Microglia Require CD4 T Cells to Complete the Fetal-to-Adult Transition.

The brain is a site of relative immune privilege. Although CD4 T cells have been reported in the central nervous system, their presence in the healthy brain remains controversial, and their function remains largely unknown. We used a combination of imaging, single cell, and surgical approaches to identify a CD69+ CD4 T cell population in both the mouse and human brain, distinct from circulating CD4 T cells. The brain-resident population was derived through in situ differentiation from activated circulatory cells and was shaped by self-antigen and the peripheral microbiome. Single-cell sequencing revealed that in the absence of murine CD4 T cells, resident microglia remained suspended between the fetal and adult states. This maturation defect resulted in excess immature neuronal synapses and behavioral abnormalities. These results illuminate a role for CD4 T cells in brain development and a potential interconnected dynamic between the evolution of the immunological and neurological systems. VIDEO ABSTRACT.

Astrocyte-targeted gene delivery of interleukin 2 specifically increases brain-resident regulatory T cell numbers and protects against pathological neuroinflammation.

The ability of immune-modulating biologics to prevent and reverse pathology has transformed recent clinical practice. Full utility in the neuroinflammation space, however, requires identification of both effective targets for local immune modulation and a delivery system capable of crossing the blood-brain barrier. The recent identification and characterization of a small population of regulatory T (Treg) cells resident in the brain presents one such potential therapeutic target. Here, we identified brain interleukin 2 (IL-2) levels as a limiting factor for brain-resident Treg cells. We developed a gene-delivery approach for astrocytes, with a small-molecule on-switch to allow temporal control, and enhanced production in reactive astrocytes to spatially direct delivery to inflammatory sites. Mice with brain-specific IL-2 delivery were protected in traumatic brain injury, stroke and multiple sclerosis models, without impacting the peripheral immune system. These results validate brain-specific IL-2 gene delivery as effective protection against neuroinflammation, and provide a versatile platform for delivery of diverse biologics to neuroinflammatory patients.

An immunological puzzle: The adaptive immune system fuels Alzheimer's disease pathology.

Alzheimer's disease (AD) is a devastating neurodegenerative disorder characterized by a concerning rise in prevalence. It is projected that the number of affected individuals will reach a staggering 150 million by 2050. While recent advancements in monoclonal antibodies targeting Aß have shown some clinical effects, there is an urgent need for improved therapies to effectively address the impeding surge of AD patients worldwide. To achieve this, a deeper understanding of the intricate mechanisms underlying the disease is crucial. In recent years, mounting evidence has underscored the vital role of the innate immune system in AD pathology. However, limited findings persist regarding the involvement of the adaptive immune system. Here, we report on the impact of the adaptive immune system on various aspects of AD by using AppNL-G-F mice crossed into a Rag2-/- background lacking mature adaptive immune cells. In addition, to simulate the continuous exposure to various challenges such as infections that is commonly observed in humans, the innate immune system was activated through the repetitive induction of peripheral inflammation. We observed a remarkably improved performance on complex cognitive tasks when a mature adaptive immune system is absent. Notably, this observation is pathologically associated with lower Aß plaque accumulation, reduced glial activation, and better-preserved neuronal networks in the mice lacking a mature adaptive immune system. Collectively, these findings highlight the detrimental role of the adaptive immune system in AD and underscore the need for effective strategies to modulate it for therapeutic purposes.

Prenatal Radiation Exposure Leads to Higher-Order Telencephalic Dysfunctions in Adult Mice That Coincide with Reduced Synaptic Plasticity and Cerebral Hypersynchrony.

Higher-order telencephalic circuitry has been suggested to be especially vulnerable to irradiation or other developmentally toxic impact. This report details the adult effects of prenatal irradiation at a sensitive time point on clinically relevant brain functions controlled by telencephalic regions, hippocampus (HPC), and prefrontal cortex (PFC). Pregnant C57Bl6/J mice were whole-body irradiated at embryonic day 11 (start of neurogenesis) with X-ray intensities of 0.0, 0.5, or 1.0 Gy. Female offspring completed a broad test battery of HPC-/PFC-controlled tasks that included cognitive performance, fear extinction, exploratory, and depression-like behaviors. We examined neural functions that are mechanistically related to these behavioral and cognitive changes, such as hippocampal field potentials and long-term potentiation, functional brain connectivity (by resting-state functional magnetic resonance imaging), and expression of HPC vesicular neurotransmitter transporters (by immunohistochemical quantification). Prenatally exposed mice displayed several higher-order dysfunctions, such as decreased nychthemeral activity, working memory defects, delayed extinction of threat-evoked response suppression as well as indications of perseverative behavior. Electrophysiological examination indicated impaired hippocampal synaptic plasticity. Prenatal irradiation also induced cerebral hypersynchrony and increased the number of glutamatergic HPC terminals. These changes in brain connectivity and plasticity could mechanistically underlie the irradiation-induced defects in higher telencephalic functions.

Natural disease course of Crohn's disease during the first 5 years after diagnosis in a European population-based inception cohort: an Epi-IBD study.

OBJECTIVE: The Epi-IBD cohort is a prospective population-based inception cohort of unselected patients with inflammatory bowel disease from 29 European centres covering a background population of almost 10 million people. The aim of this study was to assess the 5-year outcome and disease course of patients with Crohn's disease (CD). DESIGN: Patients were followed up prospectively from the time of diagnosis, including collection of their clinical data, demographics, disease activity, medical therapy, surgery, cancers and deaths. Associations between outcomes and multiple covariates were analysed by Cox regression analysis. RESULTS: In total, 488 patients were included in the study. During follow-up, 107 (22%) patients received surgery, while 176 (36%) patients were hospitalised because of CD. A total of 49 (14%) patients diagnosed with non-stricturing, non-penetrating disease progressed to either stricturing and/or penetrating disease. These rates did not differ between patients from Western and Eastern Europe. However, significant geographic differences were noted regarding treatment: more patients in Western Europe received biological therapy (33%) and immunomodulators (66%) than did those in Eastern Europe (14% and 54%, respectively, P<0.01), while more Eastern European patients received 5-aminosalicylates (90% vs 56%, P<0.05). Treatment with immunomodulators reduced the risk of surgery (HR: 0.4, 95% CI 0.2 to 0.6) and hospitalisation (HR: 0.3, 95% CI 0.2 to 0.5). CONCLUSION: Despite patients being treated early and frequently with immunomodulators and biological therapy in Western Europe, 5-year outcomes including surgery and phenotype progression in this cohort were comparable across Western and Eastern Europe. Differences in treatment strategies between Western and Eastern European centres did not affect the disease course. Treatment with immunomodulators reduced the risk of surgery and hospitalisation.

Sex-Based Differences in Incidence of Inflammatory Bowel Diseases-Pooled Analysis of Population-Based Studies From Western Countries.

BACKGROUND & AIMS: Although the incidence of inflammatory bowel diseases (IBDs) varies with age, few studies have examined variations between the sexes. We therefore used population data from established cohorts to analyze sex differences in IBD incidence according to age at diagnosis. METHODS: We identified population-based cohorts of patients with IBD for which incidence and age data were available (17 distinct cohorts from 16 regions of Europe, North America, Australia, and New Zealand). We collected data through December 2016 on 95,605 incident cases of Crohn's disease (CD) (42,831 male and 52,774 female) and 112,004 incident cases of ulcerative colitis (UC) (61,672 male and 50,332 female). We pooled incidence rate ratios of CD and UC for the combined cohort and compared differences according to sex using random effects meta-analysis. RESULTS: Female patients had a lower risk of CD during childhood, until the age range of 10-14 years (incidence rate ratio, 0.70; 95% CI, 0.53-0.93), but they had a higher risk of CD thereafter, which was statistically significant for the age groups of 25-29 years and older than 35 years. The incidence of UC did not differ significantly for female vs male patients (except for the age group of 5-9 years) until age 45 years; thereafter, men had a significantly higher incidence of ulcerative colitis than women. CONCLUSIONS: In a pooled analysis of population-based studies, we found age at IBD onset to vary with sex. Further studies are needed to investigate mechanisms of sex differences in IBD incidence.

Disease course of inflammatory bowel disease unclassified in a European population-based inception cohort: An Epi-IBD study.

BACKGROUND AND AIM: A definitive diagnosis of Crohn's disease (CD) or ulcerative colitis (UC) is not always possible, and a proportion of patients will be diagnosed as inflammatory bowel disease unclassified (IBDU). The aim of the study was to investigate the prognosis of patients initially diagnosed with IBDU and the disease course during the following 5 years. METHODS: The Epi-IBD study is a prospective population-based cohort of 1289 IBD patients diagnosed in centers across Europe. Clinical data were captured prospectively throughout the follow-up period. RESULTS: Overall, 476 (37%) patients were initially diagnosed with CD, 701 (54%) with UC, and 112 (9%) with IBDU. During follow-up, 28 (25%) IBDU patients were changed diagnoses to either UC (n = 20, 71%) or CD (n = 8, 29%) after a median of 6 months (interquartile range: 4-12), while 84 (7% of the total cohort) remained IBDU. A total of 17 (15%) IBDU patients were hospitalized for their IBD during follow-up, while 8 (7%) patients underwent surgery. Most surgeries (n = 6, 75%) were performed on patients whose diagnosis was later changed to UC; three of these colectomies led to a definitive diagnosis of UC. Most patients (n = 107, 96%) received 5-aminosalicylic acid, while 11 (10%) patients received biologicals, of whom five remained classified as IBDU. CONCLUSIONS: In a population-based inception cohort, 7% of IBD patients were not given a definitive diagnosis of IBD after 5 years of follow-up. One in four patients with IBDU eventually was classified as CD or UC. Overall, the disease course and medication burden in IBDU patients were mild.

High fat diet treatment impairs hippocampal long-term potentiation without alterations of the core neuropathological features of Alzheimer disease.

Type 2 diabetes (T2DM) and obesity might increase the risk for AD by 2-fold. Different attempts to model the effect of diet-induced diabetes on AD pathology in transgenic animal models, resulted in opposite conclusions. Here, we used a novel knock-in mouse model for AD, which, differently from other models, does not overexpress any proteins. Long-term high fat diet treatment triggers a reduction in hippocampal N-acetyl-aspartate/myo-inositol metabolites ratio and impairs long term potentiation in hippocampal acute slices. Interestingly, these alterations do not correlate with changes in the core neuropathological features of AD, i.e. amyloidosis and Tau hyperphosphorylation. The data suggest that AD phenotypes associated with high fat diet treatment seen in other models for AD might be exacerbated because of the overexpressing systems used to study the effects of familial AD mutations. Our work supports the increasing insight that knock-in mice might be more relevant models to study the link between metabolic disorders and AD.

Therapeutic preferences and outcomes in newly diagnosed patients with Crohn's diseases in the biological era in Hungary: a nationwide study based on the National Health Insurance Fund database.

BACKGROUND: Accelerated treatment strategy, including tight disease control and early aggressive therapy with immunosuppressives (IS) and biological agents have become increasingly common in inflammatory bowel disease (IBD). The aim of the present study was to estimate the early treatment strategy and outcomes in newly diagnosed patients with Crohn's disease (CD) between 2004 and 2008 and 2009-2015 in the whole IBD population in Hungary based on the administrative database of the National Health Insurance Fund (OEP). METHODS: We used the administrative database of the OEP, the only nationwide state-owned health insurance provider in Hungary. Patients were identified through previously reported algorithms using the ICD-10 codes for CD in the out-, inpatient (medical, surgical) non-primary care records and drug prescription databases between 2004 and 2015. Patients were stratified according to the year of diagnosis and maximum treatment steps during the first 3 years after diagnosis. RESULTS: A total of 6173 (male/female: 46.12%/53.87%) newly diagnosed CD patients with physician-diagnosed IBD were found in the period of 2004-2015. The use of 5-ASA and steroids remained common in the biological era, while immunosuppressives and biologicals were started earlier and became more frequent among patients diagnosed after 2009. The probability of biological therapy was 2.9%/6.4% and 8.4%/13.7% after 1 and 3 years in patients diagnosed in 2004-2008/2009-2015. The probability of hospitalization in the first 3 years after diagnosis was different before and after 2009, according to the maximal treatment step (overall 55.7%vs. 47.4% (p = 0.001), anti-TNF: 73%vs. 66.7% (p = 0.103), IS: 64.6% vs. 56.1% (p = 0.001), steroid: 44.2%vs. 36.8% (p < 0.007), 5-ASA: 32.6% vs. 26.7% p = 0.157)). In contrast, surgery rates were not significantly different in patients diagnosed before and after 2009 according to the maximum treatment step (overall 16.0%vs.15.3%(p = 0.672) anti-TNF 26.7%vs.27.2% (p = 0.993), IS: 24.1%vs22.2% (p = 0.565), steroid 8.1%vs.7.9% (p = 0.896), 5-ASA 10%vs. 11% (p = 0.816)). CONCLUSIONS: IS and biological exposure became more frequent, while hospitalization decreased and surgery remained low but constant during the observation period. Use of steroids and 5-ASA remained high after 2009. The association between the maximal treatment step and hospitalization/surgery rates suggests that maximal treatment step can be regarded as proxy severity marker in patients with IBD.

Drug persistence and need for dose intensification to adalimumab therapy; the importance of therapeutic drug monitoring in inflammatory bowel diseases.

BACKGROUND: Therapeutic drug monitoring (TDM) aid therapeutic decision making in patients with inflammatory bowel disease (IBD) who lose response to anti-TNF therapy. Our aim was to evaluate the frequency and predictive factors of loss of response (LOR) to adalimumab using TDM in IBD patients. METHODS: One hundred twelve IBD patients (with 214 TDM measurements, CD/UC 84/28, male/female 50/62, mean age CD/UC: 36/35 years) were enrolled in this consecutive cohort from two referral centres in Hungary. Demographic data were comprehensively collected and harmonized monitoring strategy was applied. Previous and current therapy, laboratory data and clinical activity were recorded at the time of TDM. Patients were evaluated either at the time of suspected LOR or during follow-up. TDM measurements were determined by commercial ELISA (LISA TRACKER, Theradiag, France). RESULTS: Among 112 IBD patients, LOR/drug persistence was 25.9%/74.1%. The cumulative ADA positivity (>10 ng/mL) and low TL (<5.0 µg/mL) was 12.1% and 17.8% after 1 year and 17.3% and 29.5% after 2 years of adalimumab therapy. Dose intensification was needed in 29.5% of the patients. Female gender and ADA positivity were associated with LOR (female gender: p < 0.001, OR:7.8 CI 95%: 2.5-24.3, ADA positivity: p = 0.007 OR:3.6 CI 95%: 1.4-9.5). CONCLUSIONS: ADA development, low TL and need for dose intensification were frequent during adalimumab therapy and support the selective use of TDM in IBD patients treated with adalimumab. ADA positivity and gender were predictors of LOR.

Real-Life Efficacy, Immunogenicity and Safety of Biosimilar Infliximab.

Recently, the use of biosimilar infliximab (IFX) in the treatment of inflammatory bowel diseases has become widespread in some European and non-European countries. Data on the efficacy, safety and immunogenicity from real-life cohorts are accumulating. The first reports showed similar outcomes in the induction and maintenance of remission, mucosal healing, safety and immunogenicity profile to the originator IFX. In the present review, we aimed to summarize the existing knowledge on the efficacy, safety and immunogenicity profile of biosimilar IFX reported from real-life cohorts.

Association of extraintestinal manifestations and anaemia with disease outcomes in patients with inflammatory bowel disease.

OBJECTIVE: The association between extraintestinal manifestations (EIMs) and disease activity suggest a common pathogenetic link with inflammatory bowel disease (IBD). We report on the association of EIMs and anaemia with long-term disease outcomes, including treatment steps, hospitalization, and surgery in the prospective population-based IBD inception cohort from Veszprem province. METHODS: Data of 678 incident IBD patients (Crohn's disease/ulcerative colitis(CD/UC): 331/347) diagnosed from 1st January 2000 to 31st December 2012 were analyzed (CD: m/f: 176/155, median age at diagnosis: 28, IQR: 21-40 years, disease duration: 6, IQR: 2-9 years; UC: m/f: 200/147, median age at diagnosis: 36, IQR: 26-50 years, duration: 7, IQR: 4-10 years). RESULTS: EIMs were present in 30% of the CD and 17.3% of the UC patients. In CD, female gender (p = 0.02) need for steroid (p  < 0.001) and azathioprine (AZA) (p = 0.02), while in UC, young age at onset (p = 0.03), extensive disease (p = 0.003), female gender (p = 0.07), need for steroids (p < 0.001) and AZA (p = 0.004) and need for IBD-related hospitalization (p = 0.01) were associated with the presence of EIMs. Anaemia was present in 56.7% of the CD and 30.2% of the UC patients. In both CD and UC anaemia was associated with age at onset (pCD = 0.001, pUC = 0.04), disease location/extent (pCD = 0.02, pUC < 0.001), steroid and AZA use (for both pCD,UC < 0.001), need for surgery/colectomy (pCD < 0.001, pUC = 0.002) and hospitalization (pCD = 0.004, pUC < 0.001) and in CD, it was associated with anti TNF therapy(p = 0.002). CONCLUSIONS: The presence of EIMs was associated with disease phenotype in UC and with treatment strategy in both CD and UC. Additionally, anaemia was associated with hospitalization and surgery in both CD and UC, suggesting that EIMs and anaemia may be helpful in stratifying disease severity in IBD.

'Treat to Target' - Lessons Learnt.

BACKGROUND: Therapeutic management in inflammatory bowel diseases (IBD) has significantly changed in the last decades with the advent of biological therapy resulting in new treatment targets other than clinical symptoms. KEY MESSAGES: Patient stratification in the early stage of the disease is an important step to identify patients with poor prognosis, who might benefit from early aggressive treatment to avoid complications in the later disease course. Recent randomized and hypothesis driven (e.g., Randomized Evaluation of an Algorithm for Crohn's Treatment, Post-Operative Crohn's Endoscopic Recurrence) clinical trials conducted in the biological era underscore the need of objective disease monitoring including assessment of biomarkers (e.g., C-reactive protein and calprotectin), mucosal healing and, for biologically treated patients, therapeutic drug monitoring beside clinical symptom assessment in both Crohn's disease and ulcerative colitis. CONCLUSIONS: Assessing the treatment efficacy objectively has become an important element of patient monitoring besides clinical symptom assessment. Further clinical studies are needed to assess whether implementation of new therapeutic algorithms based on these targets and tight monitoring in clinical practice have the potential to further improve long-term disease outcomes in IBD.

[Indications, diagnoses and quality markers in upper and lower endoscopies in 2010 and 2011 at the 1st Department of Medicine, Semmelweis University, Budapest]. / A felso és alsó endoszkópiák indikációja, a diagnózisok megoszlása és minoségi mutatók 2010­2011-ben a Semmelweis Egyetem I. Belgyógyászati Klinikáján.

INTRODUCTION AND AIM: The aim was to assess the incidence of endoscopic findings based on the indication of the procedures in upper/lower endoscopies, and measuring quality indicators of colonoscopies at the 1st Department of Medicine, Semmelweis University, Budapest. METHOD: Data of 2987 patients (male/female:1361/1626, mean age: 60.7 years(y), SD: 16.7y) between 01.01.2010 and 31.12.2011 were analyzed. Both inpatient and outpatient records were collected. RESULTS: Incidence of peptic ulcer disease, esophageal varices, gastric polyps and gastric cancer were 10.8%, 4.5%, 6.1%, 2.9% in upper endoscopies, respectively. In colonoscopies colorectal polyps, diverticulosis, colorectal cancer and IBD were found in 29.9%, 22.4%, 6.9%, 9.7%, respectively. In patients having upper endoscopy with GI bleeding indication, older age (p<0.001), male gender (p<0.001, OR: 1.64), acenocoumarol/heparin use (p<0,001, peptic ulcers and esophageal varices were more frequent (p<0.001, OR: 2.83 and p<0.001, OR: 2.79), while in colonoscopies colorectal cancer had higher incidence (p<0.001, OR:3.27). 81% of colonoscopies were complete. Causes of incomplete procedures were ineffective bowel preparation (38.2%), technical difficulties (25.1%) and strictures (20.5%). CONCLUSION: The endoscopic findings and quality indicators (adenoma detection rate, coecal intubation rate) were in line with that reported in published series. Orv. Hetil., 2016, 157(52), 2074-2081.

Deficiency of the miR-29a/b-1 cluster leads to ataxic features and cerebellar alterations in mice.

miR-29 is expressed strongly in the brain and alterations in expression have been linked to several neurological disorders. To further explore the function of this miRNA in the brain, we generated miR-29a/b-1 knockout animals. Knockout mice develop a progressive disorder characterized by locomotor impairment and ataxia. The different members of the miR-29 family are strongly expressed in neurons of the olfactory bulb, the hippocampus and in the Purkinje cells of the cerebellum. Morphological analysis showed that Purkinje cells are smaller and display less dendritic arborisation compared to their wildtype littermates. In addition, a decreased number of parallel fibers form synapses on the Purkinje cells. We identified several mRNAs significantly up-regulated in the absence of the miR-29a/b-1 cluster. At the protein level, however, the voltage-gated potassium channel Kcnc3 (Kv3.3) was significantly up-regulated in the cerebella of the miR-29a/b knockout mice. Dysregulation of KCNC3 expression may contribute to the ataxic phenotype.

Functional Dissociation of Group III Metabotropic Glutamate Receptors Revealed by Direct Comparison between the Behavioral Profiles of Knockout Mouse Lines.

BACKGROUND: Group III metabotropic glutamate receptors (mGlu4, mGlu7, mGlu8) display differential brain distribution, which suggests different behavioral functions. However, comparison across the available animal studies remains methodologically hazardous and controversial. The present report directly compares knockouts for each group III receptor subtype using a single behavioral test battery and multivariate analysis. METHODS: The behavioral phenotypes of C57BL/6J mice lacking mGlu4, mGlu7, or mGlu8 and their respective littermates were examined using a multimetric test battery, which included elements of neuromotor performance, exploratory behavior, and learning and memory. Multivariate statistical methods were used to identify subtype-specific behavioral profiles and variables that distinguished between these mouse lines. RESULTS: It generally appears that mGlu7 plays a significant role in hippocampus-dependent spatial learning and in some fear-related behaviors, whereas mGlu4 is most clearly involved in startle and motivational processes. Excepting its influence on body weight, the effect of mGlu8 deletion on behavior appears more subtle than that of the other group III receptors. These receptors have been proposed as potential drug targets for a variety of psychopathological conditions. CONCLUSION: On the basis of these controlled comparisons, we presently conclude that the different group III receptors indeed have quite distinct behavioral functions.

Low incidence of venous thromboembolism in inflammatory bowel diseases: prevalence and predictors from a population-based inception cohort.

OBJECTIVE: Patients with inflammatory bowel diseases (IBD) are considered to have an increased risk for venous thromboembolism (VTE). The aim of the present study was to analyze the incidence and risk factors of VTE in a population-based inception cohort in the Veszprem province database between 1977 and 2012. MATERIAL AND METHODS: A total of 1708 incepted IBD patients were included (male/female: 879/829; CD (Crohn's disease): 648, age at onset: 29, interquartile range (IQR): 22-39; UC (ulcerative colitis): 1060, age at onset: 36, IQR: 26-50 years). Both in- and outpatient records were collected and comprehensively reviewed and followed up for a total of 21,369 patient-years. RESULTS: Twenty-two VTE events were identified in 19 patients (6 events in 5 CD and 16 in 14 UC patients). The incidence rate of VTE in IBD was 1.03 per 1000 patient-years. The risk of VTE in UC was associated with extensive location (odds ratio (OR): 3.25, 95% confidence interval (CI): 1.13-9.35), presence of fulminant episode during the disease course (OR: 4.15, 95% CI: 1.28-13.5), smoking (OR: 3.46, 95% CI: 1.14-10.5), and need for steroids (OR: 2.97, 95% CI: 0.99-8.92). CONCLUSION: The incidence of VTE was lower than previously reported. The incidence was higher in males and in UC it was associated with extensive disease, fulminant episodes, corticosteroids-requiring disease and smoking, but not with age at onset.

The Drosophila L1CAM homolog Neuroglian signals through distinct pathways to control different aspects of mushroom body axon development.

The spatiotemporal integration of adhesion and signaling during neuritogenesis is an important prerequisite for the establishment of neuronal networks in the developing brain. In this study, we describe the role of the L1-type CAM Neuroglian protein (NRG) in different steps of Drosophila mushroom body (MB) neuron axonogenesis. Selective axon bundling in the peduncle requires both the extracellular and the intracellular domain of NRG. We uncover a novel role for the ZO-1 homolog Polychaetoid (PYD) in axon branching and in sister branch outgrowth and guidance downstream of the neuron-specific isoform NRG-180. Furthermore, genetic analyses show that the role of NRG in different aspects of MB axonal development not only involves PYD, but also TRIO, SEMA-1A and RAC1.

Pleiotropic effects of trisomy and pharmacologic modulation on structural, functional, molecular, and genetic systems in a Down syndrome mouse model.

Down syndrome (DS) is characterized by skeletal and brain structural malformations, cognitive impairment, altered hippocampal metabolite concentration and gene expression imbalance. These alterations were usually investigated separately, and the potential rescuing effects of green tea extracts enriched in epigallocatechin-3-gallate (GTE-EGCG) provided disparate results due to different experimental conditions. We overcame these limitations by conducting the first longitudinal controlled experiment evaluating genotype and GTE-EGCG prenatal chronic treatment effects before and after treatment discontinuation. Our findings revealed that the Ts65Dn mouse model reflected the pleiotropic nature of DS, exhibiting brachycephalic skull, ventriculomegaly, neurodevelopmental delay, hyperactivity, and impaired memory robustness with altered hippocampal metabolite concentration and gene expression. GTE-EGCG treatment modulated most systems simultaneously but did not rescue DS phenotypes. On the contrary, the treatment exacerbated trisomic phenotypes including body weight, tibia microarchitecture, neurodevelopment, adult cognition, and metabolite concentration, not supporting the therapeutic use of GTE-EGCG as a prenatal chronic treatment. Our results highlight the importance of longitudinal experiments assessing the co-modulation of multiple systems throughout development when characterizing preclinical models in complex disorders and evaluating the pleiotropic effects and general safety of pharmacological treatments.

Tauroursodeoxycholic acid (TUDCA) supplementation prevents cognitive impairment and amyloid deposition in APP/PS1 mice.

Alzheimer's disease (AD) is a neurodegenerative disease hallmarked by extracellular Aß(1-42) containing plaques, and intracellular neurofibrillary tangles (NFT) containing hyperphosphorylated tau protein. Progressively, memory deficits and cognitive disabilities start to occur as these hallmarks affect hippocampus and frontal cortex, regions highly involved in memory. Connective tissue growth factor (CTGF) expression, which is high in the vicinity of Aß plaques and NFTs, was found to influence γ-secretase activity, the molecular crux in Aß(1-42) production. Tauroursodeoxycholic acid (TUDCA) is an endogenous bile acid that downregulates CTGF expression in hepatocytes and has been shown to possess therapeutic efficacy in neurodegenerative models. To investigate the possible in vivo therapeutic effects of TUDCA, we provided 0.4% TUDCA-supplemented food to APP/PS1 mice, a well-established AD mouse model. Six months of TUDCA supplementation prevented the spatial, recognition and contextual memory defects observed in APP/PS1 mice at 8 months of age. Furthermore, TUDCA-supplemented APP/PS1 mice displayed reduced hippocampal and prefrontal amyloid deposition. These effects of TUDCA supplementation suggest a novel mechanistic route for Alzheimer therapeutics.