Uterine fibrosis is an acquired disorder leading to menstrual irregularities, implantation impairment, and abortion. Mesenchymal stromal cells (MSCs) have antifibrotic properties through chemokine secretion. MSC-conditioned media (MSC-CM) contain paracrine components—exosomes—with a great potential for repairing damaged tissue or preventing fibrosis. The main goal of this study was to evaluate the preventive effects of bone marrow-derived MSC-CM (BM-MSC-CM) on uterine fibrosis after uterine curettage in rabbits. This study included 12 female rabbits (24 uterine horns in total). Excised uteri of each of the 12 female rabbits were randomly divided into four groups of intact negative control, curettage positive control, BM-MSC injection, and BM-MSC-CM injection in the way that two corresponding uteri from a rabbit were allocated to different groups. The MSC-CM were collected from cultivated BM-MSCs 48 hours after having been washed three times and replaced in serum-free media. Through a surgical approach, the caudal parts of the uteri were submitted to traumatic endometrial curettage, except for the intact negative uteri. After suturing the uterine walls, BM-MSCs or BM-MSC-CM were injected in the curettage site. Endometrial regeneration was histologically evaluated 30 days after treatment. Based on the evaluation of histomorphometric indices, curettage with or without preventive injections increased the growth of endometrial layers. However, the amount of fibrotic tissue in the CM and the BM-MSC injection groups was the same as the normal control groups, and all were less than the curettage group. A single injection of CM of MSCs after 30 days prevented the fibrotic tissue formation induced by curettage in endometrial layers of rabbits. Injecting BM-MSC-CM immediately after curettage prevented and reduced the uterine fibrosis similar to BM-MSCs in a rabbit model.

中文翻译：

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子宫内膜刮除术后立即宫内注射骨髓间充质基质细胞介导的介质对子宫纤维化的预防作用

子宫纤维化是一种导致月经不调，着床障碍和流产的获得性疾病。间质基质细胞（MSC）通过趋化因子分泌具有抗纤维化特性。MSC条件培养基（MSC-CM）含有旁分泌成分（外泌体），具有修复受损组织或预防纤维化的巨大潜力。这项研究的主要目的是评估兔刮宫术后骨髓来源的MSC-CM（BM-MSC-CM）对子宫纤维化的预防作用。该研究包括12只雌性兔子（总共24只子宫角）。将12只雌性兔子的切除子宫随机分为完整的阴性对照，刮宫阳性对照，BM-MSC注射液和BM-MSC-CM注射液四组，方法是将来自兔子的两个相应子宫分配给不同的子宫。组。洗涤三遍并在无血清培养基中替换后48小时，从培养的BM-MSC中收集MSC-CM。通过手术方法，除了完整的阴性子宫外，子宫的尾部均接受了刮宫的子宫内膜刮除术。缝合子宫壁后，在刮宫部位注射BM-MSC或BM-MSC-CM。治疗后30天通过组织学评估子宫内膜的再生。根据组织形态计量学指标的评估，刮宫术或不进行预防性注射可增加子宫内膜层的生长。但是，CM组和BM-MSC组的纤维化组织数量与正常对照组相同，均少于刮除组。30天后单次注射CM的MSC可以防止刮除家兔子宫内膜层引起的纤维化组织形成。刮宫后立即注射BM-MSC-CM可以预防和减轻兔子模型中类似于BM-MSC的子宫纤维化。