Comment on “report of 5 novel mutations of the α-L-iduronidase gene and comparison of Korean mutations in relation with those of Japan or China in patients with mucopolysaccharidosis I”

In this comment, we highlight that the IDUA pathogenic variants 704ins5 and c.613_617dupTGCTC are the same, but have different names depending on the nomenclature guideline used. Therefore, the frequency of this variant is 17.6% of alleles in Korean patients. This commentary stresses the importance of proper variant annotation and the use of guidelines when describing or reviewing mutations

Influence of phospholipid composition on cationic emulsions/DNA complexes: physicochemical properties, cytotoxicity, and transfection on Hep G2 cells

Michelle Fraga1,2, Fernanda Bruxel1, Valeska Lizzi Lagranha2,3, Helder Ferreira Teixeira1, Ursula Matte2,31Post Graduation Program in Pharmaceutical Sciences, Universidade Federal do Rio Grande do Sul, 2Gene Therapy Center, Experimental Research Center, Hospital de Clínicas de Porto Alegre, 3Post Graduation Program in Genetics and Molecular Biology, Universidade Federal do Rio Grande do Sul, Porto Alegre, BrazilBackground: Cationic nanoemulsions have been recently considered as potential delivery systems for nucleic acids. This study reports the influence of phospholipids on the properties of cationic nanoemulsions/DNA plasmid complexes.Methods: Nanoemulsions composed of medium-chain triglycerides, stearylamine, egg lecithin or isolated phospholipids, ie, DSPC, DOPC, DSPE, or DOPE, glycerol, and water were prepared by spontaneous emulsification. Gene transfer to Hep G2 cells was analyzed using real-time polymerase chain reaction.Results: The procedure resulted in monodispersed nanoemulsions with a droplet size and zeta potential of approximately 250 nm and +50 mV, respectively. The complexation of cationic nanoemulsions with DNA plasmid, analyzed by agarose gel retardation assay, was complete when the complex was obtained at a charge ratio of ≥1.0. In these conditions, the complexes were protected from enzymatic degradation by DNase I. The cytotoxicity of the complexes in Hep G2 cells, evaluated by MTT assay, showed that an increasing number of complexes led to progressive toxicity. Higher amounts of reporter DNA were detected for the formulation obtained with the DSPC phospholipid. Complexes containing DSPC and DSPE phospholipids, which have high phase transition temperatures, were less toxic in comparison with the formulations obtained with lecithin, DOPC, and DOPE.Conclusion: The results show the effect of the DNA/nanoemulsion complexes composition on the toxicity and transfection results.Keywords: plasmids, cationic nanoemulsions, phospholipids, physicochemical characterization, gene transfer, stearylamin

Effects of gene therapy on cardiovascular symptoms of lysosomal storage diseases

Lysosomal storage diseases (LSDs) are inherited conditions caused by impaired lysosomal function and consequent substrate storage, leading to a range of clinical manifestations, including cardiovascular disease. This may lead to significant symptoms and even cardiac failure, which is an important cause of death among patients. Currently available treatments do not completely correct cardiac involvement in the LSDs. Gene therapy has been tested as a therapeutic alternative with promising results for the heart disease. In this review, we present the results of different approaches of gene therapy for LSDs, mainly in animal models, and its effects in the heart, focusing on protocols with cardiac functional analysis

Non-viral gene transfer to the tendon: comparison of two methods

Background: tendons are part of the connective tissue that joins muscle to bone. Tendon injuries are a problem, since they have a poor ability to regenerate spontaneously. Alternative treatments involving the injection of local growth factors and gene transfer has been evaluated. Thus, we compared two methods for non-viral gene transfer tendons, using the GFP gene as reporter gene.Methods: Wistar rats had the medial quadriceps tendon exposed and the plasmid was transferred by direct injection or complexed with liposomes. Quantification of GFP in the tendom and in the spleen was evaluated by histological analysis with a fluorescence microscope.Results: gene transfer to the tendon was successfully obtained in both treatments. Lipoplex, as expected, showed the highest efficiency in transducing tenocytes, however we have found GFP expression also in the spleen. Naked DNA also showed fluorescence values above the control group and the signal was limited to the tendom.Discussion: the use of GFP as a reporter gene is a classical approach to evaluate gene transfer efficiency. Non-viral gene transfer methods are safe but show low levels of transduction and transient expression. For tendon repair, however, these characteristics may prove beneficial because a transient expression may be desirable to avoid the risk of adverse effects. GFP distribution in the spleen was probably a result of lipoplexes uptake by cells from the reticular endothelial system.Conclusion: taking into account the distribution of GFP in another tissue when using lipoplex, we believe that naked DNA is a more appropriate way to perform gene transfer to the tendon, ensuring safety, low cost and easy handling

Updating the genetic code : interference RNA - a comment on the Nobel Prize in Physiology or Medicine 2006

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