Abstract

RIPAMONTI, U. The induction of bone formation: From bone morphogenetic proteins to the transforming growth factor-ß₃ protein - Redundancy, pleiotropy and the induction of cementogenesis. S. Afr. dent. j. [online]. 2021, vol.76, n.6, pp.331-356. ISSN 0375-1562.  http://dx.doi.org/10.17159/2519-0105/2021/v76no6a4.

This review proposes to translate organogenesis and the induction of bone formation by the recombinant human transforming growth factor-ß₃ (hTGF-ß₃) in the Chacma baboon Papio ursinus to periodontal tissue induction and regeneration. Naturally derived highly purified osteogenic proteins of the transforming growth factor-ß (TGF-ß) supergene family were implanted in Class II furcation defects of the first and second mandibular molars. Additional defects in P. ursinus were treated with recombinant human osteogenic protein-1 (hOP-1, also known as bone morphogenetic protein-7, hBMP-7) and hBMP-2, singly or in binary applications. In different studies defects were also implanted with hTGF-ß₃ singly or in binary application with hOP-1. Harvested specimens on day 60 and 180 were processed for undecalcified histology using tungsten-carbide knives mounted on Polycut sledge' micro-tomes or the Exakt precision cutting and grinding system. Highly purified osteogenic proteins showed the induction of Sharpey's fibres into newly formed cementoid with foci of mineralization. hOP-1 induced substantial cementogenesis whilst hBMP-2 preferentially induced alveolar bone. Intramuscular implantation of hTGF-ß₃ absorbed onto coral-derived macroporous bioreactors engineered large heterotopic multicellular bone organoids. Gene expression pathways by quantitative Reverse Transcription Polymerases Chain Reaction (qRT-PCR) show that the induction of bone is via several profiled BMPs and TGF-ßs expressed upon implantation of hTGF-ß₃ recapitulating the synergistic induction of bone as shown by binary applications of low doses of hTGF-ß₁ and hTGF-ß₃ with hOP-1. The rapid induction of bone by hTGF-ß₃ provides the framework for a paradigmatic shift from recombinant hBMPs to hTGF-ß₃ in clinical contexts, provocatively operational in periodontal tissue regeneration with substantial induction of cementogenesis in angiogenesis.

Keywords : Bone morphogenetic proteins' gene expression; qRT-PCR; TGF-ß₃ master gene; noggin; molecular redundancy; pleiotropy; cementogenesis in angiogenesis; primates.

        · text in English     · English ( pdf )