DataSheet7_Saikosaponin D Inhibits Peritoneal Fibrosis in Rats With Renal Failure by Regulation of TGFβ1/ BMP7 / Gremlin1/ Smad Pathway.xls

Peritoneal dialysis (PD) can improve the quality of life of patients with kidney disease and prolong survival. However, peritoneal fibrosis can often occur and lead to PD withdrawal. Therefore, it is imperative to better understand how to inhibit and slow down progression of peritoneal fibrosis. This study aimed to investigate the regulatory effect of Saikosaponin d (SSD), a monomer extracted from the plant Bupleurum, on peritoneal fibrosis and the contribution of TGFβ1/BMP7/Gremlin1 pathway cross-talk in this process. To this aim, we used a model 5/6 nephrectomy and peritoneal fibrosis in rats. Rats were divided into four groups, namely a control group (saline administration); a model group (dialysate administration; group M); a SSD group (dialysate and SSD administration); and a positive drug group (dialysate and Benazepril Hydrochloride administration; group M + A). Histological analysis indicated that peritoneal fibrosis occurred in all groups. WB, ELISA, and PCR essays suggested that TGFβ1 and Gremlin1 levels in group M were significantly higher than those in group C, whereas BMP7 expression was significantly lower. TGFβ1, Gremlin1 and BMP7 levels were significantly lower in the group where SSD was administered than in the other groups. The expression of BMP7 in SSD group was significantly increased. In addition, levels of Smad1/5/8 as assessed by PCR, and levels of p-Smad1/5/8 expression as assessed by WB were also significantly higher in the SSD group than in the M group. Expression of vimentin and α-SMA, two important markers of fibrosis, was also significantly decreased. Our study suggests a role for the TGFβ1/BMP7/Gremlin1/Smad pathway in peritoneal fibrosis with potential therapeutic implications. Finally, our results also suggest that the monomer SSD may be able to reverse peritoneal fibrosis via regulation of the TGFβ1/BMP7/Gremlin1/Smad pathway.

腹膜透析（Peritoneal dialysis, PD）可改善肾病患者的生活质量并延长其生存期。然而，腹膜纤维化常可发生并导致腹膜透析治疗终止，因此亟需深入了解如何抑制并延缓腹膜纤维化的进展。本研究旨在探讨从柴胡属植物中提取的单体成分柴胡皂苷d（Saikosaponin d, SSD）对腹膜纤维化的调控作用，以及转化生长因子β1（TGFβ1）/骨形态发生蛋白7（BMP7）/Gremlin1通路的串扰在该过程中的作用。为此，我们采用5/6肾切除联合大鼠腹膜纤维化模型。将大鼠分为四组：对照组（给予生理盐水）、模型组（给予透析液，M组）、SSD组（给予透析液联合SSD）以及阳性药物组（给予透析液联合盐酸贝那普利，M+A组）。组织学分析显示，各组均出现腹膜纤维化。蛋白质印迹（WB）、酶联免疫吸附试验（ELISA）及聚合酶链式反应（PCR）实验结果表明，模型组的TGFβ1与Gremlin1水平显著高于对照组，而BMP7的表达量则显著降低。SSD给药组的TGFβ1、Gremlin1水平显著低于其余各组，且BMP7的表达量显著升高。此外，通过PCR检测的Smad1/5/8水平，以及通过WB检测的p-Smad1/5/8表达水平，在SSD组中也显著高于模型组。两种重要的纤维化标志物波形蛋白（vimentin）与α-平滑肌肌动蛋白（α-SMA）的表达量也显著降低。本研究提示TGFβ1/BMP7/Gremlin1/Smad通路在腹膜纤维化中发挥作用，具有潜在的治疗价值。最后，本研究结果还表明，单体SSD或可通过调控TGFβ1/BMP7/Gremlin1/Smad通路逆转腹膜纤维化。