Influence of peripheral lipopolysaccharide (LPS) on feed intake, body temperature and hypothalamic expression of neuropeptides involved in appetite regulation in broilers and layer chicks.

1. This study examined the expression of genes related to appetite-regulating neuropeptides in the hypothalamus of broiler and layer chicks (Gallus gallus) after intraperitoneal (IP) injection of lipopolysaccharide (LPS). 2. Both broiler and layer chicks received (n = 10 per group) LPS at doses of 0 and 200 µg and feed intake was measured up to 6 h after injection. In a further experiment, (n = 8 per group) mRNA abundance of some hypothalamic neuropeptides was measured 2 h after injection. The rectal temperature of each chick was measured before and 2 h post-injection. 3. Feed intake was significantly decreased by LPS from 2 h after injection and thereafter, while the rectal temperature did not change. 4. LPS decreased the expression of appetite-enhancing neuropeptides: neuropeptide Y (NPY) and agouti-related peptide (AgRP) in broilers and, NPY in layer chicks. The expression of appetite-suppressing neuropeptides (corticotrophin-releasing factor (CRF), proopiomelanocortin (POMC) and, cocaine and amphetamine regulated-transcript (CART) was not changed in broilers, while CRF tended to decrease and POMC was significantly decreased in layers. The abundance of the cytokine tumour necrosis factor-alpha (TNF-α) did not change in broilers but was decreased in layers. 5. The findings indicated that the reduction in gene expression of hypothalamic appetite-enhancing neuropeptides NPY and AgRP is responsible for anorexia caused by LPS at a dose that did not influence body temperature.

Induction of hypothalamic GABA synthetic enzymes mRNA (Gad 1 and Gad 2) expression by negative energy balance in broiler and layer chicks.

Broiler and layer chicks have been selected for higher and lower food intake and body weight gain, respectively. It has recently been reported that glutamate decarboxylase (Gad1) mRNA, a gamma-aminobutyric acid (GABA) synthetic enzyme gene, is a reliable proxy for GABA release. Previous studies have revealed that GABAergic system has a stimulatory role on food intake in both mammals and birds. Over the recent years, evidence has identified the presence of GABAergic neurons as either the first- or second-order neurons within the various feeding nuclei of hypothalamus of laboratory rodents. They respond to the negative energy balance representing a critical role for GABA in the regulation of food intake. In the current study, the mRNA abundance of Gad 1 and Gad 2 was measured within the hypothalamus of both broiler and layer free fed, 12 h-fasted and 12 h-fasted / 3 h refed chicks. Furthermore, the effect of intracerebroventricular (ICV) injection of GABA was studied on food intake of chicks. The results indicated an increase in both Gad 1 and 2 expressions during fasting which tended to return to the baseline after refeeding. However, this increase was greater in broilers than in layers. The results also showed that ICV injection of GABA had no effect on food intake with the exception of an increase in free fed broilers. This study suggests a role for hypothalamic GABAergic system in birds that respond to negative energy balance, which seems to be more considerable in broilers than in layers.

Omega-3 from fish oil augments GVHD through the enhancement of chemotherapy conditioning regimen and selective FoxP3 depletion.

Omega-3 is known to enhance the effects of several chemotherapeutic agents and to exert several immunoregulatory actions In the present study, we evaluated the effects of a 21-day feeding regimen with omega-3-rich fish oil (FO) and its corresponding control, omega-6 rich corn oil (CO), on the BU-CY conditioning and the development of GVHD after BMT in mice. Before conditioning, FO, but not CO, feeding caused a significant attenuation in the number and functionality of splenic FoxP3+ T regulatory cells (Treg). FO feeding also enhanced the effects of the conditioning through severe depletion of Treg cells in the spleen and CD11b+ myeloid cells in both the BM and spleen. Consequently, FO-fed animals conditioned with BU-CY showed exacerbated GVHD following transplantation with allogeneic BM and splenic cells. In contrast, identical transplantation in CO-fed mice resulted in poor engraftment and body weight loss. Moreover, in standard-fed recipients, BMT with cells from FO-fed donors resulted in moderate GVHD and improved the survival time, whereas BMT with cells from CO-fed donors shortened the survival time and caused anemia. We conclude that food supplements should be considered in patients undergoing BMT and/or chemotherapy treatment.