目的 通過咪喹莫特（IMQ）乳膏涂抹誘導(dǎo)產(chǎn)生銀屑病樣皮損的小鼠模型，觀察人源臍帶間充質(zhì)干細(xì)胞（hUC-MSCs）對(duì)其整體和局部作用效果。方法 C57BL/6小鼠隨機(jī)分為對(duì)照組、模型組和hUC-MSCs組，模型組和hUC-MSCs組每日定時(shí)在小鼠裸露背部涂抹5% IMQ乳膏62.5 mg，對(duì)照組涂抹凡士林。在開始涂抹前1天（0 d）和涂抹后的第6天，對(duì)照組和模型組sc 200 μL的生理鹽水，hUC-MSCs組每只小鼠sc 2×10⁶個(gè)hUC-MSCs。采用銀屑病樣皮損面積和疾病嚴(yán)重指數(shù)（PASI）評(píng)分標(biāo)準(zhǔn)觀察銀屑病樣小鼠模型皮損變化情況；通過HE染色觀察表皮層厚度，角質(zhì)層角化程度及炎性細(xì)胞浸潤程度；采集小鼠的靜脈血，試劑盒法檢測(cè)血清白細(xì)胞介素-6（IL-6）的濃度，評(píng)估小鼠炎癥反應(yīng)。結(jié)果 hUC-MSCs組與同期模型組比較，皮損癥狀輕，通過PASI積分趨勢(shì)圖可見，hUC-MSCs能延緩皮損出現(xiàn)，同時(shí)減緩皮損嚴(yán)重程度，加快皮損部分的恢復(fù)；HE染色顯示，hUC-MSCs組角化不全的細(xì)胞明顯減少，紅細(xì)胞外溢真皮層增生和炎性細(xì)胞浸潤程度明顯低于模型組，造模后6 d表皮層厚度顯著低于模型組（P<0.01）；hUC-MSCs組血清IL-6濃度在造模后的第12天顯著低于模型組。結(jié)論 銀屑病樣小鼠模型sc hUC-MSCs后能延緩銀屑病的發(fā)生，并減輕銀屑病癥狀，加快銀屑病樣皮損部分的恢復(fù)，可能通過調(diào)節(jié)IL-6發(fā)揮免疫調(diào)節(jié)作用。

Objective To observe the global and local effects of umbilical cord mesenchymal stem cells (UC-MSCs) on psoriasis-like lesions in mice induced by imiquimod (IMQ). Methods C57BL/6 mice were randomly divided into control group, model group and hUC-MSCs group. Umbilical cord mesenchymal stem cells of 2×10⁶ were sc before and 6 days after IMQ administration, and saline was sc to mice in control and model group. The skin lesions of psoriasis-like mice were observed by PASI score; the thickness of epidermis, the degree of keratinization and the infiltration of inflammatory cells were observed by HE staining; venous blood of mice was collected to detect the concentration of IL-6 to evaluate the inflammatory reaction of mice. Results Compared with the model group of the same period, the skin lesion symptom of hUC-MSCs injection group was lighter, the PASI score was lower than that of the model group at the same time. The number of dyskeratosis cells was significantly reduced, the degree of erythrocytic overflow, dermal hyperplasia and inflammatory cell infiltration in hUC-MSCs injection group was significantly lower than that in model group. The thickness of epidermis in the model group was significantly lower than that in the model group 6 days after modeling (P<0.01). IL-6 concentration was significantly lower than that in model group on the 12th day after IMQ treatment. Conclusion hUC-MSCs can delay the occurrence of psoriasis, relieve the symptoms of psoriasis and accelerate the recovery of psoriasis like lesions in psoriasis like mice, it may play an immunomodulatory role by regulating IL-6.

國家重點(diǎn)研發(fā)計(jì)劃“干細(xì)胞及轉(zhuǎn)化研究”重點(diǎn)專項(xiàng)（2019YFA0112100）；天津市科技計(jì)劃項(xiàng)目（17ZXXYSY00020）