Isabella Gashaw

Induced Endometriosis in the Baboon (Papio anubis) Increases the Expression of the Proangiogenic Factor CYR61 (CCN1) in Eutopic and Ectopic Endometria

Abstract The expression of human CYR61 (cysteine-rich, angiogenic inducer, 61; CCN1) mRNA has been previously shown to be deregulated in the endometrium of women with endometriosis. We have chosen the baboon model (Papio anubis) of induced endometriosis to clarify whether CYR61 mRNA upregulation is predisposed to an inappropriately differentiated endometrium or is deregulated as a response to the presence of ectopic lesions. In the baboon, endometrial CYR61 mRNA expression underwent moderate cyclical variation, with a significant 7.3-fold increase detected at Day 2 postmenses when compared to endometrium from the proliferative and secretory phases. The CYR61 transcript was extensively upregulated in the eutopic endometrium from all baboons with induced endometriosis, as early as 1 mo postinoculation of menstrual tissue into the peritoneal cavity. CYR61 mRNA expression then decreased throughout progression of the disease, but remained higher compared to control tissues. Ectopic endometriotic lesions showed a further increase in CYR61 mRNA, with highest expression found in red lesions. Moreover, the expression levels of CYR61 transcripts correlated significantly with those of VEGF. Immunohistochemistry revealed the presence of CYR61 protein in glandular and luminal epithelial cells as well as in blood vessels of eutopic and ectopic endometrium. As in humans, increased levels of CYR61 mRNA correlated with the development of endometriosis in baboons. The increase of CYR61 mRNA in eutopic endometrium of baboons following peritoneal inoculation with menstrual endometrium provides evidence for a feedback mechanism from resulting lesions to induce a shift in gene expression patterns in the eutopic endometrium.

Gene signatures of testicular seminoma with emphasis on expression of ets variant gene 4

Abstract.Gene expression patterns of testicular seminoma were analysed applying oligonucleotide microarrays in 40 specimens of different tumour stages (pT1, pT2, pT3) and in normal testes. Transcripts of maternally expressed 3 transcripts were expressed in seminoma without correlation with delta-like 1 homologue expression indicating an impaired imprinting status in seminoma. Interestingly, the transcripts of bromodomain-containing 2 and nuclear autoantigenic sperm protein associated with spermatogenesis were significantly upregulated in progressing tumour stages. Transcription factors TEA domain family member 4 and ETS variant gene 4 (ETV4), weakly expressed in normal testis, were strongly augmented during tumourigenesis. For ETV4 expression, a significant correlation with the increased expression of matrix metalloproteinase 2 and a disintegrin and metalloproteinase domain 15 was determined. The ETV4 protein was localised to nuclei of spermatogonia and revealed an intense staining in seminoma cells. Taken together, we characterised additional transcription factors and spermatogenesis-associated genes involved in the progression of seminoma.

TLR3 and TLR4 expression in healthy and diseased human endometrium

BackgroundToll-like receptors (TLRs) play an essential role in the innate immune system by initiating and directing immune response to pathogens. TLRs are expressed in the human endometrium and their regulation might be crucial for the pathogenesis of endometrial diseases.MethodsTLR3 and TLR4 expression was investigated during the menstrual cycle and in postmenopausal endometrium considering peritoneal endometriosis, hyperplasia, and endometrial adenocarcinoma specimens (grade 1 to 3). The expression studies applied quantitative RT-PCR and immunolabelling of both proteins.ResultsTLR3 and TLR4 proteins were mostly localised to the glandular and luminal epithelium. In addition, TLR4 was present on endometrial dendritic cells, monocytes and macrophages. TLR3 and TLR4 mRNA levels did not show significant changes during the menstrual cycle. In patients with peritoneal endometriosis, TLR3 and TLR4 mRNA expression decreased significantly in proliferative diseased endometrium compared to controls. Interestingly, ectopic endometriotic lesions showed a significant increase of TLR3 und TLR4 mRNA expression compared to corresponding eutopic tissues, indicating a local gain of TLR expression. Endometrial hyperplasia and adenocarcinoma revealed significantly reduced receptor levels when compared with postmenopausal controls. The lowest TLR expression levels were determined in poor differentiated carcinoma (grade 3).ConclusionOur data suggest an involvement of TLR3 and TLR4 in endometrial diseases as demonstrated by altered expression levels in endometriosis and endometrial cancer.

Krüppel-like factor 4, a "pluripotency transcription factor" highly expressed in male postmeiotic germ cells, is dispensable for spermatogenesis in the mouse.

Krüppel-like factor 4 (Klf4, GKLF) was originally characterized as a zinc finger transcription factor essential for terminal differentiation and cell lineage allocation of several cell types in the mouse. Mice lacking Klf4 die postnatally within hours due to impaired skin barrier function and subsequent dehydration. Recently, KLF4 was also used in cooperation with other transcription factors to reprogram differentiated cells to pluripotent embryonic stem cell-like cells. Moreover, involvement in oncogenesis was also ascribed to KLF4, which is aberrantly expressed in some types of tumors such as breast, gastric and colon cancer. We previously have shown that Klf4 is strongly expressed in postmeiotic germ cells of mouse and human testes suggesting a role for Klf4 also during spermiogenesis. In order to analyze its function we deleted Klf4 in germ cells using the Cre-loxP system. Homologous recombination of the Klf4 locus has been confirmed by genomic southern blotting and the absence of the protein in germ cells was demonstrated by Western blotting and immunofluorescence. Despite its important roles in several significant biological settings, deletion of Klf4 in germ cells did not impair spermiogenesis. Histologically, the mutant testes appeared normal and the mice were fertile. In order to identify genes that were regulated by KLF4 in male germ cells we performed microarray analyses using a whole genome array. We identified many genes exhibiting changed expression in mutants even including the telomerase reverse transcriptase mRNA, which is a stem cell marker. However, in summary, the lack of KLF4 alone does not prevent complete spermatogenesis.

The pluripotency transcription factor Krüppel-like factor 4 is strongly expressed in intratubular germ cell neoplasia unclassified and seminoma

Germ cell tumors of the testis are the most frequent tumors in men between 20 and 40 years. Their most common subtype is the seminoma, which arises like the embryonal carcinoma from an intratubular germ cell neoplasia unclassified (IGCNU), i.e. fetal germ cells that escaped from the control of the developing testicular stem cell niche, eventually leading to a fully developed seminoma (or embryonal carcinoma). The molecular causes for the development of an IGCNU are still unknown. However, IGCNU cells share the expression of several factors with primordial germ cells and gonocytes and, interestingly, also with pluripotent embryonic stem (ES) cells and induced pluripotent stem (iPS) cells. One factor playing important roles in both iPS and ES cells is the transcription factor Krüppel-like factor 4 (KLF4). This study examined KLF4 expression data from 179 human testicular samples including normal controls and seminoma, deposited in Gene Expression Omnibus repository for microarray data at the National Centre for Biotechnology Information. Immunohistochemistry was used to detect KLF4 protein expression in IGCNU (n = 6), seminoma (n = 14) and fetal human testes (n = 14). Microarray data from three independent sources suggest higher mRNA expression in seminoma than in normal testis. Normal spermatogonia, which are the stem cells of spermatogenesis, controlled by their stem cell niche, do not express KLF4. In contrast, IGCNU and seminoma cells strongly express KLF4. In conclusion, this finding suggests that KLF4 may be an important factor for the maintenance of the developmental and the tumorigenic potential of IGCNU as well as for the malignancy of seminoma.