scholarly journals Vitamin D Receptor Activation Influences NADPH Oxidase (NOX2) Activity and Protects against Neurological Deficits and Apoptosis in a Rat Model of Traumatic Brain Injury

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.

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Yihao Zhu ◽  
Handong Wang ◽  
Jiang Fang ◽  
Wei Dai ◽  
Jiang Zhou ◽  
...  

SS-31, a novel mitochondria-targeted peptide, has been proven to provide neuroprotection in a variety of neurological diseases. Its role as a mitochondrial reactive oxygen species (ROS) scavenger and the underlying pathophysiological mechanisms in traumatic brain injury (TBI) are still not well understood. The aim of the designed study was to investigate the potential neuroprotective effects of SS-31 and fulfill our understanding of the process of the mitochondrial change in the modified Marmarou weight-drop model of TBI. Mice were randomly divided into sham, TBI, TBI + vehicle, and TBI + SS-31 groups in this study. Peptide SS-31 (5 mg/kg) or vehicle was intraperitoneally administrated 30 min after TBI with brain samples harvested 24 h later for further analysis. SS-31 treatment significantly reversed mitochondrial dysfunction and ameliorated secondary brain injury caused by TBI. SS-31 can directly decrease the ROS content, restore the activity of superoxide dismutase (SOD), and decrease the level of malondialdehyde (MDA) and the release of cytochrome c, thus attenuating neurological deficits, brain water content, DNA damage, and neural apoptosis. Moreover, SS-31 restored the expression of SIRT1 and upregulated the nuclear translocation of PGC-1α, which were proved by Western blot and immunohistochemistry. Taken together, these data demonstrate that SS-31 improves the mitochondrial function and provides neuroprotection in mice after TBI potentially through enhanced mitochondrial rebiogenesis. The present study gives us an implication for further clinical research.


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.


2017 ◽  
Vol 42 (5) ◽  
pp. 1888-1896 ◽  
Author(s):  
Changmeng Cui ◽  
Jianzhong Cui ◽  
Feng Jin ◽  
Ying Cui ◽  
Ran Li ◽  
...  

Background/Aims: Traumatic brain injury (TBI) is a major public health problem in the world and causes high rates of mortality and disability. Recent evidence suggests that vitamin D (VD) has neuroprotective actions and can promote function recovery after TBI. In vitro and in vivo studies have demonstrated that autophagy could be enhanced following supplementation with an active metabolite of VD (calcitriol). However, it is unclear whether autophagy participates in the protective effects of calcitriol after TBI. To test this hypothesis, we examined the protective effects of calcitriol on TBI-induced neurological impairment and further investigated whether calcitriol could modulate autophagy dysfunction-mediated cell death in the cortex region of rat brain. Methods: Eighty-five male rats (250-280 g) were randomly assigned to sham (n=15), TBI model (TBI, n=35) and calcitriol treatment (calcitriol, n=35) groups. Rats were injected intraperitoneally with calcitriol (1 µg/kg) at 30 min, 24 h and 48 h post-TBI in the calcitriol group. The lysosomal inhibitor, chloroquine (CQ), was used to evaluate autophagic flux in the TBI and calcitriol groups. Neurological functions were evaluated via the modified neurological severity score test at 1-7 days after TBI or sham operation, and the terminal deoxynucleotidyl transferase-mediated FITC-dUTP nick-end labeling method was used to evaluate the ability of calcitriol to inhibit apoptosis. The expression of VDR, LC3 and p62 proteins was measured by western blot analysis at 1, 3 and 7 days post-injury Results: Calcitriol treatment attenuated mNSS at 2-7 days post-TBI (P < 0.05 versus TBI group). Calcitriol dramatically increased VDR protein expression compared with the untreated counterparts at 1, 3 and 7 days post-TBI (P < 0.05). The rate of apoptotic cells in calcitriol-treated rats was significantly reduced compared to that observed in the TBI group (P < 0.05). The LC3II/LC3I ratio was decreased in the cortex region at 1, 3 and 7 days post-TBI in rats treated with calcitriol (p < 0.05 versus TBI group), and the p62 expression was also attenuated (p < 0.05 versus TBI group). The LC3II/LC3I ratio in the calcitriol group was significantly increased when pretreated with CQ (P < 0.05). Conclusion: Calcitriol treatment activated VDR protein expression and attenuated neurological deficits in this rat TBI model. The protective effects might be associated with the restoration of autophagy flux and the decrease in apoptosis in the cortex region of rat brain.


2017 ◽  
Vol 2017 ◽  
pp. 1-14 ◽  
Author(s):  
Chonghui Tang ◽  
Yudong Shan ◽  
Yilan Hu ◽  
Zhanjian Fang ◽  
Yun Tong ◽  
...  

Traumatic brain injury (TBI) can lead to physical and cognitive deficits, which are caused by the secondary injury process. Effective pharmacotherapies for TBI patients are still lacking. Fibroblast growth factor-2 (FGF2) is an important neurotrophic factor that can stimulate neurogenesis and angiogenesis and has been shown to have neuroprotective effects after brain insults. Previous studies indicated that FGF2’s neuroprotective effects might be related to its function of regulating autophagy. The present study investigated FGF2’s beneficial effects in the early stage of rat mild TBI and the underlying mechanisms. One hundred and forty-four rats were used for creating controlled cortical impact (CCI) models to simulate the pathological damage after TBI. Our results indicated that pretreatment of FGF2 played a neuroprotective role in the early stage of rat mild TBI through alleviating brain edema, reducing neurological deficits, preventing tissue loss, and increasing the number of surviving neurons in injured cortex and the ipsilateral hippocampus. FGF2 could also protect cells from various forms of death such as apoptosis or necrosis through inhibition of autophagy. Finally, autophagy activator rapamycin could abolish the protective effects of FGF2. This study extended our understanding of FGF2’s neuroprotective effects and shed lights on the pharmacological therapy after TBI.


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.


2020 ◽  
Vol 11 ◽  
Author(s):  
Fangfang Bi ◽  
Huaifen Ma ◽  
Chen Ji ◽  
Cuicui Chang ◽  
Wenbo Liu ◽  
...  

2004 ◽  
Vol 355 (3) ◽  
pp. 221-225 ◽  
Author(s):  
Helen L Hellmich ◽  
Christopher J Frederickson ◽  
Douglas S DeWitt ◽  
Ricardo Saban ◽  
Margaret O Parsley ◽  
...  

Author(s):  
Mohammad Zamanian ◽  
Małgorzata Kujawska ◽  
Marjan Nikbakht Zadeh ◽  
Amin Hassanshahi ◽  
Soudeh Ramezanpour ◽  
...  

Background & objective: Neurological diseases are becoming a significant problem worldwide, with the elderly at a higher risk of being affected. Several researchers have investigated the neuroprotective effects of Carvacrol (CAR) (5-isopropyl-2-methyl phenol). This review systematically surveys the existing literature on the impact of CAR when used as a neuroprotective agent in neurological diseases. Methods: The systematic review involved English articles published in the last ten years obtained from PubMed, Google Scholar, and Scopus databases. The following descriptors were used to search the literature: “Carvacrol” [Title] AND “neuroprotective (neuroprotection)” [Title] OR “stroke, traumatic brain injury, Alzheimer's disease, Parkinson's disease, seizure, epilepsy [Title]. Results: : A total of 208 articles were retrieved during the search process, but only 20 studies met the eligibility criteria and were included for review. A total of 20 articles were identified, in which the efficacy of CAR was described in experimental models of stroke, traumatic brain injury, Parkinson’s disease, Alzheimer’s disease, , epilepsy, and seizure, through motor deficits improvements in neurochemical activity, especially antioxidant systems, reducing inflammation, oxidative stress and apoptosis as well as inhibition of TRPC1 and TRPM7. Conclusion : The data presented in this study support the beneficial impact of CAR on behavioural and neurochemical deficits. CAR benefits accrue because of its anti-apoptotic, antioxidant, and anti-inflammatory properties. Therefore, CAR has emerged as an alternative treatment for neurological disorders based on its properties.


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