scholarly journals Genetic Approach to Elucidate the Role of Cyclophilin D in Traumatic Brain Injury Pathology

Cells ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 199
Author(s):  
Ryan D. Readnower ◽  
William Brad Hubbard ◽  
Olivia J. Kalimon ◽  
James W. Geddes ◽  
Patrick G. Sullivan

Cyclophilin D (CypD) has been shown to play a critical role in mitochondrial permeability transition pore (mPTP) opening and the subsequent cell death cascade. Studies consistently demonstrate that mitochondrial dysfunction, including mitochondrial calcium overload and mPTP opening, is essential to the pathobiology of cell death after a traumatic brain injury (TBI). CypD inhibitors, such as cyclosporin A (CsA) or NIM811, administered following TBI, are neuroprotective and quell neurological deficits. However, some pharmacological inhibitors of CypD have multiple biological targets and, as such, do not directly implicate a role for CypD in arbitrating cell death after TBI. Here, we reviewed the current understanding of the role CypD plays in TBI pathobiology. Further, we directly assessed the role of CypD in mediating cell death following TBI by utilizing mice lacking the CypD encoding gene Ppif. Following controlled cortical impact (CCI), the genetic knockout of CypD protected acute mitochondrial bioenergetics at 6 h post-injury and reduced subacute cortical tissue and hippocampal cell loss at 18 d post-injury. The administration of CsA following experimental TBI in Ppif-/- mice improved cortical tissue sparing, highlighting the multiple cellular targets of CsA in the mitigation of TBI pathology. The loss of CypD appeared to desensitize the mitochondrial response to calcium burden induced by TBI; this maintenance of mitochondrial function underlies the observed neuroprotective effect of the CypD knockout. These studies highlight the importance of maintaining mitochondrial homeostasis after injury and validate CypD as a therapeutic target for TBI. Further, these results solidify the beneficial effects of CsA treatment following TBI.

Antioxidants ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 1575
Author(s):  
Francisco J. Carvajal ◽  
Waldo Cerpa

Traumatic Brain Injury (TBI) mediates neuronal death through several events involving many molecular pathways, including the glutamate-mediated excitotoxicity for excessive stimulation of N-methyl-D-aspartate receptors (NMDARs), producing activation of death signaling pathways. However, the contribution of NMDARs (distribution and signaling-associated to the distribution) remains incompletely understood. We propose a critical role of STEP61 (Striatal-Enriched protein tyrosine phosphatase) in TBI; this phosphatase regulates the dephosphorylated state of the GluN2B subunit through two pathways: by direct dephosphorylation of tyrosine-1472 and indirectly via dephosphorylation and inactivation of Fyn kinase. We previously demonstrated oxidative stress’s contribution to NMDAR signaling and distribution using SOD2+/− mice such a model. We performed TBI protocol using a controlled frontal impact device using C57BL/6 mice and SOD2+/− animals. After TBI, we found alterations in cognitive performance, NMDAR-dependent synaptic function (decreased synaptic form of NMDARs and decreased synaptic current NMDAR-dependent), and increased STEP61 activity. These changes are reduced partially with the STEP61-inhibitor TC-2153 treatment in mice subjected to TBI protocol. This study contributes with evidence about the role of STEP61 in the neuropathological progression after TBI and also the alteration in their activity, such as an early biomarker of synaptic damage in traumatic lesions.


2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Xiao Xiao ◽  
Youjing Jiang ◽  
Weibo Liang ◽  
Yanyun Wang ◽  
Shuqiang Cao ◽  
...  

Abstract Ferroptosis, a newly discovered form of iron-dependent regulated cell death, has been implicated in traumatic brain injury (TBI). MiR-212-5p has previously been reported to be downregulated in extracellular vesicles following TBI. To investigate whether miR-212-5p is involved in the ferroptotic neuronal death in TBI mice, we first examined the accumulation of malondialdehyde (MDA) and ferrous ion, and the expression of ferroptosis-related molecules at 6 h, 12 h, 24 h, 48 h and 72 h following controlled cortical impact (CCI) in mice. There was a significant upregulation in the expression of Gpx4 and Acsl4 at 6 h, Slc7a11 from 12 h to 72 h, and Nox2 and Sat1 from 6 h to 72 h post injury. Similarly, an upregulation in the expression of Gpx4 at 6 h, Nox2 from 6 h to 72 h, xCT from 12 h to 72 h, and Sat1 at 72 h after CCI was observed at the protein level. Interestingly, MDA and ferrous ion were increased whereas miR-212-5p was decreased in the CCI group compared to the sham group. Furthermore, we found that overexpression of miR-212-5p attenuated ferroptosis while downregulation of miR-212-5p promoted ferroptotic cell death partially by targeting prostaglandin-endoperoxide synthase-2 (Ptgs2) in HT-22 and Neuro-2a cell lines. In addition, administration of miR-212-5p in CCI mice significantly improved learning and spatial memory. Collectively, these findings indicate that miR-212-5p may protect against ferroptotic neuronal death in CCI mice partially by targeting Ptgs2.


Medicina ◽  
2020 ◽  
Vol 56 (6) ◽  
pp. 300
Author(s):  
Hansen Deng ◽  
John K. Yue ◽  
Benjamin E. Zusman ◽  
Enyinna L. Nwachuku ◽  
Hussam Abou-Al-Shaar ◽  
...  

Background and Objectives: The injury burden after head trauma is exacerbated by secondary sequelae, which leads to further neuronal loss. B-cell lymphoma 2 (Bcl-2) is an anti-apoptotic protein and a key modulator of the programmed cell death (PCD) pathways. The current study evaluates the clinical evidence on Bcl-2 and neurological recovery in patients after traumatic brain injury (TBI). Materials and Methods: All studies in English were queried from the National Library of Medicine PubMed database using the following search terms: (B-cell lymphoma 2/Bcl-2/Bcl2) AND (brain injury/head injury/head trauma/traumatic brain injury) AND (human/patient/subject). There were 10 investigations conducted on Bcl-2 and apoptosis in TBI patients, of which 5 analyzed the pericontutional brain tissue obtained from surgical decompression, 4 studied Bcl-2 expression as a biomarker in the cerebrospinal fluid (CSF), and 1 was a prospective randomized trial. Results: Immunohistochemistry (IHC) in 94 adults with severe TBI showed upregulation of Bcl-2 in the pericontusional tissue. Bcl-2 was detected in 36–75% of TBI patients, while it was generally absent in the non-TBI controls, with Bcl-2 expression increased 2.9- to 17-fold in TBI patients. Terminal deoxynucleotidyl transferase-mediated biotinylated dUTP nick-end labeling (TUNEL) positivity for cell death was detected in 33–73% of TBI patients. CSF analysis in 113 TBI subjects (90 adults, 23 pediatric patients) showed upregulation of Bcl-2 that peaked on post-injury day 3 and subsequently declined after day 5. Increased Bcl-2 in the peritraumatic tissue, rising CSF Bcl-2 levels, and the variant allele of rs17759659 are associated with improved mortality and better outcomes on the Glasgow Outcome Score (GOS). Conclusions: Bcl-2 is upregulated in the pericontusional brain and CSF in the acute period after TBI. Bcl-2 has a neuroprotective role as a pro-survival protein in experimental models, and increased expression in patients can contribute to improvement in clinical outcomes. Its utility as a biomarker and therapeutic target to block neuronal apoptosis after TBI warrants further evaluation.


Stroke ◽  
2015 ◽  
Vol 46 (suppl_1) ◽  
Author(s):  
Alexander V Glushakov ◽  
Jawad A Fazal ◽  
Shuh Narumiya ◽  
Sylvain Dore

Introduction: Brain injuries promote upregulation of so-called proinflammatory prostaglandin E2 leading to overactivation of a class of its cognate G-protein coupled receptors, notably EP1, which is considered as a promising target for treatment of ischemic stroke and, possibly, other neurological disorders involving excitotoxicity. However, our recent data suggest that of EP1 receptor in intracerebral hemorrhage may play a protective role. The goal of this study was to investigate a translational potential of EP1 receptor for treatment of traumatic brain injury (TBI). Methods: The acute brain injury was induced using controlled cortical impact (CCI) in wildtype (WT) and genetic EP1 receptor knockout mice (EP1-/-). Neurological deficit scores (NDS) and anatomical brain pathology were accessed at 48h after injury. Results: CCI resulted in significant cortical lesions, localized hippocampal edema and neurological deficits compared to animals from sham group underwent craniotomy only. The NDS after CCI were significantly higher in older mice (7-11mo) compared to young adult animals (2-4mo) in both WT and EP1-/- groups. Treatment with a selective antagonist SC-51089 with repeated doses of 20-100μg/kg after CCI had no significant effects on cortical lesions, hippocampal edema and NDS in young adult mice of both WT and EP1-/- genotypes. Post-treatment with 17-pt-PGE2 (300μg/kg) had no significant effects on anatomical brain pathology in young adult mice, but improved NDS at 24h in WT but not in EP1-/- mice. Immunohistochemistry revealed significant increases in GFAP and Iba1 immunoreactivity in selected brain regions surrounding injury suggesting astrogliosis and microglia activation. EP1 receptor knockout had no effects on GFAP and Iba1 expression in young adult mice, whereas lead to a significant attenuation of GFAP immunoreactivity in older mice. Conclusions: This study provides, for the first time, a clarification on the role of EP1 receptor in a preclinical model of contusive TBI. The results suggest that EP1 receptor might be involved in complex pathways differentially associated with neurological deficits. In addition, this study provides further clarification on clinical use of EP1 receptor ligands for treatment of acute brain injuries.


PLoS ONE ◽  
2012 ◽  
Vol 7 (4) ◽  
pp. e34504 ◽  
Author(s):  
Quan-Guang Zhang ◽  
Melissa D. Laird ◽  
Dong Han ◽  
Khoi Nguyen ◽  
Erin Scott ◽  
...  

2021 ◽  
Vol 30 ◽  
pp. 096368972110357
Author(s):  
Blaise Cozene ◽  
Nadia Sadanandan ◽  
Jeffrey Farooq ◽  
Chase Kingsbury ◽  
You Jeong Park ◽  
...  

Traumatic brain injury (TBI) is a pervasive and damaging form of acquired brain injury (ABI). Acute, subacute, and chronic cell death processes, as a result of TBI, contribute to the disease progression and exacerbate outcomes. Extended neuroinflammation can worsen secondary degradation of brain function and structure. Mesenchymal stem cell transplantation has surfaced as a viable approach as a TBI therapeutic due to its immunomodulatory and regenerative features. This article examines the role of inflammation and cell death in ABI as well as the effectiveness of bone marrow-derived mesenchymal stem/stromal cell (BM-MSC) transplants as a treatment for TBI. Furthermore, we analyze new studies featuring transplanted BM-MSCs as a neurorestorative and anti-inflammatory therapy for TBI patients. Although clinical trials support BM-MSC transplants as a viable TBI treatment due to their promising regenerative characteristics, further investigation is imperative to uncover innovative brain repair pathways associated with cell-based therapy as stand-alone or as combination treatments.


2020 ◽  
Vol 34 (9) ◽  
pp. 831-843
Author(s):  
Yunliang Tang ◽  
Xiaoyang Dong ◽  
Gengfa Chen ◽  
Wen Ye ◽  
Junwei Kang ◽  
...  

Background Traumatic brain injury (TBI) is a major cause of death and disability worldwide. Oxidative stress, inflammation, and apoptosis are vital pathophysiological features post-TBI. Objectives Research has shown that vagus nerve stimulation (VNS) can attenuate oxidative stress in various diseases. However, the critical role of VNS in TBI is still not completely understood. This study investigated the protective effects and potential mechanism of VNS on TBI. Methods Male Sprague-Dawley rats were randomized into 3 groups: sham, TBI, and TBI + VNS. The TBI model was induced in rats by the free-fall drop method. The vagal nerve trunk was separated, and VNS was performed after establishing the TBI model. Results The results showed that VNS significantly ameliorated tissue damage, neurological deficits, and cerebral edema, compared with the sham VNS group. Additionally, VNS alleviated oxidative stress, inflammation, and apoptosis in the pericontusive cortex of rats after TBI. VNS also significantly suppressed expression of the nuclear factor-κB (NF-κB) protein in the nucleus and activation of the nucleotide-binding domain–like receptor protein 3 (NLRP3) inflammasome. Conclusions Taken together, the present study indicates that VNS may attenuate brain damage after TBI by inhibiting oxidative stress, inflammation, and apoptosis, possibly through the NF-κB/NLRP3 signaling pathway.


ASN NEURO ◽  
2019 ◽  
Vol 11 ◽  
pp. 175909141984709 ◽  
Author(s):  
Aleksandra Ichkova ◽  
Andrew M. Fukuda ◽  
Nina Nishiyama ◽  
Germaine Paris ◽  
Andre Obenaus ◽  
...  

Juvenile traumatic brain injury (jTBI) is the leading cause of death and disability for children and adolescents worldwide, but there are no pharmacological treatments available. Aquaporin 4 (AQP4), an astrocytic perivascular protein, is increased after jTBI, and inhibition of its expression with small interference RNA mitigates edema formation and reduces the number of reactive astrocytes after jTBI. Due to the physical proximity of AQP4 and gap junctions, coregulation of AQP4 and connexin 43 (Cx43) expressions, and the possibility of water diffusion via gap junctions, we decided to address the potential role of astrocytic gap junctions in jTBI pathophysiology. We evaluated the role of Cx43 in the spread of the secondary injuries via the astrocyte network, such as edema formation associated with blood–brain barrier dysfunctions, astrogliosis, and behavioral outcome. We observed that Cx43 was altered after jTBI with increased expression in the perilesional cortex and in the hippocampus at several days post injury. In a second set of experiments, cortical injection of small interference RNA against Cx43 decreased Cx43 protein expression, improved motor function recovery, and decreased astrogliosis but did not result in differences in edema formation as measured via T2-weighted imaging or diffusion-weighted imaging at 1 day or 3 days. Based on our findings, we can speculate that while decreasing Cx43 has beneficial roles, it likely does not contribute to the spread of edema early after jTBI.


2018 ◽  
Author(s):  
Hadijat M. Makinde ◽  
Talia B. Just ◽  
Deborah R. Winter ◽  
Steven J. Schwulst

Traumatic brain injury (TBI) is an under-recognized public health threat. Even mild brain injury, or concussions, may lead to long-term neurologic impairment. Microglia play a fundamental role in the development and progression of this subsequent neurologic impairment. Despite this, a microglia-specific injury signature has yet to be identified. In the current study we hypothesized that TBI-associated microglia would adopt longitudinal changes in their transcriptional profile associated with pathways linked to the development of motor, cognitive, and behavioral disorders. C57BL/6 mice underwent TBI via a controlled cortical impact and were followed longitudinally. FACSorted microglia from TBI mice were subjected to RNA-sequencing at 7, 30, and 90 days post-injury. We identified 4 major patterns of gene expression corresponding to the host defense response, synaptic potentiation, lipid remodeling, and membrane polarization. In particular, significant upregulation of genes involved in long-term synaptic potentiation including Ptpn5, Shank3, and Sqstm1 were observed offering new insight into a previously unknown role of microglia in the weakening of synaptic efficacy between neurons after brain injury.


2017 ◽  
Vol 38 (2) ◽  
pp. 274-289 ◽  
Author(s):  
Arjang Salehi ◽  
Amandine Jullienne ◽  
Mohsen Baghchechi ◽  
Mary Hamer ◽  
Mark Walsworth ◽  
...  

Recent data suggest that repairing the cerebral vasculature after traumatic brain injury (TBI) may help to improve functional recovery. The Wnt/β-catenin signaling pathway promotes blood vessel formation during vascular development, but its role in vascular repair after TBI remains elusive. In this study, we examined how the cerebral vasculature responds to TBI and the role of Wnt/β-catenin signaling in vascular repair. We induced a moderate controlled cortical impact in adult mice and performed vessel painting to visualize the vascular alterations in the brain. Brain tissue around the injury site was assessed for β-catenin and vascular markers. A Wnt transgenic mouse line was utilized to evaluate Wnt gene expression. We report that TBI results in vascular loss followed by increases in vascular structure at seven days post injury (dpi). Immature, non-perfusing vessels were evident in the tissue around the injury site. β-catenin protein expression was significantly reduced in the injury site at 7 dpi. However, there was an increase in β-catenin expression in perilesional vessels at 1 and 7 dpi. Similarly, we found increased number of Wnt-GFP-positive vessels after TBI. Our findings suggest that Wnt/β-catenin expression contributes to the vascular repair process after TBI.


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