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In situ proliferation and differentiation of macrophages in the dental pulp

牙髓中巨噬细胞的原位增殖和分化

基本信息

批准号：
21592342
负责人：
NAKAMURA Masanori
金额：
$ 3万
依托单位：
Showa University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2009
资助国家：
日本
起止时间：
2009 至 2011
项目状态：
已结题

项目摘要

It is well recognized that resident macrophages exist in the dental pulp. However, it is uncertain whether these macrophages proliferate and differentiate in the dental pulp in situ, or whether they constantly migrate from the blood stream into the dental pulp. In this study, we examined and compared the development of dental pulp macrophages in an organ culture system by using in vivo tooth organs to clarify the developmental mechanism of these macrophages. The first mandibular molar tooth organs from the ICR strain mice aged between 16-days of gestation(E16) to 5-days postnatal(5dPN) were used for in vivo experiments. The E16 first mandibular molar tooth organs were cultured for up to 14 days with or without 10% fetal bovine serum. Dental pulp tissues were analyzed with immunohistochemistry to detect the macrophages and with RT-PCR for the detection of factors related to the macrophage development. The growth curves for the in vivo-and in vitro-cultured cells revealed similar numbers of F4/80 positive macrophages in the dental pulp. RT-PCR analysis indicated the constant expression of M-CSF in both in vivo-and in vitro-cultured dental pulp tissues. Anti-M-CSF antibodies significantly inhibited the increase in the number of resident macrophages in the dental pulp. These results suggested that (1) most of the dental pulp macrophages proliferated and differentiated in the dental pulp without a supply of precursor cells from the blood stream, (2) M-CSF might be the candidate molecule for the development of dental pulp macrophages, and (3) serum factors might not directly affect the development of the macrophages.

众所周知，牙髓中存在驻留巨噬细胞。然而，目前尚不确定这些巨噬细胞是否在牙髓中原位增殖和分化，或者它们是否不断地从血流中迁移到牙髓中。在本研究中，我们利用活体牙齿器官来检测和比较器官培养系统中牙髓巨噬细胞的发育，以阐明这些巨噬细胞的发育机制。取孕龄16天(E16)至出生5天(5dPN)的ICR品系小鼠下颌第一磨牙器官进行活体实验。在含或不含10%胎牛血清的条件下，培养E16第一磨牙牙器官14天。用免疫组织化学方法检测牙髓组织中的巨噬细胞，用RT-PCR方法检测与巨噬细胞发育相关的因子。体内和体外培养细胞的生长曲线显示，牙髓中F4/80阳性巨噬细胞的数量相似。RT-PCR分析表明，M-CSF在体内和体外培养的牙髓组织中都有持续表达。抗M-CSF抗体可显著抑制牙髓内滞留巨噬细胞数量的增加。这些结果提示：(1)大多数牙髓巨噬细胞在牙髓中增殖和分化，而没有来自血流的前体细胞；(2)M-CSF可能是牙髓巨噬细胞发育的候选分子；(3)血清因素可能不直接影响巨噬细胞的发育。