RESUMO
Air pollution consists of complex mixtures of chemicals with serious deleterious health effects from acute and chronic exposure. To help understand the mechanisms by which adverse effects occur, the present work examines the responses of cultured human epidermal keratinocytes to specific chemicals commonly found in woodsmoke. Our earlier findings with liquid smoke flavoring (aqueous extract of charred wood) revealed that such extracts stimulated the expression of genes associated with oxidative stress and proinflammatory response, activated the aryl hydrocarbon receptor, thereby inducing cytochrome P4501A1 activity, and induced cross-linked envelope formation, a lethal event ordinarily occurring during terminal differentiation. The present results showed that furfural produced transcriptional responses resembling those of liquid smoke, cyclohexanedione activated the aryl hydrocarbon receptor, and several chemicals induced envelope formation. Of these, syringol permeabilized the cells to the egress of lactate dehydrogenase at a concentration close to that yielding envelope formation, while furfural induced envelope formation without permeabilization detectable in this way. Furfural (but not syringol) stimulated the incorporation of amines into cell proteins in extracts in the absence of transglutaminase activity. Nevertheless, both chemicals substantially increased the amount of cellular protein incorporated into envelopes and greatly altered the envelope protein profile. Moreover, the proportion of keratin in the envelopes was dramatically increased. These findings are consistent with the chemically induced protein cross-linking in the cells. Elucidating mechanisms by which this phenomenon occurs may help understand how smoke chemicals interact with proteins to elicit cellular responses, interpret bioassays of complex pollutant mixtures, and suggest additional sensitive ways to monitor exposures.
Assuntos
Queratinócitos , Madeira , Humanos , Queratinócitos/efeitos dos fármacos , Queratinócitos/metabolismo , Madeira/química , Fumaça/efeitos adversos , Furaldeído/análogos & derivados , Furaldeído/farmacologia , Células Cultivadas , Receptores de Hidrocarboneto Arílico/metabolismoRESUMO
The skin and adnexa can be difficult to interpret because they change dramatically with the hair cycle throughout life. However, a variety of methods are commonly available to collect skin and perform assays that can be useful for figuring out morphological and molecular changes. This overview provides information on basic approaches to evaluate skin and its molecular phenotype, with references for more detail, and interpretation of results on the skin and adnexa in the mouse. These approaches range from mouse genetic nomenclature, setting up a cutaneous phenotyping study, skin grafts, hair follicle reconstitution, wax stripping, electron microscopy, and Köbner reaction to very specific approaches such as lipid and protein analyses on a large scale.
Assuntos
Unhas Malformadas , Animais , Camundongos , Cabelo , Folículo Piloso , Unhas Malformadas/metabolismo , Unhas Malformadas/veterinária , PeleRESUMO
This study explores how EEG connectivity measures in children with ADHD ages 7-10 (n = 140) differ from an age-matched nonclinical database. We differentiated connectivity in networks, Brodmann area pairs, and frequencies. Subjects were in the International Collaborative ADHD Neurofeedback study, which explored neurofeedback for ADHD. Inclusion criteria were mainly rigorously diagnosed ADHD and a theta/beta power ratio (TBR) ≤ 4.5. Using statistical and machine learning algorithms, connectivity values were extracted in coherence, phase, and lag coherence at all Brodmann, subcortical, and cerebellar areas within the main networks in all EEG frequencies and then compared with a normative database. There is a higher rate of dysregulation (more than ± 1.97SD), in some cases as much as 75%, of the Brodmann pairs observed in coherence and phase between BAs 7, 10, and 11 with secondary connections from these areas to BAs 21, 30, 35, 37, 39, and 40 in the ADHD children as compared to the normative database. Left and right Brodmann areas 10 and 11 are highly disconnected to each other. The most dysregulated Brodmann Areas in ADHD are 7, 10, and 11, relevant to ADHD executive-function deficits and provide important considerations when developing interventions for ADHD children.
Assuntos
Transtorno do Deficit de Atenção com Hiperatividade , Neurorretroalimentação , Criança , Humanos , Eletroencefalografia , Córtex Cerebral , Estudos de CoortesRESUMO
Hair shafts from three trichothiodystrophy (TTD) patients with mutations in the ERCC2 (XPD) gene were examined by transmission electron microscopy. TTD is a rare, recessive disorder with mutations in several genes in the DNA repair/transcription pathway, including ERCC2. Unlike previous studies, the hair shafts were examined after relaxation of their structure by partial disulphide bond reduction in the presence of sodium dodecyl sulphate, permitting improved visualization. Compared with hair shafts of normal phenotype, TTD cuticle cells displayed aberrant marginal bands and exocuticle layers. Clusters of cells stained differently (light versus dark) in the cortex of aberrant shafts, and the keratin macrofibrils appeared much shorter in the cytoplasm. Considerable heterogeneity in these properties was evident among samples and even along the length of single hair shafts. The results are consistent with not only a paucity of high sulphur components, such as keratin-associated proteins, but also a profound imbalance in protein content and organization.
Assuntos
Doenças do Cabelo , Síndromes de Tricotiodistrofia , Reparo do DNA , Cabelo/metabolismo , Doenças do Cabelo/genética , Doenças do Cabelo/metabolismo , Humanos , Síndromes de Tricotiodistrofia/genética , Síndromes de Tricotiodistrofia/metabolismo , Raios Ultravioleta , Proteína Grupo D do Xeroderma Pigmentoso/genética , Proteína Grupo D do Xeroderma Pigmentoso/metabolismoRESUMO
To meet the growing demand for chocolate, cocoa (Theobroma cacao) agriculture is expanding and intensifying. Although this threatens tropical forests, cocoa sustainability initiatives largely overlook biodiversity conservation. To inform these initiatives, we analyzed how cocoa agriculture affects bird diversity at farm and landscape scales with a meta-analysis of 23 studies. We extracted 214 Hedges' g* comparisons of bird diversity and 14 comparisons of community similarity between a forest baseline and 4 farming systems that cover an intensification gradient in landscapes with high and low forest cover, and we summarized 119 correlations between cocoa farm features and bird diversity. Bird diversity declined sharply in low shade cocoa. Cocoa with >30% canopy cover from diverse trees retained bird diversity similar to nearby primary or mature secondary forest but held a different community of birds. Diversity of endemic species, frugivores, and insectivores (agriculture avoiders) declined, whereas diversity of habitat generalists, migrants, nectarivores, and granivores (agriculture associates) increased. As forest decreased on the landscape, the difference in bird community composition between forest and cocoa also decreased, indicating agriculture associates replaced agriculture avoiders in forest patches. Our results emphasize the need to conserve forested landscapes (land sparing) and invest in mixed-shade agroforestry (land sharing) because each strategy benefits a diverse and distinct biological community.
Impacto de la Intensificación Agrícola del Cacao sobre la Diversidad y Composición de la Comunidad de Aves Resumen Para responder a la demanda creciente de chocolate, el cultivo de cacao (Theobroma cacao) se ha expandido e intensificado. Aunque esto es una amenaza para los bosques tropicales, las iniciativas de cacao sustentable en gran medida pasan por alto la conservación de la biodiversidad. Para proporcionar información a estas iniciativas, analizamos como la agricultura del cacao afecta a la diversidad de aves a escala de rancho y de paisaje mediante un metaanálisis de 23 estudios. Extrajimos 214 comparaciones de Hedges g* de la diversidad de aves y 14 comparaciones de la similitud de comunidades entre una línea de base de bosque y 4 sistemas de cultivo que cubren un gradiente de intensificación en paisajes con cobertura de bosque alta a baja, y sintetizamos 119 correlaciones entre características de cultivos de cacao y la diversidad de aves. La diversidad de aves declinó claramente en cultivos con poca sombra. Cultivos con >30% de cobertura de diversos árboles retuvieron una diversidad de aves similar a la de bosques primarios o maduros cercanos, pero presentaron una comunidad diferente. La diversidad de especies endémicas, frugívoras e insectívoras (evasoras de agricultura) declinó, mientras que la diversidad de generalistas de hábitat, migrantes, nectarívoras y granívoras (asociadas a agricultura) incrementó. A medida que decreció el bosque en el paisaje, la diferencia en la composición de la comunidad de aves entre bosque y cacao también decreció, lo que indica que las especies asociadas a la agricultura reemplazaron a las evasoras de la agricultura en los fragmentos de bosque. Nuestros resultados enfatizan la necesidad de conservar paisajes boscosos (conservación de tierras) e invertir en agroforestería de sombra mixta (compartición de tierras) porque cada estrategia beneficia a una comunidad biológica diversa y distinta.
Assuntos
Cacau , Chocolate , Agricultura , Animais , Biodiversidade , Aves , Conservação dos Recursos Naturais/métodos , Ecossistema , FlorestasRESUMO
Long non-coding RNAs have been implicated in the regulation of a plethora of biological processes, yet it has been challenging to verify that they are truly not coding for proteins. Terminal differentiation-induced non-coding RNA (TINCR) is a 3.7-kilobase mRNA that is highly abundant in epidermal keratinocytes prior to cornification. Here, we report the presence of an evolutionarily conserved open reading frame in TINCR and the identification of peptides derived from this open reading frame in the proteome of human stratum corneum. Our results demonstrate that TINCR is a protein-coding RNA and suggest that the TINCR-encoded protein is involved in keratinocyte cornification.
Assuntos
Células Epidérmicas/metabolismo , Epiderme/metabolismo , Queratinócitos/citologia , RNA Longo não Codificante/metabolismo , Pele/metabolismo , Evolução Biológica , Diferenciação Celular , Humanos , Espectrometria de Massas , Fases de Leitura Aberta , Peptídeos/química , RNA Longo não Codificante/genética , RNA Mensageiro/metabolismo , Transcrição Gênica , Ubiquitina/metabolismoRESUMO
Epidermal keratinocytes undergo cornification to form the cellular building blocks of hard skin appendages such as nails and the protective layer on the surface of the skin. Cornification requires the cross-linking of structural proteins and the removal of other cellular components to form mechanically rigid and inert corneocytes. Autophagy has been proposed to contribute to this intracellular remodelling process, but its molecular targets in keratinocytes, if any, have remained elusive. Here, we deleted the essential autophagy factor Atg7 in K14-positive epithelia of mice and determined by proteomics the impact of this deletion on the abundance of individual proteins in cornified nails. The genetic suppression of autophagy in keratinocytes resulted in a significant increase in the number of proteins that survived cornification and in alterations of their abundance in the nail proteome. A broad range of enzymes and other non-structural proteins were elevated whereas the amounts of cytoskeletal proteins of the keratin and keratin-associated protein families, cytolinker proteins and desmosomal proteins were either unaltered or decreased in nails of mice lacking epithelial autophagy. Among the various types of non-cytoskeletal proteins, the subunits of the proteasome and of the TRiC/CCT chaperonin were most strongly elevated in mutant nails, indicating a particularly important role of autophagy in removing these large protein complexes during normal cornification. Taken together, the results of this study suggest that autophagy is active during nail keratinocyte cornification and its substrate specificity depends on the accessibility of proteins outside of the cytoskeleton and their presence in large complexes.
Assuntos
Autofagia/fisiologia , Citoplasma/metabolismo , Citoesqueleto/metabolismo , Casco e Garras/fisiologia , Queratinócitos/fisiologia , Organogênese/fisiologia , Proteólise , Animais , Diferenciação Celular/genética , Epiderme/fisiologia , Espaço Intracelular/metabolismo , Queratinas/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos CBA , Camundongos Knockout , Pele/metabolismoRESUMO
Defects in keratinocyte transglutaminase (TGM1), resulting in an improper protein scaffold for deposition of the lipid barrier, comprise a major source of autosomal recessive congenital ichthyosis. For that reason, the composition and formation of the cornified (cross-linked) protein envelope of the epidermis have been of considerable interest. Since the isopeptide cross-linked protein components are not individually isolable once incorporated, purified envelopes were analysed by mass spectrometry after trypsin digestion. Quantitative estimates of the identified components revealed some 170 proteins, each comprising at least 0.001% of the total, of which keratins were major constituents accounting for ≈74% of the total. Some prevalent non-keratin constituents such as keratinocyte proline-rich protein, loricrin and late envelope protein-7 were preferentially incorporated into envelopes. The results suggest a model where, as previously observed in hair shaft and nail plate, a diversity of cellular proteins are incorporated. They also help rationalize the minimal effect on epidermis of ablating genes for specific single envelope structural components. The quantitative profile of constituent proteins provides a foundation for future exploration of envelope perturbations that may occur in pathological conditions.
Assuntos
Epiderme/química , Proteoma , Membrana Celular/química , Proteínas do Citoesqueleto/química , Feminino , Cabelo/química , Humanos , Ictiose Lamelar/patologia , Queratinócitos/citologia , Queratinas/química , Lipídeos/química , Masculino , Proteínas de Membrana , Unhas/química , Prolina/química , Proteínas/química , Proteômica , Pele/química , Transglutaminases/químicaRESUMO
Advances in mass spectrometry-based proteomics now permit analysis of complex cellular structures. Application to epidermis and its appendages (nail plate, hair shaft) has revealed a wealth of information about their protein profiles. The results confirm known site-specific differences in levels of certain keratins and add great depth to our knowledge of site specificity of scores of other proteins, thereby connecting anatomy and pathology. An example is the evident overlap in protein profiles of hair shaft and nail plate, helping rationalize their sharing of certain dystrophic syndromes distinct from epidermis. In addition, interindividual differences in protein level are manifest as would be expected. This approach permits characterization of altered profiles as a result of disease, where the magnitude of perturbation can be quantified and monitored during treatment. Proteomic analysis has also clarified the nature of the isopeptide cross-linked residual insoluble material after vigorous extraction with protein denaturants, nearly intractable to analysis without fragmentation. These structures, including the cross-linked envelope of epidermal corneocytes, are comprised of hundreds of protein constituents, evidence for strengthening the terminal structure complementary to disulphide bonding. Along with other developing technologies, proteomic analysis is anticipated to find use in disease risk stratification, detection, diagnosis and prognosis after the discovery phase and clinical validation.
Assuntos
Dermatologia/métodos , Células Epidérmicas/metabolismo , Epiderme/metabolismo , Proteômica/métodos , Animais , Cabelo/metabolismo , Humanos , Queratinas/metabolismo , Espectrometria de Massas , Camundongos , Pele/citologia , Pele/metabolismo , Transglutaminases/metabolismoRESUMO
Forensic association of hair shaft evidence with individuals is currently assessed by comparing mitochondrial DNA haplotypes of reference and casework samples, primarily for exclusionary purposes. Present work tests and validates more recent proteomic approaches to extract quantitative transcriptional and genetic information from hair samples of monozygotic twin pairs, which would be predicted to partition away from unrelated individuals if the datasets contain identifying information. Protein expression profiles and polymorphic, genetically variant hair peptides were generated from ten pairs of monozygotic twins. Profiling using the protein tryptic digests revealed that samples from identical twins had typically an order of magnitude fewer protein expression differences than unrelated individuals. The data did not indicate that the degree of difference within twin pairs increased with age. In parallel, data from the digests were used to detect genetically variant peptides that result from common nonsynonymous single nucleotide polymorphisms in genes expressed in the hair follicle. Compilation of the variants permitted sorting of the samples by hierarchical clustering, permitting accurate matching of twin pairs. The results demonstrate that genetic differences are detectable by proteomic methods and provide a framework for developing quantitative statistical estimates of personal identification that increase the value of hair shaft evidence.
Assuntos
Perfilação da Expressão Gênica/métodos , Cabelo/metabolismo , Peptídeos/análise , Polimorfismo de Nucleotídeo Único , Proteoma/análise , Gêmeos Monozigóticos/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Cabelo/química , Humanos , Masculino , Pessoa de Meia-Idade , Peptídeos/genética , Peptídeos/metabolismo , Proteoma/genética , Proteoma/metabolismo , Proteômica , Adulto JovemRESUMO
The crosslinked envelope of the mammalian epidermal corneocyte serves as a scaffold for assembly of the lipid barrier of the epidermis. Thus, deficient envelope crosslinking by keratinocyte transglutaminase (TGM1) is a major cause of the human autosomal recessive congenital ichthyoses characterized by barrier defects. Expectations that loss of some envelope protein components would also confer an ichthyosis phenotype have been difficult to demonstrate. To help rationalize this observation, the protein profile of epidermis from loricrin knockout mice has been compared to that of wild type. Despite the mild phenotype of the knockout, some 40 proteins were incorporated into envelope material to significantly different extents compared to those of wild type. Nearly half were also incorporated to similarly altered extents into the disulfide bonded keratin network of the corneocyte. The results suggest that loss of loricrin alters their incorporation into envelopes as a consequence of protein-protein interactions during cell maturation. Mass spectrometric protein profiling revealed that keratin 1, keratin 10, and loricrin are prominent envelope components and that dozens of other proteins are also components. This finding helps rationalize the potential formation of functional envelopes, despite loss of a single component, due to the availability of many alternative transglutaminase substrates.
Assuntos
Epiderme/química , Proteínas de Membrana/genética , Proteínas/análise , Proteômica/métodos , Animais , Proteínas Filagrinas , Ictiose , Queratina-1 , Queratina-10 , Camundongos , Camundongos Knockout , Domínios e Motivos de Interação entre ProteínasRESUMO
BACKGROUND: There is a need for a simple and efficacious treatment for cutaneous leishmaniasis with an acceptable side-effect profile. METHODS: We conducted a randomized, vehicle-controlled phase 3 trial of topical treatments containing 15% paromomycin, with and without 0.5% gentamicin, for cutaneous leishmaniasis caused by Leishmania major in Tunisia. We randomly assigned 375 patients with one to five ulcerative lesions from cutaneous leishmaniasis to receive a cream containing 15% paromomycin-0.5% gentamicin (called WR 279,396), 15% paromomycin alone, or vehicle control (with the same base as the other two creams but containing neither paromomycin nor gentamicin). Each lesion was treated once daily for 20 days. The primary end point was the cure of the index lesion. Cure was defined as at least 50% reduction in the size of the index lesion by 42 days, complete reepithelialization by 98 days, and absence of relapse by the end of the trial (168 days). Any withdrawal from the trial was considered a treatment failure. RESULTS: The rate of cure of the index lesion was 81% (95% confidence interval [CI], 73 to 87) for paromomycin-gentamicin, 82% (95% CI, 74 to 87) for paromomycin alone, and 58% (95% CI, 50 to 67) for vehicle control (P<0.001 for each treatment group vs. the vehicle-control group). Cure of the index lesion was accompanied by cure of all other lesions except in five patients, one in each of the paromomycin groups and three in the vehicle-control group. Mild-to-moderate application-site reactions were more frequent in the paromomycin groups than in the vehicle-control group. CONCLUSIONS: This trial provides evidence of the efficacy of paromomycin-gentamicin and paromomycin alone for ulcerative L. major disease. (Funded by the Department of the Army; ClinicalTrials.gov number, NCT00606580.).
Assuntos
Gentamicinas/administração & dosagem , Leishmaniose Cutânea/tratamento farmacológico , Paromomicina/administração & dosagem , Administração Tópica , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Quimioterapia Combinada , Feminino , Gentamicinas/efeitos adversos , Humanos , Análise de Intenção de Tratamento , Masculino , Pessoa de Meia-Idade , Pomadas , Paromomicina/efeitos adversos , Adulto JovemRESUMO
Hemileia vastatrix caused a severe epidemic in Central America in 2012-13. The gradual development of that epidemic on nearly a continental scale suggests that dispersal at different scales played a significant role. Shade has been proposed as a way of reducing uredospore dispersal. The effect of shade (two strata: Erythrina poeppigiana below and Chloroleucon eurycyclum above) and full sun on H. vastatrix dispersal was studied with Burkard traps in relation to meteorological records. Annual and daily patterns of dispersal were observed, with peaks of uredospore capture obtained during wet seasons and in the early afternoon. A maximum of 464 uredospores in 1 day (in 14.4 m(3) of air) was recorded in October 2014. Interactions between shade/full sun and meteorological conditions were found. Rainfall, possibly intercepted by tree cover and redistributed by raindrops of higher kinetic energy, was the main driver of uredospore dispersal under shade. Wind gusts reversed this effect, probably by inhibiting water accumulation on leaves. Wind gusts also promoted dispersal under dry conditions in full sun, whereas they had no effect under shaded conditions, probably because the canopy blocked the wind. Our results indicate the importance of managing shade cover differentially in rainy versus dry periods to control the dispersal of airborne H. vastatrix uredospores.
Assuntos
Basidiomycota/fisiologia , Luz , Esporos Fúngicos/fisiologia , Coffea/microbiologia , Chuva , Fatores de Tempo , VentoRESUMO
SbIII and AsIII are known to exhibit similar chemical properties, but the degree of similarity in their effects on biological systems merits further exploration. Present work compares the responses of human epidermal keratinocytes, a known target cell type for arsenite-induced carcinogenicity, to these metalloids after treatment for a week at environmentally relevant concentrations. Previous work with these cells has shown that arsenite and antimonite have parallel effects in suppressing differentiation, altering levels of several critical enzymes and maintaining colony forming ability. More globally, protein profiling now reveals parallels in SbIII and AsIII effects. The more sensitive technique of transcriptional profiling also shows considerable parallels. Thus, gene expression changes were almost entirely in the same directions for the two treatments, although the degree of change was sometimes significantly different. Inspection of the changes revealed that RYR1 and LRIG1 were among the genes strongly suppressed, consistent with reduced calcium-dependent differentiation and maintenance of EGF-dependent proliferative potential. Moreover, levels of miRNAs in the cells were altered in parallel, with nearly 90% of the 198 most highly expressed ones being suppressed. Among these was miR-203, which is known to decrease proliferative potential. Finally, both SbIII and AsIII were seen to attenuate bone morphogenetic protein 6 induction of dual specificity phosphatases 2 and 14, consistent with maintaining epidermal growth factor receptor signaling. These findings raise the question whether SbIII, like AsIII, could act as a human skin carcinogen.
RESUMO
We describe the development of an oncology solid tumor disease-focused care coordination model. Consistent with our strategic plan to provide patient- and family-centered care and to organize care around disease management teams, we developed the role of nurse care coordinator as an integral team member in our care delivery model. Managing a defined high-risk patient population across the care trajectory, these nurses provide stable points of contact and continuity for patients and families as they navigate the complex treatments and systems required to deliver cancer care. We describe role delineation and staffing models; role clarity between the role of the nurse care coordinator and the case manager; core curriculum development; the use of workflow management tools to support the touch points of the patient and members of the care team; and the incorporation of electronic medical records and data streams to inform the care delivery model. We identify measures that we will use to evaluate the success of our program.
Assuntos
Modelos Organizacionais , Neoplasias/enfermagem , Enfermeiros Clínicos/organização & administração , Assistência Centrada no Paciente , California , Humanos , Modelos de EnfermagemRESUMO
The evolution of amniotes has involved major molecular innovations in the epidermis. In particular, distinct structural proteins that undergo covalent cross-linking during cornification of keratinocytes facilitate the formation of mechanically resilient superficial cell layers and help to limit water loss to the environment. Special modes of cornification generate amniote-specific skin appendages such as claws, feathers, and hair. In mammals, many protein substrates of cornification are encoded by a cluster of genes, termed the epidermal differentiation complex (EDC). To provide a basis for hypotheses about the evolution of cornification proteins, we screened for homologs of the EDC in non-mammalian vertebrates. By comparative genomics, de novo gene prediction and gene expression analyses, we show that, in contrast to fish and amphibians, the chicken and the green anole lizard have EDC homologs comprising genes that are specifically expressed in the epidermis and in skin appendages. Our data suggest that an important component of the cornified protein envelope of mammalian keratinocytes, that is, loricrin, has originated in a common ancestor of modern amniotes, perhaps during the acquisition of a fully terrestrial lifestyle. Moreover, we provide evidence that the sauropsid-specific beta-keratins have evolved as a subclass of EDC genes. Based on the comprehensive characterization of the arrangement, exon-intron structures and conserved sequence elements of EDC genes, we propose new scenarios for the evolutionary origin of epidermal barrier proteins via fusion of neighboring S100A and peptidoglycan recognition protein genes, subsequent loss of exons and highly divergent sequence evolution.
Assuntos
Proteínas Aviárias/genética , Evolução Molecular , Proteínas de Répteis/genética , Motivos de Aminoácidos , Animais , Proteínas Aviárias/metabolismo , Galinhas/genética , Epiderme/fisiologia , Perfilação da Expressão Gênica , Queratinócitos/metabolismo , Queratinas/genética , Queratinas/metabolismo , Dados de Sequência Molecular , Especificidade de Órgãos , Répteis/genética , Proteínas de Répteis/metabolismo , Análise de Sequência de DNA , Transcrição GênicaRESUMO
Triclocarban (3,4,4'-trichlorocarbanilide; TCC) is an antibacterial agent used in personal care products such as bar soaps. Small amounts of chemical are absorbed through the epidermis. Recent studies show that residues of reactive TCC metabolites are bound covalently to proteins in incubations with keratinocytes, raising concerns about the potential toxicity of this antimicrobial agent. To obtain additional information on metabolic activation of TCC, this study characterized the reactive metabolites trapped as glutathione conjugates. Incubations were carried out with (14)C-labeled TCC, recombinant CYP1A1 or CYP1B1, coexpressed with cytochrome P450 reductase, glutathione-S-transferases (GSH), and an NADPH-generating system. Incubations containing CYP1A1, but not 1B1, led to formation of a single TCC-GSH adduct with a conversion rate of 1% of parent compound in 2 hours. Using high-resolution mass spectrometry and diagnostic fragmentation, the adduct was tentatively identified as 3,4-dichloro-3'-glutathionyl-4'-hydroxycarbanilide. These findings support the hypothesis that TCC is activated by oxidative dehalogenation and oxidation to a quinone imine. Incubations of TCDD-induced keratinocytes with (14)C-TCC yielded a minor radioactive peak coeluting with TCC-GSH. Thus, we conclude that covalent protein modification by TCC in TCDD-induced human keratinocyte incubations is mainly caused by activation of TCC by CYP1A1 via a dehalogenated TCC derivative as reactive species.
Assuntos
Antibacterianos/farmacocinética , Carbanilidas/farmacocinética , Citocromo P-450 CYP1A1/metabolismo , Glutationa/metabolismo , Ativação Metabólica , Linhagem Celular Transformada , HumanosRESUMO
Alopecia areata (AA), a cell mediated autoimmune disease, is the second most common form of hair loss in humans. While the autoimmune disease is responsible for the underlying pathogenesis, the alopecia phenotype is ultimately due to hair shaft fragility and breakage associated with structural deficits. Quantitative trait genetic analyses using the C3H/HeJ mouse AA model identified cysteine-rich secretory protein 1 (Crisp1), a hair shaft structural protein, as a candidate gene within the major AA locus. Crisp1 transcripts in the skin at various times during disease development were barely detectable. In situ hybridization identified Crisp1 expression within the medulla of hair shafts from clinically normal strains of mice but not C3H/HeJ mice with AA. Follow-up work with 5-day-old C3H/HeJ mice with normal hair also had essentially no expression of Crisp1. Other non-inflammatory based follicular dystrophy mouse models with similar hair shaft abnormalities also have little or no Crisp1 expression. Shotgun proteomics, used to determine strain difference in hair proteins, confirmed that there was very little CRISP1 within normal C3H/HeJ mouse hair in comparison to 11 other strains. However, mutant mice with hair medulla defects also had undetectable levels of CRISP1 in their hair. Crisp1 null mice had normal skin, hair follicles, and hair shafts indicating that the lack of the CRISP1 protein does not translate directly into defects in the hair shaft or hair follicle. These results suggest that CRISP1 may be an important structural component of mouse hair and that its strain-specific dysregulation may indicate a predisposition to hair shaft disease such as AA.
Assuntos
Alopecia em Áreas/metabolismo , Cabelo/metabolismo , Glicoproteínas de Membrana/metabolismo , Alopecia em Áreas/genética , Alopecia em Áreas/patologia , Animais , Modelos Animais de Doenças , Cabelo/patologia , Hibridização In Situ , Glicoproteínas de Membrana/genética , Camundongos , Camundongos Endogâmicos C3H , Camundongos Endogâmicos C57BL , Camundongos Mutantes , Análise de Sequência com Séries de Oligonucleotídeos , Reação em Cadeia da PolimeraseRESUMO
OBJECTIVE: Impaired adipogenic differentiation exacerbates metabolic disease in obesity. This study reported that high-fat diet (HFD)-fed mice housed at thermoneutrality exhibited impaired adipogenic differentiation, attributed to increased expression of histone deacetylase 9 (HDAC9). However, the impact of HFD on adipogenic differentiation is reportedly variable, possibly reflecting divergent environmental conditions such as housing temperature. METHODS: C57BL/6J (wild-type [WT]) mice were housed at either thermoneutral (28-30°C) or ambient (20-22°C) temperature and fed HFD or chow diet (CD) for 12 weeks. For acute exposure experiments, WT or transient receptor potential cation channel subfamily M member 8 (TRPM8) knockout mice housed under thermoneutrality were acutely exposed to ambient temperature for 6 to 24 h. RESULTS: WT mice fed HFD and housed at thermoneutrality, compared with ambient temperature, gained more weight despite reduced food intake. They likewise exhibited increased inguinal adipose tissue HDAC9 expression and reduced adipogenic differentiation in vitro and in vivo compared with CD-fed mice. Conversely, HFD-fed mice housed at ambient temperature exhibited minimal change in adipose HDAC9 expression or adipogenic differentiation. Acute exposure of WT mice to ambient temperature reduced adipose HDAC9 expression independent of sympathetic ß-adrenergic signaling via a TRPM8-dependent mechanism. CONCLUSIONS: Adipose HDAC9 expression is temperature sensitive, regulating adipogenic differentiation in HFD-fed mice housed under thermoneutrality.
Assuntos
Tecido Adiposo , Habitação , Animais , Camundongos , Tecido Adiposo/metabolismo , Dieta Hiperlipídica , Histona Desacetilases/genética , Camundongos Endogâmicos C57BL , Camundongos Knockout , Obesidade/genética , Obesidade/metabolismo , TemperaturaRESUMO
Shotgun proteomic analysis was performed of epidermal scale, feather, beak and claw from the domestic chicken. To this end, the samples were separated first into solubilized and particulate fractions, the latter enriched in isopeptide cross-linking, by exhaustive extraction in sodium dodecyl sulfate under reducing conditions. Among the 205 proteins identified were 17 keratins (types α and ß), 51 involved in protein synthesis, 8 junctional, 8 histone, 5 heat shock, and 5 14-3-3 proteins. Considerable overlap among the beak, claw, feather, and scale samples was observed in protein profiles, but those from beak and claw were the most similar. Scale and feather profiles were the most distinctive, each exhibiting specific proteins. Less than 20% of the proteins were found only in the detergent-solubilized fraction, while 34-57% were found only in the particulate fraction, depending on the source, and the rest in both fractions. The results provide the first comprehensive analysis of the content of these cornified structures, reveal the efficient use of available proteins in conferring mechanical and chemical stability to them, and emphasize the importance of isopeptide cross-linking in avian epithelial cornification.