Levels of taurine, hypotaurine and homotaurine, and amino acids profiles in selected commercial seaweeds, microalgae, and algae-enriched food products

Amino acids and sulfonic acid derivatives (Taurine-Tau; Hypotaurine-HypTau; Homotaurine-HTau) of 26 different species of commercial macroalgae, microalgae and 10 algae-enriched food products from the market were quantified in a single chromatographic run. Tau and analogues were predominantly distributed in red species followed by green and brown species. Palmaria palmata, Gracilaria longissima and Porphyra sp. were the species with the highest content of Tau and total sulfonic acid derivatives (TAD). Notwithstanding, relatively high concentrations of HTau were found in green algae Ulva lactuca and G. vermicullophyla as well as in the brown algae Undaria pinnatifida. HTau and HypTau were found at lower concentrations than Tau in all species, except in Ulva lactuca. The samples with the highest protein content were the green species Chlorella vulgaris, Nannochloropsis, and Afanizomenon-flos aquae, followed by the red algae Gracilaria longissima and Gracilaria vermicullophyla. Samples of pasta formulated with algae ingredients contained the highest levels of sulfonic acid derivatives, evidencing that these products can provide levels of TAD comparable to those found in foods of animal origin. This study provides, for the first time, quantitative information regarding the distribution of sulfonic acid derivatives and total amino acids in multiple algae species as well as the nutritional impact of the inclusion of algae ingredients in commercial food matrices.info:eu-repo/semantics/acceptedVersio

Drosophila as a model system for genetic and genomic research

The sequencing of the Drosophila genome allowed the identification of most coding sequences, highlighting the necessity for a functional assignation of the identified genes. The information extracted from the sequence directly classified a considerable fraction of genes into known molecular categories, although there is still a large proportion of them that, due to poor sequence conservation, are not included into any informative class. Furthermore, in many instances the molecular nature of a protein is not particularly revealing about its functional requirements and network of interactions. In this manner, complementary genomic approaches to gene identification by sequence conservation are fundamental both in Drosophila and other organisms to assign particular functions to annotated genes. The approach more successful in the Drosophila field is the undertaking of genetic screenings to identify sets of interacting genes and genes controlling particular cellular processes. Classic genetic screens comprise all those based on a “phenotypic” paradigm, where the generation of large collections of mutant chromosomes is followed by their mapping. This approach has been recently expanded to include “genomic” tools, such as the use of microarrays and interference RNA, as well as reverse-genetics techniques, seeding the way to a “functional” annotation of the Drosophila genome.Peer reviewe

Taurine, homotaurine, GABA and hydrophobic amino acids content influences “in vitro” antioxidant and SIRT1 modulation activities of enzymatic protein hydrolysates from algae

Prevention and control of diseases and delaying the signs of ageing are nowadays one of the major goals of biomedicine. Sirtuins, a family of NAD+ dependent deacylase enzymes, could be pivotal targets of novel preventive and therapeutic strategies to achieve such aims. SIRT1 activating and inhibiting compounds, such as polyphenols and bioactive peptides, have been proposed to be involved in the development of many human diseases. The objective of this work was to assess and compare the antioxidant and SIRT1 modulation activities of enzymatic protein hydrolysates (EPHs) from a wide number of algae species (24 commercial samples and 12 samples harvested off the Atlantic coast of northern Spain). High antioxidant activities were observed in EPHs from red and green seaweed species. Moreover, 19 samples exhibited SIRT1 activation, while EPHs from the 16 samples were SIRT1 inhibitors. Pearson’s correlation test and Principal Component Analysis revealed significant correlations between (1) total peptide and hydrophobic amino acid content in EPHs and their antioxidant activities, and (2) concentrations of taurine, homotaurine, and amino acid gamma aminobutyric acid in EPHs and their SIRT1 modulation activity.info:eu-repo/semantics/publishedVersio

Effects of Rose Hip (Rosa canina L.) Extract as a Natural Ingredient on the Nutritional Composition, Oxidative Stability and Sensory Attributes of Raw and Cooked Pork Patties from Majorcan Black Pig Breed under Retail Conditions

This research evaluated the effect of rose hip (RC, Rosa Canina L.) extract as a natural antioxidant ingredient on the nutritional composition and sensory attributes of Majorcan Black Pig patties. Patties were elaborated with 1.5 and 3.0g of RC and with or without 0.03g of ascorbic acid. The results suggested that the patties with 15% fat (lower fat, higher α -tocopherol), would be healthier than the ones with 23% fat. The patties containing RC had similar amounts of vitamins C and E, which differed significantly from control. The results indicated that RC could reduce the patty lipid oxidation together with ascorbic acid and this could be a good alternative for food industry. The rose hip. Flavour did not show significant differences and its scores were low, suggesting that rose hip extract did not influence negatively the taste of the patties as well as their texture. However, future research is needed to test different concentrations of the extract.info:eu-repo/semantics/publishedVersio

Superoxide dismutating molecules rescue the toxic effects of PINK1 and parkin loss.

Reactive oxygen species exert important functions in regulating several cellular signalling pathways. However, an excessive accumulation of reactive oxygen species can perturb the redox homeostasis leading to oxidative stress, a condition which has been associated to many neurodegenerative disorders. Accordingly, alterations in the redox state of cells and mitochondrial homeostasis are established hallmarks in both familial and sporadic Parkinson's disease cases. PINK1 and Parkin are two genes which account for a large fraction of autosomal recessive early-onset forms of Parkinson's disease and are now firmly associated to both mitochondria and redox homeostasis. In this study we explored the hypothesis that superoxide anions participate in the generation of the Parkin and PINK1 associated phenotypic effect by testing the capacity of endogenous and exogenous superoxide dismutating molecules to rescue the toxic effects induced by loss of PINK1 or Parkin, in both cellular and fly models. Our results demonstrate the positive effect of an increased level of superoxide dismutase proteins on the pathological phenotypes, both in vitro and in vivo. A more pronounced effectiveness for mitochondrial SOD2 activity points to the superoxide radicals generated in the mitochondrial matrix as the prime suspect in the definition of the observed phenotypes. Moreover, we also demonstrate the efficacy of a SOD-mimetic compound, M40403, to partially ameliorate PINK1/Parkin phenotypes in vitro and in vivo. These results support the further exploration of SOD-mimetic compounds as a therapeutic strategy against Parkinson's disease

A Drosophila model of myeloproliferative neoplasm reveals a feed-forward loop in the JAK pathway mediated by p38 MAPK signalling

Myeloproliferative neoplasms (MPNs) of the Philadelphia-negative class comprise polycythaemia vera, essential thrombocythaemia and primary myelofibrosis (PMF). They are associated with aberrant numbers of myeloid lineage cells in the blood, and in the case of overt PMF, with development of myelofibrosis in the bone marrow and failure to produce normal blood cells. These diseases are usually caused by gain-of-function mutations in the kinase JAK2. Here, we use Drosophila to investigate the consequences of activation of the JAK2 orthologue in haematopoiesis. We have identified maturing haemocytes in the lymph gland, the major haematopoietic organ in the fly, as the cell population susceptible to induce hypertrophy upon targeted overexpression of JAK. We show that JAK activates a feed-forward loop, including the cytokine-like ligand Upd3 and its receptor, Domeless, which are required to induce lymph gland hypertrophy. Moreover, we present evidence that p38 MAPK signalling plays a key role in this process by inducing expression of the ligand Upd3. Interestingly, we also show that forced activation of the p38 MAPK pathway in maturing haemocytes suffices to generate hypertrophic organs and the appearance of melanotic tumours. Our results illustrate a novel pro-tumourigenic crosstalk between the p38 MAPK pathway and JAK signalling in a Drosophila model of MPNs. Based on the shared molecular mechanisms underlying MPNs in flies and humans, the interplay between Drosophila JAK and p38 signalling pathways unravelled in this work might have translational relevance for human MPNs

Regulation of Human PINK1 ubiquitin kinase by Serine167, Serine228 and Cysteine412 phosphorylation.

Loss-of-function mutations in the human PINK1 kinase (hPINK1) are causative of early-onset Parkinson’s disease (PD). Activation of hPINK1 induces phosphorylated ubiquitin to initiate removal of damaged mitochondria by autophagy. Previously we solved the structure of the insect PINK1 orthologue, Tribolium castaneum PINK1, and showed that autophosphorylation of Ser205 was critical for ubiquitin interaction and phosphorylation (Kumar, Tamjar, Waddell et al., 2017). Here we report new findings on the regulation of hPINK1 by phosphorylation. We reconstitute E. coli expressed hPINK1 activity in vitro by direct incorporation of phosphoserine at the equivalent site Serine 228 (pSer228), providing direct evidence for a role for Ser228 phosphorylation in hPINK1 activation. Furthermore, using mass spectrometry, we identify six novel Ser/Thr autophosphorylation sites including regulatory Serine167 phosphorylation (pSer167), which in addition to pSer228 is required for ubiquitin recognition and phosphorylation. Strikingly, we also detect phosphorylation of a conserved Cysteine412 (pCys412) residue in the hPINK1 activation segment. Structural modelling suggests that pCys412 inhibits ubiquitin recognition and we demonstrate that mutation of Cys412 to Ala renders hPINK1 more active towards ubiquitin when expressed in human cells. These results outline new insights into hPINK1 activation by pSer167 and pSer228 and a novel inhibitory mechanism mediated by pCys412. These findings will aid in the development of small molecule activators of hPINK1

Regulation of Human PINK1 ubiquitin kinase by Serine167, Serine228 and Cysteine412 phosphorylation.

Loss-of-function mutations in the human PINK1 kinase (hPINK1) are causative of early-onset Parkinson’s disease (PD). Activation of hPINK1 induces phosphorylated ubiquitin to initiate removal of damaged mitochondria by autophagy. Previously we solved the structure of the insect PINK1 orthologue, Tribolium castaneum PINK1, and showed that autophosphorylation of Ser205 was critical for ubiquitin interaction and phosphorylation (Kumar, Tamjar, Waddell et al., 2017). Here we report new findings on the regulation of hPINK1 by phosphorylation. We reconstitute E. coli expressed hPINK1 activity in vitro by direct incorporation of phosphoserine at the equivalent site Serine 228 (pSer228), providing direct evidence for a role for Ser228 phosphorylation in hPINK1 activation. Furthermore, using mass spectrometry, we identify six novel Ser/Thr autophosphorylation sites including regulatory Serine167 phosphorylation (pSer167), which in addition to pSer228 is required for ubiquitin recognition and phosphorylation. Strikingly, we also detect phosphorylation of a conserved Cysteine412 (pCys412) residue in the hPINK1 activation segment. Structural modelling suggests that pCys412 inhibits ubiquitin recognition and we demonstrate that mutation of Cys412 to Ala renders hPINK1 more active towards ubiquitin when expressed in human cells. These results outline new insights into hPINK1 activation by pSer167 and pSer228 and a novel inhibitory mechanism mediated by pCys412. These findings will aid in the development of small molecule activators of hPINK1

Defective proventriculus specifies the ocellar region in the Drosophila head

A pair of the Drosophila eye-antennal disc gives rise to four distinct organs (eyes, antennae, maxillary palps, and ocelli) and surrounding head cuticle. Developmental processes of this imaginal disc provide an excellent model system to study the mechanism of regional specification and subsequent organogenesis. The dorsal head capsule (vertex) of adult Drosophila is divided into three morphologically distinct subdomains: ocellar, frons, and orbital. The homeobox gene orthodenticle (otd) is required for head vertex development, and mutations that reduce or abolish ad expression in the vertex primordium lead to ocelliless flies. The homeodomain-containing transcriptional repressor Engrailed (En) is also involved in ocellar specification, and the En expression is completely lost in otd mutants. However, the molecular mechanism of ocellar specification remains elusive. Here, we provide evidence that the homeobox gene defective proventriculus (dye) is a downstream effector of Otd, and also that the repressor activity of Dye is required for en activation through a relief-of-repression mechanism. Furthermore, the Dye activity is involved in repression of the frons identity in an incoherent feedforward loop of Otd and Dye

Comprehensive Genetic Characterisation of Mitochondrial Ca2+ Uniporter Components Reveals Their Different Physiological Requirements in Vivo

Mitochondrial Ca2+ uptake is an important mediator of metabolism and cell death. Identification of components of the highly conserved mitochondrial Ca2+ uniporter has opened it up to genetic analysis in model organisms. Here, we report a comprehensive genetic characterisation of all known uniporter components conserved in Drosophila. While loss of pore-forming MCU or EMRE abolishes fast mitochondrial Ca2+ uptake, this results in only mild phenotypes when young, despite shortened lifespans. In contrast, loss of the MICU1 gatekeeper is developmental lethal, consistent with unregulated Ca2+ uptake. Mutants for the neuronally-restricted regulator MICU3 are viable with mild neurological impairment. Genetic interaction analyses reveal that MICU1 and MICU3 are not functionally interchangeable. More surprisingly, loss of MCU or EMRE does not suppress MICU1 mutant lethality, suggesting that this results from uniporter-independent functions. Our data interrogates the interplay between components of the mitochondrial Ca2+ uniporter, and sheds light on their physiological requirements in vivo.This work is supported by MRC core funding (MC_UU_00015/4, MC-A070-5PSB0 and MC_UU_00015/6) and ERC Starting grant (DYNAMITO; 309742) to A.J.W., and the Italian Ministry of Health “Ricerca Finalizzata” [GR-2011-02351151] to E.Z. T.P.G. and J.J.L. are supported by MRC Studentships awarded via the MRC MBU. V.L.H. was funded by an EMBO Long-Term Fellowship (ALTF 740-2015) co-funded by the European Commission FP7 (Marie Curie Actions, LTFCOFUND2013, GA-2013-609409). Stocks were obtained from the Bloomington Drosophila Stock Center which is supported by grant NIH P40OD018537, and material was obtained from the Drosophila Genomics Resource Center, which is supported by NIH grant 2P40OD010949