P-Phenylenediaminequinones (PPD-Qs) are oxidized derivatives of common p-phenylenediamine (PPD) antioxidants. These compounds have emerged as persistent environmental toxicants detected across diverse ecological matrices and human samples. Despite their widespread presence, the mechanistic links between PPD-Qs and male reproductive dysfunction remain largely unexplored. In this study, we employed an integrated approach combining network toxicology and molecular docking to systematically investigate the molecular mechanisms underlying the association of five PPD-Qs with male infertility and its principal subtypes: hypogonadotropic hypogonadism (HH), hyperprolactinemia (HPL), and immunological infertility (IMI). Our analysis identified 479 PPD-Q-related targets and 3142 male infertility-related targets, with 230 overlapping targets indicating potential interactions. Protein-protein interaction network analysis revealed 15 core targets associated with male infertility, while subtype-specific analyses identified 22, 13, and 66 core targets for HH, HPL, and IMI, respectively. GO and KEGG enrichment analyses delineated three primary mechanistic pathways: (1) disruption of reproductive endocrine homeostasis through estrogen, GnRH, and prolactin signaling; (2) dysregulation of cellular signaling cascades, including the MAPK and PI3K-AKT pathways; and (3) modulation of immune function and oxidative stress responses. Notably, AKT1 and ESR1 emerged as conserved targets across all conditions. Molecular docking studies demonstrated strong binding affinity (-6.6 to -9.8 kcal/mol) between PPD-Qs and core targets, with DTPD-Q exhibiting the highest affinity. Our findings establish AKT1 and ESR1 as conserved molecular targets across male infertility and its subtypes, supported by the strong computational binding affinities. By integrating network toxicology, this study extends previous research on individual PPD-Qs, demonstrating their capacity to disrupt multiple pathways involving endocrine regulation, immune function, and oxidative stress responses. These insights provide a mechanistic foundation for future environmental monitoring and the development of targeted intervention strategies.

The springtail Proisotoma minuta is a cosmopolitan species that can be found in many different habitats, especially in soil ecosystems. It is considered to be a good indicator of soil health. In this study, mitogenome information was obtained, which could lay a foundation for future fauna studies. The mitogenome of P. minuta is a circular module of 15,930 bp, including 13 protein-coding genes, 22 transfer RNA genes, and 2 ribosomal RNA genes. The mitogenome of P. minuta is composed of 35.9% A, 28.5% T, 13.7% G, and 21.3% C. Phylogenetic analysis revealed that P. minuta was well grouped in the subfamily Proisotominae and had a closer relationship with Anurophorinae than Isotominae subfamily and other families.

Lin28b and let-7 miRNA regulate mammalian pubertal initiation and Gonadotropin-releasing hormone (GnRH) production. However, it remains unclear which signaling pathways Lin28b regulates to modulate GnRH production. In this study, the mRNA expression levels of Lin28b and let-7 in the pubertal and juvenile goat hypothalamus and pituitary gland were detected, and Lin28b expression in the pubertal hypothalamus decreased significantly compared with that in juvenile tissues. It was predicted that Lin28b might inhibit GnRH1 expression, which was verified in the GnRH-producing cell model GT1-7 cells. Lin28b inhibited GnRH1 expression and promoted Kiss1/Gpr54 signaling. The pyruvate content and the expression of Hif1a and Hk2, which were related to glycolysis, were also promoted by Lin28b overexpression. Additionally, 77 differentially expressed miRNAs (DEMIs) in Lin28b-overexpressed GT1-7 cells were identified. Bioinformatics analysis and mRNA expression of the target genes of DEMIs revealed that the MAPK and PI3K-AKT-mTOR signaling pathways were key pathways that involved the regulatory effect of Lin28b on GnRH. In GT1-7 cells, GnRH1 expression was suppressed by blocking mTOR signaling with rapamycin, which was rescued by Lin28b overexpression. These results indicate that Lin28b-let-7 regulates GnRH1 expression through several pathways, including the Kiss1/Gpr54, MAPK, and mTOR signaling pathways, which are all related to glucose metabolism and provide new insights into the molecular mechanism of the regulatory role of Lin28b on GnRH production.

Springtails are considered as an important candidate bioindicator to assess soil quality spiked with trace metals, but little is known of their endophytic bacteria. In this study, a kind of Tomoceridae springtail was used, and a total of 45 effective sequences were obtained through the process of endophytic bacteria isolation, culture, polymerase chain reaction (PCR) amplification and sequencing. After NCBI-BLAST, the results showed that there were 20 bacterial colonies belonging to the genus Staphylococcus, 12 belonging to the genus Bacillus, 7 belonging to the genus Paenibacillus, 1 belonging to the genus Exiguobacterium and 5 belonging to Acinetobacter lwoffii. Furthermore, five bacterial strains from these five genera (named TomoRZH14, TomoRZH26, TomoRZH30, TomoRZH37, TomoRZH40) were selected for cellulose degradation analysis. The results showed that TomoRZH26 (Bacillus sp.) seemed to have a stronger cellulose degradation ability than those of the other four strains, while the three main components cellulase endo-β-glucanase, exo-β-glucanase and β-glucosidase in TomoRZH26 showed significantly higher enzymatic activity than in the other strains. Viscosity analysis also showed that the TomoRZH26 bacterium degraded relatively quickly in cellulase fermentation medium. In general, in this study, we preliminarily revealed several endophytic bacteria of Tomoceridae springtails and found that they had potentially strong cellulose degradation activity, which may be one of the important reasons behind springtail adaptation to this kind of soil ecological environment. Key words: springtail, endophytic bacteria, cellulose. Springtails are considered as an important candidate bioindicator to assess soil quality spiked with trace metals, but little is known of their endophytic bacteria. In this study, a kind of Tomoceridae springtail was used, and a total of 45 effective sequences were obtained through the process of endophytic bacteria isolation, culture, polymerase chain reaction (PCR) amplification and sequencing. After NCBI-BLAST, the results showed that there were 20 bacterial colonies belonging to the genus Staphylococcus, 12 belonging to the genus Bacillus, 7 belonging to the genus Paenibacillus, 1 belonging to the genus Exiguobacterium and 5 belonging to Acinetobacter lwoffii. Furthermore, five bacterial strains from these five genera (named TomoRZH14, TomoRZH26, TomoRZH30, TomoRZH37, TomoRZH40) were selected for cellulose degradation analysis. The results showed that TomoRZH26 (Bacillus sp.) seemed to have a stronger cellulose degradation ability than those of the other four strains, while the three main components cellulase endo-β-glucanase, exo-β-glucanase and β-glucosidase in TomoRZH26 showed significantly higher enzymatic activity than in the other strains. Viscosity analysis also showed that the TomoRZH26 bacterium degraded relatively quickly in cellulase fermentation medium. In general, in this study, we preliminarily revealed several endophytic bacteria of Tomoceridae springtails and found that they had potentially strong cellulose degradation activity, which may be one of the important reasons behind springtail adaptation to this kind of soil ecological environment. Key words: springtail, endophytic bacteria, cellulose.