Genome-wide analysis of DNA methylation in testis of male rat exposed to chlorpyrifos

Single-Cell RNA Sequencing Analysis of Steroidogenesis and Spermatogenesis Impairment in the Testis of db/db Mice

OBJECTIVE

The mechanism of steroidogenesis and spermatogenesis impairment in men with type 2 diabetes remains unclear. We aimed to explore the local changes of steroidogenesis and spermatogenesis in the testis of db/db mice. Research Design and Methods. We performed single-cell RNA sequencing analysis in the testis of db/db and C57BL/6J mice. The differentially expressed genes were then confirmed by real-time PCR. The histopathological characteristics of testis in db/db mice and C57BL/6J control were also performed.

RESULTS

The 20-week-old db/db mice had significantly higher blood glucose and body weight (both p < 0.001). The serum testosterone levels (4.4 ± 0.8 vs. 9.8 ± 0.7 ng/ml, p=0.001) and weight of the testis (0.16 ± 0.01 vs. 0.24 ± 0.01 g, p < 0.001) were significantly lower in db/db mice than that in C57BL/6J controls. db/db mice had a lower cross-sectional area of seminiferous tubules and thickness of the cell layer (both p < 0.05). The numbers of Sertoli cells and Leydig cells decreased in db/db mice (both p < 0.01). Single-cell RNA sequencing analysis showed that compared with the control group, the percentage of spermatogonia was significantly higher in the db/db mouse (p < 0.001), while the proportions of spermatocytes, round and elongating spermatids, and sperms were all lower in the db/db mouse (p all < 0.001). The most differentially expressed genes were found in round spermatids (n = 86), which were not found in spermatogonia, spermatocyte, and sperm. Igfbp5 was the most significantly decreased gene in Leydig cells of the db/db mouse, while the expression of Cd74, H2-Aa, and H2-Eb1 was elevated. Ccl7 and Ptgds were the most significantly increased and decreased genes in Sertoli cells of the db/db mouse.

CONCLUSIONS

The present study indicates spermiogenesis and steroidogenesis defects in db/db mice. The mechanism of steroidogenesis impairment in the testis of db/db mice deserves further investigation.

Coenzyme Q10 treatment and diazinon exposure in parental male rats: effects of the exposure on their neonatal brains

Prenatal acute and chronic exposure to organophosphorus pesticides may evoke physical and behavioral impairments in offspring development. However, the mechanism of antioxidant consumption repair to cure these impairments remains unclear. This study aimed to investigate the protective effects of COQ10 against DZN toxicity by measuring Malondialdehyde (MDA) level, superoxide dismutase (SOD) activity, the expression of MH2A, DNMT1, H2AZ, and HDAC3, and the histopathology in the brain of neonatal Wistar albino rats whose male parents were exposed to DZN and COQ10. The results showed that COQ10 could significantly decrease MDA level, histopathological alteration, and expression of DNMT1 and HDAC3 in the neonatal brain (P < 0.05). Also, an increase in SOD activity and expression of MH2A and H2AZ were observed in the neonatal brain of this group (P < 0.05). These investigations suggest that COQ10 can reduce the effects of DZN on neuronal oxidative stress and its damage to the neonatal brain.

Pterostilbene Alleviates Chlorpyrifos-Induced Damage During Porcine Oocyte Maturation

Chlorpyrifos (CPF), a widely used organophosphate pesticide, is reported to severely impair mammalian reproductive system. Pterostilbene (PTS), an effective free radical scavenger, is considered as beneficial for mammalian reproduction. However, the toxicity of CPF on oocyte maturation and whether PTS can eliminate the detrimental effect of CPF on oocytes remain unclear. Here, porcine oocytes were applied to investigate the potential effect and possible mechanism of CPF and PTS during oocyte maturation. This work demonstrated that CPF significantly delayed the meiotic progression and decreased the polar body extrusion by disturbing spindle assembly and chromosome alignment and causing DNA damage in oocytes (p < 0.05). And, CPF significantly impaired oocyte cytoplasmic maturation by inducing the high level of reactive oxygen species and decreasing glutathione content (p < 0.05). Moreover, CPF significantly triggered embryo apoptosis and reduced the blastocyst rate and cell number following parthenogenetic activation (p < 0.05). Whereas CPF-exposed oocytes were treated with PTS, these defects caused by CPF were obviously rescued, and oocyte maturation and subsequent embryonic development were also significantly ameliorated (p < 0.05). In conclusion, these results revealed that CPF exerted the toxic effect on porcine oocytes, while PTS effectively alleviated CPF-induced damage on oocytes. This work provides a potential strategy to protect oocyte maturation in mammalian species.

Genome-wide identification and functional analysis of long non-coding RNAs and mRNAs in male mice testes at the onset of puberty after low dose lead exposure

Many researchers have studied the relationship between lead (Pb) and testis injury, but the underlying mechanisms are still unknown. The participation of long non-coding RNAs (lncRNAs) in biological processes has been proposed. To comprehensively gain insight into the molecular toxicity of Pb, expression patterns are analysed through RNA sequencing (RNA-seq) in male mice treated with 200 mg/L of Pb through the drinking water for 90 days at the onset of puberty. A total of 614 differentially expressed (DE) lncRNAs were included (p ≤ 0.05 and fold change ≥2), of which 288 were up-regulated, and 326 were down-regulated. A total of 2295 DE mRNAs (p ≤ 0.05 and fold change ≥2), including 1202 up-regulated and 1093 down-regulated ones, were found in the testes of Pb-exposed group. Functional analysis results showed that several lncRNAs might be implicated in the bio-pathway of mitogen-activated protein kinase (MAPK) signaling pathway. Finally, seven pairs of lncRNA-mRNA co-expression were established in mice testes and confirmed by RT-qPCR. Moreover, the DE genes were also altered in Sertoli cells. Therefore, our research might be helpful for future exploring the effects of Pb exposure on lncRNA in testis, as well as its function.