目的 对比皮下注射与静脉注射人脐带间充质干细胞（human umbilical cord mesenchymal stem cells， hUC-MSCs）对咪喹莫特诱导银屑病小鼠模型皮损、脾脏免疫指标、病理改变及关键炎症因子的影响，为临床给药方式选择提供实验依据。 方法 选取SPF级C57BL/6J雄性小鼠35只，随机分为7组（n = 5）：空白对照组、静脉注射PBS组、皮下注射PBS组、皮下注射hUC-MSCs组、静脉注射hUC-MSCs组、皮下hUC-MSCs 联合大黄外用组、单纯大黄外用组。采用5%咪喹莫特乳膏连续涂抹背部6 d建立银屑病小鼠模型，于造模第2、4天给予相应干预。观察并记录小鼠皮损变化，进行银屑病面积与严重程度指数（psoriasis area and severity index， PASI）评分；称量脾脏重量计算脾脏指数；HE染色观察皮肤组织病理改变；酶联免疫吸附测定（ELISA）法检测血清及皮肤组织中白细胞介素-17A（IL-17A）、白细胞介素-23（IL-23）、肿瘤坏死因子-α（TNF-α）水平。 结果 各组PASI评分、皮损厚度、脾脏重量、脾脏指数差异均有显著统计学意义（P 0.01），皮下及静脉注射hUC-MSCs可下调血清与皮肤组织中IL-17A、IL-23、TNF-α水平（P 0.05）；静脉注射hUC-MSCs在皮损改善、全身免疫调节、炎症抑制方面优于皮下注射；皮下注射hUC-MSCs联合大黄外用总体疗效优于皮下注射hUC-MSCs单用（P 0.05）。 结论 hUC-MSCs可有效改善咪喹莫特诱导的小鼠银屑病样皮损、局部及全身炎症反应，静脉注射整体疗效优于皮下注射，皮下注射联合大黄外用具有增效作用。

Objective To compare the effects of subcutaneous injection and intravenous injection of human Umbilical Cord Mesenchymal Stem Cells （hUC-MSCs） on skin lesions， splenic immune indexes， pathological changes， and key inflammatory factors in imiquimod-induced psoriasis mice， aiming to provide experimental evidence for clinical administration selection. Methods 35 specific-pathogen-free （SPF） C57BL/6J male mice were randomly divided into 7 groups （n = 5）： a blank control group， an intravenous phosphate-buffered saline （PBS） group， a subcutaneous PBS group， a subcutaneous hUC-MSCs group， an intravenous hUC-MSCs group， a subcutaneous hUC-MSCs combined with topical rhubarb group， and a topical rhubarb alone group. A psoriasis mouse model was established by applying 5% imiquimod cream on the back for 6 consecutive days. Corresponding interventions were administered on the 2nd and 4th days of modeling. Skin lesion changes were observed and scored using the Psoriasis Area and Severity Index （PASI）. Spleen weight was measured to calculate the spleen index. Skin histopathological changes were observed through hematoxylin and eosin （HE） staining. The levels of interleukin-17A （IL-17A）， interleukin-23 （IL-23）， and tumor necrosis factor-α （TNF-α） in serum and skin tissue were detected by enzyme-linked immunosorbent assay （ELISA）. Results There were highly significant differences in PASI scores， skin lesion thickness， spleen weight， and spleen index among all groups （P 0.01）. Both subcutaneous and intravenous administration of hUC-MSCs downregulated the levels of IL-17A， IL-23， and TNF-α in serum and skin tissue （P 0.05）. Intravenous injection of hUC-MSCs was more effective than subcutaneous injection in improving skin lesions， regulating the systemic immune system， and inhibiting inflammation. The overall efficacy of subcutaneous hUC-MSCs combined with topical rhubarb was superior to that of subcutaneous hUC-MSCs alone （P 0.05）. Conclusions hUC-MSCs can effectively alleviate psoriasis-like skin lesions， as well as local and systemic inflammatory responses in mice induced by imiquimod. Intravenous injection exhibits better overall efficacy compared to subcutaneous injection. Moreover， subcutaneous hUC-MSCs combined with topical rhubarb have a synergistic effect.