Integrating single-nucleus sequence profiling to reveal the transcriptional dynamics of Alzheimer's disease, Parkinson's disease, and multiple sclerosis.

BACKGROUND: Alzheimer's disease (AD), Parkinson's disease (PD), and multiple sclerosis (MS) are three nervous system diseases that partially overlap clinically and genetically. However, bulk RNA-sequencing did not accurately detect the core pathogenic molecules in them. The availability of high-quality single cell RNA-sequencing data of post-mortem brain collections permits the generation of a large-scale gene expression in different cells in human brain, focusing on the molecular features and relationships between diseases and genes. We integrated single-nucleus RNA-sequencing (snRNA-seq) datasets of human brains with AD, PD, and MS to identify transcriptomic commonalities and distinctions among them. METHODS: The snRNA-seq datasets were downloaded from Gene Expression Omnibus (GEO) database. The Seurat package was used for snRNA-seq data processing. The uniform manifold approximation and projection (UMAP) were utilized for cluster identification. The FindMarker function in Seurat was used to identify the differently expressed genes. Functional enrichment analysis was carried out using the Gene Set Enrichment Analysis (GSEA) and Gene ontology (GO). The protein-protein interaction (PPI) analysis of differentially expressed genes (DEGs) was analyzed using STRING database ( http://string-db.org ). SCENIC analysis was performed using utilizing pySCENIC (v0.10.0) based on the hg19-tss-centered-10 kb-10species databases. The analysis of potential therapeutic drugs was analyzed on Connectivity Map ( https://clue.io ). RESULTS: The gene regulatory network analysis identified several hub genes regulated in AD, PD, and MS, in which HSPB1 and HSPA1A were key molecules. These upregulated HSP family genes interact with ribosome genes in AD and MS, and with immunomodulatory genes in PD. We further identified several transcriptional regulators (SPI1, CEBPA, TFE3, GRHPR, and TP53) of the hub genes, which has important implications for uncovering the molecular crosstalk among AD, PD, and MS. Arctigenin was identified as a potential therapeutic drug for AD, PD, and MS. CONCLUSIONS: Together, the integrated snRNA-seq data and findings have significant implications for unraveling the shared and unique molecular crosstalk among AD, PD, and MS. HSPB1 and HSPA1A as promising targets involved in the pathological mechanisms of neurodegenerative diseases. Additionally, the identification of arctigenin as a potential therapeutic drug for AD, PD, and MS further highlights its potential in treating these neurological disorders. These discoveries lay the groundwork for future research and interventions to enhance our understanding and treatment of AD, PD, and MS.

Single-nucleus transcriptional profiling uncovers the reprogrammed metabolism of astrocytes in Alzheimer's disease.

Astrocytes play an important role in the pathogenesis of Alzheimer's disease (AD). It is widely involved in energy metabolism in the brain by providing nutritional and metabolic support to neurons; however, the alteration in the metabolism of astrocytes in AD remains unknown. Through integrative analysis of single-nucleus sequencing datasets, we revealed metabolic changes in various cell types in the prefrontal cortex of patients with AD. We found the depletion of some important metabolites (acetyl-coenzyme A, aspartate, pyruvate, 2-oxoglutarate, glutamine, and others), as well as the inhibition of some metabolic fluxes (glycolysis and tricarbocylic acid cycle, glutamate metabolism) in astrocytes of AD. The abnormality of glutamate metabolism in astrocytes is unique and important. Downregulation of GLUL (GS) and GLUD1 (GDH) may be the cause of glutamate alterations in astrocytes in AD. These results provide a basis for understanding the characteristic changes in astrocytes in AD and provide ideas for the study of AD pathogenesis.

Single-cell analysis reveals transcriptomic reprogramming in aging primate entorhinal cortex and the relevance with Alzheimer's disease.

The entorhinal cortex is of great importance in cognition and memory, its dysfunction causes a variety of neurological diseases, particularly Alzheimer's disease (AD). Yet so far, research on entorhinal cortex is still limited. Here, we provided the first single-nucleus transcriptomic map of primate entorhinal cortex aging. Our result revealed that synapse signaling, neurogenesis, cellular homeostasis, and inflammation-related genes and pathways changed in a cell-type-specific manner with age. Moreover, among the 7 identified cell types, we highlighted the neuronal lineage that was most affected by aging. By integrating multiple datasets, we found entorhinal cortex aging was closely related to multiple neurodegenerative diseases, particularly for AD. The expression levels of APP and MAPT, which generate ß-amyloid (Aß) and neurofibrillary tangles, respectively, were increased in most aged entorhinal cortex cell types. In addition, we found that neuronal lineage in the aged entorhinal cortex is more prone to AD and identified a subpopulation of excitatory neurons that are most highly associated with AD. Altogether, this study provides a comprehensive cellular and molecular atlas of the primate entorhinal cortex at single-cell resolution and provides new insights into potential therapeutic targets against age-related neurodegenerative diseases.

Generation of an induced pluripotent stem cell line (ZZUi020-A) from a patient with Parkinson's disease harboring the intermediate-length GGC repeat expansions in the NOTCH2NLC gene.

Here, we describe the generation of an induced pluripotent stem cell (iPSC) line, from a female patient diagnosed with Parkinson's disease (PD). The patient carries a heterozygous intermediate-length GGC repeat expansions mutation in the NOTCH2NLC gene. Skin fibroblasts were reprogrammed using the non-integrating Sendai virus technology to deliver Klf4, OCT3/4, SOX2 and c-MYC factors. The generated iPSC line (ZZUi020-A) presented with expression of common pluripotency markers, showed potential of differentiating into derivatives of the three germ layers, and displayed a normal karyotype. The clone ZZUi020-A is presented thereafter, it can be used to study the mechanisms underlying NOTCH2NLC-PD pathogenesis.

NOTCH2NLC Intermediate-Length Repeat Expansions Are Associated with Parkinson Disease.

NOTCH2NLC GGC repeat expansions were recently identified in neuronal intranuclear inclusion disease (NIID); however, it remains unclear whether they occur in other neurodegenerative disorders. This study aimed to investigate the role of intermediate-length NOTCH2NLC GGC repeat expansions in Parkinson disease (PD). We screened for GGC repeat expansions in a cohort of 1,011 PD patients and identified 11 patients with intermediate-length repeat expansions ranging from 41 to 52 repeats, with no repeat expansions in 1,134 controls. Skin biopsy revealed phospho-alpha-synuclein deposition, confirming the PD diagnosis in 2 patients harboring intermediate-length repeat expansions instead of NIID or essential tremor. Fibroblasts from PD patients harboring intermediate-length repeat expansions revealed NOTCH2NLC upregulation and autophagic dysfunction. Our results suggest that intermediate-length repeat expansions in NOTCH2NLC are potentially associated with PD. ANN NEUROL 2021;89:182-187.

AAV/BBB-Mediated Gene Transfer of CHIP Attenuates Brain Injury Following Experimental Intracerebral Hemorrhage.

Cell death is a hallmark of secondary brain injury following intracerebral hemorrhage (ICH). The E3 ligase CHIP has been reported to play a key role in mediating necroptosis-an important mechanism of cell death after ICH. However, there is currently no evidence supporting a function of CHIP in ICH. In the present study, we aimed to determine whether CHIP plays an essential role in brain injury after ICH. Our findings indicated that CHIP expression was increased in the peri-hematomal area in rat models of ICH. The AAV/BBB viral platform enables non-invasive, widespread, and long-lasting global neural expression of target genes. Treatment with AAV/BBB-CHIP ameliorated brain injury and inhibited neuronal necroptosis and inflammation in wild type (WT) rats following ICH. Furthermore, rats with CHIP deficiency experienced severe brain injury and increased levels of neuronal necroptosis and inflammation relative to their WT counterparts. However, treatment with AAV/BBB-CHIP attenuated the effects of CHIP deficiency after ICH. Collectively, our results demonstrate that CHIP inhibits necroptosis and pathological inflammation following ICH, and that overexpression of CHIP may represent a therapeutic intervention for ICH. Moreover, the AAV/BBB viral platform may provide a novel avenue for the treatment of brain injury.

Exogenous nerve growth factor protects the hypoglossal nerve against crush injury.

Studies have shown that sensory nerve damage can activate the p38 mitogen-activated protein kinase (MAPK) pathway, but whether the same type of nerve injury after exercise activates the p38MAPK pathway remains unclear. Several studies have demonstrated that nerve growth factor may play a role in the repair process after peripheral nerve injury, but there has been little research focusing on the hypoglossal nerve injury and repair. In this study, we designed and established rat models of hypoglossal nerve crush injury and gave intraperitoneal injections of exogenous nerve growth factor to rats for 14 days. p38MAPK activity in the damaged neurons was increased following hypoglossal nerve crush injury; exogenous nerve growth factor inhibited this increase in acitivity and increased the survival rate of motor neurons within the hypoglossal nucleus. Under transmission electron microscopy, we found that the injection of nerve growth factor contributed to the restoration of the morphology of hypoglossal nerve after crush injury. Our experimental findings indicate that exogenous nerve growth factor can protect damaged neurons and promote hypoglossal nerve regeneration following hypoglossal nerve crush injury.

[The activation of p38MAPK in hypoglossal necleus and the effect of nerve growth factor on regeneration following hypoglossal nerve crush in rat].

OBJECTIVE: To explore the activation of phospho-p38 mitogen activated protein kinases (p-p38MAPK) and to evaluate the possible role of nerve growth factor (NGF) on neuronal protection and regeneration of injured nerve in a model of hypoglossal nerve injury in rats. METHODS: Sixty healthy adult SD rats were divided randomly into three groups: NC control group, NS control group and NGF treatment group. The rats were allowed to survive for 1, 3, 5, 7 and 14 days after operation respectively. Frozen sections were processed for immunohistochemistry (IHC) to decide the p-p38MAPK expression level in the motoneurons of hypoglossal nucleus. Nissi's staining was used to evaluate cellular morphological and architectural changes in the hypoglossal nucleus. Transmission electron microscope (TEM) study was employed to investigate the subcellular structural alternations of the hypoglossal nerve distal to the injury site. RESULTS: The expression level of p-p38MAPK was low in NC group and elevated in all operated animals. However, p-p3SMAPK immunoreactivity in the hypoglossal motoneurons in NGF group was lower than NS control group after injury. The survival rate of motoneurons in hypoglossal nucleus of injured side in NGF group was higher than that in NS group. Ultrastructural study revealed more regenerating myelinated axons which distributed homogenously in the distal site of the lesioned hypoglossal nerve from the NGF group than NS group. CONCLUSION: p-p38MAPK was slightly expression in normal hypoglossal nucleus but intensively expression after injury. NGF can down-regulate p-p38MAPK expression in the motoneurons of hypoglossal nucleus after hypoglossal nerve was crushed. Exogenous NCF can protect damaged neurons and promote nerve regeneration after hypoglossal nerve crush injury in rats.

[Study on the counting of Streptococcus mutans, Streptococcus sanguis, Haemophilus actinomycetemcomitans by methyl thiazolyl tetrazolium colorimetric method].

OBJECTIVE: To explore the feasibility of methyl thiazolyl tetrazolium (MTT) colorimetric method and the applied condition for the normal bacteria in the mouth, as Streptococcus mutans (S. mutans), Streptococcus sanguis (S. sanguis), Haemophilus actinomycetemcomitans (H. actinomycetemcomitans). METHODS: Colony forming units (CFU) which was the standard antitheses was used to count bacteria. This study would gain some parameters by changing wavelength, reactive time, dosage and so on. MTT colorimetric method was applied in the counting of S. mutans, S. sanguis and H. actinomycetemcomitans. RESULTS: When counting S. mutans, the best wavelength was 510 nm, the best range was 1.5 x 10(5) - 1.0 x 10(7) CFU x mL(-1). When counting S. sanguis, the best wavelength was 545 nm, the best range was 1.5 x 10(5) - 2.0 x 10(7) CFU x mL(-1). When counting H. actinomycetemcomitans, the best wavelength was 557 nm, the best range was 1.0 x 10(6) - 5.0 x 10(7) CFU x mL(-1). MTT colorimetric method can be used for different aged S. mutans, S. sanguis and H. actinomycetemcomitans. CONCLUSION: Oral bacteria could be counted by MTT colorimetric method, which is fast and convenient.

ZnO@Co hybrid nanotube arrays growth from electrochemical deposition: structural, optical, photocatalytic and magnetic properties.

Well-aligned ZnO@Co hybrid nanotube arrays on conductive glass substrates have been obtained by an electrochemical deposition approach. Vertical-aligned ZnO nanotubes with sizes between 300 and 600 nm in diameter and wall thickness of approximately 100 nm have been prepared by selective dissolution from the nanorods. The ZnO@Co heterostructures can be prepared by optimizing the deposition time and controlling the stability of Co2+ ions. Compared to the nanorod arrays, both nanotube arrays and the ZnO@Co heterostructures show enhanced photoluminescent properties. In addition, ZnO and ZnO@Co nanotubes show improved photocatalytic properties compared with the bare ZnO nanorod array, and the hybrid nanotubes exhibit better adsorptive properties than the bare ZnO nanotubes. Furthermore, the ZnO@Co hybrid nanotube arrays show ferromagnetism at room temperature.