Beneficial effects attributed to green tea, such as its anticancer and antioxidant properties, may be mediated by (-)-epigallocatechin-3-gallate (EGCG). In this study, the effects of EGCG on cell proliferation and UV-induced apoptosis were investigated in normal epidermal keratinocytes. When topically applied to aged human skin, EGCG stimulated the proliferation of epidermal keratinocytes, which increased the epidermal thickness. In addition, this topical application also inhibited the UV-induced apoptosis of epidermal keratinocytes. EGCG was found to increase the phosphorylation of Bad protein at the Ser112 and Ser136. Moreover, EGCG-induced Erk phosphorylation was found to be critical for the phosphorylation of Ser112 in Bad protein, and the EGCG-induced activation of the Akt pathway was found to be involved in the phosphorylation of Ser136. Furthermore, EGCG increased Bcl-2 expression but decreased Bax expression, causing an increase in the Bcl-2-to-Bax ratio. In addition, we demonstrate the differential growth inhibitory effects of EGCG on cancer cells. In conclusion, this study demonstrates that EGCG promotes keratinocyte survival and inhibits the UV-induced apoptosis via two mechanisms: by phosphorylating Ser112 and Ser136 of Bad protein through Erk and Akt pathways, respectively, and by increasing the Bcl-2-to-Bax ratio. Moreover, these two proposed mechanisms of EGCG-induced cell proliferation may differ kinetically to promote keratinocyte survival.

The Mis18 complex has been identified as a critical factor for the centromeric localization of a histone H3 variant, centromeric protein A (CENP-A), which is responsible for the specification of centromere identity in the chromosome. However, the functional role of Mis18 complex is largely unknown. Here, we generated Mis18a conditional knockout mice and found that Mis18a deficiency resulted in lethality at early embryonic stage with severe defects in chromosome segregation caused by mislocalization of CENP-A. Further, we demonstrate Mis18a's crucial role for epigenetic regulation of centromeric chromatin by reinforcing centromeric localization of DNMT3A/3B. Mis18a interacts with DNMT3A/3B, and this interaction is critical for maintaining DNA methylation and hence regulating epigenetic states of centromeric chromatin. Mis18a deficiency led to reduced DNA methylation, altered histone modifications, and uncontrolled noncoding transcripts in centromere region by decreased DNMT3A/3B enrichment. Together, our findings uncover the functional mechanism of Mis18a and its pivotal role in mammalian cell cycle.

Seborrheic keratoses are common in the Korean males, aged 40-70 years, and may be a major pigmentary problem. Both aging and cumulative sunlight exposure were found to be independent contributory factors.

An elevated At/Et ratio in the fetal pulmonary artery is independently associated with the development of RDS in preterm infants. These data suggest that fetal pulmonary artery Doppler velocimetry may provide a reliable noninvasive technique to evaluate fetal lung maturity, similar to the way in which middle cerebral artery Doppler has replaced amniocentesis for the assessment of fetal anemia.