Oestrogen-induced epithelial-mesenchymal transition of endometrial epithelial cells contributes to the development of adenomyosis.

Adenomyosis is an oestrogen-dependent disease caused by a downward extension of the endometrium into the uterine myometrium. Epithelial-mesenchymal transition (EMT) endows cells with migratory and invasive properties and can be induced by oestrogen. We hypothesized that oestrogen-induced EMT is critical in the pathogenesis of adenomyosis. We first investigated whether EMT occurred in adenomyotic lesions and whether it correlated with serum 17ß-oestradiol (E2) levels. Immunohistochemistry was performed on adenomyotic lesions and corresponding eutopic endometrium samples from women with adenomyosis. Endometria from women without endometrial disorders were used as a control. In the epithelial component of adenomyotic lesions, vimentin expression was up-regulated and E-cadherin expression was down-regulated compared to the eutopic endometrium, suggesting that EMT occurs in adenomyosis. In adenomyosis, the serum E2 level was negatively correlated with E-cadherin expression in the epithelial components of the eutopic endometrium and adenomyotic lesions, suggesting the involvement of oestrogen-induced EMT in endometrial cells. In oestrogen receptor-positive Ishikawa endometrial epithelial cells, oestrogen induced a morphological change to a fibroblast-like phenotype, a shift from epithelial marker expression to mesenchymal marker expression, increased migration and invasion, and up-regulation of the EMT regulator Slug. Raloxifene, a selective oestrogen receptor modulator, abrogated these effects. To determine the role of oestrogen-induced EMT in the implantation of ectopic endometrium, we xenotransplanted eutopic endometrium or adenomyotic lesions from adenomyosis patients into ovariectomized SCID mice. The implantation of endometrium was oestrogen-dependent and was suppressed by raloxifene. Collectively, these data highlight the crucial role of oestrogen-induced EMT in the development of adenomyosis and suggest that raloxifene may be a potential therapeutic agent for adenomyosis patients.

The RssB/RssA two-component system regulates biosynthesis of the tripyrrole antibiotic, prodigiosin, in Serratia marcescens.

Serratia marcescens CH-1 produces a red, cell-associated pigment, prodigiosin, synthesized by enzymes encoded in the pig operon. The underlying regulatory mechanism, especially its relationship with the RssAB two-component system signaling, remained uncharacterized. Here, we show that phosphorylated RssB (RssB-P) directly binds to the promoter region of the pig operon (pigA promoter), as observed using an electrophoretic mobility shift assay. Furthermore, we identify the RssB-P binding site located downstream of the -10 and -35 regions in pigA using a DNase I footprinting assay. A compilation of the RssB-P binding sites in flhDC, rssB and pigA promoter regions reveals the presence of a conserved core sequence, GAGATTTTAGCTAAATTAATBTTT (B=C, G, or T), which we believe is the RssB binding sequence. Site-specific mutation of conserved nucleotides within the conserved RssB binding sequence in the pigA promoter region leads to absence of retardation in the presence of RssB-P in vitro and elevated transcription of pigA in vivo. These data suggest that RssAB signaling negatively regulates prodigiosin production, and such inhibition is mediated through direct and specific repression of transcriptional activity of the pig operon.

Inhibition of the epstein-barr virus lytic cycle by andrographolide.

Andrographis paniculata NEES is a medicinal plant that is commonly used in Asia. This work demonstrates that 25 microg/ml of ethanolic extract from A. paniculata (EEAP) and 5 microg/ml of andrographolide, a bioactive compound in EEAP, effectively inhibit the expression of Epstein-Barr virus (EBV) lytic proteins, Rta, Zta and EA-D, during the viral lytic cycle in P3HR1 cells. Transient transfection analysis revealed that the lack of expression of Rta, Zta and EA-D is caused by the inhibition of the transcription of BRLF1 and BZLF1, two EBV immediate-early genes that encode Rta and Zta, respectively. This study finds that the inhibition prevents the virus from producing mature viral particles. Meanwhile, andrographolide is not toxic to P3HR1 cells when the concentration is below 5 microg/ml, indicating that the compound is potentially useful as an anti-EBV drug.