Objective:Intestinal barrier disruption is a critical event in sepsis and ischemia-reperfusion(I/R)injury.Enteric glial cells(EGCs)maintain barrier integrity by secreting glial cell line-derived neurotrophic factor(GD...Objective:Intestinal barrier disruption is a critical event in sepsis and ischemia-reperfusion(I/R)injury.Enteric glial cells(EGCs)maintain barrier integrity by secreting glial cell line-derived neurotrophic factor(GDNF).This study aimed to determine whether Dexmedetomidine(Dex)protects the intestinal barrier via α7-nicotinic acetylcholine receptor(α7-nAChR)signaling in EGCs.Methods:An in vitro EGC-intestinal epithelial cell(IEC)co-culture system and amurine intestinal I/Rmodel were established.EGCs were selectively ablated in vivo using benzalkonium chloride(BAC).Barrier integrity was evaluated by transmembrane electrical resistance(TEER)and plasma FITC-dextran permeability.Enzyme-Linked Immunosorbent Assay(ELISA)and Western blotting quantified levels of GDNF and Occludin.The α7-nAChR antagonist methyllycaconitine(MLA)was applied for mechanistic validation.Results:In vitro,Dex(40-100μm)dose-dependently increased GDNF expression in EGCs(p<0.05)and enhanced IEC TEER.These protective effects were abolished by MLApre-treatment(p<0.05).In vivo,Dex significantly reduced I/R-induced mucosal injury and decreased plasma FITC-dextran concentrations compared to the untreated I/R group(0.30±0.01 vs.0.43±0.02 mg/mL,p<0.05).Notably,in EGC-ablated mice,Dex failed to restore Occludin levels or reduce permeability(p>0.05),confirming EGC-dependence.Conclusion:Dexmedetomidine protects the intestinal mucosal barrier via an EGC-dependent mechanism involving α7-nAChR activation and GDNF-mediated tight junction reinforcement.These findings highlight EGCs as key effectors of Dex-induced intestinal protection and potential therapeutic targets for barrier dysfunction in critical illness.展开更多
目的:探讨天麻素对慢性不可预见应激(CUS)大鼠抑郁样行为的改善作用及对海马脑源性神经营养因子(BDNF)及胶质原纤维酸性蛋白(GDNF)表达的影响。方法:将64只SD大鼠随机分为对照组(Sham),Sham+天麻素低、中、高剂量组,模型组(CUS),模型(CU...目的:探讨天麻素对慢性不可预见应激(CUS)大鼠抑郁样行为的改善作用及对海马脑源性神经营养因子(BDNF)及胶质原纤维酸性蛋白(GDNF)表达的影响。方法:将64只SD大鼠随机分为对照组(Sham),Sham+天麻素低、中、高剂量组,模型组(CUS),模型(CUS)+天麻素低、中、高剂量组,每组8只。对照组每天腹腔注射生理盐水(1 m L/kg),连续14天;Sham+天麻素低、中、高剂量组每天腹腔注射不同剂量的天麻素(50、100或者200 mg/kg),连续14天;模型组接受CUS造模,并且在造模结束后每天腹腔注射生理盐水(1 m L/kg),连续14天;模型+天麻素低、中、高剂量组在CUS造模结束后每天腹腔注射不同剂量的天麻素(50、100或者200 mg/kg),持续14天。随后,通过糖水偏好实验和强迫游泳实验检测各组大鼠的抑郁样行为,在行为学检测结束后处死大鼠,通过Elisa检测海马GFAP和BDNF的表达情况。结果:(1)慢性不可预见应激(CUS)可以导致明显的抑郁样行为,包括糖水偏好减少(P<0.05)和强迫游泳不动时间增加(P<0.01),CUS组大鼠海马GFAP和BDNF水平下降(P<0.01)。(2)一定剂量(100和200 mg/Kg)天麻素干预可以缓解CUS大鼠的抑郁行为,CUS与CUS+GAS(M)组(P<0.05)以及CUS与CUS+GAS(H)组之间(P<0.01)存在显著性差异。(3)中高剂量的天麻素可以恢复CUS大鼠海马的BDNF和GDNF水平,CUS与CUS+GAS(M)组(P<0.05)以及CUS与CUS+GAS(H)组之间(P<0.05)的BDNF和GDNF水平存在显著性差异。结论:天麻素可以缓解CUS模型大鼠抑郁样行为,恢复CUS模型大鼠海马的BDNF和GDNF水平。展开更多
基金supported by Yunnan Provincial Science and Technology Basic Research Project(202201AY070001-075)Yunnan Health Training Project of High-Level Talents(L-2024008)“Xingdian Talents”Support Project of Yunnan Province.
文摘Objective:Intestinal barrier disruption is a critical event in sepsis and ischemia-reperfusion(I/R)injury.Enteric glial cells(EGCs)maintain barrier integrity by secreting glial cell line-derived neurotrophic factor(GDNF).This study aimed to determine whether Dexmedetomidine(Dex)protects the intestinal barrier via α7-nicotinic acetylcholine receptor(α7-nAChR)signaling in EGCs.Methods:An in vitro EGC-intestinal epithelial cell(IEC)co-culture system and amurine intestinal I/Rmodel were established.EGCs were selectively ablated in vivo using benzalkonium chloride(BAC).Barrier integrity was evaluated by transmembrane electrical resistance(TEER)and plasma FITC-dextran permeability.Enzyme-Linked Immunosorbent Assay(ELISA)and Western blotting quantified levels of GDNF and Occludin.The α7-nAChR antagonist methyllycaconitine(MLA)was applied for mechanistic validation.Results:In vitro,Dex(40-100μm)dose-dependently increased GDNF expression in EGCs(p<0.05)and enhanced IEC TEER.These protective effects were abolished by MLApre-treatment(p<0.05).In vivo,Dex significantly reduced I/R-induced mucosal injury and decreased plasma FITC-dextran concentrations compared to the untreated I/R group(0.30±0.01 vs.0.43±0.02 mg/mL,p<0.05).Notably,in EGC-ablated mice,Dex failed to restore Occludin levels or reduce permeability(p>0.05),confirming EGC-dependence.Conclusion:Dexmedetomidine protects the intestinal mucosal barrier via an EGC-dependent mechanism involving α7-nAChR activation and GDNF-mediated tight junction reinforcement.These findings highlight EGCs as key effectors of Dex-induced intestinal protection and potential therapeutic targets for barrier dysfunction in critical illness.
文摘目的:探讨天麻素对慢性不可预见应激(CUS)大鼠抑郁样行为的改善作用及对海马脑源性神经营养因子(BDNF)及胶质原纤维酸性蛋白(GDNF)表达的影响。方法:将64只SD大鼠随机分为对照组(Sham),Sham+天麻素低、中、高剂量组,模型组(CUS),模型(CUS)+天麻素低、中、高剂量组,每组8只。对照组每天腹腔注射生理盐水(1 m L/kg),连续14天;Sham+天麻素低、中、高剂量组每天腹腔注射不同剂量的天麻素(50、100或者200 mg/kg),连续14天;模型组接受CUS造模,并且在造模结束后每天腹腔注射生理盐水(1 m L/kg),连续14天;模型+天麻素低、中、高剂量组在CUS造模结束后每天腹腔注射不同剂量的天麻素(50、100或者200 mg/kg),持续14天。随后,通过糖水偏好实验和强迫游泳实验检测各组大鼠的抑郁样行为,在行为学检测结束后处死大鼠,通过Elisa检测海马GFAP和BDNF的表达情况。结果:(1)慢性不可预见应激(CUS)可以导致明显的抑郁样行为,包括糖水偏好减少(P<0.05)和强迫游泳不动时间增加(P<0.01),CUS组大鼠海马GFAP和BDNF水平下降(P<0.01)。(2)一定剂量(100和200 mg/Kg)天麻素干预可以缓解CUS大鼠的抑郁行为,CUS与CUS+GAS(M)组(P<0.05)以及CUS与CUS+GAS(H)组之间(P<0.01)存在显著性差异。(3)中高剂量的天麻素可以恢复CUS大鼠海马的BDNF和GDNF水平,CUS与CUS+GAS(M)组(P<0.05)以及CUS与CUS+GAS(H)组之间(P<0.05)的BDNF和GDNF水平存在显著性差异。结论:天麻素可以缓解CUS模型大鼠抑郁样行为,恢复CUS模型大鼠海马的BDNF和GDNF水平。
