Insulin therapy in diabetes mellitus: how can the currently available injectable insulins be most prudently and efficaciously utilised?

The BioGRID database: A comprehensive biomedical resource of curated protein, genetic, and chemical interactions

The BioGRID (Biological General Repository for Interaction Datasets, thebiogrid.org) is an open-access database resource that houses manually curated protein and genetic interactions from multiple species including yeast, worm, fly, mouse, and human. The ~1.93 million curated interactions in BioGRID can be used to build complex networks to facilitate biomedical discoveries, particularly as related to human health and disease. All BioGRID content is curated from primary experimental evidence in the biomedical literature, and includes both focused low-throughput studies and large high-throughput datasets. BioGRID also captures protein post-translational modifications and protein or gene interactions with bioactive small molecules including many known drugs. A built-in network visualization tool combines all annotations and allows users to generate network graphs of protein, genetic and chemical interactions. In addition to general curation across species, BioGRID undertakes themed curation projects in specific aspects of cellular regulation, for example the ubiquitin-proteasome system, as well as specific disease areas, such as for the SARS-CoV-2 virus that causes COVID-19 severe acute respiratory syndrome. A recent extension of BioGRID, named the Open Repository of CRISPR Screens (ORCS, orcs.thebiogrid.org), captures single mutant phenotypes and genetic interactions from published high throughput genome-wide CRISPR/Cas9-based genetic screens. BioGRID-ORCS contains datasets for over 1,042 CRISPR screens carried out to date in human, mouse and fly cell lines. The biomedical research community can freely access all BioGRID data through the web interface, standardized file downloads, or via model organism databases and partner meta-databases.

Finally, after 56 years of type 1 diabetes: a regimen that works

Prior to the availability of degludec and regular human insulin inhalation powder in the type 1 diabetic patient glycemic control with subcutaneous insulin injections was difficult to obtain due to nocturnal, pre-prandial and often severe hypoglycemia as well as post-prandial hyperglycemia and hypoglycemia due to 'stacking' of insulin. A 62-year-old female with type 1 diabetes for 56 years who could not be controlled with continuous subcutaneous insulin aspart infusion obtained glycemic control without significant hypoglycemia or increased post-prandial glycemic excursions utilizing degludec insulin for basal needs and technosphere before meals and between meals if needed. The availability of degludec and technosphere insulin improved the management of brittle type 1 diabetes.

Competitive binding-accelerated insulin release from a polypeptide nanogel for potential therapy of diabetes

A novel core cross-linked glycopolypeptide nanogel was prepared for glucose-triggered insulin delivery.

Synthesis of chiral N-phosphinyl α-imino esters and their application in asymmetric synthesis of α-amino esters by reduction

A variety of chiral N-phosphinyl α-imino esters have been synthesized for the first time from ketoesters and phosphinylamide, which were then reduced by L-selectride to give the corresponding N-phosphinyl-protected α-amino esters. The reduction proceeded very well with excellent chemical yields (88–98%) as well as high diastereoselectivities (96:4 to 99:1). Some of these products could be obtained without column chromatography and recrystallization. The chiral phosphinyl auxiliary could be easily cleaved under acidic conditions.

Evaluation of dosing and clinical outcomes in patients undergoing conversion of insulin glargine to insulin detemir

STUDY OBJECTIVES

To evaluate the dose and frequency of insulin detemir for patients with diabetes mellitus undergoing conversion from insulin glargine to insulin detemir, and to assess glycemic control, weight gain, and risk of hypoglycemia after converting to insulin detemir.

DESIGN

Retrospective medical record review.

SETTING

Large academic medical center.

PATIENTS

Thirty-one patients with type 1 (10 patients) or type 2 (21 patients) diabetes who were converted from insulin glargine to insulin detemir by usual practice between January 1, 2006, and March 3, 2007, after an Iowa Medicaid formulary switch.

MEASUREMENT AND MAIN RESULTS

Data were collected for 12 months after conversion from insulin glargine to insulin detemir. No significant change in mean basal insulin dose was noted in patients with type 1 diabetes at the end of 12 months (insulin detemir 31.1 units/day vs baseline insulin glargine 32.0 units/day, p=0.89; insulin detemir 0.41 unit/kg/day vs baseline insulin glargine 0.42 unit/kg/day, p=0.91). In patients with type 2 diabetes, however, the mean basal insulin dose was significantly higher with insulin detemir compared with baseline insulin glargine (74.2 vs 55.8 units/day, p=0.002; 0.68 vs 0.48 unit/kg/day, p=0.001) at the end of 12 months. Twice-daily administration was required in a higher proportion of patients receiving insulin detemir (15 patients [48%]) at 12 months compared with insulin glargine (4 patients [13%]) at baseline (p=0.043). A significant change in hemoglobin A(1c) was not observed in patients with type 1 diabetes (9.7% with insulin detemir vs 9.3% with insulin glargine, p=0.41) or type 2 diabetes (9.4% with insulin detemir vs 9.7% with insulin glargine at baseline, p=0.57) despite the use of higher insulin detemir doses in patients with type 2 diabetes. No significant differences in weight or frequency of hypoglycemia were noted.

CONCLUSION

Treatment with insulin detemir appears to require more frequent administration and higher insulin doses compared with insulin glargine in patients with type 2 diabetes, with 33% higher doses, on average, observed in this study. These findings suggest that a unit-for-unit conversion from insulin glargine to insulin detemir, as suggested by the manufacturer of insulin detemir, may not be adequate in patients with type 2 diabetes.

The metabolic and mitogenic properties of basal insulin analogues

CONTEXT

Retrospective, observational studies have reported an association between diabetes treatment with insulin and a higher incidence of cancer.

OBJECTIVE

Overview the literature for in vitro and in vivo studies of the metabolic and mitogenic properties of basal insulin analogues and assess the implications for clinical use.

METHODS

Relevant studies were identified through PubMed and congress abstract database searches; data on metabolic and mitogenic signalling in relation to insulin treatment of diabetes are included in this review.

RESULTS

The balance of evidence shows that although some analogues have demonstrated mitogenic potency in some in vitro studies in cancer cell lines, these findings do not translate to the in vivo setting in animals or to the clinical setting in humans.

CONCLUSIONS

The current consensus is that there is no clinical or in vivo evidence to indicate that any commercially available insulin analogue has carcinogenic effects. Large-scale, prospective clinical and observational studies will further establish any potential link.

Controlling the aggregation and rate of release in order to improve insulin formulation: molecular dynamics study of full-length insulin amyloid oligomer models

Insulin is a hormone that regulates the physiological glucose level in human blood. Insulin injections are used to treat diabetic patients. The amyloid aggregation of insulin may cause problems during the production, storage, and delivery of insulin formulations. Several modifications to the C-terminus of the B chain have been suggested in order to improve the insulin formulation. The central fragments of the A and B chains (LYQLENY and LVEALYL) have recently been identified as β-sheet-forming regions, and their microcrystalline structures have been used to build a high-resolution amyloid fibril model of insulin. Here we report on a molecular dynamics (MD) study of single-layer oligomers of the full-length insulin which aimed to identify the structural elements that are important for amyloid stability, and to suggest single glycine mutants in the β-sheet region that may improve the formulation. Structural stability, aggregation behavior and the thermodynamics of association were studied for the wild-type and mutant aggregates. A comparison of the oligomers of different sizes revealed that adding strands enhances the internal stability of the wild-type aggregates. We call this "dynamic cooperativity". The secondary structure content and clustering analysis of the MD trajectories show that the largest aggregates retain the fibril conformation, while the monomers and dimers lose their conformations. The degree of structural similarity between the oligomers in the simulation and the fibril conformation is proposed as a possible explanation for the experimentally observed shortening of the nucleation lag phase of insulin with oligomer seeding. Decomposing the free energy into electrostatic, van der Waals and solvation components demonstrated that electrostatic interactions contribute unfavorably to the binding, while the van der Waals and especially solvation effects are favorable for it. A per-atom decomposition allowed us to identify the residues that contribute most to the binding free energy. Residues in the β-sheet regions of chains A and B were found to be the key residues as they provided the largest favorable contributions to single-layer association. The positive ∆∆G (mut) values of 37.3 to 1.4 kcal mol(-1) of the mutants in the β-sheet region indicate that they have a lower tendency to aggregate than the wild type. The information obtained by identifying the parts of insulin molecules that are crucial to aggregate formation and stability can be used to design new analogs that can better control the blood glucose level. The results of our simulation may help in the rational design of new insulin analogs with a decreased propensity for self-association, thus avoiding injection amyloidosis. They may also be used to design new fast-acting and delayed-release insulin formulations.

Therapeutics of diabetes mellitus: focus on insulin analogues and insulin pumps

Aim. Inadequately controlled diabetes accounts for chronic complications and increases mortality. Its therapeutic management aims in normal HbA1C, prandial and postprandial glucose levels. This review discusses diabetes management focusing on the latest insulin analogues, alternative insulin delivery systems and the artificial pancreas. Results. Intensive insulin therapy with multiple daily injections (MDI) allows better imitation of the physiological rhythm of insulin secretion. Longer-acting, basal insulin analogues provide concomitant improvements in safety, efficacy and variability of glycaemic control, followed by low risks of hypoglycaemia. Continuous subcutaneous insulin infusion (CSII) provides long-term glycaemic control especially in type 1 diabetic patients, while reducing hypoglycaemic episodes and glycaemic variability. Continuous subcutaneous glucose monitoring (CGM) systems provide information on postprandial glucose excursions and nocturnal hypo- and/or hyperglycemias. This information enhances treatment options, provides a useful tool for self-monitoring and allows safer achievement of treatment targets. In the absence of a cure-like pancreas or islets transplants, artificial “closed-loop” systems mimicking the pancreatic activity have been also developed. Conclusions. Individualized treatment plans for insulin initiation and administration mode are critical in achieving target glycaemic levels. Progress in these fields is expected to facilitate and improve the quality of life of diabetic patients.

Insulin glulisine: a review of its use in the management of diabetes mellitus

Insulin glulisine (Apidra) is a human insulin analogue approved for the improvement of glycaemic control in adults, adolescents and children with diabetes mellitus. It has similar binding properties, and is associated with a faster onset but similar level of glucose disposal, to regular human insulin (RHI). Insulin glulisine and insulin lispro have similar effects on glucose levels. Insulin glulisine is effective when compared to other short- and rapid-acting insulins, demonstrating either noninferiority, no significant difference, or superiority in primary endpoints in studies involving patients with type 1 and type 2 diabetes. It is more effective and has a faster onset and shorter duration of activity than RHI. Insulin glulisine is as effective as insulin lispro in patients with type 1 diabetes; however, there is a need for further, well designed head-to-head comparisons with insulin lispro in patients with type 2 diabetes and with insulin aspart in patients with type 1 or type 2 diabetes to fully establish the place of insulin glulisine in the management of diabetes. Insulin glulisine has a flexible administration period, as it can be administered immediately before or after meals. Hypoglycaemia, a common risk with insulins, occurs at a similar rate among recipients of insulin glulisine to that seen with other insulins. Thus, insulin glulisine is an effective and well tolerated option for the treatment of patients with type 1 and type 2 diabetes.

Expression of human insulin gene wrapped with chitosan nanoparticles in NIH3T3 cells and diabetic rats

AIM

To study the expression of human insulin gene wrapped with chitosan nanoparticles in NIH3T3 cells and diabetic rats.

METHODS

pCMV.Ins, an expression plasmid of the human insulin gene, was constructed. In total, 100 microg pCMV.Ins wrapped with chitosan nanoparticles (chitosan-pCMV.Ins) was transfected to NIH3T3 cells and diabetes rats through lavage and coloclysis, respectively. The transfected cells were grown in Dulbecco's modified Eagle's medium, containing G418, for 72 h after transfection. The clones were selected and continued to grow in G418 medium for 24 d. The expression of human insulin was detected by immunohistochemistry. Human insulin in the culture medium of transfected cells was measured. Fasting blood glucose and plasma human insulin of diabetic rats were measured for 5 d after transfection. RT-PCR and Western blotting were performed to confirm the expression of the human insulin gene in diabetic rats.

RESULTS

Approximately 10% of NIH3T3 cells transfected by chitosan-pCMV.Ins expressed human insulin. Human insulin in the culture medium of NIH3T3 cells transfected by chitosan-pCMV.Ins significantly increased compared with that of the control group (P<0.01). Fasting blood glucose levels of the lavage group and the coloclysis group decreased significantly in 5 d (P<0.01) in comparison, while plasma insulin levels were much higher (P<0.01). The human insulin gene mRNA and human insulin were only detected in the lavage and the coloclysis groups.

CONCLUSION

The human insulin gene can be transfected and expressed successfully by chitosan- pCMV.Ins in NIH3T3 cells and diabetes rats, which indicates that chitosan is a promising, non-viral vector for gene expression.

Recombinant therapeutic proteins: production platforms and challenges

Since the approval of insulin in 1982, more than 120 recombinant drug substances have been approved and become available as extremely valuable therapeutic options. Exact copying of the most common human form is no longer a value per se, as challenges, primarily related to the pharmacokinetics of artificial recombinant drugs, can be overcome by diverging from the original. However, relatively minor changes in manufacturing or packaging may impact safety of therapeutic proteins. A major achievement is the development of recombinant proteins capable of entering a cell. Such drugs open up completely new opportunities by targeting intracellular mechanisms or by substituting intracellularly operating enzymes. Concerns that protein variants would cause an intolerable immune response turned out to be exaggerated. Although most recombinant drugs provoke some immune response, they are still well tolerated. This knowledge might result in a change in attitude towards antibody formation, i.e., neutralizing antibody activity (in vitro) may be overcome by dosing consistently on the basis of antibody titers and not only on body weight. As with other drugs, efficacy and safety of therapeutic proteins have to be demonstrated in clinical studies, and superiority over available products has to be proven instead of just claimed.