Differential Morphological Diagnosis of Various Forms of Congenital Hyperinsulinism in Children

IntroductionCongenital hyperinsulinism (CHI) has diffuse (CHI-D), focal (CHI-F) and atypical (CHI-A) forms. Surgical management depends on preoperative [18F]-DOPA PET/CT and intraoperative morphological differential diagnosis of CHI forms. Objective: to improve differential diagnosis of CHI forms by comparative analysis [18F]-DOPA PET/CT data, as well as cytological, histological and immunohistochemical analysis (CHIA).Materials and MethodsThe study included 35 CHI patients aged 3.2 ± 2.0 months; 10 patients who died from congenital heart disease at the age of 3.2 ± 2.9 months (control group). We used PET/CT, CHIA of pancreas with antibodies to ChrA, insulin, Isl1, Nkx2.2, SST, NeuroD1, SSTR2, SSTR5, DR1, DR2, DR5; fluorescence microscopy with NeuroD1/ChrA, Isl1/insulin, insulin/SSTR2, DR2/NeuroD1 cocktails.ResultsIntraoperative examination of pancreatic smears showed the presence of large nuclei, on average, in: 14.5 ± 3.5 cells of CHI-F; 8.4 ± 1.1 of CHI-D; and 4.5 ± 0.7 of control group (from 10 fields of view, x400). The percentage of Isl1+ and NeuroD1+endocrinocytes significantly differed from that in the control for all forms of CHI. The percentage of NeuroD1+exocrinocytes was also significantly higher than in the control. The proportion of ChrA+ and DR2+endocrinocytes was higher in CHI-D than in CHI-F, while the proportion of insulin+cells was higher in CHI-A. The number of SST+cells was significantly higher in CHI-D and CHI-F than in CHI-A.ConclusionFor intraoperative differential diagnosis of CHI forms, in addition to frozen sections, quantitative cytological analysis can be used. In quantitative immunohistochemistry, CHI forms differ in the expression of ChrA, insulin, SST and DR2. The development of a NeuroD1 inhibitor would be advisable for targeted therapy of CHI.

Metformin’s Therapeutic Action in the Treatment of Diabetes Does Not Involve Inhibition of Mitochondrial Glycerol Phosphate Dehydrogenase

Mitochondrial glycerol phosphate dehydrogenase (mGPD) is the rate-limiting enzyme of the glycerol phosphate redox shuttle. It was recently claimed that metformin, a first line drug used for the treatment of type 2 diabetes, inhibits liver mGPD 30-50% suppressing gluconeogenesis through a redox mechanism. Various factors cast doubt on this idea. Total body100% knockout of mGPD in mice has adverse effects in several tissues where mGPD is high, but has little or no effect in liver where mGPD is the lowest of ten tissues. Metformin has beneficial effects in humans in tissues with high levels of mGPD such as pancreatic beta cells where mGPD is much higher than in liver. Insulin secretion in mGPD knockout mouse beta cells is normal because, like liver, beta cells possess the malate aspartate redox shuttle that’s redox action is redundant to the glycerol phosphate shuttle. For these and other reasons we used four different enzyme assays to reassess whether metformin inhibited mGPD. Metformin did not inhibit mGPD in homogenates or mitochondria from insulin cells or liver cells. If metformin actually inhibited mGPD, adverse effects in tissues where the level of mGPD is much higher than in liver could prevent metformin’s use as a diabetes medicine.

A δ-cell subpopulation with a pro-β-cell identity confers efficient age-independent recovery in a zebrafish model of diabetes

Restoring damaged β-cells in diabetic patients by harnessing the plasticity of other pancreatic cells raises the questions of the efficiency of the process and of the functionality of the new Insulin-expressing cells. To overcome the weak regenerative capacity of mammals, we used regeneration-prone zebrafish to study β-cells arising following destruction. We show that most new insulin cells differ from the original β-cells as they are Somatostatin+ Insulin+, but are nevertheless functional and normalize glycemia. These bihormonal cells are transcriptionally close to a subset of δ-cells in normal islets characterized by the expression of somatostatin 1.1 (sst1.1), the β-cell genes pdx1, slc2a2 and gck, and the machinery for glucose-induced Insulin secretion. β-cell destruction triggers massive sst1.1 δ-cell conversion to bihormonal cells. Our work shows that their pro- β-cell identity predisposes this zebrafish δ-cell subpopulation to efficient age-independent neogenesis of Insulin-producing cells and provides clues to restoring functional β-cells in mammalian diabetes models.

Metformin’s Therapeutic Action in the Treatment of Diabetes Does Not Involve Inhibition of Mitochondrial Glycerol Phosphate Dehydrogenase

Mitochondrial glycerol phosphate dehydrogenase (mGPD) is the rate-limiting enzyme of the glycerol phosphate redox shuttle. It was recently claimed that metformin, a first line drug used for the treatment of type 2 diabetes, inhibits liver mGPD 30-50% suppressing gluconeogenesis through a redox mechanism. Various factors cast doubt on this idea. Total body100% knockout of mGPD in mice has adverse effects in several tissues where mGPD is high, but has little or no effect in liver where mGPD is the lowest of ten tissues. Metformin has beneficial effects in humans in tissues with high levels of mGPD such as pancreatic beta cells where mGPD is much higher than in liver. Insulin secretion in mGPD knockout mouse beta cells is normal because, like liver, beta cells possess the malate aspartate redox shuttle that’s redox action is redundant to the glycerol phosphate shuttle. For these and other reasons we used four different enzyme assays to reassess whether metformin inhibited mGPD. Metformin did not inhibit mGPD in homogenates or mitochondria from insulin cells or liver cells. If metformin actually inhibited mGPD, adverse effects in tissues where the level of mGPD is much higher than in liver could prevent metformin’s use as a diabetes medicine.

Metformin’s Therapeutic Action in the Treatment of Diabetes Does Not Involve Inhibition of Mitochondrial Glycerol Phosphate Dehydrogenase

Mitochondrial glycerol phosphate dehydrogenase (mGPD) is the rate-limiting enzyme of the glycerol phosphate redox shuttle. It was recently claimed that metformin, a first line drug used for the treatment of type 2 diabetes, inhibits liver mGPD 30-50% suppressing gluconeogenesis through a redox mechanism. Various factors cast doubt on this idea. Total body100% knockout of mGPD in mice has adverse effects in several tissues where mGPD is high, but has little or no effect in liver where mGPD is the lowest of ten tissues. Metformin has beneficial effects in humans in tissues with high levels of mGPD such as pancreatic beta cells where mGPD is much higher than in liver. Insulin secretion in mGPD knockout mouse beta cells is normal because, like liver, beta cells possess the malate aspartate redox shuttle that’s redox action is redundant to the glycerol phosphate shuttle. For these and other reasons we used four different enzyme assays to reassess whether metformin inhibited mGPD. Metformin did not inhibit mGPD in homogenates or mitochondria from insulin cells or liver cells. If metformin actually inhibited mGPD, adverse effects in tissues where the level of mGPD is much higher than in liver could prevent metformin’s use as a diabetes medicine.

GABAB-Receptor Agonist-Based Immunotherapy for Type 1 Diabetes in NOD Mice

Some immune system cells express type A and/or type B γ-aminobutyric acid receptors (GABAA-Rs and/or GABAB-Rs). Treatment with GABA, which activates both GABAA-Rs and GABAB-Rs), and/or a GABAA-R-specific agonist inhibits disease progression in mouse models of type 1 diabetes (T1D), multiple sclerosis, rheumatoid arthritis, and COVID-19. Little is known about the clinical potential of specifically modulating GABAB-Rs. Here, we tested lesogaberan, a peripherally restricted GABAB-R agonist, as an interventive therapy in diabetic NOD mice. Lesogaberan treatment temporarily restored normoglycemia in most newly diabetic NOD mice. Combined treatment with a suboptimal dose of lesogaberan and proinsulin/alum immunization in newly diabetic NOD mice or a low-dose anti-CD3 in severely hyperglycemic NOD mice greatly increased T1D remission rates relative to each monotherapy. Mice receiving combined lesogaberan and anti-CD3 displayed improved glucose tolerance and, unlike mice that received anti-CD3 alone, had some islets with many insulin+ cells, suggesting that lesogaberan helped to rapidly inhibit β-cell destruction. Hence, GABAB-R-specific agonists may provide adjunct therapies for T1D. Finally, the analysis of microarray and RNA-Seq databases suggested that the expression of GABAB-Rs and GABAA-Rs, as well as GABA production/secretion-related genes, may be a more common feature of immune cells than currently recognized.

Causal Inference with Mendelian Randomization to Explore Risk Factors of Diabetes

Abstract—Since the dawn of time, health conditions have dictated life around the world. Gradually, through the advancement of medicine and technology, more and more treatments have been discovered to combat these conditions. One of these conditions is a disease known as diabetes. Even with a plethora of treatments being utilized by individuals internationally, diabetes continues to be the one of the leading causes of death worldwide [1]. Caused by a deficiency of insulin, a hormone created and released by the pancreas, diabetes renders individuals unable to effectively utilize glucose. With low amounts of insulin, cells cannot allow glucose to enter them and be used as energy for the body, leaving high amounts of glucose to build up in the bloodstream. Several factors have been suggested as a link to causing this insulin deficiency, resulting in diabetes. However, it is important to remember that there are two types of diabetes present, Type 1 and Type 2 diabetes. This report uses Mendelian Randomization to analyze contributing factors of Type 1 and 2 diabetes and explain the roles of confounds and genetics in the pathogenesis of the disease.

If Metformin Inhibited the Mitochondrial Glycerol Phosphate Dehydrogenase It Might Not Benefit Diabetes

The mitochondrial glycerol phosphate dehydrogenase is the rate-limiting enzyme of the glycerol phosphate shuttle. It was recently claimed that metformin, a first line drug used worldwide for the treatment of type 2 diabetes, works by inhibiting the mitochondrial glycerol phosphate dehydrogenase 30-50% thus suppressing hepatic gluconeogenesis. This enzyme is 30-60 fold higher in the pancreatic islet than in liver. If metformin actually inhibited the enzyme, why would it not inhibit insulin secretion and exacerbate diabetes? Total body knockout of the mitochondrial glycerol phosphate dehydrogenase does not inhibit insulin secretion because insulin cells and liver cells possess the malate aspartate shuttle that is redundant to the action of the glycerol phosphate shuttle. In view of these and other apparent inconsistencies we reassessed the idea that metformin inhibited the mitochondrial glycerol phosphate dehydrogenase. We measured the enzyme’s activity in whole cell homogenates and mitochondria of insulin cells and liver cells using four different enzyme assays and were unable to show that metformin directly inhibits the enzyme. We conclude that metformin does not actually inhibit the enzyme. If it did, it might not be efficacious as a diabetes medicine.

Using of the method of electron microscopy for the identification and analysis of clinically implicit pathogenetic manifestations

Electron microscopic examination of B cells of pancreatic islets of the pancreas in dogs with normal (n=10) and impaired glucose tolerance (n=10) was performed. Ultrastructural features of the organization of insulin cells associated with an increased requirement of the hormone in the body with the latent form of diabetes mellitus are established. In B cells, signs of functional tension due to unregulated secretion, manifested by the expansion of endoplasmic reticulum cisterns, Golgi complex hypertrophy, an increase in the number of immature secretory granules and vacuoles in the cytoplasm are revealed in B cells.

Microscopical Study of Pancreatic Tissue of Babirusa (Babyrousa babyrussa) Using Conventional and Immunohistochemical Methods

This study utilized conventional and immunohistochemical methods, to describe the morphology and distribution of glucagon and insulin cells in the pancreas of adult male babirusa (Babyrousa babyrussa). The results of research showed that the endocrine portion (Langerhans islet) spread evenly on the acinar portion of pancreas. Observation using immunohistochemical method showed that glucagon cells were distributed on the perifer, whereas insulin cells in the center of the Langerhans islet of pancreas. In general, the number of insulin cells was higher than glucagon cells. It is interesting to note, in the pancreas babirusa also found that neonatal elements similar to the Langerhans islet, but have larger sizes (ranging between 200 -700 mm). The picture is similar to the large Langerhans islet was reported in ruminant. These cells give a negative reaction to insulin and glucagon antisera.