Cellular expression of murine Ym1 and Ym2, chitinase family proteins, as revealed by in situ hybridization and immunohistochemistry
Cellular expression of murine Ym1 and Ym2, chitinase family proteins, as revealed by in situ hybridization and immunohistochemistry
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DOI：
10.1007/s00418-004-0654-4
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发表时间：
2004-06-01
影响因子：
2.3
通讯作者：
Iwanaga, T
中科院分区：
文献类型：
--
作者：
Nio, J;Fujimoto, W;Iwanaga, T
Ym是几丁质酶家族蛋白质之一，广泛分布于哺乳动物体内，可与肝素/硫酸乙酰肝素等糖胺聚糖结合。Ym 1是一种在寄生虫感染中产生的巨噬细胞蛋白，而其亚型Ym 2在过敏性条件下在肺中上调。在本研究中，我们揭示了不同的细胞表达的Ym 1和Ym 2在正常小鼠的原位杂交和免疫组织化学。Ym 1主要在肺、脾和骨髓中表达，而Ym 2在胃中发现。肺中Ym 1表达细胞为肺泡巨噬细胞，Ym 1的免疫反应性定位于粗面内质网。在脾脏中，Ym 1表达细胞聚集在红髓中，并通过电子显微镜鉴定为未成熟的中性粒细胞。在骨髓中，未成熟的中性粒细胞具有强烈的免疫反应性，但随着成熟而失去这种免疫反应性。此外，在巨噬细胞的细胞质中的针状晶体，形成成红细胞岛，也表现出强烈的Ym 1免疫反应。Ym 2表达仅限于前胃和腺胃交界处的复层鳞状上皮。Ym 1和Ym 2的功能尚不清楚;然而，在正常条件下的不同细胞定位表明它们作为内源性凝集素在造血、组织重塑或免疫应答中的重要作用。
Ym is one of the chitinase family proteins, which are widely distributed in mammalian bodies and can bind glycosaminoglycans such as heparin/heparan sulfate. Ym1 is a macrophage protein produced in parasitic infections, while its isoform, Ym2, is upregulated in lung under allergic conditions. In the present study, we revealed the distinct cellular expression of Ym1 and Ym2 in normal mice by in situ hybridization and immunohistochemistry. Ym1 was principally expressed in the lung, spleen, and bone marrow, while Ym2 was found in the stomach. Ym1-expressing cells in the lung were alveolar macrophages, and the immunoreactivity for Ym1 was localized in rough endoplasmic reticulum. In the spleen, Ym1-expressing cells gathered in the red pulp and were electron microscopically identified as immature neutrophils. In the bone marrow, immature neutrophils were intensely immunoreactive, but lost this immunoreactivity with maturation. Moreover, needle-shaped crystals in the cytoplasm of macrophages, which formed erythroblastic islands, also showed intense Ym1 immunoreactivity. Ym2 expression was restricted to the stratified squamous epithelium in the junctional region between forestomach and glandular stomach. The function of Ym1 and Ym2 is still unclear; however, the distinct cellular localization under normal conditions suggests their important roles in hematopoiesis, tissue remodeling, or immune responses as an endogenous lectin.