Table 2.
In Vitro and in vivo studies presenting the osteogenic effects of other peptides except those derived from ECM and BMPs
| Active peptides | Abbreviation | Composition | Potential pathways | Upregulation / Downregulation of proteins or genes | Final functions | References |
|---|---|---|---|---|---|---|
| calcitonin gene-related peptides | CGRP | 37 amino acids | the cAMP, Wnt and AMPK-eNOS pathways | upregulating expression of IGF-1, IGF-1 receptor and BMP-2 receptor; ALP, OC and COLLA1 | upregulating cell proliferation, osteogenic differentiation and angiogenesis; downregulating apoptosis and inflammation | 67-85 |
| Parathyroid hormone (1-34) | PTH1-34 | 34 amino acids | G(q)-signalling, β-arrestin recruitment, ERK1/2 phosphorylation and phospholipase C pathway | upregulating expression of Runx2 and COL2A1; downregulating expression of ALP and BMP-2 | upregulating cell proliferation and chondrogenesis | 86-88 |
| osteogenic growth peptides | OGP | 14 amino acids | the G1 protein-MAPK and RhoA/ROCK pathway | upregulating osteocalcin, collagen, BMP-2, ALP and mineralization; upregulating TGF β1, β2, β3, FGF-2, IGF-I | upregulating cell proligeration and osteogenic differentiation; cartilage-to-bone transition; downregulating adipogenic differentiation | 89-96 |
| thrombin peptide 508 | TP508 | 23 amino acids | cell cycle-G1/S checkpoint, JAK/STAT, NF-kappaB, PDGF, PI3K/AKT, PTEN, and ERK/MAPK | upregulating the expression of Runx2 and OPN | upregulating cell proliferation and osteogenic differentiation; chemotaxis, angiogenesis and revascularization; downregulating apoptosis, the effect of hypoxia | 22, 97-99 |
| NEMO-binding domain peptide | NBD | 6 amino acids | NF-κB pathway | downregulating TRAP activity, actin rings; RANKL-induced c-Src kinase activity | upregulating osteogenic differentiation of cells; downregulating bone resorption | 100-103 |
| Cell penetrating peptide | CPP | 30 amino acids | – | – | transcriptional factor to deliver bone-regenerating related proteins or factors into cells | 104-106 |
| AcN-RADARADARADARADA-CONH2 | RADA16-I | 16 amino acids | – | upregulating expression of Runx2 genes, ALP and osteocalcin | transcriptional factor to deliver bone-regenerating related proteins or factors into cells | 107-109 |