title: Development of a novel immunoassay specific for mouse intact proinsulin.
abstract: The blood concentration of intact proinsulin, but not total proinsulin, has been suggested to be a diagnostic marker for type 2 diabetes mellitus (T2DM), but a sensitive assay specific for rodent intact proinsulin is lacking. Here, a novel enzyme-linked immunosorbent assay (ELISA) for mouse intact proinsulin was developed. The developed ELISA detected mouse intact proinsulin with the working range of 8.3 to 2700pg/ml. Cross-reactivity with mouse split-32,33 proinsulin was approximately 100times lower than the reactivity with mouse intact proinsulin, and no cross-reactivity with mouse insulin was detected. The developed ELISA was sufficiently sensitive to detect low levels of intact proinsulin in normal mouse plasma. The measurement by the developed ELISA revealed that intact proinsulin was elevated in the plasma of type 2 diabetic db/db mice as mice aged, and the ratio of intact proinsulin/insulin in plasma was correlated with levels of glycated hemoglobin A1c as seen in T2DM patients. These results suggest that the plasma level of intact proinsulin, but not total proinsulin, is a sensitive marker for pancreatic dysfunction and the ensuring diabetic disease progression of db/db mice. This ELISA could aid nonclinical evaluation of therapeutic interventions in T2DM.
authors.affiliation: Shionogi Pharmaceutical Research Center, Shionogi & Company, Toyonaka, Osaka 561-0825, Japan.
authors.forename: Sunao
authors.initials: S
authors.lastname: Imai
authors.affiliation: Shionogi Pharmaceutical Research Center, Shionogi & Company, Toyonaka, Osaka 561-0825, Japan.
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Takahashi
authors.affiliation: Shionogi Pharmaceutical Research Center, Shionogi & Company, Toyonaka, Osaka 561-0825, Japan.
authors.forename: Shoichi
authors.initials: S
authors.lastname: Naito
authors.affiliation: Shionogi Pharmaceutical Research Center, Shionogi & Company, Toyonaka, Osaka 561-0825, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Yamauchi
authors.affiliation: Shionogi Pharmaceutical Research Center, Shionogi & Company, Toyonaka, Osaka 561-0825, Japan.
authors.forename: Chihiro
authors.initials: C
authors.lastname: Okada
authors.affiliation: Shionogi Pharmaceutical Research Center, Shionogi & Company, Toyonaka, Osaka 561-0825, Japan.
authors.forename: Yoshihide
authors.initials: Y
authors.lastname: Notsu
authors.affiliation: Shionogi Pharmaceutical Research Center, Shionogi & Company, Toyonaka, Osaka 561-0825, Japan.
authors.forename: Ikue
authors.initials: I
authors.lastname: Sakikawa
authors.affiliation: Shionogi Pharmaceutical Research Center, Shionogi & Company, Toyonaka, Osaka 561-0825, Japan.
authors.forename: Michiyoshi
authors.initials: M
authors.lastname: Hatanaka
authors.affiliation: Shionogi Pharmaceutical Research Center, Shionogi & Company, Toyonaka, Osaka 561-0825, Japan.
authors.forename: Takanori
authors.initials: T
authors.lastname: Iwasaki
authors.affiliation: Shionogi Pharmaceutical Research Center, Shionogi & Company, Toyonaka, Osaka 561-0825, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Morita
authors.affiliation: School of Science, Osaka Prefecture University, Sakai, Osaka 599-8531, Japan.
authors.forename: Ikuo
authors.initials: I
authors.lastname: Fujii
authors.affiliation: Shionogi Pharmaceutical Research Center, Shionogi & Company, Toyonaka, Osaka 561-0825, Japan. Electronic address: shoji.yamane@shionogi.co.jp.
authors.forename: Shoji
authors.initials: S
authors.lastname: Yamane
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000906:Antibodies / Q000276:immunology; D003921:Diabetes Mellitus, Experimental / Q000097:blood; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D005260:Female; D006825:Hybridomas / Q000166:cytology; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D011384:Proinsulin / Q000097:blood* / Q000276:immunology
chemical_list: D000906:Antibodies; D011384:Proinsulin
keywords: Monoclonal antibody; Mouse insulin; Mouse intact proinsulin; Sandwich enzyme-linked immunosorbent assay; Split-32,33 proinsulin