Involvement of the G-Protein-Coupled Receptor 4 in the Increased Expression of RANK/RANKL/OPG System and Neurotrophins by Nucleus Pulposus Cells under the Degenerated Intervertebral Disc-Like Acidic Microenvironment

Figure 5

The influence of GPR4 and its downstream signaling molecules in the expression levels of matrix enzymes, including matrix metalloproteinase-3 (MMP-3), MMP-13, and aggrecanase-2 (ADAMTS-5) in the degenerated IVD-like acidic condition. The expression levels of MMP-3, MMP-13, and ADAMTS-5 were assayed by RT-PCR (a) and western blot (b). Data were represented as of 6 independent experiments performed in triplicate; ANOVA was used to find out differences between cells in the same pH level and Student’s -test was used to find out differences within the same cell between pH 7.2 and 6.5. (MMP-3: matrix metalloproteinase-3; ADAMTS-5: aggrecanase-2; ; ; ; ^§; ^§§; ^§§§).

(a)

(b)