Lineage tracing of mutant granulosa cells reveals in vivo protective mechanisms that prevent granulosa cell tumorigenesis

Antagonistic interaction between miR-143 and KRAS gene regulating male mouse germ cell apoptosis

Precisely regulated spermatocyte growth, differentiation, and apoptosis are crucial for sustainable male fertility. miR-143 has been demonstrated to regulate gene expression and cell apoptosis in various human cancers. However, the function of mmu-mir-143 (miR-143) in mammalian testes and its underlying mechanism remains unexplored. In this study, the expression of miR-143 was detected in C57BL/6 mice spermatocytes by in situ hybridization (ISH) and immunofluorescence (IF) co-staining and transfecting miR-143 inhibitor into GC-2 cells (mouse spermatogenic cells) shows that miR-143 inhibits cleaved Caspase 3 (CC3)-induced male germ cell death. The current study used IF co-staining of KI67 and γ-H2A.X in the testes of C57BL/6 mice at different developmental stages, revealing that active proliferation and apoptosis of spermatocytes occurred simultaneously in the testes at 14 day post-partum (dpp). Kras was predicted as a potential target of miR-143 in mice using of the online database TargetScan, verified by quantitative real-time PCR (qPCR), western blotting (WB), and Dual-luciferase reporter gene assay. Co-transfection of miR-143 inhibitor and Kras siRNA into GC-2 cells revealed an antagonistic correlation between miR-143 and Kras in regulating male germ cell death. Finally, miR-143 inhibitor and mimics were administered into the seminiferous tubule of 3-week-old C57BL/6 mice. The histomorphology, IF co-staining, and WB data indicated that the testes treated with the miR-143 inhibitor showed significantly aberrant phenotypes, including damaged seminiferous tubules, reduced spermatocyte quantity, and elevated levels of apoptosis. This study uncovered the mechanism by which miR-143 inhibits male germ cell apoptosis through the repression of Kras/KRAS levels and the inhibition of Caspase 3 activation, providing insight into the role of miRNA in spermatogenesis and the maintenance of male fertility.

Ti3C2 nanosheet-induced autophagy derails ovarian functions

BACKGROUND

Two-dimensional ultrathin Ti3C2 (MXene) nanosheets have gained significant attention in various biomedical applications. Although previous studies have described the accumulation and associated damage of Ti3C2 nanosheets in the testes and placenta. However, it is currently unclear whether Ti3C2 nanosheets can be translocated to the ovaries and cause ovarian damage, thereby impairing ovarian functions.

RESULTS

We established a mouse model with different doses (1.25, 2.5, and 5 mg/kg bw/d) of Ti3C2 nanosheets injected intravenously for three days. We demonstrated that Ti3C2 nanosheets can enter the ovaries and were internalized by granulosa cells, leading to a decrease in the number of primary, secondary and antral follicles. Furthermore, the decrease in follicles is closely associated with higher levels of FSH and LH, as well as increased level of E2 and P4, and decreased level of T in mouse ovary. In further studies, we found that exposure toTi3C2 nanosheets increased the levels of Beclin1, ATG5, and the ratio of LC3II/Ι, leading to autophagy activation. Additionally, the level of P62 increased, resulting in autophagic flux blockade. Ti3C2 nanosheets can activate autophagy through the PI3K/AKT/mTOR signaling pathway, with oxidative stress playing an important role in this process. Therefore, we chose the ovarian granulosa cell line (KGN cells) for in vitro validation of the impact of autophagy on the hormone secretion capability. The inhibition of autophagy initiation by 3-Methyladenine (3-MA) promoted smooth autophagic flow, thereby partially reduced the secretion of estradiol and progesterone by KGN cells; Whereas blocking autophagic flux by Rapamycin (RAPA) further exacerbated the secretion of estradiol and progesterone in cells.

CONCLUSION

Ti3C2 nanosheet-induced increased secretion of hormones in the ovary is mediated through the activation of autophagy and impairment of autophagic flux, which disrupts normal follicular development. These results imply that autophagy dysfunction may be one of the underlying mechanisms of Ti3C2-induced damage to ovarian granulosa cells. Our findings further reveal the mechanism of female reproductive toxicity induced by Ti3C2 nanosheets.

Investigation of a UPR-Related Gene Signature Identifies the Pro-Fibrotic Effects of Thrombospondin-1 by Activating CD47/ROS/Endoplasmic Reticulum Stress Pathway in Lung Fibroblasts

Unfolded protein response (UPR) signaling and endoplasmic reticulum (ER) stress have been linked to pulmonary fibrosis. However, the relationship between UPR status and pulmonary function and prognosis in idiopathic pulmonary fibrosis (IPF) patients remains largely unknown. Through a series of bioinformatics analyses, we established a correlation between UPR status and pulmonary function in IPF patients. Furthermore, thrombospondin-1 (TSP-1) was identified as a potential biomarker for prognostic evaluation in IPF patients. By utilizing both bulk RNA profiling and single-cell RNA sequencing data, we demonstrated the upregulation of TSP-1 in lung fibroblasts during pulmonary fibrosis. Gene set enrichment analysis (GSEA) results indicated a positive association between TSP-1 expression and gene sets related to the reactive oxygen species (ROS) pathway in lung fibroblasts. TSP-1 overexpression alone induced mild ER stress and pulmonary fibrosis, and it even exacerbated bleomycin-induced ER stress and pulmonary fibrosis. Mechanistically, TSP-1 promoted ER stress and fibroblast activation through CD47-dependent ROS production. Treatment with either TSP-1 inhibitor or CD47 inhibitor significantly attenuated BLM-induced ER stress and pulmonary fibrosis. Collectively, these findings suggest that the elevation of TSP-1 during pulmonary fibrosis is not merely a biomarker but likely plays a pathogenic role in the fibrotic changes in the lung.