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Objective: To explore the mechanism of spleen tissue inflammatory response induced by altitude hypoxia in mice., Methods: C57BL/6 mice were randomly assigned to a plain, i.e., low-altitude, normoxia group and an altitude hypoxia group, with 5 mice in each group. In the plain normoxia group, the mice were kept in a normoxic environment at the altitude of 400 m above sea level (with an oxygen concentration of 19.88%). The mice in the altitude hypoxia group were kept in an environment at the altitude of 4200 m above sea level (with an oxygen concentration of 14.23%) to establish the animal model of altitude hypoxia. On day 30, spleen tissues were collected to determine the splenic index. HE staining was performed to observe the histopathological changes in the spleen tissues of the mice. Real time fluorogenic quantitative PCR (RT-qPCR) and Western blot were conducted to determine the mRNA and protein expressions of interleukin (IL)-6, IL-12, and IL-1β in the spleen tissue of the mice. High-throughput transcriptome sequencing was performed with RNA sequencing (RNA-seq). KEGG enrichment analysis was performed for the differentially expressed genes (DEGs). The DEGs in the key pathways were verified by RT-qPCR., Results: Compared with the plain normoxia group, the mice exposed to high-altitude hypoxic environment had decreased spleen index ( P <0.05) and exhibited such pathological changes as decreased white pulp, enlarged germinal center, blurred edge, and venous congestion. The mRNA and protein expression levels of IL-6, IL-12, and IL-1β in the spleen tissue of mice in the altitude hypoxia group were up-regulated ( P <0.05). According to the results of transcriptome sequencing and KEGG pathway enrichment analysis, 4218 DEGs were enriched in 178 enrichment pathways ( P <0.05). DEGs were significantly enriched in multiple pathways associated with immunity and inflammation, such as T cell receptor signaling pathway, TNF signaling pathway, and IL-17 signaling pathway ( P <0.05) in the spleen of mice exposed to high-altitude hypoxic environment. Among them, IL-17 signaling pathway and the downstream inflammatory factors were highly up-regulated ( P <0.05). Compared with the plain normoxia group, the mRNA expression levels of key genes in the IL-17 signaling pathway, including IL -17, IL -17 R , and mitogen-activated protein kinase genes ( MAPKs ), and the downstream inflammatory factors, including matrix metallopeptidase 9 ( MMP 9), S100 calcium binding protein A8 gene ( S 100 A 8), S100 calcium binding protein A9 gene ( S 100 A 9), and tumor necrosis factor α ( TNF - α ), were up-regulated or down-regulated ( P <0.05) in the altitude hypoxia group. According to the validation of RT-qPCR results, the mRNA expression levels of DEGs were consistent with the RNA-seq results., Conclusion: Altitude hypoxia can induce inflammatory response in the mouse spleen tissue by activating IL-17 signaling pathway and promoting the release of downstream inflammatory factors., Competing Interests: 利益冲突　所有作者均声明不存在利益冲突, (© 2024《四川大学学报（医学版）》编辑部 版权所有Copyright ©2024 Editorial Board of Journal of Sichuan University (Medical Sciences).)

Long-term tissue culture of adult mammalian organs is a highly promising approach to bridge the gap between single cell cultures and animal experiments, and bears the potential to reduce in vivo studies. Novel biomimetic materials open up new possibilities to maintain the complex tissue structure in vitro; however, survival times of adult tissues ex vivo are still limited to a few days with established state-of-the-art techniques. Here, it is demonstrated that TiO 2 nanotube scaffolds with specific tissue-tailored characteristics can serve as superior substrates for long-term adult brain and spleen tissue culture. High viability of the explants for at least two weeks is achieved and compared to tissues cultured on standard polytetrafluoroethylene (PTFE) membranes. Histological and immunohistochemical staining and live imaging are used to investigate tissue condition after 5 and 14 d in vitro, while environmental scanning electron microscopy qualifies the interaction with the underlying scaffold. In contrast to tissues cultured on PTFE membranes, enhanced tissue morphology is detected in spleen slices, as well as minor cell death in neuronal tissue, both cultured on nanotube scaffolds. This novel biomimetic tissue model will prove to be useful to address fundamental biological and medical questions from tissue regeneration up to tumor progression and therapeutic approaches., (© 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)