Fig. 1.
HIV-1-induced activation of MAPK/ERK1/2 upregulated NF-κB signalling in polarized oral epithelial cells. (a) Polarized tonsil epithelial cells were exposed to cell-free HIVSF33 virions and active and inactive tat and gp120 proteins in combination, in the absence or presence of MEK1/inhibitor U0126 for 5 days. Untreated cells were used as a control. TER of polarized cells was then measured on day 5. Error bars indicate sem (n=3). **P<0.001, compared to the control. (b) After measurement of TER, cells were collected and used to examine the expression of phosphorylated and total ERK1/2 using Western blot assay. The same cell samples were examined for phosphorylation and degradation of IκBα and NF-κB p65. (c) To quantify phosphorylation of ERK1/2, IκBa, and NF-κB, we measured the integrated densities of pixels in the protein bands from panel (b) by ImageJ software and present the data as a bar graph. Two independent experiments showed similar results.