progesterone cream
Direct interaction of the Kruppel-like family (KLF) member, BTEB1, and PR mediates progesterone-responsive gene expression in endometrial epithelial cells.

Zhang D, Zhang XL, Michel FJ, Blum JL, Simmen FA, Simmen RC.

Interdisciplinary Concentration in Animal Molecular and Cell Biology, Department of Animal Sciences, University of Florida, Shealy Drive, Gainesville, FL 32611-0910, USA.

The present study was undertaken to evaluate the underlying mechanism(s) by which PR and a Kruppel-like family member, basic transcription element binding protein (BTEB1), mediate endometrial epithelial expression of pregnancy-associated genes. Human endometrial carcinoma cell lines (Hec-1-A) expressing high and low levels of BTEB1 were transiently transfected with a human PR isoform (PR-B) expression construct and a luciferase reporter gene driven by the uteroferrin gene promoter that is responsive to both BTEB1 and the PR ligand progesterone. Unliganded PR inhibited luciferase activity in low and high BTEB backgrounds, and this effect was reversed by the synthetic progestin R5020 in both lines. Transactivation by PR of uteroferrin promoter activity (approximately 4-fold) was maximal at lower R5020 concentrations (10 nM) in endometrial cells with higher BTEB1 expression, suggesting that nuclear BTEB1content influenced target gene promoter sensitivity to progesterone. BTEB1 and PR-B were found to physically interact in a progesterone-independent manner, using a coimmunoprecipitation assay that employed antibodies specific to either protein. Moreover, the formation of the BTEB1/PR complex, independent of progesterone, occurred within the context of uterine endometrial proteins and was diminished in late-pregnancy endometrium. Mammalian two-hybrid assays using the entire open reading frame of BTEB1 and/or PR-B fused to either the GAL4 DNA-binding domain or VP16 activation domain and a reporter gene (pG5CAT) under the control of GAL4-binding sites were used to evaluate the formation of functional PR-B/BTEB1 dimer in Cos-1 cells. GAL4/PR-B and VP16/PR-B induced ( approximately 3- to 4-fold) chloramphenicol acetyltransferase (CAT) activity in a progesterone-dependent manner, suggesting PR-dimer formation. By contrast, VP16/PR-B and GAL4/BTEB1 had no effect on basal CAT activity. The combination of VP16- and GAL4-PR-B fusion proteins with the BTEB1 expression construct, pCDNA3-BTEB1 enhanced ligand-bound PR-mediated CAT activity by approximately 3-fold. In transient cotransfection assays using the CAT reporter gene driven by the mouse mammary tumor virus-long terminal repeat promoter, which is responsive to ligand-bound PR but not BTEB1, BTEB1 increased PR-B-mediated CAT activity in a progesterone-dependent manner, consistent with a BTEB1/PR-dimer complex occurring independent of BTEB1 binding to DNA. Unliganded PR-B disrupted the DNA-binding activity of BTEB1 in gel retardation assays, and this effect was enhanced by the presence of PR ligand. Together, these findings support the conclusion that BTEB1 and PR-B are coregulatory proteins that mediate progesterone responsiveness of target genes by direct interactions, leading to the formation of a functional BTEB1/PR-dimer complex.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11751593&dopt=Abstract progesterone, progesterone cream



progesterone cream
Impact of progestins on estrogen-induced neuroprotection: synergy by progesterone and 19-norprogesterone and antagonism by medroxyprogesterone acetate.

Nilsen J, Brinton RD.

Department of Molecular Pharmacology and Toxicology, Pharmaceutical Sciences Center, University of Southern California, Los Angeles, CA 90033, USA. rbrinton hsc.usc.edu

Estrogen replacement therapy is associated with improvement of cognitive deficits and reduced incidence of Alzheimer's disease. To compare the impact of therapeutically relevant progestins on estrogen-induced neuroprotection, we treated primary hippocampal neuron cultures with 17beta-E2 and progestin, alone and in combination, 48 h before glutamate insult. Estrogen, progesterone, and 19-norprogesterone, alone or in combination, protected against glutamate toxicity. In contrast, medroxyprogesterone acetate (MPA) failed to protect against glutamate toxicity. Not only was MPA an ineffective neuroprotectant but it attenuated the estrogen- induced neuroprotection when coadministered. We addressed the role of MAPK activation in neuroprotection by ovarian steroids. Estrogen and all three progestins tested, alone or in combination, activated MAPK, indicating another mechanism of protection. Bcl-2 expression has been shown to prevent cell death and is up-regulated by 17beta-E2. Progesterone and 19-norprogesterone, alone or in combination with estrogen, increased Bcl-2 expression. In contrast, MPA blocked estrogen-induced Bcl-2 expression when coadministered. These results may have important implications for the effective use of hormone replacement therapy in the maintenance of neuronal function during menopause and aging and for protection against neurodegenerative diseases such as Alzheimer's disease.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11751611&dopt=Abstract progesterone, progesterone cream



progesterone cream
Ovarian follicular wave pattern and the effect of exogenous progesterone on follicular activity in non-mated llamas.

Chaves MG, Aba M, Aguero A, Egey J, Berestin V, Rutter B.

Area de Teriogenologia, Facultad de Ciencias Veterinarias, Universidad de Buenos Aires, Chorroarin 280, C.P.1427, Capital Federal, Argentina. chaves fvet.uba.ar

The aim of the present study was two-fold. First, to characterize the secretory profiles of oestradiol-17beta and progesterone in relation to the structural changes observed by ultrasonography during follicular dynamics in non-ovulating llamas. Second, to evaluate the effect of exogenous progesterone on follicular activity, in terms of follicle development and hormone production. In experiment one, six adult non-pregnant, non-lactating llamas were examined daily by rectal palpation and transrectal ultrasonography during 70 days. On day 54, intravaginal devices containing 0.33 g of progesterone (CIDR) were inserted and left in the vagina during 16 days. The mean duration of a follicular wave was 22.6+/-2.5 days. The follicular growth phase (follicles growing from 3mm to maximum size) averaged 9.2+/-2.8 days, the mature phase (follicles around maximum size) 5.2+/-1.4 days and regression phase (follicles with decreasing size) 8.2+/-2.2 days. Oestradiol-17beta plasma concentrations exhibited a similar wave pattern (P<0.05). In addition, oestradiol-17beta peak plasma concentrations (46.9+/-3.3 pmoll(-1)) were attained approximately 12 days after the beginning of the growing phase in connection with maximum follicle size (11.8+/-1.6mm). After CIDR insertion, a rapid increase in plasma progesterone concentrations was observed, with peak concentrations attained on day 1 after insertion. Thereafter, concentrations decreased gradually. Mean follicle size steadily decreased from the day of CIDR insertion to day 11 post-insertion (10.3+/-1.6 and 3.3+/-0.8mm, respectively). In order to investigate the effect of follicle size at CIDR insertion on the outcome of progesterone treatment, experiment two was designed. Sixteen adult non-pregnant and non-lactating llamas were divided into four groups according to follicle development at the time of CIDR insertion (group I: follicles < or =6 mm; group II: follicles between 6 and 9 mm; group III: follicles between 10 and 14 mm and group IV, regressing follicles). In groups II, III and IV, a significant decrease in follicle size was observed after the insertion of the CIDR device. In group I, no further development of dominant follicles was observed until the device was withdrawn. In all cases, the smallest diameter was registered between days 5 and 7 after the beginning of treatment. In conclusion, a detailed characterization of follicular waves using ultrasound and hormone determinations simultaneously in non-ovulating llamas and after the insertion of progesterone releasing devices, is presented.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11755715&dopt=Abstract progesterone, progesterone cream



progesterone cream
Distribution and changes in amounts of the androgen receptor in the pig uterus during the estrous cycle, early pregnancy and after treatment with sex steroids.

Cardenas H, Pope WF.

Department of Animal Sciences, The Ohio State University, 2027 Coffey Road, Columbus, Ohio 43210, USA.

Two experiments were performed to examine the expression of the androgen receptor (AR) gene in the pig uterus. In experiment 1, immunohistochemistry (IHC) was used to determine the distribution of the AR in uterine tIssue of pigs when collected at the first day of estrus (day 0) and the mid-luteal phase (day 12) of the estrous cycle, or early pregnancy (day 12, n=4 gilts per group). In experiment 2, AR immunostaining and AR mRNA in uterine tIssue were compared among ovariectomized gilts (n=4 per group) following treatment for 4 days with daily injections of: (1) progesterone (2 mg/kg bodyweight (BW)), (2) estradiol-17beta (E(2,) 2 micro g/kg BW), (3) E(2) plus progesterone (same dosages as 1 and 2 combined), (4) 5alpha-dihydrotestosterone (DHT, 7 micro g/kg BW), or (5) vehicle (corn oil). Data were analyzed using ANOVA. In experiment 1, nuclear staining for AR in luminal and glandular epithelia was strong and did not differ in intensity between the two locations. Immunostaining of AR in the myometrium was less (P<0.001) intense than in the luminal and glandular epithelia. Nuclei of stromal cells contained AR immunostaining that varied in intensity from strong (mainly in subepithelial stroma) to weak or no staining. Stages of the estrous cycle or early pregnancy did not influence AR immunostaining in the endometrial epithelia and myometrium. In experiment 2, immunostaining of AR in glandular and luminal epithelia and myometrium of ovariectomized gilts treated with vehicle or DHT was less (P<0.05) than in gilts treated with E(2), progesterone, or E(2) plus progesterone. Immunostaining of AR did not differ between ovariectomized gilts treated with vehicle or DHT, or between gilts treated with E(2), progesterone, or E(2) plus progesterone. In both experiments, intensity of AR immunostaining was greater in glandular epithelium located at the adluminal region compared with glandular epithelium located at the basal region of the endometrium. Competitive reverse-transcription PCR (RT-PCR) indicated a stimulatory effect (P<0.01) of E(2) on amounts of AR mRNA in whole endometrium. This increase in AR mRNA after E(2) treatment was not detected when E(2) was combined with progesterone. Endometrial AR mRNA was not influenced by DHT or progesterone relative to vehicle-treated gilts. In conclusion, immunoreactive AR is mainly present in luminal and glandular epithelia of the pig uterus and to a lesser extent in the myometrium, and does not change significantly during the estrous cycle or early pregnancy. Expression of the AR gene in the pig endometrium and myometrium appears to be regulated by E(2) and progesterone.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12773127&dopt=Abstract progesterone, progesterone cream



progesterone cream
[The effect of progesterone on proliferation and apoptosis in ovarian cancer cell]

[Article in Chinese]

Hu Z, Deng X.

Department of Obstetrics and Gynecology, First University Hospital, Chongqing Medical University, Chongqing 400016, China.

OBJECTIVE: To investigate the regulatory effect of progesterone on proliferation and apoptosis in ovarian cancer cell line HO8910 in vitro. METHODS: Ovarian cancer cell line HO8910 originated from human ovarian serous cystadenocarcinoma was cultured in vitro. Two groups were set up: study group (progesterone in different concentrations) and control group without progesterone. Cell proliferation was measured by 3-(4, 5-dimethylthiazol-z-yl)-2,5-dipheny tetrazolium blue (MTT) colorimetric assay. Cell cycle and apoptotic percentage were detected by flow cytometry, morphological changes of apoptotic cells were observed by light and electron microscopy, and apoptotic cells were quantitatively determined by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL). In addition, expression of intracellular bcl-2 protein was analyzed by flow cytometric indirect immunofluorescent technique. RESULTS: Progesterone of 1 x 10(-7)-1 x 10(-5) mol/L inhibited HO8910 cell growth significantly in a dose-dependent manner (P < 0.01). After treatment with progesterone, the enhanced G0/G1 arrest was accompanied with the enhanced apoptotic peak and percentage, as well apoptotic cells were found more than those in control group (P < 0.05). By light and electron microscopy, there were many morphological characteristics of apoptosis including compaction and margination of nuclear chromatin, nuclear fragments, and apoptotic bodies. Analysis on expression of intracellular bcl-2 protein showed that progesterone could down-regulate bcl-2 protein and at concentration of 1 x 10(-5) mol/L it could almost block bcl-2 expression. CONCLUSIONS: It is suggested in the present study that progesterone can inhibit the proliferation of epithelial ovarian cancer cells in vitro and there is an accordant dose-response relationship. Its anticancer effect seems to be due to induction of apoptosis which maybe a result of down-regulation of the anti-apoptotic protein bcl-2.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11776191&dopt=Abstract progesterone, progesterone cream



progesterone cream
C-7 analogues of progesterone as potent inhibitors of the P-glycoprotein efflux pump.

Leonessa F, Kim JH, Ghiorghis A, Kulawiec RJ, Hammer C, Talebian A, Clarke R.

Department of Oncology and Lombardi Cancer Center, Georgetown University School of Medicine, 3970 Reservoir Road Northwest, Washington, DC 20007, USA.

The P-glycoprotein product (Pgp) of the MDR1 gene has been implicated in the multiple drug resistance phenotype expressed by many cancers. Functioning as an efflux pump, P-glycoprotein prevents the accumulation of high intracellular concentrations of substrates. We have taken a rational approach to designing inhibitors of P-glycoprotein function, selecting a natural substrate (progesterone) as our lead compound. We hypothesized that progesterone, substituted at C-7 with an aromatic moiety(s), would exhibit reduced Pgp affinity, significantly increased antiPgp activity, and reduced affinity for progesterone receptors (PGR). We synthesized 7 alpha-[4'-(aminophenyl)thio]pregna-4-ene-3,20-dione (2), which comprises a C-7 alpha thiol bridge linking an aminophenyl moiety to progesterone, from pregna-4,6-diene-3,20-dione (1). The subsequent addition reaction of 2 with the appropriate isocyanate produced an initial series of compounds (3-6). Compounds 3-5 (respectively, -CH(2)CH(2)Cl; -CH(2)CH(3); and -CH(CH(3))C(6)H(5)) exhibit a significantly increased ability to inhibit P-glycoprotein. Potency for restoring doxorubicin accumulation in MDR1-transduced human breast cancer cells is increased up to 60-fold as compared with progesterone. Compound 5 has greater potency than verapamil and is equipotent with cyclosporin A, for inhibiting P-glycoprotein function. Furthermore, 5 does not bind to PGR, implying a potential reduction in in vivo toxicity. These data identify C-7-substituted progesterone analogues and 5, in particular, as rationally designed antiPgp compounds worthy of further evaluation/development.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11784143&dopt=Abstract progesterone, progesterone cream



progesterone cream
Dioestrous ovariectomy: a model to study the role of progesterone in the onset of canine pseudopregnancy.

Gobello C, Baschar H, Castex G, de la Sota RL, Goya RG.

Institute of Theriogenology, Faculty of Veterinary Sciences, National University of La Plata 60 y 120, La Plata (1900) Argentina.

It has been suggested that overt pseudopregnancy in bitches is caused by an increase in the concentration of serum prolactin as a result of an abrupt decrease in progesterone concentration in the late luteal phase. This hypothesis was tested by using ovariectomy at dioestrus as an experimental model. A total of 18 intact cross- and purebred bitches were used. Eleven animals were ovariectomized (day 0) between day 25 and day 40 of the oestrous cycle, and seven intact bitches were used as controls. Blood samples for determination of prolactin and progesterone concentrations were collected on days -1, 1, 2, 3 and 7 in the ovariectomized group, and on day 1 and day 7 in the control group. On day 7, the presence or absence of overt pseudopregnancy was recorded. The four ovariectomized bitches with a history of pseudopregnancy showed signs of overt pseudopregnancy (P < 0.01). On day 7, progesterone concentrations were significantly higher in the control than in the ovariectomized bitches (P < 0.01). The expected decrease in serum progesterone concentration after ovariectomy was similar in pseudopregnant bitches and non-pseudopregnant bitches. However, in pseudopregnant bitches, but not in non-pseudopregnant bitches, there was a marked increase (expressed as percentage change) in the concentration of prolactin between day -1 and day 7 (P < 0.01). It was concluded that the abrupt decrease in progesterone concentrations does not lead systematically to pseudopregnancy. Only in bitches predisposed to pseudopregnancy would an abrupt decrease in progesterone concentrations induce a substantial increase in prolactin concentrations, which in turn would trigger the typical signs of pseudopregnancy.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11787190&dopt=Abstract progesterone, progesterone cream