Résumé
Abstract Objective To investigate the effect of peroxynitrite on the cultured cochlear hair cells of C57BL/6 P3 mice in vitro as well as the role of Wnt3a, as an activator of the canonical Wnt signaling pathway, underlying the action of such an oxidative stress. Methods The in vitro primary cultured cochlear hair cells were subjected to l00 μM peroxynitrite and l00 μM peroxynitrite +25 ng/mL Wnt3a for 24 h, the cell survival and morphological changes were examined by immunofluorescence and transmission electron microscopy. Results The number of surviving hair cells was significantly reduced in the 100 μM peroxynitrite group, while it was significantly higher in the Wnt3a + peroxynitrite treated group compared with the peroxynitrite treated group. The transmission electron microscopy showed that exposure to peroxynitrite induced a dramatic decrease in the number of mitochondria and severely disrupted mitochondrial ultrastructure, while Wnt3a clearly diminished the disruption of mitochondrial structure and preserved a higher number of mitochondria. Conclusion These results indicated that peroxynitrite could cause oxidative damage to the cochlear hair cells, and low concentrations of Wnt3a has a protective effect against oxidative damage. Level of evidence: Level 2.
Résumé
This study examined the role of regulated upon activation normal T cell expressed and secreted (RANTES) and its receptor C-C chemokine receptor type 5 (CCR5) in gastric cancer metastasis and the associated mechanism.The expression of RANTES and CCR5 was detected by using immunohistochemical staining and Western blotting in the gastric cancer tissues obtained from 60 gastric cancer patients with or without lymph node metastasis (n=30 in each).The results showed that the expression levels of RANTES and CCR5 were higher in gastric cancer with lymph node metastasis than in that without metastasis (P＜0.05).The expression levels of RANTES in 30 lymph nodes with cancerous invasion were higher than in 30 normal lymph nodes (P＜0.05).Chemotactic test revealed that the number of migrating gastric cancer cells (n=295.0±54.6) induced by the protein of cancer-invading lymph nodes was greater than that by the protein mixture from cancer-invading lymph nodes and RANTES antibody (n=42.5+11.6) (P＜0.05).RT-PCR showed that the expression levels of the main Th1 cytokines (IL-2,γ-IFN) were lower in gastric cancer with lymph node metastasis (2.22±0.90,3.26±1.15 respectively)than in that without metastasis (3.07±1.67,4.77±1.52 respectively) (P＜0.05),but the expression level of the main Th 2 cytokine (IL-10) was higher in gastric cancer with lymph nodes metastasis (6.06±2.04)than in that without metastasis (4.88±1.87) (P＜0.05).It was concluded that RANTES and its receptor CCR5 may contribute to gastric cancer metastasis through influencing the balance of Th1/Th2.RANTES and CCR5 may become a marker of gastric cancer metastasis.