Biology of reproduction
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Biology of reproduction · Oct 2008
Can bovine in vitro-matured oocytes selectively process X- or Y-sorted sperm differentially?
It has been reported that the mammalian female could have a preconceptual influence on the sex of her offspring, and it has been hypothesized that this influence could go some way toward accounting for the reported lower fertility following insemination with sex-sorted sperm. To test whether in vitro matured oocytes are able to select X- or Y-bearing spermatozoa following in vitro fertilization (IVF), we fertilized in vitro 1788 oocytes with X-sorted semen, Y-sorted semen, a mix of X- and Y-sorted semen, and unsorted semen from the same bull, and cultured until Day 9. Fertility was assessed by recording cleavage rate at 48 h postinsemination (hpi) and blastocyst development until Day 9. ⋯ The proportion of female and male two- to four-cell embryos obtained following IVF with X- and Y-sorted sperm was 88% and 89%, respectively and the sex ratio at the two- to four-cell stage was not different following IVF with unsorted or sorted/recombined sperm (56.9% males vs. 57% males, respectively). At the blastocyst stage, similar percentages were obtained. In conclusion, the differences in cleavage and blastocyst development using sorted versus unsorted sperm are not due to the oocyte preferentially selecting sperm of one sex over another, but are more likely due to spermatic damage caused by the sorting procedure.
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Biology of reproduction · Jun 2008
Matrix metalloproteinase 9 (MMP9) expression in preeclamptic decidua and MMP9 induction by tumor necrosis factor alpha and interleukin 1 beta in human first trimester decidual cells.
Extravillous trophoblasts (EVTs) invade human decidua via sequential integrin-mediated binding and proteolysis of basement membrane proteins in the extracellular matrix (ECM). In preeclampsia, shallow EVT invasion impairs spiral artery and arteriole remodeling to reduce uteroplacental blood flow. Excess decidual cell-expressed matrix metalloproteinases (MMPs) 2 and 9, in response to preeclampsia-related interleukin 1 beta (IL1B) and tumor necrosis factor alpha (TNF), may inappropriately degrade these basement membrane proteins and impede EVT invasion. ⋯ Substrate gel zymography and Western blotting confirmed that each cytokine increased secreted levels of MMP9 but not MMP2. Similarly, quantitative RT-PCR found that TNF and IL1B enhanced MMP9, but not MMP2, mRNA levels. At the implantation site, inflammatory cytokine-enhanced MMP9 may promote preeclampsia by disrupting the decidual ECM to interfere with normal stepwise EVT invasion.
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Biology of reproduction · May 2006
Innate immunity at the mucosal surface: role of toll-like receptor 3 and toll-like receptor 9 in cervical epithelial cell responses to microbial pathogens.
Toll-like receptors (TLRs) are a family of pattern recognition receptors that recognize distinct molecular patterns shared by a broad range of pathogens, including nucleic acids. TLR9, for example, recognizes unmethylated deoxycytidyl-phosphate-deoxyguanosine (CpG) dinucleotides that are common in bacterial and some viral nucleic acids, whereas TLR3 recognizes double-stranded RNA and TLR7/TLR8 recognize single-stranded RNA, which would be found during viral replication. We were interested in whether TLR3, TLR9, and the related TLR9 family members TLR7/TLR8 might play a role in antiviral immune defense at the mucosal epithelial surface of the lower female reproductive tract. ⋯ Cell activation by synthetic oligodinucleotides occurred only in response to the B class sequences, and required the presence of human-specific CpG motifs. In addition, responses to CpG oligodinucleotides could be inhibited by chloroquine, demonstrating the requirement for endosomal maturation. These data demonstrate that mucosal epithelial cells express functional TLR3 and TLR9, and suggest that these receptors play a role in regulating the proinflammatory cytokine and antiviral environment of the lower female reproductive tract during infection with viral and bacterial pathogens.
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Biology of reproduction · Apr 2005
Increased myogenic responses in uterine but not mesenteric arteries from pregnant offspring of diet-restricted rat dams.
Results of epidemiological and animal studies suggest a link between poor in utero growth and cardiovascular disease in adult offspring. Few studies, however, have examined the effects of maternal undernutrition on the vasculature of pregnant female offspring, and to our knowledge, no studies have examined myogenic responses, which are essential to vascular tone development, in these animal models. Thus, myogenic responses were assessed in radial uterine arteries of pregnant female offspring to determine if diet restriction during pregnancy could contribute to transgenerational effects. ⋯ Enhanced myogenic reactivity was observed at the highest pressure tested (110 mm Hg) in uterine, but not in mesenteric, arteries from DR(off) compared to C(off). Inhibition of NOS, but not of PGHS, significantly increased myogenic responses in uterine arteries at pressures greater than 80 mm Hg in C(off) but, interestingly, not in DR(off) compared to untreated uterine arteries. Thus, impaired uterine vascular function in diet-restricted pregnant rat dams, which leads to similar impairment in their pregnant offspring, may be a mechanism through which transgenerational effects of unhealthy pregnancies occur.
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Biology of reproduction · Jan 2005
Establishment and maintenance of human embryonic stem cell lines on human feeder cells derived from uterine endometrium under serum-free condition.
Human embryonic stem (hES) cells are usually established and maintained on mouse embryonic fibroblast (MEFs) feeder layers. However, it is desirable to develop human feeder cells because animal feeder cells are associated with risks such as viral infection and/or pathogen transmission. In this study, we attempted to establish new hES cell lines using human uterine endometrial cells (hUECs) to prevent the risks associated with animal feeder cells and for their eventual application in cell-replacement therapy. ⋯ The hUEC feeders have the advantage that they can be used for many passages, whereas MEF feeder cells can only be used as feeder cells for a limited number of passages. The hUECs are available to establish and maintain hES cells, and the high expression of embryotrophic factors and extracellular matrices by hUECs may be important to the efficient growth of hES cells. Clinical applications require the establishment and expansion of hES cells under stable xeno-free culture systems.