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Effect of LLLT on endothelial cells culture.

Góralczyk K, Szymańska J, Łukowicz M, Drela E, Kotzbach R, Dubiel M, Michalska M, Góralczyk B, Zając A, Rość D - Lasers Med Sci (2014)

Bottom Line: Growth factors as vascular endothelial growth factor (VEGF), produced by the endothelial cells, take an essential part in pathological and physiological angiogenesis.Thus, the aim of the study was to investigate the influence of low-level laser therapy (LLLT) on the proliferation of endothelial cells, secretion of VEGF-A and presence of soluble VEGF receptors (sVEGFR-1 and sVEGFR-2) in the medium after in vitro culture.Isolated human umbilical vein endothelial cells (HUVECs) were irradiated using a diode laser at a wavelength of 635 nm and power density of 1,875 mW/cm(2).

View Article: PubMed Central - PubMed

Affiliation: Department of Pathophysiology, Collegium Medicum in Bydgoszcz, The Nicolaus Copernicus University in Toruń (NCU), Ul. M. Skłodowskiej-Curie 9, 85-094, Bydgoszcz, Poland, krzyg@cm.umk.pl.

ABSTRACT
Growth factors as vascular endothelial growth factor (VEGF), produced by the endothelial cells, take an essential part in pathological and physiological angiogenesis. The possibility of angiogenesis modulation by application of laser radiation may contribute to the improvement of its use in this process. Thus, the aim of the study was to investigate the influence of low-level laser therapy (LLLT) on the proliferation of endothelial cells, secretion of VEGF-A and presence of soluble VEGF receptors (sVEGFR-1 and sVEGFR-2) in the medium after in vitro culture. Isolated human umbilical vein endothelial cells (HUVECs) were irradiated using a diode laser at a wavelength of 635 nm and power density of 1,875 mW/cm(2). Depending on radiation energy density, the experiment was conducted in four groups: I 0 J/cm(2) (control group), II 2 J/cm(2), III 4 J/cm(2), and IV 8 J/cm(2). The use of laser radiation wavelength of 635 nm, was associated with a statistically significant increase in proliferation of endothelial cells (p = 0.0041). Moreover, at 635-nm wavelength, all doses of radiation significantly reduced the concentration of sVEGFR-1 (p = 0.0197).

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The hypothesis of the action of VEGF-A and soluble receptors sVEGFR-1 and sVEGFR-2 in the supernatant. a The connection of VEGF-A with VEGFR-2 receptor located on the cell membrane contributes to endothelial cell proliferation. b Competitive VEGF-A binding with soluble forms of receptors sVEGFR-1 and sVEGFR-2 present in the supernatant leads to reducing endothelial proliferation
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Fig5: The hypothesis of the action of VEGF-A and soluble receptors sVEGFR-1 and sVEGFR-2 in the supernatant. a The connection of VEGF-A with VEGFR-2 receptor located on the cell membrane contributes to endothelial cell proliferation. b Competitive VEGF-A binding with soluble forms of receptors sVEGFR-1 and sVEGFR-2 present in the supernatant leads to reducing endothelial proliferation

Mentions: In our study, varied effects of laser radiation on cells and secretion of angiogenic factors may be due to the different levels of photoreceptive interaction. The use of laser radiation in the visible light conditions resulted in the reduction of VEGF-A, sVEGFR-1, and sVEGFR-2 in the supernatant (Figs. 2, 3, and 4) with simultaneous activation of endothelial cell proliferation (Fig. 1). It is known that VEGF action is determined by VEGF binding with its membrane receptors. That causes receptors expenditure during the stimulation of endothelial cell division. In this way, the reduced amount of VEGF-A in the supernatant under the influence of laser radiation may be explained. The lowest VEGF-A concentration at doses 2 and 4 J/cm2 (λ = 635 nm) at simultaneously the highest level of cell proliferation suggests that in these conditions, the most molecules of VEGF-A are connected with receptors that significantly affected the level of EC proliferation. Lower concentrations of sVEGFR-1 and sVEGFR-2 in the supernatant as compared to the control group could contribute to the increase of cells proliferation by the influence of LLLT. Fewer VEGF-A molecules are blocked by soluble forms of receptors, which are regulators of VEGF [10, 11] (Fig. 5). This mechanism is used in cancer therapy, where the binding of VEGF and inhibiting VEGF native receptors suppress the new blood vessels creation, which reduces growth of the solid tumors and metastasis [11, 24]. In vitro studies conducted by Schindl et al. [25] confirmed the increase in HUVEC proliferation as a result of laser radiation at the wavelength range 670 nm and doses of 2, 4, 8 J/cm2.Fig. 5


Effect of LLLT on endothelial cells culture.

Góralczyk K, Szymańska J, Łukowicz M, Drela E, Kotzbach R, Dubiel M, Michalska M, Góralczyk B, Zając A, Rość D - Lasers Med Sci (2014)

The hypothesis of the action of VEGF-A and soluble receptors sVEGFR-1 and sVEGFR-2 in the supernatant. a The connection of VEGF-A with VEGFR-2 receptor located on the cell membrane contributes to endothelial cell proliferation. b Competitive VEGF-A binding with soluble forms of receptors sVEGFR-1 and sVEGFR-2 present in the supernatant leads to reducing endothelial proliferation
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC4289014&req=5

Fig5: The hypothesis of the action of VEGF-A and soluble receptors sVEGFR-1 and sVEGFR-2 in the supernatant. a The connection of VEGF-A with VEGFR-2 receptor located on the cell membrane contributes to endothelial cell proliferation. b Competitive VEGF-A binding with soluble forms of receptors sVEGFR-1 and sVEGFR-2 present in the supernatant leads to reducing endothelial proliferation
Mentions: In our study, varied effects of laser radiation on cells and secretion of angiogenic factors may be due to the different levels of photoreceptive interaction. The use of laser radiation in the visible light conditions resulted in the reduction of VEGF-A, sVEGFR-1, and sVEGFR-2 in the supernatant (Figs. 2, 3, and 4) with simultaneous activation of endothelial cell proliferation (Fig. 1). It is known that VEGF action is determined by VEGF binding with its membrane receptors. That causes receptors expenditure during the stimulation of endothelial cell division. In this way, the reduced amount of VEGF-A in the supernatant under the influence of laser radiation may be explained. The lowest VEGF-A concentration at doses 2 and 4 J/cm2 (λ = 635 nm) at simultaneously the highest level of cell proliferation suggests that in these conditions, the most molecules of VEGF-A are connected with receptors that significantly affected the level of EC proliferation. Lower concentrations of sVEGFR-1 and sVEGFR-2 in the supernatant as compared to the control group could contribute to the increase of cells proliferation by the influence of LLLT. Fewer VEGF-A molecules are blocked by soluble forms of receptors, which are regulators of VEGF [10, 11] (Fig. 5). This mechanism is used in cancer therapy, where the binding of VEGF and inhibiting VEGF native receptors suppress the new blood vessels creation, which reduces growth of the solid tumors and metastasis [11, 24]. In vitro studies conducted by Schindl et al. [25] confirmed the increase in HUVEC proliferation as a result of laser radiation at the wavelength range 670 nm and doses of 2, 4, 8 J/cm2.Fig. 5

Bottom Line: Growth factors as vascular endothelial growth factor (VEGF), produced by the endothelial cells, take an essential part in pathological and physiological angiogenesis.Thus, the aim of the study was to investigate the influence of low-level laser therapy (LLLT) on the proliferation of endothelial cells, secretion of VEGF-A and presence of soluble VEGF receptors (sVEGFR-1 and sVEGFR-2) in the medium after in vitro culture.Isolated human umbilical vein endothelial cells (HUVECs) were irradiated using a diode laser at a wavelength of 635 nm and power density of 1,875 mW/cm(2).

View Article: PubMed Central - PubMed

Affiliation: Department of Pathophysiology, Collegium Medicum in Bydgoszcz, The Nicolaus Copernicus University in Toruń (NCU), Ul. M. Skłodowskiej-Curie 9, 85-094, Bydgoszcz, Poland, krzyg@cm.umk.pl.

ABSTRACT
Growth factors as vascular endothelial growth factor (VEGF), produced by the endothelial cells, take an essential part in pathological and physiological angiogenesis. The possibility of angiogenesis modulation by application of laser radiation may contribute to the improvement of its use in this process. Thus, the aim of the study was to investigate the influence of low-level laser therapy (LLLT) on the proliferation of endothelial cells, secretion of VEGF-A and presence of soluble VEGF receptors (sVEGFR-1 and sVEGFR-2) in the medium after in vitro culture. Isolated human umbilical vein endothelial cells (HUVECs) were irradiated using a diode laser at a wavelength of 635 nm and power density of 1,875 mW/cm(2). Depending on radiation energy density, the experiment was conducted in four groups: I 0 J/cm(2) (control group), II 2 J/cm(2), III 4 J/cm(2), and IV 8 J/cm(2). The use of laser radiation wavelength of 635 nm, was associated with a statistically significant increase in proliferation of endothelial cells (p = 0.0041). Moreover, at 635-nm wavelength, all doses of radiation significantly reduced the concentration of sVEGFR-1 (p = 0.0197).

Show MeSH