Upregulated microRNA-423-5p promotes oxidative stress through targeting glutathione S-transferase mu 1 in asthenozoospermia.

The dysregulation of microRNAs (miRNAs) plays an important role in asthenozoospermia. This study evaluated the sperm microRNA-423-5p (miR-423-5p) expression in asthenozoospermia and normozoospermia, exploring the role of miR-423-5p in asthenozoospermia. Eighty participants were divided into asthenozoospermic (AZS, n = 40) and normozoospermic (Norm, n = 40) groups. Fresh semen samples were collected and the sperm cells were separated. Quantitative Real-Time polymerase chain reaction was used to measure the sperm miR-423-5p level. Receiver operating characteristic curve (ROC) was employed to test the diagnostic performance of miR-423-5p in asthenospermia. Dual-reporter luciferase assay was adopted to confirm the target gene of miR-423-5p. The target gene level in asthenozoospermia and normozoospermia was measured, and the biological function of target gene in asthenozoospermia was evaluated. Results showed that the miR-423-5p expression level in the AZS group was higher than that in Norm group, which was positively correlated with the severity of asthenozoospermia. ROC analysis of miR-423-5p showed an area under curve (AUC) of 0.69 (95% confidence interval = 0.57-0.80, p <0 .01), with 80% sensitivity and 60% specificity. Glutathione S-transferase mu 1 (GSTM1) is a target gene of miR-423-5p, which significantly decreased in the AZS group. Compared with Norm group, glutathione S-transferase (GST) activity and total antioxidant capacity (TAC) level decreased, while malondialdehyde (MDA) level increased in the AZS group. Furthermore, GST activity and TAC level were negatively correlated with miR-423-5p expression, while MDA level was positively correlated with miR-423-5p expression. In conclusion, the sperm miR-423-5p level significantly was upregulated in asthenozoospermia. High-level miR-423-5p inhibited sperm motility through targeting GSTM1 to promote oxidative stress.

Proteomic-based identification of oocyte maturation-related proteins in mouse germinal vesicle oocytes.

Oocyte proteins play an important role in oocyte maturation, fertilization and embryonic development. However, the protein composition of mouse germinal vesicle (GV) oocytes is still unclear. Using one-dimensional Sodium Dodecyl Sulphate Polyacrylamide Gel Electrophoresis (1D SDS-PAGE) and Reverse-phase liquid chromatography tandem mass spectrometry (RP-LC-MS/MS), we constructed a protein profile of mouse GV oocytes. First, our proteomics profile identified 1,405 different proteins from 11,000 mouse GV oocytes lacking zona pellucida. Second, with detailed bioinformatics analysis, a group of proteins that play an essential role in oocyte maturation was screened. In addition, the expression and localization of suppressor of G2 allele of skp1(SUGT1, also called SGT1), heterogeneous nuclear ribonucleoprotein K (Hnrpk), Seruin, Cullin1(Clu1) and nuclear distribution protein C (Nudc) in mouse ovaries and early embryos were also captured and investigated in this study. Moreover, the protein profile was submitted to the Proteomics Identifications Database (PRIDE) and is available via ProteomeXchange with the identifier PXD014314. Our research provides valuable resources for the study of oocyte proteins and oocyte maturation and helps to clarify the mechanisms of oocyte maturation.

Comparative proteomic analysis of proteins involved in oocyte meiotic maturation in mice.

After birth, oocytes stay at the diplotene stage in prophase of meiosis I. Meiosis resumes about 1 day before ovulation, and arrests in metaphase II (MII) after ovulation. The mature, MII oocytes are then ready for fertilization and to provide materials for early embryonic development. Proteomic characterization of oocytes can help identify proteins that are important for female meiotic maturation and early embryonic development. In this study, we compared the proteomic profiles between the germinal vesicle and MII mouse oocytes by two-dimensional electrophoresis; 95 differentially expressed protein spots corresponding to 63 proteins were identified. Many of these proteins are known to be essential for oocyte meiosis and early embryonic development, such as adenylosuccinate synthetase, nucleoplasmin-2, and protein-arginine deiminase type-6. Of the 12 proteins that were identified and are highly expressed in oocytes, a novel protein, E330034G19Rik, was found to be oocyte-specific. According to analysis by bioinformatics, it may regulate chromosome segregation during meiosis or cleavage. An in-depth study of these proteins will help us better understand the mechanisms of oocyte meiotic maturation, fertilization, and early embryogenesis. It will also help us understand the mechanisms of diseases that stem from abnormal oocyte maturation, such as polycystic ovary syndrome and premature ovary failure.

Study on the mechanism of visual aging in cats' primary visual cortex based on BDNF-TrkB signal pathway.

To explore the expression of brain-derived neurotrophic factor (BDNF) and specific receptor tyrosine kinase receptor B (TrkB) in the primary visual cortex of young and old cats, especially to reveal the age-related differences in the mediating mechanism of BDNF-TrkB signaling pathway in cats' visual cortex and their possible effects on synaptic plasticity, Nissl staining was used to display neurons in each layer of cats' primary visual cortex, and immunohistochemical ABC method was used to label BDNF and TrkB immunopositive cells in each layer of cats' primary visual cortex. The BDNF and TrkB receptor immunoreactive neurons and non-neurons were observed and photographed. Their density and immunoreactive intensity were measured. Results showed that BDNF and TrkB were widely expressed in all layers of visual cortex in young and old cats. Compared with the young group, the density and intensity of BDNF and TrkB positive cells in each layer of primary visual cortex in the old group decreased significantly (P < 0.01). The findings indicate that the expression levels of BDNF and TrkB in the primary visual cortex of cats decrease with age, suggesting that the change of BDNF-TrkB signal pathway caused by the weakening of brain-derived neurotrophic factor activity may be one of the important reasons for the decline of visual function.

Data on comparative proteomic profiling of human sperm affected by 4-tert-octylphenol in vitro.

This data article presents proteomic profiling and posttranslational modifications of sperm proteins relating to the research paper "4-tert-octylphenol injures motility and viability of human sperm by affecting cAMP-PKA/PKC-tyrosine phosphorylation signals." (Huang et al., 2018). Comparative proteomics was applied to identify the target biomarkers and the relevant molecular events of human sperm which were exposed to 0 (Dimethyl sulfoxide, DMSO), 0.1, or 0.3 mM 4-tert-octylphenol (4t-OP) for two hours in vitro. All differentially expressed (DE) proteins were then mapped to the human sperm proteome 2.0 (Wang et al., 2016) to clarify the posttranslational modifications (PTMs) of the DE proteins. We provide the associated mass spectrometry raw files; the PTMs in all the DE proteins, in DE proteins related to apoptosis, and in DE proteins related to motility. These data highlight the molecular mechanism relating to injured motility and viability of human sperm affected by 4t-OP.

4-tert-octylphenol injures motility and viability of human sperm by affecting cAMP-PKA/PKC-tyrosine phosphorylation signals.

4-tert-octylphenol (4t-OP) is a well-known xenoestrogen. Our objective was to explore the effects and molecular mechanisms of 4t-OP on human sperm. Sperm samples were exposed to 0, 0.1, or 0.3 mM 4t-OP for two hours. Results showed that both sperm viability and motility were significantly injured by 0.3 mM 4t-OP. We applied comparative proteomics to explore the molecular targets affected by 4t-OP. 81 differentially expressed (DE) proteins were identified. Bioinformatic analysis showed that these proteins were highly associated with motility and apoptosis, and were mostly enriched in cAMP-PKA/PKC-phosphorylation-associated pathway. We further verified that 0.1 mM and 0.3 mM 4t-OP significantly decreased cAMP activity of sperm. Expression of RACK1 and PRDX6 were detected by western blot (WB) to verify their tendencies in gels; antiapoptotic factor BCL2 was also detected by WB. The data indicated that 4-tert-octylphenol injures the motility and viability of human sperm probably by affecting cAMP-PKA/PKC-tyrosine phosphorylation signals.

Rearrangement of a mitochondrial tRNA gene of the concave-eared torrent frog, Amolops tormotus.

In this study, the complete nucleotide sequence (17,962 bp) of the mitochondrial DNA of Amolops tormotus was determined using polymerase chain reaction (PCR). The gene content, base composition and codon usage of A. tormotus conformed to those of typical vertebrate patterns. Among 22 tRNAs, the novel position of the tRNA-His gene was in the D-loop region, which was a novel mtDNA gene rearrangement in amphibians. Phylogenetic analyses were based on a 885-bp sequence of 12S and 16S rRNA for species of Amolops and other related species, concatenated sequences of the 11 protein-encoding genes of 13 species.

Population genetics and phylogeography of Bufo gargarizans in China.

The Chinese toad Bufo gargarizans has an extensive range, covering nearly all of China. This study addresses the population genetic structure of this toad and the relation to geographic location. Partial sequences of the mtDNA control region were obtained from 14 populations, 29 haplotypes were defined, and 73 variable sites were found, including 66 parsimony informative sites. All population genetic analyses indicated no clear geographic pattern in the distribution of haplotypes. The genetic divergence between the populations was significant. Phylogeographic analyses suggested that past fragmentation and/or long-distance colonization seemed to have shaped the present-day distribution of the haplotypes of B. gargarizans.

Complete nucleotide sequences and gene organization of mitochondrial genome of Bufo gargarizans.

The complete mitochondrial genome of Bufo gargarizans was sequenced using overlapping polymerase chain reaction (PCR) amplicons (GenBank Accession No. DQ275350). The genome is 17,277 base pairs in length, containing 13 protein-coding genes (ATP6, ATP8, COI-III, ND1-6, ND4L, Cyt b), 2 ribosomal RNAs (12S rRNA and 16S rRNA), 22 transfer RNAs and a putative control region. We analyzed the sequence using bioinformatics methods comparing the obtained mtDNA sequence with other toads and frogs. Based on the concatenated nucleotide sequences of protein-coding genes, we constructed a phylogenetic tree with maximum likelihood (ML) and maximum parsimony (MP) methods and discussed the phylogenetic relationships among 11 species of Anura.