The Role of “Mixed” Orexigenic and Anorexigenic Signals and Autoantibodies Reacting with Appetite-Regulating Neuropeptides and Peptides of the Adipose Tissue-Gut-Brain Axis: Relevance to Food Intake and Nutritional Status in Patients with Anorexia Nervosa and Bulimia Nervosa

Abstract

Eating disorders such as anorexia (AN) and bulimia nervosa (BN) are characterized by abnormal eating behavior. The essential aspect of AN is that the individual refuses to maintain a minimal normal body weight. The main features of BN are binge eating and inappropriate compensatory methods to prevent weight gain. The gut-brain-adipose tissue (AT) peptides and neutralizing autoantibodies play an important role in the regulation of eating behavior and growth hormone release. The mechanisms for controlling food intake involve an interplay between gut, brain, and AT. Parasympathetic, sympathetic, and serotoninergic systems are required for communication between brain satiety centre, gut, and AT. These neuronal circuits include neuropeptides ghrelin, neuropeptide Y (NPY), peptide YY (PYY), cholecystokinin (CCK), leptin, putative anorexigen obestatin, monoamines dopamine, norepinephrine (NE), serotonin, and neutralizing autoantibodies. This extensive and detailed report reviews data that demonstrate that hunger-satiety signals play an important role in the pathogenesis of eating disorders. Neuroendocrine dysregulations of the AT-gut-brain axis peptides and neutralizing autoantibodies may result in AN and BN. The circulating autoantibodies can be purified and used as pharmacological tools in AN and BN. Further research is required to investigate the orexigenic/anorexigenic synthetic analogs and monoclonal antibodies for potential treatment of eating disorders in clinical practice.

Anti-Ganglioside, Anti-Glutamate, and Anti-Gad Antibody Levels in Attention-Deficit Hyperactivity Disorder

“…There is evidence suggesting that anti-neuronal antibodies may be involved in the etiopathogenesis of autism, neuropsychiatric systemic lupus erythematosus, and multiple sclerosis (19,20). In addition, there has been an increase in the number of studies evaluating autoimmunity in the etiology of psychiatric diseases such as obsessive compulsive disorder, Tourette syndrome, and anorexia nervosa (13)(14)(15). Antibodies against glutamate NMDA receptors, GAD, and gliadin are closely related to CNS disorders (16,18).…”

“…In particular, it was shown that the auto-antibodies against glutamate N-Methyl-D-aspartate (NMDA) receptors, glutamic acid decarboxylase (GAD), and gliadin are closely related with central nerve system disorders (10)(11)(12). In addition, there is an increasing body of evidence indicating that the autoimmune mechanism may play a role in the etiology of ADHD similar to studies on the etiology of other psychiatric disorders, such as schizophrenia, obsessive compulsive disorder, and anorexia nervosa (13)(14)(15). In one study, it was proposed that anti-GAD65 auto-antibodies may be associated with ADHD (16).…”

The Role of Psychotropic Medications in the Management of Anorexia Nervosa: Rationale, Evidence and Future Prospects

“…In summary, the majority of these pharmacological agents did not show significant benefits in AN treatment but it is also not certain whether their potential is fully explored. Also not well understood and not well studied in human AN are neuropeptides and whether they can improve recovery [98]. …”

Ghrelin and eating disorders

“…Several genes that play an important role in appetite regulation and satiety are considered candidates and may be related to the development of ED [14][15][16][17][18] , but the results of these studies are still inconsistent 19,20 .…”