Traumatic brain injury induces potent inflammatory responses that can exacerbate secondary blood-brain barrier（BBB） disruption, neuronal injury, and neurological dysfunction. Dexmedetomidine is a novel α2-adrenergi...Traumatic brain injury induces potent inflammatory responses that can exacerbate secondary blood-brain barrier（BBB） disruption, neuronal injury, and neurological dysfunction. Dexmedetomidine is a novel α2-adrenergic receptor agonist that exert protective effects in various central nervous system diseases. The present study was designed to investigate the neuroprotective action of dexmedetomidine in a mouse traumatic brain injury model, and to explore the possible mechanisms. Adult male C57 BL/6 J mice were subjected to controlled cortical impact. After injury, animals received 3 days of consecutive dexmedetomidine therapy（25 μg/kg per day）. The modified neurological severity score was used to assess neurological deficits. The rotarod test was used to evaluate accurate motor coordination and balance. Immunofluorescence was used to determine expression of ionized calcium binding adapter molecule-1, myeloperoxidase, and zonula occluden-1 at the injury site. An enzyme linked immunosorbent assay was used to measure the concentration of interleukin-1β（IL-1β）, tumor necrosis factor α, and IL-6. The dry-wet weight method was used to measure brain water content. The Evans blue dye extravasation assay was used to measure BBB disruption. Western blot assay was used to measure protein expression of nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing 3（NLRP3）, caspase-1 p20, IL-1β, nuclear factor kappa B（NF-κB） p65, occluding, and zonula occluden-1. Flow cytometry was used to measure cellular apoptosis. Results showed that dexmedetomidine treatment attenuated early neurological dysfunction and brain edema. Further, dexmedetomidine attenuated post-traumatic inflammation, up-regulated tight junction protein expression, and reduced secondary BBB damage and apoptosis. These protective effects were accompanied by down-regulation of the NF-κB and NLRP3 inflammasome pathways. These findings suggest that dexmedetomidine exhibits neuroprotective effects against acute（3 d展开更多
Traumatic brain injury（TBI） can result in poor functional outcomes and death, and overall outcomes are varied. Growth factors, such as angiopoietin-1（Ang-1）, vascular endothelial growth factor（VEGF）, and granulo...Traumatic brain injury（TBI） can result in poor functional outcomes and death, and overall outcomes are varied. Growth factors, such as angiopoietin-1（Ang-1）, vascular endothelial growth factor（VEGF）, and granulocyte-colony stimulating factor（G-CSF）, play important roles in the neurological functions. This study investigated the relationship between serum growth factor levels and long-term outcomes after TBI. Blood samples from 55 patients were collected at 1, 3 and 7 days after TBI. Blood samples from 39 healthy controls were collected as a control group. Serum Ang-1, G-CSF, and VEGF levels were measured using ELISA. Patients were monitored for 3 months using the Glasgow Outcome Scale-Extended（GOSE）. Patients having a GOSE score of 〉 5 at 3 months were categorized as a good outcome, and patients with a GOSE score of 1-5 were categorized as a bad outcome. Our data demonstrated that TBI patients showed significantly increased growth factor levels within 7 days compared with healthy controls. Serum levels of Ang-1 at 1 and 7 days and G-CSF levels at 7 days were significantly higher in patients with good outcomes than in patients with poor outcomes. VEGF levels at 7 days were remarkably higher in patients with poor outcomes than in patients with good outcomes. Receiver operating characteristic analysis showed that the best cut-off points of serum growth factor levels at 7 days to predict functional outcome were 1,333 pg/mL for VEGF, 447.2 pg/mL for G-CSF, and 90.6 ng/mL for Ang-1. These data suggest that patients with elevated levels of serum Ang-1, G-CSF, and decreased VEGF levels had a better prognosis in the acute phase of TBI（within 7 days）. This study was registered with the Chinese Clinical Trial Registry（registration number： ChiCTR1800018251） on September 7, 2018.展开更多
基金supported by the National Natural Science Foundation of China,No.81330029,81671380the Natural Science Foundation of Tianjin City of China,No.17JCZDJC35900
文摘Traumatic brain injury induces potent inflammatory responses that can exacerbate secondary blood-brain barrier（BBB） disruption, neuronal injury, and neurological dysfunction. Dexmedetomidine is a novel α2-adrenergic receptor agonist that exert protective effects in various central nervous system diseases. The present study was designed to investigate the neuroprotective action of dexmedetomidine in a mouse traumatic brain injury model, and to explore the possible mechanisms. Adult male C57 BL/6 J mice were subjected to controlled cortical impact. After injury, animals received 3 days of consecutive dexmedetomidine therapy（25 μg/kg per day）. The modified neurological severity score was used to assess neurological deficits. The rotarod test was used to evaluate accurate motor coordination and balance. Immunofluorescence was used to determine expression of ionized calcium binding adapter molecule-1, myeloperoxidase, and zonula occluden-1 at the injury site. An enzyme linked immunosorbent assay was used to measure the concentration of interleukin-1β（IL-1β）, tumor necrosis factor α, and IL-6. The dry-wet weight method was used to measure brain water content. The Evans blue dye extravasation assay was used to measure BBB disruption. Western blot assay was used to measure protein expression of nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing 3（NLRP3）, caspase-1 p20, IL-1β, nuclear factor kappa B（NF-κB） p65, occluding, and zonula occluden-1. Flow cytometry was used to measure cellular apoptosis. Results showed that dexmedetomidine treatment attenuated early neurological dysfunction and brain edema. Further, dexmedetomidine attenuated post-traumatic inflammation, up-regulated tight junction protein expression, and reduced secondary BBB damage and apoptosis. These protective effects were accompanied by down-regulation of the NF-κB and NLRP3 inflammasome pathways. These findings suggest that dexmedetomidine exhibits neuroprotective effects against acute（3 d
基金supported by the National Natural Science Foundation of China,No.81330029(to JNZ),81501057(to YT)the Science&Technology Development Fund of Tianjin Education Commission for Higher Education in China,No.2016YD02(to YW)the Technology Program Fund of Tianjin Health and Family Planning Commission for the Key Field of Traditional Chinese Medicine,No.2018001(to ZGW)
文摘Traumatic brain injury（TBI） can result in poor functional outcomes and death, and overall outcomes are varied. Growth factors, such as angiopoietin-1（Ang-1）, vascular endothelial growth factor（VEGF）, and granulocyte-colony stimulating factor（G-CSF）, play important roles in the neurological functions. This study investigated the relationship between serum growth factor levels and long-term outcomes after TBI. Blood samples from 55 patients were collected at 1, 3 and 7 days after TBI. Blood samples from 39 healthy controls were collected as a control group. Serum Ang-1, G-CSF, and VEGF levels were measured using ELISA. Patients were monitored for 3 months using the Glasgow Outcome Scale-Extended（GOSE）. Patients having a GOSE score of 〉 5 at 3 months were categorized as a good outcome, and patients with a GOSE score of 1-5 were categorized as a bad outcome. Our data demonstrated that TBI patients showed significantly increased growth factor levels within 7 days compared with healthy controls. Serum levels of Ang-1 at 1 and 7 days and G-CSF levels at 7 days were significantly higher in patients with good outcomes than in patients with poor outcomes. VEGF levels at 7 days were remarkably higher in patients with poor outcomes than in patients with good outcomes. Receiver operating characteristic analysis showed that the best cut-off points of serum growth factor levels at 7 days to predict functional outcome were 1,333 pg/mL for VEGF, 447.2 pg/mL for G-CSF, and 90.6 ng/mL for Ang-1. These data suggest that patients with elevated levels of serum Ang-1, G-CSF, and decreased VEGF levels had a better prognosis in the acute phase of TBI（within 7 days）. This study was registered with the Chinese Clinical Trial Registry（registration number： ChiCTR1800018251） on September 7, 2018.
