Upregulation of postsynaptic cAMP/PKA/CREB signaling alleviates copper(Ⅱ)-induced oxidative stress and pyroptosis in MN9D cells

• DOI: 10.1016/j.tox.2023.153582
• Publication Date: 2023-06-22T01:46:19Z
• Authors: Qian Zhou; Ying Zhang; Lu Lu; Wei Shi; Hu Zhang; Weizhuo Qin; Yucheng Wang; Yuepu Pu; Lihong Yin
• Keywords: Mice; Oxidative Stress; Kelch-Like ECH-Associated Protein 1; Inflammasomes; NF-E2-Related Factor 2; Dopaminergic Neurons; Pyroptosis; Animals; Cyclic AMP Response Element-Binding Protein; Copper; 3. Good health; Up-Regulation; Signal Transduction

It has been widely reported that long-term exposure to copper increases the prevalence and mortality of Parkinson's disease. Our previous study showed that CuSO4 exposure induced a significant increase in the expression of cleaved Caspase1 proteins and the loss of dopaminergic neurons in the SNpc of mice. In this study, the effects of copper(Ⅱ) on cAMP/PKA/CREB pathway and pyroptosis-related proteins in MN9D cells were investigated by setting up copper(Ⅱ) exposure groups with different concentration gradients, to provide possible molecular evidence for studying the mechanism of copper(Ⅱ)-induced degeneration of dopaminergic neurons. We found that after 48 h of copper(Ⅱ) exposure, the cu content in MN9D cells increased in a dose-dependent manner, and the proliferation activity decreased significantly. In addition, copper(Ⅱ) exposure caused up-regulation of PDE4D and down-regulation of D1R, cAMP, PKA and p-CREB/CREB. Simultaneously, we proved that copper(Ⅱ) exposure induced oxidative stress in MN9D cells, including decreased GSH-Px content, Keap1 expression and mitochondrial membrane potential, increased malondialdehyde content, ROS intensity, and Nrf2, NQO1, HO-1, HSP-70 expression, further causing up-regulation of inflammasome and GSDMD protein. After pretreatment with Roflupram, the level of copper(Ⅱ)-induced oxidative damage decreased, the expression of inflammasome and GSDMD proteins were down-regulated. However, the protective effects of ROF were blocked by H-89. In summary, copper(Ⅱ) treatment induced oxidative stress and inflammasome-mediated pyroptosis in MN9D cells, which may be related to copper(Ⅱ)-induced postsynaptic cAMP, PKA, and CREB signal transduction disorders.