Figure 4.

DAPT attenuates the ubiquitination and degradation of occludin during permanent MCAO. (A) Temporal changes in occludin degradation after pMCAO at the indicated epitopes. (B) Occludin is ubiquitinated in the rat brain following pMCAO. The high molecular weight occludin isoform, which is suggestive of polyubiquitinated occludin, was observed in the rat brain, as detected by the immunoprecipitation of occludin followed by immunoblotting with an anti‐ubiquitin antibody. (C) DAPT pretreatment significantly decreased the ubiquitination of occludin. The asterisk indicates the high molecular weight band. (D) DAPT treatment suppressed both the ubiquitination and degradation of occludin during permanent MCAO. The asterisk indicates the high molecular weight band (a) and the 65‐kDa band for occludin (b) in vehicle‐ and DAPT‐treated rats following pMCAO. (E) Changes in the expression of band (a) and band (b) were analyzed quantitatively as ratio of the values observed in the ipsilateral/contralateral brain. Data are expressed as the percentage of the values observed in vehicle‐treated animals (mean ± SEM, n = 5). *P < 0.05 versus vehicle‐treated rats. Con, contralateral hemisphere; Ipsi, ipsilateral hemisphere.