Medical/biological study (experimental study)

Low frequency pulsed electromagnetic field affects proliferation, tissue-specific gene expression, and cytokines release of human tendon cells med./bio.

By: de Girolamo L, Stanco D, Galliera E, Vigano M, Colombini A, Setti S, Vianello E, Corsi Romanelli MM, Sansone V

Published in: Cell Biochem Biophys 2013; 66 (3): 697-708

Aim of study (acc. to author)

To examine the in vitro effects of low frequency pulsed electromagnetic fields on primary human tendon cells.

Background/further details

Tendon samples were obtained from 8 patients. The explants were exposed for 4, 8 or 12 hours and investigated 0, 1, 2, 7 or 10 hours (see "methods") after the exposure.

Endpoint

molecular biosynthesis: gene expression, cytokine release
cell viability/cell division/proliferation: cell viability, proliferation, apoptosis

Exposure

- 75 Hz
- magnetic field
- low frequency
- signals/pulses

Exposure	Parameters
Exposure 1: 75 Hz Exposure duration: continuous for 4, 8 or 12 hours	magnetic flux density: 1.5 mT peak value (+/- 0.2 mT)

Exposure 1

Main characteristics

Frequency	75 Hz
Type	magnetic field
Waveform	pulsed
Exposure duration	continuous for 4, 8 or 12 hours
Additional info	pulse duration: 1.3 ms; duty cycle 0.1

Exposure setup

Exposure source	coil(s)
Chamber	plates with 24 or 96 wells or culture flask
Setup	pair of rectangular horizontal coils (18 x 13 cm), each made of 1000 turns of copper wire, placed opposite to each other; 24-well plates or culture flask were placed between the pair of coils, plane of coils was parallel to culture layer; exposure device placed in 5 % CO₂ and 37 °C incubator
Sham exposure	A sham exposure was conducted.

Parameters

Measurand	Value	Type	Method	Mass	Remarks
magnetic flux density	1.5 mT	peak value	measured	-	+/- 0.2 mT

Additional parameter details

induced electric voltage 2 V/m +/- 0,5 V/m

Reference articles

Ongaro A et al. (2012): Electromagnetic fields (EMFs) and adenosine receptors modulate prostaglandin E(2) and cytokine release in human osteoarthritic synovial fibroblasts
Ongaro A et al. (2011): Chondroprotective effects of pulsed electromagnetic fields on human cartilage explants
Varani K et al. (2008): Characterization of adenosine receptors in bovine chondrocytes and fibroblast-like synoviocytes exposed to low frequency low energy pulsed electromagnetic fields
De Mattei M et al. (2003): Effects of electromagnetic fields on proteoglycan metabolism of bovine articular cartilage explants

Exposed system:

intact cell/cell culture
tendon cells

Methods Endpoint/measurement parameters/methodology

molecular biosynthesis: tendon specific gene expression of SCX, COL1A1 and VEGF-A (0 and 2 days after exposure) (RT-PCR); amount of DNA (fluorescence spectrometry); levels of cytokines (interleukin-1beta (IL-1beta), IL-6, IL-10, tumor necrosis factor-alpha, transforming growth factor-beta, vascular endothelial growth factor-A (VEGF-A)) at 0, 24 and 48 hours after exposure (ELISA)
cell viability/cell division/proliferation: cell viability (fluorescence microscopy), apoptosis (annexin V-FITC and propidium iodide staining, flow cytometry), cell viability and proliferation (0, 2, 7 and 10 days after exposure) (MTT assay, spectrophotometry)

Investigated system:

isolated bio./chem. substance
DNA/RNA
intact cell/cell culture
cell culture medium

Time of investigation:

before exposure
after exposure

Main outcome of study (acc. to author)

No significant differences in cell viability between PEMF-exposed and control cell cultures were observed. Immediately after the exposure, the content of DNA in the 8 hours-exposed group was significantly increased when compared to the control group. After one day, the release of IL-1beta was significantly increased after 12 hours-exposure in comparison to the control, while the release of IL-6 and IL-10 was significantly increased after 8 and 12 hours-exposure. Immediately after 8 and 12 hours-exposure, the release of transforming growth factor-beta and vascular endothelial growth factor-A, as well as the expression of the corresponding gene VEGF-A, was significantly increased.
The data indicate that low frequency pulsed electromagnetic fields are not cytotoxic and could influence the proliferation (not statistically significant), the release of cytokines and alter gene expression in tendon cells.

Study character:

medical/biological study
experimental study
full/main study

Study funded by

IGEA, Carpi, Italy
Ministero della Salute (Ministry of Health), Italy

D'Angelo C et al. (2015): Experimental model for ELF-EMF exposure: Concern for human health
Esposito M et al. (2013): Differentiation of Human Umbilical Cord-derived Mesenchymal Stem Cells, WJ-MSCs, into Chondrogenic Cells in the Presence of Pulsed Electromagnetic Fields
Ongaro A et al. (2012): Electromagnetic fields (EMFs) and adenosine receptors modulate prostaglandin E(2) and cytokine release in human osteoarthritic synovial fibroblasts
Gomez-Ochoa I et al. (2011): Pulsed electromagnetic fields decrease proinflammatory cytokine secretion (IL-1beta and TNF-alpha) on human fibroblast-like cell culture
Denaro V et al. (2011): Effect of pulsed electromagnetic fields on human tenocyte cultures from supraspinatus and quadriceps tendons
Ongaro A et al. (2011): Chondroprotective effects of pulsed electromagnetic fields on human cartilage explants
Benazzo F et al. (2008): Effects of biophysical stimulation in patients undergoing arthroscopic reconstruction of anterior cruciate ligament: prospective, randomized and double blind study
Varani K et al. (2008): Characterization of adenosine receptors in bovine chondrocytes and fibroblast-like synoviocytes exposed to low frequency low energy pulsed electromagnetic fields
Owegi R et al. (2006): Localized pulsed magnetic fields for tendonitis therapy
Strauch B et al. (2006): Pulsed Magnetic Field Therapy Increases Tensile Strength in a Rat Achilles' Tendon Repair Model
Robotti E et al. (1999): The effect of pulsed electromagnetic fields on flexor tendon healing in chickens
Greenough CG (1996): The effect of pulsed electromagnetic fields on flexor tendon healing in the rabbit
Guzelsu N et al. (1994): Effect of electromagnetic stimulation with different waveforms on cultured chick tendon fibroblasts
Lin Y et al. (1992): Effects of pulsing electromagnetic fields on the ligament healing in rabbits
Murray JC et al. (1985): Modulation of collagen production in cultured fibroblasts by a low-frequency, pulsed magnetic field
Binder A et al. (1984): Pulsed electromagnetic field therapy of persistent rotator cuff tendinitis. A double-blind controlled assessment