TREM-1抑制肽LR12对脓毒症小鼠心肌损伤的改善作用及其机制

doi:10.13481/j.1671-587X.20260208

摘要/Abstract

摘要：

目的探讨髓系细胞触发受体1（TREM-1）抑制肽LR12对脓毒症小鼠心肌损伤的作用，并阐明其可能的作用机制。方法采用盲肠结扎穿刺术（CLP）建立脓毒症小鼠模型。将40只雄性小鼠随机分为假手术组、模型组、CLP+LR12对照肽（LR12-scr）组、CLP+LR12组和CLP+DNaseⅠ组，每组8只。除假手术组外，其余各组小鼠均行CLP建立脓毒症模型，术后1 h分别腹腔注射LR12-scr、LR12和DNaseⅠ。术后24 h，观察各组小鼠状态和行为表现。采用小动物超声系统检测各组小鼠心脏功能，酶联免疫吸附试验（ELISA）法检测各组小鼠血清中血清肌酸激酶同工酶（CK-MB）和心肌肌钙蛋白I（cTnI）及炎症指标白细胞介素1β（IL-1β）、白细胞介素6（IL-6）和肿瘤坏死因子α（TNF-α）水平以及心肌组织中髓过氧化物酶（MPO）-DNA（MPO-DNA）和中性粒细胞弹性蛋白酶（NE）-DNA（NE-DNA）水平，HE染色法观察各组小鼠心肌组织病理形态表现，免疫荧光染色法检测各组小鼠心肌组织中淋巴细胞抗原6G（Ly6G）和瓜氨酸化组蛋白H3（cit-H3）蛋白共表达情况，Western blotting法检测各组小鼠心肌组织中TREM1、MPO、NE和cit-H3蛋白表达水平。结果与假手术组比较，模型组小鼠精神萎靡，心肌组织排列紊乱，心肌细胞萎缩、变形；与模型组比较，CLP+LR12组和CLP+DNaseⅠ组小鼠精神状态及心肌组织损伤明显改善，CLP+LR12-scr组无明显变化。心脏功能检测，与假手术组比较，模型组小鼠左心室射血分数（LVEF）和左心室短轴缩短率（LVFS）明显降低（P<0.01）；与模型组比较，CLP+LR12组和CLP+DNaseⅠ组小鼠LVEF及LVFS明显升高（P<0.01）。ELISA法，与假手术组比较，模型组小鼠血清中CK-MB和cTnI水平及IL-1β、IL-6和TNF-α水平均明显升高（P<0.01），心肌组织中MPO-DNA和NE-DNA水平明显升高（P<0.01）；与模型组比较，CLP+LR12组和CLP+DNaseⅠ组小鼠血清中CK-MB及cTnI水平以及IL-1β、IL-6和TNF-α水平明显降低（P<0.01），心肌组织中MPO-DNA和NE-DNA水平明显降低（P<0.01）；CLP+LR12-scr组上述指标均无明显变化（P>0.05）。与假手术组比较，模型组小鼠心肌组织中Ly6G和cit-H3蛋白共表达增加；与模型组比较，CLP+LR12组和CLP+DNaseⅠ组小鼠心肌组织中Ly6G及cit-H3蛋白共表达减少。Western blotting法，与假手术组比较，模型组小鼠心肌组织中TREM-1、MPO、NE和cit-H3蛋白表达水平均明显升高（P<0.01）；与模型组比较，CLP+LR12组小鼠心肌组织中TREM-1、MPO、NE和cit-H3蛋白表达水平明显降低（P<0.01），CLP+DNaseⅠ组小鼠心肌组织中MPO、NE和cit-H3蛋白表达水平明显降低（P<0.01），TREM-1蛋白表达水平差异无统计学意义（P>0.05）。结论 TREM-1抑制肽LR12可改善脓毒症小鼠的心功能，减轻心肌炎症和损伤，其机制可能与抑制中性粒细胞胞外诱捕网（NETs）形成有关。

关键词: 脓毒症, 心肌损伤, 髓系细胞触发受体1, 中性粒细胞胞外诱捕网, LR12

Abstract:

Objective To discuss the effect of triggering receptor expressed on myeloid cells-1 （TREM-1） inhibitory peptide LR12 on myocardial injury in the septic mice， and to clarify its possible mechanism. Methods The mouse model of sepsis was established by cecal ligation and puncture （CLP）. Forty male mice were randomly divided into sham operation group， model group， CLP+LR12 control peptide （LR12-scr） group， CLP+LR12 group， and CLP+DNase Ⅰ group， and there were 8 mice in each group. Except for sham operation group， the mice in the other groups underwent CLP to establish the sepsis models， and were intraperitoneally injected with LR12-scr， LR12， and DNase Ⅰ at 1 h after operation， respectively. At 24 h after operation， the status and behavior of the mice in various groups were observed. A small animal ultrasound system was used to detect the cardiac function of the mice in various groups； enzyme-linked immunosorbent assay （ELISA） method was used to detect the levels of creatine kinase isoenzyme-MB （CK-MB）， cardiac troponin I （cTnI）， and inflammatory indicators interleukin-1β （IL-1β）， interleukin-6 （IL-6）， and tumor necrosis factor-α （TNF-α） in serum， as well as the levels of myeloperoxidase （MPO）-DNA and neutrophil elastase （NE）-DNA in myocardium tissue of the mice in various groups； HE staining was used to observe the pathomorphology of myocardium tissue of the mice in various groups； immunofluorescence staining was used to detect the co-expression of lymphocyte antigen 6G （Ly6G） and citrullinated histone H3 （cit-H3） proteins in myocardium tissue of the mice in various groups； Western blotting method was used to detect the expression levels of TREM-1， MPO， NE， and cit-H3 proteins in myocardium tissue of the mice in various groups. Results Compared with sham operation group， the mice in model group were listless， with disordered arrangement of myocardium tissue， and atrophy and deformation of cardiomyocytes； compared with model group， the mental state and myocardium tissue injury of the mice in CLP+LR12 group and CLP+DNase Ⅰ group were significantly improved， while no significant change was observed in CLP+LR12-scr group. The cardiac function detection results showed that compared with sham operation group， the left ventricular ejection fraction （LVEF） and left ventricular fractional shortening （LVFS） of the mice in model group were significantly decreased （P<0.01）； compared with model group， the LVEF and LVFS of the mice in CLP+LR12 group and CLP+DNase Ⅰ group were significantly increased （P<0.01）. The ELISA results showed that compared with sham operation group， the levels of CK-MB， cTnI， IL-1β， IL-6， and TNF-α in serum and the levels of MPO-DNA and NE-DNA in myocardium tissue of the mice in model group were significantly increased （P<0.01）； compared with model group， the levels of CK-MB， cTnI， IL-1β， IL-6， and TNF-α in serum and the levels of MPO-DNA and NE-DNA in myocardium tissue of the mice in CLP+LR12 group and CLP+DNase Ⅰ group were significantly decreased （P<0.01）； no significant changes in the above indicators were observed in CLP+LR12-scr group （P>0.05）. The immunofluorescence staining results showed that compared with sham operation group， the co-expression of Ly6G and cit-H3 proteins in myocardium tissue of the mice in model group was increased； compared with model group， the co-expression of Ly6G and cit-H3 proteins in myocardium tissue of the mice in CLP+LR12 group and CLP+DNase Ⅰ group was decreased. The Western blotting method results showed that compared with sham operation group， the expression levels of TREM-1， MPO， NE， and cit-H3 proteins in myocardium tissue of the mice in model group were significantly increased （P<0.01）； compared with model group， the expression levels of TREM-1， MPO， NE， and cit-H3 proteins in myocardium tissue of the mice in CLP+LR12 group were significantly decreased （P<0.01）， while the expression levels of MPO， NE， and cit-H3 proteins in myocardium tissue of the mice in CLP+DNase Ⅰ group were significantly decreased （P<0.01）， and there was no significant difference in the expression level of TREM-1 protein （P>0.05）. Conclusion TREM-1 inhibitory peptide LR12 can improve the cardiac function and alleviate myocardial inflammation and injury in the septic mice， and its mechanism may be related to inhibiting the formation of neutrophil extracellular traps （NETs）.

Key words: Sepsis, Myocardial injury, Triggering receptor expressed on myeloid cells-1, Neutrophil extracellular trap, LR12

中图分类号:

R542.2

李金玉,李忠辉,程爱斌,部璇,白静,王建军. TREM-1抑制肽LR12对脓毒症小鼠心肌损伤的改善作用及其机制[J]. 吉林大学学报(医学版), 2026, 52(2): 366-374.

Jinyu LI,Zhonghui LI,Aibin CHENG,Xuan BU,Jing BAI,Jianjun WANG. Improvement effect of TREM-1 inhibitory peptide LR12 on myocardial injury in septic mice and its mechanism[J]. Journal of Jilin University(Medicine Edition), 2026, 52(2): 366-374.

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Group	LVEF	LVFS
Sham operation	66.85±3.17	37.28±3.06
Model	45.19±2.26^*	26.34±2.40^*
CLP+ LR12-scr	46.72±2.05	27.10±1.82
CLP+LR12	57.26±2.83^△	31.13±2.47^△
CLP+DNase Ⅰ	61.09±3.29^△	34.84±2.11^△

Group	CK-MB [λ_B/(U·L^-1)]	cTnI [ρ_B/(ng·L^-1)]
Sham operation	28.73±1.86	19.21±1.52
Model	57.65±4.18^*	53.37±4.83^*
CLP+LR12-scr	58.43±4.35	51.82±4.70
CLP+LR12	40.08±3.07^△	35.88±2.14^△
CLP+DNase Ⅰ	34.23±2.79^△	29.43±2.53^△

Group	IL-1β	IL-6	TNF-α
Sham operation	34.08±3.81	12.34±1.05	110.20±9.72
Model	83.05±6.24^*	33.18±2.16^*	188.62±12.65^*
CLP+LR12-scr	82.46±7.01	32.52±2.71	186.17±15.43
CLP+LR12	55.15±3.72^△	24.48±1.22^△	163.35±13.08^△
CLP+DNase Ⅰ	48.02±4.35^△	18.20±1.07^△	147.91±16.13^△

Group	MPO-DNA[w_B/（μg·g^-1）]	NE-DNA[w_B/（ng·g^-1）]
Sham operation	10.32±1.15	7.88±1.36
Model	31.89±4.04^*	27.53±2.28^*
CLP+LR12-scr	30.42±3.85	25.76±3.19
CLP+LR12	22.98±2.72^△	17.60±1.88^△
CLP+DNaseⅠ	19.36±2.24^△	15.87±1.45^△