Expression and involvement of the novel extracellular -matrix-degrading enzymes ADAMTS during osteogenesis and bone regeneration.

ADAMTS是降解细胞外基质分子的新酶家族。本研究项目研究了ADAMTS和蛋白聚糖（ADAMTS的假定底物）在骨生成和骨再生、牙齿萌出和牙根形成以及软骨发育过程中的表达。2003年我们采用RT-PCR、原位杂交和免疫组织化学方法对胚胎和出生后大鼠骨、软骨和牙齿进行了研究，并对ADAMTS家族和多功能蛋白聚糖在骨发生和发育过程中的表达进行了研究。ADAMTS 1、4、5和多功能蛋白聚糖的表达在一定的扁平成骨细胞群体中被鉴定。2004年，ADAMTS 1、4、5和多功能蛋白聚糖在牙齿萌出和牙根形成过程中也定位于牙髓细胞、成牙本质细胞、成牙骨质细胞、牙骨质细胞、牙周膜细胞、成骨细胞和骨细胞中。2005年，软骨细胞显示在发育中的软骨中表达ADAMTS 1、4、5及其推定的底物聚集蛋白聚糖。本研究证实ADAMTS 1、4、5及其蛋白聚糖底物（如多功能蛋白聚糖和聚集蛋白聚糖）在成骨细胞、骨细胞、牙髓细胞、成牙本质细胞、成牙骨质细胞、成牙骨质细胞、牙骨质细胞、成牙骨质细胞、成牙骨质细胞牙周膜细胞和软骨细胞。ADAMTS家族的表达与蛋白聚糖的表达相关。结果表明，这些细胞通过表达和分泌ADAMTS降解蛋白多糖，并产生构成细胞外基质重要组成部分的蛋白多糖。

ADAMTS is a family of novel enzymes that degrade extracellular matrx molecules. This research project studied expression of ADAMTS and proteoglycans, which are putative substrates for ADAMTS, during osteogenesis and bone regeneration, tooth eruption and root formation, and cartilage development. Embryonic and postnatal rat bone, cartilage and teeth were examined using RT-PCR, in situ hybridization and immunohistochemistry.We investigated expression of the ADAMTS family and versican in the process of osteogenesis and bone development by RT-PCR and in situ hybridization in 2003. The expression of ADAMTS 1, 4, 5 and versican was identified in a certain population of osteoblasts that are flat in shape. ADAMTS 1, 4, 5 and versican were also localized in dental pulp cells, odontoblats, cementoblasts, cementocytes, periodontal ligament cells, osteoblasts and osteocytes during tooth eruption and root formation in 2004. Chondrocytes were shown to express ADAMTS1, 4, 5 together with their putative substrate, aggrecan, in developing cartilage in 2005. We have already started a new experiment to investigate expression of ADAMTS and versican during bone regeneration using our original rat experimental model and recognized that ADAMTS 1 is expressed characteristically.The present study demonstrated that ADAMTS 1, 4, 5 and their putative substrate of proteoglycans, such as versican and aggrecan, are expressed by ostoblasts, osteocytes, dental pulp cells, odontoblasts, cementoblasts, cementocytes, periodontal ligament cells and chondrocytes. The expression of the ADAMTS family was shown to correlate with that of the proteoglycans. The results suggest that these cells degrade the proteoglycans by expressing and secreting ADAMTS as well as produce the proteoglycans that constitute important parts of the extracellular matrix.