MicroRNAs de parásitos cestodos: rol biológico y estudio de su potencial como blancos terapéuticos de enfermedades desatendidas
Parasitic diseases caused by cestodes pose a significant challenge to global public health. \nAmong these, echinococcosis and cysticercosis are classified by the World Health Organization as neglected diseases. The parasites responsible for these conditions belong to the genera Echinococcus and Taen...
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| Formato: | Tesis doctoral acceptedVersion |
| Lenguaje: | Español |
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Universidad de Buenos Aires. Facultad de Ciencias Veterinarias
2025
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| Acceso en línea: | http://repositoriouba.sisbi.uba.ar/gsdl/cgi-bin/library.cgi?a=d&c=avaposgra&cl=CL1&d=HWA_7998 https://repositoriouba.sisbi.uba.ar/gsdl/collect/avaposgra/index/assoc/HWA_7998.dir/7998.PDF |
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| Sumario: | Parasitic diseases caused by cestodes pose a significant challenge to global public health. \nAmong these, echinococcosis and cysticercosis are classified by the World Health Organization as neglected diseases. The parasites responsible for these conditions belong to the genera Echinococcus and Taenia, respectively, and exhibit unique characteristics throughout their life \ncycle, requiring complex and precise regulation of gene expression. MicroRNAs (miRNAs), a class of small RNAs, play a crucial role in the regulation of various biological processes, such as development and metabolism, primarily by repressing target mRNAs through binding mainly to \nthe 3' untranslated region (3'UTR). The parasitic miRNA miR-71 is one of the most expressed miRNAs across all life stages of cestodes studied, regulating essential genes in these organisms and being absent in the genomes of vertebrate hosts. For these reasons, miR-71 is particularly \nrelevant and of interest for studying and understanding the developmental basis and pathogenesis of parasitic cestodes. Additionally, it could be considered a potential selective drug target for the treatment of cestodiasis. \nThis thesis conducted a functional analysis of miRNAs of interest, such as miR-71, in laboratory models representing other cestodes, such as M. vogae and H. microstoma. \nAdditionally, the distribution and expression of these miRNAs were evaluated in various cell types and tissues of these organisms. To inhibit miR-71, antisense oligonucleotides (anti-miRs) were employed. Subsequently, the effects of this inhibition on in vitro parasite development and the \nexpression of predicted target genes using bioinformatics tools were analyzed. This approach enabled miR-71 silencing in complete in vitro parasites. The inhibition of miR-71 facilitated further studies on parasite development, where the inhibition was associated with increased development, correlating with the overexpression of certain target genes whose predicted functions were related to developmental processes. Furthermore, different formulations for \noligonucleotide transfection were assessed, highlighting the use of cationic liposomes, which enabled the incorporation of fluorescent oligonucleotides through the tegument of M. vogae larvae. \nTo study the effects of miR-71 silencing on the progression of parasitic infections, mice were infected with parasites treated with anti-miR-71. Additionally, repeated intraperitoneal inoculations of anti-miR-71 were performed on mice previously infected with M. vogae, showing a reduction in parasite mass obtained after the establishment of the infection compared to control groups. \nAdditionally, in situ hybridizations were conducted on complete parasites to identify the spatial expression patterns of miRNAs in M. vogae and H. microstoma. The combination with immunohistofluorescence techniques allowed the detection of colocalization of the analyzed miRNAs with markers of nervous and muscle tissue, as well as germ cells in various phases of the cell cycle. miR-71 expression was detected diffusely and homogeneously across all parasite \ntissues, showing colocalization with markers of nervous tissue and the cell cycle. Furthermore, the presence of miR-1, typically associated with muscle tissue, was identified through its colocalization with tropomyosin-1. These findings underscore the potential importance of miRNAs given their broad expression. \nIn conclusion, this thesis represents the first functional characterization of miRNAs in complete cestode models, exploring their role in development, infection progression, and analyzing their expression in different tissues and cell types. These findings, particularly on miR71, which is highly expressed and absent in hosts, provide a solid basis for future studies and for developing potential treatments to help control these neglected zoonoses. |
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