RESUMEN
Endoplasmic reticulum (ER) retention of misfolded glycoproteins is mediated by the ER-localized eukaryotic glycoprotein secretion checkpoint, UDP-glucose glycoprotein glucosyl-transferase (UGGT). The enzyme recognizes a misfolded glycoprotein and flags it for ER retention by re-glucosylating one of its N-linked glycans. In the background of a congenital mutation in a secreted glycoprotein gene, UGGT-mediated ER retention can cause rare disease, even if the mutant glycoprotein retains activity ("responsive mutant"). Using confocal laser scanning microscopy, we investigated here the subcellular localization of the human Trop-2-Q118E, E227K and L186P mutants, which cause gelatinous drop-like corneal dystrophy (GDLD). Compared with the wild-type Trop-2, which is correctly localized at the plasma membrane, these Trop-2 mutants are retained in the ER. We studied fluorescent chimeras of the Trop-2 Q118E, E227K and L186P mutants in mammalian cells harboring CRISPR/Cas9-mediated inhibition of the UGGT1 and/or UGGT2 genes. The membrane localization of the Trop-2 Q118E, E227K and L186P mutants was successfully rescued in UGGT1-/- cells. UGGT1 also efficiently reglucosylated Trop-2-Q118E-EYFP in cellula. The study supports the hypothesis that UGGT1 modulation would constitute a novel therapeutic strategy for the treatment of pathological conditions associated to misfolded membrane glycoproteins (whenever the mutation impairs but does not abrogate function), and it encourages the testing of modulators of ER glycoprotein folding quality control as broad-spectrum rescue-of-secretion drugs in rare diseases caused by responsive secreted glycoprotein mutants.
Asunto(s)
Pliegue de Proteína , Enfermedades Raras , Animales , Humanos , Enfermedades Raras/metabolismo , Glicoproteínas/genética , Glicoproteínas/metabolismo , Retículo Endoplásmico/metabolismo , Mutación , Mamíferos/metabolismo , Glucosiltransferasas/metabolismoRESUMEN
Dendritic cells (DCs) can be divided by lineage into myeloid dendritic cells (mDCs) and plasmacytoid dendritic cells (pDCs). They both are present in mucosal tissues and regulate the immune response by secreting chemokines and cytokines. Inflammatory bowel diseases (IBDs) are characterized by a leaky intestinal barrier and the consequent translocation of bacterial lipopolysaccharide (LPS) to the basolateral side. This results in DCs activation, but the response of pDCs is still poorly characterized. In the present study, we compared mDCs and pDCs responses to LPS administration. We present a broad panel of DCs secreted factors, including cytokines, chemokines, and growth factors. Our recent studies demonstrated the anti-inflammatory effects of quercetin administration, but to date, there is no evidence about quercetin's effects on pDCs. The results of the present study demonstrate that pDCs can respond to LPS and that quercetin exposure modulates soluble factors release through the same molecular pathway used by mDCs (Slpi, Hmox1, and AP-1).
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Antioxidantes/farmacología , Síndrome de Liberación de Citoquinas/tratamiento farmacológico , Citocinas/metabolismo , Células Dendríticas/efectos de los fármacos , Células Mieloides/efectos de los fármacos , Quercetina/farmacología , Animales , Antioxidantes/administración & dosificación , Células Cultivadas , Síndrome de Liberación de Citoquinas/inmunología , Síndrome de Liberación de Citoquinas/metabolismo , Síndrome de Liberación de Citoquinas/patología , Citocinas/efectos de los fármacos , Células Dendríticas/citología , Células Dendríticas/inmunología , Células Dendríticas/metabolismo , Ratones , Células Mieloides/citología , Células Mieloides/inmunología , Células Mieloides/metabolismo , Quercetina/administración & dosificaciónRESUMEN
Glycoproteins traversing the eukaryotic secretory pathway begin life in the endoplasmic reticulum (ER), where their folding is surveyed by the 170-kDa UDP-glucose:glycoprotein glucosyltransferase (UGGT). The enzyme acts as the single glycoprotein folding quality control checkpoint: it selectively reglucosylates misfolded glycoproteins, promotes their association with ER lectins and associated chaperones, and prevents premature secretion from the ER. UGGT has long resisted structural determination and sequence-based domain boundary prediction. Questions remain on how this single enzyme can flag misfolded glycoproteins of different sizes and shapes for ER retention and how it can span variable distances between the site of misfold and a glucose-accepting N-linked glycan on the same glycoprotein. Here, crystal structures of a full-length eukaryotic UGGT reveal four thioredoxin-like (TRXL) domains arranged in a long arc that terminates in two ß-sandwiches tightly clasping the glucosyltransferase domain. The fold of the molecule is topologically complex, with the first ß-sandwich and the fourth TRXL domain being encoded by nonconsecutive stretches of sequence. In addition to the crystal structures, a 15-Å cryo-EM reconstruction reveals interdomain flexibility of the TRXL domains. Double cysteine point mutants that engineer extra interdomain disulfide bridges rigidify the UGGT structure and exhibit impaired activity. The intrinsic flexibility of the TRXL domains of UGGT may therefore endow the enzyme with the promiscuity needed to recognize and reglucosylate its many different substrates and/or enable reglucosylation of N-linked glycans situated at variable distances from the site of misfold.
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Glucosiltransferasas/química , Glucosiltransferasas/fisiología , Animales , Chaetomium/genética , Chaetomium/metabolismo , Cristalografía por Rayos X/métodos , Retículo Endoplásmico/metabolismo , Eucariontes/metabolismo , Células Eucariotas/metabolismo , Glucosiltransferasas/metabolismo , Glicoproteínas/metabolismo , Conformación Molecular , Dominios Proteicos/fisiología , Pliegue de Proteína , Transporte de Proteínas/fisiología , Especificidad por SustratoRESUMEN
Iron overload is an undesired effect of frequent blood transfusions or genetic diseases. Myelodysplastic syndrome (MDS) patients become transfusion dependent, but due to the combination of ineffective haematopoiesis and repeated blood transfusions they are often subject to iron overload. In this study, we demonstrate that iron-overload mimicking condition alters bone marrow progenitor differentiation towards dendritic cells (DCs). Cells cultured in iron-enriched culture medium for seven days fail to differentiate into conventional CD11c+MHCIIhi DCs and fail to efficiently respond to LPS (Lipopolysaccharides). Cells appear smaller than control DCs but vital and able to perform FITC-dextran (Fluorescein isothiocyanate-dextran) endocytosis. At molecular level, cells cultured in iron-enriched conditions show increased ARG1 and PU.1, and decreased IRF8 expression.
Asunto(s)
Médula Ósea/metabolismo , Antígeno CD11c/metabolismo , Diferenciación Celular/fisiología , Células Dendríticas/metabolismo , Antígenos de Histocompatibilidad Clase II/metabolismo , Sobrecarga de Hierro/metabolismo , Animales , Arginasa/genética , Arginasa/metabolismo , Médula Ósea/efectos de los fármacos , Células de la Médula Ósea/metabolismo , Citocinas/metabolismo , Células Dendríticas/efectos de los fármacos , Regulación de la Expresión Génica , Hematopoyesis , Inflamación , Factores Reguladores del Interferón/genética , Factores Reguladores del Interferón/metabolismo , Lipopolisacáridos/efectos adversos , Ratones , Proteínas Proto-Oncogénicas/genética , Proteínas Proto-Oncogénicas/metabolismo , Receptor Toll-Like 4/genética , Receptor Toll-Like 4/metabolismo , Transactivadores/metabolismoRESUMEN
(1) Background: Colorectal cancer (CRC) is among the best examples of the relationship between inflammation and increased cancer risk. (2) Methods: To examine the effects of spontaneous low-grade chronic inflammation on the pathogenesis of CRC, we developed a new murine model of colitis-associated cancer (CAC) by crossing Mucin 2 mutated mice (Winnie) with ApcMin/+ mice. (3) Results: The resulting Winnie-ApcMin/+ model combines an inflammatory background with a genetic predisposition to small intestinal polyposis. Winnie-ApcMin/+ mice show an early occurrence of inflammatory signs and dysplastic lesions in the distal colon with a specific molecular signature. (4) Conclusion: The Winnie-ApcMin/+ model is a perfect model to demonstrate that chronic inflammation represents a crucial risk factor for the onset and progression of tumoral lesions in individuals genetically predisposed to CRC.
Asunto(s)
Neoplasias Asociadas a Colitis/etiología , Susceptibilidad a Enfermedades , Genes APC , Animales , Apoptosis/genética , Biopsia , Proliferación Celular , Citoesqueleto , Modelos Animales de Enfermedad , Progresión de la Enfermedad , Predisposición Genética a la Enfermedad , Inmunohistoquímica , Mucosa Intestinal/metabolismo , Mucosa Intestinal/patología , Ratones , Clasificación del TumorRESUMEN
BACKGROUND: Global warming and extreme or adverse events induced by climatic fluctuations are an important threat for plants growth and agricultural production. Adaptability to environmental changes prevalently derives from a large set of genetic traits affecting physiological and agronomic parameters. Therefore, the identification of genotypes that are good yield performer at high temperatures is becoming increasingly necessary for future breeding programs. Here, we analyzed the performances of different tomato landraces grown under elevated temperatures in terms of yield and nutritional quality of the fruit. Finally, we evaluated the antioxidant and anti-inflammatory activities of fruit extracts from the tomato landraces selected. RESULTS: The tomato landraces analyzed here in a hot climate differed in terms of yield performance, physicochemical parameters of fruit (pH, titratable acidity, degrees Brix, firmness), bioactive compounds (ascorbic acid, carotenoids, and polyphenols), and anti-inflammatory potential. Three of these landraces (named E30, E94, and PDVIT) showed higher fruit quality and nutritional value. An estimated evaluation index allowed identification of PDVIT as the best performer in terms of yield and fruit quality under high temperatures. CONCLUSION: The analyses performed here highlight the possibility to identify new landraces that can combine good yield performances and fruit nutritional quality at high temperatures, information that is useful for future breeding programs. © 2020 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
Asunto(s)
Frutas/química , Calor , Solanum lycopersicum/crecimiento & desarrollo , Solanum lycopersicum/genética , Antioxidantes/análisis , Ácido Ascórbico/análisis , Carotenoides/análisis , Italia , Valor Nutritivo , Fitomejoramiento , Polifenoles/análisisRESUMEN
Lipid droplets (LDs) are ubiquitous organelles in plant cells, but their physiological roles are largely unknown. To gain insight into the function of LDs in plants, we have characterized the Arabidopsis homologs of SEIPIN proteins, which are crucial factors for LD biogenesis in yeast and animals. SEIPIN1 is expressed almost exclusively in embryos, while SEIPIN2 and SEIPIN3 have broader expression profiles with maximal levels in embryos and pollen, where LDs accumulate most abundantly. Genetic analysis demonstrates that all three SEIPINs contribute to proper LD biogenesis in embryos, whereas in pollen, only SEIPIN2 and SEIPIN3 play a significant role. The double seipin2 seipin3 and triple seipin mutants accumulate extremely enlarged LDs in seeds and pollen, which hinders their subsequent mobilization during germination. Interestingly, electron microscopy analysis reveals the presence of nuclear LDs attached to type I nucleoplasmic reticulum in triple seipin mutant embryos, supporting that SEIPINs are essential for maintaining the correct polarity of LD budding at the nuclear envelope, restricting it to the outer membrane. In pollen, the perturbations in LD biogenesis and turnover are coupled to reduced germination in vitro and with lower fertilization efficiency in vivo. In seeds, germination per se is not affected in seipin2 seipin3 and triple seipin mutants, but there is a striking increase in seed dormancy levels. Our findings reveal the relevance of SEIPIN-dependent LD biogenesis in pollen transmission and in adjusting the timing of seed germination, two key adaptive traits of great importance in agriculture.
Asunto(s)
Proteínas de Arabidopsis/metabolismo , Arabidopsis/genética , Gotas Lipídicas/metabolismo , Arabidopsis/fisiología , Proteínas de Arabidopsis/genética , Cloroplastos/metabolismo , Subunidades gamma de la Proteína de Unión al GTP/genética , Subunidades gamma de la Proteína de Unión al GTP/metabolismo , Germinación , Polen/genética , Polen/fisiología , Semillas/genética , Semillas/fisiologíaRESUMEN
Multiple stresses are becoming common challenges in modern agriculture due to environmental changes. A large set of phytochemicals collectively known as oxylipins play a key role in responses to several stresses. Understanding the fine-tuned plant responses to multiple and simultaneous stresses could open new perspectives for developing more tolerant varieties. We carried out the molecular and biochemical profiling of genes, proteins and active compounds involved in oxylipin metabolism in response to single/combined salt and wounding stresses on Medicago truncatula. Two new members belonging to the CYP74 gene family were identified. Gene expression profiling of each of the six CYP74 members indicated a tissue- and time-specific expression pattern for each member in response to single/combined salt and wounding stresses. Notably, hormonal profiling pointed to an attenuated systemic response upon combined salt and leaf wounding stresses. Combined, these results confirm the important role of jasmonates in legume adaptation to abiotic stresses and point to the existence of a complex molecular cross-talk among signals generated by multiple stresses.
Asunto(s)
Medicago truncatula/fisiología , Oxilipinas/metabolismo , Cloruro de Sodio/farmacología , Estrés Fisiológico , Sistema Enzimático del Citocromo P-450/genética , Sistema Enzimático del Citocromo P-450/metabolismo , Perfilación de la Expresión Génica , Regulación de la Expresión Génica de las Plantas/efectos de los fármacos , Genoma de Planta , Medicago truncatula/efectos de los fármacos , Medicago truncatula/genética , Familia de Multigenes , Filogenia , Reguladores del Crecimiento de las Plantas/metabolismo , Hojas de la Planta/efectos de los fármacos , Hojas de la Planta/metabolismo , Raíces de Plantas/efectos de los fármacos , Raíces de Plantas/metabolismo , Estrés Fisiológico/efectos de los fármacos , Estrés Fisiológico/genéticaRESUMEN
The biosynthesis of enveloped viruses depends heavily on the host cell endoplasmic reticulum (ER) glycoprotein quality control (QC) machinery. This dependency exceeds the dependency of host glycoproteins, offering a window for the targeting of ERQC for the development of broad-spectrum antivirals. We determined small-angle X-ray scattering (SAXS) and crystal structures of the main ERQC enzyme, ER α-glucosidase II (α-GluII; from mouse), alone and in complex with key ligands of its catalytic cycle and antiviral iminosugars, including two that are in clinical trials for the treatment of dengue fever. The SAXS data capture the enzyme's quaternary structure and suggest a conformational rearrangement is needed for the simultaneous binding of a monoglucosylated glycan to both subunits. The X-ray structures with key catalytic cycle intermediates highlight that an insertion between the +1 and +2 subsites contributes to the enzyme's activity and substrate specificity, and reveal that the presence of d-mannose at the +1 subsite renders the acid catalyst less efficient during the cleavage of the monoglucosylated substrate. The complexes with iminosugar antivirals suggest that inhibitors targeting a conserved ring of aromatic residues between the α-GluII +1 and +2 subsites would have increased potency and selectivity, thus providing a template for further rational drug design.
Asunto(s)
Antivirales/farmacología , Retículo Endoplásmico/enzimología , Inhibidores de Glicósido Hidrolasas/farmacología , alfa-Glucosidasas/química , Animales , Catálisis , Cristalografía por Rayos X , Ratones , Conformación Proteica , Subunidades de Proteína , Dispersión del Ángulo Pequeño , Especificidad por SustratoRESUMEN
Inflammatory bowel diseases (IBDs) are chronic and relapsing immune disorders that result, or possibly originate, from epithelial barrier defects. Intestinal organoids are a new reliable tool to investigate epithelial response in models of chronic inflammation. We produced organoids from the ulcerative colitis murine model Winnie to explore if the chronic inflammatory features observed in the parental intestine were preserved by the organoids. Furthermore, we investigated if quercetin administration to in vitro cultured organoids could suppress LPS-induced inflammation in wild-type organoids (WT-organoids) and spontaneous inflammation in ulcerative colitis organoids (UC-organoids). Our data demonstrate that small intestinal organoids obtained from Winnie mice retain the chronic intestinal inflammatory features characteristic of the parental tissue. Quercetin administration was able to suppress inflammation both in UC-organoids and in LPS-treated WT-organoids. Altogether, our data demonstrate that UC-organoids are a reliable experimental system for investigating chronic intestinal inflammation and pharmacological responses.
Asunto(s)
Mucosa Intestinal/efectos de los fármacos , Quercetina/farmacología , Animales , Colitis Ulcerosa/metabolismo , Colitis Ulcerosa/patología , Modelos Animales de Enfermedad , Expresión Génica/efectos de los fármacos , Técnicas In Vitro , Mucosa Intestinal/metabolismo , Mucosa Intestinal/ultraestructura , Lipocalina 2/genética , Lipocalina 2/metabolismo , Lipopolisacáridos/toxicidad , Ratones , Ratones Endogámicos C57BL , Microscopía Electrónica de Transmisión , Inhibidor Secretorio de Peptidasas Leucocitarias/genética , Inhibidor Secretorio de Peptidasas Leucocitarias/metabolismo , Factor de Necrosis Tumoral alfa/genética , Factor de Necrosis Tumoral alfa/metabolismoRESUMEN
Conformational switching induced in ethane-bridged bisporphyrins was used as a sensitive transduction method for revealing the presence of urea dissolved in water via nonenzymatic approach. Bisporphyrins were deposited on solid quartz slides by means of the spin-coating method. Molecular conformations of Zn and Ni monometalated bis-porphyrins were influenced by water solvated urea molecules and their fluorescence emission was modulated by the urea concentration. Absorption, fluorescence and Raman spectroscopies allowed the identification of supramolecular processes, which are responsible for host-guest interaction between the active layers and urea molecules. A high selectivity of the sensing mechanism was highlighted upon testing the spectroscopic responses of bis-porphyrin films to citrulline and glutamine used as interfering agents. Additionally, potential applicability was demonstrated by quantifying the urea concentration in real physiological samples proposing this new approach as a valuable alternative analytical procedure to the traditionally used enzymatic methods.
Asunto(s)
Etano/química , Compuestos Organometálicos/química , Porfirinas/química , Urea/análisis , Conformación Molecular , Compuestos Organometálicos/síntesis químicaRESUMEN
Small molecule modulators of the Endoplasmic Reticulum glycoprotein folding quality control (ERQC) machinery have broad-spectrum antiviral activity against a number of enveloped viruses and have the potential to rescue secretion of misfolded but active glycoproteins in rare diseases. In vivo assays of candidate inhibitors in mammals are expensive and cannot be afforded at the preliminary stages of drug development programs. The strong conservation of the ERQC machinery across eukaryotes makes transgenic plants an attractive system for low-cost, easy and fast proof-of-concept screening of candidate ERQC inhibitors. The Arabidopsis thaliana immune response is mediated by glycoproteins, the folding of which is controlled by ERQC. We have used the plant response to bacterial peptides as a means of assaying an ERQC inhibitor in vivo. We show that the treatment of the plant with the iminosugar NB-DNJ, which is a known ER α-glucosidase inhibitor in mammals, influences the immune response of the plant to the bacterial peptide elf18 but not to the flagellin-derived flg22 peptide. In the NB-DNJ-treated plant, the responses to elf18 and flg22 treatments closely follow the ones observed for the ER α-glucosidase II impaired plant, At psl5-1. We propose Arabidopsis thaliana as a promising platform for the development of low-cost proof-of-concept in vivo ERQC modulation.
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Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Degradación Asociada con el Retículo Endoplásmico/efectos de los fármacos , Glicoproteínas/metabolismo , Inhibidores de Glicósido Hidrolasas/farmacología , Arabidopsis/efectos de los fármacos , Arabidopsis/genética , Inhibidores de Glicósido Hidrolasas/química , Proteínas Recombinantes/metabolismo , alfa-Glucosidasas/metabolismoRESUMEN
Currently little is known as to how nutritionally derived compounds may affect dendritic cell (DC) maturation and potentially prevent inappropriate inflammatory responses that are characteristic of chronic inflammatory syndromes. Previous observations have demonstrated that two polyphenols quercetin and piperine delivered through reconstituted oil bodies (ROBs-QP) can influence DC maturation in response to LPS leading to a modulated inflammatory response. In the present study, we examined the molecular effects of ROBs-QP exposure on DC differentiation in mice and identified a unique molecular signature in response to LPS administration that potentially modulates DC maturation and activity in inflammatory conditions. Following LPS administration, ROBs-QP-exposed DCs expressed an altered molecular profile as compared with control DCs, including cytokine and chemokine production, chemokine receptor repertoire, and antigen presentation ability. In vivo ROBs-QP administration suppresses antigen-specific T-cell division in the draining lymph nodes resulting from a reduced ability to create stable immunological synapse. Our data demonstrate that polyphenols exposure can drive DCs toward a new anti-inflammatory molecular profile capable of dampening the inflammatory response, highlighting their potential as complementary nutritional approaches in the treatment of chronic inflammatory syndromes.
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Alcaloides/farmacología , Benzodioxoles/farmacología , Proliferación Celular/efectos de los fármacos , Células Dendríticas/efectos de los fármacos , Piperidinas/farmacología , Polifenoles/farmacología , Alcamidas Poliinsaturadas/farmacología , Quercetina/farmacología , Linfocitos T/efectos de los fármacos , Animales , Presentación de Antígeno/efectos de los fármacos , Diferenciación Celular/efectos de los fármacos , Citocinas/genética , Citocinas/inmunología , Células Dendríticas/inmunología , Células Dendríticas/patología , Expresión Génica , Inflamación/inducido químicamente , Inflamación/genética , Inflamación/inmunología , Inflamación/patología , Lipopolisacáridos , Activación de Linfocitos/efectos de los fármacos , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Cultivo Primario de Células , Receptores de Quimiocina/genética , Receptores de Quimiocina/inmunología , Linfocitos T/inmunología , Linfocitos T/patologíaRESUMEN
Plants frequently live in environments characterized by the presence of simultaneous and different stresses. The intricate and finely tuned molecular mechanisms activated by plants in response to abiotic and biotic environmental factors are not well understood, and less is known about the integrative signals and convergence points activated by plants in response to multiple (a)biotic stresses. Phytohormones play a key role in plant development and response to (a)biotic stresses. Among these, one of the most important signaling molecules is an oxylipin, the plant hormone jasmonic acid. Oxylipins are derived from oxygenation of polyunsaturated fatty acids. Jasmonic acid and its volatile derivative methyl jasmonate have been considered for a long time to be the bioactive forms due to their physiological effects and abundance in the plant. However, more recent studies showed unambiguously that they are only precursors of the active forms represented by some amino acid conjugates. Upon developmental or environmental stimuli, jasmonates are synthesized and accumulate transiently. Upon perception, jasmonate signal transduction process is finely tuned by a complex mechanism comprising specific repressor proteins which in turn control a number of transcription factors regulating the expression of jasmonate responsive genes. We discuss the latest discoveries about the role of jasmonates in plants resistance mechanism against biotic and abiotic stresses. Finally, the deep interplay of different phytohormones in stresses signaling will be also discussed.
Asunto(s)
Ciclopentanos/metabolismo , Oxilipinas/metabolismo , Reguladores del Crecimiento de las Plantas/metabolismo , Proteínas de Plantas/metabolismo , Factores de Transcripción/metabolismo , Regulación de la Expresión Génica de las Plantas , Proteínas de Plantas/genética , Factores de Transcripción/genéticaRESUMEN
We report about the response of Arabidopsis thaliana to chronic and temporary Cd2+ stress, and the Cd2+ induced activation of ER stress and unfolded protein response (UPR). Cd2+-induced UPR proceeds mainly through the bZIP60 arm, which in turn activates relevant ER stress marker genes such as BiP3, CNX, PDI5 and ERdj3B in a concentration- (chronic stress) or time- (temporary stress) dependent manner. A more severe Cd-stress triggers programmed cell death (PCD) through the activation of the NAC089 transcription factor. Toxic effects of Cd2+ exposure are reduced in the Atbzip28/bzip60 double mutant in terms of primary root length and fresh shoot weight, likely due to reduced UPR and PCD activation. We also hypothesised that the enhanced Cd2+ tolerance of the Atbzip28/bzip60 double mutant is due to an increase in brassinosteroids signaling, since the amount of the brassinosteroid insensitive1 receptor (BRI1) protein decreases under Cd2+ stress only in Wt plants. These data highlight the complexity of the UPR pathway, since the ER stress response is strictly related to the type of the treatment applied and the multifaceted connections of ER signaling. The reduced sensing of Cd2+ stress in plants with UPR defects can be used as a novel strategy for phytoremediation.
Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Cadmio/toxicidad , Cadmio/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Respuesta de Proteína Desplegada/genética , Estrés del Retículo Endoplásmico/genética , Arabidopsis/metabolismo , Proteínas Portadoras/metabolismo , Proteínas del Choque Térmico HSP40/metabolismoRESUMEN
In the past decades, many studies have widely examined the effects of dietary polyphenols on human health. Polyphenols are well known for their antioxidant properties and for their chelating abilities, by which they can be potentially employed in cases of pathological conditions, such as iron overload. In this review, we have highlighted the chelating abilities of polyphenols, which are due to their structural specific sites, and the differences for each class of polyphenols. We have also explored how the dietary polyphenols and their iron-binding abilities can be important in inflammatory/immunomodulatory responses, with a special focus on the involvement of macrophages and dendritic cells, and how they might contribute to reshape the gut microbiota into a healthy profile. This review also provides evidence that the axes "polyphenol-iron metabolism-inflammatory responses" and "polyphenol-iron availability-gut microbiota" have not been very well explored so far, and the need for further investigation to exploit such a potential to prevent or counteract pathological conditions.
RESUMEN
Endoplasmic reticulum (ER) retention of mis-folded glycoproteins is mediated by the ERlocalised eukaryotic glycoprotein secretion checkpoint, UDP-glucose glycoprotein glucosyl-transferase (UGGT). The enzyme recognises a mis-folded glycoprotein and flags it for ER retention by reglucosylating one of its N-linked glycans. In the background of a congenital mutation in a secreted glycoprotein gene, UGGT-mediated ER retention can cause rare disease even if the mutant glycoprotein retains activity ("responsive mutant"). Here, we investigated the subcellular localisation of the human Trop-2 Q118E variant, which causes gelatinous droplike corneal dystrophy (GDLD). Compared with the wild type Trop-2, which is correctly localised at the plasma membrane, the Trop-2-Q118E variant is found to be heavily retained in the ER. Using Trop-2-Q118E, we tested UGGT modulation as a rescue-of-secretion therapeutic strategy for congenital rare disease caused by responsive mutations in genes encoding secreted glycoproteins. We investigated secretion of a EYFP-fusion of Trop-2-Q118E by confocal laser scanning microscopy. As a limiting case of UGGT inhibition, mammalian cells harbouring CRISPR/Cas9-mediated inhibition of the UGGT1 and/or UGGT2 gene expressions were used. The membrane localisation of the Trop-2-Q118E-EYFP mutant was successfully rescued in UGGT1-/- and UGGT1/2-/- cells. UGGT1 also efficiently reglucosylated Trop-2-Q118E-EYFP in cellula. The study supports the hypothesis that UGGT1 modulation constitutes a novel therapeutic strategy for the treatment of Trop-2-Q118E associated GDLD, and it encourages the testing of modulators of ER glycoprotein folding Quality Control (ERQC) as broad-spectrum rescueof-secretion drugs in rare diseases caused by responsive secreted glycoprotein mutants.
RESUMEN
Misfolded glycoprotein recognition and endoplasmic reticulum (ER) retention are mediated by the ER glycoprotein folding quality control (ERQC) checkpoint enzyme, UDP-glucose glycoprotein glucosyltransferase (UGGT). UGGT modulation is a promising strategy for broad-spectrum antivirals, rescue-of-secretion therapy in rare disease caused by responsive mutations in glycoprotein genes, and many cancers, but to date no selective UGGT inhibitors are known. The small molecule 5-[(morpholin-4-yl)methyl]quinolin-8-ol (5M-8OH-Q) binds a CtUGGTGT24 "WY" conserved surface motif conserved across UGGTs but not present in other GT24 family glycosyltransferases. 5M-8OH-Q has a 47 µM binding affinity for CtUGGTGT24in vitro as measured by ligand-enhanced fluorescence. In cellula, 5M-8OH-Q inhibits both human UGGT isoforms at concentrations higher than 750 µM. 5M-8OH-Q binding to CtUGGTGT24 appears to be mutually exclusive to M5-9 glycan binding in an in vitro competition experiment. A medicinal program based on 5M-8OH-Q will yield the next generation of UGGT inhibitors.
RESUMEN
The plant polyphenol trans-resveratrol (3, 5, 4'-trihydroxystilbene) mainly found in grape, peanut and other few plants, displays a wide range of biological effects. Numerous in vitro studies have described various biological effects of resveratrol. In order to provide more information regarding absorption, metabolism, and bioavailability of resveratrol, various research approaches have been performed, including in vitro, ex vivo, and in vivo models. In recent years, the induction of resveratrol synthesis in plants which normally do not accumulate such polyphenol, has been successfully achieved by molecular engineering. In this context, the ectopic production of resveratrol has been reported to have positive effects both on plant resistance to biotic stress and the enhancement of the nutritional value of several widely consumed fruits and vegetables. The metabolic engineering of plants offers the opportunity to change the content of specific phytonutrients in plant - derived foods. This review focuses on the latest findings regarding on resveratrol bioproduction and its effects on the prevention of the major pathological conditions in man.
Asunto(s)
Dieta , Alimentos Funcionales , Ingeniería Metabólica/métodos , Plantas Comestibles/metabolismo , Plantas Modificadas Genéticamente/metabolismo , Estilbenos/metabolismo , Adaptación Fisiológica , Frutas , Humanos , Valor Nutritivo , Plantas Comestibles/genética , Resveratrol , VerdurasRESUMEN
The metabolic engineered Bronze tomato line is characterized by the constitutive over-expression of the VvStSy gene encoding a structural protein responsible for the stilbenoids biosynthesis and the fruit-specific over-expression of AmDel/Rosea1 and AtMYB12 genes encoding transcription factors that activate the polyphenol biosynthetic pathway. This tomato line is known for the increased levels of polyphenols in ripe fruits and for beneficial health promoting antioxidant and anti-inflammatory effects. In this study we analyzed the transcriptional and metabolic profiling in mature green, breaker, orange and ripe fruits compared to the normal tomato counterparts during ripening, to unravel the effect of regulatory and structural transgenes on metabolic fluxes of primary and secondary metabolisms. Our results showed that the shikimate synthase (SK) gene was up-regulated in the Bronze fruit, and the transcriptional activation is consistent with the metabolic changes observed throughout fruit ripening. These results paralleled with a reduced level of simple sugars and malate, highlighting the consumption of primary metabolites to favor secondary metabolites production and accumulation. Finally, carotenoids quantification revealed a change in the lycopene/ß-carotene ratio in the Bronze fruit as a consequence of significant lower level of the first and higher levels of the latter. The high polyphenols and ß-carotene content displayed by the Bronze fruit at the later stages of fruit ripening renders this line an interesting model to study the additive or synergic effects of these phyto-chemicals in the prevention of human pathologies.