Dual functions of CNS inflammation in food intake and metabolic regulation.

Western diet (WD) consumption induces chronic mild inflammation in the hypothalamus. However, metabolic consequences of increased hypothalamic inflammatory cytokines remain unclear. This research first aimed to examine whether increased proinflammatory cytokines in the brain influenced feeding or metabolism. Rats that received an intracerebroventricular third ventricle injection (i3vt) of 0.5 pg TNFα daily for six days consumed significantly more calories than saline-injected rats, with no differences between treatment groups in terms of body weight, blood triglycerides nor glucose regulation. Continuously infusing TNFα for three weeks decreased hepatic fatty acid synthase (FAS) and increased body weight and the epididymal adipose sterol regulatory element-binding protein 1c (SREBP-1c) gene expression. Differences were not due to food intake nor voluntary wheel running activity. The second aim of this research was to examine whether inhibition of inflammation signaling in the brain at early stage of switching from chow to WD would affect diet-induced obesity development. WD-fed rats with i3vt NFκB inhibitor had greater caloric intake than rats given i3vt saline. These studies suggest elevated inflammatory cytokines in the brain induce food intake acutely and favor fat storage and weight gain in the long term. However, in the early stage of WD consumption, hypothalamic inflammatory signaling inhibits caloric intake and may serve as a warning signal of energy imbalance.

Reprint of "Repeated adolescent activity-based anorexia influences central estrogen signaling and adulthood anxiety-like behaviors in rats".

Anorexia nervosa (AN) typically presents in adolescence and is highly comorbid with anxiety and depression, which often persist after elimination of AN symptomology. The activity-based anorexia (ABA) paradigm allows for evaluation of behavioral and neuroendocrine consequences of AN-like behaviors, including voluntary anorexia, hyperactivity, and disruption of the hypothalamic-pituitary-gonadal (HPG) and the hypothalamic pituitary adrenal (HPA) axis. Because ABA in adolescent females results in increased anxiety-like behavior in adulthood and the estrogen signaling system has been shown to play a role in anxiety and food intake, we investigated the role of ovarian hormones in adolescent ABA-treated rats, and long-term effects of mid- and late adolescent ABA exposure on behavior and estrogen signaling. While previous research demonstrated that two bouts of ABA during adolescence resulted in decreased time in the open arm of the elevated plus maze (EPM) and increased activity of the HPA axis in response to a novel stressor, here we show that one bout of ABA in mid-or late-adolescence did not result in the same behavioral outcome. Two exposures to ABA during adolescence were necessary to produce long-term anxiety-like behavior on the EPM. Finally, removal of ovarian hormones by ovariectomy (OVX) prior to puberty did not attenuate long-term behavioral consequences of ABA in adolescence, and estrogen receptor ß (ERß) expression level in the amygdala of ABA rats was significantly lower than control subjects. Taken together, these studies identify enduring effects of ABA in adolescent females that may be mediated by ABA-induced changes to CNS ERß signaling that increase anxiety-like behaviors.

Brain and behavioral perturbations in rats following Western diet access.

Energy dense "Western" diets (WD) are known to cause obesity as well as learning and memory impairments, blood-brain barrier damage, and psychological disturbances. Impaired glucose (GLUT1) and monocarboxylate (MCT1) transport may play a role in diet-induced dementia development. In contrast, ketogenic diets (KD) have been shown to be neuroprotective. We assessed the effect of 10, 40 and 90 days WD, KD and Chow maintenance on spontaneous alternation (SA) and vicarious trial and error (VTE) behaviors in male rats, then analyzed blood glucose, insulin, and ketone levels; and hippocampal GLUT1 and MCT1 mRNA. Compared to Chow and KD, rats fed WD had increased 90 day insulin levels. SA was decreased in WD rats at 10, but not 40 or 90 days. VTE was perturbed in WD-fed rats, particularly at 10 and 90 days, indicating hippocampal deficits. WD rats had lower hippocampal GLUT1 and MCT1 expression compared to Chow and KD, and KD rats had increased 90 day MCT1 expression compared to Chow and WD. These data suggest that WD reduces glucose and monocarboxylate transport at the hippocampus, which may result in learning and memory deficits. Further, KD consumption may be useful for MCT1 transporter recovery, which may benefit cognition.

Human interleukin-10 genotypes are associated with different precore/core gene mutation patterns in children with chronic hepatitis B virus infection.

OBJECTIVE: To elucidate the association between human interleukin-10 (IL-10) genotypes and hepatitis B virus (HBV) precore/core gene mutation in children with chronic HBV infection. STUDY DESIGN: The study group comprised of 21 children with chronic HBV infection with spontaneous hepatitis B e antigen (HBeAg) seroconversion who were followed for more than 10 years. Another nine children without HBeAg seroconversion served as the control subjects. Sera at the immune tolerance and inflammatory phase (alanine aminotransferase, >80 IU/L) were subjected to HBV precore/core sequence analysis. IL-10 -1082 polymorphism was also determined. RESULTS: HBV precore/core gene mutation increased significantly more in the inflammatory phase than in the tolerance phase (G1896A, 76.2% versus 4.8%; C1913A, 33.3% versus 0%; C2189A, 28.6% versus 4.8%; G2304A, 52.4% versus 14.3%) in study group (n = 21) but not the control group (n = 9). Subjects with the G/G genotype at the IL-10-1082 polymorphism site had higher C2189A mutation rate than the A allele carriers (P = .02). C2189A mutation carriers are associated with more viral load decrement from tolerance to inflammatory phase (P = .01) and earlier spontaneous HBeAg seroconversion (P = .01). CONCLUSIONS: The G/G genotype at the IL-10 -1082 polymorphism is associated with higher C2189A mutations, lower HBV viral load at immune inflammatory phase, and earlier spontaneous HBeAg seroconversion than A allele carriers.