SIL1 improves cognitive impairment in APP23/PS45 mice by regulating amyloid precursor protein processing and Aß generation.

SIL1, an endoplasmic reticulum (ER)-resident protein, is reported to play a protective role in Alzheimer's disease (AD). However, the effect of SIL1 on amyloid precursor protein (APP) processing remains unclear. In this study, the role of SIL1 in APP processing was explored both in vitro and in vivo. In the in vitro experiment, SIL1 was either overexpressed or knocked down in cells stably expressing the human Swedish mutant APP695. In the in vivo experiment, AAV-SIL1-EGFP or AAV-EGFP was microinjected into APP23/PS45 mice and their wild-type littermates. Western blotting (WB), immunohistochemistry, RNA sequencing (RNA-seq), and behavioral experiments were performed to evaluate the relevant parameters. Results indicated that SIL1 expression decreased in APP23/PS45 mice. Overexpression of SIL1 significantly decreased the protein levels of APP, presenilin-1 (PS1), and C-terminal fragments (CTFs) of APP in vivo and in vitro. Conversely, knockdown of SIL1 increased the protein levels of APP, ß-site APP cleavage enzyme 1 (BACE1), PS1, and CTFs, as well as APP mRNA expression in 2EB2 cells. Furthermore, SIL1 overexpression reduced the number of senile plaques in APP23/PS45 mice. Importantly, Y-maze and Morris Water maze tests demonstrated that SIL1 overexpression improved cognitive impairment in APP23/PS45 mice. These findings indicate that SIL1 improves cognitive impairment in APP23/PS45 mice by inhibiting APP amyloidogenic processing and suggest that SIL1 is a potential therapeutic target for AD by modulating APP processing.

ICA1 affects APP processing through the PICK1-PKCα signaling pathway.

AIMS: Islet cell autoantigen 1 (ICA1) is involved in autoimmune diseases and may affect synaptic plasticity as a neurotransmitter. Databases related to Alzheimer's disease (AD) have shown decreased ICA1 expression in patients with AD. However, the role of ICA1 in AD remains unclear. Here, we report that ICA1 expression is decreased in the brains of patients with AD and an AD mouse model. RESULTS: The ICA1 increased the expression of amyloid precursor protein (APP), disintegrin and metalloprotease 10 (ADAM10), and disintegrin and metalloprotease 17 (ADAM17), but did not affect protein half-life or mRNA levels. Transcriptome sequencing analysis showed that ICA1 regulates the G protein-coupled receptor signaling pathway. The overexpression of ICA1 increased PKCα protein levels and phosphorylation. CONCLUSION: Our results demonstrated that ICA1 shifts APP processing to non-amyloid pathways by regulating the PICK1-PKCα signaling pathway. Thus, this study suggests that ICA1 is a novel target for the treatment of AD.

Diphthamide deficiency promotes association of eEF2 with p53 to induce p21 expression and neural crest defects.

Diphthamide is a modified histidine residue unique for eukaryotic translation elongation factor 2 (eEF2), a key ribosomal protein. Loss of this evolutionarily conserved modification causes developmental defects through unknown mechanisms. In a patient with compound heterozygous mutations in Diphthamide Biosynthesis 1 (DPH1) and impaired eEF2 diphthamide modification, we observe multiple defects in neural crest (NC)-derived tissues. Knockin mice harboring the patient's mutations and Xenopus embryos with Dph1 depleted also display NC defects, which can be attributed to reduced proliferation in the neuroepithelium. DPH1 depletion facilitates dissociation of eEF2 from ribosomes and association with p53 to promote transcription of the cell cycle inhibitor p21, resulting in inhibited proliferation. Knockout of one p21 allele rescues the NC phenotypes in the knockin mice carrying the patient's mutations. These findings uncover an unexpected role for eEF2 as a transcriptional coactivator for p53 to induce p21 expression and NC defects, which is regulated by diphthamide modification.

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.

Spatio-temporal evolution law of gas-temperature coupling field in "110 method" goaf and prevention of spontaneous combustion.

To investigate the distribution characteristics of spontaneous combustion disaster (SCD) zones in the goaf of "110" mining method with U + L ventilation system and formulate corresponding fire prevention measures, enclosed coal oxidation experiments were carried out to measure the oxidation characteristics of Dongrong Coal Mine bituminous coal sample. A coupled 3DEC-CFD (3 dimensional Distinct Element Code) model was established. The 3D transient distribution characteristics of SCD zones in the "110" mining goaf under U+L ventilation condition were analyzed. Nitrogen injection in the tailgate was proposed for coal spontaneous combustion prevention. The results show that air leakage changed the distribution of oxygen and temperature fields in the "110" goaf, causing the region 20~60 m parallel to the retained roadway to remain in the oxidation zone for spontaneous combustion. As the working face advanced, the area change curve of SCD zones in the "110" goaf exhibited a "double inflection point" pattern. Eliminating the "retained roadway oxidation zone" can effectively reduce the spontaneous combustion risks in the "110" goaf and ensure mining safety. This study enriches the mechanisms of coal spontaneous combustion.

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.

Smoke dispersion test and emergency control plan of fire in mine roadway during downward ventilation.

To explore the wind flow turbulence and smoke flow diffusion law during the mine downward ventilation fire, two similar experimental platforms of a inclined single pipe test device and a loop system multiple pipe test device were built. The change data of the air flow in the pipeline during the fire period under different air volumes were measured. The evolution process of downward ventilation fire in the whole roadway network domain in Dayan Mine was simulated, and the emergency plan was put forward. The results show that in the experiment, the combustion intensity of the fire source is positively correlated with the ventilation power, and the fire wind pressure increases with the increase of the inclination angle of the pipeline. The throttling effect of the fire area and the combustion of the fire source together make the air volume in the pipeline change rapidly. The critical wind speed that makes the downward ventilation flow fire wind pressure equal to the fan power is 1.8 m s-1. The stronger the fan capacity, the stronger the ability of the main air path to overcome the resistance of the fire zone and maintain the original state. In the simulation, the most dangerous place when the downward ventilation fire smoke is reversed is the area (weak flow area) in the mine tunnel network where the ventilation power is weaker than the fire wind power. This study can provide a theoretical basis for the formulation of emergency plans for mine fire accidents.

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.

Dynamic distribution and prevention of spontaneous combustion of coal in gob-side entry retaining goaf.

The 11101 working face of Qipanjing Mine was taken as the research object to explore the dynamic change law of the spontaneous combustion of the remaining coal in the gob-side entry retaining goaf area. A sealed oxygen consumption experiment was conducted to determine the (critical) oxygen volume fraction in the suffocation zone and continuous oxygen consumption rate of coal samples. The parameters of the working face were measured on site, and the air volume fraction in the goaf was monitored using a beam tube. Considering upward ventilation and the effect of gravity, a UDF control program for the falling medium in the gob-side entry retaining goaf was written. Based on the experimental results, a control program for the continuous oxygen consumption rate of the remnant coal was compiled, the dynamic distribution of the flow field in the gob-side entry retaining goaf was simulated with different advancing positions and air leakage at the working face, and a prediction model for the spontaneous combustion danger area was established. Finally, fire prevention measures via grouting in the return air lane side and nitrogen injection in the retaining lane side were put forward. The results showed that with the variation in the advancing position of the working face or in the air leakage of the air intake lane, the range of the natural hazardous area of the gob-side entry retaining goaf presents a distribution with a power function SF = xn+b (0 < n < 1). The theoretically proposed fire-fighting measures can effectively reduce the risk of spontaneous combustion of coal.

Chronic Alcohol Exposure Alters Gene Expression and Neurodegeneration Pathways in the Brain of Adult Mice.

BACKGROUND: Chronic alcohol consumption can alter the structure of the central nervous system and disrupt cognitive function. Alcoholics are more likely to develop neurodegenerative disorders such as Alzheimer's disease (AD) and Parkinson's disease (PD). However, the role of alcohol in promoting neurotoxicity and neurodegeneration remains unclear. OBJECTIVE: In this study, we aimed at estimating the effects of chronic binge alcohol exposure on brain transcriptome and behavior changes in a chronic "Drinking in the Dark" (DID) mouse model. METHODS: The adult C57BL/6J male mice were exposed to alcohol for 4 weeks. RNA-seq was applied to assess the effects of chronic alcohol exposure on transcriptome in brain. The open field test and novel object recognition test were used to assess the changes of anxiety level, locomotive function, and short-term memory induced by alcohol. RNA-seq analysis revealed that chronic alcohol exposure caused significant change in the brain transcriptome, especially in prefrontal cortex. RESULTS: The gene dysregulation caused by chronic alcohol exposure includes pathways related to mitochondrial energy metabolism (such as oxidative phosphorylation) and multiple neurodegenerative diseases (such as AD and PD). Furthermore, the pathway and network analyses suggest that the genes involved in mitochondrial energy metabolism, ubiquitin-proteasome system, Wnt signaling pathway, and microtubules may attribute to the neurotoxicity and neurodegeneration caused by chronic alcohol consumption. Additionally, locomotive function was also significantly impaired. CONCLUSION: This work provides gene transcriptional profile data for future research on alcohol-induced neurodegenerative diseases, especially AD and PD.

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.

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.