Chemical chaperones improve protein secretion and rescue mutant factor VIII in mice with hemophilia A

• Published in: PloS one 2012-09, Vol.7 (9), p.e44505-e44505
• Main Authors: Roth, Stefanie D, Schüttrumpf, Jörg, Milanov, Peter, Abriss, Daniela, Ungerer, Christopher, Quade-Lyssy, Patricia, Simpson, Jeremy C, Pepperkok, Rainer, Seifried, Erhard, Tonn, Torsten
• Format: Article
• Language: English
• Subjects: Analysis of Variance; Animals; Betaine; Betaine - metabolism; Betaine - pharmacology; Biology; Blotting, Western; Chaperones; CHO Cells; Coagulation; Coagulation factors; Cricetinae; Cricetulus; Endoplasmic reticulum; Factor IX; Factor VIII; Factor VIII - genetics; Factor VIII - metabolism; Factor VIII deficiency; Flow Cytometry; Gene transfer; Genetic Vectors; Golgi apparatus; Health aspects; Hemophilia; Hemophilia A - drug therapy; Hemophilia A - metabolism; House mouse; Humans; Industrial production; Intracellular; Lentivirus; Medical treatment; Medicine; Mice; Mice, Inbred C57BL; Mice, Knockout; Microscopy, Fluorescence; Molecular Chaperones - metabolism; Pathogenesis; Plasma levels; Protein Folding; Protein transport; Protein Transport - drug effects; Protein Transport - physiology; Recombinant proteins; Recombinant Proteins - biosynthesis; Secretion; Solubility
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0044505

Inefficient intracellular protein trafficking is a critical issue in the pathogenesis of a variety of diseases and in recombinant protein production. Here we investigated the trafficking of factor VIII (FVIII), which is affected in the coagulation disorder hemophilia A. We hypothesized that chemical chaperones may be useful to enhance folding and processing of FVIII in recombinant protein production, and as a therapeutic approach in patients with impaired FVIII secretion. A tagged B-domain-deleted version of human FVIII was expressed in cultured Chinese Hamster Ovary cells to mimic the industrial production of this important protein. Of several chemical chaperones tested, the addition of betaine resulted in increased secretion of FVIII, by increasing solubility of intracellular FVIII aggregates and improving transport from endoplasmic reticulum to Golgi. Similar results were obtained in experiments monitoring recombinant full-length FVIII. Oral betaine administration also increased FVIII and factor IX (FIX) plasma levels in FVIII or FIX knockout mice following gene transfer. Moreover, in vitro and in vivo applications of betaine were also able to rescue a trafficking-defective FVIII mutant (FVIIIQ305P). We conclude that chemical chaperones such as betaine might represent a useful treatment concept for hemophilia and other diseases caused by deficient intracellular protein trafficking.