title: Pro-B-type natriuretic peptide is cleaved intracellularly: impact of distance between O-glycosylation and cleavage sites.
abstract: We investigated the molecular mechanism underlying the processing of pro-B-type natriuretic peptide (proBNP). Rat neonatal atrial and ventricular myocytes were cultured separately. We examined the molecular forms of secreted and intracellular BNP in atrial and ventricular myocytes; levels of corin and furin mRNA in atrial and ventricular myocytes; the effect their knockdown on proBNP processing; plasma molecular forms of BNP from rats and humans with and without heart failure; and the impact of the distance between the glycosylation and cleavage sites in wild-type and mutant human proBNP, expressed in rat myocytes transfected with lentiviral vectors. BNP was the major molecular form secreted by atrial and ventricular myocytes. Transfection of furin siRNA reduced proBNP processing in both atrial and ventricular myocytes; however, transfection of corin siRNA did not reduce it. BNP was the major molecular form in rat plasma, whereas proBNP was the major form in human plasma. The relative fraction of human BNP in rat myocytes expressing human proBNP was about 60%, but increasing the distance between the glycosylation and cleavage sites through mutation, increased the processed fraction correspondingly. These results suggest that proBNP is processed into BNP intracellularly by furin. The level of proBNP processing is lower in humans than rats, most likely due to the smaller distance between the O-glycosylation and cleavage sites in humans.
authors.affiliation: Department of Cardiology, Kyoto University Graduate School of Medicine, Kyoto, Japan; Department of Cardiology and Nephrology, Dokkyo Medical University, Mibu, Japan; nishikim@kuhp.kyoto-u.ac.jp.
authors.forename: Toshio
authors.initials: T
authors.lastname: Nishikimi
authors.affiliation: Department of Cardiology, Kyoto University Graduate School of Medicine, Kyoto, Japan;
authors.forename: Yasuaki
authors.initials: Y
authors.lastname: Nakagawa
authors.affiliation: National Cerebral and Cardiovascular Center Research Institute, Osaka, Japan; and.
authors.forename: Naoto
authors.initials: N
authors.lastname: Minamino
authors.affiliation: Department of Laboratory Medicine, Dokkyo Medical University, Mibu, Japan;
authors.forename: Masashi
authors.initials: M
authors.lastname: Ikeda
authors.affiliation: Department of Laboratory Medicine, Dokkyo Medical University, Mibu, Japan;
authors.forename: Kyoko
authors.initials: K
authors.lastname: Tabei
authors.affiliation: Department of Cardiology, Kyoto University Graduate School of Medicine, Kyoto, Japan;
authors.forename: Aoi
authors.initials: A
authors.lastname: Fujishima
authors.affiliation: National Cerebral and Cardiovascular Center Research Institute, Osaka, Japan; and.
authors.forename: Kentaro
authors.initials: K
authors.lastname: Takayama
authors.affiliation: Department of Laboratory Medicine, Dokkyo Medical University, Mibu, Japan;
authors.forename: Kazumi
authors.initials: K
authors.lastname: Akimoto
authors.affiliation: Department of Cardiology, Kyoto University Graduate School of Medicine, Kyoto, Japan;
authors.forename: Chinatsu
authors.initials: C
authors.lastname: Yamada
authors.affiliation: Department of Cardiology, Kyoto University Graduate School of Medicine, Kyoto, Japan;
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Nakao
authors.affiliation: Department of Cardiology, Kyoto University Graduate School of Medicine, Kyoto, Japan;
authors.forename: Takeya
authors.initials: T
authors.lastname: Minami
authors.affiliation: Department of Cardiology, Kyoto University Graduate School of Medicine, Kyoto, Japan;
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Kuwabara
authors.affiliation: Department of Cardiology, Kyoto University Graduate School of Medicine, Kyoto, Japan;
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Kinoshita
authors.affiliation: Department of Cardiology, Shiga Medical University, Shiga, Japan.
authors.forename: Takayoshi
authors.initials: T
authors.lastname: Tsutamoto
authors.affiliation: Department of Cardiology and Nephrology, Dokkyo Medical University, Mibu, Japan;
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Ishimitsu
authors.affiliation: National Cerebral and Cardiovascular Center Research Institute, Osaka, Japan; and.
authors.forename: Kenji
authors.initials: K
authors.lastname: Kangawa
authors.affiliation: Department of Cardiology, Kyoto University Graduate School of Medicine, Kyoto, Japan;
authors.forename: Koichiro
authors.initials: K
authors.lastname: Kuwahara
authors.affiliation: Department of Cardiology, Kyoto University Graduate School of Medicine, Kyoto, Japan;
authors.forename: Kazuwa
authors.initials: K
authors.lastname: Nakao
mesh_terms: D000368:Aged; D000818:Animals; D009320:Atrial Natriuretic Factor / Q000378:metabolism; D002478:Cells, Cultured; D017077:Culture Media, Conditioned; D005260:Female; D045683:Furin / Q000378:metabolism; D006031:Glycosylation; D006325:Heart Atria / Q000166:cytology / Q000378:metabolism; D006333:Heart Failure / Q000378:metabolism; D006352:Heart Ventricles / Q000166:cytology / Q000378:metabolism; D006801:Humans; D008297:Male; D008875:Middle Aged; D032342:Muscle Cells / Q000378:metabolism; D020097:Natriuretic Peptide, Brain / Q000235:genetics / Q000378:metabolism*; D010446:Peptide Fragments / Q000235:genetics / Q000378:metabolism*; D051381:Rats; D020303:Rats, Inbred Dahl; D012697:Serine Endopeptidases / Q000378:metabolism; D013045:Species Specificity
chemical_list: D017077:Culture Media, Conditioned; D010446:Peptide Fragments; C109794:pro-brain natriuretic peptide (1-76); D020097:Natriuretic Peptide, Brain; D009320:Atrial Natriuretic Factor; D012697:Serine Endopeptidases; C492879:corin protein, rat; D045683:Furin
keywords: B-type natriuretic peptide; atrial natriuretic peptide; corin; furin; processing