在江蘇省中醫藥管理局科研項目(批準號：YB2020088)、揚州市“綠揚金鳳”衛生創新領軍人才基金項目(批準號: YZLYJF2020WSCX037)等資助下，南京鼓樓醫院集團儀征醫院王小紅主任醫師團隊在紅景天苷治療重癥急性胰腺炎機制方面取得進展。研究成果以“紅景天苷通過調節 miR-217-5p/YAF2 軸減輕重癥急性胰腺炎觸發的胰腺損傷和炎癥(Salidroside alleviates severe acute pancreatitis- triggered pancreatic injury and inflammation by regulating miR-217-5p/YAF2 axis)”為題，于2022年8月10日在線發表于《國際免疫藥理學》(International Immuno- pharmacology)。文章鏈接：https://doi.org/10.1016/j.intimp.2022.109123
急性胰腺炎(Acute pancreatitis)是臨床常見的急腹癥之一，其以輕癥多見，病程呈自限性，其中10%～30%的患者會進展為重癥急性胰腺炎(Severe acute pancreatitis, SAP)。SAP病情進展快，病情危重，常并發多臟器功能不全綜合征，病死率高達20%～30%，給家庭和社會帶來沉重負擔。因此，探索SAP的發病機制，尋找有效的治療藥物及方法顯得尤為重要。
該團隊通過鑒定與紅景天苷相關的miRNA并探索了其潛在機制。該團隊通過建立SAP大鼠動物模型和miRNA微陣列，確定紅景天苷對miRNA表達譜的影響，并通過實時定量PCR驗證它們的變化。該團隊觀察到，在這些miRNA中，經紅景天苷處理后miR-217-5p顯著下調。miR-217-5p過表達可以通過直接靶向 YY1相關因子2 (YAF2)的3'UTR來逆轉由紅景天苷介導抑制的免疫反應。
該研究揭示了紅景天苷通過調節炎癥反應發揮對SAP的保護作用，而在調節炎癥反應的機制中涉及了miR-217-5p。此外，抑制miR-217-5p可通過靶向YAF2的3'UTR 促進YAF2表達，隨后激活p38 MAPK 通路。(見Figure1, 2, 3, 4)
該研究結果為紅景天苷治療SAP的作用機制提出了新的見解，并有助于制定SAP的有效治療策略。
Figure 1 Overexpression of miR-217-5p aggravated cell injury and promoted pro-inflammatory cytokine production. (A) The overexpression efficiency of miR-217-5p mimics was confirmed by qRT-PCR. (B) The effect of miR-217-5p overexpression on cell viability was evaluated by CCK-8 assay. (C-D) The effects of miR-217-5p overexpression on activities of amylase (C) and lipase (D) were detected by automatic biochemical analysis. (E-H) The levels of pro-inflammatory cytokines TNF-α (E), IL? 1β (F), IL-6 (G) and IL-8 (H) from cultured cell medium were determined by ELISA kits according to instructions of the manufacturer. (I-K) Pearson’s correlation analysis was performed to analyze the association between miR-217-5p expression and pancreatic injury score (I), serum amylase activities (J) and serum lipase activities (K). For B-H, *P<0.05, **P<0.01 compared with SAP group, #P<0.05, ##P<0.01 compared with miRNA negative control group.
Figure 2 miR-217-5p directly targeted the 3’UTR of YAF2. (A) Relative expression levels of 26 candidate target genes for miR-217-5p were detected by qRT-PCR in AR42J cells after transfected with miR-217-5p mimics or miRNA negative control. (B) The binding position and complementary sequences of miR-217-5p in the 3’UTR of YAF2, which was predicted by TargetScan. (C) The wt- and mut-YAF2 3’UTR sequences for miR-217-5p. (D) Luciferase reporter constructs containing wt- and mut-YAF2 3’UTR were co-transfected with miR-217-5p mimics or miRNA negative control into AR42J cells. After 48h transfection, the luciferase activities were measured. (E) Relative level of YAF2 recruited by Bio-miR-217-5p or Bio-miRNA-NC probes were measured by miRNA pull-down assay. **P<0.01.
Figure 3 Sal upregulated YAF2 expression via downregulating miR-217-5p. (A-C) The mRNA (A) and protein (B-C) levels of YAF2 in SAP rat pancreatic tissues were determined by qRT-PCR and Western blot, respectively. (D-F) The mRNA (D) and protein (E-F) levels of YAF2 in AR42J cells were determined by qRT-PCR and Western blot, respectively. **P<0.01 compared with sham group, #P<0.05, ##P<0.01 compared with SAP group.
Figure 4 Knockdown of YAF2 reversed Sal induced alleviation of cell injury and inflammation in a YAF2-dependent manner and involving in p38 MAPK pathway. (A) siRNA specific for YAF2 was transfected into AR42J cells and the knockdown efficiency was validated by qRT-PCR. (B) Cell viability was detected by CCK-8 assay. (C-D) The effects of YAF2 knockdown on activities of amylase (C) and lipase (D) were determined by automatic biochemical analysis. (E-H) The effects of YAF2 knockdown on the pro-inflammatory cytokines TNF-α (E), IL? 1β (F), IL-6 (G) and IL-8 (H) were determined by ELISA kits. (I) Western blot was performed to detect the expression levels of p38 and p-p38 in AR42J cells after different treatment. (J-K) Quantitative analysis of p-p38 (J) and p38 (K) from 7I. For A, **P<0.01 compared with siRNA negative control. For B-K, *P<0.05, **P<0.01 compared with SAP group, #P<0.05, ##P<0.01 compared with miRNA or siRNA negative control group.