Suppressive effect of epigallocatechin‐3‐O‐gallate on endoglin molecular regulation in myocardial fibrosis in vitro and in vivo

Epigallocatechin‐3‐O‐gallate (EGCG), derived from green tea, has been studied extensively because of its diverse physiological and pharmacological properties. This study evaluates the protective effect of EGCG on angiotensin II (Ang II)‐induced endoglin expression in vitro and in vivo. Cardiac fibroblasts (CFs) from the thoracic aorta of adult Wistar rats were cultured and induced with Ang II. Western blotting, Northern blotting, real‐time PCR and promoter activity assay were performed. Ang II increased endoglin expression significantly as compared with control cells. The specific extracellular signal‐regulated kinase inhibitor SP600125 (JNK inhibitor), EGCG (100 μM) and c‐Jun N‐terminal kinase (JNK) siRNA attenuated endoglin proteins following Ang II induction. In addition, pre‐treated Ang II‐induced endoglin with EGCG diminished the binding activity of AP‐1 by electrophoretic mobility shift assay. Moreover, the luciferase assay results revealed that EGCG suppressed the endoglin promoter activity in Ang II‐induced CFs by AP‐1 binding. Finally, EGCG and the JNK inhibitor (SP600125) were found to have attenuated endoglin expression significantly in Ang II‐induced CFs, as determined through confocal microscopy. Following in vivo acute myocardial infarction (AMI)‐related myocardial fibrosis study, as well as immunohistochemical and confocal analyses, after treatment with endoglin siRNA and EGCG (50 mg/kg), the area of myocardial fibrosis reduced by 53.4% and 64.5% and attenuated the left ventricular end‐diastolic and systolic dimensions, and friction shortening in hemodynamic monitor. In conclusion, epigallocatechin‐3‐O‐gallate (EGCG) attenuated the endoglin expression and myocardial fibrosis by anti‐inflammatory effect in vitro and in vivo, the novel suppressive effect was mediated through JNK/AP‐1 pathway.     

Polyethylenimine/small interfering RNA‐mediated knockdown of vascular endothelial growth factor in vivo exerts anti‐tumor effects synergistically with Bevacizumab

Background

RNA interference is a powerful method for the knockdown of pathologically relevant genes. The in vivo delivery of siRNAs, preferably through systemic, nonviral administration, poses the major challenge in the therapeutic application of RNAi. Small interfering RNA (siRNA) complexation with polyethylenimines (PEI) may represent a promising strategy for siRNA‐based therapies and, recently, the novel branched PEI F25‐LMW has been introduced in vitro. Vascular endothelial growth factor (VEGF) is frequently overexpressed in tumors and promotes tumor growth, angiogenesis and metastasis and thus represents an attractive target gene in tumor therapy.

Methods

In subcutaneous tumor xenograft mouse models, we established the therapeutic efficacy and safety of PEI F25‐LMW/siRNA‐mediated knockdown of VEGF. In biodistribution and siRNA quantification studies, we optimized administration strategies and, employing chemically modified siRNAs, compared the anti‐tumorigenic efficacies of: (i) PEI/siRNA‐mediated VEGF targeting; (ii) treatment with the monoclonal anti‐VEGF antibody Bevacizumab (Avastin®); and (iii) a combination of both.

Results

Efficient siRNA delivery is observed upon systemic administration, with the biodistribution being dependent on the mode of injection. Toxicity studies reveal no hepatotoxicity, proinflammatory cytokine induction or other side‐effects of PEI F25‐LMW/siRNA complexes or polyethylenimine, and tumor analyses show efficient VEGF knockdown upon siRNA delivery, leading to reduced tumor cell proliferation and angiogenesis. The determination of anti‐tumor effects reveals that, in pancreas carcinoma xenografts, single treatment with PEI/siRNA complexes or Bevacizumab is already highly efficacious, whereas, in prostate carcinoma, synergistic effects of both treatments are observed.

Conclusions

PEI F25‐LMW/siRNA complexes, which can be stored frozen as opposed to many other carriers, represent an efficient, safe and promising avenue in anti‐tumor therapy, and PEI/siRNA‐mediated, therapeutic VEGF knockdown exerts anti‐tumor effects. Copyright © 2010 John Wiley & Sons, Ltd.     

Low‐generation asymmetric dendrimers exhibit minimal toxicity and effectively complex DNA

Conventional dendrimers are spherical symmetrically branched polymers ending with active surface functional groups. Polyamidoamine (PAMAM) dendrimers have been widely studied as gene delivery vectors and have proven effective at delivering DNA to cells in vitro. However, higher‐generation (G4‐G8) PAMAM dendrimers exhibit toxicity due to their high cationic charge density and this has limited their application in vitro and in vivo. Another limitation arises when attempts are made to functionalize spherical dendrimers as targeting moieties cannot be site‐specifically attached. Therefore, we propose that lower‐generation asymmetric dendrimers, which are likely devoid of toxicity and to which site‐specific attachment of targeting ligands can be achieved, would be a viable alternative to currently available dendrimers. We synthesized and characterized a series of peptide‐based asymmetric dendrimers and compared their toxicity profile and ability to condense DNA to spherical PAMAM G1 dendrimers. We show that asymmetric dendrimers are minimally toxic and condense DNA into stable toroids which have been reported necessary for efficient cell transfection. This paves the way for these systems to be conjugated with targeting ligands for gene delivery in vitro and in vivo. Copyright © 2011 European Peptide Society and John Wiley & Sons, Ltd.     

DNA/PEI/Alginate polyplex as an efficient<Emphasis Type="Italic">in vivo</Emphasis> gene delivery system

A novel non-viral gene delivery system comprised of a DNA/PEI/Alginate (DPA) polyplex was prepared and assessedin vitro andin vivo. Coating the positively charged DNA/PEI (DP) complex with a polyanion resulted in a high level ofin vitro reporter gene transfection in the presence of 50 vol% serum due to the minimized cytotoxicity of PEI and the reduced nonspecific interactions with serum components. Among the tested anionic polymers, which included sodium alginate, poly(methacrylic acid) and poly(acrylic acid), the sodium alginate showed the highest gene transfection efficiency. The DPA polyplex also showed a reduced level of erythrocyte aggregation in target cells when compared with the DP complex. According toin vivo studies in which reporter genes encoding green fluorescent protein (GFP) and luciferase were used, injection of the DPA polyplex into tumor cells in six week old female C57/BL6 mice resulted in a much higher level of GFP expression and approximately 7 fold higher luciferase expression than treatment with the DP complex. Taken together, these results demonstrated that the anionic alginate coating of the DP complex contributed to efficient gene deliveryin vitro andin vivo.     

Properties of gene knockdown system by vector‐based siRNA in zebrafish

RNA interference (RNAi) has emerged as a powerful tool to silence specific genes. Vector‐based RNAi systems have been developed to downregulate targeted genes in a spatially and temporally regulated fashion both in vitro and in vivo. The zebrafish (Danio rerio) is a model animal that has been examined based on a wide variety of biological techniques, including embryonic manipulations, forward and reverse genetics, and molecular biology. However, a heritable and tissue‐specific knockdown of gene expression has not yet been developed in zebrafish. We examined two types of vector, which produce small interfering RNA (siRNA), the direct effector in RNAi system; microRNA (miRNA) process mimicking vectors with a promoter for RNA polymerase II and short hairpin RNA (shRNA) expressing vector through a promoter for RNA polymerase III. Though gene‐silencing phenotypes were not observed in the miRNA process mimicking vectors, the transgenic embryos of the second vector (Tg(zU6‐shGFP)), shRNA expressing vector for enhanced green fluorescence protein, revealed knockdown of the targeted gene. Interestingly, only the embryos from Tg(zU6‐shGFP) female but not from the male fish showed the downregulation. Comparison of the quantity of siRNA produced by each vector indicates that the vectors tested here induced siRNA, but at low levels barely sufficient to silence the targeted gene.     

Gene therapy with an improved doxycycline-regulated plasmid encoding a tumour necrosis factor-alpha inhibitor in experimental arthritis

Inhibition of tumour necrosis factor (TNF)-alpha with biological molecules has proven an effective treatment for rheumatoid arthritis, achieving a 20% improvement in American College of Rheumatology score in up to 65% of patients. The main drawback to these and many other biological treatments has been their expense, which has precluded their widespread application. Biological molecules could alternatively be delivered by gene therapy as the encoding DNA. We have developed novel plasmid vectors termed pGTLMIK and pGTTMIK, from which luciferase and a dimeric TNF receptor II (dTNFR) are respectively expressed in a doxycycline (Dox)-regulated manner. Regulated expression of luciferase from the self-contained plasmid pGTLMIK was examined in vitro in a variety of cell lines and in vivo following intramuscular delivery with electroporation in DBA/1 mice. Dox-regulated expression of luciferase from pGTLMIK of approximately 1,000-fold was demonstrated in vitro, and efficient regulation was observed in vivo. The vector pGTTMIK encoding dTNFR was delivered by the same route with and without administration of Dox to mice with collagen-induced arthritis. When pGTTMIK was delivered after the onset of arthritis, progression of the disease in terms of both paw thickness and clinical score was inhibited when Dox was also administered. Vectors with similar regulation characteristics may be suitable for clinical application.     

Neuropilin 1 expression correlates with the Radio‐resistance of human non‐small‐cell lung cancer cells

The purpose of this study was to determine the correlation between over‐expression of the neuropilin 1 (NRP1) gene and growth, survival, and radio‐sensitivity of non‐small cell lung carcinoma (NSCLC) cells. 3‐[4,5‐dimethylthylthiazol‐2‐yl]‐2,5 diphenyltetrazolium broide (MTT) and colony assays were then performed to determine the effect of NRP1 inhibition on the in vitro growth of NSCLC cells. The Annexin V‐Fluorescein Isothiocyanate (FITC) apoptosis detection assay was performed to analyse the effect of NRP1 enhancement on apoptosis of NSCLC cells. Transwell invasion and migration assays were employed to examine the metastatic ability of A549 cells post X‐ray irradiation. In addition, Western blot assays were carried out to detect the protein level of VEGFR2, PI3K and NF‐κB. Finally, to examine the effect of shNRP1 on proliferation and radio‐sensitivity in vivo, a subcutaneous tumour formation assay in nude mice was performed. Microvessel density in tumour tissues was assessed by immunohistochemistry. The stable transfected cell line (shNRP1‐A549) showed a significant reduction in colony‐forming ability and proliferation not only in vitro, but also in vivo. Moreover, shRNA‐mediated NRP1 inhibition also significantly enhanced the radio‐sensitivity of NSCLC cells both in vitro and in vivo. The over‐expression of NRP1 was correlated with growth, survival and radio‐resistance of NSCLC cells via the VEGF‐PI3K‐ NF‐κB pathway, and NRP1 may be a molecular therapeutic target for gene therapy or radio‐sensitization of NSCLC.     

荧光素酶mRNA的构建及电穿孔介导的mRNA体内表达特性北大核心CSCD

为构建一种非复制型mRNA平台并探究电穿孔介导的mRNA对小鼠健康状况的影响及蛋白的表达情况,以荧光素酶作为靶标基因,用T7 RNA聚合酶体外转录及酶法加帽加尾的策略制备mRNA,用活体基因导入仪通过电穿孔的方式体内递送mRNA,借助小动物活体成像系统观测荧光素酶蛋白在小鼠体内的表达强度和持续时间。结果表明,使用该非复制型mRNA平台得到的mRNA成功在体内外表达,电穿孔介导的mRNA对小鼠健康体征无明显影响,所有的小鼠均成功表达了荧光素酶蛋白,蛋白表达在电穿孔后第1天达到峰值,在第4天迅速下降,但蛋白表达强度和持续时间存在较大的小鼠个体间差异。研究对非复制型mRNA的构建及其应用于疫苗或肿瘤药物研发具有重要参考价值。     

Hyaluronic acid complexed to biodegradable poly L‐arginine for targeted delivery of siRNAs

Background

Small interfering RNA (siRNA) has been recognized as a new therapeutic drug to treat various diseases by inhibition of oncogene or viral gene expression. Because hyaluronic acid (HA) has been described as a biocompatible biomaterial, we tested the nanoparticles formed by electrostatic complexation of negatively‐charged HA and cationic poly L ‐arginine (PLR) for siRNA delivery systems.

Methods

Different electrostatic complexes of HA and PLR (HPs) were formulated: HP101 with 50% (w/w) HA and HP110 with 9% (w/w) HA.

Results

Gel retardation assays showed that HP101 and HP110 could form complexes with siRNAs. The diameters of these complexes were less than 200 nm. Cellular delivery efficiency of siRNAs by HPs depended on cell surface CD44 density. The HP‐mediated delivery of siRNAs was highest in WM266.4 cells followed by B16F10 cells and COS‐7 cells, in parallel with CD44 surface densities of these cell lines. TC₅₀ values (i.e. the HP concentrations at which 50% of cells were viable after treatment) were used as indicators of cytotoxicity. HP101 showed TC₅₀ values that were 2‐fold and 23‐fold higher than those of HP110 and PLR, respectively. After delivery into cells, siRNA exerted target‐specific RNA interference effects on mRNA and protein levels. Three days after treatment of red fluorescent protein (RFP)‐expressing B16F10 cells with RFP‐specific siRNA complexed to HP101, cellular fluorescence signals were reduced. Intratumoral administration of RFP‐specific siRNA via HP101 delivery significantly reduced the expression of RFP in tumor tissues.

Conclusions

HP101 may function as a biocompatible polymeric carrier of siRNAs and have possible application to localized siRNA delivery in vivo. Copyright © 2009 John Wiley & Sons, Ltd.     

LncRNA SNHG1 functions as a ceRNA to antagonize the effect of miR‐145a‐5p on the down‐regulation of NUAK1 in nasopharyngeal carcinoma cell

How lncRNA SNHG1 influences the aggressiveness of nasopharyngeal carcinoma cells as well as the underlying mechanism was studied. The lncRNA differences were analysed by GSE12452 gene microarray. The expression of SNHG1, MiR‐145‐5p and NUAK1 was identified by qRT‐PCR and western blot. Transfection was conducted to construct nasopharyngeal carcinoma cells with different expressions of SNHG1, miR‐145‐5p and NUAK1. Dual‐luciferase reporter assay was performed to explore the relationship between SNHG1, miR‐145‐5p and NUAK1. Wound‐healing assay and transwell invasion experiments were employed to study changes in cell migration capacity and cell invasion, respectively. Tumour xenografts were performed to observe lung metastasis of nude mice inoculated with transfected CNE cells. SNHG1 is highly expressed in nasopharyngeal carcinoma tissues and in cell lines. Down‐regulation of SNHG1 facilitated the expression of miR‐145‐5p and further suppressed the level of NAUK1 in CNE and HNE‐1 cells. Silencing of SNHG1, up‐regulation of miR‐145‐5p and inhibition of NAUK1 by relative transfection all attenuated the aggressiveness of CNE and HNE‐1 cells both in vivo and in vitro. Moreover, the impaired cell migration and invasion by SNHG1 siRNA could be rescued by cotransfection of miR‐145‐5p in CNE and HNE‐1 cells. LncRNA SNHG1 promoted the expression of NUAK1 by down‐regulating miR‐145‐5p and thus promoted the aggressiveness of nasopharyngeal carcinoma cells through AKT signalling pathway and induced epithelial‐mesenchymal transition (EMT).     

Imaging of luciferase and GFP‐transfected human tumours in nude mice

Studies were performed to compare green ?uorescent protein (GFP)‐transfected and ?re?y luciferase (Luc)‐transfected MCF‐7 human breast tumour cells both in vitro and in vivo. For in vitro studies, cells were serially diluted in 96‐well microplates and analysed using a NightOwl LB 981 Molecular Light Imager and a Victor multilabel reader. For in vivo studies, nude mice were injected either intraperitoneally, intravenously or subcutaneously with transfected cells and then imaged using the NightOwl Imager after intraperitoneal injection of d ‐luciferin for Luc tumours, or excitation at 470 nm for GFP tumours. In vitro imaging studies revealed that both GFP and Luc transfectants were quanti?able. However, the Luc‐transfected cells were detectable at a signi?cantly lower concentration compared to GFP transfectants. In vivo studies demonstrated that GFP‐transfected tumours were detectable as subcutaneous and intraperitoneal tumours but not as deep tissue lesions, whereas Luc‐transfected tumours were detectable as subcutaneous and intraperitoneal tumours and as deep tissue lesions resulting from intraperitoneal or intravenous inoculation. These ?ndings demonstrate that GFP‐transfected cells may be useful for imaging studies of super?cial tumours where both excitation and emission wavelengths are able to penetrate tissues, whereas luciferase‐transfected cells appear superior for imaging studies of primary and metastatic tumours in distant sites and deep tissues. Copyright © 2003 John Wiley & Sons, Ltd.     

The apolipoprotein A‐I mimetic peptide,D‐4F,restrains neointimal formation through heme oxygenase‐1 up‐regulation

D‐4F, an apolipoprotein A‐I (apoA‐I) mimetic peptide, possesses distinctly anti‐atherogenic effects. However, the biological functions and mechanisms of D‐4F on the hyperplasia of vascular smooth muscle cells (VSMCs) remain unclear. This study aimed to determine its roles in the proliferation and migration of VSMCs. In vitro, D‐4F inhibited VSMC proliferation and migration induced by ox‐LDL in a dose‐dependent manner. D‐4F up‐regulated heme oxygenase‐1 (HO‐1) expression in VSMCs, and the PI3K/Akt/AMP‐activated protein kinase (AMPK) pathway was involved in these processes. HO‐1 down‐regulation with siRNA or inhibition with zinc protoporphyrin (Znpp) impaired the protective effects of D‐4F on the oxidative stress and the proliferation and migration of VSMCs. Moreover, down‐regulation of ATP‐binding cassette transporter A1 (ABCA1) abolished the activation of Akt and AMPK, the up‐regulation of HO‐1 and the anti‐oxidative effects of D‐4F. In vivo, D‐4F restrained neointimal formation and oxidative stress of carotid arteries in balloon‐injured Sprague Dawley rats. And inhibition of HO‐1 with Znpp decreased the inhibitory effects of D‐4F on neointimal formation and ROS production in arteries. In conclusion, D‐4F inhibited VSMC proliferation and migration in vitro and neointimal formation in vivo through HO‐1 up‐regulation, which provided a novel prophylactic and therapeutic strategy for anti‐restenosis of arteries.     

Small interfering RNA delivery into the liver by cationic cholesterol derivative-based liposomes

Purpose: Previously, we reported that the cationic liposomes composed of a cationic cholesterol derivative, cholesteryl (2-((2-hydroxyethyl)amino)ethyl)carbamate (OH-C-Chol) and 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE) (termed LP-C), could deliver small interfering RNAs (siRNAs) with high transfection efficiency into tumor cells. In this study, to develop a liposomal vector for siRNA delivery in vivo, we prepared the poly(ethyleneglycol) (PEG)-modified cationic liposomes (LP-C-PEG) and evaluated their transfection efficiency in vitro and in vivo.

Materials and methods: We prepared LP-C-PEG/siRNA complexes (LP-C-PEG lipoplexes) formed in water or 50?mM NaCl solution, and evaluated their siRNA biodistribution and gene silencing effect in mice after intravenous injection.

Results: LP-C-PEG lipoplexes strongly exhibited in vitro gene silencing effects in human breast tumor MCF-7 cells as well as LP-C lipoplexes. In particular, formation of LP-C and LP-C-PEG lipoplexes in the NaCl solution increased the cellular association. When LP-C-PEG lipoplexes with Cy5.5-labeled siRNA formed in water or NaCl solution were injected into mice, accumulation of the siRNA was observed in the liver. Furthermore, injection of LP-C-PEG lipoplexes with ApoB siRNA could suppress ApoB mRNA levels in the liver and reduce very-low-density lipoprotein/low-density lipoprotein levels in serum compared with that after Cont siRNA transfection, although the presence of NaCl solution in forming the lipoplexes did not affect gene silencing effects in vivo.

Conclusions: LP-C-PEG may have potential as a gene vector for siRNA delivery to the liver.     

Atelocollagen-mediated synthetic small interfering RNA delivery for effective gene silencing in vitro and in vivo

Silencing gene expression by siRNAs is rapidly becoming a powerful tool for the genetic analysis of mammalian cells. However, the rapid degradation of siRNA and the limited duration of its action call for an efficient delivery technology. Accordingly, we describe here that Atelocollagen complexed with siRNA is resistant to nucleases and is efficiently transduced into cells, thereby allowing long-term gene silencing. Site-specific in vivo administration of an anti-luciferase siRNA/Atelocollagen complex reduced luciferase expression in a xenografted tumor. Furthermore, Atelocollagen-mediated transfer of siRNA in vivo showed efficient inhibition of tumor growth in an orthotopic xenograft model of a human non-seminomatous germ cell tumor. Thus, for clinical applications of siRNA, an Atelocollagen-based non-viral delivery method could be a reliable approach to achieve maximal function of siRNA in vivo.