Postiglione L, Montagnani S, Riccio A, Ladogana P, Salzano S, Vallefuoco L, Rossi G
Dip. di Biologia e Patologia Molecolare e Cellulare, Università degli Studi Federico II, Naples, Italy.
Life Sci. 1998;63(5):327-36. doi: 10.1016/s0024-3205(98)00281-1.
In the present study the effects of Granulocyte-Macrophage Colony Stimulating Factor (GM-CSF) on fibroblast growth and activity have been studied. In this regard the AA have evaluated in primary cultures of human gengival normal fibroblasts (PG1 cells): a)-the expression of GM-CSF receptor (GM-CSFR) (alfa unit) on the cell surface; b)-the in vitro effects of different doses of GM-CSF on the GM-CSFR expression and on the proliferation and activity of fibroblasts. PG1 cells have been stimulated in vitro with different concentrations of GM-CSF (10, 50, 80, 100 and 150 ng/ml) using promonocytic cell line U937 as positive control for GM-CSFR expression. GM-CSFR was investigated by flow cytometry, with mouse monoclonal antibody (mAb) against the alfa chain of the human GM-CSFR and fluorescein-conjugated goat antimouse immunoglobulin G (IgG). At high GM-CSF concentration (80 ng/ml) the AA observed: 1)-A marked increase of GM-CSFR expression evaluated as fluorescence intensity (about three fold in respect to the controls); 2)-Maximal increase of PG1 cells proliferation. Moreover immunofluorescence on fibroblasts obtained from culture plates showed increased actin stress fibers and fibronectin production with low stimulation by GM-CSF, while higher concentration of this cytokine determined increased proliferation of cells, but a decreased formation of actine fibers and vinculin plaques. These results demonstrate: 1)-The presence of GM-CSFR on the surface of fibroblasts; 2)-The proliferation and the synthesis activity of these cells (in vitro) are modulated by different concentration of GM-CSF. We hypothesize that GM-CSF until 80 ng/ml can upregulate the expression of the receptor. Therefore, on the basis of previous findings of high serum levels of GM-CSF in course of scleroderma, a disease characterized by fibroblast hyperactivity, a possible role of this cytokine in the pathogenic process of this disease can be hypothesized.
在本研究中，对粒细胞-巨噬细胞集落刺激因子（GM-CSF）对成纤维细胞生长和活性的影响进行了研究。在这方面，研究人员在人牙龈正常成纤维细胞（PG1细胞）的原代培养物中进行了评估：a）-细胞表面GM-CSF受体（GM-CSFR）（α亚基）的表达；b）-不同剂量的GM-CSF对GM-CSFR表达以及对成纤维细胞增殖和活性的体外影响。使用原单核细胞系U937作为GM-CSFR表达的阳性对照，用不同浓度的GM-CSF（10、50、80、100和150 ng/ml）体外刺激PG1细胞。通过流式细胞术，使用抗人GM-CSFRα链的小鼠单克隆抗体（mAb）和荧光素偶联的山羊抗小鼠免疫球蛋白G（IgG）来研究GM-CSFR。在高GM-CSF浓度（80 ng/ml）下，研究人员观察到：1）-以荧光强度评估的GM-CSFR表达显著增加（相对于对照约增加三倍）；2）-PG1细胞增殖的最大增加。此外，对从培养板获得的成纤维细胞进行的免疫荧光显示，在GM-CSF低刺激下，肌动蛋白应力纤维和纤连蛋白产生增加，而该细胞因子的较高浓度则导致细胞增殖增加，但肌动蛋白纤维和纽蛋白斑的形成减少。这些结果表明：1）-成纤维细胞表面存在GM-CSFR；2）-这些细胞的增殖和合成活性（体外）受到不同浓度GM-CSF的调节。我们假设，高达80 ng/ml的GM-CSF可以上调受体的表达。因此，基于先前在硬皮病病程中发现的高血清GM-CSF水平（硬皮病是以成纤维细胞过度活跃为特征的疾病），可以推测这种细胞因子在该疾病的致病过程中可能发挥作用。
