Gene expression profile analysis from biomarkers of skin aging process

Orientador: Maria Beatriz PuzziTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciências MédicasResumo: Introdução: Nos últimos anos, tem-se observado o aumento no número de estudos relacionados ao processo de envelhecimento da pele, devido principalmente ao interesse da população em prevenir ou retardar o aparecimento dos sinais do tempo. O envelhecimento da pele é decorrente de um processo natural do corpo humano e sofre influência direta do background genético do indivíduo. Também pode sofrer com ação do ambiente externo, intensificando as dermatoses comuns do envelhecimento. Objetivo: Neste presente trabalho analisamos a expressão gênica de fibroblastos humanos originários de indivíduos jovens e idosos, mantidos em cultura celular de monocamada, a fim de se determinar um padrão gênico de envelhecimento da pele. Metodologias e métodos: Utilizando fibroblastos humanos primários, comparamos três modelos in vitro de envelhecimento, através da técnica de proliferação celular acelerada, radiação UVB e células provenientes de doadores idosos, com relação ao seu comportamento celular e gênico considerando 29 genes: CASP3, SIRT1, LMNA, COL1A1, COL1A2, COL3A1, COL4A1, COL7A1, MMP1, MMP2, MMP3, MMP7, MMP8, MMP9, MMP10, MMP12, MMP13, MMP14, TIMP1, TIMP2, TIMP3, TIMP4, IL1B, IL1A, IL6, IL8, IL10, TP53, PTGS2 relacionados ao processo de envelhecimento da pele. Resultados e discussão: Foi possível observar redução na velocidade de proliferação celular nos modelos de envelhecimento quando comparados ao controle jovem sem tratamento. Os resultados de expressão gênica foram analisados através da plataforma Ingenuity Pathway Analysis e 12 genes foram identificados como potenciais biomarcadores para o processo de envelhecimento da pele. Os genes COL1A1 e COL1A2, relacionados à síntese de colágeno tipo I, demonstraram inibição de expressão enquanto os genes MMP1 e MMP3, relacionados à degradação de matriz extracelular, apresentaram aumento, corroborando sua importância no processo de envelhecimento da pele. Os genes responsáveis pela síntese de citocinas pró- inflamatórias IL6, IL1A, IL1B e PTGS2 apresentaram inibição da expressão ao mesmo tempo em que o IL10, gene que codifica uma citocina anti-inflamatória, apresentou aumento, sugerindo que estas citocinas atuam no dano e recuperação da pele envelhecida. Além disso, os genes CXCL8, TP53 e LMNA também foram positivamente modulados, sugerindo possuir papel importante no processo de envelhecimento celular. Conclusão: Os modelos in vitro de envelhecimento de pele, quando analisados isoladamente, não apresentaram marcadores gênicos exclusivos porém, quando analisados conjuntamente, foi possível identificar 12 genes como biomarcadores comuns entre os modelos de envelhecimento, sendo eles COL1A1, COL1A2, CXCL8, IL6, IL10, IL1A, IL1B, LMNA, MMP1, MMP3, PTGS2, TP53. Deste modo, podemos concluir que é possível definir um padrão gênico de envelhecimento da pele em modelos de cultura celular in vitro, nas condições testadasAbstract: Introduction: In recent years, it has been observed an increase in the number of works related to skin aging, due mainly to the interest of the population on prevent or delay the signs of elderly on skin. Skin aging is the result of a natural process of human body and it is influenced by genetic background. It also can be influenced by external environment, intensifying regular dermatoses of elderly. Objective: In this present work, we analyzed the gene expression of human fibroblasts from young and elderly donors, maintained in monolayer cell culture, in order to determine genetic pattern of skin aging. Materials and Methodology: Using human primary fibroblasts, we compared three in vitro skin aging models - cell proliferation technique, UVB radiation and cells from elderly donors - regarding cellular and genetic behavior, using 29 genes: CASP3, SIRT1, LMNA, COL1A1, COL1A2, COL3A1, COL4A1, COL7A1, MMP1, MMP2, MMP3, MMP7, MMP8, MMP9, MMP10, MMP12, MMP13, MMP14, TIMP1, TIMP2, TIMP3, TIMP4, IL1B, IL1A, IL6, IL8, IL10, TP53, PTGS2 related to skin aging process. Results and discussion: It was possible to observe a decrease of cellular proliferation rate on aging models when compared with young cell control, without treatment. The results of gene expression were analyzed through Ingenuity Pathway Analysis platform and 12 genes were identified as common biomarkers of skin aging. The genes COL1A1 and COL1A2, related to collagen type 1 synthesis, demonstrated inhibition of expression while MMP1 and MMP3, related to extracellular matrix degradation, demonstrated increase, corroborating their importance in the skin aging. The genes responsible for pro inflammatory cytokines synthesis IL6, IL1A, IL1B and PTGS2 showed inhibition of expression at the same time that IL10 gene, which encode an anti-inflammatory cytokine, demonstrated increase suggesting that these cytokines can act on damage and recovery of aged skin. Furthermore, the genes CXCL8, TP53 and LMNA were also positively modulated, suggesting an important role on skin aging process. Conclusion: In vitro skin aging models, when individually analyzed, did not identify unique biomarkers however, when analyzed together, it was possible to identify 12 genes as common biomarkers for skin aging, COL1A1, COL1A2, CXCL8, IL6, IL10, IL1A, IL1B, LMNA, MMP1, MMP3, PTGS2, TP53. Thus, we can conclude that is possible to determine a genetic pattern of skin aging in cell culture in vitro models, regarding established conditionsDoutoradoClinica MedicaDoutora em Ciência

Ocorrência de seqüências relacionadas com a virulência e análise filogenética de estirpes comensais e patogênicas de Escherichia coli aviário (APEC)

The presence of iron uptake (irp-2, fyuA, sitA, fepC, iucA), adhesion (iha, lpfA O157/O141, lpfA O157/O154, efa, toxB) and invasion (inv, ial-related DNA sequences and assignment to the four main Escherichia coli phylogenetic groups (A, B1, B2 e D) were determined in 30 commensal E. coli strains isolated from healthy chickens and in 49 APEC strains isolated from chickens presenting clinical signs of septicemia (n=24) swollen head syndrome (n=14) and omphalitis (n=11) by PCR. None of the strains presented DNA sequences related to the inv, ial, efa, and toxB genes. DNA sequences related to lpfA O157/O154, iucA, fepC, and irp-2 genes were significantly found among pathogenic strains, where iucA gene was associated with septicemia and swollen head syndrome and fepC and irp-2 genes were associated with swollen head syndrome strains. Phylogenetic typing showed that commensal and omphalitis strains belonged mainly to phylogenetic Group A and swollen head syndrome to phylogenetic Group D. Septicemic strains were assigned in phylogenetic Groups A and D. These data could suggest that clonal lineage of septicemic APEC strains have a multiple ancestor origin; one from a pathogenic bacteria ancestor and other from a non-pathogenic ancestor that evolved by the acquisition of virulence related sequences through horizontal gene transfer. Swollen head syndrome may constitute a pathogenic clonal group. By the other side, omphalitis strains probably constitute a non-pathogenic clonal group, and could cause omphalitis as an opportunistic infection. The sharing of virulence related sequences by human pathogenic E. coli and APEC strains could indicate that APEC strains could be a source of virulence genes to human strains and could represent a zoonotic risk.A presença de seqüências de DNA associadas à capacidade de captação de ferro (irp-2, fyuA, sitA, fepC, iucA), adesão (iha, lpfA O157/O141, lpfA O157/O154, efa, toxB) e de invasão (inv, ial) e a classificação dentro dos quatro grupos filogenéticos principais de Escherichia coli (Grupos A, B1, B2 e D) foram determinadas, através de PCR, em 30 amostras comensais de E. coli isoladas de frangos e de 49 linhagens APEC (24 isoladas de frangos com septicemia, 14 isoladas de frangos com síndrome da cabeça inchada e 11 isoladas de embriões de galinhas com onfalite). Nenhuma das linhagens apresentou os genes inv, ial, efa, e toxB. Os genes lpfA O157/O154, iucA, fepC e irp-2 foram encontrados em freqüências significativas entre as amostras patogênicas. O gene iucA foi associado com amostras causadoras de septicemia e de síndrome da cabeça inchada. Os genes fepC e irp-2 foram associados a amostras causadoras de síndrome da cabeça inchada. A análise filogenética demonstrou que linhagens comensais e causadoras de onfalite pertenceram principalmente ao Grupo filogenético A, não patogênico. Amostras causadoras de síndrome da cabeça inchada pertenceram, em sua maioria, ao Grupo patogênico D. Linhagens causadoras de septicemia pertenceram aos Grupos A e D. Estes dados sugerem que linhagens APEC causadoras de septicemia provavelmente têm uma origem ancestral múltipla: uma derivada de uma linhagem patogênica e outra de uma linhagem não patogênica que possivelmente evoluiu através da aquisição horizontal de genes de virulência. Amostras causadoras de síndrome da cabeça inchada possivelmente constituem um grupo clonal patogênico. Por outro lado, amostras causadoras de onfalite possivelmente constituem um grupo clonal não patogênico, que, possivelmente causam onfalite devido a uma infecção oportunista. A presença de genes de virulência também encontrados em E. coli de origem humana pode indicar a possível ocorrência de zoonoses causadas por APEC.533540Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

DNA Dosimetry Assessment for Sunscreen Genotoxic Photoprotection

Background: Due to the increase of solar ultraviolet radiation (UV) incidence over the last few decades, the use of sunscreen has been widely adopted for skin protection. However, considering the high efficiency of sunlight-induced DNA lesions, it is critical to improve upon the current approaches that are used to evaluate protection factors. An alternative approach to evaluate the photoprotection provided by sunscreens against daily UV radiation-induced DNA damage is provided by the systematic use of a DNA dosimeter. Methodology/Principal Findings: The Sun Protection Factor for DNA (DNA-SPF) is calculated by using specific DNA repair enzymes, and it is defined as the capacity for inhibiting the generation of cyclobutane pyrimidine dimers (CPD) and oxidised DNA bases compared with unprotected control samples. Five different commercial brands of sunscreen were initially evaluated, and further studies extended the analysis to include 17 other products representing various formulations and Sun Protection Factors (SPF). Overall, all of the commercial brands of SPF 30 sunscreens provided sufficient protection against simulated sunlight genotoxicity. In addition, this DNA biosensor was useful for rapidly screening the biological protection properties of the various sunscreen formulations. Conclusions/Significance: The application of the DNA dosimeter is demonstrated as an alternative, complementary, and reliable method for the quantification of sunscreen photoprotection at the level of DNA damage.Natura Inovacao e Tecnologia de Produtos LTDA (Sao Paulo, Brazil)Natura Inovacao e Tecnologia de Produtos LTDA (Sao Paulo, Brazil)FAPESP (Sao Paulo, Brazil)FAPESP (Sao Paulo, Brazil)CNPq (Brasilia, Brazil)CNPq (Brasilia, Brazil)Natura Inovacao e Tecnologia de Produtos LTDANatura Inovacao e Tecnologia de Produtos LTD

The Influence of Blue Light Exposure on Reconstructed 3-Dimensional Skin Model: Molecular Changes and Gene Expression Profile

Recent studies have provided information about digital eye strain and the potential damage that blue light from digital devices can cause to the eyes. In this study, we analyzed the influence of blue light exposure on reconstructed 3-dimensional skin model using RNA sequencing to identify the expression of transcripts and abnormal events. Three-dimensional skin was exposed to visible light spectrum and isolated blue wavelength for 1, 2, and 4 hours to represent acute exposure and 1 hour over 4 sequential days to represent repeated exposure, respectively, in this in vitro model. We compared gene expression levels with those of unexposed control. Samples submitted to repeated exposure showed reduced AK2 and DDX47, whereas they showed increased PABPC3 gene expression, revealing a significantly negative impact. RT-PCR validation assay with exposed 3-dimensional skin compared with unexposed control regarding 1 and 4 days of incubation showed increased IL-6 signaling mechanism activation and signal transducer and activator of transcription 3 gene STAT3 gene expression, whereas it showed decreased peroxisome proliferator–activated receptor signaling mechanism activation, suggesting an influence on inflammatory pathways. We also demonstrate upregulated gene expression of KIT, MAPK2, and PI3KC in samples from exposed condition, corroborating previous findings related to pigmentation signaling stimuli. These results reveal, to our knowledge, previously unreported data that enable studies on molecular response correlation of in vitro digital blue light exposure and human skin studies

Assessment of the genotoxic protection properties of sunscreens by DNA dosimetry.

<p>Exposure of DNA dosimeters to a solar simulator for simultaneously evaluation of DNA photoprotection efficacy of several products containing sunscreen (<b>A</b>). The DNA dosimeter transmittance spectrum (<b>B</b>).</p

DNA lesions induced by simulated sunlight in the absence (vehicle) or presence of 17 sunscreens.

<p>T4-endo V-SS (T4-endo V sensitive sites – CPDs); Fpg-SS (Fpg sensitive sites – oxidised DNA bases). The average and standard deviation in three independent experiments are shown. The experiments were performed in triplicate.</p

Correlation between the percentages of DNA photoprotection and the labelled SPF values of 17 sunscreen formulations.

<p>Correlation between the percentages of DNA photoprotection and the labelled SPF values of 17 sunscreen formulations.</p

DNA photoprotection properties provided by five brands of SPF 30 sunscreens.

<p><b>Legend:</b> DNA-SPF – Sun Protection Factor for DNA; %DNA photoprotection – percentage of DNA photoprotection; % CPD photoprotection – percentage of protection against CPDs; % oxidised DNA base photoprotection – percentage of protection against oxidised DNA bases; and 95% CI –95% confidence interval of three independent experiments performed in triplicate.</p

Determination and quantification of DNA lesions after exposure to a solar simulator.

<p>Treatment with the DNA repair enzymes T4-endo V (<b>A</b>) or Fpg (<b>B</b>). The number of DNA lesions induced by simulated sunlight in the absence (<b>vehicle</b>) or presence of five different commercially available SPF 30 sunscreens (<b>C</b>). FI (supercoiled plasmid DNA bands); FII (open-circular relaxed DNA bands); T4-endo V-SS (T4-endo V sensitive sites – CPDs); Fpg-SS (Fpg sensitive sites – oxidised DNA bases). The average and standard deviation from three independent experiments are shown. The experiments were performed in triplicate.</p