Potential limits of AAV-based gene therapy with the use of new transgenes expressing factor IX fusion proteins

Introduction: The variety of treatment for haemophilia B (HB) has recently improved with the emergence of both AAV‐based gene therapy and bioengineered human factor IX (hFIX) molecules with prolonged half‐life due to fusion to either albumin (Alb) or immunoglobulin Fc fragment (Fc). / Aim: Adeno‐associated viral vectors (AAV) mediating expression of hFIX‐Alb and hFIX‐Fc fusion proteins was investigated for gene therapy of HB to explore if their extended half‐life translates to higher plasma levels of FIX. / Methods: Single‐stranded cross‐packaged AAV2/8 vectors expressing hFIX‐Alb, hFIX‐Fc and hFIX were evaluated in vitro, and in mice. / Results: Both hFIX‐Alb and hFIX‐Fc fusion proteins were synthesized and expressed as single chains of expected size following AAV‐mediated gene transfer in vitro and in vivo. The procoagulant properties of these hFIX‐fusion proteins were comparable to wild‐type hFIX. However, their expression levels were threefold lower than wild‐type hFIX in vivo most likely due to inefficient secretion. / Conclusion: This, the first, evaluation of hFIX‐fusion proteins in the context of AAV gene transfer suggests that the hFIX‐fusion proteins are secreted inefficiently from the liver, thus preventing their optimal use in gene therapy approaches

Control of disseminated intravascular coagulation in Klippel-Trenaunay-Weber syndrome using enoxaparin and recombinant activated factor VIIa: a case report

<p>Abstract</p> <p>Introduction</p> <p>Vascular malformation is associated with coagulopathies, especially when hemostasis is challenged.</p> <p>Case presentation</p> <p>We present the case of an 11-year-old Hispanic girl with Klippel-Trenaunay-Weber syndrome that developed disseminated intravascular coagulation after minor surgery, which was controlled by blood product transfusions and enoxaparin to address an ongoing consumptive coagulopathy. The patient, however, developed bacteremia and liver trauma that resulted in severe bleeding. To the best of our knowledge, we report here the first known instance of administering recombinant coagulation factor VIIa to control acute bleeding in a patient with Klippel-Trenaunay-Weber syndrome.</p> <p>Conclusions</p> <p>This case illustrates the concept of enoxaparin maintenance to suppress an ongoing consumptive coagulopathy and the use of recombinant coagulation factor VIIa to control its potentially fatal severe bleeding episodes.</p

Protein C Mutation (A267T) Results in ER Retention and Unfolded Protein Response Activation

BACKGROUND: Protein C (PC) deficiency is associated with a high risk of venous thrombosis. Recently, we identified the PC-A267T mutation in a patient with PC deficiency and revealed by in vitro studies decreased intracellular and secreted levels of the mutant. The aim of the present study was to characterize the underlying mechanism(s). METHODOLOGY/PRINCIPAL FINDINGS: CHO-K1 cells stably expressing the wild-type (PC-wt) or the PC mutant were generated. In order to examine whether the PC mutant was subjected to increased intracellular degradation, the cells were treated with several inhibitors of various degradation pathways and pulse-chase experiments were performed. Protein-chaperone complexes were analyzed by treating the cells with a cross-linker followed by Western blotting (WB). Expression levels of the immunoglobulin-binding protein (BiP) and the phosphorylated eukaryotic initiation factor 2α (P-eIF2α), both common ER stress markers, were determined by WB to examine if the mutation induced ER stress and unfolded protein response (UPR) activation. We found no major differences in the intracellular degradation between the PC variants. The PC mutant was retained in the endoplasmic reticulum (ER) and had increased association with the Grp-94 and calreticulin chaperones. Retention of the PC-A267T in ER resulted in UPR activation demonstrated by increased expression levels of the ER stress markers BiP and P-eIF2α and caused also increased apoptotic activity in CHO-K1 cells as evidenced by elevated levels of DNA fragmentation. CONCLUSIONS/SIGNIFICANCE: The reduced intracellular level and impaired secretion of the PC mutant were due to retention in ER. In contrast to other PC mutations, retention of the PC-A267T in ER resulted in minor increased proteasomal degradation, rather it induced ER stress, UPR activation and apoptosis

‘Friends call me racist’: Experiences of repercussions from writing comments on newspaper websites

acceptedVersio

An Overview of Three Promising Mechanical, Optical, and Biochemical Engineering Approaches to Improve Selective Photothermolysis of Refractory Port Wine Stains

During the last three decades, several laser systems, ancillary technologies, and treatment modalities have been developed for the treatment of port wine stains (PWSs). However, approximately half of the PWS patient population responds suboptimally to laser treatment. Consequently, novel treatment modalities and therapeutic techniques/strategies are required to improve PWS treatment efficacy. This overview therefore focuses on three distinct experimental approaches for the optimization of PWS laser treatment. The approaches are addressed from the perspective of mechanical engineering (the use of local hypobaric pressure to induce vasodilation in the laser-irradiated dermal microcirculation), optical engineering (laser-speckle imaging of post-treatment flow in laser-treated PWS skin), and biochemical engineering (light- and heat-activatable liposomal drug delivery systems to enhance the extent of post-irradiation vascular occlusion)