Fig. 5.

BHA feeding improves secretion of wtFVIII and BDD in vivo. Hemophilia A Fviii−/− mice were fed with normal chow or chow supplemented with BHA for 4 days before gene delivery. (A) FVIII antigen in plasma and liver samples was measured at 24 h after DNA injection of the indicated vectors. (B–D) DNA vectors encoding FVIII-BDD or R593C-BDD (R593C) (27) were injected into tail vein. After 24 h, plasma and liver samples were harvested for TUNEL (B), FVIII antigen in plasma and liver (C), and real-time RT-PCR (D). A, C, and D depict three independent mice. (E) Protein misfolding and oxidative stress create a vicious cycle leading to ER stress and cell death. ROS are generated by exposure to multiple stresses and also as a byproduct of mitochondrial respiration. Protein misfolding may cause ROS through changes in oxidative phosphorylation as a consequence of energy depletion or Ca²⁺ release from the ER. In addition, GSH can be consumed to reduce improperly paired disulfide bonds within misfolded proteins. ROS production can interfere with protein folding by inactivating PDI/ERO1 thiol-disulfide exchange reactions and/or by causing aberrant disulfide bond formation. ER stress activates CHOP expression that may lead to ROS production through induction of Ero1 or Gadd34. In this model, ROS can cause protein misfolding, UPR activation, and CHOP induction.