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Aerocyte specification and lung adaptation to breathing is dependent on alternative splicing changes
Publication . Fidalgo, Marta F.; Fonseca, Catarina G.; Caldas, Paulo; Raposo, Alexandre A. S. F.; Balboni, Tania; Henao-Mišíková, Lenka; Grosso, Ana R.; Vasconcelos, Francisca F.; Franco, Cláudio A.; UCIBIO - Applied Molecular Biosciences Unit; DCV - Departamento de Ciências da Vida; Rockefeller University Press
Adaptation to breathing is a critical step in lung function and it is crucial for organismal survival. Alveoli are the lung gas exchange units and their development, from late embryonic to early postnatal stages, requires feedbacks between multiple cell types. However, how the crosstalk between the alveolar cell types is modulated to anticipate lung adaptation to breathing is still unclear. Here, we uncovered a synchronous alternative splicing switch in multiple genes in the developing mouse lungs at the transition to birth, and we identified hnRNP A1, Cpeb4, and Elavl2/ HuB as putative splicing regulators of this transition. Notably, we found that Vegfa switches from the Vegfa 164 isoform to the longer Vegfa 188 isoform exclusively in lung alveolar epithelial AT1 cells. Functional analysis revealed that VEGFA 188 (and not VEGFA 164) drives the specification of Car4-positive aerocytes, a subtype of alveolar endothelial cells specialized in gas exchanges. Our results reveal that the cell type–specific regulation of Vegfa alternative splicing just before birth modulates the epithelial-endothelial crosstalk in the developing alveoli to promote lung adaptation to breathing.
Specific Antiproliferative Properties of Proteinaceous Toxin Secretions from the Marine Annelid Eulalia sp. onto Ovarian Cancer Cells
Publication . Rodrigo, Ana P.; Mendes, Vera M.; Manadas, Bruno; Grosso, Ana R.; Alves de Matos, António P.; Baptista, Pedro V.; Costa, Pedro M.; Fernandes, Alexandra R.; UCIBIO - Applied Molecular Biosciences Unit; DCV - Departamento de Ciências da Vida; MDPI - Multidisciplinary Digital Publishing Institute
As Yondelis joins the ranks of approved anti-cancer drugs, the benefit from exploring the oceans' biodiversity becomes clear. From marine toxins, relevant bioproducts can be obtained due to their potential to interfere with specific pathways. We explored the cytotoxicity of toxin-bearing secretions of the polychaete Eulalia onto a battery of normal and cancer human cell lines and discovered that the cocktail of proteins is more toxic towards an ovarian cancer cell line (A2780). The secretions' main proteins were identified by proteomics and transcriptomics: 14-3-3 protein, Hsp70, Rab3, Arylsulfatase B and serine protease, the latter two being known toxins. This mixture of toxins induces cell-cycle arrest at G2/M phase after 3h exposure in A2780 cells and extrinsic programmed cell death. These findings indicate that partial re-activation of the G2/M checkpoint, which is inactivated in many cancer cells, can be partly reversed by the toxic mixture. Protein-protein interaction networks partake in two cytotoxic effects: cell-cycle arrest with a link to RAB3C and RAF1; and lytic activity of arylsulfatases. The discovery of both mechanisms indicates that venomous mixtures may affect proliferating cells in a specific manner, highlighting the cocktails' potential in the fine-tuning of anti-cancer therapeutics targeting cell cycle and protein homeostasis.
Genetic and microenvironmental intra-tumor heterogeneity impacts colorectal cancer evolution and metastatic development
Publication . Sobral, Daniel; Martins, Marta; Kaplan, Shannon; Golkaram, Mahdi; Salmans, Michael; Khan, Nafeesa; Vijayaraghavan, Raakhee; Casimiro, Sandra; Fernandes, Afonso; Borralho, Paula; Ferreira, Cristina; Pinto, Rui; Abreu, Catarina; Costa, Ana Lúcia; Zhang, Shile; Pawlowski, Traci; Godsey, Jim; Mansinho, André; Macedo, Daniela; Lobo-Martins, Soraia; Filipe, Pedro; Esteves, Rui; Coutinho, João; Costa, Paulo Matos; Ramires, Afonso; Aldeia, Fernando; Quintela, António; So, Alex; Liu, Li; Grosso, Ana Rita; Costa, Luis; UCIBIO - Applied Molecular Biosciences Unit; DCV - Departamento de Ciências da Vida; Nature Portfolio
Colorectal cancer (CRC) is a highly diverse disease, where different genomic instability pathways shape genetic clonal diversity and tumor microenvironment. Although intra-tumor heterogeneity has been characterized in primary tumors, its origin and consequences in CRC outcome is not fully understood. Therefore, we assessed intra- and inter-tumor heterogeneity of a prospective cohort of 136 CRC samples. We demonstrate that CRC diversity is forged by asynchronous forms of molecular alterations, where mutational and chromosomal instability collectively boost CRC genetic and microenvironment intra-tumor heterogeneity. We were able to depict predictor signatures of cancer-related genes that can foresee heterogeneity levels across the different tumor consensus molecular subtypes (CMS) and primary tumor location. Finally, we show that high genetic and microenvironment heterogeneity are associated with lower metastatic potential, whereas late-emerging copy number variations favor metastasis development and polyclonal seeding. This study provides an exhaustive portrait of the interplay between genetic and microenvironment intra-tumor heterogeneity across CMS subtypes, depicting molecular events with predictive value of CRC progression and metastasis development.
Concerted Regulation of Glycosylation Factors Sustains Tissue Identity and Function
Publication . Sobral, Daniel; Francisco, Rita; Duro, Laura; Videira, Paula Alexandra; Grosso, Ana Rita; UCIBIO - Applied Molecular Biosciences Unit; DCV - Departamento de Ciências da Vida; MDPI AG
Glycosylation is a fundamental cellular process affecting human development and health. Complex machinery establishes the glycan structures whose heterogeneity provides greater structural diversity than other post-translational modifications. Although known to present spatial and temporal diversity, the evolution of glycosylation and its role at the tissue-specific level is poorly understood. In this study, we combined genome and transcriptome profiles of healthy and diseased tissues to uncover novel insights into the complex role of glycosylation in humans. We constructed a catalogue of human glycosylation factors, including transferases, hydrolases and other genes directly involved in glycosylation. These were categorized as involved in N-, O- and lipid-linked glycosylation, glypiation, and glycosaminoglycan synthesis. Our data showed that these glycosylation factors constitute an ancient family of genes, where evolutionary constraints suppressed large gene duplications, except for genes involved in O-linked and lipid glycosylation. The transcriptome profiles of 30 healthy human tissues revealed tissue-specific expression patterns preserved across mammals. In addition, clusters of tightly co-expressed genes suggest a glycosylation code underlying tissue identity. Interestingly, several glycosylation factors showed tissue-specific profiles varying with age, suggesting a role in ageing-related disorders. In cancer, our analysis revealed that glycosylation factors are highly perturbed, at the genome and transcriptome levels, with a strong predominance of copy number alterations. Moreover, glycosylation factor dysregulation was associated with distinct cellular compositions of the tumor microenvironment, reinforcing the impact of glycosylation in modulating the immune system. Overall, this work provides genome-wide evidence that the glycosylation machinery is tightly regulated in healthy tissues and impaired in ageing and tumorigenesis, unveiling novel potential roles as prognostic biomarkers or therapeutic targets.
Endogenous Fluorescent Proteins in the Mucus of an Intertidal Polychaeta
Publication . Rodrigo, Ana P.; Lopes, Ana Catarina; Pereira, Ricardo; Anjo, Sandra I.; Manadas, Bruno; Grosso, Ana R.; Baptista, Pedro V.; Fernandes, Alexandra R.; Costa, Pedro M.; DCV - Departamento de Ciências da Vida; UCIBIO - Applied Molecular Biosciences Unit; MDPI - Multidisciplinary Digital Publishing Institute
The vast ocean holds many unexplored organisms with unique adaptive features that enable them to thrive in their environment. The secretion of fluorescent proteins is one of them, with reports on the presence of such compounds in marine annelids being scarce. The intertidal Eulalia sp. is an example. The worm secretes copious amounts of mucus, that when purified and concentrated extracts, yield strong fluorescence under UV light. Emission has two main maxima, at 400 nm and at 500 nm, with the latter responsible for the blue–greenish fluorescence. Combining proteomics and transcriptomics techniques, we identified ubiquitin, peroxiredoxin, and 14-3-3 protein as key elements in the mucus. Fluorescence was found to be mainly modulated by redox status and pH, being consistently upheld in extracts prepared in Tris-HCl buffer with reducing agent at pH 7 and excited at 330 nm. One of the proteins associated with the fluorescent signal was localized in secretory cells in the pharynx. The results indicate that the secretion of fluorescent proteinaceous complexes can be an important defense against UV for this dweller. Additionally, the internalization of fluorescent complexes by ovarian cancer cells and modulation of fluorescence of redox status bears important considerations for biotechnological application of mucus components as markers.
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Fundação para a Ciência e a Tecnologia
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CEEC IND 2017
Número da atribuição
CEECIND/02699/2017/CP1462/CT0018