目的·探究miR-128-3p/瘦素（leptin，LEP）轴对银屑病中角质形成细胞过度增殖及炎症反应的调控作用。方法·选取BALB/c小鼠，分为对照组（n=10）及模型组（n=10）。模型组小鼠背部行咪喹莫特软膏连续涂抹以构建银屑病小鼠模型。构建miR-128-3p过表达和干扰质粒、LEP干扰质粒分别转染人永生化角质形成细胞HaCaT细胞。经实时定量聚合酶链反应检测miR-128-3p及LEP的mRNA，Western blotting检测LEP蛋白表达；酶联免疫吸附实验检测培养液中肿瘤坏死因子α（tumor necrosis factor α，TNF-α）、白细胞介素-6（interleukin-6，IL-6）、IL-1β的含量；MTT实验检测细胞相对活力；EdU实验检测细胞增殖；采用双荧光素酶报告基因实验验证miR-128-3p与LEP的靶向关系。结果·与对照组小鼠比，模型组小鼠miR-128-3p表达下调，Lep的基因表达及蛋白水平升高（均P<0.05）。双荧光素酶报告基因实验证实LEP是miR-128-3p下游靶点。与模拟物阴性对照（negative control of mimic，NC mimic）组相比，miR-128-3p模拟物（miR-128-3p mimic）组miR-128-3p表达上调，LEP的基因表达及蛋白降低；miR-128-3p mimic组TNF-α、IL-6、IL-1β显著低于NC mimic；miR-128-3p上调后细胞相对活力、EdU阳性细胞率均降低（均P<0.05）。与抑制物阴性对照（negative control of inhibitor，NC inhibitor）组相比，miR-128-3p抑制物（miR-128-3p inhibitor）组miR-128-3p表达下调，LEP的基因表达及蛋白水平增加；miR-128-3p下调后细胞TNF-α、IL-6、IL-1β升高；miR-128-3p表达下调导致细胞相对活力和EdU阳性细胞率增加（均P<0.05）。进一步实验结果显示：与LEP抑制物（LEP inhibitor）组相比，miR-128-3pinhibitor+ LEP inhibitor组LEP表达上调，而TNF-α、IL-6、IL-1β水平升高，细胞相对活力及EdU阳性细胞率增加（均P<0.05）。结论·miR-128-3p靶向沉默LEP抑制角质形成细胞增殖及炎症反应，抑制银屑病发生发展。

Objective ·To explore the role of miR-128-3p/leptin (LEP) axis in the proliferation and inflammation of keratinocytes in psoriasis. Methods ·BALB/c mice were randomly divided into a control group (n=10) and a model group (n=10). Mice in the model group were given imiquimod on the back. miR-128-3p overexpression and interference plasmids, as well as LEP interference plasmids, were constructed and transfected into HaCaT cells, respectively. miR-128-3p and LEP mRNA were quantified by real-time quantitative polymerase chain reaction, and LEPprotein levels were detected by using Western blotting. Enzyme-linked immunosorbent assay was used to measure the content of tumor necrosis factor α (TNF-α), interleukin-6 (IL-6), and interleukin-1β (IL-1β) in the culture medium. MTT assay was used to evaluate cell activity and EdU assay was to used to test cell proliferation. The binding site between miR-128-3p and LEP was determined by using a dual luciferase reporter gene assay. Results ·Compared with mice in the control group, mice in the model group showed downregulated expression of miR-128-3p and upregulated expression of LEP at both RNA and protein levels (all P<0.05). The dual luciferase reporter gene assay confirmed that LEP was a downstream target of miR-128-3p. Compared with the negative control mimic (NC mimic) group, expression of miR-128-3p was up-regulated in the miR-128-3p mimic group, and expression of LEP was reduced. The levles of TNF-α, IL-6, and IL-1β were significantly lower in the miR-128-3p mimic group than in the NC mimic group. The relative cell viability and EdU-positive cell rate were also reduced after miR-128-3p up-regulation (all P<0.05). Compared with the negative control inhibitor (NC inhibitor) group, expression of miR-128-3p was down-regulated in the miR-128-3p inhibitor group, and expression of LEP was increased. The levles of TNF-α, IL-1β and IL-6 were increased after miR-128-3pdownregulation. miR-128-3p down-regulation led to an increase in relative cell viability and EdU-positive cell rate (all P<0.05). Further experimental results showed that LEP expression was up-regulated in the miR-128-3p inhibitor+LEP inhibitor group compared with that in the LEP inhibitor group, whereas the levels of TNF-α, IL-6, and IL-1β were elevated, and the relative viability of the cells and the rate of EdU-positive cells were increased (all P<0.05). Conclusion ·miR-128-3p downregulates LEP to inhibit the proliferation and inflammatory response of keratinocytes, thereby inhibiting the occurrence and development of psoriasis.