Rheumatoid arthritis （RA） is an autoimmune disease characterized by chronic synovial inflammation and joint destruction， with a complex pathogenesis. Macrophage polarization plays a pivotal role in disease progression. Recent studies demonstrate that microRNA （miRNA）， as critical post-transcriptional regulators， can participate in the inflammatory response process by regulating the polarization state of macrophages， thereby aggravating RA joint damage. This review summarizes the mechanism of action of various miRNA in regulating macrophage polarization， and emphasizes their potential therapeutic value in RA.

Objective To study the optimal timing of preoperative injection of indocyanine green in laparoscopic liver tumor resection under indocyanine green fluorescent navigation to obtain the most satisfactory fluorescence imaging effects.Methods 60 patients with liver tumors who underwent laparoscopic hepatectomy from April 2017 to October 2018 were retrospectively studied on the intraoperative fluorescence imaging effects.A simple grading of the fluorescence imaging effects was developed.The ICG R15 and preoperative injection times of ICG were correlated with the intraoperative fluorescence imaging effects.Results Of 60 patients with liver tumors,59 patients underwent laparoscopic liver resection and one patient was converted to open surgery.The overall satisfaction rate of intraoperative fluorescence imaging was 73.4％ (44/60).In the patients with an ICG R15 rate ≤ 7％,it was easier to obtain good fluorescence imagings when the preoperative administration time was longer than 48 hours.Even when the preoperative administration time was longer than 5 days,satisfactory fluorescence imaging effect could still be obtained in these patients.In the patients with an ICG R15 rate ＞ 7％,intraoperative fluorescence imagings were unsatisfactory when the administration time was less than 6 days.Relative better imagings were obtained in these patients when the preoperative administration time was more than 6 days.Conclusions When the pre-operative ICG injection dose was not changed,the preoperative administration time should be adjusted according to the value of the ICG R15 to obtain better intraoperative fluorescence imaging effects of the liver tumors.The optimal timing needs to be further studied by a large case study.