Delivery of glutamine synthetase gene by baculovirus vectors: a proof of concept for the treatment of acute hyperammonemia.

Hyperammonemia, a condition present in patients with urea cycle disorders (UCDs) or liver diseases, can cause neuropsychiatric complications, which in the worst cases result in brain damage, coma or death. Diverse treatments exist for the treatment of hyperammonemia, but they have limited efficacy, adverse effects and elevated cost. Gene therapy is a promising alternative that is explored here. A baculovirus, termed Bac-GS, containing the glutamine synthetase (GS) gene was constructed for the in vitro and in vivo treatment of hyperammonemia. Transduction of MA104 epithelial or L6 myoblast/myotubes cells with Bac-GS resulted in a high expression of the GS gene, an increase in GS concentration, and a reduction of almost half of exogenously added ammonia. When Bac-GS was tested in an acute hyperammonemia rat model by intramuscularly injecting the rear legs, the concentration of ammonia in blood decreased 351 µM, in comparison with controls. A high GS concentration was detected in gastrocnemius muscles from the rats transduced with Bac-GS. These results show that gene delivery for overexpressing GS in muscle tissue is a promising alternative for the treatment of hyperammonemia in patients with acute or chronic liver diseases and hepatic encephalopathy or UCD.

Computational modeling and simulation of the Bcl-2 family: paving the way for rational drug design.

Bcl-2 (B-cell lymphoma 2) family proteins have been studied intensively due to their association with cancer and other human diseases. These proteins were originally associated with the regulation of outer mitochondrial membrane integrity and apoptosis. However, there is experimental evidence that suggests that several members of this family play instrumental roles in other cellular pathways including autophagy, endoplasmic reticulum signaling, mitochondrial morphology and synaptic activity among others. Bcl-2 family proteins have been explored using diverse experimental and theoretical methods to obtain structural information that can provide valuable insight for drug development. This review is focused on computational studies related to Bcl-2 family proteins. Different strategies are described and evaluated, such as Molecular Dynamics simulations, docking, and rational drug design with the aim of demonstrating the importance of structural details of either ligands or proteins. The relevance of the knowledge obtained using these tools to drug design is discussed.