Estrogen-alpha and progesterone receptor expression in cystic endometrial hyperplasia and pyometra in the bitch

Estrogen-alpha receptor (ER) and progesterone receptor (PR) were examined immunohistochemically in uteri of normal bitches, in uteri of bitches with cystic endometrial hyperplasia-mucometra (CEH-M) and in uteri of bitches with endometritis-pyometra (E-P), under exogenous progesterone treatment.In the CEH-M group, the ER- and PR-scores of all uterine cell types were higher than the ER- and PR-scores of normal uteri, although these differences were not always statistically significant. The ER-scores of E-P group were significantly lower than the ER-scores of the normal uteri and CEH-M group. The PR-scores of the E-P group tended to be higher than the PR-scores of the normal uteri, except for the surface epithelium, although these differences were not statistically significant. Exogenous progesterone treated bitches with CEH-M or E-P showed reduced ER- and PR-scores in the different uterine cell types, compared with the corresponding nontreated CEH-M or E-P group.The differences in ER and PR expression between CEH-M and E-P suggest different factors in the pathogenesis of both entities. Although, these changes in ER and PR expression do not seem to be directly involved in the pathogenesis of CEH-M and E-P. It is suggested that for CEH-M and progestin induced CEH-M a hormone dependent pathway is responsible. For P, the trigger may be bacterial infection.     

Sca-1(pos) cells in the mouse mammary gland represent an enriched progenitor cell population

Mammary epithelium can functionally regenerate upon transplantation. This renewal capacity has been classically ascribed to the function of a multipotent mammary gland stem cell population, which has been hypothesized to be a primary target in the etiology of breast cancer. Several complementary approaches were employed in this study to identify and enrich mammary epithelial cells that retain stem cell characteristics. Using long-term BrdU labeling, a population of label retaining cells (LRCs) that lack expression of differentiation markers has been identified. LRCs isolated from mammary primary cultures were enriched for stem cell antigen-1 (Sca-1) and Hoechst dye-effluxing "side population" properties. Sca-1(pos) cells in the mammary gland were localized to the luminal epithelia by using Sca-1(+/GFP) mice, were progesterone receptor-negative, and did not bind peanut lectin. Finally, the Sca-1(pos) population is enriched for functional stem/progenitor cells, as demonstrated by its increased regenerative potential compared with Sca-1(neg) cells when transplanted into the cleared mammary fat pads of host mice.     

Sequestration of host plant carotenoids in the larval tissues of Helicoverpa zea

To determine the cause of the unique yellow coloration in mandibular glands of soybean-fed Helicoverpa zea larvae, the accumulation of carotenoids in various tissues of last instar larvae fed soybean, cotton and tomato foliage was quantified. Five carotenoids were detected in the foliage of all host plants but at significantly different concentrations. Xanthophylls rather than carotenes were most likely to accumulate in larval tissues. Carotenoids accumulated at different rates and some were significantly affected by larval diet. Highest levels of carotenoid accumulation, notably lutein, were detected in the testes, followed by midgut epithelium, fat body and integument. The midgut epithelium contained the greatest and the testes the least diversity of carotenoid types. Low levels of lutein were detected in both labial and mandibular glands. Tomato foliage had the highest carotenoid content and caterpillar tissues fed these leaves often had the highest amounts of carotenoid. However, the accumulation of carotenoids did not protect larvae from antibiotic effects of tomato foliage because these caterpillars had the highest mortality and slowest growth rates of all the three host plants. Transport and absorption of lipid and oxidative stress may be some reasons for differential carotenoid accumulation.     

mdr1a deficiency corrects sterility in Niemann-Pick C1 protein deficient female mice

Niemann-Pick type C disease is a progressive neurological disease with cholesterol storage in liver, and npc1-/- mice share these features and are sterile. We have searched for the cause of sterility and found normal folliculogenesis and progesterone levels but lack of implantation. Multiple drug resistance (MDR) P-glycoproteins are plasma membrane proteins implicated in the movement of drugs and lipids across membranes. Their functions are inhibited by progesterone, which has been shown to alter cellular cholesterol homeostasis and has implicated P-glycoproteins in the movement of cholesterol to the endoplasmic reticulum. We have introduced the mdr1a knockout into the npc1 mutant line. While the neurological disease continues at its usual rate, preventing the females from taking care of their litters, npc1-/-, mdr1a-/- females became fertile. Although the mdr1a P-glycoprotein co-localizes with caveolae, neither caveolin-1 nor npc1 levels were significantly altered in the livers of double homozygotes. The absence of mdr1a was confirmed by immunoblotting, but npc1 deficiency was not associated with consistent changes in cerebellar mdr1a in mdr1a+/+ mice. The results show that a mdr1a mutation is an in vivo suppressor of female sterility in npc1 deficient mice.     

Excretion and measurement of estradiol and progesterone metabolites in the feces and urine of female squirrel monkeys (Saimiri sciureus)

The first objective of the present study was to determine the metabolic form and rate of excretion of ovarian hormone metabolites in the urine and feces of female squirrel monkeys injected with radiolabeled progesterone (Po) and estradiol. The major portion of the urinary metabolites of both hormones was excreted within 16-24 hr post-injection. Estrogen and Po isotopes in feces exhibited an excretion peak at 16 hr post-injection. The majority of recovered radiolabel of both hormones was excreted in feces. Chromatographic separation of fecal extractions indicated that the major estrogen metabolites in feces are in the free as opposed to the conjugated form. The radioactivity and immunoreactivity for estrone and estradiol (E(1) and E(2), respectively) in eluates of fecal samples subjected to celite co-chromatography indicated that both free E(1) and E(2) exist as excretion products in the feces of female squirrel monkeys. The major radioactive peaks for Po metabolites showed peaks in the elution profile at or very near the Po standard, and corresponded with the celite co-chromatography elution profile of Po standard when subjected to enzyme immunoassay (EIA). The second objective was to validate the application of EIA systems to measure fecal metabolites. Reproductive events of one female squirrel monkey across one annual reproductive cycle are described using the endocrine profile generated from fecal steroid assays. Examination of this profile confirmed that longitudinal fecal sampling and steroid hormone metabolite measurement in feces was not only feasible and practical, but accurately detected known reproductive events as well.     

Porphyromonas gingivalis lipopolysaccharide interferes with salivary mucin synthesis through inducible nitric oxide synthase activation by ERK and p38 kinase

Porphyromonas gingivalis is a Gram-negative periodontopathic bacterium colonizing the oral cavity and its lipopolysaccharide (LPS) is a key factor in the development of periodontitis. We investigated the effect of P. gingivalis LPS on the cellular responses associated with mucin synthesis in sublingual salivary gland acinar cells. Exposure of the acinar cells to the LPS led to a dose-dependent decrease in mucin synthesis and was accompanied by a massive induction in inducible nitric oxide synthase (NOS-2) activity and the increase in NO production, caspase-3 activity and apoptosis. Inhibition of extracellular signal-regulated kinase (ERK) with PD98059 accelerated the LPS-induced decrease in the glycoprotein synthesis and caused further increase in apoptosis and NOS-2 activity, while the blockade of p38 mitogen-activated kinase (MAPK) with SB203580 countered the LPS-induced reduction in the glycoprotein synthesis and obviated the induced increases in NOS-2 and apoptosis. Introduction of NOS-2 inhibitor, L-NAME, not only countered the LPS-induced increase in NO generation, caspase-3 activity and apoptosis, but caused the impedance of the LPS inhibition on mucin synthesis. The findings point to the upregulation in NOS-2 expression by P. gingivalis LPS as a key detrimental culprit affecting salivary mucin synthesis.     

Synergistic effect of PEG-400 and cyclodextrin to enhance solubility of progesterone

Conclusion  PEG-400, polysorbate 80, and 2 CDs (Trappsol HPB and Captisol) were used in an attempt to improve the aqueous solubility of a model hydrophobic drug, progesterone. The aqueous solubility of progesterone improved significantly from 0.007 mg/mL by the addition of PEG-400, CDs, and polysorbate 80. In systems containing various amounts of PEG-400 and 3% Trappsol HPB in water (% wt/wt), the theoretical solubility was calculated by adding the solubilities in the individual systems. The observed solubility values were up to 96% higher than the theoretical values. The effect of synergism was significant in 5% to 50% PEG-400/water systems containing Trappsol HPB. Systems containing Captisol did not show such synergistic effects. In general, the addition of polysorbate 80 to the PEG-400/water systems containing CDs affected synergism negatively.     

Sialic acid binding protein of human endometrium: Its regulation by steroids

In the present study, we have observed that sialic acid binding protein (SABP – a 54 kDa glycoprotein which was isolated from human endometrial scrapings taken at various stages of the menstrual cycle from normal cycling females and purified to apparent homogeneity and was earlier reported from this laboratory) was found in sufficiently detectable amount in the endometrium of normal cycling women whereas it was found in lesser amount in tissue from women who have recently entered the post-menopause stage. SABP was observed in both follicular and luteal phase of menstrual cycle which was found by western blot analysis. In the de-novo synthesis experiment, synthesis and secretion of SABP was found to be stimulated by estradiol (E₂) whereas progesterone (P₄) was found to have no significant stimulatory effect on it which was also confirmed by HEC cell culture. In the HEC cell culture, priming of cells with E₂ was found to influence the effect of P₄ on SABP when it was added 2 h after E₂ administration. This was observed by doing immunoprecipitation followed by SDS-PAGE and autoradiography. Hence this report clearly indicates that E₂ regulates the synthesis and secretion of 54 kDa SABP from human endometrium. How E₂ priming of endometrium influences the effect of P₄ on SABP has been discussed.