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Cell Injury-Induced Release of Fibroblast Growth Factor 2: Relevance to Intracerebral Mesenchymal Stromal Cell Transplantations.

Aizman I, Vinodkumar D, McGrogan M, Bates D - Stem Cells Dev. (2015)

Bottom Line: We found that fibroblast growth factor (FGF)2 and FGF1, but not vascular endothelial growth factor and monocyte chemoattractant protein 1 levels were high in extracts despite being low in conditioned media.However, suspensions of killed cells strongly potentiated the astrogenic effects of live MSC.We therefore propose that both dying and surviving grafted MSC contribute to tissue regeneration.

View Article: PubMed Central - PubMed

Affiliation: 1 Department of Research, SanBio, Inc. , Mountain View, California.

ABSTRACT
Beneficial effects of intracerebral transplantation of mesenchymal stromal cells (MSC) and their derivatives are believed to be mediated mostly by factors produced by engrafted cells. However, the mesenchymal cell engraftment rate is low, and the majority of grafted cells disappear within a short post-transplantation period. Here, we hypothesize that dying transplanted cells can affect surrounding tissues by releasing their active intracellular components. To elucidate the type, amounts, and potency of these putative intracellular factors, freeze/thaw extracts of MSC or their derivatives were tested in enzyme-linked immunosorbent assays and bioassays. We found that fibroblast growth factor (FGF)2 and FGF1, but not vascular endothelial growth factor and monocyte chemoattractant protein 1 levels were high in extracts despite being low in conditioned media. Extracts induced concentration-dependent proliferation of rat cortical neural progenitor cells and human umbilical vein endothelial cells; these proliferative responses were specifically blocked by FGF2-neutralizing antibody. In the neuropoiesis assay with rat cortical cells, both MSC extracts and killed cells induced expression of nestin, but not astrocyte differentiation. However, suspensions of killed cells strongly potentiated the astrogenic effects of live MSC. In transplantation-relevant MSC injury models (peripheral blood cell-mediated cytotoxicity and high cell density plating), MSC death coincided with the release of intracellular FGF2. The data showed that MSC contain a major depot of active FGF2 that is released upon cell injury and is capable of acutely stimulating neuropoiesis and angiogenesis. We therefore propose that both dying and surviving grafted MSC contribute to tissue regeneration.

No MeSH data available.


Related in: MedlinePlus

Proliferative response of human umbilical vein endothelial cells (HUVEC) to extracts and the role of FGF2. (A) HUVEC proliferation in response to various dilutions of either MSC extract (E0), CM, or neurobasal medium after 2 day-culturing. (B) Proliferative responses of HUVEC to 15% SB623-extract (E0) (final FGF2 concentration 0.2 ng/mL), rVEGF (10 ng/mL), and rFGF2 (1 ng/mL), and to FGF2-neutralization in E0. bFM1 and IgG1 are anti-FGF2 neutralizing antibody and mouse isotype control antibody, respectively, both at 2 μg/mL. *P<0.05. No statistically significant difference between E0 alone and E0+IgG1.
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Related In: Results  -  Collection


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f3: Proliferative response of human umbilical vein endothelial cells (HUVEC) to extracts and the role of FGF2. (A) HUVEC proliferation in response to various dilutions of either MSC extract (E0), CM, or neurobasal medium after 2 day-culturing. (B) Proliferative responses of HUVEC to 15% SB623-extract (E0) (final FGF2 concentration 0.2 ng/mL), rVEGF (10 ng/mL), and rFGF2 (1 ng/mL), and to FGF2-neutralization in E0. bFM1 and IgG1 are anti-FGF2 neutralizing antibody and mouse isotype control antibody, respectively, both at 2 μg/mL. *P<0.05. No statistically significant difference between E0 alone and E0+IgG1.

Mentions: FGF2 is a very potent angiogenic factor. Therefore, extracts were tested for their ability to induce proliferation of HUVEC. On day 2, MSC-E0 strongly induced proliferation of HUVEC, while MSC-CM and NB medium had no effect (Fig. 3A). In a separate experiment, HUVEC were incubated with rVEGF, rFGF2, or SB623-E0 (15%) with or without FGF2-neutralizing and control antibodies (Fig. 3B). The response to E0 was inhibited by neutralizing bFM1, but not by control mouse IgG1, indicating that HUVEC proliferation in this assay was driven by FGF2. Notably, the activity of both native and recombinant FGF2 was similar in this assay; indeed, when the background was subtracted, the response induced by 15% E0 (which corresponded to the final FGF2 concentration of 0.2 ng/mL in this E0 preparation) was approximately four times less than the response induced by 1 ng/mL rFGF2.


Cell Injury-Induced Release of Fibroblast Growth Factor 2: Relevance to Intracerebral Mesenchymal Stromal Cell Transplantations.

Aizman I, Vinodkumar D, McGrogan M, Bates D - Stem Cells Dev. (2015)

Proliferative response of human umbilical vein endothelial cells (HUVEC) to extracts and the role of FGF2. (A) HUVEC proliferation in response to various dilutions of either MSC extract (E0), CM, or neurobasal medium after 2 day-culturing. (B) Proliferative responses of HUVEC to 15% SB623-extract (E0) (final FGF2 concentration 0.2 ng/mL), rVEGF (10 ng/mL), and rFGF2 (1 ng/mL), and to FGF2-neutralization in E0. bFM1 and IgG1 are anti-FGF2 neutralizing antibody and mouse isotype control antibody, respectively, both at 2 μg/mL. *P<0.05. No statistically significant difference between E0 alone and E0+IgG1.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4499789&req=5

f3: Proliferative response of human umbilical vein endothelial cells (HUVEC) to extracts and the role of FGF2. (A) HUVEC proliferation in response to various dilutions of either MSC extract (E0), CM, or neurobasal medium after 2 day-culturing. (B) Proliferative responses of HUVEC to 15% SB623-extract (E0) (final FGF2 concentration 0.2 ng/mL), rVEGF (10 ng/mL), and rFGF2 (1 ng/mL), and to FGF2-neutralization in E0. bFM1 and IgG1 are anti-FGF2 neutralizing antibody and mouse isotype control antibody, respectively, both at 2 μg/mL. *P<0.05. No statistically significant difference between E0 alone and E0+IgG1.
Mentions: FGF2 is a very potent angiogenic factor. Therefore, extracts were tested for their ability to induce proliferation of HUVEC. On day 2, MSC-E0 strongly induced proliferation of HUVEC, while MSC-CM and NB medium had no effect (Fig. 3A). In a separate experiment, HUVEC were incubated with rVEGF, rFGF2, or SB623-E0 (15%) with or without FGF2-neutralizing and control antibodies (Fig. 3B). The response to E0 was inhibited by neutralizing bFM1, but not by control mouse IgG1, indicating that HUVEC proliferation in this assay was driven by FGF2. Notably, the activity of both native and recombinant FGF2 was similar in this assay; indeed, when the background was subtracted, the response induced by 15% E0 (which corresponded to the final FGF2 concentration of 0.2 ng/mL in this E0 preparation) was approximately four times less than the response induced by 1 ng/mL rFGF2.

Bottom Line: We found that fibroblast growth factor (FGF)2 and FGF1, but not vascular endothelial growth factor and monocyte chemoattractant protein 1 levels were high in extracts despite being low in conditioned media.However, suspensions of killed cells strongly potentiated the astrogenic effects of live MSC.We therefore propose that both dying and surviving grafted MSC contribute to tissue regeneration.

View Article: PubMed Central - PubMed

Affiliation: 1 Department of Research, SanBio, Inc. , Mountain View, California.

ABSTRACT
Beneficial effects of intracerebral transplantation of mesenchymal stromal cells (MSC) and their derivatives are believed to be mediated mostly by factors produced by engrafted cells. However, the mesenchymal cell engraftment rate is low, and the majority of grafted cells disappear within a short post-transplantation period. Here, we hypothesize that dying transplanted cells can affect surrounding tissues by releasing their active intracellular components. To elucidate the type, amounts, and potency of these putative intracellular factors, freeze/thaw extracts of MSC or their derivatives were tested in enzyme-linked immunosorbent assays and bioassays. We found that fibroblast growth factor (FGF)2 and FGF1, but not vascular endothelial growth factor and monocyte chemoattractant protein 1 levels were high in extracts despite being low in conditioned media. Extracts induced concentration-dependent proliferation of rat cortical neural progenitor cells and human umbilical vein endothelial cells; these proliferative responses were specifically blocked by FGF2-neutralizing antibody. In the neuropoiesis assay with rat cortical cells, both MSC extracts and killed cells induced expression of nestin, but not astrocyte differentiation. However, suspensions of killed cells strongly potentiated the astrogenic effects of live MSC. In transplantation-relevant MSC injury models (peripheral blood cell-mediated cytotoxicity and high cell density plating), MSC death coincided with the release of intracellular FGF2. The data showed that MSC contain a major depot of active FGF2 that is released upon cell injury and is capable of acutely stimulating neuropoiesis and angiogenesis. We therefore propose that both dying and surviving grafted MSC contribute to tissue regeneration.

No MeSH data available.


Related in: MedlinePlus