Both the supplementation of exogenous antibodies and the induction of anti-ACBP/DBI autoantibodies yielded similar metabolic effects on mice (Figure 1). == Figure 1. an increase in autophagy in various organs, suggesting that it might mediate anti-ageing effects. KEYWORDS:Adiposity, anorexia, appetite, autophagy, obesity Obesity is the most prevalent pathological condition worldwide. Although epidemiological factors such as exaggerated carbohydrate intake and sedentary life style could constitute a basis for obesity prevention, the actual prevalence of obesity (40% of the adult US population) [1] calls for novel therapeutic interventions. Indeed, obesity has become the most important risk factor for the accelerated manifestation of age-related pathologies including cardiovascular disease and cancer [2]. Why would obesity accelerate the ageing process? Caloric excess leads to suppression of autophagy [26], which is the most important cytoplasmic rejuvenation mechanism. Upon endogenous or exogenous stress, portions of the cytoplasm including damaged organelles, misfolded protein aggregates or intracellular pathogens can be sequestered in autophagosomes for their subsequent degradation and recycling in lysosomes. It is well established that induction of autophagy by caloric restriction (CR) or so-called CR mimetics (CRMs) has a positive impact on health span and lifespan [3,5,6], suggesting that the obesity-related suppression of autophagy might, on the contrary, have negative effects on organismal health and longevity. Based on the general rule that cellular stress is communicated from within the cell to the extracellular microenvironment or the entire organism [7], we recently started the search for factors that are secreted from cells in an autophagy-dependent fashion. We found that various human and mouse cell types release acyl coenzyme A-binding protein (ACBP)/diazepam binding inhibitor (DBI) upon induction of autophagy into the extracellular space. Moreover, a 24-hour fasting period caused an elevation of circulating ACBP/DBI levels in the plasma of mice [810]. We Tolvaptan subsequently discovered that intraperitoneal or intravenous injection of recombinant ACBP/DBI protein into mice was sufficient to induce an immediate (within less than 30 min) hyperphagic response with activation of orexigenic neurons and the ENG inhibition of anorexigenic centres in the hypothalamus [8]. These effects Tolvaptan are likely to be indirect, mediated through peripheral metabolic (rather than central nervous) effects of ACBP/DBI. Indeed, ACBP/DBI injection causes the rapid upregulation of glucose transporters in hepatocytes, stimulates glucose uptake into the liver and white adipose tissue, and entails a partial reduction (by approximately 25%) of circulating glucose levels. In conditions of a glucose clamp, the hyperphagic response induced by ACBP/DBI injection is lost, and the activation of orexigenic neurons is suppressed [8]. This latter finding Tolvaptan suggest that the partial reduction in glucose levels induced by ACBP/DBI is required for the orexigenic effects of this protein, arguing in favour of a peripheral (rather than direct central-nervous) action of ACBP/DBI. Of note genetic evidence obtained in yeasts, nematodes and mice supports the notion that ACBP/DBI stimulates food-seeking behaviour across the phylogenic treat, meaning that the ablation of the genes coding for ACBP/DBI inhibits sporulation (inSaccharomyces cerevisiae), pharyngeal pumping (inCaenorhabditis elegans) and food intake (in mice) [11]. Moreover, human obesity was found to be coupled to an increase in ACBP/DBI mRNA expression in white adipose tissue, as well as to an elevation in plasma ACBP/DBI levels [8]. These findings suggest that increased ACBP/DBI might be involved in the pathogenesis of obesity. Intrigued by these findings, we designed two strategies to neutralize ACBP/DBI in mice. The first strategy consisted in the generation of a monoclonal antibody (mAb) capable of recognizing and neutralizing ACBP/DBI in an acute fashion [8]. Tolvaptan The second strategy involved repeated immunizations of mice with a recombinant ACBP/DBI protein coupled to the carrier keyhole limpet hemocyanine (KLH) together with a strong adjuvant, thus breaking self-tolerance to ACBP/DBI and inducing the production of autoantibodies. This procedure allowed for the long-term neutralization of ACBP/DBI [8]. Both the supplementation of exogenous antibodies.