[Effect of 1.8 GHz radiofrequency electromagnetic fields on gene expression of rat neurons].

Zhonghua lao dong wei sheng zhi ye bing za zhi = Zhonghua laodong weisheng zhiyebing zazhi = Chinese journal of industrial hygiene and occupational diseases · 2008 · Mixed · Low evidence

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MixedLow evidencePaper 2781

Study snapshot

PublicationZhonghua lao dong wei sheng zhi ye bing za zhi = Zhonghua laodong weisheng zhiyebing zazhi = Chinese journal of industrial hygiene and occupational diseases · 2008

Study typein_vitro

Reported directionMixed

Evidence ratingLow

Abstract

OBJECTIVE: To investigate the changes of gene expression in rat neuron induced by 1.8 GHz radiofrequency electromagnetic fields (RF EMF) to screen for RF EMF-responsive genes and the effect of different exposure times and modes on the gene expression in neuron. METHODS: Total RNA was extracted immediately and purified from the primary culture of neurons after intermittent exposed or sham-exposed to a frequency of 1.8 GHz RF EMF for 24 hours at an average special absorption rate (SAR) of 2 W/kg. Affymetrix Rat Neurobiology U34 array was applied to investigate the changes of gene expression in rat neuron. Differentially expressed genes (Egr-1, Mbp and Plp) were further confirmed by semi-quantitative revere transcription polymerase chain reaction (RT PCR). The expression levels of Egr-1, Mbp and Plp were observed at different exposure times (6, 24 h) and modes (intermittent and continuous exposure). RESULTS: Among 1200 candidate genes, 24 up-regulated and 10 down-regulated genes were found by using Affymetrix microarray suite software 5.0 which are associated with multiple cellular functions (cytoskeleton, signal transduction pathway, metabolism, etc.) after functional classification. Under 24 h and 6 h intermittent exposure, Egr-1 and Plp in experiment groups showed statistic significance (P < 0.05) compared with the control groups, while expression of Mbp did not change significantly (P > 0.05). After 24 h continuous exposure, Egr-1 and Mbp in experiment groups showed statistic significance (P < 0.05) compared with the control group, while expression of Plp did not change significantly (P > 0.05). Under the same exposure mode 6 h, expression of all the 3 genes did not change significantly. Different times (6, 24 h) and modes (intermittent and continuous exposure) of exposure exerted remarkable different influences on the expression of Egr-1, Mbp, Plp genes (P < 0.01). CONCLUSION: The changes of many genes transcription were involved in the effect of 1.8 GHz RF EMF on rat neurons; Down-regulation of Egr-1 and up-regulation of Mbp, Plp indicated the negative effects of RF EMF on neurons; The effect of RF intermittent exposure on gene expression was more obvious than that of continuous exposure; The effect of 24 h RF exposure (both intermittent and continuous) on gene expression was more obvious than that of 6 h (both intermittent and continuous).

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AI evidence extraction

Structured fields below were generated from the paper’s abstract and metadata to make the evidence easier to inspect. Automated extraction may be incomplete or incorrect; verify important details against the original paper.

Study typein_vitro

Effect directionmixed

PopulationPrimary culture of rat neurons

Sample sizeNot supplied

ExposureRF · 1800 MHz · 2 W/kg · 6 h and 24 h (intermittent or continuous)

Evidence strengthLowConfidence: 74% · Peer reviewed: yes

Main findings

After intermittent exposure to 1.8 GHz RF-EMF for 24 h at SAR 2 W/kg, microarray analysis identified 24 up-regulated and 10 down-regulated genes among 1200 candidates. RT-PCR confirmation indicated that gene expression changes depended on exposure time and mode: under 24 h and 6 h intermittent exposure, Egr-1 and Plp differed significantly vs controls while Mbp did not; after 24 h continuous exposure, Egr-1 and Mbp differed significantly while Plp did not; at 6 h under the same exposure mode, none of the three genes changed significantly. The authors conclude Egr-1 was down-regulated and Mbp/Plp up-regulated and that intermittent and 24 h exposures produced more evident effects than continuous and 6 h exposures.

Outcomes measured

Gene expression changes (microarray)
Expression of Egr-1, Mbp, Plp (RT-PCR confirmation)

Limitations

In vitro primary neuron culture; may not generalize to in vivo effects
Sample size not reported in abstract
Only three genes were confirmed by semi-quantitative RT-PCR
Exposure source/setup details not described beyond frequency, SAR, and intermittent/continuous modes

View raw extracted JSON

{
  "study_type": "in_vitro",
  "exposure": {
    "band": "RF",
    "source": null,
    "frequency_mhz": 1800,
    "sar_wkg": 2,
    "duration": "6 h and 24 h (intermittent or continuous)"
  },
  "population": "Primary culture of rat neurons",
  "sample_size": null,
  "outcomes": [
    "Gene expression changes (microarray)",
    "Expression of Egr-1, Mbp, Plp (RT-PCR confirmation)"
  ],
  "main_findings": "After intermittent exposure to 1.8 GHz RF-EMF for 24 h at SAR 2 W/kg, microarray analysis identified 24 up-regulated and 10 down-regulated genes among 1200 candidates. RT-PCR confirmation indicated that gene expression changes depended on exposure time and mode: under 24 h and 6 h intermittent exposure, Egr-1 and Plp differed significantly vs controls while Mbp did not; after 24 h continuous exposure, Egr-1 and Mbp differed significantly while Plp did not; at 6 h under the same exposure mode, none of the three genes changed significantly. The authors conclude Egr-1 was down-regulated and Mbp/Plp up-regulated and that intermittent and 24 h exposures produced more evident effects than continuous and 6 h exposures.",
  "effect_direction": "mixed",
  "limitations": [
    "In vitro primary neuron culture; may not generalize to in vivo effects",
    "Sample size not reported in abstract",
    "Only three genes were confirmed by semi-quantitative RT-PCR",
    "Exposure source/setup details not described beyond frequency, SAR, and intermittent/continuous modes"
  ],
  "evidence_strength": "low",
  "confidence": 0.74,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "1.8 GHz",
    "radiofrequency electromagnetic fields",
    "RF EMF",
    "SAR 2 W/kg",
    "rat neurons",
    "primary culture",
    "microarray",
    "Affymetrix Rat Neurobiology U34",
    "gene expression",
    "Egr-1",
    "Mbp",
    "Plp",
    "intermittent exposure",
    "continuous exposure"
  ],
  "suggested_hubs": []
}

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AI-extracted fields are generated from the abstract and metadata and may be incomplete or incorrect. This material is for informational purposes and is not medical advice.

Identifiers and source

DOI: Not supplied
PubMed: 19358751

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