l-Carnitine (l-Cn), despite the beneficial role as energy-generating substance delivering long-chain fatty acids to the β-oxidation pathway in mitochondria, has been accused to cause an endometriosis-like state to BALB/c mice manifested by increased inflammatory cytokines in serum and peritoneal fluid, accumulation of immune cells in the peritoneal cavity and uterine walls and most importantly, correlating to infertility. Exploring this type of infertility, the effect of l-Cn on preimplantation embryo development, ovarian integrity and systemic maternal immunity was studied. Using nonlinear microscopy analysis, which was shown to be a powerful tool for determining embryo quality by quantitatively estimating the lipid body (LB) content of the cells, it was shown that in vitro and in vivo administration of l-Cn significantly decreased LB mean area in zygotes. Daily intraperitoneal administration of 2.5mg l-Cn for 3, 4 and 7days to mice significantly decreased the percent of normal zygotes. However, only the 7-day treatment persisted by affecting 2- and 8-cell stage embryos, while almost abolishing blastocyst development. Such effects were accompanied by abnormal ovarian histology, showing increased numbers of corpora luteus and elevated progesterone concentration in the serum. In addition, it was shown that the 7-day l-Cn treatment pushed maternal systemic immunity toward inflammation and immunosuppression by increasing CD11b-, CD25- and CD11bGr1-positive cells in spleen, which opposed the necessity for immunostimulation at these early stages of pregnancy. In conclusion, the results presented here demonstrated that elevated doses of l-Cn affect early stages of embryo development, leading to infertility.
Christiana Kyvelidou, Dimitris Sotiriou, Tania Antonopoulou, Margarita Tsagkaraki, George J Tserevelakis, George Filippidis and Irene Athanassakis
Irene Mytilinaiou, Kiki Sarganaki, Eirini Sachouli, Sofia Tsagdi, Katerina Vardaki, Anna Vassiliadis and Irene Athanassakis
Mate choice has been postulated to be MHC-dependent, ensuring the maintenance of polymorphism for species survival. At the molecular level, MHC polymorphism is represented by class-I (MHCI), class-II (MHCII) antigens and their T cell receptors (TCRs). In order to evaluate the presence such immune molecules during male/female interaction, vaginal fluid, vaginal cells, urine, sperm, seminal fluid, cumulus cells, tubal fluid and epithelium were isolated from BALB/c mice and examined for the presence of membrane or soluble MHCI, MHCII, TCRαβ and TCRγδ, using immunofluorescence and ELISA techniques, respectively. These molecules were expressed on sperm and seminal fluid in a sperm quality-dependent manner and in vagina, fallopian tube, cumulus cells and urine in an estrus cycle-dependent manner. Vaginal cells showed increased expression of all molecules tested during estrus, while vaginal fluid showed an increase of TCRγδ and decrease of MHCI and MHCII levels, during estrus. Urine showed only increased concentrations of TCRαβ during estrus. Cumulus cells expressed MHCI, MHCII, TRCγδ but not TCRαβ, while sperm mainly expressed TCRαβ and TRCγδ. All molecules were detected in tubal fluids mostly during estrus, while they were almost undetectable during pregnancy. The vaginal environment was shown to affect sperm motility according to the estrus-cycle, whereas sperm motility was affected by antibodies against these molecules. In conclusion, the presence of complementary immune molecules in the male/female interactive environment, except for revealing novel markers for unexplained infertility, provides for the first time evidence for immune-mediated recognition of the two counterparts, enlightening thus a molecular basis for mate choice.