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Background The interaction of the receptor for advanced glycation end product (RAGE) on blood-brain-barrier(BBB) with amyloid β (Aβ) plays an important role in the occurrence and development of AD. RP1 is a RAGEspecific binding peptide, which was discovered in our previous experiments, and it has been proved to beeffective on AD cell model, however, its effects on BBB tight junctions (TJs) and on Aβ transport into the brain isunclear.Methods Immunofluorescence experiment was used to identify whether RP1 bound with RAGE specifically.BEnd3-immortalized mouse brain microvascular endothelial cells were used to construct a BBB model. TEER andFD40 tests were used to confirm the stability of the BBB model, and the colocalization of the RP1 and RAGE onthe surface bEnd3 cells was observed with confocal microscopy.Results We confirmed that RP1 can bind to RAGE specifically in vitro. Functional analyses indicated that RP1 caneffectively alleviate the destroy of TJs of BBB and the decrease of permeability of BBB caused by Aβ. Furthermore,RP1 can competitively inhibit the interaction of Aβ with the RAGE in vitro, and effectively inhibit Aβ transport intothe brain.Conclusion RP1 can inhibit BBB damage induced by Aβ and block RAGE-Aβ interaction effectively, and RP1 canbe a candidate of RAGE inhibitors contributing to AD treatment
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@#[Abstract] Objective: To investigate the influences of human lung adenocarcinoma PC-9 cells on tight junction proteins of blood brain barrier (BBB) under CXCR4/SDF-1 axis by establishing a model of BBB in vitro. Methods: The immortalized mouse brain microvascular endothelial Bends cells were used to establish a model of BBB in vitro by monolayer culture; Subsequently, transendothelial electric resistance (TEER) and fluorescein sodium permeability experiment were used to detect the function of in vitro BBB model and observe the effect of PC-9 cells on the function of BBB model, respectively. Western blotting was used to detect the effect of PC-9 cells on function of BBB model and expressions of endothelial tight junction proteins under the treatment of single or combined AMD3100 and SDF-1 (1 μg/ml AMD3100,100 ng/ml SDF-1, AMD3100+SDF-1). Transwell assay was used to detect the influence of CXCR4/SDF-1 axis on the ability of PC-9 cells transmigrating the cell layer of BBB model. Results: Monolayer culture of Bends cells can form tightly connected BBB withhighTEER,which reached (182.13±5.19) Ω.cm2 at the 96 h; in the meanwhile, fluorescein sodium permeability experiment showed that BBB had significantly lower permeability than that of control group ([40.31±2.43]% vs [150.10±3.17]%, P<0.05). The TEER of BBB decreased to (46.7±4.35) Ω·cm2 after coculture with PC-9 cells for 24 h, and at the same time the sodium fluorescein permeability of BBB significantly increased than that of pre-treatment ([136.32±4.93]% vs [50.24±6.21]%, P<0.05). PC-9 cells up-regulated the expressions of tight junction proteins of Bends cells under the treatment of AMD3100 (P<0.05). The number of PC-9 cells transmigrating the BBB inAMD3100 treatment group was significantly lower than that of CON group (43±2 vs 81±2, P<0.05). Conclusion: AMD3100 can reduce the ability of PC-9 cells destroying the tight junction of the BBB model established in vitro by Bends cells.
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Objective: To evaluate the effect of two-photon in vivo imaging on detecting the blood brain barrier (BBB) injury in the ultra-early stage of cerebral ischemic stroke. Methods: Twelve clean grade C57BL/6 healthy male mice aged 8-12 weeks were randomly divided into Sham group and middle cerebral artery occlusion (MCAO) group,which were sham operated or middle cerebral artery occluded,respectively. After 60 min of ischemia,MCAO mice were treated with reperfusion for 30-60 min after the suture being removed. The vessels and the neutrophils of mice in the two groups were labeled intravenously with Alexa-Fluora-488 conjugated dextran and rhodamine 6G,respectively. The integrity of BBB was detected by intravenous injection of tetramethylrhodamine-5-maleimide (TMR). Before and after the stroke,the real-time changes of the fluorescence intensity of the inside and outside cerebral vessels of mice in the MCAO group were observed by two-photon fluorescence microscopy. Results: The fluorescence intensity of TMR in the external cerebrovascular of mice in the MACO group was significantly increased within 30-60 min after stroke (P=0.000),suggesting there existed tracer leakage. Compared with the Sham group,the movement of neutrophils in the blood vessels of mice in the MACO group was significantly slowed down (P=0.000). Conclusion: Two-photon in vivo imaging can be used to detect the BBB injury in the ultra-early stage of cerebral ischemic stroke,which provides a certain reference value for clinical application.
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Objective To investigate the neuroprotective effects of Fasudil in cerebral I/R injury in mice.Methods 51 C57BL/6J mice was divided into two groups,CMC treated group (n=26) and Fasudil treated group (n=25),randomly.The mice were treated with Fasudil (10 mg/kg) or CMC (0.5％ CMC 10 ml/kg) separately.Then the treated mice were subjected to 60 min of focal ischemia and 18 h reperfusion.The infarct volume of brain was analyzed by TTC staining with MCID image system.BBB permeability was assessed by Evans blue extravasation and albumin leakage which was detected by immuno-blotting assay.The activity of MMP9 was analyzed by zymography.Results The infarct volume in CMC group ((99.07±6.53) mm3) was larger than that in Fasudil group ((57.02±8.93) mm3),the difference was statistically significant (P＜0.01).The activity of MMP9 in the mice treated with Fasudil was lower than that in CMC group.Compared with the CMC group(albumin (2.95±0.77),Evans blue (5.15±0.24)),the albumin and Evans blue content in the Fasudil treated group (albumin (1.04±0.18),Evans blue (1.96±0.31))reduced significanctly(all P＜0.01).Conclusion Fasudil protects I/R damage by inhibiting the activity of MMP9 to maintain blood-brain barrier permeability.
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Objective To construct an active targeting drug delivery system‐polymer vesicles(PVs), and examined the cellular uptake. Methods Maleimide‐ polyethylene glycol‐poly(lactic‐co‐glycolic acid)(MAL‐PEG‐PLGA)was used as carrier materials to prepare PVs by self‐assembling. And then PVs was modified by Tf and Tet‐1(Tf/Tet‐1‐PVs). To evaluate its ac‐tive targeting, coumarin‐6 was used as a fluorescent probe to analyze cellular uptake of PVs for both BCEC and Neuro‐2a cells. Results PVs was about 80 nm with rounded shape and had obvious film structure. Tf/Tet‐1‐PVs exhibited a significant role in promoting cellular uptake for both BCEC and Neuro‐2a cells compared with control and single ligand‐modified group. Conclusion PVs modified with dual ligands could promote the cell uptake for both brain capillary cells and nerve cells.
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Ischemic stroke results in the diverse phathophysiologies including blood brain barrier (BBB) disruption, brain edema, neuronal cell death, and synaptic loss in brain. Vitamin C has known as the potent anti-oxidant having multiple functions in various organs, as well as in brain. Dehydroascorbic acid (DHA) as the oxidized form of ascorbic acid (AA) acts as a cellular protector against oxidative stress and easily enters into the brain compared to AA. To determine the role of DHA on edema formation, neuronal cell death, and synaptic dysfunction following cerebral ischemia, we investigated the infarct size of ischemic brain tissue and measured the expression of aquaporin 1 (AQP-1) as the water channel protein. We also examined the expression of claudin 5 for confirming the BBB breakdown, and the expression of bcl 2 associated X protein (Bax), caspase-3, inducible nitric oxide synthase (iNOS) for checking the effect of DHA on the neurotoxicity. Finally, we examined postsynaptic density protein-95 (PSD-95) expression to confirm the effect of DHA on synaptic dysfunction following ischemic stroke. Based on our findings, we propose that DHA might alleviate the pathogenesis of ischemic brain injury by attenuating edema, neuronal loss, and by improving synaptic connection.
Subject(s)
Aquaporins , Aquaporin 1 , Ascorbic Acid , bcl-2-Associated X Protein , Blood-Brain Barrier , Brain , Brain Edema , Brain Injuries , Brain Ischemia , Caspase 3 , Cell Death , Claudin-5 , Dehydroascorbic Acid , Edema , Neurons , Nitric Oxide Synthase Type II , Oxidative Stress , Post-Synaptic Density , StrokeABSTRACT
Objective: To investigate the enhancing effect of Borneolum Syntheticum and Acori Talarinowii Rhizoma on penetrating blood-brain barrier (BBB) of hydroxysafflor yellow A (HSYA) in rat. Methods: The concentration of HSYA in rat plasma and brain was determinated after ig administration of 20.00 mg/kg of HSYA to rats with or without Borneolum Syntheticum and Acori Talarinowii Rhizoma. And then, the character of penetrating BBB through the result of the AUCbrain/AUCbloodwas evaluated. Results: The AUC 0-8h, were (77 228.76±2 873.19), (81 949.04±2 283.11), and (28 479.63±2 431.71) ng·mL-1·min for blood and (55 925.0± 2 434.28), (82 768.53 ±3 277.00), and (70 914.29 ±2 900.71) ng·mL-1·min for brain of the control group, Borneolum Syntheticum group, and Acori Talarinowii Rhizoma group. The AUCbrain/AUCblood, were 0.72, 1.01, and 2.49, respectively. Conclusion: Borneolum Syntheticum and Acori Talarinowii Rhizoma do enhance the penetrating BBB of HSYA (P<0.05). Further more, Acori Talarinowii Rhizoma could affect the distribution of HSYA in rats.
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Temporary disruption of the blood-brain barrier (BBB) after cerebral angiography is presumably caused by nonionic radiographic contrast medium (CM). We hereby report a case of 58-year-old woman who developed decreased mentality, global aphasia and aggravated right hemiparesis after cerebral angiography. Brain CT examination demonstrated gyriform enhancement throughout the left cerebral cortex and thalamus. MR diffusion did not reveal acute infarction. MR angiography did not show any stenosis, spasm or occlusion at the major cerebral vessels. Follow-up CT scan after 1 day did not show any gyriform enhancement. Worsened neurologic signs and symptoms were improved completely after 7 days. In the present study, disruption of the BBB with contrast medium after angiography seems to be the causative factor of transient neurologic deterioration.
Subject(s)
Female , Humans , Middle Aged , Angiography , Aphasia , Blood-Brain Barrier , Brain , Cerebral Angiography , Cerebral Cortex , Constriction, Pathologic , Diffusion , Follow-Up Studies , Infarction , Neurologic Manifestations , Paresis , Spasm , ThalamusABSTRACT
[Objective] To explore the variety of matrix metalloproteinase 9 (MMP9) and blood brain barrier (BBB) in cardiopulmonary resuscitation rats.[Methods] Eighty rats were randomly divided into 2 groups:the sham-operated group (n ＝ 40) and the resuscitation group (n ＝ 40).The two groups were anaesthetized and endotracheally intubated,the resuscitation group was also induced to cardiac arrest by aphysia.Then the rats were put to death and samples were taken at immediate,3 h,9 h,24 h,and 48 h.After that,the expression of MMP9,MMP9 mRNA,water content and Evans blue content in brain tissue were detected.Ultramicrostructure of brain tissue was observed with electron microscope.[Results] Compared to the sham-operated group,at 3 h,9 h,24 h and 48 h,the expression of MMP9 of resuscitation group was significantly changed.MMP9mRNA significantly increased.Water content statistically increased and so was Evans blue content.The change of ultramicrostructure in the resuscitation group at 3 h,9 h,24 h,and 48 h was obvious.[Conclusion] The expression of MMP9 and MMP9mRNA obviously increased in the cerebral ischemia model with CPR rats,and got to peak at 24 h.Water content and Evans blue content in brain tissue obviously increased in the cerebral ischemia model with CPR rats,BBB was destroyed,and the peak was 24 h.The injury of ultramicrostructure of brain tissue with electron microscope was obvious,and the peak was 24 h.
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The intra-tumor MTX concentration was measured in 12 patients with cerebral gliomas and 31 patients of malignant gliomas were treated with intracarotid infusion of papaverine and bis-chloroaitrosourea (BCNU). After intracarotid infusion of papaverine to open up the blood-brain-barrier (BBB), the MTX concentration within tumor tissues was 1854? 512ng/gram, which higher than that without papaverine infusion, which was 1020? 512ng/gram. The diagnosis was glioblastoma in 21 patients and anaplastic astrocytoma in 10. They received the infusion for a mean of 2.1 times with 250mg BCNU each. The mean survival time was 101.6? 32.7 weeks, with 104 weeks of median survival time. Fourteen were still living, including 11 glioblastoma and 3 anaplastic astrocytoma. Of those, four have lived over three years. We considered combination of papaverine and BCNU infusion for chemotherapy of malignant cerebral glioma is simple, safe and effective, so long as tumors were susceptible to the chemotherapeutic drugs.
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Objective To investigate the hyperglycemic effect on ultrastructural morphology and intercellular adhension molecule 1(ICAM 1) expression of BBB. Methods Hyperglycemia model was established by intravenous injection of streptozocin in SD rats. A dynamic observation on the changes of the ultrastructure and the ICAM 1 expression on endothelium of BBB in SD rats with hyperglycemia for 3 days to 8 months was carried out by transmission electron microscopy and immunohistochemical method. Results Swelling was slight in endothelium of BBB of rats with hyperglycemia for 3 days, became obvious and occurred in endfoot of astrocyte for 1 to 2 months, and some microthrombi appeared in cavity of capillary with various malformation and apoptosis was found in endothelium of BBB and neuron surrounding abnormal capillary for 3 to 8 months. With immunohistochemical study, ICAM 1 was expressed sparsely on endothelium of BBB in 3 days after injection of streptozocin, became markedly strong in 3 months, and progressed further in 6 to 8 months. There was no changes on BBB in both SD rats and negative controls. Conclusion Long term hyperglycemia could cause obvious ultrastructural changes of BBB, associated with ICAM 1 expression on endothelium of BBB induced by hyperglycemia