Expression of Indian hedgehog signaling in murine oviductal infundibulum and its relationship with epithelial homeostasis

Homeostasis of the oviductal infundibulum epithelium is continuously regulated by signaling pathways under physiological and pathological conditions. Herein, we investigated the expression of hedgehog (Hh) signaling-related components in the murine oviductal infundibulum, which is known to maintain homeostasis in the adult epithelium. Additionally, using autoimmune disease-prone MRL/MpJ-Fas(lpr/lpr) (MRL/lpr) mice showing abnormal morphofunction of the ciliated epithelium of the infundibulum related to the oviductal inflammation, we examined the relationship between Hh signaling and pathology of the infundibulum. The expression and localization of Pax8, a marker for progenitor cells in the oviductal epithelium, and Foxj1, a marker for ciliogenesis, were examined in the infundibulum. The results showed that Pax8 was downregulated and Foxj1 was upregulated with aging, suggesting that homeostasis of the infundibulum epithelium of MRL/lpr mice was disturbed at 6 months of age. In all mice, the motile cilia of ciliated epithelial cells in the infundibulum harbored Hh signaling pathway-related molecules: patched (Ptch), smoothened (Smo), and epithelial cells harbor Gli. In contrast, Ptch, Smo, and Gli2 were significantly downregulated in the infundibulum of MRL/lpr mice at 6 months of age. The expression levels of Pax8 and Foxj1 were significantly positively correlated with those of Ptch1, Smo, and Gli2. Hh signaling is thought to be involved in homeostasis of the ciliated epithelium in the infundibulum. In MRL/lpr mice, which show exacerbated severe systemic autoimmune abnormalities, molecular alterations in Hh signaling-related components are considered to interact with local inflammation in the infundibulum, leading to disturbances in epithelial homeostasis and reproductive function.

Automated summary

In this study, we investigated the expression of hedgehog signaling-related components in the murine oviductal infundibulum and found that the homeostasis of the infundibulum epithelium was disturbed in MRL/lpr mice. The motile cilia of ciliated epithelial cells in the infundibulum harbored Hh signaling pathway-related molecules. However, these molecules were significantly downregulated in MRL/lpr mice at 6 months of age. Pax8 and Foxj1 expression levels were positively correlated with those of Ptch1, Smo, and Gli2. Overall, Hh signaling is involved in the regulation of ciliated epithelium homeostasis in the infundibulum and interacts with inflammation, leading to disturbances in epithelial homeostasis and reproductive function.