Lumbar Disc Degeneration is Facilitated by MiR-100-Mediated FGFR3 Suppression.

Background/aims: The pathogenesis of lumbar disc degeneration (LDD) involved activation of matrix metalloproteinase 13 (MMP13) by differential expression of fibroblast growth factor receptor 1 (FGFR1) and FGFR3. Nevertheless, the molecular regulation of FGFR1 and FGFR3 in the lumber disc cells remains elusive.
Methods: We examined the FGFR1 and FGFR3 levels and microRNAs (miRNAs) levels in the resected LDD discs, compared to the traumatized, non-LDD discs. We analyzed the binding of miR-100 to the 3'UTR of FGFR3 mRNA and its effects on FGFR3 translation by bioinformatics analysis and by luciferase-reporter assay, respectively. We modified miR-100 levels in a human nucleus pulposus SV40 cell line (HNPSV), and examined the effects on the expression of FGFR3 and MMP13, by RT-qPCR, Western blot and ELISA.
Results: The levels of FGFR1 and miR-100 were significantly higher, while the levels of FGFR3 were significantly lower, in LDD discs, compared to the control non-LDD discs. The levels of FGFR3, but not the levels of FGFR1, inversely correlated with the levels of miR-100. Moreover, miR-100 was found to bind to the 3'UTR of FGFR3 mRNA to prevent its translation. In miR-100-modified HNPSV cells, we found that miR-100 decreased FGFR3 levels, and increased MMP13 levels.
Conclusion: miR-100 may activate MMP13 through 3'UTR-suppressoin of FGFR3 mRNA to facilitate development of LDD.
(© 2015 S. Karger AG, Basel.)