经血源子宫内膜干细胞移植通过免疫调节缓解化疗引起的小鼠肠道损伤和菌群失调

Transplantation of menstrual blood-derived endometrial stem cells allevi⁃ates chemotherapy-induced intestinal injury and flora imbalance in mice through immunomodulation

目的:研究经血源子宫内膜干细胞(menstrual blood-derived endometrial stem cells,MenSCs)对化疗引起的小鼠肠道黏膜炎和菌群失调的治疗效果及潜在机制。方法:将小鼠随机分为正常组、顺铂(cisplatin,Cis)组和Cis+MenSC组,每组10只:Cis组和Cis+MenSC组小鼠采用腹腔注射Cis(2 mg·kg^(−1)·d^(−1),连续5 d)的方式建立小鼠化疗性肠黏膜炎模型,正常组小鼠经腹腔注射同等体积生理盐水;Cis+MenSC组小鼠经尾静脉移植MenSCs,而正常组与Cis组小鼠经尾静脉注射同等体积生理盐水。给药过程中观察小鼠体征及体重变化,实验结束后分离小鼠小肠、结肠部位,通过HE染色评估小鼠肠道组织形态学改变;免疫组化染色检测肠道组织中F4/80和IL-6阳性细胞率;Western blot检测肠道组织中肠道紧密连接蛋白、炎症因子及凋亡相关蛋白的变化;粪便微生物菌群16S rDNA扩增子测序检测小鼠肠道微生物群多样性和丰度的改变情况。结果:与Cis组小鼠相比,MenSCs移植组小鼠体重显著增加,HE染色显示小肠及结肠组织炎性细胞浸润减少,肠绒毛水肿减轻,腺体排列较有序;Western blot结果显示MenSCs移植可显著上调Cis损伤后小鼠肠道组织中紧密连接蛋白ZO-1和occludin的表达(P<0.05)。随后,免疫组化染色和Western blot结果显示MenSCs移植可显著降低Cis损伤后小鼠肠道组织中巨噬细胞数量(P<0.01),下调肠道组织中促炎因子IL-1β和IL-6和促凋亡蛋白Bax的表达(P<0.01);同时显著上调肠道组织中抑炎因子IL-10和抗凋亡相关蛋白Bcl-2的表达(P<0.01)。进一步粪便微生物测序结果显示,MenSCs移植可改善Cis诱导的肠道菌群失调,显著降低有害微生物艾森伯格氏菌(Eisenbergiella tayi)和人结肠厌氧棍状菌(Anaerotruncus colihominis)的丰度(P<0.01),同时显著增加肠道中有益微生物乳杆菌(Lactobacillus apodemi)的丰度(P<0.05),有助于恢复健康肠道菌群结构和功能。结论:MenSCs移植能够减轻化疗药物造成的小鼠肠道屏障损伤,减轻化疗相关小鼠黏膜炎的症状,有助于恢复肠道菌群稳态。

AIM:To investigate the therapeutic effect of menstrual blood-derived endometrial stem cells(MenSCs)on chemotherapy-induced intestinal mucositis and flora disorders in mice,and to explore the potential mechanism.METHODS:The mice were randomly divided into 3 groups including normal treatment,cisplatin(Cis)treatment and Cis+MenSC treatment,with 10 mice in each group.To induce intestinal mucositis,the mice were treated with Cis(2 mg·kg^(−1)·d^(−1))by intraperitoneal injection for 5 consecutive days.Control mice for normal group were received equal vol-umes of normal saline.For Cis+MenSC treatment,MenSCs(1×106)was transplanted into the mice of Cis treated mice through tail vein.The performances and weight changes of mice were examined during the experiment.After the treat-ment,the small intestine and colon were isolated for subsequent HE staining,the ratio of F4/80 and IL-6 positive cells in small intestine were detected by immunohistochemical staining,and the expression of tight junction,inflammation and apoptosis related proteins was detected by Western blot.16S rDNA amplicon sequencing was performed to detect the diver-sity and richness of intestinal flora in mice.RESULTS:Compared to the Cis group,the MenSCs-treated mice showed sig-nificantly increased body weight,relieved intestinal lymphocytes infiltration,alleviated intestinal villous edema,and or-derly arranged glands in intestinal tissues.Further analysis indicated that MenSCs transplantation significantly up-regulat-ed the expression of intestinal tight junction related proteins ZO-1 and occludin in Cis-treated mice(P<0.05).Subse-quently,MenSCs transplantation significantly inhibited the macrophages infiltration in intestinal tissues(P<0.01),down-regulated the expression of pro-inflammatory factors IL-1 and IL-6 and pro-apoptotic protein Bax(P<0.01),while up-regu-lated anti-inflammatory factor IL-10 and anti-apoptotic protein Bcl-2(P<0.01).Additionally,further microflora sequenc-ing indicated that MenSCs transplantation prevented mice from Cis-induced intestinal flora disorder,and significantly re-duced the abundance of harmful bacteria such as isenbergiella tayi and Anaerotruncus colihominis(P<0.01).At the same time,the abundance of beneficial bacteria Lactobacillus apodemi was increased(P<0.05),thereby restoring the composi-tion and function of healthy intestinal flora.CONCLUSION:MenSCs transplantation alleviates the chemotherapy-in-duced damage of intestinal structure,relieves the symptoms of chemotherapy-induced mucositis and restores the homeosta-sis of intestinal flora in mice.