Effects of 2D-Shear Wave Elastography on Brain-Derived Neurotrophic Factor (BDNF) in the Brains of Neonatal Mice and Exploration of the Mechanism

Abstract

Background: The aim of this study was to explore the effect and duration of 2-dimensional shear wave elastography (2D-SWE) irradiation on the expression of brain-derived neurotrophic factor (BDNF) in the brains of neonatal mice and to preliminarily investigate whether its mechanism is neuronal apoptosis. Material/Methods: Neonatal mice (within 48 hours of birth) were subjected to 2D-SWE irradiation of the brain for 10 minutes (group S1), 20 minutes (group S2), and 30 minutes (group S3). The mice were sacrificed immediately after irradiation or 24 hours after irradiation. Brains were collected for real-time polymerase chain reaction (RT-PCR) and western blot experiments to determine the expression of BDNF in each group. TdT-mediated dUTP nickend labeling (TUNEL) was performed to observe neuronal apoptosis in the brain. Results: The results of PCR and western blots from the brains of neonatal mice that were sacrificed immediately after irradiation show that S1, S2, and S3 were significantly different from those in the control group. The PCR and western blot results of brain tissues from neonatal mice sacrificed at 24 hours after irradiation showed that there was no significant difference between the S1, S2, S3, and control groups. The results of TUNEL experiments showed that there was no statistically significant difference in the number of apoptotic neurons between the S1, S2, S3, and control groups. Conclusions: 2D-SWE irradiation of neonatal mice for more than 10 minutes downregulated the expression of BDNF. This effect disappeared within 24 hours after the irradiation, and the 2D-SWE scan seemed not to induce neuronal apoptosis.

Role of Brain Elastography in the Neonatal Setting: State of the Art of Ultrasonographic Techniques and Future Perspectives

“…The authors found that SWE irradiation for more than 10 min temporarily downregulated the expression of BDNF, although such effect disappeared within 24 h after exposure. Moreover, SWE did not significantly affect the number of apoptotic neurons [33]. Taken together, these data support the good safety profile of neonatal brain elastography, with no reported long-term side effects.…”

“…Taken together, these data support the good safety profile of neonatal brain elastography, with no reported long-term side effects. Nevertheless, considering the differences between mice and human neonates in terms of brain volume and skull hardness, studies investigating whether such biologic effects are confirmed in humans are required, and brain elastography should be used cautiously and with minimal exposure time [33].…”