Eugenio Carrasco-Marín

The child and adolescent first-episode psychosis study (CAFEPS): Design and baseline results ☆

OBJECTIVE The child and adolescent first-episode psychosis study (CAFEPS) is a multicenter, two-year, longitudinal project aiming to evaluate different clinical, neuropsychological, neuroimaging, biochemical, immunological, and genetic variables and treatment and prognostic factors in these patients. This paper describes the methods and rationale behind the study and the general characteristics of the sample. METHOD At six different centers, from March 2003 through November 2005, we consecutively recruited 110 patients, ages 9-17 years, who presented with a first psychotic episode. Controls were recruited from the same geographic areas and were matched for gender and age. RESULTS Patients had lower socioeconomic status (SES) (p=0.018) and parental years of education (p<0.001) than controls. The percentage of patients recruited increased with age (p<0.001) and there was a higher percentage of males (p<0.001). The total mean PANSS score was 89.03+/-20.1, the positive score 23.8+/-6.5 and the negative score 20.02+/-8.8. There were no significant differences between the genders with respect to age, parental years of education, SES, or scores in premorbid adjustment or general functioning. There were statistically significant positive correlations between age and positive symptoms and between all PANSS subscales and the Disability Assessment Schedule, and negative correlations between positive symptoms and global functioning. Diagnoses after the baseline evaluation were: psychotic disorder not otherwise specified (NOS) 35.5%, schizophreniform disorder 24.5%, mood disorder with psychotic symptoms 22.7%, schizophrenia 10%, schizoaffective disorder 2.7%, and other psychotic disorders 4.5%. Patients had worse premorbid adjustment (p<0.001) and global functioning (p<0.001) than controls after controlling for SES. CONCLUSIONS Infancy and adolescence adjustment and global functioning are lower in children and adolescents with psychotic disorders than in controls, severity of symptoms are related to general disability, and the most frequent diagnoses are psychotic disorders NOS.

Effect of antipsychotics on peptides involved in energy balance in drug-naive, psychotic patients after 1 year of treatment

Weight gain has become one of the most common and concerning side effects of antipsychotic treatment. The mechanisms whereby antipsychotics induce weight gain are not known. It has been suggested that peptides related to food intake and energy balance could play a role in weight gain secondary to antipsychotic therapy. To better understand the pathophysiology of antipsychotic-induced weight gain, we studied the effects of 3 antipsychotic drugs (haloperidol, olanzapine, and risperidone) on peptides involved in energy balance (insulin, ghrelin, leptin, adiponectin, visfatin, and resistin) in a population of drug-naive patients with first episode of psychosis. A significant increase in weight (10.16 kg [SD, 8.30 kg]; P < 0.001), body mass index (3.56 kg/m2 [SD, 2.89 kg/m2]; P < 0.001), and fasting insulin (3.93 &mgr;U/mL [SD, 3.93 &mgr;U/mL]; P = 0.028), leptin (6.76 ng/mL [SD, 7.21 ng/mL]; P < 0.001), and ghrelin (15.47 fmol/mL [SD, 47.90 fmol/mL]; P = 0.009) plasma levels were observed. The increments in insulin and leptin concentrations were highly correlated with the increment in weight and body mass index and seem to be a consequence of the higher fat stores. The unexpected increase in ghrelin levels might be related with the causal mechanism of weight gain induced by antipsychotics. Finally, the 3 antipsychotics had similar effects in all parameters evaluated.

Characterization of a Listeria monocytogenes Protein Interfering with Rab5a

Listeria monocytogenes (LM) phagocytic strategy implies recruitment and inhibition of Rab5a. Here, we identify a Listeria protein that binds to Rab5a and is responsible for Rab5a recruitment to phagosomes and impairment of the GDP/GTP exchange activity. This protein was identified as a glyceraldehyde‐3‐phosphate dehydrogenase (GAPDH) from Listeria (p40 protein, Lmo 2459). The p40 protein was found within the phagosomal membrane. Analysis of the sequence of LM p40 protein revealed two enzymatic domains: the nicotinamide adenine dinucleotide (NAD)‐binding domain at the N‐terminal and the C‐terminal glycolytic domain. The putative ADP‐ribosylating ability of this Listeria protein located in the N‐terminal domain was examined and showed some similarities to the activity and Rab5a inhibition exerted by Pseudomonas aeruginosa ExoS onto endosome–endosome fusion. Listeria p40 caused Rab5a‐specific ADP ribosylation and blocked Rab5a‐exchange factor (Vps9) and GDI interaction and function, explaining the inhibition observed in Rab5a‐mediated phagosome–endosome fusion. Meanwhile, ExoS impaired Rab5‐early endosomal antigen 1 (EEA1) interaction and showed a wider Rab specificity. Listeria GAPDH might be the first intracellular gram‐positive enzyme targeted to Rab proteins with ADP‐ribosylating ability and a putative novel virulence factor.

Inhibition of Rab5a exchange activity is a key step for Listeria monocytogenes survival.

Listeria monocytogenes (LM) modifies the phagocytic compartment by targeting Rab5a function through an unknown mechanism. Inhibition of Rab5a exchange by LM can be considered the main virulence mechanism as it favours viability of the parasite within the phagosome as well as the exclusion of putative listericidal lysosomal proteases such as cathepsin‐D. The significance of this survival mechanism is evidenced by the overexpression of Rab5a mutants in CHO cells that promoted GDP exchange on Rab5a and eliminated pathogenic LM. The following mutants showed listericidal effects: Rab5a:Q79L, a constitutively active mutant with accelerated GDP exchange and Rab5a GEF, Vps9, which overactivates the endogenous protein. Clearance of LM from these phagosomes was controlled by the hydrolytic action of cathepsin‐D as suggested by the lysosomal protease inhibitor chloroquine, or the cathepsin‐D inhibitor, pepstatin A, which caused a reversion of listericidal activity. Moreover, the effects of LM on Rab5a phagocytic function mimics those reported for the GDP locked dominant negative Rab5a mutant, S34N. Transfection of these mutants into CHO cells increased pathogen survival as they showed higher numbers of viable bacteria, complete inhibition of GDP exchange on Rab5a and impairment of the listericidal action probably exerted by cathepsin‐D. We cotransfected functional Rab5a GEF into this dominant negative mutant and restored normal LM intraphagosomal viability, Rab5a exchange and listericidal action of cathepsin‐D.

Cutting edge: a novel nonoxidative phagosomal mechanism exerted by cathepsin-D controls Listeria monocytogenes intracellular growth.

Deciphering how Listeria monocytogenes exploits the host cell machinery to invade mammalian cells is a key issue in understanding the pathogenesis of this food-borne pathogen, which can cause diseases ranging from gastroenteritis to meningitis and abortion. In this study, we show that the lysosomal aspartyl-protease cathepsin-D (Ctsd) is of considerable importance for nonoxidative listericidal defense mechanisms. We observed enhanced susceptibility to L. monocytogenes infection of fibroblasts and bone-marrow macrophages and increased intraphagosomal viability of bacteria in fibroblasts isolated from Ctsd-deficient mice compared with wild type. These findings are further supported by prolonged survival of L. monocytogenes in Ctsd-deficient mice after infection. Transient transfection of Ctsd in wild-type cells was sufficient to revert these wild-type phagosomes back to microbicidal compartments. Based on infection experiments with mutant bacteria, in vitro degradation, and immunoprecipitation experiments, we suggest that a major target of cathepsin D is the main virulence factor listeriolysin O.

Interleukin-12 plasma levels in drug-naïve patients with a first episode of psychosis: effects of antipsychotic drugs.

An overactivation of the Th1 activity in schizophrenia had been described. Interleukin-12 (IL-12), a proinflammatory cytokine, plays a key role in the regulation of the Th1 response. The aims of this study were to investigate the effect of first and second generation antipsychotic drugs on IL-12 production during the acute phase of the illness and its association with clinical features. Participants comprised 56 drug-naïve first episode psychotic patients and 28 healthy volunteers. Patients were initially randomly assigned to risperidone (n=16), olanzapine (n=20) or haloperidol (n=20); subject were maintained on the same medication throughout the study. Clinical assessments were conducted at baseline and at 6 weeks. IL-12 plasma levels were assessed at baseline and after 6 weeks of antipsychotic treatment. IL-12 haplotypes were also analysed. Patients showed higher IL-12 plasma levels at baseline compared with controls, and had a significant increase in IL-12 plasma level after 6 weeks of antipsychotic treatment. No significant differences in IL-12 level increase were found among the three antipsychotic treatments. IL-12 plasma levels at week 6 were not significantly associated with the severity of psychopathology at week 6. Thus, patients with a first episode of psychosis have inflammatory-like immunological function during early phases of the illness that it is independent of the antipsychotic treatment used.

The innate immunity role of cathepsin-D is linked to Trp-491 and Trp-492 residues of listeriolysin O

Listeriolysin O (LLO) is a thiol‐activated cytolysin secreted by Listeria monocytogenes. LLO and phosphatidylinositol phospholipase C are two essential virulence factors, which this bacterium needs to escape from the phagosomal compartment to the cytoplasm. Cathepsin‐D specifically cleaves LLO, between the Trp‐491 (tryptophan amino acid in three letter nomenclature) and Trp‐492 residues of the conserved undecapeptide sequence, ECTGLAWEWWR, in the domain 4 of LLO (D4). Moreover, these residues also correspond to the phagosomal‐binding epitope. Cathepsin‐D had no effect on phosphatidylinositol phospholipase C. We have observed that cathepsin‐D cleaved the related cholesterol‐dependent cytolysin pneumolysin at the same undecapeptide sequence between Trp‐435 and Trp‐436 residues. These studies also revealed an additional cathepsin‐D cleavage site in the pneumolysin D4 domain localized in the 361‐GDLLLD‐366 sequence. These differences might confer a pathogenic advantage to listeriolysin O, increasing its resistance to phagosomal cathepsin‐D action by reducing the number of cleavages sites in the D4 domain. Using ΔLLO/W491A and ΔLLO/W492A bacterial mutants, we reveal that the Trp‐491 residue has an important role linked to cathepsin‐D in Listeria innate immunity.

Catechol-O-methyltransferase Val158Met polymorphism and clinical characteristics in first episode non-affective psychosis†

Catechol‐O‐methyltransferase (COMT) Val158Met polymorphism has been identified as a potential etiologic factor in schizophrenia. It has been proposed that this polymorphism could be associated with specific clinical markers. The aim of the study was to evaluate the influence of COMT Val158Met polymorphism genotype in the phenotypic expression of first episode psychosis at onset. Age of onset, DUP, SANS, and SAPS (positive, disorganized, and negative dimensions) were studied in 169 Caucasian drug‐naïve patients with a first‐episode of non‐affective psychosis. The COMT Val158Met polymorphism was typed using PCR amplification of the relevant region followed by digestion with NlaIII and electrophoresis. A multivariate ANCOVA was performed with COMT and gender as independent variables. Patients with Val/Val genotype had significantly higher levels of SANS negative dimension scores (F: 3.539; P = 0.031) and had a younger age of onset (F: 4.649; P = 0.011) than Met carriers. Our findings suggest that the Val allele is associated with onset phenotypic features related to a poor prognosis of the illness. These data would indicate that COMT genotype may have a role in the etiological model for schizophrenia and other psychotic disorders.

LIMP-2 Links Late Phagosomal Trafficking with the Onset of the Innate Immune Response to Listeria monocytogenes A ROLE IN MACROPHAGE ACTIVATION

The innate immune response to Listeria monocytogenes depends on phagosomal bacterial degradation by macrophages. Here, we describe the role of LIMP-2, a lysosomal type III transmembrane glycoprotein and scavenger-like protein, in Listeria phagocytosis. LIMP-2-deficient mice display a macrophage-related defect in Listeria innate immunity. They produce less acute phase pro-inflammatory cytokines/chemokines, MCP-1, TNF-α, and IL-6 but normal levels of IL-12, IL-10, and IFN-γ and a 25-fold increase in susceptibility to Listeria infection. This macrophage defect results in a low listericidal potential, poor response to TNF-α activation signals, impaired phago-lysosome transformation into antigen-processing compartments, and uncontrolled LM cytosolic growth that fails to induce normal levels of acute phase pro-inflammatory cytokines. LIMP-2 transfection of CHO cells confirmed that LIMP-2 participates in the degradation of Listeria within phagosomes, controls the late endosomal/lysosomal fusion machinery, and is linked to the activation of Rab5a. Therefore, the role of LIMP-2 appears to be connected to the TNF-α-dependent and early activation of Listeria macrophages through internal signals linking the regulation of late trafficking events with the onset of the innate Listeria immune response.

Catechol-O-methyltransferase Val158Met polymorphism and negative symptoms after acute antipsychotic treatment in first-episode non-affective psychosis.

Genetic factors play an important role in the understanding of clinical response to antipsychotic treatments. We aimed to assess the effect of the catechol-O-methyltransferase (COMT) genotype in the short-term (6 weeks) clinical response of 161 first-episode psychosis patients. COMT genotype was not related to clinical response at 6 weeks. Val homozygote patients showed higher negative symptoms than Met homozygote patients. The COMT Val158 genotype seems to be related to the severity of negative symptoms rather than to clinical response.