Analysing uric acid levels to assess the effectiveness of dapagliflozin.

BACKGROUND: Sodium-glucose cotransporter-2 inhibitors are an innovative diabetes treatment that lowers blood sugar levels without insulin. A growing body of evidence suggests that blood sugar levels are tightly correlated with uric acid levels in their blood and urine. To alleviate type 2 diabetes (T2DM) suffering, we tested dapagliflozin on serum and urinary uric acid levels of patients with T2DM and measured its efficacy in reducing uric acid levels. METHODS: A study was conducted on 60 people with T2DM. Patients were treated with Dapagliflozin doses of 10 mg daily for 3 months. Three months later, we measured body weight, fasting, and postprandial blood glucose levels, Hemoglobin A1C (HbA1c), serum lipids, renal function tests, routine urine, and serum uric acid. RESULTS: A number of clinical parameters of T2DM patients were compared to those of healthy subjects of the same age group. A comprehensive analysis of all parameters was conducted to evaluate dapagliflozin's impact. After 90 days of dapagliflozin treatment, serum uric acid levels dropped significantly from 9.0 to 8 mg/dL in the dapagliflozin group, as well as uric acid percentage in urine changed from 16.1 to 23.6 %. After three months of treatment, HbA1C levels decreased from 9.8 % to 8.5 %. CONCLUSION: Following treatment with dapagliflozin, the patients' Homeostatic Model Assessment for Insulin Resistance decreased to 4.0. Further, multivariate correlation analysis showed a correlation of serum uric acid with glycemic profile positively. In conclusion, dapagliflozin lowers uric acid levels and increases insulin sensitivity in diabetic patients to improve their glycemic control.

Deficiency of Thyroid Hormone Reduces Voltage-Gated Na+ Currents as Well as Expression of Na+/K+-ATPase in the Mouse Hippocampus.

Mice lacking functional thyroid follicular cells, Pax8-/- mice, die early postnatally, making them suitable models for extreme hypothyroidism. We have previously obtained evidence in postnatal rat neurons, that a down-regulation of Na+-current density could explain the reduced excitability of the nervous system in hypothyroidism. If such a mechanism underlies the development of coma and death in severe hypothyroidism, Pax8-/- mice should show deficits in the expression of Na+ currents and potentially also in the expression of Na+/K+-ATPases, which are necessary to maintain low intracellular Na+ levels. We thus compared Na+ current densities in postnatal mice using the patch-clamp technique in the whole-cell configuration as well as the expression of three alpha and two beta-subunits of the Na+/K+-ATPase in wild type versus Pax8-/- mice. Whereas the Na+ current density in hippocampal neurons from wild type mice was upregulated within the first postnatal week, the Na+ current density remained at a very low level in hippocampal neurons from Pax8-/- mice. Pax8-/- mice also showed significantly decreased protein expression levels of the catalytic α1 and α3 subunits of the Na+/K+-ATPase as well as decreased levels of the ß2 isoform, with no changes in the α2 and ß1 subunits.

Parvocellular Oxytocin Neurons and Autism Spectrum Disorders.

The underlying mechanism of oxytocin (OT) neurons in the development of social interaction remains unclear. In a recent study, Lewis et al. characterized OT neuronal subtypes and provided evidence that expression of the autism spectrum disorder (ASD) gene Fmr1 in parvocellular OT neurons is essential for peer-peer but not filial social interactions.

Nesfatin-1 decreases the motivational and rewarding value of food.

Homeostatic and hedonic pathways distinctly interact to control food intake. Dysregulations of circuitries controlling hedonic feeding may disrupt homeostatic mechanisms and lead to eating disorders. The anorexigenic peptides nucleobindin-2 (NUCB2)/nesfatin-1 may be involved in the interaction of these pathways. The endogenous levels of this peptide are regulated by the feeding state, with reduced levels following fasting and normalized by refeeding. The fasting state is associated with biochemical and behavioral adaptations ultimately leading to enhanced sensitization of reward circuitries towards food reward. Although NUCB2/nesfatin-1 is expressed in reward-related brain areas, its role in regulating motivation and preference for nutrients has not yet been investigated. We here report that both dopamine and GABA neurons express NUCB2/nesfatin-1 in the VTA. Ex vivo electrophysiological recordings show that nesfatin-1 hyperpolarizes dopamine, but not GABA, neurons of the VTA by inducing an outward potassium current. In vivo, central administration of nesfatin-1 reduces motivation for food reward in a high-effort condition, sucrose intake and preference. We next adopted a 2-bottle choice procedure, whereby the reward value of sucrose was compared with that of a reference stimulus (sucralose + optogenetic stimulation of VTA dopamine neurons) and found that nesfatin-1 fully abolishes the fasting-induced increase in the reward value of sucrose. These findings indicate that nesfatin-1 reduces energy intake by negatively modulating dopaminergic neuron activity and, in turn, hedonic aspects of food intake. Since nesfatin-1´s actions are preserved in conditions of leptin resistance, the present findings render the NUCB2/nesfatin-1 system an appealing target for the development of novel therapeutical treatments towards obesity.

Tissue-Specific Function of Thyroid Hormone Transporters: New Insights from Mouse Models.

Thyroid hormone (TH) transporters are required for cellular transmembrane passage of TH and are thus mandatory for proper TH metabolism and action. Consequently, inactivating mutations in TH transporters such as MCT8 or OATP1C1 can cause tissue- specific changes in TH homeostasis. As the most prominent example, patients with MCT8 mutations exhibit elevated serum T3 levels, whereas their CNS appear to be in a TH deficient state. Here, we will briefly summarize recent studies of mice lacking Mct8 alone or in combination with the TH transporters Mct10 or Oatp1c1 that shed light on many aspects and pathogenic events underlying global MCT8 deficiency and also underscore the contribution of Mct10 and Oatp1c1 in tissue-specific TH transport processes. Moreover, development of conditional knock-out mice that allow a cell-specific inactivation of TH transporters in distinct tissues, disclosed cell-specific changes in TH signaling, thereby highlighting the pathophysiological significance of local control of TH action.

Differential expression patterns of sodium potassium ATPase alpha and beta subunit isoforms in mouse brain during postnatal development.

The sodium potassium ATPase (Na+/K+ ATPase) is essential for the maintenance of a low intracellular Na+ and a high intracellular K+ concentration. Loss of function of the Na+/K+ ATPase due to mutations in Na+/K+ ATPase genes, anoxic conditions, depletion of ATP or inhibition of the Na+/K+ ATPase function using cardiac glycosides such as digitalis, causes a depolarization of the resting membrane potential. While in non-excitable cells, the uptake of glucose and amino acids is decreased if the function of the Na+/K+ ATPase is compromised, in excitable cells the symptoms range from local hyper-excitability to inactivating depolarization. Although several studies have demonstrated the differential expression of the various Na+/K+ ATPase alpha and beta isoforms in the brain tissue of rodents, their expression profile during development has yet to be thoroughly investigated. An immunohistochemical analysis of postnatal day 19 mouse brain showed ubiquitous expression of Na+/K+ ATPase isoforms α1, ß1 and ß2 in both neurons and glial cells, whereas α2 was expressed mostly in glial cells and the α3 and ß3 isoforms were expressed in neurons. Furthermore, we examined potential changes in the relative expression of the different Na+/K+ ATPase isoforms in different brain areas of postnatal day 6 and in adult 9 months old animals using immunoblot analysis. Our results show a significant up-regulation of the α1 isoform in cortex, hippocampus and cerebellum, whereas, the α2 isoform was significantly up-regulated in midbrain. The ß3 isoform showed a significant up-regulation in all brain areas investigated. The up-regulation of the α3 isoform matched that of the ß2 isoform which were both significantly up-regulated in cortex, hippocampus and midbrain, suggesting that the increased maturation of the neuronal network is accompanied by an increase in expression of α3/ß2 complexes in these brain structures.

Epigallocatechin gallate (EGCG) inhibits adhesion and migration of neural progenitor cells in vitro.

Food supplements based on herbal products are widely used during pregnancy as part of a self-care approach. The idea that such supplements are safe and healthy is deeply seated in the general population, although they do not underlie the same strict safety regulations than medical drugs. We aimed to characterize the neurodevelopmental effects of the green tea catechin epigallocatechin gallate (EGCG), which is now commercialized as high-dose food supplement. We used the "Neurosphere Assay" to study the effects and unravel underlying molecular mechanisms of EGCG treatment on human and rat neural progenitor cells (NPCs) development in vitro. EGCG alters human and rat NPC development in vitro. It disturbs migration distance, migration pattern, and nuclear density of NPCs growing as neurospheres. These functional impairments are initiated by EGCG binding to the extracellular matrix glycoprotein laminin, preventing its binding to ß1-integrin subunits, thereby prohibiting cell adhesion and resulting in altered glia alignment and decreased number of migrating young neurons. Our data raise a concern on the intake of high-dose EGCG food supplements during pregnancy and highlight the need of an in vivo characterization of the effects of high-dose EGCG exposure during neurodevelopment.