Associations between antipsychotics-induced weight gain and brain networks of impulsivity

Given the unpredictable rapid onset and ubiquitous consequences of weight gain induced by antipsychotics, there is a pressing need to get insights into the underlying processes at the brain system level that will allow stratification of "at risk" patients. The pathophysiological hypothesis at hand is focused on brain networks governing impulsivity that are modulated by neuro-inflammatory processes. To this aim, we investigated brain anatomy and functional connectivity in patients with early psychosis (median age: 23 years, IQR = 21-27) using anthropometric data and magnetic resonance imaging acquired one month to one year after initiation of AP medication. Our analyses included 19 patients with high and rapid weight gain (i.e., ≥5% from baseline weight after one month) and 23 patients with low weight gain (i.e., <5% from baseline weight after one month). We replicated our analyses in young (26 years, IQR = 22-33, N = 102) and middle-aged (56 years, IQR = 51-62, N = 875) healthy individuals from the general population. In early psychosis patients, higher weight gain was associated with poor impulse control score (β = 1.35; P = 0.03). Here, the observed brain differences comprised nodes of impulsivity networks - reduced frontal lobe grey matter volume (Pcorrected = 0.007) and higher striatal volume (Pcorrected = 0.048) paralleled by disruption of fronto-striatal functional connectivity (R = -0.32; P = 0.04). Weight gain was associated with the inflammatory biomarker plasminogen activator inhibitor-1 (β = 4.9, P = 0.002). There was no significant association between increased BMI or weight gain and brain anatomy characteristics in both cohorts of young and middle-aged healthy individuals. Our findings support the notion of weight gain in treated psychotic patients associated with poor impulse control, impulsivity-related brain networks and chronic inflammation.

Redox and Immune Signaling in Schizophrenia: New Therapeutic Potential

Redox biology and immune signaling play major roles in the body, including in brain function. A rapidly growing literature also suggests that redox and immune abnormalities are implicated in neuropsychiatric conditions such as schizophrenia, bipolar disorder, autism, and epilepsy. In this article we review this literature, its implications for the pathophysiology of schizophrenia, and the potential for development of novel treatment interventions targeting redox and immune signaling. Redox biology and immune signaling in the brain are complex and not fully understood; in addition, there are discrepancies in the literature, especially in patient-oriented studies. Nevertheless, it is clear that abnormalities arise in schizophrenia from an interaction between genetic and environmental factors during sensitive periods of brain development and these abnormalities disrupt local circuits and long-range connectivity. Interventions that correct these abnormalities may be effective in normalizing brain function in psychotic disorders, especially in early phases of illness.

Caught in vicious circles: a perspective on dynamic feed-forward loops driving oxidative stress in schizophrenia

A growing body of evidence has emerged demonstrating a pathological link between oxidative stress and schizophrenia. This evidence identifies oxidative stress as a convergence point or "central hub" for schizophrenia genetic and environmental risk factors. Here we review the existing experimental and translational research pinpointing the complex dynamics of oxidative stress mechanisms and their modulation in relation to schizophrenia pathophysiology. We focus on evidence supporting the crucial role of either redox dysregulation, N-methyl-D-aspartate receptor hypofunction, neuroinflammation or mitochondria bioenergetics dysfunction, initiating "vicious circles" centered on oxidative stress during neurodevelopment. These processes would amplify one another in positive feed-forward loops, leading to persistent impairments of the maturation and function of local parvalbumin-GABAergic neurons microcircuits and myelinated fibers of long-range macrocircuitry. This is at the basis of neural circuit synchronization impairments and cognitive, emotional, social and sensory deficits characteristic of schizophrenia. Potential therapeutic approaches that aim at breaking these different vicious circles represent promising strategies for timely and safe interventions. In order to improve early detection and increase the signal-to-noise ratio for adjunctive trials of antioxidant, anti-inflammatory and NMDAR modulator drugs, a reverse translation of validated circuitry approach is needed. The above presented processes allow to identify mechanism based biomarkers guiding stratification of homogenous patients groups and target engagement required for successful clinical trials, paving the way towards precision medicine in psychiatry.

Mitochondrial, exosomal miR137-COX6A2 and gamma synchrony as biomarkers of parvalbumin interneurons, psychopathology, and neurocognition in schizophrenia

Early detection and intervention in schizophrenia requires mechanism-based biomarkers that capture neural circuitry dysfunction, allowing better patient stratification, monitoring of disease progression and treatment. In prefrontal cortex and blood of redox dysregulated mice (Gclm-KO ± GBR), oxidative stress induces miR-137 upregulation, leading to decreased COX6A2 and mitophagy markers (NIX, Fundc1, and LC3B) and to accumulation of damaged mitochondria, further exacerbating oxidative stress and parvalbumin interneurons (PVI) impairment. MitoQ, a mitochondria-targeted antioxidant, rescued all these processes. Translating to early psychosis patients (EPP), blood exosomal miR-137 increases and COX6A2 decreases, combined with mitophagy markers alterations, suggest that observations made centrally and peripherally in animal model were reflected in patients' blood. Higher exosomal miR-137 and lower COX6A2 levels were associated with a reduction of ASSR gamma oscillations in EEG. As ASSR requires proper PVI-related networks, alterations in miR-137/COX6A2 plasma exosome levels may represent a proxy marker of PVI cortical microcircuit impairment. EPP can be stratified in two subgroups: (a) a patients' group with mitochondrial dysfunction "Psy-D", having high miR-137 and low COX6A2 levels in exosomes, and (b) a "Psy-ND" subgroup with no/low mitochondrial impairment, including patients having miR-137 and COX6A2 levels in the range of controls. Psy-D patients exhibited more impaired ASSR responses in association with worse psychopathological status, neurocognitive performance, and global and social functioning, suggesting that impairment of PVI mitochondria leads to more severe disease profiles. This stratification would allow, with high selectivity and specificity, the selection of patients for treatments targeting brain mitochondria dysregulation and capture the clinical and functional efficacy of future clinical trials.

Networks of blood proteins in the neuroimmunology of schizophrenia

Levels of certain circulating cytokines and related immune system molecules are consistently altered in schizophrenia and related disorders. In addition to absolute analyte levels, we sought analytes in correlation networks that could be prognostic. We analyzed baseline blood plasma samples with a Luminex platform from 72 subjects meeting criteria for a psychosis clinical high-risk syndrome; 32 subjects converted to a diagnosis of psychotic disorder within two years while 40 other subjects did not. Another comparison group included 35 unaffected subjects. Assays of 141 analytes passed early quality control. We then used an unweighted co-expression network analysis to identify highly correlated modules in each group. Overall, there was a striking loss of network complexity going from unaffected subjects to nonconverters and thence to converters (applying standard, graph-theoretic metrics). Graph differences were largely driven by proteins regulating tissue remodeling (e.g. blood-brain barrier). In more detail, certain sets of antithetical proteins were highly correlated in unaffected subjects (e.g. SERPINE1 vs MMP9), as expected in homeostasis. However, for particular protein pairs this trend was reversed in converters (e.g. SERPINE1 vs TIMP1, being synthetical inhibitors of remodeling of extracellular matrix and vasculature). Thus, some correlation signals strongly predict impending conversion to a psychotic disorder and directly suggest pharmaceutical targets.

Detection of Cytokeratin 19 mRNA and CYFRA 21–1 (Cytokeratin 19 Fragments) in Blood of Tunisian Women with Breast Cancer

Cytokeratin 19 (CK19) is an acidic protein of 40 kDa that is part of the cytoskeleton of epithelial cells. It is highly expressed by all epithelial cells and represents a useful indicator of epithelial differentiation. The soluble fragment of CK19 (CYFRA 21–1) can be a useful circulating tumor marker and can be detected in the serum of cancer patients. The development of metastasis in patients with cancer of epithelial origin is due to the migration of tumor cells from the original tumor to distant organs. In order to detect micrometastasis in patients with breast cancer, we evaluated and compared CK19 gene expression using RT-PCR in blood samples collected from 80 healthy women and 80 patients with localized or metastatic breast cancer. The concentration of the soluble CK19 fragment CYFRA 21–1 was measured in serum of all study subjects by radioimmunoassay employing specific monoclonal antibodies. The relationship between the expression of this molecular marker and clinical stage, tumor differentiation and CK19 mRNA transcripts was investigated. We found that CK19 mRNA expression in blood (as a direct index of the presence of circulating tumor cells) was not correlated with CYFRA 21–1.

Expression of WISP3 and RhoC genes at mRNA and protein levels in inflammatory and noninflammatory breast cancer in Tunisian patients

Previous studies have shown the expression WISP3 and RhoC in cell lines of inflammatory breast cancer (IBC). The aim in the current study was to compare the expression of both genes, in biopsy samples collected from Tunisian patients with localized or metastatic breast cancer and patients with IBC. We investigated 127 patients enrolled in Salah Azaiez Institute in Tunis. Using the RT-PCR, we showed the phenotype (WISP3-, RhoC+) is significantly associated with IBC tumors, while the (WISP3+, RhoC-)phenotype is mostly associated to non-IBC tumors. The frequencies of these tumor phenotypes are significantly different between these tumor groups (p = 10(- 7); relative risk or RR = 3.25; confidential interval or CI 95% = 1.90-5.53). Immunohistochemical test revealing the presence of WISP3 and RhoC proteins correlates with the expression in the biopsy of their encoding genes as detected by RT-PCR. In conclusion, it appears that WISP3 and RhoC genes expression status defines a molecular signature of IBC.

Interleukin 10 promoter region polymorphisms in inflammatory bowel disease in Tunisian population

OBJECTIVE

To test whether IL-10 promoter region polymorphisms are associated with susceptibility to inflammatory bowel disease, we examined the contribution of interleukin- 10 (IL-10) gene polymorphisms to Crohn's disease (CD) and Ulcerative colitis disease (UC) occurrence and also to CD phenotype. MATERIELS AND METHODS: SNPs at positions -627 (C > A) and -1117 (G > A) in the IL-10 promoter were determined in a sample of 105 Tunisian patients with IBD (75 CD and 30 UC) and 90 matched healthy controls.

RESULTS

The 627 CA genotype is associated with ileal location (p = 0.015) and with stricturing (p = 510-3) and penetrating (p = 310-3) presentation of CD. An additive effect between IL10 variants and CARD15 3020 insC mutation (p = 0,006) on severe forms of CD was shown.

CONCLUSIONS

In Tunisian population, the 3020insC insertion in NOD2/CARD15 gene is a marker of susceptibility to CD, while the A allele at position -627 in the IL-10 promoter increases the risk of CD ileal location and severe disease presentation. A genetic epistasis between IL-10 gene polymorphisms and CARD15/NOD2 gene mutation was suggested.