Piccinini G, Luchetti M M, Caniglia M L, Carossino A M, Montroni M, Introna M, Gabrielli A
Institute of Internal Medicine, Haematology and Clinical Immunology, University of Ancona, Ancona, Italy.
J Invest Dermatol. 1996 Jun;106(6):1281-6. doi: 10.1111/1523-1747.ep12348998.
Systemic sclerosis (scleroderma) is characterized by excessive deposition of extracellular matrix constituents. Although it has been proposed that tissue fibrosis is due to increased fibroblast synthesis of various collagen polypeptides, there is some experimental evidence that patients with systemic sclerosis have a defect in the control of fibroblast growth. The myb family of genes includes, among others, the c-myb proto-oncogene and the structurally related gene, B-myb, which are both implicated in the regulation of differentiation and/or proliferation of hematopoietic and nonhematopoietic cells. To elucidate the molecular basis responsible for scleroderma fibroblast proliferation, we therefore elected to investigate the expression of c-myb and B-myb genes in scleroderma and control cells. Using the reverse transcriptase polymerase chain reaction technique, we detected c-myb transcripts in scleroderma skin fibroblasts rendered quiescent by serum deprivation. Under the same experimental conditions, c-myb message was not found in normal skin fibroblasts, but, after serum stimulation, c-myb RNA was clearly evident from 3 to 72 h in both normal and pathologic cells. Treatment of these cells with c-myb antisense oligonucleotides caused downregulation of c-myb expression, and the inhibition of scleroderma fibroblast proliferation was 42%, whereas in normal fibroblasts the inhibition was weaker (22%). In contrast to c-myb, in normal and scleroderma fibroblasts the level of expression of B-myb correlated with cell proliferation assessed by cell count, and densitometric analysis showed that B-myb message was 1.5-5 times higher in most of pathologic cells studied. The antisense B-myb oligonucleotides had a weaker antiproliferative effect compared with antisense c-myb, inhibiting scleroderma and normal fibroblasts by 23% and 13%, respectively. These data suggest that the B-myb and c-myb genes may play a role in scleroderma fibroblast proliferation and function.
系统性硬化症（硬皮病）的特征是细胞外基质成分过度沉积。尽管有人提出组织纤维化是由于成纤维细胞合成各种胶原蛋白多肽增加所致，但有一些实验证据表明，系统性硬化症患者在成纤维细胞生长控制方面存在缺陷。myb基因家族包括c-myb原癌基因和结构相关基因B-myb等，它们都与造血和非造血细胞的分化和/或增殖调节有关。因此，为了阐明硬皮病成纤维细胞增殖的分子基础，我们选择研究c-myb和B-myb基因在硬皮病和对照细胞中的表达。使用逆转录聚合酶链反应技术，我们在血清剥夺使静止的硬皮病皮肤成纤维细胞中检测到了c-myb转录本。在相同的实验条件下，正常皮肤成纤维细胞中未发现c-myb信息，但在血清刺激后，正常和病理细胞在3至72小时内c-myb RNA明显可见。用c-myb反义寡核苷酸处理这些细胞导致c-myb表达下调，硬皮病成纤维细胞增殖的抑制率为42%，而正常成纤维细胞中的抑制作用较弱（22%）。与c-myb相反，在正常和硬皮病成纤维细胞中，B-myb的表达水平与通过细胞计数评估的细胞增殖相关，密度分析表明，在所研究的大多数病理细胞中，B-myb信息高1.5至5倍。与反义c-myb相比，反义B-myb寡核苷酸的抗增殖作用较弱，分别抑制硬皮病和正常成纤维细胞23%和13%。这些数据表明，B-myb和c-myb基因可能在硬皮病成纤维细胞的增殖和功能中发挥作用。
