| First Author | Boyd A | Year | 2021 |
| Journal | Biochem J | Volume | 478 |
| Issue | 10 | Pages | 1891-1906 |
| PubMed ID | 33944911 | Mgi Jnum | J:314426 |
| Mgi Id | MGI:6718561 | Doi | 10.1042/BCJ20210212 |
| Citation | Boyd A, et al. (2021) The cAMP-phosphodiesterase 4 (PDE4) controls beta-adrenoceptor- and CFTR-dependent saliva secretion in mice. Biochem J 478(10):1891-1906 |
| abstractText | Saliva, while often taken for granted, is indispensable for oral health and overall well-being, as inferred from the significant impairments suffered by patients with salivary gland dysfunction. Here, we show that treatment with several structurally distinct PAN-PDE4 inhibitors, but not a PDE3 inhibitor, induces saliva secretion in mice, indicating it is a class-effect of PDE4 inhibitors. In anesthetized mice, while neuronal regulations are suppressed, PDE4 inhibition potentiates a beta-adrenoceptor-induced salivation, that is ablated by the beta-blocker Propranolol and is absent from homozygous DeltaF508-CFTR mice lacking functional CFTR. These data suggest that PDE4 acts within salivary glands to gate saliva secretion that is contingent upon the cAMP/PKA-dependent activation of CFTR. Indeed, PDE4 contributes the majority of total cAMP-hydrolytic capacity in submandibular-, sublingual-, and parotid glands, the three major salivary glands of the mouse. In awake mice, PDE4 inhibitor-induced salivation is reduced by CFTR deficiency or beta-blockers, but also by the muscarinic blocker Atropine, suggesting an additional, central/neuronal mechanism of PDE4 inhibitor action. The PDE4 family comprises four subtypes, PDE4A-D. Ablation of PDE4D, but not PDE4A-C, produced a minor effect on saliva secretion, implying that while PDE4D may play a predominant role, PDE4 inhibitor-induced salivation results from the concurrent inactivation of multiple (at least two) PDE4 subtypes. Taken together, our data reveal a critical role for PDE4/PDE4D in controlling CFTR function in an in vivo model and in inducing salivation, hinting at a therapeutic potential of PDE4 inhibition for cystic fibrosis and conditions associated with xerostomia. |
