The expression of the mitochondrial encoded gene ND4 is downregulated in cystic fibrosis

Abstract

Abstract: Cystic fibrosis (CF) is a disease produced by mutations in the CFTR channel. We have previously reported that the CFTR chloride transport activity regulates the differential expression of several genes, including SRC. Here we report that MT-ND4, a mitochondrial gene encoding a subunit of the mitochondrial Complex I (mtCx-I), is also a CFTR-dependent gene. A reduced expression of MT-ND4 was observed in CFDE cells (derived from a CF patient) when compared to CFDE cells ectopically expressing wild type CFTR. The differential expression of MT-ND4 in CF was confirmed by PCR. In situ hybridizations of deparaffinized human lung tissue slices derived from wt-CFTR or CF patients also showed downregulation of ND4 in CF. In addition, glibenclamide or CFTR(inh)-172 (CFTR chloride transport inhibitors) reduced MT-ND4 expression in cells expressing wt CFTR. These results suggest that the CFTR chloride transport activity indirectly up-regulates MT-ND4 expression.