Porcine Model of Hemophilia A

Abstract

Hemophilia A is a common X chromosome-linked genetic bleeding disorder caused by abnormalities in the coagulation factor VIII gene (F8). Hemophilia A patients suffer from a bleeding diathesis, such as life-threatening bleeding in the brain and harmful bleeding in joints and muscles. Because it could potentially be cured by gene therapy, subhuman animal models have been sought. Current mouse hemophilia A models generated by gene targeting of the F8 have difficulties to extrapolate human disease due to differences in the coagulation and immune systems between mice and humans. Here, we generated a porcine model of hemophilia A by nuclear transfer cloning from F8-targeted fibroblasts. The hemophilia A pigs showed a severe bleeding tendency upon birth, similar to human severe hemophiliacs, but in contrast to hemophilia A mice which rarely bleed under standard breed conditions. Infusion of human factor VIII was effective in stopping bleeding and reducing the bleeding frequency of a hemophilia A piglet but was blocked by the inhibitor against human factor VIII. These data suggest that the hemophilia A pig is a severe hemophilia A animal model for studying not only hemophilia A gene therapy but also the next generation recombinant coagulation factors, such as recombinant factor VIII variants with a slower clearance rate.

Generation of Live Piglets for the First Time Using Sperm Retrieved from Immature Testicular Tissue Cryopreserved and Grafted into Nude Mice

“…In general, there is a possibility that genetically manipulated animals might have certain reproductive disadvantages, such as a degree of male infertility, or the presence of neonatal lethal traits [43], [44]. Recently, porcine models of severe combined immunodeficiency [45] and hemophilia A [46] were generated by cloning technology. However, disruption of X-linked genes encoding the interleukin-2 receptor (SCID model) or coagulation factor VIII (hemophilia model) caused neonatal death in cloned male pigs owing to infections and hemophilia.…”

Embryo production by intracytoplasmic injection of sperm retrieved from Meishan neonatal testicular tissue cryopreserved and grafted into nude mice

“…Alternatively, systematic collection of neonatal testes might be an aid to conserve indigenous pigs whose populations are often small, but which possess unique phenotypes, thus having the potential to maintain the genetic diversity of pig species. As an example of the former application, we have generated progeny using fetal testis obtained from cloned pigs harboring a disruption of the X chromosome‐linked coagulation factor VIII (F8) gene (hemophilia‐A pig) (Kaneko, Kikuchi, Nakai, et al., ): such female cloned pigs ( F8 +/− ), despite having a recessive X‐linked condition, died of severe bleeding at an early age (Kaneko, Kikuchi, Nakai, et al., ), as was the case for male cloned pigs ( F8 −/Y ) (Kashiwakura et al., ). However, the above studies used testicular tissue from breeds of Western origin (Abrishami et al., ; Caires et al., ; Honaramooz et al., ; Kaneko et al., ; Kaneko, Kikuchi, Men, et al., ; Kaneko, Kikuchi, Nakai, et al., ).…”

Anti-factor IXa/X bispecific antibody ACE910 prevents joint bleeds in a long-term primate model of acquired hemophilia A

“…27,29 Although congenital hemophilia A models in dogs, sheep, rats, and pigs have been reported to develop joint bleeds, it seems difficult to express reproducible joint bleeds in individuals and to efficiently evaluate drug efficacy in a practicable experimental period. [28][29][30][31][32][33][34] Our model stably developed leg-joint damage within 8 weeks, which was possibly produced by the severe acquired hemophilic state and by bodyweight loading due to the bipedal motion of the monkeys. Thus, this model may be particularly useful in testing the efficacy of therapeutic agents from the orthopedic aspect of hemophilia A.…”