scholarly journals Lactoferrin Against SARS-CoV-2: In Vitro and In Silico Evidences

2021 ◽  
Vol 12 ◽  
Author(s):  
Elena Campione ◽  
Caterina Lanna ◽  
Terenzio Cosio ◽  
Luigi Rosa ◽  
Maria Pia Conte ◽  
...  
Keyword(s):  
Antiviral Activity ◽  
Viral Entry ◽  
In Silico ◽  
Iron Homeostasis ◽  
Host Cells ◽  
Intracellular Iron ◽  
Infection And Inflammation ◽  
Direct Recognition

Lactoferrin (Lf) is a cationic glycoprotein synthetized by exocrine glands and is present in all human secretions. It is also secreted by neutrophils in infection and inflammation sites. This glycoprotein possesses antimicrobial activity due to its capability to chelate two ferric ions per molecule, as well as to interact with bacterial and viral anionic surface components. The cationic features of Lf bind to cells, protecting the host from bacterial and viral injuries. Its anti-inflammatory activity is mediated by the ability to enter inside the nucleus of host cells, thus inhibiting the synthesis of proinflammatory cytokine genes. In particular, Lf down-regulates the synthesis of IL-6, which is involved in iron homeostasis disorders and leads to intracellular iron overload, favoring viral replication and infection. The well-known antiviral activity of Lf has been demonstrated against DNA, RNA, and enveloped and naked viruses and, therefore, Lf could be efficient in counteracting also SARS-CoV-2 infection. For this purpose, we performed in vitro assays, proving that Lf exerts an antiviral activity against SARS-COV-2 through direct attachment to both SARS-CoV-2 and cell surface components. This activity varied according to concentration (100/500 μg/ml), multiplicity of infection (0.1/0.01), and cell type (Vero E6/Caco-2 cells). Interestingly, the in silico results strongly supported the hypothesis of a direct recognition between Lf and the spike S glycoprotein, which can thus hinder viral entry into the cells. These in vitro observations led us to speculate a potential supplementary role of Lf in the management of COVID-19 patients.

scholarly journals Viral Hepatitis and Iron Dysregulation: Molecular Pathways and the Role of Lactoferrin

Molecules ◽  
2020 ◽  
Vol 25 (8) ◽  
pp. 1997 ◽  
Author(s):  
Romina Mancinelli ◽  
Luigi Rosa ◽  
Antimo Cutone ◽  
Maria Stefania Lepanto ◽  
Antonio Franchitto ◽  
...  
Keyword(s):  
Viral Hepatitis ◽  
Viral Entry ◽  
Iron Homeostasis ◽  
Iron Chelation ◽  
Host Cells ◽  
Surface Receptors ◽  
Inflammatory Processes ◽  
Related Proteins ◽  
Binding Glycoprotein

The liver is a frontline immune site specifically designed to check and detect potential pathogens from the bloodstream to maintain a general state of immune hyporesponsiveness. One of the main functions of the liver is the regulation of iron homeostasis. The liver detects changes in systemic iron requirements and can regulate its concentration. Pathological states lead to the dysregulation of iron homeostasis which, in turn, can promote infectious and inflammatory processes. In this context, hepatic viruses deviate hepatocytes’ iron metabolism in order to better replicate. Indeed, some viruses are able to alter the expression of iron-related proteins or exploit host receptors to enter inside host cells. Lactoferrin (Lf), a multifunctional iron-binding glycoprotein belonging to the innate immunity, is endowed with potent antiviral activity, mainly related to its ability to block viral entry into host cells by interacting with viral and/or cell surface receptors. Moreover, Lf can act as an iron scavenger by both direct iron-chelation or the modulation of the main iron-related proteins. In this review, the complex interplay between viral hepatitis, iron homeostasis, and inflammation as well as the role of Lf are outlined.

Impaired TLR4 and HIF expression in cystic fibrosis bronchial epithelial cells downregulates hemeoxygenase-1 and alters iron homeostasis in vitro

2014 ◽  
Vol 307 (10) ◽  
pp. L791-L799 ◽  
Author(s):  
Shashi Chillappagari ◽  
Shalini Venkatesan ◽  
Virajith Garapati ◽  
Poornima Mahavadi ◽  
Antje Munder ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Iron Homeostasis ◽  
Hypoxia Inducible Factor ◽  
Immunohistochemical Analysis ◽  
Surface Expression ◽  
Luciferase Reporter ◽  
Luciferase Reporter Gene ◽  
Intracellular Iron

Hemeoxygenase-1 (HO-1), an inducible heat shock protein, is upregulated in response to multiple cellular insults via oxidative stress, lipopolysaccharides (LPS), and hypoxia. In this study, we investigated in vitro the role of Toll-like receptor 4 (TLR4), hypoxia-inducible factor 1α (HIF-1α), and iron on HO-1 expression in cystic fibrosis (CF). Immunohistochemical analysis of TLR4, HO-1, ferritin, and HIF-1α were performed on lung sections of CFTR−/− and wild-type mice. CFBE41o- and 16HBE14o- cell lines were employed for in vitro analysis via immunoblotting, immunofluorescence, real-time PCR, luciferase reporter gene analysis, and iron quantification. We observed a reduced TLR4, HIF-1α, HO-1, and ferritin in CFBE41o- cell line and CF mice. Knockdown studies using TLR4-siRNA in 16HBE14o- revealed significant decrease of HO-1, confirming the role of TLR4 in HO-1 downregulation. Inhibition of HO-1 using tin protoporphyrin in 16HBE14o- cells resulted in increased iron levels, suggesting a probable role of HO-1 in iron accumulation. Additionally, sequestration of excess iron using iron chelators resulted in increased hypoxia response element response in CFBE41o- and 16HBE14o-, implicating a role of iron in HIF-1α stabilization and HO-1. To conclude, our in vitro results demonstrate that multiple regulatory factors, such as impaired TLR4 surface expression, increased intracellular iron, and decreased HIF-1α, downregulate HO-1 expression in CFBE41o- cells.

scholarly journals Host-Directed FDA-Approved Drugs with Antiviral Activity against SARS-CoV-2 Identified by Hierarchical In Silico/In Vitro Screening Methods

2021 ◽  
Vol 14 (4) ◽  
pp. 332
Author(s):  
Tiziana Ginex ◽  
Urtzi Garaigorta ◽  
David Ramírez ◽  
Victoria Castro ◽  
Vanesa Nozal ◽  
...  
Keyword(s):  
Antiviral Activity ◽  
Viral Entry ◽  
In Silico ◽  
Screening Methods ◽  
Speed Up ◽  
Approved Drugs ◽  
Fda Approved Drugs ◽  
Shed Light ◽  
Virtual Screening Approach

The unprecedent situation generated by the COVID-19 global emergency has prompted us to actively work to fight against this pandemic by searching for repurposable agents among FDA approved drugs to shed light into immediate opportunities for the treatment of COVID-19 patients. In the attempt to proceed toward a proper rationalization of the search for new antivirals among approved drugs, we carried out a hierarchical in silico/in vitro protocol which successfully combines virtual and biological screening to speed up the identification of host-directed therapies against COVID-19 in an effective way. To this end a multi-target virtual screening approach focused on host-based targets related to viral entry, followed by the experimental evaluation of the antiviral activity of selected compounds, has been carried out. As a result, five different potentially repurposable drugs interfering with viral entry—cepharantine, clofazimine, metergoline, imatinib and efloxate—have been identified.

scholarly journals Cleavage of the C-Terminal Fragment of Reovirus μ1 Is Required for Optimal Infectivity

2018 ◽  
Vol 92 (6) ◽  
Author(s):  
Anthony J. Snyder ◽  
Pranav Danthi
Keyword(s):  
Conformational Changes ◽  
Viral Entry ◽  
Pore Formation ◽  
Genetic Material ◽  
Host Cells ◽  
Membrane Disruption ◽  
Mammalian Orthoreovirus ◽  
Outer Capsid

ABSTRACTThe mammalian orthoreovirus (reovirus) outer capsid, which is composed of 200 μ1/σ3 heterohexamers and a maximum of 12 σ1 trimers, contains all of the proteins that are necessary for attaching to and entering host cells. Following attachment, reovirus is internalized by receptor-mediated endocytosis and acid-dependent cathepsin proteases degrade the σ3 protein. This process generates a metastable intermediate, called infectious subviral particle (ISVP), in which the μ1 membrane penetration protein is exposed. ISVPs undergo a second structural rearrangement to deposit the genome-containing core into the host cytoplasm. The conformationally altered particle is called ISVP*. ISVP-to-ISVP* conversion culminates in the release of μ1 N- and C-terminal fragments, μ1N and Φ, respectively. Released μ1N is thought to facilitate core delivery by generating size-selective pores within the endosomal membrane, whereas the precise role of Φ, particularly in the context of viral entry, is undefined. In this report, we characterize a recombinant reovirus that fails to cleave Φ from μ1in vitro. Φ cleavage, which is not required for ISVP-to-ISVP* conversion, enhances the disruption of liposomal membranes and facilitates the recruitment of ISVP*s to the site of pore formation. Moreover, the Φ cleavage-deficient strain initiates infection of host cells less efficiently than the parental strain. These results indicate that μ1N and Φ contribute to reovirus pore forming activity.IMPORTANCEHost membranes represent a physical barrier that prevents infection. To overcome this barrier, viruses utilize diverse strategies, such as membrane fusion or membrane disruption, to access internal components of the cell. These strategies are characterized by discrete protein-protein and protein-lipid interactions. The mammalian orthoreovirus (reovirus) outer capsid undergoes a series of well-defined conformational changes, which conclude with pore formation and delivery of the viral genetic material. In this report, we characterize the role of the small, reovirus-derived Φ peptide in pore formation. Φ cleavage from the outer capsid enhances membrane disruption and facilitates the recruitment of virions to membrane-associated pores. Moreover, Φ cleavage promotes the initiation of infection. Together, these results reveal an additional component of the reovirus pore forming apparatus and highlight a strategy for penetrating host membranes.

scholarly journals Host-directed FDA-approved drugs with antiviral activity against SARS-CoV-2 identified by hierarchical in silico/in vitro screening methods

2020 ◽  
Author(s):  
Tiziana Ginex ◽  
Urtzi Garaigorta ◽  
David Ramírez ◽  
Victoria Castro ◽  
Vanesa Nozal ◽  
...  
Keyword(s):  
Antiviral Activity ◽  
Viral Entry ◽  
In Silico ◽  
Drug Repurposing ◽  
Screening Methods ◽  
Speed Up ◽  
Approved Drugs ◽  
Fda Approved Drugs ◽  
Virtual Screening Approach

AbstractThe unprecedent situation generated by the COVID-19 global emergency has prompted scientists around the world to actively work to fight against this pandemic. In this sense, it is remarkable the number of drug repurposing efforts trying to shed light into the COVID-19 patients’ treatment.In the attempt to proceed toward a proper rationalization of the search for new antivirals among approved drugs, we carried out a hierarchical in silico/in vitro protocol which successfully combines virtual and biological screening to speed up the identification of host-directed therapies against COVID-19 in an effective way.A successful combination of a multi-target virtual screening approach focused on host-based targets related to viral entry and experimental evaluation of the antiviral activity of selected compounds has been carried out. As a result, three different potentially repurposable drugs interfering with viral entry, cepharantine, imatinib and efloxate, have been identified.

scholarly journals Loss of ferroportin induces memory impairment by promoting ferroptosis in Alzheimer’s disease

2021 ◽  
Author(s):  
Wen-Dai Bao ◽  
Pei Pang ◽  
Xiao-Ting Zhou ◽  
Fan Hu ◽  
Wan Xiong ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Memory Impairment ◽  
Iron Homeostasis ◽  
Critical Role ◽  
Gene Set Enrichment Analysis ◽  
Molecular Characteristics ◽  
Intracellular Iron

AbstractIron homeostasis disturbance has been implicated in Alzheimer’s disease (AD), and excess iron exacerbates oxidative damage and cognitive defects. Ferroptosis is a nonapoptotic form of cell death dependent upon intracellular iron. However, the involvement of ferroptosis in the pathogenesis of AD remains elusive. Here, we report that ferroportin1 (Fpn), the only identified mammalian nonheme iron exporter, was downregulated in the brains of APPswe/PS1dE9 mice as an Alzheimer’s mouse model and Alzheimer’s patients. Genetic deletion of Fpn in principal neurons of the neocortex and hippocampus by breeding Fpnfl/fl mice with NEX-Cre mice led to AD-like hippocampal atrophy and memory deficits. Interestingly, the canonical morphological and molecular characteristics of ferroptosis were observed in both Fpnfl/fl/NEXcre and AD mice. Gene set enrichment analysis (GSEA) of ferroptosis-related RNA-seq data showed that the differentially expressed genes were highly enriched in gene sets associated with AD. Furthermore, administration of specific inhibitors of ferroptosis effectively reduced the neuronal death and memory impairments induced by Aβ aggregation in vitro and in vivo. In addition, restoring Fpn ameliorated ferroptosis and memory impairment in APPswe/PS1dE9 mice. Our study demonstrates the critical role of Fpn and ferroptosis in the progression of AD, thus provides promising therapeutic approaches for this disease.

scholarly journals Oxidative Stress as a Possible Target in the Treatment of Toxoplasmosis: Perspectives and Ambiguities

2021 ◽  
Vol 22 (11) ◽  
pp. 5705
Author(s):  
Karolina Szewczyk-Golec ◽  
Marta Pawłowska ◽  
Roland Wesołowski ◽  
Marcin Wróblewski ◽  
Celestyna Mila-Kierzenkowska
Keyword(s):  
Oxidative Stress ◽  
Animal Studies ◽  
Treatment Options ◽  
Natural Antioxidants ◽  
Redox Status ◽  
Host Cells ◽  
Common Disease ◽  
Parasite Viability

Toxoplasma gondii is an apicomplexan parasite causing toxoplasmosis, a common disease, which is most typically asymptomatic. However, toxoplasmosis can be severe and even fatal in immunocompromised patients and fetuses. Available treatment options are limited, so there is a strong impetus to develop novel therapeutics. This review focuses on the role of oxidative stress in the pathophysiology and treatment of T. gondii infection. Chemical compounds that modify redox status can reduce the parasite viability and thus be potential anti-Toxoplasma drugs. On the other hand, oxidative stress caused by the activation of the inflammatory response may have some deleterious consequences in host cells. In this respect, the potential use of natural antioxidants is worth considering, including melatonin and some vitamins, as possible novel anti-Toxoplasma therapeutics. Results of in vitro and animal studies are promising. However, supplementation with some antioxidants was found to promote the increase in parasitemia, and the disease was then characterized by a milder course. Undoubtedly, research in this area may have a significant impact on the future prospects of toxoplasmosis therapy.

scholarly journals Antidiabetic activity of some pentacyclic acid triterpenoids, role of PTP–1B: In vitro, in silico, and in vivo approaches

2011 ◽  
Vol 46 (6) ◽  
pp. 2243-2251 ◽  
Author(s):  
Juan José Ramírez-Espinosa ◽  
Maria Yolanda Rios ◽  
Sugey López-Martínez ◽  
Fabian López-Vallejo ◽  
José L. Medina-Franco ◽  
...  
Keyword(s):  
In Silico ◽  
Antidiabetic Activity ◽  
Ptp 1B

scholarly journals A New MAP Kinase Protein Involved in Estradiol-Stimulated Reproduction of the Helminth ParasiteTaenia crassiceps

2010 ◽  
Vol 2010 ◽  
pp. 1-11 ◽  
Author(s):  
Galileo Escobedo ◽  
Gloria Soldevila ◽  
Guadalupe Ortega-Pierres ◽  
Jesús Ramsés Chávez-Ríos ◽  
Karen Nava ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Map Kinases ◽  
Host Cells ◽  
Cross Contamination ◽  
Flow Cytometry Analysis ◽  
Cellular Processes ◽  
17Β Estradiol ◽  
Activation Motif

MAP kinases (MAPK) are involved in the regulation of cellular processes such as reproduction and growth. In parasites, the role of MAPK has been scarcely studied. Here, we describe the participation of an ERK-like protein in estrogen-dependent reproduction of the helminth parasiteTaenia crassiceps. Our results show that 17β-estradiol induces a concentration-dependent increase in the bud number of in vitro cultured cysticerci. If parasites are also incubated in presence of an ERK-inhibitor, the stimulatory effect of estrogen is blocked. The expression of ERK-like mRNA and its corresponding protein was detected in the parasite. The ERK-like protein was over-expressed by all treatments. Nevertheless, a strong induction of phosphorylation of this protein was observed only in response to 17β-estradiol. Cross-contamination by host cells was discarded by flow cytometry analysis. Parasite cells expressing the ERK-like protein were exclusively located at the subtegument tissue by confocal microscopy. Finally, the ERK-like protein was separated by bidimensional electrophoresis and then sequenced, showing the conserved TEY activation motif, typical of all known ERK 1/2 proteins. Our results show that an ERK-like protein is involved in the molecular signalling during the interaction between the host andT. crassiceps, and may be considered as target for anti-helminth drugs design.

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