Panoply™ Human CFTR Knockdown Stable Cell Line

Cystic fibrosis (CF) is caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. CF cells and tissues exhibit various mitochondrial abnormalities, yet the underlying molecular mechanisms remain unclear. Here, researchers investigated the mechanism by which CFTR regulates Bcl-2 family proteins, which in turn control mitochondrial outer membrane permeability. The study found that inhibiting CFTR activates Bax and Bad while suppressing Bcl-2. Furthermore, the degradation of phosphorylated extracellular signal-regulated kinase 1/2 (ERK1/2) and AKT is significantly increased in CFTR-knockdown cells. CFTR dysfunction leads to reduced mRNA levels of heat shock protein 90 (Hsp90), and an interaction between CFTR and Hsp90 was confirmed. Inhibition of Hsp90 using SNX-2112 induces the degradation of phosphorylated AKT and ERK1/2 in Caco2 and HRT18 cells. These findings contribute to a deeper understanding of the physiological role of CFTR in CF-related diseases.

To determine whether CFTR knockdown affects mitochondrial function in Caco2 and HRT18 cells, researchers performed Western blot analysis on Bcl-2 family members (including Bcl-2, Bad, and Bax). The results showed that the expression of Bax and Bad was upregulated, while Bcl-2 expression was downregulated in CFTR-knockdown cells (Figure 1A). Furthermore, mRNA levels of Bax and Bad were increased, whereas Bcl-2 mRNA levels were decreased in CFTR-knockdown cells (Figure 1B). To further investigate the molecular mechanisms underlying CFTR knockdown-induced mitochondrial dysfunction, researchers examined the phosphorylation levels of AKT and ERK1/2, which regulate Bcl-2 family proteins. Western blot analysis revealed reduced levels of phosphorylated AKT (phospho-AKT) and phosphorylated ERK1/2 (phospho-ERK1/2) in CFTR-knockdown cells (Figure 1C). These results indicate that CFTR knockdown induces mitochondrial dysfunction in Caco2 and HRT18 cells by modulating the phosphorylation of AKT and ERK1/2.

Figure 1. Knockdown of CFTR induced mitochondrial dysfunction and degradation of phospho‐AKT and phospho‐ERK1/2. (Liu K, et al., 2019)