| 1. |
- Bylander, Anna, 1979, et al.
(författare)
-
Rapid effects of progesterone on ciliary beat frequency in the mouse fallopian tube.
- 2010
-
Ingår i: Reproductive biology and endocrinology : RB&E. - : Springer Science and Business Media LLC. - 1477-7827. ; 8:1
-
Tidskriftsartikel (refereegranskat)abstract
- ABSTRACT: BACKGROUND: The physiological regulation of ciliary beat frequency (CBF) within the fallopian tube is important for controlling the transport of gametes and the fertilized ovum. Progesterone influences gamete transport in the fallopian tube of several mammalian species. In fallopian tubes isolated from cows, treatment with 20 micromolar progesterone caused a rapid reduction of the tubal CBF. The aims of this study were to establish methodology for studying fallopian tube CBF in the mouse, as it is an important model species, and to investigate if progesterone rapidly affects the CBF of mice at nM concentrations. METHODS: A method to assess tubal CBF of mice was developed. Fallopian tubes were dissected and the tissue was cut in small pieces. Tissue samples with moving cilia were located under an inverted bright field microscope and held still against the bottom of a petri dish by a motorized needle system. Images were acquired over 90 minutes at 35 degrees C with a high-speed camera and used for assessing changes in the CBF in response to the addition of hormone. RESULTS: The baseline CBF of the mouse fallopian tube was 23.3 +/- 3.8 Hz. The CBF was stable over at least 90 minutes allowing establishment of a baseline frequency, addition of hormone and subsequent recordings. Progesterone at concentrations of 20 micromolar and 100 nM significantly reduced the CBF by 10% and 15% respectively after 30 minutes compared with controls. CONCLUSIONS: The present study demonstrates that the mouse, despite its small size, is a useful model for studying the fallopian tube CBF ex vivo. The rapid reduction in CBF by 100 nM progesterone suggests that gamete transport in the fallopian tube could be mediated by progesterone via a non-genomic receptor mechanism.
|
|
| 2. |
- Bylander, Anna, 1979, et al.
(författare)
-
The classical progesterone receptor mediates the rapid reduction of fallopian tube ciliary beat frequency by progesterone.
- 2013
-
Ingår i: Reproductive biology and endocrinology : RB&E. - : Springer Science and Business Media LLC. - 1477-7827. ; 11:1
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The transport of gametes as well as the zygote is facilitated by motile cilia lining the inside of the fallopian tube. Progesterone reduces the ciliary beat frequency within 30 minutes in both cows and mice. This rapid reduction suggest the involvement of a non-genomic signaling mechanism, although it is not known which receptors that are involved. Here we investigated the possible involvement of the classical progesterone receptor in this process. METHOD: The ciliary beat frequency of mice fallopian tube was measured ex vivo using an inverted bright field microscope and a high speed camera. The effects of the agonists progesterone and promegestone and an antagonist, mifeprestone, were investigated in wildtype mice. The effect of progesterone was also investigated in mice lacking the classical progesterone receptor. RESULTS: Progesterone, as well as the more specific PR agonist promegestone, significantly reduced the CBF at concentrations of 10--100 nanomolar within 10--30 minutes. In the absence of progesterone, the PR antagonist mifeprestone had no effect on the ciliary beat frequency at a concentration of 1 micromolar. When ciliated cells were pre-incubated with 1 micromolar mifeprestone, addition of progesterone did not reduce the ciliary beat frequency. Accordingly, in ciliated cells from mice not expressing the classical progesterone receptor, exposure to 100 nanomolar progesterone did not reduce the ciliary beat frequency. CONCLUSIONS: This is the first study to provide comprehensive evidence that the classical progesterone receptor mediates the rapid reduction of the tubal ciliary beat frequency by progesterone.
|
|
| 3. |
- Diaz-Garcia, César, et al.
(författare)
-
Pregnancy after allogeneic uterus transplantation in the rat: perinatal outcome and growth trajectory.
- 2014
-
Ingår i: Fertility and sterility. - : Elsevier BV. - 1556-5653 .- 0015-0282. ; 102:6
-
Tidskriftsartikel (refereegranskat)abstract
- Objective To investigate whether allogeneic uterine grafts in a rat model, with tacrolimus immunosuppression, can harbor pregnancies that result in offspring with normal postnatal growth. Design Experimental animal study. Setting University hospital. Animal(s) Lewis rats as uterus donors and Piebald-Virol-Glaxo rats as recipients. Intervention(s) Animals were allocated to one of the following three groups: allogeneic uterus transplantation with end-to-side anastomosis to the external iliac vessels and immunosuppression with tacrolimus (UT+Tac; n = 10); sham surgery and immunosuppression with tacrolimus (Sham+Tac; n = 10); or sham surgery (Sham; n = 10). The rats were subsequently introduced to male rats with proven fertility and in the event of resulting pregnancy cesarean sections were performed on day 22 of pregnancy. Main Outcome Measure(s) Graft viability, fertility rate, perinatal death, birth weight, postnatal birth trajectory. Result(s) Pregnancy rate was higher in the control groups (70% Sham and 80% Sham+Tac) than in the transplanted group (50% UT+Tac), although these differences did not reach the significance threshold. There were no differences between groups regarding number of living pups or neonatal deaths. Pups born from UT+Tac mothers had birth weights similar to external control animals from our breeding colony (BC): UT+Tac males 6.2 ± 0.2 g, UT+Tac females 5.5 ± 0.6 g, BC males 5.8 ± 0.2 g, BC females 5.2 ± 0.3 g; n.s. Evaluation of uteri and placentas of pregnant animals revealed a somewhat reduced vascular density in both tissues in the UT+Tac group, and that was not seen in the Sham+Tac group. Conclusion(s) Allogeneic uterus transplantation and immunosuppression with tacrolimus is compatible with normal pregnancy and perinatal outcome in a rat model.
|
|
| 4. |
- Feng, Yi, et al.
(författare)
-
Effects of androgen and leptin on behavioral and cellular responses in female rats.
- 2011
-
Ingår i: Hormones and behavior. - : Elsevier BV. - 1095-6867 .- 0018-506X. ; 60:4, s. 427-38
-
Tidskriftsartikel (refereegranskat)abstract
- The causes of anxiety and depression in women with polycystic ovary syndrome (PCOS) remain elusive. To identify steps linking androgen signaling to the regulation of affective symptoms in vivo, we compared behavioral responses in female rats continuously exposed to DHT from puberty (a model of DHT-induced PCOS) and in rats exposed to DHT for 1week. Continuous and 1week of DHT exposure resulted in a general decrease in locomotor activity and time spent on the open arms in the elevated plus maze, indicating anxiety-like behavior. Rats with DHT-induced PCOS have increases in adiposity and circulating leptin levels accompanied by leptin resistance. One week of DHT exposure decreased androgen receptor (AR) expression in the hypothalamus and leptin synthesis and function in adipocytes; it also inhibited signal transducer and activator of transcription 3 (STAT3) and attenuated leptin activity by increasing levels of soluble leptin receptor, a leptin-binding protein, in the hypothalamus. This may affect the androgen-induced anxiety-related behavior in female rats. In conclusion, our results highlight the central role of androgens in behavioral function in female rats and suggest that androgens directly regulate the AR by decreasing its hypothalamic expression. Androgens also increase leptin synthesis in adipocytes, which drives central leptin signaling, and may regulate anxiety-related behaviors. Elucidating mechanisms by which androgens modulate female anxiety-like behavior may uncover useful approaches for treating women with PCOS who have symptoms of anxiety.
|
|
| 5. |
- Feng, Yi, et al.
(författare)
-
Electrical and manual acupuncture stimulation affect oestrous cyclicity and neuroendocrine function in an 5α-dihydrotestosterone-induced rat polycystic ovary syndrome model.
- 2012
-
Ingår i: Experimental physiology. - : Wiley. - 1469-445X .- 0958-0670. ; 97:5, s. 651-62
-
Tidskriftsartikel (refereegranskat)abstract
- Both low-frequency electro-acupuncture (EA) and manual acupuncture improve menstrual frequency and decrease circulating androgens in women with polycystic ovary syndrome (PCOS). We sought to determine whether low-frequency EA is more effective than manual stimulation in regulating disturbed oestrous cyclicity in rats with PCOS induced by 5α-dihydrotestosterone. To identify the central mechanisms of the effects of stimulation, we assessed hypothalamic mRNA expression of molecules that regulate reproductive and neuroendocrine function. From age 70 days, rats received 2 Hz EA or manual stimulation with the needles five times per week for 4-5 weeks; untreated rats served as control animals. Specific hypothalamic nuclei were obtained by laser microdissection, and mRNA expression was measured with TaqMan low-density arrays. Untreated rats were acyclic. During the last 2 weeks of treatment, seven of eight (88%) rats in the EA group had epithelial keratinocytes, demonstrating oestrous cycle change (P = 0.034 versus control rats). In the manual group, five of eight (62%) rats had oestrous cycle changes (n.s. versus control animals). The mRNA expression of the opioid receptors Oprk1 and Oprm1 in the hypothalamic arcuate nucleus was lower in the EA group than in untreated control rats. The mRNA expression of the steroid hormone receptors Esr2, Pgr and Kiss1r was lower in the manual group than in the control animals. In rats with 5α-dihydrotestosterone-induced PCOS, low-frequency EA restored disturbed oestrous cyclicity but did not differ from the manual stimulation group, although electrical stimulation lowered serum testosterone in responders, those with restored oestrus cyclicity, and differed from both control animals and the manual stimulation group. Thus, EA cannot in all aspects be considered superior to manual stimulation. The effects of low-frequency EA may be mediated by central opioid receptors, while manual stimulation may involve regulation of steroid hormone/peptide receptors.
|
|
| 6. |
- Feng, Yi, et al.
(författare)
-
Spatiotemporal expression of androgen receptors in the female rat brain during the oestrous cycle and the impact of exogenous androgen administration: a comparison with gonadally intact males.
- 2010
-
Ingår i: Molecular and cellular endocrinology. - : Elsevier BV. - 1872-8057 .- 0303-7207. ; 321:2, s. 161-74
-
Tidskriftsartikel (refereegranskat)abstract
- Little is known about the regulation and cellular distribution of androgen receptors (ARs) in female rodent brains at various stages of the oestrous cycle. This information is critical for further studies of androgen signalling in the regulation of brain function under physiological and pathophysiological conditions. In this report, we show that the distribution of AR immunoreactivity in the female rat brain is consistent with reported AR mRNA hybridisation signals in the male brain, except for the dentate gyrus of the hippocampus. Immunohistochemical and Western blot analyses performed herein revealed that the onset of region-specific changes in AR proteins was strongly correlated with circulating and ovarian levels of estradiol and testosterone across the oestrous cycle. During the metestrus and diestrus stages, however, the highest levels of AR expression were abolished by chronic dihydrotestosterone (DHT) treatment. This demonstrates that fluctuations in endogenous androgens are required for the regulation of AR expression in the female rat brain. Colocalisation studies revealed that: (1) anatomical variations in AR protein localisation existed between female and male brains, (2) AR immunoreactivity was both neuronal and non-neuronal, and (3) AR protein expression was lower in female rat brains at all stages of the oestrous cycle compared to age-matched males. Our results indicate the presence of regional sex differences in AR expression and changes in the proportion of AR between different subcellular compartments. Furthermore, DHT was found to down-regulate the level of AR in the subcellular compartment in females in a region-specific manner. As a whole, the present study provides the first step toward understanding the dynamics of AR expression and regulation in the brain during normal physiological conditions and for differences in neuronal androgen effects based on sex.
|
|
| 7. |
- Feng, Yi, et al.
(författare)
-
The onset of human ectopic pregnancy demonstrates a differential expression of miRNAs and their cognate targets in the Fallopian tube
- 2014
-
Ingår i: International Journal of Clinical and Experimental Pathology. - 1936-2625. ; 7:1, s. 64-79
-
Tidskriftsartikel (refereegranskat)abstract
- Human ectopic pregnancy (EP) is a leading cause of pregnancy-related death, but the molecular basis underlying the onset of tubal EP is largely unknown. Female Dicer1 conditional knockout mice are infertile with dysfunctional Fallopian tube and have a different miRNA expression profile compared to wild-type mice, and we speculated that Dicer-mediated regulation of miRNA expression and specific miRNA-controlled targets might contribute to the onset of tubal EP. In the present study, we used microarray analysis and quantitative RT-PCR to examine the expression of miRNAs and core miRNA regulatory components in Fallopian tube tissues from women with EP. We found that the levels of DICER1, four miRNAs (let-7i, miR-149, miR-182, and miR-424), and estrogen receptor α distinguished the tubal implantation site from the non-implantation site. Computational algorithms and screening for interactions with the estrogen and progesterone receptor signaling pathways showed that the four miRNAs were predicted to target ten genes, including NEDD4, TAF15, and SPEN. Subsequent experiments showed differences in NEDD4 mRNA and protein levels between the implantation and non-implantation sites. Finally, we revealed that increases in smooth muscle cell NEDD4 and stromal cell TAF15, in parallel with a decrease in epithelial cell SPEN, were associated with tubal implantation. Our study suggests that changes in miRNA levels by the DICER-mediated miRNA-processing machinery result in aberrant expression of cell type-specific proteins that are potentially involved in the onset of tubal EP.
|
|
| 8. |
- Friberg, P. Anders, 1976, et al.
(författare)
-
Transcriptional effects of progesterone receptor antagonist in rat granulosa cells.
- 2010
-
Ingår i: Molecular and cellular endocrinology. - : Elsevier BV. - 1872-8057 .- 0303-7207. ; 315:1-2, s. 121-130
-
Tidskriftsartikel (refereegranskat)abstract
- Progesterone, acting via the nuclear progesterone receptor (PGR), reduces apoptosis in periovulatory granulosa cells, and is a likely mediator of the anti-atretic actions of LH. The underlying mechanisms, however, have not been clearly defined. In this study, we sought to identify progesterone-mediated transcriptional changes involved in apoptosis regulation. Granulosa cells from immature, gonadotropin-primed female rats were treated in vitro with 100nM of the PGR antagonist Org 31710. Transcriptional effects were analyzed after 5 and 22h of incubation using microarrays, and the expression of 85 genes was subsequently measured by quantitative PCR. Follow-up experiments focused on genes related to the functional group "apoptosis". We have identified novel, early gene targets of PGR that may be involved in the control of apoptosis and other biologically significant functions in periovulatory granulosa cells. This study expands our knowledge of events that occur during the processes of ovulation and luteinization.
|
|
| 9. |
- Johansson, Julia, 1982, et al.
(författare)
-
Electrical vs Manual Acupuncture Stimulation in a Rat Model of Polycystic Ovary Syndrome: Different Effects on Muscle and Fat Tissue Insulin Signaling
- 2013
-
Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 8:1
-
Tidskriftsartikel (refereegranskat)abstract
- In rats with dihydrotestosterone (DHT)-induced polycystic ovary syndrome (PCOS), repeated low-frequency electrical stimulation of acupuncture needles restores whole-body insulin sensitivity measured by euglycemic hyperinsulinemic clamp. We hypothesized that electrical stimulation causing muscle contractions and manual stimulation causing needle sensation have different effects on insulin sensitivity and related signaling pathways in skeletal muscle and adipose tissue, with electrical stimulation being more effective in DHT-induced PCOS rats. From age 70 days, rats received manual or low-frequency electrical stimulation of needles in abdominal and hind limb muscle five times/wk for 4–5 wks; controls were handled but untreated rats. Low-frequency electrical stimulation modified gene expression (decreased Tbc1d1 in soleus, increased Nr4a3 in mesenteric fat) and protein expression (increased pAS160/AS160, Nr4a3 and decreased GLUT4) by western blot and increased GLUT4 expression by immunohistochemistry in soleus muscle; glucose clearance during oral glucose tolerance tests was unaffected. Manual stimulation led to faster glucose clearance and modified mainly gene expression in mesenteric adipose tissue (increased Nr4a3, Mapk3/Erk, Adcy3, Gsk3b), but not protein expression to the same extent; however, Nr4a3 was reduced in soleus muscle. The novel finding is that electrical and manual muscle stimulation affect glucose homeostasis in DHT-induced PCOS rats through different mechanisms. Repeated electrical stimulation regulated key functional molecular pathways important for insulin sensitivity in soleus muscle and mesenteric adipose tissue to a larger extent than manual stimulation. Manual stimulation improved whole-body glucose tolerance, an effect not observed after electrical stimulation, but did not affect molecular signaling pathways to the same extent as electrical stimulation. Although more functional signaling pathways related to insulin sensitivity were affected by electrical stimulation, our findings suggest that manual stimulation of acupuncture needles has a greater effect on glucose tolerance. The underlying mechanism of the differential effects of the intermittent manual and the continuous electrical stimulation remains to be elucidated.
|
|
| 10. |
- Johansson, Julia, 1982, et al.
(författare)
-
Intense electroacupuncture normalizes insulin sensitivity, increases muscle GLUT4 content, and improves lipid profile in a rat model of polycystic ovary syndrome.
- 2010
-
Ingår i: American journal of physiology. Endocrinology and metabolism. - : American Physiological Society. - 1522-1555 .- 0193-1849. ; 299:4
-
Tidskriftsartikel (refereegranskat)abstract
- Polycystic ovary syndrome (PCOS) is associated with hyperandrogenism and insulin resistance, possibly reflecting defects in skeletal muscle and adipocyte insulin signaling. Low-frequency (2 Hz) electroacupuncture (EA) increases insulin sensitivity in female rats with dihydrotestosterone (DHT)-induced PCOS, but the mechanism is unclear. We hypothesized that low-frequency EA regulates mediators involved in skeletal muscle glucose uptake and metabolism and alters the lipid profile in rats with DHT-induced PCOS. To test this hypothesis, we implanted in prepubescent female rats 90-day continuous-release pellets containing DHT (PCOS). At 70 days of age, the rats were randomly subdivided into two groups: one received low-frequency EA (evoking muscle twitches) for 20-25 min five times/wk for 4-5 wk; the other did not. Controls were implanted with pellets containing vehicle only. All three groups were otherwise handled similarly. Lipid profile was measured in fasting blood samples. Insulin sensitivity was determined by euglycemic hyperinsulinemic clamp, soleus muscle protein expression of glucose transporter 4 (GLUT4), and phosphorylated and nonphosphorylated Akt, and Akt substrate of 160 kDa was determined by Western blot analysis and GLUT4 location by immunofluorescence staining. PCOS EA rats had normalized insulin sensitivity, lower levels of total high-density lipoprotein and low-density lipoprotein cholesterol, and increased expression of GLUT4 in different compartments of skeletal muscle compared with PCOS rats. Total weight and body composition did not differ in the groups. Thus, in rats with DHT-induced PCOS, low-frequency EA has systemic and local effects involving intracellular signaling pathways in muscle that may, at least in part, account for the marked improved insulin sensitivity.
|
|
