Dataset Information

Responsiveness of hypothalamo-pituitary-adrenal axis to leptin is impaired in diet-induced obese rats.

ABSTRACT: BACKGROUND/OBJECTIVES:Diet-induced obese (DIO) rats have altered stress (HPA) axis activity compared to diet-resistant (DR) rats when chronically exposed to a high-fat (HF) diet. Since stress axis is tightly regulated by leptin, an adipocyte-secreted hormone that is important for controlling body weight, we hypothesized that leptin action is impaired in DIO rats leading to alterations in HPA axis activity. SUBJECTS/METHODS:We intraperitoneally injected selectively bred DIO and DR rats with either saline or recombinant rat leptin. HPA axis activity was assessed by measuring norepinephrine (NE) in the paraventricular nucleus (PVN), corticotropin-releasing hormone (CRH) in the median eminence, and serum corticosterone (CORT). To test if HF exposure duration and the corresponding increase in leptin differentially affects HPA axis activity, we placed animals on a chow or HF diet for 1 or 6 weeks. RESULTS:Leptin injection significantly increased serum leptin levels in both DIO and DR animals. It also reduced PVN NE in both groups, indicating that noradrenergic neurons in both groups remain responsive to leptin. HF diet duration-dependently increased serum leptin only in DIO animals whereas PVN NE increased in both groups. While DR rats responded to HF diet by increasing CRH and CORT at both time-points, responses in DIO rats varied, suggesting that they have altered HPA axis activity that may be dependent on HF-induced leptin levels and/or signaling. To understand the underlying mechanisms, we measured pSTAT-3, a marker of leptin signaling, in brainstem noradrenergic neurons and found reduced pSTAT-3 in A1 region of HF-fed DIO rats. We also found higher serum free fatty acids (FFAs) and a pro-inflammatory cytokine, IL-1?. CONCLUSIONS:Collectively, these findings reveal that DIO rats have inherent neuroendocrine impairment in NE-HPA axis circuitry that worsens with the extent of HF diet exposure, possibly due to brainstem leptin resistance and/or elevated circulating FFAs and IL-1?.

SUBMITTER: Shin AC

PROVIDER: S-EPMC6423225 | biostudies-literature | 2019 Mar

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Responsiveness of hypothalamo-pituitary-adrenal axis to leptin is impaired in diet-induced obese rats.

Shin Andrew C AC MohanKumar Sheba M J SMJ Balasubramanian Priya P Sirivelu Madhu P MP Linning Katrina K Woolcock Andrew A James Michelle M MohanKumar Puliyur S PS

Nutrition & diabetes 20190318 1

<h4>Background/objectives</h4>Diet-induced obese (DIO) rats have altered stress (HPA) axis activity compared to diet-resistant (DR) rats when chronically exposed to a high-fat (HF) diet. Since stress axis is tightly regulated by leptin, an adipocyte-secreted hormone that is important for controlling body weight, we hypothesized that leptin action is impaired in DIO rats leading to alterations in HPA axis activity.<h4>Subjects/methods</h4>We intraperitoneally injected selectively bred DIO and DR ...[more]

PMID: 30886140

Similar Datasets

Project description:To describe recovery of adrenal insufficiency in asthmatic children treated with inhaled corticosteroids (ICS) and cortisol replacement therapy.Retrospective, observational study.A total of 113 patients, 74 male; age 10.4 (3.3-16.5) years; beclomethasone-equivalent ICS dose, 800 ?g, (100-1,000), tested by low dose short Synacthen (tetracosactide) test (LDSST), were studied. Test results were classified by basal and peak cortisol concentration: "normal" (basal >100 nmol/L, peak >500 nmol/L), "suboptimal" (basal >100 nmol/L, peak 350-499 nmol/L), "abnormal" (basal <100 nmol/L and/or peak <350 nmol/L). Patients with suboptimal results received hydrocortisone during periods of stress only, and those with abnormal responses received daily hydrocortisone, increased during periods of stress. A total of 73 patients (68%) had ?2 LDSSTs over 2.2 years (0.2-7.7).Change in cortisol response to repeat LDSST (movement between diagnostic groups, difference in basal and peak cortisol >15% [2× the inter-assay coefficient of variation]), change in BMI and height standard deviation score (SDS).Baseline test results were abnormal in 17 patients (15%) and all of them had repeat tests. In 13 patients (76%), test results improved (normal in six, suboptimal in seven) and four (24%) remained abnormal. Baseline tests results were suboptimal in 54 patients (48%), of whom 50 (93%) were retested. Repeat tests were normal in 36 patients (72%), remained suboptimal in 11 (22%), and were abnormal in three (6%). Baseline tests results were normal in 42 patients, of whom six patients (14%) were retested. Results remained normal in three (50%), were suboptimal in two (33%), and abnormal in one (17%). Basal and peak cortisol levels increased by >15% in 33/73 (45%) and 42/73 (57%) patients, respectively, and decreased by >15% in 14/73 (19%) and 7/73 (10%), respectively. There was no significant change in height or BMI SDS.Recovery of adrenal function is common and occurs during continued ICS and cortisol replacement therapy.

Project description:IntroductionRecent studies have reported a strong relationship between diabetes and anxiety- and depression-like behaviors; however, there is a lack of information on the underlying pathophysiology. Alkaline Zamzam water (ZW), which is rich in several trace elements, has neuroprotective properties. This study aimed to investigate the anxiolytic and antidepressant effects of ZW against diabetes-induced behavioral changes and shed light on the possible underlying mechanisms.MethodsForty-eight rats were divided into four experimental groups (n = 12): group I (control group), group II (Zamzam water group), group III (diabetic group), and group IV (diabetic + Zamzam water group). Diabetes was induced by an intraperitoneal injection of 60 mg/kg streptozotocin (STZ). At the end of the experiment, the forced swimming test (FST) was used to assess depression-like effects. The elevated plus maze test (EPMT) and open field test (OFT) were performed to evaluate anxiety-like behavior. Blood levels of the hypothalamic-pituitary-adrenal (HPA) axis were measured, and prefrontal cortex and hippocampal tissue samples were removed for histological, immunohistochemical, ELISA, and Q-PCR analyses.ResultsZW significantly decreased the immobility time in the FST, indicating an antidepressant effect (p < 0.001). Additionally, ZW significantly improved the OFT and open field entry (OFE) percentages in the EPMT, increasing center crossing and decreasing grooming and fecal boli in the OFT. This indicated an anxiolytic-like effect in diabetic rats with histological improvement. Interestingly, ZW significantly increased prefrontal cortical and hippocampal levels of antioxidant enzymes and the Nrf2/HO-1 pathway. It also modulated the HPA axis by increasing cortisol and corticotropin-releasing hormone (CRH) levels, with a decrease in ACTH and an increase in monoamine neurotransmitters. Furthermore, diabetic rats that received ZW showed a decrease in the inflammatory markers TNF-α and GFAP by immunohistochemistry and in the mRNA levels of NFκB, IL-1β, and IL6. In addition, ZW downregulated the expression of the BDNF/ERK2/CREP pathway.ConclusionOur results suggested a neuroprotective effect of ZW against diabetes-induced anxiety- and depression-like behaviors and explored the underlying mechanisms. These findings suggest a promising therapeutic strategy for patients with diabetes who experience anxiety and depression.

Dataset Information

Responsiveness of hypothalamo-pituitary-adrenal axis to leptin is impaired in diet-induced obese rats.

Publications

Responsiveness of hypothalamo-pituitary-adrenal axis to leptin is impaired in diet-induced obese rats.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets