PTEN (phosphatase and tensin homologue deleted on chromosome 10) is a

PTEN (phosphatase and tensin homologue deleted on chromosome 10) is a dual-specificity lipid and protein phosphatase. levels of Akt phosphorylation in the penumbral cortex. These results demonstrate that the pharmacological inhibition of PTEN protects against I/R injury in a dose-dependent manner and the protective effect might be induced through upregulation of the phosphoinositide-3 kinase/Akt pro-survival pathway suggesting a new therapeutic strategy to combat ischemic brain injury. 0.013 0.5 mg/kg (27.04% ± 7.27% 0 and 1.00 mg/kg (25.56% ± 7.25% 0 significantly decreased infarct volume by 24.85% 36.84% and 40.29% respectively (Figure 1). The maximum effect was observed with 1.0 mg/kg bpV suggesting dose-dependent protection by bpV with respect to infarct volume in the rat I/R model. In subsequent experiments we chose a dose of 1 1.0 mg/kg body weight to study the protection by bpV. Figure 1 (a) Coronal sections of rat brain 2 mm thick stained with 2 3 5 chloride (TTC). Non-ischemic areas appear red and ischemic areas appear white. Note the decrease in ischemic area of rats treated with bisperoxovanadium (bpV); (b … 2.2 Effects of bpV on Neurological Deficits Neurological deficits were assessed 6 12 and 24 h after reperfusion (evaluation system presented in Section 3.4). The groups treated with bpV exhibited remarkably reduced neurological deficit scores compared with the saline-treated group at 12 h after reperfusion (Figure 2 < 0.05). However at 6 and 24 h after reperfusion no significant difference between the Rabbit Polyclonal to HSP90A. groups was found (Figure 2 > 0.05). Figure 2 Neurological deficits scores of both bisperoxovanadium (bpV)- and saline-treated animals 6 12 and 24 h after reperfusion. Neurological deficits were significantly ameliorated in rats treated with bpV compared with saline-treated controls at 12 h after … 2.3 bpV Decreased Neuron Apoptosis Induced by Cerebral Ischemic/Reperfusion Injury Induction of apoptosis was quantified by assessing TUNEL-positive cells in penumbra 24 h after reperfusion as shown in Figure 1c. TUNEL-positive cells were not observed in sham-operated animals (Figure 3). In saline-treated animals that underwent I/R injury cells in the penumbral cortex were strongly positive for YM201636 TUNEL staining. This effect was not observed in bpV-treated animals (< 0.01). Figure 3 Bisperoxovanadium (bpV) administration blocks TUNEL-positive staining in the penumbral cortex 24 h after ischemia/reperfusion injury. (a) Photomicrographs of TUNEL-positive cells in the penumbral cortex. Scale bar = 100 μm; (b) Bar graphs of TUNEL-positive ... 2.4 Effect of bpV on Phosphorylation of Akt (Ser473) To investigate YM201636 whether PI3K/Akt is involved in the neuroprotective effect of bpV we performed European blot analysis to assess the phosphorylation of Akt (p-Akt Ser 473) in penumbra area. bpV significantly improved p-Akt (Ser 473) compared with the saline group (Number 4a). p-ERK served like a positive control. Consistent with previously reported findings [13] our results showed that YM201636 levels of p-ERK1/2 improved early and then declined to near the levels seen in managed animals. We also examined immunoreactivity in YM201636 the penumbral cortex 12 h after reperfusion where p-Akt immunoreactivity was markedly improved (Number 4b). Number 4 (a) Representative European blots for p-Akt (Ser 473) and p-ERK1/2 with β-actin and tubulin providing as a loading control. = 5; (b) Photomicrographs of p-Akt (Ser473) in the penumbral cortex in sham saline-treated and bpV-treated animals. The ... 2.5 Discussion In this study our results indicate that administration of bpV at doses of 0.25 0.5 and 1.0 mg/kg effectively reduced mind damage by 24.85% 36.84% and 40.29% respectively. However there was no significant difference between the 0.5 and 1.0 mg/kg organizations (> 0.05) indicating that the protective effect of bpV reached a plateau and increasing the drug dose would not have a greater protective effect. The optimal dose 1 mg/kg bpV produced a neuroprotective effect that resulted in reduced cell apoptosis and significantly improved p-Akt activity in the penumbral cortex. bpV treatment also improved neurological scores at 12 h but not at 24 h after reperfusion. This result is definitely congruent with earlier studies demonstrating reduced infarct quantities and improved practical end result [14 15 The majority of delayed neuronal degeneration is due to apoptosis. Results showed fewer TUNEL-positive cells in bpV-treated than in saline-treated rats. Activation of the.