Blocking Tat and cocaine-mediated ERK activation reverses ZO-1 disruption in HPMECs.

<p>Phosphorylated ERK was detected by western blot analysis of HPMECs treated with (A) Tat and cocaine for different time intervals as indicated and (B) with cocaine and/or Tat for 1.5 hours. (C) ZO-1 expression analysis in HPMECs pre-treated with U0126 for 30 min followed by Tat and cocaine treatment for 24 hours. Membrane fraction was isolated using compartment protein fractionation kit and ZO-1 was detected by western blot analysis. Lower panels show the average densitometry analysis normalized to β-actin for total cellular extract (A and B) and β-integrin in case of membrane fraction (C) of at least three independent experiments. Mean (±S.E.M.). *P≤0.05, **P≤0.01, ***P≤0.001 compared to control; ^#P≤0.001 compared to cocaine treatment. ^$p<0.001 compared to Tat treatment, ^@P≤0.01, compared to combined cocaine and Tat treatment.