Cathepsins are a family of lysosomal/endosomal proteolytic enzymes that include serine, aspartate, and cysteine proteases. The role of cathepsin in neurodegenerative diseases, including Alzheimer’s disease and Parkinson’s disease, remains elusive. We evaluated the expression level and localization of different cathepsins in the olfactory bulbs of mice with experimental autoimmune encephalomyelitis (EAE), a model of human multiple sclerosis. Quantitative real-time PCR results and Western blotting analyses revealed that serine, aspartate, and cysteine cathepsins are expressed at significantly higher levels in the olfactory bulbs of mice with EAE in the paralytic stage compared with those of control mice. Immunohistochemical analyses indicated that cathepsin A, D, and S were expressed in the glomerulus layer, external plexiform layer, and mitral cell layer. Furthermore, cathepsins were detected in astrocytes, microglia, inflammatory cells, and vascular cells in the olfactory bulb of EAE mice at the paralytic stage. Collectively, these results suggest that the upregulation of cathepsins in the olfactory bulb of mice with EAE is associated with transient olfactory dysfunction in autoimmune encephalomyelitis.

组织蛋白酶是溶酶体/内体蛋白水解酶家族，包括丝氨酸、天冬氨酸和半胱氨酸蛋白酶。组织蛋白酶在包括阿尔茨海默病和帕金森病在内的神经退行性疾病中的作用仍然难以捉摸。我们评估了实验性自身免疫性脑脊髓炎 (EAE) 小鼠嗅球中不同组织蛋白酶的表达水平和定位，这是一种人类多发性硬化症模型。定量实时 PCR 结果和蛋白质印迹分析表明，与对照小鼠相比，麻痹期 EAE 小鼠的嗅球中丝氨酸、天冬氨酸和半胱氨酸组织蛋白酶的表达水平显着升高。免疫组织化学分析表明，组织蛋白酶 A、D 和 S 在肾小球层、外丛状层、和二尖瓣细胞层。此外，在麻痹期EAE小鼠嗅球的星形胶质细胞、小胶质细胞、炎症细胞和血管细胞中检测到组织蛋白酶。总的来说，这些结果表明，EAE小鼠嗅球组织蛋白酶的上调与自身免疫性脑脊髓炎的短暂嗅觉功能障碍有关。