Insulin receptor is a multi-domain signalling protein acting as a dimer. It comprises an extracellular ectodomain, a transmembrane domain and intracellular tyrosine kinase domain. Upon insulin binding, conformational changes in insulin as well as in insulin receptor occur and trigger the signaling cascade via the kinase domain. Abnormalities in insulin and insulin receptor function cause diabetes mellitus, a widespread disorder which can be consequence of genetic factors as well as lifestyle and is manifested by increased level of blood glucose. A common treatment of diabetes mellitus is via insulin analogues with different molecular properties. Insulin/insulin receptor interactions in the binding pocket are divided into two groups, so-called "site1" and "site2". The molecular details of the interactions in site1 are well known, while site2 residues are still not completely elucidated. It is important to shed light on the binding properties of insulin and insulin receptor, especially site2 interactions, because it could contribute to improved design of new insulin analogues. In this work, we used the very recent breakthroughs in the structural biology of insulin receptor to study the interactions by computational chemistry methods. It was thus possible to assess the noncovalent interactions and...

While genome‐wide association studies as well as candidate gene studies have revealed a great deal of insight into the contribution of genetics to obesity development and susceptibility, advances in adipose tissue research have substantially changed the understanding of adipose tissue function. Its perception has changed from passive lipid storage tissue to active endocrine organ regulating and modulating whole‐body energy homeostasis and metabolism and inflammatory and immune responses by secreting a multitude of bioactive molecules, termed adipokines. The expression of human vaspin (serpinA12) is positively correlated to body mass index and insulin sensitivity and increases glucose tolerance in vivo, suggesting a compensatory role in response to diminished insulin signaling in obesity. Recently, considerable insight has been gained into vaspin structure, function, and specific target tissue‐dependent effects, and several lines of evidence suggest vaspin as a promising candidate for drug development for the treatment of obesity‐related insulin resistance and inflammation. These will be summarized in this review with a focus on molecular mechanisms and pathways.

Human pancreatic beta cells are susceptible to infection by enteroviruses, especially Coxsackie B viruses, and such infections could contribute to the development of Type 1 diabetes. Enteroviruses gain entry via cell surface receptors, one of which, the Coxsackie and Adenovirus receptor (CAR), is a transmembrane cell adhesion protein which serves as a key entry receptor for Coxsackie B viruses and is thought to be localised mainly within regions where contacts are formed between adjacent cells. CAR exists as at least 5 isoforms and this study has examined their expression profile and distribution in the human pancreas utilising; formalin-fixed paraffin-embedded pancreatic sections from non-diabetic individuals, type 1 diabetes patients and a human tissue microarray. Isolated human islets, human pancreatic beta and ductal cell lines were also studied. Immunological and molecular approaches were employed to examine the expression and cellular localisation of the known CAR isoforms in human pancreas. One specific isoform of CAR (CAR-SIV) with a unique C terminal PDZ binding domain, was highly expressed in human beta cells at the protein level. Surprisingly, it was distributed in a punctate manner mainly within the cytoplasm of the cells, rather than at the cell surface. In human beta cells, within the cytoplasm CAR-SIV co-localised with ZnT8, PC1/3 and insulin but less so with proinsulin suggesting that CAR-SIV is associated with insulin secretory granules. Immunogold labelling and electron microscopic analysis revealed that CAR-SIV is localised both to maturing insulin secretory granules and to fully mature, dense-core (insulin) secretory granules. Intriguingly, CAR-SIV colocalises and interacts with a cytosolic protein, PICK1, which plays a role in the budding, maturation and trafficking of insulin secretory granules. On this basis, a model is proposed whereby CAR-SIV and PICK1 interact to regulate the maturation and trafficking of insulin secretory granules. Overall, this study suggests that the specialised role and subcellular localisation of CAR-SIV in human beta cells may contribute to their sensitivity to enteroviral infection following externalisation of the protein at the cell surface, during insulin exocytosis.

Type 1 diabetes mellitus is chronic disease and the diploma thesis deals with the needs of students with this type of diabetes in selected primary schools. In the theoretical part I deal with the diet of these students, the education of children and their families, the problems arising from this disease and last but not least, the treatment and types of treatment for type I diabetes. I also mentioned the possible mental problems that can occur in children. In the practical part I found out the specific needs of students suffering from this disease. In my diploma thesis I set one main goal and that was to find out the needs of students. The data were provided with an unstructured interwiew with students from selected primary school. I addressed exactly 12 respondents with whom I interviewed. All interviews were without a single comlication and problem. I first met all the respondents to create friendly atmosphere for the upcoming convercation. During the interviews a large amount of data was indentified for processing. Thanks to the interviewe I came to the conclusion that students in primary school suffering from type I diabetes have certain needs. For example they need to have a mobile phone with them at all times and know subconsciously that they can call for help at any time. Furthermore...

An implantable closed-loop insulin delivery device (INsmart device) containing a glucose responsive gel has been developed within the INsmart research group, over a period of 10 years, to mimic pancreas. In this thesis, the reliability and performance capability of the INsmart device was studied for future clinical use. Investigations into the device material compatibility with insulin solution, assessed by monitoring insulin loss and degradant formation over a period of 31 days using RP-HPLC have shown that stainless steel and titanium are the most compatible materials. Polycarbonate contributes to insulin loss after 11 days, resin might not be the best material and polyurethane is the least compatible for future device designs. To study insulin delivery mechanism and kinetics from the device, fluorescently labelled human insulin (FITC-insulin) was synthesised and characterised using RP-HPLC and MS, to produce a product with predominantly di-labelled conjugate (>75%) with no unreacted FITC or native insulin. Clinically used insulin analogues were also fluorescently labelled to produce predominantly di-labelled FITC-insulin conjugate with potential future biological and in vitro applications. The drug release mechanism from the glucose sensitive gel held in the INsmart device, studied using fluorescein sodium was determined as a Fickian diffusion controlled release mechanism. The diffusion coefficient (D) for FITC-insulin in the non-polymerised dex2M-conA gel (NP gel) determined using mathematical models, QSS and TL slope methods was 1.05 ± 0.02 x 10-11 m2/s and in the cross-linked dex500MA-conAMA gel (CL gel) was 0.75 ± 0.06 x 10-11 m2/s. In response to physiologically relevant glucose triggers in the NP gel, the diffusivity of FITC-insulin increases with increasing glucose concentrations, showing a second order polynomial fit, device thus showing glucose sensitivity and graded response, mimicking pancreas. Rheological measurements further confirmed the gel glucose responsiveness demonstrated by a third order polynomial fit between FITC-insulin D and the NP complex viscosity in response to increasing glucose concentration. The knowledge of FITC-insulin diffusion kinetics in the gel has aided in making some theoretical predictions for the capability and performance of the INsmart device. Alternate device geometry and design optimisation is also explored.