Regulation of food intake by inflammatory cytokines in the brain

Activity-based anorexia (ABA) model: Effects on brain neuroinflammation, redox balance and neuroplasticity during the acute phase

Several evidences suggest that immuno-inflammatory responses are involved in the pathogenesis of anorexia nervosa (AN). Herein we investigate the possible alteration of key mediators of inflammation, redox balance, and neuroplasticity in the brain of rats showing an anorexic-like phenotype. We modeled AN in adolescent female rats using the activity-based anorexia (ABA) paradigm and measured gene expression levels of targets of interest in the prefrontal cortex (PFC) and dorsal hippocampus (DH). We observed reduced mRNA levels of pro-inflammatory cytokines IL-1β and TNF-α, the inflammasome NLRP3, and the microglial marker CD11b in both PFC and DH of ABA animals. Conversely, the mRNA of IL-6, which acts as both a pro-inflammatory and anti-inflammatory cytokine, was increased. Moreover, we observed an overall upregulation of different antioxidant enzymes in PFC, while their profile was not affected or opposite in the DH, with the exception of MT1α. Interestingly, ABA animals showed elevated levels of the neuroplasticity marker BDNF in both PFC and DH. Our data indicate that ABA induction is associated with anatomical-specific cerebral alteration of mediators of neuroinflammation, oxidative balance and neuroplasticity. Although more research should be conducted, these results add important information about the role of these systems in the complex AN etiopathogenesis.

Cancer cachexia: biomarkers and the influence of age

Cancer cachexia (Ccx) is a complex metabolic condition characterized by pronounced muscle and fat wasting, systemic inflammation, weakness and fatigue. Up to 30% of cancer patients succumb directly to Ccx, yet therapies that effectively address this perturbed metabolic state are rare. In recent decades, several characteristics of Ccx have been established in mice and humans, of which we here highlight adipose tissue dysfunction, muscle wasting and systemic inflammation, as they are directly linked to biomarker discovery. To counteract cachexia pathogenesis as early as possible and mitigate its detrimental impact on anti-cancer treatments, identification and validation of clinically endorsed biomarkers assume paramount importance. Ageing was recently shown to affect both the validity of Ccx biomarkers and Ccx development, but the underlying mechanisms are still unknown. Thus, unravelling the intricate interplay between ageing and Ccx can help to counteract Ccx pathogenesis and tailor diagnostic and treatment strategies to individual needs.

Cancer cachexia: Focus on cachexia factors and inter-organ communication

ABSTRACT

Cancer cachexia is a multi-organ syndrome and closely related to changes in signal communication between organs, which is mediated by cancer cachexia factors. Cancer cachexia factors, being the general name of inflammatory factors, circulating proteins, metabolites, and microRNA secreted by tumor or host cells, play a role in secretory or other organs and mediate complex signal communication between organs during cancer cachexia. Cancer cachexia factors are also a potential target for the diagnosis and treatment. The pathogenesis of cachexia is unclear and no clear effective treatment is available. Thus, the treatment of cancer cachexia from the perspective of the tumor ecosystem rather than from the perspective of a single molecule and a single organ is urgently needed. From the point of signal communication between organs mediated by cancer cachexia factors, finding a deeper understanding of the pathogenesis, diagnosis, and treatment of cancer cachexia is of great significance to improve the level of diagnosis and treatment. This review begins with cancer cachexia factors released during the interaction between tumor and host cells, and provides a comprehensive summary of the pathogenesis, diagnosis, and treatment for cancer cachexia, along with a particular sight on multi-organ signal communication mediated by cancer cachexia factors. This summary aims to deepen medical community's understanding of cancer cachexia and may conduce to the discovery of new diagnostic and therapeutic targets for cancer cachexia.

Interactions between corticotropin releasing factor signaling and prophylactic antibiotics on measures of intestinal function in weaned and transported pigs

The study objective was to evaluate the interaction between corticotrophin releasing factor (CRF) receptor signaling and prophylactic antibiotic administration on intestinal physiology in newly weaned and transported pigs. Pigs (n = 56; 5.70 ± 1.05 kg) were weaned (20.49 ± 0.64 d), a blood sample was taken, and then pigs were given an intraperitoneal injection of saline (SAL; n = 28 pigs) or a CRF receptor antagonist (CRFA; n = 28 pigs; 30 μg/kg body weight; Astressin B), and then were transported in a livestock trailer for 12 h and 49 min. A second and third intraperitoneal injection was given at 4 h 42 min and 11 h 36 min into the transport process, respectively. Following transport, 4 SAL and 4 CRFA pigs were blood sampled and euthanized. The remaining 48 pigs were individually housed and given dietary antibiotics [AB; n = 12 SAL and 12 CRFA pigs; chlortetracycline (441 ppm) + tiamulin (38.6 ppm)] or no dietary antibiotics (NAB; n = 12 SAL and 12 CRFA pigs) for 14 d post-transport. Blood was collected at 12 h and on d 3, 7, and 14, and then pigs were euthanized on d 7 (n = 24) and d 14 (n = 24) post-weaning and transport. Circulating cortisol was reduced (p = 0.05) in CRFA pigs when compared to SAL pigs post-weaning and transport. On d 7, jejunal villus height and crypt depth was greater overall (p < 0.05) in AB-fed pigs versus NAB-fed pigs. On d 14, ileal crypt depth was reduced (p = 0.02) in CRFA pigs when compared to SAL pigs. Jejunal CRF mRNA abundance tended to be reduced (p = 0.09) on d 7 in CRFA pigs versus SAL pigs. On d 14, jejunal tumor necrosis factor-alpha was reduced (p = 0.01) in AB-fed pigs versus NAB-fed pigs. On d 7, change in glucose short-circuit current tended to be increased (p = 0.07) in CRFA pigs fed the AB diet when compared to CRFA pigs fed the NAB diet. In conclusion, CRFA pigs and pigs fed AB had some similar biological intestinal function measures post-weaning and transport.

Identification of State Markers in Anorexia Nervosa: Replication and Extension of Inflammation Associated Biomarkers Using Multiplex Profiling in Anorexia Nervosa and Atypical Anorexia Nervosa

Proteomics provides an opportunity for detection and monitoring of anorexia nervosa (AN) and its related variant, atypical-AN (atyp-AN). However, research to date has been limited by the small number of proteins explored, exclusive focus on adults with AN, and lack of replication across studies. This study performed Olink Proseek Multiplex profiling of 92 proteins involved in inflammation among females with AN and atyp-AN (N = 64), all < 90% of expected body weight, and age-matched healthy controls (HC; N=44). After correction for multiple testing, nine proteins differed significantly in the AN/atyp-AN group relative to HC group ( lower levels: CXCL1, HGF, IL-18R1, TNFSF14, TRANCE; higher levels: CCL23, Flt3L, LIF-R, MMP-1). The expression levels of three proteins ( lower IL-18R1, TRANCE; higher LIF-R) were uniquely disrupted in females with AN. No unique expression levels emerged for atyp-AN. Across the whole sample, twenty-one proteins correlated positively with BMI (ADA, AXIN1, CD5, CD244, CD40, CD6, CXCL1, FGF-21, HGF, IL-10RB, IL-12B, IL18, IL-18R1, IL6, LAP TGF-beta-1, SIRT2, STAMBP, TNFRSF9, TNFSF14, TRAIL, TRANCE) and six (CCL11, CCL23, FGF-19, IL8, LIF-R, OPG) were negatively correlated with BMI. Overall, our results replicate the prior study demonstrating a dysregulated inflammatory status in AN, and extend these results to atyp-AN (AN/atyp-AN all < 90% of expected body weight). Of the 27 proteins correlated with BMI, 18 were replicated from a prior study using similar methods, highlighting the promise of inflammatory protein expression levels as biomarkers of disease monitoring. Additional studies of individuals across the entire weight spectrum are needed to understand the role of inflammation in atyp-AN.

Formulating Diets for Improved Health Status of Pigs: Current Knowledge and Perspectives

Our understanding of nutrition has been evolving to support both performance and immune status of pigs, particularly in disease-challenged animals which experience repartitioning of nutrients from growth towards the immune response. In this sense, it is critical to understand how stress may impact nutrient metabolism and the effects of nutritional interventions able to modulate organ (e.g., gastrointestinal tract) functionality and health. This will be pivotal in the development of effective diet formulation strategies in the context of improved animal performance and health. Therefore, this review will address qualitative and quantitative effects of immune system stimulation on voluntary feed intake and growth performance measurements in pigs. Due to the known repartitioning of nutrients, the effects of stimulating the immune system on nutrient requirements, stratified according to different challenge models, will be explored. Finally, different nutritional strategies (i.e., low protein, amino acid-supplemented diets; functional amino acid supplementation; dietary fiber level and source; diet complexity; organic acids; plant secondary metabolites) will be presented and discussed in the context of their possible role in enhancing the immune response and animal performance.

Effect of Cyclic Heat Stress on Hypothalamic Oxygen Homeostasis and Inflammatory State in the Jungle Fowl and Three Broiler-Based Research Lines

Heat stress (HS) is devastating to poultry production sustainability due its detrimental effects on performance, welfare, meat quality, and profitability. One of the most known negative effects of HS is feed intake depression, which is more pronounced in modern high-performing broilers compared to their ancestor unselected birds, yet the underlying molecular mechanisms are not fully defined. The present study aimed, therefore, to determine the hypothalamic expression of a newly involved pathway, hypoxia/oxygen homeostasis, in heat-stressed broiler-based research lines and jungle fowl. Three populations of broilers (slow growing ACRB developed in 1956, moderate growing 95RB from broilers available in 1995, and modern fast growing MRB from 2015) and unselected Jungle fowl birds were exposed to cyclic heat stress (36°C, 9 h/day for 4 weeks) in a 2 × 4 factorial experimental design. Total RNAs and proteins were extracted from the hypothalamic tissues and the expression of target genes and proteins was determined by real-time quantitative PCR and Western blot, respectively. It has been previously shown that HS increased core body temperature and decreased feed intake in 95RB and MRB, but not in ACRB or JF. HS exposure did not affect the hypothalamic expression of HIF complex, however there was a line effect for HIF-1α (P = 0.02) with higher expression in JF under heat stress. HS significantly up regulated the hypothalamic expression of hemoglobin subunits (HBA1, HBBR, HBE, HBZ), and HJV in ACRB, HBA1 and HJV in 95RB and MRB, and HJV in JF, but it down regulated FPN1 in JF. Additionally, HS altered the hypothalamic expression of oxygen homeostasis- up and down-stream signaling cascades. Phospho-AMPK^Thr172 was activated by HS in JF hypothalamus, but it decreased in that of the broiler-based research lines. Under thermoneutral conditions, p-AMPK^Thr172 was higher in broiler-based research lines compared to JF. Ribosomal protein S6K1, however, was significantly upregulated in 95RB and MRB under both environmental conditions. HS significantly upregulated the hypothalamic expression of NF-κB2 in MRB, RelB, and TNFα in ACRB, abut it down regulated RelA in 95RB. The regulation of HSPs by HS seems to be family- and line-dependent. HS upregulated the hypothalamic expression of HSP60 in ACRB and 95RB, down regulated HSP90 in JF only, and decreased HSP70 in all studied lines. Taken together, this is the first report showing that HS modulated the hypothalamic expression of hypoxia- and oxygen homeostasis-associated genes as well as their up- and down-stream mediators in chickens, and suggests that hypoxia, thermotolerance, and feed intake are interconnected, which merit further in-depth investigations.

Weight loss from caloric restriction vs Roux-en-Y gastric bypass surgery differentially regulates systemic and portal vein GDF15 levels in obese Zucker fatty rats

Weight loss from caloric restriction (i.e. dieting) tends to be modest and short-lived, whereas from bariatric surgeries such as Roux-en-Y gastric bypass (RYGB) is pronounced and generally sustained. The reasons behind these opposing outcomes between interventions remain unclear, but likely involve differential effects on gut-brain communication. Growth differentiation factor 15 (GDF15) is a ubiquitously-induced, centrally-acting, anorexigenic cytokine whose systemic levels are elevated under a variety of conditions associated with a negative energy balance, including in patients following RYGB. We therefore asked whether systemic and portal vein GDF15 levels differ between obese Zucker fatty rats that experienced similar weight loss from RYGB or from forced caloric restriction (CR). Compared with ad libitum fed (ALF) controls, body weight, visceral adiposity and food intake of RYGB and CR rats were markedly lower during the postoperative observation period. Both systemic and portal vein GDF15 levels in RYGB rats at postoperative day 28 were higher compared with ALF rats and particularly compared with CR rats. Further, systemic and portal vein GDF15 levels negatively correlated with body weight and food intake specifically in RYGB rats. These findings provide evidence that, unlike dieting, RYGB might achieve sustained weight loss and appetite suppression partly through increased GDF15 release from epithelial cells of the gastrointestinal tract.

Gut microbiota absence and transplantation affect growth and intestinal functions: An investigation in a germ-free pig model

This study was conducted to investigate host–microbiota interactions and explore the effects of maternal gut microbiota transplantation on the growth and intestinal functions of newborns in a germ-free (GF) pig model. Twelve hysterectomy-derived GF Bama piglets were reared in 6 sterile isolators. Among them, 6 were considered as the GF group, and the other 6 were orally inoculated with healthy sow fecal suspension as fecal microbiota transplanted (FMT) group. Another 6 piglets from natural birth were regarded as the conventional (CV) group. The GF and FMT groups were hand-fed with Co60-γ-irradiated sterile milk powder, while the CV group was reared by lactating Bama sows. All groups were fed for 21 days. Then, all piglets and then were switched to sterile feed for another 21 days. Results showed that the growth performance, nutrient digestibility, and concentrations of short-chain fatty acids in the GF group decreased (P < 0.05). Meanwhile, the serum urea nitrogen concentration and digesta pH values in the GF group increased compared with those in the FMT and CV groups (P < 0.05). Compared with the CV group, the GF group demonstrated upregulation in the mRNA expression levels of intestinal barrier function-related genes in the small intestine (P < 0.05). In addition, the mRNA abundances of intestinal development and absorption-related genes in the small intestine and colon were higher in the GF group than in the CV and FMT groups (P < 0.05). The FMT group exhibited greater growth performance, lipase activity, and nutrient digestibility (P < 0.05), higher mRNA expression levels of intestinal development and barrier-related genes in the small intestine (P < 0.05), and lower mRNA abundances of pro-inflammatory factor in the colon and jejunum (P < 0.05) than the CV group. In conclusion, the absence of gut microbes impaired the growth and nutrient digestibility, and healthy sow gut microbiota transplantation increased the growth and nutrient digestibility and improved the intestinal development and barrier function of newborn piglets, indicating the importance of intestinal microbes for intestinal development and functions.

The Potential Mechanisms of High-Velocity, Low-Amplitude, Controlled Vertebral Thrusts on Neuroimmune Function: A Narrative Review

The current COVID-19 pandemic has necessitated the need to find healthcare solutions that boost or support immunity. There is some evidence that high-velocity, low-amplitude (HVLA) controlled vertebral thrusts have the potential to modulate immune mediators. However, the mechanisms of the link between HVLA controlled vertebral thrusts and neuroimmune function and the associated potential clinical implications are less clear. This review aims to elucidate the underlying mechanisms that can explain the HVLA controlled vertebral thrust--neuroimmune link and discuss what this link implies for clinical practice and future research needs. A search for relevant articles published up until April 2021 was undertaken. Twenty-three published papers were found that explored the impact of HVLA controlled vertebral thrusts on neuroimmune markers, of which eighteen found a significant effect. These basic science studies show that HVLA controlled vertebral thrust influence the levels of immune mediators in the body, including neuropeptides, inflammatory markers, and endocrine markers. This narravtive review discusses the most likely mechanisms for how HVLA controlled vertebral thrusts could impact these immune markers. The mechanisms are most likely due to the known changes in proprioceptive processing that occur within the central nervous system (CNS), in particular within the prefrontal cortex, following HVLA spinal thrusts. The prefrontal cortex is involved in the regulation of the autonomic nervous system, the hypothalamic-pituitary-adrenal axis and the immune system. Bi-directional neuro-immune interactions are affected by emotional or pain-related stress. Stress-induced sympathetic nervous system activity also alters vertebral motor control. Therefore, there are biologically plausible direct and indirect mechanisms that link HVLA controlled vertebral thrusts to the immune system, suggesting HVLA controlled vertebral thrusts have the potential to modulate immune function. However, it is not yet known whether HVLA controlled vertebral thrusts have a clinically relevant impact on immunity. Further research is needed to explore the clinical impact of HVLA controlled vertebral thrusts on immune function.

Activation of the Nrf2/HO-1 signaling pathway by dimethyl fumarate ameliorates complete Freund's adjuvant-induced arthritis in rats

The nuclear factor erythroid 2-related factor (Nrf2) signaling pathway has recently emerged as a novel therapeutic target in treating various diseases. Therefore, the present study aimed to assess the protective role of the Nrf2 activator, dimethyl fumarate (DMF) in the complete Freund's adjuvant (CFA)- induced arthritis model. DMF (25, 50, and 100 mg/kg) and dexamethasone (2 mg/kg) were orally administered for 14 days. Pain-related tests, paw volume, and arthritic scores were measured weekly. Serum TNF-α, IL-1β, cyclic citrullinated peptide (CCP), C-reactive protein (CRP), and rheumatoid factor (RF) levels were estimated. Nitrite, malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione (GSH), catalase (CAT), and myeloperoxidase (MPO) levels were also evaluated. NF-κB, Nrf2, HO-1, and COX-2 levels were estimated in the joint tissue. DMF treatment exerted anti-arthritic activity by enhancing the nociceptive threshold, improving arthritis scores, and reducing paw edema. Also, DMF suppressed changes in oxidative stress markers and inflammatory mediators and enhanced Nrf2 and HO-1 levels in CFA-injected rats. These findings indicate that the anti-arthritic activity of DMF may be mediated by the activation of the Nrf2/HO-1 pathway, which reduced oxidative damage and inflammation.

The Role of the Gut Microbiome, Immunity, and Neuroinflammation in the Pathophysiology of Eating Disorders

There is a growing recognition that both the gut microbiome and the immune system are involved in a number of psychiatric illnesses, including eating disorders. This should come as no surprise, given the important roles of diet composition, eating patterns, and daily caloric intake in modulating both biological systems. Here, we review the evidence that alterations in the gut microbiome and immune system may serve not only to maintain and exacerbate dysregulated eating behavior, characterized by caloric restriction in anorexia nervosa and binge eating in bulimia nervosa and binge eating disorder, but may also serve as biomarkers of increased risk for developing an eating disorder. We focus on studies examining gut dysbiosis, peripheral inflammation, and neuroinflammation in each of these eating disorders, and explore the available data from preclinical rodent models of anorexia and binge-like eating that may be useful in providing a better understanding of the biological mechanisms underlying eating disorders. Such knowledge is critical to developing novel, highly effective treatments for these often intractable and unremitting eating disorders.

Neuronal regulation of immunity: why, how and where?

Neuroimmunology is one of the fastest-growing fields in the life sciences, and for good reason; it fills the gap between two principal systems of the organism, the nervous system and the immune system. Although both systems affect each other through bidirectional interactions, we focus here on one direction - the effects of the nervous system on immunity. First, we ask why is it beneficial to allow the nervous system any control over immunity? We evaluate the potential benefits to the immune system that arise by taking advantage of some of the brain's unique features, such as its capacity to integrate and synchronize physiological functions, its predictive capacity and its speed of response. Second, we explore how the brain communicates with the peripheral immune system, with a focus on the endocrine, sympathetic, parasympathetic, sensory and meningeal lymphatic systems. Finally, we examine where in the brain this immune information is processed and regulated. We chart a partial map of brain regions that may be relevant for brain-immune system communication, our goal being to introduce a conceptual framework for formulating new hypotheses to study these interactions.

A systematic review of in vitro cytokine production in eating disorders

BACKGROUND

Eating disorders (EDs) have been associated with alterations in cytokine concentrations and production. This review examines whether in vitro cytokine production (i) is altered in people with EDs compared to healthy participants; and (ii) changes in response to treatment?

METHODS

Using PRISMA guidelines, we systematically reviewed articles reporting group comparisons or longitudinal assessments of spontaneous and/or stimulated cytokine production in vitro in people with EDs.

RESULTS

Twelve studies were included. Cross-sectional results were mixed in anorexia nervosa. Only one study measured cytokine production in bulimia nervosa. Two longitudinal studies showed that daily yoghurt consumption increases phytohemagglutinin-stimulated interferon-γ production in anorexia nervosa.

CONCLUSION

The mixed results could be accounted for by variations in experimental design. Our findings suggest that cytokine production could possibly be modulated through dietary interventions. However, due to the methodological heterogeneity and shortcomings of the included studies, it seems unreasonable to draw further conclusions.

In Vitro and In Vivo Characterization of Novel Stable Peptidic Ghrelin Analogs: Beneficial Effects in the Settings of Lipopolysaccharide-Induced Anorexia in Mice

Ghrelin, the only known orexigenic gut hormone produced primarily in the stomach, has lately gained attention as a potential treatment of anorexia and cachexia. However, its biologic stability is highly limited; therefore, a number of both peptide and nonpeptide ghrelin analogs have been synthesized. In this study, we provide in vitro and in vivo characterization of a series of novel peptide growth hormone secretagogue receptor (GHS-R1a) agonists, both under nonpathologic conditions and in the context of lipopolysaccharide (LPS)-induced anorexia. These analogs were based on our previous series modified by replacing the Ser³ with diaminopropionic acid (Dpr), the N-terminal Gly with sarcosine, and Phe⁴ with various noncoded amino acids. New analogs were further modified by replacing the n-octanoyl bound to Dpr³ with longer or unsaturated fatty acid residues, by incorporation of the second fatty acid residue into the molecule, or by shortening the peptide chain. These modifications preserved the ability of ghrelin analogs to bind to the membranes of cells transfected with GHS-R1a, as well as the GHS-R1a signaling activation. The selected analogs exhibited long-lasting and potent orexigenic effects after a single s.c. administration in mice. The stability of new ghrelin analogs in mice after s.c. administration was significantly higher when compared with ghrelin and [Dpr³]ghrelin, with half-lives of approximately 2 hours. A single s.c. injection of the selected ghrelin analogs in mice with LPS-induced anorexia significantly increased food intake via the activation of orexigenic pathways and normalized blood levels of proinflammatory cytokines, demonstrating the anti-inflammatory potential of the analogs.

Lipopolysaccharide immune stimulation but not β-mannanase supplementation affects maintenance energy requirements in young weaned pigs

Background

Pathogen or diet-induced immune activation can partition energy and nutrients away from growth, but clear relationships between immune responses and the direction and magnitude of energy partitioning responses have yet to be elucidated. The objectives were to determine how β-mannanase supplementation and lipopolysaccharide (LPS) immune stimulation affect maintenance energy requirements (MEm) and to characterize immune parameters, digestibility, growth performance, and energy balance.

Methods

In a randomized complete block design, 30 young weaned pigs were assigned to either the control treatment (CON; basal corn, soybean meal and soybean hulls diet), the enzyme treatment (ENZ; basal diet + 0.056% β-mannanase), or the immune system stimulation treatment (ISS; basal diet + 0.056% β-mannanase, challenged with repeated increasing doses of Escherichia coli LPS). The experiment consisted of a 10-d adaptation period, 5-d digestibility and nitrogen balance measurement, 22 h of heat production (HP) measurements, and 12 h of fasting HP measurements in indirect calorimetry chambers. The immune challenge consisted of 4 injections of either LPS (ISS) or sterile saline (CON and ENZ), one every 48 h beginning on d 10. Blood was collected pre- and post-challenge for complete blood counts with differential, haptoglobin and mannan binding lectin, 12 cytokines, and glucose and insulin concentrations.

Results

Beta-mannanase supplementation did not affect immune status, nutrient digestibility, growth performance, energy balance, or ME_m. The ISS treatment induced fever, elevated proinflammatory cytokines and decreased leukocyte concentrations (P < 0.05). The ISS treatment did not impact nitrogen balance or nutrient digestibility (P > 0.10), but increased total HP (21%) and ME_m (23%), resulting in decreased lipid deposition (−30%) and average daily gain (−18%) (P < 0.05).

Conclusions

This experiment provides novel data on β-mannanase supplementation effects on immune parameters and energy balance in pigs and is the first to directly relate decreased ADG to increased ME_m independent of changes in feed intake in immune challenged pigs. Immune stimulation increased energy partitioning to the immune system by 23% which limited lipid deposition and weight gain. Understanding energy and nutrient partitioning in immune-stressed pigs may provide insight into more effective feeding and management strategies.

Electronic supplementary material

The online version of this article (10.1186/s40104-018-0264-y) contains supplementary material, which is available to authorized users.

Neural, Hormonal, and Cognitive Correlates of Metabolic Dysfunction and Emotional Reactivity

OBJECTIVE

Prediabetes and type 2 diabetes (i.e., hyperglycemia) are characterized by insulin resistance. These problems with energy metabolism may exacerbate emotional reactivity to negatively valenced stimuli and related phenomena such as predisposition toward negative affect, as well as cognitive deficits. Higher emotional reactivity is seen with hyperglycemia and insulin resistance. However, it is largely unknown how metabolic dysfunction correlates with related neural, hormonal, and cognitive outcomes.

METHODS

Among 331 adults from the Midlife in the United States study, eye-blink response (EBR) we cross sectionally examined to gauge reactivity to negative, positive, or neutrally valenced pictures from international affect picture system stimuli proximal to an acoustic startle probe. Increased EBR to negative stimuli was considered an index of stress reactivity. Frontal alpha asymmetry, a biomarker of negative affect predisposition, was determined using resting electroencephalography. Baseline urinary cortisol output was collected. Cognitive performance was gauged using the Brief Test of Adult Cognition by telephone. Fasting glucose and insulin characterized hyperglycemia or the homeostatic model assessment of insulin resistance.

RESULTS

Higher homeostatic model assessment of insulin resistance corresponded to an increased startle response, measured by EBR magnitude, for negative versus positive stimuli (R = 0.218, F(1,457) = 5.48, p = .020, euglycemia: M(SD) = .092(.776), hyperglycemia: M(SD) = .120(.881)). Participants with hyperglycemia versus euglycemia showed greater right frontal alpha asymmetry (F(1,307) = 6.62, p = .011, euglycemia: M(SD) = .018(.167), hyperglycemia: M(SD) = -.029(.160)), and worse Brief Test of Adult Cognition by telephone arithmetic performance (F(1,284) = 4.25, p = .040, euglycemia: M(SD) = 2.390(1.526), hyperglycemia: M(SD) = 1.920(1.462)). Baseline urinary cortisol (log10 μg/12 hours) was also dysregulated in individuals with hyperglycemia (F(1,324) = 5.09, p = .025, euglycemia: M(SD) = 1.052 ± .332, hyperglycemia: M(SD) = .961 (.362)).

CONCLUSIONS

These results suggest that dysmetabolism is associated with increased emotional reactivity, predisposition toward negative affect, and specific cognitive deficits.

Multiplex Quantification Identifies Novel Exercise-regulated Myokines/Cytokines in Plasma and in Glycolytic and Oxidative Skeletal Muscle

Exercise is known to confer major health benefits, but the underlying mechanisms are not well understood. The systemic effects of exercise on multi-organ systems are thought to be partly because of myokines/cytokines secreted by skeletal muscle. The extent to which exercise alters cytokine expression and secretion in different muscle fiber types has not been systematically examined. Here, we assessed changes in 66 mouse cytokines in serum, and in glycolytic (plantaris) and oxidative (soleus) muscles, in response to sprint, endurance, or chronic wheel running. Both acute and short-term exercise significantly altered a large fraction of cytokines in both serum and muscle, twenty-three of which are considered novel exercise-regulated myokines. Most of the secreted cytokine receptors profiled were also altered by physical activity, suggesting an exercise-regulated mechanism that modulates the generation of soluble receptors found in circulation. A greater overlap in cytokine profile was seen between endurance and chronic wheel running. Between fiber types, both acute and chronic exercise induced significantly more cytokine changes in oxidative compared with glycolytic muscle. Further, changes in a subset of circulating cytokines were not matched by their changes in muscle, but instead reflected altered expression in liver and adipose tissues. Last, exercise-induced changes in cytokine mRNA and protein were only minimally correlated in soleus and plantaris. In sum, our results indicate that exercise regulates many cytokines whose pleiotropic actions may be linked to positive health outcomes. These data provide a framework to further understand potential crosstalk between skeletal muscle and other organ compartments.

Tuberculosis, the Disrupted Immune-Endocrine Response and the Potential Thymic Repercussion As a Contributing Factor to Disease Physiopathology

Upon the pathogen encounter, the host seeks to ensure an adequate inflammatory reaction to combat infection but at the same time tries to prevent collateral damage, through several regulatory mechanisms, like an endocrine response involving the production of adrenal steroid hormones. Our studies show that active tuberculosis (TB) patients present an immune-endocrine imbalance characterized by an impaired cellular immunity together with increased plasma levels of cortisol, pro-inflammatory cytokines, and decreased amounts of dehydroepiandrosterone. Studies in patients undergoing specific treatment revealed that cortisol levels remained increased even after several months of initiating therapy. In addition to the well-known metabolic and immunological effects, glucocorticoids are involved in thymic cortical depletion with immature thymocytes being quite sensitive to such an effect. The thymus is a central lymphoid organ supporting thymocyte T-cell development, i.e., lineage commitment, selection events and thymic emigration. While thymic TB is an infrequent manifestation of the disease, several pieces of experimental and clinical evidence point out that the thymus can be infected by mycobacteria. Beyond this, the thymic microenvironment during TB may be also altered because of the immune-hormonal alterations. The thymus may be then an additional target of organ involvement further contributing to a deficient control of infection and disease immunopathology.

Hypothalamic expression of inflammatory mediators in an animal model of binge eating

Binge eating episodes are characterized by uncontrollable, distressing eating of a large amount of highly palatable food and represent a central feature of bingeing related eating disorders. Research suggests that inflammation plays a role in the onset and maintenance of eating-related maladaptive behavior. Markers of inflammation can be selectively altered in discrete brain regions where they can directly or indirectly regulate food intake. In the present study, we measured expression levels of different components of cytokine systems (IL-1, IL-6, IL-18, TNF-α and IFN-ɣ) and related molecules (iNOS and COX2) in the preoptic and anterior-tuberal parts of the hypothalamus of a validated animal model of binge eating. In this animal model, based on the exposure to both food restriction and frustration stress, binge-like eating behavior for highly palatable food is not shown when animals are exposed to the frustration stress during the estrus phase. We found a characteristic down-regulation of the IL-18/IL-18 receptor system (with increased expression of the inhibitor of the pro-inflammatory cytokine IL-18, IL-18BP, together with a decreased expression of the binding chain of the IL-18 receptor) and a three-fold increase in the expression of iNOS specifically in the anterior-tuberal region of the hypothalamus of animals that develop a binge-like eating behavior. Differently, when food restricted animals were stressed during the estrus phase, IL-18 expression increased, while iNOS expression was not significantly affected. Considering the role of this region of the hypothalamus in controlling feeding related behavior, this can be relevant in eating disorders and obesity. Our data suggest that by targeting centrally selected inflammatory markers, we may prevent that disordered eating turns into a full blown eating disorder.

Nutritional Supplement of Hatchery Eggshell Membrane Improves Poultry Performance and Provides Resistance against Endotoxin Stress

Eggshells are significant part of hatchery waste which consist of calcium carbonate crust, membranes, and proteins and peptides of embryonic origins along with other entrapped contaminants including microbes. We hypothesized that using this product as a nutritional additive in poultry diet may confer better immunity to the chickens in the paradigm of mammalian milk that enhances immunity. Therefore, we investigated the effect of hatchery eggshell membranes (HESM) as a short term feed supplement on growth performance and immunity of chickens under bacterial lipopolysaccharide (LPS) challenged condition. Three studies were conducted to find the effect of HESM supplement on post hatch chickens. In the first study, the chickens were fed either a control diet or diets containing 0.5% whey protein or HESM as supplement and evaluated at 5 weeks of age using growth, hematology, clinical chemistry, plasma immunoglobulins, and corticosterone as variables. The second and third studies were done to compare the effects of LPS on control and HESM fed birds at 5 weeks of age following at 4 and 24 h of treatment where the HESM was also sterilized with ethanol to deplete bacterial factors. HESM supplement caused weight gain in 2 experiments and decreased blood corticosterone concentrations. While LPS caused a significant loss in body weight at 24 h following its administration, the HESM supplemented birds showed significantly less body weight loss compared with the control fed birds. The WBC, heterophil/lymphocyte ratio, and the levels of IgG were low in chickens fed diets with HESM supplement compared with control diet group. LPS challenge increased the expression of pro-inflammatory cytokine gene IL-6 but the HESM fed birds showed its effect curtailed, also, which also, favored the up-regulation of anti-inflammatory genes compared with control diet fed chickens. Post hatch supplementation of HESM appears to improve performance, modulate immunity, and increase resistance of chickens to endotoxin.

Obesity Impacts Fever and Sickness Behavior During Acute Systemic Inflammation

Obesity is reaching dramatic proportions in humans and is associated with a higher risk for cardiovascular disease, diabetes, and cognitive alterations, and a higher mortality during infection and inflammation. The focus of the present review is on the influence of obesity on the presentation of fever, sickness behavior, and inflammatory responses during acute systemic inflammation.

Novel and disruptive biological strategies for resolving gut health challenges in monogastric food animal production

Use of feed antibiotics as growth promoters for control of pathogens associated with monogastric food animal morbidity and mortality has contributed to the development of antimicrobial resistance, which has now become a threat to public health on a global scale. Presently, a number of alternative feed additives have been developed and are divided into two major categories, including 1) the ones that are supposed to directly and indirectly control pathogenic bacterial proliferation; and 2) the other ones that are intended to up-regulate host gut mucosal trophic growth, whole body growth performance and active immunity. A thorough review of literature reports reveal that efficacy responses of current alternative feed additives in replacing feed antibiotics to improve performances and gut health are generally inconsistent dependent upon experimental conditions. Current alternative feed additives typically have no direct detoxification effects on endotoxin lipopolysaccharides (LPS) and this is likely the major reason that their effects are limited. It is now understood that pathogenic bacteria mediate their negative effects largely through LPS interactions with toll-like receptor 4, causing immune responses and infectious diseases. Therefore, disruptive biological strategies and a novel and new generation of feed additives need to be developed to replace feed antibiotic growth promoters and to directly and effectively detoxify the endotoxin LPS and improve gut health and performance in monogastric food animals.

Dynamic and extensive metabolic state-dependent regulation of cytokine expression and circulating levels

Cytokines play diverse and critical roles in innate and acquired immunity, and several function within the central nervous system and in peripheral tissues to modulate energy metabolism. The extent to which changes in energy balance impact the expression and circulating levels of cytokines (many of which have pleiotropic functions) has not been systematically examined. To investigate metabolism-related changes in cytokine profiles, we used a multiplex approach to assess changes in 71 circulating mouse cytokines in response to acute (fasting and refeeding) and chronic (high-fat feeding) alterations in whole body metabolism. Refeeding significantly decreased serum levels of IL-22, IL-1α, soluble (s)IL-2Rα, and soluble vascular endothelial growth factor receptor 3 (VEGFR3), but markedly increased granulocyte colony-stimulating factor (G-CSF), IL-1β, chemokine (C-C motif) ligand (CCL2), sIL-1RI, lipocalin-2, pentraxin-3, tissue inhibitor of metalloproteinase (TIMP-1), and serum amyloid protein (SAP) relative to the fasted state. Interestingly, only a few of these changes paralleled the alterations in expression of their corresponding mRNAs. Functional studies demonstrated that central delivery of G-CSF increased, whereas IL-22 decreased, food intake. Changes in food intake were not accompanied by acute alterations in orexigenic (Npy and Agrp) and anorexigenic (Pomc and Cart) neuropeptide gene expression in the hypothalamus. In the context of chronic high-fat feeding, circulating levels of chemokine (C-X-C) ligand (CXCL1), serum amyloid protein A3 (SAA3), TIMP-1, α1-acid glycoprotein (AGP), and A2M were increased, whereas IL-12p40, CCL4, sCD30, soluble receptor for advanced glycation end products (sRAGE), CCL12, CCL20, CX3CL1, IL-16, IL-22, and haptoglobin were decreased relative to mice fed a control low-fat diet. These results demonstrate that both short- and long-term changes in whole body metabolism extensively alter cytokine expression and circulating levels, thus providing a foundation and framework for further investigations to ascertain the metabolic roles for these molecules in physiological and pathological states.

JAK-STAT and feeding

The regulation of energy balance requires a complex system to homeostatically maintain the adult body at a precise set point. The central nervous system, particularly the hypothalamus, plays a key role in integrating a variety of signals that can relay information about the body's energy stores. As part of this system, numerous cytokines and hormones contribute to the regulation of food intake and energy homeostasis. Cytokines, and some hormones, are known to act through JAK-STAT intracellular signaling pathways. The hormone leptin, which plays a vital role in appetite regulation, signals through the JAK-STAT pathway, and it is through this involvement that the JAK-STAT pathway has become an established component in the mechanisms regulating food intake within the body. Emerging research, however, is now showing that this involvement of JAK-STAT is not limited to its activation by leptin. Furthermore, while the JAK-STAT pathway may simply act to transmit the anorectic signal of circulating factors, this intracellular signaling pathway may also become impaired when normal regulation of energy balance is disrupted. Thus, altered JAK-STAT signaling may contribute to the breakdown of the normal homeostatic mechanisms maintaining body weight in obesity.

Macrophage depletion disrupts immune balance and energy homeostasis

Increased macrophage infiltration in tissues including white adipose tissue and skeletal muscle has been recognized as a pro-inflammatory factor that impairs insulin sensitivity in obesity. However, the relationship between tissue macrophages and energy metabolism under non-obese physiological conditions is not clear. To study a homeostatic role of macrophages in energy homeostasis, we depleted tissue macrophages in adult mice through conditional expression of diphtheria toxin (DT) receptor and DT-induced apoptosis. Macrophage depletion robustly reduced body fat mass due to reduced energy intake. These phenotypes were reversed after macrophage recovery. As a potential mechanism, severe hypothalamic and systemic inflammation was induced by neutrophil (NE) infiltration in the absence of macrophages. In addition, macrophage depletion dramatically increased circulating granulocyte colony-stimulating factor (G-CSF) which is indispensable for NE production and tissue infiltration. Our in vitro study further revealed that macrophages directly suppress G-CSF gene expression. Therefore, our study indicates that macrophages may play a critical role in integrating immune balance and energy homeostasis under physiological conditions.

Hypoxemia-induced leptin secretion: a mechanism for the control of food intake in diseased fish

Leptin is a potent anorexigen, but little is known about the physiological conditions under which this cytokine regulates food intake in fish. In this study, we characterized the relationships between food intake, O2-carrying capacity, liver leptin-A1 (lep-a1) gene expression, and plasma leptin-A1 in rainbow trout infected with a pathogenic hemoflagellate, Cryptobia salmositica. As lep gene expression is hypoxia-sensitive and Cryptobia-infected fish are anemic, we hypothesized that Cryptobia-induced anorexia is mediated by leptin. A 14-week time course experiment revealed that Cryptobia-infected fish experience a transient 75% reduction in food intake, a sharp initial drop in hematocrit and hemoglobin levels followed by a partial recovery, a transient 17-fold increase in lep-a1 gene expression, and a sustained increase in plasma leptin-A1 levels. In the hypothalamus, peak anorexia was associated with decreases in mRNA levels of neuropeptide Y (npy) and cocaine- and amphetamine-regulated transcript (cart), and increases in agouti-related protein (agrp) and pro-opiomelanocortin A2 (pomc). In contrast, in non-infected fish pair-fed to infected animals, lep-a1 gene expression and plasma levels did not differ from those of non-infected satiated fish. Pair-fed fish were also characterized by increases in hypothalamic npy and agrp, no changes in pomc-a2, and a reduction in cart mRNA expression. Finally, peak infection was characterized by a significant positive correlation between O2-carrying capacity and food intake. These findings show that hypoxemia, and not feed restriction, stimulates leptin-A1 secretion in Cryptobia-infected rainbow trout and suggest that leptin contributes to anorexia by inhibiting hypothalamic npy and stimulating pomc-a2.

Hypothalamic eIF2α signaling regulates food intake

The reversible phosphorylation of the α subunit of eukaryotic initiation factor 2 (eIF2α) is a highly conserved signal implicated in the cellular adaptation to numerous stresses such as the one caused by amino acid limitation. In response to dietary amino acid deficiency, the brain-specific activation of the eIF2α kinase GCN2 leads to food intake inhibition. We report here that GCN2 is rapidly activated in the mediobasal hypothalamus (MBH) after consumption of a leucine-deficient diet. Furthermore, knockdown of GCN2 in this particular area shows that MBH GCN2 activity controls the onset of the aversive response. Importantly, pharmacological experiments demonstrate that the sole phosphorylation of eIF2α in the MBH is sufficient to regulate food intake. eIF2α signaling being at the crossroad of stress pathways activated in several pathological states, our study indicates that hypothalamic eIF2α phosphorylation could play a critical role in the onset of anorexia associated with certain diseases.

Butyrylcholinesterase as a prognostic marker: a review of the literature

BACKGROUND

Butyrylcholinesterase (BChE) is an α-glycoprotein synthesized in the liver. Its serum level decreases in many clinical conditions such as acute and chronic liver damage, inflammation, injury and infections, and malnutrition.

METHODS AND RESULTS

This review collects the main evidence on the emerging role of butyrylcholinesterase as a prognostic marker of liver and nonliver diseases as well as a marker of protein-energy malnutrition and obesity. In fact, serum concentrations and BChE activity seem to accurately reflect the availability of amino acidic substrates and/or derangement in protein synthesis due to hepatocellular damage. In cancer, with or without liver impairment, serum BChE levels serve as an accurate functional and prognostic indicator, useful for monitoring clinical and therapeutic interventions according to patients' prognosis. In the absence of inflammation, BChE could also serve as an index of the effectiveness of nutritional support.

CONCLUSIONS

Serum BChE assessment should be included in routine clinical diagnostic procedures to evaluate patient clinical conditions, in particular in cases of inflammation and/or protein-energy malnutrition.

Targeting IL-1 in depression

INTRODUCTION

Depression is associated with inflammation, Th1 and Th17 responses, oxidative and nitrosative stress (O&NS), autoimmune responses against neoantigenic determinants, and neuroprogression (i.e., neurodegeneration, impaired plasticity and reduced neurogenesis). These pathways involve increased monocytic activation and interleukin-1 (IL-1) levels.

AREAS COVERED

This review will highlight the putative role of IL-1 in depression and the potential use of IL-1 signaling blockade as a treatment of depression. Electronic databases, i.e., Scopus, PUBMED and Google Scholar were employed using keywords: depression, depressive-like, interleukin-1, and interleukin-1 receptor antagonist (IL-1RA).

EXPERT OPINION

Ample studies show that depression is accompanied by increased levels of IL-1 and IL-1RA, which attenuates the pro-inflammatory activities of IL-1. In some, but not all studies, antidepressant treatment decreased IL-1β levels. In translational models, IL-1β administration elicits depressive-like behaviors, neuroinflammation and neuroprogression, whereas treatment with IL-1RA yields antidepressant-like effects and attenuates neuroprogression. Anakinra, an IL-1RA, targets not only IL-1 signaling, but also Th1, Th17, O&NS and neuroprogressive pathways and therefore may be advanced to clinical Phase-II trials in depression due to medical conditions associated with an elevated IL-1/IL-1RA ratio.

Evaluation of chronic immune system stimulation models in growing pigs

Two experiments (EXPs) were conducted to evaluate models of immune system stimulation (ISS) that can be used in nutrient metabolism studies in growing pigs. In EXP I, the pig's immune response to three non-pathogenic immunogens was evaluated, whereas in EXP II the pig's more general response to one of the immunogens was contrasted with observations on non-ISS pigs. In EXP I, nine growing barrows were fitted with a jugular catheter, and after recovery assigned to one of three treatments. Three immunogens were tested during a 10-day ISS period: (i) repeated injection of increasing amounts of Escherichia coli lipopolysaccharide (LPS); (ii) repeated subcutaneous injection of turpentine (TURP); and (iii) feeding grains naturally contaminated with mycotoxins (MYCO). In EXP II, 36 growing barrows were injected repeatedly with either saline (n = 12) or increasing amounts of LPS (n = 24) for 7 days (initial dose 60 μg/kg body weight). Treating pigs with TURP and LPS reduced feed intake (P < 0.02), whereas feed intake was not reduced in pigs on MYCO. Average daily gain (ADG; kg/day) of pigs on LPS (0.50) was higher than that of pigs on TURP (0.19), but lower than that of pigs on MYCO (0.61; P < 0.01). Body temperature was elevated in pigs on LPS and TURP, by 0.8°C and 0.7°C, respectively, relative to pre-ISS challenge values (39.3°C; P < 0.02), but remained unchanged in pigs on MYCO. Plasma concentrations of interleukin-1β were increased in pigs treated with LPS and TURP (56% and 55%, respectively, relative to 22.3 pg/ml for pre-ISS; P < 0.01), but not in MYCO-treated pigs. Plasma cortisol concentrations remained unchanged for pigs on MYCO and TURP, but were reduced in LPS-treated pigs (30% relative to 29.8 ng/ml for pre-ISS; P < 0.05). Red blood cell glutathione concentrations were lower in TURP-treated pigs (13% relative to 1.38 μM for pre-ISS; P < 0.05), but were unaffected in pigs on LPS and MYCO. In EXP I, TURP caused severe responses including skin ulceration and substantial reductions in feed intake and ADG, whereas MYCO did not induce effective ISS. In EXP II, ISS increased relative organ weights, eye temperature, white blood cell count and plasma acute-phase proteins (P < 0.05), confirming that repeated injection with increasing amounts of LPS induced chronic and relatively mild ISS. Repeated injection with increasing amounts of LPS is a suitable model for studying nutrient metabolism and evaluating the efficacy of nutritional intervention during chronic ISS in growing pigs.

Leptin, a neuroendocrine mediator of immune responses, inflammation, and sickness behaviors

Effective immune responses are coordinated by interactions among the nervous, endocrine, and immune systems. Mounting immune, inflammatory, and sickness responses requires substantial energetic investments, and as such, an organism may need to balance energy allocation to these processes with the energetic demands of other competing physiological systems. The metabolic hormone leptin appears to be mediating trade-offs between the immune system and other physiological systems through its actions on immune cells and the brain. Here we review the evidence in both mammalian and non-mammalian vertebrates that suggests leptin is involved in regulating immune responses, inflammation, and sickness behaviors. Leptin has also been implicated in the regulation of seasonal immune responses, including sickness; however, the precise physiological mechanisms remain unclear. Thus, we discuss recent data in support of leptin as a mediator of seasonal sickness responses and provide a theoretical model that outlines how seasonal cues, leptin, and proinflammatory cytokines may interact to coordinate seasonal immune and sickness responses.

The role of NPY in hypothalamic mediated food intake

Neuropeptide Y (NPY) is a highly conserved neuropeptide with orexigenic actions in discrete hypothalamic nuclei that plays a role in regulating energy homeostasis. NPY signals via a family of high affinity receptors that mediate the widespread actions of NPY in all hypothalamic nuclei. These actions are also subject to tight, intricate regulation by numerous peripheral and central energy balance signals. The NPY system is embedded within a densely-redundant network designed to ensure stable energy homeostasis. This redundancy may underlie compensation for the loss of NPY or its receptors in germline knockouts, explaining why conventional knockouts of NPY or its receptors rarely yield a marked phenotypic change. We discuss insights into the hypothalamic role of NPY from studies of its physiological actions, responses to genetic manipulations and interactions with other energy balance signals. We conclude that numerous approaches must be employed to effectively study different aspects of NPY action.

Pathophysiology and treatment options for cardiac anorexia

The anorexia-cachexia syndrome (ACS) occurs in many chronic illnesses, such as cancer, AIDS, and chronic obstructive pulmonary disease in addition to chronic congestive heart failure (CHF). Comparable to other chronic states, the ACS complicates CHF and impacts its prognosis; however, the available treatment options for this syndrome remain unsatisfactory. This review article focuses on the complex pathophysiology of cardiac anorexia. We focus on the recent data demonstrating the relationships between central appetite-regulating structures, inflammatory processes, and neurohormonal activation, and their respective roles in the development of anorexia. We then describe the different treatment options and discuss some future prospects for the management for cardiac anorexia.

Growth in children and adolescents with sickle cell disease in Yemen

BACKGROUND

Physical growth is known to be impaired in children with sickle cell disease (SCD) and the prevalence and severity vary with geographical location. The factors which contribute to this sub-optimal growth are poorly understood.

OBJECTIVES

To describe the growth status of children and adolescents with SCD in Yemen using the new WHO reference values and to assess correlation of growth indicators with disease severity and with haematological and biochemical parameters.

METHODS

A cross-sectional study of children <16 years with SCD was conducted at Al-Wahda General Teaching Hospital, Aden. Anthropometric measurements of weight, length/height, mid-upper-arm circumference (MUAC) and body mass index (BMI) were collected. Disease severity was assessed using a severity index (SI) score.

RESULTS

A total of 102 children (56 male) were included and their mean age was 7.2 years (range 6 months to 15 years). Low weight, height and BMI-for-age Z-scores (<-2 SD) were observed in 45%, 54% and 35% of children, respectively. Regression analyses indicated an association of low height-for-age with male gender (p=0.02), low weight-for-age and weight-for-height with increased age (both p<0.001), low weight-for-age with raised alkaline phosphatase (p=0.04), and low BMI with reduced plasma albumin (p=0.04). There was no correlation between growth deficits and SI or anaemia severity.

CONCLUSION

Growth is severely impaired in children and adolescents with SCD in Yemen. Growth monitoring and nutritional support should be included in their comprehensive care package.

Individual differences in maternal response to immune challenge predict offspring behavior: contribution of environmental factors

Maternal infection during pregnancy elevates risk for schizophrenia and related disorders in offspring. Converging evidence suggests the maternal inflammatory response mediates the interaction between maternal infection, altered brain development, and behavioral outcome. The extent to which individual differences in the maternal response to immune challenge influence the development of these abnormalities is unknown. The present study investigated the impact of individual differences in maternal response to the viral mimic polyinosinic:polycytidylic acid (poly I:C) on offspring behavior. We observed significant variability in body weight alterations of pregnant rats induced by administration of poly I:C on gestational day 14. Furthermore, the presence or absence of maternal weight loss predicted MK-801 and amphetamine stimulated locomotor abnormalities in offspring. MK-801 stimulated locomotion was altered in offspring of all poly I:C treated dams; however, the presence or absence of maternal weight loss resulted in decreased and modestly increased locomotion, respectively. Adult offspring of poly I:C treated dams that lost weight exhibited significantly decreased amphetamine stimulated locomotion, while offspring of poly I:C treated dams without weight loss performed similarly to vehicle controls. Social isolation and increased maternal age predicted weight loss in response to poly I:C but not vehicle injection. In combination, these data identify environmental factors associated with the maternal response to immune challenge and functional outcome of offspring exposed to maternal immune activation.

Functional role of c-Jun-N-terminal kinase in feeding regulation

c-Jun-N-terminal kinase (JNK) is a signaling molecule that is activated by proinflammatory signals, endoplasmic reticulum (ER) stress, and other environmental stressors. Although JNK has diverse effects on immunological responses and insulin resistance in peripheral tissues, a functional role for JNK in feeding regulation has not been established. In this study, we show that central inhibition of JNK activity potentiates the stimulatory effects of glucocorticoids on food intake and that this effect is abolished in mice whose agouti-related peptide (AgRP) neurons are degenerated. JNK1-deficient mice feed more upon central administration of glucocorticoids, and glucocorticoid receptor nuclear immunoreactivity is enhanced in the AgRP neurons. JNK inhibition in hypothalamic explants stimulates Agrp expression, and JNK1-deficient mice exhibit increased Agrp expression, heightened hyperphagia, and weight gain during refeeding. Our study shows that JNK1 is a novel regulator of feeding by antagonizing glucocorticoid function in AgRP neurons. Paradoxically, JNK1 mutant mice feed less and lose more weight upon central administration of insulin, suggesting that JNK1 antagonizes insulin function in the brain. Thus, JNK may integrate diverse metabolic signals and differentially regulate feeding under distinct physiological conditions.

Plasma MIC-1 correlates with systemic inflammation but is not an independent determinant of nutritional status or survival in oesophago-gastric cancer

Background:

Macrophage inhibitory cytokine-1(MIC-1) is a potential modulator of systemic inflammation and nutritional depletion, both of which are adverse prognostic factors in oesophago-gastric cancer (OGC).

Methods:

Plasma MIC-1, systemic inflammation (defined as plasma C-reactive protein (CRP) of ⩾10 mg l^–1 or modified Glasgow prognostic score (mGPS) of ⩾1), and nutritional status were assessed in newly diagnosed OGC patients (n=293). Healthy volunteers (n=35) served as controls.

Results:

MIC-1 was elevated in patients (median=1371 pg ml^–1; range 141–39 053) when compared with controls (median=377 pg ml^–1; range 141–3786; P<0.001). Patients with gastric tumours (median=1592 pg ml^–1; range 141–12 643) showed higher MIC-1 concentrations than patients with junctional (median=1337 pg ml^–1; range 383–39 053) and oesophageal tumours (median=1180 pg ml^–1; range 258–31 184; P=0.015). Patients showed a median weight loss of 6.4% (range 0.0–33.4%), and 42% of patients had an mGPS of ⩾1 or plasma CRP of ⩾10 mg l^–1 (median=9 mg l^–1; range 1–200). MIC-1 correlated positively with disease stage (r²=0.217; P<0.001), age (r²=0.332; P<0.001), CRP (r²=0.314; P<0.001), and mGPS (r²=0.336; P<0.001), and negatively with Karnofsky Performance Score (r²=−0.269; P<0.001). However, although MIC-1 correlated weakly with dietary intake (r²=0.157; P=0.031), it did not correlate with weight loss, BMI, or anthropometry. Patients with MIC-1 levels in the upper quartile showed reduced survival (median=204 days; 95% CI 157–251) when compared with patients with MIC-1 levels in the lower three quartiles (median=316 days; 95% CI 259–373; P=0.036), but MIC-1 was not an independent prognostic indicator.

Conclusions:

There is no independent link between plasma MIC-1 levels and depleted nutritional status or survival in OGC.

Neuroendocrine and physiological regulation of intake with particular reference to domesticated ruminant animals

The central nervous system undertakes the homeostatic role of sensing nutrient intake and body reserves, integrating the information, and regulating energy intake and/or energy expenditure. Few tasks regulated by the brain hold greater survival value, particularly important in farmed ruminant species, where the demands of pregnancy, lactation and/or growth are not easily met by often bulky plant-based and sometimes nutrient-sparse diets. Information regarding metabolic state can be transmitted to the appetite control centres of the brain by a diverse array of signals, such as stimulation of the vagus nerve, or metabolic 'feedback' factors derived from the pituitary gland, adipose tissue, stomach/abomasum, intestine, pancreas and/or muscle. These signals act directly on the neurons located in the arcuate nucleus of the medio-basal hypothalamus, a key integration, and hunger (orexigenic) and satiety (anorexigenic) control centre of the brain. Interest in human obesity and associated disorders has fuelled considerable research effort in this area, resulting in increased understanding of chronic and acute factors influencing feed intake. In recent years, research has demonstrated that these results have relevance to animal production, with genetic selection for production found to affect orexigenic hormones, feeding found to reduce the concentration of acute controllers of orexigenic signals, and exogenous administration of orexigenic hormones (i.e. growth hormone or ghrelin) reportedly increasing DM intake in ruminant animals as well as single-stomached species. The current state of knowledge on factors influencing the hypothalamic orexigenic and anorexigenic control centres is reviewed, particularly as it relates to domesticated ruminant animals, and potential avenues for future research are identified.

Brain regulation of appetite and satiety

Interest in the control of feeding has increased as a result of the obesity epidemic and rising incidence of metabolic diseases. The brain detects alterations in energy stores and triggers metabolic and behavioral responses designed to maintain energy balance. Energy homeostasis is controlled mainly by neuronal circuits in the hypothalamus and brainstem, whereas reward and motivation aspects of eating behavior are controlled by neurons in limbic regions and the cerebral cortex. This article provides an integrated perspective on how metabolic signals emanating from the gastrointestinal tract, adipose tissue, and other peripheral organs target the brain to regulate feeding, energy expenditure, and hormones. The pathogenesis and treatment of obesity and abnormalities of glucose and lipid metabolism are discussed.