Successful transduction of liver in hemophilia by AAV-Factor IX and limitations imposed by the host immune response

We have previously shown that a single portal vein infusion of a recombinant adeno-associated viral vector (rAAV) expressing canine Factor IX (F.IX) resulted in long-term expression of therapeutic levels of F.IX in dogs with severe hemophilia B. We carried out a phase 1/2 dose-escalation clinical study to extend this approach to humans with severe hemophilia B. rAAV-2 vector expressing human F.IX was infused through the hepatic artery into seven subjects. The data show that: (i) vector infusion at doses up to 2 x 10(12) vg/kg was not associated with acute or long-lasting toxicity; (ii) therapeutic levels of F.IX were achieved at the highest dose tested; (iii) duration of expression at therapeutic levels was limited to a period of approximately 8 weeks; (iv) a gradual decline in F.IX was accompanied by a transient asymptomatic elevation of liver transaminases that resolved without treatment. Further studies suggested that destruction of transduced hepatocytes by cell-mediated immunity targeting antigens of the AAV capsid caused both the decline in F.IX and the transient transaminitis. We conclude that rAAV-2 vectors can transduce human hepatocytes in vivo to result in therapeutically relevant levels of F.IX, but that future studies in humans may require immunomodulation to achieve long-term expression.     

Effect of Leukemia Inhibitory Factor on the Myelinogenic Ability of Schwann-Like Cells Induced from Human Adipose-Derived Stem Cells

The Schwann cells (SCs) may be obtain from nerve biopsies for autologous transplantation. However, it is difficult to obtain sufficient amount of SCs for clinical applications. Human adipose-derived stem cells (ADSCs) can be induced to differentiate into Schwann-like cells (S-like cells) and used for autologous transplantation. However, effect of leukemia inhibitory factor (LIF) on the myelinogenic ability of SC-like cells induced from human ADSC is not investigated yet. The aim of this study was to evaluate of the effect of exogenous LIF on myelinogenic potential of differentiated cells in vitro. ADSCs were harvested from human fat tissue and characterized using flow cytometry. Human ADSCs were treated for sphere formation and LIF was added to terminal differentiation medium. GFAP/S100β and MBP markers were used to confirm differentiation of human ADSCs, and myelinogenic ability of SC-like cells, respectively, using both immunostaining and real-time RT-PCR analysis. The analysis for GFAP⁺/S100β⁺ revealed that LIF can increase both differentiated cells rates and the percentage of myelinating SC-like cells (p < 0.05). Our data showed that SC-like cells induced from human ADSCs were able to generate myelin when exposed to LIF and these cells could be a potential source for the treatment of peripheral and central axonal injuries.     

Promotion of Viral IRES-Mediated Translation Initiation under Mild Hypothermia

Internal ribosome entry site (IRES)-mediated translation is an essential replication step for certain viruses. As IRES-mediated translation is regulated differently from cap-dependent translation under various cellular conditions, we sought to investigate whether temperature influences efficiency of viral IRES-mediated translation initiation by using bicistronic reporter constructs containing an IRES element of encephalomyocarditis virus (EMCV), foot-and-mouth disease virus (FMDV), hepatitis C virus (HCV), human rhinovirus (HRV) or poliovirus (PV). Under mild hypothermic conditions (30 and 35°C), we observed increases in the efficiency of translation initiation by HCV and HRV IRES elements compared to translation initiation at 37°C. The promotion of HRV IRES activity was observed as early as 2 hours after exposure to mild hypothermia. We also confirmed the promotion of translation initiation by HRV IRES under mild hypothermia in multiple cell lines. The expression levels and locations of polypyrimidine tract-binding protein (PTB) and upstream of N-Ras (unr), the IRES trans-acting factors (ITAFs) of HCV and HRV IRES elements, were not modulated by the temperature shift from 37°C to 30°C. Taken together, this study demonstrates that efficiency of translation initiation by some viral IRES elements is temperature dependent.     

Concurrent vitamin D supplementation and exercise training improve cardiac fibrosis via TGF-β/Smad signaling in myocardial infarction model of rats

Journal of Physiology and Biochemistry - Although the role of vitamin D in various types of disorders such as cancer and diabetes has been well recognized, its relation to cardiovascular diseases...