Transforming and epidermal growth factors in degenerated intervertebral discs

We studied the presence of anabolic growth factors in human herniated intervertebral discs (IVD) using a reverse transcriptase-polymerase chain reaction (RT-PCR) and immunohistochemistry Messenger RNA (mRNA) was isolated from the nucleus pulposus using oligo (dT)(25) superparamagnetic beads and probing with gene-specific primers in RT-PCR. mRNA coding for TGF-alpha (3/10), EGF (0/10), TGF-beta 1 (0/10) and TGF-beta 3 (2/10) or the EGF receptor (EGF-R; 0/10) and TGF-beta type-II receptor (0/10) was found only occasionally, Beta-actin was always present and positive sample controls confirmed the validity of the RT-PCR assay. These RT-PCR findings were confirmed using immunohistochemical staining of EGF and TFG-beta, whereas TGF-alpha protein was always found associated with discocytes, We conclude that the nucleus pulposus of the herniated ND is vulnerable to proteolytic degradation and depletion of proteoglycans due to the lack and/or low production of anabolic growth factors/receptors which could increase the local synthesis of the extracellular matrix.