Figure 6.
Ciliary beat frequency (CBF) in C2 KO mouse airway epithelial cells expressing sAC variants. Depicted here are the baseline and ΔCBF values from C2 KO mice upon HCO3− exposure in the presence or absence of KH7, a specific sAC inhibitor. Data are shown as mean (± SEM) from at least eight cell culture experiments seeded from two or more different animal tracheas. Left panel shows CBF baselines, and right panel shows ΔCBF in response to HCO3− with and without 25 μM KH7. *Statistically significant difference to pooled wild-type (WT) CBF baselines or to CBF decreases upon exposure to HCO3− in the absence of KH7. Even though KH7 doesn’t influence baseline CBF in WT cells, C2 KO cells (KO + not infected [NI]) or C2 KO cells infected with HA-sACex2-ex12v2-flag had a lower baseline CBF than WT and HA-sACex5v2-ex12v2-flag–infected cells (A). (B) quantitative comparisons of CBF decreases as a fraction of baseline in WT and sAC C2 KO mouse airway epithelial cells. In sAC C2 KO cells, there was no difference between the two perfusates (± KH7), again indicating absence of sAC activity. However, infection with the HA-sACex5v2-ex12v2-flag variant rescued WT CBF behavior, indicating restored sAC activity for CBF regulation. It is of note that the in vitro active form of sAC (HA-sACex2-ex12v2-flag) did not rescue CBF, indicating that sAC has to be present in cilia for proper regulation.