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Correction to: Prolotherapy agent P2G is associated with upregulation of fibroblast growth factor-2 genetic expression in vitro
Journal of Experimental Orthopaedics volume 7, Article number: 100 (2020)
Correction to: J Exp Ortop 7, 97 (2020)
Following publication of the original article , the below Abstract was missing.
Purpose: Osteoarthritis (OA) is a prevalent, progressively degenerative disease. Researchers have rigorously documented clinical improvement in participants receiving prolotherapy for OA. The mechanism of action is unknown; therefore, basic science studies are required. One hypothesized mechanism is that prolotherapy stimulates tissue proliferation, including that of cartilage. Accordingly, this in vitro study examines whether the prolotherapy agent phenol-glycerin-glucose (P2G) is associated with upregulation of proliferation-enhancing cytokines, primarily fibroblast growth factor-2 (FGF-2).
Methods: Murine MC3T3-E1 cells were cultured in a nonconfluent state to retain an undifferentiated osteochondroprogenic status. A limitation of MC3T3-E1 cells is that they do not fully reproduce primary human chondrocyte phenotypes; however, they are useful for modeling cartilage regeneration in vitro due to their greater phenotypic stability than primary cells. Two experiments were conducted: one in duplicate and one in triplicate. Treatment consisted of phenol-glycerin-glucose (P2G, final concentration of 1.5%). The results were assessed by quantitative Reverse Transcriptase-Polymerase Chain Reaction (qRT-PCR) to detect mRNA expression of the FGF-2, IGF-1, CCND-1 (Cyclin-D), TGF-β1, AKT, STAT1, and BMP2 genes.
Results: P2G - treated preosteoblasts expressed higher levels of FGF-2 than water controls (hour 24, p<0.001; hour 30, p<0.05; hour 38, p<0.01). Additionally, CCND-1 upregulation was observed (p<0.05), possibly as a cellular response to FGF-2 upregulation.
Conclusions: The prolotherapy agent P2G appears to be associated with upregulation of the cartilage cell proliferation enhancer cytokine FGF-2, suggesting an independent effect of P2G consistent with clinical evidence. Further study investigating the effect of prolotherapy agents on cellular proliferation and cartilage regeneration is warranted.
The original article  has been corrected.
Johnston E, Emani C, Kochan A et al (2020) Prolotherapy agent P2G is associated with upregulation of fibroblast growth factor-2 genetic expression in vitro. J Exp Ortop 7:97 https://doi.org/10.1186/s40634-020-00312-z
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Johnston, E., Emani, C., Kochan, A. et al. Correction to: Prolotherapy agent P2G is associated with upregulation of fibroblast growth factor-2 genetic expression in vitro. J EXP ORTOP 7, 100 (2020). https://doi.org/10.1186/s40634-020-00323-w