Preproenkephalin Expression in Peripheral Blood Mononuclear Cells of Acutely Underweight and Recovered Patients with Anorexia Nervosa

Abstract

Background: The prohormone preproenkephalin (ppE) and its derived peptides are involved in leukocyte functioning as well as in the regulation of hunger and satiety. Various abnormalities of the immune and endocrine systems have been described in states of malnutrition such as anorexia nervosa (AN). We hypothesized that ppE expression in AN patients may vary depending on the state of the disorder and the extent of malnutrition. Methods: Expression of ppE mRNA was analysed in peripheral blood mononuclear cells of 29 underweight and 29 weight-recovered patients with AN and compared to that in 29 healthy control women. The extent of malnutrition was characterized by BMI and plasma leptin. Psychological distress and eating disorder specific-psychopathology was determined with the Symptom Checklist-90-Revised and the Eating Disorders Inventory-2. Results: ppE gene expression was similar in all 3 groups and was not related to nutritional status or eating disorder symptoms. However, a significant negative correlation was found between ppE expression and obsessive-compulsive, depressive and anxious symptoms. In addition, ppE expression was higher in smokers compared to non-smokers. Conclusion:Although malnutrition and hypoleptinaemia as seen in patients with AN were not related to peripheral ppE expression, we demonstrated reduced ppE expression in patients with elevated psychological distress. Similar associations have been shown in animal models of stress. It remains speculative if psychological symptoms and/or stress may augment immune abnormalities in AN patients via a pathway that is independent of nutritional status and involves ppE.

Assessment of gene expression in peripheral blood using RNAseq before and after weight restoration in anorexia nervosa

“…Janas-Kozik et al (2008) found that a leptin receptor transcript showed statistically significant differences between individuals with AN and controls. Several other investigations compared expression of P-glycoprotein (Storch et al, 2008) and prohormone preproenkephalin (Weiss et al, 2010), failed to find significant differences. Although limited in number, these studies have provided some preliminary information regarding transcriptomic profiling in AN.…”

Contemporary views on the genetics of anorexia nervosa

“…Kahl et al observed an increase in TNF-α and IL-6 expression in AN at hospital admission time compared with controls, and TNF-α remained significantly higher while IL-6 expression decreased in weight-restored patients (Kahl et al, 2004). In studies on expression of P-glycoprotein (Storch et al, 2008) and prohormone preproenkephalin (ppE mRNA) (Weiss et al, 2010), neither study could identify evidence to support a significant difference between AN and healthy controls, although ppE mRNA level was negatively associated with depressive and anxious symptoms (Weiss et al, 2010). …”

Messenger RNA expression profile of sleep-related genes in peripheral blood cells in patients with chronic kidney disease

“…Recent studies have revealed that gene expression in peripheral blood cells (PBCs) could be useful for the diagnosis and monitoring of disease activity in psychiatric disorders, such as anorexia nervosa, depression and migraine [21][22][23]. However, the expression of genes that relate to sleep disorders has not been identified.…”