The inability to tan properly after sun exposure strongly correlates with increased incidence of skin cancer. The melanocortin 1 receptor (MC1R) is a transmembrane Gs-coupled cell surface receptor found on epidermal melanocytes that transmits pro-survival and pro-differentiation signals mediated by the second messenger cAMP. Humans carrying loss-of-function polymorphisms in MC1R signaling exhibit higher incidences of skin cancers including melanoma. This study focused on the physiologic effects of topical application of forskolin, an adenylate cyclase activator, in extension (Mc1re/e) K14-SCF animals, which model the fair-skinned UV-sensitive human. Twice daily application of the drug promoted accelerated pigmentation, increased skin darkening due to epidermal deposition of melanin pigment, and induced epidermal melanin, which protected the skin against UV injury as judged by “minimal erythematous dose” (MED). Moreover, MC1R signaling regulated the expression of antioxidant enzymes at the transcriptional level. The human melanoma cell line A375, known to harbor a loss-of-function signaling mutation in MC1R, was used to determine effects of cAMP stimulation on the expression of antioxidant enzymes. We observed increases in expression of genes that control the biosynthesis and regulation of glutathione including the transcription factor nuclear factor (erythroid-derived 2)-like 2 (Nrf2), glutathione peroxidase, GPX, and glutathione reductase GSR. In addition, there is an increase in manganese superoxide dismutase (MnSOD) at the protein level. There was accumulation of MnSOD in the mitochondria after pharmacologic induction of cAMP with forskolin. Addition of the oxidative agent H2O2 enhanced the expression of MnSOD at the protein level as early as one hour after MC1R stimulation. Oxygen consumption rate on mitochondria was measured using Seahorse analysis; pharmacologic activation of MC1R/cAMP signaling did not affect mitochondrial metabolism. In addition, topical application of a crude extract of Solidago inhibited UV-induced inflammation in K14-SCF mice. Several UV-induced cytokines, including TNF-α, were down-regulated at the transcriptional level after topical application of Solidago extract. Together, these results indicate that MC1R signaling protects melanocytes from UV damage by regulating antioxidant enzyme expression and suggest that pharmacologic cAMP induction may be a useful preventive mechanism against UV-mediated skin sunburn and oxidative injury.

O melanoma é uma doença complexa, associada com diversos fatores de risco genéticos e ambientais. Este o tipo mais agressivo de câncer de pele e origina-se nos melanócitos, as células da pele produtoras de pigmento nos mamíferos. Polimorfismos de base única (Single Nucleotide Polymorphisms - SNPs) presentes em genes envolvidos na pigmentação têm sido descritos envolvidos na modulação de risco para o melanoma, porém o conhecimento neste campo ainda é bastante limitado. Neste estudo, foi avaliado o efeito de quatro SNPs em quatro genes de pigmentação: TYR (rs1126809), HERC2 (rs1129038), SLC24A5 (rs1426654) e SLC45A2 (rs16891982) no aumento de risco para melanoma, usando análises de regressão logística multivariada e redução de dimensão multifatorial (MDR), em uma abordagem caso-controle. Em 255 indivíduos (120 pacientes com melanoma e 135 controles sem melanoma) provenientes do Rio Grande do Sul, Brasil, identificamos associação com o risco para melanoma em três dos quatro SNPs investigados (HERC2 rs1129038, P=0.017; SLC24A5 rs1426654, P<0.001; e SLC45A2 rs16891982, P=0.002). Além disso, a interação entre rs1426654 e rs16891982 (genótipos AA e GG, respectivamente), aumentou significamente o risco para melanoma nas análises de regressão logística multivariada e análises de MDR [OR = 6.936 (CI 95%: 1.607 – 50.294), P= 0.022]. Estes resultados contribuem para o conhecimento atual, indicando que esses SNPs contribuem para o aumento de risco de desenvolvimento de melanoma. / The melanoma is a complex disease, associated with several environmental and genetic risk factors. This is the most aggressive type of skin cancer and originates in melanocytes, the pigment producing skin cells in mammals. Single nucleotide polymorphisms (SNPs) in pigmentation genes have been describe in melanoma risk modulation but our knowledge in the field is still limited. Here, we assessed the effect of SNPs in four pigmentation genes – TYR (rs1126809), HERC2 (rs1129038), SLC24A5 (rs1426654), and SLC45A2 (rs16891982) on increase of melanoma risk using multivariate logistic regression and a multifactorial dimension reduction (MDR) analysis, in a case-control approach. In 255 individuals (120 melanoma patients and 135 controls free melanoma) from Rio Grande do Sul, Brazil, we identified an association of melanoma risk with three of the four SNPs studied (HERC2 rs1129038, P=0.017; SLC24A5 rs1426654, P<0.001; and SLC45A2 rs16891982, P=0.002). In addition, the interaction between rs1426654 and rs16891982 (AA and GG genotypes, respectively) significantly increased the risk of melanoma [OR = 6.936 (CI 95%: 1.607 – 50.294), P= 0.022] in both MRD and multivariate logistic regression analyses. Our results contribute to the current knowledge, indicating that SNPs contribute to the increase risk of melanoma.

O melanoma é uma doença complexa, associada com diversos fatores de risco genéticos e ambientais. Este o tipo mais agressivo de câncer de pele e origina-se nos melanócitos, as células da pele produtoras de pigmento nos mamíferos. Polimorfismos de base única (Single Nucleotide Polymorphisms - SNPs) presentes em genes envolvidos na pigmentação têm sido descritos envolvidos na modulação de risco para o melanoma, porém o conhecimento neste campo ainda é bastante limitado. Neste estudo, foi avaliado o efeito de quatro SNPs em quatro genes de pigmentação: TYR (rs1126809), HERC2 (rs1129038), SLC24A5 (rs1426654) e SLC45A2 (rs16891982) no aumento de risco para melanoma, usando análises de regressão logística multivariada e redução de dimensão multifatorial (MDR), em uma abordagem caso-controle. Em 255 indivíduos (120 pacientes com melanoma e 135 controles sem melanoma) provenientes do Rio Grande do Sul, Brasil, identificamos associação com o risco para melanoma em três dos quatro SNPs investigados (HERC2 rs1129038, P=0.017; SLC24A5 rs1426654, P<0.001; e SLC45A2 rs16891982, P=0.002). Além disso, a interação entre rs1426654 e rs16891982 (genótipos AA e GG, respectivamente), aumentou significamente o risco para melanoma nas análises de regressão logística multivariada e análises de MDR [OR = 6.936 (CI 95%: 1.607 – 50.294), P= 0.022]. Estes resultados contribuem para o conhecimento atual, indicando que esses SNPs contribuem para o aumento de risco de desenvolvimento de melanoma. / The melanoma is a complex disease, associated with several environmental and genetic risk factors. This is the most aggressive type of skin cancer and originates in melanocytes, the pigment producing skin cells in mammals. Single nucleotide polymorphisms (SNPs) in pigmentation genes have been describe in melanoma risk modulation but our knowledge in the field is still limited. Here, we assessed the effect of SNPs in four pigmentation genes – TYR (rs1126809), HERC2 (rs1129038), SLC24A5 (rs1426654), and SLC45A2 (rs16891982) on increase of melanoma risk using multivariate logistic regression and a multifactorial dimension reduction (MDR) analysis, in a case-control approach. In 255 individuals (120 melanoma patients and 135 controls free melanoma) from Rio Grande do Sul, Brazil, we identified an association of melanoma risk with three of the four SNPs studied (HERC2 rs1129038, P=0.017; SLC24A5 rs1426654, P<0.001; and SLC45A2 rs16891982, P=0.002). In addition, the interaction between rs1426654 and rs16891982 (AA and GG genotypes, respectively) significantly increased the risk of melanoma [OR = 6.936 (CI 95%: 1.607 – 50.294), P= 0.022] in both MRD and multivariate logistic regression analyses. Our results contribute to the current knowledge, indicating that SNPs contribute to the increase risk of melanoma.

Submitted by Erika Demachki (erikademachki@gmail.com) on 2015-04-01T20:56:35Z No. of bitstreams: 2 Dissertação - Lana Bezerra Fernandes - 2014.pdf: 2091741 bytes, checksum: d2de505d009cccbbff3717ebe19797ba (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Erika Demachki (erikademachki@gmail.com) on 2015-04-01T21:13:22Z (GMT) No. of bitstreams: 2 Dissertação - Lana Bezerra Fernandes - 2014.pdf: 2091741 bytes, checksum: d2de505d009cccbbff3717ebe19797ba (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2015-04-01T21:13:22Z (GMT). No. of bitstreams: 2 Dissertação - Lana Bezerra Fernandes - 2014.pdf: 2091741 bytes, checksum: d2de505d009cccbbff3717ebe19797ba (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2014-04-05 / BACKGROUND: During pregnancy immunological, metabolic, endocrine and vascular changes responsible for physiological and pathological skin changes occur. OBJECTIVES: To determine the prevalence of physiological skin changes and specific pregnancy dermatoses, comparing the period of gestation of their appearance and compare type of prenatal care (low and high risk) and the skin changes. METHODS: A cross-sectional study with 905 pregnant women in the antenatal clinic of low-and high-risk Clinical Hospital / UFG. The patient was submitted to a complete dermatological examination, following head-foot dynamics. Laboratory tests and biopsies were required for differential diagnosis. The variables were analyzed by calculating relative and absolute frequencies and chi-square test for categorical variables. Set value of 5% for significance. RESULTS: Physiological skin changes showed most high phototype and its prevalence was 88.95%. Among these the most common abnormality was hyperpigmentation (87.95%), followed by the appearance of new stretch marks (46.96%). The period of emergence of the changes was greater in the 3rd quarter and compared to other quarters was no statistical difference between them and the type of prenatal care was no statistical difference. The specific skin dermatoses showed most high phototype and its prevalence was 8.72%. Among these the Atopic Eruption was the most common (70.88%), followed by intrahepatic cholestasis (18.98%). The 3rd quarter was the only one to show a statistical difference compared to other quarters. However, when compared to the emergence of these type of prenatal this difference was not significant. CONCLUSION: The prevalence of cutaneous physiological changes of pregnancy was 88.95%, and the specific dermatoses of pregnancy was 8.72% The most common time of onset of physiological changes was in the 3rd trimester, as well as the specific dermatoses. No statistical difference in prenatal low risk compared to high risk was observed, whereas the cutaneous physiological changes specific dermatoses / FUNDAMENTO: Durante a gravidez ocorrem alterações imunológicas, metabólicas, endócrinas e vasculares responsáveis por alterações cutâneas fisiológicas e patológicas. OBJETIVOS: Estabelecer a prevalência das alterações cutâneas fisiológicas e das dermatoses específicas gestacionais, comparar o período da idade gestacional de seu surgimento e comparar tipo de pré-natal (baixo e alto risco) quanto às alterações dermatológicas. MÉTODOS: Estudo transversal analítico realizado com 905 gestantes no ambulatório de pré-natal de baixo e alto risco do Hospital das Clínicas/UFG. A gestante foi submetida ao exame dermatológico completo, obedecendo dinâmica cefalo-podal. Foram solicitados exames laboratoriais e biópsias para diagnósticos diferenciais. As variáveis foram estudadas através dos cálculos de frequências relativas e absolutas e teste Qui-quadrado para variáveis categóricas. Estabelecido valor de 5% para significância. RESULTADOS: As alterações cutâneas fisiológicas apresentaram maioria fototipo alto e sua prevalência foi de 88,95%. Dentre estas a alteração mais comum foi a pigmentar (87,95%), seguida pelo aparecimento de novas estrias (46,96%). O período de surgimento das alterações foi maior no 3º trimestre e comparado aos outros trimestres houve diferença estatística entre eles e quanto ao tipo de pré-natal não foi houve diferença estatística. As dermatoses cutâneas específicas apresentaram maioria fototipo alto e sua prevalência foi de 8,72%. Dentre estas a Erupção Atópica foi a mais comum (70,88%); seguida pela Colestase Intra-hepática (18,98%). O 3º trimestre foi o único a apresentar diferença estatística comparado aos demais trimestres. Já quando comparado o surgimento destas ao tipo do pré-natal esta diferença não se mostrou significativa. CONCLUSÃO: A prevalência de alterações fisiológicas cutâneas gestacionais foi de 88,95%, sendo que a das dermatoses específicas gestacionais foi de 8,72%. O momento mais comum de surgimento de alterações fisiológicas foi no 3º trimestre gestacional, assim como o das dermatoses específicas. Não se observou diferença estatística no pré-natal de baixo risco comparado com o de alto risco, considerando as alterações fisiológicas cutâneas e as dermatoses específicas gestacionais.

京都大学 / 0048 / 新制・論文博士 / 博士(人間・環境学) / 乙第12883号 / 論人博第40号 / 新制||人||169(附属図書館) / 26||論人博||40(吉田南総合図書館) / 31601 / (主査)教授 石原 昭彦, 教授 船橋 新太郎, 教授 林 達也, 准教授 神﨑 素樹, 准教授 久代 恵介 / 学位規則第4条第2項該当 / Doctor of Human and Environmental Studies / Kyoto University / DFAM

No description available.

No / Skin pigmentation is a multistep process of melanin synthesis by melanocytes, its transfer to recipient keratinocytes and its degradation. As dyspigmentation is a prominent marker of skin ageing, novel effective agents that modulate pigmentation safely are being sought for both clinical and cosmetic use. Here, a number of plant extracts were examined for their effect on melanogenesis (by melanin assay and Western blotting) and melanin transfer (by confocal immunomicroscopy of gp100-positive melanin granules in cocultures and by SEM analysis of filopodia), in human melanocytes and in cocultures with phototype-matched normal adult epidermal keratinocytes. Mulberry, Kiwi and Sophora extracts were assessed against isobutylmethylxanthine, hydroquinone, vitamin C and niacinamide. Compared with unstimulated control, all extracts significantly reduced melanogenesis in human melanoma cells and normal adult epidermal melanocytes. These extracts also reduced melanin transfer and reduced filopodia expression on melanocytes, similar to hydroquinone and niacinamide, indicating their effectiveness as multimode pigmentation actives.

黑色素生成是為了保護皮膚細胞免受紫外光傷害的一個生化過程。在這過程中，黑色素在人類表皮底層的黑色素細胞的黑色素體內產生。該過程可以被基因，荷爾蒙或環境因素所影響。黑色素的製造量是依賴速度限制酶酪氨酸酶的活性，黑色素體的數量和大小，黑色素體通過黑色素細胞的偽足傳送致角質細胞的速度及黑色素體在角質細胞內的分佈。這些細胞過程會受皮膚顏色或紫外光曝光量的變化而影響。當黑色素的產生超過黑色素的降解，黑色素沉著毛病便出現。根據不同的皮膚類型，年齡組別及累積紫外光曝光程度而引發雀斑或黃褐斑的形成。很多治療方法市面上能夠提供，它們包括人工合成化粧品，激光，整容手術等。這些治療方法通常會產生副作用及蘊藏高風險。因此從天然物質裏尋找治療藥物便成了美容學的一個新的研究方向。在這研究裏，十種草本植物就從自古以來用作治療黑色素沉著毛病的傅統中藥中被挑選出來。那些草本植物被四種擁有不同極性的溶劑提取。小鼠黑色素細胞被用以篩選提取物的降黑色素能力。結果發現當歸的正己烷及二氯甲烷的提取物有正面效用。當歸的化學成份4-乙基間苯二酚、4-乙基苯酚及1-十四烷醇也能降低小鼠黑色素細胞的黑色素量。數種生化技術繼而被應用作研究有效化學物的藥理。他們包括西方墨點法、環磷酸腺苷測試、蛋白激酶A活性測試及酪氨酸酶活性測試。 / Melanogenesis is a biochemical process designated for protecting skin cells from ultraviolet (UV)-induced damage. During the process, melanin is produced in the melanosomes of the melanocytes located at the basal epidermis of human. The process could be affected by genetic, hormonal or environmental factors. Amount of melanin synthesized depending on the activity of the rate-limiting enzyme tyrosinase, number and size of melanosomes, the transfer rate of melanosomes to keratinocytes through the melanocyte dendritic projections and the distribution pattern of melanosomes within keratinocytes. These cellular processes are influenced by variations in skin color or UV exposure amount. When melanin synthesis exceeds melanin degradation, hyperpigmentation disorder arises. This lead to the formation of freckles or chloasma according to different skin types, age groups and degree of cumulative UV exposure. A number of treatments are commercially available, they include applying synthetic cosmetics, laser, plastic surgery, etc. These treatments usually produce side-effects and possess high risk. Therefore, searching for therapeutic agents from natural compounds has become a new research direction in cosmetology. In this study, ten herbs were chosen from traditional Chinese medicine (TCM) which had been applied for treating hyperpigmentation. The herbs were extracted by four solvents with different polarity. The extracts were screened for their hypopigmentary ability by using melan-a cells. It was found that the hexane and dichloromethane extracts of Angelica sinensis possessed positive effects. 4-ethylresorcinol, 4-ethylphenol and 1-tetradecanol, the chemical constituents of A. sinensis, also attenuated melanin amount in melan-a cells. Moreover, several biochemical techniques were utilized to study the pharmaceutical mechanisms of the potent compounds. They include Western blot, cyclic adenosine monophosphate (cAMP) assay, protein kinase A (PKA) activity assay and tyrosinase activity assay. / Detailed summary in vernacular field only. / Lam, Rosanna Yen Yen. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references (leaves 127-146). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese. / Abstract --- p.i / Chinese Abstract --- p.iii / Acknowledgements --- p.iv / List of Publications --- p.v / Table of Contents --- p.vi / List of Abbreviations --- p.xii / List of Figures --- p.xv / List of Tables --- p.xviii / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Demand of cosmetics --- p.1 / Chapter 1.2 --- Skin structures and functions --- p.1 / Chapter 1.2.1 --- Epidermis --- p.3 / Chapter 1.2.1.1 --- Stratum corneum --- p.4 / Chapter 1.2.1.2 --- Stratum granulosum --- p.4 / Chapter 1.2.1.3 --- Stratum spinosum --- p.4 / Chapter 1.2.1.4 --- Stratum basale --- p.4 / Chapter 1.2.2 --- Dermis --- p.5 / Chapter 1.2.3 --- Hypodermis --- p.5 / Chapter 1.3 --- Sun irradiation --- p.5 / Chapter 1.4 --- Variety of skin types --- p.6 / Chapter 1.5 --- Biochemical reactions within melanocyte --- p.7 / Chapter 1.6 --- Pigmentation disorder --- p.14 / Chapter 1.7 --- From the view of traditional Chinese medicine --- p.16 / Chapter 1.8 --- Treatments available for hyperpigmentation --- p.18 / Chapter 1.9 --- Aims of study and application of strategies --- p.19 / Chapter Chapter 2 --- Investigation of the inhibitory effect of herbal extracts and their constituent compounds on melanin synthesis --- p.20 / Chapter 2.1 --- Introduction --- p.20 / Chapter 2.2 --- Materials and methods --- p.21 / Chapter 2.2.1 --- Materials --- p.21 / Chapter 2.2.2 --- Herbal extraction --- p.23 / Chapter 2.2.3 --- Cell culture --- p.25 / Chapter 2.2.4 --- Growth curve and melanin production curve --- p.25 / Chapter 2.2.5 --- SRB assay --- p.26 / Chapter 2.2.6 --- Calibration curve for SRB assay --- p.27 / Chapter 2.2.7 --- Measurement of melanin production --- p.27 / Chapter 2.2.8 --- Calibration curve for melanin production assay --- p.28 / Chapter 2.2.9 --- Statistical analysis --- p.28 / Chapter 2.3 --- Results --- p.29 / Chapter 2.3.1 --- Growth curve and melanin production curve for assay development --- p.29 / Chapter 2.3.2 --- Calibration curves of SRB assay and melanin production assay --- p.32 / Chapter 2.3.3 --- Hypopigmentary effect of 40 herbal extracts --- p.35 / Chapter 2.3.4 --- Hypopigmentary effects of chemical components of A. sinensis --- p.41 / Chapter 2.4 --- Discussion --- p.49 / Chapter Chapter 3 --- Study of the effect of potential compounds on melanogenic protein expression by Western blot --- p.54 / Chapter 3.1 --- Introduction --- p.54 / Chapter 3.2 --- Materials and methods --- p.56 / Chapter 3.2.1 --- Materials --- p.56 / Chapter 3.2.2 --- Cell culture --- p.56 / Chapter 3.2.3 --- Preparation of cell lysates --- p.57 / Chapter 3.2.4 --- Protein assay --- p.57 / Chapter 3.2.5 --- SDS-PAGE and membrane transfer --- p.58 / Chapter 3.2.6 --- Washing of blotted antibodies and film exposure --- p.59 / Chapter 3.3 --- Results --- p.61 / Chapter 3.4 --- Discussion --- p.70 / Chapter Chapter 4 --- Study of the effect of potential compounds on melanogenic gene expression by RT-PCR --- p.76 / Chapter 4.1 --- Introduction --- p.76 / Chapter 4.2 --- Materials and methods --- p.76 / Chapter 4.2.1 --- Materials --- p.77 / Chapter 4.2.2 --- Cell culture --- p.77 / Chapter 4.2.3 --- RNA extraction --- p.78 / Chapter 4.2.4 --- cDNA synthesis --- p.78 / Chapter 4.2.5 --- PCR --- p.80 / Chapter 4.3 --- Results --- p.83 / Chapter 4.4 --- Discussion --- p.85 / Chapter Chapter 5 --- Study of the effect of potential compounds on cAMP level by EIA --- p.85 / Chapter 5.1 --- Introduction --- p.86 / Chapter 5.2 --- Materials and methods --- p.86 / Chapter 5.2.1 --- Materials --- p.86 / Chapter 5.2.2 --- Cell culture --- p.86 / Chapter 5.2.3 --- Preparation of cell lysates --- p.86 / Chapter 5.2.4 --- Protein assay --- p.87 / Chapter 5.2.5 --- The cAMP assay --- p.88 / Chapter 5.2.6 --- Preparation of cAMP calibration curve --- p.88 / Chapter 5.2.7 --- Calculation --- p.89 / Chapter 5.2.8 --- Statistical analysis --- p.89 / Chapter 5.3 --- Results --- p.90 / Chapter 5.4 --- Discussion --- p.94 / Chapter Chapter 6 --- Study of the effect of potential compounds on PKA activity by PKA activity assay --- p.96 / Chapter 6.1 --- Introduction --- p.96 / Chapter 6.2 --- Materials and methods --- p.96 / Chapter 6.2.1 --- Materials --- p.97 / Chapter 6.2.2 --- Cell culture --- p.97 / Chapter 6.2.3 --- Preparation of cell lysates --- p.98 / Chapter 6.2.4 --- Protein assay --- p.98 / Chapter 6.2.5 --- The PKA kinase activity assay --- p.100 / Chapter 6.2.6 --- Calculation --- p.100 / Chapter 6.2.7 --- Statistical analysis --- p.100 / Chapter 6.3 --- Results --- p.101 / Chapter 6.4 --- Discussion --- p.104 / Chapter Chapter 7 --- Study of the effect of potential compounds on tyrosinase activity by enzyme inhibition assay --- p.107 / Chapter 7.1 --- Introduction --- p.107 / Chapter 7.2 --- Materials and methods --- p.108 / Chapter 7.2.1 --- Materials --- p.108 / Chapter 7.2.2 --- Assay development for mushroom tyrosinase --- p.109 / Chapter 7.2.3 --- Mushroom tyrosinase inhibition assay --- p.109 / Chapter 7.2.4 --- Cell culture --- p.110 / Chapter 7.2.5 --- Preparation of cellular tyrosinase --- p.110 / Chapter 7.2.6 --- Protein assay --- p.111 / Chapter 7.2.7 --- Cellular tyrosinase inhibition assay --- p.111 / Chapter 7.2.8 --- Calculation --- p.112 / Chapter 7.2.9 --- Statistical analysis --- p.112 / Chapter 7.3 --- Results --- p.113 / Chapter 7.4 --- Discussion --- p.120 / Chapter Chapter 8 --- General discussion --- p.123 / References --- p.127

Submitted by Ana Maria Fiscina Sampaio (fiscina@bahia.fiocruz.br) on 2012-08-30T21:44:55Z No. of bitstreams: 1 Thais Ferreira Bonfim. Ancestralidade genômica em uma amostra de portadores do HIV-1 do Estado da Bahia - CPqGM - Dissertação de Mestrado - 2008.pdf: 2375743 bytes, checksum: 3d0b1edd686e7965b81d1f26113f0f78 (MD5) / Made available in DSpace on 2012-08-30T21:44:55Z (GMT). No. of bitstreams: 1 Thais Ferreira Bonfim. Ancestralidade genômica em uma amostra de portadores do HIV-1 do Estado da Bahia - CPqGM - Dissertação de Mestrado - 2008.pdf: 2375743 bytes, checksum: 3d0b1edd686e7965b81d1f26113f0f78 (MD5) Previous issue date: 2012 / Fundação Oswaldo Cruz. Centro de Pesquisas Gonçalo Moniz. Salvador, Bahia, Brasil / A população brasileira apresenta extensa variabilidade genética, resultado da miscigenação entre ameríndios, europeus e africanos. Contudo, a proporção de africanos, ameríndios e europeus difere significativamente a depender da região geográfica. Atualmente são utilizados marcadores moleculares conhecidos como Marcadores Informativos de Ancestralidade (AIM) para avaliar mistura genética nas populações. A cor da pele é um dos fenótipos que mais variam entre e em populações humanas de diferentes etnias e regiões geográficas, devido à grande heterogeneidade gênica e ação da seleção natural. Muitos genes já foram descritos como associados à pigmentação, e alguns deles apresentam frequências alélicas distintas entre diferentes grupos étnicos, porém os mecanismos que respondem pela variação da pigmentação normal da pele ainda não estão completamente estabelecidos. O objetivo deste estudo foi estimar a ancestralidade genética, analisar polimorfismos em genes que modulam a variação normal da pigmentação da pele e verificar associação entre ancestralidade e pigmentação, utilizando nove AIM (AT3-I/D, APO, SB19.3, PV92, FYnull, LPL, CKMM, GC-F, GC-S e CYP3A4), seis polimorfismos em genes envolvidos na pigmentação da pele (SCL45A2, SCL24A5, MC1R, OCA2, TYR, ASIP) em duas tribos indígenas do Norte do Brasil – Tiriyó e Waiampi; em indivíduos caracterizados fenotipicamente como negros de Salvador, numa amostra de miscigenados da Bahia e em descendentes de japoneses e de europeus de Ribeirão Preto-SP. As frequências alélicas de todos os marcadores encontradas nos afro e eurodescendentes foram similares às encontradas nos ancestrais africanos e europeus e a estimativa de mistura mostrou respectivamente maior contribuição africana - 71% e 66%; e europeia - 86% e 99% com AIM e com os marcadores de pigmentação respectivamente. Os japoneses mostraram frequências alélicas diferentes quando comparadas com os Nativos Americanos, e a contribuição Ameríndia/Asiática observada foi 81% com AIM e 86% com marcadores de pigmentação. Entre os índios Tiriyó e Waiampi foi observada baixa contribuição de povos não indígenas nas estimativas de mistura com AIM (< 10%) e nenhuma mistura quando avaliados apenas os marcadores de pigmentação, sugerindo que essas tribos conservam muitas características ancestrais. As estimativas de mistura nos indivíduos miscigenados da Bahia mostrou predomínio de contribuição europeia utilizando os marcadores de pigmentação da pele e maior contribuição africana utilizando os AIM. A distribuição genotípica dos marcadores de pigmentação da pele foi concordante com a classificação fenotípica realizada nos miscigenados (Bahia) em brancos, mulatos e negros, corroborando dados da literatura que mostram o envolvimento desses marcadores na variação normal da pigmentação da pele em diferentes grupos étnicos. / The Brazilian population presents extensive genetic variability, resulting from admixture among Amerindian, Europeans and Africans. However, the proportion of Africans Amerindians and Europeans differ depending on the geographic region. To evaluate the admixture and understand how it occurred, nowadays has been used molecular markers known as Ancestry Informative Markers (AIMs). Skin color is one of the phenotypes that vary most among human populations and different ethnic groups and geographic regions, due to genetic heterogeneity and natural selection. Many genes that are involved in the synthesis of melanin, and proteins involved in cellular metabolism have been described as associated with pigmentation (eye color, hair and skin), and some of them have different allele frequencies between different ethnic groups, but the mechanisms that involved with the variation of the normal skin pigmentation are not yet fully established. The aims of this study was to estimate the genomic ancestry and analyze polymorphisms in genes that modulate normal variation in pigmentation and verify the association between ancestry and skin pigmentation, using nine AIMs (AT3-I/D, APO, SB19.3, PV92, FYnull, LPL, CKMM, GC-F and GC-S) and six genes relate to pigmentation (SCL45A2, SCL24A5, MC1R, OCA2, TYR, ASIP) in two Amerindian tribes from North of Brazil,Tiriyó and Waiampi; urban samples of African descents from Salvador and European and Japanese descents from Ribeirão Preto,SP. The results show that allele frequencies of all markers found in blacks and whites were similar to those in European and African populations and the estimation of admixture with AIMs presents greater African contribution (71%) and European (86%), respectively; which was also observed with the pigmentation markers (99% of European contribution in whites and 66% of African contribution in blacks). The analysis in the Japanese showed allelic frequencies different from the Amerindians and the Amerindian/ Asian contribution observed were 81% with the AIMs and 86% with the pigmentation markers. Among the Amerindians from Tiriyó and Waiampi was observed low contribution of non- Amerindian populations in the admixture estimation with AIMs and even no admixture when used markers of pigmentation, suggesting that, despite the intense process of admixture occurred in Brazil, some tribes still present a homogeneous genetic profile and, preserve the ancestors’ characteristics. The ancestry estimation with markers of skin pigmentation in admixed individuals from Bahia showed high levels of European and Amerindian ancestry contribution compared with the African contribution, which had been the most significant in studies with AIMs, but when analyzed the genotypic distribution of pigmentation markers’ between admixed individuals phenotypically classified as white, mulatto and black, it can be observed that the most frequent allele in Europeans and Africans were in homozygosity among blacks and whites, confirming published data that show the involvement of these markers in mechanisms that determinate the skin pigmentation in different ethnic groups, but also suggest that these markers are not useful tools to define ancestry in admixed populations.

Adverse effects of amiodarone are rarely seen in pediatric patients, but may occur if amiodarone is applied for long-term treatment. Two rather rare phenomena are blue-gray skin pigmentation and pulmonary mass. They represent important differential diagnoses from more common clinical complications like pneumonia and drug-induced toxic skin lesions.