Your browser doesn't support javascript.
Show: 20 | 50 | 100
Results 1 - 18 de 18
Filter
1.
Molecules ; 27(13)2022 Jul 01.
Article in English | MEDLINE | ID: covidwho-1934177

ABSTRACT

Human serum amyloid A (SAA) is an exchangeable apolipoprotein (apo) in high-density lipoprotein (HDL) that influences HDL quality and functionality, particularly in the acute phase of inflammation. On the other hand, the structural and functional correlations of HDL containing SAA and apoA-I have not been reported. The current study was designed to compare the change in HDL quality with increasing SAA content in the lipid-free and lipid-bound states in reconstituted HDL (rHDL). The expressed recombinant human SAA1 (13 kDa) was purified to at least 98% and characterized in the lipid-free and lipid-bound states with apoA-I. The dimyristoyl phosphatidylcholine (DMPC) binding ability of apoA-I was impaired severely by the addition of SAA, while SAA alone could not bind with DMPC. The recombinant human SAA1 was incorporated into the rHDL (molar ratio 95:5:1, 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC): cholesterol: apoA-I) with various apoA-I:SAA molar ratios from 1:0 to 1:0.5, 1:1 and 1:2. With increasing SAA1 content, the rHDL particle size was reduced from 98 Å to 93 Å, and the α-helicity of apoA-I:SAA was decreased from 73% to 40% for (1:0) and (1:2), respectively. The wavelength maximum fluorescence (WMF) of tryptophan in rHDL was red-shifted from 339 nm to 345 nm for (1:0) and (1:2) of apoA-I:SAA, respectively, indicating that the addition of SAA to rHDL destabilized the secondary structure of apoA-I. Upon denaturation by urea treatment from 0 M to 8 M, SAA showed only a 3 nm red-shift in WMF, while apoA-I showed a 16 nm red-shift in WMF, indicating that SAA is resistant to denaturation and apoA-I had higher conformational flexibility than SAA. The glycation reaction of apoA-I in the presence of fructose was accelerated up to 1.8-fold by adding SAA in a dose-dependent manner than that of apoA-I alone. In conclusion, the incorporation of SAA in rHDL impaired the structural stability of apoA-I and exacerbated glycation of HDL and apoA-I.


Subject(s)
Apolipoprotein A-I , Lipoproteins, HDL , Apolipoprotein A-I/chemistry , Cholesterol , Dimyristoylphosphatidylcholine , Humans , Lipoproteins, HDL/metabolism , Serum Amyloid A Protein
2.
mSphere ; 7(3): e0016422, 2022 06 29.
Article in English | MEDLINE | ID: covidwho-1923114

ABSTRACT

Bourbon virus (BRBV) was first discovered in 2014 in a fatal human case. Since then it has been detected in the tick Amblyomma americanum in the states of Missouri and Kansas in the United States. Despite the high prevalence of BRBV in ticks in these states, very few human cases have been reported, and the true infection burden of BRBV in the community is unknown. Here, we developed two virus neutralization assays, a vesicular stomatitis virus (VSV)-BRBV pseudotyped rapid assay and a BRBV focus reduction neutralization assay, to assess the seroprevalence of BRBV neutralizing antibodies in human sera collected in 2020 in St. Louis, MO. Of 440 human serum samples tested, three (0.7%) were able to potently neutralize both VSV-BRBV and wild-type BRBV. These findings suggest that human infections with BRBV are more common than previously recognized. IMPORTANCE Since the discovery of the Bourbon virus (BRBV) in 2014, a total of five human cases have been identified, including two fatal cases. BRBV is thought to be transmitted by the lone star tick, which is prevalent in the eastern, southeastern, and midwestern United States. BRBV has been detected in ticks in Missouri and Kansas, and serological evidence suggests that it is also present in North Carolina. However, the true infection burden of BRBV in humans is not known. In the present study, we developed two virus neutralization assays to assess the seroprevalence of BRBV-specific antibodies in human sera collected in 2020 in St. Louis, MO. We found that a small subset of individuals are seropositive for neutralizing antibodies against BRBV. Our data suggest that BRBV infection in humans is more common than previously thought.


Subject(s)
Thogotovirus , Ticks , Animals , Antibodies, Neutralizing , Humans , Missouri/epidemiology , Seroepidemiologic Studies , United States
3.
Metabolites ; 12(7)2022 Jun 27.
Article in English | MEDLINE | ID: covidwho-1911471

ABSTRACT

Obesity, type 2 diabetes (T2D), and severe coronavirus disease 2019 (COVID-19) are closely associated. The aim of this study was to elucidate the casual and mediating relationships of human serum metabolites on the pathways from obesity/T2D to COVID-19 using Mendelian randomization (MR) techniques. We performed two-sample MR to study the causal effects of 309 metabolites on COVID-19 severity and susceptibility, based on summary statistics from genome-wide association studies (GWAS) of metabolites (n = 7824), COVID-19 phenotypes (n = 2,586,691), and obesity (n = 322,154)/T2D traits (n = 898,130). We conducted two-sample network MR analysis to determine the mediating metabolites on the causal path from obesity/T2D to COVID-19 phenotypes. We used multivariable MR analysis (MVMR) to discover causal metabolites independent of body mass index (BMI). Our MR analysis yielded four causal metabolites that increased the risk of severe COVID-19, including 2-stearoylglycerophosphocholine (OR 2.15; 95% CI 1.48-3.11), decanoylcarnitine (OR 1.32; 95% CI 1.17-1.50), thymol sulfate (OR 1.20; 95% CI 1.10-1.30), and bradykinin-des-arg(9) (OR 1.09; 95% CI 1.05-1.13). One significant mediator, gamma-glutamyltyrosine, lay on the causal path from T2D/obesity to severe COVID-19, with 16.67% (0.64%, 32.70%) and 6.32% (1.76%, 10.87%) increased risk, respectively, per one-standard deviation increment of genetically predicted T2D and BMI. Our comprehensive MR analyses identified credible causative metabolites, mediators of T2D and obesity, and obesity-independent causative metabolites for severe COVID-19. These biomarkers provide a novel basis for mechanistic studies for risk assessment, prognostication, and therapeutic purposes in COVID-19.

4.
Life (Basel) ; 12(6)2022 Jun 10.
Article in English | MEDLINE | ID: covidwho-1911448

ABSTRACT

In an effort to identify functional-energetic correlations leading to the development of efficient anti-SARS-CoV-2 therapeutic agents, we have designed synthetic analogs of aurintricarboxylic acid (ATA), a heterogeneous polymeric mixture of structurally related linear homologs known to exhibit a host of biological properties, including antiviral activity. These derivatives are evaluated for their ability to interact with a plasma transporter protein (human serum albumin), eukaryotic (yeast) ribosomes, and a SARS-CoV-2 target, the RNA-dependent RNA polymerase (RdRp). The resultant data are critical for characterizing drug distribution, bioavailability, and effective inhibition of host and viral targets. Promising lead compounds are selected on the basis of their binding energetics which have been characterized and correlated with functional activities as assessed by inhibition of RNA replication and protein synthesis. Our results reveal that the activity of heterogeneous ATA is mimicked by linear compounds of defined molecular weight, with a dichlorohexamer salicylic-acid derivative exhibiting the highest potency. These findings are instrumental for optimizing the design of structurally defined ATA analogs that fulfill the requirements of an antiviral drug with respect to bioavailability, homogeneity, and potency, thereby expanding the arsenal of therapeutic regimens that are currently available to address the urgent need for effective SARS-CoV-2 treatment strategies.

5.
Journal of Men's Health ; 18(3), 2022.
Article in English | EMBASE | ID: covidwho-1884949

ABSTRACT

Background: Neuroendocrine cancer of the prostate can present in diverse clinical pictures, potentially hampering the diagnosis and probably leading to underdiagnosis. Methods: Two cases are presented corresponding respectively to two forms of the disease: de novo neuroendocrine cancer and dedifferenciation of an adenocarcinoma of the prostate to neuroendocrine cancer under long term luteinising hormone releasing hormone (LHRH) agonist treatment. Results: Suspicion of neuroendocrine cancer may be raised in prostate cancer patients presenting either clinical or radiological metastatic progression without prostate specific antigen (PSA) rise, or relatively extended metastatic disease right at diagnosis associated to relatively low PSA, yet any non-pulmonary visceral metastases. Neuroendocrine cancer of the prostate can also turn out to be the origin of an adenocarcinoma of unknown primary. Conclusion: In case these considerations are respected the risk of missing the correct diagnosis of a neuroendocrine cancer of the prostate may be minimised.

6.
Biomed Pharmacother ; 151: 113124, 2022 Jul.
Article in English | MEDLINE | ID: covidwho-1850707

ABSTRACT

The substrate-analog furin inhibitor MI-1851 can suppress the cleavage of SARS-CoV-2 spike protein and consequently produces significant antiviral effect on infected human airway epithelial cells. In this study, the interaction of inhibitor MI-1851 was examined with human serum albumin using fluorescence spectroscopy and ultrafiltration techniques. Furthermore, the impacts of MI-1851 on human microsomal hepatic cytochrome P450 (CYP) 1A2, 2C9, 2C19, 2D6 and 3A4 activities were assessed based on fluorometric assays. The inhibitory action was also examined on human recombinant CYP3A4 enzyme and on hepatocytes. In addition, microsomal stability (60 min) and cytotoxicity were tested as well. MI-1851 showed no relevant interaction with human serum albumin and was significantly depleted by human microsomes. Furthermore, it did not inhibit CYP1A2, 2C9, 2C19 and 2D6 enzymes. In human hepatocytes, CYP3A4 was significantly suppressed by MI-1851 and weak inhibition was noticed in regard to human microsomes and human recombinant CYP3A4. Finally, MI-1851 did not impair the viability and the oxidative status of primary human hepatocytes (up to 100 µM concentration). Based on these observations, furin inhibitor MI-1851 appears to be potential drug candidates in the treatment of COVID-19, due to the involvement of furin in S protein priming and thus activation of the pandemic SARS-CoV-2.


Subject(s)
Cytochrome P-450 Enzyme Inhibitors , Furin , Albumins/pharmacology , COVID-19/drug therapy , Cytochrome P-450 CYP3A/metabolism , Cytochrome P-450 Enzyme Inhibitors/metabolism , Cytochrome P-450 Enzyme Inhibitors/pharmacology , Cytochrome P-450 Enzyme Inhibitors/toxicity , Cytochrome P-450 Enzyme System/drug effects , Cytochrome P-450 Enzyme System/metabolism , Furin/antagonists & inhibitors , Furin/metabolism , Furin/pharmacology , Humans , Microsomes, Liver , SARS-CoV-2/drug effects , Serum Albumin, Human/metabolism , Spike Glycoprotein, Coronavirus
7.
Ir J Med Sci ; 2022 Feb 19.
Article in English | MEDLINE | ID: covidwho-1701458

ABSTRACT

PURPOSE: We aimed to assess the combined role of vitamin D and albumin serum levels as predictors of COVID-19 disease progression. METHODS: We conducted a prospective observational study on adult patients hospitalized for SARS-CoV-2 pneumonia (March-September 2020). Vitamin D and albumin serum levels were measured on admission. These variables were categorized in albumin < 3.5 or ≥ 3.5 g/dL and vitamin D < 30 ng/mL or ≥ 30 ng/mL. We excluded patients with known bone diseases, renal failure, hypercalcemia and/or treated with antiepileptic drugs and steroids, and patients who received previous vitamin D supplementation. A composite outcome including any ventilatory support, PaO2/FiO2 ratio, and 60-day mortality was defined. RESULTS: Sixty-nine patients were enrolled, of whom 50% received non-invasive (NIV) or invasive mechanical ventilation (IMV), 10% died, whereas 89% and 66% presented low albumin and low vitamin D serum levels, respectively. No correlation between vitamin D and albumin levels was found. In multivariable logistic regression analyses adjusted for sex and age-corrected comorbidities, patients having albumin < 3.5 g/dL and vitamin D < 30 ng/mL showed a significant increased risk for all study outcomes, namely NIV/IMV (OR 3.815; 95% CI 1.122-12.966; p = 0.032), NIV/IMV or death (OR 3.173; 95% CI 1.002-10.043; p = 0.049) and PaO2/FIO2 ≤ 100 (OR 3.410; 95% CI 1.138-10.219; p = 0.029). CONCLUSION: The measurement of both vitamin D and serum albumin levels on COVID-19 patients' admission, and their combined evaluation, provides a simple prognostic tool that could be employed to guide prompt clinical decisions.

8.
Biosensors (Basel) ; 12(1)2022 Jan 07.
Article in English | MEDLINE | ID: covidwho-1613612

ABSTRACT

C-reactive protein (CRP) is a non-specific biomarker of inflammation and may be associated with cardiovascular disease. In recent studies, systemic inflammatory responses have also been observed in cases of coronavirus disease 2019 (COVID-19). Molecularly imprinted polymers (MIPs) have been developed to replace natural antibodies with polymeric materials that have low cost and high stability and could thus be suitable for use in a home-care system. In this work, a MIP-based electrochemical sensing system for measuring CRP was developed. Such a system can be integrated with microfluidics and electronics for lab-on-a-chip technology. MIP composition was optimized using various imprinting template (CRP peptide) concentrations. Tungsten disulfide (WS2) was doped into the MIPs. Doping not only enhances the electrochemical response accompanying the recognition of the template molecules but also raises the top of the sensing range from 1.0 pg/mL to 1.0 ng/mL of the imprinted peptide. The calibration curve of the WS2-doped peptide-imprinted polymer-coated electrodes in the extended-gate field-effect transistor platform was obtained and used for the measurement of CRP concentration in real human serum.


Subject(s)
C-Reactive Protein/analysis , Molecularly Imprinted Polymers , Sulfides , Tungsten Compounds , Electrochemical Techniques , Electrodes , Humans , Peptides
9.
Journal of Electroanalytical Chemistry ; : 116018, 2022.
Article in English | ScienceDirect | ID: covidwho-1611822

ABSTRACT

Human serum albumin (HSA) is an abundant protein in blood serum and an indicator of several illnesses, for instance, Covid-19, wherein, a severe decrement in the concentration level is noticed that leads to a higher risk of mortality. The conventional ELISA-based protocol has been referred for the analysis which is less sensitive, cumbersome and time-consuming (4-6 hours). Herein, we introduce, a new sandwich-type electrochemical immunosensor based on Thionine(Th)-redox immobilized f-MWCNT(f-carboxylic functionalized)+PEDOT.PSS modified glassy carbon/screen-printed electrode (GCE/f-MWCNT+PEDOT@Th) for quick (∼20 min), low-sample volume (1 µL) and low concentration (10-9 g/mL) analysis of HSA. The GCE/f-MWCNT+PEDOT@Th showed a highly stable and fouling-free surface-confined redox feature at an apparent standard electrode potential, Eo’=-0.25 V vs Ag/AgCl with a surface-excess value, ΓTh=14×10-9 mol cm-2. A sandwich-type electrochemical immunosensor was prepared by sequential immobilization of 1 µL respective solutions without any linking agent on the chemically modified electrode followed by incubation at 37°C for 3—5 min and testing its bioelectrocatalytic H2O2 (500 µM) reduction reaction in pH 7 PBS. Interrelated solution phased and experimental conditions were systematically optimized. Under an optimal working condition, the as-prepared bioelectrode, CME-Ab1p-SkM-HSA-Ab1m-Ab2HRP showed a reliable calibration plot of HSA in a concentration window, 10-9—10-4 g/mL. The obtained calibration plot was parallel to the ELISA of HSA in a limited concentration window, 10-7—10-4 g/mL. As a proof of concept, electrochemical immunosensing of urinary HSA has been demonstrated. Since, the new approach is simple, rapid, and efficient over conventional ELISA, it can be extendable to various HSA-real sample analyses.

10.
Biomed Pharmacother ; 146: 112513, 2022 Feb.
Article in English | MEDLINE | ID: covidwho-1575252

ABSTRACT

The interactions of four sulfonylated Phe(3-Am)-derived inhibitors (MI-432, MI-463, MI-482 and MI-1900) of type II transmembrane serine proteases (TTSP) such as transmembrane protease serine 2 (TMPRSS2) were examined with serum albumin and cytochrome P450 (CYP) isoenzymes. Complex formation with albumin was investigated using fluorescence spectroscopy. Furthermore, microsomal hepatic CYP1A2, 2C9, 2C19 and 3A4 activities in presence of these inhibitors were determined using fluorometric assays. The inhibitory effects of these compounds on human recombinant CYP3A4 enzyme were also examined. In addition, microsomal stability assays (60-min long) were performed using an UPLC-MS/MS method to determine depletion percentage values of each compound. The inhibitors showed no or only weak interactions with albumin, and did not inhibit CYP1A2, 2C9 and 2C19. However, the compounds tested proved to be potent inhibitors of CYP3A4 in both assays performed. Within one hour, 20%, 12%, 14% and 25% of inhibitors MI-432, MI-463, MI-482 and MI-1900, respectively, were degraded. As essential host cell factor for the replication of the pandemic SARS-CoV-2, the TTSP TMPRSS2 emerged as an important target in drug design. Our study provides further preclinical data on the characterization of this type of inhibitors for numerous trypsin-like serine proteases.


Subject(s)
Antiviral Agents/metabolism , Cytochrome P-450 Enzyme System/metabolism , Protease Inhibitors/metabolism , Serine Endopeptidases/metabolism , Serum Albumin, Human/metabolism , Antiviral Agents/analysis , Antiviral Agents/pharmacology , Dose-Response Relationship, Drug , Humans , Isoenzymes/metabolism , Microsomes, Liver/drug effects , Microsomes, Liver/metabolism , Protease Inhibitors/analysis , Protease Inhibitors/pharmacology , Protein Binding/physiology , Serine Endopeptidases/analysis , Spectrometry, Fluorescence/methods , Tandem Mass Spectrometry/methods
11.
Elife ; 102021 11 25.
Article in English | MEDLINE | ID: covidwho-1534519

ABSTRACT

Human serum albumin (HSA) is the frontline antioxidant protein in blood with established anti-inflammatory and anticoagulation functions. Here, we report that COVID-19-induced oxidative stress inflicts structural damages to HSA and is linked with mortality outcome in critically ill patients. We recruited 39 patients who were followed up for a median of 12.5 days (1-35 days), among them 23 had died. Analyzing blood samples from patients and healthy individuals (n=11), we provide evidence that neutrophils are major sources of oxidative stress in blood and that hydrogen peroxide is highly accumulated in plasmas of non-survivors. We then analyzed electron paramagnetic resonance spectra of spin-labeled fatty acids (SLFAs) bound with HSA in whole blood of control, survivor, and non-survivor subjects (n=10-11). Non-survivors' HSA showed dramatically reduced protein packing order parameter, faster SLFA correlational rotational time, and smaller S/W ratio (strong-binding/weak-binding sites within HSA), all reflecting remarkably fluid protein microenvironments. Following loading/unloading of 16-DSA, we show that the transport function of HSA may be impaired in severe patients. Stratified at the means, Kaplan-Meier survival analysis indicated that lower values of S/W ratio and accumulated H2O2 in plasma significantly predicted in-hospital mortality (S/W≤0.15, 81.8% (18/22) vs. S/W>0.15, 18.2% (4/22), p=0.023; plasma [H2O2]>8.6 µM, 65.2% (15/23) vs. 34.8% (8/23), p=0.043). When we combined these two parameters as the ratio ((S/W)/[H2O2]) to derive a risk score, the resultant risk score lower than the mean (<0.019) predicted mortality with high fidelity (95.5% (21/22) vs. 4.5% (1/22), log-rank χ2=12.1, p=4.9×10-4). The derived parameters may provide a surrogate marker to assess new candidates for COVID-19 treatments targeting HSA replacements and/or oxidative stress.


Subject(s)
COVID-19/mortality , Neutrophils/physiology , Oxidative Stress , Serum Albumin/adverse effects , Adult , Aged , Aged, 80 and over , Case-Control Studies , Egypt/epidemiology , Electron Spin Resonance Spectroscopy , Female , Humans , Hydrogen Peroxide/blood , Male , Middle Aged , Prospective Studies , Time Factors
12.
Front Immunol ; 12: 693462, 2021.
Article in English | MEDLINE | ID: covidwho-1485053

ABSTRACT

Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was first reported in December 2019 in Wuhan, China, and then rapidly spread causing an unprecedented pandemic. A robust serological assay is needed to evaluate vaccine candidates and better understand the epidemiology of coronavirus disease (COVID-19). Methods: We used the full-length spike (S) protein of SARS-CoV-2 for the development of qualitative and quantitative IgG and IgA anti-S enzyme linked immunosorbent assays (ELISA). A total of 320 sera used for assay development were comprised of pandemic sera from SARS-CoV-2 infected adults (n=51) and pre-pandemic sera (n=269) including sera from endemic human coronavirus infected adults. Reverse cumulative curves and diagnostic test statistics were evaluated to define the optimal serum dilution and OD cutoff value for IgG anti-S and IgA anti-S ELISAs. The IgG and IgA anti-S, and three functional antibodies (ACE-2 receptor blocking antibody, lentipseudovirus-S neutralizing antibody, and SARS-CoV-2 neutralizing antibody) were measured using additional SARS-CoV-2 PCR positive sera (n=76) and surveillance sera (n=25). Lastly, the IgG and IgA anti-S levels were compared in different demographic groups. Results: The optimal serum dilution for the qualitative IgG anti-S ELISA was at 1:1024 yielding a 99.6% specificity, 92.2% sensitivity, 92.9% positive predictive value (PPV), and 99.6% negative predictive value (NPV) at a SARS-CoV-2 seroprevalence of 5%. The optimal serum dilution for the qualitative IgA anti-S ELISA was at 1:128 yielding a 98.9% specificity, 76.5% sensitivity, 78.3% PPV, and 98.8% NPV at the same seroprevalence. Significant correlations were demonstrated between the IgG and IgA (r=0.833 for concentrations, r=0.840 for titers) as well as between IgG and three functional antibodies (r=0.811-0.924 for concentrations, r=0.795-0.917 for titers). The IgG and IgA anti-S levels were significantly higher in males than females (p<0.05), and in adults with moderate/severe symptoms than in adults with mild/moderate symptoms (p<0.001). Conclusion: We developed a highly specific and sensitive IgG anti-S ELISA assay to SARS-CoV-2 using full length S protein. The IgG anti-S antibody level was strongly associated with IgA and functional antibody levels in adults with SARS-CoV-2 infection. Gender and disease severity, rather than age, play an important role in antibody levels.


Subject(s)
Antibodies, Viral/immunology , COVID-19/immunology , Immunoglobulin A/immunology , Immunoglobulin G/immunology , SARS-CoV-2/immunology , Adult , COVID-19/diagnosis , COVID-19 Serological Testing , Female , HEK293 Cells , Humans
13.
Int J Biol Macromol ; 193(Pt A): 948-955, 2021 Dec 15.
Article in English | MEDLINE | ID: covidwho-1471998

ABSTRACT

The severe acute respiratory syndrome corona virus-2 (SARS-CoV-2) keeps on destroying normal social integrity worldwide, bringing about extraordinary medical services, cultural and financial interruption. Individuals with diabetes have been demonstrated to be at higher risk of complications and even death when exposed to SARS-CoV-2. Regardless of pandemic scale infection, there is presently limited comprehension on the potential impact of SARS-CoV-2 on individuals with diabetes. Human serum albumin (HSA) is the most abundant circulating plasma protein in human serum and attracted more interest from researchers because most susceptible to non-enzymatic glycation reactions. Albumin down-regulates the expression of ACE2 that is the target receptor of COVID-19. Hypoalbuminemia, coagulopathy, and vascular disease have been connected in COVID-19 and appear to predict outcomes independent of age and morbidity. This review discusses the most recent evidence that the ACE/ACE2 ratio could influence by human serum albumin both the susceptibility of individuals to SARS-CoV-2 infection and the outcome of the COVID-19 disease.


Subject(s)
Angiotensin-Converting Enzyme 2/blood , COVID-19 , SARS-CoV-2/metabolism , Serum Albumin, Human/metabolism , Blood Coagulation Disorders/blood , Blood Coagulation Disorders/diagnosis , Blood Coagulation Disorders/therapy , COVID-19/blood , COVID-19/diagnosis , COVID-19/therapy , Disease Susceptibility , Humans , Vascular Diseases/blood , Vascular Diseases/diagnosis , Vascular Diseases/therapy
14.
Saudi J Biol Sci ; 29(1): 53-64, 2022 Jan.
Article in English | MEDLINE | ID: covidwho-1415785

ABSTRACT

Human serum albumin (HSA) is the most prevalent protein in the blood plasma which binds an array of exogenous compounds. Drug binding to HSA is an important consideration when developing new therapeutic molecules, and it also aids in understanding the underlying mechanisms that govern their pharmacological effects. This study aims to investigate the molecular binding of coronavirus disease 2019 (COVID-19) therapeutic candidate molecules to HSA and to identify their putative binding sites. Binding energies and interacting residues were used to evaluate the molecular interaction. Four drug candidate molecules (ß-D-N4-hydroxycytidine, Chloroquine, Disulfiram, and Carmofur) demonstrate weak binding to HSA, with binding energies ranging from -5 to -6.7 kcal/mol. Ivermectin, Hydroxychloroquine, Remdesivir, Arbidol, and other twenty drug molecules with binding energies ranging from -6.9 to -9.5 kcal/mol demonstrated moderate binding to HSA. The strong HSA binding drug candidates consist of fourteen molecules (Saquinavir, Ritonavir, Dihydroergotamine, Daclatasvir, Paritaprevir etc.) with binding energies ranging from -9.7 to -12.1 kcal/mol. All these molecules bind to different HSA subdomains (IA, IB, IIA, IIB, IIIA, and IIIB) through molecular forces such as hydrogen bonds and hydrophobic interactions. Various pharmacokinetic properties (gastrointestinal absorption, blood-brain barrier permeation, P-glycoprotein substrate, and cytochrome P450 inhibitor) of each molecule were determined using SwissADME program. Further, the stability of the HSA-ligand complexes was analyzed through 100 ns molecular dynamics simulations considering various geometric properties. The binding free energy between free HSA and compounds were calculated using Molecular mechanics Poisson-Boltzmann surface area (MM/PBSA) and molecular mechanics generalized Born surface area (MM/GBSA) approach. The findings of this study might be useful in understanding the mechanism of COVID-19 drug candidates binding to serum albumin protein, as well as their pharmacodynamics and pharmacokinetics.

15.
Exp Physiol ; 107(7): 674-682, 2022 Jul.
Article in English | MEDLINE | ID: covidwho-1314102

ABSTRACT

What is the topic of this review? Human serum albumin (HSA) a common factor in COVID-19 vulnerabilities. What advances does it highlight? Understanding of HSA capacity, and systemic vulnerabilities to COVID-19. Raising HSA in COVID-19 patients may alleviate systemic injury caused by diminished native HSA binding. A change in fluid therapy administration into the portal system of the liver is proposed to safely raise HSA levels. ABSTRACT: The specific nature of the vulnerabilities to COVID-19 are an intrinsic part of COVID-19 infection in many patients. This paper proposes that vulnerabilities to COVID-19 may be intensified by a decrease in human serum albumin (HSA) as a ligand carrier for nutrients. A mechanism for COVID-19 vulnerabilities is evident from consideration of ligand carriers such as HSA as intermediaries. We hypothesise that low levels of pool HSA binding, caused for whatever reason, affect the performance of albumin as a carrier protein reducing the availability of nutrients. Hypoalbuminaemia (low HSA) has been implicated as an indicator of COVID-19 and long-COVID-19. The levels of HSA directly affect the immune system and vulnerabilities to age, diabetes and obesity in COVID-19. Any slight reduction in available HSA has profound effects on ligand concentrations in the small capillaries where damage occurs in COVID-19. The clinical implication is that attempts should be made to return HSA to clinical levels to compensate for the additional ligands caused by infection (SARS-CoV-2 virions, antibodies and cellular breakdown products). Therapeutic albumin is usually given peripherally, and usual preparations are unbound to ligands, but we suggest that a clinical trial of HSA therapy via the hepatic portal vein should be considered.


Subject(s)
COVID-19 , COVID-19/complications , Humans , Ligands , Protein Binding , SARS-CoV-2 , Serum Albumin/metabolism , Serum Albumin/therapeutic use , Serum Albumin, Human/metabolism
16.
Cells ; 10(3)2021 03 04.
Article in English | MEDLINE | ID: covidwho-1125522

ABSTRACT

Since the outbreak of the COVID-19 crisis, the handling of biological samples from confirmed or suspected SARS-CoV-2-positive individuals demanded the use of inactivation protocols to ensure laboratory operators' safety. While not standardized, these practices can be roughly divided into two categories, namely heat inactivation and solvent-detergent treatments. These routine procedures should also apply to samples intended for Extracellular Vesicles (EVs) analysis. Assessing the impact of virus-inactivating pre-treatments is therefore of pivotal importance, given the well-known variability introduced by different pre-analytical steps on downstream EVs isolation and analysis. Arguably, shared guidelines on inactivation protocols tailored to best address EVs-specific requirements will be needed among the analytical community, yet deep investigations in this direction have not yet been reported. We here provide insights into SARS-CoV-2 inactivation practices to be adopted prior to serum EVs analysis by comparing solvent/detergent treatment vs. heat inactivation. Our analysis entails the evaluation of EVs recovery and purity along with biochemical, biophysical and biomolecular profiling by means of a set of complementary analytical techniques: Nanoparticle Tracking Analysis, Western Blotting, Atomic Force Microscopy, miRNA content (digital droplet PCR) and tetraspanin assessment by microarrays. Our data suggest an increase in ultracentrifugation (UC) recovery following heat treatment; however, it is accompanied by a marked enrichment in EVs-associated contaminants. On the other hand, solvent/detergent treatment is promising for small EVs (<150 nm range), yet a depletion of larger vesicular entities was detected. This work represents a first step towards the identification of optimal serum inactivation protocols targeted to EVs analysis.


Subject(s)
COVID-19/blood , Containment of Biohazards/methods , Extracellular Vesicles/chemistry , Virus Inactivation , COVID-19/virology , Detergents/pharmacology , Extracellular Vesicles/drug effects , Extracellular Vesicles/genetics , Hot Temperature , Humans , MicroRNAs/analysis , Microarray Analysis , Microscopy, Atomic Force , SARS-CoV-2 , Tetraspanins/analysis , Ultracentrifugation
17.
Bioanalysis ; 13(5): 387-394, 2021 Mar.
Article in English | MEDLINE | ID: covidwho-1116300

ABSTRACT

Aim: For oncolytic virus trials, regulatory agencies often require pharmaceutical industry to evaluate risks of released viruses from patients to environment. This study was to establish a real-time PCR method to assess viral shedding and viral stability in human urine. Results/methodology: Herein, we describe an incubation of viral drug product in human urine and use of real-time PCR as a simple, efficient and high throughput assay to assess the level and stability of a nonenveloped and single stranded RNA virus. The viral stability issue is critical to the collection, transport, storage and testing of clinical samples. Discussion/conclusion: In summary, this simple method provides useful viral stability information at various temperatures and detergents. A similar approach may apply to other RNA viruses (including SARS-CoV-2).


Subject(s)
RNA, Viral/metabolism , Real-Time Polymerase Chain Reaction , Virus Diseases/diagnosis , COVID-19/diagnosis , COVID-19/virology , Detergents/chemistry , Humans , RNA Stability , RNA, Viral/blood , RNA, Viral/urine , SARS-CoV-2/genetics , SARS-CoV-2/isolation & purification , Temperature , Virus Diseases/virology
18.
Front Cardiovasc Med ; 7: 153, 2020.
Article in English | MEDLINE | ID: covidwho-838591

ABSTRACT

The emergence of the COVID-19 virus and the subsequent pandemic have driven a great deal of research activity. The effects of COVID-19 are caused by the severe respiratory syndrome coronavirus 2 (SARS-CoV-2) and it is the underlying actions of SARs-CoV-2 virions on the endothelial glycocalyx that we consider here. One of the key factors in COVID-19 infection is its almost unique age-related profile, with a doubling in mortality every 10 years after the age of 50. The endothelial glycocalyx layer is essential in maintaining normal fluid homeostasis, but is fragile and prone to pathophysiological damage. It is physiologically significant in capillary microcirculation and in fluid distribution to the tissues. Human serum albumin (HSA), the most abundant protein in plasma, is created in the liver which also maintains its concentration, but this reduces by 10-15% after 50 years of age. HSA transports hormones, free fatty acids and maintains oncotic pressure, but SARS-CoV-2 virions bind competitively to HSA diminishing its normal transport function. Furthermore, hypoalbuminemia is frequently observed in patients with such conditions as diabetes, hypertension, and chronic heart failure, i.e., those most vulnerable to SARS-CoV-2 infection. Hypoalbuminemia, coagulopathy, and vascular disease have been linked in COVID-19 and have been shown to predict outcome independent of age and morbidity. Hypoalbuminemia is also known factor in sepsis and Acute respiratory distress syndrome (ARDS) occurs when fluids build-up in the alveoli and it is associated with sepsis, whose mechanism is systemic, being associated with the fluid and logistic mechanisms of the circulation. Glycocalyx damage is associated with changes plasma protein concentration, particularly HSA and blockage of albumin transport can produce the systemic symptoms seen in SARS-CoV-2 infection and sepsis. We therefore conclude that albumin binding to SARS-CoV-2 virions may inhibit the formation of the endothelial glycocalyx by inhibition of albumin transport binding sites. We postulate that albumin therapy to replace bound albumin might alleviate some of the symptoms leading to sepsis and that clinical trials to test this postulation should be initiated as a matter of urgency.

SELECTION OF CITATIONS
SEARCH DETAIL