Fig. 2: Zinc chelator reverses ischemic injury, CDK5 activating and Tyr15 phosphorylation, but not p35 cleavage in MCAO rats. | Cell Death & Disease

Fig. 2: Zinc chelator reverses ischemic injury, CDK5 activating and Tyr15 phosphorylation, but not p35 cleavage in MCAO rats.

From: Zinc induces CDK5 activation and neuronal death through CDK5-Tyr15 phosphorylation in ischemic stroke

Fig. 2

a Timeline of the experiment. One dose of zinc chelator CQ (10 mg/kg) or vehicle (DMSO) was injected into the SD rats intraperitoneally (i.p.) 60 min before MCAO. b Ischemia-induced CDK5 activating was reversed by CQ pretreatment. CDK5 activities were detected by evaluating the phosphorylation level of Histone-H1. Representative blots with antibodies as indicated. c CDK5 activities were evaluated by calculating the ratio of phosphorylated to total Histone-H1 levels in b (n = 6 animals per group, one-way ANOVA followed by LSD’s post hoc tests, from left to right, p = 0.006, p = 0.005, **p < 0.01). d Infarct size in MCAO rat brain was reduced by the pretreatment of zinc chelator CQ. Representative TTC-stained serial brain sections were shown from sham, MCAO and CQ + MCAO rats. e Quantification of infarct volume (vol) indicated by TTC staining (n = 3 animals per group, one-way ANOVA followed by LSD’s post hoc tests, p = 0.0009, ***p < 0.001). f CQ reduced CA1 pyramidal cell death induced by ischemia. Representative Nissl staining image of the hippocampus sections from sham, MCAO and CQ + MCAO rats. g Quantification of survival neuron numbers indicated by Nissl staining (n = 3 animals per group, one-way ANOVA followed by LSD’s post hoc tests, from left to right, p = 0.0006, p = 0.0019, **p < 0.01,***p < 0.001). h Ischemia-induced phosphorylation of CDK5 at Tyr15 was reversed by CQ pretreatment. Levels of total and Tyr15 phosphorylated CDK5, p35 and p25 in brain homogenates were detected by using the indicated antibodies. i Quantitative analysis of the protein levels in h (n = 6 animals per group, one-way ANOVA followed by LSD’s post hoc tests, from left to right, p = 0.0006, p = 0.0025, p = 0.0043, p = 4.1839E-05, p = 0.0024, p = 4.40967E-05, ***p < 0.001, **p < 0.01). j Calpain activity was further enhanced by CQ pretreatment. Activities of calpain were analyzed in the three groups by ELISA assay (n = 6 animals per group, one-way ANOVA followed by LSD’s post hoc tests, from left to right, p = 0.0042, p = 0.0071, **p < 0.01)

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