Generation and Analysis of Cartilage-Specific CCN2 Overexpression in Transgenic Mice

Recent progress in gene-editing technology has provided a strong impact for improved our understanding of molecular functions in living organisms. Here we describe our method to generate transgene-overexpressing mouse models, which method involves the use of tissue-specific promoters for analyzing a certain molecule (s) in special tissues. The protocol described in this chapter uses the Col2a1 promoter-enhancer, which is known for driving specific and strong transgene expression in cartilage and is based on several of our studies showing a positive role of the connective tissue growth factor (CCN2) in cartilage-bone development and maintenance of articular cartilage. These mice show strongly accelerated endochondral ossification resulting in enhanced bone elongation, as well as resistance to age-related articular degeneration. This protocol also describes how to analyze the molecular mechanisms of these phenomena by use of chondrocytes isolated from CCN2-overexpressing cartilage.