Iron metabolism is a critical factor in tumorigenesis and development. Although TP53 mutations are prevalent in glioblastoma (GBM), the mechanisms by which TP53 regulates iron metabolism remain elusive. We reveal an imbalance iron homeostasis in GBM via TCGA database analysis. TP53 mutations disrupted iron homeostasis in GBM, characterized by elevated total iron levels and reduced ferritin (FTH). The gain-of-function effect triggered by TP53 mutations upregulates itchy E3 ubiquitin-protein ligase (ITCH) protein expression in astrocytes, leading to FTH degradation and an increase in free iron levels. TP53-mut astrocytes were more tolerant to the high iron environment induced by exogenous ferric ammonium citrate (FAC), but the increase in intracellular free iron made them more sensitive to Erastin-induced ferroptosis. Interestingly, we found that Erastin combined with FAC treatment significantly increased ferroptosis. These findings provide new insights for drug development and therapeutic modalities for GBM patients with TP53 mutations from iron metabolism perspectives.
Ferroptosis/drug effects* ; Humans ; Iron/metabolism* ; Glioblastoma/metabolism* ; Tumor Suppressor Protein p53/metabolism* ; Homeostasis/physiology* ; Ferritins/metabolism* ; Brain Neoplasms/genetics* ; Mutation ; Astrocytes/drug effects* ; Cell Line, Tumor ; Piperazines/pharmacology* ; Quaternary Ammonium Compounds/pharmacology* ; Ferric Compounds

Astrocytes in the spinal dorsal horn (SDH) exhibit diverse reactive phenotypes under neuropathic conditions, yet the mechanisms driving this diversity and its implications in chronic pain remain unclear. Here, we report that spared nerve injury (SNI) induces marked upregulation of both complement component 3 (C3⁺, A1-like) and S100 calcium-binding protein A10 (S100A10⁺, A2-like) astrocyte subpopulations in the SDH, with elevated microglial cytokines including interleukin-1α, tumor necrosis factor-α, and complement component 1q. Transcriptomic, immunohistochemical, and Western blot analyses reveal co-activation of multiple reactive astrocyte states over a unidirectional shift toward an A1-like phenotype. Fibroblast growth factor 8 (FGF8), a neuroprotective factor via FGFR3, mitigated microglia-induced C3⁺ astrocyte reactivity in vitro and suppressed spinal C3 expression and mechanical allodynia following intrathecal administration in SNI mice. These findings reveal a microglia-astrocyte signaling axis that promotes A1 reactivity and position FGF8 as a promising therapeutic candidate for neuropathic pain by modulating astrocyte heterogeneity.
Animals ; Astrocytes/drug effects* ; Neuralgia/pathology* ; Receptor, Fibroblast Growth Factor, Type 3/metabolism* ; Signal Transduction/physiology* ; Male ; Mice ; Microglia/drug effects* ; Fibroblast Growth Factor 8/pharmacology* ; Mice, Inbred C57BL ; Hyperalgesia/drug therapy* ; Spinal Cord/drug effects* ; Complement C3/metabolism* ; Spinal Cord Dorsal Horn/metabolism*

Traumatic injury of the central nervous system (CNS) including brain and spinal cord remains a leading cause of morbidity and disability in the world. Delineating the mechanisms underlying the secondary and persistent injury versus the primary and transient injury has been drawing extensive attention for study during the past few decades. The sterile neuroinflammation during the secondary phase of injury has been frequently identified substrate underlying CNS injury, but as of now, no conclusive studies have determined whether this is a beneficial or detrimental role in the context of repair. Recent pioneering studies have demonstrated the key roles for the innate and adaptive immune responses in regulating sterile neuroinflammation and CNS repair. Some promising immunotherapeutic strategies have been recently developed for the treatment of CNS injury. This review updates the recent progress on elucidating the roles of the innate and adaptive immune responses in the context of CNS injury, the development and characterization of potential immunotherapeutics, as well as outstanding questions in this field.
Adaptive Immunity ; Astrocytes ; physiology ; Brain Injuries, Traumatic ; immunology ; therapy ; Histone Deacetylases ; therapeutic use ; Humans ; Immunity, Innate ; immunology ; Immunotherapy ; methods ; Inflammasomes ; drug effects ; physiology ; Macrophage Activation ; Spinal Cord Injuries ; immunology ; therapy

BACKGROUNDMitochondrial dysfunction has been reported to be one of the contributing factors of sepsis-associated encephalopathy (SAE). Mitochondrial biogenesis controls mitochondrial homeostasis and responds to changes in cellular energy demand. In addition, it is enhanced or decreased due to mitochondrial dysfunction during SAE. The aim of this study was to explore the changes of mitochondrial biogenesis of astrocytes under septic conditions.

METHODSLipopolysaccharide (LPS; 50 ng/ml) and interferon-γ (IFN-γ; 200 U/ml) were incubated with astrocytes to model the effects of a septic insult on astrocytes in vitro. The mitochondrial ultrastructure and volume density were evaluated by transmission electron microscopy. Intracellular adenosine triphosphate (ATP) levels were detected by the firefly luciferase system. The expression of protein markers of mitochondrial biogenesis and the binding ability of mitochondrial transcription factor A (TFAM) were determined by western blot and electrophoretic mobility shift assays, respectively. The mitochondrial DNA (mtDNA) content was detected by real-time polymerase chain reaction.

RESULTSThe number of mildly damaged mitochondria was found to be significantly greater after treatment for 6 hours, as compared with at 0 hour (P < 0.05). The mitochondrial volume density was significantly elevated at 24 hours, as compared with at 0 hour (P < 0.05). The ATP levels at 6 hours, 12 hours, and 24 hours were significantly greater than those at 0 hour (P < 0.05). The protein markers of mitochondrial biogenesis were significantly increased at 6 hours and 12 hours, as compared with at 0 hour (P < 0.05). The TFAM binding activity was not significantly changed among the four time points analyzed. The mtDNA contents were significantly increased at 12 hours and 24 hours, as compared with at 0 hour (P < 0.05).

CONCLUSIONSUnder septic conditions, mitochondrial biogenesis of astrocytes increased to meet the high-energy demand and to promote mitochondrial recovery. Furthermore, the TFAM-DNA binding ability was not sensitive to sepsis-induced injury.

Animals ; Astrocytes ; drug effects ; metabolism ; Blotting, Western ; Cells, Cultured ; DNA, Mitochondrial ; genetics ; Electrophoretic Mobility Shift Assay ; Interferon-gamma ; pharmacology ; Lipopolysaccharides ; pharmacology ; Microscopy, Electron, Transmission ; Mitochondrial Turnover ; drug effects ; physiology ; Nitric Oxide ; metabolism ; Rats ; Reactive Nitrogen Species ; metabolism ; Sepsis ; metabolism ; Tumor Necrosis Factor-alpha ; metabolism

OBJECTIVETo investigate the effect of lead-exposed astrocyte conditioned medium (ACM) on the synaptic formation of neurons and to provide reference for the mechanism of lead neurotoxicity.

METHODSAstrocytes were cultured in the medium containing 50, 100, 200, 400, and 800 µmol/L lead acetate for 72 h. Alamar Blue was used to assess the cell viability of astrocytes, and then ACM was collected. Primarily cultured neurons were divided into six groups: pure culture group, non-glutamic acid (Glu)-induced ACM treatment group, Glu-induced lead-free ACM treatment group, and Glu-induced 50, 100, and 200 µmol/L lead acetate-exposed ACM treatment groups. Neurons were collected after being cultured in ACM for 24, 48, or 72 h. The content of synaptophysin (SYP) in neurons was determined by Western blot. The SYP expression in neurons was measured by immunofluorescence after being cultured in ACMfor 72 h.

RESULTSIn all lead-exposed groups, the cell viability of astrocytes declined with increasing concentration of lead (P < 0.05). The Western blot showed that compared with the pure culture group, the non-Glu-induced ACM treatment group and Glu-induced lead- free ACM treatment group had significantly increased content of SYP in neurons (P < 0.01); compared with the non-Glu-induced ACM treatment group, the Glu-induced ACM treatment groups had significantly reduced SYP expression in neurons (P < 0.05); compared with the Glu-induced lead-free ACM treatment group, all lead-exposed ACM treatment groups had the content of SYP in neurons significantly reduced with increasing concentration of lead after 72-h culture (P < 0.01), the 200 µmol/L lead-exposed ACM treatment group had significantly reduced content of SYP in neurons after 48-h culture (P < 0.01), and all lead-exposed ACM treatment groups showed no significant changes in the content of SYP in neurons after 24-h culture. Double-labeling immunofluorescence of SYP showed that all lead-exposed ACM treatment groups had a significant decrease in the number of SYP-fluorescent particles after 72-h culture (P < 0.05).

CONCLUSIONAstrocytes promote synaptic formation of neurons, which may be inhibited during lead exposure.

Astrocytes ; drug effects ; physiology ; Cell Survival ; drug effects ; Cells, Cultured ; Culture Media, Conditioned ; metabolism ; Glutamic Acid ; metabolism ; Lead ; toxicity ; Neurons ; drug effects ; Synapses ; drug effects ; physiology

PURPOSE: Lamotrigine, a novel anticonvulsant, is a sodium channel blocker that is efficacious in certain forms of neuropathic pain. Recently, microglial and astrocytic activation has been implicated in the development of nerve injury-induced neuropathic pain. We have assessed the effects of continuous intrathecal administration of lamotrigine on the development of neuropathic pain and glial activation induced by L5/6 spinal-nerve ligation in rats. MATERIALS AND METHODS: Following left L5/6 spinal nerve ligation (SNL), Sprague-Dawley male rats were intrathecally administered lamotrigine (24, 72, or 240 microg/day) or saline continuously for 7 days. Mechanical allodynia of the left hind paw to von Frey filament stimuli was determined before surgery (baseline) and once daily for 7 days postoperatively. On day 7, spinal activation of microglia and astrocytes was evaluated immunohistochemically, using antibodies to the microglial marker OX-42 and the astrocyte marker glial fibrillary acidic protein (GFAP). RESULTS: Spinal-nerve ligation induced mechanical allodynia in saline-treated rats, with OX-42 and GFAP immunoreactivity being significantly increased on the ipsilateral side of the spinal cord. Continuously administered intrathecal lamotrigine (240 microg/day) prevented the development of mechanical allodynia, and lower dose of lamotrigine (72 microg/day) ameliorated allodynia. Intrathecal lamotrigine (72 and 240 microg/day) inhibited nerve ligation-induced microglial and astrocytic activation, as evidenced by reduced numbers of cells positive for OX-42 and GFAP. CONCLUSION: Continuously administered intrathecal lamotrigine blocked the development of mechanical allodynia induced by SNL with suppression of microglial and astrocytic activation. Continuous intrathecal administration of lamotrigine may be a promising therapeutic intervention to prevent neuropathy.
Animals ; Astrocytes/drug effects/*physiology ; Disease Models, Animal ; Hyperalgesia/*drug therapy ; Infusions, Spinal ; Ligation ; Male ; Microglia/drug effects/*physiology ; Neuralgia/drug therapy ; Rats ; Rats, Sprague-Dawley ; Spinal Nerves/*injuries ; Triazines/administration & dosage/*therapeutic use ; Voltage-Gated Sodium Channel Blockers/administration & dosage/*therapeutic use

Metallothionein (MT) is a kind of metal binding protein. As an important member in metallothionein family, MT-I/II regulates metabolism and detoxication of brain metal ion and scavenges free radicals. It is capable of anti-inflammatory response and anti-oxidative stress so as to protect the brain tissue. During the repair process of brain injury, the latest study showed that MT-I/II could stimulate brain anti-inflammatory factors, growth factors, neurotrophic factors and the expression of the receptor, and promote the extension of axon of neuron, which makes contribution to the regeneration of neuron and has important effect on the recovery of brain injury. Based on the findings, this article reviews the structure, expression, distribution, adjustion, function, mechanism in the repair of brain injury of MT-I/II and its application prospect in forensic medicine. It could provide a new approach for the design and manufacture of brain injury drugs as well as for age estimation of the brain injury.
Animals ; Astrocytes/metabolism* ; Brain/metabolism* ; Brain Injuries/pathology* ; Cytokines/metabolism* ; Forensic Medicine/methods* ; Gene Expression Regulation/drug effects* ; Humans ; Metallothionein/physiology* ; Neurons/metabolism* ; Neuroprotective Agents/pharmacology* ; Oxidative Stress/drug effects*

OBJECTIVETo determine the effects of organic amine diphenhydramine on the 3-(4, 5-Dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide dye (MTT) reduction assay.

METHODSThe primarily cultured cortical astrocytes were incubated with various concentrations of diphenhydramine for 24 h. To analyze the effects of diphenhydramine and other organic amines on the MTT assay, the data obtained from the MTT assay were compared with the results obtained from morphological observation and hoechst 33342 and propidium iodide (PI) nucleus double staining.

RESULTThe MTT assay showed that diphenhydramine (10(-4)mol/L), pyrilamine (10 (-4)mol/L) and zolantidine (10 (-5)mol/L) caused a significant increase in MTT reduction in astrocytes. However there was no proliferation, apoptosis or necrosis detected by hoechst and PI nucleus double staining. Light microscopy revealed that exocytosis of formazan granules was inhibited by diphenhydramine.

CONCLUSIONDiphenhydramine and other organic amines may enhance MTT reduction by suppression of MTT formazan exocytosis in astrocytes, which may affect the results of cell viability studies.

Animals ; Astrocytes ; drug effects ; metabolism ; physiology ; Cell Survival ; Cells, Cultured ; Diphenhydramine ; pharmacology ; Drug Interactions ; Formazans ; pharmacokinetics ; Rats ; Rats, Sprague-Dawley ; Tetrazolium Salts ; pharmacokinetics

The objective of present study is to investigate the effect of human cytomegalovirus (HCMV) infection on human hippocampus neural stem cells NSCs differentiation in vitro, Fetal hippocampus tissue was dissociated mechanically and then cultured in proliferation medium with EGF and bFGF. Immunofluorescence method was used to detect the expression of NSCs marker-Nestin within these cells. Cultured in 10% FBS, NSCs began to differentiate. On the onset of the differentiation, HCMV AD169 (MOI=5) was added into the differentiation medium. After 7 days differentiation, the effect of HCMV infection on NSCs differentiation was observed by detecting the rate of nestin, GFAP and HCMV immediate-early (IE) positive cells with confocal microscopy and immunofluorescence method. The resucts showed most of the cells (passage 4-6 ) were Nestin positive and could differentiate into NSE-positive neurons and GFAP-positive astrocytes. On day 7 postinfection, 86% +/- 12% of infected cells were IE positive. The percentage of Nestin-positive cells was 50% +/- 19% and 93% +/- 10% (t= 6.03, P<0.01)and those of GFAP-positive cells was 81% +/- 11% and 55 +/- 17% (t=3.77, P<0.01) in uninfected and infected cells respectively. These findings indicated that NSCs were HCMV permissive cell and HCMV AD 169 infection suppressed the differentiation of Hippocampus-genetic human neural stem cells into astrocytes.
Astrocytes ; cytology ; Cell Differentiation ; drug effects ; Cells, Cultured ; Cytomegalovirus ; growth & development ; physiology ; Epidermal Growth Factor ; pharmacology ; Fibroblast Growth Factor 2 ; pharmacology ; Hippocampus ; cytology ; Humans ; Intermediate Filament Proteins ; metabolism ; Microscopy, Fluorescence ; Multipotent Stem Cells ; cytology ; drug effects ; metabolism ; virology ; Nerve Tissue Proteins ; metabolism ; Nestin ; Neurons ; cytology

Astrocytes maintain homeostasis of neuronal microenvironment, provide metabolic and trophic support to neurons and modulate neuronal responses to injury. Rotenone specifically inhibits mitochondrial complex I, and long exposure to rotenone may increase the risk for Parkinson's disease (PD) and cause Parkinsonism. However, little is known about the role of astrocytes in the process of rotenone-induced dopaminergic neuron injury. In order to investigate this issue, we used MN9D cells as a cell model of dopaminergic neurons and rotenone as a toxin to initiate mitochondrial deficiency. MN9D cells treated with the normal medium or astrocyte-conditioned medium (ACM) were exposed to different concentrations of rotenone for different time followed by cell viability measurement by MTT assay. Besides, various concentrations of ACM and temporally different treatments were devised to evaluate protective efficiency of ACM. Growth curve of cells in the normal medium or ACM was continuously assessed by cell counting for 8 d. The influence of rotenone and ACM on cellular oxidative stress was determined by DCFH-DA staining followed by flow cytometric analysis. Glutathione (GSH) content after treatment of ACM or rotenone was measured by GSH assay kit. Our results showed that rotenone decreased viability of MN9D cells in a dose-dependent manner and ACM treatment significantly attenuated rotenone toxicity at each concentration. No significant difference in growth rate was observed between the normal medium and ACM treatment. Four concentrations of ACM, namely 1/3ACM, 1/2ACM, 2/3ACM and pure ACM, all displayed protection, increasing cell viability to (124.15+/-0.79)%, (126.59+/-0.82) %, (125.84+/-0.61) % and (117.15+/-1.63) % of the cells exposed directly to rotenone, respectively. Treatment with ACM through the whole experiment except the initial 24 h, 24 h before or at the same time of rotenone addition all exerted protective effects, with cell viability being (110.11+/-2.52)%, (113.30+/-2.36) %, (114.42+/-2.00)% of the cells exposed directly to rotenone, respectively. Conversely, ACM treatment 12 h after rotenone addition had no protective effect, with cell viability being (102.54+/-1.36)% of the cells exposed directly to rotenone. Moreover, ACM treatment up-regulated GSH level in MN9D cells nearly twofold. Incubation with 100 nmol/L rotenone for 24 h depleted GSH level by nearly two thirds of the control, but ACM treatment mitigated the drop of GSH level, maintaining its content at (147.83+/-0.63)% of the control. Consistent with GSH change, rotenone administration resulted in a positive rate of 96.24% of DCF staining, implying a great extent of oxidative stress, whereas treatment with ACM reduced the extent of oxidative stress to a positive rate of 78.31%. Taken together, these findings suggest that astrocytes protect MN9D cells from oxidative stress caused by rotenone, and GSH partially accounts for the protection. Therefore, astrocytes may play a protective role in the process of PD.
Animals ; Astrocytes ; physiology ; Cells, Cultured ; Cytoprotection ; Glutathione ; analysis ; physiology ; Neurons ; drug effects ; metabolism ; Oxidative Stress ; Rats ; Rats, Sprague-Dawley ; Rotenone ; toxicity