The Effects of Arginine-Based Supplements on Fatigue Levels following COVID-19 Infection: A Prospective Study in Romania.

The purpose of this study was to examine the effects of two arginine-based supplements on the fatigue level of patients following the COVID-19 infection. This is a prospective study of the SARS-CoV-2-infected patients divided into two groups (according to family physicians' prescriptions, Group 1 of patients were treated with Astenor Energy® containing arginine aspartate, B6 vitamin, biotin and magnesium, and Group 2 of patients were treated with Astenor Forte® containing L-arginine and malic acid). The patients visited their family physicians from October 2021 to January 2022, complaining of physical and/or mental fatigue following the COVID-19 infection. We recorded 505 patients (146 patients in Group 1 and 359 patients in Group 2) and analyzed the fatigue level using the Fatigue Assessment Scale (FAS) through its total (FAS-T), mental (FAS-M) and physical (FAS-P) scores, at baseline and after three months of treatment. There was no difference between the two groups in terms of age (p = 0.265), but more men were included in Group 1 than in Group 2 (p = 0.001). The patients from Group 2 were significantly more likely to be treated at home than those included in Group 1 (89.7% vs. 65.1%, p < 0.0001) because of the lower severity of the COVID-19 infection (asymptomatic or mild: 82.5% vs. 48.7%, p < 0.0001). After 3 months of treatment, patients indicated no fatigue in the higher percentage compared to than at the baseline (68.7% vs. 27.7%), and the fatigue level significantly decreased both in Group 1 (median baseline 33.0 vs. follow-up 17.00, p < 0.0001) and Group 2 (median baseline 25.0 vs. follow-up 17.00, p < 0.0001). These findings suggest that supplements with L-arginine may be proposed as a remedy to restore physical and mental performance affected by the fatigue burden in people with COVID-19 or following the COVID-19 infection.

Hydroxytyrosol and Arginine as Antioxidant, Anti-Inflammatory and Immunostimulant Dietary Supplements for COVID-19 and Long COVID.

Phytochemicals from plant extracts are becoming increasingly popular in the world of food science and technology because they have positive effects on human health. In particular, several bioactive foods and dietary supplements are being investigated as potential treatments for chronic COVID. Hydroxytyrosol (HXT) is a natural antioxidant, found in olive oil, with antioxidant anti-inflammatory properties that has been consumed by humans for centuries without reported adverse effects. Its use was approved by the European Food Safety Authority as a protective agent for the cardiovascular system. Similarly, arginine is a natural amino acid with anti-inflammatory properties that can modulate the activity of immune cells, reducing the production of pro-inflammatory cytokines such as IL-6 and TNF-α. The properties of both substances may be particularly beneficial in the context of COVID-19 and long COVID, which are characterised by inflammation and oxidative stress. While l-arginine promotes the formation of •NO, HXT prevents oxidative stress and inflammation in infected cells. This combination could prevent the formation of harmful peroxynitrite, a potent pro-inflammatory substance implicated in pneumonia and COVID-19-associated organ dysfunction, as well as reduce inflammation, improve immune function, protect against free radical damage and prevent blood vessel injury. Further research is needed to fully understand the potential benefits of HXT and arginine in the context of COVID-19.

Serine-arginine protein kinases and their targets in viral infection and their inhibition.

Accumulating evidence has consolidated the interaction between viral infection and host alternative splicing. Serine-arginine (SR) proteins are a class of highly conserved splicing factors critical for the spliceosome maturation, alternative splicing and RNA metabolism. Serine-arginine protein kinases (SRPKs) are important kinases that specifically phosphorylate SR proteins to regulate their distribution and activities in the central pre-mRNA splicing and other cellular processes. In addition to the predominant SR proteins, other cytoplasmic proteins containing a serine-arginine repeat domain, including viral proteins, have been identified as substrates of SRPKs. Viral infection triggers a myriad of cellular events in the host and it is therefore not surprising that viruses explore SRPKs-mediated phosphorylation as an important regulatory node in virus-host interactions. In this review, we briefly summarize the regulation and biological function of SRPKs, highlighting their involvement in the infection process of several viruses, such as viral replication, transcription and capsid assembly. In addition, we review the structure-function relationships of currently available inhibitors of SRPKs and discuss their putative use as antivirals against well-characterized viruses or newly emerging viruses. We also highlight the viral proteins and cellular substrates targeted by SRPKs as potential antiviral therapeutic candidates.

Accessing isotopically labeled proteins containing genetically encoded phosphoserine for NMR with optimized expression conditions

Phosphoserine (pSer) sites are primarily located within disordered protein regions, making it difficult to experimentally ascertain their effects on protein structure and function. Therefore, the production of 15N- (and 13C)-labeled proteins with site-specifically encoded pSer for NMR studies is essential to uncover molecular mechanisms of protein regulation by phosphorylation. While genetic code expansion technologies for the translational installation of pSer in Escherichia coli are well established and offer a powerful strategy to produce site-specifically phosphorylated proteins, methodologies to adapt them to minimal or isotope-enriched media have not been described. This shortcoming exists because pSer genetic code expansion expression hosts require the genomic DELTAserB mutation, which increases pSer bioavailability but also imposes serine auxotrophy, preventing growth in minimal media used for isotopic labeling of recombinant proteins. Here, by testing different media supplements, we restored normal BL21(DE3) DELTAserB growth in labeling media but subsequently observed an increase of phosphatase activity and mis-incorporation not typically seen in standard rich media. After rounds of optimization and adaption of a high-density culture protocol, we were able to obtain >=10 mg/L homogenously labeled, phosphorylated superfolder GFP. To demonstrate the utility of this method, we also produced the intrinsically disordered serine/arginine-rich region of the SARS-CoV-2 Nucleocapsid protein labeled with 15N and pSer at the key site S188 and observed the resulting peak shift due to phosphorylation by 2D and 3D heteronuclear single quantum correlation analyses. We propose this cost-effective methodology will pave the way for more routine access to pSer-enriched proteins for 2D and 3D NMR analyses. GCE4All Biomedical Technology Development and Dissemination Center was supported by National Institute of General Medical Science, OSU NMR Facility funded in part by the National Institutes of Health, the Medical Research Foundation at OHSU and the Collins Medical Trust, National Science Foundation EAGER, and by the M. J. Murdock Charitable Trust.Copyright © 2023 The American Society for Biochemistry and Molecular Biology, Inc.

Clinical cases of extrapulmonary manifestations in patients with coronavirus disease (COVID-19)

The aim of the work - to provide variants of extrapulmonary manifestations of coronavirus disease (COVID-19) based on the analysis of the relevant course of the disease in adults.Results. The paper presents two clinical cases of coronavirus disease (COVID-19) with the manifestation of extrapulmonary symptoms, which required some individualization of therapy.The first clinical observation showed that in a 56-year-old patient with moderate COVID-19, the development of oxygen dependence on the 8th day of the disease was combined with the manifestation of extrapulmonary symptoms in the form of cutaneous manifestations. Individualization of glucocorticosteroid therapy and endothelioprotective therapy has been shown to be effective in regressing both oxygen dependence and cutaneous vasculitis.The second clinical observation showed that in a 35-year-old patient, moderate COVID-19 without oxygen dependence was accompanied by the development of extrapulmonary manifestations, namely short-lasting diarrheal syndrome, which manifested in the onset of the disease and of the development of orchiepididymitis on the 9th day of illness, which required the appointment of anti-inflammatory therapy.Conclusions. The abovementioned clinical observations of COVID-19 cases show relatively rare cases of SARS-CoV-2-associated extrapulmonary manifestations in patients with moderate disease, but their development necessitated individualization of treatment.

Review novel insights into the diagnostic and prognostic function of copeptin in daily clinical practice.

As is shown in previous reports, arginine vasopressin (AVP), as one of the most important hormones within circulation in human beings, is of great clinically significance given that it could maintain the body fluid balance and vascular tone. However, the laboratory measurements AVP in daily clinical practice are shown to be difficult and with low accuracy. Concerning on this notion, it is unpractical to use the serum levels of AVP in diagnosing multiple diseases. On the other hand, another key serum biomarker, copeptin, is confirmed as the C-terminal of the AVP precursor which could be released in equal amounts with AVP, resultantly making it as a sensitive marker of arginine vasopressin release. Notably, emerging recent evidence has demonstrated the critical function of copeptin as a clinical indicator, especially in the diagnosis and prognosis of several diseases in diverse organs, such as cardiovascular disease, kidney disease, and pulmonary disease. In addition, copeptin was recently verified to play an important role in diagnosing multiple acute diseases when combined it with other gold standard serum biomarkers, indicating that copeptin could be recognized as a vital disease marker. Herein, in the current review, the functions of copeptin as a new predictive diagnostic and prognostic biomarker of various diseases, according to the most recent studies, are well summarized. Furthermore, the importance of using copeptin as a serum biomarker in diverse medical departments and the impact of this on improving healthcare service is also summarized in the current review.

Long COVID: Is there a kidney link?

Metabolic causes such as altered bioenergetics and amino acid metabolism may play a major role in Long COVID. Renal-metabolic regulation is an integral part of these pathways but has not been systematically or routinely investigated in Long COVID. Here we discuss the biochemistry of renal tubular injury as it may contribute to Long COVID symptoms. We propose three potential mechanisms that could be involved in Long COVID namely creatine phosphate metabolism, un-reclaimed glomerular filtrate and COVID specific proximal tubule cells (PTC) injury-a tryptophan paradigm. This approach is intended to allow for improved diagnostics and therapy for the long-haul sufferers.

Regression of treatment-resistant gyrate atrophy-associated intraretinal cystic spaces using long-term diet restriction: A case report.

PURPOSE: Gyrate atrophy of the choroid and retina (GA) is a rare genetic ophthalmologic condition which primarily manifests in childhood. It is characterized by hyperornithinemia and progressive chorioretinal atrophy. Patients may develop macular intraretinal cystic spaces (ICS) for which various treatment modalities have been reported. We report a patient who failed to demonstrate visual or anatomic improvement following multiple treatments for GA-associated ICS but showed improvement following prolonged dietary modification and vitamin supplementation. CASE DESCRIPTION: A 6-year-old male patient presented with previously undiagnosed GA associated with ICS. He received 6 consecutive monthly intravitreal bevacizumab injections as well as topical nepafenac and dorzolamide for treatment of ICS without significant change detected by optical coherence tomography (OCT) following treatment. He was also maintained on an arginine restricted diet with vitamin B6 supplementation. Over the course of the ensuing year, the patient was lost to follow-up due to the coronavirus disease 2019 pandemic. When he returned, his vision was stable, and OCT showed regression of the ICS. His mother reported that he had continued only on dietary restriction and vitamin B6 supplementation with no other medications or interventions. Plasma ornithine level measurement confirmed dietary compliance. Further follow-up showed continued stabilization of the condition. CONCLUSION: In addition to retarding progressive chorioretinal atrophy, prolonged dietary modifications may result in improvement of treatment-resistant GA-associated ICS. Parents' education on the value of dietary modifications for patients with GA is highly recommended.

New Short RNA Motifs Potentially Relevant in the SARS-CoV-2 Genome

Background: The coronavirus disease has led to an exhaustive exploration of the SARS-CoV-2 genome. Despite the amount of information accumulated, the prediction of short RNA motifs encoding peptides mediating protein-protein or protein-drug interactions has received limited attention. Objective(s): The study aims to predict short RNA motifs that are interspersed in the SARS-CoV-2 genome. Method(s): A method in which 14 trinucleotide families, each characterized by being composed of triplets with identical nucleotides in all possible configurations, was used to find short peptides with biological relevance. The novelty of the approach lies in using these families to search how they are distributed across genomes of different CoV genera and then to compare the distributions of these families with each other. Result(s): We identified distributions of trinucleotide families in different CoV genera and also how they are related, using a selection criterion that identified short RNA motifs. The motifs were reported to be conserved in SARS-CoVs;in the remaining CoV genomes analysed, motifs contained, exclusively, different configurations of the trinucleotides A, T, G and A, C, G. Eighty-eight short RNA motifs, ranging in length from 12 to 49 nucleotides, were found: 50 motifs in the 1a polyprotein-encoding orf, 27 in the 1b polyprotein-encoding orf, 5 in the spike-encoding orf, and 6 in the nucleocapsid-encoding orf. Although some motifs (~27%) were found to be intercalated or attached to functional peptides, most of them have not yet been associated with any known functions. Conclusion(s): Some of the trinucleotide family distributions in different CoV genera are not random;they are present in short peptides that, in many cases, are intercalated or attached to functional sites of the proteome.Copyright © 2022 Bentham Science Publishers.

Efficacy and Safety of Original Drug Based on Hexapeptide Succinate in Complex Covid-19 Therapy in Adults Hospitalized Patients

Currently, there are data that that make it possible to speak about a high clinical efficacy of the use of succinic salt of tyrosylD-alanyl-glycyl-phenylalanyl-leucyl-arginine (hexapeptide succinate) for the COVID-19 treatment. This article is devoted to the results of clinical trials of the original Russian drug based on it. The aim of the study was to evaluate a clinical efficacy, safety and tolerability of intramuscular and inhalation use of hexapeptide succinate in complex therapy in comparison with standard therapy in patients with moderate COVID-19. Materials and methods. The research was conducted from February 28, 2022 to November 22, 2022 based on 10 research centers in the Russian Federation. The study included hospitalized patients (n=312) over 18 years of age with moderate COVID-19 who had undergone a screening procedure and were randomized into 3 groups: group 1 received standard therapy in accordance with the Interim Guidelines in force at the time of the study, within 10 days;group 2 received hexapeptide succinate (Ambervin Pulmo) intramuscularly at the dose of 1 mg once a day for 10 days;group 3 received hexapeptide succinate (Ambervin Pulmo) 10 mg once a day by inhalation for 10 days. Results. According to the results of the study, therapy with the drug hexapeptide succinate, both intramuscular and inhaled, provided an acceleration of recovery up to the complete absence of the disease signs in more than 80% of hospitalized COVID-19 patients. By the end of the therapy course with the drug, more than 60% of patients had met the criteria for discharge from hospital and could continue the treatment on an outpatient basis. About 70% of patients in the inhalation group and 80% in the intramuscular hexapeptide succinate injection group had concomitant diseases (hypertension - 28%, obesity - 14%), which indicates the effectiveness of this drug use in comorbid patients. The use of the drug contributed to the restoration of damaged lung tissues, normalization of oxygenation, the disappearance of shortness of breath and a decrease in the duration of the disease symptoms compared with standard therapy. As a result of a comparative analysis of adverse events in terms of their presence, severity, causal relationship with the therapy and outcome, there were no statistically significant differences between the treatment groups. Conclusion. Thus, the results of the clinical study of the succinate hexapeptide efficacy and safety showed the feasibility of using the drug in pathogenetic therapy COVID-19 regimens.Copyright © 2022 Volgograd State Medical University, Pyatigorsk Medical and Pharmaceutical Institute. All rights reserved.

Study in-silico oleanane triterpenoids in Aquilaria spp. as a COVID-19 antiviral

Covid-19, a disease characterized by Severe Acute Respiratory Syndrome, is caused by Coronavirus-2 (SARS-CoV-2). This virus causes tissue damage and a decrease in the respiratory system. Agarwood (Aquilaria spp) is a plant that has various pharmacological activities, including relieving respiratory diseases. One of the several secondary metabolites reported in Aquilaria spp. is oleanane triterpenoids, suspected of having antiviral activity. This research was aimed to determine the potential of oleanane triterpenoids from Agarwood as a covid-19 antiviral by in silico study. The research methods were molecular docking, prediction of Lipinski rules of five, and prediction of ADME. As a receptor, main protease (Mpro) Covid-19 was used. The four oleanane triterpenoid compounds in Agarwood demonstrated a higher affinity for the main protease covid-19 (G 11-oxo-beta-amyrin = -9.8 kcal/mol, G hederagenin-an = -9.6 kcal/mol, G 3beta-acetoxyfriedelane = -9.4 kcal/mol, G ursolic acid = -9.5 kcal/mol) than Lopinavir (G = -6.2 kcal/mol) and Remdesivir (G = -7.2 kcal/mol). The major amino acids involved in ligand and receptor interactions are methionine 49 and 165, proline 168, glutamine 189, arginine 188, and threonine 25. According to the prediction of Lipinski's rule of five and ADME, hederageninan is potential for development as oral medicine.

FETAL GROWTH RETARDATION AS A COMPLICATION OF POST-COVID ENDOTHELIITIS: CAUSES, CONSEQUENCES, WAYS OF PREVENTION.

The risk of fetal intrauterine growth retardation (IUGR) is increased in women who have experienced acute infections, as well as in pregnant women with gynecological pathology and endocrine diseases. A woman's lack of nutrition also makes a negative contribution to the development of IUGR. The frequency of IUGR in the population is very variable and depends on a number of reasons. In practically healthy pregnant women, IUGR is registered in 3-5% of cases, in case of complicated obstetric and gynecological diagnosis and complicated pregnancy - in 10-25%. Morphofunctional disorders in the chorion/placenta in pregnant women with COVID-19 on the background of post-covid endotheliitis are the main pathogenetic factor in the development of preeclampsia, ectopic pregnancy, antenatal fetal death, and impaired condition of the fetus and newborns. Sufficient saturation of the pregnant woman's body with the nitric oxide donor L-arginine and L-carnitine (main cofactor of fatty acid metabolism in cells) with the improvement of microcirculation and the correction of hypovolemic disorders in the fetoplacental complex can be considered one of the real ways to prevent IUGR in women in the post-covid period. A review of the scientific literature on pathogenesis, diagnosis, impact on the life and health of a newborn with IUGR in women after COVID-19, as well as the possibilities of medical correction of placental dysfunction during pregnancy was performed. This analysis and our own clinical experience allow us to state the fact that after a coronavirus infection during pregnancy, one of the frequent and threatening for the further development of the child is the formation of placental dysfunction and IUGR. One of the ways to prevent these conditions is to saturate the woman's body with the nitric oxide donor L-arginine from the stage of pre-gravid preparation, which will provide the opportunity for adequate angiogenesis and development of the embryo/fetus. In the case of additional risk factors, such as coronavirus disease, complex therapy blood (Rheosorbilact), in combination with a nitric oxide donor and L-carnitine as an endothelium-protective agent (Tivor-L).Copyright © 2022 Authors. All rights reserved.

Hierarchical Superstructure of Plant Polyphenol and Arginine Surfactant for Long-Lasting and Target-Selective Antimicrobial Application.

Antimicrobial agents are massively used to disinfect the pathogen contaminated surfaces since the Corona Virus Disease 2019 (COVID-19) outbreak. However, their defects of poor durability, strong irritation, and high environmental accumulation are exposed. Herein, a convenient strategy is developed to fabricate long-lasting and target-selective antimicrobial agent with the special hierarchical structure through bottom-up assembly of natural gallic acid with arginine surfactant. The assembly starts from rodlike micelles, further stacking into hexagonal columns and finally interpenetrating into spherical assemblies, which avoid explosive release of antimicrobial units. The assemblies show anti-water washing and high adhesion on various surfaces; and thus, possess highly efficient and broad-spectrum antimicrobial activities even after using up to eleven cycles. Both in vitro and in vivo experiments prove that the assemblies are highly selective in killing pathogens without generating toxicity. The excellent antimicrobial virtues well satisfy the increasing anti-infection demands and the hierarchical assembly exhibits great potential as a clinical candidate.

Thromboinflammation: From Atherosclerosis to COVID-19.

The activating interplay of thrombosis and inflammation (thromboinflammation) has been established as a major underlying pathway, driving not only cardiovascular disease but also autoimmune disease and most recently, COVID-19. Throughout the years, innate immune cells have emerged as important modulators of this process. As the most abundant white blood cell in humans, neutrophils are well-positioned to propel thromboinflammation. This includes their ability to trigger an organized cell death pathway with the release of decondensed chromatin structures called neutrophil extracellular traps. Decorated with histones and cytoplasmic and granular proteins, neutrophil extracellular traps exert cytotoxic, immunogenic, and prothrombotic effects accelerating disease progression. Distinct steps leading to extracellular DNA release (NETosis) require the activities of PAD4 (protein arginine deiminase 4) catalyzing citrullination of histones and are supported by neutrophil inflammasome. By linking the immunologic function of neutrophils with the procoagulant and proinflammatory activities of monocytes and platelets, PAD4 activity holds important implications for understanding the processes that fuel thromboinflammation. We will also discuss mechanisms whereby vascular occlusion in thromboinflammation depends on the interaction of neutrophil extracellular traps with ultra-large VWF (von Willebrand Factor) and speculate on the importance of PAD4 in neutrophil inflammasome assembly and neutrophil extracellular traps in thromboinflammatory diseases including atherosclerosis and COVID-19.

Cystatin-c May Indicate Subclinical Renal Involvement, While Orosomucoid Is Associated with Fatigue in Patients with Long-COVID Syndrome.

Long-COVID syndrome is associated with high healthcare costs, but its pathophysiology is not yet fully understood. Inflammation, renal impairment or disturbance of the NO system emerge as potential pathogenetic factors. We aimed to investigate the relationship between symptoms of long-COVID syndrome and serum levels of cystatin-c (CYSC), orosomucoid (ORM), l-arginine, symmetric dimethylarginine (SDMA) and asymmetric dimethylarginine (ADMA). A total of 114 patients suffering from long-COVID syndrome were included in this observational cohort study. We found that serum CYSC was independently associated with the anti-spike immunoglobulin (S-Ig) serum level (OR: 5.377, 95% CI: 1.822-12.361; p = 0.02), while serum ORM (OR: 9.670 (95% CI: 1.34-9.93; p = 0.025) independently predicted fatigue in patients with long-COVID syndrome, both measured at baseline visit. Additionally, the serum CYSC concentrations measured at the baseline visit showed a positive correlation with the serum SDMA levels. The severity of abdominal and muscle pain indicated by patients at the baseline visit showed a negative correlation with the serum level of L-arginine. In summary, serum CYSC may indicate subclinical renal impairment, while serum ORM is associated with fatigue in long-COVID syndrome. The potential role of l-arginine in alleviating pain requires further studies.

Beneficial effects of L-Arginine in patients hospitalized for COVID-19: New insights from a randomized clinical trial.

We have recently demonstrated in a double-blind randomized trial the beneficial effects of L-Arginine in patients hospitalized for COVID-19. We hypothesize that one of the mechanisms underlying the favorable effects of L-Arginine is its action on inflammatory cytokines. To verify our hypothesis, we measured longitudinal plasma levels of pro-inflammatory and anti-inflammatory cytokines implied in the pathophysiology of COVID-19 in patients randomized to receive oral L-Arginine or placebo. The study was successfully completed by 169 patients. Patients in the L-Arginine arm had a reduced respiratory support evaluated at 10 and 20 days; moreover, the time to hospital discharge was significantly shorter in the L-Arginine group. The assessment of circulating cytokines revealed that L-Arginine significantly reduced the circulating levels of pro-inflammatory IL-2, IL-6, and IFN-γ and increased the levels of the anti-inflammatory IL-10. Taken together, these findings indicate that adding L-Arginine to standard therapy in COVID-19 patients markedly reduces the need of respiratory support and the duration of in-hospital stay; moreover, L-Arginine significantly regulates circulating levels of pro-inflammatory and anti-inflammatory cytokines.

Inhalation of L-arginine-modified liposomes targeting M1 macrophages to enhance curcumin therapeutic efficacy in ALI.

Acute lung injury/acute respiratory distress syndrome (ALI/ARDS), characterized by uncontrolled lung inflammation, is one of the most devastating diseases with high morbidity and mortality. As the first line of defense system, macrophages play a crucial role in the pathogenesis of ALI/ARDS. Therefore, it has great potential to selectively target M1 macrophages to improve the therapeutic effect of anti-inflammatory drugs. L-arginine plays a key role in regulating the immune function of macrophages. The receptors mediating L-arginine uptake are highly expressed on the surface of M1-type macrophages. In this study, we designed an L-arginine-modified liposome for aerosol inhalation to target M1 macrophages in the lung, and the anti-inflammatory drug curcumin was encapsulated in liposomes as model drug. Compared with unmodified curcumin liposome (Cur-Lip), L-arginine functionalized Cur-Lip (Arg-Cur-Lip) exhibited higher uptake by M1 macrophages in vitro and higher accumulation in inflamed lungs in vivo. Furthermore, Arg-Cur-Lip showed more potent therapeutic effects in LPS-induced RAW 264.7 cells and the rat model of ALI. Overall, these findings indicate that L-arginine-modified liposomes have great potential to enhance curcumin treatment of ALI/ARDS by targeting M1 macrophages, which may provide an option for the treatment of acute lung inflammatory diseases such as coronavirus disease 2019 (COVID-19), severe acute respiratory syndrome and middle east respiratory syndrome.

THE ROLE OF ARGININE AND ENDOTHELIAL NITRIC OXIDE SYNTHASE IN THE PATHOGENESIS OF COVID-19 COMPLICATED BY METABOLIC SYNDROME

This literature review presents the role of endothelial nitric oxide synthase (eNOS) and nitric oxide (NO), as well as arginine, the enzyme substrate, in the disease of metabolic syndrome and COVID-19 (SARS-CoV-2 virus). Metabolic syndrome is a combination of obesity, insulin resistance, hyperglycemia, dyslipidemia and hypertension. Ithas been shown thatin elderly people, patients withobesity, metabolic syndrome, type 2 diabetes mellitus (DM2), and patients with COVID-19, endothelial dysfunction (ED) and vascular endothelial activation are detected. ED is the main cause of a number of pathological conditions during the development of COVID-19 and earlier in patients with metabolic syndrome, while a sharp drop in the level ofnitric oxide (NO)is detecteddue to a decrease in the expression andactivity ofeNO synthase and enzyme depletion, which leads to a violation of the integrity of blood vessels, that is, to vasoconstrictive, inflammatory and thrombotic conditions, followedby ischemia oforgans andedema oftissues. It shouldbe notedthat metabolic syndrome, DM2, hypertension and obesity, in particular, are age-related diseases, and it is known that blood glucose levels increase with age, which reduces the bioavailability of NO in endothelial cells. Defects in the metabolism of NO cause dysfunction in the pulmonary blood vessels, the level of NO decreases, which leads to impaired lung function and coagulopathy. The review presents possible mechanisms of these disorders associated with ED, the release of eNO synthase, changes in phosphorylation and regulation of enzyme activity, as well as insulin resistance. A modern view of the role of the polymorphism of the eNO synthase gene in the development of these pathologies is presented. To increase the level of endothelial NO, drugs are offered that regulate the bioavailability of NO. These include arginine, agonist NO – minoxidil, steroid hormones, statins, metformin. However, further research and clinical trials are needed to develop treatment strategies that increase NO levels in the endothelium. © 2022 Scientific Centre for Family Health and Human Reproduction Problems. All right reserved.

Detection of concentration-dependent conformational changes in SARS-CoV-2 nucleoprotein by agarose native gel electrophoresis.

The nucleoprotein (NP) of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is abundantly expressed during infection, making it a diagnostic target protein. We analyzed the structure of the NP in solution using a recombinant protein produced in E. coli. A codon-optimized Profinity eXact™-tagged NP cDNA was cloned into pET-3d vector and transformed into E. coli T7 Express. The recombinant protein was first purified via chromatographic step using an affinity tag-based system that was followed by tag cleavage with sodium fluoride, resulting in proteolytic removal of the N-terminal tag sequence. The digested sample was then loaded directly onto a size exclusion chromatography run in the presence of L-Arg-HCl, resulting in removal of host nucleic acids and endotoxin. The molecular mass of the main NP fraction was determined by mass photometry as a dimeric form of NP, consistent with the blue native PAGE results. Interestingly, analysis of the purified NP by our newly developed agarose native gel electrophoresis revealed that it behaved like an acidic protein at low concentration despite its alkaline isoelectric point (theoretical pI = 10) and displayed a unique character of concentration-dependent charge and shape changes. This study should shed light into the behavior of NP in the viral life cycle.

GSK3326595 is a promising drug to prevent SARS-CoV-2 Omicron and other variants infection by inhibiting ACE2-R671 di-methylation.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) caused COVID-19 epidemic is worsening. Binding of the Spike1 protein of SARS-CoV-2 with the angiotensin-converting enzyme 2 (ACE2) receptor mediates entry of the virus into host cells. Many reports show that protein arginine methylation by protein arginine methyltransferases (PRMTs) is important for the functions of these proteins, but it remains unclear whether ACE2 is methylated by PRMTs. Here, we show that PRMT5 catalyses ACE2 symmetric dimethylation at residue R671 (meR671-ACE2). We indicate that PRMT5-mediated meR671-ACE2 promotes SARS-CoV-2 receptor-binding domain (RBD) binding with ACE2 probably by enhancing ACE2 N-glycosylation modification. We also reveal that the PRMT5-specific inhibitor GSK3326595 is able to dramatically reduce ACE2 binding with RBD. Moreover, we discovered that meR671-ACE2 plays an important role in ACE2 binding with Spike1 of the SARS-CoV-2 Omicron, Delta, and Beta variants; and we found that GSK3326595 strongly attenuates ACE2 interaction with Spike1 of the SARS-CoV-2 Omicron, Delta, and Beta variants. Finally, SARS-CoV-2 pseudovirus infection assays uncovered that PRMT5-mediated meR671-ACE2 is essential for SARS-CoV-2 infection in human cells, and pseudovirus infection experiments confirmed that GSK3326595 can strongly suppress SARS-CoV-2 infection of host cells. Our findings suggest that as a clinical phase II drug for several kinds of cancers, GSK3326595 is a promising candidate to decrease SARS-CoV-2 infection by inhibiting ACE2 methylation and ACE2-Spike1 interaction.