Effects of intracerebroventricular injection of rosiglitazone on appetite-associated parameters in chicks

The Small Molecule PPARγ Agonist GL516 Induces Feeding-Stimulatory Effects in Hypothalamus Cells Hypo-E22 and Isolated Hypothalami

PPARγ agonists are implicated in the regulation of diabetes and metabolic syndrome and have therapeutic potential in brain disorders. PPARγ modulates appetite through its central effects, especially on the hypothalamic arcuate nucleus (ARC). Previous studies demonstrated that the small molecule GL516 is a PPARγ agonist able to reduce oxidative stress and apoptosis with a potential neuroprotective role. Herein, we investigated the effects of GL516, in vitro and ex vivo, on the levels of hypothalamic dopamine (DA) and serotonin (5-HT). The gene expressions of neuropeptide Y, CART, AgRP, and POMC, which play master roles in the neuroendocrine regulation of feeding behavior and energy balance, were also evaluated. HypoE22 cells were treated with H₂O₂ (300 μM) for 2 h e 30’ and with different concentrations of GL516 (1 nM-100 µM). The cell viability was evaluated after 24 and 48 h of culturing using the MTT test. DA and 5-HT levels in the HypoE22 cell supernatants were analyzed through HPLC; an ex vivo study on isolated hypothalamic specimens challenged with scalar concentrations of GL516 (1–100 µM) and with pioglitazone (10 µM) was carried out. The gene expressions of CART, NPY, AgRP, and POMC were also determined by a quantitative real-time PCR. The results obtained showed that GL516 was able to reduce DA and 5-HT turnover; moreover, it was effective in stimulating NPY and AgRP gene expressions with a concomitant reduction in CART and POMC gene expressions. These results highlight the capability of GL516 to modulate neuropeptide pathways deeply involved in appetite control suggesting an orexigenic effect. These findings emphasize the potential use of GL516 as a promising candidate for therapeutical applications in neurodegenerative diseases associated with the reduction in food intake and stimulation of catabolic pathways.

Evaluation of eating disorders and their association with glycemic control and metabolic parameters in adult patients with type 2 diabetes mellitus

BACKGROUND

There is little data on the prevalence and effects of eating disorders in patients with T2DM.

AIMS

To evaluate the presence of eating disorders (ED) and their association with glycemic control and metabolic parameters in adult patients with type 2 diabetes mellitus (T2DM).

METHODS

A cross-sectional study was conducted in the endocrinology outpatient unit of our tertiary care centre between January 2017 to December 2018. Eating Attitudes Test (EAT-26) and Binge Eating Scale (BES) questionnaires were used to screen for ED in adults with T2DM (group 1) and controls without T2DM (group 2). Cut off scores ≥18 on BES was considered as a positive screen for Binge eating disorder in participants with and without T2DM. A score of ≥30 on EAT-26 was defined as abnormal for participants with T2DM and ≥20 for those without T2DM. Formal psychiatric assessment was done to diagnose ED in those who screened positive on the basis of scores on BES or EAT-26 or both. Demographic, anthropometric and relevant medical details like duration of treatment, glycemic control, complications were recorded.

RESULTS

A total of 512 individuals (256 in each group) participated in this study. Out of these, 10.9% of individuals with T2DM and 14.1% of those without T2DM screened positive for ED, with no significant difference in the two groups. After a detailed psychiatric assessment, two patients (0.8%) in each group were confirmed to have ED. Participants with T2DM who were on thiazolidinediones had higher odds (2.2) of screening positive for an ED.(p = 0.03).

CONCLUSIONS

Our study reveals that eating disorders are not very common in our clinical population of T2DM, and the prevalence is comparable to BMI matched individuals without T2DM. The prevalence rates of eating disorders are lower (in both controls and patients with T2DM) than those reported from developed western countries.

Prospective of managing impaired brain insulin signalling in late onset Alzheimers disease with excisting diabetic drugs

Late onset Alzheimer's disease (AD) is the most common cause of dementia among elderly. The exact cause of the disease is until now unknown and there is no complete cure for the disease. Growing evidence suggest that AD is a metabolic disorder associated with impairment in brain insulin signalling. These findings enriched the scope for the repurposing of diabetic drugs in AD management. Even though many of these drugs are moving in a positive direction in the ongoing clinical studies, the extent of the success has seen to influence by several properties of these drugs since they were originally designed to manage the peripheral insulin resistance. In depth understandings of these properties is hence highly significant to optimise the use of diabetic drugs in the clinical management of AD; which is the primary aim of the present review article.

Dietary macronutrient composition and central neuropeptide Y injection affect dietary preference and hypothalamic gene expression in chicks

OBJECTIVE

The objective of this study was to determine the influence of dietary macronutrient composition on central NPY's orexigenic effect in chicks.

METHODS

Day-of-hatch chicks were fed one of three diets (3000 kcal ME/kg) ad libitum from hatch: high carbohydrate (HC), high fat (HF; 30% ME derived from soybean oil), and high protein (HP; 25 vs. 22% CP). In Experiment 1, chicks received intracerebroventricular injections of 0 (vehicle), 0.2, or 2.0 nmol NPY on day 4 and food intake was recorded for 6 hours. In Experiment 2, chicks were given all three diets before and after injection. In Experiment 3, hypothalamus was collected at 1-hour post-injection for gene expression analysis.

RESULTS

The HC diet-fed chicks responded with a greater increase, while the chicks fed the HF diet had a lower threshold response in food intake to NPY. Neuropeptide Y dose-dependently increased food intake in chicks fed the HC and HP diets. Chicks administered 0.2 nmol NPY preferred the HC and HP diets over the HF diet. Relative quantities of hypothalamic NPYR1 and MC4R mRNA were reduced by NPY in chicks that consumed the HP and HC diets, respectively.

DISCUSSION

Consumption of the HC diet was associated with the most robust NPY-induced increase in food intake. Injection of NPY accentuated differences among dietary groups in hypothalamic gene expression of several appetite-associated factors, results suggesting that the NPY/agouti-related peptide and melanocortin pathways are associated with some of the diet- and NPY-induced differences observed in this study.