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Proceedings of the National Academy of... Mar 2020Neurodegenerative diseases feature specific misfolded or misassembled proteins associated with neurotoxicity. The precise mechanisms by which protein aggregates first...
Neurodegenerative diseases feature specific misfolded or misassembled proteins associated with neurotoxicity. The precise mechanisms by which protein aggregates first arise in the majority of sporadic cases have remained unclear. Likely, a first critical mass of misfolded proteins starts a vicious cycle of a prion-like expansion. We hypothesize that viruses, having evolved to hijack the host cellular machinery for catalyzing their replication, lead to profound disturbances of cellular proteostasis, resulting in such a critical mass of protein aggregates. Here, we investigated the effect of influenza virus (H1N1) strains on proteostasis of proteins associated with neurodegenerative diseases in Lund human mesencephalic dopaminergic cells in vitro and infection of knockout mice in vivo. We demonstrate that acute H1N1 infection leads to the formation of α-synuclein and Disrupted-in-Schizophrenia 1 (DISC1) aggregates, but not of tau or TDP-43 aggregates, indicating a selective effect on proteostasis. Oseltamivir phosphate, an antiinfluenza drug, prevented H1N1-induced α-synuclein aggregation. As a cell pathobiological mechanism, we identified H1N1-induced blocking of autophagosome formation and inhibition of autophagic flux. In addition, α-synuclein aggregates appeared in infected cell populations connected to the olfactory bulbs following intranasal instillation of H1N1 in knockout mice. We propose that H1N1 virus replication in neuronal cells can induce seeds of aggregated α-synuclein or DISC1 that may be able to initiate further detrimental downstream events and should thus be considered a risk factor in the pathogenesis of synucleinopathies or a subset of mental disorders. More generally, aberrant proteostasis induced by viruses may be an underappreciated factor in initiating protein misfolding.
Topics: Animals; Dopaminergic Neurons; Female; Homeodomain Proteins; Humans; Influenza A Virus, H1N1 Subtype; Influenza, Human; Mice; Mice, Knockout; Nerve Tissue Proteins; Orthomyxoviridae Infections; Protein Multimerization; Proteostasis; Synucleinopathies; alpha-Synuclein
PubMed: 32152117
DOI: 10.1073/pnas.1906466117 -
Journal of Infection and Chemotherapy :... Aug 2019Four neuraminidase (NA) inhibitors and an RNA synthesis inhibitor were recently approved and are currently in clinical use for influenza. Among NA inhibitors,...
Four neuraminidase (NA) inhibitors and an RNA synthesis inhibitor were recently approved and are currently in clinical use for influenza. Among NA inhibitors, oseltamivir phosphate (OSE, Tamiflu) and zanamivir are approved worldwide, whereas peramivir and laninamivir octanoate (LAN, Inavir) are regionally approved for human use. Therefore, OSE has been used to treat infections of highly pathogenic influenza viruses, such as H5N1 and H7N9, which caused epidemic in southeast Asia and Egypt, and China, respectively. Generally, OSE is administered twice daily for 5 days by oral administration, and LAN once by inhalation for completing influenza therapy. In this study, we compared the efficacy of OSE and LAN administered according to the regimens in mice infected with highly lethal influenza viruses. The drugs were administered at the early and late stages of infection, which correspond to mild and severe inflammation in the lungs, respectively. Based on the drugs' regimens for human, a single administration of LAN at both stages of inflammation showed superior efficacy to repeated administration of OSE. LAN, as in OSE, could also be efficacious in treating severe influenza in humans.
Topics: Animals; Antiviral Agents; Cell Line; Dogs; Enzyme Inhibitors; Female; Guanidines; Inflammation; Influenza A Virus, H5N1 Subtype; Influenza A Virus, H7N9 Subtype; Madin Darby Canine Kidney Cells; Mice; Mice, Inbred BALB C; Neuraminidase; Orthomyxoviridae Infections; Oseltamivir; Pyrans; Sialic Acids; Zanamivir
PubMed: 30935767
DOI: 10.1016/j.jiac.2019.02.023 -
Journal of Pharmaceutical Sciences May 2019Baloxavir marboxil, a prodrug that is metabolized to baloxavir acid, suppresses viral replication by inhibiting cap-dependent endonuclease. Our aim is to characterize...
Baloxavir marboxil, a prodrug that is metabolized to baloxavir acid, suppresses viral replication by inhibiting cap-dependent endonuclease. Our aim is to characterize its pharmacokinetics and exposure-response relationships. Population pharmacokinetic analysis of the baloxavir acid was performed using 8310 plasma concentration data points from 1109 subjects. Exposure-response analyses were performed regarding the time to alleviation of symptoms and the reduction in the influenza virus titer. A 2-compartment model with first-order absorption and lag time well described the plasma concentration data for baloxavir acid, and body weight and race were found to be the most important factors influencing the clearance and distribution volume. A dose regimen based on the body weight (40 mg for patients weighing <80 kg and 80 mg for patients weighing ≥80 kg) could provide sufficient exposures for expecting efficacy irrespective of body weight or race; however, the exposures were dependent on the body weight and race. Exposure-response analyses suggested that the reduction in the influenza virus titer was greater in any exposure-based groups in baloxavir marboxil treatment than in the oseltamivir phosphate treatment and placebo groups. In conclusion, the population pharmacokinetic model and exposure-response relationships would be useful for understanding the pharmacokinetic and pharmacodynamic characteristics of baloxavir acid.
Topics: Adolescent; Adult; Aged; Antiviral Agents; Child; Dibenzothiepins; Female; Humans; Influenza, Human; Male; Middle Aged; Morpholines; Oseltamivir; Oxazines; Prodrugs; Pyridines; Pyridones; Thiepins; Triazines; Virus Replication; Young Adult
PubMed: 30557562
DOI: 10.1016/j.xphs.2018.12.005 -
PloS One 2015The ferret is a suitable small animal model for preclinical evaluation of efficacy of antiviral drugs against various influenza strains, including highly pathogenic H5N1...
The ferret is a suitable small animal model for preclinical evaluation of efficacy of antiviral drugs against various influenza strains, including highly pathogenic H5N1 viruses. Rigorous pharmacokinetics/pharmacodynamics (PK/PD) assessment of ferret data has not been conducted, perhaps due to insufficient information on oseltamivir PK. Here, based on PK data from several studies on both uninfected and influenza-infected groups (i.e., with influenza A viruses of H5N1 and H3N2 subtypes and an influenza B virus) and several types of anesthesia we developed a population PK model for the active compound oseltamivir carboxylate (OC) in the ferret. The ferret OC population PK model incorporated delayed first-order input, two-compartment distribution, and first-order elimination to successfully describe OC PK. Influenza infection did not affect model parameters, but anesthesia did. The conclusion that OC PK was not influenced by influenza infection must be viewed with caution because the influenza infections in the studies included here resulted in mild clinical symptoms in terms of temperature, body weight, and activity scores. Monte Carlo simulations were used to determine that administration of a 5.08 mg/kg dose of oseltamivir phosphate to ferret every 12 h for 5 days results in the same median OC area under the plasma concentration-time curve 0-12 h (i.e., 3220 mg h/mL) as that observed in humans during steady state at the approved dose of 75 mg twice daily for 5 days. Modeling indicated that PK variability for OC in the ferret model is high, and can be affected by anesthesia. Therefore, for proper interpretation of PK/PD data, sparse PK sampling to allow the OC PK determination in individual animals is important. Another consideration in appropriate design of PK/PD studies is achieving an influenza infection with pronounced clinical symptoms and efficient virus replication, which will allow adequate evaluation of drug effects.
Topics: Administration, Oral; Animals; Antiviral Agents; Ferrets; Influenza A Virus, H3N2 Subtype; Influenza A Virus, H5N1 Subtype; Male; Models, Biological; Monte Carlo Method; Oseltamivir
PubMed: 26460484
DOI: 10.1371/journal.pone.0138069 -
JAMA Internal Medicine Oct 2017Potential research participants may assume that randomized trials comparing new interventions with older interventions always hypothesize greater efficacy for the new...
IMPORTANCE
Potential research participants may assume that randomized trials comparing new interventions with older interventions always hypothesize greater efficacy for the new intervention, as in superiority trials. However, antibiotic trials frequently use "noninferiority" hypotheses allowing a degree of inferior efficacy deemed "clinically acceptable" compared with an older effective drug, in exchange for nonefficacy benefits (eg, decreased adverse effects). Considering these different benefit-harm trade-offs, proper informed consent necessitates supplying different information on the purposes of superiority and noninferiority trials.
OBJECTIVE
To determine the degree to which the study purpose is explained to potential participants in randomized clinical trials of antibiotics and the degree to which study protocols justify their selection of noninferiority hypotheses and amount of "clinically acceptable" inferiority.
DESIGN AND SETTING
Cross-sectional analysis of study protocols, statistical analysis plans (SAPs), and informed consent forms (ICFs) from clinical study reports submitted to the European Medicines Agency. The ICFs were read by both methodologists and patient investigators.
MAIN OUTCOMES AND MEASURES
Protocols and SAPs were used as the reference standard to determine prespecified primary hypothesis and record rationale for selection of noninferiority hypotheses and noninferiority margins. This information was cross-referenced against ICFs to determine whether ICFs explained the study purpose.
RESULTS
We obtained trial documents from 78 randomized trials with prespecified efficacy hypotheses (6 superiority, 72 noninferiority) for 17 antibiotics conducted between 1991 and 2011 that enrolled 39 407 patients. Fifty were included in the ICF analysis. All ICFs contained sections describing study purpose; however, none consistently conveyed study hypothesis to both methodologists and patient investigators. Methodologists found that 1 of 50 conveyed a study purpose. Patient investigators found that 11 of 50 conveyed a study purpose, 7 accurately and 4 inaccurately compared with the reference standard. Seventy-one of 72 noninferiority trial protocols or SAPs provided no rationale for selection of noninferiority hypothesis. None provided a clinical rationale for the chosen amount of decreased efficacy.
CONCLUSIONS AND RELEVANCE
Patients were not accurately informed of study purpose, which raises questions regarding the ethics of informed consent in antibiotic trials. Noninferiority and superiority trials entail different benefit-harm trade-offs that must be conveyed for ethical informed consent.
Topics: Anti-Bacterial Agents; Consent Forms; Cross-Sectional Studies; Humans; Informed Consent; Randomized Controlled Trials as Topic; Retrospective Studies
PubMed: 28828473
DOI: 10.1001/jamainternmed.2017.3820 -
Biomedicine & Pharmacotherapy =... Apr 2024Sphingolipid transporter 1 (SPNS1) is a significant differentially expressed gene (DEGs) in esophageal squamous cell carcinoma (ESCC). According to 3 pairs clinic...
Sphingolipid transporter 1 (SPNS1) is a significant differentially expressed gene (DEGs) in esophageal squamous cell carcinoma (ESCC). According to 3 pairs clinic cohorts, transcriptomic (155 pairs of ESCC samples and GSE53624, and proteomic data from PXD021701 including 124 ESCC samples) we found that SPNS1 was significantly higher in ESCC tissues compared to adjacent normal esophagus tissues. ESCC patients with high SPNS1 had a significantly poorer clinical prognosis than those with low SPNS1. Knockdown of SPNS1 significantly inhibited the proliferation, migration, and invasion abilities of ESCC cells, while promoting apoptosis. And overexpression of SPNS1 exhibited opposite functions. Furthermore, ESCC cells became more sensitive to 5-fluorouracil (5-FU) when SPNS1 was knocked down. Transcriptome sequencing revealed that NEU1 was one significant DEG affected by SPNS1 and positively correlated with SPNS1 expression. Oseltamivir phosphate (OP), one NEU1 inhibitor, markedly reversed 5-FU resistance, migration, and proliferation induced by high expression of SPNS1 both in vivo and in vitro. Our findings indicated that SPNS1 might promote the progression of ESCC by upregulating NEU1 expression and influencing chemotherapy sensitivity. These results provide new perceptions into potential therapeutic targets for ESCC treatment. The present study aimed to investigate the role and underlying mechanism of SPNS1 in ESCC.
Topics: Humans; Esophageal Squamous Cell Carcinoma; Oseltamivir; Esophageal Neoplasms; Proteomics; Cell Line, Tumor; Cell Proliferation; Fluorouracil; Cell Movement; Gene Expression Regulation, Neoplastic
PubMed: 38460365
DOI: 10.1016/j.biopha.2024.116367 -
Clinical and Translational Medicine Dec 2014Snail, a transcriptional factor and repressor of E-cadherin is well known for its role in cellular invasion. It can regulate epithelial to mesenchymal transition (EMT)...
BACKGROUND
Snail, a transcriptional factor and repressor of E-cadherin is well known for its role in cellular invasion. It can regulate epithelial to mesenchymal transition (EMT) during embryonic development and in epithelial cells. Snail also mediates tumor progression and metastases. Silencing of Snail and its associate member Slug in human A2780 ovarian epithelial carcinoma cell line was investigated to identify its role in tumor neovascularization.
METHODS
Live cell sialidase, WST-1 cell viability and immunohistochemistry assays were used to evaluate sialidase activity, cell survival and the expression levels of tumor E-cadherin, N-cadherin, VE-cadherin, and host endothelial CD31+(PECAM-1) cells in archived paraffin-embedded ovarian A2780, A2780 Snail shRNA GIPZ lentiviral knockdown (KD) and A2780 Slug shRNA GIPZ lentiviral KD tumors grown in RAGxCγ double mutant mice.
RESULTS
Oseltamivir phosphate (OP), anti-Neu1 antibodies and MMP-9 specific inhibitor blocked Neu1 activity associated with epidermal growth factor (EGF) stimulated A2780 ovarian epithelial carcinoma cells. Silencing Snail in A2780 cells abrogated the Neu1 activity following EGF stimulation of the cells compared to A2780 and A2780 Slug KD cells. OP treatment of A2780 and cisplatin-resistant A2780cis cells reproducibly and dose-dependently abated the cell viability with a LD50 of 7 and 4 μm, respectively, after 48 h of incubation. Heterotopic xenografts of A2780 and A2780 Slug KD tumors developed robust and bloody tumor vascularization in RAG2xCγ double mutant mice. OP treatment at 50 mg/kg daily intraperitoneally did not significantly impede A2780 tumor growth rate but did cause a significant reduction of lung metastases compared with the untreated and OP 30mg/kg cohorts. Silencing Snail in A2780 tumor cells completely abrogated tumor vascularization, tumor growth and spread to the lungs in RAGxCγ double mutant mice. A2780 and A2780 Slug KD tumors expressed high levels of human N- and VE-cadherins, and host CD31+ endothelial cells, while A2780 Snail KD tumors expressed E-cadherin and reduced host CD31+ cells. OP 50mg/kg cohort tumors had reduced numbers of host CD31+ cells compared to a higher expression levels of CD31+ cells in tumors from the untreated control and OP 30mg/kg cohorts.
CONCLUSION
Snail transcriptional factor is an important intermediate player in human ovarian tumor neovascularization.
PubMed: 26932374
DOI: 10.1186/s40169-014-0028-z -
Viruses Jan 2022Human infections caused by the H5 highly pathogenic avian influenza virus (HPAIV) sporadically threaten public health. The susceptibility of HPAIVs to baloxavir acid...
Human infections caused by the H5 highly pathogenic avian influenza virus (HPAIV) sporadically threaten public health. The susceptibility of HPAIVs to baloxavir acid (BXA), a new class of inhibitors for the influenza virus cap-dependent endonuclease, has been confirmed in vitro, but it has not yet been fully characterized. Here, the efficacy of BXA against HPAIVs, including recent H5N8 variants, was assessed in vitro. The antiviral efficacy of baloxavir marboxil (BXM) in H5N1 virus-infected mice was also investigated. BXA exhibited similar in vitro activities against H5N1, H5N6, and H5N8 variants tested in comparison with seasonal and other zoonotic strains. Compared with oseltamivir phosphate (OSP), BXM monotherapy in mice infected with the H5N1 HPAIV clinical isolate, the A/Hong Kong/483/1997 strain, also caused a significant reduction in viral titers in the lungs, brains, and kidneys, thereby preventing acute lung inflammation and reducing mortality. Furthermore, compared with BXM or OSP monotherapy, combination treatments with BXM and OSP using a 48-h delayed treatment model showed a more potent effect on viral replication in the organs, accompanied by improved survival. In conclusion, BXM has a potent antiviral efficacy against H5 HPAIV infections.
Topics: A549 Cells; Animals; Antiviral Agents; Chemokines; Cytokines; Dibenzothiepins; Drug Therapy, Combination; Female; Humans; Influenza A Virus, H5N1 Subtype; Influenza A virus; Lung; Mice; Mice, Inbred BALB C; Morpholines; Orthomyxoviridae Infections; Oseltamivir; Pneumonia; Pyridones; Sequence Analysis; Triazines; Virus Replication
PubMed: 35062315
DOI: 10.3390/v14010111 -
Tetrahedron Sep 2020Influenza is a serious respiratory disease responsible for significant morbidity and mortality due to both annual epidemics and pandemics; its treatment involves the use... (Review)
Review
Influenza is a serious respiratory disease responsible for significant morbidity and mortality due to both annual epidemics and pandemics; its treatment involves the use of neuraminidase inhibitors. (-)-Oseltamivir phosphate (Tamiflu) approved in 1999, is one of the most potent oral anti-influenza neuraminidase inhibitors. Consequently, more than 70 Tamiflu synthetic procedures have been developed to date. Herein, we highlight the evolution of Tamiflu synthesis since its discovery over 20 years ago in the quest for a truly efficient, safe, cost-effective and environmentally benign synthetic procedure. We have selected a few representative routes to give a clear account of the past, present and the future with the advent of enabling technologies.
PubMed: 32839628
DOI: 10.1016/j.tet.2020.131440 -
Antimicrobial Agents and Chemotherapy Nov 2015End-stage renal disease (ESRD) patients receiving hemodialysis (HD) are at heightened risk for influenza, but the optimal oseltamivir dosage regimen for treating or...
Investigating clinically adequate concentrations of oseltamivir carboxylate in end-stage renal disease patients undergoing hemodialysis using a population pharmacokinetic approach.
End-stage renal disease (ESRD) patients receiving hemodialysis (HD) are at heightened risk for influenza, but the optimal oseltamivir dosage regimen for treating or preventing influenza in this high-risk population is still uncertain. Pharmacokinetic data for 24 adults with ESRD were pooled from a single-dose and a multiple-dose study to develop a population pharmacokinetic model using nonlinear mixed-effects modeling. The final model comprised five compartments, two each to describe the systemic pharmacokinetics of oseltamivir phosphate and its metabolite, oseltamivir carboxylate (OC), and a delay compartment to describe oseltamivir metabolism. Estimated OC clearance in the model was markedly faster during HD sessions (7.43 liters/min) than at other times (0.19 liter/min). Model simulations showed that 30 mg oseltamivir given after every HD session is the most suitable regimen for influenza treatment, producing trough OC concentrations above the median value achieved with the 75-mg twice-daily regimen in patients with normal renal function and peak concentrations below the highest oseltamivir exposures known to be well tolerated (median exposures after twice-daily dosing of 450 mg). Administration of the first dose following diagnosis of influenza need not wait until after the next HD session: addition of a single 30-mg dose during the 12 h before the next HD session raises OC exposures quickly without posing any safety risk. Further simulation showed that 30 mg oseltamivir given after every other HD session is the most suitable regimen for influenza prophylaxis.
Topics: Adolescent; Adult; Aged; Antiviral Agents; Female; Humans; Kidney Failure, Chronic; Male; Middle Aged; Models, Theoretical; Oseltamivir; Renal Dialysis; Young Adult
PubMed: 26282419
DOI: 10.1128/AAC.01024-15