If we can figure out how to grow via articular cartilage that will be a lot easier than to try to create neo-growth plates.
Spatial Regulation of Gene Expression During Growth of Articular Cartilage in Juvenile Mice.
“In juvenile mammals, the epiphyses of long bones grow by chondrogenesis within the articular cartilage. A bWe used laser-capture microdissection to isolate chondrocytes from the superficial, middle, and deep zones of growing tibial articular cartilage in the 1-wk old mouse and then investigated expression patterns by microarray. To identify molecular markers for each zone of the growing articular cartilage, we found genes showing zone-specific expression and confirmed by real-time PCR and in situ hybridization.Bioinformatic analyses implicated ephrin receptor signaling, Wnt signaling, and BMP signaling in the spatial regulation of chondrocyte differentiation during growth. Molecular markers were identified for superficial (e.g. Cilp, Prg4), middle (Cxcl14, Tnn), and deep zone (Sfrp5, Frzb). Comparison between juvenile articular and growth plate cartilage revealed that the superficial-to-deep zone transition showed similarity with the hypertrophic-to-resting zone transition{This is interesting, the study speculates that both the resting zone and deep zone may come from the same pool of epiphyseal chondrocytes}.ConclusionsLaser capture microdissection combined with microarray analysis identified novel signaling pathways that are spatially regulated in growing mouse articular cartilage and revealed similarities between the molecular architecture of the growing articular cartilage and that of growth plate cartilage.”
“While cell proliferation occurs sparingly in adult articular cartilage, it is much more common in juvenile articular cartilage. Growth of the articular cartilage reportedly occurs appositionally from the articular surface, suggesting that the SZ may contain actively dividing chondrocytes, or a progenitor cell population that is capable of generating new chondrocytes”<-these properties could be exploited to induce new longitudinal bone growth
“DZ[Deep Zone Articular Cartilage] expressed a high level of Wnt5b, which promotes chondrogenesis and inhibits hypertrophy “
