Our previous study verified the protective effects of Lycium barbarum polysaccharides(LBP)on retinal neurons and blood vessels in acute ocular hypertension(AOH)mice.To investigate the effect of LBP on the reactivity o...Our previous study verified the protective effects of Lycium barbarum polysaccharides(LBP)on retinal neurons and blood vessels in acute ocular hypertension(AOH)mice.To investigate the effect of LBP on the reactivity of retinal glial cells,an AOH mouse model was established in one eye by maintaining ocular hypertension of 90 mm Hg for 60 minutes.Either LBP solution(1 mg/kg)or phosphate-buffered saline was administrated to the mice by gavage daily,starting 7 days before the AOH insult and continuing until the mice were sacrificed for specimen collection on day 4 post-insult.After AOH insult,increased numbers of astrocytes and microglia were observed,together with decreased expression of the following glial cell biomarkers in the retinal ganglion cells of AOH mice:glial fibrillary acidic protein,glutamine synthetase,aquaporin-4,S-100 proteins,ionized calcium-binding adaptor molecule 1,amyloid precursor protein and receptor of advanced glycosylation end-products.After intervention with LBP,the above changes were significantly reduced.Remarkably,morphological remodeling of blood vessel-associated retinal astrocytes,marked by glial fibrillary acidic protein,was also observed.These results,taken together,suggest that LBP regulated the production of amyloid-βand expression of receptor of advanced glycosylation end-products,as well as mediating the activity of retinal glial cells,which may lead to the promotion of better maintenance of the blood-retinal barrier and improved neuronal survival in AOH insult.This study was approved by the Committee for the Use of Live Animals in Teaching and Research(approval No.CULTRA-#1664-08).展开更多
Monosialoganglioside 1(GM1) is the main ganglioside subtype and has neuroprotective properties in the central nervous system. In this study, we aimed to determine whether GM1 alleviates neurotoxicity induced by modera...Monosialoganglioside 1(GM1) is the main ganglioside subtype and has neuroprotective properties in the central nervous system. In this study, we aimed to determine whether GM1 alleviates neurotoxicity induced by moderate and high concentrations of propofol combined with remifentanil in the immature central nervous system. Hippocampal neural stem cells were isolated from newborn Sprague-Dawley rats and treated with remifentanil(5, 10, 20 ng/m L) and propofol(1.0, 2.5, 5.0 μg/m L), and/or GM1(12.5, 25, 50 μg/m L). GM1 reversed combined propofol and remifentanil-induced decreases in the percentage of 5-bromodeoxyuridine(+) cells and also reversed the increase in apoptotic cell percentage during neural stem cell proliferation and differentiation. However, GM1 with combined propofol and remifentanil did not affect β-tubulin(+) or glial fibrillary acidic protein(+) cell percentage during neural stem cell differentiation. In conclusion, we show that GM1 alleviates the damaging effects of propofol combined with remifentanil at moderate and high exposure concentrations in neural stem cells in vitro, and exerts protective effects on the immature central nervous system.展开更多
Reperfusion therapy is the preferred treatment for ischemic stroke,but is hindered by its short treatment window,especially in patients with diabetes whose reperfusion after prolonged ischemia is often accompanied by ...Reperfusion therapy is the preferred treatment for ischemic stroke,but is hindered by its short treatment window,especially in patients with diabetes whose reperfusion after prolonged ischemia is often accompanied by exacerbated hemorrhage.The mechanisms underlying exacerbated hemorrhage are not fully understood.This study aimed to identify this mechanism by inducing prolonged 2-hour transient intraluminal middle cerebral artery occlusion in diabetic Ins2Akita/+mice to mimic patients with diabetes undergoing delayed mechanical thrombectomy.The results showed that at as early as 2 hours after reperfusion,Ins2Akita/+mice exhibited rapid development of neurological deficits,increased infarct and hemorrhagic transformation,together with exacerbated down-regulation of tight-junction protein ZO-1 and upregulation of blood-brain barrier-disrupting matrix metallopeptidase 2 and matrix metallopeptidase 9 when compared with normoglycemic Ins2+/+mice.This indicated that diabetes led to the rapid compromise of vessel integrity immediately after reperfusion,and consequently earlier death and further aggravation of hemorrhagic transformation 22 hours after reperfusion.This observation was associated with earlier and stronger up-regulation of pro-angiogenic vascular endothelial growth factor(VEGF)and its downstream phospho-Erk1/2 at 2 hours after reperfusion,which was suggestive of premature angiogenesis induced by early VEGF up-regulation,resulting in rapid vessel disintegration in diabetic stroke.Endoplasmic reticulum stress-related pro-apoptotic C/EBP homologous protein was overexpressed in challenged Ins2Akita/+mice,which suggests that the exacerbated VEGF up-regulation may be caused by overwhelming endoplasmic reticulum stress under diabetic conditions.In conclusion,the results mimicked complications in patients with diabetes undergoing delayed mechanical thrombectomy,and diabetes-induced accelerated VEGF up-regulation is likely to underlie exacerbated hemorrhagic transformation.Thus,suppression of the VEGF pathway could be a potential approach to allow reperfusion therapy in patients with diabetic stroke beyond the current treatment window.Experiments were approved by the Committee on the Use of Live Animals in Teaching and Research of the University of Hong Kong[CULATR 3834-15(approval date January 5,2016);3977-16(approval date April 13,2016);and 4666-18(approval date March 29,2018)].展开更多
基金supported in part by the National Basic Research Program of China,No.81300766(to XSM)the Cultivation and Innovation Fund from the First Affiliated Hospital of Jinan University,China,No.802168(to XSM)+2 种基金Hygiene&Health Appropriated Technology and Promoting Project of Guangdong Province of China,No.201905270933056876(to XSM)the fund of Leading Talents of Guangdong Province of China,No.87014002(to KFS)a grant from Ningxia Key Research and Development Program,and Programme of Introducing Talents of Discipline to Universities of China,No.B14036(to KFS)。
文摘Our previous study verified the protective effects of Lycium barbarum polysaccharides(LBP)on retinal neurons and blood vessels in acute ocular hypertension(AOH)mice.To investigate the effect of LBP on the reactivity of retinal glial cells,an AOH mouse model was established in one eye by maintaining ocular hypertension of 90 mm Hg for 60 minutes.Either LBP solution(1 mg/kg)or phosphate-buffered saline was administrated to the mice by gavage daily,starting 7 days before the AOH insult and continuing until the mice were sacrificed for specimen collection on day 4 post-insult.After AOH insult,increased numbers of astrocytes and microglia were observed,together with decreased expression of the following glial cell biomarkers in the retinal ganglion cells of AOH mice:glial fibrillary acidic protein,glutamine synthetase,aquaporin-4,S-100 proteins,ionized calcium-binding adaptor molecule 1,amyloid precursor protein and receptor of advanced glycosylation end-products.After intervention with LBP,the above changes were significantly reduced.Remarkably,morphological remodeling of blood vessel-associated retinal astrocytes,marked by glial fibrillary acidic protein,was also observed.These results,taken together,suggest that LBP regulated the production of amyloid-βand expression of receptor of advanced glycosylation end-products,as well as mediating the activity of retinal glial cells,which may lead to the promotion of better maintenance of the blood-retinal barrier and improved neuronal survival in AOH insult.This study was approved by the Committee for the Use of Live Animals in Teaching and Research(approval No.CULTRA-#1664-08).
基金supported by the Natural Science Foundation of Hubei Province of China,No.2012FFC060the Natural Science Foundation of Hubei University of Medicine of China,No.2011QDZR-2+4 种基金a grant from the Scientific and Technological Project of Shiyan City of Hubei Province of China,No.14Y13a grant from the National College Student Innovation and Entrepreneurship Training Program of Education Ministry of China,No.201610929005 and No.201210929004the Educational Scientific Foundation of Hubei University of Medicine of China in 2016,No.2016027the Fund of Disciplines Construction of Hubei University of Medicine of China in 2015,No.2015the Scientific Foundation of Affiliated Taihe Hospital of Hubei University of Medicine of China in 2016,No.2016JJXM001
文摘Monosialoganglioside 1(GM1) is the main ganglioside subtype and has neuroprotective properties in the central nervous system. In this study, we aimed to determine whether GM1 alleviates neurotoxicity induced by moderate and high concentrations of propofol combined with remifentanil in the immature central nervous system. Hippocampal neural stem cells were isolated from newborn Sprague-Dawley rats and treated with remifentanil(5, 10, 20 ng/m L) and propofol(1.0, 2.5, 5.0 μg/m L), and/or GM1(12.5, 25, 50 μg/m L). GM1 reversed combined propofol and remifentanil-induced decreases in the percentage of 5-bromodeoxyuridine(+) cells and also reversed the increase in apoptotic cell percentage during neural stem cell proliferation and differentiation. However, GM1 with combined propofol and remifentanil did not affect β-tubulin(+) or glial fibrillary acidic protein(+) cell percentage during neural stem cell differentiation. In conclusion, we show that GM1 alleviates the damaging effects of propofol combined with remifentanil at moderate and high exposure concentrations in neural stem cells in vitro, and exerts protective effects on the immature central nervous system.
基金supported by Health and Medical Research Fund,the Food and Health Bureau,The Government of the Hong Kong Special Administrative Region(03142256)General Research Fund,Hong Kong Research Grants Council(GRF#HKU773613M)+1 种基金Seed Funding Programme for Basic Research(201811159123,201910159191)The University of Hong Kong(all to ACYL)。
文摘Reperfusion therapy is the preferred treatment for ischemic stroke,but is hindered by its short treatment window,especially in patients with diabetes whose reperfusion after prolonged ischemia is often accompanied by exacerbated hemorrhage.The mechanisms underlying exacerbated hemorrhage are not fully understood.This study aimed to identify this mechanism by inducing prolonged 2-hour transient intraluminal middle cerebral artery occlusion in diabetic Ins2Akita/+mice to mimic patients with diabetes undergoing delayed mechanical thrombectomy.The results showed that at as early as 2 hours after reperfusion,Ins2Akita/+mice exhibited rapid development of neurological deficits,increased infarct and hemorrhagic transformation,together with exacerbated down-regulation of tight-junction protein ZO-1 and upregulation of blood-brain barrier-disrupting matrix metallopeptidase 2 and matrix metallopeptidase 9 when compared with normoglycemic Ins2+/+mice.This indicated that diabetes led to the rapid compromise of vessel integrity immediately after reperfusion,and consequently earlier death and further aggravation of hemorrhagic transformation 22 hours after reperfusion.This observation was associated with earlier and stronger up-regulation of pro-angiogenic vascular endothelial growth factor(VEGF)and its downstream phospho-Erk1/2 at 2 hours after reperfusion,which was suggestive of premature angiogenesis induced by early VEGF up-regulation,resulting in rapid vessel disintegration in diabetic stroke.Endoplasmic reticulum stress-related pro-apoptotic C/EBP homologous protein was overexpressed in challenged Ins2Akita/+mice,which suggests that the exacerbated VEGF up-regulation may be caused by overwhelming endoplasmic reticulum stress under diabetic conditions.In conclusion,the results mimicked complications in patients with diabetes undergoing delayed mechanical thrombectomy,and diabetes-induced accelerated VEGF up-regulation is likely to underlie exacerbated hemorrhagic transformation.Thus,suppression of the VEGF pathway could be a potential approach to allow reperfusion therapy in patients with diabetic stroke beyond the current treatment window.Experiments were approved by the Committee on the Use of Live Animals in Teaching and Research of the University of Hong Kong[CULATR 3834-15(approval date January 5,2016);3977-16(approval date April 13,2016);and 4666-18(approval date March 29,2018)].
