Exposure to static magnetic fields increases insulin secretion in rat INS-1 cells by activating the transcription of the insulin gene and up-regulating the expression of vesicle-secreted proteins

Abstract

Purpose: To evaluate the effect of static magnetic fields (SMFs) on insulin secretion and explore the mechanisms underlying exposure to SMF-induced insulin secretion in rat insulinoma INS-1 cells.

Materials and methods: INS-1 cells were exposed to a 400 mT SMF for 72 h, and the proliferation of INS-1 cells was detected by (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The secretion of insulin was measured with an enzyme linked immunosorbent assays (ELISA), the expression of genes was detected by real-time PCR, and the expression of proteins was measured by Western blotting.

Results: Exposure to an SMF increased the expression and secretion of insulin by INS-1 cells but did not affect cell proliferation. Moreover, SMF exposure up-regulated the expression of several pancreas-specific transcriptional factors. Specifically, the activity of the rat insulin promoter was enhanced in INS-1 cells exposed to an SMF, and the expression levels of synaptosomal-associated protein 25 (SNAP-25) and syntaxin-1A were up-regulated after exposure to an SMF.

Conclusions: SMF exposure can promote insulin secretion in rat INS-1 cells by activating the transcription of the insulin gene and up-regulating the expression of vesicle-secreted proteins.

Keywords:

• Static magnetic fields
• transcriptional factors
• insulin secretion
• diabetes
• SNAP-25
• syntaxin-1A

Acknowledgements

Thanks to SINO-GERMAN LIDE BIOLOGICAL TECHNOLOGY CO., LTD for providing technical support. This work was financially supported by the National Natural Science Foundation of China (Nos. 31171303, 31401170 and 31270837).

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes on contributors

Libin Mao, MB, is a postgraduate student, College of Biotechnology, University of Science and Technology, Tianjin, China.

Huiqin Wang, MB, is a postgraduate student, College of Biotechnology, University of Science and Technology, Tianjin, China.

Fenghui Ma, BS, is a postgraduate student, College of Biotechnology, University of Science and Technology, Tianjin, China.

Zhixia Guo, BS, is a postgraduate student, College of Biotechnology, University of Science and Technology, Tianjin, China.

Hongpeng He, PhD, is an associated professor, College of Biotechnology, University of Science and Technology, Tianjin, China.

Hao Zhou, ME, is an assistant engineer, College of Biotechnology, University of Science and Technology, Tianjin, China.

Nan Wang, PhD, is a professor, College of Biotechnology, University of Science and Technology, Tianjin, China.