Purpose Ex vivo gene therapy can improve the outcome of islet transplantation for treating type I diabetes. Hepatocyte growth factor (HGF) increases β-cell proliferation and promotes revascularization of islets, while interleukin-1 receptor antagonist (hIL-1Ra) inhibits islet cell apoptosis. Methods We constructed Adv-hHGF-hIL-1Ra by cloning hHGF and hIL-1Ra coding sequences and polyA signal under separate CMV promoters in Adenoquick plasmid. Results There was dose and time dependent expression of these genes after transduction of Adv-hHGF-hIL-1Ra into human islets. Compared to un-transduced islets, hHGF and hIL-1Ra gene expression at protein levels was more than 60 and 40 times higher at 1000 MOI, respectively. Transduced islets were viable after incubation with the cocktail of TNF-α, IL-1β and IFN-γ, as evidenced by insulin release in response to glucose concentration. Co-expression of hHGF and hIL-1Ra led to significant decrease in caspase-3 induced by the cytokines. Compared to un-transduced islets, transduction of islets with Adv-hHGF-hIL-1Ra at 1000 MOI prior to transplantation under the kidney capsules of streptozotocin-induced-diabetic NOD-SCID mice reduced blood glucose levels, and increased serum insulin and c-peptide levels. Conclusions Transduction of islets with Adv-hHGF-hIL-1Ra efficiently expresses both growth factor and antiapoptotic genes, decreases caspase-3 and improves the outcome of islet transplantation.

Ex vivo gene transfer can improve the outcome of islet transplantation for treating type I diabetes. Earlier we have shown co-expression of human vascular endothelial growth factor (hVEGF) and human interleukin-1 receptor antagonist (hIL-1Ra) after transfection of plasmid DNA encoding these two genes. Due to poor transfection efficiency of plasmid DNA and the better known islet transduction efficiency of adenoviral (Adv) vectors, in this study, we constructed Adv-hVEGF-hIL-1Ra by cloning hVEGF and hIL-1Ra coding sequences and polyA signal under separate cytomegalovirus (CMV) promoters in Adenoquick plasmid (Ad 13.1). There was dose and time dependent expression of these genes after transduction of Adv-hVEGF-hIL1Ra into human islets. The mRNA expression of hVEGF and hIL-1Ra was more than 100 times higher than that of the non-transduced and bipartite plasmid transfected control islets. Transduced islets were viable as evidenced by insulin release upon glucose challenge. Co-expression of hVEGF and hIL-1Ra by islets showed decrease in caspase-3 activity and apoptosis induced by a cocktail of inflammatory cytokines such as TNF-α, IL-1β and IFN-γ. Compared to non-treated or Adv-LacZ transduced islets, transduction of islets with Adv-hVEGF-hIL-1Ra prior to transplantation under the kidney capsules of diabetic NOD-SCID mice reduced the blood glucose levels, and increased serum insulin and c-peptide levels. Immunohistochemical staining of the islet bearing kidney sections at day 20 after transplantation was positive for human insulin, hVEGF and von Willebrand factor. These results indicate that the bipartite Adv vector efficiently expresses both growth factor and antiapoptotic genes, decreases apoptosis and improves the outcome of islet transplantation.

Excipients are generally pharmacologically inert, but can interact with drugs in the dosage form and the physiological factors at the site of absorption to affect the bioavailability of a drug product. A general mechanistic understanding of the basis of these interactions is essential to design robust drug products. This paper focuses on drug-excipient interactions in solid dosage forms that impact drug bioavailability, the drug substance and drug product properties affected by excipients, and the impact of excipients on physiologic processes. The extent to which drug bioavailability is affected by these interactions would vary on a case-by-case basis depending upon factors such as the potency and dose of the drug, therapeutic window, site of absorption, rate limiting factor in drug absorption (e.g., permeability or solubility limited), or whether drug metabolism, efflux, complexation, or degradation at the site of absorption play a role in determining its bioavailability. Nonetheless, a mechanistic understanding of drug-excipient interactions and their impact on drug release and absorption can help develop formulations that exhibit optimum drug bioavailability.

This study provides evidence that endogenous Hh signaling is an early mediator of liver injury and inflammation after I/R. CYA abrogates normothermic I/R injury in rats by inhibiting the MAPK pathway and decreasing the acute inflammatory response. This novel strategy of preconditioning livers with Hh antagonist may have effective therapeutic potential in preventing acute liver injury.

Islet transplantation has the potential to treat type I diabetes, however, its clinical application is limited due to the massive apoptotic cell death and other post-transplantation challenges to islet grafts. Therefore, the objective of this study was to determine whether ex vivo transduction of rat insulin producing INS-1E cells and human islets with adenoviral vector encoding human X-linked inhibitor of apoptosis (Adv-hXIAP) can protect them from inflammatory cytokines and improve their viability and function. There was dose dependent XIAP gene expression. XIAP expression led to decrease in the activities of caspase 3/7, 8 and 9, resulting in reduced apoptotic cell death induced by a cocktail of inflammatory cytokines such as IL-1β, TNFα, and IFNγ. Prolonged normoglycemic control could be achieved by transplantation of Adv-XIAP transduced human islets under the kidney capsule of streptozotocin induced diabetic NOD-SCID mice. Immunohistological staining of the islets bearing kidney sections at day 42 after transplantation was positive for insulin. Moreover, the protective effect of XIAP was reversed by co-administration of XIAP inhibitor embelin. These results indicate that ex vivo transduction of islets with Adv-XIAP will decrease cytokine induced apoptosis and improve the outcome of islet transplantation.