Abstract
Combined radiation-wound injury (CRWI) is characterized by blood vessel damage and pro-inflammatory cytokine deficiency. Studies have identified that the direct application of leptin plays a significant role in angiogenesis and inflammation. We established a sustained and stable leptin expression system to study the mechanism. A lentivirus method was employed to explore the angiogenic potential and peripheral inflammation of irradiated human umbilical vein endothelial cells (HUVECs). Leptin was transfected into human placenta-derived mesenchymal stem cells (HPMSCs) with lentiviral vectors. HUVECs were irradiated by X-ray at a single dose of 20 Gy. Transwell migration assay was performed to assess the migration of irradiated HUVECs. Based on the Transwell systems, co-culture systems of HPMSCs and irradiated HUVECs were established. Cell proliferation was measured by cell counting kit-8 (CCK-8) assay. The secretion of pro-inflammatory cytokines (human granulocyte macrophage-colony stimulating factor (GM-CSF), interleukin (IL)-1α, IL-6, and IL-8) was detected by enzyme-linked immunosorbent assay (ELISA). The expression of pro-angiogenic factors (vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF)) mRNA was detected by real-time quantitative polymerase chain reaction (RT-qPCR) assay. Relevant molecules of the nuclear factor-κB (NF-κB) and Janus kinase (JAK)/signal transducer and activator of transcription (STAT) signaling pathways were detected by western blot assay. Results showed that leptin-modified HPMSCs (HPMSCs/ leptin) exhibited better cell proliferation, migration, and angiogenic potential (expressed more VEGF and bFGF). In both the single HPMSCs/leptin and the co-culture systems of HPMSCs/leptin and irradiated HUVECs, the increased secretion of pro-inflammatory cytokines (human GM-CSF, IL-1α, and IL-6) was associated with the interaction of the NF-κB and JAK/STAT signaling pathways. We conclude that HPMSCs/leptin could promote angiogenic potential and peripheral inflammation of HUVECs after X-ray radiation.