scholarly journals NADPH Oxidase 2 Regulates NLRP3 Inflammasome Activation in the Brain after Traumatic Brain Injury

2017 ◽  
Vol 2017 ◽  
pp. 1-18 ◽  
Author(s):  
Merry W. Ma ◽  
Jing Wang ◽  
Krishnan M. Dhandapani ◽  
Darrell W. Brann
Keyword(s):  
Oxidative Stress ◽  
Traumatic Brain Injury ◽  
Brain Injury ◽  
Nadph Oxidase ◽  
Nlrp3 Inflammasome ◽  
Healing Process ◽  
Inflammasome Activation ◽  
Nlrp3 Inflammasome Activation ◽  
Nadph Oxidase 2

Traumatic brain injury (TBI) is a leading cause of death and disability worldwide. After the initial primary mechanical injury, a complex secondary injury cascade involving oxidative stress and neuroinflammation follows, which may exacerbate the injury and complicate the healing process. NADPH oxidase 2 (NOX2) is a major contributor to oxidative stress in TBI pathology, and inhibition of NOX2 is neuroprotective. The NLRP3 inflammasome can become activated in response to oxidative stress, but little is known about the role of NOX2 in regulating NLRP3 inflammasome activation following TBI. In this study, we utilized NOX2 knockout mice to study the role of NOX2 in mediating NLRP3 inflammasome expression and activation following a controlled cortical impact. Expression of NLRP3 inflammasome components NLRP3 and apoptosis-associated speck-like protein containing a CARD (ASC), as well as its downstream products cleaved caspase-1 and interleukin-1β (IL-1β), was robustly increased in the injured cerebral cortex following TBI. Deletion of NOX2 attenuated the expression, assembly, and activity of the NLRP3 inflammasome via a mechanism that was associated with TXNIP, a sensor of oxidative stress. The results support the notion that NOX2-dependent inflammasome activation contributes to TBI pathology.

scholarly journals miR-29a-5p Alleviates Traumatic Brain Injury- (TBI-) Induced Permeability Disruption via Regulating NLRP3 Pathway

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Aijun Zhang ◽  
Youming Lu ◽  
Lei Yuan ◽  
Pengqi Zhang ◽  
Dongdong Zou ◽  
...  
Keyword(s):  
Traumatic Brain Injury ◽  
Endothelial Cells ◽  
Brain Injury ◽  
Water Content ◽  
Nlrp3 Inflammasome ◽  
Cell Permeability ◽  
Luciferase Reporter ◽  
Inflammasome Activation ◽  
Nlrp3 Inflammasome Activation

Objective. Inactivation of NLRP3 inflammasome plays a role in reducing the permeability of endothelial cells and improving blood-brain barrier (BBB) dysfunction following traumatic brain injury (TBI). However, the mechanism controlling NLRP3 inflammasome activation remains unclear. This study is aimed at defining the role of miR-29a-5p in NLRP3 inflammasome activation and permeability of endothelial cells under TBI. Methods. The scratch injury model on brain bEnd.3 microvascular endothelial cells was used as in vitro TBI model cells. Effects of miR-29a mimics and inhibitors on TBI model cells were observed by examining their action on FITC, TEER, and protein contents of ZO-1 and occludin, and cell permeability-associated protein. Luciferase reporter assay evaluated miR-29a-5p targeting to NLRP3. ELISA examined of IL-1β and IL-18 levels. miR-29a-5p mimic was injected into TBI mouse and its effect on BBB, indicated by Evans blue (EB) staining assay and cerebral water content, and NLRP3 activation was examined. Results. miR-29a-3p and miR-29a-5p mimics decrease the concentration of FITC, and increase TEER and the protein contents of ZO-1 and occludin in TBI model cells. miR-29a-5p silencing disrupted the permeability of mouse bEnd.3 cells. miR-29a-5p targets to NLRP3 through the binding on its 3 ′ UTR and negatively regulates its expression in TBI model cells. NLRP3 inhibition and miR-29a-5p silencing together caused significantly decreased FITC concentration and increased TEER value and release of IL-1β and IL-18. miR-29a-5p mimic alleviated the BBB and cerebral water content and inactivates NLRP3 in the mouse TBI model. Conclusions. miR-29a-5p mimics protect TBI-induced increased endothelial cell permeability and BBB dysfunction via suppressing NLRP3 expression and activation.

scholarly journals Saffron extract attenuates neuroinflammation in rmTBI mouse model by suppressing NLRP3 inflammasome activation via SIRT1

PLoS ONE ◽  
2021 ◽  
Vol 16 (9) ◽  
pp. e0257211
Author(s):  
Mariam J. Shaheen ◽  
Amira M. Bekdash ◽  
Hana A. Itani ◽  
Jamilah M. Borjac
Keyword(s):  
Traumatic Brain Injury ◽  
Brain Injury ◽  
Inflammatory Response ◽  
Neurodegenerative Diseases ◽  
Nlrp3 Inflammasome ◽  
Inflammasome Activation ◽  
Nuclear Factor ◽  
Caspase 1 ◽  
Nlrp3 Inflammasome Activation ◽  
Saffron Extract

Traumatic brain injury (TBI) remains a major cause of morbidity and disability worldwide and a healthcare burden. TBI is an important risk factor for neurodegenerative diseases hallmarked by exacerbated neuroinflammation. Neuroinflammation in the cerebral cortex plays a critical role in secondary injury progression following TBI. The NOD-like receptors (NLR) family pyrin domain containing 3 (NLRP3) inflammasome is a key player in initiating the inflammatory response in various central nervous system disorders entailing TBI. This current study aims to investigate the role of NLRP3 in repetitive mild traumatic brain injury (rmTBI) and identify the potential neuroprotective effect of saffron extract in regulating the NLRP3 inflammasome. 24 hours following the final injury, rmTBI causes an upregulation in mRNA levels of NLRP3, caspase-1, the apoptosis-associated speck-like protein containing a CARD (ASC), nuclear factor kappa B (NF-κB), interleukin-1Beta (IL-1β), interleukin 18 (IL-18), nuclear factor erythroid 2–related factor 2 (NRF2) and heme oxygenase 1 (HMOX1). Protein levels of NLRP3, sirtuin 1 (SIRT1), glial fibrillary acidic protein (GFAP), ionized calcium-binding adaptor molecule 1 (Iba1), and neuronal nuclei (Neu N) also increased after rmTBI. Administration of saffron alleviated the degree of TBI, as evidenced by reducing the neuronal damage, astrocyte, and microglial activation. Pretreatment with saffron inhibited the activation of NLRP3, caspase-1, and ASC concurrent to reduced production of the inflammatory cytokines IL-1β and IL-18. Additionally, saffron extract enhanced SIRT1 expression, NRF2, and HMOX1 upregulation. These results suggest that NLRP3 inflammasome activation and the subsequent inflammatory response in the mice cortex are involved in the process of rmTBI. Saffron blocked the inflammatory response and relieved TBI by activating detoxifying genes and inhibiting NLRP3 activation. The effect of saffron on the NLRP3 inflammasome may be SIRT1 and NF-κB dependent in the rmTBI model. Thus, brain injury biomarkers will help in identifying a potential therapeutic target in treating TBI-induced neurodegenerative diseases.

Eff ects of hyperbaric oxygen on NLRP3 infl ammasome activation in the brain aft er carbon monoxide poisoning

2020 ◽  
pp. 607-619
Author(s):  
Ya’nan Qi ◽  
◽  
Zhibao Guo ◽  
Huijun Hu ◽  
Xiang’en Meng ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Nadph Oxidase ◽  
Hyperbaric Oxygen ◽  
Nlrp3 Inflammasome ◽  
Carbon Monoxide Poisoning ◽  
Enzyme Linked Immunosorbent Assay ◽  
Inflammasome Activation ◽  
Protein Levels ◽  
Nlrp3 Inflammasome Activation ◽  
Myelin Injury

Neuroinflammation plays an important role in brain damage after acute carbon monoxide poisoning (ACOP). The nucleotide-binding domain, leucine-rich-containing family, pyrin domain-containing (NLRP) 3 inflammasome triggers the activation of inflammatory caspases and maturation of interleukin (IL)-1β and -18, and has been linked to various human autoinflammatory and autoimmune diseases. In this study we investigated the effects of hyperbaric oxygen (HBO2) on NLRP3 inflammasome activation after ACOP. Mice were randomly divided into four groups: sham group (exposure to normobaric air – i.e., 21% O2 at 1 atmosphere absolute); HBO2-only group; CO + normobaric air group; and CO + HBO2 group. Cognitive function was evaluated with the Morris water maze; myelin injury was assessed by Fluoro-Myelin GreenTM fluorescent myelin staining and myelin basic protein (MBP) immunostaining; and mRNA and protein levels of NLRP3 inflammasome complex proteins were measured by quantitative real-time PCR and Western blot, respectively. Additionally, serum and brain levels of IL-1β and -18 and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase were determined by enzyme-linked immunosorbent assay. It was found that HBO2 improved learning and memory, and alleviated myelin injury in mice subjected to acute CO exposure. Furthermore, HBO2 decreased NLRP3, absent in melanoma 2 (AIM2), caspase-1, and apoptosis-associated speck-like protein containing a C-terminal caspase recruitment domain mRNA and protein levels, and reduced brain and serum concentrations of IL-1β and -18 and NADPH oxidase. These results indicate that HBO2 suppresses the inflammatory response after ACOP by blocking NLRP3 inflammasome activation, thereby alleviating cognitive deficits.

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