A retrospective analysis of pathological changes of testicular tissue in normal adult rats

Rat testicular model is widely used in experiments on andrology, pharmacology and reproductive toxicology. Generally, normal adult rat is considered to have normal testes. However, whether normal adult rats appeared abnormal testes have not been evaluated. The objective of this study was to evaluate the incidence of abnormal testes in normal adult Sprague Dawley (SD) rats and pathological changes in testicular tissues. Six hundred and sixteen adult male SD rats used in previous studies as controls were retrospectively analysed. Testicular tissues were stained with haematoxylin–eosin for observation of pathology. Among 616 rats, 14 rats had pathological testes, and the incidence of abnormal testis was 2.3%. In the 14 rats with abnormal testes, 10 rats were microrchidia (71.4%) and four rats showed normal testicular size. Testicular abnormality included complete interruption of spermatogenesis, partial germ cell arrest, progressive hypospermatogenesis, seminiferous epithelia vacuolation and inflammatory status. Bilateral testicular tissues had similar pathological changes in abnormal testes. The findings in this study demonstrate that the normal adult rats have abnormal testes. We should pay attention to the possibility of abnormal testes when using normal adult male rats for establishing a testicular model.     

shRNA-mediated GSTP1 gene silencing enhances androgen-independent cell line DU145 chemosensitivity

Purpose

Design short hairpin RNA (shRNA) interference sequence to silence glutathione S-transferase P1 (GSTP1) gene of androgen-independent prostate cancer cell line DU145, and then to explore its effect on sensitivity to chemotherapeutics.

Methods

Target sequence was picked up to form the shRNA. DU145 cell was divided into five groups according to the shRNA added for transfection: shRNA255, shRNA554, shRNA593, negative-shRNA and blank group. Fluorescence microscope was used to pick up the shRNA with the highest transfection ratio. Western blotting and RT-PCR were taken to pick up the shRNA with the best gene silencing result. 3-(4,5-Dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide assay and terminal de-oxynucleotidyl transferase-mediated dUTP nick end-labeling assay were used to detect survival ratio and apoptosis ratio of DU145 administered of fluorouracil (5-FU) or paclitaxel (PA) at different concentrations before and after shRNA transfection.

Results

Three different shRNA oligonucleotides (shRNA255; shRNA554; shRNA593) targeting the coding sequence of GSTP1 mRNA and one negative control shRNA were constructed. The transfection ratio of shRNA554 (76.2 ± 0.68 %) was higher than that of shRNA255 (63.3 ± 1.04 %) (P < 0.01) or shRNA593 (72.7 ± 0.33 %) (P < 0.01). After transfection of shRNA554, the mRNA and protein of level were the lowest, P < 0.01. The survival ratio of DU145 administered with 5-FU of different concentrations (30, 60, 120, 240 μg/ml) declined after transfection (P < 0.01). Besides, the apoptosis ratio increased after transfection (P < 0.01). Similarly the survival ratio of DU145 administered with PA of different concentrations (0.2, 2, 10, 20 μg/ml) declined (P < 0.01) and the apoptosis ratio increased (P < 0.01) after transfection.

Conclusions

The gene GSTP1 silence via shRNA transfection to androgen-independent prostate cancer cell line DU145 enhances the sensitivity to chemotherapeutics.     

Effects of aescin on testicular repairment in rats with experimentally induced varicocele

This study was conducted to investigate the effects of aescin treatment in a rodent model treated with an experimentally induced varicocele. Experimental varicocele was induced by partial ligation of the left renal vein of rats. Aescin administration was performed daily for 4 weeks after the varicocele induction. Seven weeks later, a contrast‐enhanced ultrasound was performed of the rats' testis to assess testicular blood flow. The animals were sacrificed, and H&E staining was then used to evaluate testicular pathological changes and polymorphonuclear leucocytes density. Cauda epididymal sperm counts and motility were evaluated. Blood was collected for the measurement of follicle‐stimulating hormone, luteinising hormone and testosterone. Contrast‐enhanced ultrasound showed that there were significant decreases in testicular blood flow in the aescin‐treated groups compared with those in control varicocele group. Testicular oedema was detected in those rats treated with a varicocele but without aescin, while no oedema was found in the experimental group. H&E staining showed dysfunctional spermatogenesis in both cohorts; however, polymorphonuclear leucocytes density was significantly reduced in aescin‐treated groups. There was an increase in sperm counts of the aescin‐treated groups. Our study demonstrated that aescin could exert therapeutical effects on reversal of testicular lesions in varicocele rats.