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Attenuation of the macrophage inflammatory activity by TiO₂ nanotubes via inhibition of MAPK and NF-κB pathways.

Neacsu P, Mazare A, Schmuki P, Cimpean A - Int J Nanomedicine (2015)

Bottom Line: Results showed that the Ti/TiO2 significantly reduce the expression levels of the phosphorylated forms of p38, ERK1/2, c-Jun NH2-terminal kinase (JNK), IKKβ, and IkB-α.Furthermore, a significant reduction in the p65 nuclear accumulation on the nanotubular surface was remarked.However, the selective inhibitor for JNK signaling pathway (SP600125) was effective in reducing tumor necrosis factor alpha release as well as monocyte chemotactic protein-1 and nitric oxide production.

View Article: PubMed Central - PubMed

Affiliation: Department of Biochemistry and Molecular Biology, University of Bucharest, Bucharest, Romania.

ABSTRACT
Biomaterial implantation in a living tissue triggers the activation of macrophages in inflammatory events, promoting the transcription of pro-inflammatory mediator genes. The initiation of macrophage inflammatory processes is mainly regulated by signaling proteins of mitogen-activated protein kinase (MAPK) and by nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) pathways. We have previously shown that titania nanotubes modified Ti surfaces (Ti/TiO2) mitigate the immune response, compared with flat Ti surfaces; however, little is known regarding the underlying mechanism. Therefore, the aim of this study is to investigate the mechanism(s) by which this nanotopography attenuates the inflammatory activity of macrophages. Thus, we analyzed the effects of TiO2 nanotubes on the activation of MAPK and NF-κB signaling pathways in standard and lipopolysaccharide-evoked conditions. Results showed that the Ti/TiO2 significantly reduce the expression levels of the phosphorylated forms of p38, ERK1/2, c-Jun NH2-terminal kinase (JNK), IKKβ, and IkB-α. Furthermore, a significant reduction in the p65 nuclear accumulation on the nanotubular surface was remarked. Following, by using specific MAPK inhibitors, we observed that lipopolysaccharide-induced production of monocyte chemotactic protein-1 and nitric oxide was significantly inhibited on the Ti/TiO2 surface via p38 and ERK1/2, but not via JNK. However, the selective inhibitor for JNK signaling pathway (SP600125) was effective in reducing tumor necrosis factor alpha release as well as monocyte chemotactic protein-1 and nitric oxide production. Altogether, these data suggest that titania nanotubes can attenuate the macrophage inflammatory response via suppression of MAPK and NF-κB pathways providing a potential mechanism for their anti-inflammatory activity.

No MeSH data available.


Related in: MedlinePlus

(A) A top-view SEM image of TiO2 nanotubes (Ti/TiO2). (B) Effects of Ti/TiO2 surface vs cpTi on p38, ERK1/2, and JNK activation in the absence or presence of LPS in RAW 264.7 macrophages.Notes: Cells were allowed to adhere on the surfaces for 24 hours and then incubated with 1 µg·mL−1 LPS for specified times. Phosphorylated proteins were detected by the ELISA technique as described in Materials and methods. The data are expressed as mean ± SD. *P<0.05; ***P<0.001.Abbreviations: cpTi, commercial pure titanium; SEM, scanning electron microscope; JNK, c-Jun NH2-terminal kinase; LPS, lipopolysaccharide; ELISA, enzyme-linked immunosorbent assay; MAPK, mitogen-activated protein kinase; ERK, extracellular signal-regulated kinase; SD, standard deviation; vs, versus.
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f1-ijn-10-6455: (A) A top-view SEM image of TiO2 nanotubes (Ti/TiO2). (B) Effects of Ti/TiO2 surface vs cpTi on p38, ERK1/2, and JNK activation in the absence or presence of LPS in RAW 264.7 macrophages.Notes: Cells were allowed to adhere on the surfaces for 24 hours and then incubated with 1 µg·mL−1 LPS for specified times. Phosphorylated proteins were detected by the ELISA technique as described in Materials and methods. The data are expressed as mean ± SD. *P<0.05; ***P<0.001.Abbreviations: cpTi, commercial pure titanium; SEM, scanning electron microscope; JNK, c-Jun NH2-terminal kinase; LPS, lipopolysaccharide; ELISA, enzyme-linked immunosorbent assay; MAPK, mitogen-activated protein kinase; ERK, extracellular signal-regulated kinase; SD, standard deviation; vs, versus.

Mentions: The morphological and chemical characterization of the nanotubular surface used in the present work was previously described.33 Briefly, the morphology of TiO2 nanotubes consists of ~78 nm diameter, ~1 µm length, and ~18 nm tube spacing (the top morphology is shown in Figure 1A). In addition, the nanotubular surface exhibits a higher roughness and hydrophilicity than the flat surface of cpTi, that is, the nanotubular samples have an average roughness of 104.1 nm and CA of 22.6°, while cpTi has an average roughness of 28.1 nm and a less hydrophilic surface with a CA of 75.4°.33


Attenuation of the macrophage inflammatory activity by TiO₂ nanotubes via inhibition of MAPK and NF-κB pathways.

Neacsu P, Mazare A, Schmuki P, Cimpean A - Int J Nanomedicine (2015)

(A) A top-view SEM image of TiO2 nanotubes (Ti/TiO2). (B) Effects of Ti/TiO2 surface vs cpTi on p38, ERK1/2, and JNK activation in the absence or presence of LPS in RAW 264.7 macrophages.Notes: Cells were allowed to adhere on the surfaces for 24 hours and then incubated with 1 µg·mL−1 LPS for specified times. Phosphorylated proteins were detected by the ELISA technique as described in Materials and methods. The data are expressed as mean ± SD. *P<0.05; ***P<0.001.Abbreviations: cpTi, commercial pure titanium; SEM, scanning electron microscope; JNK, c-Jun NH2-terminal kinase; LPS, lipopolysaccharide; ELISA, enzyme-linked immunosorbent assay; MAPK, mitogen-activated protein kinase; ERK, extracellular signal-regulated kinase; SD, standard deviation; vs, versus.
© Copyright Policy
Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC4608594&req=5

f1-ijn-10-6455: (A) A top-view SEM image of TiO2 nanotubes (Ti/TiO2). (B) Effects of Ti/TiO2 surface vs cpTi on p38, ERK1/2, and JNK activation in the absence or presence of LPS in RAW 264.7 macrophages.Notes: Cells were allowed to adhere on the surfaces for 24 hours and then incubated with 1 µg·mL−1 LPS for specified times. Phosphorylated proteins were detected by the ELISA technique as described in Materials and methods. The data are expressed as mean ± SD. *P<0.05; ***P<0.001.Abbreviations: cpTi, commercial pure titanium; SEM, scanning electron microscope; JNK, c-Jun NH2-terminal kinase; LPS, lipopolysaccharide; ELISA, enzyme-linked immunosorbent assay; MAPK, mitogen-activated protein kinase; ERK, extracellular signal-regulated kinase; SD, standard deviation; vs, versus.
Mentions: The morphological and chemical characterization of the nanotubular surface used in the present work was previously described.33 Briefly, the morphology of TiO2 nanotubes consists of ~78 nm diameter, ~1 µm length, and ~18 nm tube spacing (the top morphology is shown in Figure 1A). In addition, the nanotubular surface exhibits a higher roughness and hydrophilicity than the flat surface of cpTi, that is, the nanotubular samples have an average roughness of 104.1 nm and CA of 22.6°, while cpTi has an average roughness of 28.1 nm and a less hydrophilic surface with a CA of 75.4°.33

Bottom Line: Results showed that the Ti/TiO2 significantly reduce the expression levels of the phosphorylated forms of p38, ERK1/2, c-Jun NH2-terminal kinase (JNK), IKKβ, and IkB-α.Furthermore, a significant reduction in the p65 nuclear accumulation on the nanotubular surface was remarked.However, the selective inhibitor for JNK signaling pathway (SP600125) was effective in reducing tumor necrosis factor alpha release as well as monocyte chemotactic protein-1 and nitric oxide production.

View Article: PubMed Central - PubMed

Affiliation: Department of Biochemistry and Molecular Biology, University of Bucharest, Bucharest, Romania.

ABSTRACT
Biomaterial implantation in a living tissue triggers the activation of macrophages in inflammatory events, promoting the transcription of pro-inflammatory mediator genes. The initiation of macrophage inflammatory processes is mainly regulated by signaling proteins of mitogen-activated protein kinase (MAPK) and by nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) pathways. We have previously shown that titania nanotubes modified Ti surfaces (Ti/TiO2) mitigate the immune response, compared with flat Ti surfaces; however, little is known regarding the underlying mechanism. Therefore, the aim of this study is to investigate the mechanism(s) by which this nanotopography attenuates the inflammatory activity of macrophages. Thus, we analyzed the effects of TiO2 nanotubes on the activation of MAPK and NF-κB signaling pathways in standard and lipopolysaccharide-evoked conditions. Results showed that the Ti/TiO2 significantly reduce the expression levels of the phosphorylated forms of p38, ERK1/2, c-Jun NH2-terminal kinase (JNK), IKKβ, and IkB-α. Furthermore, a significant reduction in the p65 nuclear accumulation on the nanotubular surface was remarked. Following, by using specific MAPK inhibitors, we observed that lipopolysaccharide-induced production of monocyte chemotactic protein-1 and nitric oxide was significantly inhibited on the Ti/TiO2 surface via p38 and ERK1/2, but not via JNK. However, the selective inhibitor for JNK signaling pathway (SP600125) was effective in reducing tumor necrosis factor alpha release as well as monocyte chemotactic protein-1 and nitric oxide production. Altogether, these data suggest that titania nanotubes can attenuate the macrophage inflammatory response via suppression of MAPK and NF-κB pathways providing a potential mechanism for their anti-inflammatory activity.

No MeSH data available.


Related in: MedlinePlus