Archive for the ‘Proteins’ Category


Spatial and Temporal Patterns of Expression: DISCUSSION(4)

Jan 20, 2013 Author: Walter Mcneil | Filed under: Proteins

DISCUSSION(4)

Implantation occurs on the antimesometrial side of the uterus during early pregnancy. The decidualization of stroma cells begins on the antimesometrial side and later spreads to the mesometrial side. The greater expression of CRBP, CRABP, and CRABP II on the mesometrial side at Day 1 suggests that the retinoic acid signal is involved in establishing the functional differences of the uterus that lead to successful implantation. Later, with decidualization, the binding proteins appeared first on the antimesometrial side, suggesting that the actual step of implantation also involves the retinoic acid signal.

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  • Spatial and Temporal Patterns of Expression: DISCUSSION(3)

    Jan 19, 2013 Author: Walter Mcneil | Filed under: Proteins

    The presence of CRBP in those cells also expressing CRABP(II) is consistent with its role in the production of retinoic acid. CRBP was also present in the smooth muscle cell layers that expressed CRABP. There its role is less clear. Smooth muscle cells from the uterus of the pseudopregnant rat were found not to synthesize retinoic acid. It is generally accepted that CRBP also mediates retinol esterification as well as production of retinoic acid. We have observed that the smooth muscle of the small intestine possesses large stores of retinol esters and that it contains both CRBP and the enzyme activity responsible for the esterification of retinol, lecithin-retinol acyltransferase, suggesting that the muscle may serve as a local store of vitamin A. buy diabetes drugs

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  • Spatial and Temporal Patterns of Expression: DISCUSSION(2)

    Jan 18, 2013 Author: Walter Mcneil | Filed under: Proteins

    DISCUSSION(2)

    On Day 6-7 during the postimplantation period, CRABP(II) was expressed in the decidual cells in the implantation chamber. CRBP was also found in the same area. Preliminary data in this laboratory have shown that both human and rat uterine stromal cells that are induced to de-cidualize in vitro gain the ability to produce retinoic acid from retinol (unpublished results). Recently it was reported that decidual cells have both RARs and RXRs. This suggests that retinoic acid, locally generated from retinol, could be involved in the differentiation of stromal cells to decidual cells and/or that it may function in the process of implantation and/or early embryo development. Previous work has demonstrated that retinol-deficient pregnant rats frequently resorbed embryos and that this was accompanied by obvious placental lesions. ventolin inhaler

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  • Spatial and Temporal Patterns of Expression: DISCUSSION(1)

    Jan 17, 2013 Author: Walter Mcneil | Filed under: Proteins

    The observations we have reported here indicate that the local generation of retinoic acid is an important signal in the preparation of the uterus for implantation of the embryo. Although we did not determine retinoic acid production directly, we believe that we can infer, from the expression of CRABP(II) in certain cells, that those cells are producing retinoic acid as a paracrine, and perhaps, autocrine hormone. This inference is based on our previous work with the pseudopregnant rat model. We established that uterine epithelial cells synthesize retinoic acid in culture only if isolated at the time of CRABP(II) expression. That such retinoic acid synthesis also occurs in the intact animal was verified by the demonstration that high levels of retinoic acid could be extracted from isolated uteri only at the time when CRABP(II) was expressed. Thus, we assume that the same correlation between CRABP(II) expression and retinoic acid synthesis exists for the uterus of the pregnant animal. birth control pills

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  • Spatial and Temporal Patterns of Expression: RESULTS(4)

    Jan 16, 2013 Author: Walter Mcneil | Filed under: Proteins

    RESULTS(4)

    We previously had not noted CRABP expression in the stromal cells of normal cycling rats, but in those studies the uteri were examined only in cross section. In order to determine whether the temporal and region-dependent expression of CRABP in the stromal cells was unique to the pregnant uterus, we prepared new sections of the normal cycling uterus, now cut longitudinally. We observed that some of the stromal cells on the mesometrial side stained positively for CRABP, but only during the estrous stage (Fig. 3F). Further, cells that were positive for CRABP were considerably fewer in number than for the Day 1 pregnant uterus. The staining was found to have the same regional dependence described above. The cross sections stained for the estrous state in our previous study came from the middle region. ventolin inhalers

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  • Spatial and Temporal Patterns of Expression: RESULTS(3)

    Jan 15, 2013 Author: Walter Mcneil | Filed under: Proteins

    Because we had not seen epithelial and stromal cell staining in our previous study of the normal estrous cycle, we reexamined this question with the better antibody preparation used in this study. With the more avid antibody preparation we now detected CRBP staining in the luminal epithelial cells at estrus (coincident with the expression of CRABP[II]) and detected stromal cell staining during dies-trus. Only faint or no staining was noted for CRBP at these sites during proestrus and metestrus (Fig. 2, G and H, and data not shown). The intensity of CRBP staining in the normally cycling animal was less than that seen in the luminal epithelium at Day 1 of pregnancy, which perhaps contributed to the failure to detect staining with the weaker antibody preparation (data not shown).

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  • Spatial and Temporal Patterns of Expression: RESULTS(2)

    Jan 14, 2013 Author: Walter Mcneil | Filed under: Proteins

    RESULTS(2)Cell-Specific Localization of CRBP

    Incubation of uterine sections with anti-CRBP resulted in staining of both the inner and outer muscle layers throughout the periimplantation period (Fig. 2). The intensity was uniform for both layers of smooth muscle at Day 1. However, after Day 1, the staining intensity of the smooth muscle became region dependent. In some areas, the staining for CRBP was stronger on the mesometrial side than on the antimesometrial side (Fig. 2B). At Day 1, in addition to the staining of smooth muscle cells, strong staining was noted in many of the cells of the luminal epithelium and also some stromal cells, localized to the mesometrial side of the uterus (Fig. 2A).
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  • Spatial and Temporal Patterns of Expression: RESULTS(1)

    Jan 13, 2013 Author: Walter Mcneil | Filed under: Proteins

    Cellular Retinoid-Binding Protein Expression Levels in the Uterus of the Pregnant Rat

    To determine the relative levels of expression of each of the proteins during early pregnancy, cytosols were prepared from frozen uteri (3-4 uterine horns were pooled) collected at various times during the periimplantation period. Equal amounts of cytosolic protein from each sample (50 |xg) were separated on SDS-PAGE gels, transferred to a polyvinyl difluoride membrane, and probed with antibodies previously shown to be specific for the binding proteins against which they were generated.

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