Creemers L B, Jansen I D, Hoeben K A, Beertsen W, Everts V
Department of Periodontology, Academic Centre of Dentistry, Louwesweg 1, Amsterdam, The Netherlands.
Biochem Biophys Res Commun. 1998 Oct 20;251(2):429-36. doi: 10.1006/bbrc.1998.9357.
The contribution of vacuolar H+-ATPases (V-ATPases) to collagen degradation was investigated in soft connective tissue explants (periosteum). Immunolocalisation showed faint to intense staining of cells throughout the periosteum. The V-ATPase inhibitors, bafilomycin A1 and folimycin, decreased overall collagen degradation by 40 and 50% after 24 and 48 h, respectively. The participation of V-ATPases in intracellular degradation of collagen was demonstrated by the decrease of the amount of phagocytosed collagen in fibroblasts upon inhibition of pump activity. The inhibition of degradation was not due to a reduction in activity of gelatinase A, an enzyme previously found to mediate collagen degradation, as assessed by zymographic analysis of tissue and conditioned medium. Bafilomycin A1 even induced an increase of gelatinase A and B levels in both fractions. In conclusion, acidification by V-ATPases may represent an important mechanism in extracellular and intracellular collagen degradation in soft connective tissue.
在软结缔组织外植体（骨膜）中研究了液泡H⁺-ATP酶（V-ATP酶）对胶原蛋白降解的作用。免疫定位显示，整个骨膜中的细胞染色从微弱到强烈。V-ATP酶抑制剂巴弗洛霉素A1和福利霉素分别在24小时和48小时后使总体胶原蛋白降解减少了40%和50%。通过抑制泵活性后成纤维细胞中吞噬的胶原蛋白量减少，证明了V-ATP酶参与细胞内胶原蛋白的降解。通过对组织和条件培养基的酶谱分析评估，降解的抑制并非由于先前发现介导胶原蛋白降解的明胶酶A活性降低所致。巴弗洛霉素A1甚至使两个组分中的明胶酶A和B水平升高。总之，V-ATP酶介导的酸化可能是软结缔组织中细胞外和细胞内胶原蛋白降解的重要机制。
