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3.
Anal Chim Acta ; 1298: 342383, 2024 Apr 15.
Article in English | MEDLINE | ID: mdl-38462344

ABSTRACT

Developing an accurate and precise approach for the simultaneous detection of ochratoxin A (OTA) and aflatoxin B1 (AFB1) is significant for food safety surveillance. Herein, a photoelectrochemical sensing platform was constructed based on polycarboxylic ionic liquid functionalized metal-organic framework integrated with gold nanoparticles (Yb-MOFs@AuNPs). Sulfhydryl functionalized hairpin DNA (hDNA) was immobilized on a Yb-MOFs@AuNPs modified glassy carbon electrode (GCE) surface through Au-S bond. After blocking residual active binding sites with BSA, gold nanoparticles-labeled AFB1 aptamer (AuNPs-Apt 1) and gold nanorods-labeled OTA aptamer (AuNRs-Apt 2) were introduced to construct a photoelectrochemical aptasensor for the simultaneous determination of AFB1 and OTA. Due to the surface plasmon resonance effect and the nanometer size effect of gold nanomaterials, the photoelectrochemical aptasensor can output photocurrent responses as being excited with different wavelengths at 520 nm and 808 nm, respectively. When the AFB1 and OTA concentration in the range of 0.001-50.0 ng mL-1, a good linear relationship between the photocurrent difference (ΔI) before and after recognizing targets and the logarithm of AFB1 or OTA concentration was obtained. The detection limits for AFB1 and OTA were 0.40 pg mL-1 and 0.19 pg mL-1, respectively. AFB1 and OTA in corn samples were detected simultaneously by the photoelectrochemical aptasensor.


Subject(s)
Aptamers, Nucleotide , Biosensing Techniques , Ionic Liquids , Metal Nanoparticles , Ochratoxins , Gold/chemistry , Aflatoxin B1/analysis , Metal Nanoparticles/chemistry , Aptamers, Nucleotide/chemistry , Limit of Detection , Electrochemical Techniques
4.
Acta Physiol (Oxf) ; 238(2): e13974, 2023 06.
Article in English | MEDLINE | ID: mdl-37186158

ABSTRACT

AIM: Multiple sclerosis (MS) is an autoimmune disease, and its typical characteristics are neuroinflammation and the demyelination of neurons in the central nervous system (CNS). Sterile alpha and TIR motif containing 1 (SARM1) is an essential factor mediating axonal degeneration and SARM1 deletion reduces the neuroinflammation in spinal cord injury. This study aimed to explore the roles of SARM1 and its underlying mechanisms in MS. METHODS: Experimental autoimmune encephalomyelitis (EAE, a model of MS) model was established. Immunostaining, western blot, electron microscope, and HE staining were used to examine the pathological manifestations such as inflammation, demyelination, and neuronal death in SARM1f/f EAE mice and SARM1Nestin -CKO EAE mice. In addition, RNA-seq, real-time PCR and double-immunostaining were used to examine the underlying mechanism of SARM1 in EAE mice. RESULTS: SARM1 was upregulated in neurons of the spinal cords of EAE mice. SARM1 knockout in CNS ameliorated EAE with less neuroinflammation, demyelination, and dead neurons. Mechanically, SARM1 knockout resulted in the reduction of insulin-like growth factor (IGF)-binding protein 2 (IGFBP2) in neurons of EAE mice, which might inhibit the neuroinflammation through inhibiting NF-κB signaling. Finally, activation of NF-κB partially aggravated the neuroinflammation and demyelination deficits of SARM1Nestin -CKO EAE mice. CONCLUSIONS: These results identified the unknown role of SARM1 in the promotion of neuroinflammation and demyelination and revealed a novel drug target pathway of SARM1/IGFBP2/NF-κB for MS.


Subject(s)
Encephalomyelitis, Autoimmune, Experimental , Mice , Animals , Encephalomyelitis, Autoimmune, Experimental/metabolism , Encephalomyelitis, Autoimmune, Experimental/pathology , NF-kappa B/metabolism , Nestin , Neuroinflammatory Diseases , Cytokines/metabolism , Mice, Inbred C57BL , Cytoskeletal Proteins/genetics , Armadillo Domain Proteins/genetics
5.
Front Cell Dev Biol ; 11: 1173432, 2023.
Article in English | MEDLINE | ID: mdl-37143892

ABSTRACT

Gastrointestinal malignancies are common digestive system tumor worldwide. Nucleoside analogues have been widely used as anticancer drugs for the treatment of a variety of conditions, including gastrointestinal malignancies. However, low permeability, enzymatic deamination, inefficiently phosphorylation, the emergence of chemoresistance and some other issues have limited its efficacy. The prodrug strategies have been widely applied in drug design to improve pharmacokinetic properties and address safety and drug-resistance issues. This review will provide an overview of the recent developments of prodrug strategies in nucleoside analogues for the treatment of gastrointestinal malignancies.

6.
Article in English | MEDLINE | ID: mdl-37065635

ABSTRACT

Background: Bufei Yishen formula (BYF) is an effective prescription for the clinical treatment of chronic obstructive pulmonary disease (COPD). However, the molecular mechanism by which it exerts its pharmacological effects remains to be explored. Methods: The human bronchial cell line BEAS-2B was treated with cigarette smoke extract (CSE). Cellular senescence markers were detected by Western blot and ELISA. Potential transcription factor of klotho was predicted using JASPAR and USCS databases. Results: CSE induced cellular senescence with intracellular accumulation of cellular senescence biomarkers (p16, p21 and p27) and increased secretion of senescence-related secretory phenotypic (SASP) factors (IL-6, IL-8, and CCL3). In contrast, BYF treatment inhibited CSE-induced cellular senescence. CSE suppressed the transcription, expression and secretion of klotho, whereas BYF treatment rescued its transcription, expression and secretion. CSE downregulated the protein level of ZNF263, whereas BYF treatment rescued the expression of ZNF263. Furthermore, ZNF263-overexpressing BEAS-2B cells could inhibit CSE-induced cellular senescence and SASP factor secretion by upregulating the expression of klotho. Conclusion: This study revealed a novel pharmacological mechanism by which BYF alleviates clinical symptoms of COPD patients, and regulating ZNF263 and klotho expression may be beneficial to the treatment and prevention of COPD.


Subject(s)
Drugs, Chinese Herbal , Pulmonary Disease, Chronic Obstructive , Humans , Pulmonary Disease, Chronic Obstructive/drug therapy , Pulmonary Disease, Chronic Obstructive/genetics , Pulmonary Disease, Chronic Obstructive/metabolism , Drugs, Chinese Herbal/pharmacology , Bronchi , Cellular Senescence , DNA-Binding Proteins
7.
Anal Chim Acta ; 1251: 340982, 2023 Apr 22.
Article in English | MEDLINE | ID: mdl-36925306

ABSTRACT

Circulating tumor cells (CTCs) are commonly considered as the major cause of tumor metastasis and can eventually lead to death. Therefore, developing a high-performance method for the determination of CTCs is very significant for promoting the cancer survival rate. Photoelectrochemical biosensing systems have been extensively investigated and applied for bioassays. Herein, Bi2O2S nanoflowers were successfully prepared through a simple one-step hydrothermal method. After being integrated with gold nanoparticles with a diameter of ∼45 nm, AuNPs/Bi2O2S nanocomposites were coated onto an ITO electrode surface to build a photoelectrochemical sensing platform which can be excited with near-infrared light to produce photocurrent response. Subsequently, mercapto-group functionalized aptamer (SH-Apt) was fixed onto the AuNPs/Bi2O2S/ITO surface. Due to the overexpress of MUC1 protein in the cell membrane, MCF-7 cells were specifically trapped on the SH-Apt/AuNPs/Bi2O2S/ITO surface. The introduce of MCF-7 cells lead to an obvious decrease on the photocurrent response. The photocurrent variation shows a satisfied linear relationship to the logarithm of MCF-7 cells concentration ranged from 50 to 6 × 105 cell mL-1. The detection limit obtained is 17 cell mL-1. The PEC biosensor shows excellent sensitivity, selectivity and stability for sensing MCF-7 cells, even for determining MCF-7 cells in clinical serum samples.


Subject(s)
Aptamers, Nucleotide , Biosensing Techniques , Metal Nanoparticles , Humans , Gold , MCF-7 Cells , Electrochemical Techniques/methods , Biosensing Techniques/methods , Limit of Detection
8.
Glia ; 71(5): 1197-1216, 2023 05.
Article in English | MEDLINE | ID: mdl-36617748

ABSTRACT

The homeostasis of glutamate is mainly regulated by the excitatory amino acid transporters (EAATs), especially by EAAT2 in astrocytes. Excessive glutamate in the synaptic cleft caused by dysfunction or dysregulation of EAAT2 can lead to excitotoxicity, neuronal death and cognitive dysfunction. However, it remains unclear about the detailed regulation mechanism of expression and function of astrocytic EAAT2. In this study, first, we found increased neuronal death and impairment of cognitive function in YAPGFAP -CKO mice (conditionally knock out Yes-associated protein [YAP] in astrocytes), and identified EAAT2 as a downstream target of YAP through RNA sequencing. Second, the expression of EAAT2 was decreased in cultured YAP-/- astrocytes and the hippocampus of YAPGFAP -CKO mice, and glutamate uptake was reduced in YAP-/- astrocytes, but increased in YAP-upregulated astrocytes. Third, further investigation of the mechanism showed that the mRNA and protein levels of ß-catenin were decreased in YAP-/- astrocytes and increased in YAP-upregulated astrocytes. Wnt3a activated YAP signaling and up-regulated EAAT2 through ß-catenin. Furthermore, over-expression or activation of ß-catenin partially restored the downregulation of EAAT2, the impairment of glutamate uptake, neuronal death and cognitive decline that caused by YAP deletion. Finally, activation of EAAT2 also rescued neuronal death and cognitive decline in YAPGFAP -CKO mice. Taken together, our study identifies an unrecognized role of YAP signaling in the regulation of glutamate homeostasis through the ß-catenin/EAAT2 pathway in astrocytes, which may provide novel insights into the pathogenesis of brain diseases that closely related to the dysfunction or dysregulation of EAAT2, and promote the development of clinical strategy.


Subject(s)
Astrocytes , YAP-Signaling Proteins , Animals , Mice , Astrocytes/metabolism , beta Catenin/metabolism , Glutamic Acid/metabolism , Homeostasis , Amino Acid Transport Systems/metabolism , Excitatory Amino Acid Transporter 2/metabolism , Excitatory Amino Acid Transporter 1/genetics , Excitatory Amino Acid Transporter 1/metabolism
9.
Front Plant Sci ; 13: 1013263, 2022.
Article in English | MEDLINE | ID: mdl-36212288

ABSTRACT

The ornamental crabapple is a multipurpose landscaping tree that bears brilliant fruit throughout the winter. However, whether or not its fruit persists after maturation is specifically correlated to cultivar characteristics. In this work, we screened two different types that display fruit-retention ("Donald Wyman," "Red Jewel," and "Sugar Tyme") and fruit-abscission ("Radiant" and "Flame") in Northern China across the whole winter using multi-year successional records. Fruit-abscission was determined predominantly by the abscission zone established at the base of the pedicel, regardless of fruit size and pedicel length, according to the results of the comparative research. The primary physiological rationale was the accumulation of hydrolases activity (pectinesterase, cellulase, polygalacturonase, and ß-glucosidase). Comparative transcriptomics further identified a number of upregulated DEGs involved in the synthesis pathways of canonical phytohormones, such as ethylene, jasmonic acid, abscisic acid, and cytokinin, as well as 12 transcription factors linked in downstream signaling in fruit-abscission cultivars. Finally, a model incorporating multi-layered modulation was proposed for the fruit abscission of ornamental crabapple. This study will serve as the foundation for the development of fruit-viewing crabapples that have an extended ornamental lifetime.

10.
Cell Death Dis ; 13(9): 759, 2022 09 02.
Article in English | MEDLINE | ID: mdl-36055989

ABSTRACT

Astrocytes are important components of the innate immune response in the central nervous system (CNS), involving in the inflammatory and neurotoxic responses that occur in CNS diseases, such as multiple sclerosis (MS). Recent studies have shown that SARM1 plays a critical role in axonal degeneration and inflammation. However, the detailed role of astrocytic SARM1 in MS remains unclear. Here, we established the MS model of mice - experimental autoimmune encephalomyelitis (EAE) and found that SARM1 was upregulated in astrocytes of the spinal cords of EAE mice. Moreover, conditional knockout of astrocytic SARM1 (SARM1GFAP-CKO mice, SARM1Aldh1L1-CKO mice) delayed EAE with later onset, alleviated the inflammatory infiltration, and inhibited the demyelination and neuronal death. Mechanically, RNA-seq revealed that the expression of glial-derived neurotrophic factor (GDNF) was upregulated in SARM1-/- astrocytes. Western blot and immunostaining further confirmed the upregulation of GDNF in spinal cord astrocytes of SARM1GFAP-CKO EAE mice. Interestingly, the downregulation of GDNF by streptozotocin (STZ, a drug used to downregulate GDNF) treatment worsened the deficits of SARM1GFAP-CKO EAE mice. These findings identify that astrocytic SARM1 promotes neuroinflammation and axonal demyelination in EAE by inhibiting the expression of GDNF, reveal the novel role of SARM1/GDNF signaling in EAE, and provide new therapeutic ideas for the treatment of MS.


Subject(s)
Armadillo Domain Proteins/metabolism , Cytoskeletal Proteins/metabolism , Encephalomyelitis, Autoimmune, Experimental , Glial Cell Line-Derived Neurotrophic Factor/metabolism , Multiple Sclerosis , Animals , Astrocytes/metabolism , Glial Cell Line-Derived Neurotrophic Factor/genetics , Mice , Mice, Inbred C57BL , Mice, Knockout , Multiple Sclerosis/genetics , Multiple Sclerosis/metabolism , Neuroinflammatory Diseases , Spinal Cord/metabolism
11.
ACS Appl Bio Mater ; 5(10): 4741-4759, 2022 10 17.
Article in English | MEDLINE | ID: mdl-36102324

ABSTRACT

Stem cells play a critical role in peripheral nerve regeneration. Nerve scaffolds fabricated by specific materials can help induce the neurogenic differentiation of stem cells. Therefore, it is a potential strategy to enhance therapeutic efficiency. Graphene family nanomaterials are widely applied in repairing peripheral nerves. However, the mechanism underlying the pro-regeneration effects remains elusive. In this review, we first discuss the properties of graphene family nanomaterials, including monolayer and multilayer graphene, few-layer graphene, graphene oxide, reduced graphene oxide, and graphene quantum dots. We also introduce their applications in regulating stem cell differentiation. Then, we review the potential mechanisms of the neurogenic differentiation of stem cells facilitated by the materials. Finally, we discuss the existing challenges in this field to advance the development of nerve biomaterials.


Subject(s)
Graphite , Nanostructures , Biocompatible Materials , Cell Differentiation , Graphite/pharmacology , Nanostructures/therapeutic use , Nerve Regeneration , Peripheral Nerves , Stem Cells , Tissue Engineering
12.
Cell Death Dis ; 13(7): 638, 2022 07 22.
Article in English | MEDLINE | ID: mdl-35869039

ABSTRACT

Autism spectrum disorder (ASD), a group of neurodevelopmental disorder diseases, is characterized by social deficits, communication difficulties, and repetitive behaviors. Sterile alpha and TIR motif-containing 1 protein (SARM1) is known as an autism-associated protein and is enriched in brain tissue. Moreover, SARM1 knockdown mice exhibit autism-like behaviors. However, its specific mechanism in ASD pathogenesis remains unclear. Here we generated parvalbumin-positive interneurons (PVI)-specific conditional SARM1 knockout (SARM1PV-CKO) mice. SARM1PV-CKO male mice showed autism-like behaviors, such as mild social interaction deficits and repetitive behaviors. Moreover, we found that the expression level of parvalbumin was reduced in SARM1PV-CKO male mice, together with upregulated apoptosis-related proteins and more cleaved-caspase-3-positive PVIs, suggesting that knocking out SARM1 may cause a reduction in the number of PVIs due to apoptosis. Furthermore, the expression of c-fos was shown to increase in SARM1PV-CKO male mice, in combination with upregulation of excitatory postsynaptic proteins such as PSD-95 or neuroligin-1, indicating enhanced excitatory synaptic input in mutant mice. This notion was further supported by the partial rescue of autism-like behavior deficits by the administration of GABA receptor agonists in SARM1PV-CKO male mice. In conclusion, our findings suggest that SARM1 deficiency in PVIs may be involved in the pathogenesis of ASD.


Subject(s)
Autism Spectrum Disorder , Autistic Disorder , Animals , Armadillo Domain Proteins/genetics , Autism Spectrum Disorder/genetics , Autistic Disorder/genetics , Autistic Disorder/pathology , Cytoskeletal Proteins/genetics , Disease Models, Animal , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , Neurons/metabolism , Parvalbumins/metabolism
14.
Clin Transl Med ; 12(3): e770, 2022 03.
Article in English | MEDLINE | ID: mdl-35343092

ABSTRACT

BACKGROUND: Cyclin C (CCNC) was reported to take part in regulating mitochondria-derived oxidative stress under cisplatin stimulation. However, its effect in gastric cancer is unknown. This study aimed to investigate the role of cyclin C and its ubiquitylation in regulating cisplatin resistance in gastric cancer. METHODS: The interaction between HECT domain and ankyrin repeat-containing E3 ubiquitin-protein ligase 1 (HACE1) and cyclin C was investigated by GST pull-down assay, co-immunoprecipitation and ubiquitylation assay. Mitochondria-derived oxidative stress was studied by MitoSOX Red assay, seahorse assay and mitochondrial membrane potential measurement. Cyclin C-associated cisplatin resistance was studied in vivo via xenograft. RESULTS: HACE1 catalysed the ubiquitylation of cyclin C by adding Lys11-linked ubiquitin chains when cyclin C translocates to cytoplasm induced by cisplatin treatment. The ubiquitin-modified cyclin C then anchor at mitochondira, which induced mitochondrial fission and ROS synthesis. Depleting CCNC or mutation on the ubiquitylation sites decreased mitochondrial ROS production and reduced cell apoptosis under cisplatin treatment. Xenograft study showed that disrupting cyclin C ubiquitylation by HACE1 conferred impairing cell apoptosis response upon cisplatin administration. CONCLUSIONS: Cyclin C is a newly identified substrate of HACE1 E3 ligase. HACE1-mediated ubiquitylation of cyclin C sheds light on a better understanding of cisplatin-associated resistance in gastric cancer patients. Ubiquitylation of cyclin C by HACE1 regulates cisplatin-associated sensitivity in gastric cancer. With cisplatin-induced nuclear-mitochondrial translocation of cyclin C, its ubiquitylation by HACE1 increased mitochondrial fission and mitochondrial-derived oxidative stress, leading to cell apoptosis.


Subject(s)
Cisplatin , Stomach Neoplasms , Cisplatin/pharmacology , Cyclin C/genetics , Humans , Stomach Neoplasms/drug therapy , Ubiquitin-Protein Ligases/genetics , Ubiquitin-Protein Ligases/metabolism , Ubiquitination
15.
J Bone Miner Metab ; 40(3): 448-459, 2022 May.
Article in English | MEDLINE | ID: mdl-35347430

ABSTRACT

INTRODUCTION: The influence of enamel matrix derivative (EMD) on proliferation and osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) was explored in high glucose (HG) microenvironment with interaction of Wnt/ß-catenin pathway. MATERIALS AND METHODS: Extraction of BMSCs from Sprague-Dawley rats, culture, and identification were manifested. The cells were treated with different concentration of EMD in HG to figure out the most available concentration for proliferation and osteogenic differentiation. Then, observation of cell growth curve and cell cycle changes, and detection of Osterix, runt-related transcription factor 2 (Runx2), COL-I, early osteogenic indexes, Calcium salt deposition, and ß-catenin protein in Wnt/ß-catenin pathway were assured. After adding Wnt/ß-catenin pathway inhibitor (XAV-939) in the cells with osteogenesis induction, detection of binding of ß-catenin to Osterix was clarified. RESULTS: Via identification BMSCs cultured in vitro was qualified. Different concentrations of EMD could accelerate cell proliferation in HG and osteogenesis induction, and 75 µg/mL EMD had the best effect. The HG augmented BMSCs proliferation and the propidium iodide index of flow cytometry cycle was elevated in HG, which were strengthened via the EMD. After BMSCs' osteogenesis induction, Osterix, Runx2, CoL-1, early osteogenic indexes, and calcium salt deposition were reduced, but elevated via EMD. ß-Catenin was the lowest in the HG, but elevated after EMD. After addition of XAV-939, reduction of ß-catenin and the downstream (Osterix and Runx2) were manifested. Detection of binding protein bands was in ß-catenin and Osterix of the HG after EMD treatment. CONCLUSION: EMD may facilitate the osteogenic differentiation of BMSCs via activating the Wnt/ß-catenin pathway in HG.


Subject(s)
Mesenchymal Stem Cells , Osteogenesis , Wnt Signaling Pathway , Animals , Bone Marrow Cells/metabolism , Calcium/metabolism , Cell Differentiation , Cells, Cultured , Core Binding Factor Alpha 1 Subunit/genetics , Core Binding Factor Alpha 1 Subunit/metabolism , Glucose/pharmacology , Rats , Rats, Sprague-Dawley , beta Catenin/metabolism
16.
Stem Cell Reports ; 17(3): 664-677, 2022 03 08.
Article in English | MEDLINE | ID: mdl-35148842

ABSTRACT

The horizontal basal cells (HBCs) of olfactory epithelium (OE) serve as reservoirs for stem cells during OE regeneration, through proliferation and differentiation, which is important in recovery of olfactory function. However, the molecular mechanism of regulation of HBC proliferation and differentiation after injury remains unclear. Here, we found that yes-associated protein (YAP) was upregulated and activated in HBCs after OE injury. Deletion of YAP in HBCs led to impairment in OE regeneration and functional recovery of olfaction after injury. Mechanically, YAP was activated by S1P/S1PR2 signaling, thereby promoting the proliferation of HBCs and OE regeneration after injury. Finally, activation of YAP signaling enhanced the proliferation of HBCs and improved functional recovery of olfaction after OE injury or in Alzheimer's disease model mice. Taken together, these results reveal an S1P/S1PR2/YAP pathway in OE regeneration in response to injury, providing a promising therapeutic strategy for OE injury.


Subject(s)
Olfactory Mucosa , Stem Cells , Animals , Cell Differentiation/physiology , Mice , Signal Transduction , Stem Cells/metabolism
17.
Biosens Bioelectron ; 202: 113905, 2022 Apr 15.
Article in English | MEDLINE | ID: mdl-35033829

ABSTRACT

A visible and near-infrared light dual responsive "signal-off" and "signal-on" photoelectrochemical aptasensor was constructed for determining prostate-specific antigen (PSA) based on MoS2 nanoflowers and gold nanobipyramids. The dual responsive photoelectrochemical aptasensor can provide accurate results for PSA determination. For the photoelectrochemical aptasensor fabrication, amino-group functionalized aptamers were immobilized on a MoS2 nanoflowers modified glassy carbon electrode surface for the specific recognition, and thus to achieve a "signal-off" aptasensor for PSA under visible light illumination. Subsequently, gold nanobipyramids integrated with thiol-functional aptamer were introduced to the "signal-off" aptasensing interface after PSA recognition. Under excitation with near-infrared light at 808 nm, the photocurrent response can be amplified significantly due to the excellent conductivity and local surface plasmon resonance effect of gold nanobipyramids, thus to producing a "signal-on" model for determining PSA. Under the optimized conditions, the dual-responsive photoelectrochemical aptasensor shows a linear response to the logarithm of PSA concentration in the range of 0.005-100 ng/mL. The detection limits for PSA determination with a "signal-off" or a "signal-on" mode are 1.75 pg mL-1 and 0.39 pg mL-1, respectively. The dual-responsive photoelectrochemical aptasensor was also employed for determining PSA in clinical serum samples with satisfactory selectivity and excellent accuracy.


Subject(s)
Aptamers, Nucleotide , Biosensing Techniques , Metal Nanoparticles , Prostate-Specific Antigen/analysis , Biosensing Techniques/methods , Electrochemical Techniques/methods , Gold , Humans , Light , Limit of Detection , Male
18.
Front Mol Neurosci ; 14: 720984, 2021.
Article in English | MEDLINE | ID: mdl-34720871

ABSTRACT

Objective: The objective of this study is to explore the role of GRIN2A gene in idiopathic generalized epilepsies and the potential underlying mechanism for phenotypic variation. Methods: Whole-exome sequencing was performed in a cohort of 88 patients with idiopathic generalized epilepsies. Electro-physiological alterations of the recombinant N-methyl-D-aspartate receptors (NMDARs) containing GluN2A mutants were examined using two-electrode voltage-clamp recordings. The alterations of protein expression were detected by immunofluorescence staining and biotinylation. Previous studies reported that epilepsy related GRIN2A missense mutations were reviewed. The correlation among phenotypes, functional alterations, and molecular locations was analyzed. Results: Three novel heterozygous missense GRIN2A mutations (c.1770A > C/p.K590N, c.2636A > G/p.K879R, and c.3199C > T/p.R1067W) were identified in three unrelated cases. Electrophysiological analysis demonstrated R1067W significantly increased the current density of GluN1/GluN2A NMDARs. Immunofluorescence staining indicated GluN2A mutants had abundant distribution in the membrane and cytoplasm. Western blotting showed the ratios of surface and total expression of the three GluN2A-mutants were significantly increased comparing to the wild type. Further analysis on the reported missense mutations demonstrated that mutations with severe gain-of-function were associated with epileptic encephalopathy, while mutations with mild gain of function were associated with mild phenotypes, suggesting a quantitative correlation between gain-of-function and phenotypic severity. The mutations located around transmembrane domains were more frequently associated with severe phenotypes and absence seizure-related mutations were mostly located in carboxyl-terminal domain, suggesting molecular sub-regional effects. Significance: This study revealed GRIN2A gene was potentially a candidate pathogenic gene of idiopathic generalized epilepsies. The functional quantitative correlation and the molecular sub-regional implication of mutations helped in explaining the relatively mild clinical phenotypes and incomplete penetrance associated with GRIN2A variants.

19.
Cell Death Dis ; 12(10): 907, 2021 10 05.
Article in English | MEDLINE | ID: mdl-34611127

ABSTRACT

Cholesterols are the main components of myelin, and are mainly synthesized in astrocytes and transported to oligodendrocytes and neurons in the adult brain. It has been reported that Hippo/yes-associated protein (YAP) pathways are involved in cholesterol synthesis in the liver, however, it remains unknown whether YAP signaling can prevent the demyelination through promoting cholesterol synthesis in experimental autoimmune encephalomyelitis (EAE), a commonly used animal model of multiple sclerosis characterized by neuroinflammation and demyelination. Here, we found that YAP was upregulated and activated in astrocytes of spinal cords of EAE mice through suppression of the Hippo pathway. YAP deletion in astrocytes aggravated EAE with earlier onset, severer inflammatory infiltration, demyelination, and more loss of neurons. Furthermore, we found that the neuroinflammation was aggravated and the proliferation of astrocytes was decreased in YAPGFAP-CKO EAE mice. Mechanically, RNA-seq revealed that the expression of cholesterol-synthesis pathway genes such as HMGCS1 were decreased in YAP-/- astrocytes. qPCR, western blot, and immunostaining further confirmed the more significant reduction of HMGCS1 in spinal cord astrocytes of YAPGFAP-CKO EAE mice. Interestingly, upregulation of cholesterol-synthesis pathways by diarylpropionitrile (DPN) (an ERß-ligand, to upregulate the expression of HMGCS1) treatment partially rescued the demyelination deficits in YAPGFAP-CKO EAE mice. Finally, activation of YAP by XMU-MP-1 treatment promoted the expression of HMGCS1 in astrocytes and partially rescued the demyelination and inflammatory infiltration deficits in EAE mice. These findings identify unrecognized functions of astrocytic YAP in the prevention of demyelination through promoting cholesterol synthesis in EAE, and reveal a novel pathway of YAP/HMGCS1 for cholesterol synthesis in EAE pathology.


Subject(s)
Astrocytes/metabolism , Cholesterol/biosynthesis , Demyelinating Diseases/genetics , Encephalomyelitis, Autoimmune, Experimental/genetics , Gene Expression Regulation , Animals , Astrocytes/pathology , Body Weight , Cell Proliferation , Down-Regulation/genetics , Encephalomyelitis, Autoimmune, Experimental/pathology , Encephalomyelitis, Autoimmune, Experimental/physiopathology , Hippo Signaling Pathway , Inflammation/pathology , Mice, Knockout , Models, Biological , Neurons/metabolism , Neurons/pathology , RNA, Messenger/genetics , RNA, Messenger/metabolism , Recovery of Function , Spinal Cord/pathology , Spinal Cord/ultrastructure , Up-Regulation/genetics , YAP-Signaling Proteins/deficiency , YAP-Signaling Proteins/metabolism
20.
Aging Cell ; 20(9): e13465, 2021 09.
Article in English | MEDLINE | ID: mdl-34415667

ABSTRACT

Senescent astrocytes accumulate with aging and contribute to brain dysfunction and diseases such as Alzheimer's disease (AD), however, the mechanisms underlying the senescence of astrocytes during aging remain unclear. In the present study, we found that Yes-associated Protein (YAP) was downregulated and inactivated in hippocampal astrocytes of aging mice and AD model mice, as well as in D-galactose and paraquat-induced senescent astrocytes, in a Hippo pathway-dependent manner. Conditional knockout of YAP in astrocytes significantly promoted premature senescence of astrocytes, including reduction of cell proliferation, hypertrophic morphology, increase in senescence-associated ß-galactosidase activity, and upregulation of several senescence-associated genes such as p16, p53 and NF-κB, and downregulation of Lamin B1. Further exploration of the underlying mechanism revealed that the expression of cyclin-dependent kinase 6 (CDK6) was decreased in YAP knockout astrocytes in vivo and in vitro, and ectopic overexpression of CDK6 partially rescued YAP knockout-induced senescence of astrocytes. Finally, activation of YAP signaling by XMU-MP-1 (an inhibitor of Hippo kinase MST1/2) partially rescued the senescence of astrocytes and improved the cognitive function of AD model mice and aging mice. Taken together, our studies identified unrecognized functions of YAP-CDK6 pathway in preventing astrocytic senescence in vitro and in vivo, which may provide further insights and new targets for delaying brain aging and aging-related neurodegenerative diseases such as AD.


Subject(s)
Alzheimer Disease/metabolism , Astrocytes/metabolism , Cellular Senescence , Cyclin-Dependent Kinase 6/metabolism , YAP-Signaling Proteins/metabolism , Animals , Cells, Cultured , Cognition , Mice , Mice, Inbred C57BL , Signal Transduction
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