Proceedings from the 2018 Canadian Association for the Study of the Liver Single Topic Conference—Decompensated Cirrhosis : from clinic to transplant

Actes publiés dans le Canadian Liver Journal; vol. 2, no. 4, Fall 2019, p. 137-170

Allele specific repair of splicing mutations in cystic fibrosis through AsCas12a genome editing.

Funder: Fondazione Fibrosi Cistica - FFC#1/2017Cystic fibrosis (CF) is an autosomal recessive disease caused by mutations in the CFTR gene. The 3272-26A>G and 3849+10kbC>T CFTR mutations alter the correct splicing of the CFTR gene, generating new acceptor and donor splice sites respectively. Here we develop a genome editing approach to permanently correct these genetic defects, using a single crRNA and the Acidaminococcus sp. BV3L6, AsCas12a. This genetic repair strategy is highly precise, showing very strong discrimination between the wild-type and mutant sequence and a complete absence of detectable off-targets. The efficacy of this gene correction strategy is verified in intestinal organoids and airway epithelial cells derived from CF patients carrying the 3272-26A>G or 3849+10kbC>T mutations, showing efficient repair and complete functional recovery of the CFTR channel. These results demonstrate that allele-specific genome editing with AsCas12a can correct aberrant CFTR splicing mutations, paving the way for a permanent splicing correction in genetic diseases

Márquez.A.Thesis.pdf

One of the first cognitive dysfunctions to arise with aging is memory loss, affecting an estimated 85% of elderly in the U.S. over the age of 80 with Age Associated Memory Impairment. A common feature in humans and animals experiencing memory loss with aging is the decline in N-methyl-D-aspartate (NMDA) receptorbinding densities in the brain. Variability in the effects of aging on the GluN1 subunit suggests that inflammation may play a role in NMDA receptor aging. The purpose of the present study was to determine the effects of an anti-inflammatory drug, ibuprofen, on spatial long-term & short-term memory and cognitive flexibility in male C57BL/6 mice from four different age groups (5, 14, 20, and 26 months of age at the end of testing). Mice were fed either Ibuprofen (375 ppm) in NIH31 diet or NIH31 diet alone for 6 weeks prior to testing. This dose had been shown to reduce pathology in an Alzheimer’s disease mouse model. Behavioral testing using the Morris Water Maze showed a significant effect of age on acquisition of spatial reference memory, the formation of spatial memory bias in probe trials, cognitive flexibility in reversal trials, and working memory, with 20 and 26 month old mice performing significantly worse than 5 month old mice. Ibuprofen enhanced overall performance in the working memory task when data was collapsed across naïve and test trials and ages. The oldest mice receiving ibuprofen showed significantly better delayed working memory, but near significantly (p=0.08) worse spatial reference memory, as compared to age-matched controls. In situ hybridization assays showed significant decreases over all ages in the mRNA densities for the GluN2B subunit, all GluN1 splice variants, and the GluN1-1 splice forms in the frontal lobes of mice consuming ibuprofen. The GluN1-3 splice form mRNA was significantly increased across ages in the frontal lobes of the ibuprofen-treated mice. There was no effect of ibuprofen on IL-1beta expression in the brains or spleens of these mice. These findings suggest that inflammation may play a role in working memory declines in aged animals, but the reducing effects of ibuprofen across ages on several factors, without reducing age-related increases in cytokine expression suggests that ibuprofen has effects on mRNA for the NMDA receptor that are unrelated to aging or inflammation.Keywords: aging, anti-inflammatory, N-Methyl-D-Aspartate receptor, memor

marquez loza final seminar.pdf

One of the first cognitive dysfunctions to arise with aging is memory loss, affecting an estimated 85% of elderly in the U.S. over the age of 80 with Age Associated Memory Impairment. A common feature in humans and animals experiencing memory loss with aging is the decline in N-methyl-D-aspartate (NMDA) receptorbinding densities in the brain. Variability in the effects of aging on the GluN1 subunit suggests that inflammation may play a role in NMDA receptor aging. The purpose of the present study was to determine the effects of an anti-inflammatory drug, ibuprofen, on spatial long-term & short-term memory and cognitive flexibility in male C57BL/6 mice from four different age groups (5, 14, 20, and 26 months of age at the end of testing). Mice were fed either Ibuprofen (375 ppm) in NIH31 diet or NIH31 diet alone for 6 weeks prior to testing. This dose had been shown to reduce pathology in an Alzheimer’s disease mouse model. Behavioral testing using the Morris Water Maze showed a significant effect of age on acquisition of spatial reference memory, the formation of spatial memory bias in probe trials, cognitive flexibility in reversal trials, and working memory, with 20 and 26 month old mice performing significantly worse than 5 month old mice. Ibuprofen enhanced overall performance in the working memory task when data was collapsed across naïve and test trials and ages. The oldest mice receiving ibuprofen showed significantly better delayed working memory, but near significantly (p=0.08) worse spatial reference memory, as compared to age-matched controls. In situ hybridization assays showed significant decreases over all ages in the mRNA densities for the GluN2B subunit, all GluN1 splice variants, and the GluN1-1 splice forms in the frontal lobes of mice consuming ibuprofen. The GluN1-3 splice form mRNA was significantly increased across ages in the frontal lobes of the ibuprofen-treated mice. There was no effect of ibuprofen on IL-1beta expression in the brains or spleens of these mice. These findings suggest that inflammation may play a role in working memory declines in aged animals, but the reducing effects of ibuprofen across ages on several factors, without reducing age-related increases in cytokine expression suggests that ibuprofen has effects on mRNA for the NMDA receptor that are unrelated to aging or inflammation.Keywords: N-Methyl-D-Aspartate receptor, aging, memory, anti-inflammatoryKeywords: N-Methyl-D-Aspartate receptor, aging, memory, anti-inflammator

The Portuguese State and the União dos Povos de Angola (1960-1965). Political Discourses in Times of Decolonization

Dissertação de Mestrado em História apresentada à Faculdade de LetrasA 15 de Março de 1961, a União dos Povos de Angola (UPA) lançou a primeira luta sustentada pela independência de Angola. A UPA justificou a sua luta através de um discurso nacionalista que promovia a descolonização de Angola. A conceção nacionalista da UPA foi largamente influenciada pelas teorias propostas por Frantz Fanon. A este respeito, a UPA considerou que as ações violentas contra os colonizadores brancos e os seus alegados colaboradores mestiços e negros assimilados eram necessárias para eliminar definitivamente o colonialismo português. Assim, esta dissertação recusa as perspetivas simplistas que classificam a UPA de “tribalista” e de “racista”. Pelo contrário, interpreta o discurso político da UPA à luz da teoria da descolonização de Frantz Fanon. Por outro lado, face a eclosão do conflito, o Estado Português assumiu uma posição de resistência política e militar, recusando a descolonização de Angola. Essa posição foi justificada através de um discurso político que atestava que o conflito nacionalista era produto da interferência das potências externas – nomeadamente da União Soviética e dos Estados Unidos da América – nos assuntos internos portugueses. Assim, o discurso político adotado por Portugal refletia o contexto internacional da Guerra Fria, cujas consequências eram evidentes no panorama africano. Neste sentido, esta dissertação procura alcançar uma compreensão mais plena dos discursos políticos da UPA e do Estado Português na fase inicial da luta armada pela independência de Angola (1960-1965). De facto, tanto a UPA, como o Estado Português esperavam justificar – e legitimar – a respetiva posição no conflito angolano. Mas, enquanto a UPA esperava que o seu discurso incentivasse a obtenção de ajuda económica e material necessária para sustentar a guerra de independência, o Estado Português pretendia defender a sua recusa em descolonizar, numa altura em que o colonialismo tinha caído em desfavor na cena internacional.On March 15, 1961, the União dos Povos de Angola (UPA) launched the first sustained struggle for Angolan independence. The UPA justified its struggle through a nationalist discourse promoting the decolonization of Angola. The UPA’s conception of Angolan nationalism was largely influenced by the theories proposed by Frantz Fanon. In this regard, the UPA considered that violent actions against white settlers and their alleged mestizo and black assimilado collaborators, were necessary to definitively eliminate Portuguese colonialism. Thus, this dissertation rejects the reductive perspectives that classify the UPA as "tribal" and "racist". On the contrary, it interprets UPA's political discourse in light of Frantz Fanon's theory of decolonization. At the same time, the Portuguese State faced the outbreak of the armed conflict, assuming a position of political and military resistance, refusing to decolonize Angola. This position was justified by a political discourse that contended that the nationalist conflict was the product of the interference of external powers - namely the Soviet Union and the United States of America - in Portuguese internal affairs. Thus, the political discourse adopted by Portugal reflected the international context of the Cold War, whose consequences were evident throughout Africa. In this sense, this dissertation seeks to achieve a deeper understanding of the political discourses of the UPA and the Portuguese State in the initial phase of Angola's armed struggle for independence (1960-1965). The UPA and the Portuguese State both hoped to justify – and legitimize – their position in the Angolan conflict. While the UPA hoped that its discourse would encourage the necessary economic and material aid to sustain a war of independence, the Portuguese State intended to defend its refusal to decolonize, at a time when colonialism had fallen out of favor in the international scene

Lentiviral Vectors for the Treatment and Prevention of Cystic Fibrosis Lung Disease

Despite the continued development of cystic fibrosis transmembrane conductance regulator (CFTR) modulator drugs for the treatment of cystic fibrosis (CF), the need for mutation agnostic treatments remains. In a sub-group of CF individuals with mutations that may not respond to modulators, such as those with nonsense mutations, CFTR gene transfer to airway epithelia offers the potential for an effective treatment. Lentiviral vectors are well-suited for this purpose because they transduce nondividing cells, and provide long-term transgene expression. Studies in primary cultures of human CF airway epithelia and CF animal models demonstrate the long-term correction of CF phenotypes and low immunogenicity using lentiviral vectors. Further development of CF gene therapy requires the investigation of optimal CFTR expression in the airways. Lentiviral vectors with improved safety features have minimized insertional mutagenesis safety concerns raised in early clinical trials for severe combined immunodeficiency using γ-retroviral vectors. Recent clinical trials using improved lentiviral vectors support the feasibility and safety of lentiviral gene therapy for monogenetic diseases. While work remains to be done before CF gene therapy reaches the bedside, recent advances in lentiviral vector development reviewed here are encouraging and suggest it could be tested in clinical studies in the near future

The Sirt1 activator SRT3025 expands hematopoietic stem and progenitor cells and improves hematopoiesis in Fanconi anemia mice

Fanconi anemia is a genetic bone marrow failure syndrome. The current treatment options are suboptimal and do not prevent the eventual onset of aplastic anemia requiring bone marrow transplantation. We previously showed that resveratrol, an antioxidant and an activator of the protein deacetylase Sirt1, enhanced hematopoiesis in Fancd2 mutant mice and improved the impaired stem cell quiescence observed in this disease. Given that Sirt1 is important for the function of hematopoietic stem cells, we hypothesized that Sirt1 activation may improve hematopoiesis. Indeed, Fancd2−/− mice and wild-type mice treated with the selective Sirt1 activator SRT3025 had increased numbers of hematopoietic stem and progenitor cells, platelets and white blood cells. SRT3025 was also protective against acetaldehyde-induced hematopoietic damage. Unlike resveratrol, however, SRT3025 did not affect stem cell quiescence, suggesting distinct mechanisms of action. Conditional deletion of Sirt1 in hematopoietic cells did not abrogate the beneficial effects of SRT3025, indicating that the drug did not act by directly stimulating Sirt1 in stem cells, but must be acting indirectly via extra-hematopoietic effects. RNA-Seq transcriptome analysis revealed the down-regulation of Egr1–p21 expression, providing a potential mechanism for improved hematopoiesis. Overall, our data indicate that SRT3025 or related compounds may be beneficial in Fanconi anemia and other bone marrow failure syndromes