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Dietary β-carotene regulates interleukin-1β-induced expression of apolipoprotein E in astrocytes isolated from stroke-prone spontaneously hypertensive rats.

Stroke-prone spontaneously hypertensive rats (SHRSP) have an abnormality in cholesterol synthesis, but the pathological relevance of this to stroke and related neuronal disorders is not yet clear. The induction of astrocyte-derived cholesterol transportation to neurons by apolipoprotein E (apoE) promotes neuronal repair after brain injuries such as stroke. Such repair is reduced by interleukin-1 beta (IL-1β) and stroke conditions. Furthermore, fibroblast growth factor 1 (FGF1) regulates the production of apoE-cholesterol-rich high density lipoproteins (HDL) and induces gliosis of astrocytes. O…

Frequency and large T (LT) sequence of JC polyomavirus DNA in oligodendrocytes, astrocytes and granular cells in non-PML brain.

Progressive multifocal leukoencephalopathy (PML) and JCV granular cell neuronopathy occur secondary to JCV polyomavirus (JCV) infection of oligodendrocytes and cerebellar granular cell neurons (CGNs) during immunosuppression. Pure populations of astrocytes, oligodendrocytes, CGNs and microglia from frontal cortex and cerebellum of 17 non-PML patients (9 immunocompetent; 8 immunosuppressed) were isolated by laser capture microdissection (LCM). JCV large T (LT) antigen DNA was detected by triple nested polymerase chain reaction (PCR). Sequence analysis was performed to assess LT gene variation. …

In vivo expression of polyglutamine-expanded huntingtin by mouse striatal astrocytes impairs glutamate transport: a correlation with Huntington's disease subjects.

Huntington's disease (HD) is a neurodegenerative disorder previously thought to be of primary neuronal origin, despite ubiquitous expression of mutant huntingtin (mHtt). We tested the hypothesis that mHtt expressed in astrocytes may contribute to the pathogenesis of HD. To better understand the contribution of astrocytes in HD in vivo, we developed a novel mouse model using lentiviral vectors that results in selective expression of mHtt into striatal astrocytes. Astrocytes expressing mHtt developed a progressive phenotype of reactive astrocytes that was characterized by a marked decreased expr…

Pathological and biochemical alterations of astrocytes in ovariectomized rats injected with D-galactose: a potential contribution to Alzheimer's disease processes.

Astrocytes are implicated in the pathological changes of Alzheimer's disease. Our previous studies have demonstrated that estrogen deprivation and oxidative stress act synergistically to accelerate the progress of Alzheimer's disease. Long-term D-galactose injection combined with ovariectomy may serve as a rodent model for Alzheimer's disease. To address the potential contribution of astroglia to the Alzheimer's disease pathogenesis, we investigated pathological and biochemical alterations of astrocytes under this animal model. Ovariectomized rats injected with D-galactose for 2 weeks showed e…

Activation of the epidermal growth factor receptor in optic nerve astrocytes leads to early and transient induction of cyclooxygenase-2.

PURPOSE: The epidermal growth factor receptor (EGFR) appears in astrocytes after neural injury. The authors' laboratory has reported the presence of EGFR in glaucomatous optic nerves. The activation of EGFR is often associated with induction of cyclooxygenase (COX)-2. In this study, the induction of COX-2 pathway in rat optic nerve astrocytes was investigated. METHODS: Induction of COX-2 was determined by immunoblot and immunocytochemistry in optic nerve astrocytes stimulated with EGF. EGF-induced prostaglandin (PG)E(2) release into the culture medium was assayed by ELISA. The effects of the …

Reduced expression of NO-sensitive guanylyl cyclase in reactive astrocytes of Alzheimer disease, Creutzfeldt-Jakob disease, and multiple sclerosis brains.

In Alzheimer's disease (AD) brains increased NO synthase (NOS) expression is found in reactive astrocytes surrounding amyloid plaques. We have recently shown that treatment with beta-amyloid peptides or IL-1beta down-regulates NO-sensitive soluble guanylyl cyclase (sGC) in cultured astrocytes and in adult rat brain. In this work, we have examined sGC activity and expression in postmortem brain tissue of AD patients and matched controls. No significant alteration was observed in basal or NO-stimulated sGC activity, nor in sGC beta1 and alpha1 subunit levels in cortical extracts of AD brains. Im…

Critical role of mitochondrial reactive oxygen species formation in visible laser irradiation-induced apoptosis in rat brain astrocytes (RBA-1).

Laser irradiation-induced phototoxicity has been intensively applied in clinical photodynamic therapy for the treatment of a variety of tumors. However, the precise laser damage sites as well as the underlying mechanisms at the subcellular level are unknown. Using a mitochondrial fluorescent marker, MitoTracker Green, severe mitochondrial swelling was noted in laser-irradiated rat brain astrocytes. Nucleus condensation and fragmentation revealed by propidium iodide nucleic acid staining indicated that laser-irradiated cells died from apoptosis. Using an intracellular reactive oxygen species (R…

Adenosine and purine nucleosides protect rat primary astrocytes from peroxynitrite-potentiated, glucose deprivation-induced death: preservation of intracellular ATP level.

Previously we have reported that immunostimulated astrocytes became highly vulnerable to glucose deprivation. In the present study we examined the effect of various kinds of nucleosides on the augmented death of glucose-deprived immunostimulated astrocytes. Preincubation with interferon-gamma (100 U/ml) and lipopolysaccharide (1 microg/ml) for 48 h and continuous exposure to glucose deprivation (4 h) significantly induced the lactate dehydrogenase (LDH) release, as a marker of cell injury or death, from astrocytes. The glucose deprivation-induced augmented cell death in immunostimulated astroc…

Interleukin-6 enhances expression of adenosine A(1) receptor mRNA and signaling in cultured rat cortical astrocytes and brain slices.

The inhibitory neuromodulator adenosine is released in the brain in high concentrations under conditions of exaggerated neuronal activity such as ischemia and seizures, or electroconvulsive treatment. By inhibiting neural overactivity, adenosine counteracts seizure activity and promotes neuronal survival. Since stimulation of adenosine A(2b) receptors on astrocytes induces increased synthesis and release of interleukin-6, which also exerts neuroprotective effects, we hypothesized that the effects of interleukin-6 and of adenosine might be related. We report here that stimulation with interleuk…

Upregulation of the low density lipoprotein receptor at the blood-brain barrier: intercommunications between brain capillary endothelial cells and astrocytes.

In contrast to the endothelial cells in large vessels where LDL receptors are downregulated, brain capillary endothelial cells in vivo express an LDL receptor. Using a cell culture model of the blood-brain barrier consisting of a coculture of brain capillary endothelial cells and astrocytes, we observed that the capacity of endothelial cells to bind LDL is enhanced threefold when cocultured with astrocytes. We next investigated the ability of astrocytes to modulate endothelial cell LDL receptor expression. We have shown that the lipid requirement of astrocytes increases the expression of endot…

A transgenic mouse model to assess the interaction of cytotoxic T lymphocytes with virally infected, class I MHC-expressing astrocytes.

Astrocytes provide crucial support for neurons and their impairment by viruses or their interactions with anti-viral or autoimmune responses could contribute to neurological disease. We have developed a transgenic mouse model to assess lymphocyte-astrocyte interactions. The major histocompatibility complex (MHC) class I molecule, Db, was expressed in astrocytes under the transcriptional control of regulatory sequences from the glial fibrillary acidic protein (GFAP) gene. Baseline cerebral MHC class I mRNA levels from transgenic mice were elevated over those of non-transgenic controls, and a pr…

Factors determining the migration of astrocytes into the developing retina: migration does not depend on intact axons or patent vessels.

Astrocytes migrate into the cat retina from the optic nerve, beginning from embryonic day (E) 52. Once they have entered the retina they concentrate along major axon bundles and fail to enter regions of the retina with high densities of neurones, in particular the area centralis region of the ganglion cell layer. These nonuniformities appear as the astrocytes spread over the retina during development, and in this study we have examined factors that might control their spread. First we examined astrocytes in a retina in which the axon bundles had degenerated following an optic nerve lesion at b…

Reduced BCL2 level in astrocytes contributes to blood-brain barrier disruption in the striatum of offspring exposed to maternal preeclampsia.

Maternal preeclampsia (PE) contributes to neurodevelopmental disorders. However, the underlying molecular mechanism remains unclear. We investigated the potential biological regulatory mechanisms by establishing an animal model and primary cell culture. Data from the Adolescent Brain Cognitive Development human study revealed that the striatum mediates maternal PE and offspring behavioral disorders. In a rat PE model, offspring exhibited abnormal behaviors and reduced striatal vascular density, with disrupted blood-brain barrier (BBB) and swollen astrocytes. Primary astrocytes and brain microv…

FFAs secreted by A1 astrocytes contribute to RGCs apoptosis via PERK/eIF2α/ATF4/CHOP pathway in retinal ischemia/reperfusion injury.

PURPOSE: To explore the specific mechanisms of retinal neuronal apoptosis induced by A1 polarization of astrocytes under retinal ischemia/reperfusion (RI/R) injury. METHODS: 1) In vivo, SD rats were selected for acute intraocular hypertension (AIH) model. In vitro, A1 astrocytes model was induced by the tumor necrosis factor α (TNF-α), interleukin-1α (IL-1α) and complement 1q (C1q) and oxygen and glucose deprivation/recovery (OGD/R) model of R28 cells. 2) Immunofluorescence was used to assess the expression of GFAP, C3, S100A10 and ELOVL1 genes morphologically. Apoptotic cell death was assess…

Medial prefrontal cortical CB1Rs and astrocytes are involved in depression and the antidepressant effects of running exercise in male rats.

Depression represents a growing global health challenge, with current pharmacological treatments often exhibiting limited efficacy and significant side effects. Although physical exercise, particularly running exercise, has shown promising antidepressant properties, its underlying neurobiological mechanisms remain poorly understood. In this study, we investigated whether cannabinoid receptor type 1 (CB1R) in the medial prefrontal cortex (mPFC) contributed to the therapeutic benefits of running exercise, which might be associated with astrocyte-related changes. Using a chronic restraint stress

Excitatory neurons and astrocytes-specific dysregulation and aberrant interactions are vulnerable to FCDI as suggested by single-cell spatial transcriptomics.

BACKGROUND: Focal cortical dysplasia (FCD) is a common neurodevelopmental disorder characterised by cortical malformations and is a major ca … l transcriptomic atlas of the epileptogenic cortex from FCDI patients. Excitatory neurons (ENs) and astrocytes (Ast) exhibited the most prominent alterations in FCDI. Hub genes associated with FCDI were identified in ENs, and a transcription factor (TF)‒hub gene regulatory network was constructed. Notably, CBLN2highEx-1 was identified as being potentially in …

MERTK-related engulfment of norepinephrinergic neuronal presynaptic membrane by astrocytes following acute TBI and potentiation effect of peripheral nerve modulation.

OBJECTIVES: The study investigated the locus coeruleus (LC) changes after acute traumatic brain injury (TBI) and the effects of peripheral n … ted neuronal activation, and rescued arousal and stress functions. CONCLUSION: After acute TBI, LC astrocytes phagocytose norepinephrinergic presynaptic proteins via MERTK. LF-PNM enhances this process, improving post-TBI arousal and stress dysfunction.

Third-trimester estradiol is associated with isolated maternal hypothyroxinemia and attenuated TSH-FT4 coupling: evidence from rats and human astrocytes.

INTRODUCTION: Isolated maternal hypothyroxinemia (IMH), defined by low free thyroxine (FT4) with thyroid-stimulating hormone (TSH) within th … s used gestational-stage Wistar rats, ovariectomized Wistar rats with 17β-E2 replacement, and Human Astrocytes treated with T4 ± E2 ± ICI 182,780. RESULTS: Higher E2 was associated with IMH (OR 2.93 per doubling) and lower FT4 (-1.74 pmol/L per doubling), whereas the adjusted TSH-FT4 association was not statistically significant. In rats, late gestation and …

Комплексный метаанализ транскриптомов астроцитов человека показывает, что в ответ на подстрекательские и иммунные стимулы потенциальные признаки повторяются.

Астроциты являются ключевыми регуляторами подстрекательской и иммунной реакции в центральной нервной системе, особенно в патологических условиях. Мы проводили систематический поиск баз данных НКОИ по ГЭП и ЭНА в целях выявления транскриптивных исследований стимулируемых астроцитов. Этот метаанализ объединяет 11 наборов данных RNA-Seq, охватывающих в общей сложности 153 пробы (91 стимулируемый и 62 средства контроля), подвергающиеся воздействию провоспалительных стимулов, таких, как цитокины (TNF-α, IL-6 и IL-1β), пальмовая кислота и патогены, такие, как SARS-COV-2 и Borrelia burborferi. Благод

Совпадение в аннотации оригинала
Astrocytes are key regulators of inflammatory and immune responses in the central nervous system, particularly under pathological conditions. We conducted a systematic search of the NCBI GEO and ENA databases to identify transcriptomic studies of stimulated astrocytes. This meta-analysis integrates 11 RNA-Seq datasets, encompassing a total of 153 samples (91…

Impact of Benzo(a)pyrene and Pyrene Exposure on Activating Autophagy and Correlation with Endoplasmic Reticulum Stress in Human Astrocytes.

Benzo(a)pyrene (B(a)P) and pyrene, the most prominent subtypes of polycyclic aromatic hydrocarbons (PAHs), contaminate environments as organic pollutants. They adversely affect body systems, including degeneration of the central nervous system. This study investigated the in vitro toxic effects of B(a)P and pyrene on proliferation, endoplasmic reticulum (ER) stress induction, and autophagy in human astrocytes using U-87 MG human astrocytoma cells as a model. Both B(a)P and pyrene were toxic to U-87 MG cells in a concentration-dependent manner. Astrocytic proliferation was interfered with, enha…