scholarly journals Covalently tethering siRNA to hydrogels for localized, controlled release and gene silencing

2019 ◽  
Vol 5 (8) ◽  
pp. eaax0801 ◽  
Author(s):  
Minh Khanh Nguyen ◽  
Cong Truc Huynh ◽  
Alex Gilewski ◽  
Samantha E. Wilner ◽  
Keith E. Maier ◽  
...  

Small interfering RNA (siRNA) has found many applications in tissue regeneration and disease therapeutics. Effective and localized siRNA delivery remains challenging, reducing its therapeutic potential. Here, we report a strategy to control and prolong siRNA release by directly tethering transfection-capable siRNA to photocrosslinked dextran hydrogels. siRNA release is governed via the hydrolytic degradation of ester and/or disulfide linkages between the siRNA and hydrogels, which is independent of hydrogel degradation rate. The released siRNA is shown to be bioactive by inhibiting protein expression in green fluorescent protein–expressing HeLa cells without the need of a transfection agent. This strategy provides an excellent platform for controlling nucleic acid delivery through covalent bonds with a biomaterial and regulating cellular gene expression, which has promising potential in many biomedical applications.

Pharmaceutics ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 805
Author(s):  
Christopher Janich ◽  
Daniel Ivanusic ◽  
Julia Giselbrecht ◽  
Elena Janich ◽  
Shashank Reddy Pinnapireddy ◽  
...  

One major disadvantage of nucleic acid delivery systems is the low transfection or transduction efficiency of large-sized plasmids into cells. In this communication, we demonstrate the efficient transfection of a 15.5 kb green fluorescent protein (GFP)-fused HIV-1 molecular clone with a nucleic acid delivery system prepared from the highly potent peptide-mimicking cationic lipid OH4 in a mixture with the phospholipid DOPE (co-lipid). For the transfection, liposomes were loaded using a large-sized plasmid (15.5 kb), which encodes a replication-competent HIV type 1 molecular clone that carries a Gag-internal green fluorescent protein (HIV-1 JR-FL Gag-iGFP). The particle size and charge of the generated nanocarriers with 15.5 kb were compared to those of a standardized 4.7 kb plasmid formulation. Stable, small-sized lipoplexes could be generated independently of the length of the used DNA. The transfer of fluorescently labeled pDNA-HIV1-Gag-iGFP in HEK293T cells was monitored using confocal laser scanning microscopy (cLSM). After efficient plasmid delivery, virus particles were detectable as budding structures on the plasma membrane. Moreover, we observed a randomized distribution of fluorescently labeled lipids over the plasma membrane. Obviously, a significant exchange of lipids between the drug delivery system and the cellular membranes occurs, which hints toward a fusion process. The mechanism of membrane fusion for the internalization of lipid-based drug delivery systems into cells is still a frequently discussed topic.


2008 ◽  
Vol 295 (5) ◽  
pp. H2079-H2086 ◽  
Author(s):  
Katsuhiko Ohori ◽  
Tetsuji Miura ◽  
Masaya Tanno ◽  
Takayuki Miki ◽  
Takahiro Sato ◽  
...  

The aim of this study was to determine the role of GSK-3β in cardiomyocyte protection afforded by erythropoietin (EPO) against oxidant stress-induced apoptosis. Treatment with EPO (10 units/ml) induced Ser473 phosphorylation of Akt and Ser9 phosphorylation of GSK-3β and significantly reduced the proportion of apoptotic H9c2 cardiomyocytes after exposure to H2O2 from 38.3 ± 2.7% to 26.0 ± 2.9%. This protection was not detected in cells transfected with constitutively active GSK-3β (S9A), which lacks Ser9 for inhibitory phosphorylation. The antiapoptotic effect of EPO was mimicked completely by GSK-3β knockdown using small interfering RNA and partly by the transfection with kinase-deficient GSK-3β (K85R). The level of colocalization of intracellular GSK-3β with mitochondria assessed by enhanced green fluorescent protein-tagged GSK-3β or immunocytochemistry was not altered by EPO treatment. However, EPO increased the level of Ser9-phospho-GSK-3β colocalized with mitochondria by 50% in a phosphatidylinositol 3-kinase-dependent manner. Mitochondrial translocation of Bcl-2-associated X protein (BAX) after exposure to H2O2 was inhibited by EPO pretreatment and by GSK-3β knockdown. These results suggest that the suppression of GSK-3β activity by Akt-mediated Ser9 phosphorylation in the mitochondria affords cardiomyocytes tolerance against oxidant-induced apoptosis, possibly by inhibiting the access of BAX to the mitochondria.


2020 ◽  
Vol 16 ◽  
Author(s):  
Erdal Eroğlu ◽  
Hüseyin Saygın Portakal ◽  
Ayşenur Pamukçu

Background: Despite great hopes for small interfering RNA (siRNA)-based gene therapies, restrictions, including the presence of nucleases, reticuloendothelial system and undesired electrostatic interactions between nucleic acids and the cell membrane, limit the success of these approaches. In the last few decades, non-viral nucleic acid delivery vectors in nano size with high biocompatibility, low toxicity and proton sponge effect have emerged as magic bullets to overcome these drawbacks. Objective: This study aimed to develop poly(2-hydroxyethyl methacrylate) (pHEMA)-chitosan nanoparticles (PCNp), and to transfect green fluorescent protein (GFP)-silencing siRNA (GsiR) in vitro. Method: First, PCNp displaying core-shell structure was synthesized and thereafter GsiR was encapsulated into the core of PCNp. The synthesized PCNp with/without GsiR were characterized using ultraviolet-visible (UV-vis)-spectroscopy, Fourier-transform infrared (FTIR) spectroscopy, thermal decomposition, atomic force microscopy (AFM), scanning electron microscopy (SEM), zeta potential and dynamic light scattering (DLS) measurements. Encapsulation of siRNA into the pHEMA core coated with chitosan shell was demonstrated using fluorescence and FTIR spectroscopy. Results: The surface charge of PCNSs and PCNSs-GsiR were found to be +39.5 and +40.2, respectively. In DLS analysis, an insignificant shift in the Z-average diameter of PCNp was observed from 109 nm to 133 nm using encapsulation of GsiR. In comparison to other studied nanomaterials and a commercial transfection reagent, our findings suggest a promising GFP-silencing effect of 45%. Conclusion: To our knowledge, we have obtained comparable silencing activity with the other studied equivalents despite using the lowest concentration of siRNA in existing literature.


2008 ◽  
Vol 295 (3) ◽  
pp. C632-C641 ◽  
Author(s):  
Atsushi Yonezawa ◽  
Satohiro Masuda ◽  
Toshiya Katsura ◽  
Ken-ichi Inui

Absorption of riboflavin is mediated by transporter(s). However, a mammalian riboflavin transporter has yet to be identified. In the present study, the novel human and rat riboflavin transporters hRFT1 and rRFT1 were identified on the basis of our rat kidney mRNA expression database (Horiba N, Masuda S, Takeuchi A, Saito H, Okuda M, Inui K. Kidney Int 66: 29–45, 2004). hRFT1 and rRFT1 cDNAs have an open reading frame encoding 448- and 450-amino acid proteins, respectively, that exhibit 81.1% identity and 96.4% similarity to one another. In addition, an inactive splice variant of hRFT1, hRFT1sv, was also cloned. The hRFT1sv cDNA, which encodes a 167-amino acid protein, retains an intron between exons 2 and 3 of hRFT1. Real-time PCR revealed that the sum of hRFT1 and hRFT1sv mRNAs was expressed strongly in the placenta and small intestine and was detected in all tissues examined. In addition, hRFT1 and hRFT1sv were expressed in human embryonic kidney (HEK)-293 and Caco-2 cells. HEK-293 cells transfected with green fluorescent protein-tagged hRFT1 and rRFT1 exhibited a fluorescent signal in the plasma membrane. Overexpression of hRFT1 and rRFT1, but not hRFT1sv, increased the cellular accumulation of [3H]riboflavin. The transfection of small interfering RNA targeting both hRFT1 and hRFT1sv significantly decreased the uptake of [3H]riboflavin by HEK-293 and Caco-2 cells. Riboflavin transport is Na+, potential, and pH independent. Kinetic analyses demonstrated that the Michaelis-Menten constants for the uptake by HEK-293 and Caco-2 cells were 28.1 and 63.7 nM, respectively. We propose that hRFT1 and rRFT1 are novel mammalian riboflavin transporters, which belong to a new mammalian riboflavin transporter family.


2009 ◽  
Vol 20 (21) ◽  
pp. 4531-4540 ◽  
Author(s):  
Maria Sverdlov ◽  
Vasily Shinin ◽  
Aaron T. Place ◽  
Maricela Castellon ◽  
Richard D. Minshall

Transcytosis via caveolae is critical for maintaining vascular homeostasis by regulating the tissue delivery of macromolecules, hormones, and lipids. In the present study, we test the hypothesis that interactions between F-actin cross-linking protein filamin A and caveolin-1 facilitate the internalization and trafficking of caveolae. Small interfering RNA-mediated knockdown of filamin A, but not filamin B, reduced the uptake and transcytosis of albumin by ∼35 and 60%, respectively, without altering the actin cytoskeletal structure or cell–cell adherens junctions. Mobility of both intracellular caveolin-1–green fluorescent protein (GFP)-labeled vesicles measured by fluorescence recovery after photobleaching and membrane-associated vesicles measured by total internal reflection-fluorescence microscopy was decreased in cells with reduced filamin A expression. In addition, in melanoma cells that lack filamin A (M2 cells), the majority of caveolin-1-GFP was localized on the plasma membrane, whereas in cells in which filamin A expression was reconstituted (A7 cells and M2 cells transfected with filamin A-RFP), caveolin-1-GFP was concentrated in intracellular vesicles. Filamin A association with caveolin-1 in endothelial cells was confirmed by cofractionation of these proteins in density gradients, as well as by coimmunoprecipitation. Moreover, this interaction was enhanced by Src activation, associated with increased caveolin-1 phosphorylation, and blocked by Src inhibition. Taken together, these data suggest that filamin A association with caveolin-1 promotes caveolae-mediated transport by regulating vesicle internalization, clustering, and trafficking.


2008 ◽  
Vol 89 (11) ◽  
pp. 2761-2766 ◽  
Author(s):  
Jingmin Ji ◽  
Andrea Glaser ◽  
Marion Wernli ◽  
Jan Martin Berke ◽  
Darius Moradpour ◽  
...  

Viruses have evolved strategies to overcome the antiviral effects of the host at different levels. Besides specific defence mechanisms, the host responds to viral infection via the interferon pathway and also by RNA interference (RNAi). However, several viruses have been identified that suppress RNAi. We addressed the question of whether hepatitis C virus (HCV) suppresses RNAi, using cell lines constitutively expressing green fluorescent protein (GFP) and inducibly expressing HCV proteins. It was found that short interfering RNA-mediated GFP gene silencing was inhibited when the entire HCV polyprotein was expressed. Further studies showed that HCV structural proteins, and in particular envelope protein 2 (E2), were responsible for this inhibition. Co-precipitation assays demonstrated that E2 bound to Argonaute-2 (Ago-2), a member of the RNA-induced silencing complex, RISC. Thus, HCV E2 that interacts with Ago-2 is able to suppress RNAi.


2009 ◽  
Vol 297 (2) ◽  
pp. C451-C458 ◽  
Author(s):  
Chi-Lun Chang ◽  
Ming-Chih Ho ◽  
Po-Huang Lee ◽  
Chi-Yen Hsu ◽  
Wei-Pang Huang ◽  
...  

Sphingosine 1-phosphate (S1P) is a platelet- and endothelial cell-released lysophospholipid that regulates various cellular functions through activating a specific family of G protein-coupled receptors. Both platelet activation and angiogenesis play important roles in cancer development, implying that cancer cells might encounter a large amount of S1P during these processes. Cancer cells, in the meantime, may experience nutrient deprivation and rely on autophagy for early development. Whether extracellular S1P regulates autophagy remains to be tested. In the present work, we investigated whether autophagy is regulated by S1P in PC-3 cells. Through monitoring the modification patterns of LC3 by Western blotting, we demonstrated that autophagy was induced by exogenously applied S1P in PC-3 cells. This observation was further confirmed by fluorescence microscopy using PC-3 cells stably expressing enhanced green fluorescent protein-LC3. By applying small interfering RNA and dihydro-S1P, S1P5 activation was found to be involved in this process. Besides, mammalian target of rapamycin signaling was inhibited upon S1P treatment. Taken together, our results suggest that, under serum-starved conditions, S1P further upregulates autophagic activity through S1P5-dependent pathways in PC-3 cells.


Blood ◽  
2005 ◽  
Vol 106 (7) ◽  
pp. 2295-2301 ◽  
Author(s):  
Doreen E. Wesche-Soldato ◽  
Chun-Shiang Chung ◽  
Joanne Lomas-Neira ◽  
Lesley A. Doughty ◽  
Stephen H. Gregory ◽  
...  

Abstract Although studies have shown increased evidence of death receptor-driven apoptosis in intestinal lymphoid cells, splenocytes, and the liver following the onset of polymicrobial sepsis, little is known about the mediators controlling this process or their pathologic contribution. We therefore attempted to test the hypothesis that the hydrodynamic administration of small interfering RNA (siRNA) against the death receptor, Fas or caspase-8, should attenuate the onset of morbidity and mortality seen in sepsis, as produced by cecal ligation and puncture (CLP). We initially show that in vivo administration of green fluorescent protein (GFP) siRNA in GFP transgenic mice results in a decrease in GFP fluorescence in most tissues. Subsequently, we also found that treating septic nontransgenic mice with siRNA targeting Fas or caspase-8 but not GFP (used as a control here) decreased the mRNA, in a sustained fashion up to 10 days, and protein expression of Fas and caspase-8, respectively. In addition, transferase-mediated dUTP (deoxyuridine triphosphate) nick end labeling (TUNEL) and active caspase-3 analyses revealed a decrease in apoptosis in the liver and spleen but not the thymus following siRNA treatment. Indices of liver damage were also decreased. Finally, the injection of Fas or caspase-8 given not only 30 minutes but up to 12 hours after CLP significantly improved the survival of septic mice.


Author(s):  
E.V. Bogdanenko ◽  
L.A. Sergievich ◽  
A.V. Karnaukhov ◽  
N.A. Karnaukhova ◽  
I.A. Lizunova ◽  
...  

Введение. Культивированные мезенхимальные стромальные стволовые клетки (МССК), выделенные из костного мозга (КМ), можно использовать для лечения обширных ран, однако это очень дорого, трудоёмко и возможно только через несколько дней после их получения. При этом цельный донорский КМ можно вводить системно непосредственно после травмы без выделения МССК, так как они содержатся в нём естественным образом. Это важно для предотвращения гибели и инвалидизации пострадавших. Цель исследования - изучение терапевтического потенциала цельного донорского КМ, пересаживаемого мышам-реципиентам после нанесения им механических травм. Методика. Эксперимент выполнен на 38 животных. На следующий день после облучения в дозе 6,5 Гр 18 мышам-реципиентам линии C57BL/6 наносили резаную рану в межлопаточной области спины, а затем вводили внутривенно 100 мкл суспензии клеток донорского цельного КМ, несущих маркерный ген зеленого флуоресцентного белка EGFP. Реципиентов забивали через 1, 2, 3, 7, 11, 14, 21, 28 и 35 сут после трансплантации. Под флуоресцентным микроскопом изучали участки кожи, прилегающие к ране, а также дно раны и струп. Скорость заселения этих зон сравнивали со скоростью заселения участков кожи без раны на пояснице данных реципиентов и в межлопаточной и поясничной областях (20) у облучённых животных-реципиентов без травмы. Результаты. Уже на следующий день после трансплантации в участках кожи, прилегающих к ране, и на дне раны обнаруживали донорские клетки. Через 7 сут наблюдалось массированное заселение раны флуоресцирующими клетками различных типов; в то же время в участках кожи без раны на пояснице данных реципиентов донорские клетки появились в существенных количествах только через 11 сут. Донорские клетки сохранялись в коже по меньшей мере 35 сут после трансплантации без всяких признаков элиминирования. У животных без травмы заселение кожи донорскими клетками происходило медленнее, чем у травмированных, с похожим типом заселения обеих изучаемых зон (межлопаточной и поясничной). Заключение. Полученные результаты позволяют предположить, что повреждённые ткани выделяют цитокины, обладающие способностью привлекать большинство донорских клеток именно к ране. МССК цельного КМ заращивали рану с очень большой скоростью, из чего можно предположить, что его трансплантация сразу после получения различных травм по эффективности может быть не хуже, чем лечение культивированными МССК, а по оперативности воздействия и экономичности намного его превосходить.Introduction. Cultured mesenchymal stromal stem cells (MSSC), isolated from the bone marrow (BM) may be used to treat extensive wounds, but this treatment is very expensive, time consuming and possible only in several days after the injury. However, donor whole BM can be systemically administered directly after an injury without isolating MSSC because they are naturally contained in the BM. This is important for preventing death and disability of accident victims. The aim of the work was to study the therapeutic potential of donor whole BM transplanted to recipient mice after inflicting a mechanical trauma. Methods. On the next day after irradiation at a dose of 6.5 Gy, recipient C57BL/6 mice were subjected to a cut wound in the interscapulum and then injected intravenously with 100 μl of cell suspension of the donor whole BM carrying a marker gene of the green fluorescent protein, EGFP. Recipients were sacrificed in 1, 2, 3, 7, 11, 14, 21, 28, and 35 days after transplantation. The bottom of the wound and the scab on it and also areas of the skin adjacent to the wound were examined by fluorescent microscopy. The rate of colonization of these zones was compared to the rate of colonization of non-injured lumbar skin areas of these recipients and interscapular and lumbar regions of irradiated recipients without traumas. Results. Already on the next day after transplantation, the donor cells were detected in skin areas adjacent to the wound and on the bottom of the wound. In 7 days, massive wound colonization with various types of fluorescent cells was observed; at the same time, substantial amount of donor cells appeared in the non-injured lumbar skin of these recipients only in 11 days. The donor cells remained in the skin for at least 35 days after transplantation without any signs of elimination. Colonization of skin with the donor cells was slower in animals without than with wounds with a similar type of colonization in both of the studied zones (interscapular and lumbar). Conclusions. The study results suggested that damaged tissues secrete cytokines that are capable of attracting the majority of donor cells specifically to the wound. MSSC of the whole BM healed the wound very fast, which indicated that the MSSC transplantation immediately after a trauma is not inferior in effectiveness to the treatment with cultured MSSC and may be much superior in both promptness of the effect and cost-efficiency.


2018 ◽  
Vol 19 (7) ◽  
pp. 2096 ◽  
Author(s):  
Julia Poletaeva ◽  
Ilya Dovydenko ◽  
Anna Epanchintseva ◽  
Kseniya Korchagina ◽  
Dmitrii Pyshnyi ◽  
...  

Elaboration of non-viral vehicles for delivery of therapeutic nucleic acids, in particular siRNA, into a cell is an actively growing field. Gold nanoparticles (AuNPs) occupy a noticeable place in these studies, and various nanoconstructions containing AuNPs are reported. We aimed our work to the rational design of AuNPs-based siRNA delivery vehicle with enhanced transfection efficiency. We optimized the obtaining of non-covalent siRNAs-AuNPs cores: ionic strength, temperature and reaction time were determined. Formation of cores was confirmed using gel electrophoresis. Stable associates were prepared, and then enveloped into a lipid layer composed of phosphatidylcholine, phosphatidylethanolamine and novel pH-sensitive lipidoid. The constructions were modified with [Str-(RL)4G-NH2] peptide (the resulting construction). All intermediate and resulting nanoconstructions were analyzed by dynamic light scattering (DLS) and transmission electron microscopy (TEM) to control their physico-chemical properties. To examine the biological effect of the delivery vehicle, green fluorescent protein (GFP)-expressing human embryonic kidney (HEK) Phoenix cells were incubated with the resulting construction containing anti-GFP siRNA, with the siRNA effect being studied by flow cytometry and confocal microscopy. Transfection of the cells with the resulting construction reduced the GFP fluorescence as efficiently as Lipofectamin 3000. Thus, siRNA vehicle based on non-covalently bound siRNA-AuNP core and enveloped into a lipid layer provides efficient delivery of siRNA into a cell followed by specific gene silencing.


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