Showing papers by "Maria Teresa Cruz published in 2019"

Apple Pomace Extract as a Sustainable Food Ingredient

Abstract: Apple pomace is a by-product of apple processing industries with low value and thus frequent disposal, although with valuable compounds. Acidified hot water extraction has been suggested as a clean, feasible, and easy approach for the recovery of polyphenols. This type of extraction allowed us to obtain 296 g of extract per kg of dry apple pomace, including 3.3 g of polyphenols and 281 g of carbohydrates. Ultrafiltration and solid-phase extraction using C18 cartridges of the hot water extract suggested that, in addition to the apple native polyphenols detected by ultra-high-pressure liquid chromatography coupled to a diode-array detector and mass spectrometry UHPLC-DAD-ESI-MSn, polyphenols could also be present as complexes with carbohydrates. For the water-soluble polyphenols, antioxidant and anti-inflammatory effects were observed by inhibiting chemically generated hydroxyl radicals (OH•) and nitrogen monoxide radicals (NO•) produced in lipopolysaccharide-stimulated macrophages. The water-soluble polyphenols, when incorporated into yogurt formulations, were not affected by fermentation and improved the antioxidant properties of the final product. This in vitro research paves the way for agro-food industries to achieve more diversified and sustainable solutions towards their main by-products.

Biomaterial-based platforms for in situ dendritic cell programming and their use in antitumor immunotherapy.

Abstract: Dendritic cells (DCs) are central players in the immune system, with an exquisite capacity to initiate and modulate immune responses. These functional characteristics have led to intense research on the development of DC-based immunotherapies, particularly for oncologic diseases. During recent decades, DC-based vaccines have generated very promising results in animal studies, and more than 300 clinical assays have demonstrated the safety profile of this approach. However, clinical data are inconsistent, and clear evidence of meaningful efficacy is still lacking. One of the reasons for this lack of evidence is the limited functional abilities of the used ex vivo-differentiated DCs. Therefore, alternative approaches for targeting and modulating endogenous DC subpopulations have emerged as an attractive concept. Here, we sought to revise the evolution of several strategies for the in situ mobilization and modulation of DCs. The first approaches using chemokine-secreting irradiated tumor cells are addressed, and special attention is given to the cutting-edge injectable bioengineered platforms, programmed to release chemoattractants, tumor antigens and DC maturating agents. Finally, we discuss how our increasing knowledge of DC biology, the use of neoantigens and their combination with immune checkpoint inhibitors can leverage the refinement of these polymeric vaccines to boost their antitumor efficacy.

Unveiling the Antifungal Potential of Two Iberian Thyme Essential Oils: Effect on C. albicans Germ Tube and Preformed Biofilms

Abstract: Fungal infections remain a burden worldwide, thus underpinning the need for effective new therapeutic approaches. In the present study, the antifungal effect of the essential oils of two thyme species, Thymus camphoratus and Thymus carnosus, used in traditional medicine in Portugal, as well as their major compounds was assessed. A special focus was placed on their effect on Candida albicans virulence factors. Also, the safety profile of the essential oils was assessed on keratinocytes. The essential oils were analyzed by gas chromatography (GC) and gas chromatography/mass spectroscopy (GC/MS). The minimal inhibitory and minimal fungicidal concentrations of the essential oils and their main compounds were assessed on reference and clinical strains. Also, their effect on C. albicans germ tube formation, metabolism, and biofilm disruption were considered. T. camphoratus oil was rich in 1,8-cineole and α-pinene whereas T. carnosus oil showed high amounts of borneol and camphene. Regarding the antifungal effect, both oils were more active against Cryptococcus neoformans and dermatophytes and very effective in inhibiting C. albicans germ tube formation, at doses well below their MIC and in a higher extend than the isolated compounds and fluconazole, an antifungal drug widely used in the clinic. The oils also disrupted preformed C. albicans biofilms. Furthermore, no toxicity was observed at pharmacological relevant concentrations towards keratinocytes. Our study validates the traditional uses ascribed to these Iberian species. Furthermore, it brings new insights on the antifungal potential and mechanism of action of these thyme species, thus paving the way for the development of novel effective antifungal drugs.

Ischaemia alters the effects of cardiomyocyte-derived extracellular vesicles on macrophage activation.

Abstract: Myocardial ischaemia is associated with an exacerbated inflammatory response, as well as with a deregulation of intercellular communication systems. Macrophages have been implicated in the maintenance of heart homeostasis and in the progression and resolution of the ischaemic injury. Nevertheless, the mechanisms underlying the crosstalk between cardiomyocytes and macrophages remain largely underexplored. Extracellular vesicles (EVs) have emerged as key players of cell-cell communication in cardiac health and disease. Hence, the main objective of this study was to characterize the impact of cardiomyocyte-derived EVs upon macrophage activation. Results obtained demonstrate that EVs released by H9c2 cells induced a pro-inflammatory profile in macrophages, via p38MAPK activation and increased expression of iNOS, IL-1β and IL-6, being these effects less pronounced with ischaemic EVs. EVs derived from neonatal cardiomyocytes, maintained either in control or ischaemia, induced a similar pattern of p38MAPK activation, expression of iNOS, IL-1β, IL-6, IL-10 and TNFα. Importantly, adhesion of macrophages to fibronectin was enhanced by EVs released by cardiomyocytes under ischaemia, whereas phagocytic capacity and adhesion to cardiomyocytes were higher in macrophages incubated with control EVs. Additionally, serum-circulating EVs isolated from human controls or acute myocardial infarction patients induce macrophage activation. According to our model, in basal conditions, cardiomyocyte-derived EVs maintain a macrophage profile that ensure heart homeostasis, whereas during ischaemia, this crosstalk is affected, likely impacting healing and post-infarction remodelling.

Células Estaminais Pluripotentes Induzidas no Tratamento da Doença de Alzheimer

Abstract: Em 2006, dois investigadores demonstraram ser possivel desdiferenciar celulas somaticas por um processo designado de reprogramacao celular, levando-as a atingir de novo o estado pluripotente. O surgimento das celulas estaminais pluripotentes induzidas (iPSCs) causou um impacto extremamente relevante na comunidade cientifica devido ao facto de se superarem muitas das limitacoes que as celulas estaminais embrionarias e adultas apresentavam. A Doenca de Alzheimer (DA) e uma doenca neurodegenerativa caracterizada pela perda de memoria e de outras funcoes cognitivas. A ausencia de terapeuticas eficazes para prevenir ou reverter a doenca constitui um problema grave de saude publica. Esta revisao pretende abordar as principais limitacoes das iPSCs, com foco especial na DA, nomeadamente como estrategia modificadora da doenca para retardar a sua progressao e melhorar a qualidade de vida dos doentes, no screening de novos farmacos e ainda como uma opcao terapeutica individualizada.

Development of a novel dendritic cell-based immunotherapy targeting cancer stem cells.

Abstract: e14009Background: Dendritic cells (DCs) are one of the central tools in cellular anti-tumor immunotherapy, being characterized by their capacity for acquiring and processing antigens and ability to...

Plant Letters: A citizen science project uncovering historical biodiversity data

Abstract: The XIXth century saw an enormous accumulation of biological specimens coming to Europe from all over the world, which are now part of museums, herbaria and other natural history collections. For many centuries, the exchange of letters was the privileged means of circulating information and knowledge. At the University of Coimbra (UC), the Life Sciences Department safeguards almost 5000 letters and other documentation addressed to directors, gardeners and other collaborators of the Botanic Garden. These records of Portuguese botanical science and expeditions of plant discovery, collection and identification are held in thousands of handwritten letters, species lists and assorted notebooks, in more than five different languages. Historical repositories such as this archive, but also the biological and museum collections and objects that it documents, imply added responsibilities to the University of Coimbra, as the information contained within the documentation, pertains not only to a country (in this case Portugal), but also to its developing historical roles and actions. As a colonial power for many centuries, the records of Portuguese scientific activity and occupation strategies of overseas territories, in Africa, South America, Asia and the Pacific, are also documented, and its valuable data (e.g., historical biological records) is of crucial importance to these now independent countries. Received correspondence is a great resource for understanding the process of knowledge creation and circulation in the plant sciences, including botany and agriculture, as well as the scientific colonial practices and their implication for the amassing of biological collections at the UC. In order to uncover historical biodiversity data within this archival material, we have implemented Plant Letters (https://www.zooniverse.org/projects/catedraunesco/plant-letters), a citizen science transcription project that seeks to uncover the stories within these historical archives, the tales of travelers and scientists, on the quest of recording of the world’s diversity, mostly in the Portuguese ex-colonies in sub-Saharan Africa. Using the collaborative platform Zooniverse (https://www.zooniverse.org), users are requested to engage with the archive and transcribe mostly handwritten letters in several languages, giving dimension to our continuous efforts of promoting open and widespread access to information. The project invites everyone to transcribe handwritten or typed letters received by the Botanic Garden between about 1870 and 1928, from more than 1100 correspondents from around the world. The main purpose of this project is to track plant species, locations and scientists in the correspondence received in the 19th and 20th centuries at the Botanic Garden of the University of Coimbra. To do so, Plant Letters seeks in users, both experts or simply curious, a source of participation in the construction of knowledge, making use of collective intelligence, in a lively exchange of information, experiences and knowledge. In transcribing the letters, we want to retrieve information that can include: inquiries and doubts about plant classification and taxonomy; historical plant species locations, distribution records and abundance; biological material circulation (plant and seed exchanges); track the path of herbarium and museum specimens in our collections; unravel networks of botanical knowledge. inquiries and doubts about plant classification and taxonomy; historical plant species locations, distribution records and abundance; biological material circulation (plant and seed exchanges); track the path of herbarium and museum specimens in our collections; unravel networks of botanical knowledge. Transcribing the information contained in these documents will allow us to: track plant specimens as they travelled from their native countries to the scientists who named them; to determine historical plant locations in parts of sub-Saharan Africa; to better understand the scientific processes of plant discovery, taxonomy and botany; and to collect information that gives context to biological specimens in museum objects and other natural history collections. All of these data, valuable to the present and future conservation of tropical flora, will be made available, bearing in mind the open science principles.