Wu Z, Nagata K, Iijima T
Department of Oral Anatomy and Cell Biology, Faculty of Dental Science, Kyushu University, Fukuoka, Japan.
Histochem Cell Biol. 2000 Dec;114(6):453-9. doi: 10.1007/s004180000222.
To study the role of nerve growth factor (NGF) in local inflammation, we investigated the expression of NGF and its receptors, trkA and p75, in the ankle joints of adjuvant-induced arthritic rats. Infiltrated mononuclear cells revealed a positive immunoreactivity for NGF and trkA; they were also positive for immunostaining for W3/25 and ED1, which mainly stain T cells and macrophages, respectively. Changes in the ratios of NGF-positive cells to mononuclear cells showed a relatively similar pattern for trkA-positive cells, which peaked at weeks 2 to 3 after the adjuvant injection. In double-immunofluorescence staining, 80% and 65% of NGF-positive cells stained for W3/25 and ED1, respectively. Similarly, 67% and 80% of trkA-positive cells also corresponded to W3/25- and ED1-positive cells, respectively. However, p75 immunoreactivity localized on the nerve fibers but not on the cells of the ankle joints. Dense meshworks of p75-positive nerve fibers with numerous terminal varicosities were observed at weeks 2 to 4. The present findings suggest that infiltrated mononuclear cells may secrete NGF in an autocrine or paracrine manner in the inflamed synovium. An upregulation of NGF in these mononuclear cells and an increase in density of the synovial nerve fibers may be involved in the development of adjuvant arthritis in rats.
为研究神经生长因子（NGF）在局部炎症中的作用，我们调查了佐剂诱导性关节炎大鼠踝关节中NGF及其受体trkA和p75的表达情况。浸润的单核细胞对NGF和trkA呈阳性免疫反应；它们对W3/25和ED1免疫染色也呈阳性，W3/25和ED1分别主要标记T细胞和巨噬细胞。NGF阳性细胞与单核细胞的比例变化显示trkA阳性细胞呈现相对相似的模式，在佐剂注射后第2至3周达到峰值。在双重免疫荧光染色中，80%的NGF阳性细胞对W3/25染色呈阳性，65%对ED1染色呈阳性。同样，67%的trkA阳性细胞也分别对应W3/25阳性细胞和ED1阳性细胞。然而，p75免疫反应定位于神经纤维而非踝关节的细胞上。在第2至4周观察到p75阳性神经纤维的密集网络，伴有大量终末膨体。本研究结果表明，浸润的单核细胞可能在炎症滑膜中以自分泌或旁分泌方式分泌NGF。这些单核细胞中NGF的上调以及滑膜神经纤维密度的增加可能参与了大鼠佐剂性关节炎的发展。
