Medical/biological study (experimental study)

Effects of 50 Hz sinusoidal magnetic fields on Hsp27, Hsp70, Hsp90 expression in porcine aortic endothelial cells (PAEC) med./bio.

By: Bernardini C, Zannoni A, Turba ME, Bacci ML, Forni M, Mesirca P, Remondini D, Castellani G, Bersani F

Published in: Bioelectromagnetics 2007; 28 (3): 231-237

Aim of study (acc. to author)

To study the influence of 50 Hz sinusoidal magnetic field on Hsp27, Hsp70, and Hsp90 expression in a model of primary culture of porcine aortic endothelial cells.

Background/further details

Endothelial cells are involved in the onset of many diseases.

Endpoint

molecular biosynthesis: gene expression of Hsp27, Hsp70, and Hsp90

Exposure

- 50/60 Hz
- magnetic field

Exposure	Parameters
Exposure 1: 50 Hz Exposure duration: continuous for 4 h	magnetic flux density: 1 mT effective value

Exposure 1

Main characteristics

Frequency	50 Hz
Type	magnetic field
Waveform	sinusoidal
Exposure duration	continuous for 4 h

Exposure setup

Exposure source	coils were wound by a pair of parallel wires, outer coils 42 turns and inner coils 37 turns
Chamber	Both sham and exposure coil systems were placed in the same incubator. A µ-metal foil was placed between the two systems resulting in 30% reduction of the magnetic field.
Setup	Four coaxial coils placed horizontally and thus parallel with respect to the surface of the culture well plates. The diameter of the external coils (top and bottom) was 18 cm, while that of the internal ones was 20 cm. The geometry of the coil system was calculated to optimize the extension of the magnetic field uniformity. the distances between the external and internal coils from the center of the symmetry were 9 and 3 cm, respectively. According to these conditions the uniformity was better than 2% within a cylindrical region of ca. 11 cm (along the coil axis) x 9 cm, thus allowing simultaneous exposure of 6 culture well plates.
Sham exposure	A sham exposure was conducted.
Additional info	Sham field conditions (5 µT) were achieved by configuring the coils in counter wound arrangement to cancel each others magnetic field.

Parameters

Measurand	Value	Type	Method	Mass	Remarks
magnetic flux density	1 mT	effective value	measured	-	-

Measurement and calculation details

The magnetic field was measured with a Hall probe Gaussmeter.

Exposed system:

intact cell/cell culture
porcine aortic endothelial cells

Methods Endpoint/measurement parameters/methodology

molecular biosynthesis: gene expression of Hsp27, Hsp70, and Hsp90 (mRNA expression, protein expression, protein localization inside the cells; RT-PCR quantification; Western blot; immunofluorescence staining )

Investigated system:

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

Time of investigation:

after exposure

Main outcome of study (acc. to author)

Extremely low frequency magnetic field exposure induced an increase in the mRNA levels of the three proteins, which was statistically significant for Hsp70. On the contrary, no influence on Hsp27, Hsp70, and Hsp90 protein levels was observed. The magnetic field exposure affected the cellular distribution of Hsp27; in particular a partial relocalization in the nucleus was found.

Study character:

medical/biological study
experimental study
full/main study

Study funded by

Fondazione del Monte di Bologna e Ravenna, Italy
Istituto Superiore per la Prevenzione e la Sicurezza del Lavoro (ISPESL; National Institute for Occupational Safety and Prevention), Italy
Ministero dell' Università e della Ricerca (MIUR (formerly MURST (Ministero dell' Università e della Ricerca Scientifica e Tecnologica); Ministry of University and Research), Italy

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