Preimplantation embryos are sensitive to oxidative stress-induced damage that can be caused by reactive oxygen species (ROS) originating from normal embryonic metabolism and/or the external surroundings. Paraquat (PQ), a commonly used pesticide and potent ROS generator, can induce embryotoxicity. The present study aimed to investigate the effects of melatonin on PQ-induced damage during embryonic development in bovine preimplantation embryos. PQ treatment significantly reduced the ability of bovine embryos to develop to the blastocyst stage, and the addition of melatonin markedly reversed the developmental failure caused by PQ (20.9% versus 14.3%). Apoptotic assay showed that melatonin pretreatment did not change the total cell number in blastocysts, but the incidence of apoptotic nuclei and the release of cytochrome c were significantly decreased. Using real-time quantitative polymerase chain reaction analysis, we found that melatonin pre-incubation significantly altered the expression levels of genes associated with redox signaling, particularly by attenuating the transcript level of Txnip and reinforcing the expression of Trx. Furthermore, melatonin pretreatment significantly reduced the expression of the pro-apoptotic caspase-3 and Bax, while the expression of the anti-apoptotic Bcl-2 and XIAP was unaffected. Western blot analysis showed that melatonin protected bovine embryos from PQ-induced damage in a p38-dependent manner, but extracellular signal-regulated kinase (ERK) and c-JUN N-terminal kinase (JNK) did not appear to be involved. Together, these results identify an underlying mechanism by which melatonin enhances the developmental potential of bovine preimplantation embryos under oxidative stress conditions.
Aberrant activation of signaling pathways is frequently observed and reported to be associated with the progression and poor prognosis of prostate cancer (PCa). We aimed to identify key biological processes regulated by androgen receptor (AR) using gene co-expression network from single cell resolution. The bimodal index was used to evaluate whether two subpopulations exist among the single cells. Gene expression among single cells revealed averaging pitfalls and bimodality pattern. Weighted gene co-expression network analysis (WGCNA) was used to identify modules of highly correlated genes. Twenty-nine gene modules were identified and AR-regulated modules were screened by significantly overlapping reported androgen induced differentially expressed genes. The biological function “generation of precursor metabolites and energy” was significantly enriched by AR-regulated modules with bimodality, presenting differential androgen response among subpopulations. Integrating with public ChIP-seq data, two genes FECH, and CROT has AR binding sites. Public in vitro studies also show that androgen regulates FECH and CROT. After receiving androgen deprivation therapy, patients lowly express FECH and CROT. Further survival analysis indicates that FECH/CROT signature can predict PCa recurrence. We reveal the heterogeneous function of “generation of precursor metabolites and energy” upon androgen stimulation from the perspective of single cells. Inhibitors targeting this biological process will facilitate to prevent prostate cancer progression.
Wurtzite Cu2SnS3 nanocrystals are synthesized through a green hydrothermal method based on a top-down strategy and are further demonstrated as a promising sensitizer for efficient photoelectrochemical water splitting.
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