背景:盆底肌肉损伤是阴道分娩的常见后果。非甾体抗炎药是广泛使用的产后镇痛药。多项研究报道了这些药物对肢体肌肉再生的负面影响,但是它们对出生损伤后盆底肌肉恢复的影响尚未被探索。
目的:使用经过验证的大鼠模型,我们评估了非甾体类抗炎药对模拟出生损伤后急性和长期盆底肌肉恢复的影响.
方法:将3个月大的SpragueDawley大鼠随机分为以下组:(1)对照组,(2)模拟产伤,(3)模拟产伤+非甾体抗炎药,或(4)非甾体抗炎药。使用完善的阴道球囊扩张方案诱导模拟产伤。布洛芬在饮用水中给药(0.2mg/mL),被动物随意食用。在出生损伤/布洛芬施用后1、3、5、7、10和28天对动物实施安乐死。大鼠肛提肌的耻骨尾肌部分,which,就像人类的耻骨尾骨,经历更大的分娩相关菌株,收获(N=3-9/时间点/组)。在急性和28天时间点评估再生(胚胎肌球蛋白重链)和成熟肌纤维的横截面面积,分别。在28天时间点评估肌内胶原含量。使用抗Pax7和抗肌生成素抗体评估肌生成,以鉴定活化和分化的肌肉干细胞。分别。使用抗CD45抗体评估总体免疫浸润。在损伤后3、5和10天通过定量逆转录酶聚合酶链反应评估编码促炎和抗炎细胞因子的基因的表达。
结果:在伤后28天,与模拟出生损伤组相比,模拟出生损伤+非甾体抗炎药组的阴尾肌纤维尺寸明显更小(P<0.0001)。胚胎肌球蛋白重链+纤维的中位大小也显著减少,在损伤后3天,相对于模拟出生损伤组,模拟出生损伤+非甾体抗炎药组的纤维面积分布较小(P<.0001),提示在存在非甾体类抗炎药的情况下再生的开始延迟。受伤后10天,模拟出生损伤组的中位胚胎肌球蛋白重链+纤维大小从损伤后7天开始下降(P<0.0001),横截面积分布紧密,表明该再生状态接近完成。然而,在模拟产伤+非甾体抗炎药组中,胚胎肌球蛋白重链+纤维的大小随着横截面积分布的扩大而持续增加(P<0.0001),这意味着这些动物的再生延迟。非甾体抗炎药在损伤后7天减少了肌肉干细胞池(P<0.0001),并延迟了肌肉干细胞的分化。如损伤后7天持续升高的肌细胞数所示(P<0.05)。相比之下,在模拟出生损伤组中,在损伤后5天,肌细胞+细胞的比例恢复到基线水平.对编码促炎和抗炎细胞因子的基因表达的分析表明,在模拟出生损伤+非甾体抗炎药组中,Tgfb1仅在损伤后5天而不是10天时短暂升高。与以前的研究一致,相对于未受伤的动物,模拟出生损伤后给予非甾体抗炎药导致肌内胶原沉积增加.非甾体抗炎药组和未扰动对照组之间的任何感兴趣的结果没有显着差异。
结论:非甾体类抗炎药在临床前模拟出生损伤模型中对盆底肌肉再生产生负面影响。这似乎是由这些药物对骨盆肌肉干细胞功能的负面影响驱动的,导致出生损伤后盆底肌肉再生的时间进展延迟。这些发现为研究产后非甾体抗炎药对盆底肌肉损伤高危女性肌肉再生的影响提供了动力。
Pelvic floor muscle injury is a common consequence of vaginal childbirth. Nonsteroidal anti-inflammatory drugs are widely used postpartum analgesics. Multiple studies have reported negative effects of these drugs on limb muscle regeneration, but their impact on pelvic floor muscle recovery following birth injury has not been explored.
Using a validated rat model, we assessed the effects of nonsteroidal anti-inflammatory drug on acute and longer-term pelvic floor muscle recovery following simulated birth injury.
Three-month old Sprague Dawley rats were randomly assigned to the following groups: (1) controls, (2) simulated birth injury, (3) simulated birth injury+nonsteroidal anti-inflammatory drug, or (4) nonsteroidal anti-inflammatory drug. Simulated birth injury was induced using a well-established vaginal balloon distension protocol. Ibuprofen was administered in drinking water (0.2 mg/mL), which was consumed by the animals ad libitum. Animals were euthanized at 1, 3, 5, 7, 10, and 28 days after birth injury/ibuprofen administration. The pubocaudalis portion of the rat levator ani, which, like the human pubococcygeus, undergoes greater parturition-associated strains, was harvested (N=3-9/time point/group). The cross-sectional areas of regenerating (embryonic myosin heavy chain+) and mature myofibers were assessed at the acute and 28-day time points, respectively. The intramuscular collagen content was assessed at the 28-day time point. Myogenesis was evaluated using anti-Pax7 and anti-myogenin antibodies to identify activated and differentiated muscle stem cells, respectively. The overall immune infiltrate was assessed using anti-CD45 antibody. Expression of genes coding for pro- and anti-inflammatory cytokines was assessed by quantitative reverse transcriptase polymerase chain reaction at 3, 5, and 10 days after injury.
The pubocaudalis fiber size was significantly smaller in the simulated birth injury+nonsteroidal anti-inflammatory drug compared with the simulated birth injury group at 28 days after injury (P<.0001). The median size of embryonic myosin heavy chain+ fibers was also significantly reduced, with the fiber area distribution enriched with smaller fibers in the simulated birth injury+nonsteroidal anti-inflammatory drug group relative to the simulated birth injury group at 3 days after injury (P<.0001), suggesting a delay in the onset of regeneration in the presence of nonsteroidal anti-inflammatory drugs. By 10 days after injury, the median embryonic myosin heavy chain+ fiber size in the simulated birth injury group decreased from 7 days after injury (P<.0001) with a tight cross-sectional area distribution, indicating nearing completion of this state of regeneration. However, in the simulated birth injury+nonsteroidal anti-inflammatory drug group, the size of embryonic myosin heavy chain+ fibers continued to increase (P<.0001) with expansion of the cross-sectional area distribution, signifying a delay in regeneration in these animals. Nonsteroidal anti-inflammatory drugs decreased the muscle stem cell pool at 7 days after injury (P<.0001) and delayed muscle stem cell differentiation, as indicated by persistently elevated number of myogenin+ cells 7 days after injury (P<.05). In contrast, a proportion of myogenin+ cells returned to baseline by 5 days after injury in the simulated birth injury group. The analysis of expression of genes coding for pro- and anti-inflammatory cytokines demonstrated only transient elevation of Tgfb1 in the simulated birth injury+nonsteroidal anti-inflammatory drug group at 5 but not at 10 days after injury. Consistently with previous studies, nonsteroidal anti-inflammatory drug administration following simulated birth injury resulted in increased deposition of intramuscular collagen relative to uninjured animals. There were no significant differences in any outcomes of interest between the nonsteroidal anti-inflammatory drug group and the unperturbed controls.
Nonsteroidal anti-inflammatory drugs negatively impacted pelvic floor muscle regeneration in a preclinical simulated birth injury model. This appears to be driven by the negative impact of these drugs on pelvic muscle stem cell function, resulting in delayed temporal progression of pelvic floor muscle regeneration following birth injury. These findings provide impetus to investigate the impact of postpartum nonsteroidal anti-inflammatory drug administration on muscle regeneration in women at high risk for pelvic floor muscle injury.