Glucose-sensitive insulin with attenuation of hypoglycaemia.

The risk of inducing hypoglycaemia (low blood glucose) constitutes the main challenge associated with insulin therapy for diabetes. Insulin doses must be adjusted to ensure that blood glucose values are within the normal range, but matching insulin doses to fluctuating glucose levels is difficult because even a slightly higher insulin dose than needed can lead to a hypoglycaemic incidence, which can be anything from uncomfortable to life-threatening. It has therefore been a long-standing goal to engineer a glucose-sensitive insulin that can auto-adjust its bioactivity in a reversible manner according to ambient glucose levels to ultimately achieve better glycaemic control while lowering the risk of hypoglycaemia.

Disrupted hypothalamic transcriptomics and proteomics in a mouse model of type 2 diabetes exposed to recurrent hypoglycaemia.

Aims/hypothesis: Repeated exposures to insulin-induced hypoglycaemia in people with diabetes progressively impairs the counterregulatory response (CRR) that restores normoglycaemia. This defect is characterised by reduced secretion of glucagon and other counterregulatory hormones. Evidence indicates that glucose-responsive neurons located in the hypothalamus orchestrate the CRR.

Standard procedures for blood withdrawal in conscious male rats induce stress and profoundly affect glucose tolerance and secretion of glucoregulatory hormones.

Objective: A fundamental difference between physiological and pharmacological studies in rats and humans is that withdrawal of blood from conscious rats necessitates restraint which inevitably inflicts a higher level of stress. We investigated the impact of handling on acute glucose regulation and secretion of glucoregulatory hormones in rats.

Methods: Fasted male Sprague Dawley rats (375-400 g, n = 11) were given an oral glucose tolerance test (OGTT) by gavage (2 g/kg).

An integrated platform approach enables discovery of potent, selective and ligand-competitive cyclic peptides targeting the GIP receptor.

In any drug discovery effort, the identification of hits for further optimisation is of crucial importance. For peptide therapeutics, display technologies such as mRNA display have emerged as powerful methodologies to identify these desired hit ligands against targets of interest. The diverse peptide libraries are genetically encoded in these technologies, allowing for next-generation sequencing to be used to efficiently identify the binding ligands.

Molecular Engineering of Insulin Icodec, the First Acylated Insulin Analog for Once-Weekly Administration in Humans.

Here, we describe the molecular engineering of insulin icodec to achieve a plasma half-life of 196 h in humans, suitable for once-weekly subcutaneously administration. Insulin icodec is based on re-engineering of the ultra-long oral basal insulin OI338 with a plasma half-life of 70 h in humans. This systematic re-engineering was accomplished by (1) further increasing the albumin binding by changing the fatty diacid from a 1,18-octadecanedioic acid (C18) to a 1,20-icosanedioic acid (C20) and (2) further reducing the insulin receptor affinity by the B16Tyr → His substitution.

Temporal Development of Dyslipidemia and Nonalcoholic Fatty Liver Disease (NAFLD) in Syrian Hamsters Fed a High-Fat, High-Fructose, High-Cholesterol Diet.

The use of translationally relevant animal models is essential, also within the field of nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH). Compared to frequently used mouse and rat models, the hamster may provide a higher degree of physiological similarity to humans in terms of lipid profile and lipoprotein metabolism. However, the effects in hamsters after long-term exposure to a NASH diet are not known.

Insulin treatment improves liver histopathology and decreases expression of inflammatory and fibrogenic genes in a hyperglycemic, dyslipidemic hamster model of NAFLD.

Background: Non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH) are highly prevalent comorbidities in patients with Type 2 diabetes. While many of these patients eventually will need treatment with insulin, little is known about the effects of insulin treatment on histopathological parameters and hepatic gene expression in diabetic patients with co-existing NAFLD and NASH. To investigate this further, we evaluated the effects of insulin treatment in NASH diet-fed hamsters with streptozotocin (STZ) -induced hyperglycemia.

Insulin Treatment Attenuates Small Nerve Fiber Damage in Rat Model of Type 2 Diabetes.

Introduction: Current clinical guidelines for management of diabetic peripheral neuropathy (DPN) emphasize good glycemic control. However, this has limited effect on prevention of DPN in type 2 diabetic (T2D) patients. This study investigates the effect of insulin treatment on development of DPN in a rat model of T2D to assess the underlying causes leading to DPN.

Variation in diagnostic NAFLD/NASH read-outs in paired liver samples from rodent models.

Introduction: In animal models of non-alcoholic fatty liver disease (NAFLD), assessment of disease severity and treatment effects of drugs rely on histopathological scoring of liver biopsies. However, little is known about the sampling variation in liver samples from animal models of NAFLD, even though several histopathological hallmarks of the disease are known to be affected by sampling variation in patients. The aim of this study was to assess the sampling variation in multiple paired liver biopsies from three commonly used diet-induced rodent models of NAFLD.

Peripherally delivered hepatopreferential insulin analog insulin-406 mimics the hypoglycaemia-sparing effect of portal vein human insulin infusion in dogs.

Aims: We previously quantified the hypoglycaemia-sparing effect of portal vs peripheral human insulin delivery. The current investigation aimed to determine whether a bioequivalent peripheral vein infusion of a hepatopreferential insulin analog, insulin-406, could similarly protect against hypoglycaemia.

Materials And Methods: Dogs received human insulin infusions into either the hepatic portal vein (PoHI, n = 7) or a peripheral vein (PeHI, n = 7) for 180 minutes at four-fold the basal secretion rate (6.

Targeting insulin to the liver corrects defects in glucose metabolism caused by peripheral insulin delivery.

Peripheral hyperinsulinemia resulting from subcutaneous insulin injection is associated with metabolic defects which include abnormal glucose metabolism. The first aim of this study was to quantify the impairments in liver and muscle glucose metabolism that occur when insulin is delivered via a peripheral vein compared to when it is given through its endogenous secretory route (the hepatic portal vein) in overnight fasted conscious dogs. The second aim was to determine if peripheral delivery of a hepato-preferential insulin analog could restore the physiologic response to insulin that occurs under meal feeding conditions.

Dietary fat stimulates development of NAFLD more potently than dietary fructose in Sprague-Dawley rats.

Background: In humans and animal models, excessive intake of dietary fat, fructose and cholesterol has been linked to the development of non-alcoholic fatty liver disease (NAFLD). However, the individual roles of the dietary components remain unclear. To investigate this further, we compared the effects of a high-fat diet, a high-fructose diet and a combination diet with added cholesterol on the development of NAFLD in rats.

Diabetic Phenotype in the Small Intestine of Zucker Diabetic Fatty Rats.

Background/aims: In contrast to streptozotocin (STZ)-induced rodent models of diabetes, there are no thorough characterizations of the intestinal phenotype and the underlying changes in the global gene-expression of genetic models of diabetes, such as the Zucker diabetic fatty (ZDF) rat. The aim of the present study was to characterize the intestine in the ZDF rat.

Methods: The intestine of ZDF rats and lean controls was examined macroscopically and histologically, and ribonucleic acid sequencing (RNAseq) was performed in samples of jejunal mucosa.

Insulin Delivery Into the Peripheral Circulation: A Key Contributor to Hypoglycemia in Type 1 Diabetes.

Hypoglycemia limits optimal glycemic control in type 1 diabetes mellitus (T1DM), making novel strategies to mitigate it desirable. We hypothesized that portal (Po) vein insulin delivery would lessen hypoglycemia. In the conscious dog, insulin was infused into the hepatic Po vein or a peripheral (Pe) vein at a rate four times of basal.

Structure-activity studies in the development of a hydrazone based inhibitor of adipose-triglyceride lipase (ATGL).

Adipose triglyceride lipase (ATGL) catalyzes the degradation of cellular triacylglycerol stores and strongly determines the concentration of circulating fatty acids (FAs). High serum FA levels are causally linked to the development of insulin resistance and impaired glucose tolerance, which eventually progresses to overt type 2 diabetes. ATGL-specific inhibitors could be used to lower circulating FAs, which can counteract the development of insulin resistance.

Treatment of diabetic rats with insulin or a synthetic insulin receptor agonist peptide leads to divergent metabolic responses.

In addition to lowering of blood glucose, treatment with insulin also induces lipid synthesis and storage. Patients with type 2 diabetes often suffer from lipid-related comorbidities including dyslipidemia, obesity, and fatty liver disease. We examined here in two separate studies changes in lipid dynamics in Zucker diabetic fatty (ZDF) rats, in response to 7 days of treatment with either insulin or the insulin receptor agonist peptide S597.

Open flow microperfusion: pharmacokinetics of human insulin and insulin detemir in the interstitial fluid of subcutaneous adipose tissue.

Aims: To compare the time profile of insulin detemir and human insulin concentrations in the interstitial fluid (ISF) of subcutaneous adipose tissue during constant i.v. infusion and to investigate the relationship between the pharmacokinetics of both insulin molecules in plasma and the ISF of subcutaneous adipose tissue.

Treatment with insulin analog X10 and IGF-1 increases growth of colon cancer allografts.

Obesity and type 2 diabetes are associated with an increased risk for development of certain forms of cancer, including colon cancer. The publication of highly controversial epidemiological studies in 2009 raised the possibility that use of the insulin analog glargine increases this risk further. However, it is not clear how mitogenic effects of insulin and insulin analogs measured in vitro correlate with tumor growth-promoting effects in vivo.

Development of small-molecule inhibitors targeting adipose triglyceride lipase.

Adipose triglyceride lipase (ATGL) is rate limiting in the mobilization of fatty acids from cellular triglyceride stores. This central role in lipolysis marks ATGL as an interesting pharmacological target as deregulated fatty acid metabolism is closely linked to dyslipidemic and metabolic disorders. Here we report on the development and characterization of a small-molecule inhibitor of ATGL.

Adipose weight gain during chronic insulin treatment of mice results from changes in lipid storage without affecting de novo synthesis of palmitate.

Insulin treatment is associated with increased adipose mass in both humans and mice. However, the underlying dynamic basis of insulin induced lipid accumulation in adipose tissue remains elusive. To assess this, young female C57BL6/J mice were fed a low fat diet for 3 weeks, treated subsequently with 7 days of constant subcutaneous insulin infusion by osmotic minipumps and compared to mice with only buffer infused.

Contraction-induced lipolysis is not impaired by inhibition of hormone-sensitive lipase in skeletal muscle.

In skeletal muscle hormone-sensitive lipase (HSL) has long been accepted to be the principal enzyme responsible for lipolysis of intramyocellular triacylglycerol (IMTG) during contractions. However, this notion is based on in vitro lipase activity data, which may not reflect the in vivo lipolytic activity. We investigated lipolysis of IMTG in soleus muscles electrically stimulated to contract ex vivo during acute pharmacological inhibition of HSL in rat muscles and in muscles from HSL knockout (HSL-KO) mice.

Juvenile eye growth, when completed? An evaluation based on IOL-Master axial length data, cross-sectional and longitudinal.

Purpose: To test Sorsby's classical statement of axial eye growth as completed at the age of 13 years, with a view also to differentiating between basic eye growth and juvenile elongation associated with eventual refractive change towards myopia.

Methods: (i) A total of 160 healthy eyes close to emmetropia were included in a cross-sectional set-up (age 4-20 years, 91 males, 69 females), and (ii) 78 longitudinal data sets (67 male and 11 female annual repeat exams over 2-7 years, n=30; age span 4-19 years) were available for evaluating individual axial elongation. The IOL-Master equipment was preferred for conventional ultrasound oculometry due to its extreme repeatability of measuring values, thus making it well fitted for evaluating very small differences.

Fatty acyl esterification and deesterification of 17β-estradiol in human breast subcutaneous adipose tissue.

Context: Adipose tissue has an important role in peripheral estrogen synthesis. One of the metabolic pathways of estradiol (E(2)) is its conversion to lipophilic fatty acyl esters.

Objective: The aim was to study the metabolism of E(2) fatty acyl esters in adipose tissue and, specifically, the role of hormone-sensitive lipase (HSL) in steroid ester hydrolysis.

Eye size in threshold retinopathy of prematurity, based on a Danish preterm infant series: early axial eye growth, pre- and postnatal aspects.

Purpose: To validate a hypothesis of restricted postnatal ocular growth associated with advanced retinopathy of prematurity (ROP), with a view also to preceding intrauterine growth retardation.

Methods: A clinically uniform sample of 28 preterm neonates was examined under general anesthesia from 1997 to 2002 for threshold retinopathy of prematurity (T-ROP), axial ultrasound oculometry being part of the evaluation (valid data in 53 eyes). Median values for gestational age at delivery (GA) and birth weight (BW) 27 weeks and 855 g, respectively, ranges 24.