Limits...
Activation of the FGF signaling pathway and subsequent induction of mesenchymal stem cell differentiation by inorganic polyphosphate.

Kawazoe Y, Katoh S, Onodera Y, Kohgo T, Shindoh M, Shiba T - Int. J. Biol. Sci. (2008)

Bottom Line: The effect of poly(P) on the osteogenic differentiation of HDPCs and human MSCs (hMSCs) were also investigated.Furthermore, induced expression of MMP1, OPN and OC genes in both cells was confirmed by real-time PCR.The results suggest that the activation of the FGF signaling pathway by poly(P) induces both proliferation and mineralization of stem cells.

View Article: PubMed Central - PubMed

Affiliation: Regenetiss Inc., 1-9-4, Asahigaoka, Hino, Tokyo 191-0065, Japan.

ABSTRACT
Inorganic polyphosphate [poly(P)] is a biopolymer existing in almost all cells and tissues, although its biological functions in higher eukaryotes have not been completely elucidated. We previously demonstrated that poly(P) enhances the function of fibroblast growth factors (FGFs) by stabilizing them and strengthening the affinity between FGFs and their cell surface receptors. Since FGFs play crucial roles in bone regeneration, we further investigated the effect of poly(P) on the cell differentiation of human stem cells via FGF signaling systems. Human dental pulp cells (HDPCs) isolated from human dental pulp show the characteristics of multipotent mesenchymal stem cells (MSCs). HDPCs secreted FGFs and the proliferation of HDPCs was shown to be enhanced by treatment with poly(P). Cell surface receptor-bound FGF-2 was stably maintained for more than 40 hours in the presence of poly(P). The phosphorylation of ERK1/2 was also enhanced by poly(P). The effect of poly(P) on the osteogenic differentiation of HDPCs and human MSCs (hMSCs) were also investigated. After 5 days of treatment with poly(P), type-I collagen expression of both cell types was enhanced. The C-terminal peptide of type-I collagen was also released at higher levels in poly(P)-treated HDPCs. Microarray analysis showed that expression of matrix metalloproteinase-1 (MMP1), osteopontin (OPN), osteocalcin (OC) and osteoprotegerin was induced in both cell types by poly(P). Furthermore, induced expression of MMP1, OPN and OC genes in both cells was confirmed by real-time PCR. Calcification of both cell types was clearly observed by alizarin red staining following treatment with poly(P). The results suggest that the activation of the FGF signaling pathway by poly(P) induces both proliferation and mineralization of stem cells.

Show MeSH

Related in: MedlinePlus

Production and maturation of type I collagen. Type-I collagen expression in HDPCs (A) and hMSCs (B). Cells were treated with or without poly(P) for 5 days, and the expression of type-I collagen was detected by immunostaining as described in Materials and Methods. Open bars, relative expression level of type-I collagen in non-treated cells; gray bars, level in 1 mM poly(P)-treated cells. Significant differences between the values of the poly(P)-treated group [Poly(P)] and the control group (None) were determined by Student's t test. Asterisk (*), p <0.01 to the control (none). (C) Expression levels of PIP in cell culture supernatants. The concentration of PIP released from HDPCs was determined by ELISA. Open circles, PIP released from cells that were not subjected to any treatment; closed squares, PIP released fromcells that were treated with 1 mM poly(P). Each value is the average ± SD of three independent experiments. Significant differences between two values (Poly(P) and None) at the same time point were determined by Student's t test. Asterisk (*), p <0.01 to control (none). Double asterisk (**), p <0.05 to control (none).
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC2238184&req=5

Figure 4: Production and maturation of type I collagen. Type-I collagen expression in HDPCs (A) and hMSCs (B). Cells were treated with or without poly(P) for 5 days, and the expression of type-I collagen was detected by immunostaining as described in Materials and Methods. Open bars, relative expression level of type-I collagen in non-treated cells; gray bars, level in 1 mM poly(P)-treated cells. Significant differences between the values of the poly(P)-treated group [Poly(P)] and the control group (None) were determined by Student's t test. Asterisk (*), p <0.01 to the control (none). (C) Expression levels of PIP in cell culture supernatants. The concentration of PIP released from HDPCs was determined by ELISA. Open circles, PIP released from cells that were not subjected to any treatment; closed squares, PIP released fromcells that were treated with 1 mM poly(P). Each value is the average ± SD of three independent experiments. Significant differences between two values (Poly(P) and None) at the same time point were determined by Student's t test. Asterisk (*), p <0.01 to control (none). Double asterisk (**), p <0.05 to control (none).

Mentions: During cell calcification, extracellular matrix forma­tion is followed by cell proliferation. The extracel­lular matrices consist primarily of type-I colla­gen, the production of which is induced during bone differentiation 27. HDPCs treated with poly(P) for 5 days expressed a larger amount of type-I collagen than did non-treated cells (Fig. 4A). The estimated ex­pression level of type-I collagen was significantly in­creased in poly(P)-treated cells, being 1.7-fold higher than that in non-treated cells. Similarly, type-I colla­gen expression was also greatly enhanced by poly(P) in hMSCs, the level being1.2-fold higher than that in non-treated cells (Fig. 4B).


Activation of the FGF signaling pathway and subsequent induction of mesenchymal stem cell differentiation by inorganic polyphosphate.

Kawazoe Y, Katoh S, Onodera Y, Kohgo T, Shindoh M, Shiba T - Int. J. Biol. Sci. (2008)

Production and maturation of type I collagen. Type-I collagen expression in HDPCs (A) and hMSCs (B). Cells were treated with or without poly(P) for 5 days, and the expression of type-I collagen was detected by immunostaining as described in Materials and Methods. Open bars, relative expression level of type-I collagen in non-treated cells; gray bars, level in 1 mM poly(P)-treated cells. Significant differences between the values of the poly(P)-treated group [Poly(P)] and the control group (None) were determined by Student's t test. Asterisk (*), p <0.01 to the control (none). (C) Expression levels of PIP in cell culture supernatants. The concentration of PIP released from HDPCs was determined by ELISA. Open circles, PIP released from cells that were not subjected to any treatment; closed squares, PIP released fromcells that were treated with 1 mM poly(P). Each value is the average ± SD of three independent experiments. Significant differences between two values (Poly(P) and None) at the same time point were determined by Student's t test. Asterisk (*), p <0.01 to control (none). Double asterisk (**), p <0.05 to control (none).
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2238184&req=5

Figure 4: Production and maturation of type I collagen. Type-I collagen expression in HDPCs (A) and hMSCs (B). Cells were treated with or without poly(P) for 5 days, and the expression of type-I collagen was detected by immunostaining as described in Materials and Methods. Open bars, relative expression level of type-I collagen in non-treated cells; gray bars, level in 1 mM poly(P)-treated cells. Significant differences between the values of the poly(P)-treated group [Poly(P)] and the control group (None) were determined by Student's t test. Asterisk (*), p <0.01 to the control (none). (C) Expression levels of PIP in cell culture supernatants. The concentration of PIP released from HDPCs was determined by ELISA. Open circles, PIP released from cells that were not subjected to any treatment; closed squares, PIP released fromcells that were treated with 1 mM poly(P). Each value is the average ± SD of three independent experiments. Significant differences between two values (Poly(P) and None) at the same time point were determined by Student's t test. Asterisk (*), p <0.01 to control (none). Double asterisk (**), p <0.05 to control (none).
Mentions: During cell calcification, extracellular matrix forma­tion is followed by cell proliferation. The extracel­lular matrices consist primarily of type-I colla­gen, the production of which is induced during bone differentiation 27. HDPCs treated with poly(P) for 5 days expressed a larger amount of type-I collagen than did non-treated cells (Fig. 4A). The estimated ex­pression level of type-I collagen was significantly in­creased in poly(P)-treated cells, being 1.7-fold higher than that in non-treated cells. Similarly, type-I colla­gen expression was also greatly enhanced by poly(P) in hMSCs, the level being1.2-fold higher than that in non-treated cells (Fig. 4B).

Bottom Line: The effect of poly(P) on the osteogenic differentiation of HDPCs and human MSCs (hMSCs) were also investigated.Furthermore, induced expression of MMP1, OPN and OC genes in both cells was confirmed by real-time PCR.The results suggest that the activation of the FGF signaling pathway by poly(P) induces both proliferation and mineralization of stem cells.

View Article: PubMed Central - PubMed

Affiliation: Regenetiss Inc., 1-9-4, Asahigaoka, Hino, Tokyo 191-0065, Japan.

ABSTRACT
Inorganic polyphosphate [poly(P)] is a biopolymer existing in almost all cells and tissues, although its biological functions in higher eukaryotes have not been completely elucidated. We previously demonstrated that poly(P) enhances the function of fibroblast growth factors (FGFs) by stabilizing them and strengthening the affinity between FGFs and their cell surface receptors. Since FGFs play crucial roles in bone regeneration, we further investigated the effect of poly(P) on the cell differentiation of human stem cells via FGF signaling systems. Human dental pulp cells (HDPCs) isolated from human dental pulp show the characteristics of multipotent mesenchymal stem cells (MSCs). HDPCs secreted FGFs and the proliferation of HDPCs was shown to be enhanced by treatment with poly(P). Cell surface receptor-bound FGF-2 was stably maintained for more than 40 hours in the presence of poly(P). The phosphorylation of ERK1/2 was also enhanced by poly(P). The effect of poly(P) on the osteogenic differentiation of HDPCs and human MSCs (hMSCs) were also investigated. After 5 days of treatment with poly(P), type-I collagen expression of both cell types was enhanced. The C-terminal peptide of type-I collagen was also released at higher levels in poly(P)-treated HDPCs. Microarray analysis showed that expression of matrix metalloproteinase-1 (MMP1), osteopontin (OPN), osteocalcin (OC) and osteoprotegerin was induced in both cell types by poly(P). Furthermore, induced expression of MMP1, OPN and OC genes in both cells was confirmed by real-time PCR. Calcification of both cell types was clearly observed by alizarin red staining following treatment with poly(P). The results suggest that the activation of the FGF signaling pathway by poly(P) induces both proliferation and mineralization of stem cells.

Show MeSH
Related in: MedlinePlus