Study type: Medical/biological study (experimental study)

Mammalian Stem Cells Reprogramming in Response to Terahertz Radiation med./bio.

By: Bock J, Fukuyo Y, Kang S, Phipps ML, Alexandrov LB, Rasmussen KO, Bishop AR, Rosen ED, Martinez JS, Chen HT, Rodriguez G, Alexandrov BS, Usheva A
Published in: PLoS One 2010; 5 (12): e15806
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Aim of study (acc. to editor)

To study the effects of extended exposure to a broad-spectrum Terahertz irradiation on cellular functions that are closely related to gene transcription in mouse stem cells.

Background/further details

Additionally, molecular dynamics computer simulations were performed.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 10 THz
Modulation type: pulsed
Exposure duration: continuous for 2, 4, 6 and 9 h

General information

broad-spectrum THz radiation centered at ~10 THz

Exposure 1

Main characteristics
Frequency 10 THz
Type
Exposure duration continuous for 2, 4, 6 and 9 h
Modulation
Modulation type pulsed
Repetition frequency 1 kHz
Additional info

pulse duration: 35 fs
Exposure setup
Exposure source
Setup field directed at the bottom of the parafilm-sealed culture dish; irradiated and control dishes in thermal contact
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
power 30 MW peak value - - per pulse
power density 1 mW/cm² average over time - - broadband

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

Lipid droplet-like inclusions appeared in the cellular cytoplasm after 6 hours of exposure. Extended exposure (9 h) resulted in specific changes in cellular functions that are closely related to gene transcription. The biochip data showed that whereas 89% of the genes in mouse stem cells did not respond to the applied terahertz exposure, certain genes are activated (approx. 6% of the genes, upregulation more than two times), while other are repressed (approx. 5% of the genes, downregulation more than two times). RT-PCR experiments with selected gene probes corresponding to transcripts in the three groups of genes (i.e. of upregulated, downregulated genes and unchanged regulation) confirmed the gene specific effect. The response was not only gene specific but also exposure conditions (i.e. exposure duration) dependent.
The findings suggest that the applied terahertz irradiation accelerates cell differentiation toward adipose phenotype by activating the transcription factor peroxisome proliferator-activated receptor gamma (PPARG). Finally, the molecular dynamics computer simulations indicate that the local breathing dynamics of the PPARG promoter DNA coincides with the gene specific response to the terahertz irradiation.
The authors propose that terahertz exposure is a potential tool for cellular reprogramming.

Study character:

Study funded by

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