scholarly journals Vitamin D confers neuroprotective effects in traumatic brain injury by activating Nrf2 signaling through an autophagy-mediated mechanism

Author(s):  
Changmeng Cui ◽  
Changshui Wang ◽  
Feng Jin ◽  
Mengqi Yang ◽  
Lingsheng Kong ◽  
...  

Abstract Background: Traumatic brain injury (TBI) initiates an oxidative cascade that contributes to the delayed progressive damage, whereas autophagy is critical in maintaining homeostasis during stressful challenge. We previously demonstrated that vitamin D (VitD) shows strong neuroprotective and anti-oxidative properties in the animal models of TBI. Therefore, the present study aimed to further explore the potential interrelationship between oxidative stress and autophagy in the progression of TBI and therapeutic mechanism of VitD. Methods: Neuroprotective effects of calcitriol, the active form of VitD, were examined following TBI. We further evaluated the impacts of TBI and VitD treatment on autophagic process and nuclear factor E2-related factor 2 (Nrf2) signaling. To confirm the mechanism, chloroquine (CQ) treatment and Nrf2 −/− mice were used to block autophagy and Nrf2 pathway, respectively. Results: We found that treatment of calcitriol markedly ameliorated the neurological deficits and histopathological changes following TBI. The brain damage impaired autophagic flux and impeded Nrf2 signaling, the major regulator in antioxidant response, consequently leading to uncontrolled and excessive oxidative stress. Meanwhile, calcitriol promoted autophagic process and activated Nrf2 signaling as evidenced by the reduced Keap1 expression and enhanced Nrf2 translocation, thereby mitigating TBI-induced oxidative damage. To further confirm whether autophagy was responsible for Keap1 degradation and Nrf2 activation, the lysosomal inhibitor, CQ, was used to block autophagy. Our data suggested that CQ treatment abrogated calcitriol-induced autophagy and compromised Nrf2 activation with increased Keap1 accumulation and reduced expression of Nrf2-targeted genes. Additionally, both CQ treatment and Nrf2 genetic knockout abolished the protective effects of VitD against both TBI-induced neurological deficits and neuronal apoptosis. Conclusions: Therefore, our work demonstrated a neuroprotective role of VitD in TBI by triggering Nrf2 activation, which might be mediated by autophagy.

2021 ◽  
Author(s):  
Changmeng Cui ◽  
Changshui Wang ◽  
Feng Jin ◽  
Mengqi Yang ◽  
Lingsheng Kong ◽  
...  

Abstract Background: Traumatic brain injury (TBI) initiates an oxidative cascade that contributes to the delayed progressive damage, whereas autophagy is critical in maintaining homeostasis during stressful challenge. We previously demonstrated that vitamin D (VitD) shows strong neuroprotective and anti-oxidative properties in the animal models of TBI. Therefore, the present study aimed to further explore the potential interrelationship between oxidative stress and autophagy in the progression of TBI and therapeutic mechanism of VitD. Methods: Neuroprotective effects of calcitriol, the active form of VitD, were examined following TBI. We further evaluated the impacts of TBI and VitD treatment on autophagic process and nuclear factor E2-related factor 2 (Nrf2) signaling. To confirm the mechanism, chloroquine (CQ) treatment and Nrf2−/− mice were used to block autophagy and Nrf2 pathway, respectively. Results: We found that treatment of calcitriol markedly ameliorated the neurological deficits and histopathological changes following TBI. The brain damage impaired autophagic flux and impeded Nrf2 signaling, the major regulator in antioxidant response, consequently leading to uncontrolled and excessive oxidative stress. Meanwhile, calcitriol promoted autophagic process and activated Nrf2 signaling as evidenced by the reduced Keap1 expression and enhanced Nrf2 translocation, thereby mitigating TBI-induced oxidative damage. To further confirm whether autophagy was responsible for Keap1 degradation and Nrf2 activation, the lysosomal inhibitor, CQ, was used to block autophagy. Our data suggested that CQ treatment abrogated calcitriol-induced autophagy and compromised Nrf2 activation with increased Keap1 accumulation and reduced expression of Nrf2-targeted genes. Additionally, both CQ treatment and Nrf2 genetic knockout abolished the protective effects of VitD against both TBI-induced neurological deficits and neuronal apoptosis. Conclusions: Therefore, our work demonstrated a neuroprotective role of VitD in TBI by triggering Nrf2 activation, which might be mediated by autophagy.


2021 ◽  
Vol 27 (1) ◽  
Author(s):  
Changmeng Cui ◽  
Changshui Wang ◽  
Feng Jin ◽  
Mengqi Yang ◽  
Lingsheng Kong ◽  
...  

Abstract Background The present study aimed to further explore the potential interaction between oxidative stress and autophagy in the progression of traumatic brain injury (TBI) and therapeutic mechanism of calcitriol, the active form of vitamin D (VitD). Methods Neuroprotective effects of calcitriol were examined following TBI. We further evaluated the impacts of TBI and calcitriol treatment on autophagic process and nuclear factor E2-related factor 2 (Nrf2) signaling. Results We found that treatment of calcitriol markedly ameliorated the neurological deficits and histopathological changes following TBI. The brain damage impaired autophagic flux and impeded Nrf2 signaling, the major regulator in antioxidant response, consequently leading to uncontrolled and excessive oxidative stress. Meanwhile, calcitriol promoted autophagic process and activated Nrf2 signaling as evidenced by the reduced Keap1 expression and enhanced Nrf2 translocation, thereby mitigating TBI-induced oxidative damage. In support, we further found that chloroquine (CQ) treatment abrogated calcitriol-induced autophagy and compromised Nrf2 activation with increased Keap1 accumulation and reduced expression of Nrf2-targeted genes. Additionally, both CQ treatment and Nrf2 genetic knockout abolished the protective effects of calcitriol against both TBI-induced neurological deficits and neuronal apoptosis. Conclusions Therefore, our work demonstrated a neuroprotective role of calcitriol in TBI by triggering Nrf2 activation, which might be mediated by autophagy.


2020 ◽  
Author(s):  
Han Wang ◽  
Xiaoming Zhou ◽  
Lingyun Wu ◽  
Guangjie Liu ◽  
Weidong Xu ◽  
...  

Abstract Background: Aucubin (Au) has anti-oxidative and anti-inflammatory bioactivities; however, its effects on a traumatic brain injury (TBI) model remain unknown. We explored the potential role of Au in a H2O2-induced oxidant damage in primary cortical neurons and weight-drop induced-TBI in a mouse model.Methods: Neuronal apoptosis, brain water content, histological damages and neurological deficits and cognitive functions were measured. We performed western blot, TdT-mediated dUTP Nick-End Labeling (TUNEL) staining, Nissl staining, quantitative real time polymerase chain reaction (q-PCR), immunofluorescence/immunohistochemistry and enzyme linked immunosorbent assay (ELISA). RNA interference experiments were performed to determine the effects of Nuclear factor erythroid-2 related factor 2 (Nrf2) on TBI mice with intraperitoneal injection of Au.Results: We found that Au enhanced the translocation of Nrf2 into the nucleus, activated antioxidant enzymes, suppressed excessive generation of reactive oxygen species (ROS) and reduced cell apoptosis in vitro and vivo experiments. In the mice model of TBI, Au markedly attenuated brain edema, histological damages and improved neurological and cognitive deficits. Au significantly suppressed high mobility group box 1(HMGB1)-mediated aseptic inflammation. Nrf2 knockdown in TBI mice blunted the antioxidant and anti-inflammatory neuroprotective effects of the Au.Conclusions: Taken together, our data suggest that Au provides a neuroprotective effect in TBI mice model by inhibiting oxidative stress and inflammatory responses; the mechanisms involve triggering Nrf2-induced antioxidant system.


2020 ◽  
Author(s):  
Han Wang ◽  
Xiaoming Zhou ◽  
Lingyun Wu ◽  
Guangjie Liu ◽  
Weidong Xu ◽  
...  

Abstract Background: Aucubin (Au) has anti-oxidative and anti-inflammatory bioactivities; however, its effects on a traumatic brain injury (TBI) model remain unknown. We explored the potential role of Au in a H 2 O 2 -induced oxidant damage in primary cortical neurons and weight-drop induced-TBI in a mouse model. Methods: Neuronal apoptosis, brain water content, histological damages and neurological deficits and cognitive functions were measured. We performed western blot, TdT-mediated dUTP Nick-End Labeling (TUNEL) staining, Nissl staining, quantitative real time polymerase chain reaction (q-PCR), immunofluorescence/immunohistochemistry and enzyme linked immunosorbent assay (ELISA). RNA interference experiments were performed to determine the effects of Nuclear factor erythroid-2 related factor 2 (Nrf2) on TBI mice with intraperitoneal injection of Au. Results: We found that Au enhanced the translocation of Nrf2 into the nucleus, activated antioxidant enzymes, suppressed excessive generation of reactive oxygen species (ROS) and reduced cell apoptosis in vitro and vivo experiments. In the mice model of TBI, Au markedly attenuated brain edema, histological damages and improved neurological and cognitive deficits. Au significantly suppressed high mobility group box 1(HMGB1)-mediated aseptic inflammation. Nrf2 knockdown in TBI mice blunted the antioxidant and anti-inflammatory neuroprotective effects of the Au. Conclusions: Taken together, our data suggest that Au provides a neuroprotective effect in TBI mice model by inhibiting oxidative stress and inflammatory responses; the mechanisms involve triggering Nrf2-induced antioxidant system.


2020 ◽  
pp. 096032712098422
Author(s):  
Xiaobin Liu ◽  
Min Li ◽  
Jiabao Zhu ◽  
Weidong Huang ◽  
Jinning Song

Sestrin2 (SESN2) is stress-inducible protein that confers cytoprotective effects against various noxious stimuli. Accumulating evidence has documented that SESN2 has potent anti-apoptosis and anti-oxidative stress functions. However, whether it provides neuroprotection in traumatic brain injury (TBI) models remains unexplored. The purpose of this study was to explore the regulatory effect of SESN2 on TBI using in vivo and in vitro models. We found that TBI resulted in a marked induction of SESN2 in the cerebral cortex tissues of mice. SESN2 overexpression in the brain by in vivo gene transfer significantly decreased neurological deficit, brain edema, and neuronal apoptosis of mice with TBI. Moreover, the overexpression of SESN2 significantly decreased the oxidative stress induced by TBI in mice. In vitro studies of TBI demonstrated that SESN2 overexpression decreased apoptosis and oxidative stress in scratch-injured cortical neurons. Notably, SESN2 overexpression increased the nuclear levels of nuclear factor-erythroid 2-related factor 2 (Nrf2) and enhanced the activation of Nrf2 antioxidant signaling in in vivo and in vitro models of TBI. In addition, the inhibition of Nrf2 significantly abolished SESN2-mediated neuroprotective effects in vivo and in vitro. In conclusion, these results of our work demonstrate that SESN2 protects against TBI by enhancing the activation of Nrf2 antioxidant signaling.


2019 ◽  
Vol 20 (3) ◽  
pp. 502 ◽  
Author(s):  
Buyandelger Batsaikhan ◽  
Jing-Ya Wang ◽  
Michael Scerba ◽  
David Tweedie ◽  
Nigel Greig ◽  
...  

Traumatic brain injury (TBI) is a major cause of mortality and disability worldwide. Long-term deficits after TBI arise not only from the direct effects of the injury but also from ongoing processes such as neuronal excitotoxicity, inflammation, oxidative stress and apoptosis. Tumor necrosis factor-α (TNF-α) is known to contribute to these processes. We have previously shown that 3,6′-dithiothalidomide (3,6′-DT), a thalidomide analog that is more potent than thalidomide with similar brain penetration, selectively inhibits the synthesis of TNF-α in cultured cells and reverses behavioral impairments induced by mild TBI in mice. In the present study, we further explored the therapeutic potential of 3,6′-DT in an animal model of moderate TBI using Sprague-Dawley rats subjected to controlled cortical impact. A single dose of 3,6′-DT (28 mg/kg, i.p.) at 5 h after TBI significantly reduced contusion volume, neuronal degeneration, neuronal apoptosis and neurological deficits at 24 h post-injury. Expression of pro-inflammatory cytokines in the contusion regions were also suppressed at the transcription and translation level by 3,6′-DT. Notably, neuronal oxidative stress was also suppressed by 3,6′-DT. We conclude that 3,6′-DT may represent a potential therapy to ameliorate TBI-induced functional deficits.


2017 ◽  
Vol 37 (6) ◽  
Author(s):  
Ligang Wang ◽  
Libo Wang ◽  
Zhibo Dai ◽  
Pei Wu ◽  
Huaizhang Shi ◽  
...  

Oxidative stress has been strongly implicated in the pathogenesis of traumatic brain injury (TBI). Mitochondrial ferritin (Ftmt) is reported to be closely related to oxidative stress. However, whether Ftmt is involved in TBI-induced oxidative stress and neurological deficits remains unknown. In the present study, the controlled cortical impact model was established in wild-type and Ftmt knockout mice as a TBI model. The Ftmt expression, oxidative stress, neurological deficits, and brain injury were measured. We found that Ftmt expression was gradually decreased from 3 to 14 days post-TBI, while oxidative stress was gradually increased, as evidenced by reduced GSH and superoxide dismutase levels and elevated malondialdehyde and nitric oxide levels. Interestingly, the extent of reduced Ftmt expression in the brain was linearly correlated with oxidative stress. Knockout of Ftmt significantly exacerbated TBI-induced oxidative stress, intracerebral hemorrhage, brain infarction, edema, neurological severity score, memory impairment, and neurological deficits. However, all these effects in Ftmt knockout mice were markedly mitigated by pharmacological inhibition of oxidative stress using an antioxidant, N-acetylcysteine. Taken together, these results reveal an important correlation between Ftmt and oxidative stress after TBI. Ftmt deficiency aggravates TBI-induced brain injuries and neurological deficits, which at least partially through increasing oxidative stress levels. Our data suggest that Ftmt may be a promising molecular target for the treatment of TBI.


2017 ◽  
Vol 2017 ◽  
pp. 1-13 ◽  
Author(s):  
Changmeng Cui ◽  
Sixin Song ◽  
Jianzhong Cui ◽  
Yan Feng ◽  
Junling Gao ◽  
...  

Traumatic brain injury (TBI) is a worldwide phenomenon which results in significant neurological and cognitive deficits in humans. Vitamin D (VD) is implicated as a therapeutic strategy for various neurological diseases now. Recently, inhibition of the NADPH oxidase (NOX2) was reported to protect against oxidative stress (ROS) production. However, whether alterations in NOX2expression and NOX activity are associated with calcitriol (active metabolite of VD) treatment following TBI remains unclear. In the present study, rats were randomly assigned to the sham, TBI, and calcitriol-treated groups. Calcitriol was administered intraperitoneally (2 μg/kg) at 30 min, 24 h, and 48 h after TBI insult. We observed that calcitriol treatment alleviated neurobehavioral deficits and brain edema following TBI. At the molecular levels, administration of calcitriol activated the expression of VDR and downregulated NOX2as well as suppressed apoptosis cell rate in the hippocampus CA1 region of TBI rats. In conclusion, our findings indicate that the protective effects of calcitriol may be related to the modulation of NADPH oxidase and thereby ultimately inhibited the progression of apoptosis. Calcitriol may be promising as a protective intervention following TBI, and more study is warranted for its clinical testing in the future.


2021 ◽  
Vol 12 ◽  
Author(s):  
Agustín. J. Montivero ◽  
Marisa. S. Ghersi ◽  
M. Jazmín Silvero C ◽  
Emilce Artur de la Villarmois ◽  
Johanna Catalan-Figueroa ◽  
...  

Traumatic Brain Injury (TBI) remains a leading cause of morbidity and mortality in adults under 40 years old. Once primary injury occurs after TBI, neuroinflammation and oxidative stress (OS) are triggered, contributing to the development of many TBI-induced neurological deficits, and reducing the probability of critical trauma patients´ survival. Regardless the research investment on the development of anti-inflammatory and neuroprotective treatments, most pre-clinical studies have failed to report significant effects, probably because of the limited blood brain barrier permeability of no-steroidal or steroidal anti-inflammatory drugs. Lately, neurotrophic factors, such as the insulin-like growth factor 1 (IGF-1), are considered attractive therapeutic alternatives for diverse neurological pathologies, as they are neuromodulators linked to neuroprotection and anti-inflammatory effects. Considering this background, the aim of the present investigation is to test early IGF-1 gene therapy in both OS markers and cognitive deficits induced by TBI. Male Wistar rats were injected via Cisterna Magna with recombinant adenoviral vectors containing the IGF-1 gene cDNA 15 min post-TBI. Animals were sacrificed after 60 min, 24 h or 7 days to study the advanced oxidation protein products (AOPP) and malondialdehyde (MDA) levels, to recognize the protein oxidation damage and lipid peroxidation respectively, in the TBI neighboring brain areas. Cognitive deficits were assessed by evaluating working memory 7 days after TBI. The results reported significant increases of AOPP and MDA levels at 60 min, 24 h, and 7 days after TBI in the prefrontal cortex, motor cortex and hippocampus. In addition, at day 7, TBI also reduced working memory performance. Interestingly, AOPP, and MDA levels in the studied brain areas were significantly reduced after IGF-1 gene therapy that in turn prevented cognitive deficits, restoring TBI-animals working memory performance to similar values regarding control. In conclusion, early IGF-1 gene therapy could be considered a novel therapeutic approach to targeting neuroinflammation as well as to preventing some behavioral deficits related to TBI.


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