The Role Of The Notch Signling Pathway In Regulating Spine Development And Cartilage Differentiation

ObjectiveTo investigate the effect of the Notch signaling pathway on theregulation of the process of spinal growth and development in mice, andfurther study the regulation role of Dll-1, Jag-1on BMP-2inducedchondrogenic differentiation of disc NP cells in vitro.MethodsThe RT-PCR was used to detect the mRNA expression of thecomponents of Notch signaling pathway in intervertebral discs derivedfrom different stages of intervertebral discs development. The mostimportant signaling molecules Jag-1and DLL-1were screened out andtheir expression profile were further detected by usingimmunohistochemical method. NP cells were divided into Ad-GFP+Ad-RFP（Group A）、Ad-BMP-2+Ad-RFP（Group B）、Ad-BMP-2+Ad-Dll-1（Group C）、Ad-BMP-2+Ad-Jag-1（Group D），and then infectedwith recombinant adenovirus expressing Dll-1,Jag-1and BMP-2, RT-PCRwas performed to detect the expression of the characteristic products of cartilage cells, aggrecan (ACAN) and collagen (collagen type ⅡCOL2A1), toluidine blue staining was carried out to measure the secretionof cartilage oligomeric matrix protein by cells in culture.Results1.In general, the expression of Notch signal molecules were overalldecreased during mouse intervertebral discs development, especially thetendency of Dll-1, Dll-3, Jag-1,which play an important regulatory role inthe process of spine growth.2.BMP-2overexpression promoted the NP cells differentiation intocartilage cells with increased expression of ACAN and COL2A1, andenhanced toluidine blue staining.3. Dll-1has a role in coordinating stimulus expression withJag-1.The overexpression of adenovirus-mediated Dll-1, Jag-1significantlyinhibited the effect of chondrogenic differentiation induced by BMP-2.ConclusionThe components of Notch signaling pathway, especially Dll-1,Jag-1,play an important regulatory role in the normal spine development andsignificantly a negative regulatory roles in differentiation process of discchondrocytes. This work has established the important foundation for thefurther research of Notch signaling to the Spine developmental disease.