RESUMO
In this study we showed that Rottlerin (also called Kamala or Mallotoxin), a natural product purified from Mallotus phillippinensis, is a potent suppressor of human keratinocytes (HaCaT cell line) proliferation. Following Rottlerin treatment, Thymidine incorporation into DNA and re-epithelialisation in a scratch wound model was decreased. At the molecular level, Rottlerin hampered the NFkB activation process, causing loss of cyclin D1 and promoting, in a PKCdelta-dependent pathway, ERK activation, which, in turn induced the cell cycle inhibitor p21 Cip1/Kip1. The NFkB-dependent drop in cyclin D1, along with the PKCdelta/ERK-dependent induction of p21 Cip1/Kip1, is responsible for growth arrest. These results open the way to further investigation on the Rottlerin therapeutic potential against keratinocyte hyper-proliferative disorders.
Assuntos
Acetofenonas/farmacologia , Benzopiranos/farmacologia , Inibidores do Crescimento/farmacologia , Queratinócitos/efeitos dos fármacos , Inibidores de Proteínas Quinases/farmacologia , Transporte Ativo do Núcleo Celular/efeitos dos fármacos , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Transformada/efeitos dos fármacos , Células Cultivadas/citologia , Células Cultivadas/efeitos dos fármacos , Ciclina D1/biossíntese , Ciclina D2 , Inibidor de Quinase Dependente de Ciclina p21/biossíntese , Inibidor de Quinase Dependente de Ciclina p21/genética , Ciclinas/biossíntese , Ciclinas/genética , Avaliação Pré-Clínica de Medicamentos , MAP Quinases Reguladas por Sinal Extracelular/antagonistas & inibidores , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Genes bcl-1/efeitos dos fármacos , Humanos , Técnicas In Vitro , Queratinócitos/citologia , NF-kappa B/antagonistas & inibidores , Fosforilação/efeitos dos fármacos , Proteína Quinase C-delta/antagonistas & inibidores , Proteína Quinase C-delta/fisiologia , Processamento de Proteína Pós-Traducional/efeitos dos fármacos , Cicatrização/efeitos dos fármacosRESUMO
Because the precise immunopathological events occurring in appendicitis are not completely understood, possible local production of endothelin-1 (ET-1) in human appendix was investigated. We used immunohistochemistry and in situ hybridization to detect the presence, distribution, and phenotype of ET-1-positive cells and prepro-ET-1 (pp-ET-1) mRNA-expressing cells. ET-1-positive stromal cells and pp-ET-1 mRNA-expressing cells were detected with different distributions and relative frequencies in normal control appendix, histologically normal appendix, and inflamed appendix. Six of 20 histologically normal appendixes from patients with a clinical diagnosis of acute appendicitis had many ET-1-positive stromal cells and high pp-ET-1 mRNA expression, similar to inflamed appendix. Forty percent of the pp-ET-1 mRNA-expressing cells were neutrophils, and the other positive cells were mast cells and macrophages. We suggest that local production of ET-1 by neutrophils and other inflammatory cells could be a molecular sign of focal inflammation in histologically normal appendixes and that ET-1 could be implicated, with other cytokines, in the pathogenesis of appendicitis by inducing appendiceal ischemia through vasoconstriction.