Yang S, Ries W L, Key L L
Department of Pharmacology, Medical University of South Carolina, Charleston, South Carolina 29425, USA.
Calcif Tissue Int. 1998 Oct;63(4):346-50. doi: 10.1007/s002239900538.
Osteoclasts use a variety of chemical agents to degrade bone. One important component of this process is the generation of superoxide. It has been reported that nicotinamide adenine dinucleotide phosphate (NADPH) oxidase is the enzyme responsible for superoxide production in phagocyte; however, the NADPH oxidase present in osteoclasts has not been studied in detail. One of the membrane-bound subunits of the NADPH oxidase is gp91(phox) which represents the rate-limiting component for the formation of the NADPH oxidase complex. This study was designed to demonstrate the presence of gp91(phox) in individual osteoclasts using the RT-PCR technique developed for limited numbers of cells. Compared with white cells, 1.8 times the amount of gp91(phox) mRNA was found in osteoclasts. This difference may be related to the size of the osteoclast and the multiple nuclei present. The presence of gp91(phox) in osteoclasts was confirmed at protein level by immunocytochemistry. Osteoclastic superoxide generation is inhibited by diphenylene iodonium, a specific inhibitor of the NADPH oxidase. These studies suggest that superoxide generation by osteoclasts correlates with the activity of NADPH oxidase.
破骨细胞利用多种化学物质降解骨骼。这一过程的一个重要组成部分是超氧化物的产生。据报道，烟酰胺腺嘌呤二核苷酸磷酸（NADPH）氧化酶是吞噬细胞中超氧化物产生的负责酶；然而，破骨细胞中存在的NADPH氧化酶尚未得到详细研究。NADPH氧化酶的膜结合亚基之一是gp91（phox），它是NADPH氧化酶复合物形成的限速成分。本研究旨在使用针对有限数量细胞开发的RT-PCR技术，证明单个破骨细胞中存在gp91（phox）。与白细胞相比，在破骨细胞中发现的gp91（phox）mRNA量是白细胞的1.8倍。这种差异可能与破骨细胞的大小和多核的存在有关。通过免疫细胞化学在蛋白质水平上证实了破骨细胞中存在gp91（phox）。NADPH氧化酶的特异性抑制剂二苯基碘鎓可抑制破骨细胞超氧化物的产生。这些研究表明，破骨细胞产生超氧化物与NADPH氧化酶的活性相关。
