138 research outputs found
Compensatory signals associated with the activation of human GC 5' splice sites
No full textGC 5? splice sites (5?ss) are present in ?1% of human introns, but factors promoting their efficient selection are poorly understood. Here, we describe a case of X-linked agammaglobulinemia resulting from a GC 5?ss activated by a mutation in BTK intron 3. This GC 5?ss was intrinsically weak, yet it was selected in >90% primary transcripts in the presence of a strong and intact natural GT counterpart. We show that efficient selection of this GC 5?ss required a high density of GAA/CAA-containing splicing enhancers in the exonized segment and was promoted by SR proteins 9G8, Tra2? and SC35. The GC 5?ss was efficiently inhibited by splice-switching oligonucleotides targeting either the GC 5?ss itself or the enhancer. Comprehensive analysis of natural GC-AG introns and previously reported pathogenic GC 5?ss showed that their efficient activation was facilitated by higher densities of splicing enhancers and lower densities of silencers than their GT 5?ss equivalents. Removal of the GC-AG introns was promoted to a minor extent by the splice-site strength of adjacent exons and inhibited by flanking Alu repeats, with the first downstream Alus located on average at a longer distance from the GC 5?ss than other transposable elements. These results provide new insights into the splicing code that governs selection of noncanonical splice site
C.I. Acid Black 1 transfer from dilute solution to perlite framework in organic waste management
No full textDyes, considered as toxic and persistent pollutants, must be removed from organic wastes prior to their composting and application in sustainable agriculture. Azo dyes, capable of altering the physicochemical properties of soil, are difficult to expel by conventional wastewater treatments. C.I. Acid Black 1 (AB 1), a sulfonated azo dye, inhibits nitrification and ammonification in the soil, lessens the nitrogen use efficacy in crop production and passes substantially unaltered through an activated sludge process. The retention of C.I. Acid Black 1 by raw and expanded perlite was investigated in order to examine the potential effectiveness of this aluminosilicate material toward organic waste cleanup. Dye adsorption proved spontaneous and endothermic in nature, increasing with temperature for both perlites. Expanded perlite having a more open structure exhibited a better performance compared to the raw material. Several of the most widely recognized two-parameter theoretical models, i.e., Langmuir, Freundlich, Temkin, Brunauer–Emmett–Teller (BET), Harkins–Jura, Halsey, Henderson, and Smith, were applied to reveal physicochemical features characterizing the adsorption. The Langmuir, Freundlich, Temkin, BET, Henderson, and Smith equations best fitted experimental data indicating that the adsorption of anionic dye on perlites is controlled by their surface, i.e., non-uniformity in structure and charge. This heterogeneity of surface is considered responsible for promoting specific dye adsorption areas creating dye “islands” with local dye supersaturations. © The Author(s) 2024
The gene involved in X-linked agammaglobulinaemia is a member of the src family of protein-tyrosine kinases
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Macrophage-dependence of mitogen responsiveness: Macrophages exposed to zymosan enhance the response to polyanions
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Oligonucleotide therapies for RNA and DNA : modulation of natural splice-variants, DNA structure and characterization of new synthetic nucleotides and reporter cell lines
No full textOligonucleotide therapy is an evolving field having shown fast and important developments in the last years. From genetics to metabolic, inflammatory, immunodeficiency diseases, cancer and viral infections the medical applications for this type of therapy are becoming broader every day. However, the major challenge for these therapies is still the delivery; thus new chemistries, as well as improved delivery vectors are needed. Equally, the lack of relevant reporter systems hampers the characterization and progress of these emergent “drugs.”This thesis work was aimed to address some of the gaps presented above. Thus, the introduction section starts with a brief overview of the gene therapy. It continues with an explanation of the oligonucleotide therapy strategies and technologies used for RNA and DNA targeting and ends with a clinical case for each approach. The methodology section explains the theoretical and practical aspects of the most relevant techniques in this study and the results section explain the rational and gives a brief presentation of the main results and conclusions for each paper.Paper I presents a new splice-switching approach for treating diseases by regulating proteins at the splicing level. The new principle was to convert the normal splice form to a natural, but less abundant and inactive, splice variant to treat hypercholesterolemia. Paper II shows the development and characterization of a new collection of reporter cell lines for splice- switching. These reporter cell lines can serve as models for cell-type-specific screenings of different ON chemistries and delivery vectors. Paper III and IV demonstrate the development and characterization of a new nucleic acid chemical modification providing an oligomer with cell penetrating properties. Finally, in paper V a new mechanism for gene expression regulation at the genome level is presented.List of scientific papersI. RNA therapeutics inactivate PCSK9 by inducing a unique intracellular retention form. Cristina S. J. Rocha, Oscar P. B. Wiklander, Lilian Larsson, Pedro M. D. Moreno, Paolo Parini, Karin E. Lundin, C.I. Evard Smith. Journal of Molecular and Cellular Cardiology. 2015: 82, 186-93 https://doi.org/10.1016/j.yjmcc.2015.03.009 II. Four novel splice-switch reporter cell lines: distinct impact of oligonucleotide chemistry and delivery vector on biological activity. Cristina S. J. Rocha, Karin E. Lundin, Mark A. Behlke, Rula Zain, Samir EL Andaloussi, C.I. Edvard Smith. Nucleic Acid Therapeutics. September 2016, ahead of print. [Accepted] https://doi.org/10.1089/nat.2016.0631 III. Nuclease resistant oligonucleotides with cell penetrating properties. Stefan Milton, Dmytro Honcharenko, Cristina S. J. Rocha, Pedro M. D. Moreno, C. I. Edvard Smith and Roger Strömberg. Chemical Communications. 2015: 51(9), 4044-4047 https://doi.org/10.1039/c4cc08837a IV. Fully and partially AECM-modified oligonucleotides. Synthesis and initial studies on cellular uptake and splice-switching activity in different reporter cell lines. Dmytro Honcharenko, Cristina S. J. Rocha, Jyotirmoy Maity, Ulf Tedebark, Stefan Milton, Rula Zain, C. I. Edvard Smith and Roger Strömberg. [Manuscript]V. Disruption of higher order DNA structures in Friedreich’s ataxia (GAA)n repeats by PNA and LNA targeting. Helen Bergquist, Cristina S. J. Rocha, Rubén Álvarez-Asencio, Chi-Hung Ngyuen, Mark. W. Rutland, C. I. Edvard Smith, Liam Good, Peter E. Nielsen, Rula Zain. [Submitted]</p
Map of the country between the frontiers of Arkansas and New Mexico, embracing the section explored in 1849, 50, 51 & 52
No full textScale approximately 1:1,520,6401 map ; 67 x 148 cmRelief shown by hachures.Shows trails, wagon roads, and forts.Also a continuation of the emigrant road from Fort Smith and Fulton down the Valley of the Gila.""H. Lawrence, 86 John St. N.Y."From the author's Exploration of the Red River of Louisiana, in the year 1852. Washington, D.C. : Robt. Armstrong, 1853.Prime meridian: Greenwich.Wheat, C.I. Mapping the Trans-Mississippi West, |c v.3, no. 791, p. 327-32
The influence of gene deletions and duplications within the IGHC locus on serum immunoglobulin subclass levels
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