Integrating TSPO PET imaging and transcriptomics to unveil the role of neuroinflammation and amyloid-ß deposition in Alzheimer's disease.

PURPOSE: Despite the revealed role of immunological dysfunctions in the development and progression of Alzheimer's disease (AD) through animal and postmortem investigations, direct evidence regarding the impact of genetic factors on microglia response and amyloid-ß (Aß) deposition in AD individuals is lacking. This study aims to elucidate this mechanism by integrating transcriptomics and TSPO, Aß PET imaging in clinical AD cohort. METHODS: We analyzed 85 patients with PET/MR imaging for microglial activation (TSPO, [18F]DPA-714) and Aß ([18F]AV-45) within the prospective Alzheimer's Disease Immunization and Microbiota Initiative Study Cohort (ADIMIC). Immune-related differentially expressed genes (IREDGs), identified based on AlzData, were screened and verified using blood samples from ADIMIC. Correlation and mediation analyses were applied to investigate the relationships between immune-related genes expression, TSPO and Aß PET imaging. RESULTS: TSPO uptake increased significantly both in aMCI (P < 0.05) and AD participants (P < 0.01) and showed a positive correlation with Aß deposition (r = 0.42, P < 0.001). Decreased expression of TGFBR3, FABP3, CXCR4 and CD200 was observed in AD group. CD200 expression was significantly negatively associated with TSPO PET uptake (r =-0.33, P = 0.013). Mediation analysis indicated that CD200 acted as a significant mediator between TSPO uptake and Aß deposition (total effect B = 1.92, P = 0.004) and MMSE score (total effect B =-54.01, P = 0.003). CONCLUSION: By integrating transcriptomics and TSPO PET imaging in the same clinical AD cohort, this study revealed CD200 played an important role in regulating neuroinflammation, Aß deposition and cognitive dysfunction.

Multi-omics data reveals aberrant gut microbiota-host glycerophospholipid metabolism in association with neuroinflammation in APP/PS1 mice.

Numerous studies have described the notable impact of gut microbiota on the brain in Alzheimer's disease (AD) via the gut - brain axis. However, the molecular mechanisms underlying the involvement of gut microbiota in the development of AD are limited. This study aimed to explore the potential mechanisms of gut microbiota in AD by integrating multi-omics data. In this study, APP/PS1 and WT mice at nine months of age were used as study mouse model. Cognitive function was assessed using the Morris water maze test. The levels of Aß plaque and neuroinflammation in the brain were detected using immunofluorescence and PET/CT. In addition, we not only used 16S rRNA gene sequencing and metabolomics to explore the variation characteristics of gut microbiota and serum metabolism abundance, but also combined spatial metabolomics and transcriptomics to explore the change in the brain and identify their potential correlation. APP/PS1 mice showed significant cognitive impairment and amyloid-ß deposits in the brain. The abundance of gut microbiota was significantly changed in APP/PS1 mice, including decreased Desulfoviobrio, Enterococcus, Turicibacter, and Ruminococcus and increased Pseudomonas. The integration of serum untargeted metabolomics and brain spatial metabolomics showed that glycerophospholipid metabolism was a common alteration pathway in APP/PS1 mice. Significant proliferation and activation of astrocyte and microglia were observed in APP/PS1 mice, accompanied by alterations in immune pathways. Integration analysis and fecal microbiota transplantation (FMT) intervention revealed potential association of gut microbiota, host glycerophospholipid metabolism, and neuroinflammation levels in APP/PS1 mice.

ABCA7-Associated Clinical Features and Molecular Mechanisms in Alzheimer's Disease.

Alzheimer's disease (AD) is the most common type of neurodegenerative disease and its pathogenesis is still unclear. Genetic factors are thought to account for a large proportion of the overall AD phenotypes. ATP-binding cassette transporter A7 (ABCA7) is one of the most important risk gene for AD. Multiple forms of ABCA7 variants significantly increase the risk of AD, such as single-nucleotide polymorphisms, premature termination codon variants, missense variants, variable number tandem repeat, mutations, and alternative splicing. AD patients with ABCA7 variants usually exhibit typical clinical and pathological features of traditional AD with a wide age of onset range. ABCA7 variants can alter ABCA7 protein expression levels and protein structure to affect protein functions such as abnormal lipid metabolism, amyloid precursor protein (APP) processing, and immune cell function. Specifically, ABCA7 deficiency can cause neuronal apoptosis by inducing endoplasmic reticulum stress through the PERK/eIF2α pathway. Second, ABCA7 deficiency can increase Aß production by upregulating the SREBP2/BACE1 pathway and promoting APP endocytosis. In addition, the ability of microglia to phagocytose and degrade Aß is destroyed by ABCA7 deficiency, leading to reduced clearance of Aß. Finally, disturbance of lipid metabolism may also be an important method by which ABCA7 variants influence the incidence rate of AD. In the future, more attention should be given to different ABCA7 variants and ABCA7 targeted therapies for AD.

Investigating the causal association between branched-chain amino acids and Alzheimer's disease: A bidirectional Mendelian randomized study.

Background: There are many metabolic pathway abnormalities in Alzheimer's disease (AD). Several studies have linked branched-chain amino acid (BCAA) metabolism disorders with AD but have not obtained consistent results. The purpose of this study is to explore the causal association between BCAA concentration and the risk of AD. Methods: A bidirectional Mendelian randomized (MR) study was applied to explore the causal effect between BCAA level and the risk of AD. Genetic instrumental variables from the genome-wide association study (GWAS) of serum BCAA levels [total BCAAs (115,047 participants), valine (115,048 participants), leucine (115,074 participants), and isoleucine (115,075 participants)] from the UK Biobank and AD (21,982 AD cases and 41,944 controls) from the International Genomics of Alzheimer's Project were applied to explore the causal effect through the inverse variance-weighted (IVW) method, MR-Egger, and weighted median, accompanied by multiple pluripotency and heterogeneity tests. Results: The forward MR analysis showed that there was no causal effect of total BCAAs (OR: 1.067, 95% CI: 0.838-1.358; p = 0.838), valine (OR: 1.106, 95% CI: 0.917-1.333; p = 0.292), leucine (OR: 1.096, 95% CI: 0.861-1.396; p = 0.659), and isoleucine (OR: 1.457, 95% CI: 1.024-2.742; p = 0.037) levels on the risk of AD. The reverse analysis showed that AD was related to reduced levels of total BCAAs (OR: 0.979, 95% CI: 0.989-0.990; p < 0.001), valine (OR: 0.977, 95% CI: 0.963-0.991; p = 0.001), leucine (OR: 0.983, 95% CI: 0.973-0.994; p = 0.002), and isoleucine (OR: 0.982, 95% CI: 0.971-0.992; p = 0.001). Conclusion: We provide robust evidence that AD was associated with a decreased level of BCAAs, which can serve as a marker for early diagnosis of AD.

Integrating peripheral blood and brain transcriptomics to identify immunological features associated with Alzheimer's disease in mild cognitive impairment patients.

Background: Immune system dysfunction has been proven to be an important pathological event in Alzheimer's disease (AD). Mild cognitive impairment (MCI), as a transitional stage between normal cognitive function and AD, was an important research object for the screening of early diagnostic markers and therapeutic targets for AD. However, systematic assessment of peripheral immune system changes in MCI patients and consistent analysis with that in the CNS were still lacking. Methods: Peripheral blood transcriptome data from the AddNeuroMed Cohort (n = 711) was used as a training dataset to assess the abundance of 24 immune cells through ImmuCellAI and to identify MCI-related immune signaling pathways and hub genes. The expression level of the immune hub gene was validated in peripheral blood (n = 587) and brain tissue (78 entorhinal cortex, 140 hippocampi, 91 temporal cortex, and 232 frontal cortex) validation datasets. Finally, reliable immune hub genes were applied for Gene Set Enrichment Analysis and correlation analysis of AD pathological characteristics. Results: MCI patients have early changes in the abundance of various types of immune cells in peripheral blood, accompanied by significant changes in NF-kB, TNF, JAK-STAT, and MAPK signaling pathways. Five hub immune-related differentially expressed genes (NFKBIA, CD4, RELA, CASP3, and HSP90AA1) were screened by the cytoHubba plugin in Cytoscape and the least absolute shrinkage and selection operator (LASSO) regression. Their expression levels were significantly correlated with infiltration score and the abundance of monocytes, natural killer cells, Th2 T cells, T follicular helper cells, and cytotoxic T cells. After validation with independent datasets derived from peripheral blood and brain, RELA and HSP90AA1 were identified as two reliable immune hub genes in MCI patients and had consistent changes in AD. The Gene Set Enrichment Analysis (GSEA) showed that their expression levels were closely associated with Alzheimer's disease, JAK-STAT, calcium signaling pathway, etc. In addition, the expression level of RELA was positively correlated with ß- and γ-secretase activity and Braak stage. The expression level of HSP90AA1 was negatively correlated with α- and ß-secretase activity. Conclusion: Immune system dysfunction was an early event in AD. It provides a new target for the early diagnosis and treatment of AD.

Injection of amyloid-ß to lateral ventricle induces gut microbiota dysbiosis in association with inhibition of cholinergic anti-inflammatory pathways in Alzheimer's disease.

BACKGROUND: Alzheimer's disease (AD) is the most common neurodegenerative disease and its pathogenesis is still unclear. There is dysbiosis of gut microbiota in AD patients. More importantly, dysbiosis of the gut microbiota has been observed not only in AD patients, but also in patients with mild cognitive impairment (MCI). However, the mechanism of gut microbiota dysbiosis in AD is poorly understood. Cholinergic anti-inflammatory pathway is an important pathway for the central nervous system (CNS) regulation of peripheral immune homeostasis, especially in the gut. Therefore, we speculated that dysfunction of cholinergic anti-inflammatory pathway is a potential pathway for dysbiosis of the gut microbiota in AD. METHODS: In this study, we constructed AD model mice by injecting Aß1-42 into the lateral ventricle, and detected the cognitive level of mice by the Morris water maze test. In addition, 16S rDNA high-throughput analysis was used to detect the gut microbiota abundance of each group at baseline, 2 weeks and 4 weeks after surgery. Furthermore, immunofluorescence and western blot were used to detect alteration of intestinal structure of mice, cholinergic anti-inflammatory pathway, and APP process of brain and colon in each group. RESULTS: Aß1-42 i.c.v induced cognitive impairment and neuron damage in the brain of  mice. At the same time, Aß1-42 i.c.v induced alteration of gut microbiota at 4 weeks after surgery, while there was no difference at the baseline and 2 weeks after surgery. In addition, changes in colon structure and increased levels of pro-inflammatory factors were detected in Aß1-42 treatment group, accompanied by inhibition of cholinergic anti-inflammatory pathways. Amyloidogenic pathways in both the brain and colon were accelerated in Aß1-42 treatment group. CONCLUSIONS: The present findings suggested that Aß in the CNS can induce gut microbiota dysbiosis, alter intestinal structure and accelerate the amyloidogenic pathways, which were related to inhibiting cholinergic anti-inflammatory pathways.

Identification of potential predictive biomarkers and biological pathways and the correction with immune infiltration in the activation of Crohn's disease.

Crohn's disease (CD), a subtype of inflammatory bowel disease (IBD), has increasing prevalence in the world. Due to the lack of cure strategy, most patients with CD develop progressive disease companying with a series of serious complications. Therefore, exploring molecular mechanism differences between active and inactive CD will help in the screening of predict markers and therapeutic targets. In this study, we analyzed differentially expressed genes (DEGs) and molecular pathways through between active and inactive CD patients. In addition, the abundance of 22 immune cell types were assessed by using the CIBERSORT. The hub DEGs were screened out by the CytoHubba in Cytoscape, followed by the least absolute shrinkage and selection operator (LASSO) regression. Finally, the clinical predictive model was constructed by binary logistic regression model. The diagnostic efficacy was tested by receiver operating characteristic (ROC) curve and verified in independent datasets. The results showed that there were 137 DEGs between the active and inactive CD. Most of them were involved in regulating the immunity process. In addition, the decreased abundance of CD8 T cells and the increased abundance of M0, M1 macrophages, and neutrophils were closely related to CD activation. CXCL9, C3AR1, IL1B, and TLR4 were the hub gene and can be applied to the prediction of CD activation. Our results provided important targets for the prediction of CD activation and the selection of therapeutic targets.

Mechanisms of Short-Chain Fatty Acids Derived from Gut Microbiota in Alzheimer's Disease.

Short-chain fatty acids (SCFAs) are important metabolites derived from the gut microbiota through fermentation of dietary fiber. SCFAs participate a number of physiological and pathological processes in the human body, such as host metabolism, immune regulation, appetite regulation. Recent studies on gut-brain interaction have shown that SCFAs are important mediators of gut-brain interactions and are involved in the occurrence and development of many neurodegenerative diseases, including Alzheimer's disease. This review summarizes the current research on the potential roles and mechanisms of SCFAs in AD. First, we introduce the metabolic distribution, specific receptors and signaling pathways of SCFAs in human body. The concentration levels of SCFAs in AD patient/animal models are then summarized. In addition, we illustrate the effects and mechanisms of SCFAs on the cognitive level, pathological features (Aß and tau) and neuroinflammation in AD. Finally, we analyze the translational value of SCFAs as potential therapeutic targets for the treatment of AD.

Exploration of the Common Gene Characteristics and Molecular Mechanism of Parkinson's Disease and Crohn's Disease from Transcriptome Data.

Parkinson's disease (PD) is the second most common neurodegenerative disorder, and the mechanism of its occurrence is still not fully elucidated. Accumulating evidence has suggested that the gut acts as a potential origin of PD pathogenesis. Recent studies have identified that inflammatory bowel disease acts as a risk factor for Parkinson's disease, although the underlying mechanisms remain elusive. The aim of this study was to further explore the molecular mechanism between PD and Crohn's disease (CD). The gene expression profiles of PD (GSE6613) and CD (GSE119600) were downloaded from the Gene Expression Omnibus (GEO) database and were identified as the common differentially expressed genes (DEGs) between the two diseases. Next, analyses were performed, including functional enrichment analysis, a protein-protein interaction network, core genes identification, and clinical correlation analysis. As a result, 178 common DEGs (113 upregulated genes and 65 downregulated genes) were found between PD and CD. The functional analysis found that they were enriched in regulated exocytosis, immune response, and lipid binding. Twelve essential hub genes including BUB1B, BUB3, DLGAP5, AURKC, CBL, PCNA, RAF1, LYN, RPL39L, MRPL13, RSL24D1, and MRPS11 were identified from the PPI network by using cytoHubba. In addition, inflammatory and metabolic pathways were jointly involved in these two diseases. After verifying expression levels in an independent dataset (GSE99039), a correlation analysis with clinical features showed that LYN and RAF1 genes were associated with the severity of PD. In conclusion, our study revealed the common pathogenesis of PD and CD. These common pathways and hub genes may provide novel insights for mechanism research.

Identification of Immune Hub Genes Associated With Braak Stages in Alzheimer's Disease and Their Correlation of Immune Infiltration.

Background: Alzheimer's disease (AD) is the most common type of neurodegenerative disease. Tau pathology is one of the pathological features of AD, and its progression is closely related to the progress of AD. Immune system dysfunction is an important mediator of Tau pathological progression, but the specific molecular mechanism is still unclear. The purpose of this study is to determine the immune hub genes and peripheral immune cell infiltration associated with the Braak stages, and the molecular mechanisms between them. Methods: In this study, 60 samples with different Braak stages in the GSE106241 dataset were used to screen Braak stages-related immune hub genes by using the WGCNA package in R and cytoHubba plugin. The temporal lobe expression data in the Alzdata database were used to verify the results. The correlation between the expression level of immune core genes and the pathological features of AD was analyzed to evaluate the abundance of peripheral immune cell infiltration and screened Braak stages-related cells. Finally, we used correlation analysis of immune hub genes and immune cells and Gene Set Enrichment Analysis (GSEA) of them. Results: Seven genes (GRB2, HSP90AA1, HSPA4, IGF1, KRAS, PIK3R1, and PTPN11) were identified as immune core genes after the screening of the test datasets and validation of independent data. Among them, Kirsten rat sarcoma viral oncogene homolog (KRAS) and Phosphoinositide-3-Kinase Regulatory Subunit 1 (PIK3R1) were the most closely related to Tau and Aß pathology in AD. In addition, the ImmuneScore increased gradually with the increase of Braak stages. Five types of immune cells (plasma cells, T follicular helper cells, M2 macrophage, activated NK cells, and eosinophils) were correlated with Braak stages. KRAS and PIK3R1 were the immune core genes most related to the abnormal infiltration of peripheral immune cells. They participated in the regulation of the pathological process of AD through axon guidance, long-term potentiation, cytokine-cytokine receptor interaction, RNA polymerase, etc. Conclusion: The KRAS and PIK3R1 genes were identified as the immune hub genes most associated with Tau pathological progress in AD. The abnormal infiltration of peripheral immune cells mediated by these cells was involved in the Tau pathological process. This provides new insights for AD.

Clinical and genetic analyses of 150 patients with paroxysmal kinesigenic dyskinesia.

BACKGROUND: Mutations in PRRT2 and 16p11.2 microdeletion including PRRT2 have been identified as the pathogenic cause of paroxysmal kinesigenic dyskinesia (PKD). OBJECTIVE: The objective was to investigate the clinical and genetic features of PKD and to analyze the genotype-phenotype correlation. METHODS: We recruited PKD patients, recorded clinical manifestations, and performed PRRT2 screening in 150 PKD patients by unified PKD registration forms. Genotype-phenotype correlation analyses were conducted in probands. High-knee-exercise (HKE) tests were applied in one hundred and six patients. RESULTS: Eight PRRT2 mutations were detected, accounting for 22.76% of the probands. Three mutations (c.649dupC, c.649delC, and c.510_513delTCTG) were already reported, while four mutations (c.252_264delCACAGACCTCAGC, c.503_504delCT, c.679C > T, and c.804C > A) were first reported. One heterozygous microdeletion of 606 kb in 16p11.2 was detected in one patient. Compared with non-PRRT2 mutation carriers, the PRRT2 mutation carriers were younger at onset, experienced longer attacks, and tended to present with complicated PKD, combined phenotypes of dystonia and chorea. 57.01% of patients could effectively induce movement disorders through the HKE test. A good response was shown in 81.93% of the patients prescribed with antiepileptic drugs. 13.54% (13/96) had abnormal EEG results. CONCLUSIONS: PRRT2 mutations are common in patients with PKD and are significantly associated with an earlier age at onset, longer duration of attacks, a complicated form of PKD, combined phenotypes of dystonia and chorea. Patients with microdeletion of 16p11.2 may have more severe manifestations. The HKE test could contribute to the diagnosis of PKD. Carbamazepine is still the first choice for PKD patients, but individualized treatment should be formulated.

Multi-Omics Characterization of Type 2 Diabetes Mellitus-Induced Cognitive Impairment in the db/db Mouse Model.

Type 2 diabetes mellitus (T2DM) is a complex metabolic disorder frequently accompanied by cognitive impairment. Contributing factors such as modern lifestyle, genetic predisposition, and gene environmental interactions have been postulated, but the pathogenesis remains unclear. In this study, we attempt to investigate the potential mechanisms and interventions underlying T2DM-induced cognitive deficits from the brain-gut axis perspective. A combined analysis of the brain transcriptome, plasma metabolome, and gut microbiota in db/db mice with cognitive decline was conducted. Transcriptome analysis identified 222 upregulated gene sets and 85 downregulated gene sets, mainly related to mitochondrial respiratory, glycolytic, and inflammation. In metabolomic analysis, a total of 75 significantly altered metabolites were identified, correlated with disturbances of glucose, lipid, bile acid, and steroid metabolism under disease state. Gut microbiota analysis suggested that the species abundance and diversity of db/db mice were significantly increased, with 23 significantly altered genus detected. Using the multi-omics integration, significant correlations among key genes (n = 33), metabolites (n = 41), and bacterial genera (n = 21) were identified. Our findings suggest that disturbed circulation and brain energy metabolism, especially mitochondrial-related disturbances, may contribute to cognitive impairment in db/db mice. This study provides novel insights into the functional interactions among the brain, circulating metabolites, and gut microbiota.

TMEM151A Variants Cause Paroxysmal Kinesigenic Dyskinesia: A Large-Sample Study.

BACKGROUND: Paroxysmal kinesigenic dyskinesia (PKD) is the most common type of paroxysmal dyskinesias. Only one-third of PKD patients are attributed to proline-rich transmembrane protein 2 (PRRT2) mutations. OBJECTIVE: We aimed to explore the potential causative gene for PKD. METHODS: A cohort of 196 PRRT2-negative PKD probands were enrolled for whole-exome sequencing (WES). Gene Ranking, Identification and Prediction Tool, a method of case-control analysis, was applied to identify the candidate genes. Another 325 PRRT2-negative PKD probands were subsequently screened with Sanger sequencing. RESULTS: Transmembrane Protein 151 (TMEM151A) variants were mainly clustered in PKD patients compared with the control groups. 24 heterozygous variants were detected in 25 of 521 probands (frequency = 4.80%), including 18 missense and 6 nonsense mutations. In 29 patients with TMEM151A variants, the ratio of male to female was 2.63:1 and the mean age of onset was 12.93 ± 3.15 years. Compared with PRRT2 mutation carriers, TMEM151A-related PKD were more common in sporadic PKD patients with pure phenotype. There was no significant difference in types of attack and treatment outcome between TMEM151A-positive and PRRT2-positive groups. CONCLUSIONS: We consolidated mutations in TMEM151A causing PKD with the aid of case-control analysis of a large-scale WES data, which broadens the genotypic spectrum of PKD. TMEM151A-related PKD were more common in sporadic cases and tended to present as pure phenotype with a late onset. Extensive functional studies are needed to enhance our understanding of the pathogenesis of TMEM151A-related PKD. © 2021 International Parkinson and Movement Disorder Society.

Variants in LAMC3 Causes Occipital Cortical Malformation.

Occipital cortical malformation (OCCM) is a disease caused by malformations of cortical development characterized by polymicrogyria and pachygyria of the occipital lobes and childhood-onset seizures. The recessive or complex heterozygous variants of the LAMC3 gene are identified as the cause of OCCM. In the present study, we identified novel complex heterozygous variants (c.470G > A and c.4030 + 1G > A) of the LAMC3 gene in a Chinese female with childhood-onset seizures. Cranial magnetic resonance imaging was normal. Functional experiments confirmed that both variant sites caused premature truncation of the laminin γ3 chain. Bioinformatics analysis predicted 10 genes interacted with LAMC3 with an interaction score of 0.4 (P value = 1.0e-16). The proteins encoded by these genes were mainly located in the basement membrane and extracellular matrix component. Furthermore, the biological processes and molecular functions from gene ontology analysis indicated that laminin γ3 chain and related proteins played an important role in structural support and cellular processes through protein-containing complex binding and signaling receptor binding. KEGG pathway enrichment predicted that the LAMC3 gene variant was most likely to participate in the occurrence and development of OCCM through extracellular matrix receptor interaction and PI3K-Akt signaling pathway.

Inflammatory pathways in Alzheimer's disease mediated by gut microbiota.

In the past decade, numerous studies have demonstrated the close relationship between gut microbiota and the occurrence and development of Alzheimer's disease (AD). However, the specific mechanism is still unclear. Both the neuroinflammation and systemic inflammation serve as the key hubs to accelerate the process of AD by promoting pathology and damaging neuron. What's more, the gut microbiota is also crucial for the regulation of inflammation. Therefore, this review focused on the role of gut microbiota in AD through inflammatory pathways. Firstly, this review summarized the relationship and interaction among gut microbiota, inflammation, and AD. Secondly, the direct and indirect regulatory effects of gut microbiota on AD through inflammatory pathways were described. These effects were mainly mediated by the component of the gut microbiota (lipopolysaccharides (LPS) and amyloid peptides), the metabolites of bacteria (short-chain fatty acids, branched amino acids, and neurotransmitters) and functional by-products (bile acids). In addition, potential treatments (fecal microbiota transplantation, antibiotics, probiotics, prebiotics, and dietary interventions) for AD were also discussed through these mechanisms. Finally, according to the current research status, the key problems to be solved in the future studies were proposed.

Neurodevelopmental disorder caused by a truncating de novo variant of IRF2BPL.

BACKGROUND: Mutations in the IRF2BPL gene can cause neurodevelopmental disorders. We describe the clinical and genetic characteristics of a Chinese patient with a novel abnormality in this gene, explore the potential pathogenic mechanism and summarize the clinical characteristics of 25 patients with IRF2BPL mutations. METHODS: We identified the gene mutation sites by whole-exome and Sanger sequencing. The protein-protein interaction network of the IRF2BPL gene was constructed using bioinformatic techniques, and its function was enriched. We conducted a functional experiment to explore the potential pathogenicity of the identified IRF2BPL gene mutation. RESULTS: An 8-year-old girl presented with progressive cerebellar ataxia, including involuntary tremor and slurred speech. Electroencephalography and electromyography revealed no abnormalities. Structural cranial MRI was also normal, but genetic analysis identified a truncating de novo variant in IRF2BPL. Bioinformatics predicted that IRF2BPL would be associated with IRF2 and 10 other genes and involved in ubiquitin binding and other pathways. The cellular location of IRF2BPL was altered, and compared to control cells, the level of ubiquitinated proteins was significantly decreased in cells harbouring the mutation. CONCLUSION: In this study, we identified a truncating de novo variant of IRF2BPL as a causative gene in the neurodevelopmental disorder of a Chinese girl. Impairment of the ubiquitin-proteasome pathway caused by this IRF2BPL mutation may play an important role in this neurodevelopmental disorder.

c.1263+1G>A Is a Latent Hotspot for CYP27A1 Mutations in Chinese Patients With Cerebrotendinous Xanthomatosis.

BACKGROUND: Cerebrotendinous xanthomatosis (CTX) is an autosomal recessive disorder of bile acid synthesis caused by mutations in the CYP27A1 gene. CTX is an underdiagnosed and potentially treatable disease, thus a detailed appreciation of the phenotypic spectrum and genetic characteristics are crucial for early diagnosis and treatment. OBJECTIVES AND METHODS: Four CTX families with mutations in the CYP27A1 gene were enrolled in our study. We investigated the clinical characteristics and molecular genetic features of the probands with CTX. Genetic analysis was performed for detecting gene variants. Sanger sequencing and segregation analysis were conducted for haplotype analysis. RESULTS: All the four probands were compound heterozygote for two CYP27A1 variants, including one mutation in c.1263+1G>A (intron 7) splice site, two novel likely pathogenic mutations (c.255+1G>T and c.1561dupA) and three pathogenic mutations including c.379C>T, c.1263+1G>A and c.1537C>T previously reported. All of the subjects presented with spastic paraparesis. The other common clinical features included ataxia, childhood-onset diarrhea, cataracts, intellectual disability, tendinous xanthomas and dentate nuclei signal alterations at MRI. CONCLUSION: Two novel likely pathogenic mutations (c.255+1G>T and c.1561dupA) were reported in our study. The 1263+1G>A mutation was commonly seen in Chinese reported case series (7/25, 28%) and could be a latent hotspot for Chinese CTX mutations. Our study expanded the mutation spectrum of CYP27A1 gene and provide an insightful view of the phenotypic spectrum and genetic characteristics to help early diagnosis and treatment with to improve neurologic dysfunction.

Neuropeptide S Ameliorates Cognitive Impairment of APP/PS1 Transgenic Mice by Promoting Synaptic Plasticity and Reducing Aß Deposition.

Alzheimer's disease (AD) is a devastating disease in the elderly with no known effective treatment. It is characterized by progressive deterioration of memory and cognition. Many new potential targets are being investigated to develop effective therapeutic strategies for AD. Neuropeptide S (NPS) is an endogenous peptide in the central nervous system, which has been shown to play a beneficial role in learning and memory. However, whether NPS can ameliorate cognitive deficits in AD remains unclear. In this study, we examined the effects of NPS treatment on the cognitive behaviors and pathological hallmarks in 8-month-old APPswe/PS1dE9 (APP/PS1) AD mice. We found that the APP/PS1 mice exhibited lower levels of NPS receptors (NPSRs) in the hippocampal area, and NPS administration increased c-Fos expression in the hippocampus and cortex, which suggests the NPS/NPSR system may contribute to the pathogenesis of AD. After an intracerebroventricular injection of NPS (1 nmol) for 2 weeks, we found NPS treatment ameliorated spatial memory deficits and promoted dendrite ramification and spine generation in hippocampal CA1 neurons, which was accompanied by the upregulation of postsynaptic density protein 95 (PSD95) and synapsin1. We also demonstrated that the injection of NPS decreased Aß plaque deposits by decreasing the γ-secretase activity and the phosphorylation of APP at Thr668. Furthermore, application of NPS reversed the deficits in hippocampal late-phase long-term potentiation (LTP). These findings suggest NPS attenuated cognitive deficits by reducing pathological features in APP/PS1 mice, and NPS might be a potential therapeutic agent for AD.

Dehydrocostus Lactone Suppresses LPS-induced Acute Lung Injury and Macrophage Activation through NF-κB Signaling Pathway Mediated by p38 MAPK and Akt.

Acute lung injury (ALI) is a severe clinical disease marked by dysregulated inflammation response and has a high rate of morbidity and mortality. Macrophages, which play diverse roles in the inflammatory response, are becoming therapeutic targets in ALI. In this study we investigated the effects of dehydrocostus lactone (DHL), a natural sesquiterpene, on macrophage activation and LPS-induced ALI. The macrophage cell line RAW264.7 and primary lung macrophages were incubated with DHL (0, 3, 5, 10 and 30 µmol/L) for 0.5 h and then challenged with LPS (100 ng/mL) for up to 8 hours. C57BL/6 mice were intratracheally injected with LPS (5 mg/kg) to induce acute lung injury (ALI) and then treated with a range of DHL doses intraperitoneally (5 to 20 mg/kg). The results showed that DHL inhibited LPS-induced production of proinflammatory mediators such as iNOS, NO, and cytokines including TNF-α, IL-6, IL-1ß, and IL-12 p35 by suppressing the activity of NF-κB via p38 MAPK/MK2 and Akt signaling pathway in macrophages. The in vivo results revealed that DHL significantly attenuated LPS-induced pathological injury and reduced cytokines expression in the lung. NF-κB, p38 MAPK/MK2 and Akt signaling molecules were also involved in the anti-inflammatory effect. Collectively, our findings suggested that DHL is a promising agent for alleviating LPS-induced ALI.

Lanatoside C protects mice against bleomycin-induced pulmonary fibrosis through suppression of fibroblast proliferation and differentiation.

It has been established that lanatoside C, a FDA-approved cardiac glycoside, reduces proliferation of cancer cell lines. The proliferation of fibroblasts is critical to the pathogenesis of pulmonary fibrosis (PF), a progressive and fatal fibrotic lung disease lacking effective treatment. In this study we have investigated the impact of lanatoside C on a bleomycin (BLM)-induced mouse model of PF and through the evaluation of fibroblast proliferation and activation in vitro. We evaluated explanted lung tissue by histological staining, western blot analysis, qRT-PCR and survival analysis, demonstrating that lanatoside C was able to protect mice against BLM-induced pulmonary fibrosis. The proliferation of cultured pulmonary fibroblasts isolated from BLM-induced PF mice was suppressed by lanatoside C, as hypothesized, through the induction of cell apoptosis and cell cycle arrest at the G2/M phase. The Akt signalling pathway was involved in this process. Interestingly, the production of α-SMA, fibronectin, and collagen I and III in response to TGF-ß1 in healthy mouse fibroblasts was suppressed following lanatoside C administration by inhibition of TGF-ß1/Smad signalling. In addition, TGF-ß1-induced migration in lung fibroblasts was also impeded after lanatoside C treatment. Together, our data revealed that lanatoside C alleviated BLM-induced pulmonary fibrosis in mice via attenuation of growth and differentiation of fibroblasts, suggesting that it has potential as a candidate therapy for PF patients.