Exposure to socioenvironmental stress as a predictor of physical and mental health

The literature demonstrates links between socioenvironmental characteristics, dysregulation of the stress response system, and PTSD, though few studies integrate these factors in one model. In a secondary analysis of cross-sectional data collected by the Survey of the Health of Wisconsin (SHOW), structural equation modeling evaluated the relationships between socioenvironmental stress, cumulative biological risk (CBR), and PTSD symptom severity. The model hypothesized that exposure to socioenvironmental stress was associated with PTSD and that this relationship is mediated by increased CBR. Indices suggest the model provided a good fit to the data and supported socioenvironmental stress and CBR as valid latent constructs. Although the association between CBR and PTSD was not found to be statistically significant in this study, socioenvironmental stress was a significant predictor of PTSD and CBR. Given the role of socioenvironmental factors on CBR and PTSD symptoms, providers need to better assess and incorporate social stressors within evaluation and treatment.

Analyzing spatial correlations in tissue using angle-resolved low coherence interferometry measurements guided by co-located optical coherence tomography

Angle-resolved low coherence interferometry (a/LCI) is an optical technique used to measure nuclear morphology in situ. However, a/LCI is not an imaging modality and can produce ambiguous results when the measurements are not properly oriented to the tissue architecture. Here we present a 2D a/LCI system which incorporates optical coherence tomography imaging to guide the measurements. System design and characterization are presented, along with example cases which demonstrate the utility of the combined measurements. In addition, future development and applications of this dual modality approach are discussed.

Ventriculomegaly associated with ependymal gliosis and declines in barrier integrity in the aging human and mouse brain

Age-associated ventriculomegaly is typically attributed to neurodegeneration; however, additional factors might initiate or contribute to progressive ventricular expansion. By directly linking postmortem human MRI sequences with histological features of periventricular tissue, we show that substantial lateral ventricle surface gliosis is associated with ventriculomegaly. To examine whether loss of ependymal cell coverage resulting in ventricle surface glial scarring can lead directly to ventricle enlargement independent of any other injury or degenerative loss, we modeled in mice the glial scarring found along the lateral ventricle surface in aged humans. Neuraminidase, which cleaves glycosidic linkages of apical adherens junction proteins, was administered intracerebroventricularly to denude areas of ependymal cells. Substantial ependymal cell loss resulted in reactive gliosis rather than stem cell-mediated regenerative repair of the ventricle lining, and the gliotic regions showed morphologic and phenotypic characteristics similar to those found in aged humans. Increased levels of aquaporin-4, indicative of edema, observed in regions of periventricular gliosis in human tissue were also replicated in our mouse model. 3D modeling together with volume measurements revealed that mice with ventricle surface scarring developed expanded ventricles, independent of neurodegeneration. Through a comprehensive, comparative analysis of the lateral ventricles and associated periventricular tissue in aged humans and mouse, followed by modeling of surface gliosis in mice, we have demonstrated a direct link between lateral ventricle surface gliosis and ventricle enlargement. These studies highlight the importance of maintaining an intact ependymal cell lining throughout aging.

Complement C1q formation of immune complexes with milk caseins and wheat glutens in schizophrenia

Immune system factors including complement pathway activation are increasingly linked to the etiology and pathophysiology of schizophrenia. Complement protein, C1q, binds to and helps to clear immune complexes composed of immunoglobulins coupled to antigens. The antigenic stimuli for C1q activation in schizophrenia are not known. Food sensitivities characterized by elevated IgG antibodies to bovine milk caseins and wheat glutens have been reported in individuals with schizophrenia. Here, we examined the extent to which these food products might comprise the antigen component of complement C1q immune complexes in individuals with recent onset schizophrenia (n=38), non-recent onset schizophrenia (n=61) and non-psychiatric controls (n=63). C1q seropositivity was significantly associated with both schizophrenia groups (recent onset, odds ratio (OR)=8.02, p≤0.008; non-recent onset, OR=3.15, p≤0.03) compared to controls (logistic regression models corrected for age, sex, race and smoking status). Casein- and/or gluten-IgG binding to C1q was significantly elevated in the non-recent onset group compared to controls (OR=4.36, p≤0.01). Significant amounts of C1q-casein/gluten-related immune complexes and C1q correlations with a marker for gastrointestinal inflammation in non-recent onset schizophrenia suggests a heightened rate of food antigens in the systemic circulation, perhaps via a disease-associated altered intestinal permeability. In individuals who are in the early stages of disease onset, C1q activation may reflect the formation of immune complexes with non-casein- or non-gluten-related antigens, the presence of C1q autoantibodies, and/or a dissociated state of immune complex components. In conclusion, complement activation may be a useful biomarker to diagnose schizophrenia early during the course of the disease. Future prospective studies should evaluate the impacts of casein- and gluten-free diets on C1q activation in schizophrenia.

Gastrointestinal inflammation and associated immune activation in schizophrenia

Immune factors are implicated in normal brain development and in brain disorder pathogenesis. Pathogen infection and food antigen penetration across gastrointestinal barriers are means by which environmental factors might affect immune-related neurodevelopment. Here, we test if gastrointestinal inflammation is associated with schizophrenia and therefore, might contribute to bloodstream entry of potentially neurotropic milk and gluten exorphins and/or immune activation by food antigens. IgG antibodies to Saccharomyces cerevisiae (ASCA, a marker of intestinal inflammation), bovine milk casein, wheat-derived gluten, and 6 infectious agents were assayed. Cohort 1 included 193 with non-recent onset schizophrenia, 67 with recent onset schizophrenia and 207 non-psychiatric controls. Cohort 2 included 103 with first episode schizophrenia, 40 of whom were antipsychotic-naïve. ASCA markers were significantly elevated and correlated with food antigen antibodies in recent onset and non-recent onset schizophrenia compared to controls (p≤0.00001-0.004) and in unmedicated individuals with first episode schizophrenia compared to those receiving antipsychotics (p≤0.05-0.01). Elevated ASCA levels were especially evident in non-recent onset females (p≤0.009), recent onset males (p≤0.01) and in antipsychotic-naïve males (p≤0.03). Anti-food antigen antibodies were correlated to antibodies against Toxoplasma gondii, an intestinally-infectious pathogen, particularly in males with recent onset schizophrenia (p≤0.002). In conclusion, gastrointestinal inflammation is a relevant pathology in schizophrenia, appears to occur in the absence of but may be modified by antipsychotics, and may link food antigen sensitivity and microbial infection as sources of immune activation in mental illness.

Dietary antigens, epitope recognition, and immune complex formation in recent onset psychosis and long-term schizophrenia

Peptides derived from dietary antigens such as bovine milk caseins are opioid receptor ligands and contribute to schizophrenia-associated hyperpeptidemia and hyperpeptiduria. The IgG antibody response to bovine caseins is increased in schizophrenia and recent onset psychosis. To identify specific casein peptide sequences that are antigenic in patients vs controls, we measured serum IgG binding to 10-26 amino acid long linear epitopes of casein with immunoassays for the entire group (n=95 recent onset psychosis; n=103 long-term schizophrenia; n=65 control), and with peptide microarray libraries in a casein-sensitive subset (n=14 recent onset; n=10 control). In the entire group, we compared anti-casein peptide IgG vs anti-whole casein IgG and evaluated whether peptide immune complexes contributed to IgG binding results. Anti-whole casein IgG levels correlated with anti-casein peptide IgG in controls only (R2=0.17-0.25, p≤0.002-0.03). In recent onset psychosis, IgG binding to linear peptide sequences was significantly decreased 3.8-5.7-fold compared to controls in immunoassays (OR 0.18-0.26, p≤0.0001-0.001). In peptide microarrays, recent onset patients again showed significantly reduced IgG binding and fewer epitopes than controls (p≤0.00001-0.05). Anti-peptide IgG levels did not differ between patients with long-term schizophrenia and controls. Finally, significantly more recent onset individuals had casein peptide-IgG immune complexes than controls (OR 4.96, p≤0.001). These findings suggest an immunological specificity that differs in early vs later stages of neuropsychiatric diseases and an IgG saturation by casein-derived peptides that may in part explain the reduced IgG binding to small linear epitopes observed in these patients.

Subunit and whole molecule specificity of the anti-bovine casein immune response in recent onset psychosis and schizophrenia

Previous studies show increased antibody levels to bovine casein in some individuals with schizophrenia. The immunogenicity of specific domains of bovine casein varies among people with milk sensitivities and thus could vary among different neuropsychiatric disorders. Using ELISAs and immunoblotting, we characterized IgG class antibody specificity to whole bovine casein and to the alpha(s), beta, and kappa subunits in individuals with recent onset psychosis (n=95), long-term schizophrenia (n=103), and non-psychiatric controls (n=65). In both patient groups, we found elevated IgG to casein proteins, particularly to whole casein and the alpha(s) subunit (p<or=0.0001). Odds ratios of casein seroprevalence for recent onset psychosis (age-, gender-, race-, smoking-adjusted) were significant for whole casein (8.13, p<or=0.0001), and the alpha(s) (7.89, p<or=0.0001), beta (5.23, p<or=0.001) and kappa (5.70, p<or=0.0001) subunits. Odds ratios for long-term schizophrenia were significant for whole casein (7.85, p<or=0.0001), and the alpha(s) (4.78, p<or=0.003) and kappa (4.92, p<or=0.004) subunits. Within the recent onset group, odds ratios were particularly significant for a subgroup of people with psychotic disorders that included major depressive disorders (8.22-16.48, p<or=0.0001). In a different recent onset subgroup (schizophrenia-spectrum disorders), PANSS scores for negative symptoms were correlated with casein antibody levels for the alpha(s) and kappa subunits (p<or=0.001-0.01). Immunoblotting patterns also exhibited group specificity, with kappa predominant in recent onset and alpha(s) in schizophrenia (Fisher's Exact Test, p<or=0.001). The elevated IgG and unique patterns of antibody specificity to bovine casein among diagnostic groups provide a rationale for clinical trials to evaluate efficacies of dietary modifications in individuals with neuropsychiatric diseases.