Background The mesenchymal stem cells (MSCs) were used to repair tissue injury. However, the treatment effect was not satisfactory. We investigated whether lncRNA MIR155HG could promote survival and migration of MSCs under oxidative stress, which mimics in vivo environments. Furthermore, we studied the protective effect of exosomes secreted by MSCs transfected with MIR155HG on endothelial cells. This study aimed to determine whether exploiting MSCs and exosomes modified with lncRNA MIR155HG would exert synergistic therapeutic effect to attenuate vein graft intimal hyperplasia more effectively. Methods Lentivirus containing lncRNA MIR155HG overexpressing vector was packaged and used to infect MSCs. Then, CCK-8 assay, flow cytometry, Transwell assay, and Elisa assay were used to assess the functional changes of MSCs with overexpressed MIR155HG (OE-MSCs). Furthermore, the associated pathways were screened by Western blot. MIR155HG-MSCs-derived exosomes (OE-exo) were collected and co-cultured with human umbilicus vein endothelial cell (HUVEC). We validated the protective effect of OE-exo on HUVEC. In vivo, both MSCs and exosomes modified with MIR155HG were injected into a vein graft rat model via tail vein. We observed MSCs homing and intimal hyperplasia of vein graft using a fluorescent microscope and histological stain. Results Our study found that lncRNA MIR155HG promoted proliferation, migration, and anti-apoptosis of MSCs. NF-κB pathway took part in the regulation process induced by MIR155HG. OE-exo could enhance the activity and healing ability of HUVEC and reduce apoptosis. In vivo, OE-MSCs had a higher rate of homing to vascular endothelium. The combined treatment with OE-MSCs and OE-exo protected vascular endothelial integrity, reduced inflammatory cell proliferation, and significantly attenuated intimal hyperplasia of vein graft. Conclusion LncRNA MIR155HG could promote the survival and activity of MSCs, and reduce the apoptosis of HUVECs using exosome delivery. Exploiting MSCs and exosomes modified with MIR155HG could attenuate vein graft intimal hyperplasia more effectively and maximize the surgical effect.

Background Left atrial appendage occlusion (LAAO) is an alternative to oral anticoagulation (OAC) to decrease the risk of stroke in patients with nonvalvular atrial fibrillation (NVAF); however, certain complications remain a concern. Amplatzer Amulet and Watchman are the two most popular used devices for preventing stroke in patients with NVAF. We assessed the safety and efficacy of LAAO using the Amplatzer Amulet and Watchman. Methods A meta‐analysis was conducted to compare the safety and efficacy outcomes associated with the use of the Amplatzer Amulet and Watchman 2.5. The Newcastle‐Ottawa Scale has been utilized to assess the quality of study. Results The meta‐analysis includes seven studies involving 2926 patients (1418 patients with an amulet and 1508 with a Watchman 2.5). Generally, adverse event rates for both systems were minimal. No significant differences between the two devices were found in safety (pericardial effusion, device embolization, and cardiac tamponade) or efficacy outcomes (death, TIA, stroke, major/minor bleeding, device leak, and thromboembolic events). Conclusions The data suggest LAAO is a safe procedure, regardless of which device was used. LAAO devices generally have low complication rates. Outcomes were comparable between the two groups with no significant differences in their safety or efficacy.