ABSTRACT
Objective To establish an allogeneic rat model of endometriosis and to evaluate the effects of gonadotropin-releasing hormone (GnRH) agonist GenSci006 on experimental rat endometriosis. Methods Endometrium from SPF grade donor female SD rats were transplanted onto the abdominal wall of recipient female rats to construct an allogeneic endometriosis model. The rats undergoing sham surgery were divided into the sham group. Three weeks later, the length, width and height of the ectopic endometrium were measured, and the volume of the endometrium (V1) was calculated before drug administration. The modeling rats were randomly divided into four groups: model group, triptorelin group (0.25 mg/kg), GenSci006-1 group (0.125 mg/kg) and GenSci006-2 group (0.25 mg/kg). Each group had 16 rats and received a single dose of the corresponding drug. The sham group and model group were administered an equal volume of solvent. Three weeks after administration, ectopic endometrium was measured to calculate the volume V2 and inhibition rate. The effect of GenSci006 on rat uterus and ovarian tissues was assessed by comparing organ coefficients and changes in pathological sections. Enzyme-linked immunosorbent assay (ELISA) was used to measure the levels of serum estradiol (E2), progesterone (P4), follicle stimulating hormone (FSH), and luteinizing hormone (LH). Real-time fluorescent quantitative PCR was used to detect the expression of GnRH receptor (GnRHR) mRNA in the hypothalamus and pituitary. Western blot was used to detect the expression of estradiol receptor alpha (ERα), beta (ERβ) and progesterone receptor (PR) in ectopic endometrium. Results Three weeks after administration, compared with the model group, the body weight of rats in the triptorelin and GenSci006-2 groups significantly increased (P < 0.05), while the volume of ectopic endometrium significantly decreased (P < 0.05). Compared with the sham group, the model group showed no significant changes in uterine and ovarian organ coefficients or endometrial thickness (P > 0.05). Compared with the model group, the uterine organ coefficients and endometrial thickness were significantly reduced in the triptorelin and GenSci006-2 groups (P < 0.05). Compared with the sham group, the serum levels of E2, P4, FSH and LH in the model group showed no significant changes (P > 0.05). Compared with the model group, the ovarian organ coefficient and serum P4 levels of rats in the Triptorelin, GenSci006-1, and GenSci006-2 groups were significantly reduced (P < 0.05), while the serum LH levels of rats in the GenSci006-1 group were significantly increased (P < 0.05). However, there were no significant changes in serum E2 and FSH levels in each group (P > 0.05). Compared with the model group, the expression levels of GnRHR mRNA in the pituitary tissue of rats in the triptorelin and GenSci006-2 groups were significantly downregulated (P < 0.05), with no significantly changes in the hypothalamus (P > 0.05). There were no significant changes in the expression level of GnRHR mRNA in the hypothalamus or the protein levels of ERα, ERβ and PR in the ectopic endometrial tissue in any group (P > 0.05). Conclusion The allogeneic endometriosis rat model is a suitable animal model for screening and evaluating drugs for treating endometriosis. The volume of ectopic endometrium, inhibition rate, uterine and ovarian organ coefficients, and serum E2 levels may serve as indicators for detecting drug efficacy.
ABSTRACT
Aim To investigate the proliferative effect and the apoptosis of rat epididymal epithelial cells induced by podophyllotoxin and its underlying mechanisms.Methods Primary epididymal epithelial cells were cultured in vitro.CCK-8 assay was used to analyze proliferation of epididymal epithelial cells induced by podophyllotoxin on 24, 48 and 72 h.The ultra structural changes of the epididymal epithelial cells were observed by transmission electron microscope.AnnexinV-FITC/PI staining was used to quantify the percentages of apoptosis in the total cell population.The TdTmediated dUTP nick end labeling(TUNEL) technique was applied to observe the morphological changes of apoptotic cells.The expression of tumor necrosis factor alpha(TNF-α) mRNA was investigated by real-time RT-PCR.The level of TNF-α in cell culture supernatant was measured by enzyme-linked immunosorbent assay(ELISA) technology.Western blot was per-formed to determine the protein expression of cytochrome C, caspase-3, caspase-8, caspase-9.Results Podophyllotoxin significantly inhibited the activity of proliferation and induced apoptosis of epididymal epithelial cells in a dose-and time-dependent manner(P<0.05), with a 50％ inhibitory concentration(IC50) value and corresponding 95％ confidence intervals(CI) of 59.36(15.50～227.41), 0.37(0.080～1.70), 0.077(0.017～0.35) μmol·L-1 at 24, 48 and 72 h, respectively.Podophyllotoxin induced cell volume turned round and cell nuclear fragmentation and mitochondrial vacuolation.RT-PCR and ELISA results showed that podophyllotoxin improved the expression of TNF-α mRNA and protein.Western blot results demonstrated that podophyllotoxin activated the protein expression of cytochrome C, caspase-3, caspase-8 and caspase-9.Conclusion Podophyllotoxin can induce rat epididymal epithelial cell apoptosis through both the mitochondria-regulated intrinsic pathway and the TNF receptor-mediated extrinsic pathway.