TGF-β1 suppresses CCL3/4 expression through the ERK signaling pathway and inhibits intervertebral disc degeneration and inflammation-related pain in a rat model

Exp Mol Med. 2017 Sep 22;49(9):e379. doi: 10.1038/emm.2017.136.


The objective of this study was to investigate the regulatory effects of TGF-β1 on CCL3/4 expression and inflammation-related pain during intervertebral disc degeneration (IVDD). TGF-β1 and CCL3/4 expression patterns in different degenerative human nucleus pulposus (NP) tissues were measured by qPCR and immunohistochemistry (IHC), and the effects of TGF-β1 on CCL3/4 expression were measured by qPCR, ELISA and immunofluorescence. The roles of NF-κB and MAPK in TGF-β1-mediated CCL3/4 promoter activity were studied using siRNAs, western blotting and qPCR. After establishing an IVDD rat model in vivo, we administered intradiscal injections of TGF-β1. The effects of TGF-β1 on IVDD were determined by MRI and histological analyses, and the effects of TGF-β1 on dorsal root ganglion (DRG) inflammation and pain development were determined by IHC staining and pain-behavior testing, respectively. TGF-β1 and CCL3/4 expression was elevated in degenerative NP tissue. CCL4 expression was significantly inhibited by TGF-β1 treatment. Pharmacological inhibition or siRNA knockdown of the ERK1/2 signaling attenuated TGF-β1-mediated suppression of CCL4 expression. In vivo, TGF-β1 injection inhibited the development of degenerative features in the IVDD model. Moreover, TGF-β1 prevented the inflammatory response and pain development. The results of this study show that TGF-β1 downregulates CCL4 expression through ERK1/2 signaling activation in NP cells. Furthermore, TGF-β1 can prevent degenerative processes, inhibit inflammatory responses in the DRG and prevent pain development in the IVDD rat model. The results of this study indicate that TGF-β1 may represent a therapeutic target for the control of inflammation-related pain associated with IVDD.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Animals
  • Biomarkers
  • Chemokine CCL3 / genetics*
  • Chemokine CCL3 / metabolism
  • Chemokine CCL4 / genetics*
  • Chemokine CCL4 / metabolism
  • Disease Models, Animal
  • Female
  • Gene Expression Regulation* / drug effects
  • Humans
  • Intervertebral Disc Degeneration / diagnosis
  • Intervertebral Disc Degeneration / drug therapy
  • Intervertebral Disc Degeneration / genetics*
  • Intervertebral Disc Degeneration / metabolism*
  • Low Back Pain / drug therapy
  • Low Back Pain / etiology
  • MAP Kinase Signaling System* / drug effects
  • Male
  • Middle Aged
  • Models, Biological
  • Pain / drug therapy
  • Pain / etiology
  • RNA Interference
  • RNA, Small Interfering / genetics
  • Rats
  • Transforming Growth Factor beta1 / metabolism*
  • Transforming Growth Factor beta1 / pharmacology
  • Young Adult


  • Biomarkers
  • Chemokine CCL3
  • Chemokine CCL4
  • RNA, Small Interfering
  • Transforming Growth Factor beta1