Institute of Integrated Traditional Chinese and Western Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
Department of Obstetrics and Gynecology, School of medicine, Wayne state university, Detroit, MI, USA.
Phytomedicine. 2024 Jan;123:155164. doi: 10.1016/j.phymed.2023.155164. Epub 2023 Oct 25.
Recurrent pregnancy loss (RPL) is a tricky puzzle that disturbs female reproduction worldwide. According to previous research, Bushen Antai recipe (BAR), a classic Chinese herbal formula widely used in clinic for miscarriage, exhibited multifaceted benefits in improving embryo implantation and attenuating early pregnancy loss. Myeloid-derived suppressor cells (MDSCs), a set of immunoregulatory cells critical in inflammation balance, get growing attention for their indispensable role in successful pregnancy.
To investigate the therapeutic efficacy of BAR in abortion-prone mice and explore the potential mechanisms of BAR regarding MDSCs.
RPL mice (CBA/J females paired with DBA/2 males, BALB/c males were used as the control) were administered with BAR1 (5.7 g/kg), BAR2 (11.4 g/kg), progesterone (P4), or distilled water from embryo day (D) 0.5 until D10.5. The rate of embryo absorption on D10.5 and the health status of progeny were measured. The systemic inflammatory states and the placenta-uterus milieu were assessed by serum cytokine levels, placenta-uterus architecture, and related protein expression at the maternal-fetal interface. Flow cytometry analysis was carried out to measure the frequency of MDSCs. Furthermore, we established the MDSCs-depletion mouse model by using C57BL/6 females mated with BALB/c males via intraperitoneal injection of anti-Gr-1 antibody on D6.5, while irrelative LTF antibody was used as the control. Similarly, BAR1, BAR2, P4, or distilled water was separately applied. Embryo absorption rate, systemic inflammatory states, placenta-uterus milieu, and MDSCs frequency were evaluated as mentioned above.
Significantly, embryo absorption rate was increased with disrupted placenta-uterus milieu and exorbitant proinflammatory cytokines in RPL mice, meanwhile, MDSCs number in the placenta-uterus unit were apparently reduced (p < 0.001). BAR treatment markedly alleviated the poor conditions above and increased MDSCs number (p < 0.0001). Flow cytometry analysis validated the efficacy of anti-Gr-1 antibody and the raised embryo absorption rate confirmed the essentiality of MDSCs in normal pregnancy (p < 0.01). Besides, the placenta-uterus milieu was destroyed, accompanied by the impaired expression of immune tolerance and angiogenesis related factors in the MDSCs-depletion mice. Even though, BAR treatment reversed the embryo resorption phenotype and optimized the serum cytokine milieu, mobilizing MDSCs and rejuvenating active intercellular communication. Thereby, BAR facilitated the expression of MDSCs-related functional molecules, promoting immune tolerance and vascular remodeling at the placenta-uterus unit.
We unfurled the remarkable therapeutic ability of BAR in abortion-prone mice, and this was achieved by mobilizing MDSCs, thus favoring immune tolerance and angiogenesis at the maternal-fetal interface.
复发性流产（RPL）是一个棘手的难题，困扰着全球女性的生殖健康。根据以往的研究，补肾安胎方（BAR）是一种广泛应用于临床治疗流产的经典中药方剂，在改善胚胎着床和减轻早期妊娠丢失方面具有多方面的益处。髓系来源抑制细胞（MDSCs）是一组在炎症平衡中起关键作用的免疫调节细胞，因其在成功妊娠中的不可或缺作用而受到越来越多的关注。
研究 BAR 在易流产小鼠中的治疗效果，并探讨 BAR 对 MDSCs 的潜在作用机制。
将 RPL 小鼠（CBA/J 雌鼠与 DBA/2 雄鼠交配，BALB/c 雄鼠作为对照）从胚胎第 0.5 天（D0.5）至第 10.5 天（D10.5）给予 BAR1（5.7 g/kg）、BAR2（11.4 g/kg）、孕激素（P4）或蒸馏水。测量 D10.5 时胚胎吸收率和后代的健康状况。通过血清细胞因子水平、胎盘-子宫结构和母胎界面相关蛋白表达来评估全身炎症状态和胎盘-子宫环境。通过流式细胞术分析测量 MDSCs 的频率。此外，我们通过在 D6.5 时向 C57BL/6 雌鼠腹腔注射抗 Gr-1 抗体建立 MDSCs 耗竭小鼠模型，并用无关的 LTF 抗体作为对照。同样，分别应用 BAR1、BAR2、P4 或蒸馏水。如上所述评估胚胎吸收率、全身炎症状态、胎盘-子宫环境和 MDSCs 频率。
显著的是，RPL 小鼠的胚胎吸收率增加，胎盘-子宫环境破坏，促炎细胞因子水平升高，同时胎盘-子宫单位中的 MDSCs 数量明显减少（p < 0.001）。BAR 治疗明显缓解了上述不良情况，并增加了 MDSCs 的数量（p < 0.0001）。流式细胞术分析验证了抗 Gr-1 抗体的疗效，提高的胚胎吸收率证实了 MDSCs 在正常妊娠中的重要性（p < 0.01）。此外，MDSCs 耗竭小鼠的胎盘-子宫环境被破坏，免疫耐受和血管生成相关因子的表达受损。尽管如此，BAR 治疗逆转了胚胎吸收表型，并优化了血清细胞因子环境，动员 MDSCs 并恢复了活跃的细胞间通讯。因此，BAR 促进了 MDSCs 相关功能分子的表达，促进了胎盘-子宫单位的免疫耐受和血管重塑。
我们揭示了 BAR 在易流产小鼠中的显著治疗能力，这是通过动员 MDSCs 实现的，从而有利于母胎界面的免疫耐受和血管生成。
