Effect of PFOA exposure on diminished ovarian reserve and its metabolism.

Owing to its difficulty in degrading and ease of accumulation in the body, perfluorooctanoic acid (PFOA) has a detrimental effect on reproduction. This study aimed to examine the effect of PFOA concentration in follicular fluid during ovulation stimulation on embryo quality and the impact of PFOA exposure on the metabolic components of follicular fluid. This was a single-center prospective study that included 25 patients with diminished ovarian reserve (DOR), 25 with normal ovarian reserve (NOR), and 25 with polycystic ovary syndrome (PCOS). Follicular fluid samples were analyzed using ultra-high performance liquid chromatography-tandem mass spectrometry. We demonstrated that the PFOA levels of follicular fluid in the DOR group were higher than those in the NOR group and PCOS group (P < 0.05). PFOA concentration in the PCOS group was negatively correlated with high-quality embryos (P < 0.05). To gain more insight into the impact of PFOA on the metabolic composition of follicular fluid, we classified the DOR group based on the PFOA concentration, for which metabolomic analysis was performed. In the high-concentration PFOA group, there was an increase and a decrease in three and nine metabolites, respectively, compared to that in the low-concentration group. These results suggest that PFOA may alter the metabolic composition of follicular fluid, thus, affecting ovarian reserve function.

Oncogenic Activity of Glucocorticoid Receptor ß Is Controlled by Ubiquitination-Dependent Interaction with USP49 in Glioblastoma Cells.

Previous studies have demonstrated that glucocorticoid receptor ß (GRß) functions as an oncoprotein, regulating the malignant phenotypes and stem-like cell maintaining in human glioblastoma (GBM). Of the glucocorticoid receptor (GR) isoforms, GRß and GRα are highly homologous, though the mechanism underlying the distinct functions of these two isoforms in GBM has not been clarified. Here by establishing a carboxyl-terminal (COOH-terminal) deletion mutant, we determined that GRß can be ubiquitinated. We also found that its COOH terminal is essential for this ubiquitination. The mutation of a lysine to arginine at residue 733 (K733R) blocked the ubiquitination of GRß, indicating that K733 is a key site for ubiquitination. Using K733R to establish nonubiquitinated GRß, we demonstrated that ubiquitination not only regulates the stability and nuclear translocation of GRß, but is also a vital mechanism for its oncogenic functions in vitro and in vivo. Protein interaction assay further indicated that ubiquitin-specific protease 49 (USP49) is a GRß-binding protein and the interaction depends on GRß ubiquitination. USP49 knockdown resulted in a decrease of cell proliferation, invasion, and an increase of cell apoptosis. More importantly, USP49 knockdown increased ubiquitination and amplified the oncogenic effects of GRß, confirming the decisive role of ubiquitination on GRß carcinogenicity. Taken together, these findings established that ubiquitination is a vial process for GRß the execution of oncogenic functions in GBM and that the K733 site is crucial for ubiquitination of GRß. IMPLICATIONS: This work is the first identify of the activation GRß by a single lysine point-mediated ubiquitination and proteasome degradation, which determines its oncogenic functions in GBM.

PKCγ promotes axonal remodeling in the cortico-spinal tract via GSK3ß/ß-catenin signaling after traumatic brain injury.

Traumatic brain injury (TBI) is a common cause of death and disability. Enhancing the midline-crossing of the contralateral corticospinal tract (CST) to the denervated side of spinal cord facilitates functional recovery after TBI. Activation of the gamma isoform of PKC (PKCγ) in contralateral CST implicates its roles in promoting CST remodeling after TBI. In this study, we deployed loss and gain of function strategies in N2a cells and primary cortical neurons in vitro, and demonstrated that PKCγ is not only important but necessary for neuronal differentiation, neurite outgrowth and axonal branching but not for axonal extension. Mechanically, through the phosphorylation of GSK3ß, PKCγ stabilizes the expression of cytosolic ß-catenin and increase GAP43 expression, thus promoting axonal outgrowth. Further, rAAV2/9-mediated delivery of constitutive PKCγ in the corticospinal tract after unilateral TBI in vivo additionally showed that specifically delivery of active PKCγ mutant to cortical neuron promotes midline crossing of corticospinal fibers from the uninjured side to the denervated cervical spinal cord. This PKCγ-mediated injury response promoted sensorimotor functional recovery. In conclusion, PKCγ mediates stability of ß-catenin through the phosphorylation of GSK3ß to facilitate neuronal differentiation, neurite outgrowth and axonal branching, and PKCγ maybe a novel therapeutic target for physiological and functional recovery after TBI.

Generation of chimeric minipigs by aggregating 4- to 8-cell-stage blastomeres from somatic cell nuclear transfer with the tracing of enhanced green fluorescent protein.

BACKGROUND: Blastocyst complementation is an important technique for generating chimeric organs in organ-deficient pigs, which holds great promise for solving the problem of a shortage of organs for human transplantation procedures. Porcine chimeras have been generated using embryonic germ cells, embryonic stem cells, and induced pluripotent stem cells; however, there are no authentic pluripotent stem cells for pigs. In previous studies, blastomeres from 4- to 8-cell-stage parthenogenetic embryos were able to generate chimeric fetuses efficiently, but the resulting fetuses did not produce live-born young. Here, we used early-stage embryos from somatic cell nuclear transfer (SCNT) to generate chimeric piglets by the aggregation method. Then, the distribution of chimerism in various tissues and organs was observed through the expression of enhanced green fluorescent protein (EGFP). METHODS: Initially, we determined whether 4- to 8- or 8- to 16-cell-stage embryos were more suitable to generate chimeric piglets. Chimeras were produced by aggregating two EGFP-tagged Wuzhishan minipig (WZSP) SCNT embryos and two Bama minipig (BMP) SCNT embryos. The chimeric piglets were identified by coat color and microsatellite and swine leukocyte antigen analyses. Moreover, the distribution of chimerism in various tissues and organs of the piglets was evaluated by EGFP expression. RESULTS: We found that more aggregated embryos were produced using 4- to 8-cell-stage embryos (157/657, 23.9%) than 8- to 16-cell-stage embryos (100/499, 20.0%). Thus, 4- to 8-cell-stage embryos were used for the generation of chimeras. The rate of blastocysts development after aggregating WZSP with BMP embryos was 50.6%. Transfer of 391 blastocysts developed from 4- to 8-cell-stage embryos to five recipients gave rise to 18 piglets, of which two (11.1%) were confirmed to be chimeric by their coat color and microsatellite examination of the skin. One of the chimeric piglets died at 35 days and was subsequently autopsied, whereas the other piglet was maintained for the following observations. The heart and kidneys of the dead piglet showed chimerism, whereas the spinal cord, stomach, pancreas, intestines, muscle, ovary, and brain had no chimerism. CONCLUSIONS: To our knowledge, this is the first report of porcine chimeras generated by aggregating 4- to 8-cell-stage blastomeres from SCNT. We detected chimerism only in the skin, heart, and kidneys. Collectively, these results indicate that aggregation using 4- to 8-cell-stage SCNT embryos offers a practical approach for producing chimeric minipigs. Furthermore, it also provides a potential platform for generating interspecific chimeras between pigs and non-human primates for xenotransplantation.

Effect of Genetic Diversity in Swine Leukocyte Antigen-DRA Gene on Piglet Diarrhea.

The swine leukocyte antigens (SLAs) are the multigene families related to immune responses. Little is known about the effect of the DRA gene on diarrheal disease. This study reported the genetic diversity of the DRA gene in exons 1, 3 and 4 in 290 Chinese Yantai black pigs. No variation was identified in exon 3. In exon 1, three genotypes and two alleles were identified, generated by two single nucleotide polymorphisms (SNPs). In exon 4, there were eight genotypes and five alleles containing seven SNPs were detected with four SNPs being novel SNPs. The low polymorphism found in swine DRA is consistent with the concept that the DRA gene is highly conserved among all mammalian species. Statistical analyses indicated that the genotypes of exon 1 were not significantly associated with piglet diarrhea (p > 0.05); however, genotypes C4C4 (1.80 ± 0.33) and A4E4 (1.66 ± 0.25) of exon 4 were significantly susceptible to diarrhea (p < 0.01). These indicate that the particular genotypes of the DRA gene are susceptible to diarrheal disease, which provides valuable information for disease-resistance breeding in swine.