Protein import into the endosymbiotic organelles of apicomplexan parasites

The organelles of endosymbiotic origin, plastids, and mitochondria, evolved through the serial acquisition of endosymbionts by a host cell. These events were accompanied by gene transfer from the symbionts to the host, resulting in most of the organellar proteins being encoded in the cell nuclear genome and trafficked into the organelle via a series of translocation complexes. Much of what is known about organelle protein translocation mechanisms is based on studies performed in common model organisms; e.g., yeast and humans or Arabidopsis. However, studies performed in divergent organisms are gradually accumulating. These studies provide insights into universally conserved traits, while discovering traits that are specific to organisms or clades. Apicomplexan parasites feature two organelles of endosymbiotic origin: a secondary plastid named the apicoplast and a mitochondrion. In the context of the diseases caused by apicomplexan parasites, the essential roles and divergent features of both organelles make them prime targets for drug discovery. This potential and the amenability of the apicomplexan Toxoplasma gondii to genetic manipulation motivated research about the mechanisms controlling both organelles’ biogenesis. Here we provide an overview of what is known about apicomplexan organelle protein import. We focus on work done mainly in T. gondii and provide a comparison to model organisms

Estudio de enzimas clave en el metabolismo energético del ciliado parásito del rodaballo Philasterides dicentrarchi: ¿posibles dianas terapéuticas para el desarrollo de fármacos frente a la escuticociliatosis?

La escuticociliatosis del rodaballo en cultivo, producida por el ciliado Philasterides dicentrarchi, es una enfermedad parasitaria que provoca grandes pérdidas económicas en el sector y para la cual no se dispone de medidas efectivas de control. En este trabajo, se han estudiado diferentes enzimas implicadas en el metabolismo energético del parásito, que podrían actuar como dianas terapéuticas, así como posibles tratamientos que actúen a nivel de éstas. En primer lugar, se estudió el funcionamiento de la respiración mitocondrial del escuticociliado, revelándose la existencia de una ruta alternativa en la que está presente una oxidasa alternativa y cuyos inhibidores afectan al crecimiento del ciliado, por lo que se propone el empleo de los inhibidores antioxidantes no tóxicos, propilgalato y resveratrol, como tratamientos frente a la escuticociliatosis y se plantea esta enzima como una diana quimioterapéutica interesante, teniendo en cuenta su ausencia en el hospedador. Por otra parte, se realizó la caracterización de una pirofosfatasa inorgánica translocadora de protones que presenta dos isoformas, generadas mediante un proceso de corte y empalme alternativo, que se localizan en las membranas de vacuolas citoplasmáticas y sacos alveolares, estructuras acídicas relacionadas con procesos de osmorregulación, las cuales se muestran como estructuras tipo acidocalcisoma, ya que funcionan además como almacén de Ca+2. Se ha observado que fármacos antimaláricos, como la cloroquina y la artemisinina, y análogos del pirofosfato presentan actividad antiparasitaria relacionada con su efecto sobre enzimas del metabolismo del PPi y del Ca+2, la pirofosfatasa inorgánica translocadora de protones y la Ca+2- ATPasa. Estas enzimas participan en la homeostasis del pH intracelular y del Ca+2, mecanismos vitales para la supervivencia del parásito, lo que demuestra que las pirofosfatasas también son moléculas diana clave para el desarrollo de nuevos fármacos frente a la escuticociliatosis

Alternative Building Materials (ABM): Towards Adoption of Common Terminology and Definitions

There are differences in the definitions of Alternative Building Materials (ABM) and differences in the terminologies that are used in describing ABM by different researchers in the construction industry. ABM is a generic term, which is characterised of or relating to a class or group of building materials, not really specific. It encompasses building and construction materials that in literature are referred to by different names such as alternative materials, local building materials, unconventional building materials, alternative residential construction materials, sustainable building materials, indigenous building materials, vernacular building materials, green building materials, environmentally responsible building materials, eco-friendly building materials, etc. The research employed systematic literature review and content analysis to generate and analysedall the necessary information as the methodology.  A working (operational) definition of Alternative Building Materials is being offered as building materials that are an alternative to conventional building materials in the form of total or partial substitution of the materials or its constituents for the purpose of reducing the cost, addressing environmental issues or dealing with lack of conventional materials. The characteristics of ABM have been identified to include low or no chemical emissions that can lead to poor indoor air quality, recycled content (post-consumer and pre-consumer), no CFC, HCFC, or other ozone depleting substances content, low embodied energy, locally produced, possibility of repairs and replacements with local means and social acceptability amongst others. Some of the benefits of utilizing ABM include; low embodied energy (often leading to reduced greenhouse gas emissions), ease of construction, widespread availability and low cost. Keywords: Alternative Building Materials, Definition, Adoption, Terminology, Characteristics DOI: 10.7176/CER/12-11-03 Publication date: November 30th 202

Evidence for a Myotomal Hox/Myf Cascade Governing Nonautonomous Control of Rib Specification within Global Vertebral Domains

Hox genes are essential for the patterning of the axial skeleton. Hox group 10 has been shown to specify the lumbar domain by setting a rib-inhibiting program in the presomitic mesoderm (PSM). We have now produced mice with ribs in every vertebra by ectopically expressing Hox group 6 in the PSM, indicating that Hox genes are also able to specify the thoracic domain. We show that the information provided by Hox genes to specify rib-containing and rib-less areas is first interpreted in the myotome through the regional-specific control of Myf5 and Myf6 expression. This information is then transmitted to the sclerotome by a system that includes FGF and PDGF signaling to produce vertebrae with or without ribs at different axial levels. Our findings offer a new perspective of how Hox genes produce global patterns in the axial skeleton and support a redundant nonmyogenic role of Myf5 and Myf6 in rib formation.Fundação para a Ciência e a Tecnologia grants: (PTDC/BIA-BCM/71619/2006, POCTI-ISFL-4-664, SFRH/BD/27306/2006, SFRH/BPD/26668/2006)

Molecular Targets Implicated in the Antiparasitic and Anti-Inflammatory Activity of the Phytochemical Curcumin in Trichomoniasis

Trichomoniasis, is the most prevalent non-viral sexually transmitted disease worldwide. Although metronidazole (MDZ) is the recommended treatment, several strains of the parasite are resistant to MDZ, and new treatments are required. Curcumin (CUR) is a polyphenol with anti-inflammatory, antioxidant and antiparasitic properties. In this study, we evaluated the effects of CUR on two biochemical targets: on proteolytic activity and hydrogenosomal metabolism in Trichomonas vaginalis. We also investigated the role of CUR on pro-inflammatory responses induced in RAW 264.7 phagocytic cells by parasite proteinases on pro-inflammatory mediators such as the nitric oxide (NO), tumor necrosis factor α (TNFα), interleukin-1beta (IL-1β), chaperone heat shock protein 70 (Hsp70) and glucocorticoid receptor (mGR). CUR inhibited the growth of T. vaginalis trophozoites, with an IC50 value between 117 ± 7 μM and 173 ± 15 μM, depending on the culture phase. CUR increased pyruvate:ferredoxin oxidoreductase (PfoD), hydrogenosomal enzyme expression and inhibited the proteolytic activity of parasite proteinases. CUR also inhibited NO production and decreased the expression of pro-inflammatory mediators in macrophages. The findings demonstrate the potential usefulness of CUR as an antiparasitic and anti-inflammatory treatment for trichomoniasis. It could be used to control the disease and mitigate the associated immunopathogenic effectsThis research was funded by Xunta de Galicia (Spain), grant number ED431C2017/31S

Exploring the powerful phytoarsenal of white grape marc against bacteria and parasites causing significant diseases

Natural extracts containing high polyphenolic concentration possess antibacterial, antiparasitic and fungicidal activities. The present research characterises white grape marc, a winemaking by-product describing their physicochemical features and antimicrobial capacities. Main components of 2 different extracts generated were phenolic acids, flavan-3-ols and their gallates, and flavonols and their glycosides. As a result of this complex composition white grape marc extracts showed pronounced bioactivities with potential uses in agricultural, pharmaceutical and cosmetic industries, among others. Specifically, polyphenol compounds were extracted by using hydro-organic solvent mixtures from the by-product of Albariño white wines (Galicia, NW Spain) production. In the present work the “in vitro” antimicrobial activity of the bioactive extracts was evaluated using two different hydro-organic mixtures (HOL & HOP). The microorganisms tested included Gram positive and negative bacteria, two Apicomplexan parasite species and one Oomycota parasite. Microbial species investigated are causing agents of several human and animal diseases, such as foodborne illnesses (Bacillus cereus, Eschericha coli, Salmonella enterica), skin infections (Staphylococcus aureus), mastitis (Streptococcus uberis), parasite infections as Malaria (Plasmodium falciparum) or Toxoplasmosis (Toxoplasma gondii), and plant infections as "chestnut ink" in chestnuts or "root rot" in avocado, both diseases caused by Phytophthora cinnamomi. Both extracts verified activity against all the tested species demonstrating their potentiality to be used for the development of biocides to control a wide range of pathogenic agents; at the same time that they contribute to winemaking industry residues valorisationThis research was supported by projects GPC2017/04 (Consolidated Research Groups Program) & ED431E 2018/01 Cross-Research in Environmental Technologies (CRETUS) (Xunta de Galicia, Spain)info:eu-repo/semantics/publishedVersio

Enzymes involved in pyrophosphate and calcium metabolism as targets for anti-scuticociliate chemotherapy

This is the peer reviewed version of the following article: Mallo, N., Lamas, J., DeFelipe, A.P., Sueiro, R.A., Fontenla, F. and Leiro JM. (2016), Enzymes Involved in Pyrophosphate and Calcium Metabolism as Targets for Antiscuticociliate Chemotherapy. J Eukaryot Microbiol 63(4): 505-15. doi: 10.1111/jeu.12294, which has been published in final form at https://doi.org/10.1111/jeu.12294. This article may be used for noncommercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived VersionsInorganic pyrophosphate (PPi) is a key metabolite in cellular bioenergetics under chronic stress conditions in prokaryotes, protists and plants. Inorganic pyrophosphatases (PPases) are essential enzymes controlling the cellular concentration of PPi and mediating intracellular pH and Ca(2+) homeostasis. We report the effects of the antimalarial drugs chloroquine (CQ) and artemisinin (ART) on the in vitro growth of Philasterides dicentrarchi, a scuticociliate parasite of turbot; we also evaluated the action of these drugs on soluble (sPPases) and vacuolar H+-PPases (H+-PPases). CQ and ART inhibited the in vitro growth of ciliates with IC50 values of respectively 74 ± 9 μM and 80 ± 8 μM. CQ inhibits the H+ translocation (with an IC50 of 13.4 ± 0.2 μM), while ART increased translocation of H+ and acidification. However, both drugs caused a decrease in gene expression of H+-PPases. CQ significantly inhibited the enzymatic activity of sPPases, decreasing the consumption of intracellular PPi. ART inhibited intracellular accumulation of Ca(2+) induced by ATP, indicating an effect on the Ca(2+) -ATPase. The results suggest that CQ and ART deregulate enzymes associated with PPi and Ca(2+) metabolism, altering the intracellular pH homeostasis vital for parasite survival and providing a target for the development of new drugs against scuticociliatosisThis study was financially supported by grant AGL2014-57125-R from the Ministerio de Economía y Competitividad (Spain), by the European Commission, under the Horizon 2020 programme (Grant Agreement 634429, PARAFISHCONTROL), and 430 by grant GPC2014/069 from the Xunta de Galicia (Spain)S

Combined antiparasitic and anti‐inflammatory effects of the natural polyphenol curcumin on turbot scuticociliatosis

This is the peer reviewed version of the following article: Mallo, N. , DeFelipe, A. P., Folgueira, I. , Sueiro, R. A., Lamas, J. and Leiro, J. M. (2017), Combined antiparasitic and anti‐inflammatory effects of the natural polyphenol curcumin on turbot scuticociliatosis. J Fish Dis, 40: 205217. doi:10.1111/jfd.12503, which has been published in final form at https://doi.org/10.1111/jfd.12503. This article may be used for noncommercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived VersionsThe histiophagous scuticociliate Philasterides dicentrarchi is the aetiological agent of scuticociliatosis, a parasitic disease of farmed turbot. Curcumin, a polyphenol from Curcuma longa (turmeric), is known to have antioxidant and anti-inflammatory properties. We investigated the in vitro effects of curcumin on the growth of P. dicentrarchi and on the production of pro-inflammatory cytokines in turbot leucocytes activated by parasite cysteine proteases. At 100 μm, curcumin had a cytotoxic effect and completely inhibited the growth of the parasite. At 50 μm, curcumin inhibited the protease activity of the parasite and expression of genes encoding two virulence-associated proteases: leishmanolysin-like peptidase and cathepsin L-like. At concentrations between 25 and 50 μm, curcumin inhibited the expression of S-adenosyl-L-homocysteine hydrolase, an enzyme involved in the biosynthesis of the amino acids methionine and cysteine. At 100 μm, curcumin inhibited the expression of the cytokines tumour necrosis factor-alpha (TNF-α) and interleukin-1 beta (IL-1β) produced in turbot leucocytes activated by parasite proteases. Results show that curcumin has a dual effect on scuticociliatosis: an antiparasitic effect on the catabolism and anabolism of ciliate proteins, and an anti-inflammatory effect that inhibits the production of proinflammatory cytokines in the host. The present findings suggest the potential usefulness of this polyphenol in treating scuticociliatosisThis work was financially supported by the European Union’s Horizon 2020 research and innovation programme under grant agreement No. 634429 (PARAFISHCONTROL) and by the Ministerio de Economía y Competitividad (Spain) under grant agreement AGL2014-57125-RS

Exploring the powerful phytoarsenal of white grape marc against bacteria and parasites causing significant diseases

Natural extracts containing high polyphenolic concentration possess antibacterial, anti-parasitic and fungicidal activities. The present research characterises two extracts based on white grape marc, a winemaking by-product, describing their physicochemical features and antimicrobial capacities. The main components of these extracts are phenolic acids, flavan-3-ols and their gallates and flavonols and their glycosides. As a result of this complex composition, the extracts showed pronounced bioactivities with potential uses in agricultural, pharmaceutical and cosmetic industries. Polyphenol compounds were extracted by using hydro-organic solvent mixtures from the by-product of Albariño white wines (Galicia, NW Spain) production. The in vitro antimicrobial activity of these extracts was evaluated on Gram-positive and Gram-negative bacteria and Apicomplexan and Oomycota parasites. Microbial species investigated are causing agents of several human and animal diseases, such as foodborne illnesses (Bacillus cereus, Escherichia coli, Salmonella enterica, and Toxoplasma gondii), skin infections and/or mastitis (Staphylococcus aureus and Streptococcus uberis), malaria (Plasmodium falciparum) and plant infections as “chestnut ink” or “root rot” (Phytophthora cinnamomi). Both extracts showed activity against all the tested species, being nontoxic for the host. So, they could be used for the development of biocides to control a wide range of pathogenic agents and contribute to the enhancement of winemaking industry by-products

Structural analysis of mitochondrial rRNA gene variants identified in patients with deafness

The last few years have witnessed dramatic advances in our understanding of the structure and function of the mammalian mito-ribosome. At the same time, the first attempts to elucidate the effects of mito-ribosomal fidelity (decoding accuracy) in disease have been made. Hence, the time is right to push an important frontier in our understanding of mitochondrial genetics, that is, the elucidation of the phenotypic effects of mtDNA variants affecting the functioning of the mito-ribosome. Here, we have assessed the structural and functional role of 93 mitochondrial (mt-) rRNA variants thought to be associated with deafness, including those located at non-conserved positions. Our analysis has used the structural description of the human mito-ribosome of the highest quality currently available, together with a new understanding of the phenotypic manifestation of mito-ribosomal-associated variants. Basically, any base change capable of inducing a fidelity phenotype may be considered non-silent. Under this light, out of 92 previously reported mt-rRNA variants thought to be associated with deafness, we found that 49 were potentially non-silent. We also dismissed a large number of reportedly pathogenic mtDNA variants, 41, as polymorphisms. These results drastically update our view on the implication of the primary sequence of mt-rRNA in the etiology of deafness and mitochondrial disease in general. Our data sheds much-needed light on the question of how mt-rRNA variants located at non-conserved positions may lead to mitochondrial disease and, most notably, provide evidence of the effect of haplotype context in the manifestation of some mt-rRNA variants