The concentration and affinity of luteinizing hormone (LH) receptors in bovine luteal tissues during the oestrous cycle and pregnancy were investigated by Scatchard analysis of the binding of 125I-labeled human chorionic gonadotropin. Corpora lutea (CL) were classified into five stages of the oestrous cycle and three stages of pregnancy. The concentration of LH receptors sharply increased from the early I stage of the oestrous cycle (Days 2-3; 3.09 fmol mg(-1) protein) to the early II stage (Days 5-6; 9.44 fmol mg(-1) protein) and then remained constant until the late luteal stage (Days 15-17; 8.14-9.56 fmol mg(-1) protein). The LH receptors could not be analysed in the regressed luteal tissue due to the small amounts of binding. There was no significant difference in the concentrations of LH receptors (5.63-9.64 fmol mg(-1) protein) among the three stages of pregnancy. Moreover, the concentrations of the receptors in the CL of pregnancy were comparable to those in the mid-cycle CL. The binding affinity did not change significantly during the oestrous cycle and pregnancy. Based on these results, it is assumed that the luteal function during the entire period of pregnancy might be regulated, at least in part, by LH, which is mediated via its specific receptors, and that the luteal function during pregnancy seems not to be regulated by changes in the binding capacity and affinity of LH receptors. To understand the physiological roles of LH in regulating luteal function in pregnant cows, further studies are required.
BackgroundNectins are cell adhesion molecules that play a pivotal role in adherens junctions and tight junctions. Our previous study using whole-genome oligonucleotide microarrays revealed that nectin-4 was upregulated in pre-eclamptic placentas. We investigated the role of nectin-4 in the etiology of pre-eclampsia.MethodsWe investigated the expression of nectin-4 using real-time RT–PCR, western blot and immunostaining. Additionally, we performed matrigel invasion assay and cytotoxicity assay using cells overexpressing the nectin-4.ResultsNECTIN4 transcripts were elevated in pre-eclamptic placentas relative to uncomplicated pregnancies. Nectin-4 protein levels in pre-eclamptic placentas were higher on a semi-quantitative western blot. Nectin-4 was localized at the apical cell membrane in syncytiotrophoblast cells and not at the adherens junctions. Nectin-4 was also detected in cytotrophoblasts and a subset of cells in the decidua. Nectin-4 overexpressing trophoblast cells migrated normally in the matrix. However, Natural killer (NK) cells showed a strong cytotoxic effect against nectin-4 overexpressing trophoblast cells. No causative genetic variation was evident in the NECTIN4 gene from a pre-eclamptic placenta.ConclusionsThere are as yet unknown factors that induce nectin-4 overexpression in trophoblast cells that may contribute to abnormal placentation via an aberrant immune response and the onset of a pre-eclamptic pregnancy.Electronic supplementary materialThe online version of this article (10.1186/s12881-018-0681-y) contains supplementary material, which is available to authorized users.
To determine the physiological significance of tumour necrosis factor-alpha (TNFalpha) in the regulation of luteal functions in pig, this study was conducted to identify the presence of functional TNFalpha receptors in porcine corpora lutea (CL) throughout the oestrous cycle and the early gestation. The CL were isolated from pigs on days 4, 6, 8, 12 or 15 of the oestrous cycle (n=3; day 0 = oestrus) and days 15, 20 or 25 of gestation (n=3; day 0 = mating). A Scatchard analysis revealed the presence of a high-affinity binding site for TNFalpha in all samples (dissociation constant; 2.7 +/- 0.51 to 5.8 +/- 0.50 nM). The concentration of TNFalpha receptors was higher on day 15 of the oestrous cycle than on days 4 and 8 of the oestrous cycle (p < 0.05). Furthermore, TNFalpha receptor concentrations in the CL on days 15, 20 and 25 of gestation were significantly lower than on day 15 of the oestrous cycle (p< 0.05). On day 9 of the oestrous cycle, exposure of cultured luteal cells to 0.06-60 nM TNFalpha stimulated prostaglandin (PG) F2alpha and PGE2 secretion in a dose-dependent manner (p < 0.05). These results indicate that functional TNFalpha receptors are present in the porcine CL throughout the oestrous cycle and early gestation, and suggest that TNFalpha plays one or more physiological roles in regulating CL function throughout the oestrous cycle and the early gestation period. In addition, TNFalpha receptor concentration in the CL of the late luteal stage (day 15) of the oestrous cycle was higher than on the respective day in the early pregnant pig, suggesting that TNFalpha plays a role in accomplishing luteolysis in the porcine CL.
Background: Soluble fms-like tyrosine kinase 1 (sFlt-1) is believed to be a prominent component in the pathogenesis of pre-eclampsia, although the precise etiology has remained elusive. In this study, the etiological role of FLT1 variant was further validated in pre-eclampsia by examining this association in a Japanese sample population. Methods: The genotypes of three variants (rs4769613, rs12050029 and rs149427560) were examined in the upstream region of the FLT1 gene in placentas from pre-eclamptic (n=47) or normotensive control (n=49) pregnancy samples. Additionally, FLT1 mRNA levels in placenta were determined by qRT-PCR. ELISA was further used to detect circulating sFlt-1 levels in maternal sera. The intergroup comparisons were made using the Mann-Whitney U test or one way analysis of variance and P values of less than 0.05 were considered statistically significant. Results: First, the rs4769613 (C>T) and rs12050029 (G>A) genotypes were examined in placentas but no significant differences were found in the genotype or allele-type frequencies. Next, nearby short tandem repeat, rs149427560, was examined which manifested four size variants. In the genotypewise analysis, the frequency of the 474/476 heterozygote was significantly lower in pre-eclampsia (p<0.05). As expected, the FLT1 mRNA levels were significantly elevated in the pre-eclamptic placentas and sFlt-1 was higher in pre-eclamptic maternal sera. However, the genotype of these variants did not affect the FLT1 mRNA or serum sFlt-1 levels. Conclusion: Our findings did not support the hypothesis that genetic variations around the FLT1 gene affect the subtle expression changes underlying the etiologic pathway of pre-eclampsia. The hypothesis deserves further investigation through a larger sample size.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.