Molecular Neurobiology

, Volume 51, Issue 2, pp 558–570

1,25-dyhydroxyvitamin D3 Attenuates l-DOPA-Induced Neurotoxicity in Neural Stem Cells

Article

DOI: 10.1007/s12035-014-8835-1

Cite this article as:
Jang, W., Park, HH., Lee, KY. et al. Mol Neurobiol (2015) 51: 558. doi:10.1007/s12035-014-8835-1

Abstract

The neurotoxicity of levodopa (l-DOPA) on neural stem cells (NSCs) and treatment strategies to protect NSCs from this neurotoxicity remain to be elucidated. Recently, an active form of vitamin D3 has been reported to display neuroprotective properties. Therefore, we investigated the protective effect of 1,25-dyhydroxyvitamin D3 (calcitriol) on l-DOPA-induced NSC injury. We measured cell viability via the cell counting kit-8 (CCK-8) and lactate dehydrogenase (LDH) assays and Annexin V/PI staining followed by flow cytometry, cell proliferation using the BrdU and colony-forming unit (CFU) assays, cell differentiation via immunocytochemistry, the levels of free radicals via 2′,7′-dichlorodihydrofluorescein diacetate (DCFH-DA) staining, apoptosis via DAPI and TUNEL staining, and intracellular signaling protein expression via Western blot. Antibody microarrays were also employed to detect changes in the expression of prosurvival- and death-related proteins. Treatment of NSCs with l-DOPA reduced their viability and proliferation. This treatment also increased the levels of free radicals and decreased the expression levels of intracellular signaling proteins that are associated with cell survival. However, simultaneous exposure to calcitriol significantly reduced these effects. The calcitriol-mediated protection against l-DOPA toxicity was blocked by the phosphoinositide 3-kinase (PI3K) inhibitor LY294004. l-DOPA also inhibited the expression of Nestin and Ki-67, and co-treatment with calcitriol alleviated these effects. The expression levels of GFAP, DCX, and Tuj1 were not significantly affected by treatment with l-DOPA or calcitriol. Calcitriol protects against l-DOPA-induced NSC injury by promoting prosurvival signaling, including activation of the PI3K pathway, and reducing oxidative stress.

Keywords

l-DOPA Neural stem cells 1,25-dyhydroxyvitamin D3 Neuroprotection 

Supplementary material

12035_2014_8835_MOESM1_ESM.pdf (85 kb)
Supplementary Fig. 1The effect of calcitriol on the proliferation of NSCs. The BrdU assays revealed that treatment with high-dose calcitriol (100 μM) reduces NSC proliferation. *p < 0.05. (PDF 85 kb)
12035_2014_8835_MOESM2_ESM.pdf (359 kb)
Supplementary Fig. 2Immunostaining of NSC proliferation and the expression of neuronal markers in NSCs exposed to various concentrations of calcitriol. Treatment with calcitriol at concentrations greater than 10 μM decreased the expression of Nestin and Ki-67 but displayed no effect on that of DAPI or Tuj-1. *p < 0.05 and **p < 0.01 (compared to the control group). (PDF 359 kb)
12035_2014_8835_MOESM3_ESM.pdf (192 kb)
Supplementary Fig. 3The levels of TH and AADC activity in NSCs after exposure to 200 μM l-DOPA for 48 hr and different concentrations of calcitriol. There was no significant difference in the TH and AADC activity levels between the control, l-DOPA alone, and l-DOPA and various concentrations of calcitriol groups. (PDF 191 kb)

Copyright information

© Springer Science+Business Media New York 2014

Authors and Affiliations

  1. 1.Department of NeurologyHanyang University College of MedicineSeoulSouth Korea
  2. 2.Department of Neurology, Gangneung Asan Hospital, College of MedicineUniversity of UlsanGangneungSouth Korea
  3. 3.Department of Translational MedicineHanyang University Graduate School of Biomedical Science and EngineeringSeoulRepublic of Korea
  4. 4.Department of NeurologyHanyang University College of MedicineGuri-siSouth Korea
  5. 5.Department of NeurologyHanyang University College of MedicineSeoulSouth Korea