Proinsulin-Transferrin Fusion Protein Exhibits a Prolonged and Selective Effect on the Control of Hepatic Glucose Production in an Experimental Model of Type 1 Diabetes.
An ideal basal insulin (INS) replacement therapy requires the distribution or action of exogenous INS to more closely mimic physiological INS in terms of its preferential hepatic action. In this paper, we introduce a novel strategy to exert liver-specific INS action by hepatic activation of INS's precursor, proinsulin (ProINS). We demonstrated the conversion of human ProINS-transferrin (Tf) fusion protein, ProINS-Tf, into an active and immuno-reactive form of INS-Tf in the liver via the slow Tf receptor mediated recycling pathway. ProINS-Tf displayed prolonged basal blood glucose lowering effects for up to 40 h in streptozotocin-induced type 1 diabetic mice following a single subcutaneous injection. The effect of ProINS-Tf on blood glucose levels was observed predominantly under fasting conditions, with little effect under free-feeding conditions. In addition, both the pyruvate tolerance assay in normal mice and the Akt-phosphorylation assay in H-4-II-E hepatoma cells indicated that the hepatic-activated ProINS-Tf possessed a much longer effect on the control of hepatic glucose production than INS. These results indicated that ProINS-Tf may serve as an effective and safe hepatoselective INS analog to reduce the frequency of INS injections as well as avert severe hypoglycemia episodes and other side effects frequently encountered with long-acting INS therapeutics due to their peripheral action.
Department of Pharmacology and Pharmaceutical Sciences, University of Southern California , 1985 Zonal Avenue, Los Angeles, California 90033, United States.
Juntang
J
Shao
Department of Pharmacology and Pharmaceutical Sciences, University of Southern California , 1985 Zonal Avenue, Los Angeles, California 90033, United States.
Jennica L
JL
Zaro
Department of Pharmacology and Pharmaceutical Sciences, University of Southern California , 1985 Zonal Avenue, Los Angeles, California 90033, United States.
Wei-Chiang
WC
Shen
D000818:Animals; D003921:Diabetes Mellitus, Experimental / Q000188:drug therapy / Q000378:metabolism; D003922:Diabetes Mellitus, Type 1 / Q000188:drug therapy* / Q000378:metabolism*; D005947:Glucose / Q000378:metabolism*; D006801:Humans; D008099:Liver / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D010766:Phosphorylation / Q000187:drug effects; D011384:Proinsulin / Q000235:genetics / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism* / Q000627:therapeutic use*; D014168:Transferrin / Q000235:genetics / Q000378:metabolism*
D011993:Recombinant Fusion Proteins; D014168:Transferrin; D011384:Proinsulin; D005947:Glucose
INS prodrug; diabetes; fasting hyperglycemia; hepatoselective INS analog; insulin delivery; transferrin fusion protein