ABSTRACT
The concept of the glial-vascular unit (GVU) was raised recently to emphasize the close associations between brain cells and cerebral vessels, and their coordinated reactions to diverse neurological insults from a "glio-centric" view. GVU is a multicellular structure composed of glial cells, perivascular cells, and perivascular space. Each component is closely linked, collectively forming the GVU. The central roles of glial and perivascular cells and their multi-level interconnections in the GVU under normal conditions and in central nervous system (CNS) disorders have not been elucidated in detail. Here, we comprehensively review the intensive interactions between glial cells and perivascular cells in the niche of perivascular space, which take part in the modulation of cerebral blood flow and angiogenesis, formation of the blood-brain barrier, and clearance of neurotoxic wastes. Next, we discuss dysfunctions of the GVU in various neurological diseases, including ischemic stroke, spinal cord injury, Alzheimer's disease, and major depression disorder. In addition, we highlight the possible therapies targeting the GVU, which may have potential clinical applications.
Subject(s)
Humans , Neuroglia , Nervous System Diseases , Blood-Brain Barrier , Alzheimer Disease , Glymphatic SystemABSTRACT
The glymphatic system plays a pivotal role in maintaining cerebral homeostasis. Chronic cerebral hypoperfusion, arising from small vessel disease or carotid stenosis, results in cerebrometabolic disturbances ultimately manifesting in white matter injury and cognitive dysfunction. However, whether the glymphatic system serves as a potential therapeutic target for white matter injury and cognitive decline during hypoperfusion remains unknown. Here, we established a mouse model of chronic cerebral hypoperfusion via bilateral common carotid artery stenosis. We found that the hypoperfusion model was associated with significant white matter injury and initial cognitive impairment in conjunction with impaired glymphatic system function. The glymphatic dysfunction was associated with altered cerebral perfusion and loss of aquaporin 4 polarization. Treatment of digoxin rescued changes in glymphatic transport, white matter structure, and cognitive function. Suppression of glymphatic functions by treatment with the AQP4 inhibitor TGN-020 abolished this protective effect of digoxin from hypoperfusion injury. Our research yields new insight into the relationship between hemodynamics, glymphatic transport, white matter injury, and cognitive changes after chronic cerebral hypoperfusion.
Subject(s)
Animals , Mice , Brain Ischemia , Carotid Stenosis/drug therapy , Cognitive Dysfunction/etiology , Digoxin , Disease Models, Animal , Mice, Inbred C57BL , White MatterABSTRACT
Objective To explore the effect of 14,15-epoxyeicosatrienoic acids (14,15-EET) on the inflammatory response of BV2 cells under oxygen and glucose depriviation/reoxygenation (OGD/R) conditions.Methods BV2 cells were randomly divided into three groups,blank control group,vehicle control group,and 14,15-EET group.Under treatment of 14,15-EET,the concentration of inflammatory factor in BV2 cell culture media was detected by ELISA at different time points (reoxygenation for 0,3,6,12,24 h) after OGD1h.The viability of BV2 cells was detected by MTT assay at different time points.At the same conditions,using Transwell migration experiment,migration ability of BV2 cells was observed.Results The 14,15-EET group had the lower levels of inflammatory factor secretion,lower viability and weaker ability of migration than the vehicle control group.The above results were most statistically significant at OGD1h/R12h.Conclusion 14,15-EET can inhibit the inflammation of BV2 cells induced by the injury of OGD reperfusion.
ABSTRACT
This study was aimed to examine the effect of TREK-1 silencing on the function of astrocytes. Three 21-nucleotide small interfering RNA (siRNA) duplexes (siT1, siT2, siT3) targeting TREK-1 were constructed. Cy3-labeled dsRNA oligmers were used to determine the transfection efficiency in cultured astrocytes. TREK-1-specific siRNA duplexes (siT1, siT2, siT3) at the optimal concentration were transfected into cultured astrocytes, and the most efficient siRNA was identified by the method of immunocytochemical staining and Western blotting. The proliferation of astrocytes tranfected with TREK-1-targeting siRNA under hypoxia condition was measured by fluorescence-activated cell sorting (FACS). The results showed that TREK-1 was expressed in cultured astrocytes. The dsRNA oligmers targeting TREK-1 could be transfected efficiently in cultured astrocytes and down-regulate the expression of TREK-1 in astrocytes. Moreover, the down-regulation of TREK-1 in astrocytes contributed to the proliferation of astrocytes under hypoxia condition as determined by cell cycle analysis. It was concluded that siRNA is a powerful technique that can be used to knockdown the expression of TREK-1 in astrocytes, which helps further investigate the function of TREK-1 channel in astrocytes under physicological and pathological condition.
Subject(s)
Animals , Rats , Astrocytes , Physiology , Cells, Cultured , Gene Silencing , Physiology , Potassium Channels , Potassium Channels, Tandem Pore Domain , Genetics , RNA Interference , Physiology , RNA, Small Interfering , GeneticsABSTRACT
This study was aimed to examine the effect of TREK-1 silencing on the function of astrocytes. Three 21-nucleotide small interfering RNA (siRNA) duplexes (siT1, siT2, siT3) targeting TREK-1 were constructed. Cy3-labeled dsRNA oligmers were used to determine the transfection efficiency in cultured astrocytes. TREK-1-specific siRNA duplexes (siT1, siT2, siT3) at the optimal concentration were transfected into cultured astrocytes, and the most efficient siRNA was identified by the method of immunocytochemical staining and Western blotting. The proliferation of astrocytes tranfected with TREK-1-targeting siRNA under hypoxia condition was measured by fluorescence-activated cell sorting (FACS). The results showed that TREK-1 was expressed in cultured astrocytes. The dsRNA oligmers targeting TREK-1 could be transfected efficiently in cultured astrocytes and down-regulate the expression of TREK-1 in astrocytes. Moreover, the down-regulation of TREK-1 in astrocytes contributed to the proliferation of astrocytes under hypoxia condition as determined by cell cycle analysis. It was concluded that siRNA is a powerful technique that can be used to knockdown the expression of TREK-1 in astrocytes, which helps further investigate the function of TREK-1 channel in astrocytes under physicological and pathological condition.
ABSTRACT
Objective To investigate the dynamic changes of ATP content in rat cerebral cortex after transient ischemia followed by reperfusion and the relationship between the change of energy and the recovery of neural function.Methods The rats were subjected to 10 min of middle cerebral artery occlusion (MCAO). At the time point of 0 h, 1 h, 3 h, 6 h, 12 h, 24 h and 72 h after reperfusion, ATP contents of frontal and parietal cortex were measured by capillary zone electrophoresis.Results At the end of 10 min ischemia, ATP content fell dramatically to less than 20% of the control level. After reperfusion, ATP content recovered gradually. After 1 h, 3 h, 6 h and 12 h of reperfusion, ATP content returned to 70.5%, 65.7%, 84.8% and 86.9% of the control level ( P=0.052, 0.030, 0.332 and 0.491). From 24 h on until 72 h after reperfusion, ATP content decreased again, reaching half of the control level ( P=0.003 and P=0.023). After 10 min ischemia, limb function recovered gradually and completely at last. From 24 h on until 72 h after reperfusion, unwillingness of action and eating was found.Conclusions The recovery of cellular energy system function is delayed even though the reperfusion is in time after transient cerebral ischemia. Furthermore, secondary failure of cellular energy system function occurrs with the reperfusion proceeding. These phenomena are probably responsible for the delayed recovery of neural function after cerebral ischemia in spite of reperfusion.