Bisperoxovandium (pyridin-2-squaramide) targets both PTEN and ERK1/2 to confer neuroprotection

BACKGROUND AND PURPOSE We and others have shown that inhibiting phosphatase and tensin homolog deleted on chromosome 10 (PTEN) or activating ERK1/ 2 confer neuroprotection. As bisperoxovanadium compounds are well-established inhibitors of PTEN, we designed bisperoxovandium (pyridin-2-squaramide) [ bpV(pis)] and determined whether and how bpV(pis) exerts a neuroprotective effect in cerebral ischaemia-reperfusion injury. EXPERIMENTAL APPROACH Malachite green-based phosphatase assay was used to measure PTEN activity. A western blot assay was used to measure the phosphorylation level of Akt and ERK1/ 2 (p-Akt and p-ERK1/ 2). Oxygen-glucose deprivation (OGD) was used to injure cultured cortical neurons. Cell death and viability were assessed by LDH and MTT assays. To verify the effects of bpV(pis) in vivo, Sprague-Dawley rats were subjected to middle cerebral artery occlusion, and brain infarct volume was measured and neurological function tests performed. KEY RESULTS bpV(pis) inhibited PTEN activity and increased p-Akt in SH-SY5Y cells but not in PTEN-deleted U251 cells. bpV(pis) also elevated p-ERK1/ 2 in both SH-SY5Y and U251 cells. These data indicate that bpV(pis) enhances Akt activation through PTEN inhibition but increases ERK1/ 2 activation independently of PTEN signalling. bpV(pis) prevented OGD-induced neuronal death in vitro and reduced brain infarct volume and promoted functional recovery in stroke animals. This neuroprotective effect of bpV(pis) was blocked by inhibiting Akt and/ or ERK1/ 2. CONCLUSIONS AND IMPLICATIONS bpV(pis) confers neuroprotection in OGD-induced injury in vitro and in cerebral ischaemia in vivo by suppressing PTEN and activating ERK1/ 2. Thus, bpV(pis) is a bi-target neuroprotectant that may be developed as a drug candidate for stroke treatment.