Macrophage Activation Syndrome in Coinciding Pandemics of Obesity and COVID-19: Worse than Bad.

Epigenetic changes have long-lasting impacts, which influence the epigenome and are maintained during cell division. Thus, human genome changes have required a very long timescale to become a major contributor to the current obesity pandemic. Whereas bidirectional effects of coronavirus disease 2019 (COVID-19) and obesity pandemics have given the opportunity to explore, how the viral microribonucleic acids (miRNAs) use the human's transcriptional machinery that regulate gene expression at a posttranscriptional level. Obesity and its related comorbidity, type 2 diabetes (T2D), and new-onset diabetes due to severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2) are additional risk factors, which increase the severity of COVID-19 and its related mortality. The higher mortality rate of these patients is dependent on severe cytokine storm, which is the sum of the additional cytokine production by concomitant comorbidities and own cytokine synthesis of COVID-19. Patients with obesity facilitate the SARS-CoV-2 entry to host cell via increasing the host's cell receptor expression and modifying the host cell proteases. After entering the host cells, the SARS-CoV-2 genome directly functions as a messenger ribonucleic acid (mRNA) and encodes a set of nonstructural proteins via processing by the own proteases, main protease (Mpro), and papain-like protease (PLpro) to initiate viral genome replication and transcription. Following viral invasion, SARS-CoV-2 infection reduces insulin secretion via either inducing ß-cell apoptosis or reducing intensity of angiotensin-converting enzyme 2 (ACE2) receptors and leads to new-onset diabetes. Since both T2D and severity of COVID-19 are associated with the increased serum levels of pro-inflammatory cytokines, high glucose levels in T2D aggravate SARS-CoV-2 infection. Elevated neopterin (NPT) value due to persistent interferon gamma (IFN-γ)-mediated monocyte-macrophage activation is an indicator of hyperactivated pro-inflammatory phenotype M1 macrophages. Thus, NPT could be a reliable biomarker for the simultaneously occurring COVID-19-, obesity- and T2D-induced cytokine storm. While host miRNAs attack viral RNAs, viral miRNAs target host transcripts. Eventually, the expression rate and type of miRNAs also are different in COVID-19 patients with different viral loads. It is concluded that specific miRNA signatures in macrophage activation phase may provide an opportunity to become aware of the severity of COVID-19 in patients with obesity and obesity-related T2D.

Investigation of SARS-CoV-2 IgG Binding Capability to Variants of the SARS-CoV-2 Virus.

The SARS-CoV-2 pandemic has confirmed that the ability to rapidly mutate may be extremely beneficial for a virus. Not long after the first wave, new variants emerged with altered infectivity, disease severity, and mortality. These new strains most notably had numerous mutations of the spike (S) protein, a surface protein responsible for binding to and entering the host cell. The Delta and Omicron strains demonstrated increased immune evasion and improved binding affinity to the host cell receptor, angiotensin-converting enzyme 2 (ACE2). This study examines the ability of wild-type SARS-CoV-2 IgG to bind Delta and Omicron antigens, as well as their functional binding capabilities to two different S-ACE2 complexes. Twenty SARS-CoV-2 positive samples from patients who had recovered from infection with ancestral SARS-CoV-2 in the first wave of COVID-19 and 10 pre-pandemic control samples were studied. SARS-CoV-2 exposed patients showed significantly higher levels of IgG to SARS-CoV-2 S1/RBD (p < 0.001), N protein (p < 0.001), and Omicron spike variant (p = 0.01), but not to Delta spike variant (p = 0.966) when compared with controls. Furthermore, patient samples showed significantly greater inhibition of SARS-CoV-2 S1/RBD and E484K spike to ACE2 binding (p < 0.001 and p = 0.015, respectively). Conversely, there was no correlation between the binding inhibition of S1/RBD and E484K spike to ACE2 receptor. This study shows there is considerable cross-reactivity of IgG generated by wild-type SARS-CoV-2 infection to the Delta and Omicron variants.

Retrospective Comparison of Influenza and COVID-19-Associated Acute Respiratory Distress Syndrome (ARDS): An Experience From a Tertiary Care Hospital.

Background The COVID-19 pandemic has had a profound impact on global healthcare systems, often compared to seasonal influenza due to similarities in clinical presentation. This study aims to compare the clinical characteristics, comorbidities, and outcomes of critically ill patients with COVID-19 and those with influenza admitted to a tertiary care hospital in Islamabad, Pakistan. Methods This retrospective cohort study included 120 patients, 60 with confirmed COVID-19 and 60 with confirmed influenza, all of whom required ICU admission and mechanical ventilation between January 1, 2021, and January 1, 2024. Data were collected from electronic medical records, including demographic information, comorbidities, and clinical outcomes. Descriptive statistics were used to compare the two groups. Results The median age of COVID-19 patients was 55 years (range 30-78), while that of influenza patients was 58 years (range 31-80). Both groups had a slight male predominance (COVID-19: 66.7%, Influenza: 63.3%). Comorbidities were common in both groups, with 75.0% of COVID-19 patients and 83.3% of influenza patients having at least one comorbidity. The most common comorbidities included hypertension (COVID-19: 30.0%, Influenza: 33.3%) and diabetes (COVID-19: 20.0%, Influenza: 25.0%). Clinical outcomes revealed a higher mortality rate among influenza patients (43.3%) compared to COVID-19 patients (28.3%). ICU admission rates were identical for both groups at 66.7%, and mechanical ventilation was required for 66.7% of ICU-admitted patients in both groups. The presence of cardiovascular comorbidities significantly impacted patient outcomes, with higher mortality observed in influenza patients with such comorbidities (44.7%) compared to COVID-19 patients (28.9%). Conclusion This study highlights the significant burden of both COVID-19 and influenza on critically ill patients, particularly those with cardiovascular comorbidities. While influenza patients in this cohort exhibited higher mortality rates, both groups demonstrated substantial ICU admission rates and a need for mechanical ventilation.

Receptors Involved in COVID-19-Related Anosmia: An Update on the Pathophysiology and the Mechanistic Aspects.

Olfactory perception is an important physiological function for human well-being and health. Loss of olfaction, or anosmia, caused by viral infections such as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has received considerable attention, especially in persistent cases that take a long time to recover. This review discusses the integration of different components of the olfactory epithelium to serve as a structural and functional unit and explores how they are affected during viral infections, leading to the development of olfactory dysfunction. The review mainly focused on the role of receptors mediating the disruption of olfactory signal transduction pathways such as angiotensin converting enzyme 2 (ACE2), transmembrane protease serine type 2 (TMPRSS2), neuropilin 1 (NRP1), basigin (CD147), olfactory, transient receptor potential vanilloid 1 (TRPV1), purinergic, and interferon gamma receptors. Furthermore, the compromised function of the epithelial sodium channel (ENaC) induced by SARS-CoV-2 infection and its contribution to olfactory dysfunction are also discussed. Collectively, this review provides fundamental information about the many types of receptors that may modulate olfaction and participate in olfactory dysfunction. It will help to understand the underlying pathophysiology of virus-induced anosmia, which may help in finding and designing effective therapies targeting molecules involved in viral invasion and olfaction. To the best of our knowledge, this is the only review that covered all the receptors potentially involved in, or mediating, the disruption of olfactory signal transduction pathways during COVID-19 infection. This wide and complex spectrum of receptors that mediates the pathophysiology of olfactory dysfunction reflects the many ways in which anosmia can be therapeutically managed.

Effective Treatment of COVID-19 Infection with Repurposed Drugs: Case Reports.

The COVID-19 pandemic response has been hindered by the absence of an efficient antiviral therapy for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The reason why the previous preventative approach to COVID-19 solely through vaccines has failed could be a lack of understanding of how quickly the SARS-CoV-2 virus evolves. Given the absence of specific treatments for the virus, efforts have been underway to explore treatment options. Drug repurposing involves identifying new therapeutic uses for approved drugs, proving to be a time-saving strategy with minimal risk of failure. In this study, we report the successful use of a multidrug approach in patients with COVID-19. Successful administration of multidrug therapy, such as combinations of hydroxychloroquine and azithromycin, doxycycline and ivermectin, or ivermectin, doxycycline, and azithromycin, has been reported. Multidrug therapy is effective because of the differing mechanisms of action of these drugs, and it may also mitigate the emergence of drug-resistant SARS-CoV-2 strains. The medicines were lopinavir/ritonavir (Kaletra), bamlanivimab (monoclonal antibody), glycopyrrolate-formoterol (Bevespi), ciclesonide (Alvesco), famotidine (Pepcid), and diphenhydramine (Benadryl).

Potential Protective Factors for Allergic Rhinitis Patients Infected with COVID-19.

At the beginning of the 2019 coronavirus disease (COVID-19) pandemic, airway allergic diseases such as asthma and allergic rhinitis (AR) were considered as risk factors for COVID-19, as they would aggravate symptoms. With further research, more and more literature has shown that airway allergic disease may not be a high-risk factor, but may be a protective factor for COVID-19 infection, which is closely related to its low-level expression of the ACE2 receptor and the complex cytokines network as underlying molecular regulatory mechanisms. In addition, steroid hormones and age factors could not be ignored. In this review, we have summarized some current evidence on the relationship between COVID-19 and allergic rhinitis to highlight the underlying mechanisms of COVID-19 infection and provide novel insights for its prevention and treatment. The key findings show that allergic rhinitis and its related molecular mechanisms may have a protective effect against COVID-19 infection.

Susceptibility and transmissibility of SARS-CoV-2 variants in transgenic mice expressing the cat angiotensin-converting enzyme 2 (ACE-2) receptor.

The emergence of SARS-CoV-2 in 2019 and its rapid spread throughout the world has caused the largest pandemic of our modern era. The zoonotic origin of this pathogen highlights the importance of the One Health concept and the need for a coordinated response to this kind of threats. Since its emergence, the virus has caused >7 million deaths worldwide. However, the animal source for human outbreaks remains unknown. The ability of the virus to jump between hosts is facilitated by the presence of the virus receptor, the highly conserved angiotensin-converting enzyme 2 (ACE2), found in various mammals. Positivity for SARS-CoV-2 has been reported in various species, including domestic animals and livestock, but their potential role in bridging viral transmission to humans is still unknown. Additionally, the virus has evolved over the pandemic, resulting in variants with different impacts on human health. Therefore, suitable animal models are crucial to evaluate the susceptibility of different mammalian species to this pathogen and the adaptability of different variants. In this work, we established a transgenic mouse model that expresses the feline ACE2 protein receptor (cACE2) under the human cytokeratin 18 (K18) gene promoter's control, enabling high expression in epithelial cells, which the virus targets. Using this model, we assessed the susceptibility, pathogenicity, and transmission of SARS-CoV-2 variants. Our results show that the sole expression of the cACE2 receptor in these mice makes them susceptible to SARS-CoV-2 variants from the initial pandemic wave but does not enhance susceptibility to omicron variants. Furthermore, we demonstrated efficient contact transmission of SARS-CoV-2 between transgenic mice that express either the feline or the human ACE2 receptor.

A Host Receptor Nanodisc-Based Biosensor Platform for the Detection of a Specific Virus and Its Variants.

The host receptor is a key element in the initial stage of the virus entry into the host. The use of this host receptor is valuable as a sensing element for selectively and sensitively detecting specific viruses. Also, viruses tend to escape neutralizing antibodies through viral mutation but still utilize the cell entry process using the same host receptors, so it would be a powerful detection tool even for the mutant viruses. The angiotensin-converting enzyme 2 (ACE2) receptor, which is the representative host receptor, performs an essential function in facilitating viral penetration by interacting with the receptor-binding domain (RBD) of the SARS-CoV-2 spike protein. In this study, we introduce a novel approach, where we fabricated a carbon nanotube field-effect transistor (CNT-FET) sensor and combined it with ACE2 receptor-embedded nanodisc (ND). ACE2 was produced using an E. coli expression system, purified, and integrated into the ND platform. ACE2 NDs showed robust functionality through interactions with a pseudotyped virus (PV) containing the spike protein, enabling sensitive detection of both SARS-CoV-2 and its genetic variations at 102 PFU/mL. The ACE ND-based sensor exhibited excellent selectivity by accurately differentiating SARS-CoV-2 wild-type and variants (Omicron, Delta) from other viruses (ZIKA and MERS-CoV). As a result of comparative analysis, ACE2 ND showed approximately 49% superior long-term functionality up to the second week compared to that of soluble ACE2. These findings highlight the high selectivity and sensitivity of host receptor-based sensors for detecting viral variants and provide a promising tool to prevent the spread of unknown viruses.

SARS-CoV-2 and the Angiotensin-Converting Enzyme 2 Receptor: Angiotensin-Converting Enzyme Inhibitor/Angiotensin 2 Receptor Blocker Utilization and a Shift Towards the Renin-Angiotensin-Aldosterone System Classical Pathway.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus responsible for the coronavirus disease 2019 (COVID-19) pandemic, uses the surface angiotensin-converting enzyme 2 (ACE2) receptor as the site of entry into host cardiac, respiratory, intestinal, renal, and nervous system cells. Predisposing risk factors such as cardiovascular disease increase the risk of developing severe disease. Hypertension is characterized by the stimulation of the renin-angiotensin-aldosterone system (RAAS). Angiotensin-converting enzyme inhibitors (ACEis) and angiotensin 2 receptor blockers (ARBs), medications used to treat hypertension, inhibit RAAS and its downstream effects; however, they have also been shown to upregulate ACE2 receptors. In this review, we aim to evaluate the effectiveness of ACEi/ARBs as an adjunct therapy in patients with SARS-CoV-2 as well as examine the possible protective effects and impact on infection rate and disease severity. A PubMed literature search excluding sources outside the United States and duplicates was performed using the following search criteria: "COVID-19 AND cardiovascular disease AND ACEi AND ARB", "SARS-COVID-19 OR COVID-19, AND ACEi AND ARB AND Infection rate", "COVID-19 AND ACEi and ARB", "Omicron BA.1 and BA.2 AND ACE2 OR ARBs", "Omicron AND ACEi AND ARBs". This resulted in 33 final sources. The review concluded that ACEi/ARB therapy may continue to improve COVID-19 survival as previous treatment is associated with positive clinical outcomes. Patients taking ACEis or ARBs were found to have a decreased risk of hospitalization, reduced severity of COVID-19 pneumonia, a lesser need for mechanical ventilation, and an overall reduction in mortality rate. No statistically significant association between ACEi/ARB use and enhanced COVID-19 infectivity was found. The Omicron variant is theoretically more infectious and was associated with increased negative clinical outcomes in those undertreated with ACEis/ARBs. The majority of the literature supports the current guidelines from the American College of Cardiology (ACC), American Heart Association (AHA), European Society of Cardiology (ESC), and Heart Failure Society of America (HFSA), which state that ACEi and ARB medications should not be withdrawn from or initiated on patients with cardiovascular disease who are infected with SARS-CoV-2. More research needs to be conducted on the association between the emerging COVID-19 variants and ACEis/ARBs to give clinicians confidence when treating patients within this subgroup of the population.

Characterization of a pangolin SARS-CoV-2-related virus isolate that uses the human ACE2 receptor.

Various SARS-CoV-2-related coronaviruses have been increasingly identified in pangolins, showing a potential threat to humans. Here we report the infectivity and pathogenicity of the SARS-CoV-2-related virus, PCoV-GX/P2V, which was isolated from a Malayan pangolin (Manis javanica). PCoV-GX/P2V could grow in human hepatoma, colorectal adenocarcinoma cells, and human primary nasal epithelial cells. It replicated more efficiently in cells expressing human angiotensin-converting enzyme 2 (hACE2) as SARS-CoV-2 did. After intranasal inoculation to the hACE2-transgenic mice, PCoV-GX/P2V not only replicated in nasal turbinate and lungs, but also caused interstitial pneumonia, characterized by infiltration of mixed inflammatory cells and multifocal alveolar hemorrhage. Existing population immunity established by SARS-CoV-2 infection and vaccination may not protect people from PCoV-GX/P2V infection. These findings further verify the hACE2 utility of PCoV-GX/P2V by in vivo experiments using authentic viruses and highlight the importance for intensive surveillance to prevent possible cross-species transmission.