Post-transcriptional stimulation of transforming growth factor β1 mRNA by TGF-β1 treatment of transformed human osteoblasts

✍ Scribed by Changbao Liu; Kathleen Wallace; Congzhu Shi; Susan Heyner; Barry Komm; Dr. John G. Haddad

• Publisher: American Society for Bone and Mineral Research
• Year: 2009
• Tongue: English
• Weight: 818 KB
• Volume: 11
• Category: Article
• ISSN: 0884-0431
• DOI: 10.1002/jbmr.5650110210

✦ Synopsis

Following exogenous administration of transforming growth factor-pl (TGF-PI) polypeptide to the human osteosarcoma cell line TE-85, we observed a 2to 6-fold stimulation of steady-state TGF-PI mRNA. The stimulation was dose-and time-dependent, as judged from Northern blot hybridization analyses. A 2to 6-fold increase of the TGF-PI polypeptide was also found in the media of these cells after TGF-PI treatments. The autostimulation of TGF-PI mRNA was nullified by cycloheximide treatment of the cells. The in vitro transcription rates of the TGF-Pl gene by isolated nuclei were not altered by TGF-Pl treatment. Under conditions of transcriptional inhibition, the stability of TGF-PI mRNA was enhanced nearly two-fold by TGF-PI treatment.

Our findings indicate that TGF-Pl can stimulate autologous gene expression and subsequent polypeptide translation by a post-transcriptional mechanism requiring protein synthesis in human ostenblast-like cells. The recognized versatility of TGF-p1 autostimulation mechanisms (transcriptional and post-transcriptional) in other mesenchymal cells may apply also to skeletal cells, further underscoring the broad and potent activities of this cytokine.

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