Development of a recombinant cell-based system for the characterisation of phosphodiesterase 4 isoforms and evaluation of inhibitors

Biochem Pharmacol. 1999 Jun 15;57(12):1375-82. doi: 10.1016/s0006-2952(99)00062-3.


We described the development of a recombinant cell-based system for the characterisation of phosphodiesterase (PDE) 4 isoforms and the evaluation of inhibitors. The Chinese hamster ovary (CHO) cell, which was found to have a low endogenous PDE4 background and no beta-adrenergic receptors (beta-AR), was transiently transfected with beta-AR and various PDE4 isoforms which were expressed as functionally coupled molecules. From correlations of elevation of adenosine 3',5'-cyclic monophosphate in situ and the inhibition of catalytic activity in vitro with the various PDE4 isoforms, it was apparent that PDE4A4, 4B2, 4C2, 4D2, and 4D3 all adopted a high-affinity binding conformation (i.e. expressed the high-affinity rolipram binding site) in the CHO cell, whereas PDE4A330 was expressed in a low-affinity conformation in situ. This gives the opportunity of using this system to screen and optimise inhibitors against a low-affinity conformation of PDE4 in situ and use a high-affinity conformation of PDE4 as a counterscreen, as inhibitor activity against this conformer has been linked with undesirable side effects. This system could also be utilised to screen inhibitors against various PDE4 isoforms in isolation against a low endogenous PDE background in situ for isoform-selective inhibitors.

MeSH terms

  • 3',5'-Cyclic-AMP Phosphodiesterases / analysis*
  • 3',5'-Cyclic-AMP Phosphodiesterases / antagonists & inhibitors
  • 3',5'-Cyclic-AMP Phosphodiesterases / genetics
  • Adrenergic beta-Agonists / pharmacology
  • Animals
  • CHO Cells
  • COS Cells
  • Catalysis
  • Cricetinae
  • Cyclic AMP / metabolism
  • Cyclic Nucleotide Phosphodiesterases, Type 4
  • Dose-Response Relationship, Drug
  • Drug Evaluation, Preclinical / methods
  • Enzyme Activation
  • Enzyme Inhibitors / pharmacology*
  • Humans
  • Isoenzymes / analysis*
  • Isoenzymes / antagonists & inhibitors
  • Isoenzymes / genetics
  • Isoproterenol / pharmacology
  • Receptors, Adrenergic, beta-2 / drug effects
  • Receptors, Adrenergic, beta-2 / metabolism
  • Recombinant Proteins / analysis
  • Recombinant Proteins / antagonists & inhibitors
  • Recombinant Proteins / genetics
  • Time Factors
  • Transfection


  • Adrenergic beta-Agonists
  • Enzyme Inhibitors
  • Isoenzymes
  • Receptors, Adrenergic, beta-2
  • Recombinant Proteins
  • Cyclic AMP
  • 3',5'-Cyclic-AMP Phosphodiesterases
  • Cyclic Nucleotide Phosphodiesterases, Type 4
  • Isoproterenol