Limits...
Silica nanoparticles increase human adipose tissue-derived stem cell proliferation through ERK1/2 activation.

Kim KJ, Joe YA, Kim MK, Lee SJ, Ryu YH, Cho DW, Rhie JW - Int J Nanomedicine (2015)

Bottom Line: Silicon dioxide composites have been found to enhance the mechanical properties of scaffolds and to support growth of human adipose tissue-derived stem cells (hADSCs) both in vitro and in vivo.In this study, we examined the effect of different sized particles on growth and mitogen-activated protein kinase signaling in hADSCs.Silica NPs increased the proliferation of hADSCs, but silica MPs had no significant effect in this regard.

View Article: PubMed Central - PubMed

Affiliation: Department of Plastic Surgery, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea ; Department of Molecular Biomedicine, The Catholic University of Korea, Seoul, Republic of Korea.

ABSTRACT

Background: Silicon dioxide composites have been found to enhance the mechanical properties of scaffolds and to support growth of human adipose tissue-derived stem cells (hADSCs) both in vitro and in vivo. Silica (silicon dioxide alone) exists as differently sized particles when suspended in culture medium, but it is not clear whether particle size influences the beneficial effect of silicon dioxide on hADSCs. In this study, we examined the effect of different sized particles on growth and mitogen-activated protein kinase signaling in hADSCs.

Methods: Silica gel was prepared by a chemical reaction using hydrochloric acid and sodium silicate, washed, sterilized, and suspended in serum-free culture medium for 48 hours, and then sequentially filtered through a 0.22 μm filter (filtrate containing nanoparticles smaller than 220 nm; silica NPs). hADSCs were incubated with silica NPs or 3 μm silica microparticles (MPs), examined by transmission electron microscopy, and assayed for cell proliferation, apoptosis, and mitogen-activated protein kinase signaling.

Results: Eighty-nine percent of the silica NPs were around 50-120 nm in size. When hADSCs were treated with the study particles, silica NPs were observed in endocytosed vacuoles in the cytosol of hADSCs, but silica MPs showed no cell entry. Silica NPs increased the proliferation of hADSCs, but silica MPs had no significant effect in this regard. Instead, silica MPs induced slight apoptosis. Silica NPs increased phosphorylation of extracellular signal-related kinase (ERK)1/2, while silica MPs increased phosphorylation of p38. Silica NPs had no effect on phosphorylation of Janus kinase or p38. Pretreatment with PD98059, a MEK inhibitor, prevented the ERK1/2 phosphorylation and proliferation induced by silica NPs.

Conclusion: Scaffolds containing silicon dioxide for tissue engineering may enhance cell growth through ERK1/2 activation only when NPs around 50-120 nm in size are included, and single component silica-derived NPs could be useful for bioscaffolds in stem cell therapy.

No MeSH data available.


Related in: MedlinePlus

Activation of mitogen-activated protein kinases by differently sized silica particles.Notes: (A) Protein extracts from the cells incubated in each type of medium for 10, 20, 30 and 60 minutes after starving in FBS-free medium for 24 hours were immunoblotted. (B, C) Quantitative analysis of ERK1/2 and p38 phosphorylation level by densitometric analysis. Three independent experiments were performed (*P<0.01, **P<0.001). (D) ERK1/2 activation by silica NPs was evaluated by treatment with PD98059, a MEK-ERK inhibitor. Protein was extracted from cells pretreated with PD98059 for 30 minutes, followed by treatment with silica NPs for 10 minutes. Quantitative analysis of three independent experiments by densitometric analysis was performed. ERK1/2 phosphorylation by basic fibroblast growth factor and silica NPs was prevented by pretreatment with PD98059 (*P<0.01, **P<0.001). (E) A proliferation assay was performed by measuring DNA content in cells pretreated with PD98059 followed by treatment with silica NPs. Total DNA (ng/μL) was increased in the silica NPs with 1% FBS group, whereas the pretreated group showed reduced proliferation. Experiments were performed in triplicate at least.Abbreviations: ERK, extracellular signal-related kinase; JNK, Janus kinase; NPs, nanoparticles; MPs, microparticles; bFGF, basic fibroblast growth factor; p-, phosphorylated; MEK, mitogen-activated protein kinase kinase; FBS, fetal bovine serum.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4378289&req=5

f4-ijn-10-2261: Activation of mitogen-activated protein kinases by differently sized silica particles.Notes: (A) Protein extracts from the cells incubated in each type of medium for 10, 20, 30 and 60 minutes after starving in FBS-free medium for 24 hours were immunoblotted. (B, C) Quantitative analysis of ERK1/2 and p38 phosphorylation level by densitometric analysis. Three independent experiments were performed (*P<0.01, **P<0.001). (D) ERK1/2 activation by silica NPs was evaluated by treatment with PD98059, a MEK-ERK inhibitor. Protein was extracted from cells pretreated with PD98059 for 30 minutes, followed by treatment with silica NPs for 10 minutes. Quantitative analysis of three independent experiments by densitometric analysis was performed. ERK1/2 phosphorylation by basic fibroblast growth factor and silica NPs was prevented by pretreatment with PD98059 (*P<0.01, **P<0.001). (E) A proliferation assay was performed by measuring DNA content in cells pretreated with PD98059 followed by treatment with silica NPs. Total DNA (ng/μL) was increased in the silica NPs with 1% FBS group, whereas the pretreated group showed reduced proliferation. Experiments were performed in triplicate at least.Abbreviations: ERK, extracellular signal-related kinase; JNK, Janus kinase; NPs, nanoparticles; MPs, microparticles; bFGF, basic fibroblast growth factor; p-, phosphorylated; MEK, mitogen-activated protein kinase kinase; FBS, fetal bovine serum.

Mentions: We examined whether differently sized silica particles affected MAPK signaling. After ADSCs were exposed to silica NP or MP medium for 10 to 60 minutes, we measured the phosphorylation levels of ERK1/2, p38, and JNK (Figure 4A). As shown in Figure 4B, the silica NP medium markedly increased the phosphorylation of ERK1/2 after 10 minutes, and phosphorylation decreased gradually thereafter. The silica NP medium did not significantly affect p38 phosphorylation, but the silica MP medium showed increased levels of the phosphorylated form of p38 (Figure 4C). However, there was no change in phosphorylation of JNK in either the silica NP or MP medium (Figure S4B).


Silica nanoparticles increase human adipose tissue-derived stem cell proliferation through ERK1/2 activation.

Kim KJ, Joe YA, Kim MK, Lee SJ, Ryu YH, Cho DW, Rhie JW - Int J Nanomedicine (2015)

Activation of mitogen-activated protein kinases by differently sized silica particles.Notes: (A) Protein extracts from the cells incubated in each type of medium for 10, 20, 30 and 60 minutes after starving in FBS-free medium for 24 hours were immunoblotted. (B, C) Quantitative analysis of ERK1/2 and p38 phosphorylation level by densitometric analysis. Three independent experiments were performed (*P<0.01, **P<0.001). (D) ERK1/2 activation by silica NPs was evaluated by treatment with PD98059, a MEK-ERK inhibitor. Protein was extracted from cells pretreated with PD98059 for 30 minutes, followed by treatment with silica NPs for 10 minutes. Quantitative analysis of three independent experiments by densitometric analysis was performed. ERK1/2 phosphorylation by basic fibroblast growth factor and silica NPs was prevented by pretreatment with PD98059 (*P<0.01, **P<0.001). (E) A proliferation assay was performed by measuring DNA content in cells pretreated with PD98059 followed by treatment with silica NPs. Total DNA (ng/μL) was increased in the silica NPs with 1% FBS group, whereas the pretreated group showed reduced proliferation. Experiments were performed in triplicate at least.Abbreviations: ERK, extracellular signal-related kinase; JNK, Janus kinase; NPs, nanoparticles; MPs, microparticles; bFGF, basic fibroblast growth factor; p-, phosphorylated; MEK, mitogen-activated protein kinase kinase; FBS, fetal bovine serum.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4378289&req=5

f4-ijn-10-2261: Activation of mitogen-activated protein kinases by differently sized silica particles.Notes: (A) Protein extracts from the cells incubated in each type of medium for 10, 20, 30 and 60 minutes after starving in FBS-free medium for 24 hours were immunoblotted. (B, C) Quantitative analysis of ERK1/2 and p38 phosphorylation level by densitometric analysis. Three independent experiments were performed (*P<0.01, **P<0.001). (D) ERK1/2 activation by silica NPs was evaluated by treatment with PD98059, a MEK-ERK inhibitor. Protein was extracted from cells pretreated with PD98059 for 30 minutes, followed by treatment with silica NPs for 10 minutes. Quantitative analysis of three independent experiments by densitometric analysis was performed. ERK1/2 phosphorylation by basic fibroblast growth factor and silica NPs was prevented by pretreatment with PD98059 (*P<0.01, **P<0.001). (E) A proliferation assay was performed by measuring DNA content in cells pretreated with PD98059 followed by treatment with silica NPs. Total DNA (ng/μL) was increased in the silica NPs with 1% FBS group, whereas the pretreated group showed reduced proliferation. Experiments were performed in triplicate at least.Abbreviations: ERK, extracellular signal-related kinase; JNK, Janus kinase; NPs, nanoparticles; MPs, microparticles; bFGF, basic fibroblast growth factor; p-, phosphorylated; MEK, mitogen-activated protein kinase kinase; FBS, fetal bovine serum.
Mentions: We examined whether differently sized silica particles affected MAPK signaling. After ADSCs were exposed to silica NP or MP medium for 10 to 60 minutes, we measured the phosphorylation levels of ERK1/2, p38, and JNK (Figure 4A). As shown in Figure 4B, the silica NP medium markedly increased the phosphorylation of ERK1/2 after 10 minutes, and phosphorylation decreased gradually thereafter. The silica NP medium did not significantly affect p38 phosphorylation, but the silica MP medium showed increased levels of the phosphorylated form of p38 (Figure 4C). However, there was no change in phosphorylation of JNK in either the silica NP or MP medium (Figure S4B).

Bottom Line: Silicon dioxide composites have been found to enhance the mechanical properties of scaffolds and to support growth of human adipose tissue-derived stem cells (hADSCs) both in vitro and in vivo.In this study, we examined the effect of different sized particles on growth and mitogen-activated protein kinase signaling in hADSCs.Silica NPs increased the proliferation of hADSCs, but silica MPs had no significant effect in this regard.

View Article: PubMed Central - PubMed

Affiliation: Department of Plastic Surgery, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea ; Department of Molecular Biomedicine, The Catholic University of Korea, Seoul, Republic of Korea.

ABSTRACT

Background: Silicon dioxide composites have been found to enhance the mechanical properties of scaffolds and to support growth of human adipose tissue-derived stem cells (hADSCs) both in vitro and in vivo. Silica (silicon dioxide alone) exists as differently sized particles when suspended in culture medium, but it is not clear whether particle size influences the beneficial effect of silicon dioxide on hADSCs. In this study, we examined the effect of different sized particles on growth and mitogen-activated protein kinase signaling in hADSCs.

Methods: Silica gel was prepared by a chemical reaction using hydrochloric acid and sodium silicate, washed, sterilized, and suspended in serum-free culture medium for 48 hours, and then sequentially filtered through a 0.22 μm filter (filtrate containing nanoparticles smaller than 220 nm; silica NPs). hADSCs were incubated with silica NPs or 3 μm silica microparticles (MPs), examined by transmission electron microscopy, and assayed for cell proliferation, apoptosis, and mitogen-activated protein kinase signaling.

Results: Eighty-nine percent of the silica NPs were around 50-120 nm in size. When hADSCs were treated with the study particles, silica NPs were observed in endocytosed vacuoles in the cytosol of hADSCs, but silica MPs showed no cell entry. Silica NPs increased the proliferation of hADSCs, but silica MPs had no significant effect in this regard. Instead, silica MPs induced slight apoptosis. Silica NPs increased phosphorylation of extracellular signal-related kinase (ERK)1/2, while silica MPs increased phosphorylation of p38. Silica NPs had no effect on phosphorylation of Janus kinase or p38. Pretreatment with PD98059, a MEK inhibitor, prevented the ERK1/2 phosphorylation and proliferation induced by silica NPs.

Conclusion: Scaffolds containing silicon dioxide for tissue engineering may enhance cell growth through ERK1/2 activation only when NPs around 50-120 nm in size are included, and single component silica-derived NPs could be useful for bioscaffolds in stem cell therapy.

No MeSH data available.


Related in: MedlinePlus