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The intestinal microbiota is known to influence postnatal growth. We previously found that a strain of Lactiplantibacillus plantarum (strain LpWJL) buffers the adverse effects of chronic undernutrition on the growth of juvenile germ-free mice. Here, we report that LpWJL sustains the postnatal growth of malnourished conventional animals and supports both insulin-like growth factor-1 (IGF-1) and insulin production and activity. We have identified cell walls isolated from LpWJL, as well as muramyl dipeptide and mifamurtide, as sufficient cues to stimulate animal growth despite undernutrition. Further, we found that NOD2 is necessary in intestinal epithelial cells for LpWJL-mediated IGF-1 production and for postnatal growth promotion in malnourished conventional animals. These findings indicate that, coupled with renutrition, bacteria cell walls or purified NOD2 ligands have the potential to alleviate stunting.
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Microbioma Gastrointestinal , Crescimento , Intestinos , Lactobacillaceae , Desnutrição , Proteína Adaptadora de Sinalização NOD2 , Animais , Camundongos , Parede Celular/química , Células Epiteliais/microbiologia , Células Epiteliais/fisiologia , Microbioma Gastrointestinal/fisiologia , Vida Livre de Germes , Transtornos do Crescimento/fisiopatologia , Transtornos do Crescimento/terapia , Insulina/metabolismo , Fator de Crescimento Insulin-Like I/metabolismo , Mucosa Intestinal/microbiologia , Mucosa Intestinal/fisiologia , Intestinos/microbiologia , Intestinos/fisiologia , Lactobacillaceae/fisiologia , Desnutrição/fisiopatologia , Desnutrição/terapia , Proteína Adaptadora de Sinalização NOD2/metabolismo , Crescimento/efeitos dos fármacos , Crescimento/fisiologia , Acetilmuramil-Alanil-Isoglutamina/farmacologia , Acetilmuramil-Alanil-Isoglutamina/uso terapêuticoRESUMO
Background: Aframomum sp. is a genus of plants in the Zingiberaceae family. It includes several species, some of which are used in cosmetics for their various properties, making them useful in skincare products, particularly for anti-aging, moisturizing, and brightening the skin. However, to date, there is no experimental evidence on its natural extracts obtained or modified using microorganisms (bio-fermentation) as an anti-aging agent. Objective: The present study aimed to evaluate the antiaging effect of a Bio-fermented Aframomum angustifolium (BAA) extract on 3D bioprinted skin equivalent. Methods: The consortium of microorganisms contained Komagataeibacter, Gluconobacter, Acetobacter, Saccharomyces, Torulaspora, Brettanomyces, Hanseniaspora, Leuconostoc, Lactobacillus, Schizosaccharomyces. It was developed on a media containing water, sugar, and infused black tea leaves. The seeds of Aframomum angustifolium previously grounded were mixed with the culture medium, and the ferments in growth; this fermentation step lasted 10 days. Then, the medium was collected and filtered (0.22 µm) to obtain the BAA extract. To enhance our comprehension of the impact of BAA extract on skin aging, we developed skin equivalents using bio-printing methods with the presence or absence of keratinocyte stem cells (KSC). These skin equivalents were derived from keratinocytes obtained from both a middle-aged donor, with and without KSC. Moreover, we examined the effects of treating the KSC-depleted skin equivalents with Bio-fermented Aframomum angustifolium (BAA) extract for 5 days. Skin equivalents containing KSC-depleted keratinocytes exhibited histological characteristics typical of aged skin and were compared to skin equivalents derived from young donors. Results: The BAA extract contained specific organic acids such as lactic, gluconic, succinic acid and polyphenols. KSC-depleted skin equivalents that were treated with BAA extract exhibited higher specular reflection, indicating better hydration of the stratum corneum, higher mitotic activity in the epidermis basal layer, improved dermal-epidermal connectivity, and increased rigidity of the dermal-epidermal junction compared to non-treated KSC-depleted equivalents. BAA extract treatments also resulted in changes at the dermis level, with an increase in total collagen and a decrease in global laxity, suggesting that this extract could help maintain youthful-looking skin. Conclusion: In summary, our findings indicated that BAA extract treatments have pleiotropic beneficial effects on skin equivalents and that the bio-fermentation provides new biological activities to this plant.
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Reconstructed human epidermis equivalents (RHE) have been developed as a clinical skin substitute and as the replacement for animal testing in both research and industry. KiPS, or keratinocytes derived from induced pluripotent stem cells (iPSCs) are frequently used to generate RHE. In this study, we focus on the mitochondrial performance of the KiPS derived from iPSCs obtained from two donors. We found that the KiPS derived from the older donor have more defective mitochondria. Treatment of these KiPS with a plant extract enriched in compounds known to protect mitochondria improved mitochondrial respiration and rendered them fully competent to derive high-quality RHE. Overall, our results suggest that improving mitochondrial function in KiPS is one of the key aspects to obtain a functional RHE and that our plant extracts can improve in this process.
Assuntos
Queratinócitos , Extratos Vegetais , Animais , Células Epidérmicas , Epiderme/metabolismo , Humanos , Queratinócitos/metabolismo , Mitocôndrias , Extratos Vegetais/metabolismo , Extratos Vegetais/farmacologiaRESUMO
Mus musculus is the classic mammalian model for biomedical research. Despite global efforts to standardize breeding and experimental procedures, the undefined composition and interindividual diversity of the microbiota of laboratory mice remains a limitation. In an attempt to standardize the gut microbiome in preclinical mouse studies, here we report the development of a simplified mouse microbiota composed of 15 strains from 7 of the 20 most prevalent bacterial families representative of the fecal microbiota of C57BL/6J Specific (and Opportunistic) Pathogen-Free (SPF/SOPF) animals and the derivation of a standardized gnotobiotic mouse model called GM15. GM15 recapitulates extensively the functionalities found in the C57BL/6J SOPF microbiota metagenome, and GM15 animals are phenotypically similar to SOPF or SPF animals in two different facilities. They are also less sensitive to the deleterious effects of post-weaning malnutrition. In this work, we show that the GM15 model provides increased reproducibility and robustness of preclinical studies by limiting the confounding effect of fluctuation in microbiota composition, and offers opportunities for research focused on how the microbiota shapes host physiology in health and disease.
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Fezes/microbiologia , Microbioma Gastrointestinal/fisiologia , Vida Livre de Germes , Organismos Livres de Patógenos Específicos , Sequenciamento Completo do Genoma/métodos , Animais , Bactérias/classificação , Bactérias/genética , Peso Corporal/genética , Peso Corporal/fisiologia , Feminino , Microbioma Gastrointestinal/genética , Masculino , Metagenômica/métodos , Camundongos Endogâmicos C57BL , Fenótipo , Especificidade da EspécieRESUMO
Selenoproteins, in which the selenium atom is present in the rare amino acid selenocysteine, are vital components of cell homeostasis, antioxidant defense, and cell signaling in mammals. The expression of the selenoproteome, composed of 25 selenoprotein genes, is strongly controlled by the selenium status of the body, which is a corollary of selenium availability in the food diet. Here, we present an alternative strategy for the use of the radioactive 75Se isotope in order to characterize the selenoproteome regulation based on (i) the selective labeling of the cellular selenocompounds with non-radioactive selenium isotopes (76Se, 77Se) and (ii) the detection of the isotopic enrichment of the selenoproteins using size-exclusion chromatography followed by inductively coupled plasma mass spectrometry detection. The reliability of our strategy is further confirmed by western blots with distinct selenoprotein-specific antibodies. Using our strategy, we characterized the hierarchy of the selenoproteome regulation in dose-response and kinetic experiments.
Assuntos
Isótopos/metabolismo , Proteoma/metabolismo , Selênio/metabolismo , Selenocisteína/metabolismo , Selenoproteínas/metabolismo , Antioxidantes/metabolismo , Linhagem Celular , Células HEK293 , Humanos , Reprodutibilidade dos TestesRESUMO
Compelling evidence suggests that heavy metals have potentially harmful effects on the skin. However, knowledge about cellular signaling events and toxicity subsequent to human skin cell exposure to metals is still poorly documented. The aim of this study was to focus on the interaction between four different heavy metals (lead, nickel, cadmium, and mercury) at doses mimicking chronic low-levels of environmental exposure and the effect on skin to get better insight into metal-cell interactions. We provide evidence that the two metals (lead and nickel) can permeate the skin and accumulate at high concentrations in the dermis. The skin barrier was disrupted after metal exposure and this was accompanied by apoptosis, DNA damage and lipid oxidation. Skin antioxidant enzymes such as glutathione peroxidase and methionine sulfoxide reductase are also heavy metal targets. Taken together, our findings provide insight into potential mechanisms of metal-induced oxidative stress production and the cellular consequences of these events.
Assuntos
Cádmio/toxicidade , Chumbo/toxicidade , Mercúrio/toxicidade , Níquel/toxicidade , Pele/efeitos dos fármacos , Adulto , Apoptose/efeitos dos fármacos , Dano ao DNA/efeitos dos fármacos , Feminino , Humanos , Metais Pesados/toxicidade , Imagem Molecular , Estresse Oxidativo/efeitos dos fármacos , Pele/diagnóstico por imagem , Pele/metabolismoRESUMO
Selenium is an essential trace element which is incorporated in the form of a rare amino acid, the selenocysteine, into an important group of proteins, the selenoproteins. Among the twenty-five selenoprotein genes identified to date, several have important cellular functions in antioxidant defense, cell signaling and redox homeostasis. Many selenoproteins are regulated by the availability of selenium which mostly occurs in the form of water-soluble molecules, either organic (selenomethionine, selenocysteine, and selenoproteins) or inorganic (selenate or selenite). Recently, a mixture of selenitriglycerides, obtained by the reaction of selenite with sunflower oil at high temperature, referred to as Selol, was proposed as a novel non-toxic, highly bioavailable and active antioxidant and antineoplastic agent. Free selenite is not present in the final product since the two phases (water soluble and oil) are separated and the residual water-soluble selenite discarded. Here we compare the assimilation of selenium as Selol, selenite and selenate by various cancerous (LNCaP) or immortalized (HEK293 and PNT1A) cell lines. An approach combining analytical chemistry, molecular biology and biochemistry demonstrated that selenium from Selol was efficiently incorporated in selenoproteins in human cell lines, and thus produced the first ever evidence of the bioavailability of selenium from selenized lipids.
Assuntos
Óleos de Plantas/metabolismo , Ácido Selênico/metabolismo , Ácido Selenioso/metabolismo , Compostos de Selênio/metabolismo , Selenoproteínas/biossíntese , Triglicerídeos/metabolismo , Linhagem Celular Tumoral , Células HEK293 , HumanosRESUMO
Numerous studies suggest that amphibians are highly sensitive to endocrine disruptors (ED) but their precise role in population decline remains unknown. This study shows that frogs exposed to a mixture of ED throughout their life cycle, at environmentally relevant concentrations, developed an unexpected metabolic syndrome. Female Silurana (Xenopus) tropicalis exposed to a mixture of benzo[a]pyrene and triclosan (50â¯ng·L-1 each) from the tadpole stage developed liver steatosis and transcriptomic signature associated with glucose intolerance syndrome, and pancreatic insulin hyper secretion typical of pre-diabetes. These metabolic disorders were associated with delayed metamorphosis and developmental mortality in their progeny, both of which have been linked to reduced adult recruitment and reproductive success. Indeed, F1 females were smaller and lighter and presented reduced reproductive capacities, demonstrating a reduced fitness of ED-exposed Xenopus. Our results confirm that amphibians are highly sensitive to ED even at concentrations considered to be safe for other animals. This study demonstrates that ED might be considered as direct contributing factors to amphibian population decline, due to their disruption of energetic metabolism.
Assuntos
Benzo(a)pireno/toxicidade , Disruptores Endócrinos/toxicidade , Doenças Metabólicas/veterinária , Metamorfose Biológica/efeitos dos fármacos , Triclosan/toxicidade , Xenopus/metabolismo , Animais , Relação Dose-Resposta a Droga , Feminino , Fígado/efeitos dos fármacos , Fígado/fisiologia , Fígado/fisiopatologia , Doenças Metabólicas/induzido quimicamente , Doenças Metabólicas/metabolismo , Síndrome Metabólica/induzido quimicamente , Síndrome Metabólica/metabolismo , Síndrome Metabólica/veterinária , Reprodução/efeitos dos fármacos , TranscriptomaRESUMO
Cold Atmospheric Plasma (CAP) is a novel promising tool developed in several biomedical applications such as cutaneous wound healing or skin cancer. Nevertheless, in vitro studies are lacking regarding to CAP effects on cellular actors involved in healthy skin healing and regarding to the mechanism of action. In this study, we investigated the effect of a 3 minutes exposure to CAP-Helium on human dermal fibroblasts and Adipose-derived Stromal Cells (ASC) obtained from the same tissue sample. We observed that CAP treatment did not induce cell death but lead to proliferation arrest with an increase in p53/p21 and DNA damages. Interestingly we showed that CAP treated dermal fibroblasts and ASC developed a senescence phenotype with p16 expression, characteristic morphological changes, Senescence-Associated ß-galactosidase expression and the secretion of pro-inflammatory cytokines defined as the Senescence-Associated Secretory Phenotype (SASP). Moreover this senescence phenotype is associated with a glycolytic switch and an increase in mitochondria content. Despite this senescence phenotype, cells kept in vitro functional properties like differentiation potential and immunomodulatory effects. To conclude, we demonstrated that two main skin cellular actors are resistant to cell death but develop a senescence phenotype while maintaining some functional characteristics after 3 minutes of CAP-Helium treatment in vitro.
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Ciclo Celular/efeitos dos fármacos , Senescência Celular/efeitos dos fármacos , Fibroblastos/efeitos dos fármacos , Células-Tronco Mesenquimais/efeitos dos fármacos , Gases em Plasma/farmacologia , Tecido Adiposo/citologia , Tecido Adiposo/metabolismo , Ciclo Celular/genética , Senescência Celular/genética , Inibidor p16 de Quinase Dependente de Ciclina/genética , Inibidor p16 de Quinase Dependente de Ciclina/metabolismo , Inibidor de Quinase Dependente de Ciclina p21/genética , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Fibroblastos/citologia , Fibroblastos/metabolismo , Regulação da Expressão Gênica , Hélio/química , Humanos , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/metabolismo , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Cultura Primária de Células , Transdução de Sinais , Pele/citologia , Pele/metabolismo , Fatores de Tempo , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismoRESUMO
Glycine is the proteinogenic amino-acid of lowest molecular weight, harboring a hydrogen atom as a side-chain. In addition to being a building-block for proteins, glycine is also required for multiple metabolic pathways, such as glutathione synthesis and regulation of one-carbon metabolism. Although generally viewed as a non-essential amino-acid, because it can be endogenously synthesized to a certain extent, glycine has also been suggested as a conditionally essential amino acid. In metabolic disorders associated with obesity, type 2 diabetes (T2DM), and non-alcoholic fatty liver disease (NAFLDs), lower circulating glycine levels have been consistently observed, and clinical studies suggest the existence of beneficial effects induced by glycine supplementation. The present review aims at synthesizing the recent advances in glycine metabolism, pinpointing its main metabolic pathways, identifying the causes leading to glycine deficiency-especially in obesity and associated metabolic disorders-and evaluating the potential benefits of increasing glycine availability to curb the progression of obesity and obesity-related metabolic disturbances. This study focuses on the importance of diet, gut microbiota, and liver metabolism in determining glycine availability in obesity and associated metabolic disorders.
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Diabetes Mellitus Tipo 2/sangue , Glicina/farmacocinética , Doenças Metabólicas/sangue , Hepatopatia Gordurosa não Alcoólica/sangue , Obesidade/sangue , Disponibilidade Biológica , Diabetes Mellitus Tipo 2/etiologia , Dieta/efeitos adversos , Microbioma Gastrointestinal , Humanos , Fígado/metabolismo , Doenças Metabólicas/etiologia , Hepatopatia Gordurosa não Alcoólica/etiologia , Obesidade/complicaçõesRESUMO
Many epithelial cancers show cell cycle dysfunction tightly correlated with the overexpression of the serine/threonine kinase Aurora A (AURKA). Its role in mitotic progression has been extensively characterised, and evidence for new AURKA functions emerges. Here, we reveal that AURKA is located and imported in mitochondria in several human cancer cell lines. Mitochondrial AURKA impacts on two organelle functions: mitochondrial dynamics and energy production. When AURKA is expressed at endogenous levels during interphase, it induces mitochondrial fragmentation independently from RALA. Conversely, AURKA enhances mitochondrial fusion and ATP production when it is over-expressed. We demonstrate that AURKA directly regulates mitochondrial functions and that AURKA over-expression promotes metabolic reprogramming by increasing mitochondrial interconnectivity. Our work paves the way to anti-cancer therapeutics based on the simultaneous targeting of mitochondrial functions and AURKA inhibition.
Assuntos
Aurora Quinase A/metabolismo , Metabolismo Energético , Mitocôndrias/metabolismo , Trifosfato de Adenosina/biossíntese , Animais , Aurora Quinase A/química , Biocatálise , Linhagem Celular Tumoral , Respiração Celular , Citosol/metabolismo , Drosophila melanogaster/metabolismo , Complexo IV da Cadeia de Transporte de Elétrons/metabolismo , Células HEK293 , Humanos , Mitocôndrias/ultraestrutura , Dinâmica Mitocondrial , Modelos Biológicos , Peptídeos/metabolismo , Transporte Proteico , Proteólise , Regulação para CimaRESUMO
Despite numerous studies suggesting that amphibians are highly sensitive to endocrine disruptors (EDs), both their role in the decline of populations and the underlying mechanisms remain unclear. This study showed that frogs exposed throughout their life cycle to ED concentrations low enough to be considered safe for drinking water, developed a prediabetes phenotype and, more commonly, a metabolic syndrome. Female Xenopus tropicalis exposed from tadpole stage to benzo(a)pyrene or triclosan at concentrations of 50 ngâ L-1 displayed glucose intolerance syndrome, liver steatosis, liver mitochondrial dysfunction, liver transcriptomic signature, and pancreatic insulin hypersecretion, all typical of a prediabetes state. This metabolic syndrome led to progeny whose metamorphosis was delayed and occurred while the individuals were both smaller and lighter, all factors that have been linked to reduced adult recruitment and likelihood of reproduction. We found that F1 animals did indeed have reduced reproductive success, demonstrating a lower fitness in ED-exposed Xenopus Moreover, after 1 year of depuration, Xenopus that had been exposed to benzo(a)pyrene still displayed hepatic disorders and a marked insulin secretory defect resulting in glucose intolerance. Our results demonstrate that amphibians are highly sensitive to EDs at concentrations well below the thresholds reported to induce stress in other vertebrates. This study introduces EDs as a possible key contributing factor to amphibian population decline through metabolism disruption. Overall, our results show that EDs cause metabolic disorders, which is in agreement with epidemiological studies suggesting that environmental EDs might be one of the principal causes of metabolic disease in humans.
Assuntos
Benzo(a)pireno/toxicidade , Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Extinção Biológica , Intolerância à Glucose , Triclosan/toxicidade , Xenopus/metabolismo , Animais , Feminino , Intolerância à Glucose/induzido quimicamente , Intolerância à Glucose/metabolismo , Larva/metabolismo , Metamorfose Biológica/efeitos dos fármacosRESUMO
BACKGROUND: Selenoproteins (25 genes in human) co-translationally incorporate selenocysteine using a UGA codon, normally used as a stop signal. The human selenoproteome is primarily regulated by selenium bioavailability with a tissue-specific hierarchy. METHODS: We investigated the hierarchy of selenoprotein expression in response to selenium concentration variation in four cell lines originating from kidney (HEK293, immortalized), prostate (LNCaP, cancer), skin (HaCaT, immortalized) and liver (HepG2, cancer), using complementary analytical methods. We performed (i) enzymatic activity, (ii) RT-qPCR, (iii) immuno-detection, (iv) selenium-specific mass spectrometric detection after non-radioactive 76Se labeling of selenoproteins, and (v) luciferase-based reporter constructs in various cell extracts. RESULTS: We characterized cell-line specific alterations of the selenoproteome in response to selenium variation that, in most of the cases, resulted from a translational control of gene expression. We established that UGA-selenocysteine recoding efficiency, which depends on the nature of the SECIS element, dictates the response to selenium variation. CONCLUSIONS: We characterized that selenoprotein hierarchy is cell-line specific with conserved features. This analysis should be done prior to any experiments in a novel cell line. GENERAL SIGNIFICANCE: We reported a strategy based on complementary methods to evaluate selenoproteome regulation in human cells in culture.
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A method to determine total gold (Au) and/or silver (Ag) elemental concentrations from gold nanoparticles, Au-Ag nanoshells (NS) and silica coated Au-Ag nanoshells was developed, evaluated and validated. Samples were mineralized in a mixture of concentrated aqua regia and hydrofluoric acid at 65⯰C for 4â¯h. Mineralized solutions were diluted and standard solutions were prepared in aqua regia 5%. ICP-MS analysis was performed with or without the use of a reaction cell (CRC). For the determination of elemental concentrations of nanopowders and test suspensions, the average recovery was 99⯱â¯2% and 101⯱â¯2% for gold and silver respectively. The repeatability was evaluated by the Relative Standard Deviation (RSD). The overall analytical RSD was ≤4% (nâ¯=â¯3) and the RSD associated to ICP-MS analysis was ≤2% (nâ¯=â¯10). The limits of detection were 0.005 and 0.002⯵g(element)â¯L-1 (analyzed solution), and the limits of quantitation 0.017 and 0.005⯵g(element)â¯L-1 (analyzed solution), for 197Au and 109Ag respectively. The Ag/Au mass ratios of the NS in the different samples considered were all equal to (0.93⯱â¯0.04). From this information, the average thickness of gold and silver layers in the nanoshells was deduced, being 7.5⯱â¯0.5 and 23⯱â¯3â¯nm respectively. Finally, the developed method was successfully applied to in vitro studies to evaluate NS cellular uptake in HaCaT keratinocyte cells confirming the method robustness toward biological medium. Experiments in cell culture medium gave coherent concentrations, 70-100% of uncoated or silica-coated NS being recovered, distributed between the culture medium and the cells (internalized). The analytical repeatability (over the whole procedure, or that of the ICP-MS analysis only) remains in the same order of magnitude as in test suspensions. Minimum concentrations less than or equal to 1⯵g(element)â¯g-1(suspension) were determined with the same accuracy.
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Ouro/análise , Espectrometria de Massas/métodos , Nanoconchas/análise , Prata/análise , Calibragem , Linhagem Celular , Ouro/farmacologia , Humanos , Queratinócitos/efeitos dos fármacos , Nanopartículas Metálicas/química , Nanoconchas/química , Pós , Reprodutibilidade dos Testes , Dióxido de Silício/química , Prata/farmacologiaRESUMO
Glutathione peroxidase 1 (Gpx1), one of the most responsive selenoproteins to the variation of selenium concentration, is often used to evaluate "selenium status" at a cellular or organismal level. The four major types of analytical methodologies to quantify Gpx1 were revisited. They include (i) an enzymatic assay, (ii, iii) polyacrylamide gel electrophoresis (PAGE) with (ii) western blot detection of protein or (iii) inductively coupled plasma mass spectrometry (ICP MS) detection of selenium, and (iv) size-exclusion chromatography with ICP MS detection. Each of the four methods was optimized for the quantification of Gpx1 with maximum sensitivity. The methods based on the enzymatic and immunodetection offer a much higher sensitivity but their accuracy is compromised by the limited selectivity and limited dynamic range. The advantages, drawbacks and sources of error of each technique are critically discussed and the need for the cross-validation of the results using the different techniques to assure the quality assurance of quantitative analysis is emphasized.
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Glutationa Peroxidase/análise , Selênio/química , Animais , Bovinos , Ativação Enzimática , Eritrócitos/química , Eritrócitos/metabolismo , Glutationa Peroxidase/metabolismo , Imunoensaio , Espectrometria de Massas , Glutationa Peroxidase GPX1RESUMO
Selenoproteins are essential components of antioxidant defense, redox homeostasis, and cell signaling in mammals, where selenium is found in the form of a rare amino acid, selenocysteine. Selenium, which is often limited both in food intake and cell culture media, is a strong regulator of selenoprotein expression and selenoenzyme activity. Aging is a slow, complex, and multifactorial process, resulting in a gradual and irreversible decline of various functions of the body. Several cellular aspects of organismal aging are recapitulated in the replicative senescence of cultured human diploid fibroblasts, such as embryonic lung fibroblast WI-38 cells. We previously reported that the long-term growth of young WI-38 cells with high (supplemented), moderate (control), or low (depleted) concentrations of selenium in the culture medium impacts their replicative lifespan, due to rapid changes in replicative senescence-associated markers and signaling pathways. In order to gain insight into the molecular link between selenium levels and replicative senescence, in the present work, we have applied a quantitative proteomic approach based on 2-Dimensional Differential in-Gel Electrophoresis (2D-DIGE) to the study of young and presenescent cells grown in selenium-supplemented, control, or depleted media. Applying a restrictive cut-off (spot intensity ±50% and a p value < 0.05) to the 2D-DIGE analyses revealed 81 differentially expressed protein spots, from which 123 proteins of interest were identified by mass spectrometry. We compared the changes in protein abundance for three different conditions: (i) spots varying between young and presenescent cells, (ii) spots varying in response to selenium concentration in young cells, and (iii) spots varying in response to selenium concentration in presenescent cells. Interestingly, a 72% overlap between the impact of senescence and selenium was observed in our proteomic results, demonstrating a strong interplay between selenium, selenoproteins, and replicative senescence.
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A paradox is a seemingly absurd or impossible concept, proposition, or theory that is often difficult to understand or explain, sometimes apparently self-contradictory, and yet ultimately correct or true. How is it possible, for example, that oxygen "a toxic environmental poison" could be also indispensable for life (Beckman and Ames Physiol Rev 78(2):547-81, 1998; Stadtman and Berlett Chem Res Toxicol 10(5):485-94, 1997)?: the so-called Oxygen Paradox (Davies and Ursini 1995; Davies Biochem Soc Symp 61:1-31, 1995). How can French people apparently disregard the rule that high dietary intakes of cholesterol and saturated fats (e.g., cheese and paté) will result in an early death from cardiovascular diseases (Renaud and de Lorgeril Lancet 339(8808):1523-6, 1992; Catalgol et al. Front Pharmacol 3:141, 2012; Eisenberg et al. Nat Med 22(12):1428-1438, 2016)?: the so-called, French Paradox. Doubtless, the truth is not a duality and epistemological bias probably generates apparently self-contradictory conclusions. Perhaps nowhere in biology are there so many apparently contradictory views, and even experimental results, affecting human physiology and pathology as in the fields of free radicals and oxidative stress, antioxidants, foods and drinks, and dietary recommendations; this is particularly true when issues such as disease-susceptibility or avoidance, "healthspan," "lifespan," and ageing are involved. Consider, for example, the apparently paradoxical observation that treatment with low doses of a substance that is toxic at high concentrations may actually induce transient adaptations that protect against a subsequent exposure to the same (or similar) toxin. This particular paradox is now mechanistically explained as "Adaptive Homeostasis" (Davies Mol Asp Med 49:1-7, 2016; Pomatto et al. 2017a; Lomeli et al. Clin Sci (Lond) 131(21):2573-2599, 2017; Pomatto and Davies 2017); the non-damaging process by which an apparent toxicant can activate biological signal transduction pathways to increase expression of protective genes, by mechanisms that are completely different from those by which the same agent induces toxicity at high concentrations. In this review, we explore the influences and effects of paradoxes such as the Oxygen Paradox and the French Paradox on the etiology, progression, and outcomes of many of the major human age-related diseases, as well as the basic biological phenomenon of ageing itself.
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Adaptação Fisiológica , Envelhecimento/genética , Dieta Rica em Proteínas/estatística & dados numéricos , Hipercolesterolemia/epidemiologia , Estresse Oxidativo/fisiologia , Oxigênio/metabolismo , Idoso , Idoso de 80 Anos ou mais , Envelhecimento/fisiologia , Feminino , França , Radicais Livres/metabolismo , Avaliação Geriátrica , Humanos , Masculino , Pessoa de Meia-Idade , Medição de RiscoRESUMO
The microbial environment influences animal physiology. However, the underlying molecular mechanisms of such functional interactions are largely undefined. Previously, we showed that during chronic undernutrition, strains of Lactobacillus plantarum, a major commensal partner of Drosophila, promote host juvenile growth and maturation partly through enhanced expression of intestinal peptidases. By screening a transposon insertion library of Lactobacillus plantarum in gnotobiotic Drosophila larvae, we identify a bacterial cell-wall-modifying machinery encoded by the pbpX2-dlt operon that is critical to enhance host digestive capabilities and promote animal growth and maturation. Deletion of this operon leads to bacterial cell wall alteration with a complete loss of D-alanylation of teichoic acids. We show that L. plantarum cell walls bearing D-alanylated teichoic acids are directly sensed by Drosophila enterocytes to ensure optimal intestinal peptidase expression and activity, juvenile growth and maturation during chronic undernutrition. We thus conclude that besides peptidoglycan, teichoic acid modifications participate in the host-commensal bacteria molecular dialogue occurring in the intestine.
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Drosophila/crescimento & desenvolvimento , Drosophila/microbiologia , Lactobacillus plantarum/metabolismo , Desnutrição/metabolismo , Simbiose , Ácidos Teicoicos/metabolismo , Alanina/metabolismo , Animais , Fenômenos Biológicos , Parede Celular/metabolismo , Drosophila/genética , Genes Bacterianos/genética , Lactobacillus plantarum/genética , Larva/genética , Larva/crescimento & desenvolvimento , Larva/microbiologia , Microbiota/fisiologia , Mutagênese , Peptidoglicano/metabolismoRESUMO
Compelling evidence suggests that volatile organic compounds (VOCs) have potentially harmful effects to the skin. However, knowledge about cellular signaling events and toxicity subsequent to VOC exposure to human skin cells is still poorly documented. The aim of this study was to focus on the interaction between 5 different VOCs (hexane, toluene, acetaldehyde, formaldehyde and acetone) at doses mimicking chronic low level environmental exposure and the effect on human keratinocytes to get better insight into VOC-cell interactions. We provide evidence that the proteasome, a major intracellular proteolytic system which is involved in a broad array of processes such as cell cycle, apoptosis, transcription, DNA repair, protein quality control and antigen presentation, is a VOC target. Proteasome inactivation after VOC exposure is accompanied by apoptosis, DNA damage and protein oxidation. Lon protease, which degrades oxidized, dysfunctional, and misfolded proteins in the mitochondria is also a VOC target. Using human skin explants we found that VOCs prevent cell proliferation and also inhibit proteasome activity in vivo. Taken together, our findings provide insight into potential mechanisms of VOC-induced proteasome inactivation and the cellular consequences of these events.
Assuntos
Queratinócitos/efeitos dos fármacos , Queratinócitos/metabolismo , Estresse Oxidativo , Processamento de Proteína Pós-Traducional/efeitos dos fármacos , Compostos Orgânicos Voláteis/farmacologia , Apoptose/efeitos dos fármacos , Biomarcadores , Dano ao DNA , Glutationa/metabolismo , Humanos , Imunofenotipagem , Oxirredução , Complexo de Endopeptidases do Proteassoma/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Compostos Orgânicos Voláteis/análiseRESUMO
Compelling evidence suggests that mitochondrial dysfunction leading to reactive oxygen species (ROS) production and protein oxidation could represent a critical event in the pathogenesis of Parkinson's disease (PD). Pioneering studies have shown that the mitochondrial matrix contains the Lon protease, which degrades oxidized, dysfunctional, and misfolded protein. Using the PD animal model of 1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine (MPTP) intoxication in mice, we showed that Lon protease expression increased in the ventral mesencephalon of intoxicated animals, concomitantly with the appearance of oxidized proteins and dopaminergic cell loss. In addition, we report that Lon is inactivated by ROS. Moreover, proteomic experiments provide evidence of carbonylation in α-ketoglutarate dehydrogenase (KGDH), aconitase or subunits of respiratory chain complexes. Lon protease inactivation upon MPTP treatment in mice raises the possibility that Lon protease dysfunction is an early event in the pathogenesis of PD.