Contactin-associated protein-like 2 (CNTNAP2) mutations impair the essential α-secretase cleavages, leading to autism-like phenotypes.

Mutations in the Contactin-associated protein-like 2 (CNTNAP2) gene are associated with autism spectrum disorder (ASD), and ectodomain shedding of the CNTNAP2 protein plays a role in its function. However, key enzymes involved in the C-terminal cleavage of CNTNAP2 remain largely unknown, and the effect of ASD-associated mutations on this process and its role in ASD pathogenesis remain elusive. In this report we showed that CNTNAP2 undergoes sequential cleavages by furin, ADAM10/17-dependent α-secretase and presenilin-dependent γ-secretase. We identified that the cleavage sites of ADAM10 and ADAM17 in CNTNAP2 locate at its C-terminal residue I79 and L96, and the main α-cleavage product C79 by ADAM10 is required for the subsequent γ-secretase cleavage to generate CNTNAP2 intracellular domain (CICD). ASD-associated CNTNAP2 mutations impair the α-cleavage to generate C79, and the inhibition leads to ASD-like repetitive and social behavior abnormalities in the Cntnap2-I1254T knock-in mice. Finally, exogenous expression of C79 improves autism-like phenotypes in the Cntnap2-I1254T knock-in and Cntnap2-/- knockout mice. This data demonstrates that the α-secretase is essential for CNTNAP2 processing and its function. Our study indicates that inhibition of the cleavage by pathogenic mutations underlies ASD pathogenesis, and upregulation of its C-terminal fragments could have therapeutical potentials for ASD treatment.

Enhanced Gasdermin-E-mediated Pyroptosis in Alzheimer's Disease.

Amyloid ß protein (Aß) is a critical factor in the pathogenesis of Alzheimer's disease (AD). Aß induces apoptosis, and gasdermin-E (GSDME) expression can switch apoptosis to pyroptosis. In this study, we demonstrated that GSDME was highly expressed in the hippocampus of APP23/PS45 mouse models compared to that in age-matched wild-type mice. Aß treatment induced pyroptosis by active caspase-3/GSDME in SH-SY5Y cells. Furthermore, the knockdown of GSDME improved the cognitive impairments of APP23/PS45 mice by alleviating inflammatory response. Our findings reveal that GSDME, as a modulator of Aß and pyroptosis, plays a potential role in Alzheimer's disease pathogenesis and shows that GSDME is a therapeutic target for AD.

PCP4 Promotes Alzheimer's Disease Pathogenesis by Affecting Amyloid-ß Protein Precursor Processing.

BACKGROUND: Down syndrome (DS) is caused by an extra copy of all or part of chromosome 21. The patients with DS develop typical Alzheimer's disease (AD) neuropathology, indicating the role of genes on human chromosome 21 (HSA21) in the pathogenesis of AD. Purkinje cell protein 4 (PCP4), also known as brain-specific protein 19, is a critical gene located on HSA21. However, the role of PCP4 in DS and AD pathogenesis is not clear. OBJECTIVE: To explore the role of PCP4 in amyloid-ß protein precursor (AßPP) processing in AD. METHODS: In this study, we investigated the role of PCP4 in AD progression in vitro and in vivo. In vitro experiments, we overexpressed PCP4 in human Swedish mutant AßPP stable expression or neural cell lines. In vitro experiments, APP23/PS45 double transgenic mice were selected and treated with AAV-PCP4. Multiple topics were detected by western blot, RT-PCR, immunohistochemical and behavioral test. RESULTS: We found that PCP4 expression was altered in AD. PCP4 was overexpressed in APP23/PS45 transgenic mice and PCP4 affected the processing of AßPP. The production of amyloid-ß protein (Aß) was also promoted by PCP4. The upregulation of endogenous AßPP expression and the downregulation of ADAM10 were due to the transcriptional regulation of PCP4. In addition, PCP4 increased Aß deposition and neural plaque formation in the brain, and exuberated learning and memory impairment in transgenic AD model mice. CONCLUSION: Our finding reveals that PCP4 contributes to the pathogenesis of AD by affecting AßPP processing and suggests PCP4 as a novel therapeutic target for AD by targeting Aß pathology.

GPSAdb: a comprehensive web resource for interactive exploration of genetic perturbation RNA-seq datasets.

Gene knock-out/down methods are commonly used to explore the functions of genes of interest, but a database that systematically collects perturbed data is not available currently. Manual curation of all the available human cell line perturbed RNA-seq datasets enabled us to develop a comprehensive human perturbation database (GPSAdb, https://www.gpsadb.com/). The current version of GPSAdb collected 3048 RNA-seq datasets associated with 1458 genes, which were knocked out/down by siRNA, shRNA, CRISPR/Cas9, or CRISPRi. The database provides full exploration of these datasets and generated 6096 new perturbed gene sets (up and down separately). GPSAdb integrated the gene sets and developed an online tool, genetic perturbation similarity analysis (GPSA), to identify candidate causal perturbations from differential gene expression data. In summary, GPSAdb is a powerful platform that aims to assist life science researchers to easily access and analyze public perturbed data and explore differential gene expression data in depth.

Astrocyte-Ablation of Mtnr1b Increases Anxiety-Like Behavior in Adult Male Mice.

BACKGROUND: Astrocytes are essential for synaptic transmission, and their dysfunction can result in neuropsychiatric disorders such as anxiety and depression. Many studies have shown that global knockout of Melatonin receptor 2 (Mtnr1b) is associated with the development of various mental disorders. AIM: This study aimed to investigate the effects of astrocyte ablation of Mtnr1b on cognitive function and anxiety-like behavior in mice, as well as the potential biological mechanisms. METHODS: A conditional Cre-loxP system allowing deletion of Mtnr1b from astrocytes was developed to investigate the specific role Mtnr1b. Control and Mtnr1b cKO𝐺𝑓𝑎𝑝 mice were selected for cognitive function behavioral testing (Morris water maze test, novel object recognition test) and emotion-related behavioral testing (open field, elevated plus maze). After testing, brain tissue was collected and examined by immunofluorescence for the expression of neuronal nuclei (NeuN), glutamate decarboxylase 67 (GAD67), and vesicular glutamate transporter 1 (vGluT1). RNA-seq was performed on hippocampal tissue from control and Mtnr1b cKO𝐺𝑓𝑎𝑝 mice to identify differentially expressed genes. Additional confirmation of differential gene expression was performed using real-time quantitative polymerase chain reaction (qRT-PCR). RESULTS: Mtnr1b cKO𝐺𝑓𝑎𝑝 mice were not significantly different from control mice in the Morris water maze and novel object recognition tests. Results from the open field and elevated plus maze tests showed that Mtnr1b cKO𝐺𝑓𝑎𝑝 mice exhibited significantly more anxiety-like behavior than did controls. Immunofluorescence revealed that the number of mature neurons did not differ significantly between Mtnr1b cKO𝐺𝑓𝑎𝑝 mice and controls. The expression of GAD67 in the hippocampal CA1 and CA3 areas of Mtnr1b cKO𝐺𝑓𝑎𝑝 mice was significantly lower than in the control group, but no significant difference was detected for vGluT1 expression. RNA-seq and qRT-PCR results showed that Mtnr1b knockout in astrocytes led to a decrease in the levels of gamma-aminobutyric acid sub-type A (GABAA) receptors and Kir2.2. CONCLUSIONS: The astrocyte-specific knockout in Mtnr1b cKO𝐺𝑓𝑎𝑝 mice results in anxiety-like behavior, which is caused by down-regulation of gamma-aminobutyric acid-ergic (GABAergic) synaptic function.

Regulation of the Human IL-10RB Gene Expression by Sp8 and Sp9.

BACKGROUND: Interleukin-10 (IL-10) is a classic anti-inflammatory cytokine that exerts its effects via the receptor complexes IL-10RA and IL-10RB. Loss of IL-10RB results in many diseases. Moreover, IL-10RB is closely associated with neuronal survival and synaptic formation. However, the regulation of IL-10RB gene expression remains elusive. OBJECTIVE: To investigate whether the expression of IL-10RB gene is increased in brain of Alzheimer's disease (AD) and its transcriptional regulation. METHODS: We examined the gene expression of AD patient brain from public database and detected the protein expression of AD model mouse brain by western blot. We constructed a variety of reporter gene plasmids with different lengths or mutation sites, tested the promoter activity and defined the functional region of the promoter with the luciferase reporter assay. The protein-DNA binding between transcription factors and the promoter was analyzed using chromatin immunoprecipitation (ChIP) and electrophoretic mobility shift assay (EMSA). RESULTS: We found that the IL-10RB is elevated in the brain of AD patient and AD model mice. The minimal promoter of the IL-10RB gene is located in the -90 to +51 bp region (relative to the transcriptional start site) and is sufficient for high-level expression of the IL-10RB gene. Transcription factors Sp8 and Sp9 bind to the IL-10RB promoter in vitro. The overexpression or knockdown of Sp8 and Sp9 affected the IL-10RB promoter activity and its gene expression. CONCLUSION: Our study functionally characterized the promoter of the IL-10RB gene and demonstrated that Sp8 and Sp9 regulated its expression.

Gallic acid inhibits neuroinflammation and reduces neonatal hypoxic-ischemic brain damages.

Neuroinflammation is a leading cause of secondary neuronal injury in neonatal hypoxic-ischemic encephalopathy (HIE). Regulation of neuroinflammation may be beneficial for treatment of HIE and its secondary complications. Gallic acid (GA) has been shown to have anti-inflammatory and antioxidant effects. In this report we found that oxygen-glucose deprivation and/reoxygenation (OGD/R)-induced cell death, and the generation of excessive reactive oxygen species (ROS) and inflammatory cytokines by microglia were inhibited by GA treatment. Furthermore, GA treatment reduced neuroinflammation and neuronal loss, and alleviated motor and cognitive impairments in rats with hypoxic-ischemic brain damage (HIBD). Together, our results reveal that GA is an effective regulator of neuroinflammation and has potential as a pharmaceutical intervention for HIE therapy.

Inhibition of cystathionine ß-synthase promotes apoptosis and reduces cell proliferation in chronic myeloid leukemia.

Increased endogenous hydrogen sulfide (H2S) level by cystathionine ß-synthase (CBS) has been shown to closely relate tumorigenesis. H2S promotes angiogenesis, stimulates bioenergy metabolism and inhibits selective phosphatases. However, the role of CBS and H2S in chronic myeloid leukemia (CML) remains elusive. In this study, we found that CBS and H2S levels were increased in the bone marrow mononuclear cells of pediatric CML patients, as well as in the CML-derived K562 cells and CBS expression levels were correlated with different disease phases. Inhibition of CBS reduced the proliferation of the CML primary bone marrow mononuclear cells and induced growth inhibition, apoptosis, cell cycle arrest, and migration suppression in K562 cells and tumor xenografts. The knockdown of CBS expression by shRNA and inhibiting CBS activity by AOAA decreased the endogenous H2S levels, promoted mitochondrial-related apoptosis and inhibited the NF-κB-mediated gene expression. Our study suggests that inhibition of CBS induces cell apoptosis, as well as limits cell proliferation and migration, a potential target for the treatment of chronic myeloid leukemia.

Spatiotemporal consistency analysis of attention-deficit/hyperactivity disorder children.

PURPOSE: To identify the local spatiotemporal consistency of spontaneous brain activity of attention-deficit/hyperactivity disorder (ADHD) adolescents and its relation with clinical performance. MATERIALS AND METHODS: A cohort of 50 adolescents with ADHD-I or ADHD-C and a cohort of age- and gender- matched 46 typical development controls (TDC) were recruited from ADHD-200 dataset. FOur-dimensional (spatiotemporal) Consistency of local neural Activities (FOCA) metric was used to analyze the local spatiotemporal consistency, which integrating local temporal homogeneity and regional stability of brain activity states. The difference of normalized FOCA (nFOCA) values among ADHD-Inattentive (ADHD-I), ADHD-Combined (ADHD-C) and TDC were detected using ANOVA and post-hoc analysis. Furthermore, partial correlations were analyzed to investigate the relationship between nFOCA values and clinical manifestations. RESULTS: Compared with TDC, ADHD-C and ADHD-I adolescents demonstrated alterations of FOCA in bilateral middle temporal gyrus, superior occipital gyrus, postcentral gyrus, precuneus, and right inferior temporal gyrus, lingual gyrus, superior frontal gyrus, left middle cingulum gyrus, middle occipital gyrus and cerebellum area. CONCLUSIONS: Our study suggests that the FOCA method perhaps has potential to provide important insights into understanding the pathophysiological mechanism of ADHD and its subtypes.

A novel de novo nonsense mutation in ZC4H2 causes Wieacker-Wolff Syndrome.

BACKGROUND: Wieacker-Wolff syndrome (WWS) is a congenital X-linked neuromuscular disorder, which was firstly reported in 1985. Zinc finger C4H2-type containing (ZC4H2) gene has been found to be associated with the disease pathogenesis. However, the underlying mechanism remains elusive. METHODS: Whole-exome sequencing was performed to identify the mutations. Expression plasmids were constructed and cell culture and immune-biochemical assays were used to examine the effects of the mutation. RESULTS: We reported a female patient with classical symptoms of WWS and discovered a novel nonsense heterozygous mutation (p.R67X; c.199C>T) in ZC4H2 gene in the patient but not in her parents. The mutation resulted in a 66 amino-acid truncated ZC4H2 protein. The mutation is located in the key helix domain and it altered the subcellular locations of the mutant ZC4H2 protein. X-chromosome inactivation (XCI) pattern analysis revealed that the XCI ratio of the proband was 22:78. CONCLUSION: Female heterozygous carriers with nonsense mutation with a truncated ZC4H2 protein could lead to the pathogenesis of Wieacker-Wolff syndrome and our study provides a potential new target for the disease treatment.