Genetic analyses in the gooseneck barnacles(Genus "Pollicipes")

[Resumo] Os percebes do xénero Pollicipes son crustáceos mariños de vida sésil que habitan costas rochosas expostas a fortes mareas e ondas nas zonas costeiras occidentais de Europa, África e América. En base a diferenzas morfolóxicas do pedúnculo describíronse dous fenotipos: percebes de sol e de sombra. Os resultados obtidos permitiron reconstruír filoxenias nesta familia en base a marcadores mitocondriais (16S ADNr e COI) e nucleares (18S-28S ADNr e EF1α) que mostraron topoloxías discrepantes debido ás diferentes forzas evolutivas ás que se atopa sometido cada marcador. Os datos estruturais obtidos nas rexións ITS1, 5.8S e ITS2 permitiron identificar a orixe monofilética de certos taxones así como establecer os patróns de pregamento de ditas rexións no subfilo Crustacea. Os marcadores microsatélites optimizados permitiron comprobar a existencia de panmixis entre as poboacións dos percebes P. pollicipes nas costas atlánticas e elaborar un modelo loxístico para determinar a súa posible orixe xeográfica. Os estudios de expresión xénica permitiron validar a utilidade dos xenes de referencia albumina, HSP70, HSP90, actina, β-actina e histona H3 para este tipo de estudios e detectar diferenzas significativas entre certos xenes relacionados coa integridade e musculatura do pedúnculo entre os dous fenotipos do percebe.[Resumen] Los percebes del género Pollicipes son crustáceos marinos de vida sésil que habitan costas rocosas expuestas a fuertes mareas y oleajes en las zonas costeras occidentales de Europa, África y América. En base a diferencias morfológicas del pedúnculo se han descrito dos fenotipos: percebes de sol y de sombra. Los resultados obtenidos permitieron reconstruir filogenias en esta familia en base a marcadores mitocondriales (16S ADNr y COI) y nucleares (18S-28S ADNr y EF1α) que mostraron topologías discrepantes debido a las diferentes fuerzas evolutivas a las que se encuentra sometido cada marcador. Los datos estructurales obtenidos en las regiones ITS1, 5.8S e ITS2 permitieron identificar el origen monofilético de ciertos taxones así como establecer los patrones de plegamiento de dichas regiones en el subfilo Crustacea. Los marcadores microsatélites optimizados permitieron comprobar la existencia de panmixis entre las poblaciones de los percebes P. pollicipes en las costas atlánticas y elaborar un modelo logístico para determinar su posible origen geográfico. Los estudios de expresión génica permitieron validar la utilidad de los genes de referencia albúmina, HSP70, HSP90, actina, β-actina e histona H3 para este tipo de estudios y detectar diferencias significativas entre ciertos genes relacionados con la integridad y musculatura del pedúnculo entre los dos fenotipos de percebe.[Abstract] Barnacles from the genus Pollicipes are marine crustaceans of sessile lifestyle which inhabit rocky coasts exposed to string waves and tides in western coasts of Europe, Africa and America. Two phenotypes have been described based on morphological differences of the peduncle: sun barnacles and shadow barnacles. Obtained results let reconstruct phylogenies in this family using mitochondrial (16S rDNA and COI) and nuclear (18S-28S rDNA and EF1α) markers which showed discrepant topologies due to the different evolutionary forces which drive the molecular evolution of each marker. Structural data obtained from ITS1, 5.8S and ITS2 regions let identified the monophyletic origin of certain taxa, and establish the folding of these regions in subphylum Crustacea. Optimised microsatellite markers let corroborate the existence of panmixis between wild populations of P. pollicipes in Atlantic coasts and develop a logistic model to determine the geographical origin of these populations. Genic expression assays let validate the utility of the reference genes albumin, HSP70, HSP90, actin, β-actin and histone H3 in this kind of studies and detected significant differences between certain genes related to peduncular integrity and muscularity between both phenotypes

Preclinical characterization of antagomiR-218 as a potential treatment for myotonic dystrophy

Myotonic dystrophy type 1 (DM1) is a rare neuromuscular disease caused by expansion of unstable CTG repeats in a non-coding region of the DMPK gene. CUG expansions in mutant DMPK transcripts sequester MBNL1 proteins in ribonuclear foci. Depletion of this protein is a primary contributor to disease symptoms such as muscle weakness and atrophy and myotonia, yet upregulation of endogenous MBNL1 levels may compensate for this sequestration. Having previously demonstrated that antisense oligonucleotides against miR-218 boost MBNL1 expression and rescue phenotypes in disease models, here we provide preclinical characterization of an antagomiR-218 molecule using the HSALR mouse model and patient-derived myotubes. In HSALR, antagomiR-218 reached 40-60 pM 2weeks after injection, rescued molecular and functional phenotypes in a dose- and time-dependent manner, and showed a good toxicity profile after a single subcutaneous administration. In muscle tissue, antagomiR rescued the normal subcellular distribution of Mbnl1 and did not alter the proportion of myonuclei containing CUG foci. In patient-derived cells, antagomiR-218 improved defective fusion and differentiation and rescued up to 34% of the gene expression alterations found in the transcriptome of patient cells. Importantly, miR-218 was found to be upregulated in DM1 muscle biopsies, pinpointing this microRNA (miRNA) as a relevant therapeutic target.This work was funded by research grants from Instituto de Salud Carlos III, including funds from FEDER, to M.P.-A. and B.L. (PI17/00352) and HR17-00268 (TATAMI project) from the “la Caixa” Banking Foundation to R.A. I.G.-M. was funded by the Precipita Project titled “Desarrollo de una terapia innovadora contra la distrofia miotónica,” E.C.-H. and J.M.F.-C. were supported by the post-doctoral fellowships APOSTD/2019/142 and APOSTD/2017/088 from the Fondo Social Europeo for science and investigation, while J.E.-E. was the recipient of a Santiago Grisolia fellowship (Grisolip2018/098) from the Generalidad Valenciana. Part of the equipment employed in this work has been funded by Generalitat Valenciana and co-financed with ERDF funds (OP ERDF of Comunitat Valenciana 2014-2020). Antibody MB1a (4A8) was provided by MDA Monoclonal Antibody Resource

Peptide-conjugated antimiRs improve myotonic dystrophy type 1 phenotypes by promoting endogenous MBNL1 expression

Myotonic dystrophy type 1 (DM1) is a rare neuromuscular disease caused by a CTG repeat expansion in the DMPK gene that generates toxic RNA with a myriad of downstream alterations in RNA metabolism. A key consequence is the sequestration of alternative splicing regulatory proteins MBNL1/2 by expanded transcripts in the affected tissues. MBNL1/2 depletion interferes with a developmental alternative splicing switch that causes the expression of fetal isoforms in adults. Boosting the endogenous expression of MBNL proteins by inhibiting the natural translational repressors miR-23b and miR-218 has previously been shown to be a promising therapeutic approach. We designed antimiRs against both miRNAs with a phosphorodiamidate morpholino oligonucleotide (PMO) chemistry conjugated to cell-penetrating peptides (CPPs) to improve delivery to affected tissues. In DM1 cells, CPP-PMOs significantly increased MBNL1 levels. In some candidates, this was achieved using concentrations less than two orders of magnitude below the median toxic concentration, with up to 5.38-fold better therapeutic window than previous antagomiRs. In HSALR mice, intravenous injections of CPP-PMOs improve molecular, histopathological, and functional phenotypes, without signs of toxicity. Our findings place CPP-PMOs as promising antimiR candidates to overcome the treatment delivery challenge in DM1 therapy