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1.
Int. j. morphol ; 42(3): 718-727, jun. 2024. ilus, tab
Article in English | LILACS | ID: biblio-1564598

ABSTRACT

SUMMARY: Prior research on post-COVID-19 or long COVID primarily focused on the presence of SARS-CoV-2 mostly in symptomatic patients. This study aimed to investigate the persistence of SARS-CoV-2 after 1 year of asymptomatic or mild COVID-19. SARS-CoV-2 infected and control K18-hACE2 transgenic mice (n=25) were studied. Moderate and severe symptomatic subjects were sacrificed after eight days, while mild or asymptomatic mice were kept in BSL-III for twelve months. Analyses included general condition, histochemistry, immunohistochemistry, transmission electron microscopy, and qRT-PCR. Lungs from the twelve-month group showed thickening of alveolar walls, with some lungs exhibiting the recruitment of inflammatory cells, the presence of SARS- CoV-2 mRNA, immunopositivity for the SARS-CoV-2 spike protein, and TEM showed viruses (60-125 nm) within vesicles, indicating continued replication. Certain lung samples showed persistent SARS-CoV-2 presence in Club cells, endothelial cells, and macrophages. The eight-day group exhibited viral interstitial pneumonitis, SARS-CoV-2 immunopositivity, and mRNA. The eight-day hearts displayed viral mRNA, while the twelve-month hearts tested negative. Some asymptomatic twelve-month subjects presented reduced surfactant, basal membrane thickening, fibrosis, and mild autonomic nerve degeneration. In this study conducted on mice, findings indicate the potential for chronic persistence of SARS-CoV-2 in the lungs one year post initial mild or asymptomatic infection, which could suggest the possibility of recurrent episodes in similar human conditions. The observed thickening of alveolar walls and potential fibrotic areas in these mice may imply an increased risk of post-COVID fibrosis in humans. Furthermore, the presence of SARS-CoV-2-positive inflammatory cells in some asymptomatic murine cases could herald a progression toward ongoing inflammation and chronic lung disease in humans. Therefore, the necessity for further studies in human subjects and vigilant monitoring of high-risk human populations is underscored.


Investigaciones anteriores sobre COVID-19 o COVID prolongado se centraron principalmente en la presencia de SARS-CoV-2 principalmente en pacientes sintomáticos. Este estudio tuvo como objetivo investigar la persistencia del SARS-CoV-2 después de 1 año de COVID-19 asintomático o leve. Se estudiaron ratones transgénicos K18-hACE2 infectados con SARS-CoV-2 y de control (n=25). Los animales con síntomas moderados y graves se sacrificaron después de ocho días, mientras que los ratones con síntomas leves o asintomáticos se mantuvieron en BSL-III durante doce meses. Los análisis incluyeron estado general, histoquímica, inmunohistoquímica, microscopía electrónica de transmisión y qRT- PCR. Los pulmones del grupo de doce meses mostraron engrosamiento de las paredes alveolares, y algunos pulmones exhibieron reclutamiento de células inflamatorias, presencia de ARNm del SARS-CoV-2, inmunopositividad para la proteína de la espícula del SARS-CoV-2 y TEM mostró virus (60 -125 nm) dentro de las vesículas, lo que indica una replicación continua. Ciertas muestras de pulmón mostraron una presencia persistente de SARS- CoV-2 en exocrinocitos bronquiolares, células endoteliales y macrófagos. El grupo de ocho días presentó neumonitis intersticial viral, inmunopositividad al SARS-CoV-2 y ARNm. Los corazones de ocho días mostraron ARNm viral, mientras que los corazones de doce meses dieron negativo. Algunos animales asintomáticos de doce meses presentaron disminución del surfactante, engrosamiento de la membrana basal, fibrosis y degeneración leve del nervio autónomo. En este estudio realizado en ratones, los hallazgos indican la posibilidad de persistencia crónica del SARS-CoV-2 en los pulmones un año después de la infección inicial leve o asintomática, lo que podría sugerir la posibilidad de episodios recurrentes en condiciones humanas similares. El engrosamiento observado de las paredes alveolares y las posibles áreas fibróticas en estos ratones puede implicar un mayor riesgo de fibrosis post-COVID en humanos. Además, la presencia de células inflamatorias positivas para SARS- CoV-2 en algunos casos murinos asintomáticos podría presagiar una progresión hacia una inflamación continua y una enfermedad pulmonar crónica en humanos. Por lo tanto, se subraya la necesidad de realizar más estudios en seres humanos y realizar un seguimiento atento de las poblaciones humanas de alto riesgo.


Subject(s)
Animals , Mice , Asymptomatic Infections , COVID-19/pathology , Lung/pathology , Pulmonary Fibrosis/pathology , RNA, Messenger , RNA, Viral/analysis , Immunohistochemistry , Mice, Transgenic , Weight Loss , Microscopy, Electron, Transmission , Real-Time Polymerase Chain Reaction , SARS-CoV-2/isolation & purification , COVID-19/virology , Post-Acute COVID-19 Syndrome/pathology , Lung/ultrastructure , Lung/virology
2.
Neuroscience Bulletin ; (6): 261-272, 2023.
Article in English | WPRIM | ID: wpr-971551

ABSTRACT

The extracellular domain (p75ECD) of p75 neurotrophin receptor (p75NTR) antagonizes Aβ neurotoxicity and promotes Aβ clearance in Alzheimer's disease (AD). The impaired shedding of p75ECD is a key pathological process in AD, but its regulatory mechanism is largely unknown. This study was designed to investigate the presence and alterations of naturally-occurring autoantibodies against p75ECD (p75ECD-NAbs) in AD patients and their effects on AD pathology. We found that the cerebrospinal fluid (CSF) level of p75ECD-NAbs was increased in AD, and negatively associated with the CSF levels of p75ECD. Transgenic AD mice actively immunized with p75ECD showed a lower level of p75ECD and more severe AD pathology in the brain, as well as worse cognitive functions than the control groups, which were immunized with Re-p75ECD (the reverse sequence of p75ECD) and phosphate-buffered saline, respectively. These findings demonstrate the impact of p75ECD-NAbs on p75NTR/p75ECD imbalance, providing a novel insight into the role of autoimmunity and p75NTR in AD.


Subject(s)
Mice , Animals , Alzheimer Disease/pathology , Receptor, Nerve Growth Factor , Amyloid beta-Peptides , Autoantibodies , Mice, Transgenic
3.
Sheng Li Xue Bao ; (6): 671-681, 2023.
Article in Chinese | WPRIM | ID: wpr-1007782

ABSTRACT

Alzheimer's disease (AD) is a typical cognitive disorder with an increasing incidence in recent years. AD is also one of the main causes of disability and death of the elderly in current aging society. One of the most common symptoms of AD is spatial memory impairment, which occurs in more than 60% of patients. This memory loss is closely related to the impairment of cognitive maps in the brain. The entorhinal grid cells and the hippocampal place cells are important cellular basis for spatial memory and navigation functions in the brain. Understanding the abnormal firing pattern of these neurons and their impaired coordination to neural oscillations in transgenic rodents is crucial for identifying the therapeutic targets for AD. In this article, we review recent studies on neural activity based on transgenic rodent models of AD, with a focus on the changes in the firing characteristics of neurons and the abnormal electroencephalogram (EEG) rhythm in the entorhinal cortex and hippocampus. We also discuss potential cell-network mechanism of spatial memory disorders caused by AD, so as to provide a scientific basis for the diagnosis and treatment of AD in the future.


Subject(s)
Animals , Mice , Alzheimer Disease/genetics , Animals, Genetically Modified , Cognition , Cognitive Dysfunction , Hippocampus/physiology , Memory Disorders , Mice, Transgenic , Neurons/physiology
4.
Biomed. environ. sci ; Biomed. environ. sci;(12): 1028-1044, 2023.
Article in English | WPRIM | ID: wpr-1007879

ABSTRACT

OBJECTIVE@#To explore whether the protein Deglycase protein 1 (DJ1) can ameliorate Alzheimer's disease (AD)-like pathology in Amyloid Precursor Protein/Presenilin 1 (APP/PS1) double transgenic mice and its possible mechanism to provide a theoretical basis for exploring the pathogenesis of AD.@*METHODS@#Adeno-associated viral vectors (AAV) of DJ1-overexpression or DJ1-knockdown were injected into the hippocampus of 7-month-old APP/PS1 mice to construct models of overexpression or knockdown. Mice were divided into the AD model control group (MC), AAV vector control group (NC), DJ1-overexpression group (DJ1 +), and DJ1-knockdown group (DJ1 -). After 21 days, the Morris water maze test, immunohistochemistry, immunofluorescence, and western blotting were used to evaluate the effects of DJ1 on mice.@*RESULTS@#DJ1 + overexpression decreased the latency and increased the number of platform traversals in the water maze test. DJ1 - cells were cured and atrophied, and the intercellular structure was relaxed; the number of age spots and the expression of AD-related proteins were significantly increased. DJ1 + increased the protein expression of Nuclear factor erythroid 2-related factor 2 (NRF2), heme oxygenase-1 (HO-1), light chain 3 (LC3), phosphorylated AMPK (p-AMPK), and B cell lymphoma-2 (BCL-2), as well as the antioxidant levels of total superoxide dismutase (T-SOD), total antioxidant capacity (T-AOC), and Glutathione peroxidase (GSH-PX), while decreasing the levels of Kelch-like hydrates-associated protein 1 (Keap1), mammalian target of rapamycin (mTOR), p62/sequestosome1 (p62/SQSTM1), Caspase3, and malondialdehyde (MDA).@*CONCLUSION@#DJ1-overexpression can ameliorate learning, memory, and AD-like pathology in APP/PS1 mice, which may be related to the activation of the NRF2/HO-1 and AMPK/mTOR pathways by DJ1.


Subject(s)
Animals , Mice , Alzheimer Disease/therapy , AMP-Activated Protein Kinases/metabolism , Amyloid beta-Protein Precursor/metabolism , Antioxidants/metabolism , Disease Models, Animal , Hippocampus/metabolism , Kelch-Like ECH-Associated Protein 1/metabolism , Mammals/metabolism , Mice, Inbred C57BL , Mice, Transgenic , NF-E2-Related Factor 2/metabolism , Presenilin-1/metabolism , TOR Serine-Threonine Kinases/metabolism
5.
Article in Chinese | WPRIM | ID: wpr-986997

ABSTRACT

OBJECTIVE@#To explore the molecular pathological mechanism of liver metabolic disorder in severe spinal muscular atrophy (SMA).@*METHODS@#The transgenic mice with type Ⅰ SMA (Smn-/- SMN20tg/2tg) and littermate control mice (Smn+/- SMN20tg/2tg) were observed for milk suckling behavior and body weight changes after birth. The mice with type Ⅰ SMA mice were given an intraperitoneal injection of 20% glucose solution or saline (15 μL/12 h), and their survival time was recorded. GO enrichment analysis was performed using the RNA-Seq data of the liver of type Ⅰ SMA and littermate control mice, and the results were verified using quantitative real-time PCR. Bisulfite sequencing was performed to examine CpG island methylation level in Fasn gene promoter region in the liver of the neonatal mice.@*RESULTS@#The neonatal mice with type Ⅰ SMA showed normal milk suckling behavior but had lower body weight than the littermate control mice on the second day after birth. Intraperitoneal injection of glucose solution every 12 h significantly improved the median survival time of type Ⅰ SMA mice from 9±1.3 to 11± 1.5 days (P < 0.05). Analysis of the RNA-Seq data of the liver showed that the expression of the target genes of PPARα related to lipid metabolism and mitochondrial β oxidation were down-regulated in the liver of type Ⅰ SMA mice. Type Ⅰ SMA mice had higher methylation level of the Fasn promoter region in the liver than the littermate control mice (76.44% vs 58.67%). In primary cultures of hepatocytes from type Ⅰ SMA mice, treatment with 5-AzaC significantly up-regulated the expressions of the genes related to lipid metabolism by over 1 fold (P < 0.01).@*CONCLUSION@#Type Ⅰ SMA mice have liver metabolic disorder, and the down-regulation of the target genes of PPARα related to lipid and glucose metabolism due to persistent DNA methylation contributes to the progression of SMA.


Subject(s)
Mice , Animals , PPAR alpha , Liver Diseases , Muscular Atrophy, Spinal/genetics , Mice, Transgenic , Body Weight , Glucose
6.
Zhongguo Zhong Yao Za Zhi ; (24): 4015-4026, 2023.
Article in Chinese | WPRIM | ID: wpr-1008597

ABSTRACT

The purpose of this study was to investigate the effect of aqueous extract of Corni Fructus on β-amyloid protein 25-35(Aβ_(25-35))-induced brain injury and neuroinflammation in Alzheimer's disease(AD) mice to provide an experimental basis for the treatment of AD by aqueous extract of Corni Fructus. Sixty C57BL/6J male mice were randomly divided into a sham group, a model group, a positive control group(huperizine A, 0.2 mg·kg~(-1)), a low-dose aqueous extract of Corni Fructus group(1.3 g·kg~(-1)), a medium-dose aqueous extract of Corni Fructus group(2.6 g·kg~(-1)), and a high-dose aqueous extract of Corni Fructus group(5.2 g·kg~(-1)). The AD model was induced by lateral ventricular injection of Aβ_(25-35) in mice except for those in the sham group, and AD model mice were treated with corresponding drugs by gavage for 24 days. The behavioral test was performed one week before animal dissection. Hematoxylin-eosin(HE) staining was performed to observe the morphology of neurons in the hippocampal region. Flow cytometry was used to detect the apoptosis level of primary hippocampal cells in mice. ELISA kits were used to detect the levels of β-amyloid protein 1-42(Aβ_(1-42)) and phosphorylated microtubule-associated protein Tau(p-Tau) in mouse brain tissues. Immunofluorescence and Western blot were used to detect the expression of related proteins in mouse brain tissues. MTT assay was used to detect the effect of compounds in aqueous extract of Corni Fructus on Aβ_(25-35)-induced N9 cell injury. Molecular docking was employed to analyze the interactions of caffeic acid, trans-p-hydroxy cinnamic acid, isolariciresinol-9'-O-β-D-glucopyranoside, esculetin, and(+)-lyoniresinol with β-amyloid precursor protein(APP), interleukin-6(IL-6), and tumor necrosis factor-α(TNF-α). Aqueous extract of Corni Fructus could improve the learning and memory abilities of Aβ_(25-35)-induced mice by increasing the duration of the autonomous activity, the rate of autonomous alternation, the preference coefficient, and the discrimination coefficient, and reduce Aβ_(25-35)-induced brain injury and neuroinflammation in mice by increasing the expression levels of interleukin-10(IL-10) and B-cell lymphoma-2(Bcl-2) in brain tissues, decreasing the expression levels of Aβ_(1-42), p-Tau, IL-6, TNF-α, cysteine aspartate-specific protease 3(caspase-3), cysteine aspartate-specific protease 9(caspase-9), and Bcl-2-associated X protein(Bax), and decreasing the number of activated glial cells in brain tissues. The results of cell experiments showed that esculetin and(+)-lyoniresinol could improve Aβ_(25-35)-induced N9 cell injury. Molecular docking results showed that caffeic acid, trans-p-hydroxy cinnamic acid, isolariciresinol-9'-O-β-D-glucopyranoside, esculetin, and(+)-lyoniresinol had good binding affinity with APP and weak binding affinity with IL-6 and TNF-α. Aqueous extract of Corni Fructus could ameliorate cognitive dysfunction and brain damage in Aβ_(25-35)-induced mice by reducing the number of apoptotic cells and activated glial cells in the brain and decreasing the expression level of inflammatory factors. Caffeic acid, trans-p-hydroxy cinnamic acid, isolariciresinol-9'-O-β-D-glucopyranoside, esculetin, and(+)-lyoniresinol may be the material basis for the anti-AD effect of aqueous extract of Corni Fructus.


Subject(s)
Mice , Male , Animals , Alzheimer Disease/drug therapy , Amyloid beta-Peptides/metabolism , Cornus/metabolism , Neuroinflammatory Diseases , Tumor Necrosis Factor-alpha/metabolism , Interleukin-6 , Aspartic Acid , Cysteine/therapeutic use , Molecular Docking Simulation , Mice, Inbred C57BL , Brain Injuries , Peptide Hydrolases , Disease Models, Animal , Mice, Transgenic
7.
Zhongguo Zhong Yao Za Zhi ; (24): 4027-4038, 2023.
Article in Chinese | WPRIM | ID: wpr-1008598

ABSTRACT

The effect and mechanism of Heixiaoyao Powder on the polarization of microglia(MG) in APP/PS1 double transgenic mice were explored based on NADPH oxidase 2(NOX2)/reactive oxygen species(ROS)/nuclear factor kappaB(NF-κB) signaling pathway. Fifty 4-month-old male APP/PS1 mice were randomly divided into a model group, an MCC950 group(10 mg·kg~(-1)), and low-, medium-, and high-dose Heixiaoyao Powder groups(6.45, 12.89, and 25.78 g·kg~(-1)). Thirty male C57BL/6J mice of the same age and strain were randomly divided into a blank group, a blank + intragastric intervention group, and a blank + intraperitoneal injection group. Drug intervention lasted 90 days. Morris water maze test was used to detect learning and cognitive ability. Nissl staining and transmission electron microscopy were used to observe the pathological morphology and ultrastructure of hippocampal neurons. Immunofluorescence was used to detect the positive expression of M1-type marker CD16/32~+/Iba-1~+, M2-type marker CD206~+/Iba-1~+ of MG and the expression of hippocampal ROS. The colorimetric method was used to detect the content of malondialdehyde(MDA) and superoxide dismutase(SOD) in the hippocampus. Enzyme linked immunosorbent assay(ELISA) was used to detect the levels of inflammatory factors, including interleukin-6(IL-6), interleukin-8(IL-8), and tumor necrosis factor-α(TNF-α), in the hippocampus. Western blot was used to detect the protein expression of β-amyloid protein(Aβ), Iba-1, CD16/32, CD206, NOX2, NF-κB, p-NF-κB, NF-κB inhibitor alpha(IκBα), and p-IKBα in the hippocampus. The results showed that as compared with the blank group, the model group showed prolonged target quadrant movement distance and escape latency(P<0.01), shortened target quadrant retention time and percentage(P<0.01), disorganized neuronal cells with swelling, nuclear disappearance or bias, reduced number of cells, dissolved or absent Nissl bodies, and a clear area in the cytoplasm, damaged and shrunk cell membrane with abnormal cell morphology, few organelles in the cytoplasm, reduced and swollen mitochondria, increased MG M1-type marker CD16/32~+/Iba-1~+(P<0.01), decreased M2-type marker CD206~+/Iba-1~+(P<0.01), increased ROS activity and MDA content(P<0.01), decreased SOD level(P<0.01), elevated inflammatory factors IL-6, IL-8, and TNF-α(P<0.01), up-regulated protein expression and phosphorylation of Aβ, CD16/32, Iba-1, NOX2, NF-κB, and IKBα(P<0.01), and down-regulated CD206(P<0.01). There was no statistically significant difference between the blank group, the blank + intragastric intervention group, and the blank + intraperitoneal injection group. After the intervention of Heixiaoyao Powder, the Heixiaoyao Powder groups showed shortened target quadrant movement distance and escape latency(P<0.01), prolonged target quadrant retention time and percentage(P<0.01), increased and neatly arranged cells with relieved swelling, increased Nissl bodies, regular cell morphology, and intact cell membrane, relieved swelling of mitochondria, slightly expanded endoplasmic reticulum, decreased CD16/32~+/Iba-1~+(P<0.05 or P<0.01), increased CD206~+/Iba-1~+(P<0.01), decreased ROS activity and MDA content(P<0.01), increased SOD level(P<0.01), decreased content of inflammatory factors IL-6, IL-8, and TNF-α(P<0.01), down-regulated protein expression and phosphorylation of Aβ, CD16/32, Iba-1, NOX2, NF-κB, and IKBα(P<0.01), and up-regulated CD206(P<0.01). In conclusion, Heixiaoyao Powder can alleviate neuronal damage and improve the learning and memory abilities of APP/PS1 mice. The mechanism of action may be related to the inhibition of NOX2/ROS/NF-κB signaling pathway, regulating the polarization of MG, increasing the expression of M2 type, inhibiting the expression of M1 type, and reducing the release of inflammatory factor.


Subject(s)
Mice , Male , Animals , NF-kappa B/genetics , Microglia , Reactive Oxygen Species , Interleukin-8 , Powders , Tumor Necrosis Factor-alpha , Interleukin-6 , Mice, Inbred C57BL , Signal Transduction , Mice, Transgenic , Superoxide Dismutase
8.
Zhongguo Zhong Yao Za Zhi ; (24): 4039-4045, 2023.
Article in Chinese | WPRIM | ID: wpr-1008599

ABSTRACT

This study aimed to investigate the mechanism of Psoraleae Fructus in improving the learning and memory ability of APP/PS1 mice by serum metabolomics, screen the differential metabolites of Psoraleae Fructus on APP/PS1 mice, and reveal its influence on the metabolic pathway of APP/PS1 mice. Thirty 3-month-old APP/PS1 mice were randomly divided into a model group and a Psoraleae Fructus extract group, and another 15 C57BL/6 mice of the same age were assigned to the blank group. The learning and memory ability of mice was evaluated by the Morris water maze and novel object recognition tests, and metabolomics was used to analyze the metabolites in mouse serum. The results of the Morris water maze test showed that Psoraleae Fructus shortened the escape latency of APP/PS1 mice(P<0.01), and increased the number of platform crossing and residence time in the target quadrant(P<0.01). The results of the novel object recognition test showed that Psoraleae Fructus could improve the novel object recognition index of APP/PS1 mice(P<0.01). Eighteen differential metabolites in serum were screened out by metabolomics, among which the levels of arachidonic acid, tryptophan, and glycerophospholipid decreased after drug administration, while the levels of glutamyltyrosine increased after drug administration. The metabolic pathways involved included arachidonic acid metabolism, glycerophospholipid metabolism, tryptophan metabolism, linoleic acid metabolism, α-linolenic acid metabolism, and glycerolipid metabolism. Therefore, Psoraleae Fructus can improve the learning and memory ability of APP/PS1 mice, and its mechanism may be related to the effects in promoting energy metabolism, reducing oxidative damage, protecting central nervous system, reducing neuroinflammation, and reducing Aβ deposition. This study is expected to provide references for Psoraleae Fructus in the treatment of Alzheimer's disease(AD) and further explain the mechanism of Psoraleae Fructus in the treatment of AD.


Subject(s)
Mice , Animals , Amyloid beta-Protein Precursor/genetics , Mice, Transgenic , Arachidonic Acid , Tryptophan , Mice, Inbred C57BL , Alzheimer Disease/genetics , Maze Learning , Glycerophospholipids , Disease Models, Animal , Amyloid beta-Peptides/metabolism
9.
Article in Chinese | WPRIM | ID: wpr-1009420

ABSTRACT

Objective To explore the effect of knocking down Rho-associated coiled-coil kinase (ROCK2) gene on the cognitive function of amyloid precursor protein/presenilin-1 (APP/PS1) double transgenic mice and its mechanism. Methods APP/PS1 double transgenic mice were randomly divided into AD model group (AD group), ROCK2 gene knock-down group (shROCK2 group), ROCK2 gene knock-down control group (shNCgroup), and wild-type C57BL/6 mice of the same age served as the wild-type control (WT group). Morris water maze and Y maze were employed to test the cognitive function of mice. Neuron morphology was detected by Nissl staining. Immunofluorescence histochemical staining was used to detect the expression of phosphorylated dynamin-related protein 1 (p-Drp1) and mitochondrial fusion 1 (Mfn1). Western blot analysis was used to detect the expression ROCK2, cleaved-caspase-3 (c-caspase-3), B-cell lymphoma 2 (Bcl2), Bcl2-related protein X (BAX), p-Drp1, mitochondrial fission 1 (Fis1), optic atrophy 1 (OPA1), Mfn1 and Mfn2. Results Compared with AD group mice, the expression of ROCK2 in shROCK2 group mice was significantly reduced; the cognitive function was significantly improved with the number of neurons in the hippocampal CA3 and DG areas increasing, and nissl bodies were deeply stained; the expression of c-caspase-3 and BAX was decreased, while the expression of Bcl2 was increased; the expression of mitochondrial division related proteins p-Drp1 and Fis1 were decreased, while the expression of mitochondrial fusion-related proteins OPA1, Mfn1 and Mfn2 were increased. Conclusion Knock-down of ROCK2 gene can significantly improve the cognitive function and inhibit the apoptosis of nerve cells of APP/PS1 mice. The mechanism may be related to promoting mitochondrial fusion and inhibiting its division.


Subject(s)
Animals , Mice , Alzheimer Disease/pathology , Amyloid beta-Peptides/metabolism , Amyloid beta-Protein Precursor , Apoptosis/genetics , bcl-2-Associated X Protein , Caspase 3 , Cognition , Disease Models, Animal , Mice, Inbred C57BL , Mice, Transgenic , Mitochondrial Dynamics/genetics
10.
Chinese Journal of Biotechnology ; (12): 231-247, 2023.
Article in Chinese | WPRIM | ID: wpr-970371

ABSTRACT

This study aims to investigate the effect of anti-PD-1 antibody expressed in mouse mammary gland on the surface antigen protein of spleen T cells, cytokine expression, spleen CD4+ T cell proliferation and proliferation related pathways of transgenic mice at the cellular level. Transgenic mice expressing anti-human PD-1 antibody at 8 weeks of age without pregnancy and 18 weeks of age with lactation were divided into two groups, with transgenic negative mice in each group as the control. Spleen lymphocytes were extracted and the changes of spleen lymphocytes were detected. Compared with transgenic negative mice, the proportion of effector T cells of spleen T cells in the immune system of transgenic mice with anti-PD-1 antibody expressed in breast increased, the proportion of Treg cells decreased, and the IFN-γ, IL-17 and IL-2 expressed in CD4+ T cells increased in varying degrees. Moreover, IL-4, IL-10 and TGF-β in CD4+ T cells did not change, nor did some cell surface protein molecules related to T cell stimulate. There was no significant difference in T cell proliferation between transgenic positive and transgenic negative mice. In transgenic positive mice, the expression of phosphorylated proteins in PI3K/Akt/mTOR and RAS/MEK/ERK pathways were partially up-regulated, but the whole pathway was not completely up-regulated. Therefore, it is feasible to use transgenic mice as host to express monoclonal antibodies related to immune system such as anti-PD-1 antibody.


Subject(s)
Mice , Animals , Female , Mice, Transgenic , Spleen/metabolism , CD4-Positive T-Lymphocytes/metabolism , Phosphatidylinositol 3-Kinases/metabolism , Cytokines/metabolism
11.
Neuroscience Bulletin ; (6): 881-892, 2023.
Article in English | WPRIM | ID: wpr-982411

ABSTRACT

Mutations in genes encoding amyloid precursor protein (APP) and presenilins (PSs) cause familial forms of Alzheimer's disease (AD), a neurodegenerative disorder strongly associated with aging. It is currently unknown whether and how AD risks affect early brain development, and to what extent subtle synaptic pathology may occur prior to overt hallmark AD pathology. Transgenic mutant APP/PS1 over-expression mouse lines are key tools for studying the molecular mechanisms of AD pathogenesis. Among these lines, the 5XFAD mice rapidly develop key features of AD pathology and have proven utility in studying amyloid plaque formation and amyloid β (Aβ)-induced neurodegeneration. We reasoned that transgenic mutant APP/PS1 over-expression in 5XFAD mice may lead to neurodevelopmental defects in early cortical neurons, and performed detailed synaptic physiological characterization of layer 5 (L5) neurons from the prefrontal cortex (PFC) of 5XFAD and wild-type littermate controls. L5 PFC neurons from 5XFAD mice show early APP/Aβ immunolabeling. Whole-cell patch-clamp recording at an early post-weaning age (P22-30) revealed functional impairments; although 5XFAD PFC-L5 neurons exhibited similar membrane properties, they were intrinsically less excitable. In addition, these neurons received smaller amplitude and frequency of miniature excitatory synaptic inputs. These functional disturbances were further corroborated by decreased dendritic spine density and spine head volumes that indicated impaired synapse maturation. Slice biotinylation followed by Western blot analysis of PFC-L5 tissue revealed that 5XFAD mice showed reduced synaptic AMPA receptor subunit GluA1 and decreased synaptic NMDA receptor subunit GluN2A. Consistent with this, patch-clamp recording of the evoked L23>L5 synaptic responses revealed a reduced AMPA/NMDA receptor current ratio, and an increased level of AMPAR-lacking silent synapses. These results suggest that transgenic mutant forms of APP/PS1 overexpression in 5XFAD mice leads to early developmental defects of cortical circuits, which could contribute to the age-dependent synaptic pathology and neurodegeneration later in life.


Subject(s)
Mice , Animals , Alzheimer Disease/pathology , Amyloid beta-Peptides/metabolism , Receptors, N-Methyl-D-Aspartate/metabolism , Amyloid beta-Protein Precursor/metabolism , Mice, Transgenic , Neurons/metabolism , Receptors, AMPA/metabolism , Disease Models, Animal
12.
Neuroscience Bulletin ; (6): 1069-1086, 2023.
Article in English | WPRIM | ID: wpr-982423

ABSTRACT

Cortical interneurons can be categorized into distinct populations based on multiple modalities, including molecular signatures and morpho-electrical (M/E) properties. Recently, many transcriptomic signatures based on single-cell RNA-seq have been identified in cortical interneurons. However, whether different interneuron populations defined by transcriptomic signature expressions correspond to distinct M/E subtypes is still unknown. Here, we applied the Patch-PCR approach to simultaneously obtain the M/E properties and messenger RNA (mRNA) expression of >600 interneurons in layer V of the mouse somatosensory cortex (S1). Subsequently, we identified 11 M/E subtypes, 9 neurochemical cell populations (NCs), and 20 transcriptomic cell populations (TCs) in this cortical lamina. Further analysis revealed that cells in many NCs and TCs comprised several M/E types and were difficult to clearly distinguish morpho-electrically. A similar analysis of layer V interneurons of mouse primary visual cortex (V1) and motor cortex (M1) gave results largely comparable to S1. Comparison between S1, V1, and M1 suggested that, compared to V1, S1 interneurons were morpho-electrically more similar to M1. Our study reveals the presence of substantial M/E variations in cortical interneuron populations defined by molecular expression.


Subject(s)
Mice , Animals , Neocortex/physiology , Mice, Transgenic , Interneurons/physiology
13.
Neuroscience Bulletin ; (6): 929-946, 2023.
Article in English | WPRIM | ID: wpr-982431

ABSTRACT

A decline in the activities of oxidative phosphorylation (OXPHOS) complexes has been consistently reported in amyotrophic lateral sclerosis (ALS) patients and animal models of ALS, although the underlying molecular mechanisms are still elusive. Here, we report that receptor expression enhancing protein 1 (REEP1) acts as an important regulator of complex IV assembly, which is pivotal to preserving motor neurons in SOD1G93A mice. We found the expression of REEP1 was greatly reduced in transgenic SOD1G93A mice with ALS. Moreover, forced expression of REEP1 in the spinal cord extended the lifespan, decelerated symptom progression, and improved the motor performance of SOD1G93A mice. The neuromuscular synaptic loss, gliosis, and even motor neuron loss in SOD1G93A mice were alleviated by increased REEP1 through augmentation of mitochondrial function. Mechanistically, REEP1 associates with NDUFA4, and plays an important role in preserving the integrity of mitochondrial complex IV. Our findings offer insights into the pathogenic mechanism of REEP1 deficiency in neurodegenerative diseases and suggest a new therapeutic target for ALS.


Subject(s)
Mice , Animals , Amyotrophic Lateral Sclerosis/metabolism , Superoxide Dismutase-1/metabolism , Superoxide Dismutase/metabolism , Mice, Transgenic , Spinal Cord/pathology , Mitochondria/physiology , Disease Models, Animal
14.
Neuroscience Bulletin ; (6): 290-302, 2022.
Article in English | WPRIM | ID: wpr-929083

ABSTRACT

Deficits in the clearance of amyloid β protein (Aβ) by the peripheral system play a critical role in the pathogenesis of sporadic Alzheimer's disease (AD). Impaired uptake of Aβ by dysfunctional monocytes is deemed to be one of the major mechanisms underlying deficient peripheral Aβ clearance in AD. In the current study, flow cytometry and biochemical and behavioral techniques were applied to investigate the effects of polysaccharide krestin (PSK) on AD-related pathology in vitro and in vivo. We found that PSK, widely used in therapy for various cancers, has the potential to enhance Aβ uptake and intracellular processing by human monocytes in vitro. After administration of PSK by intraperitoneal injection, APP/PS1 mice performed better in behavioral tests, along with reduced Aβ deposition, neuroinflammation, neuronal loss, and tau hyperphosphorylation. These results suggest that PSK holds promise as a preventive agent for AD by strengthening the Aβ clearance by blood monocytes and alleviating AD-like pathology.


Subject(s)
Animals , Mice , Alzheimer Disease/pathology , Amyloid beta-Peptides/metabolism , Amyloid beta-Protein Precursor/metabolism , Cognition , Disease Models, Animal , Mice, Transgenic , Monocytes/pathology , Polysaccharides/therapeutic use , Proteoglycans
15.
Chinese Journal of Biotechnology ; (12): 196-206, 2022.
Article in Chinese | WPRIM | ID: wpr-927704

ABSTRACT

Essential fatty acids are those that could not be synthesized by the body itself but crucial for health and life. Studies have shown that ω-3 fatty acids may facilitate human physiological functions. Mammals lack ω-3 desaturase gene, and the Δ15 fatty acid desaturase (Δ15 Des) from Caenorhabditis elegans can transform the ω-6 polyunsaturated fatty acids (PUFAs) into ω-3 PUFAs. Transgenic mice expressing Δ15 Des enzyme activity was constructed by using a PiggyBac transposon (PB). Homozygous transgenic mice with stable inheritance was bred in a short time, with a positive rate of 35.1% achieved. The mice were fed with 6% ω-6 PUFAs and the changes of fatty acids in mice were detected by gas chromatography (GC). The expression level of Δ15 Des in mice was detected by quantitative PCR (qPCR) and Western blotting (WB). qPCR and GC analysis revealed that the percentage of positive mice harboring the active gene was 61.53%. Compared with traditional methods, the transformation efficiency and activity of Δ15 Des were significantly improved, and homozygotes showed higher activity than that of heterozygotes. This further verified the efficient transduction efficiency of the PiggyBac transposon system.


Subject(s)
Animals , Mice , Caenorhabditis elegans/genetics , Fatty Acid Desaturases/genetics , Fatty Acids , Fatty Acids, Omega-3 , Mice, Transgenic
16.
Article in Chinese | WPRIM | ID: wpr-927891

ABSTRACT

Objective: To uncover the time-dependent expression pattern of ptk2b gene and ptk2b-encoded protein, protein tyrosine kinase 2 beta(PTK2B), in the brain tissues of transgenic animal models of Alzheimer's disease (AD) and its relationship with the levels of Aβ1-42, phosphorylation of Tau (p-Tau) and low density lipoprotein receptor-related protein-1(LRP-1) in blood and brain tissues. Methods: In this study, 5-, 10- and 15-month-old APPswe/PS1dE9 double-transgenic mice harboring the genotype of AD confirmed by the gene test were divided into the 5-, 10- and 15-month-old experiment groups, and simultaneously, age-matched C57BL/6J mice were placed into the corresponding control groups, with 8 mice in each group. All mice were subjected to the Morris Water Maze for test of cognitive and behavioral ability. Expression profiles of PTK2B, Aβ1-42, p-Tau/Tau and LRP-1 in the hippocampus or blood of mice were quantified by using the immunohistochemistry staining, Western blot or enzyme-linked immunosorbent assay (ELISA), while the mRNA expression of ptk2b in the hippocampus was quantified by using the real-time quantitative polymerase chain reaction (qRT-PCR). Results: Results of experiment groups demonstrated that as mice aged, the expression levels of PTK2B, ptk2b mRNA, Aβ1-42 and p-Tau/Tau in the hippocampus were increased, and the expression of LRP-1 was decreased gradually. While in the blood, the level of Aβ1-42 was decreased, and the cognitive and behavioral ability was decreased in an age-dependent manner (all P< 0.05). However, comparisons among the control groups, only the age-dependent downregulation of LRP-1 were observed in hippocampus(P<0.05), but other indicators had no significant differences (P>0.05). Conclusion: In the hippocampus of APP/PS1 double-transgenic mice, the expressions of PTK2B, Aβ1-42 and p-Tau/Tau are upregulated, LRP-1 is downregulated, while cognitive and behavioral ability is decreased, and such changes are presented in a time-dependent manner.


Subject(s)
Animals , Mice , Alzheimer Disease/metabolism , Amyloid beta-Peptides , Amyloid beta-Protein Precursor/genetics , Focal Adhesion Kinase 2/metabolism , Hippocampus/metabolism , Low Density Lipoprotein Receptor-Related Protein-1 , Maze Learning , Mice, Inbred C57BL , Mice, Transgenic , RNA, Messenger
17.
Biol. Res ; 55: 10-10, 2022. ilus
Article in English | LILACS | ID: biblio-1383914

ABSTRACT

BACKGROUND: In Alzheimer's disease (AD), the neuroinflammatory response mediated by the activation of senescent microglia is closely related to energy dysmetabolism. However, the mechanism underlying the interaction between the energy metabolism of aging microglia and neuroinflammation remains unclear. METHODS: We used biochemical methods, enzyme-linked immunosorbent assay (ELISA), immunofluorescence, and western blot to determine the effects and mechanism of CD38 knockdown on energy metabolism and neuroinflammation in Aß1-40 injured BV2 cells. Using AD model mice, we detected CD38 enzyme activity, energy metabolism factors (ATP, NAD +, and NAD +/NADH), and neuroinflammatory factors (IL-1ß, IL-6, and TNF-α) following the addition of CD38 inhibitor. Using a combination of biochemical analysis and behavioral testing, we analyzed the effects of the CD38 inhibitor on energy metabolism disorder, the neuroinflammatory response, and the cognition of AD mice. RESULTS: Following Aß1-40 injury, SA-ß-Gal positive cells and senescence-related proteins P16 and P21 increased in BV2 cells, while energy-related molecules (ATP, NAD +, and NAD +/NADH) and mitochondrial function (mitochondrial ROS and MMP) decreased. Further studies showed that CD38 knockdown could improve Aß1-40-induced BV2 cells energy dysmetabolism and reduce the levels of IL-1ß, IL-6, and TNF-α. In vivo results showed an increase in senile plaque deposition and microglial activation in the hippocampus and cortex of 34-week-old APP/PS1 mice. Following treatment with the CD38 inhibitor, senile plaque deposition decreased, the number of Iba1 +BV2 cells increased, the energy metabolism disorder was improved, the proinflammatory cytokines were reduced, and the spatial learning ability was improved. CONCLUSIONS: Our results confirm that senescent microglia appeared in the brain of 34-week-old APP/PS1 mice, and that Aß1-40 can induce senescence of BV2 cells. The expression of CD38 increases in senescent BV2 cells, resulting in energy metabolism disorder. Therefore, reducing CD38 expression can effectively improve energy metabolism disorder and reduce proinflammatory cytokines. Following intervention with the CD38 inhibitor in APP/PS1 mice, the energy metabolism disorder was improved in the hippocampus and cortex, the level of proinflammatory cytokines was reduced, and cognitive impairment was improved.


Subject(s)
Animals , Mice , Alzheimer Disease/metabolism , Brain , Mice, Transgenic , Microglia , Disease Models, Animal , Hippocampus
18.
Sheng Li Xue Bao ; (6): 471-481, 2021.
Article in Chinese | WPRIM | ID: wpr-887682

ABSTRACT

Sleep exerts important functions in the regulation of cognition and emotion. Recent studies have found that sleep disorder is one of the important risk factors for Alzheimer's disease (AD), but the effects of chronic sleep deprivation on the cognitive functions of AD model mice and its possible mechanism are still unclear. In the present study, 8-month-old male APP/PS1/tau triple transgenic AD model (3xTg-AD) mice and wild type (WT) mice (n = 8 for each group) were subjected to chronic sleep deprivation by using the modified multiple platform method, with 20 h of sleep deprivation each day for 21 days. Then, open field test, elevated plus maze test, sugar water preference test, object recognition test, Y maze test and conditioned fear memory test were performed to evaluate anxiety- and depression-like behaviors, and multiple cognitive functions. In addition, the immunohistochemistry technique was used to observe pathological characteristics in the hippocampus of mice. The results showed that: (1) Chronic sleep deprivation did not affect anxiety- (P = 0.539) and depression-like behaviors (P = 0.874) in 3xTg-AD mice; (2) Chronic sleep deprivation exacerbated the impairments of object recognition memory (P < 0.001), working memory (P = 0.002) and the conditioned fear memory (P = 0.039) in 3xTg-AD mice; (3) Chronic sleep deprivation increased amyloid β (Aβ) deposition (P < 0.001) and microglial activation (P < 0.001) in the hippocampus of 3xTg-AD mice, without inducing abnormal tau phosphorylation and neurofibrillary tangles. These results indicate that chronic sleep deprivation exacerbates the impairments of recognition memory, working memory and conditioned fear memory in 3xTg-AD mice by aggravating Aβ deposition and the excessive activation of microglia in the hippocampus.


Subject(s)
Animals , Male , Mice , Alzheimer Disease , Amyloid beta-Peptides , Amyloid beta-Protein Precursor/genetics , Cognition , Disease Models, Animal , Mice, Inbred C57BL , Mice, Transgenic , Presenilin-1 , Sleep Deprivation , tau Proteins
19.
Biomed. environ. sci ; Biomed. environ. sci;(12): 19-28, 2021.
Article in English | WPRIM | ID: wpr-878317

ABSTRACT

Objective@#In the present study, the ABCA1 was used as a label to capture specific exosomes, the level of ABCA1-labeled exosomal microRNA-135a (miR-135a) was evaluated for the diagnosis of Alzheimer's disease (AD), especially in patients with early stages of AD.@*Methods@#This is a preliminary research focused on the levels of ABCA1 in WBCs, RBCs, HT-22 cells, and neuron cells. The diagnostic value of ABCA1-labeled exosomal miR-135a was examined using the CSF and serum of APP/PS1 double transgenic mice, and 152 patients with SCD, 131 patients with MCI, 198 patients with DAT, and 30 control subjects.@*Results@#The level of ABCA1 exosomes harvested from HT-22 cells and neuron culture medium was significantly higher compared to that of RBCs and WBCs ( @*Conclusion@#This study outlines a method to capture specific exosomes and detect them using immunological methods, which is more efficient for early diagnosis of AD.


Subject(s)
Aged , Aged, 80 and over , Animals , Female , Humans , Male , ATP Binding Cassette Transporter 1/cerebrospinal fluid , Alzheimer Disease/cerebrospinal fluid , Biomarkers/cerebrospinal fluid , Cell Line , Cognitive Dysfunction/cerebrospinal fluid , Erythrocytes/metabolism , Exosomes , Leukocytes/metabolism , Mice, Transgenic , MicroRNAs/blood , Neurons/metabolism
20.
Article in English | WPRIM | ID: wpr-922254

ABSTRACT

To investigate the effects of on behavior and blood brain barrier (BBB) in Alzheimer's disease mice. Thirty-eight 4-month-old APP/PS1 double transgenic mice were randomly divided into three groups: model group, low-dose group and high-dose group. Saline, and 12 g·kg·d were given to each group by continuous gavage once a day for respectively. The changes in activities of daily live and fear conditioning memory behavior of mice were examined by nesting behavior test and fear conditioning test, respectively. The β-amyloid protein (Aβ) depositions in cortex and hippocampal CA1 area of mice were detected by thioflavin T staining. The CD34 and activities fibrinogen (Fib) immunofluorescence double staining were used to determine the vascular endothelial integrity and BBB exudation. Compared with model mice, activities of daily live were significantly improved in low-dose and high-dose groups (both <0.01), the fear memory ability was significantly increased in high-dose group (<0.01). The amount of Aβ deposition in cortex and hippocampal CA1 decreased significantly in high-dose group, the area ratio decreased significantly; the area ratio of Aβ deposition in hippocampal CA1 region in low-dose group also decreased (all <0.05). The proportions of CD34 positive area of cortex in low and high dose groups increased, the percentage of fibrinogen positive area decreased (all <0.05). The proportion of CD34 positive area in hippocampal CA1 region in high-dose group was significantly increased, the percentage of fibrinogen positive area decreased significantly (both <0.05). especially high-dose can improve the activities of daily live and fear conditioning memory function of APP/PS1 mice, reduce the deposition of Aβ in brain. The mechanism may be related to the reduction of BBB permeability and the protection of the integrity of BBB.


Subject(s)
Animals , Mice , Alzheimer Disease , Amyloid beta-Protein Precursor , Blood-Brain Barrier/metabolism , Disease Models, Animal , Hippocampus/metabolism , Mice, Inbred C57BL , Mice, Transgenic
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