scholarly journals UV-induced neuronal degeneration in the rat cerebral cortex

Author(s):  
Mariko Nakata ◽  
Masayuki Shimoda ◽  
Shinya Yamamoto

Abstract Irradiation with ultraviolet (UV) light on the cortical surface can induce a focal brain lesion (UV lesion) in rodents. In the present study, we investigated the process of establishing a UV lesion. Rats underwent UV irradiation (365 nm wavelength, 2.0 mWh) over the dura, and time-dependent changes in the cortical tissue were analyzed histologically. We found that the majority of neurons in the lesion started to degenerate within 24 hours and the rest disappeared within 5 days after irradiation. UV-induced neuronal degeneration progressed in a layer-dependent manner. Moreover, UV-induced terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) positivity and heme oxygenase-1 (HO-1) immunoreactivity were also detected. These findings suggest that UV irradiation in the brain can induce gradual neural degeneration and oxidative stress. Importantly, UV vulnerability may vary among cortical layers. UV-induced cell death may be due to apoptosis; however, there remains a possibility that UV-irradiated cells were degenerated via processes other than apoptosis. The UV lesion technique will not only assist in investigating brain function at a targeted site but may also serve as a pathophysiological model of focal brain injury and/or neurodegenerative disorders.

Stroke ◽  
2021 ◽  
Author(s):  
Luiz Ricardo C. Vasconcellos ◽  
Letícia Martimiano ◽  
Danillo Pereira Dantas ◽  
Filipe Mota Fonseca ◽  
Hilton Mata-Santos ◽  
...  

Background and Purpose: Heme is a red blood cell component released in the brain parenchyma following intracerebral hemorrhage. However, the study of the pathophysiological mechanisms triggered by heme in the brain is hampered by the lack of well-established in vivo models of intracerebral heme injection. This study aims to optimize and characterize a protocol of intrastriatal heme injection in mice, with a focus on the induction of lipid peroxidation, neuroinflammation and, ultimately, sensorimotor deficits. We also evaluated the involvement of NLRP3 (NOD-, LRR-, and pyrin domain-containing protein 3), an inflammasome sensor, in the behavior deficits induced by heme in this model. Methods: Mice were injected with heme in the striatum for the evaluation of neuroinflammation and brain damage through histological and biochemical techniques. Immunoblot was used to evaluate the expression of proteins involved in heme/iron metabolism and antioxidant responses and the activation of the MAPK (mitogen-activated protein kinase) signaling pathway. For the assessment of neurological function, we followed-up heme-injected mice for 2 weeks using the rotarod, elevated body swing, and cylinder tests. Mice injected with the vehicle (sham), or autologous blood were used as controls. Results: Heme induced lipid peroxidation and inflammation in the brain. Moreover, heme increased the expression of HO-1 (heme oxygenase-1), ferritin, p62, and superoxide dismutase 2, and activated the MAPK signaling pathway promoting pro-IL (interleukin)-1β production and its cleavage to the active form. Heme-injected mice exhibited signs of brain damage and reactive astrogliosis around the injection site. Behavior deficits were observed after heme or autologous blood injection in comparison to sham-operated controls. In addition, behavior deficits and IL-1β production were reduced in Nlrp3 knockout mice in comparison to wild-type mice. Conclusions: Our results show that intracerebral heme injection induces neuroinflammation, and neurological deficits, in an NLRP3-dependent manner, suggesting that this is a feasible model to evaluate the role of heme in neurological disorders.


2017 ◽  
Vol 127 (3) ◽  
pp. 522-531 ◽  
Author(s):  
Ruobing Xu ◽  
Shu Wang ◽  
Weishan Li ◽  
Zhen Liu ◽  
Jiaxin Tang ◽  
...  

OBJECTIVEIn this study, the authors investigated the involvement of 15(S)-hydroxyeicosatetraenoic acid (15(S)-HETE) in the regulation of peroxisome proliferator-activated receptor–γ (PPARγ) after intracerebral hemorrhage (ICH) and its effects on hemorrhage-induced inflammatory response and oxidative stress in an experimental rodent model.METHODSTo simulate ICH in a rat model, the authors injected autologous whole blood into the right striatum of male Sprague-Dawley rats. The distribution and expression of 12/15-lipoxygenase (12/15-LOX) were determined by immunohistochemistry and Western blot analysis, respectively. Immunofluorescent double labeling was used to study the cellular localization of 12/15-LOX, and 15(S)-HETE was measured with a 15(S)-HETE enzyme immunoassay kit. Neurological deficits in the animals were assessed through behavioral testing, and apoptotic cell death was determined with terminal deoxynucleotidyl transferase–mediated biotinylated dUTP nick-end labeling.RESULTSRats with ICH had increased expression of 12/15-LOX predominantly in neurons and also in oligodendrocytes, astrocytes, and microglia. Moreover, ICH elevated production of 15(S)-HETE in the brain area ipsilateral to the blood injection. The PPARγ agonist, exogenous 15(S)-HETE, significantly increased PPARγ protein levels and increased PPARγ-regulated gene (i.e., catalase) expression in the ICH rats. Reduced expression of the gene for the proinflammatory protein nuclear factor κB coincided with decreased neuron damage and improved functional recovery from ICH. A PPARγ antagonist, GW9662, reversed the effects of exogenous 15(S)-HETE on the PPARγ-regulated genes.CONCLUSIONSThe induction of 15(S)-HETE during simulated ICH suggests generation of endogenous signals of neuroprotection. The effects of exogenous 15(S)-HETE on brain hemorrhage–induced inflammatory responses and oxidative stress might be mediated via PPARγ.


2021 ◽  
Vol 39 (1) ◽  
pp. 73-84
Author(s):  
Jianqiang Song ◽  
Guoliang Du ◽  
Haiyun Wu ◽  
Xiangliang Gao ◽  
Zhen Yang ◽  
...  

Background: Traumatic brain injury (TBI) has been a serious public health issue. Clinically, there is an urgent need for agents to ameliorate the neuroinflammation and oxidative stress induced by TBI. Our previous research has demonstrated that quercetin could protect the neurological function. However, the detailed mechanism underlying this process remains poorly understood. Objective: This research was designed to investigate the mechanisms of quercetin to protect the cortical neurons. Methods: A modified weight-drop device was used for the TBI model. 5, 20 or 50 mg/kg quercetin was injected intraperitoneally to rats at 0.5, 12 and 24 h post TBI. Rats were sacrificed three days post injury and their cerebral cortex was obtained from the injured side. The rats were randomly assigned into three groups of equal number: TBI and quercetin group, TBI group, and Sham group. The brain water content was calculated to estimate the brain damage induced by TBI. Immunohistochemical and Western blot assays were utilized to investigate the neurobehavioral status. Enzyme-linked immunosorbent assay and reverse transcription polymerase chain reaction were performed to evaluate the inflammatory responses. The cortical oxidative stress was measured by estimating the activities of malondialdehyde, superoxide dismutase, catalase and glutathione-Px. Western blot was utilized to evaluate the expression of nuclear factor erythroid 2-related factor 2 (Nrf-2) and heme oxygenase 1 (HO-1). Results: Quercetin attenuated the brain edema and microgliosis in TBI rats. Quercetin treatment attenuated cortical inflammatory responses and oxidative stress induced by TBI insults. Quercetin treatment activated the cortical Nrf2/HO-1 pathway in TBI rats. Conclusions: Quercetin ameliorated the TBI-induced neuroinflammation and oxidative stress in the cortex through activating the Nrf2/HO-1 pathway.


Pharmacology ◽  
2019 ◽  
Vol 105 (1-2) ◽  
pp. 47-53 ◽  
Author(s):  
Wenyong Pan ◽  
Zhigang Cao ◽  
Dongyang Liu ◽  
Yingbin Jiao

Background: Traumatic brain injury (TBI) is considered a major burden across the globe affecting both individuals and their families. Therefore, the present study was conducted to determine the protective effect of diphenhydramine (DPM) against TBI in experimental rats. Methods: The effect of DPM was evaluated on the cerebral edema (CE) and neuronal degeneration after the induction of experimental brain injury in rats. The effect of DPM was also investigated on the inflammatory cytokines, for example, tumor necrosis factor-α and interleukin 1β and oxidative stress markers, such as malondialdehyde, superoxide dismutase, and glutathione peroxidase. Western blot analysis was used to investigate the effect of DPM on B-cell lymphoma 2 (Bcl-2), Bcl-2-associated X protein (Bax) and cleaved caspase-3. Results: Results of the study suggest that DPM causes reduction in CE and prevents neuronal degeneration. It also causes reduction in inflammation and oxidative stress in a dose-dependent manner. The level of Bax was found to be elevated, together with reduction in the Bcl-2 level in the DPM-treated group. Conclusion: DPM exerts a neuroprotective effect after TBI via the attenuation of oxidative stress, inflammation, and mitochondrial apoptosis pathways.


2020 ◽  
Vol 21 (3) ◽  
pp. 91-98
Author(s):  
Mohamed Abomosallam ◽  
Mahmoud Elalfy ◽  
Fathy Sleem

Objective: To evaluate the postnatal toxicity of copper oxychloride (COC) in lactating female albino rats. Design: Randomized controlled experimental study. Animals: Eighteen pregnant female albino rats weight 150±10 g and 6-7 week old. Procedures: Eighteen pregnant female albino rats were divided into 3 groups treated orally with copper oxychloride 0, 73.5, 147 mg/kg (equivalent 1/20 and 1/10 of LD50) daily from first day of parturition for 21 days. Female rats and its offspring were euthanized at 21 days of treatment. The postnatal toxic effect in the neonates and dams were estimated through biochemical biomarkers as metabolic and oxidative stress biomarkers, histopathological and hematological evaluation. Results: There was a significant increase in liver enzymes activities as ALT and GGT and oxidative stress biomarker as MDA (P < 0.05) in both suckling pups and lactating dams beside decrease the level of metabolic biomarkers as glucose, total protein and cholesterol (P < 0.05). Additionally, antioxidant enzymes as SOD and CTA (P < 0.05) were reduced significantly in the treated groups in a dose dependent manner in comparison to control group. Moreover the histopathological revealed that Dams treated with COC at both doses shown degenerative changes and intralobular histiocytic infiltration with intralobular fibroblastic proliferation in the hepatic tissue. Neuronal necrosis, neuronophagia and astrocytosis in the brain tissue with degenerative changes of purkinje cells in cerebellum. Fibrous tissue proliferation of renal glomeruli with degenerative changes in renal tubular epithelium and marked lymphoid depletion in the splenic tissue in dose dependent manner. While Suckling pups of treated dams with different doses of COC shown focal histiocytic and lymphocytic infiltration besides congestion of portal vein and margination of leukocytes, focal edema in the neuropils with focal hemorrhagic areas in the brain tissue, degeneration in the renal glomeruli and severe lymphoid depletion with congestion of the splenic sinusoids in dose dependent manner. Conclusion and clinical relevance: The potential postnatal toxic effect of copper oxychloride in neonates and lactating female albino rats through transmammary transmission in milk clarified from biochemical and histopathological evaluation of dams and its pups.


2018 ◽  
Vol 40 (5-6) ◽  
pp. 437-450 ◽  
Author(s):  
Jana Krystofova ◽  
Praneeti Pathipati ◽  
Jeffrey Russ ◽  
Ann Sheldon ◽  
Donna Ferriero

Brain damage after hypoxia-ischemia (HI) occurs in an age-dependent manner. Neuroprotective strategies assumed to be effective in adults might have deleterious effects in the immature brain. In order to create effective therapies, the complex pathophysiology of HI in the developing brain requires exploring new mechanisms. Critical determinants of neuronal survival after HI are the extent of vascular dysfunction, inflammation, and oxidative stress, followed later by tissue repair. The key enzyme of these processes in the human body is arginase (ARG) that acts via the bioavailability of nitric oxide, and the synthesis of polyamines and proline. ARG is expressed throughout the brain in different cells. However, little is known about the effect of ARG in pathophysiological states of the brain, especially hypoxia-ischemia. Here, we summarize the role of ARG during neurodevelopment as well as in various brain pathologies.


2019 ◽  
Vol 20 (3) ◽  
pp. 507 ◽  
Author(s):  
Shanshan Wang ◽  
Qian Luo ◽  
Peihong Fan

Hemp seed (Fructus cannabis) is rich in lignanamides, and initial biological screening tests showed their potential anti-inflammatory and anti-oxidative capacity. This study investigated the possible effects and underlying mechanism of cannabisin F, a hempseed lignanamide, against inflammatory response and oxidative stress in lipopolysaccharide (LPS)-stimulated BV2 microglia cells. Cannabisin F suppressed the production and the mRNA levels of pro-inflammatory mediators such as interleukin 6 (IL-6) and tumor necrosis factor α (TNF-α) in a concentration-dependent manner in LPS-stimulated BV2 microglia cell. Furthermore, cannabisin F enhanced SIRT1 expression and blocked LPS-induced NF-κB (Nuclear factor kappa B) signaling pathway activation by inhibiting phosphorylation of IκBα (Inhibit proteins of nuclear factor kappaB) and NF-κB p65. And the SIRT1 inhibitor EX527 significantly inhibited the effect of cannabisin F on pro-inflammatory cytokines production, suggesting that the anti-inflammatory effects of cannabisin F are SIRT1-dependent. In addition, cannabisin F reduced the production of cellular reactive oxygen species (ROS) and promoted the expression of Nrf2 (Nuclear factor erythroid-2 related factor 2) and HO-1 (Heme Oxygenase-1), suggesting that the anti-oxidative effects of cannabisin F are related to Nrf2 signaling pathway. Collectively, these results suggest that the neuro-protection effect of cannabisin F against LPS-induced inflammatory response and oxidative stress in BV2 microglia cells involves the SIRT1/NF-κB and Nrf2 pathway.


2019 ◽  
Vol 17 (4) ◽  
pp. 426-431
Author(s):  
Jin Xuezhu ◽  
Li Jitong ◽  
Nie Leigang ◽  
Xue Junlai

The main purpose of this study is to investigate the role of citrus leaf extract in carbon tetrachloride-induced hepatic injury and its potential molecular mechanism. Carbon tetrachloride was used to construct hepatic injury animal model. To this end, rats were randomly divided into 4 groups: control, carbon tetrachloride-treated, and two carbon tetrachloride + citrus leaf extract-treated groups. The results show that citrus leaf extract treatment significantly reversed the effects of carbon tetrachloride on the body weight changes and liver index. Besides, treatment with citrus leaf extract also reduced the levels of serum liver enzymes and oxidative stress in a dose-dependent manner. H&E staining and western blotting suggested that citrus leaf extract could repair liver histological damage by regulating AMPK and Nrf-2.


2018 ◽  
Vol 24 (20) ◽  
pp. 2283-2302 ◽  
Author(s):  
Vivian B. Neis ◽  
Priscila B. Rosa ◽  
Morgana Moretti ◽  
Ana Lucia S. Rodrigues

Heme oxygenase (HO) family catalyzes the conversion of heme into free iron, carbon monoxide and biliverdin. It possesses two well-characterized isoforms: HO-1 and HO-2. Under brain physiological conditions, the expression of HO-2 is constitutive, abundant and ubiquitous, whereas HO-1 mRNA and protein are restricted to small populations of neurons and neuroglia. HO-1 is an inducible enzyme that has been shown to participate as an essential defensive mechanism for neurons exposed to oxidant challenges, being related to antioxidant defenses in certain neuropathological conditions. Considering that neurodegenerative diseases (Alzheimer’s Disease (AD), Parkinson’s Disease (PD) and Multiple Sclerosis (MS)) and neuropsychiatric disorders (depression, anxiety, Bipolar Disorder (BD) and schizophrenia) are associated with increased inflammatory markers, impaired redox homeostasis and oxidative stress, conditions that may be associated with alterations in HO-levels/activity, the purpose of this review is to present evidence on the possible role of HO-1 in these Central Nervous System (CNS) diseases. In addition, the possible therapeutic potential of targeting brain HO-1 is explored in this review.


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