title: A novel bioassay for the activity determination of therapeutic human brain natriuretic peptide (BNP).
abstract: BACKGROUND
  Recombinant human brain natriuretic peptide (rhBNP) is an important peptide-based therapeutic drug indicated for the treatment of acute heart failure. Accurate determination of the potency of therapeutic rhBNP is crucial for the safety and efficacy of the drug. The current bioassay involves use of rabbit aortic strips, with experiments being complicated and time-consuming and markedly variable in results. Animal-less methods with better precision and accuracy should be explored. We have therefore developed an alternative cell-based assay, which relies on the ability of BNP to induce cGMP production in HEK293 cells expressing BNP receptor guanylyl cyclase-A.
  
  
  RESULTS
  An alternative assay based on the measurement of BNP-induced cGMP production was developed. Specifically, the bioassay employs cells engineered to express BNP receptor guanylyl cyclase-A (GCA). Upon rhBNP stimulation, the levels of the second messager cGMP in these cells drastically increased and subsequently secreted into culture supernatants. The quantity of cGMP, which corresponds to the rhBNP activity, was determined using a competitive ELISA developed by us. Compared with the traditional assay, the novel cell-based assay demonstrated better reproducibility and precision.
  
  
  CONCLUSIONS
  The optimized cell-based assay is much simpler, more rapid and precise compared with the traditional assay using animal tissues. To our knowledge, this is the first report on a novel and viable alternative assay for rhBNP potency analysis.
authors.affiliation: National Institute for the Control of Pharmaceutical and Biological Products, Beijing, People's Republic of China.
authors.forename: Lei
authors.initials: L
authors.lastname: Yu
authors.forename: Chunming
authors.initials: C
authors.lastname: Rao
authors.forename: Xinchang
authors.initials: X
authors.lastname: Shi
authors.forename: Yonghong
authors.initials: Y
authors.lastname: Li
authors.forename: Kai
authors.initials: K
authors.lastname: Gao
authors.forename: Xuguang
authors.initials: X
authors.lastname: Li
authors.forename: Junzhi
authors.initials: J
authors.lastname: Wang
mesh_terms: D001681:Biological Assay / Q000379:methods*; D006152:Cyclic GMP / Q000378:metabolism; D015870:Gene Expression; D057809:HEK293 Cells; D006333:Heart Failure / Q000188:drug therapy; D006801:Humans; D020097:Natriuretic Peptide, Brain / Q000032:analysis* / Q000627:therapeutic use; D011994:Recombinant Proteins / Q000032:analysis* / Q000627:therapeutic use
chemical_list: D011994:Recombinant Proteins; D020097:Natriuretic Peptide, Brain; D006152:Cyclic GMP