946 resultados para Designer receptors
Resumo:
The human ether-a-go-go-related gene (hERG) encodes the voltage-gated K+ channel, hERG (Kv11.1). This channel passes the rapidly-activating delayed rectifier K+ current (IKr), which is important for cardiac repolarization. A reduction in IKr due to loss-of-function mutations or drug interactions causes long QT syndrome (LQTS), which can lead to cardiac arrhythmias and sudden cardiac death. The density of hERG channels in the plasma membrane is a key determinant of normal physiological function, and is balanced by trafficking to and from the cell surface. Many LQTS-associated hERG mutations result in a trafficking deficiency of otherwise functional channels. Thus, elucidating mechanisms of hERG regulation at the plasma membrane is useful for the prevention and treatment of LQTS. We previously demonstrated that M3 muscarinic receptor activation increases mature hERG expression through a Gq protein-dependent protein kinase C (PKC) pathway. In addition to conventional Gq protein-coupling, M3 receptors recruit β-arrestins upon agonist binding. Traditionally known for their role in receptor desensitization and internalization, β-arrestins also act as adaptor proteins to facilitate G protein-independent signaling. In the present work, I investigated the exclusive effect of β-arrestin signaling on hERG expression by utilizing an arrestin-biased M3 designer receptor (M3D-arr) exclusively activated by clozapine-N-oxide (CNO). By expressing M3D-arr in hERG-HEK cells and treating with CNO under various conditions, I found that M3D-arr activation increased mature hERG expression and current. Within this paradigm, M3D-arr recruited β-arrestin to the plasma membrane, and promoted the PI3K-dependent activation of Akt. I further found that the activated Akt acted through phosphatidylinositol 3-phosphate 5-kinase (PIKfyve) and Rab11 to facilitate endosomal recycling of hERG channels to the plasma membrane.
Resumo:
Designer biopolymers (DBPs) represent state of the art genetically engineered biomacromolecules designed to condense plasmid DNA, and overcome intra- and extra- cellular barriers to gene delivery. Three DBPs were synthesized, each with the tumor molecular targeting peptide-1 (TMTP-1) motif to specifically target metastases. Each DBP was complexed with a pEGFP-N1 reporter plasmid to permit physiochemical and biological assay analysis. Results indicated that two of the biopolymers (RMHT and RM3GT) effectively condensed pEGFP-N1 into cationic nanoparticles< 100nm and were capable of transfecting PC-3 metastatic prostate cancer cells. Conversely the anionic RMGT DBP nanoparticles could not transfect PC-3 cells. RMHT and RM3GT nanoparticles were stable in the presence of serum and protected the cargo from degradation. Additionally it was concluded that cell viability could recover post-transfection with these DBPs, which were less toxic than the commercially available transfection reagent Lipofectamine® 2000. With both DBPs, a higher transfection efficacy was observed in PC-3 cells than in the moderately metastatic, DU145, and normal, PNT2-C2, cell lines. Blocking of the TMTP-1 receptors inhibited gene transfer indicating internalization via this receptor. In conclusion RMHT and RM3GT are fully functional DBPs that address major obstacles to gene delivery and target metastatic cells expressing the TMTP-1 receptor.
Resumo:
As an understanding of users' tacit knowledge and latent needs embedded in user experience has played a critical role in product development, users’ direct involvement in design has become a necessary part of the design process. Various ways of accessing users' tacit knowledge and latent needs have been explored in the field of user-centred design, participatory design, and design for experiencing. User-designer collaboration has been used unconsciously by traditional designers to facilitate the transfer of users' tacit knowledge and to elicit new knowledge. However, what makes user-designer collaboration an effective strategy has rarely been reported on or explored. Therefore, interaction patterns between the users and the designers in three industry-supported user involvement cases were studied. In order to develop a coding system, collaboration was defined as a set of coordinated and joint problem solving activities, measured by the elicitation of new knowledge from collaboration. The analysis of interaction patterns in the user involvement cases revealed that allowing users to challenge or modify their contextual experiences facilitates the transfer of knowledge and new knowledge generation. It was concluded that users can be more effectively integrated into the product development process by employing collaboration strategies to intensify the depth of user involvement.
Resumo:
Currently, fashion quite comfortably covers the space between unique pieces and serialisation, mobilising as necessary the discourses of art or commerce; however, the question of what a fashion designer is remains open. Historically, the image of the fashion designer has been constructed within a heroic and Romantic narrative centred on the concept of designers as artists and hence authors. The recent development of the fashion industry as an image-driven industry, on the one hand, and the placement of fashion in museum contexts on the other, requires a re-thinking of the function of the designer. This paper does not set out to identify a theory that establishes a truthful answer to the position and significance of the fashion designer within the fashion system, but it proposes that an analytical and critical understanding of the fashion designer requires a contextualisation of the philosophies and institutions (including fashion magazines and fashion criticism) that support it.
Resumo:
As user involvement becomes a necessary part of the product development process, various ways of accessing users' latent needs have been developed and studied. Reviews of literatures in user involvement and product development have revealed that accessing users' latent needs and transferring them into design process could be facilitated by effectively implementing user-designer collaboration during the early stage of the design process. In this paper, various types of user-designer collaboration were observed and then distinct characteristics of user-designer collaboration were classified into three categories. 1) Passive objectivity, 2) workplace democratisation, and 3) shared contexts were observed as strategies for better user-designer collaboration, which have been employed in the area of user-centred design, user participatory design and design for experiencing. Based on the literature review, this paper proposed a basic collaboration mechanism between the users and the designers during the early stage of the design process and then discussed how its mechanism will help to describe the interactions between the users and the designers during the user involvement sessions.
Resumo:
ROLE OF LOW AFFINITY β1-ADRENERGIC RECEPTOR IN NORMAL AND DISEASED HEARTS Background: The β1-adrenergic receptor (AR) has at least two binding sites, 1HAR and 1LAR (high and low affinity site of the 1AR respectively) which cause cardiostimulation. Some β-blockers, for example (-)-pindolol and (-)-CGP 12177 can activate β1LAR at higher concentrations than those required to block β1HAR. While β1HAR can be blocked by all clinically used β-blockers, β1LAR is relatively resistant to blockade. Thus, chronic β1LAR activation may occur in the setting of β-blocker therapy, thereby mediating persistent βAR signaling. Thus, it is important to determine the potential significance of β1LAR in vivo, particularly in disease settings. Method and result: C57Bl/6 male mice were used. Chronic (4 weeks) β1LAR activation was achieved by treatment with (-)-CGP12177 via osmotic minipump. Cardiac function was assessed by echocardiography and catheterization. (-)-CGP12177 treatment in healthy mice increased heart rate and left ventricular (LV) contractility without detectable LV remodelling or hypertrophy. In mice subjected to an 8-week period of aorta banding, (-)-CGP12177 treatment given during 4-8 weeks led to a positive inotropic effect. (-)-CGP12177 treatment exacerbated LV remodelling indicated by a worsening of LV hypertrophy by ??% (estimated by weight, wall thickness, cardiomyocyte size) and interstitial/perivascular fibrosis (by histology). Importantly, (-)-CGP12177 treatment to aorta banded mice exacerbated cardiac expression of hypertrophic, fibrogenic and inflammatory genes (all p<0.05 vs. non-treated control with aorta banding).. Conclusion: β1LAR activation provides functional support to the heart, in both normal and diseased (pressure overload) settings. Sustained β1LAR activation in the diseased heart exacerbates LV remodelling and therefore may promote disease progression from compensatory hypertrophy to heart failure. Word count: 270
Resumo:
The following paper explores the use of collaborative pedagogical approaches to advance foundational architectural design education, by linking design process to sustainable technology principles. After a brief discussion on architectural design education, the mentioned collaborative approach is described. This approach facilitates students’ exchange of knowledge between two courses, despite no explicit/assessable requirement to do so. The result for the students is deeper learning and a design process that is enriched through collaboration with sustainable technology. The success of this approach has been measured through questionnaires, evaluation surveys, and a comparative assessment of students common to both courses. The paper focuses on the challenges and innovations in connecting architectural design and technology education, where students are encouraged to implement lessons learnt, thereby closing the gap that these courses have traditionally represented.
Resumo:
The ghrelin axis consists of the gene products of the ghrelin gene (GHRL), and their receptors, including the classical ghrelin receptor GHSR. While it is well-known that the ghrelin gene encodes the 28 amino acid ghrelin peptide hormone, it is now also clear that the locus encodes a range of other bioactive molecules, including novel peptides and non-coding RNAs. For many of these molecules, the physiological functions and cognate receptor(s) remain to be determined. Emerging research techniques, including proteogenomics, are likely to reveal further ghrelin axis-derived molecules. Studies of the role of ghrelin axis genes, peptides and receptors, therefore, promises to be a fruitful area of basic and clinical research in years to come.
Resumo:
Alcohol use disorders (AUDs) are complex and developing effective treatments will require the combination of novel medications and cognitive behavioral therapy approaches. Epidemiological studies have shown there is a high correlation between alcohol consumption and tobacco use, and the prevalence of smoking in alcoholics is as high as 80% compared to about 30% for the general population. Both preclinical and clinical data provide evidence that nicotine administration increases alcohol intake and nonspecific nicotinic receptor antagonists reduce alcohol-mediated behaviors. As nicotine interacts specifically with the neuronal nicotinic acetylcholine receptor (nAChR) system, this suggests that nAChRs play an important role in the behavioral effects of alcohol. In this review, we discuss the importance of nAChRs for the treatment of AUDs and argue that the use of FDA approved nAChR ligands, such as varenicline and mecamylamine, approved as smoking cessation aids may prove to be valuable treatments for AUDs. We also address the importance of combining effective medications with behavioral therapy for the treatment of alcohol dependent individuals.