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Lipid and non-lipid factors affecting macrophage dysfunction and inflammation in atherosclerosis
Publication . Gibson, Mark S.; Domingues, Neuza; Vieira, Otilia V.; NOVA Medical School|Faculdade de Ciências Médicas (NMS|FCM); Centro de Estudos de Doenças Crónicas (CEDOC); Frontiers
Atherosclerosis is a chronic inflammatory disease and a leading cause of human mortality. The lesional microenvironment contains a complex accumulation of variably oxidized lipids and cytokines. Infiltrating monocytes become polarized in response to these stimuli, resulting in a broad spectrum of macrophage phenotypes. The extent of lipid loading in macrophages influences their phenotype and consequently their inflammatory status. In response to excess atherogenic ligands, many normal cell processes become aberrant following a loss of homeostasis. This can have a direct impact upon the inflammatory response, and conversely inflammation can lead to cell dysfunction. Clear evidence for this exists in the lysosomes, endoplasmic reticulum and mitochondria of atherosclerotic macrophages, the principal lesional cell type. Furthermore, several intrinsic cell processes become dysregulated under lipidotic conditions. Therapeutic strategies aimed at restoring cell function under disease conditions are an ongoing coveted aim. Macrophages play a central role in promoting lesional inflammation, with plaque progression and stability being directly proportional to macrophage abundance. Understanding how mixtures or individual lipid species regulate macrophage biology is therefore a major area of atherosclerosis research. In this review, we will discuss how the myriad of lipid and lipoprotein classes and products used to model atherogenic, proinflammatory immune responses has facilitated a greater understanding of some of the intricacies of chronic inflammation and cell function. Despite this, lipid oxidation produces a complex mixture of products and with no single or standard method of derivatization, there exists some variation in the reported effects of certain oxidized lipids. Likewise, differences in the methods used to generate macrophages in vitro may also lead to variable responses when apparently identical lipid ligands are used. Consequently, the complexity of reported macrophage phenotypes has implications for our understanding of the metabolic pathways, processes and shifts underpinning their activation and inflammatory status. Using oxidized low density lipoproteins and its oxidized cholesteryl esters and phospholipid constituents to stimulate macrophage has been hugely valuable, however there is now an argument that only working with low complexity lipid species can deliver the most useful information to guide therapies aimed at controlling atherosclerosis and cardiovascular complications.
Improvement of neuronal differentiation by carbon monoxide
Publication . Almeida, Ana S.; Soares, Nuno L.; Sequeira, Catarina O.; Pereira, Sofia A.; SA, Pereira; Sonnewald, Ursula; Vieira, Helena L.A.; NOVA Medical School|Faculdade de Ciências Médicas (NMS|FCM); Centro de Estudos de Doenças Crónicas (CEDOC); Instituto de Tecnologia Química e Biológica António Xavier (ITQB); Elsevier
Over the last decades, the silent-killer carbon monoxide (CO) has been shown to also be an endogenous cytoprotective molecule able to inhibit cell death and modulate mitochondrial metabolism. Neuronal metabolism is mostly oxidative and neurons also use glucose for maintaining their anti-oxidant status by generation of reduced glutathione (GSH) via the pentose-phosphate pathway (PPP). It is established that neuronal differentiation depends on reactive oxygen species (ROS) generation and signalling, however there is a lack of information about modulation of the PPP during adult neurogenesis. Thus, the main goal of this study was to unravel the role of CO on cell metabolism during neuronal differentiation, particularly by targeting PPP flux and GSH levels as anti-oxidant system. A human neuroblastoma SH-S5Y5 cell line was used, which differentiates into post-mitotic neurons by treatment with retinoic acid (RA), supplemented or not with CO-releasing molecule-A1 (CORM-A1). SH-SY5Y cell differentiation supplemented with CORM-A1 prompted an increase in neuronal yield production. It did, however, not alter glycolytic metabolism, but increased the PPP. In fact, CORM-A1 treatment stimulated (i) mRNA expression of 6-phosphogluconate dehydrogenase (PGDH) and transketolase (TKT), which are enzymes for oxidative and non-oxidative phases of the PPP, respectively and (ii) protein expression and activity of glucose 6-phosphate dehydrogenase (G6PD) the rate-limiting enzyme of the PPP. Likewise, whenever G6PD was knocked-down CO-induced improvement on neuronal differentiation was reverted, while pharmacological inhibition of GSH synthesis did not change CO's effect on the improvement of neuronal differentiation. Both results indicate the key role of PPP in CO-modulation of neuronal differentiation. Furthermore, at the end of SH-SY5Y neuronal differentiation process, CORM-A1 supplementation increased the ratio of reduced and oxidized glutathione (GSH/GSSG) without alteration of GSH metabolism. These data corroborate with PPP stimulation. In conclusion, CO improves neuronal differentiation of SH-S5Y5 cells by stimulating the PPP and modulating the GSH system.
Zebrafish larvae are a suitable model to investigate the metabolic phenotype of drug-induced renal tubular injury
Publication . Morello, Judit; Derks, Rico J.E.; Lopes, Susana S.; Steenvoorden, Evelyne; Monteiro, Emilia C.; Monteiro, E.C.; Mayboroda, Oleg A.; Pereira, Sofia A.; SA, Pereira; Centro de Estudos de Doenças Crónicas (CEDOC); NOVA Medical School|Faculdade de Ciências Médicas (NMS|FCM); Frontiers Media
Prevention and treatment of drug-induced renal injury (DIRI) rely on the availability of sensitive and specific biomarkers of early kidney injury and predictive animal models of human pathophysiology. This study aimed to evaluate the potential of zebrafish larvae as translational model in metabolic profiling of DIRI. Zebrafish larvae were exposed to the lethal concentration for 10% of the larvae (LC10) or ½ LC10 of gentamicin, paracetamol and tenofovir as tenofovir disoproxil fumarate (TDF) and tenofovir (TFV). Metabolites were extracted from whole larvae and analyzed by liquid chromatography-mass spectrometry. Principal component analysis showed that drug exposition to the LC10 of paracetamol, TFV, and TDF was the main source of the variance of the data. To identify the metabolites responsible for the toxic effects of the drugs, partial least squares discriminant analyses were built between the LC10 and ½ LC10 for each drug. Features with variable importance in projection> 1.0 were selected and Venn diagrams were built to differentiate between the common and drug specific metabolites of DIRI. Creatine, tyrosine, glutamine, guanosine, hypoxanthine were identified as common metabolites, adenosine and tryptophan as paracetamol-specific and xanthine and oxidized glutathione as tenofovir-specific. Those metabolic changes can be associated with alterations in energy metabolism, xenobiotic detoxification and protein catabolism, all described in the human pathophysiology of DIRI. Thus, zebrafish proved to be a suitable model to characterize the metabolic changes associated with DIRI. This information can be useful to early diagnose DIRI and to improve our knowledge on the mechanisms of DIRI.
Study, development and implementations of methodologies that allow optimizing refinery wastewater treatment processes and minimize impact risks on the surrounding
Publication . Rita, Ana Isabel Batista; Sanches, Sandra; Madeira, Luís; Santos, Maria António
The main objective of the work developed in this thesis was to address spent caustic treatment as a way to decrease the high organic load of this effluent and reduce its great impact on the quality of the wastewater sent to wastewater treatment plants, particularly in terms of oil and grease (O&G) contamination. The naphthenic spent caustic generated by Galp refinery in Sines was used as case study.
Spent caustic effluents are very challenging due to their very hazardous nature in terms of toxicity as well as their extreme pH (approximately 12-13). Spent caustic treatment is presently a challenge for refineries, due to its composition rich in mercaptans, sulphides and other aromatic compounds. In general, proton nuclear magnetic ressonance (NMR), Fourier transform infrared spectroscopy (FT-IR) and gas chromatography mass spectromery (GC-MS) analyses suggested that aromatic structures account for a significant part of the organic structures that constitute naphthenic spent caustic, which are also present in the final wastewater. It was found that acid crudes processing with lower molecular-weight acid components seem to have a great impact on polar O&G concentration increase in spent caustic and therefore in the final wastewater.
Nanofiltration (NF) is a very effective technology when treatment and separation/recovery of specific components is required since it is able to remove low molecular weight organic molecules like hydrocarbons and phenolic compounds. The potential application of polymeric and ceramic membranes was addressed by conducting ageing studies (only in the case of polymeric membranes) and NF experiments to assess their retention properties and lifespan. Contrarily to expectations, neither of the tested types of membranes presented attractive results for spent caustic treatment, due to very quick losses of their retention properties; analysis by FT-IR and Inductively coupled plasma atomic emission spectroscopy (ICPAES) corroborated the ocurrence of desintegration mechanisms in the structure of the tested membranes. A different strategy based on chemical treatments was followed to treat spent caustic: (i) neutralization, followed by Fenton oxidation post-treatment (approach 1) and (ii) neutralization, followed by liquid-liquid extraction (approach 2). Approach 1 (lab scale tests) allowed to remove 95 % of polar O&G, with a 70% decrease in the acute toxicity after treatment. Approach 2 (pilot scale tests) allowed to remove 99 % of polar O&G. Both technologies allowed direct discharge of treated spent caustic into the Sines refinery wastewater circuit, with approach 2 being the best option since it presented the highest annual savings (1.5 yearly effluent management cost.
The results obtained in the present thesis may be useful for the development/optimization of industrial-scale plants in petroleum refineries for the treatment of naphthenic spent caustic effluents, providing an effective treatment technology proposal, with interesting effluent management cost reduction.
The mercapturomic profile of health and non-communicable diseases
Publication . Gonçalves-Dias, Clara; Morello, Judit; Semedo, Valdir; Correia, M. João; Coelho, Nuno R.; Monteiro, Emilia C.; Monteiro, E.C.; Antunes, Alexandra M.M.; Pereira, Sofia A.; SA, Pereira; NOVA Medical School|Faculdade de Ciências Médicas (NMS|FCM); Centro de Estudos de Doenças Crónicas (CEDOC); MDPI - Multidisciplinary Digital Publishing Institute
The mercapturate pathway is a unique metabolic circuitry that detoxifies electrophiles upon adducts formation with glutathione. Since its discovery over a century ago, most of the knowledge on the mercapturate pathway has been provided from biomonitoring studies on environmental exposure to toxicants. However, the mercapturate pathway-related metabolites that is formed in humans—the mercapturomic profile—in health and disease is yet to be established. In this paper, we put forward the hypothesis that these metabolites are key pathophysiologic factors behind the onset and development of non-communicable chronic inflammatory diseases. This review goes from the evidence in the formation of endogenous metabolites undergoing the mercapturate pathway to the methodologies for their assessment and their association with cancer and respiratory, neurologic and cardiometabolic diseases.
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Fundação para a Ciência e a Tecnologia
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5876
Número da atribuição
UID/Multi/04462/2013