新疆双峰驼乳清蛋白对脓毒症小鼠心肌损伤的保护作用

Observation of the protective effect of Xinjiang Bactrian camel whey protein on myocardial injury in septic mice

摘要:

目的 探讨新疆双峰驼乳清蛋白（CWP）对脓毒症小鼠心肌损伤的保护作用。方法 将40只C57BL/6雄性小鼠随机分为假手术组（Sham组）、革兰阳性菌脓毒症组（G⁺组）、革兰阳性菌脓毒症+驼乳清蛋白组（G⁺CWP组）、革兰阴性菌脓毒症组（G^-组）、革兰阴性菌脓毒症+驼乳清蛋白组（G^-CWP组），每组8只。G⁺CWP组和G^-CWP组分别灌胃CWP（200 mg/kg），1次/d。Sham组、G⁺组、G^-组用同等剂量生理盐水灌胃，连续处理7 d后复制脓毒症模型。G⁺组和G⁺CWP组腹腔注射金黄色葡萄球菌1 mL，G^-组和G^-CWP组腹腔注射大肠埃希菌1 mL，Sham组腹腔注射1 mL生理盐水作为对照。模型复制24 h后，用超声心动图检测各组小鼠心功能指标［左室射血分数（LVEF）、左室短轴缩短率（LVFS）、心排血量（CO）］；采用酶联免疫吸附试验（ELISA）检测血清心肌损伤标志物［肌酸激酶同工酶（CK-MB）、心肌肌钙蛋白Ⅰ（cTnI）］及炎症因子［肿瘤坏死因子-α（TNF-α）、白细胞介素-1β（IL-1β）、IL-6、IL-10］；苏木精-伊红（HE）染色检测心肌组织病理学变化；免疫组织化学染色检测NF-κB p65蛋白阳性表达。结果 心脏超声结果显示：与Sham组相比，G⁺组和G^-组LVEF、LVFS、CO均下降（P <0.05）；与G⁺组和G^-组相比，G⁺CWP组和G^-CWP组LVEF、LVFS、CO均上升（P <0.05）。ELISA结果显示：与Sham组相比，G⁺组和G^-组CK-MB、cTnI均升高（P <0.05），TNF-α、IL-1β、IL-6、IL-10均升高（P <0.05）；与G⁺组和G^-组相比，G⁺CWP组、G^-CWP组CK-MB、cTnI、TNF-α、IL-1β、IL-6均降低（P <0.05），IL-10均上升（P <0.05）。HE染色结果显示：与Sham组相比，G⁺组和G^-组心肌组织可见明显病理损伤；与G⁺组和G^-组相比，G⁺CWP组、G^-CWP组心肌损伤病理改变及炎症因子浸润减轻。免疫组织化学染色结果显示：与Sham组相比，G⁺组和G^-组NF-κB p65蛋白阳性表达率升高（P <0.05），与G⁺组和G^-组相比，G⁺CWP组、G^-CWP组NF-κB p65蛋白阳性表达率下降（P <0.05）。结论 CWP可减轻脓毒症小鼠炎症反应及心肌病理损伤，并改善心功能，其机制可能与调控NF-κB信号通路有关。

Abstract:

Objective To explore the protective effect of Xinjiang Bactrian camel whey protein on myocardial injury in septic mice.Methods Forty male C57BL/6 mice were randomly divided into five groups: Sham operation group (Sham group), Gram-positive bacterial sepsis group (G⁺group), Gram-positive bacterial sepsis + camel whey protein group (G⁺CWP group), Gram-negative bacterial sepsis group (G^-group), and Gram-negative bacterial sepsis + camel whey protein group (G^-CWP group), with 8 mice in each group. The G⁺CWP group and G^-CWP group were intragastrically administered 200 mg/kg CWP once a day, while the Sham group, G⁺group, and G^-group were given the same volume of normal saline. After continuous treatment for 7 days, the sepsis model was established. The G⁺group/G⁺CWP group and G^-group/G- CWP group were respectively injected with 1 mL of Staphylococcus aureus and Escherichia coli intraperitoneally, and the Sham group was given the same volume of normal saline. Twenty-four hours post-modeling, cardiac function parameters (LVEF, LVFS, CO) were measured in each group. Serum cardiac injury markers (CK-MB, cTnI) and inflammatory cytokines (TNF-α, IL-1β, IL-6, IL-10) were detected via ELISA. Hematoxylin-eosin (HE) staining assessed myocardial histopathological changes. Immunohistochemical staining was used to detect the positive expression of NF-κB p65 protein.Results Echocardiographic findings revealed that compared with the Sham group, cardiac function parameters including LVEF, LVFS, and CO were significantly reduced in the G⁺ group and G^- group. Compared with the G⁺ group and G^- group, cardiac function parameters including LVEF, LVFS, and CO were elevated in both the G⁺CWP group and G^-CWP group (P < 0.05); ELISA results showed that compared with the Sham group, the myocardial injury markers CK-MB and cTnI were significantly elevated, and levels of inflammatory factors TNF-α, IL-1β, IL-6, and IL-10 were markedly increased. Compared to the G⁺group/G^-group, the G⁺CWP group/G^-CWP group showed significantly reduced levels of CK-MB, cTnI, TNF-α, IL-1β, and IL-6, while IL-10 levels increased (P < 0.05); Hematoxylin and eosin staining revealed that compared with the Sham group, the G⁺/G^- group exhibited significant pathological damage in myocardial tissue. Compared with the G⁺/G^- group, the G⁺CWP group and G^-CWP group showed reduced pathological changes in myocardial injury and decreased infiltration of inflammatory cells. Immunohistochemical staining results revealed that compared with the Sham group, the NF-κB p65 positive expression rate was significantly elevated in the G⁺/G^- group. Compared with the G⁺/G^- group, the NF-κB p65 positive expression rate was markedly reduced in the G⁺CWP group and G^-CWP group (P < 0.05).Conclusion Camel whey protein can alleviate the inflammatory response and myocardial pathological damage in septic mice and improve cardiac function. The mechanism may be related to the regulation of the NF-κB signaling pathway.