Aire Controls in Trans the Production of Medullary Thymic Epithelial Cells Expressing Ly-6C/Ly-6G.

Medullary thymic epithelial cells (mTECs), which express a wide range of tissue-restricted Ags (TRAs), contribute to the establishment of self-tolerance by eliminating autoreactive T cells and/or inducing regulatory T cells. Aire controls a diverse set of TRAs within Aire-expressing cells by employing various transcriptional pathways. As Aire has a profound effect on transcriptomes of mTECs, including TRAs not only at the single-cell but also the population level, we suspected that Aire (Aire+ mTECs) might control the cellular composition of the thymic microenvironment. In this study, we confirmed that this is indeed the case by identifying a novel mTEC subset expressing Ly-6 family protein whose production was defective in Aire-deficient thymi. Reaggregated thymic organ culture experiments demonstrated that Aire did not induce the expression of Ly-6C/Ly-6G molecules from mTECs as Aire-dependent TRAs in a cell-intrinsic manner. Instead, Aire+ mTECs functioned in trans to maintain Ly-6C/Ly-6G+ mTECs. Thus, Aire not only controls TRA expression transcriptionally within the cell but also controls the overall composition of mTECs in a cell-extrinsic manner, thereby regulating the transcriptome from mTECs on a global scale.

Increased brain gyrification in the schizophrenia spectrum.

AIM: Increased brain gyrification in diverse cortical regions has been reported in patients with schizophrenia, possibly reflecting deviations in early neurodevelopment. However, it remains unknown whether patients with schizotypal disorder exhibit similar changes. METHODS: This magnetic resonance imaging study investigated brain gyrification in 46 patients with schizotypal disorder (29 male, 17 female), 101 patients with schizophrenia (55 male, 46 female), and 77 healthy controls (44 male, 33 female). T1-weighted magnetic resonance images were obtained for each participant. Using FreeSurfer software, the local gyrification index (LGI) of the entire cortex was compared across the groups. RESULTS: Both schizophrenia and schizotypal disorder patients showed a significantly higher LGI in diverse cortical regions, including the bilateral prefrontal and left parietal cortices, as compared with controls, but its extent was broader in schizophrenia especially for the right prefrontal and left occipital regions. No significant correlations were found between the LGI and clinical variables (e.g., symptom severity, medication) for either of the patient groups. CONCLUSION: Increased LGI in the frontoparietal regions was common to both patient groups and might represent vulnerability to schizophrenia, while more diverse changes in schizophrenia patients might be associated with the manifestation of florid psychosis.

Altered brain gyrification in deficit and non-deficit schizophrenia.

BACKGROUND: Patients with the deficit form of schizophrenia (D-SZ) are characterized by severe primary negative symptoms and differ from patients with the non-deficit form of schizophrenia (ND-SZ) in several aspects. No study has measured brain gyrification, which is a potential marker of neurodevelopment, in D-SZ and ND-SZ. METHODS: We obtained magnetic resonance scans from 135 schizophrenia patients and 50 healthy controls. The proxy scale for deficit syndrome (PDS) was used for the classification of D-SZ and ND-SZ. The local gyrification index (LGI) of the entire cortex was measured using FreeSurfer. Thirty-seven D-SZ and 36 ND-SZ patients were included in the LGI analyses. We compared LGI across the groups. RESULTS: SZ patients exhibited hyper-gyral patterns in the bilateral dorsal medial prefrontal and ventromedial prefrontal cortices, bilateral anterior cingulate gyri and right lateral parietal/occipital cortices as compared with HCs. Although patients with D-SZ or ND-SZ had higher LGI in similar regions compared with HC, the hyper-gyral patterns were broader in ND-SZ. ND-SZ patients exhibited a significantly higher LGI in the left inferior parietal lobule relative to D-SZ patients. Duration of illness inversely associated with LGI in broad regions only among ND-SZ patients. CONCLUSIONS: The common hyper-gyral patterns among D-SZ and ND-SZ suggest that D-SZ and ND-SZ may share neurodevelopmental abnormalities. The different degrees of cortical gyrification seen in the left parietal regions, and the distinct correlation between illness chronicity and LGI observed in the prefrontal and insular cortices may be related to the differences in the clinical manifestations among D-SZ and ND-SZ.

Surface morphology of the orbitofrontal cortex in individuals at risk of psychosis: a multicenter study.

Changes in the surface morphology of the orbitofrontal cortex (OFC), such as a fewer orbital sulci and altered sulcogyral pattern of the 'H-shaped' orbital sulcus, have been reported in schizophrenia, possibly reflecting abnormal neurodevelopment during gestation. However, whether high-risk subjects for developing psychosis also exhibit these gross morphologic anomalies is not well documented. This multicenter MRI study from four scanning sites in Japan investigated the distribution of the number of intermediate and posterior orbital sulci, as well as the OFC sulcogyral pattern, in 125 individuals with an at-risk mental state (ARMS) [of whom 22 later developed psychosis (ARMS-P) and 89 did not (ARMS-NP)] and 110 healthy controls. The ARMS group as a whole had a significantly lower number of intermediate and posterior orbital sulci compared with the controls, which was associated with prodromal symptomatology. However, there was no group difference in OFC pattern distribution. The ARMS-P and -NP groups did not differ in OFC surface morphology. These results suggest that gross morphology of the OFC in high-risk subjects may at least partly reflect neurodevelopmental pathology related to vulnerability to psychosis.

Olfactory deficits in individuals at risk for psychosis and patients with schizophrenia: relationship with socio-cognitive functions and symptom severity.

Odor identification deficits are well documented in patients with schizophrenia, but it remains unclear whether individuals at clinical high-risk for psychosis exhibit similar changes and whether their olfactory function is related to social/cognitive functions and symptomatology. In this study, we investigated odor detection sensitivity and identification ability in 32 individuals with at-risk mental state (ARMS), 59 schizophrenia patients, and 169 healthy controls using a T&T olfactometer. The ARMS and schizophrenia subjects were administered the Brief Assessment of Cognition in Schizophrenia (BACS), the Schizophrenia Cognition Rating Scale (SCoRS), and the Social and Occupational Functioning Assessment Scale (SOFAS) to assess their cognitive and social functions, and the Positive and Negative Syndrome Scale (PANSS) for clinical symptoms. Both the ARMS and schizophrenia subjects had lower odor identification ability when compared with healthy controls, while no significant difference was found in the odor detection sensitivity. The lower odor identification ability in the ARMS group correlated with the severity of negative symptoms and weakly correlated with lower performance on the BACS verbal fluency test. The olfactory measures of schizophrenia patients did not correlate with illness duration, medication, symptom severity, and social and cognitive functions. For the ARMS and schizophrenia groups, the olfactory measures did not correlate with the SOFAS and SCoRS scores. These findings suggest that high-risk subjects for psychosis already show odor identification deficits similar to those observed in schizophrenia patients, which probably reflect a biological trait related to vulnerability to psychosis.

Increased Frontal Gyrification Negatively Correlates with Executive Function in Patients with First-Episode Schizophrenia.

Previous neuroimaging studies of gyrification, a possible marker of early neurodevelopment, in schizophrenia patients have reported inconsistent results. In addition, it remains unclear whether aberrant gyrification in schizophrenia patients, if present, is associated with cognitive impairment, which is one of the core features of schizophrenia. Magnetic resonance images were obtained from 62 patients with first-episode schizophrenia and 57 healthy control subjects. Using FreeSurfer software, local gyrification index (LGI) of the entire cortex was compared between the groups. The relationship between LGI and performance in the Wisconsin Card Sorting Test (WCST) was also examined in a subgroup of patients (n= 28). Compared with the controls, the patients showed a significantly higher LGI in a wide range of bilateral frontal regions as well as in the right inferior parietal and bilateral occipital regions. The number of WCST categories archived in patients was negatively correlated with the LGI mainly in the rostral middle frontal and anterior cingulate regions in the right hemisphere. Our findings suggested a widespread hypergyrification pattern in schizophrenia patients, which supported early neurodevelopmental abnormalities. Our results also suggested that executive dysfunction in schizophrenia patients may be at least partly related to aberrant neurodevelopment, especially in the right frontal regions.

Temporal lineage tracing of Aire-expressing cells reveals a requirement for Aire in their maturation program.

Understanding the cellular dynamics of Aire-expressing lineage(s) among medullary thymic epithelial cells (AEL-mTECs) is essential for gaining insight into the roles of Aire in establishment of self-tolerance. In this study, we monitored the maturation program of AEL-mTECs by temporal lineage tracing, in which bacterial artificial chromosome transgenic mice expressing tamoxifen-inducible Cre recombinase under control of the Aire regulatory element were crossed with reporter strains. We estimated that the half-life of AEL-mTECs subsequent to Aire expression was ∼7-8 d, which was much longer than that reported previously, owing to the existence of a post-Aire stage. We found that loss of Aire did not alter the overall lifespan of AEL-mTECs, inconsistent with the previous notion that Aire expression in medullary thymic epithelial cells (mTECs) might result in their apoptosis for efficient cross-presentation of self-antigens expressed by AEL-mTECs. In contrast, Aire was required for the full maturation program of AEL-mTECs, as exemplified by the lack of physiological downregulation of CD80 during the post-Aire stage in Aire-deficient mice, thus accounting for the abnormally increased CD80(high) mTECs seen in such mice. Of interest, increased CD80(high) mTECs in Aire-deficient mice were not mTEC autonomous and were dependent on cross-talk with thymocytes. These results further support the roles of Aire in the differentiation program of AEL-mTECs.

Orbitofrontal sulcogyral pattern and olfactory sulcus depth in the schizophrenia spectrum.

Morphological changes in the orbitofrontal cortex (OFC), such as an altered sulcogyral pattern of the 'H-shaped' orbital sulcus and a shallow olfactory sulcus, have been demonstrated in schizophrenia, possibly reflecting deviations in early neurodevelopment. However, it remains unclear whether patients with schizotypal features exhibit similar OFC changes. This magnetic resonance imaging study examined the OFC sulcogyral pattern (Types I, II, III, and IV) and olfactory sulcus morphology in 102 patients with schizophrenia, 47 patients with schizotypal disorder, and 84 healthy controls. The OFC sulcogyral pattern distribution between the groups was significantly different on the right hemisphere, with the schizophrenia patients showing a decrease in Type I (vs controls and schizotypal patients) and an increase in Type III (vs controls) expression. However, the schizotypal patients and controls did not differ in the OFC pattern. There were significant group differences in the olfactory sulcus depth bilaterally (schizophrenia patients < schizotypal patients < controls). Our findings suggest that schizotypal disorder, a milder form of schizophrenia spectrum disorders, partly shares the OFC changes (i.e., altered depth of the olfactory sulcus) with schizophrenia, possibly reflecting a common disease vulnerability. However, altered distribution of the OFC pattern specific to schizophrenia may at least partly reflect neurodevelopmental pathology related to a greater susceptibility to overt psychosis.

Possible relation between olfaction and anxiety in healthy subjects.

AIMS: While olfaction is a sense closely associated with the limbic system and emotions, the relation between emotional status and olfactory functioning has not been well documented. This study aimed to examine the possible effect of anxiety on olfaction in healthy subjects. METHODS: We investigated the effect of state and trait anxiety on the detection and recognition thresholds for five different odors in 124 healthy subjects (62 men and 62 women, mean age = 27.2 years) using a T&T olfactometer. RESULTS: While the influences of age, socioeconomic status, IQ, and smoking history on olfaction were not significant, women had a lower recognition threshold for the odor of sweet fruit and a higher detection threshold for that of rotten food as compared with men. Both state and trait anxiety ratings were significantly associated with reduced olfactory ability, especially for identification of rose odor. CONCLUSIONS: These findings suggest that emotional status affects olfactory functioning in healthy subjects. Our findings may also partly explain the mild olfactory impairment reported in clinical conditions, such as anxiety disorders.

Rab13 small G protein and junctional Rab13-binding protein (JRAB) orchestrate actin cytoskeletal organization during epithelial junctional development.

During epithelial junctional development, both vesicle transport and reorganization of the actin cytoskeleton must be spatiotemporally regulated. Coordination of these cellular functions is especially important, but the precise mechanism remains elusive. Previously, we identified junctional Rab13-binding protein (JRAB)/molecules interacting with CasL-like 2 (MICAL-L2) as an effector of the Rab13 small G protein, and we found that the Rab13-JRAB system may be involved in the formation of cell-cell adhesions via transport of adhesion molecules. Here, we showed that JRAB interacts with two actin-binding proteins, actinin-1 and -4, and filamentous actin via different domains and regulates actin cross-linking and stabilization through these interactions. During epithelial junctional development, JRAB is prominently enriched in the actin bundle at the free border; subsequently, JRAB undergoes a Rab13-dependent conformational change that is required for maturation of cell-cell adhesion sites. These results suggest that Rab13 and JRAB regulate reorganization of the actin cytoskeleton throughout epithelial junctional development from establishment to maturation of cell-cell adhesion.

IL-21-dependent B cell death driven by prostaglandin E2, a product secreted from follicular dendritic cells.

In germinal centers (GCs), B cells are selected through interaction with follicular dendritic cells bearing immune complexes and follicular helper T (Tfh) cells secreting Tfh cytokines, including IL-21. To analyze these cellular interactions, we have explored culture conditions that can simulate GC B cell selection in vitro using a mouse follicular dendritic cell line, FL-YB. FL-YB cells efficiently enhanced viability of cocultured mouse B cells in a BAFF-dependent fashion. Interestingly, we found that addition of IL-21, a major Tfh cytokine, readily induced death of B cells that were cocultured with FL-YB cells, whereas IL-21 alone sustained viability of B cells in the absence of FL-YB cells. The IL-21-induced death was dependent on a low m.w. soluble factor that was released from FL-YB cells, which was finally identified as PGE(2). Treatment of B cells with IL-21 plus PGE(2), but not either alone, resulted in enhanced expression of a proapoptotic protein Bim and the upstream transcription factor Foxo1. A PGE(2) receptor isoform, EP4, was responsible for IL-21/PGE(2)-induced B cell death. Thus, PGE(2) is an endogenous chemical mediator that can switch pleiotropic actions of IL-21 on B cells. IL-21/PGE(2)-induced B cell death was rescued if B cells were costimulated via CD40. In immunized mice, deficiency of IL-21R in B cells led to a significant decrease in the frequency of activated caspase-3-positive GC B cells concomitant with impaired affinity maturation of Abs. Taken together, results implicate a physiological role of IL-21/PGE(2)-induced B cell death in GC B cell selection.

Lymphotoxin signal promotes thymic organogenesis by eliciting RANK expression in the embryonic thymic stroma.

It has recently become clear that signals mediated by members of the TNFR superfamily, including lymphotoxin-ß receptor (LTßR), receptor activator for NF-κB (RANK), and CD40, play essential roles in organizing the integrity of medullary thymic epithelial cells (mTECs) required for the establishment of self-tolerance. However, details of the mechanism responsible for the unique and cooperative action of individual and multiple TNFR superfamily members during mTEC differentiation still remain enigmatic. In this study, we show that the LTßR signal upregulates expression of RANK in the thymic stroma, thereby promoting accessibility to the RANK ligand necessary for mTEC differentiation. Cooperation between the LTßR and RANK signals for optimal mTEC differentiation was underscored by the exaggerated defect of thymic organogenesis observed in mice doubly deficient for these signals. In contrast, we observed little cooperation between the LTßR and CD40 signals. Thus, the LTßR signal exhibits a novel and unique function in promoting RANK activity for mTEC organization, indicating a link between thymic organogenesis mediated by multiple cytokine signals and the control of autoimmunity.

A Comprehensive Oral Intake Evaluation Tool (the Kuchi-kara Taberu Index) Facilitated Functional Eating Rehabilitation: A Case Report in a Frail Older Patient with Malnutrition and Suspected Iatrogenic Sarcopenia.

Frail older hospital patients are susceptible to malnutrition and iatrogenic sarcopenia. This can be linked to the decreased appetite and oral intake that can arise in largely bed-bound patients who do not get up even for rehabilitation and meals. The KT index was devised as an easy-to-use evaluation tool to address oral intake issues, and it has potential utility for expediting a multidisciplinary comprehensive rehabilitation program. To our knowledge, no reports have described real-world evidence on multidisciplinary team interventions with this tool. Herein, we report the case of a frail older patient whose oral intake improved following a KT Index-based intervention.

Thalamic and striato-pallidal volumes in schizophrenia patients and individuals at risk for psychosis: A multi-atlas segmentation study.

Despite previous neuroimaging studies demonstrating morphological abnormalities of the thalamus and other subcortical structures in patients with schizophrenia, the potential role of the thalamus and its subdivisions in the pathophysiology of this illness remains elusive. It is also unclear whether similar changes of these structures occur in individuals at high risk for psychosis. In this study, magnetic resonance imaging was employed with the Multiple Automatically Generated Templates (MAGeT) brain segmentation algorithm to determine volumes of the thalamic subdivisions, the striatum (caudate, putamen, and nucleus accumbens), and the globus pallidus in 62 patients with schizophrenia, 38 individuals with an at-risk mental state (ARMS) [4 of whom (10.5%) subsequently developed schizophrenia], and 61 healthy subjects. Cognitive function of the patients was assessed by using the Brief Assessment of Cognition in Schizophrenia (BACS) and the Schizophrenia Cognition Rating Scale (SCoRS). Thalamic volume (particularly the medial dorsal and ventral lateral nuclei) was smaller in the schizophrenia group than the ARMS and control groups, while there were no differences for the striatum and globus pallidus. In the schizophrenia group, the reduction of thalamic ventral lateral nucleus volume was significantly associated with lower BACS score. The pallidal volume was positively correlated with the dose of antipsychotic treatment in the schizophrenia group. These results suggest that patients with schizophrenia, but not those with ARMS, exhibit volume reduction in specific thalamic subdivisions, which may underlie core clinical features of this illness.

Reduced Cortical Thickness in Schizophrenia and Schizotypal Disorder.

Schizotypal disorder is characterized by odd behavior and attenuated forms of schizophrenic features without the manifestation of overt and sustained psychoses. Past studies suggest that schizotypal disorder shares biological and psychological commonalties with schizophrenia. Structural magnetic resonance imaging (MRI) studies have demonstrated both common and distinct regional gray matter changes between schizophrenia and schizotypal disorder. However, no study has compared cortical thickness, which is thought to be a specific indicator of cortical atrophy, between schizophrenia and schizotypal disorder. The subjects consisted of 102 schizophrenia and 46 schizotypal disorder patients who met the International Classification of Diseases, 10th edition criteria and 79 gender- and age-matched healthy controls. Each participant underwent a T1-weighted 3-D MRI scan using a 1.5-Tesla scanner. Cortical thickness was estimated using FreeSurfer. Consistent with previous studies, schizophrenia patients exhibited wide-spread cortical thinning predominantly in the frontal and temporal regions as compared with healthy subjects. Patients with schizotypal disorder had a significantly reduced cortical thickness in the left fusiform and parahippocampal gyri, right medial superior frontal gyrus, right inferior frontal gyrus, and right medial orbitofrontal cortex as compared with healthy controls. Schizophrenia patients had thinner cortices in the left precentral and paracentral gyri than those with schizotypal disorder. Common cortical thinning patterns observed in schizophrenia and schizotypal disorder patients may be associated with vulnerability to psychosis. Our results also suggest that distinct cortical changes in schizophrenia and schizotypal disorder may be associated with the differences in the manifestation of clinical symptoms among these disorders.

Subcortical Brain Volume Abnormalities in Individuals With an At-risk Mental State.

Previous structural magnetic resonance imaging studies of psychotic disorders have demonstrated volumetric alterations in subcortical (ie, the basal ganglia, thalamus) and temporolimbic structures, which are involved in high-order cognition and emotional regulation. However, it remains unclear whether individuals at high risk for psychotic disorders with minimal confounding effects of medication exhibit volumetric changes in these regions. This multicenter magnetic resonance imaging study assessed regional volumes of the thalamus, caudate, putamen, nucleus accumbens, globus pallidus, hippocampus, and amygdala, as well as lateral ventricular volume using FreeSurfer software in 107 individuals with an at-risk mental state (ARMS) (of whom 21 [19.6%] later developed psychosis during clinical follow-up [mean = 4.9 years, SD = 2.6 years]) and 104 age- and gender-matched healthy controls recruited at 4 different sites. ARMS individuals as a whole demonstrated significantly larger volumes for the left caudate and bilateral lateral ventricles as well as a smaller volume for the right accumbens compared with controls. In male subjects only, the left globus pallidus was significantly larger in ARMS individuals. The ARMS group was also characterized by left-greater-than-right asymmetries of the lateral ventricle and caudate nucleus. There was no significant difference in the regional volumes between ARMS groups with and without later psychosis onset. The present study suggested that significant volume expansion of the lateral ventricle, caudate, and globus pallidus, as well as volume reduction of the accumbens, in ARMS subjects, which could not be explained only by medication effects, might be related to general vulnerability to psychopathology.

Olfactory sulcus morphology in teenagers with first-presentation borderline personality disorder.

Gray matter reduction of the orbitofrontal cortex (OFC) has been reported in borderline personality disorder (BPD), but it remains unknown whether the BPD patients exhibit morphologic changes of the olfactory sulcus, a potential marker of forebrain development located on the OFC. We used magnetic resonance imaging to investigate the length and depth of the olfactory sulcus in 20 teenagers (15 females and 5 males) with first-presentation BPD and 20 healthy controls (15 females and 5 males). While there was no group difference in the length of the sulcus, the BPD patients (especially those with a history of trauma) had a significantly shallower right olfactory sulcus compared with controls. In addition, sulcus depth was negatively correlated with the severity of impulsivity and affective instability in the BPD patients. These preliminary findings may suggest a significant role of environmental risk factors (i.e., trauma exposure) during childhood to adolescence in the neurobiology of BPD.

Reduced pineal gland volume across the stages of schizophrenia.

A few magnetic resonance imaging (MRI) studies reported reduced pineal gland volume in chronic schizophrenia (Sz), implicating the involvement of melatonin in the pathophysiology of the illness. However, it is not known whether this abnormality, if present, exists at the early illness stages and/or develops progressively over the course of the illness. This MRI study examined pineal gland volume in 64 patients with first-episode schizophrenia (FESz), 40 patients with chronic Sz, 22 individuals with at-risk mental state (ARMS), and 84 healthy controls. Longitudinal changes in pineal volume (mean inter-scan interval = 2.5 ±â€¯0.7 years) were also examined in a subsample of 23 FESz, 16 chronic Sz, and 21 healthy subjects. In the cross-sectional comparison, the ARMS, FESz, and chronic Sz groups had significantly smaller pineal volume to the same degree as compared with healthy controls. A longitudinal comparison demonstrated that pineal volume did not change over time in any group. There was no association between pineal volume and clinical variables (e.g., symptom severity, medication) in the ARMS and Sz groups. The results suggest that a smaller pineal gland may be a static vulnerability marker of Sz, which probably reflects an early neurodevelopmental abnormality.

Potential role of orbitofrontal surface morphology on social and cognitive functions in high-risk subjects for psychosis and schizophrenia patients.

This MRI study examined the surface morphology of the orbitofrontal cortex (OFC) and its relation to social and cognitive functions in 38 individuals with at-risk mental state (ARMS) and 63 schizophrenia patients in comparison with 61 healthy controls. The ARMS and schizophrenia groups had increased right OFC Type III expression and fewer orbital sulci, which were partly associated with social and cognitive impairments. OFC underdevelopment may underlie vulnerability to psychosis, as well as the core clinical features of the illness.

Association between olfactory sulcus morphology and olfactory functioning in schizophrenia and psychosis high-risk status.

Olfactory impairment has been reported in patients with schizophrenia and individuals with a high risk of psychosis, but its neural basis is largely unknown. We used magnetic resonance imaging to investigate the morphology of the olfactory sulcus (an indicator of olfactory system development) and its relation to olfactory function in 38 persons with an at-risk mental state (ARMS), 62 patients with schizophrenia, and 61 healthy controls. Odor detection and identification were examined with a T & T olfactometer. Compared with the controls, the olfactory sulcus was significantly shallower and odor identification was inferior among the ARMS and schizophrenia subjects. Across all subjects, but not within each group, the olfactory sulcus depth was significantly related to better identification of odors. Our results support the concept that olfactory sulcus morphology reflects the neurodevelopmental process of the olfactory system.