TMEV infection induces cleavage of TDP-43 and abnormal splicing.

(A) Western blot of BHK-21 cells that are either uninfected or 8 hours after infection with DA, DAΔL, GDVII or GDVIIΔL virus. As a positive control for cleavage of TDP-43, BHK-21 cells were treated with 10 μM MG-132 for 8hrs. Western blots of cell lysates were immunostained with antibody against TDP-43 (C-terminal) and VP1. In addition to the predicted full-length normal 43-kDa band, 35-kDa and 25-kDa bands are prominently seen in the RIPA-insoluble fraction from wt and TMEVΔL virus-infected cells. The levels of full-length and cleaved TDP-43 were quantitated by densitometric analysis using NIH ImageJ and presented under each blot. The value of each of the bands in the MG132-treated or infected cells was compared to the uncleaved band in mock, which was set to 1. (B) Representative agarose gel electrophoresis of RT-PCR products in CFTR minigene-transfected cells that were or were not infected with DA or GDVII virus. Exon 9 included (+) and excluded (–) RT-PCR products are shown. (C) Spliced versus unspliced ratios were calculated and then normalized to the value of L929 cells that received vector, but were not infected. Mean values are from three different experiments performed. *P < 0.001.