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During the first two decades of the 21st century, remarkable progresses have been achieved in the field of RNA-based therapeutics. From antisense RNA to RNA modification, the therapeutic potential of RNA-based technologies has nothing but increased. In our lab, we have been addressing the potential of different RNA-based drugs to either correct or ameliorate the sub-cellular phenotype of a number of severe, life-threatening diseases: the so-called Lysosomal Storage Disorders (LSDs). Among them, we are focusing our efforts on those which present with a predominant neurological phenotype, since there are virtually no approved treatments for any of them. Briefly, two major research lines are being pursued: the first relies on the design of mutation-specific approaches to correct abnormal splicing processes in LSD-related genes, whenever they underlie pathology. The second depends upon selective downregulation of genes involved in the biosynthethic cascades that give origin to the substrates that accumulate in each pathology. Here we present an overview on our results with both approaches on Sanfilippo syndrome, a sub-group of severe neurodegenerative LSDs. For the mutation-specific, splicing correction approach, we are using U1snRNA vectors to restore the splicing defect caused by the HGSNAT mutation c.234+1G>A, that leads to Sanfilippo C disease. We started by demonstrating in vitro that a modified U1snRNA vector designed to improve the definition of HGSNAT exon 2 could partially restore its normal splicing process. Now, we are evaluating its therapeutic potential in vivo, in mice expressing the human splicing defect. For the substrate reduction approach, we are using siRNAs. By acting over a specific biosynthethic cascade, siRNAs promote an overall decrease of the accumulating substrate. So far, we have already tested this approach in patients’ fibroblasts and observed a high inhibition of the target mRNAs and a decrease in storage. Overall, there are substantial differences between these two approaches but they also face common challenges and show equally promising results. FCT (SFRH/BPD/101965/2014; SFRH/BD/124372/2016) N/A

Atualmente, as abordagens terapêuticas de RNA estão em grande desenvolvimento e algumas destas terapias foram já aprovadas para uso clínico. Uma das estratégias mais conhecidas tem como base a utilização de oligonucleótidos antisense (OA), pequenos oligonucleótidos sintéticos que se ligam aos RNA alvo por meio de emparelhamento de bases. Estas moléculas podem atuar de diferentes formas, sendo a diminuição da expressão génica devido à degradação pela RNase-H dos mRNA alvo e a modulação do processo de splicing para induzir a inclusão ou exclusão de um exão (exon skipping), as mais amplamente aplicadas. Particularmente para as doenças raras, diferentes aplicações de OA estão em desenvolvimento, com vários ensaios clínicos em curso e com 3 destas terapêuticas já em prática clínica. As Doenças Lisossomais de Sobrecarga (DLS) são um grupo de doenças hereditárias do metabolismo raras que podem originar uma patologia grave e progressiva devido a uma disfunção lisossomal específica. Atualmente, não existe cura para as DLS, embora para algumas destas doenças haja estratégias de tratamento. Assim, as abordagens terapêuticas de RNA podem representar uma importante estratégia terapêutica alternativa ou adjuvante. O grupo de investigação em DLS do Departamento de Genética Humana do INSA – Porto, tem contribuído para o desenvolvimento de novas abordagens terapêuticas de RNA tendo sido já obtidos resultados positivos para diferentes DLS. Para a validação pré-clínica de novas terapias, tanto os modelos in vitro como in vivo são necessários e largamente utilizados. Num estudo anterior efetuado in vitro, para a mutação c.3503_3504delTC no gene GNPTAB, que origina a Mucolipidose tipo II α/β, foi testada uma estratégia terapêutica de exon-skipping utilizando diferentes OA em fibroblastos de doentes, tendo resultado na produção de um mRNA in-frame1. Neste estudo, pretendeu-se avaliar o potencial terapêutico desta abordagem tanto in vitro (fibroblastos de murganho C57BL/6) como in vivo (murganhos C57BL/6) e os resultados preliminares obtidos serão apresentados e discutidos. 1. Matos L, Vilela R, Rocha M, et al. Development of an antisense oligonucleotide-mediated exon skipping therapeutic strategy for Mucolipidosis II: validation at RNA level. Hum Gene Ther, 2020, 31(13-14):775-783. N/A

A alimentação em meio hospitalar tem vindo a ser objeto de debate junto dos profissionais de saúde, dado o papel determinante que desempenha no tratamento e recuperação do doente. O estudo teve como objetivo avaliar a qualidade nutricional de refeições hospitalares recolhidas entre 2017 e 2019. Foram analisadas laboratorialmente 32 refeições completas constituídas por prato de carne (53,1 %), prato de pescado (40,6%) e vegetariano (6,3%). A avaliação nutricional incluiu a quantificação dos valores de energia, hidratos de carbono, proteína, gordura total, fibra alimentar e sal e posterior estudo da adequabilidade nutricional, através da verificação dos desvios relativos às recomendações nutricionais estabelecidas para uma população que se considerou como sendo de doentes adultos na faixa etária entre os 19 e os 74 anos. As refeições constituídas por prato de carne apresentaram valores médios superiores de densidade energética, proteína, gordura e hidratos de carbono, comparativamente com as restantes refeições. As refeições com prato vegetariano foram as que revelaram um teor médio de sal mais baixo. Nos três tipos de refeições verificou-se um incumprimento das recomendações nutricionais relativamente aos teores de energia, proteína e sal. Este estudo vai ao encontro dos que consideram a vigilância nutricional periódica como uma forma de evidenciar tendências e identificar desvios, permitindo a implementação de ações corretivas apropriadas e atempadas para a melhoria da qualidade nutricional das refeições hospitalares. The provision of hospital meals has been a topic of debate among health professionals, given the decisive role it plays in the treatment and recovery of patients. This study aimed to assess the nutritional quality of hospital meals collected between 2017 and 2019. A total of 32 complete meals consisting of meat dishes (53.1 %), fish dishes (40.6%) and vegetarian (6.3%) were laboratory analysed. The nutritional evaluation included the quantification of energy, carbohydrates, protein, total fat, dietary fibre and salt contents and subsequent study of nutritional adequacy, through the verification of the deviations relative to the nutritional recommendations established for a population, which was considered to be adult patients aged between 19-74 years. The meals consisting of a meat dish presented higher mean values of energy, protein, fat and carbohydrates when compared with the other meals. In the vegetarian meals, it was observed the lowest mean salt content. In all three types of meals, there was a lack of compliance with the nutritional recommendations in terms of energy, protein and salt content. This study is in accordance with those who consider periodic nutritional surveillance as a way to highlight trends and identify deviations, allowing the implementation of appropriate and timely corrective actions to improve the nutritional quality of hospital meals. info:eu-repo/semantics/publishedVersion

Mucolipidosis type II alpha/beta (ML II alpha/beta) is one of the most severe Lysosomal Storage Disorders and is caused by the deficiency of the enzyme GlcNAc-1-phosphotransferase. This enzyme is responsible for the addition of the mannose 6-phosphate marker to lysosomal enzymes, which allow their targeting to lysosomes. Of the several mutations that occur in ML II alpha/beta, the deletion of 2 nucleotides from GNPTAB exon19 (c.3503_3504del) is the most frequent, making it a good target for a specific mutation therapy as there is no therapy for this disease. In this study, we explored the possibility of an innovative therapeutic strategy based on the use of antisense oligonucleotides (AOs) for ML II alpha/beta. In a previous in vitro study in ML II alpha/beta patient fibroblasts, AOs were used to promote the exon 19 skipping from the GNPTAB pre-mRNA, resulting successfully in the production of an in-frame mRNA1. Currently, our objective is to evaluate the therapeutic potential of this approach, both in vitro in C57BL/6 fibroblasts and in vivo in C57BL/6 mice. For this, 18 animals were used, divided into 6 groups: groups 1 and 4 were injected with saline solution, groups 2 and 5 were injected with AO at 25 mg/kg and groups 3 and 6 were injected with AO at 50 mg/kg. All animals were injected by intraperitoneal route and were sacrificed after 4 days (groups 1, 2, 3) or 7 days (groups 4, 5, 6) post-treatment. At the end of the experiment, the organs were collected and frozen at -80ºC, for later RNA extraction, cDNA synthesis and RT-PCR. After results analysis, the exon 19 skipping was not observed using any of the tested doses or incubation periods. So, we can theorize that the doses administered were not sufficient to achieve a response or the AO might have had a high clearance rate. As for the in vitro experience, the C57BL/6 fibroblasts were seeded in 6-well plates and subsequently transfected with concentrations of AO ranging from 10nM to 600nM. After 24h or 48h of incubation, cells were collected and cDNA analysis revealed a full length transcript but also another one of lower molecular weight compatible with exon-skipping. These are preliminary data, so in the near future more experiments will be done. 1. Matos L, Vilela R, Rocha M, et al. Development of an antisense oligonucleotide-mediated exon skipping therapeutic strategy for Mucolipidosis II: validation at RNA level. Hum Gene Ther, 2020, 31(13-14):775-783. N/A

Over the last years, most of our work has been focused on the development of alternative, RNA-based therapies for a number of Lysosomal Storage Disorders (LSD), being Mucopolysaccharidosis (MPS) one of the most relevant. Currently, there are two major research lines being pursued: the first relies on the design of mutation-specific approaches to correct abnormal splicing processes in LSD-related genes whenever they underlie pathology and the second depends upon selective downregulation of one gene involved in the very early stages of the glycosaminoglycans’ (GAG) biosynthethic cascade to promote substrate reduction in MPS diseases. There are substantial differences between these two approaches, but they also face common challenges. Two major possible drug types, depending on the genotype that underlies pathology, are being used: U1snRNA and siRNAs. U1snRNAs are specifically designed to overcome particular splicing mutations. These RNA drugs are, therefore, mutation-specific and constitute patient-tailored approaches. We have already demonstrated in fibroblasts that a modified U1snRNA vector (comprising exon 1 to exon 3) designed to improve the definition of exon 2 5’ SDS of the HGSNAT can restore the splicing defect caused by the mutation c.234+1G>A, that leads to MPSIIIC disease (Matos et al., 2014). Currently, our goal is to evaluate in vivo the therapeutic potential of that modified U1 snRNA by testing it in mice expressing the human splicing defect. A preliminary assay was performed and showed promising results. The second group of RNA drugs, siRNAs, holds a different potential. By acting over the GAGs’ biosynthethic cascade, siRNAs will promote an overall decrease of the accumulating substrate. So far, we have already tested this approach in MPSIII patients’ fibroblasts and the overall results are quite promising. We observed a high inhibition of the XYLT1 (a gene that encodes an enzyme involved in an early stage of the HS biosynthetic cascade) mRNAs (around 80%) and a decrease in GAGs storage (only assessed for types C and D until now). Currently, we are evaluating the effect of that decrease on the overall GAGs storage 7 days post-transfection, also with promising results. Here we present an overview on our results with both approaches on MPS diseases. N/A

Introduction: The RNA molecule has become an increasingly promising target for the therapy of various diseases. Mucolipidosis type II α/β (ML II α/β) is one of the most severe Lysosomal Storage Disorders and is caused by the deficiency of the enzyme GlcNAc-1- phosphotransferase. This enzyme is responsible for the addition of the mannose 6-phosphate (M6P) marker to lysosomal enzymes, which allow their targeting to lysosomes. GlcNAc-1- phosphotransferase is encoded by the GNPTAB and GNPTG genes. Of the several mutations that occur in ML II α/β, the deletion of 2 nucleotides from GNPTAB exon19 (c.3503_3504del) is the most frequent, being a good target for a mutation specific therapy as there is no therapy for this disease 1,2. In this study, we explored the possibility of an innovative therapeutic strategy based on the use of antisense oligonucleotides (AOs) for ML II. In a previous in vitro study in ML II patient fibroblasts, AOs were used to promote the exon 19 skipping from the GNPTAB pre-mRNA, resulting successfully in the production of an in-frame mRNA 3. Currently, our objective is to evaluate the therapeutic potential of this approach in vivo in mice (Mus musculus) of the strain C57BL/6. Material & Methods: Eighteen animals with an average body mass of 25 g were used. During the study, individual body weight, food and water intake were recorded. The animals were divided into 6 groups: groups 1 and 4 were injected with saline solution, groups 2 and 5 were injected with AO at 25 mg / kg and groups 3 and 6 were injected with AO at 50 mg / kg. All animals were injected intraperitoneally and sacrificed after 4 days (groups 1, 2 and 3) or after 7 days (groups 4, 5 and 6). At the end of the experiment, the organs were collected, weighted and frozen at -80ºC, for later RNA extraction, cDNA synthesis and PCR. Statistical analysis was performed using the GraphPad Prism® for Windows program. Statistical significance between groups was determined by analysis of variance (ANOVA), followed by a Bonferroni test. All ethical issues were followed by the guidelines of the Portuguese General Directorate of Food and Veterinary. Results: Our results show that mice from groups 5 and 6 have a lower liver mass compared to the other groups, with significant differences (p

Obesity is an emerging health problem worldwide. Hypercaloric or hyperlipidemic diets have been used as models of obesity induction in laboratory animals. Obesity can be influenced by regular consumption of natural bioactive compounds. Mushrooms, such as Ganoderma lucidum (GL), have been used in the human diet since ancient times and include a wide variety of biomolecules with medicinal properties. The main objective of this work was to study the effects of G. lucidum in an animal model of obesity. info:eu-repo/semantics/publishedVersion

The K14HPV16 mice is a skin squamous carcinoma model that can be used to test antitumoral properties of several chemical and natural compounds1. Lavandula penduculata (Mill.) Cav., known as lavender, belongs to the Laminaceae family and has been used in traditional medicine as infusions to treat several conditions2. This work aimed to evaluate the effects of the hydroethanolic French lavender extract (FLE) in an HPV16-transgenic mice model lesions. The extract was obtained through a maceration with ethanol/water (80:20, v/v) and its phenolic composition was determined by HPLC-DADESI/ MS. The FLE was dissolved in drinking water at 6.8 mg/10mL/animal and the animals were supplemented during 29 consecutive days. Twentyeight male mice were randomly divided into four groups: (n=7/group): group I (HPV16- control); II (HPV16- FLE); III (HPV16+ control) and IV (HPV16+ FLE). After 29 days all animals were sacrificed by xylazineketamine overdose following cardiac puncture to obtain blood samples. Skin samples (chest and ear), kidney, liver and spleen were processed for histological analysis.A total of thirteen compounds were identified in the hydroethanolic extract, being salvianolic acid B and rosmarinic acid the main molecules present. Moreover, the compounds revealed to be stable in the drinking water for 5 days. Histological analyses of skin samples from wild-type mice exposed (group II) and not exposed (group I) to FLE showed normal skin histology. Group III showed skin chest epidermal hyperplasia in 100% of the mice while group IV showed less epidermal hyperplasia frequency (66.6%) (p>0.05). Concerning to liver, kidney, and spleen lesions there are no differences between groups (p>0.05). The lavender extract did not prevent the progression of HPV-16 induced cutaneous lesions in this model. These data deserve more investigation to clarify the effect of lavender extract on HPV-16 lesions. This work was supported by European Investment Funds by FEDER/ COMPETE/POCI - Operational Competitiveness and Internationalization Program and National Funds by FCT - Portuguese Foundation for Science and Technology, under the projects Project UIDB/04033/2020 (CITAB), and PhD fellowship SFRH/BD/136747/2018 and 2020.04789.BD. The authors are also grateful to FCT for financial support through national funds FCT/MCTES to CIMO (UIDB/00690/2020). L. Barros thanks FCT, P.I for her contract through the institutional scientific employment program. This work was also funded by the European Regional Development Fund (ERDF) through the Regional Operational Program North 2020, within the scope of Project GreenHealth - Norte-01-0145-FEDER-000042. The authors would like to thank BPGV for the samples provided. info:eu-repo/semantics/publishedVersion

Lavandula penduculata (Mill.) Cav., common English name French lavender, belongs to the Lamiaceae family and has been used as a medicinal plant in infusions for respiratory and digestive systems and as a therapeutic agent with antiseptic action for cleaning wounds [1,2]. The K14HPV16 mice is a skin squamous carcinoma model that can be used to test the antitumoral properties of several chemical and natural products [3]. The aim of this work was to evaluate the effect of the hydroethanolic French lavender extract (FLE) on body weight, relative organs weights, food and water consumption in an HPV-16-transgenic mice model. The extract was obtained from a maceration with ethanol/water (80:20, v/v), and the phenolic composition was determined through HPLC-DAD-ESI/MS. Twenty-eight male mice were randomly divided into four groups (n=7/group) according to their genotype: group I (HPV16- control); II (HPV16- FLE); III (HPV16+ control) and IV (HPV16+ FLE). The FLE was administrated orally in drinking water at 6.8 mg/10mL/animal to animals from groups II and IV and changed every 4 days. The animals were kept under controlled conditions such as temperature, light and humidity This work was supported by European Investment Funds by FEDER/ COMPETE/POCI - Operational Competitiveness and Internationalization Program and National Funds by FCT - Portuguese Foundation for Science and Technology, under the projects Project UIDB/04033/2020 (CITAB), and PhD fellowship SFRH/BD/136747/2018 and 2020.04789.BD. The authors are also grateful to FCT for financial support through national funds FCT/MCTES to CIMO (UIDB/00690/2020). L. Barros thanks FCT, P.I for her contract through the institutional scientific employment program. This work was also funded by the European Regional Development Fund (ERDF) through the Regional Operational Program North 2020, within the scope of Project GreenHealth - Norte-01-0145-FEDER-000042. The authors would like to thank BPGV for the samples provided. info:eu-repo/semantics/publishedVersion

Infection by Human Papillomavirus (HPV) is the main cause of cervical cancer, highlighting the importance of studying compounds that may reduce viral activity and its lesions/symptoms. The aromatic herb spearmint (Mentha spicata) (MS) has proven anti-tumor properties [1]. Thus, this study aimed to evaluate the effects of an hydroethanolic extract obtained from spearmint in HPV16-transgenic (HPV+/-) mice. The extract was obtained through maceration with ethanol/water (80:20, v/v), and the phenolic composition was determined through HPLC-DAD-ESI/MS. Thirty-three female mice (16 HPV-/- and 17 HPV+/-) were randomly divided into six groups: Group (G) I – HPV-/- w/o Mentha (n=5); G II – HPV-/- w/ Mentha (0.5 mg/ml; n=6); G III – HPV-/- w/ Mentha (0.55 mg/ml; n=5); G IV – HPV+/- w/o Mentha (n=6); G V – HPV+/- w/ Mentha (0.5 mg/ml; n=6); G VI – HPV+/- w/ Mentha (0.55 mg/ml; n=5). The spearmint extract was administered in the animal’s drinking water for 28 days. During the study, water and food intake as well the animals’ weights were recorded weekly. Afterwards, the animals were sacrificed, and their organs were collected for oxidative stress and genetic damage analysis. A total of thirteen compounds were identified in the hydroethanolic extract, being salvianolic acid B, rosmarinic acid and luteolin-7-O-glucuronide, the main compounds found. Moreover, the compounds revealed to be stable in the drinking water during the 5 tested days. Results show that HPV+/- (GIV, V and VI) have lower weight but higher water and food intake, as expected. Analysis of HPV+/- mice GIV showed a significant increase of superoxide dismutase activity when compared with GV (p=0.0029) and VI (p=0.0011). This suggests that group IV was subjected to a higher oxidative stress, as expected. These results could also mean that MS is responsible for a decrease in the oxidative stress known to be induced by HPV, which in turn decreases SOD, further the role of MS as an antioxidant. Regarding genetic damage, no statistically significant changes between groups were found in the comet and micronucleus assays, implying that spearmint has no influence on genotoxicity at the concentrations employed. There were no significant differences concerning basal DNA damage between WT and transgenic individuals as seen in other studies [2]. Further studies are required to clarify the antioxidant and antigenotoxic effects of spearmint. Interact R&D project, NORTE-01-0145-FEDER-000017, in its ISAC research line, ERDF-NORTE 2020. The authors are also grateful to FCT, for financial support through national funds FCT/MCTES to CIMO (UIDB/00690/2020); L. Barros thanks the national funding by FCT, P.I., through the institutional scientific employment program-contract. info:eu-repo/semantics/publishedVersion

Obesity is a pandemic disease, and its evolution can be influenced by regular consumption of natural bioactive compounds. Mushrooms, such as Ganoderma lucidum (GL), include a wide variety of biomolecules with potential anti-obesity effects. This work aimed to study the influence of GL in an animal model of obesity. Forty-eight male mice (C57BL/6J) were divided into 5 groups: Group (G)-1-Western Control Diet; G-2-Western Diet 0.2% Cholesterol (WDC); G-3-WDC+0.7g/kg of GL; G-4-WDC+1.4g/ kg of GL; G-5 WDC+2.8g/kg of GL. Water and food consumption were recorded weekly. Animals were weighed individually, and their temperature was measured on the back and abdomen (thermographic camera FLIRE6390). Thirteen weeks later, animals were sacrificed, and organs collected. A liver portion was used for histopathology analysis (ethical approval nº 8776). Chemical characterization of the GL extract was profiled by HPLC-DAD-ESI/MS. Ganoderic acid H and p-hydroxybenzoic acid were the main triterpenic and phenolic acids in the extract, respectively. Food and water consumption were no different among groups. All animals showed weight gain (11-16%): animals without GL supplementation showed the highest weight gain (G2 and G1, respectively); the groups with GL showed the lowest weight gain, which decreased as the mushroom concentration increased. Basal and final body temperatures remained constant. Liver weight was different among groups (p

Em, 1959 Russel e Burch propuseram os 3Rs (Reduce, Refine e Replacement) em experimentação animal e desde então as diversas entidades envolvidas na temática têm feito esforços conjuntos para os aplicar (1). Nesse sentido foi gradualmente introduzida a avaliação e registo dos humane endpoints (HE) dos animais durante procedimentos experimentais, para monitorizar o seu sofrimento e tomar decisões sobre a necessidade, ou não, de finalizar o ensaio antes da data prevista (2). Contudo, apesar das exigências legais, observa-se grande escassez de publicações sobre a avaliação de HE nos procedimentos com animais de laboratório. Assim, é nosso objetivo com este trabalho apresentar os HE durante a aplicação diária de um creme com Cytinus hypocistis numa estirpe de murganhos transgénicos. Financiamento nacional pela FCT, Fundação para a Ciência e a Tecnologia, no âmbito da bolsa de doutoramento 2020.07675.BD de Beatriz Medeiros Fonseca. info:eu-repo/semantics/publishedVersion

Human papillomavirus (HPV) infections are associated with the development of several anogenital cancers. K14HPV16 transgenic model is an animal model that mimics HPV-induced lesions. Cytinus hypocistis (L.) is an endophytic parasitic plant that has been shown to possess several antibacterial and antiproliferative properties1. During antiproliferative studies in animal models, the toxicological analysis is also required. Therefore, the present research aims to study the toxic effects of applying a topical formulation enriched with Cytinus hypocistis extracts (FCH) on K14HPV16 mice. Three different concentrations of FCH were used to enrich a base cream, the phenolic compounds were analyzed by HPLC-DAD-ESI/MS and were applied to the animal’s ears for 28 days. Thirty female mice were equally divided into six groups (G) (n=5): G1 (HPV16+-C1); G2 (HPV16+-C2); G3 (HPV16+-C3); G4 (HPVC3); G5 (HPV+-control); and G6 (HPV-control). The animals were kept under controlled conditions and biological variables were registered throughout the study. In the end, animals were sacrificed, and the organs collected and weighed. The main phenolic compound present in the base cream enriched with C. hypocistis was galloyl-bis-HHDPglucose. Food and water intake were constant throughout the trial. G3 presented a higher relative weight of the liver and lungs than the control animals, and a significant difference in body weight relatively to G4 (p

Splicing is an essential cellular process to generate mature transcripts from pre-mRNA. One of the most important factors for mRNA transcription is the U1snRNA, a spliceosomal component that recognizes 5’ splicing donor sites (SDS) at specific regions in pre-mRNA. Splicing mutations represent one of the most frequent (~20%) genetic defects in Mucopolysaccharidosis IIIC (MPS IIIC), a Lysosomal Storage Disorder (LSD) caused by mutations in the HGSNAT gene, encoding an enzyme involved in heparan sulphate degradation. Exon-skipping has been demonstrated as, probably, the most frequent aberrant splicing defect, and occurs due to mutations in the 5’ SDS. Application of modified U1snRNAs to improve recognition of mutated 5’ SDS represent a potential therapeutic strategy to recover the normal splicing process. The c.234+1G>A is a frequent mutation among patients of countries around the Mediterranean basin (Portugal, Spain, Morocco and Tunisia). It’s located in the + 1 position of intron 2 of HGSNAT gene and leads to the skipping of exon 2. We demonstrated in fibroblast cells that a modified U1snRNA vector (comprising exon 1 to exon 3) designed to improve the definition of exon 2 5’ SDS of the HGSNAT can restore the splicing defect caused by the mutation c.234+1G>A (Matos et al., 2014). Currently our goal is to evaluate in vivo the therapeutic potential of the modified U1 snRNA by testing it in mice expressing the human splicing defect N/A

Relatório final de estágio profissionalizante do 6.º ano

Splicing is an essential cellular process to generate mature transcripts from pre-mRNA. One of the most important factors for mRNA transcription is the U1snRNA, a spliceosomal component that recognizes 5’ splicing donor sites (SDS) at specific regions in pre-mRNA. Splicing mutations represent one of the most frequent (~20%) genetic defects in Mucopolysaccharidosis IIIC (MPS IIIC), a Lysosomal Storage Disorder (LSD) caused by mutations in the HGSNAT gene, encoding an enzyme involved in heparan sulphate degradation. . Exon-skipping has been demonstrated as, probably, the most frequent aberrant splicing defect, and occurs due to mutations in the 5’ SDS. Application of modified U1snRNAs to improve recognition of mutated 5’ SDS represent a potential therapeutic strategy to recover the normal splicing process. The c.234+1G>A is a frequent mutation among patients of countries around the Mediterranean basin (Portugal, Spain, Morocco and Tunisia). It’s located in the + 1 position of intron 2 of HGSNAT gene and leads to the skipping of exon 2. We demonstrated in fibroblast cells that a modified U1snRNA vector (comprising exon 1 to exon 3) designed to improve the definition of exon 2 5’ SDS of the HGSNAT can restore the splicing defect caused by the mutation c.234+1G>A (Matos et al., 2014). Currently our goal is to evaluate in vivo the therapeutic potential of the modified U1 snRNA by testing it in mice expressing the human splicing defect. FCT N/A

Tila platyphyllos Scop. is a popular broad-leave tree, native to central and southern Europe info:eu-repo/semantics/publishedVersion

The Human Papillomavirus (HPV) is the prime cause of cervix cancer in women info:eu-repo/semantics/publishedVersion