The Wnt signaling pathway plays a crucial role in neurodevelopment and in regulating the function and structure of the adult nervous system. Schizophrenia (SCZ) and bipolar disorder (BD) are severe ...mental disorders with evidence of subtle neurodevelopmental, structural and functional neuronal abnormalities. We aimed to elucidate the role of aberrant regulation of the Wnt system in these disorders by evaluating plasma levels of secreted Wnt modulators in patients (SCZ = 551 and BD = 246) and healthy controls (HCs = 639) using enzyme immune-assay. We also investigated the expression of 141 Wnt-related genes in whole blood in a subsample (SCZ = 338, BD = 241, and HCs = 263) using microarray analysis. Both SCZ and BD had dysregulated mRNA expression of Wnt-related genes favoring attenuated canonical (beta-catenin-dependent) signaling, and there were also indices of enhanced non-canonical Wnt signaling. In particular, FZD7, which may activate all Wnt pathways, but favors non-canonical signaling, and NFATc3, a downstream transcription factor and readout of the non-canonical Wnt/Ca
pathway, were significantly increased in SCZ and BD (p < 3 × 10
). Furthermore, patients had lower plasma levels of soluble dickkopf 1 and sclerostin (p < 0.01) compared with HC. Our findings suggest that SCZ and BD are characterized by abnormal Wnt gene expression and plasma protein levels, and we propose that drugs targeting the Wnt pathway may have a role in the treatment of severe mental disorders.
A proinflammatory imbalance in the tumor necrosis factor (TNF) system may contribute to the pathogenesis of schizophrenia (SCZ) and bipolar disorders (BDs) and related comorbidities. We investigated ...the relative distribution of TNF-related molecules in blood and dorsolateral prefrontal cortex (DLPFC) in these disorders.
We measured plasma levels of TNF, soluble TNF receptor 1 (sTNFR1), soluble TNF receptor 2 (sTNFR2), and a disintegrin and metalloprotease-17 (ADAM17) using enzyme immunoassays and calculated the TNF/sTNFRs ratio (TNF/sTNFR1+sTNFR2) in a sample of 816 SCZ and BD spectrum patients and 624 healthy controls (HCs). TNF, TNFRSF1A (TNFR1), TNFRSF1B (TNFR2), and ADAM17 mRNA levels were determined in whole blood, and postmortem DLPFC obtained from an independent cohort (n = 80 SCZ, n = 44 BD, and n = 86 HC).
In peripheral blood, we show increased TNF-related measures in patients compared to HC, with an increased TNF/sTNFRs ratio (p = 6.00 × 10-5), but decreased TNF mRNA expression (p = 1 × 10-4), with no differences between SCZ and BD. Whole blood ADAM17 mRNA expression was markedly higher in BD vs SCZ patients (p = 1.40 × 10-14) and vs HC (p = 1.22 × 10-8). In postmortem DLPFC, we found no significant differences in mRNA expression of TNF pathway genes between any groups.
SCZ and BD patients have increased plasma TNF pathway markers without corresponding increase in blood cell gene expression. ADAM17 expression in leukocytes is markedly different between the two disorders, while alterations in TNF-related gene expression in DLPFC are uncertain. Further studies are necessary to elucidate the aberrant regulation of the TNF pathway in severe mental disorders.
Pyridoxine (vitamin B6)-responsive epilepsies are severe forms of epilepsy that manifest as seizures immediately after birth, sometimes
, sometimes months, or years after birth. Seizures may be ...treated efficiently by life-long supplementation with pyridoxine or its biologically active form, pyridoxal phosphate, but even so patients may become intellectually disabled, for which there currently is no effective treatment. The condition may be caused by mutations in several genes (
, or
). Mutations in
, and
entail build-up of reactive aldehydes (α-aminoadipic semialdehyde, γ-glutamic semialdehyde) that may react non-enzymatically with macromolecules of brain cells. Such reactions may alter the function of macromolecules, and they may produce "advanced glycation end products" (AGEs). AGEs trigger inflammation in the brain. This understanding points to aldehyde-quenching, anti-AGE, or anti-inflammatory therapies as possible strategies to protect cognitive development and prevent intellectual disability in affected children. Studies on how aldehydes traverse cell membranes and how they affect brain function could further the development of therapies for patients with pyridoxine-responsive epilepsies.
Prader-Willi syndrome (PWS) is a rare genetic neurodevelopmental syndrome with highly increased risk of obesity and cardiovascular disease (CVD). Recent evidence suggests that inflammation is ...implicated in the pathogenesis. Here we investigated CVD related immune markers to shed light on pathogenetic mechanisms.
We performed a cross-sectional study with 22 participants with PWS and 22 healthy controls (HC), and compared levels of 21 inflammatory markers that reflect activity in different aspects of CVD related immune pathways and analyzed their association with clinical CVD risk factors.
Serum levels of matrix metalloproteinase 9 (MMP-9) was (median (range)) 121 (182) ng/ml in PWS versus 44 (51) ng/ml in HC, p = 1 × 10
), myeloperoxidase (MPO) was 183 (696) ng/ml versus 65 (180) ng/ml, p = 1 × 10
) and macrophage inhibitory factor (MIF) was 46 (150) ng/ml versus 121 (163) ng/ml (p = 1 × 10
), after adjusting for age and sex. Also other markers tended to be elevated (OPG, sIL2RA, CHI3L1, VEGF) but not significantly after Bonferroni correction (p > 0.002). As expected PWS had higher body mass index, waist circumference, leptin, C-reactive protein, glycosylated hemoglobin (HbA1c), VAI and cholesterol, but MMP-9, MPO and MIF remained significantly different in PWS after adjustment for these clinical CVD risk factors.
PWS had elevated levels of MMP-9 and MPO and of reduced levels of MIF, which were not secondary to comorbid CVD risk factors. This immune profile suggests enhanced monocyte/neutrophil activation, impaired macrophage inhibition with enhanced extracellular matrix remodeling. These findings warrant further studies targeting these immune pathways in PWS.
The Notch signaling pathway plays a crucial role in neurodevelopment and in adult brain homeostasis. We aimed to further investigate Notch pathway activity in bipolar disorder (BD) and schizophrenia ...(SCZ) by conducting a pathway analysis. We measured plasma levels of Notch ligands (DLL1 and DLK1) using enzyme immunoassays in a large sample of patients (SCZ n = 551, BD n = 246) and healthy controls (HC n = 639). We also determined Notch pathway related gene expression levels by microarray analyses from whole blood in a subsample (SCZ n = 338, BD n = 241 and HC n = 263). We found significantly elevated Notch ligand levels in plasma in both SCZ and BD compared to HC. Significant gene expression findings included increased levels of RFNG and KAT2B (p < 0.001), and decreased levels of PSEN1 and CREBBP in both patient groups (p < 0.001). RBPJ was significantly lower in SCZ vs HC (p < 0.001), and patients using lithium had higher levels of RBPJ (p < 0.001). We provide evidence of altered Notch signaling in both SCZ and BD compared to HC, and suggest that Notch signaling pathway may be disturbed in these disorders. Lithium may ameliorate aberrant Notch signaling. We propose that drugs targeting Notch pathway could be relevant in the treatment of psychotic disorders.
Background: Alterations in the inflammatory system have been associated with schizophrenia and major depression, while bipolar disorder has been less studied. Most previous studies examined small ...samples, and the literature is inconsistent with regard to specific underlying immune mechanisms. In the present study, we examined markers representing different inflammatory pathways, and the aim was to investigate whether the levels of inflammatory parameters in a representative sample of bipolar disorder and schizophrenia are elevated compared to healthy controls, and to investigate whether the inflammatory profile is different between the groups.
Methods: Plasma levels of soluble tumor necrosis factor receptor 1 (sTNF‐R1), interleukin‐1 receptor antagonist (IL‐1Ra), interleukin‐6 (IL‐6), high‐sensitivity CRP (hs‐CRP), soluble CD40L ligand (sCD40L), and von Willebrand factor (vWf) were measured with ELISA techniques in a catchment area based sample of consecutively referred patients with severe mental disorders N = 311, comprising bipolar disorder (n = 125) and schizophrenia (n = 186) and in healthy volunteers (n = 244).
Results: Plasma levels of sTNF‐R1 and vWf were statistically significantly increased in both bipolar disorder and schizophrenia compared to controls (p < 0.00001), and were also increased in unmedicated patients, but there were no major differences between the two diagnostic groups. Controlling for age, gender, ethnicity, cardiovascular disorders, kidney and liver function, and other confounders did not affect the results. There were no differences in other inflammation factors between the groups.
Conclusion: The present results indicate specific alterations of endothelium‐related inflammation processes in both bipolar disorder and schizophrenia.
Abstract
Autism spectrum disorder (ASD) is a highly heritable condition with a large variation in cognitive function. Here we investigated the shared genetic architecture between cognitive traits ...(intelligence (INT) and educational attainment (EDU)), and risk loci jointly associated with ASD and the cognitive traits. We analyzed data from genome-wide association studies (GWAS) of INT (
n
= 269,867), EDU (
n
= 766,345) and ASD (cases
n
= 18,381, controls
n
= 27,969). We used the bivariate causal mixture model (MiXeR) to estimate the total number of shared genetic variants, local analysis of co-variant annotation (LAVA) to estimate local genetic correlations, conditional false discovery rate (cond/conjFDR) to identify specific overlapping loci. The MiXeR analyses showed that 12.7k genetic variants are associated with ASD, of which 12.0k variants are shared with EDU, and 11.1k are shared with INT with both positive and negative relationships within overlapping variants. The majority (59–68%) of estimated shared loci have concordant effect directions, with a positive, albeit modest, genetic correlation between ASD and EDU (r
g
= 0.21,
p
= 2e−13) and INT (r
g
= 0.22,
p
= 4e−12). We discovered 43 loci jointly associated with ASD and cognitive traits (conjFDR<0.05), of which 27 were novel for ASD. Functional analysis revealed significant differential expression of candidate genes in the cerebellum and frontal cortex. To conclude, we quantified the genetic architecture shared between ASD and cognitive traits, demonstrated mixed effect directions, and identified the associated genetic loci and molecular pathways. The findings suggest that common genetic risk factors for ASD can underlie both better and worse cognitive functioning across the ASD spectrum, with different underlying biology.
Clinical genetic testing (CGT) of children with autism spectrum disorder (ASD) may have positive and negative effects. Knowledge about parents' attitudes is needed to ensure good involvement of ...caregivers, which is crucial for accurate diagnosis and effective clinical management. This study aimed to assess parents' attitudes toward CGT for ASD. Parent members of the Norwegian Autism Society were given a previously untested questionnaire and 1455 answered. Linear regression analyses were conducted to evaluate contribution of parent and child characteristics to attitude statements. Provided it could contribute to a casual explanation of their child's ASD, 76% would undergo CGT. If it would improve the possibilities for early interventions, 74% were positive to CGT. Between 49-67% agreed that CGT could have a negative impact on health insurance, increase their concern for the child's future and cause family conflicts. Parents against CGT (9%) were less optimistic regarding positive effects, but not more concerned with negative impacts. The severity of the children's ASD diagnosis had a weak positive association with parent's positive attitudes to CGT (
-values range from <0.001 to 0.975). Parents prefer that CGT is offered to those having a child with ASD (65%), when the child's development deviates from normal (48%), or before pregnancy (36%). A majority of the parents of children with ASD are positive to CGT due to possibilities for an etiological explanation.
Abstract Background Increased inflammation, endothelial dysfunction, and structural brain abnormalities have been reported in both schizophrenia and bipolar disorder, but the relationships between ...these factors are unknown. We aimed to identify associations between markers of inflammatory and endothelial activation and structural brain variation in psychotic disorders. Methods We measured von Willebrand factor (vWf) as a marker of endothelial cell activation and six inflammatory markers (tumor necrosis factor-receptor 1, osteoprotegerin, interleukin-1-receptor antagonist, interleukin-6, C-reactive protein, CD40 ligand) in plasma and 16 brain structures obtained from MRI scans of 356 individuals (schizophrenia spectrum; n = 121, affective spectrum; n = 95, healthy control subjects; n = 140). The relationship between the inflammatory and endothelial markers and brain measurements were investigated across groups. Results There was a positive association (p = 2.5 × 10 − 4 ) between plasma levels of vWf and total volume of the basal ganglia which remained significant after correction for multiple testing. Treatment with first generation antipsychotics was associated with basal ganglia volume only (p = 0.009). After adjusting for diagnosis and antipsychotic medication, vWf remained significantly associated with increased basal ganglia volume (p = 0.008), in particular the right globus pallidus (p = 3.7 × 10 − 4 ). The relationship between vWf and basal ganglia volume was linear in all groups, but the intercept was significantly higher in the schizophrenia group (df = 2, F = 8.2, p = 3.4 × 10 − 4 ). Conclusion Our results show a strong positive correlation between vWf levels and basal ganglia volume, in particular globus pallidus, independent of diagnosis. vWf levels were significantly higher in schizophrenia, which could indicate a link between endothelial cell activation and basal ganglia morphology in schizophrenia patients.
Creatine transporter deficiency (CTD) is an X-linked form of intellectual disability (ID) caused by SCL6A8 mutations. Limited information exists on the adult course of CTD, and there are no treatment ...studies in adults.
We report two half-brothers with CTD, 36 and 31 years at intervention start. Their clinical phenotypes were consistent with CTD, and intervention was indicated because of progressive disease course, with increased difficulties speaking, walking and eating, resulting in fatigue, and malnutrition. We therefore performed treatment trials with arginine, glycine and a proprietary product containing creatine and betaine, and then a trial supplementing with betaine alone.
In the older patient, glycine and arginine were accompanied by adverse effects, while betaine containing proprietary product gave improved balance, speech and feeding. When supplementation stopped, his condition deteriorated, and improved again after starting betaine supplement. Betaine supplementation was also beneficial in the younger patient, reducing his exhaustion, feeding difficulties and weight loss, making him able to resume his protected work.
We report for the first time that betaine supplement was well tolerated and efficient in adults with CTD, while arginine and/or glycine were accompanied by side effects. Thus, betaine is potentially a new useful treatment for CTD patients. We discuss possible underlying treatment mechanisms. Betaine has been reported to have antagonistic effect on NKCC1 channels, a mechanism shared with bumetanide, a medication with promising results in both in autism and epilepsy. Further studies of betaine's effects in well-designed studies are warranted.
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