Trophoblasts

Meanwhile we have shown that the excision activation of ICOR channels is due to disinhibition [72]. The respective inhibitor, operationally named cytosolic inhibitor (Cl), is present in the cytosol of placenta trophoblast cells HT29- and Tg4-colonic carcinoma cells and RE cells of normal and CF patients. The molecule has an apparent molecular weight of 700-1 500 Da it is amphiphilic heat stable and not digested by trypsin, proteases, nucleotidases, lipases or amylase [72]. Burc-khardt, Fromter and their collaborators [114] have confirmed our results and extracted a similar or identical Cl from kidney cortex. 

Significant additional interest in the potential role of oxytocin in labour developed from 1993, when it was reported for the first time that oxytocin, which had previously been thought to only be produced in the hypothalamus, may also be synthesised locally in the uterus as indicated by the presence of mRNA encoding for oxytocin [11]. This observation has recently been confirmed by using immunohistochemistry and mass spectrometry to confirm the presence of local oxytocin peptide in the uterus. These studies localised oxytocin to the chorionic trophoblast, decidual stroma and glandular epithelium, and demonstrated that local uterine concentrations of oxytocin increased with the onset of labour [12]. 

Secondary hyperthyroidism TSH-secreting pituitary tumors Trophoblastic (hCG-secreting) tumors Gestational thyrotoxicosis... 

Cross JC 2000 Genetic insights into trophoblast differentiation and placental morphogenesis. Sem Cell Dev Biol 11 105-113... 

Guillemot F, Caspary T, Tilghman SM et al 1995 Genomic imprinting of Mash2, a mouse gene required for trophoblast development. Nat Genet 9 235—242 Hao Y, Crenshaw T, Moulton T, Newcomb E, Tycko B 1993 Tumour-suppressor activity of H19 RNA. Nature 365 764-767... 

Vadillo OF, Avila VMA, Guerrero HC, Arechavaleta VF, Montoya BJ. Apoptosis in trophoblast of patients with recurrent spontaneous abortion of unidentified cause. Ginecol Obstet Mex 2000 68 122-131. 

Breast Cancer Resistance Protein (BCRP, also known as MXR or ABCP), first cloned from mitoxantrone and anthracycline-resistant breast and colon cancer cells [188, 189] is a half-transporter efflux pump believed to function as a homo-or hetero-dimer. Following its identification, BCRP-mediated drug resistance was observed for topoisomerase inhibitors including camptothecins [190, 191] and in-dolocarbazoles [192]. In normal tissues, BCRP was detected in placental syncytio-trophoblasts, hepatocyte canalicular membrane, apical intestinal epithelia and vascular endothelial cells [193]. These findings support the important role BCRP plays in modulating topotecan bioavailability, fetal exposure and hepatic elimination [194]. Considering that the substrates and tissue distributions for BCRP overlap somewhat with MDR1 and MRPs [195], additional studies will be required to define the relative contribution of each of these transporters in the overall and tis-... 

R. Pandian, J.L. Lu, and J. Ossolinska-Plewnia, Fully automated chemiluminometric assay for hyper-glycosylated human chorionic gonadotropin (invasive trophoblast antigen). Clin. Chem. 49, 808-810 (2003). 

Cencic, A. and La Bonnardiere, C. 2002. Trophoblastic interferon-gamma current knowledge and possible role in early pig pregnancy. Veterinary Research 33(2), 139-157. 

Carter, A.M., Enders, A.C., Comparative aspects of trophoblast development and placenta-tion, Reprod. Biol. Endocrinol., 2, 2004. 

Role of MDR1 and MRP1 in trophoblast cells, elucidated using retroviral gene transfer. American Journal of Physiology. Cell Physiology, 285,... 

G-CSF receptors are also found on human myeloid leukaemia cells, leu-kaemic cell lines, human placenta, trophoblastic cells, vascular endothelial... 

However, only the extracellular domains immediately adjacent to the cell membrane and the (32 microglobulin peptide have clear homology with the immunoglobulin domains. The al and ct2 segments of class I and the al and (31 domains in class II have quite an unusual structure. Class I molecules are present on virtually every cell in the body, the most notable exception being the syncytial trophoblast of the placenta. Class II expression is far more restricted B cells, dendritic cells which present antigen to T cells, and macrophage express abundant class II molecule on their surfaces. However, most other tissues can be induced to express class II molecules under the influence of soluble mediators such as 7-interferon. 

Blastocyst The mammalian embryo in the post-morula stage in which a fluid-filled cavity, enclosed primarily by trophoblast, contains an inner cell mass which becomes the embryonic disc. [NIH]... 

Keywords Placenta Trophoblast Multidrug resistance Transport Cell culture... 

Primarily to elucidate transporter localization and function, vesicles enriched in trophoblast apical or basolateral membranes have frequently been utilized. To give a few instances, they have been used to investigate P-gp-mediated transport, mechanisms of transport of cationic compounds, drug interactions with nutrient transport, and differences in amino acid transport in pathological conditions of the placenta [36, 40-42], Briefly, for preparation of microvillus membrane vesicles the cord, amniochorion and decidua are removed from placenta, and the tissue cut on the maternal side. The mince is stirred to loosen... 

Advances in cell culture techniques have allowed the use of trophoblast cell cultures to evaluate the various transporter and metabolic systems of the placenta. Many studies have used primary cultures of undifferentiated cytotro-phoblasts isolated from placentas, whereas others have used trophoblast cell lines as a model. Trophoblast cell lines can be generated from normal tissues or malignant tissues and also from embryonal carcinomas exhibiting trophoblast differentiation [48],... 

The choriocarcinoma cell line JAr bears close resemblance to early trophoblast, as their secretion pattern of hCG and steroids is similar, and the cells can differentiate into syncytiotrophoblasts in vitro [71], In a study comparing efflux transporter expression and activity in trophoblast cell lines and choriocarcinoma cells, the expression profiles indicated that while BeWo are more... 

Xu et al. [76] have showed that human embryonic stem cells by treatment with bone morphogenetic protein-4 can be driven to differentiate into tro-phoblasts which have the ability to syncytialize and form confluent mono-layers. The differentiated cells express a number of trophoblast markers and secrete placental hormones and thus may provide an alternative placental model. Under the culture conditions used, however, the cells propagated poorly. 

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