Hereditary spastic paraplegia with thin corpus callosum and SPG11 mutation: A neuropathological evaluation.

Hereditary spastic paraplegia (HSP) with thin corpus callosum can be due to a variety of genetic causes, the most common of which are biallelic variants in SPG11 (HSP11). Only six cases of neuropathologic examination of HSP11 have been reported. Here we present neuropathological findings in another case of HSP11 with novel mutation (homozygous c.6439_6442del) and clinical features of three additional cases of HSP11. These four cases of HSP11 had similar disease courses with prominent lower extremity weakness and spasticity but varied cognitive symptoms and brain magnetic resonance imaging (MRI) findings. Neuropathological examination of one case included ex vivo MRI of the cerebrum, histologic and immunohistochemical evaluation, and Western blot for SPG11. The case was notable for a small cerebrum with decreased volume of cortex, white matter, and deep gray nuclei. The corpus callosum was thin, and the substantia nigra showed marked pallor. Microscopically, the cortex had normal lamination and mild loss of neurons with mild gliosis, the corpus callosum was thin with limited gliosis, and the substantia nigra had marked decrease in neurons and pigment, with minimal gliosis. In contrast, the basal ganglia, thalamus, and spinal cord (anterior horns, corticospinal, and spinocerebellar tracts) had prominent neuron loss and gliosis. Myelin-laden macrophages were found in multiple sites but were most common in the corpus callosum. No hyperphosphorylated tau or TDP-43 aggregates, Lewy bodies, or amyloid ß plaques were found. Compared to control, SPG11 was absent in HSP11 brain and markers of autophagy were elevated by Western blot. Comparison with prior reports of HSP with thin corpus callosum and HSP11 demonstrates a disease with a broad range of structural changes of the brain, including features of abnormal development and degeneration.

Suppression of melanoma by mice lacking MHC-II: Mechanisms and implications for cancer immunotherapy.

Immune checkpoint inhibitors interfere with T cell exhaustion but often fail to cure or control cancer long-term in patients. Using a genetic screen in C57BL/6J mice, we discovered a mutation in host H2-Aa that caused strong immune-mediated resistance to mouse melanomas. H2-Aa encodes an MHC class II α chain, and its absence in C57BL/6J mice eliminates all MHC-II expression. H2-Aa deficiency, specifically in dendritic cells (DC), led to a quantitative increase in type 2 conventional DC (cDC2) and a decrease in cDC1. H2-Aa-deficient cDC2, but not cDC1, were essential for melanoma suppression and effectively cross-primed and recruited CD8 T cells into tumors. Lack of T regulatory cells, also observed in H2-Aa deficiency, contributed to melanoma suppression. Acute disruption of H2-Aa was therapeutic in melanoma-bearing mice, particularly when combined with checkpoint inhibition, which had no therapeutic effect by itself. Our findings suggest that inhibiting MHC-II may be an effective immunotherapeutic approach to enhance immune responses to cancer.

A machine learning approach in a monocentric cohort for predicting primary refractory disease in Diffuse Large B-cell lymphoma patients.

INTRODUCTION: Primary refractory disease affects 30-40% of patients diagnosed with DLBCL and is a significant challenge in disease management due to its poor prognosis. Predicting refractory status could greatly inform treatment strategies, enabling early intervention. Various options are now available based on patient and disease characteristics. Supervised machine-learning techniques, which can predict outcomes in a medical context, appear highly suitable for this purpose. DESIGN: Retrospective monocentric cohort study. PATIENT POPULATION: Adult patients with a first diagnosis of DLBCL admitted to the hematology unit from 2017 to 2022. AIM: We evaluated in our Center five supervised machine-learning (ML) models as a tool for the prediction of primary refractory DLBCL. MAIN RESULTS: One hundred and thirty patients with Diffuse Large B-cell lymphoma (DLBCL) were included in this study between January 2017 and December 2022. The variables used for analysis included demographic characteristics, clinical condition, disease characteristics, first-line therapy and PET-CT scan realization after 2 cycles of treatment. We compared five supervised ML models: support vector machine (SVM), Random Forest Classifier (RFC), Logistic Regression (LR), Naïve Bayes (NB) Categorical classifier and eXtreme Gradient Boost (XGboost), to predict primary refractory disease. The performance of these models was evaluated using the area under the receiver operating characteristic curve (ROC-AUC), accuracy, false positive rate, sensitivity, and F1-score to identify the best model. After a median follow-up of 19.5 months, the overall survival rate was 60% in the cohort. The Overall Survival at 3 years was 58.5% (95%CI, 51-68.5) and the 3-years Progression Free Survival was 63% (95%CI, 54-71) using Kaplan-Meier method. Of the 124 patients who received a first line treatment, primary refractory disease occurred in 42 patients (33.8%) and 2 patients (1.6%) experienced relapse within 6 months. The univariate analysis on refractory disease status shows age (p = 0.009), Ann Arbor stage (p = 0.013), CMV infection (p = 0.012), comorbidity (p = 0.019), IPI score (p<0.001), first line of treatment (p<0.001), EBV infection (p = 0.008) and socio-economics status (p = 0.02) as influencing factors. The NB Categorical classifier emerged as the top-performing model, boasting a ROC-AUC of 0.81 (95% CI, 0.64-0.96), an accuracy of 83%, a F1-score of 0.82, and a low false positive rate at 10% on the validation set. The eXtreme Gradient Boost (XGboost) model and the Random Forest Classifier (RFC) followed with a ROC-AUC of 0.74 (95%CI, 0.52-0.93) and 0.67 (95%CI, 0.46-0.88) respectively, an accuracy of 78% and 72% respectively, a F1-score of 0.75 and 0.67 respectively, and a false positive rate of 10% for both. The other two models performed worse with ROC-AUC of 0.65 (95%CI, 0.40-0.87) and 0.45 (95%CI, 0.29-0.64) for SVM and LR respectively, an accuracy of 67% and 50% respectively, a f1-score of 0.64 and 0.43 respectively, and a false positive rate of 28% and 37% respectively. CONCLUSION: Machine learning algorithms, particularly the NB Categorical classifier, have the potential to improve the prediction of primary refractory disease in DLBCL patients, thereby providing a novel decision-making tool for managing this condition. To validate these results on a broader scale, multicenter studies are needed to confirm the results in larger cohorts.

Nonredundant Role of Leishmanolysin-Like (Lmln) Zinc-Metallopeptidase in Retinal Homeostasis.

PURPOSE: To determine if Lmln, a Zinc-metallopeptidase, is important for retinal homeostasis. DESIGN: Basic research in mouse models of retinal degeneration. METHODS: Combining an unbiased N-ethyl-N-nitrosourea mutagenesis pipeline in mice with optical coherence tomography (OCT) screening and automated meiotic mapping, we identified an allele (nemeth) that seemed to be associated with outer nuclear layer (ONL) thinning. Since nemeth was predicted to lead to a nonsense mutation of the Lmln gene, we targeted Lmln using CRISPR/Cas-9 technology and characterized the impact on retinal anatomy and function. RESULTS: OCT imaging demonstrated an outer retinal degeneration in Lmln-/- mice (P = 7.3 × 10-9 for ONL at 2 m) that progressed over the first 6 months of life and then stabilized. Light microscopy showed loss of ONL nuclei (P ranged between .00033 and .0097 for posterior measurements), and a TUNEL assay revealed a small but significant increase in apoptosis (P = .034). Lmln-/- mice accumulated fundus spots (P = .0030 by 2 m of age) and activated subretinal microglia (P ranged from .0007 to 8 × 10-13 for Gal3+ cells). Scotopic electroretinography demonstrated a decrease in retinal function in Lmln-/- mice both at 6 m (only a-wave, P < .01 for all stimuli) and at 10 m of age (P < .01 for both a-wave and b-wave with all stimuli). CONCLUSIONS: Our work revealed a previously unknown essential role for Lmln in maintaining retinal anatomy and function. Further studies using this new model will be aimed at determining the cellular expression of Lmln and its mechanisms of action within the retina.

Disruption of the ZFP574-THAP12 complex suppresses B cell malignancies in mice.

Despite the availability of life-extending treatments for B cell leukemias and lymphomas, many of these cancers remain incurable. Thus, the development of new molecular targets and therapeutics is needed to expand treatment options. To identify new molecular targets, we used a forward genetic screen in mice to identify genes required for development or survival of lymphocytes. Here, we describe Zfp574, an essential gene encoding a zinc finger protein necessary for normal and malignant lymphocyte survival. We show that ZFP574 interacts with zinc finger protein THAP12 and promotes the G1-to-S-phase transition during cell cycle progression. Mutation of ZFP574 impairs nuclear localization of the ZFP574-THAP12 complex. ZFP574 or THAP12 deficiency results in cell cycle arrest and impaired lymphoproliferation. Germline mutation, acute gene deletion, or targeted degradation of ZFP574 suppressed Myc-driven B cell leukemia in mice, but normal B cells were largely spared, permitting long-term survival, whereas complete lethality was observed in control animals. Our findings support the identification of drugs targeting ZFP574-THAP12 as a unique strategy to treat B cell malignancies.

Clinical Characteristics and Outcomes of Patients with Traumatic Spinal Cord Injury at a Tertiary Care Center in the Philippines.

OBJECTIVES: Traumatic spinal cord injury (TSCI) is a devastating condition that may result to lifelong complications that affect patient outcome and quality of life. Because of the increasing incidence of TSCI, it is important to comprehend the extent of this condition in terms of demographics, mechanism, and degree of disability to raise awareness and develop strategies in approaching care for these patients. There is a lack of information regarding data on TSCI in Southeast Asia, especially in the Philippines. This study aims to describe the clinical characteristics and outcomes of patients with TSCI in a tertiary care hospital in the Philippines. METHODS: This is a retrospective descriptive cohort study in individuals aged 18 years older who were admitted for TSCI in a Philippine tertiary care hospital between 2022 and 2023. Of 118 admitted patients, 100 patients were included in the study. The data were obtained from the review of patients' medical records. Demographics of TSCI, mechanism, presenting clinical characteristics, American Spinal Injury Association Impairment Scale (AIS) grade, radiographic findings, outcomes, and complications were analyzed. RESULTS: A total of 100 patients with TSCI were included in the study. The mean age of the patients was 43.4 ± 15.8 in years, with male patients being predominant, at 92%. The most common mechanism of injury was motor vehicular crash, at 68%, followed by fall, at 22%. Most patients, 38%, were graded AIS C, on admission. The most common level of injury was cervical, at 70%. The usual complications recorded were sacral ulcer 28%, and hospital-acquired pneumonia, 20%. CONCLUSIONS: TSCI is common in young adult male patients with motor vehicular crash as the mechanism of injury. Most patients in the study had incomplete spinal cord injury (AIS C), with the cervical region as the most common level. The recorded mean length of hospital stay was 1-2 weeks. The most common co-occurring extra spinal injury was traumatic brain injury. At discharge, most developed sacral ulcer and hospital-acquired pneumonia, with stable neurologic status. A multicenter prospective data collection with a larger population and inclusion of more variables are necessary to formulate a regression model and establish the factors that improve the outcomes of TSCI.

Viable mutations of mouse midnolin suppress B cell malignancies.

In a genetic screen, we identified two viable missense alleles of the essential gene Midnolin (Midn) that were associated with reductions in peripheral B cells. Causation was confirmed in mice with targeted deletion of four of six MIDN protein isoforms. MIDN was expressed predominantly in lymphocytes where it augmented proteasome activity. We showed that purified MIDN directly stimulated 26S proteasome activity in vitro in a manner dependent on the ubiquitin-like domain and a C-terminal region. MIDN-deficient B cells displayed aberrant activation of the IRE-1/XBP-1 pathway of the unfolded protein response. Partial or complete MIDN deficiency strongly suppressed Eµ-Myc-driven B cell leukemia and the antiapoptotic effects of Eµ-BCL2 on B cells in vivo and induced death of Sp2/0 hybridoma cells in vitro, but only partially impaired normal lymphocyte development. Thus, MIDN is required for proteasome activity in support of normal lymphopoiesis and is essential for malignant B cell proliferation over a broad range of differentiation states.

Prognosis of glioblastoma patients improves significantly over time interrogating historical controls.

BACKGROUND: Glioblastoma (GBM) is the most common devastating primary brain cancer in adults. In our clinical practice, median overall survival (mOS) of GBM patients seems increasing over time. METHODS: To address this observation, we have retrospectively analyzed the prognosis of 722 newly diagnosed GBM patients, aged below 70, in good clinical conditions (i.e. Karnofsky Performance Status -KPS- above 70%) and treated in our department according to the standard of care (SOC) between 2005 and 2018. Patients were divided into two groups according to the year of diagnosis (group 1: from 2005 to 2012; group 2: from 2013 to 2018). RESULTS: Characteristics of patients and tumors of both groups were very similar regarding confounding factors (age, KPS, MGMT promoter methylation status and treatments). Follow-up time was fixed at 24 months to ensure comparable survival times between both groups. Group 1 patients had a mOS of 19 months ([17.3-21.3]) while mOS of group 2 patients was not reached. The recent period of diagnosis was significantly associated with a longer mOS in univariate analysis (HR=0.64, 95% CI [0.51 - 0.81]), p < 0.001). Multivariate Cox analysis showed that the period of diagnosis remained significantly prognostic after adjustment on confounding factors (adjusted Hazard Ratio (aHR) 0.49, 95% CI [0.36-0.67], p < 0.001). CONCLUSION: This increase of mOS over time in newly diagnosed GBM patients could be explained by better management of potentially associated non-neurological diseases, optimization of validated SOC, better management of treatments side effects, supportive care and participation in clinical trials.

Fatigue Impacts Quality of Life in People with Spinocerebellar Ataxias.

BACKGROUND: Fatigue is a prevalent and debilitating symptom in neurological disorders, including spinocerebellar ataxias (SCAs). However, the risk factors of fatigue in the SCAs as well as its impact have not been well investigated. OBJECTIVES: To study the prevalence of fatigue in SCAs, the factors contributing to fatigue, and the influence of fatigue on quality of life. METHODS: Fatigue was assessed in 418 participants with SCA1, SCA2, SCA3, and SCA6 from the Clinical Research Consortium for the Study of Cerebellar Ataxia using the Fatigue Severity Scale. We conducted multi-variable linear regression models to examine the factors contributing to fatigue as well as the association between fatigue and quality of life. RESULTS: Fatigue was most prevalent in SCA3 (52.6%), followed by SCA1 (36.7%), SCA6 (35.7%), and SCA2 (35.6%). SCA cases with fatigue had more severe ataxia and worse depressive symptoms. In SCA3, those with fatigue had a longer disease duration and longer pathological CAG repeat numbers. In multi-variable models, depressive symptoms, but not ataxia severity, were associated with more severe fatigue. Fatigue, independent of ataxia and depression, contributed to worse quality of life in SCA3 and SCA6 at baseline, and fatigue continued affecting quality of life throughout the disease course in all types of SCA. CONCLUSIONS: Fatigue is a common symptom in SCAs and is closely related to depression. Fatigue significantly impacts patients' quality of life. Therefore, screening for fatigue should be considered a part of standard clinical care for SCAs.

Dynamic molecular architecture and substrate recruitment of cullin3-RING E3 ligase CRL3KBTBD2.

Phosphatidylinositol 3-kinase α, a heterodimer of catalytic p110α and one of five regulatory subunits, mediates insulin- and insulin like growth factor-signaling and, frequently, oncogenesis. Cellular levels of the regulatory p85α subunit are tightly controlled by regulated proteasomal degradation. In adipose tissue and growth plates, failure of K48-linked p85α ubiquitination causes diabetes, lipodystrophy and dwarfism in mice, as in humans with SHORT syndrome. Here we elucidated the structures of the key ubiquitin ligase complexes regulating p85α availability. Specificity is provided by the substrate receptor KBTBD2, which recruits p85α to the cullin3-RING E3 ubiquitin ligase (CRL3). CRL3KBTBD2 forms multimers, which disassemble into dimers upon substrate binding (CRL3KBTBD2-p85α) and/or neddylation by the activator NEDD8 (CRL3KBTBD2~N8), leading to p85α ubiquitination and degradation. Deactivation involves dissociation of NEDD8 mediated by the COP9 signalosome and displacement of KBTBD2 by the inhibitor CAND1. The hereby identified structural basis of p85α regulation opens the way to better understanding disturbances of glucose regulation, growth and cancer.

Neuroinflammatory disease signatures in SPG11-related hereditary spastic paraplegia patients.

Biallelic loss of SPG11 function constitutes the most frequent cause of complicated autosomal recessive hereditary spastic paraplegia (HSP) with thin corpus callosum, resulting in progressive multisystem neurodegeneration. While the impact of neuroinflammation is an emerging and potentially treatable aspect in neurodegenerative diseases and leukodystrophies, the role of immune cells in SPG11-HSP patients is unknown. Here, we performed a comprehensive immunological characterization of SPG11-HSP, including examination of three human postmortem brain donations, immunophenotyping of patients' peripheral blood cells and patient-specific induced pluripotent stem cell-derived microglia-like cells (iMGL). We delineate a previously unknown role of innate immunity in SPG11-HSP. Neuropathological analysis of SPG11-HSP patient brain tissue revealed profound microgliosis in areas of neurodegeneration, downregulation of homeostatic microglial markers and cell-intrinsic accumulation of lipids and lipofuscin in IBA1+ cells. In a larger cohort of SPG11-HSP patients, the ratio of peripheral classical and intermediate monocytes was increased, along with increased serum levels of IL-6 that correlated with disease severity. Stimulation of patient-specific iMGLs with IFNγ led to increased phagocytic activity compared to control iMGL as well as increased upregulation and release of proinflammatory cytokines and chemokines, such as CXCL10. On a molecular basis, we identified increased STAT1 phosphorylation as mechanism connecting IFNγ-mediated immune hyperactivation and SPG11 loss of function. STAT1 expression was increased both in human postmortem brain tissue and in an Spg11-/- mouse model. Application of an STAT1 inhibitor decreased CXCL10 production in SPG11 iMGL and rescued their toxic effect on SPG11 neurons. Our data establish neuroinflammation as a novel disease mechanism in SPG11-HSP patients and constitute the first description of myeloid cell/ microglia activation in human SPG11-HSP. IFNγ/ STAT1-mediated neurotoxic effects of hyperreactive microglia upon SPG11 loss of function indicate that immunomodulation strategies may slow down disease progression.

Improvements in Plaque Psoriasis Associated with Calcipotriol/Betamethasone Aerosol Foam Treatment: A Post Hoc Analysis of Non-interventional Studies and Clinical Experience.

INTRODUCTION: Plaque psoriasis is a chronic relapsing inflammatory skin disease that is associated with extensive disease burden that often requires long-term therapy. Treatment of psoriasis with 4 weeks of the aerosol foam formulation of calcipotriol/betamethasone dipropionate (Cal/BD; Enstilar®, LEO Pharma) has been demonstrated to be effective, well tolerated, and associated with high patient satisfaction. Cal/BD foam is approved as a first-line treatment in multiple countries, where several non-interventional studies (NIS) have corroborated the beneficial efficacy and safety profiles determined in the randomized clinical trials. Heterogenicity in these NIS, however, prevents the use of a data pooling strategy for comparisons of effectiveness outcomes across different patient populations. METHODS: Therefore, here, we report on a post hoc analysis of effectiveness data consolidated from six prospective NIS to discern any differences in improvement in signs and symptoms of psoriasis attributable to Cal/BD foam treatment across the countries. In addition, we provide real-world experience of clinicians with Cal/BD foam treatment, factoring in changes in usage since these NIS were performed in their local markets. RESULTS: This post hoc analysis of Cal/BD foam NIS brings together data outside of randomized clinical trials from six countries to provide real-world evidence in 1388 patients showing that 4 weeks of Cal/BD foam is an effective and safe treatment option with quick onset of action for patients with psoriasis. CONCLUSION: These results show that regardless of NIS location, Cal/BD foam remains a well-tolerated, efficacious option for patient care that could be used as a first-line topical therapy for mild-to-severe psoriasis.

E3 ubiquitin ligase Herc3 deficiency leads to accumulation of subretinal microglia and retinal neurodegeneration.

Activated microglia have been implicated in the pathogenesis of age-related macular degeneration (AMD), diabetic retinopathy, and other neurodegenerative and neuroinflammatory disorders, but our understanding of the mechanisms behind their activation is in infant stages. With the goal of identifying novel genes associated with microglial activation in the retina, we applied a semiquantitative fundus spot scoring scale to an unbiased, state-of-the-science mouse forward genetics pipeline. A mutation in the gene encoding the E3 ubiquitin ligase Herc3 led to prominent accumulation of fundus spots. CRISPR mutagenesis was used to generate Herc3-/- mice, which developed prominent accumulation of fundus spots and corresponding activated Iba1 + /CD16 + subretinal microglia, retinal thinning on OCT and histology, and functional deficits by Optomotory and electrophysiology. Bulk RNA sequencing identified activation of inflammatory pathways and differentially expressed genes involved in the modulation of microglial activation. Thus, despite the known expression of multiple E3 ubiquitin ligases in the retina, we identified a non-redundant role for Herc3 in retinal homeostasis. Our findings are significant given that a dysregulated ubiquitin-proteasome system (UPS) is important in prevalent retinal diseases, in which activated microglia appear to play a role. This association between Herc3 deficiency, retinal microglial activation and retinal degeneration merits further study.

Comparing the multivariate relationships of conceptual adversity models and structural brain development in adolescent girls: A registered report.

Adverse experiences throughout development confer risk for a multitude of negative long-term outcomes, but the processes via which these experiences are neurobiologically embedded are still unclear. Adolescence provides an opportunity to understand how these experiences impact the brain's rapidly changing structure. Two models are central to current adversity conceptualizations: a cumulative risk model, where all types of experiences are combined to represent accumulating stress, and a dimensional model, where certain features of experience (e.g., threat or deprivation) exert unique neurophysiological influence. In this registered report, we extended upon previous research by using a form of representational similarity analysis to examine whether the dimensional and cumulative risk models of adversity predict cortical thinning in frontoparietal and frontotemporal networks and volumetric changes in subcortical regions throughout adolescence. Drawing from a longitudinal sample of 179 adolescent girls (ages 10-13 years at the first wave) from Lane County, Oregon, United States, and up to four waves of follow-up data, we found that operationalizing adversity by similarity in threat and deprivation provided better prediction of brain development than similarity in overall adversity. However, these dimensions do not exhibit unique associations with developmental changes in the hypothesized brain changes. These results underscore the significance of carefully defining adversity and considering its impact on the entire brain. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Essential role of MFSD1-GLMP-GIMAP5 in lymphocyte survival and liver homeostasis.

We detected ENU-induced alleles of Mfsd1 (encoding the major facilitator superfamily domain containing 1 protein) that caused lymphopenia, splenomegaly, progressive liver pathology, and extramedullary hematopoiesis (EMH). MFSD1 is a lysosomal membrane-bound solute carrier protein with no previously described function in immunity. By proteomic analysis, we identified association between MFSD1 and both GLMP (glycosylated lysosomal membrane protein) and GIMAP5 (GTPase of immunity-associated protein 5). Germline knockout alleles of Mfsd1, Glmp, and Gimap5 each caused lymphopenia, liver pathology, EMH, and lipid deposition in the bone marrow and liver. We found that the interactions of MFSD1 and GLMP with GIMAP5 are essential to maintain normal GIMAP5 expression, which in turn is critical to support lymphocyte development and liver homeostasis that suppresses EMH. These findings identify the protein complex MFSD1-GLMP-GIMAP5 operating in hematopoietic and extrahematopoietic tissues to regulate immunity and liver homeostasis.

Development and validation of risk of CPS decline (RCD): a new prediction tool for worsening cognitive performance among home care clients in Canada.

BACKGROUND: To develop and validate a prediction tool, or nomogram, for the risk of a decline in cognitive performance based on the interRAI Cognitive Performance Scale (CPS). METHODS: Retrospective, population-based, cohort study using Canadian Resident Assessment Instrument for Home Care (RAI-HC) data, collected between 2010 and 2018. Eligible home care clients, aged 18+, with at least two assessments were selected randomly for model derivation (75%) and validation (25%). All clients had a CPS score of zero (intact) or one (borderline intact) on intake into the home care program, out of a possible score of six. All individuals had to remain as home care recipients for the six months observation window in order to be included in the analysis. The primary outcome was any degree of worsening (i.e., increase) on the CPS score within six months. Using the derivation cohort, we developed a multivariable logistic regression model to predict the risk of a deterioration in the CPS score. Model performance was assessed on the validation cohort using discrimination and calibration plots. RESULTS: We identified 39,292 eligible home care clients, with a median age of 79.0 years, 62.3% were female, 38.8% were married and 38.6% lived alone. On average, 30.3% experienced a worsening on the CPS score within the six-month window (i.e., a change from 0 or 1 to 2, 3, 4, 5, or 6). The final model had good discrimination (c-statistic of 0.65), with excellent calibration. CONCLUSIONS: The model accurately predicted the risk of deterioration on the CPS score over six months among home care clients. This type of predictive model may provide useful information to support decisions for home care clinicians who use interRAI data internationally.

Essential requirement for IER3IP1 in B cell development.

In a forward genetic screen of mice with N-ethyl-N-nitrosourea-induced mutations for aberrant immune function, we identified animals with low percentages of B220+ cells in the peripheral blood. The causative mutation was in Ier3ip1, encoding immediate early response 3 interacting protein 1 (IER3IP1), an endoplasmic reticulum membrane protein mutated in an autosomal recessive neurodevelopmental disorder termed Microcephaly with simplified gyration, Epilepsy and permanent neonatal Diabetes Syndrome (MEDS) in humans. However, no immune function for IER3IP1 had previously been reported. The viable hypomorphic Ier3ip1 allele uncovered in this study, identical to a reported IER3IP1 variant in a MEDS patient, reveals an essential hematopoietic-intrinsic role for IER3IP1 in B cell development and function. We show that IER3IP1 forms a complex with the Golgi transmembrane protein 167A and limits activation of the unfolded protein response mediated by inositol-requiring enzyme-1α and X-box binding protein 1 in B cells. Our findings suggest that B cell deficiency may be a feature of MEDS.

OVOL2 sustains postnatal thymic epithelial cell identity.

Distinct pathways and molecules may support embryonic versus postnatal thymic epithelial cell (TEC) development and maintenance. Here, we identify a mechanism by which TEC numbers and function are maintained postnatally. A viable missense allele (C120Y) of Ovol2, expressed ubiquitously or specifically in TECs, results in lymphopenia, in which T cell development is compromised by loss of medullary TECs and dysfunction of cortical TECs. We show that the epithelial identity of TECs is aberrantly subverted towards a mesenchymal state in OVOL2-deficient mice. We demonstrate that OVOL2 inhibits the epigenetic regulatory BRAF-HDAC complex, specifically disrupting RCOR1-LSD1 interaction. This causes inhibition of LSD1-mediated H3K4me2 demethylation, resulting in chromatin accessibility and transcriptional activation of epithelial genes. Thus, OVOL2 controls the epigenetic landscape of TECs to enforce TEC identity. The identification of a non-redundant postnatal mechanism for TEC maintenance offers an entry point to understanding thymic involution, which normally begins in early adulthood.

The dual lipid desaturase/hydroxylase DEGS2 controls phytoceramide levels necessary to counter intestinal inflammation.

Intestinal immunity is dependent on barrier function to maintain quiescence. The mechanisms for the maintenance of this barrier are not fully understood. Delta 4-desaturase, sphingolipid 2 (DEGS2) is a lipid desaturase and hydroxylase that catalyzes the synthesis of ceramide and phytoceramide from dihydroceramide. Using a forward genetic approach, we found and validated a mutation in Degs2 as causative of increasing susceptibility to colitis and altering the phytoceramide balance in the colon. DEGS2 is expressed in the intestinal epithelium, and the colitis phenotype is dependent on the non-hematopoietic compartment of the mouse. In the absence of DEGS2, the colon lacks phytoceramides and accumulates large amounts of the precursor lipid dihydroceramide. In response to dextran sodium sulfate (DSS)-induced colitis, colonic epithelial cells in DEGS2-deficient mice had increased cell death and decreased proliferation compared to those in wild-type mice. These findings demonstrate that DEGS2 is needed to maintain epithelial integrity, protect against DSS-induced colitis and maintain lipid balance in vivo.