Study type: Medical/biological study (experimental study)

EMF acts on rat bone marrow mesenchymal stem cells to promote differentiation to osteoblasts and to inhibit differentiation to adipocytes. med./bio.

Published in: Bioelectromagnetics 2010; 31 (4): 277-285

Aim of study (acc. to author)

To study the role of sinusoidal electromagnetic fields of 15 Hz (1 mT) on rat mesenchymal stem cell differentiation (adipogenesis and osteogenesis) and thus, to evaluate the possible mechanism of electromagnetic fields in prevention or treatment of osteoporosis.

Background/further details

The bone marrow contains mesenchymal stem cells that exhibit the ability to differentiate into adipocytes and osteoblasts. A reciprocal relationship exists between bone marrow mesenchymal stem cells adipogenesis and osteogenesis. The balance between this osteoblast and adipocyte differentiation is disrupted in various human diseases.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 15 Hz
Exposure duration: continuous for 8 h/day on 3 days
Exposure 2: 15 Hz
Exposure duration: continuous for 15 days or 21 days
Mineralized Bone Matrix Formation
Exposure 3: 15 Hz
Exposure duration: continuous for 21 days
Assessment of Cytoplasmic Lipid Droplet Formation
Exposure 4: 15 Hz
Exposure duration: continuous for 14 days
Immunoblot Analysis

Exposure 1

Main characteristics
Frequency 15 Hz
Type
Waveform
Exposure duration continuous for 8 h/day on 3 days
Additional info Alkaline Phosphatase Activity
Exposure setup
Exposure source
Setup pair of Helmholtz coils with a diameter of 30 cm, positioned 30 cm apart, placed inside an incubator; culture dishes positioned between the coils; EMF uniformity about 90 % in the exposure area
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 1 mT - - - -

Exposure 2

Main characteristics
Frequency 15 Hz
Type
Waveform
Exposure duration continuous for 15 days or 21 days
Additional info Mineralized Bone Matrix Formation
Exposure setup
Exposure source
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 1 mT - - - -

Exposure 3

Main characteristics
Frequency 15 Hz
Type
Waveform
Exposure duration continuous for 21 days
Additional info Assessment of Cytoplasmic Lipid Droplet Formation
Exposure setup
Exposure source
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 1 mT - - - -

Exposure 4

Main characteristics
Frequency 15 Hz
Type
Waveform
Exposure duration continuous for 14 days
Additional info Immunoblot Analysis
Exposure setup
Exposure source
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 1 mT - - - -

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

The data showed that the electromagnetic field promoted osteogenic cell differentiation of the stem cells and concurrently inhibited adipocyte formation. The electromagnetic field increased alkaline phosphatase enzyme activity and mineralized nodule formation, and stimulated osteoblast-specific gene expression of RUNX2, ALP, BMP2, DLX5, and BSP. In contrast, the electromagnetic field exposure decreased adipogenesis and inhibited adipocyte-specific gene expression of adipsin, AP2, and PPARγ2, and also inhibited protein expression of PPARγ2.
These findings suggest that commitment of mesenchymal stem cells into osteogenic or adipogenic lineages is influenced by the electromagnetic field.

Study character:

Study funded by

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