RESUMEN
BACKGROUND: Cytosine methylation of regulatory regions, such as promoters and enhancers, plays a key role in regulating gene expression, however, its role in kidney development has not been analyzed. METHODS: To identify functionally important epigenome-modifying enzymes and genome regions where methylation modifications are functionally important for kidney development, we performed genome-wide methylation analysis, expression profiling, and systematic genetic targeting of DNA methyltransferases (Dnmt1, Dnmt3a, and Dnmt3b) and Ten-eleven translocation methylcytosine hydroxylases (Tet2) in nephron progenitor cells (Six2Cre) in mice. RESULTS: Genome-wide methylome analysis indicated dynamic changes on promoters and enhancers during development. Six2CreDnmt3af/f, Six2CreDnmt3bf/f, and Six2CreTet2f/f mice showed no significant structural or functional renal abnormalities. In contrast, Six2CreDnmt1f/f mice died within 24 hours of birth, from a severe kidney developmental defect. Genome-wide methylation analysis indicated a marked loss of methylation of transposable elements. RNA sequencing detected endogenous retroviral transcripts. Expression of intracellular viral sensing pathways (RIG-I), early embryonic, nonrenal lineage genes and increased cell death contributed to the phenotype development. In podocytes, loss of Dnmt1, Dnmt3a, Dnmt3b, or Tet2 did not lead to functional or structural differences at baseline or after toxic injury. CONCLUSIONS: Genome-wide cytosine methylation and gene expression profiling showed that by silencing embryonic, nonrenal lineage genes and transposable elements, DNMT1-mediated cytosine methylation is essential for kidney development.
Asunto(s)
ADN (Citosina-5-)-Metiltransferasa 1/genética , Metilación de ADN , Epigenoma/genética , Proteínas de Homeodominio/genética , Riñón/crecimiento & desarrollo , Células Madre/fisiología , Factores de Transcripción/genética , Animales , ADN (Citosina-5-)-Metiltransferasa 1/metabolismo , ADN (Citosina-5-)-Metiltransferasas/genética , ADN Metiltransferasa 3A , Elementos Transponibles de ADN , Proteínas de Unión al ADN/genética , Dioxigenasas , Elementos de Facilitación Genéticos , Expresión Génica , Silenciador del Gen , Riñón/enzimología , Masculino , Ratones , Podocitos/citología , Podocitos/fisiología , Regiones Promotoras Genéticas , Proteínas Proto-Oncogénicas/genética , ARN Viral/análisis , Análisis de Secuencia de ARN , Células Madre/citología , Transcriptoma , ADN Metiltransferasa 3BRESUMEN
The fruits of Juniperus communis have been traditionally used in the treatment of skin diseases. In our preliminary experiment, the MeOH extract of J. communis effectively suppressed mushroom tyrosinase activity. Three monoflavonoids and five biflavonoids were isolated from J. communis by bioassay-guided isolation and their inhibitory effect against tyrosinase was evaluated. According to the results of all isolates, hypolaetin 7-O-ß-xylopyranoside isolated from J. communis exhibited most potent effect of decreasing mushroom tyrosinase activity with an IC50 value of 45.15 µM. Further study provided direct experimental evidence for hypolaetin 7-O-ß-D-xylopyranoside-attenuated tyrosinase activity in α-MSH-stimulated B16F10 murine melanoma cell. Hypolaetin 7-O-ß-D-xylopyranoside from the EtOAc fraction of J. communis was also effective at suppressing α-MSH-induced melanin synthesis. This is the first report of the enzyme tyrosinase inhibition by J. communis and its constituent. Therapeutic attempts with J. communis and its active component, hypolaetin 7-O-ß-D-xylopyranoside, might be useful in treating melanin pigmentary disorders.