly damages neurons, leading to long-term neurological sequelae. This review aims to provide an update on the mechanisms involved in the development of the long-term sequelae of SARS-CoV-2 infection in the 3 main areas of lung injury, neuronal injury, and neurodegenerative diseases, including Alzheimer disease, Parkinson disease, and multiple sclerosis, and highlights the need for patient monitoring following the acute stage of infection with SARS-CoV-2 to provide a rationale for the prevention, diagnosis, and management of these potential long-term sequelae.

Inflammation and thrombosis in COVID-19 pathophysiology: proteinase-activated and purinergic receptors as drivers and candidate therapeutic targets

Evolving information has identified disease mechanisms and dysregulation of host biology that might be targeted therapeutically in coronavirus disease 2019 (COVID-19). Thrombosis and coagulopathy, associated with pulmonary injury and inflammation, are emerging clinical features of COVID-19. We present a framework for mechanisms of thrombosis in COVID-19 that initially derive from interaction of SARS-CoV-2 with ACE2, resulting in dysregulation of angiotensin signaling and subsequent inflammation and tissue injury. These responses result in increased signaling by thrombin (proteinase-activated) and purinergic receptors, which promote platelet activation and exert pathological effects on other cell types (e.g., endothelial cells, epithelial cells, and fibroblasts), further enhancing inflammation and injury. Inhibitors of thrombin and purinergic receptors may, thus, have therapeutic effects by blunting platelet-mediated thromboinflammation and dysfunction in other cell types. Such inhibitors include agents (e.g., anti-platelet drugs) approved for other indications, and that could be repurposed to treat, and potentially improve the outcome of, COVID-19 patients. COVID-19, caused by the SARS-CoV-2 virus, drives dysregulation of angiotensin signaling, which, in turn, increases thrombin-mediated and purinergic-mediated activation of platelets and increase in inflammation. This thromboinflammation impacts the lungs and can also have systemic effects. Inhibitors of receptors that drive platelet activation or inhibitors of the coagulation cascade provide opportunities to treat COVID-19 thromboinflammation.

Effects of the severe acute respiratory syndrome coronavirus (SARS-CoV) and the Middle East respiratory syndrome coronavirus (MERS-CoV) on the nervous system. What can we expect from SARS -CoV-2?

Coronaviruses cause respiratory and gastrointestinal disorders in animals and humans. The current SARS-CoV-2, the COVID-19 infectious agent, belongs to a subgroup called betacoronavirus including the SARS-CoV and MERS-CoV responsible for epidemics in 2002 and 2012, respectively. These viruses can also infect the nervous system due to their affinity for the human angiotensin-converting enzyme 2 (ACE2) expressed in neurons and glial cells. Infections with SARS-CoV, MERS-CoV, and now SARS-CoV-2 also produce neurological signs such as acute cerebrovascular disease, impaired consciousness, and muscle injury, as well as dizziness, hypogeusia, hyposmia, hypoxia, neuralgia, and hypoxic encephalopathy. For this reason, close attention should be paid to the neurological manifestations of COVID-19 patients.

Emerging Mechanisms of Pulmonary Vasoconstriction in SARS-CoV-2-Induced Acute Respiratory Distress Syndrome (ARDS) and Potential Therapeutic Targets

The 1918 influenza killed approximately 50 million people in a few short years, and now, the world is facing another pandemic. In December 2019, a novel coronavirus named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused an international outbreak of a respiratory illness termed coronavirus disease 2019 (COVID-19) and rapidly spread to cause the worst pandemic since 1918. Recent clinical reports highlight an atypical presentation of acute respiratory distress syndrome (ARDS) in COVID-19 patients characterized by severe hypoxemia, an imbalance of the renin-angiotensin system, an increase in thrombogenic processes, and a cytokine release storm. These processes not only exacerbate lung injury but can also promote pulmonary vascular remodeling and vasoconstriction, which are hallmarks of pulmonary hypertension (PH). PH is a complication of ARDS that has received little attention; thus, we hypothesize that PH in COVID-19-induced ARDS represents an important target for disease amelioration. The mechanisms that can promote PH following SARS-CoV-2 infection are described. In this review article, we outline emerging mechanisms of pulmonary vascular dysfunction and outline potential treatment options that have been clinically tested.

Case Report: Paralytic Ileus: A Potential Extrapulmonary Manifestation of Severe COVID-19

The COVID-19 pandemic has recently spread worldwide, presenting primarily in the form of pneumonia or other respiratory disease. In addition, gastrointestinal manifestations have increasingly been reported as one of the extrapulmonary features of the virus. We report two cases of SARS-CoV-2 infection complicated by paralytic ileus. The first patient was a 33-year-old man who was hospitalized with severe COVID-19 pneumonia requiring ventilator support and intensive care. He developed large bowel dilatation and perforation of the mid-transverse colon, and underwent laparotomy and colonic resection. Histopathology of the resected bowel specimen showed acute inflammation, necrosis, and hemorrhage, supporting a role for COVID-19–induced micro-thrombosis leading to perforation. The second patient was a 33-year-old man who had severe COVID-19 pneumonia, renal failure, and acute pancreatitis. His hospital course was complicated with paralytic ileus, and he improved with conservative management. Both cases were observed to have elevated liver transaminases, which is consistent with other studies. Several authors have postulated that the angiotensin-converting enzyme 2 receptors, the host receptors for COVID-19, that are present on enterocytes in both the small and large bowel might mediate viral entry and resultant inflammation. This is a potential mechanism of paralytic ileus in cases of severe COVID-19 infection. Recognizing paralytic ileus as a possible complication necessitates timely diagnosis and management.

The Landscape of Coronavirus Disease 2019 (COVID-19) and Integrated Analysis SARS-CoV-2 Receptors and Potential Inhibitors in Lung Adenocarcinoma Patients

The outbreak of novel coronavirus disease 2019 (COVID-19) has become the largest health threat worldwide, with more than 34.40 million positive cases and over 1.02 million deaths confirmed. In this study, we confirmed that significantly differentially expressed genes in COVID-19 patients were mainly involved in the regulation of immune and inflammation-related signaling pathways. It is worth noting that many infected COVID-19 patients have malignant tumors, and their prognosis is poor. To explore the susceptibility factors of cancer patients, we assessed the expression of ACE2, TMPRSS2, and the endocytic regulator AAK1 in lung adenocarcinoma (LUAD) patients and explored their effects on immune infiltration. We found that the expression of ACE2 and TMPRSS2 in LUAD patients was significantly increased, which may explain why LUAD patients are susceptible to SARS-CoV-2, and the patients with high-expression genes presented increased infiltration of immune cells such as B cells and CD4 T cells. In addition, we also identified miR-432-5p as a potential targeted molecule and bexarotene as a potential targeted drug of the three genes through bioinformatic analysis and further verified the anti-inflammatory effect of bexarotene, providing new ideas for the treatment of COVID-19.

The Cross-Talk between Age, Hypertension and Inflammation in COVID-19 Patients: Therapeutic Targets

This paper presents a brief overview of the complex interaction between age, hypertension, the renin–angiotensin–aldosterone system (RAAS), inflammation, and severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) infection. Coronavirus disease 2019 (COVID-19) is more frequent and more severe in comorbid elderly patients, especially those with hypertension, diabetes, obesity, or cardiovascular diseases. There are concerns regarding the use of RAAS inhibitors in patients with COVID-19. Some physicians have considered the need for interrupting RAAS inhibition in order to reduce the possibility of SARS-CoV2 entering lung cells after binding to angiotensin-converting enzyme 2 (ACE2) receptors. We offer a different point of view in relation to the need for continuing to use RAAS inhibitors in patients with COVID-19. We focused our article on elderly patients because of the distinctive imbalance between the immune response, which is depressed, and the exacerbated inflammatory response, ‘inflammaging’, which makes the geriatric patient an appropriate candidate for therapeutic strategies aimed at modulating the inflammatory response. Indeed, COVID-19 is an inflammatory storm that starts and worsens during the course of the disease. During the COVID-19 pandemic, various therapeutic approaches have been tested, including antiviral drugs, interferon, anti-interleukins, hydroxychloroquine, anti-inflammatories, immunoglobulins from recovered patients, and heparins. Some of these therapeutic approaches did not prove to be beneficial, or even induced serious complications. Based on current evidence, in the early stages of the disease modulation of the inflammatory response through the inhibition of neprilysin and modulation of the RAAS could affect the course and outcome of COVID-19.

Protein-driven mechanism of multiorgan damage in COVID-19

We propose a new plausible mechanism by mean of which SARS-CoV-2 produces extrapulmonary damages in severe COVID-19 patients. The mechanism consist on the existence of vulnerable proteins (VPs), which are (i) mainly expressed outside the lungs; (ii) their perturbations is known to produce human diseases; and (iii) can be perturbed directly or indirectly by SARS-CoV-2 proteins. These VPs are perturbed by other proteins, which are: (i) mainly expressed in the lungs, (ii) are targeted directly by SARS-CoV-2 proteins, (iii) can navigate outside the lungs as cargo of extracellular vesicles (EVs); and (iv) can activate VPs via subdiffusive processes inside the target organ. Using bioinformatic tools and mathematical modeling we identifies 26 VPs and their 38 perturbators, which predict extracellular damages in the immunologic endocrine, cardiovascular, circulatory, lymphatic, musculoskeletal, neurologic, dermatologic, hepatic, gastrointestinal, and metabolic systems, as well as in the eyes. The identification of these VPs and their perturbators allow us to identify 27 existing drugs which are candidates to be repurposed for treating extrapulmonary damage in severe COVID-19 patients. After removal of drugs having undesirable drug-drug interactions we select 7 drugs and one natural product: apabetalone, romidepsin, silmitasertib, ozanezumab, procaine, azacitidine, amlexanox, volociximab, and ellagic acid, whose combinations can palliate the organs and systems found to be damaged by COVID-19. We found that at least 4 drugs are needed to treat all the multiorgan damages, for instance: the combination of romidepsin, silmitasertib, apabetalone and azacitidine.

COVID-19 and liver disease: An update

The SARS-CoV-2 pandemic has proven to be a serious challenge for the Spanish healthcare system. The impact of the virus on the liver is not well known, but in patients with chronic liver disease, mostly in advanced stages, it can critically compromise survival and trigger decompensation. Treatment in this subpopulation is complex due to the potential hepatotoxicity of some of the medicinal products used. Moreover, the pandemic has also negatively impacted patients with liver disease who have not contracted COVID-19, since the reallocation of human and material resources to the care of patients with the virus has resulted in a decrease in the treatment, diagnosis and follow-up of patients with liver disease, which will surely have negative consequences in the near future. Efficient reorganization of hepatology units is a priority to minimise the impact of the pandemic on a population as vulnerable as liver disease patients.

Stabilizing Cellular Barriers: Raising the Shields Against COVID-19

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its clinical manifestation (COVID-19; coronavirus disease 2019) have caused a worldwide health crisis. Disruption of epithelial and endothelial barriers is a key clinical turning point that differentiates patients who are likely to develop severe COVID-19 outcomes: it marks a significant escalation in respiratory symptoms, loss of viral containment and a progression toward multi-organ dysfunction. These barrier mechanisms are independently compromised by known COVID-19 risk factors, including diabetes, obesity and aging: thus, a synergism between these underlying conditions and SARS-CoV-2 mechanisms may explain why these risk factors correlate with more severe outcomes. This review examines the key cellular mechanisms that SARS-CoV-2 and its underlying risk factors utilize to disrupt barrier function. As an outlook, we propose that glucagon-like peptide 1 (GLP-1) may be a therapeutic intervention that can slow COVID-19 progression and improve clinical outcome following SARS-CoV-2 infection. GLP-1 signaling activates barrier-promoting processes that directly oppose the pro-inflammatory mechanisms commandeered by SARS-CoV-2 and its underlying risk factors.

Findings of Hepatic Severe Acute Respiratory Syndrome Coronavirus-2 Infection

BACKGROUND & AIMS

Liver injury due to coronavirus disease 2019 (COVID-19) is being increasingly recognized. Abnormal liver chemistry tests of varying severities occur in a majority of patients. However, there is a dearth of accompanying liver histologic studies in these patients.

METHODS

The current report details the clinical courses of 2 patients having severe COVID-19 hepatitis. Liver biopsies were analyzed under light microscopy, portions of liver tissue were hybridized with a target probe to the severe acute respiratory syndrome coronavirus-2 S gene, and small sections from formalin-fixed paraffin-embedded liver tissue were processed for electron microscopy.

RESULTS

The liver histology of both cases showed a mixed inflammatory infiltrate with prominent bile duct damage, endotheliitis, and many apoptotic bodies. In situ hybridization and electron microscopy suggest the intrahepatic presence of severe acute respiratory syndrome coronavirus-2, the findings of which may indicate the possibility of direct cell injury.

CONCLUSIONS

On the basis of the abundant apoptosis and severe cholangiocyte injury, these histopathologic changes suggest a direct cytopathic injury. Furthermore, some of the histopathologic changes may resemble acute cellular rejection occurring after liver transplantation. These 2 cases demonstrate that severe COVID-19 hepatitis can occur even in the absence of significant involvement of other organs.

Investigation of angiotensin-I-converting enzyme (ACE) inhibitory tri-peptides: a combination of 3D-QSAR and molecular docking simulations

Angiotensin-I-converting enzyme (ACE) is a key enzyme in the regulation of peripheral blood pressure and electrolyte homeostasis. Therefore, ACE is considered as a promising target for treatment of hypertension. In the present work, in order to investigate the binding interactions between ACE and tri-peptides, three-dimensional quantitative structure-activity relationship (3D-QSAR) models using comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) methods were developed. Three different alignment methods (template ligand-based, docking-based, and common scaffold-based) were employed to construct reliable 3D-QSAR models. Statistical parameters derived from the QSAR models indicated that the template ligand-based CoMFA (R cv 2 = 0.761, R pred 2 = 0.6257) and CoMSIA (R cv 2 = 0.757, R pred 2 = 0.6969) models were better than the other alignment-based models. In addition, molecular docking studies were carried out to predict the binding modes of the peptides to ACE. The peptide-enzyme interactions were consistent with the derived 3D contour maps. Overall, the insights gained from this study would offer theoretical references for understanding the mechanism of action of tri-peptides when binding to ACE and aid in the design of more potent tri-peptides.

Single cell sequencing unraveling genetic basis of severe COVID19 in obesity

COVID-19 has shown a substantial variation in the rate and severity by which it impacts different demographic groups. Specifically, it has shown a predilection towards obese patients as well as well as other vulnerable groups including predilection of males over females, old age over young age and black races over Caucasian ones. Single cell sequencing studies have highlighted the role of cell polarity and the co-expression of proteases, such as Furin, along with ACE2 in the genesis of coronavirus disease rather than exclusively link tissue involvement with ACE2 levels thought previously. It has also forged a connection between the genetic and immune cellular mechanisms underlying COVID infection and the inflammatory state of obese patients, offering a more accurate explanation as to why obese patients are at increased risk of poor COVID outcomes. These commonalities encompass macrophage phenotype switching, genetic expression switching, and overexpression of the pro-inflammatory cytokines, depletion of the regulatory cytokines, in situ T cell proliferation, and T cell exhaustion. These findings demonstrate the necessity of single cell sequencing as a rapid means to identify and treat those who are most likely to need hospital admission and intensive care, in the hopes of precision medicine. Furthermore, this study underlines the use of immune modulators such as Leptin sensitizers, rather than immune suppressors as anti-inflammation therapies to switch the inflammatory response from a drastic immunological type 1 response to a beneficial type 2 effective one.

Air pollution by NO2 and PM2.5 explains COVID-19 infection severity by overexpression of angiotensin-converting enzyme 2 in respiratory cells: a review

Many major cities that witnessed heavy air pollution by nitrogen dioxide (NO2) and particulate matter (PM) have experienced a high rate of infection and severity of the coronavirus disease pandemic (COVID-19). This phenomenon could be explained by the overexpression of the angiotensin converting enzyme 2 (ACE-2) on epithelial cell surfaces of the respiratory tract. Indeed, ACE-2 is a receptor for coronaviruses including the severe acute respiratory syndrome coronavirus 1 and 2 (SARS-CoV), and ACE-2 is overexpressed under chronic exposure to air pollution such as NO2 and PM2.5. In this review, we explain that ACE-2 acts as the sole receptor for the attachment of the SARS-CoV-2 via its spike protein. The fact that respiratory and vascular epithelial cells express ACE-2 has been previously observed during the 2003 epidemic of the SARS-CoV-1 in China, and during the 2012 Middle East respiratory syndrome in Saudi Arabia. High ACE-2 expression in respiratory epithelial cells under air pollution explains the positive correlation between the severity in COVID-19 patients and elevated air pollution, notably high NO2 and PM2.5 levels. Specific areas in India, China, Italy, Russia, Chile and Qatar that experience heavy air pollution also show high rates of COVID-19 infection and severity. Overall, we demonstrate a link between NO2 emissions, PM2.5 levels, ACE-2 expression and COVID-19 infection severity. Therefore, air pollution should be reduced in places where confirmed cases of COVID-19 are unexpectedly high.

Absence of SARS-CoV-2 in semen of a COVID-19 patient cohort

Background

Since SARS‐CoV‐2 infection was first identified in December 2019, the novel coronavirus‐induced pneumonia COVID‐19 spread rapidly and triggered a global pandemic. Recent bioinformatics evidence suggested that angiotensin‐converting enzyme 2—the main cell entry target of SARS‐CoV‐2—was predominantly enriched in spermatogonia, Leydig and Sertoli cells, which suggests the potential vulnerability of the male reproductive system to SARS‐CoV‐2 infection.

Objectives

To identify SARS‐CoV‐2 RNA in seminal plasma and to determine semen characteristics from male patients in the acute and recovery phases of infection.

Methods

From February 26 to April 2, 2020, 23 male patients with COVID‐19 were recruited. The clinical characteristics, laboratory findings and chest computed tomography scans of all patients were recorded in detail. We also investigated semen characteristics and the viral RNA load in semen from these patients in the acute and recovery phases of SARS‐CoV‐2 infection using approved methods.

Results

The age range of the 23 patients was 20‐62 years. All patients tested negative for SARS‐CoV‐2 RNA in semen specimens. Among them, the virus had been cleared in 11 patients, as they tested negative. The remaining 12 patients tested negative for SARS‐CoV‐2 RNA in semen samples, but were positive in sputum and fecal specimens. The median interval from diagnosis to providing semen samples was 32 days, when total sperm counts, total motile sperm counts, and sperm morphology of the patients were within normal ranges.

Discussion and Conclusion

In this cohort of patients with a recent infection or recovering from COVID‐19, there was no SARS‐CoV‐2 RNA detected in semen samples, which indicates the unlikely possibility of sexual transmission through semen at about 1 month after first detection.

SARS-CoV-2 leading to acute pancreatitis: an unusual presentation

During SARS-CoV-2 (severe acute respiratory syndrome coronavirus-2) pandemic, the etiologic agent of COVID-19, several studies described the involvement of other tissues besides the respiratory tract, such as the gastrointestinal tract. Angiotensin-converting enzyme-2, the functional virus host cell receptor expressed by organs and tissues, seems to have an important role in the pathophysiology and presentation of this disease. In pancreas, this receptor is expressed in both exocrine glands and islets, being a potential target for the virus and subsequent pancreatic injury. There are few articles reporting pancreatic injury in COVID-19 patients but most of them do not report acute pancreatitis. Diagnosing acute pancreatitis secondary to SARS-CoV-2 infection is challenging due to the need to rule out other etiologies as well the notable heterogeneous presentations. Herein we report the case of a patient with COVID-19 who developed severe acute pancreatitis.