RESUMO
Extracellular acyl-coenzyme A binding protein [ACBP encoded by diazepam binding inhibitor (DBI)] is a phylogenetically ancient appetite stimulator that is secreted in a nonconventional, autophagy-dependent fashion. Here, we show that low ACBP/DBI plasma concentrations are associated with poor prognosis in patients with anorexia nervosa, a frequent and often intractable eating disorder. In mice, anorexia induced by chronic restraint stress (CRS) is accompanied by a reduction in circulating ACBP/DBI concentrations. We engineered a chemical-genetic system for the secretion of ACBP/DBI through a biotin-activatable, autophagy-independent pathway. In transgenic mice expressing this system in hepatocytes, biotin-induced elevations in plasma ACBP/DBI concentrations prevented anorexia induced by CRS or chemotherapeutic agents including cisplatin, doxorubicin, and paclitaxel. ACBP/DBI reversed the CRS or cisplatin-induced increase in plasma lipocalin-2 concentrations and the hypothalamic activation of anorexigenic melanocortin 4 receptors, for which lipocalin-2 is an agonist. Daily intravenous injections of recombinant ACBP/DBI protein or subcutaneous implantation of osmotic pumps releasing recombinant ACBP/DBI mimicked the orexigenic effects of the chemical-genetic system. In conclusion, the supplementation of extracellular and peripheral ACBP/DBI might constitute a viable strategy for treating anorexia.
Assuntos
Anorexia , Inibidor da Ligação a Diazepam , Animais , Inibidor da Ligação a Diazepam/metabolismo , Anorexia/tratamento farmacológico , Anorexia/metabolismo , Humanos , Camundongos Transgênicos , Camundongos , Anorexia Nervosa/metabolismo , Anorexia Nervosa/tratamento farmacológico , Lipocalina-2/metabolismo , Lipocalina-2/sangue , Hipotálamo/metabolismo , Masculino , Feminino , Camundongos Endogâmicos C57BL , Restrição Física , Hepatócitos/metabolismo , Hepatócitos/efeitos dos fármacosRESUMO
Acyl-CoA binding protein (ACBP) encoded by diazepam binding inhibitor (DBI) is an extracellular inhibitor of autophagy acting on the gamma-aminobutyric acid A receptor (GABAAR) γ2 subunit (GABAARγ2). Here, we show that lipoanabolic diets cause an upregulation of GABAARγ2 protein in liver hepatocytes but not in other major organs. ACBP/DBI inhibition by systemically injected antibodies has been demonstrated to mediate anorexigenic and organ-protective, autophagy-dependent effects. Here, we set out to develop a new strategy for developing ACBP/DBI antagonists. For this, we built a molecular model of the interaction of ACBP/DBI with peptides derived from GABAARγ2. We then validated the interaction between recombinant and native ACBP/DBI protein and a GABAARγ2-derived eicosapeptide (but not its F77I mutant) by pull down experiments or surface plasmon resonance. The GABAARγ2-derived eicosapeptide inhibited the metabolic activation of hepatocytes by recombinant ACBP/DBI protein in vitro. Moreover, the GABAARγ2-derived eicosapeptide (but not its F77I-mutated control) blocked appetite stimulation by recombinant ACBP/DBI in vivo, induced autophagy in the liver, and protected mice against the hepatotoxin concanavalin A. We conclude that peptidomimetics disrupting the interaction between ACBP/DBI and GABAARγ2 might be used as ACBP/DBI antagonists. This strategy might lead to the future development of clinically relevant small molecules of the ACBP/DBI system.
Assuntos
Inibidor da Ligação a Diazepam , Ácido gama-Aminobutírico , Animais , Camundongos , Inibidor da Ligação a Diazepam/farmacologiaRESUMO
Orthotopic models of hepatocellular carcinoma (HCC) consist in the implantation of tumor cells into the liver by direct intrahepatic injection. In this model, tumorigenesis is triggered within the hepatic microenvironment, thus mimicking the metastatic behavior of HCC. Herein, we detail a surgically mediated methodology that allows the reproducible and effective induction of liver-sessile tumors in mice. We enumerate the steps to be followed before and after the surgical procedure, including HCC cell preparation, the quantity of cancer cells to be injected, presurgical preparation of the mice, and finally, postoperative care. The surgical procedure involves laparotomy to expose the liver, injection of cells into the left-lateral hepatic lobe, and closure of the incision with sutures followed by wound clips. We also provide information concerning the subsequent tumor growth follow-up, as well as the application of bioluminescence imaging to monitor tumor development.
Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Camundongos , Animais , Carcinoma Hepatocelular/patologia , Neoplasias Hepáticas/patologia , Linhagem Celular , Diagnóstico por Imagem , Linhagem Celular Tumoral , Modelos Animais de Doenças , Microambiente TumoralRESUMO
Non-alcoholic steatohepatitis (NASH) is a severe form of non-alcoholic fatty liver disease (NAFLD). Obesity is a known risk factor of NASH, which, in turn, increases the risk of developing cirrhosis (liver scarring) and hepatocellular carcinoma (HCC). In addition to being a potentially life-threatening condition, public health concerns surrounding NASH are amplified by the lack of FDA-approved treatments. Although various preclinical models reflecting both the histopathology and the pathophysiological progression of human NASH exist, most of these models are diet-based and require 6-13 months for NASH symptom manifestation. Here, we describe a simple and rapid-progression model of NASH and NASH-driven HCC in mice. Mice received a western diet equivalent (WD; i.e., a high-fat, high-fructose, and high-cholesterol diet), high-sugar water (23.1 g/L fructose and 18.9 g/L glucose), and weekly intraperitoneal injections of carbon tetrachloride (CCl4) at a dose of 0.2 µL/g of body weight. The resulting phenotype, consisting in liver fibrosis and HCC, appeared within 24 weeks of diet/treatment initiation and presented similar histological and transcriptomic features as human NASH and NASH-driven HCC, thereby supporting the adequacy of this preclinical model for the development and evaluation of drugs that can prevent or reverse these diseases.
Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Hepatopatia Gordurosa não Alcoólica , Humanos , Camundongos , Animais , Hepatopatia Gordurosa não Alcoólica/etiologia , Hepatopatia Gordurosa não Alcoólica/patologia , Carcinoma Hepatocelular/genética , Tetracloreto de Carbono/toxicidade , Neoplasias Hepáticas/patologia , Dieta Ocidental/efeitos adversos , Modelos Animais de Doenças , Cirrose Hepática/patologia , Frutose , Dieta Hiperlipídica/efeitos adversos , Fígado/patologia , Camundongos Endogâmicos C57BLRESUMO
Hepatocellular carcinoma (HCC) is the most common type of liver cancer and the second most common cause of cancer-related death. HCC is associated to chronic diseases such as viral hepatitis, alcoholic, and non-alcoholic fatty liver disease (NAFLD), diabetes mellitus, and obesity, among others. Although pre-clinical models have been investigated to mimic the transition from NAFLD to HCC, they do not accurately reproduce the phenotypic evolution from simple steatosis to steatohepatitis, fibrosis/cirrhosis, and HCC. Hence, these models have failed to demonstrate the influence of diabetes on hepatic carcinogenesis. Here, we report a novel mouse model of HCC triggered by fast-developing diabetes and NAFLD. The first step consists in a single intraperitoneal injection of a low dose of streptozotocin into neonatal C57BL/6J mice to induce type 2 diabetes. In a second step, mice are fed with high-fat diet to accelerate the development of simple steatosis. Continuous high-fat diet exacerbates hepatic fat deposition with increased lobular inflammation (by activation of foam cell-like macrophages) and fibrosis (by activating hepatic stellate cells), two representative pathological traits of steatohepatitis/fibrosis. After 20 weeks, all mice developed multiple HCCs. This model of hepatic carcinogenesis triggered by diabetes mellitus and NAFLD offers the advantage of being rapid and accurately recapitulates the pathogenesis of human HCC without the need of administering hepatic carcinogens.
Assuntos
Carcinoma Hepatocelular , Diabetes Mellitus Tipo 2 , Neoplasias Hepáticas , Hepatopatia Gordurosa não Alcoólica , Humanos , Camundongos , Animais , Carcinoma Hepatocelular/etiologia , Carcinoma Hepatocelular/patologia , Hepatopatia Gordurosa não Alcoólica/etiologia , Hepatopatia Gordurosa não Alcoólica/patologia , Neoplasias Hepáticas/etiologia , Neoplasias Hepáticas/patologia , Estreptozocina , Dieta Hiperlipídica/efeitos adversos , Diabetes Mellitus Tipo 2/patologia , Camundongos Endogâmicos C57BL , Fígado/patologia , Modelos Animais de Doenças , Cirrose Hepática/patologia , Carcinogênese/patologiaRESUMO
The metabolic rearrangements of hepatic metabolism associated with liver cancer are still incompletely understood. There is an ongoing need to identify novel and more efficient diagnostic biomarkers and therapeutic targets based on the metabolic mechanisms of these diseases. In comparison to traditional diagnostic biomarkers, metabolomics is a comprehensive technique for discovering chemical signatures for liver cancer screening, prediction, and earlier diagnosis. Lipids are a large and diverse group of complex biomolecules that are at the heart of liver physiology and play an important role in the development and progression of cancer. In this chapter, we described two detailed protocols for targeted lipids analysis: glycerophospholipids and mono, di, tri-acylglycerides, both by Flow Injection Analysis (FIA) HPLC coupled to a SelexIon/QTRAP 6500+ system. These approaches provide a targeted lipidomic metabolomic signature of dissimilar metabolic disorders affecting liver cancers.
Assuntos
Glicerofosfolipídeos , Neoplasias Hepáticas , Humanos , Metabolômica/métodos , BiomarcadoresRESUMO
Liver cancers are characterized by interindividual and intratumoral heterogeneity, which makes early diagnosis and the development of therapies challenging. Desorption electrospray ionization mass spectrometry (DESI-MS) imaging is a potent and sensitive MS ionization technique for direct, unaltered 2D and 3D imaging of metabolites in complex biological samples. Indeed, DESI gently desorbs and ionizes analyte molecules from the sample surface using an electrospray source of highly charged aqueous spray droplets in ambient conditions. DESI-MS imaging of biological samples allows untargeted analysis and characterization of metabolites in liver cancers to identify new biomarkers of malignancy. In this chapter, we described a detailed protocol using liver cancer samples collected and stored for histopathology examination, either as frozen or as formalin-fixed, paraffin-embedded specimens. Such hepatocellular carcinoma samples can be subjected to DESI-MS analyses, illustrating the capacity of spatially resolved metabolomics to distinguish malignant lesions from adjacent normal liver tissue.
Assuntos
Neoplasias Hepáticas , Espectrometria de Massas por Ionização por Electrospray , Humanos , Espectrometria de Massas por Ionização por Electrospray/métodos , Metabolômica , Neoplasias Hepáticas/diagnóstico por imagem , BiomarcadoresRESUMO
Autophagy defects accelerate aging, while stimulation of autophagy decelerates aging. Acyl-coenzyme A binding protein (ACBP), which is encoded by a diazepam-binding inhibitor (DBI), acts as an extracellular feedback regulator of autophagy. As shown here, knockout of the gene coding for the yeast orthologue of ACBP/DBI (ACB1) improves chronological aging, and this effect is reversed by knockout of essential autophagy genes (ATG5, ATG7) but less so by knockout of an essential mitophagy gene (ATG32). In humans, ACBP/DBI levels independently correlate with body mass index (BMI) as well as with chronological age. In still-healthy individuals, we find that high ACBP/DBI levels correlate with future cardiovascular events (such as heart surgery, myocardial infarction, and stroke), an association that is independent of BMI and chronological age, suggesting that ACBP/DBI is indeed a biomarker of "biological" aging. Concurringly, ACBP/DBI plasma concentrations correlate with established cardiovascular risk factors (fasting glucose levels, systolic blood pressure, total free cholesterol, triglycerides), but are inversely correlated with atheroprotective high-density lipoprotein (HDL). In mice, neutralization of ACBP/DBI through a monoclonal antibody attenuates anthracycline-induced cardiotoxicity, which is a model of accelerated heart aging. In conclusion, plasma elevation of ACBP/DBI constitutes a novel biomarker of chronological aging and facets of biological aging with a prognostic value in cardiovascular disease.
Assuntos
Doenças Cardiovasculares , Proteínas de Transporte , Animais , Humanos , Camundongos , Doenças Cardiovasculares/genética , Coenzima A/metabolismo , Inibidor da Ligação a Diazepam/genética , Inibidor da Ligação a Diazepam/metabolismo , Proteínas Nucleares/metabolismoRESUMO
DBI/ACBP (diazepam binding inhibitor, also known as acyl coenzyme A binding protein), acts as a paracrine inhibitor of macroautophagy/autophagy. We characterized a monoclonal antibody neutralizing mouse DBI/ACBP (a-DBI) for its cytoprotective effects on several organs (heart, liver and lung) that were damaged by surgical procedures (ligation of coronary and hepatic arteries or bile duct ligation), a variety of different toxins (acetaminophen, bleomycin, carbon tetrachloride or concanavalin A) or a methionine/choline-deficient diet (MCD). In all these models of organ damage, a-DBI prevents cell loss, inflammation and fibrosis through pathways that are blocked by pharmacological or genetic inhibition of autophagy. The hepatoprotective effects of a-DBI against MCD are mimicked by three alternative strategies to block DBI/ACBP signaling, in particular (i) induction of DBI/ACBP-specific autoantibodies, (ii) tamoxifen-inducible knockout of the Dbi gene, and (iii) a point mutation in Gabrg2 (gamma-aminobutyric acid A receptor, subunit gamma 2; Gabrg2F77I) that abolishes binding of DBI/ACBP. We conclude that a-DBI-mediated neutralization of extracellular DBI/ACBP mediates potent autophagy-dependent organ protection by on-target effects, hence unraveling a novel and potentially useful strategy for autophagy enhancement. "Autophagy checkpoint inhibition" can be achieved by targeting DBI/ACBP.
Assuntos
Autofagia , Macroautofagia , Camundongos , AnimaisRESUMO
Acyl-coenzyme A (CoA)-binding protein (ACBP), also known as diazepam-binding inhibitor (DBI), is an extracellular feedback regulator of autophagy. Here, we report that injection of a monoclonal antibody neutralizing ACBP/DBI (α-DBI) protects the murine liver against ischemia/reperfusion damage, intoxication by acetaminophen and concanavalin A, and nonalcoholic steatohepatitis caused by methionine/choline-deficient diet as well as against liver fibrosis induced by bile duct ligation or carbon tetrachloride. α-DBI downregulated proinflammatory and profibrotic genes and upregulated antioxidant defenses and fatty acid oxidation in the liver. The hepatoprotective effects of α-DBI were mimicked by the induction of ACBP/DBI-specific autoantibodies, an inducible Acbp/Dbi knockout or a constitutive Gabrg2F77I mutation that abolishes ACBP/DBI binding to the GABAA receptor. Liver-protective α-DBI effects were lost when autophagy was pharmacologically blocked or genetically inhibited by knockout of Atg4b. Of note, α-DBI also reduced myocardium infarction and lung fibrosis, supporting the contention that it mediates broad organ-protective effects against multiple insults.
Assuntos
Inibidor da Ligação a Diazepam , Receptores de GABA-A , Animais , Camundongos , Acetaminofen , Anticorpos Monoclonais/metabolismo , Antioxidantes , Autoanticorpos/metabolismo , Autofagia , Tetracloreto de Carbono , Proteínas de Transporte/genética , Colina , Coenzima A/metabolismo , Concanavalina A/metabolismo , Diazepam , Inibidor da Ligação a Diazepam/metabolismo , Ácidos Graxos/metabolismo , Fibrose , Inflamação , MetioninaRESUMO
Acyl-coenzyme-A-binding protein (ACBP), also known as a diazepam-binding inhibitor (DBI), is a potent stimulator of appetite and lipogenesis. Bioinformatic analyses combined with systematic screens revealed that peroxisome proliferator-activated receptor gamma (PPARγ) is the transcription factor that best explains the ACBP/DBI upregulation in metabolically active organs including the liver and adipose tissue. The PPARγ agonist rosiglitazone-induced ACBP/DBI upregulation, as well as weight gain, that could be prevented by knockout of Acbp/Dbi in mice. Moreover, liver-specific knockdown of Pparg prevented the high-fat diet (HFD)-induced upregulation of circulating ACBP/DBI levels and reduced body weight gain. Conversely, knockout of Acbp/Dbi prevented the HFD-induced upregulation of PPARγ. Notably, a single amino acid substitution (F77I) in the γ2 subunit of gamma-aminobutyric acid A receptor (GABAAR), which abolishes ACBP/DBI binding to this receptor, prevented the HFD-induced weight gain, as well as the HFD-induced upregulation of ACBP/DBI, GABAAR γ2, and PPARγ. Based on these results, we postulate the existence of an obesogenic feedforward loop relying on ACBP/DBI, GABAAR, and PPARγ. Interruption of this vicious cycle, at any level, indistinguishably mitigates HFD-induced weight gain, hepatosteatosis, and hyperglycemia.
Assuntos
Inibidor da Ligação a Diazepam , Receptores de GABA-A , Animais , Proteínas de Transporte , Coenzima A/metabolismo , Inibidor da Ligação a Diazepam/genética , Inibidor da Ligação a Diazepam/metabolismo , Camundongos , PPAR gama/genética , PPAR gama/metabolismo , Receptores de GABA/metabolismo , Receptores de GABA-A/genética , Receptores de GABA-A/metabolismo , Aumento de Peso , Ácido gama-AminobutíricoRESUMO
BACKGROUND: Neural stem cells (NSC) in divide asymmetrically to generate one cell that retains stem cell identity and another that is routed to differentiation. Prolonged mitotic activity of the NSCs gives rise to the plethora of neurons and glial cells that wire the brain and nerve cord. Genetic insults, such as excess of Notch signaling, perturb the normal NSC proliferation programs and trigger the formation of NSC hyperplasias, which can subsequently progress to malignancies. Hes proteins are crucial mediators of Notch signaling, and in the NSC context they act by repressing a cohort of early pro-differentiation transcription factors. Downregulation of these pro-differentiation factors makes NSC progeny cells susceptible to adopting an aberrant stem cell program. We have recently shown that Hes overexpression in Drosophila leads to NSC hyperplasias that progress to malignant tumours after allografting to adult hosts. METHODS: We have combined genetic analysis, tissue allografting and transcriptomic approaches to address the role of Hes genes in NSC malignant transformation. RESULTS: We show that the E (spl) genes are important mediators in the progression of Notch hyperplasias to malignancy, since allografts lacking the E (spl) genes grow much more slowly. We further present RNA profiling of Hes-induced tumours at two different stages after allografting. We find that the same cohort of differentiation-promoting transcription factors that are repressed in the primary hyperplasias continue to be downregulated after transplantation. This is accompanied by an upregulation of stress-response genes and metabolic reprogramming. CONCLUSIONS: The combination of dedifferentiation and cell physiology changes most likely drive tumour growth.
Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos , Neoplasias , Células-Tronco Neurais , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Diferenciação Celular , Proliferação de Células , Drosophila/genética , Drosophila/metabolismo , Hiperplasia/metabolismo , Neoplasias/genética , Neoplasias/metabolismo , Receptores Notch/genética , Receptores Notch/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismoRESUMO
Autophagy is an evolutionarily conserved biological process required for the turnover of the cytoplasm of eukaryotic cell. Beyond its catabolic nature, autophagy has a plethora of pro-survival functions, thus combatting hypoxia, nutrient shortage, and unfolded protein accumulation. Here, we introduce the naturally short-lived turquoise killifish Nothobranchius furzeri as an emerging model to study autophagic function in vivo, in response to environmental challenges. We show that starvation in killifish is sufficient to increase autophagic flux in the liver, thus enhancing the lipidation of microtubule-associated protein light chain 3 (LC3) and reducing the abundance of the autophagic substrate sequestosome-1 (SQSTM1). We describe an immunoblot-based comprehensive protocol to monitor fluctuations in autophagy in this model organism.
Assuntos
Fundulidae , Animais , AutofagiaRESUMO
Imaging flow cytometry allows for the quantitative assessment of fluorescent signals at the subcellular level. Here, we describe the use of a biosensor cell line, namely, U2OS osteosarcoma cells equipped with a fusion protein comprising monomeric red fluorescent protein (mRFP), green fluorescent protein (GFP) and microtubule-associated proteins 1A/1B light chain 3B (best known as LC3), for the assessment of autophagic flux by imaging flow cytometry. We detail all analysis tools required to distinguish autophagosomes (that emit both a red and a green fluorescence) and autolysosomes (that emit a red fluorescence, yet lose the green fluorescent signal) and to quantitate autophagic flux in a convenient fashion.
Assuntos
Autofagossomos , Autofagia , Citometria de Fluxo , Proteínas de Fluorescência Verde/genética , Humanos , Lisossomos , Proteínas Associadas aos MicrotúbulosRESUMO
In mice, the plasma concentrations of the appetite-stimulatory and autophagy-inhibitory factor acyl-coenzyme A binding protein (ACBP, also called diazepam-binding inhibitor, DBI) acutely increase in response to starvation, but also do so upon chronic overnutrition leading to obesity. Here, we show that knockout of Acbp/Dbi in adipose tissue is sufficient to prevent high-fat diet-induced weight gain in mice. We investigated ACBP/DBI plasma concentrations in several patient cohorts to discover a similar dual pattern of regulation. In relatively healthy subjects, ACBP/DBI concentrations independently correlated with body mass index (BMI) and age. The association between ACBP/DBI and BMI was lost in subjects that underwent major weight gain in the subsequent 3-9 years, as well as in advanced cancer patients. Voluntary fasting, undernutrition in the context of advanced cancer, as well as chemotherapy were associated with an increase in circulating ACBP/DBI levels. Altogether, these results support the conclusion that ACBP/DBI may play an important role in body mass homeostasis as well as in its failure.
Assuntos
Índice de Massa Corporal , Peso Corporal/efeitos dos fármacos , Inibidor da Ligação a Diazepam/farmacologia , Animais , Estudos de Coortes , Feminino , França , Alemanha , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Obesidade/metabolismo , Obesidade/patologiaRESUMO
Neural stem cells divide during embryogenesis and juvenile life to generate the entire complement of neurons and glia in the nervous system of vertebrates and invertebrates. Studies of the mechanisms controlling the fine balance between neural stem cells and more differentiated progenitors have shown that, in every asymmetric cell division, progenitors send a Delta-Notch signal to their sibling stem cells. Here, we show that excessive activation of Notch or overexpression of its direct targets of the Hes family causes stem-cell hyperplasias in the Drosophila larval central nervous system, which can progress to malignant tumours after allografting to adult hosts. We combined transcriptomic data from these hyperplasias with chromatin occupancy data for Dpn, a Hes transcription factor, to identify genes regulated by Hes factors in this process. We show that the Notch/Hes axis represses a cohort of transcription factor genes. These are excluded from the stem cells and promote early differentiation steps, most likely by preventing the reversion of immature progenitors to a stem-cell fate. We describe the impact of two of these 'anti-stemness' factors, Zfh1 and Gcm, on Notch/Hes-triggered tumorigenesis.
Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Carcinogênese/metabolismo , Proteínas de Ligação a DNA/metabolismo , Proteínas de Drosophila/metabolismo , Redes Reguladoras de Genes , Células-Tronco Neurais/metabolismo , Transdução de Sinais , Transcrição Gênica , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Carcinogênese/genética , Proteínas de Ligação a DNA/genética , Proteínas de Drosophila/genética , Drosophila melanogaster , Receptores Notch/genética , Receptores Notch/metabolismoRESUMO
Acyl coenzyme A binding protein (ACBP), also known as diazepam binding inhibitor (DBI) is a multifunctional protein with an intracellular action (as ACBP), as well as with an extracellular role (as DBI). The plasma levels of soluble ACBP/DBI are elevated in human obesity and reduced in anorexia nervosa. Accumulating evidence indicates that genetic or antibody-mediated neutralization of ACBP/DBI has anorexigenic effects, thus inhibiting food intake and inducing lipo-catabolic reactions in mice. A number of anorexiants have been withdrawn from clinical development because of their side effects including an increase in depression and suicide. For this reason, we investigated the psychiatric impact of ACBP/DBI in mouse models and patient cohorts. Intravenously (i.v.) injected ACBP/DBI protein conserved its orexigenic function when the protein was mutated to abolish acyl coenzyme A binding, but lost its appetite-stimulatory effect in mice bearing a mutation in the γ2 subunit of the γ-aminobutyric acid (GABA) A receptor (GABAAR). ACBP/DBI neutralization by intraperitoneal (i.p.) injection of a specific mAb blunted excessive food intake in starved and leptin-deficient mice, but not in ghrelin-treated animals. Neither i.v. nor i.p. injected anti-ACBP/DBI antibody affected the behavior of mice in the dark-light box and open-field test. In contrast, ACBP/DBI increased immobility in the forced swim test, while anti-ACBP/DBI antibody counteracted this sign of depression. In patients diagnosed with therapy-resistant bipolar disorder or schizophrenia, ACBP/DBI similarly correlated with body mass index (BMI), not with the psychiatric diagnosis. Patients with high levels of ACBP/DBI were at risk of dyslipidemia and this effect was independent from BMI, as indicated by multivariate analysis. In summary, it appears that ACBP/DBI neutralization has no negative impact on mood and that human depression is not associated with alterations in ACBP/DBI concentrations.