Dual Specificity Phosphatase 6 Protects Neural Stem Cells from β-Amyloid-Induced Cytotoxicity through ERK1/2 Inactivation

Abstract

Alzheimer’s disease (AD) is a devastating neurodegenerative disease with limited treatment options and no cure. Beta-amyloid (Aβ) is a hallmark of AD that has potent neurotoxicity in neural stem cells (NSCs). Dual specificity phosphatase 6 (DUSP6) is a member of the mitogen-activated protein kinases (MAPKs), which is involved in regulating various physiological and pathological processes. Whether DUSP6 has a protective effect on Aβ-induced NSC injury remains to be explored. C17.2 neural stem cells were transfected with DUSP6-overexpressed plasmid. NSCs with or without DUSP6 overexpression were administrated with Aβ25–35 at various concentrations (i.e., 0, 2.5, 5 μM). DUSP6 expression after Aβ treatment was detected by Real-Time Polymerase Chain Reaction (RT-PCR) and Western blot and cell vitality was examined by the CCK8 assay. The oxidative stress (intracellular reactive oxygen species (ROS) and malondialdehyde (MDA)), endoplasmic reticulum stress (ER calcium level) and mitochondrial dysfunction (cytochrome c homeostasis) were tested. The expression of p-ERK1/2 and ERK1/2 were assayed by Western blot. Our results showed that Aβ decreased the expression of DUSP6 in a dose-dependent manner. The overexpression of DUSP6 increased the cell vitality of NSCs after Aβ treatment. Oxidative stress, ER stress, and mitochondrial dysfunction induced by Aβ could be restored by DUSP6 overexpression. Additionally, the Aβ-induced ERK1/2 activation was reversed. In summary, DUSP6 might have a neuroprotective effect on Aβ-induced cytotoxicity, probably via ERK1/2 activation.

Melatonin ameliorates endoplasmic reticulum stress in N2a neuroblastoma cell hypoxia-reoxygenation injury by activating the AMPK-Pak2 pathway

“…After exposure to stress conditions, such as hypoxia, inflammation, and irradiation, ER stress is activated, evidenced by the accumulation of unfolded/misfolded proteins, cytoplasmic calcium overload, and ROS outburst (Kim et al 2018;Yang et al 2019). At the molecular level, there are three signaling branches of the ER stress pathway, and they are transcription factor-6 (ATF-6), inositol requiring enzyme 1 (IRE1), and PERK (Liao et al 2018;Shah et al 2019). In the present study, we found that PAMPK was significantly increased in response to HR injury and was inhibited by melatonin.…”

Curcumin Protects Human Umbilical Vein Endothelial Cells against H2O2-Induced Cell Injury

“…The effects of curcumin and H 2 O 2 on HUVECs viability were detected by the CCK-8 assay. In brief, cells were cultured on a 96-well plate at a density of 1 × 10 4 per well for 24 h and then administrated with curcumin (0 μ M, 10 μ M, 20 μ M, 30 μ M, 40 μ M, and 50 μ M) for 12 h or with H 2 O 2 (0 μ M, 25 μ M, 50 μ M, 75 μ M, 100 μ M) for another 12 h. Then, the HUVECs were incubated at 37°C for 2 h. Thereafter, a multifunctional microplate reader (SpectraMax M5, Sunnyvale, CA, USA) was adopted to read the absorbance values at 450 nm [16].…”

Dual-Specificity Phosphatase Regulation in Neurons and Glial Cells

“…Indeed, when miR-125b is overexpressed in hippocampal neurons or directly injected into a mouse hippocampus, it reproduces several hallmarks of AD, such as tau hyperphosphorylation, sustained ERK activation, and DUSP6 decrease [101]. The potential neuroprotective role of DUSP6 in AD is suggested by the results obtained in the C17.2 neural stem cell line, in which DUSP6 overexpression protects against amyloid peptide fragment (Ab 31–35) toxicity and restores normal ERK signaling [102].…”