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1.
J Vis Exp ; (181)2022 Mar 22.
Article in English | MEDLINE | ID: covidwho-1786125

ABSTRACT

The development of functional lipid nanoparticles (LNPs) is one of the major challenges in the field of drug delivery systems (DDS). Recently, LNP-based RNA delivery systems, namely, RNA-loaded LNPs have attracted attention for RNA therapy. In particular, mRNA-loaded LNP vaccines were approved to prevent COVID-19, thereby leading to the paradigm shift toward the development of next-generation nanomedicines. For the LNP-based nanomedicines, the LNP size is a significant factor in controlling the LNP biodistribution and LNP performance. Therefore, a precise LNP size control technique is indispensable for the LNP production process. Here, we report a protocol for size controlled LNP production using a microfluidic device, named iLiNP. siRNA loaded LNPs are also produced using the iLiNP device and evaluated by in vitro experiment. Representative results are shown for the LNP size, including siRNA-loaded LNPs, Z-potential, siRNA encapsulation efficiency, cytotoxicity, and target gene silencing activity.


Subject(s)
COVID-19 , Nanoparticles , Humans , Lab-On-A-Chip Devices , Lipids , Liposomes , RNA, Small Interfering/metabolism , Tissue Distribution
2.
Molecules ; 27(6)2022 Mar 17.
Article in English | MEDLINE | ID: covidwho-1760783

ABSTRACT

Shigella species account for the second-leading cause of deaths due to diarrheal diseases among children of less than 5 years of age. The emergence of multi-drug-resistant Shigella isolates and the lack of availability of Shigella vaccines have led to the pertinence in the efforts made for the development of new therapeutic strategies against shigellosis. Consequently, designing small-interfering RNA (siRNA) candidates against such infectious agents represents a novel approach to propose new therapeutic candidates to curb the rampant rise of anti-microbial resistance in such pathogens. In this study, we analyzed 264 conserved sequences from 15 different conserved virulence genes of Shigella sp., through extensive rational validation using a plethora of first-generation and second-generation computational algorithms for siRNA designing. Fifty-eight siRNA candidates were obtained by using the first-generation algorithms, out of which only 38 siRNA candidates complied with the second-generation rules of siRNA designing. Further computational validation showed that 16 siRNA candidates were found to have a substantial functional efficiency, out of which 11 siRNA candidates were found to be non-immunogenic. Finally, three siRNA candidates exhibited a sterically feasible three-dimensional structure as exhibited by parameters of nucleic acid geometry such as: the probability of wrong sugar puckers, bad backbone confirmations, bad bonds, and bad angles being within the accepted threshold for stable tertiary structure. Although the findings of our study require further wet-lab validation and optimization for therapeutic use in the treatment of shigellosis, the computationally validated siRNA candidates are expected to suppress the expression of the virulence genes, namely: IpgD (siRNA 9) and OspB (siRNA 15 and siRNA 17) and thus act as a prospective tool in the RNA interference (RNAi) pathway. However, the findings of our study require further wet-lab validation and optimization for regular therapeutic use for treatment of shigellosis.


Subject(s)
Dysentery, Bacillary , Shigella , Child , Diarrhea/drug therapy , Dysentery, Bacillary/drug therapy , Dysentery, Bacillary/genetics , Humans , RNA Interference , RNA, Small Interfering/metabolism , Shigella/genetics
3.
Curr Mol Pharmacol ; 15(1): 143-158, 2022.
Article in English | MEDLINE | ID: covidwho-1679980

ABSTRACT

There are no available antivirals for many viruses or strains, while current antivirals are limited by toxicity and drug resistance. Therefore, alternative strategies, such as RNA interference (RNAi) are required. RNAi suppresses gene expression of any mRNA, making it an attractive candidate for antiviral therapeutics. Studies have evaluated siRNAs in a range of viruses, with some showing promising results. However, issues with stability and delivery of siRNAs remain. These issues may be minimized by modifying the siRNA structure, using an efficient delivery vector and targeting multiple regions of a virus's genome in a single dose. Finding these solutions could accelerate the progress of RNAi-based antivirals. This review highlights selected examples of antiviral siRNAs, limitations of RNAi and strategies to overcome these limitations.


Subject(s)
Viruses , Antiviral Agents , RNA Interference , RNA, Small Interfering/genetics , RNA, Small Interfering/metabolism , Viruses/genetics , Viruses/metabolism
4.
Nucleic Acids Res ; 50(1): 333-349, 2022 01 11.
Article in English | MEDLINE | ID: covidwho-1591186

ABSTRACT

A promising approach to tackle the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) could be small interfering (si)RNAs. So far it is unclear, which viral replication steps can be efficiently inhibited with siRNAs. Here, we report that siRNAs can target genomic RNA (gRNA) of SARS-CoV-2 after cell entry, and thereby terminate replication before start of transcription and prevent virus-induced cell death. Coronaviruses replicate via negative sense RNA intermediates using a unique discontinuous transcription process. As a result, each viral RNA contains identical sequences at the 5' and 3' end. Surprisingly, siRNAs were not active against intermediate negative sense transcripts. Targeting common sequences shared by all viral transcripts allowed simultaneous suppression of gRNA and subgenomic (sg)RNAs by a single siRNA. The most effective suppression of viral replication and spread, however, was achieved by siRNAs that targeted open reading frame 1 (ORF1) which only exists in gRNA. In contrast, siRNAs that targeted the common regions of transcripts were outcompeted by the highly abundant sgRNAs leading to an impaired antiviral efficacy. Verifying the translational relevance of these findings, we show that a chemically modified siRNA that targets a highly conserved region of ORF1, inhibited SARS-CoV-2 replication ex vivo in explants of the human lung. Our work encourages the development of siRNA-based therapies for COVID-19 and suggests that early therapy start, or prophylactic application, together with specifically targeting gRNA, might be key for high antiviral efficacy.


Subject(s)
COVID-19/virology , Lung/virology , RNA, Small Interfering , RNA, Viral , SARS-CoV-2/genetics , Virus Replication , 3' Untranslated Regions , Animals , Antiviral Agents/pharmacology , COVID-19/drug therapy , Cell Survival , Databases, Genetic , HEK293 Cells , Humans , Nucleic Acid Conformation , Oligonucleotides , Open Reading Frames , RNA, Small Interfering/metabolism
5.
Sci Rep ; 11(1): 24442, 2021 12 24.
Article in English | MEDLINE | ID: covidwho-1577650

ABSTRACT

Therapeutic interventions targeting viral infections remain a significant challenge for both the medical and scientific communities. While specific antiviral agents have shown success as therapeutics, viral resistance inevitably develops, making many of these approaches ineffective. This inescapable obstacle warrants alternative approaches, such as the targeting of host cellular factors. Respiratory syncytial virus (RSV), the major respiratory pathogen of infants and children worldwide, causes respiratory tract infection ranging from mild upper respiratory tract symptoms to severe life-threatening lower respiratory tract disease. Despite the fact that the molecular biology of the virus, which was originally discovered in 1956, is well described, there is no vaccine or effective antiviral treatment against RSV infection. Here, we demonstrate that targeting host factors, specifically, mTOR signaling, reduces RSV protein production and generation of infectious progeny virus. Further, we show that this approach can be generalizable as inhibition of mTOR kinases reduces coronavirus gene expression, mRNA transcription and protein production. Overall, defining virus replication-dependent host functions may be an effective means to combat viral infections, particularly in the absence of antiviral drugs.


Subject(s)
Coronavirus/metabolism , Respiratory Syncytial Virus, Human/metabolism , TOR Serine-Threonine Kinases/metabolism , Viral Proteins/metabolism , A549 Cells , Coronavirus/drug effects , Coronavirus/genetics , Gene Expression Regulation, Viral/drug effects , Humans , Protein Biosynthesis/drug effects , Protein Kinase Inhibitors/pharmacology , Protein Kinase Inhibitors/therapeutic use , RNA Interference , RNA, Small Interfering/metabolism , Rapamycin-Insensitive Companion of mTOR Protein/antagonists & inhibitors , Rapamycin-Insensitive Companion of mTOR Protein/genetics , Rapamycin-Insensitive Companion of mTOR Protein/metabolism , Regulatory-Associated Protein of mTOR/antagonists & inhibitors , Regulatory-Associated Protein of mTOR/genetics , Regulatory-Associated Protein of mTOR/metabolism , Respiratory Syncytial Virus Infections/drug therapy , Respiratory Syncytial Virus Infections/pathology , Respiratory Syncytial Virus Infections/virology , Respiratory Syncytial Virus, Human/drug effects , Respiratory Syncytial Virus, Human/isolation & purification , TOR Serine-Threonine Kinases/antagonists & inhibitors , TOR Serine-Threonine Kinases/genetics , Viral Proteins/genetics
6.
AAPS J ; 24(1): 8, 2021 12 06.
Article in English | MEDLINE | ID: covidwho-1555615

ABSTRACT

Lipidoid nanoparticles (LNPs) are the delivery platform in Onpattro, the first FDA-approved siRNA drug. LNPs are also the carriers in the Pfizer-BioNTech and Moderna COVID-19 mRNA vaccines. While these applications have demonstrated that LNPs effectively deliver nucleic acids to hepatic and muscle cells, it is unclear if LNPs could be used for delivery of siRNA to neural cells, which are notoriously challenging delivery targets. Therefore, the purpose of this study was to determine if LNPs could efficiently deliver siRNA to neurons. Because of their potential delivery utility in either applications for the central nervous system and the peripheral nervous system, we used both cortical neurons and sensory neurons. We prepared siRNA-LNPs using C12-200, a benchmark ionizable cationic lipidoid along with helper lipids. We demonstrated using dynamic light scattering that the inclusion of both siRNA and PEG-lipid provided a stabilizing effect to the LNP particle diameters and polydispersity indices by minimizing aggregation. We found that siRNA-LNPs were safely tolerated by primary dorsal root ganglion neurons. Flow cytometry analysis revealed that Cy5 siRNA delivered via LNPs into rat primary cortical neurons showed uptake levels similar to Lipofectamine RNAiMAX-the gold standard commercial transfection agent. However, LNPs demonstrated a superior safety profile, whereas the Lipofectamine-mediated uptake was concomitant with significant toxicity. Fluorescence microscopy demonstrated a time-dependent increase in the uptake of LNP-delivered Cy5 siRNA in a human cortical neuron cell line. Overall, our results suggest that LNPs are a viable platform that can be optimized for delivery of therapeutic siRNAs to neural cells.


Subject(s)
Ganglia, Spinal/metabolism , Lipids/chemistry , Nanoparticles , Neurons/metabolism , RNA, Small Interfering/administration & dosage , RNAi Therapeutics , Transfection , Animals , Carbocyanines/metabolism , Fluorescent Dyes/metabolism , Ganglia, Spinal/cytology , Humans , MCF-7 Cells , Microscopy, Fluorescence , Nanotechnology , Primary Cell Culture , RNA, Small Interfering/genetics , RNA, Small Interfering/metabolism , Rats , Time Factors
7.
Life Sci Alliance ; 5(3)2022 03.
Article in English | MEDLINE | ID: covidwho-1552086

ABSTRACT

Murine neural stem cells (NSCs) were recently shown to release piRNA-containing exosomes/microvesicles (Ex/Mv) for exerting antiviral immunity, but it remains unknown if these Ex/Mv could target SARS-CoV-2 and whether the PIWI-piRNA system is important for these antiviral actions. Here, using in vitro infection models, we show that hypothalamic NSCs (htNSCs) Ex/Mv provided an innate immunity protection against SARS-CoV-2. Importantly, enhanced antiviral actions were achieved by using induced Ex/Mv that were derived from induced htNSCs through twice being exposed to several RNA fragments of SARS-CoV-2 genome, a process that was designed not to involve protein translation of these RNA fragments. The increased antiviral effects of these induced Ex/Mv were associated with increased expression of piRNA species some of which could predictably target SARS-CoV-2 genome. Knockout of piRNA-interacting protein PIWIL2 in htNSCs led to reductions in both innate and induced antiviral effects of Ex/Mv in targeting SARS-CoV-2. Taken together, this study demonstrates a case suggesting Ex/Mv from certain cell types have innate and adaptive immunity against SARS-CoV-2, and the PIWI-piRNA system is important for these antiviral actions.


Subject(s)
Argonaute Proteins/metabolism , COVID-19/immunology , COVID-19/metabolism , Cell-Derived Microparticles/metabolism , Exosomes , RNA, Small Interfering/metabolism , RNA/metabolism , SARS-CoV-2 , A549 Cells , Angiotensin-Converting Enzyme 2/metabolism , Animals , Genome, Viral , Humans , Hypothalamus/metabolism , Immune System , Immunity, Innate , In Vitro Techniques , Mice
8.
Chem Pharm Bull (Tokyo) ; 69(12): 1141-1159, 2021.
Article in English | MEDLINE | ID: covidwho-1546823

ABSTRACT

Considerable efforts have been made on the development of lipid nanoparticles (LNPs) for delivering of nucleic acids in LNP-based medicines, including a first-ever short interfering RNA (siRNA) medicine, Onpattro, and the mRNA vaccines against the coronavirus disease 2019 (COVID-19), which have been approved and are currently in use worldwide. The successful rational design of ionizable cationic lipids was a major breakthrough that dramatically increased delivery efficiency in this field. The LNPs would be expected to be useful as a platform technology for the delivery of various therapeutic modalities for genome editing and even for undiscovered therapeutic mechanisms. In this review, the current progress of my research, including the molecular design of pH-sensitive cationic lipids, their applications for various tissues and cell types, and for delivering various macromolecules, including siRNA, antisense oligonucleotide, mRNA, and the clustered regularly interspaced short palindromic repeats (CRISPR)-associated (Cas) system will be described. Mechanistic studies regarding relationships between the physicochemical properties of LNPs, drug delivery, and biosafety are also summarized. Furthermore, current issues that need to be addressed for next generation drug delivery systems are discussed.


Subject(s)
Drug Carriers/chemistry , Lipids/chemistry , Liposomes/chemistry , Nanoparticles/chemistry , COVID-19/immunology , COVID-19/prevention & control , COVID-19/virology , Cations/chemistry , Hydrogen-Ion Concentration , RNA, Guide/chemistry , RNA, Guide/metabolism , RNA, Small Interfering/chemistry , RNA, Small Interfering/metabolism , SARS-CoV-2/isolation & purification , /metabolism
9.
Sci Rep ; 11(1): 21462, 2021 11 02.
Article in English | MEDLINE | ID: covidwho-1500517

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of the coronavirus disease-19 (COVID-19). More than 143 million cases of COVID-19 have been reported to date, with the global death rate at 2.13%. Currently, there are no licensed therapeutics for controlling SARS-CoV-2 infection. The antiviral effects of heme oxygenase-1 (HO-1), a cytoprotective enzyme that inhibits the inflammatory response and reduces oxidative stress, have been investigated in several viral infections. To confirm whether HO-1 suppresses SARS-CoV-2 infection, we assessed the antiviral activity of hemin, an effective and safe HO-1 inducer, in SARS-CoV-2 infection. We found that treatment with hemin efficiently suppressed SARS-CoV-2 replication (selectivity index: 249.7012). Besides, the transient expression of HO-1 using an expression vector also suppressed the growth of the virus in cells. Free iron and biliverdin, which are metabolic byproducts of heme catalysis by HO-1, also suppressed the viral infection. Additionally, hemin indirectly increased the expression of interferon-stimulated proteins known to restrict SARS-CoV-2 replication. Overall, the findings suggested that HO-1, induced by hemin, effectively suppressed SARS-CoV-2 in vitro. Therefore, HO-1 could be potential therapeutic candidate for COVID-19.


Subject(s)
Antiviral Agents/therapeutic use , COVID-19/drug therapy , Heme Oxygenase-1/metabolism , Hemin/therapeutic use , Animals , Antiviral Agents/chemistry , Antiviral Agents/pharmacology , COVID-19/virology , Cell Survival/drug effects , Chlorocebus aethiops , Heme Oxygenase-1/antagonists & inhibitors , Heme Oxygenase-1/genetics , Hemin/chemistry , Hemin/pharmacology , Humans , RNA Interference , RNA, Small Interfering/metabolism , RNA, Viral/metabolism , SARS-CoV-2/genetics , SARS-CoV-2/isolation & purification , SARS-CoV-2/physiology , Up-Regulation/drug effects , Vero Cells , Virus Replication/drug effects
10.
Chem Biol Drug Des ; 99(2): 233-246, 2022 02.
Article in English | MEDLINE | ID: covidwho-1488186

ABSTRACT

Coronavirus (SARS-CoV-2) as a global pandemic has attracted the attention of many scientific centers to find the right treatment. We expressed and purified the recombinant receptor-binding domain (RBD) of the SARS-CoV-2 spike (S) protein, and specific RBD aptamers were designed using SELEX method. RNAi targeting nucleocapsid phosphoprotein was synthesized and human lung cells were inoculated with aptamer-functionalized lipid nanoparticles (LNPs) containing RNAi. The results demonstrated that RBD aptamer having KD values of 0.290 nm possessed good affinity. Based on molecular docking and efficacy prediction analysis, siRNA molecule was showed the best action. LNPs were appropriately functionalized by aptamer and contained RNAi molecules. Antiviral assay using q-PCR and ELISA demonstrated that LNP functionalized with 35 µm Apt and containing 30 nm RNAi/ml of cell culture had the best antiviral activity compared to other concentrations. Applied aptamer in the nanocarrier has two important functions. First, it can deliver the drug (RNAi) to the surface of epithelial cells. Second, by binding to the SARS-CoV-2 spike protein, it inhibits the virus entrance into cells. Our data reveal an interaction between the aptamer and the virus, and RNAi targeted the virus RNA. CT scan and the clinical laboratory tests in a clinical case study, a 36-year old man who presented with severe SARS-CoV-2, demonstrated that inhalation of 10 mg Apt-LNPs-RNAi nebulized/day for six days resulted in an improvement in consolidation and ground-glass opacity in lungs on the sixth day of treatment. Our findings suggest the treatment of SARS-CoV-2 infection through inhalation of Aptamer-LNPs-RNAi.


Subject(s)
Antiviral Agents/administration & dosage , Aptamers, Nucleotide/chemistry , COVID-19/drug therapy , Liposomes/chemistry , Nanoparticles/chemistry , RNA, Small Interfering/administration & dosage , Spike Glycoprotein, Coronavirus/metabolism , Adenosine Monophosphate/analogs & derivatives , Adenosine Monophosphate/pharmacology , Administration, Inhalation , Adult , Alanine/analogs & derivatives , Alanine/pharmacology , Antiviral Agents/chemistry , Antiviral Agents/metabolism , Antiviral Agents/pharmacology , COVID-19/pathology , COVID-19/virology , Cell Line , Humans , Lung/diagnostic imaging , Lung/pathology , Male , Protein Domains/genetics , RNA Interference , RNA, Small Interfering/chemistry , RNA, Small Interfering/metabolism , RNA, Small Interfering/pharmacology , Recombinant Proteins/biosynthesis , Recombinant Proteins/isolation & purification , Recombinant Proteins/metabolism , SARS-CoV-2/isolation & purification , SARS-CoV-2/metabolism , SELEX Aptamer Technique , Severity of Illness Index , Spike Glycoprotein, Coronavirus/antagonists & inhibitors , Spike Glycoprotein, Coronavirus/genetics , Viral Load/drug effects
11.
Bioorg Chem ; 117: 105460, 2021 12.
Article in English | MEDLINE | ID: covidwho-1487614

ABSTRACT

The current pneumonia outbreak, which began in early December 2019 near Wuhan City, Hubei Province, China, is caused by a novel corona virus (CoV) known as '2019-nCoV' or '2019 novel corona virus or COVID-19' by the World Health Organization (WHO). Vaccines are available to prevent corona virus contagious infection or to reduce the viral load in body but virus is continuously mutating itself to infect people at severity. In this critical scenario this review provide a compiled study for techniques and tools that can be used to treat corona virus infections and its variants by some modern techniques and natural products such as inhibitors, siRNA technique and plant based approaches. This review focuses on healthy treatment and strategies that can be used effectively to treat the disease globally by reducing the post COVID symptoms.


Subject(s)
Biological Products/chemistry , Spike Glycoprotein, Coronavirus/antagonists & inhibitors , Angiotensin-Converting Enzyme 2/antagonists & inhibitors , Angiotensin-Converting Enzyme 2/metabolism , Biological Products/metabolism , Biological Products/therapeutic use , COVID-19/drug therapy , COVID-19/pathology , COVID-19/virology , Coronavirus 3C Proteases/antagonists & inhibitors , Coronavirus 3C Proteases/metabolism , Humans , Plants/chemistry , Plants/metabolism , RNA, Small Interfering/metabolism , RNA, Small Interfering/therapeutic use , SARS-CoV-2/genetics , SARS-CoV-2/isolation & purification , SARS-CoV-2/metabolism , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/metabolism
12.
J Virol ; 95(24): e0059621, 2021 11 23.
Article in English | MEDLINE | ID: covidwho-1443352

ABSTRACT

Cellular factors have important roles in all facets of the flavivirus replication cycle. Deciphering viral-host protein interactions is essential for understanding the flavivirus life cycle as well as development of effective antiviral strategies. To uncover novel host factors that are co-opted by multiple flaviviruses, a CRISPR/Cas9 genome wide knockout (KO) screen was employed to identify genes required for replication of Zika virus (ZIKV). Receptor for Activated Protein C Kinase 1 (RACK1) was identified as a novel host factor required for ZIKV replication, which was confirmed via complementary experiments. Depletion of RACK1 via siRNA demonstrated that RACK1 is important for replication of a wide range of mosquito- and tick-borne flaviviruses, including West Nile Virus (WNV), Dengue Virus (DENV), Powassan Virus (POWV) and Langat Virus (LGTV) as well as the coronavirus SARS-CoV-2, but not for YFV, EBOV, VSV or HSV. Notably, flavivirus replication was only abrogated when RACK1 expression was dampened prior to infection. Utilising a non-replicative flavivirus model, we show altered morphology of viral replication factories and reduced formation of vesicle packets (VPs) in cells lacking RACK1 expression. In addition, RACK1 interacted with NS1 protein from multiple flaviviruses; a key protein for replication complex formation. Overall, these findings reveal RACK1's crucial role to the biogenesis of pan-flavivirus replication organelles. IMPORTANCE Cellular factors are critical in all facets of viral lifecycles, where overlapping interactions between the virus and host can be exploited as possible avenues for the development of antiviral therapeutics. Using a genome-wide CRISPR knockout screening approach to identify novel cellular factors important for flavivirus replication we identified RACK1 as a pro-viral host factor for both mosquito- and tick-borne flaviviruses in addition to SARS-CoV-2. Using an innovative flavivirus protein expression system, we demonstrate for the first time the impact of the loss of RACK1 on the formation of viral replication factories known as 'vesicle packets' (VPs). In addition, we show that RACK1 can interact with numerous flavivirus NS1 proteins as a potential mechanism by which VP formation can be induced by the former.


Subject(s)
CRISPR-Cas Systems , Flavivirus/genetics , Neoplasm Proteins/genetics , Receptors for Activated C Kinase/genetics , Virus Replication , A549 Cells , Aedes , Animals , COVID-19 , Chlorocebus aethiops , Culicidae , Dengue Virus/genetics , Genome-Wide Association Study , HEK293 Cells , Host-Pathogen Interactions/genetics , Humans , RNA, Small Interfering/metabolism , RNA, Viral/metabolism , SARS-CoV-2 , Vero Cells , West Nile virus/genetics , Zika Virus/genetics , Zika Virus Infection/virology
13.
J Virol ; 95(24): e0134521, 2021 11 23.
Article in English | MEDLINE | ID: covidwho-1441856

ABSTRACT

Porcine deltacoronavirus (PDCoV), an emerging enteropathogenic coronavirus, causes serious diarrhea in suckling piglets and has the potential for cross-species transmission. Although extensive studies have been reported on the biology and pathogenesis of PDCoV, the mechanisms by which PDCoV enters cells are not well characterized. In this study, we investigated how PDCoV enters IPI-2I cells, a line of porcine intestinal epithelial cells derived from pig ileum. Immunofluorescence assays, small interfering RNA (siRNA) interference, specific pharmacological inhibitors, and dominant negative mutation results revealed that PDCoV entry into IPI-2I cells depended on clathrin, dynamin, and a low-pH environment but was independent of caveolae. Specific inhibition of phosphatidylinositol 3-kinase (PI3K) and the Na+/H+ exchanger (NHE) revealed that PDCoV entry involves macropinocytosis and depends on NHE rather than on PI3K. Additionally, Rab5 and Rab7, but not Rab11, regulated PDCoV endocytosis. This is the first study to demonstrate that PDCoV uses clathrin-mediated endocytosis and macropinocytosis as alternative endocytic pathways to enter porcine intestinal epithelial cells. We also discussed the entry pathways of PDCoV into other porcine cell lines. Our findings reveal the entry mechanisms of PDCoV and provide new insight into the PDCoV life cycle. IMPORTANCE An emerging enteropathogenic coronavirus, PDCoV, has the potential for cross-species transmission, attracting extensive attenuation. Characterizing the detailed process of PDCoV entry into cells will deepen our understanding of the viral infection and pathogenesis and provide clues for therapeutic intervention against PDCoV. With the objective, we used complementary approaches to dissect the process in PDCoV-infected IPI-2I cells, a line of more physiologically relevant intestinal epithelial cells to PDCoV infection in vivo. Here, we demonstrate that PDCoV enters IPI-2I cells via macropinocytosis, which does not require a specific receptor, and clathrin-mediated endocytosis, which requires a low-pH environment and dynamin, while a caveola-mediated endocytic pathway is used by PDCoV to enter swine testicular (ST) cells and porcine kidney (LLC-PK1) cells. These findings provide a molecular detail of the cellular entry pathways of PDCoV and may direct us toward novel antiviral drug development.


Subject(s)
Coronavirus Infections/virology , Deltacoronavirus/physiology , Dynamins/metabolism , Endocytosis , Epithelial Cells/virology , Animals , Cell Line , Cell Survival , Clathrin/metabolism , Coronavirus/genetics , Hydrogen-Ion Concentration , Ileum/virology , Kidney/virology , Phosphatidylinositol 3-Kinases/metabolism , Pinocytosis , RNA, Small Interfering/metabolism , Swine , Swine Diseases/virology , Virus Internalization , rab5 GTP-Binding Proteins/metabolism
14.
Cells ; 10(10)2021 09 23.
Article in English | MEDLINE | ID: covidwho-1438524

ABSTRACT

The ability of the ribonucleic acid (RNA) to self-replicate, combined with a unique cocktail of chemical properties, suggested the existence of an RNA world at the origin of life. Nowadays, this hypothesis is supported by innovative high-throughput and biochemical approaches, which definitively revealed the essential contribution of RNA-mediated mechanisms to the regulation of fundamental processes of life. With the recent development of SARS-CoV-2 mRNA-based vaccines, the potential of RNA as a therapeutic tool has received public attention. Due to its intrinsic single-stranded nature and the ease with which it is synthesized in vitro, RNA indeed represents the most suitable tool for the development of drugs encompassing every type of human pathology. The maximum effectiveness and biochemical versatility is achieved in the guise of non-coding RNAs (ncRNAs), which are emerging as multifaceted regulators of tissue specification and homeostasis. Here, we report examples of coding and ncRNAs involved in muscle regeneration and discuss their potential as therapeutic tools. Small ncRNAs, such as miRNA and siRNA, have been successfully applied in the treatment of several diseases. The use of longer molecules, such as lncRNA and circRNA, is less advanced. However, based on the peculiar properties discussed below, they represent an innovative pool of RNA biomarkers and possible targets of clinical value.


Subject(s)
MicroRNAs/metabolism , Muscle, Skeletal/metabolism , Muscle, Skeletal/pathology , RNA, Messenger/metabolism , RNA, Untranslated/genetics , Regeneration , Animals , Biomarkers/metabolism , COVID-19 , Homeostasis , Humans , Mice , Muscle, Skeletal/virology , Myocardium/metabolism , Origin of Life , RNA, Circular , RNA, Long Noncoding/genetics , RNA, Small Interfering/metabolism , RNA, Small Untranslated/genetics , RNA, Viral/metabolism , SARS-CoV-2/genetics
15.
J Virol ; 95(24): e0153721, 2021 11 23.
Article in English | MEDLINE | ID: covidwho-1434898

ABSTRACT

Autophagy is thought to be involved in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. However, how SARS-CoV-2 interferes with the autophagic pathway and whether autophagy contributes to virus infection in vivo is unclear. In this study, we identified SARS-CoV-2-triggered autophagy in animal models, including the long-tailed or crab-eating macaque (Macaca fascicularis), human angiotensin-converting enzyme 2 (hACE2) transgenic mice, and xenografted human lung tissues. In Vero E6 and Huh-7 cells, SARS-CoV-2 induces autophagosome formation, accompanied by consistent autophagic events, including inhibition of the Akt-mTOR pathway and activation of the ULK-1-Atg13 and VPS34-VPS15-Beclin1 complexes, but it blocks autophagosome-lysosome fusion. Modulation of autophagic elements, including the VPS34 complex and Atg14, but not Atg5, inhibits SARS-CoV-2 replication. Moreover, this study represents the first to demonstrate that the mouse bearing xenografted human lung tissue is a suitable model for SARS-CoV-2 infection and that autophagy inhibition suppresses SARS-CoV-2 replication and ameliorates virus-associated pneumonia in human lung tissues. We also observed a critical role of autophagy in SARS-CoV-2 infection in an hACE2 transgenic mouse model. This study, therefore, gives insights into the mechanisms by which SARS-CoV-2 manipulates autophagosome formation, and we suggest that autophagy-inhibiting agents might be useful as therapeutic agents against SARS-CoV-2 infection. IMPORTANCE Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) caused a global pandemic with limited therapeutics. Insights into the virus-host interactions contribute substantially to the development of anti-SARS-CoV-2 therapeutics. The novelty of this study is the use of a new animal model: mice xenografted with human lung tissues. Using a combination of in vitro and in vivo studies, we have obtained experimental evidence that induction of autophagy contributes to SARS-CoV-2 infection and improves our understanding of potential therapeutic targets for SARS-CoV-2.


Subject(s)
Angiotensin-Converting Enzyme 2/genetics , Autophagy , COVID-19/drug therapy , COVID-19/virology , Lung/virology , SARS-CoV-2 , Virus Replication , Angiotensin-Converting Enzyme 2/metabolism , Animals , Autophagosomes , Cell Line, Tumor , Chlorocebus aethiops , Humans , Lung/pathology , Macaca , Male , Mice , Mice, Transgenic , Pneumonia, Viral/drug therapy , RNA, Small Interfering/metabolism , Vero Cells
16.
Nat Commun ; 12(1): 4584, 2021 07 28.
Article in English | MEDLINE | ID: covidwho-1387354

ABSTRACT

Interferon-induced transmembrane proteins (IFITMs 1, 2 and 3) can restrict viral pathogens, but pro- and anti-viral activities have been reported for coronaviruses. Here, we show that artificial overexpression of IFITMs blocks SARS-CoV-2 infection. However, endogenous IFITM expression supports efficient infection of SARS-CoV-2 in human lung cells. Our results indicate that the SARS-CoV-2 Spike protein interacts with IFITMs and hijacks them for efficient viral infection. IFITM proteins were expressed and further induced by interferons in human lung, gut, heart and brain cells. IFITM-derived peptides and targeting antibodies inhibit SARS-CoV-2 entry and replication in human lung cells, cardiomyocytes and gut organoids. Our results show that IFITM proteins are cofactors for efficient SARS-CoV-2 infection of human cell types representing in vivo targets for viral transmission, dissemination and pathogenesis and are potential targets for therapeutic approaches.


Subject(s)
Angiotensin-Converting Enzyme 2/genetics , Antigens, Differentiation/genetics , Membrane Proteins/genetics , RNA-Binding Proteins/genetics , SARS-CoV-2/genetics , Spike Glycoprotein, Coronavirus/genetics , Amino Acid Sequence , Angiotensin-Converting Enzyme 2/antagonists & inhibitors , Angiotensin-Converting Enzyme 2/metabolism , Antibodies, Neutralizing/pharmacology , Antigens, Differentiation/metabolism , Binding Sites , COVID-19/virology , Gene Expression Regulation , Host-Pathogen Interactions/drug effects , Host-Pathogen Interactions/genetics , Humans , Interferon-beta/pharmacology , Membrane Proteins/antagonists & inhibitors , Membrane Proteins/metabolism , Protein Binding , Protein Interaction Domains and Motifs , RNA, Small Interfering/genetics , RNA, Small Interfering/metabolism , RNA-Binding Proteins/antagonists & inhibitors , RNA-Binding Proteins/metabolism , SARS-CoV-2/drug effects , SARS-CoV-2/metabolism , Sequence Alignment , Sequence Homology, Amino Acid , Spike Glycoprotein, Coronavirus/metabolism , Virus Attachment/drug effects
17.
Science ; 373(6551): 231-236, 2021 07 09.
Article in English | MEDLINE | ID: covidwho-1304152

ABSTRACT

In mammals, early resistance to viruses relies on interferons, which protect differentiated cells but not stem cells from viral replication. Many other organisms rely instead on RNA interference (RNAi) mediated by a specialized Dicer protein that cleaves viral double-stranded RNA. Whether RNAi also contributes to mammalian antiviral immunity remains controversial. We identified an isoform of Dicer, named antiviral Dicer (aviD), that protects tissue stem cells from RNA viruses-including Zika virus and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-by dicing viral double-stranded RNA to orchestrate antiviral RNAi. Our work sheds light on the molecular regulation of antiviral RNAi in mammalian innate immunity, in which different cell-intrinsic antiviral pathways can be tailored to the differentiation status of cells.


Subject(s)
DEAD-box RNA Helicases/genetics , DEAD-box RNA Helicases/metabolism , RNA Interference , RNA Viruses/physiology , RNA, Viral/metabolism , Ribonuclease III/genetics , Ribonuclease III/metabolism , Stem Cells/enzymology , Stem Cells/virology , Alternative Splicing , Animals , Brain/enzymology , Brain/virology , Cell Line , DEAD-box RNA Helicases/chemistry , Humans , Immunity, Innate , Isoenzymes/chemistry , Isoenzymes/genetics , Isoenzymes/metabolism , Mice , Organoids/enzymology , Organoids/virology , RNA Virus Infections/enzymology , RNA Virus Infections/immunology , RNA Virus Infections/virology , RNA Viruses/genetics , RNA Viruses/immunology , RNA, Double-Stranded/metabolism , RNA, Small Interfering/metabolism , Ribonuclease III/chemistry , SARS-CoV-2/genetics , SARS-CoV-2/immunology , SARS-CoV-2/physiology , Virus Replication , Zika Virus/genetics , Zika Virus/immunology , Zika Virus/physiology , Zika Virus Infection/enzymology , Zika Virus Infection/immunology , Zika Virus Infection/virology
18.
J Biol Chem ; 296: 100759, 2021.
Article in English | MEDLINE | ID: covidwho-1219049

ABSTRACT

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of the COVID-19 global pandemic, utilizes the host receptor angiotensin-converting enzyme 2 (ACE2) for viral entry. However, other host factors might also play important roles in SARS-CoV-2 infection, providing new directions for antiviral treatments. GRP78 is a stress-inducible chaperone important for entry and infectivity for many viruses. Recent molecular docking analyses revealed putative interaction between GRP78 and the receptor-binding domain (RBD) of the SARS-CoV-2 Spike protein (SARS-2-S). Here we report that GRP78 can form a complex with SARS-2-S and ACE2 on the surface and at the perinuclear region typical of the endoplasmic reticulum in VeroE6-ACE2 cells and that the substrate-binding domain of GRP78 is critical for this interaction. In vitro binding studies further confirmed that GRP78 can directly bind to the RBD of SARS-2-S and ACE2. To investigate the role of GRP78 in this complex, we knocked down GRP78 in VeroE6-ACE2 cells. Loss of GRP78 markedly reduced cell surface ACE2 expression and led to activation of markers of the unfolded protein response. Treatment of lung epithelial cells with a humanized monoclonal antibody (hMAb159) selected for its safe clinical profile in preclinical models depleted cell surface GRP78 and reduced cell surface ACE2 expression, as well as SARS-2-S-driven viral entry and SARS-CoV-2 infection in vitro. Our data suggest that GRP78 is an important host auxiliary factor for SARS-CoV-2 entry and infection and a potential target to combat this novel pathogen and other viruses that utilize GRP78 in combination therapy.


Subject(s)
Angiotensin-Converting Enzyme 2/genetics , Heat-Shock Proteins/genetics , Host-Pathogen Interactions/genetics , SARS-CoV-2/drug effects , Spike Glycoprotein, Coronavirus/genetics , Virus Internalization/drug effects , Angiotensin-Converting Enzyme 2/metabolism , Animals , Antibodies, Monoclonal/pharmacology , Binding Sites , Chlorocebus aethiops , Endoplasmic Reticulum/drug effects , Endoplasmic Reticulum/metabolism , Endoplasmic Reticulum/virology , Gene Expression Regulation , Heat-Shock Proteins/antagonists & inhibitors , Heat-Shock Proteins/metabolism , Humans , Mutation , Protein Binding , Protein Domains , Protein Multimerization , RNA, Small Interfering/genetics , RNA, Small Interfering/metabolism , SARS-CoV-2/genetics , SARS-CoV-2/metabolism , Signal Transduction , Spike Glycoprotein, Coronavirus/metabolism , Unfolded Protein Response , Vero Cells
19.
Proc Natl Acad Sci U S A ; 118(19)2021 05 11.
Article in English | MEDLINE | ID: covidwho-1214021

ABSTRACT

To realize RNA interference (RNAi) therapeutics, it is necessary to deliver therapeutic RNAs (such as small interfering RNA or siRNA) into cell cytoplasm. A major challenge of RNAi therapeutics is the endosomal entrapment of the delivered siRNA. In this study, we developed a family of delivery vehicles called Janus base nanopieces (NPs). They are rod-shaped nanoparticles formed by bundles of Janus base nanotubes (JBNTs) with RNA cargoes incorporated inside via charge interactions. JBNTs are formed by noncovalent interactions of small molecules consisting of a base component mimicking DNA bases and an amino acid side chain. NPs presented many advantages over conventional delivery materials. NPs efficiently entered cells via macropinocytosis similar to lipid nanoparticles while presenting much better endosomal escape ability than lipid nanoparticles; NPs escaped from endosomes via a "proton sponge" effect similar to cationic polymers while presenting significant lower cytotoxicity compared to polymers and lipids due to their noncovalent structures and DNA-mimicking chemistry. In a proof-of-concept experiment, we have shown that NPs are promising candidates for antiviral delivery applications, which may be used for conditions such as COVID-19 in the future.


Subject(s)
DNA/chemistry , Drug Delivery Systems , Endosomes/metabolism , Nanostructures/administration & dosage , Amino Acids/chemistry , Cell Survival , Endocytosis , Humans , Nanostructures/chemistry , Nanotubes, Peptide/chemistry , RNA, Small Interfering/administration & dosage , RNA, Small Interfering/chemistry , RNA, Small Interfering/metabolism , RNAi Therapeutics
20.
Respir Res ; 22(1): 99, 2021 Apr 06.
Article in English | MEDLINE | ID: covidwho-1169963

ABSTRACT

BACKGROUND: COVID-19 pneumonia has been associated with severe acute hypoxia, sepsis-like states, thrombosis and chronic sequelae including persisting hypoxia and fibrosis. The molecular hypoxia response pathway has been associated with such pathologies and our recent observations on anti-hypoxic and anti-inflammatory effects of whole aqueous extract of Adhatoda Vasica (AV) prompted us to explore its effects on relevant preclinical mouse models. METHODS: In this study, we tested the effect of whole aqueous extract of AV, in murine models of bleomycin induced pulmonary fibrosis, Cecum Ligation and Puncture (CLP) induced sepsis, and siRNA induced hypoxia-thrombosis phenotype. The effect on lung of AV treated naïve mice was also studied at transcriptome level. We also determined if the extract may have any effect on SARS-CoV2 replication. RESULTS: Oral administration AV extract attenuates increased airway inflammation, levels of transforming growth factor-ß1 (TGF-ß1), IL-6, HIF-1α and improves the overall survival rates of mice in the models of pulmonary fibrosis and sepsis and rescues the siRNA induced inflammation and associated blood coagulation phenotypes in mice. We observed downregulation of hypoxia, inflammation, TGF-ß1, and angiogenesis genes and upregulation of adaptive immunity-related genes in the lung transcriptome. AV treatment also reduced the viral load in Vero cells infected with SARS-CoV2. CONCLUSION: Our results provide a scientific rationale for this ayurvedic herbal medicine in ameliorating the hypoxia-hyperinflammation features and highlights the repurposing potential of AV in COVID-19-like conditions.


Subject(s)
Anti-Inflammatory Agents/pharmacology , COVID-19/drug therapy , Drug Repositioning , Hypoxia/drug therapy , Justicia , Lung/drug effects , Plant Extracts/pharmacology , Pneumonia/prevention & control , Pulmonary Fibrosis/drug therapy , Sepsis/drug therapy , Animals , Anti-Inflammatory Agents/isolation & purification , Bleomycin , COVID-19/metabolism , COVID-19/virology , Cecum/microbiology , Cecum/surgery , Cytokines/genetics , Cytokines/metabolism , Disease Models, Animal , Hypoxia/genetics , Hypoxia/metabolism , Hypoxia-Inducible Factor 1, alpha Subunit/genetics , Hypoxia-Inducible Factor 1, alpha Subunit/metabolism , Hypoxia-Inducible Factor-Proline Dioxygenases/genetics , Hypoxia-Inducible Factor-Proline Dioxygenases/metabolism , Inflammation Mediators/metabolism , Justicia/chemistry , Ligation , Lung/metabolism , Lung/microbiology , Lung/pathology , Male , Mice, Inbred BALB C , Mice, Inbred C57BL , Plant Extracts/isolation & purification , Pneumonia/genetics , Pneumonia/metabolism , Pneumonia/microbiology , Pulmonary Fibrosis/chemically induced , Pulmonary Fibrosis/genetics , Pulmonary Fibrosis/metabolism , RNA Interference , RNA, Small Interfering/genetics , RNA, Small Interfering/metabolism , Sepsis/genetics , Sepsis/metabolism , Sepsis/microbiology , Transcriptome
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