10 research outputs found
Efficient In Vivo Liver-Directed Gene Editing Using CRISPR/Cas9
n vivo tissue-specific genome editing at the desired loci is still a challenge. Here, we report that AAV9-delivery of truncated guide RNAs (gRNAs) and Cas9 under the control of a computationally designed hepatocyte-specific promoter lead to liver-specific and sequence-specific targeting in the mouse factor IX (F9) gene. The efficiency of in vivo targeting was assessed by T7E1 assays, site-specific Sanger sequencing, and deep sequencing of on-target and putative off-target sites. Though AAV9 transduction was apparent in multiple tissues and organs, Cas9 expression was restricted mainly to the liver, with only minimal or no expression in other non-hepatic tissues. Consequently, the insertions and deletion (indel) frequency was robust in the liver (up to 50%) in the desired target loci of the F9 gene, with no evidence of targeting in other organs or other putative off-target sites. This resulted in a substantial loss of FIX activity and the emergence of a bleeding phenotype, consistent with hemophilia B. The in vivo efficacy of the truncated gRNA was as high as that of full-length gRNA. Cas9 expression was transient in neonates, representing an attractive âhit-and-runâ paradigm. Our findings have potentially broad implications for somatic gene targeting in the liver using the CRISPR/Cas9 platform
Approaches in biotechnological applications of natural polymers
Natural polymers, such as gums and mucilage, are biocompatible, cheap, easily available and non-toxic materials of native origin. These polymers are increasingly preferred over synthetic materials for industrial applications due to their intrinsic properties, as well as they are considered alternative sources of raw materials since they present characteristics of sustainability, biodegradability and biosafety. As definition, gums and mucilages are polysaccharides or complex carbohydrates consisting of one or more monosaccharides or their derivatives linked in bewildering variety of linkages and structures. Natural gums are considered polysaccharides naturally occurring in varieties of plant seeds and exudates, tree or shrub exudates, seaweed extracts, fungi, bacteria, and animal sources. Water-soluble gums, also known as hydrocolloids, are considered exudates and are pathological products; therefore, they do not form a part of cell wall. On the other hand, mucilages are part of cell and physiological products. It is important to highlight that gums represent the largest amounts of polymer materials derived from plants. Gums have enormously large and broad applications in both food and non-food industries, being commonly used as thickening, binding, emulsifying, suspending, stabilizing agents and matrices for drug release in pharmaceutical and cosmetic industries. In the food industry, their gelling properties and the ability to mold edible films and coatings are extensively studied. The use of gums depends on the intrinsic properties that they provide, often at costs below those of synthetic polymers. For upgrading the value of gums, they are being processed into various forms, including the most recent nanomaterials, for various biotechnological applications. Thus, the main natural polymers including galactomannans, cellulose, chitin, agar, carrageenan, alginate, cashew gum, pectin and starch, in addition to the current researches about them are reviewed in this article.. }To the Conselho Nacional de Desenvolvimento CientfĂico e TecnolĂłgico (CNPq) for fellowships (LCBBC and MGCC) and the Coordenação de Aperfeiçoamento de Pessoal de NvĂel Superior (CAPES) (PBSA). This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit, the Project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462) and COMPETE 2020 (POCI-01-0145-FEDER-006684) (JAT)
Novel hyperactive transposons for genetic modification of induced pluripotent and adult stem cells: a nonviral paradigm for coaxed differentiation
Adult stem cells and induced pluripotent stem cells (iPS) hold great promise for regenerative medicine. The development of robust non-viral approaches for stem cell gene transfer would facilitate functional studies and potential clinical applications. We have previously generated hyperactive transposases derived from Sleeping Beauty, using an in vitro molecular evolution and selection paradigm. We now demonstrate that these hyperactive transposases resulted in superior gene transfer efficiencies and expression in mesenchymal and muscle stem/progenitor cells, consistent with higher expression levels of therapeutically relevant proteins including coagulation factor IX. Their differentiation potential and karyotype was not affected. Moreover, stable transposition could also be achieved in iPS which retained their ability to differentiate along neuronal, cardiac and hepatic lineages without causing cytogenetic abnormalities. Most importantly, transposon-mediated delivery of the myogenic PAX3 transcription factor into iPS coaxed their differentiation into MYOD(+) myogenic progenitors and multinucleated myofibers, suggesting that PAX3 may serve as a myogenic "molecular switch" in iPS. Hence, this hyperactive transposon system represents an attractive non-viral gene transfer platform with broad implications for regenerative medicine, cell and gene therapy.status: publishe
Chemical acetylation of nixtamalized maize flour and structural, rheological and physicochemical properties of flour, dough and tortillas
Ethnic differences in cardiovascular risk in rheumatic disease: focus on Asians
Rheumatic diseases are associated with high cardiovascular morbidity and mortality. Considerable differences exist in the frequency of cardiovascular disease (CVD) risk factors and events among people of different ethnic origins, but little is known of the ethnic variations in the relative distribution of CVD risk factors and the degree of atherosclerosis in patients with rheumatic diseases. Understanding this variation will provide insight into the underlying pathogenesis of CVD in patients with rheumatic diseases, and aid in future studies of the detection and management of this complication. In general, although Asian patients seem to have fewer background CVD risk factors and are less affected by metabolic syndrome (MetS) than their non-Asian counterparts, those with rheumatic disease are equally as susceptible to CVD. Furthermore, it seems that systemic inflammation and mechanisms that do not involve conventional CVD risk factors and MetS have an important role in the development of atherosclerosis in patients with rheumatic diseases. Here we examine the frequency of conventional CVD risk factors and the prevalence of MetS in both Asian and non-Asian patients with selected rheumatic diseases. We also discuss the burden of CVD, as evaluated using various surrogate markers in these patients, and their overall CVD mortality rate. © 2011 Macmillan Publishers Limited. All rights reserved.postprin
A Theoretical Investigation of low energy band gap polymers: polythiophene systems
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