scholarly journals Cytotoxicity assessment, inflammatory properties, and cellular uptake of Neutraplex lipid-based nanoparticles in THP-1 monocyte-derived macrophages

2017 ◽  
Vol 4 ◽  
pp. 184954351774625 ◽  
Author(s):  
Eric Berger ◽  
Dalibor Breznan ◽  
Sandra Stals ◽  
Viraj J Jasinghe ◽  
David Gonçalves ◽  
...  

Current antiretroviral drugs used to prevent or treat human immunodeficiency virus type 1 (HIV-1) infection are not able to eliminate the virus within tissues or cells where HIV establishes reservoirs. Hence, there is an urgent need to develop targeted delivery systems to enhance drug concentrations in these viral sanctuary sites. Macrophages are key players in HIV infection and contribute significantly to the cellular reservoirs of HIV because the virus can survive for prolonged periods in these cells. In the present work, we investigated the potential of the lipid-based Neutraplex nanosystem to deliver anti-HIV therapeutics in human macrophages using the human monocyte/macrophage cell line THP-1. Neutraplex nanoparticles as well as cationic and anionic Neutraplex nanolipoplexes (Neutraplex/small interfering RNA) were prepared and characterized by dynamic light scattering. Neutraplex nanoparticles showed low cytotoxicity in CellTiter-Blue reduction and lactate dehydrogenase release assays and were not found to have pro-inflammatory effects. In addition, confocal studies showed that the Neutraplex nanoparticles and nanolipoplexes are rapidly internalized into THP-1 macrophages and that they can escape the late endosome/lysosome compartment allowing the delivery of small interfering RNAs in the cytoplasm. Furthermore, HIV replication was inhibited in the in vitro TZM-bl infectivity assay when small interfering RNAs targeting CXCR4 co-receptor was delivered by Neutraplex nanoparticles compared to a random small interfering RNA sequence. This study demonstrates that the Neutraplex nanosystem has potential for further development as a delivery strategy to efficiently and safely enhance the transport of therapeutic molecules into human monocyte-derived macrophages in the aim of targeting HIV-1 in this cellular reservoir.

2014 ◽  
Vol 17 (4) ◽  
pp. 733-735 ◽  
Author(s):  
M. Adamek ◽  
G. Rauch ◽  
G. Brogden ◽  
D. Steinhagen

Abstract A Cyprinid herpesvirus 3 infection of carp induces a disease which causes substantial losses in carp culture. Here we present the use of a possible strategy for the management of the virus infection RNA interference based on small interfering RNAs. As a result of in vitro studies, we found that a mixture of short interfering RNAs specific for viral DNA enzyme synthesis and capsid proteins of the CyHV-3 can be a potential inhibitor of virus replication in fibroblastic cells. This gives the basis for the development of a combinatorial RNA interference strategy to treat CyHV-3 infections.


2020 ◽  
Vol 48 (8) ◽  
pp. 4028-4040
Author(s):  
Pawan Kumar ◽  
Rohan Degaonkar ◽  
Dale C Guenther ◽  
Mikhail Abramov ◽  
Guy Schepers ◽  
...  

Abstract In this report, we investigated the hexopyranose chemical modification Altriol Nucleic Acid (ANA) within small interfering RNA (siRNA) duplexes that were otherwise fully modified with the 2′-deoxy-2′-fluoro and 2′-O-methyl pentofuranose chemical modifications. The siRNAs were designed to silence the transthyretin (Ttr) gene and were conjugated to a trivalent N-acetylgalactosamine (GalNAc) ligand for targeted delivery to hepatocytes. Sense and antisense strands of the parent duplex were synthesized with single ANA residues at each position on the strand, and the resulting siRNAs were evaluated for their ability to inhibit Ttr mRNA expression in vitro. Although ANA residues were detrimental at the 5′ end of the antisense strand, the siRNAs with ANA at position 6 or 7 in the seed region had activity comparable to the parent. The siRNA with ANA at position 7 in the seed region was active in a mouse model. An Oligonucleotide with ANA at the 5′ end was more stable in the presence of 5′-exonuclease than an oligonucleotide of the same sequence and chemical composition without the ANA modification. Modeling studies provide insight into the origins of regiospecific changes in potency of siRNAs and the increased protection against 5′-exonuclease degradation afforded by the ANA modification.


2006 ◽  
Vol 174 (5) ◽  
pp. 677-687 ◽  
Author(s):  
Hak Kyun Kim ◽  
Yong Sun Lee ◽  
Umasundari Sivaprasad ◽  
Ankit Malhotra ◽  
Anindya Dutta

Three muscle-specific microRNAs, miR-206, -1, and -133, are induced during differentiation of C2C12 myoblasts in vitro. Transfection of miR-206 promotes differentiation despite the presence of serum, whereas inhibition of the microRNA by antisense oligonucleotide inhibits cell cycle withdrawal and differentiation, which are normally induced by serum deprivation. Among the many mRNAs that are down-regulated by miR-206, the p180 subunit of DNA polymerase α and three other genes are shown to be direct targets. Down-regulation of the polymerase inhibits DNA synthesis, an important component of the differentiation program. The direct targets are decreased by mRNA cleavage that is dependent on predicted microRNA target sites. Unlike small interfering RNA–directed cleavage, however, the 5′ ends of the cleavage fragments are distributed and not confined to the target sites, suggesting involvement of exonucleases in the degradation process. In addition, inhibitors of myogenic transcription factors, Id1-3 and MyoR, are decreased upon miR-206 introduction, suggesting the presence of additional mechanisms by which microRNAs enforce the differentiation program.


Author(s):  
Korakot Nganvongpanit ◽  
Patama Chaochird ◽  
Puntita Siengdee ◽  
Peraphan Pothacharoen ◽  
Kasisin Klunklin ◽  
...  

Endocrinology ◽  
2009 ◽  
Vol 150 (5) ◽  
pp. 2463-2471 ◽  
Author(s):  
Kyung-Bon Lee ◽  
Anilkumar Bettegowda ◽  
Gabbine Wee ◽  
James J. Ireland ◽  
George W. Smith

Previous studies established a positive relationship between oocyte competence and follistatin mRNA abundance. Herein, we used the bovine model to test the hypothesis that follistatin plays a functional role in regulation of early embryogenesis. Treatment of early embryos with follistatin during in vitro culture (before embryonic genome activation) resulted in a dose-dependent decrease in time to first cleavage, increased numbers of blastocysts, and increased blastocyst total and trophectoderm cell numbers. To determine the requirement of endogenous follistatin for early embryogenesis, follistatin ablation/replacement studies were performed. Microinjection of follistatin small interfering RNA into zygotes reduced follistatin mRNA and protein and was accompanied by a reduction in number of embryos developing to eight- to 16-cell and blastocyst stages and reduced blastocyst total and trophectoderm cell numbers. Effects of follistatin ablation were rescued by culture of follistatin small interfering RNA-injected embryos in the presence of exogenous follistatin. To investigate whether follistatin regulation of early embryogenesis is potentially mediated via inhibition of endogenous activin activity, the effects of treatment of embryos with exogenous activin, SB-431542 (inhibitor of activin, TGF-β, and nodal type I receptor signaling) and follistatin plus SB-431542 were investigated. Activin treatment mimicked positive effects of follistatin on time to first cleavage and blastocyst development, whereas negative effects of SB-431542 treatment were observed. Stimulatory effects of follistatin on embryogenesis were not blocked by SB-431542 treatment. Results support a functional role for oocyte-derived follistatin in bovine early embryogenesis and suggest that observed effects of follistatin are likely not mediated by classical inhibition of activin activity.


2019 ◽  
Vol 93 (7) ◽  
Author(s):  
Yann Breton ◽  
Vincent Desrosiers ◽  
Michel Ouellet ◽  
Alexandre Deshiere ◽  
Cynthia Torresilla ◽  
...  

ABSTRACT The molecular basis for HIV-1 susceptibility in primary human monocyte-derived macrophages (MDMs) was previously evaluated by comparing the transcriptome of infected and bystander populations. Careful analysis of the data suggested that the ubiquitin ligase MDM2 acted as a positive regulator of HIV-1 replication in MDMs. In this study, MDM2 silencing through transcript-specific small interfering RNAs in MDMs induced a reduction in HIV-1 reverse transcription and integration along with an increase in the expression of p53-induced genes, including CDKN1A. Experiments with Nutlin-3, a pharmacological inhibitor of MDM2 p53-binding activity, showed a similar effect on HIV-1 infection, suggesting that the observed restriction in HIV-1 production results from the release/activation of p53 and not the absence of MDM2 per se. Knockdown and inhibition of MDM2 also both correlate with a decrease in the Thr592-phosphorylated inactive form of SAMHD1. The expression level of MDM2 and the p53 activation status are therefore important factors in the overall susceptibility of macrophages to HIV-1 infection, bringing a new understanding of signaling events controlling the process of virus replication in this cell type. IMPORTANCE Macrophages, with their long life span in vivo and their resistance to HIV-1-mediated cytopathic effect, might serve as viral reservoirs, contributing to virus persistence in an infected individual. Identification of host factors that increase the overall susceptibility of macrophages to HIV-1 might provide new therapeutic targets for the efficient control of viral replication in these cells and limit the formation of reservoirs in exposed individuals. In this study, we demonstrate the importance of p53 regulation by MDM2, which creates a cellular environment more favorable to the early steps of HIV-1 replication. Moreover, we show that p53 stabilization reduces virus infection in human macrophages, highlighting the important role of p53 in antiviral immunity.


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