RESUMO
This study describes the identification and target deconvolution of small molecule inhibitors of oncogenic Yes-associated protein (YAP1)/TAZ activity with potent anti-tumor activity in vivo. A high-throughput screen (HTS) of 3.8 million compounds was conducted using a cellular YAP1/TAZ reporter assay. Target deconvolution studies identified the geranylgeranyltransferase-I (GGTase-I) complex as the direct target of YAP1/TAZ pathway inhibitors. The small molecule inhibitors block the activation of Rho-GTPases, leading to subsequent inactivation of YAP1/TAZ and inhibition of cancer cell proliferation in vitro. Multi-parameter optimization resulted in BAY-593, an in vivo probe with favorable PK properties, which demonstrated anti-tumor activity and blockade of YAP1/TAZ signaling in vivo.
Assuntos
Proteínas Adaptadoras de Transdução de Sinal , Antineoplásicos , Proliferação de Células , Ensaios de Triagem em Larga Escala , Transdução de Sinais , Fatores de Transcrição , Proteínas de Sinalização YAP , Humanos , Fatores de Transcrição/metabolismo , Fatores de Transcrição/antagonistas & inibidores , Proteínas de Sinalização YAP/metabolismo , Antineoplásicos/farmacologia , Antineoplásicos/química , Antineoplásicos/síntese química , Transdução de Sinais/efeitos dos fármacos , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/antagonistas & inibidores , Animais , Proliferação de Células/efeitos dos fármacos , Camundongos , Proteínas rho de Ligação ao GTP/metabolismo , Proteínas rho de Ligação ao GTP/antagonistas & inibidores , Linhagem Celular Tumoral , Fosfoproteínas/metabolismo , Fosfoproteínas/antagonistas & inibidores , Ensaios de Seleção de Medicamentos Antitumorais , Alquil e Aril Transferases/antagonistas & inibidores , Alquil e Aril Transferases/metabolismo , Bibliotecas de Moléculas Pequenas/química , Bibliotecas de Moléculas Pequenas/farmacologia , Descoberta de Drogas , Camundongos Nus , Aciltransferases/antagonistas & inibidores , Aciltransferases/metabolismo , Fenótipo , Relação Estrutura-Atividade , Proteínas com Motivo de Ligação a PDZ com Coativador TranscricionalRESUMO
Alcoholic liver disease (ALD) affects millions of people worldwide and is a major cause of morbidity and mortality. However, fewer than 10% of heavy drinkers progress to later stages of injury, suggesting other factors in ALD development, including environmental exposures and genetics. Females display greater susceptibility to the early damaging effects of ethanol. Estrogen (E2) and ethanol metabolizing enzymes (cytochrome P450, CYP450) are implicated in sex differences of ALD. Sex steroid hormones are developmentally regulated by the hypothalamic-pituitary-gonadal (HPG) axis, which controls sex-specific cycling of gonadal steroid production and expression of hepatic enzymes. The aim of this study was to determine if early postnatal inhibition of adult cyclic E2 alters ethanol metabolizing enzyme expression contributing to the development of ALD in adulthood. An androgenized rat model was used to inhibit cyclic E2 production. Control females (Ctrl), androgenized females (Andro) and Andro females with E2 implants were administered either an ethanol or isocalorically-matched control Lieber-DeCarli diet for four weeks and liver injury and CYP450 expression assessed. Androgenization exacerbated the deleterious effects of ethanol demonstrated by increased steatosis, lipid peroxidation, profibrotic gene expression and decreased antioxidant defenses compared to Ctrl. Additionally, CYP2E1 expression was down-regulated in Andro animals on both diets. No change was observed in CYP1A2 protein expression. Further, continuous exogenous administration of E2 to Andro in adulthood attenuated these effects, suggesting that E2 has protective effects in the androgenized animal. Therefore, early postnatal inhibition of cyclic E2 modulates development and progression of ALD in adulthood.
Assuntos
Androgênios/farmacologia , Estrogênios/farmacologia , Etanol/efeitos adversos , Hepatopatias Alcoólicas/tratamento farmacológico , Hepatopatias Alcoólicas/etiologia , Animais , Animais Recém-Nascidos , Sistema Enzimático do Citocromo P-450/genética , Progressão da Doença , Estrogênios/uso terapêutico , Fígado Gorduroso Alcoólico/tratamento farmacológico , Fígado Gorduroso Alcoólico/etiologia , Fígado Gorduroso Alcoólico/genética , Fígado Gorduroso Alcoólico/metabolismo , Feminino , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Hepatopatias Alcoólicas/genética , Hepatopatias Alcoólicas/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Ratos , Ratos Wistar , Caracteres Sexuais , Superóxido Dismutase/metabolismoRESUMO
BACKGROUND: Liver fibrosis is the excessive accumulation of extracellular matrix (ECM) components that disrupt normal liver microcirculation and lead to organ injury. Hepatic stellate cells (HSCs), following transdifferentiation, are the central mediators of hepatic fibrosis through increased secretion of ECM components, including type I collagen. AIMS: The mechanism(s) by which the antioxidant S-adenosyl-L-methionine (SAMe) acts to modulate type I collagen secretion in activated HSCs was examined. METHODS: Hepatic stellate cells were culture-activated for 13-15 days and treated with SAMe. Type I collagen, proteasomal activity and resident endoplasmic reticulum (ER) protein [78-kDa glucose-regulated protein (Grp78) and protein disulphide isomerase (PDI)] expression were measured. Nuclear factor-κB (NF-κB) activity, and its role in SAMe-mediated collagen inhibition, was determined. Type I collagen polyubiquitination was examined. RESULTS: S-adenosyl-L-methionine significantly inhibited type I collagen secretion without significant changes in type I collagen mRNA expression. SAMe also increased NF-κB activity, and blocking NF-κB activity using a dominant-negative IκBα abolished the SAMe-mediated type I collagen secretion. Examination of the post-transcriptional fate of procollagen demonstrated that SAMe treatment led to intracellular type I collagen polyubiquitination accompanied by diminution of proteasomal activity. Expression of Grp78 and PDI (resident ER proteins) were significantly decreased by SAMe treatment. CONCLUSIONS: S-adenosyl-L-methionine inhibits collagen processing leading to increased ubiquitination and decreased secretion. These findings represent a novel mechanism for modulating type I collagen expression in activated HSCs.
Assuntos
Antioxidantes/farmacologia , Colágeno Tipo I/metabolismo , Células Estreladas do Fígado/efeitos dos fármacos , Processamento de Proteína Pós-Traducional/efeitos dos fármacos , S-Adenosilmetionina/farmacologia , Análise de Variância , Animais , Colágeno Tipo I/genética , Cadeia alfa 1 do Colágeno Tipo I , Relação Dose-Resposta a Droga , Regulação para Baixo , Retículo Endoplasmático/efeitos dos fármacos , Retículo Endoplasmático/metabolismo , Chaperona BiP do Retículo Endoplasmático , Proteínas de Choque Térmico/metabolismo , Células Estreladas do Fígado/metabolismo , Masculino , Camundongos , NF-kappa B/metabolismo , Células NIH 3T3 , Complexo de Endopeptidases do Proteassoma/metabolismo , Isomerases de Dissulfetos de Proteínas/metabolismo , Transporte Proteico , RNA Mensageiro/metabolismo , Ratos , Ratos Sprague-Dawley , Transdução de Sinais/efeitos dos fármacos , Fatores de Tempo , Transcrição Gênica/efeitos dos fármacos , Ubiquitinação , Regulação para CimaRESUMO
AIM: To identify signaling pathways and genes that initiate and commit hepatic stellate cells (HSCs) to transdifferentiation. METHODS: Primary HSCs were isolated from male Sprague-Dawley rats and cultured on plastic for 0-10 d. Gene expression was assessed daily (quiescent to day 10 culture-activation) by real time polymerase chain reaction and data clustered using AMADA software. The significance of JAK/STAT signaling to HSC transdifferentiation was determined by treating cells with a JAK2 inhibitor. RESULTS: Genetic cluster analyses, based on expression of these 21 genes, showed similar expression profiles on days 1-3, days 5 and 6, and days 7-10, while freshly isolated cells (day Q) and day 4 cells were genotypically distinct from any of the other days. Additionally, gene expression clustering revealed strong upregulation of interleukin-6, JAK2 and STAT3 mRNA in the early stages of activation. Inhibition of the JAK/STAT signaling pathway impeded the morphological transdifferentiation of HSCs which correlated with decreased mRNA expression of several profibrotic genes including collagens, α-SMA, PDGFR and TGFßR. CONCLUSION: These data demonstrate unique clustered genetic profiles during the daily progression of HSC transdifferentiation and that JAK/STAT signaling may be critical in the early stages of transdifferentiation.