cAMP-specific 3',5'-cyclic phosphodiesterase 4B (PDE4B) (PDE4B)

cAMP-specific 3',5'-cyclic phosphodiesterase 4B (PDE4B) is a member of the PDE4 family that specifically hydrolyzes the second messenger cyclic adenosine monophosphate (cAMP) (UniProt [1.1.1]). It is predominantly expressed in immune cells and the central nervous system, where it serves as a critical regulator of inflammatory responses and neurotransmission (ResearchGate [1.3.1]). By controlling cAMP levels, PDE4B influences the production of pro-inflammatory cytokines and modulates pathways involved in mood and cognition (NIH [1.2.3]). In various disease states, PDE4B is often upregulated, contributing to chronic inflammation in conditions like COPD, asthma, and psoriasis, and it has also been linked to psychiatric disorders such as schizophrenia (Frontiers [1.2.4]). Therapeutic targeting of PDE4B with small-molecule inhibitors aims to elevate cAMP levels to suppress inflammation and potentially improve cognitive or mood symptoms (Patsnap [1.2.1]). However, the clinical use of many PDE4 inhibitors is limited by significant gastrointestinal side effects and psychiatric concerns, which has led to the development of more selective PDE4B inhibitors and degraders to improve the therapeutic window (NIH [1.3.3]). Selective inhibition of the B isoform is hypothesized to maintain anti-inflammatory efficacy while reducing the emetic effects associated with PDE4D inhibition (NIH [1.3.3]). Recent clinical trials for selective PDE4B inhibitors, such as BI 1015550, have shown promise in treating progressive fibrosing interstitial lung diseases (Frontiers [1.2.4]).

Other names

PDE4BDPDE4PDE32PDEIVBcAMP-specific phosphodiesterase 4B3',5'-cyclic-AMP phosphodiesterase 4B

Inhibition of PDE4B prevents the degradation of the second messenger cAMP, leading to elevated intracellular cAMP levels (Patsnap [1.2.1]). This elevation activates protein kinase A (PKA) and exchange protein directly activated by cAMP (EPAC), which subsequently modulate downstream signaling pathways to suppress the production of pro-inflammatory cytokines (e.g., TNF-alpha, IL-6) and regulate neurotransmitter release and synaptic plasticity (NIH [1.2.3]).