Normal Adult Female Mice Research Articles

Estrogen regulates the expression of Ndrg2 in astrocytes

N-myc downstream-regulated gene 2 (Ndrg2) is a newly identified molecule that is mainly expressed in astrocytes within the central nervous system (CNS) and is involved in the proliferation and activation of astrocytes. 17β-estradiol (E2) is one of the most important circulating hormones, and in the CNS, astrocytes are a target and potential mediator of the action of E2. Our most recent study found that DPN, an estrogen receptor (ER) β-specific agonist, activated the Ndrg2 promoter and elevated endogenous NDRG2 protein expression in MCF7, HSG and T-47D cells. However, whether E2 regulates Ndrg2 expression in astrocytes remains unknown. Here, we conducted both in vivo and in vitro experiments and found that ERβ co-localized with NDRG2 in astrocytes. Furthermore, in primary cultured astrocytes, we demonstrated that E2 up-regulated Ndrg2 mRNA and protein expression in a dose- and time-dependent manner and that the ERβ agonist DPN but not the ERα agonist PPT up-regulated Ndrg2 expression. In vivo, we found that in the hippocampus of adult ovariectomized (OVX) female mice, Ndrg2 mRNA and protein expression were significantly decreased compared with those in normal adult female mice. After the OVX mice received continuous subcutaneous injections of 50μg/kg E2, 100μg/kg E2 or the ERβ agonist DPN for 10 days, the Ndrg2 expression significantly increased compared with that of the OVX mice. Our results indicate that E2 may affect astrocytes by regulating Ndrg2 expression.

Lepidium meyenii (Maca) increases litter size in normal adult female mice

BackgroundLepidium meyenii, known as Maca, grows exclusively in the Peruvian Andes over 4000 m altitude. It has been used traditionally to increase fertility. Previous scientific studies have demonstrated that Maca increases spermatogenesis and epididymal sperm count. The present study was aimed to investigate the effects of Maca on several fertility parameters of female mice at reproductive age.MethodsAdult female Balb/C mice were divided at random into three main groups: i) Reproductive indexes group, ii) Implantation sites group and iii) Assessment of uterine weight in ovariectomized mice. Animals received an aqueous extract of lyophilized Yellow Maca (1 g/Kg BW) or vehicle orally as treatment. In the fertility indexes study, animals received the treatment before, during and after gestation. The fertility index, gestation index, post-natal viability index, weaning viability index and sex ratio were calculated. Sexual maturation was evaluated in the female pups by the vaginal opening (VO) day. In the implantation study, females were checked for implantation sites at gestation day 7 and the embryos were counted. In ovariectomized mice, the uterine weight was recorded at the end of treatment.ResultsImplantation sites were similar in mice treated with Maca and in controls. All reproductive indexes were similar in both groups of treatment. The number of pups per dam at birth and at postnatal day 4 was significantly higher in the group treated with Maca. VO day occurred earlier as litter size was smaller. Maca did not affect VO day. In ovariectomized mice, the treatment with Maca increased significantly the uterine weights in comparison to their respective control group.ConclusionAdministration of aqueous extract of Yellow Maca to adult female mice increases the litter size. Moreover, this treatment increases the uterine weight in ovariectomized animals. Our study confirms for the first time some of the traditional uses of Maca to enhance female fertility.

Gender and age related expression of Oct-6 – a POU III domain transcription factor, in the adult mouse brain

Oct-6 is a POU III domain transcription factor whose primary role is thought to be developmental. It is expressed in embryonic stem cells, Schwann cells, and in neuronal subpopulations during telencephalic development. Its best characterised role is in Schwann cells where it is thought to regulate myelin specific gene expression. Expression of Oct-6 was recently discovered in neurons in post-mortem human schizophrenic specimens while being undetectable in matched controls. This study of human tissue contrasted in a number of regards with earlier studies of rodent brain, and questioned what we can consider to be normal adult expression of this gene. In this study, we have investigated Oct-6 expression via in situ hybridisation and Western blot analysis in normal adult female mice of different ages. We show that both RNA and protein levels of Oct-6 expression are highly sustained in the adult and aging cerebellum, whereas they are attenuated in the telencephalon by PW30 (postnatal week 30). These observations suggest that Oct-6 expression takes place in a sex and age dependent way.

The differential fate of mesonephric tubular-derived efferent ductules in estrogen receptor-alpha knockout versus wild-type female mice.

We investigated mesonephric tubular-derived efferent ductules in female wild-type (WT) and estrogen receptor-alpha knockout (ERalphaKO) mice from late fetal to adult life. On gestational day 17, efferent ductules in both fetal WT and ERalphaKO females were well developed and morphologically similar, although one third the size of the male counterpart. Unexpectedly, efferent ductules with a ciliated epithelium were still present on postnatal day 10 in WT and ERalphaKO females. By day 23, however, marked phenotypic differences occurred in efferent ductules of WT and ERbetaKO vs. ERalphaKO female mice. In the latter, efferent ductules became hypertrophied and dilated, whereas only small tubules remained in WT and ERbetaKO adult mice. The serum testosterone concentrations were similar in 21- to 25-day-old ERalphaKO, heterozygous, and WT female mice, suggesting that increased testosterone was not inducing enlargement of efferent ductules in ERalphaKO females. In conclusion, remnants of efferent ductules persisted in normal adult female mice, although these structures were greatly reduced in size compared with efferent ductules in ERalphaKO female mice. The underlying mechanism inducing hypertrophy and dilation of efferent ductules in ERalphaKO females is not clear, but secretory and/or reabsorptive function of female efferent ductules may involve ERalpha.

Study on cellular events in post-thymectomy autoimmune oophoritis in mice. II. Requirement of Lyt-1 cells in normal female mice for the prevention of oophoritis.

Autoimmune oophoritis that develops in A/J mice after neonatally thymectomy (NTx) was prevented by a single intraperitoneal injection of spleen cells or thymocytes from normal adult female mice. Prevention of oophoritis was achieved when spleen cells were given within 2 wk after Tx. When spleen cells were obtained from neonatally oophorectomized mice, four times more cells were required for the prevention of oophoritis, but those from the mice oophorectomized on day 7 after birth had equivalent capacity to prevent oophoritis to those from normal female mice. The spleen cells from normal A/J mice that prevented the development of oophoritis in NTx A/J mice were Thy-1+, Lyt-1+,23-, Ia-, Qa-1-, sensitive to in vitro irradiation with 400 rad, resistant to administration of cyclophosphamide or anti-thymocyte serum, and were not eliminated by adult thymectomy. Thymocytes with oophoritis-preventing capacity were also found to be Lyt-1+,23- and TL-1,2,3-. These results seem to correlate well with the finding that the Lyt-1 subpopulation is substantially decreased in NTx mice. The results suggest that, in this post-thymectomy autoimmune oophoritis, NTx abrogates the Lyt-1 T cell subpopulation that serves as suppressive or regulatory cells over developing self-reactive cells directed toward ovarian antigens, and eventually may cause autoimmune oophoritis.

EFFECT OF OVARIECTOMY ON PITUITARY AND SERUM GONADOTROPHINS IN THE MOUSE.

The effect of ovariectomy on the concentration of follicle-stimulating hormone (FSH) and luteinizing hormone (LH, ICSH) in the anterior pituitary and in the serum of 2 strains of mice was determined by means of quantitative and specific bio-assay methods (HCG-augmentation assay of Steelman and Pohley for FSH and ovarian ascorbic acid depletion assay of Parlow for LH). The concentration of FSH in the anterior pituitary of normal adult female mice was 13 μg equivalents of NIH-FSH-S1 per mg dry weight. By the 3rd month after ovariectomy the concentration of FSH had increased approximately 5-fold and remained at this level for an additional 6 months. FSH activity was not detectable in the serum of normal adult female mice. At 3 months and 9 months after ovariectomy the concentration of FSH in serum was 9 and 12 μg of NIH-FSH-Sl/ml. The concentration of LH in the anterior pituitary of normal adult mice was 3 μg equivalents of NIH-LH-S1 per mg dry weight. This concentration was the same in the ovariectomized mi...