Galectin 2 (gal-2) expression is downregulated on protein and mRNA level in placentas of preeclamptic (PE) patients.

INTRODUCTION: Galectin 2 (gal-2) belongs to the proto type group and consists of two homologous carbohydrate recognition domains (CRDs) resulting in multiple sugar binding sites. The expression of gal-2 has been shown to be involved in processes of angiogenesis and inflammation but was not analyzed before in preeclamptic (PE) placentas. Therefore the aim of this study was an analysis of expression and localization of gal-2 in placentas from patients suffering from PE. METHODS: Placental tissues were obtained from 14 women following a normal course of pregnancy and 13 women with PE. Expression of gal-2 was evaluated with immunohistochemistry and a semi quantitative score. Gal-2 mRNA expression was quantified in placental tissue using real time TaqMan PCR. Identification of gal-2 expressing cells in the decidua was achieved by double immunofluorescence microscopy. RESULTS: Expression of gal-2 is downregulated in the syncytiotrophoblast of preeclamptic placentas. Downregulation of gal-2 could also be identified in the decidua of PE patients. These findings on protein level could be supported by the results of TaqMan PCR. Gal-2 is downregulated in PE placentas on mRNA level. Finally, gal-2 expressing cells could be identified as extravillous trophoblast cells in both normal pregnancy and PE. DISCUSSION: Gal-2 was identified as an inhibitor of arteriogenesis in a murine model supposedly via modulation of the monocyte/macrophage population. In PE, both the formation of spiral arteries as well as influx of macrophages are dramatically changed. Therefore we might speculate that disturbed transformation of spiral arteries in PE might correlate with the downregulated gal-2 expression by the trophoblast.

Ethical Issues Currently Being Discussed in Relation to Reproductive Medicine and the Laws Governing Reproductive Medicine.

Reproductive medicine laws in Germany currently mean that the relationship status of prospective parents is taken into consideration in decisions on whether their application for assisted reproduction is approved or rejected. In the light of new forms of shared parenthood, we should ask ourselves whether the current regulations are still an appropriate way of guaranteeing the best for the child. Current medical practices and their legal basis will be illustrated using the examples of sperm, egg and embryo donation. From an ethical perspective, the question at stake is to what extent an "Ethics of Parenthood" can make it possible to act responsibly with regard to the changes occurring in forms of shared parenthood. Such an ethics is aimed at supporting parents in realising the reproductive autonomy guaranteed in the German Constitution through social and ethical aspects of the child-parent relationship.

Assessment of follicular development in cryopreserved primate ovarian tissue by xenografting: prepubertal tissues are less sensitive to the choice of cryoprotectant.

Improvements in cancer survival rates have renewed interest in the cryopreservation of ovarian tissue for fertility preservation. We used the marmoset as a non-human primate model to assess the effect of different cryoprotectives on follicular viability of prepubertal compared to adult ovarian tissue following xenografting. Cryopreservation was performed with dimethylsulfoxide (DMSO), 1,2-propanediol (PrOH), or ethylene glycol (EG) using a slow freezing protocol. Subsequently, nude mice received eight grafts per animal from the DMSO and the PrOH groups for a 4-week grafting period. Fresh, cryopreserved-thawed, and xenografted tissues were serially sectioned and evaluated for the number and morphology of follicles. In adult tissue, the percentage of morphologically normal primordial follicles significantly decreased from 41.2 ± 4.5% (fresh) to 13.6 ± 1.8 (DMSO), 9.5 ± 1.7 (PrOH), or 6.8 ± 1.0 (EG) following cryopreservation. After xenografting, the percentage of morphologically normal primordial (26.2 ± 2.5%) and primary follicles (28.1 ± 5.4%) in the DMSO group was significantly higher than that in the PrOH group (12.2 ± 3 and 5.4 ± 2.1% respectively). Proliferating cell nuclear antigen (PCNA) staining suggests the resumption of proliferative activity in all cellular compartments. In prepubertal tissues, primordial but not primary follicles display a similar sensitivity to cryopreservation, and no significant differences between DMSO and PrOH following xenografting were observed. In conclusion, DMSO shows a superior protective effect on follicular morphology compared with PrOH and EG in cryopreserved tissues. Xenografting has confirmed better efficacy of DMSO versus PrOH in adult but not in prepubertal tissues, probably owing to a greater capacity of younger animals to compensate for cryoinjury.

Notch-1, c-kit and GFRalpha-1 are developmentally regulated markers for premeiotic germ cells.

Culture, transfection and immortalization of mouse germ line stem cells, germ cell transplantation and grafting of testicular tissue are milestones of recent biotechnological breakthroughs. Alone and in combination they offer new pathways to explore the cellular mechanisms responsible for pluripotency and the requirements of cells to enter the germ line. Efficient markers, isolation and culture systems as well as transfection approaches are developed to elucidate the molecular and cellular mechanisms leading to the development of male germ line cells. Here, we describe the localization pattern of c-kit, Notch-1 and GFRalpha-1 in postnatal, immature and adult testes. All three proteins are potentially useful markers for spermatogonial characterization and enrichment. First attempts and various future perspectives to use spermatogonial stem cells as pathway for the introduction of transgenes are discussed.

Spermatogonia: stem cells with a great perspective.

Interest in spermatogonia has grown in recent years as a result of exciting developments in stem cell research in general and the development of new research tools allowing the isolation, culture and transplantation of these cells. This review focuses on the methodological breakthroughs and highlights the recent findings that have substantially increased understanding of spermatogonial physiology. The article provides a comprehensive overview of the hormonal regulation of spermatogonia and presents several new approaches to the use of spermatogonia in basic science and medicine. In the near future these techniques will allow the development of novel routes for the generation of transgenic lifestock, the treatment of infertility, the targeting for male contraception, and an alternative strategy for fertility preservation of oncological patients.

Male germ cell transplantation: an experimental approach with a clinical perspective.

Germ cell transplantation was developed in strains of mice. The infusion of germ cell preparations into the seminiferous tubules of infertile hosts led to repopulation of the testis with donor germ cells and restored fertility. Meanwhile, this technique has become a powerful tool to study the expansion of the testicular stem cell population and the kinetics of spermatogonial proliferation and re-induction of spermatogenesis. Further approaches, such as the transfer of rat/hamster/rabbit germ cells into mouse testes or cryopreservation or culture of spermatogonia, have widened the spectrum of applications associated with germ cell transplantation. Since the devastating effects of chemo- or radiotherapy on spermatogonia are the cause of infertility in oncological patients, germ cell transplantation might become an alternative approach for gonadal protection in prepubertal and postpubertal male tumour patients. This review focusses on recent developments with respect to germ cell transplantation and highlights the problems and perspectives of future clinical applications.

Magnetic cell sorting is a fast and effective method of enriching viable spermatogonia from Djungarian hamster, mouse, and marmoset monkey testes.

Germ cell transplantation, which offers promising new approaches for research and clinical applications, has focused interest on spermatogonia. This paper describes a procedure that permits the isolation of large quantities of viable spermatogonia. The immunomagnetic isolation procedure was applied to testicular cell suspensions from photoinhibited and photostimulated Djungarian hamsters, mice, and marmoset monkeys. The cells were incubated with a polyclonal rabbit anti-c-kit IgG, binding of which was characterized by immunohistochemical staining. For magnetic labeling, a secondary anti-rabbit IgG conjugated to ferromagnetic microbeads was used. Separation columns allowed the retention of magnetically labeled cells within the matrix. The magnetic fractions were eluted after removal of the column from the magnetic field. All fractions were analyzed for cellular morphology and by flow cytometry. The final enrichment of c-kit-positive cells in the magnetic fraction using fully active testes was in the range of 25-55% with a viability rate of 80-90%. The magnetic fractions of all three species were characterized by high numbers of diploid cells. Cytological analysis revealed a strong enrichment of spermatogonia. No haploid cells were retained in the magnetic fraction. In comparison to conventional procedures, magnetic cell separation is an efficient and fast approach for isolation of spermatogonia.