Di Rosa Michelino, Musumeci Maria, Scuto Anna, Musumeci Salvatore, Malaguarnera Lucia
Department of Biomedical Sciences, University of Catania, Italy.
Clin Chem Lab Med. 2005;43(5):499-502. doi: 10.1515/CCLM.2005.088.
Human chitotriosidase is a chitinolytic enzyme and mainly produced by activated macrophages. Recently, we observed that prolactin, which is structurally related to several cytokines and is involved in regulating monocyte/macrophage functions, upregulates chitotriosidase gene expression in human macrophages, suggesting that chitotriosidase is not only a biochemical marker of macrophage activation in lysosomal diseases and hematological disorders, but also may reflect induction of an immunological response. To confirm this hypothesis we evaluated by quantitative real-time PCR the mRNA chitotriosidase levels in human monocytes/macrophages following treatment with pro-inflammatory stimuli such as interferon-gamma, tumor necrosis factor-alpha, lipopolysaccharide, and interleukin-10, an anti-inflammatory cytokine. Stimulation of macrophages with interferon-gamma, tumor necrosis factor-alpha and lipopolysaccharide resulted in increased levels of chitotriosidase mRNA, as well as chitotriosidase activity, whereas interleukin-10 decreased chitotriosidase synthesis. This finding is consistent with the hypothesis that the production of chitotriosidase by macrophages could have biological relevance in the immune response.
人壳三糖苷酶是一种几丁质分解酶，主要由活化的巨噬细胞产生。最近，我们观察到，催乳素在结构上与多种细胞因子相关，并参与调节单核细胞/巨噬细胞功能，它能上调人巨噬细胞中壳三糖苷酶基因的表达，这表明壳三糖苷酶不仅是溶酶体疾病和血液系统疾病中巨噬细胞活化的生化标志物，还可能反映免疫反应的诱导情况。为了证实这一假设，我们通过定量实时聚合酶链反应评估了用促炎刺激物（如γ干扰素、肿瘤坏死因子-α、脂多糖）以及抗炎细胞因子白细胞介素-10处理后人单核细胞/巨噬细胞中壳三糖苷酶mRNA的水平。用γ干扰素、肿瘤坏死因子-α和脂多糖刺激巨噬细胞会导致壳三糖苷酶mRNA水平以及壳三糖苷酶活性升高，而白细胞介素-10则会降低壳三糖苷酶的合成。这一发现与巨噬细胞产生壳三糖苷酶可能在免疫反应中具有生物学意义的假设相一致。
