Increased levels of insulin and insulin-like growth factor-1 hybrid receptors and decreased glycosylation of the insulin receptor alpha- and beta-subunits in scrapie-infected neuroblastoma N2a cells.

We have previously shown that ScN2a cells (scrapie-infected neuroblastoma N2a cells) express 2-fold- and 4-fold-increased levels of IR (insulin receptor) and IGF-1R (insulin-like growth factor-1 receptor) respectively. In addition, the IR alpha- and beta-subunits are aberrantly processed, with apparent molecular masses of 128 and 85 kDa respectively, as compared with 136 and 95 kDa in uninfected N2a cells. Despite the 2-fold increase in IR protein, the number of (125)I-insulin-binding sites was slightly decreased in ScN2a cells [Ostlund, Lindegren, Pettersson and Bedecs (2001) Brain Res. 97, 161-170]. In order to determine the cellular localization of IR in ScN2a cells, surface biotinylation was performed, showing a correct IR trafficking and localization to the cell surface. The present study shows for the first time that neuroblastoma N2a cells express significant levels of IR-IGF-1R hybrid receptors, and in ScN2a cells the number of hybrid receptors was 2-fold higher than that found in N2a cells, potentially explaining the apparent loss of insulin-binding sites due to a lower affinity for insulin compared with the homotypic IR. Furthermore, the decreased molecular mass of IR subunits in ScN2a cells is not caused by altered phosphorylation or proteolytic processing, but rather by altered glycosylation. Enzymic deglycosylation of immunoprecipitated IR from N2a and ScN2a cells with endoglycosidase H, peptide N-glycosidase F and neuraminidase all resulted in subunits with increased electrophoretic mobility; however, the 8-10 kDa shift remained. Combined enzymic or chemical deglycosylation using anhydrous trifluoromethane sulphonic acid treatment ultimately showed that the IR alpha- and beta-subunits from ScN2a cells are aberrantly glycosylated. The increased formation of IR-IGF-1R hybrids in ScN2a cells may be part of a neuroprotective response to prion infection. The degree and functional significance of aberrantly glycosylated proteins in ScN2a cells remain to be determined

In: Rolka, R., Rekowski, P. & Siberring, J. (Eds.), Peptides 2006 : Proceedings of the Twenty-Ninth European Peptide Symposium, Gdansk, Poland, 3 - 8 Sept. 2006, No. 0212

INTRODUCTION: Many cell-penetrating peptides (CPP) have been utilised as biologically inert vectors. A majority of these studies employ sychnologically organised constructs in which a bioactive cargo (message) is chemically conjugated to the CPP (address). Previously, we have adopted a sychnologic strategy to modulate intracellular signal transduction. Using chimeric constructs composed of the CPP transportan 10, conjugated to partial sequences that correspond to functional domains of signal transduction proteins, we have selectively modulated a variety of cellular activities including secretion and activation of p42/p44 mitogen-activated protein kinases [1, 2]. However, a QSAR-based algorithm can now be used to predict CPP that reside within the primary sequences of proteins [3]. We have adapted this strategy to identify CPP within signal transducing proteins including functional domains that govern protein-protein interactions. Data presented herein indicate that it is now feasible to identify rhegnylogic sequences, containing vectoral-independent discontinuously organised pharmacophores, that are cell penetrant modulators of signal transduction pathways

Framework for systematic identification of ethical aspects of healthcare technologies : the SBU approach

Objectives: Assessment of ethical aspects of a technology is an important component of health technology assessment (HTA). Nevertheless, how the implementation of ethical assessment in HTA is to be organized and adapted to specific regulatory and organizational settings remains unclear. The objective of this study is to present a framework for systematic identification of ethical aspects of health technologies. Furthermore, the process of developing and adapting the framework to a specific setting is described. Methods: The framework was developed based on an inventory of existing approaches to identification and assessment of ethical aspects in HTA. In addition, the framework was adapted to the Swedish legal and organizational healthcare context, to the role of the HTA agency and to the use of non-ethicists. The framework was reviewed by a group of ethicists working in the field as well as by a wider set of interested parties including industry, interest groups, and other potential users. Results: The framework consists of twelve items with sub-questions, short explanations, and a concluding overall summary. The items are organized into four different themes: the effects of the intervention on health, its compatibility with ethical norms, structural factors with ethical implications, and long term ethical consequences of using the intervention. Conclusions: In this study, a framework for identifying ethical aspects of health technologies is proposed. The general considerations and methodological approach to this venture will hopefully inspire and present important insights to organizations in other national contexts interested in making similar adaptations