scholarly journals Enriching neural stem cell and anti‐inflammatory glial phenotypes with electrical stimulation after traumatic brain injury in male rats

2021 ◽  
Author(s):  
Eunyoung Park ◽  
Johnathan G. Lyon ◽  
Melissa Alvarado‐Velez ◽  
Martha I. Betancur ◽  
Nassir Mokarram ◽  
...  
Keyword(s):  
Traumatic Brain Injury ◽  
Stem Cell ◽  
Electrical Stimulation ◽  
Brain Injury ◽  
Neural Stem Cell ◽  
Male Rats ◽  
Anti Inflammatory

scholarly journals Adenosine kinase inhibition promotes proliferation of neural stem cells after traumatic brain injury

2020 ◽  
Vol 2 (1) ◽  
Author(s):  
Hoda M Gebril ◽  
Rizelle Mae Rose ◽  
Raey Gesese ◽  
Martine P Emond ◽  
Yuqing Huo ◽  
...  
Keyword(s):  
Traumatic Brain Injury ◽  
Cell Proliferation ◽  
Stem Cell ◽  
Brain Injury ◽  
Neural Stem Cell ◽  
Adenosine Kinase ◽  
Health Concern ◽  
Stem Cell Proliferation ◽  
Neural Stem Cell Proliferation ◽  
The Brain

Abstract Traumatic brain injury (TBI) is a major public health concern and remains a leading cause of disability and socio-economic burden. To date, there is no proven therapy that promotes brain repair following an injury to the brain. In this study, we explored the role of an isoform of adenosine kinase expressed in the cell nucleus (ADK-L) as a potential regulator of neural stem cell proliferation in the brain. The rationale for this hypothesis is based on coordinated expression changes of ADK-L during foetal and postnatal murine and human brain development indicating a role in the regulation of cell proliferation and plasticity in the brain. We first tested whether the genetic disruption of ADK-L would increase neural stem cell proliferation after TBI. Three days after TBI, modelled by a controlled cortical impact, transgenic mice, which lack ADK-L (ADKΔneuron) in the dentate gyrus (DG) showed a significant increase in neural stem cell proliferation as evidenced by significant increases in doublecortin and Ki67-positive cells, whereas animals with transgenic overexpression of ADK-L in dorsal forebrain neurons (ADK-Ltg) showed an opposite effect of attenuated neural stem cell proliferation. Next, we translated those findings into a pharmacological approach to augment neural stem cell proliferation in the injured brain. Wild-type C57BL/6 mice were treated with the small molecule adenosine kinase inhibitor 5-iodotubercidin for 3 days after the induction of TBI. We demonstrate significantly enhanced neural stem cell proliferation in the DG of 5-iodotubercidin-treated mice compared to vehicle-treated injured animals. To rule out the possibility that blockade of ADK-L has any effects in non-injured animals, we quantified baseline neural stem cell proliferation in ADKΔneuron mice, which was not altered, whereas baseline neural stem cell proliferation in ADK-Ltg mice was enhanced. Together these findings demonstrate a novel function of ADK-L involved in the regulation of neural stem cell proliferation after TBI.

scholarly journals Enriching neural stem cell and pro-healing glial phenotypes with electrical stimulation after traumatic brain injury in male rats

2020 ◽  
Author(s):  
Eunyoung Park ◽  
Johnathan G. Lyon ◽  
Melissa Alvarado-Velez ◽  
Martha I. Betancur ◽  
Nassir Mokarram ◽  
...  
Keyword(s):  
Traumatic Brain Injury ◽  
Stem Cells ◽  
Electrical Stimulation ◽  
Brain Injury ◽  
Neural Stem Cells ◽  
Acute Phase ◽  
Immune Cells ◽  
Male Rats ◽  
Cell Phenotype ◽  
Injury Site

AbstractTraumatic Brain Injury (TBI) by an external physical impact results in compromised brain function via undesired neuronal death. Following the injury, resident and peripheral immune cells, astrocytes, and neural stem cells (NSCs) cooperatively contribute to the recovery of the neuronal function after TBI. However, excessive pro-inflammatory responses of immune cells, and the disappearance of endogenous NSCs at the injury site during the acute phase of TBI, can exacerbate TBI progression leading to incomplete healing. Therefore, positive outcomes may depend on early interventions to control the injury-associated cellular milieu in the early phase of injury. Here, we explore electrical stimulation (ES) of the injury site in a rodent model (male Sprague-Dawley rats) to investigate its overall effect on the constituent brain cell phenotype and composition during the acute phase of TBI. Our data showed that a brief ES for 1h on day 2 of TBI promoted pro-healing phenotypes of microglia as assessed by CD206 expression and increased the population of NSCs and Nestin+ astrocytes at 7 days post-TBI. Also, ES effectively increased the number of viable neurons when compared to the unstimulated control group. Given the salience of microglia and neural stem cells for healing after TBI, our results strongly support the potential benefit of the therapeutic use of ES during the acute phase of TBI to regulate neuroinflammation and to enhance neuroregeneration.Significance StatementTraumatic brain injury (TBI) occurs when a head injury leads to a disruption of normal function in the brain and is a major cause of death and disability, worldwide. The authors used electrical stimulation during the acute phase of TBI, which promoted pro-healing phenotypes of microglia and increased the number of neural stem cells and Nestin+ astrocytes, thereby enhancing neuronal viability. These findings support further study of electrical stimulation to regulate neuroinflammation and to enhance neuroregeneration after TBI.Graphical AbstractFIGURE 1.

scholarly journals Mesenchymal Stem Cell–Derived Exosomes Improve Functional Recovery in Rats After Traumatic Brain Injury: A Dose-Response and Therapeutic Window Study

2020 ◽  
Vol 34 (7) ◽  
pp. 616-626 ◽  
Author(s):  
Yanlu Zhang ◽  
Yi Zhang ◽  
Michael Chopp ◽  
Zheng Gang Zhang ◽  
Asim Mahmood ◽  
...  
Keyword(s):  
Traumatic Brain Injury ◽  
Stem Cell ◽  
Brain Injury ◽  
Mesenchymal Stem Cell ◽  
Intravenous Injection ◽  
Dose Response ◽  
Time Dependent ◽  
Male Rats ◽  
Therapeutic Window ◽  
Single Intravenous Injection

Background. Mesenchymal stem cell (MSC)-derived exosomes play a critical role in regenerative medicine. Objective. To determine the dose- and time-dependent efficacy of exosomes for treatment of traumatic brain injury (TBI). Methods. Male rats were subjected to a unilateral moderate cortical contusion. In the dose-response study, animals received a single intravenous injection of exosomes (50, 100, 200 µg per rat) or vehicle, with treatment initiated at 1 day after injury. In the therapeutic window study, animals received a single intravenous injection of 100 µg exosomes or vehicle starting at 1, 4, or 7 days after injury. Neurological functional tests were performed weekly after TBI for 5 weeks. Spatial learning was measured on days 31 to 35 after TBI using the Morris water maze test. Results. Compared with the vehicle, regardless of the dose and delay in treatment, exosome treatment significantly improved sensorimotor and cognitive function, reduced hippocampal neuronal cell loss, promoted angiogenesis and neurogenesis, and reduced neuroinflammation. Exosome treatment at 100 µg per rat exhibited a significant therapeutic effect compared with the 50- or 200-µg exosome groups. The time-dependent exosome treatment data demonstrated that exosome treatment starting at 1 day post-TBI provided a significantly greater improvement in functional and histological outcomes than exosome treatments at the other 2 delayed treatments. Conclusions. These results indicate that exosomes have a wide range of effective doses for treatment of TBI with a therapeutic window of at least 7 days postinjury. Exosomes may provide a novel therapeutic intervention in TBI.

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