人参皂苷Rg1干预小鼠巨大肩袖损伤后的肌肉退变

Effect of ginsenoside Rg1 on muscle degeneration after massive rotator cuff injury in mice

背景:肩袖肌退变(肌肉萎缩、纤维化和脂肪浸润)是肩袖撕裂后出现的常见问题,严重影响肩关节功能和手术预后。人参皂苷Rg1具有抗氧化、抗细胞凋亡、降血脂等生物效应,然而人参皂苷Rg1对肩袖损伤后肌肉退变的影响未见报道。目的:探讨人参皂苷Rg1对巨大肩袖损伤小鼠肌肉退变的影响。方法:将60只C57BL/6J小鼠随机分为假手术组、模型组、人参皂苷Rg1低剂量组、人参皂苷Rg1高剂量组,每组15只。假手术组小鼠切开右肩皮肤后缝合,其余3组小鼠均行右侧肩关节肩袖损伤造模,模拟巨大肩袖撕裂手术切断冈上肌肌腱和肩胛上神经压迫。术后假手术组和模型组腹腔注射生理盐水0.5 mL;人参皂苷Rg1低、高剂量组予以腹腔注射人参皂苷Rg130,60 mg/kg,1次/d,共注射6周。末次注射后次日予以步态分析评估小鼠肢体功能,安乐死后取术侧冈上肌测量肌肉萎缩率、肌肉收缩力,肌肉组织进行油红O染色、Masson染色,RT-PCR检测萎缩、纤维化、脂肪浸润相关基因的表达。结果与结论:①与模型组相比,人参皂苷Rg1低、高剂量组爪印面积、步长显著增加(P<0.05);②与模型组相比,人参皂苷Rg1低、高剂量组肌纤维横截面积、冈上肌收缩力显著增加(P<0.05),湿肌质量减少比率、脂肪浸润面积比率、胶原纤维面积比率显著下降(P<0.05);③与模型组相比,人参皂苷Rg1低、高剂量组肌肉组织中萎缩、纤维化和脂肪浸润相关基因的表达显著下降(P<0.05);④人参皂苷Rg1低、高剂量组爪印面积、冈上肌收缩力、肌纤维横截面积无统计学差异(P>0.05),人参皂苷Rg1高剂量组其他指标均优于低剂量组(P<0.05);⑤结果说明,人参皂苷Rg1能显著减轻小鼠巨大肩袖撕裂后肩袖肌萎缩、纤维化和脂肪浸润,并有利于肌肉力量及肢体功能的改善。

BACKGROUND:Rotator cuff muscle degeneration(muscle atrophy,fibrosis and fatty infiltration)is a common condition after rotator cuff tears,which seriously affects shoulder function and surgical outcomes.Ginsenoside Rg1 has biological effects such as anti-oxidation,anti-apoptosis and lipid-lowering.However,the effect of ginsenoside Rg1 on muscle degeneration after rotator cuff tear has not been reported.OBJECTIVE:To investigate the effect of ginsenoside Rg1 on muscle degeneration after massive rotator cuff tear in mice.METHODS:Sixty C57BL/6J mice were randomly divided into sham group,model group,ginsenoside Rg1 low dose group and ginsenoside Rg1 high dose group,with 15 mice in each group.The skin of the right shoulder of mice in the sham group was cut and sutured.Massive rotator cuff tear mouse models of the right shoulder were established in the other three groups.Supraspinatus tendon and suprascapular nerve compression were administrated.Mice in the sham and model groups were intraperitoneally injected with 0.5 mL of saline after operation,while those in the ginsenoside Rg1 low and high dose groups were intraperitoneally injected with ginsenoside Rg130 and 60 mg/kg respectively,once a day,for 6 weeks.Mice were assessed for limb function by gait analysis the day after the last injection.After euthanasia,the supraspinatus muscle on the operated side was taken to measure the muscle atrophy rate and muscle contractility.Muscle tissue was stained with oil red O and Masson.RT-PCR was used to detect the expression of atrophy,fibrosis,and fatty infiltration related genes.RESULTS AND CONCLUSION:Compared with the model group,low-and high-dose ginsenoside Rg1 significantly increased paw print area and step length(P<0.05).Compared with the model group,low-and high-dose ginsenoside Rg1 significantly increased myofiber cross-sectional area and supraspinatus contractility(P<0.05),and significantly decreased wet muscle mass reduction ratio,fatty infiltration area ratio,and collagen fiber area ratio(P<0.05).Compared with the model group,low-and high-dose ginsenoside Rg1 significantly decreased the expression of atrophy,fibrosis,and fatty infiltration related genes(P<0.05).There was no significant difference in paw print area,supraspinatus muscle contractility,and myofiber cross-sectional area between ginsenoside Rg1 low and high dose groups(P>0.05),and all other indexes were better in the ginsenoside Rg1 high dose group than in the ginsenoside Rg1 low dose group(P<0.05).To conclude,ginsenoside Rg1 could significantly reduce muscle atrophy,fibrosis and fatty infiltration following massive rotator cuff tear in mice,which is beneficial to improve muscle strength and limb function.