CKIP-1 alleviates oxygen-glucose deprivation/reoxygenation-induced apoptosis and oxidative stress in cultured hippocampal neurons by downregulating Keap1 and activating Nrf2/ARE signaling.

Accumulating evidence has shown that casein kinase 2 interacting protein-1 (CKIP-1) is a pivotal regulator of apoptosis and oxidative stress. However, whether CKIP-1 is involved in regulating neuronal injury during the progression of cerebral ischemia/reperfusion injury remains unknown. In the present study, we aimed to investigate the potential role and underlying mechanism of CKIP-1 in regulating neuronal apoptosis and oxidative stress induced by oxygen-glucose deprivation/reoxygenation (OGD/R) treatment in vitro. Herein, we found that OGD/R treatment resulted in a significant increase in CKIP-1 expression in cultured hippocampal neurons. The silencing of CKIP-1 exacerbated OGD/R-induced neuronal apoptosis and production of reactive oxygen species. By contrast, CKIP-1 overexpression reduced the apoptosis and reactive oxygen species production induced by the OGD/R treatment. Mechanistically, CKIP-1 inhibited the expression of Kelch-like ECH-associated protein 1 (Keap1) and promoted the expression of nuclear factor E2-related factor 2 (Nrf2). In addition, CKIP-1 increased the activation of antioxidant response element and the expression of downstream antioxidant genes. However, Keap1 overexpression or Nrf2 knockdown partially reversed the neuroprotective effect of CKIP-1 overexpression. Taken together, our results demonstrate that CKIP-1 overexpression alleviates OGD/R-induced neuronal injury by enhancing the Nrf2-mediated anti-oxidative stress signaling pathway, revealing a neuroprotective role of CKIP-1. Our study suggests CKIP-1 as a potential therapeutic target for neuroprotection.