摘要
目的研究内质网兰尼碱受体1(RyR1)表达及磷酸化修饰在脓毒症相关膈肌功能障碍中的作用。方法将30只SPF级成年雄性SD大鼠按随机数字表法随机分成5组:Sham组、CLP-6 h组、CLP-12 h组、CLP-24 h组和CLP-24 h+KN-93组,6只/组。Sham组仅腹腔探查,不进行盲肠结扎穿孔;CLP-6 h组、CLP-12 h组、CLP-24 h组、CLP-24 h+KN-93组通过盲肠结扎穿孔术(CLP)建立脓毒症模型。CLP-24 h+KN-93组于术后立即单次腹腔注射KN-93,各组分别在建模后相应时间点取膈肌标本进行指标检测。采用RM6240生物信息采集系统测量膈肌复合肌动作电位(CMAP),计算离体膈肌疲劳指数,拟合频率收缩曲线;Western blot检测膈肌CaMKⅡ、RyR1及P-RyR1蛋白表达水平。结果随脓毒症时间的延长,膈肌CMAP幅值下降,时程延长,且在24 h最为明显,CLP-24 h+KN-93组较CLP-24 h组幅值升高,时程缩短,差异有统计学意义(P<0.05)。膈肌疲劳指数随脓毒症时间的延长而逐渐升高(P<0.05),CLP-24 h+KN-93组与CLP-24h组差异无统计学意义(P>0.05)。随脓毒症时间的延长,膈肌各组频率收缩曲线逐渐降低,且CLP-24 h组下降最为明显,CLP-24 h+KN-93组较CLP-24 h组明显升高(P<0.05)。随脓毒症病程的发展,RyR1表达水平CLP-24 h组较Sham组明显降低(P<0.05);各组P-RyR1水平随脓毒症时间的延长而逐渐升高,CLP-24 h+KN-93组较CLP-24 h组明显降低(P<0.05);CaMKⅡ表达水平CLP-24 h组较Sham组明显升高,CLP-24 h+KN-93组较CLP-24 h组明显降低(P<0.05)。结论脓毒症提高CaMKⅡ表达促进膈肌内质网RyR1受体磷酸化增强从而导致膈肌功能障碍。
Objective To explore the role of endoplasmic reticulum ryanodine receptor 1(RyR1)expression and phosphorylation in sepsis-induced diaphragm dysfunction.Methods Thirty SPF male SD rats were randomized equally into 5 groups,including a sham-operated group,3 sepsis model groups observed at 6,12,or 24 h following cecal ligation and perforation(CLP;CLP-6h,CLP-12h,and CLP-24h groups,respectively),and a CLP-24h group with a single intraperitoneal injection of KN-93 immediately after the operation(CLP-24h+KN-93 group).At the indicated time points,diaphragm samples were collected for measurement of compound muscle action potential(CMAP),fatigue index of the isolated diaphragm and fitted frequencycontraction curves.The protein expression levels of CaMK II,RyR1 and P-RyR1 in the diaphragm were detected using Western blotting.Results In the rat models of sepsis,the amplitude of diaphragm CMAP decreased and its duration increased with time following CLP,and the changes were the most obvious at 24 h and significantly attenuated by KN-93 treatment(P<0.05).The diaphragm fatigue index increased progressively following CLP(P<0.05)irrespective of KN-93 treatment(P>0.05).The frequency-contraction curve of the diaphragm muscle decreased progressively following CLP,and was significantly lower in CLP-24 h group than in CLP-24 h+KN-93 group(P<0.05).Compared with that in the sham-operated group,RyR1 expression level in the diaphragm was significantly lowered at 24 h(P<0.05)but not at 6 or 12 following CLP,irrespective of KN-93 treatment;The expression level of P-RyR1 increased gradually with time after CLP,and was significantly lowered by KN-93 treatment at 24 h following CLP(P<0.05).The expression level of CaMKⅡincreased significantly at 24 h following CLP,and was obviously lowered by KN-93 treatment(P<0.05).Conclusion Sepsis causes diaphragmatic dysfunction by enhancing CaMKⅡexpression and RyR1 receptor phosphorylation in the endoplasmic reticulum of the diaphragm.
作者
吴松林
李学欣
关发升
冯建国
贾静
李京
刘力
WU Songlin;LI Xuexin;GUAN Fasheng;FENG Jianguo;JIA Jing;LI Jing;LIU Li(Department of Anesthesiology,The Affiliated Hospital of Southwest Medical University,Luzhou 646000,China;Anesthesiology and Critical Care Medicine Key Laboratory of Luzhou,Southwest Medical University,Luzhou 646000,China)
出处
《南方医科大学学报》
CAS
CSCD
北大核心
2023年第4期631-636,共6页
Journal of Southern Medical University
基金
四川省科技计划联合创新重点项目(2022YFS0632)。
关键词
脓毒症
膈肌
RyR1
磷酸化
肌无力
sepsis
diaphragm dysfunction
RyR1
phosphorylation
muscle weakness
