Ribosomal DNA methylation in human and mouse oocytes increases with age

An age-dependent increase in ribosomal DNA (rDNA) methylation has been observed across a broad spectrum of somatic tissues and the male mammalian germline. Bisulfite pyrosequencing (BPS) was used to determine the methylation levels of the rDNA core promoter and the rDNA upstream control element (UCE) along with two oppositely genomically imprinted control genes (PEG3 and GTL2) in individual human germinal vesicle (GV) oocytes from 90 consenting women undergoing fertility treatment because of male infertility. Apart from a few (4%) oocytes with single imprinting defects (in either PEG3 or GTL2), the analyzed GV oocytes displayed correct imprinting patterns. In 95 GV oocytes from 42 younger women (26-32 years), the mean methylation levels of the rDNA core promoter and UCE were 7.4±4.0% and 9.3±6.1%, respectively. In 79 GV oocytes from 48 older women (33-39 years), methylation levels increased to 9.3±5.3% (P = 0.014) and 11.6±7.4% (P = 0.039), respectively. An age-related increase in oocyte rDNA methylation was also observed in 123 mouse GV oocytes from 29 4-16-months-old animals. Similar to the continuously mitotically dividing male germline, ovarian aging is associated with a gain of rDNA methylation in meiotically arrested oocytes. Oocytes from the same woman can exhibit varying rDNA methylation levels and, by extrapolation, different epigenetic ages

Genetic polymorphism in an inflammasome component, cervical mycoplasma detection and female infertility in women undergoing in vitro fertilization

The inflammasome is an inducible cytoplasmic structure that is responsible for production and release of biologically active interleukin-1 (IL-1). A polymorphism in the inflammasome component NALP3 has been associated with decreased IL-1 levels and increased occurrence of vaginal Candida infection. We hypothesized that this polymorphism-induced variation would influence susceptibility to infertility. DNA was obtained from 243 women who were undergoing in vitro fertilization (IVF) and tested for a length polymorphism in intron 2 of the gene coding for NALP3 (gene symbol CIAS1). At the conclusion of testing the findings were analyzed in relation to clinical parameters and IVF outcome. The frequency of the 12 unit repeat allele, associated with maximal inflammasome activity, was 62.3% in cases of female infertility vs. 75.6% in cases where only the male partner had a detectable fertility problem (p = 0.0095). Conversely, the frequency of the 7 unit repeat allele was 28.9% in those with a female fertility problem, 17.0% in women with infertile males and 18.4% in idiopathic infertility (p = 0.0124). Among the women who were cervical culture-positive for mycoplasma the frequency of the 7 unit repeat was 53.7% as opposed to 19.5% in those negative for this infection (p < 0.0001). We conclude that the CIAS1 7 unit repeat polymorphism increases the likelihood of mycoplasma infection-associated female infertility. (C) 2009 Elsevier Ireland Ltd. All rights reserved

Desquamated epithelial cells covered with a polymicrobial biofilm typical for bacterial vaginosis are present in randomly selected cryopreserved donor semen

We tested whether the bacterial biofilm typical for bacterial vaginosis (BV) can be found on desquamated epithelial cells in cryopreserved donor semen. Bacteria were detected with FISH. Bacterial biofilm, covering the epithelial layer in vaginal biopsies of 20 women with BV, was evaluated on desquamated epithelial cells found in the urine of these same women and their male partners (N=20) and compared with the bacterial biofilm found on desquamated epithelial cells in randomly selected cryopreserved semen samples (N=20). Urine from 20 healthy women of laboratory and clinic personnel and urine from their partners were used as controls. Desquamated epithelial cells covered with a polymicrobial Gardnerella biofilm were identified in urine samples from all women with BV and 13 of their male partners and in none of the female controls and their partners. Gardnerella biofilm, typical for BV, was found in the semen of three of the 20 donors. Donor semen might be a vector for BV

Specific inhibition of fibroblast activation protein (FAP)-alpha prevents tumor progression in vitro

Solid tumors modulate their environment to keep non-malignant stromal cells in a tumor-promoting state. The main cells in the stroma of epithelial derived tumors are cancer associated fibroblasts (CAF) that are critical to tumorigenesis and angiogenesis. CAFs also supply the tumor cells with growth factors and extracellular matrix (ECM) degrading enzymes. They are thus essential for tumor initiation as well as tumor progression and metastasis, suggesting that they represent an ideal cellular target of an integrative tumor therapy. Fibroblast activation protein (FAP) is a well-defined marker, expressed at high levels on the cell surface of CAFs. FAP, a constitutively active serine peptidase with both dipeptidyl peptidase IV (DPP IV) and collagenase/gelatinase activity, promotes malignant and invasive behavior of epithelial cancers. High stromal expression levels of FAP correlate with poor prognosis. FAP is difficult to detect in non-diseased adult tissue, but it is generally expressed at sites of tissue remodeling.; In our experiments, we aimed for a reduction of the pro-tumorigenic activities of CAFs by depleting FAP from fibroblasts growing in a composite environment with epithelial tumor cells.; FAP depletion was achieved by two therapeutically relevant approaches: a novel internalizing anti-FAP IgG1 antibody and FAP gene knock-down by siRNA delivery. The antibody effectively removed FAP from the cell surface and was capable of reversing the FAP mediated migratory and invasive capacity. FAP RNA interference was equally effective when compared to the antibody.; Thus, targeting FAP on CAF suppresses pro-tumorigenic activities and may result in a clinically effective reduction of tumor progression and dissemination

Mutations in the N-terminal kinase-like domain of the repressor of photomorphogenesis SPA1 severely impair SPA1 function but not light responsiveness in Arabidopsis

The COP1/SPA complex is an E3 ubiquitin ligase that acts as a key repressor of photomorphogenesis in dark-grown plants. While both COP1 and the four SPA proteins contain coiled-coil and WD-repeat domains, SPA proteins differ from COP1 in carrying an N-terminal kinase-like domain that is not present in COP1. Here, we have analyzed the effects of deletions and missense mutations in the N-terminus of SPA1 when expressed in a spa quadruple mutant background devoid of any other SPA proteins. Deletion of the large N-terminus of SPA1 severely impaired SPA1 activity in transgenic plants with respect to seedling etiolation, leaf expansion and flowering time. This DN SPA1 protein showed a strongly reduced affinity for COP1 in vitro and in vivo, indicating that the N-terminus contributes to COP1/SPA complex formation. Deletion of only the highly conserved 95 amino acids of the kinase-like domain did not severely affect SPA1 function nor interactions with COP1 or cryptochromes. In contrast, missense mutations in this part of the kinase-like domain severely abrogated SPA1 function, suggesting an overriding negative effect of these mutations on SPA1 activity. We therefore hypothesize that the sequence of the kinase-like domain has been conserved during evolution because it carries structural information important for the activity of SPA1 in darkness. The N-terminus of SPA1 was not essential for light responsiveness of seedlings, suggesting that photoreceptors can inhibit the COP1/SPA complex in the absence of the SPA1 N-terminal domain. Together, these results uncover an important, but complex role of the SPA1 N-terminus in the suppression of photomorphogenesis