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Toward ELF Magnetic Fields for the Treatment of Cancer
Published in Marko S. Markov, James T. Ryaby, Erik I. Waldorff, Pulsed Electromagnetic Fields for Clinical Applications, 2020
Leonardo Makinistian, Igor Belyaev
Jeong et al. investigated the effect of chronic exposure to ELF-MF (1 mT, 50 Hz, 12 days) on astrocytic differentiation of mesenchymal stem cells (MSCs) from adult bone marrow (BM) [87]. ELF-MF exposure reduced the rate of proliferation and enhanced astrocytic differentiation. The ELF-MF-treated cells showed increased levels of the glial fibrillary acidic protein (GFAP, an astrocyte marker), while those of the early neuronal marker (Nestin) and stemness marker (OCT3/4) were downregulated. The ROS level was significantly elevated by ELF-MF exposure, which strengthens the modulatory role of SIRT1 and SIRT1 downstream molecules (TLE1, HES1, and MASH1) during astrocytic differentiation. After nicotinamide (5 mM) mediated inhibition of SIRT1, levels of TLE1, HES1, and MASH1 were examined; TLE1 was significantly upregulated, and MASH1 was downregulated. These results suggest that ELF-MFs induce astrocytic differentiation through induction of ROS and activation of SIRT1 and SIRT1 downstream molecules.
Mechanobiology in Health and Disease in the Central Nervous System
Published in Jiro Nagatomi, Eno Essien Ebong, Mechanobiology Handbook, 2018
Theresa A. Ulrich, Sanjay Kumar
On the cellular level, the innate physiological response to CNS trauma or disease is related to mechanobiological phenomena in a number of interesting ways. For example, one of the hallmarks of astrocyte activation is increased expression of cytoskeletal intermediate filaments, including glial fibrillary associated protein, vimentin, and nestin, in addition to upregulation of focal adhesion proteins, such as vinculin, talin, and paxillin, and the actin-crosslinking protein alpha-actinin, implying that activated astrocytes should express a highly contractile phenotype [118,119,128]. The increase in tissue volume accompanying astrocyte hypertrophy and hyperplasia increases the stress on surrounding cells, as does secretion of additional ECM proteins, such as collagen IV and laminin [129], which subsequently form a scar of collagenous basement membrane that is thought to be one of the major impediments to axonal regeneration [130]. This local increase in stress can produce positive feedback to initiate further pathological changes, including enhanced expression of endothelin, a potent vasoconstrictor and astrocytic mitogen that is also associated with astrocyte activation in response to a variety of pathologies [116].
Experimental Results on Cellular and Subcellular Systems Exposed to Low-Frequency and Static Magnetic Fields
Published in Ben Greenebaum, Frank Barnes, Biological and Medical Aspects of Electromagnetic Fields, 2018
Myrtill Simkó, Mats-Olof Mattsson
The same stem cells and ELF-MF exposure protocol was recently used in a study where the aim was to find out if MF exposure can induce astrocyte differentiation (Jeong et al. 2017). The stem cells respond differently to different chemical inducers, and by using other media additives, an astrocyte differentiation pathway can be initiated. Cells were exposed for 12 days to the 50 Hz field (1 mT). Compared to controls, MF-exposed cells displayed lower proliferation (−39%) and lower expression levels of the markers nestin and OCT3/4, whereas the levels of the astrocyte-specific intermediate filament protein glial fibrillary acidic protein (GFAP) were strongly increased. Intracellular ROS levels were increased by 76% as a consequence of exposure. The levels of the ROS-dependent sirtuin protein (SIRT1) were increased on both mRNA and protein levels, as well as some SIRT1 downstream proteins (TLE1, HES1, MASH1).
PEG-SH-GNPs-SAPNS@miR-29a delivery system promotes neural regeneration and recovery of motor function after spinal cord injury
Published in Journal of Biomaterials Science, Polymer Edition, 2023
Junming Wan, Hanzhong Liu, Jiachun Li, Yuqing Zeng, Haiyong Ren, Yanqing Hu
At the early stage of spinal cord injury in SD rats, we found that the expression of Nestin mRNA decreased significantly, then increased rapidly to a peak after 1 week and fluctuations later (Figure 1A). The results revealed characteristic of the expression of Nestin protein was similar to Nestin mRNA (Figure 1B). RT-PCR was used to detect the relative expression of miR-29a at different stages of spinal cord injury in rats. At the early stage (1–7 days), the expression of miR-29a decreased rapidly, then increased gradually, and reached the peak at 3 weeks (Figure 1C). The results revealed that the character of the expression of miR-29a and Nestin was accompanied by the inhibition and recovery procedure of spinal cord injury.