Objective: Non-ionizing radiofrequency radiation, which finds application in various sectors such as industry, commerce, medicine, and particularly in mobile phone technology, has emerged as a topic of significant concern during pregnancy. The aim of this study was to investigate the effect of cell phone radio-frequency (RF) radiation during pregnancy on the Matrix metalloproteinase 2 (MMP-2) and (MMP-9) 9 expressions after neonatal hypoxia-ischemia (HI) in rats.

Materials and methods: Two groups were formed by randomly assigning female Wistar rats: Group 1 consisted of female rats that were not exposed to RF radiation during pregnancy, while Group 2 comprised female rats that were exposed to RF radiation during pregnancy. After delivery, male offspring were divided into four groups including: (a) SHAM, (b) Exposure (EXP), (c) hypoxia-ischemia (HI), (d) HI/Exposure (HI/EXP). Seven days after HI induction, neurobehavioral tests were performed, and then brain tissue was taken from the skull to measure MMP-2 and MMP-9 expressions, inflammation, oxidative stress, infarct volume and cerebral edema.

Results: MMP-9 mRNA expression in the HI/EXP group was significantly higher than the HI, SHAM and EXP groups. MMP-2 mRNA expression levels in the HI group were significantly higher than Sham and the EXP groups.

TNF-α and Total oxidant capacity (TOC) levels in the HI/EXP group were significantly higher than HI, EXP and SHAM groups. Total antioxidant capacity (TAC) level in the HI/EXP group were significantly lower than HI, EXP and SHAM groups. Cerebral edema and infarct volume in the HI/EXP group were significantly greater than the HI group. Sensory-motor function was significantly weaker in HI/EXP as compared HI group.

Conclusion: Our findings indicate that during pregnancy, exposure to mobile phone RF radiation intensifies damage from HI in rat pups by elevating MMP-9 activity.

Excerpts 

In line with our study, Azimipour et. al (2020) showed Exposure to cell phone radiation affects the growth and maturation rate of murine ovarian follicles by altering the expression of MMP-2 and MMP-9 genes [12]. In another study, Friedman et. al. (2007) discovered that mobile phone electromagnetic irradiation triggers the activation of plasma membrane NADH oxidase, which leads to the generation of reactive oxygen species (ROS) [13]. These ROS, in turn, directly stimulate the activity of matrix metalloproteinases (MMPs) [13]. In addition, the results of our study showed that exposure to mobile phone RF radiation during pregnancy increases the level of inflammation and oxidative stress, brain edema and the volume of the infarcted area, which leads to the aggravation of brain damage after neonatal HI. In our study, the greater increase in inflammation in the group exposed to mobile phone RF radiation could be due to the greater increase in MMP9 expression.

Overall, increased MMP9 levels during neonatal HI lead to BBB disruption and immune cell infiltration, resulting in increased production of ROS and pro-inflammatory cytokines [9], [25]. This cascade of events ultimately leads to enhanced oxidative stress within the brain.

Khayat S, Fanaei H, Lakzaee N. Effects of prenatal mobile phone radiation exposure on MMP9 expression: Implications for inflammation, oxidative stress, and sensory-motor impairment after neonatal hypoxia- ischemia in rats. Toxicol Rep. 2023 Oct 13;11:378-384