LAUSR

OBJECTIVE Intestinal acute graft-versus-host disease (aGVHD) is a serious complication of allogeneic hematopoietic stem cell transplantation (allo-HSCT). Abnormal autophagy levels in intestinal aGVHD have been confirmed in many studies. LncRNAs exert coregulatory functions and participate in a variety of intracellular regulatory processes. In this study, we investigated how lnc-AC145676.2.1-6-3 regulates dysregulated STX3-related autophagy in aGVHD. MATERIALS AND METHODS First, we established a mouse model of aGVHD by transplanting a mononuclear cell suspension from Balb/c donor mice treated with 60Co X-rays into CB6F1 recipient mice. STX3-related indicators were analyzed by Western blotting (WB) and immunohistochemistry which confirmed that STX3 plays an important role in dysregulating autophagy in intestinal aGVHD. TNF-αinduced Caco-2 cells, which is an in vitro model of intestinal barrier dysfunction, were established to verify the effect of STX3. The direct interaction between the partners of lnc-AC145676.2.1-6-3-mediated hsa-miR-1292-3p and STX3 axis was evaluated by the Dual-Luciferase activity assay. We performed PCR, WB, and immunofluorescence in Caco-2 cells to determine whether the abnormal autophagy levels were influenced by lnc-AC145676.2.1-6-3. RESULTS The results showed that lnc-AC145676.2.1-6-3 could significantly suppress the number of autophagic vacuoles, the LC3-II/I ratio, and beclin1 levels by increasing STX3 levels. CONCLUSIONS Lnc-AC145676.2.1-6-3 may play an important role in intestinal aGVHD by targeting STX3.