[Impact of Cadmium on the expressions of piRNAs in the rat testis].

OBJECTIVE: To study the impact of cadmium (Cd) on the expressions of PIWI-interacting RNAs (piRNA) in the rat testis and its possible action mechanism. METHODS: Twelve 6-week-old SD rats were randomly divided into a Cd-exposure and a control group, the former gavaged with CdCl2 at 3 mg/kg/d and the latter with normal saline, all for 28 successive days. Then the testicular tissues were collected from the rats, sperm concentration and motility were obtained by computer-assisted sperm analysis (CASA), and piRNA sequencing was performed using the gene chip, followed by bioinformatics analysis of differentially expressed piRNAs. RESULTS: Compared with the controls, the rats in the Cd-exposure group showed significantly decreased sperm concentration and motility (P < 0.05). The expressions of 272 piRNAs were up-regulated and 402 down-regulated after 28 days of Cd exposure, and 4 of the up-regulated piRNAs were consistent with the results of gene chip verification. Bioinformatics analysis showed that the 4 up-regulated piRNA target genes were involved in 50 biological processes, such as negative regulation of apoptosis, positive regulation of gene expression and positive regulation of GTPase activity, and mainly concentrated in 13 signaling pathways including transcription dysregulation, calcium and mitogen-activated protein kinase signaling pathways in cancer. Among them, PIRNA-DQ765261 had a binding site with Bcl-2. CONCLUSION: Cadmium can induce changes in the expressions piRNAs in the rat testicular tissue, and some piRNAs may be involved in the autophagy and apoptosis of sperm. Bcl-2 may be the target of PIRNA-DQ765261.

Di(2-ethylhexyl)phthalate induces reproductive toxicity via JAZF1/TR4 pathway and oxidative stress in pubertal male rats.

Di(2-ethylhexyl)phthalate (DEHP) is a typical endocrine-disrupting chemical and reproductive toxicant. Although previous studies have attempted to describe the mechanism by which DEHP exposure results in reproductive dysfunction, few studies focused on puberty, a critical period of reproductive development, and the increased susceptibility to injury in adolescents. To elucidate the mechanism underpinning the testicular effects of DEHP in puberty, we sought to investigate the JAZF1/TR4 pathway in the testes of pubertal rats. Specifically, we focused on the role of the JAZF1/TR4 pathway in male reproduction, including the genes JAZF1, TR4, Sperm 1, and Cyclin A1. In the present study, rats were exposed to increasing concentrations of DEHP (0, 250, 500, and 1000 mg/kg/day) by oral gavages for 30 days. Then we assayed testicular zinc and oxidative stress levels. Our results indicated that DEHP exposure could lead to oxidative stress and decrease the contents of testicular zinc. Additionally, significant morphological changes and cell apoptosis were observed in testes exposed to DEHP, as identified by hematoxylin and eosin staining and the terminal deoxynucleotidyl transferase-mediated nick and labeling assay. By measuring the expression levels of the above relevant genes by qPCR, we found the DEHP-induced increased expression of JAZF1 and decreased expression of TR4, Sperm 1, and Cyclin A1. Therefore, we have demonstrated that in vivo exposure to DEHP might induce reproductive toxicity in pubertal male rats through the JAZF1/TR4 pathway and oxidative stress.

[Construction of a recombinant plasmid of BC022687 and identification of its expression and localization in CHO cells].

OBJECTIVE: To construct a mammalian expression plasmid of the BC022687 gene and investigate the expression and localization of the fusion protein in Chinese hamster ovary (CHO) cells. METHODS: The BC022687 coding sequence was amplified by polymerase chain reaction (PCR) and subcloned into the pEGFP-C1 vector carrying the gene of green fluorescence protein (GFP). After the target region was sequenced, the recombinant plasmid was transfected into CHO cells, and its expression in the CHO cells was determined by Western blot. The localization of GFP-tagged BC022687 in the CHO cells was observed by laser scanning confocal microscopy. RESULTS: BC022687 was successfully cloned into the mammalian expression vector pEGFP-C1, with the restriction fragment length of 950 bp. The expression of the fusion protein was confirmed, with the relative molecular weight of 64 000. The GFP-tagged BC022687 protein was mainly localized in the cytoplasm, and also presented in the centrioles in the transfected CHO cells. CONCLUSION: The successful construction of the plasmid expressing BC022687 in CHO cells has laid a foundation for further studies on the role of this protein in ciliogenesis.

Tissue-type plasminogen activator and its inhibitor plasminogen activator inhibitor type 1 are coordinately expressed during ovulation in the rhesus monkey.

Ovulation is a gonadotropin-controlled process that is essential for the propagation of all mammalian species. In the present study, we used a pregnant mare serum gonodotropin/human chorionic gonadotropin (hCG)-induced, synchronized ovulation model in rhesus monkeys and systematically investigated the roles of the plasminogen activator (PA) system in the ovulatory process of the primate. At different follicular developmental stages throughout the periovulatory period, samples of ovaries, granulosa cells, and theca-interstitial cells as well as follicular fluid were collected, and levels of PA and PA inhibitor type-1 (PAI-1) were evaluated by fibrin overlay, reverse fibrin overlay, Northern blot analysis, and in situ hybridization, respectively. We showed that in response to an injection of ovulation-triggering hCG, which mimics the preovulatory surge of LH in the circulation, granulosa cell-derived tissue-type PA (tPA) was substantially elevated in preovulatory follicles and reached its maximum level just before ovulation. Although theca-interstitial cell-derived PAI-1 was also stimulated by pregnant mare serum gonodotropin and hCG treatments, however, the maximum level of PAI-1 appeared 12 h earlier than that of tPA. When ovulation approached, accompanying the highest tPA level in the preovulatory follicles, the follicular PAI-1 level declined dramatically to its minimum value. Moreover, our data on the expression of follicular PA and PAI-1 over the periovulatory period were reinforced by results obtained at the mRNA level. Our data suggest that the coordinated expression of tPA and PAI-1 may be of importance for the follicular rupture process during ovulation in the primate.