LncRNA Tug1 involves in the pulmonary vascular remodeling in mice with hypoxic pulmonary hypertension via the microRNA-374c-mediated Foxc1.

Hypoxic pulmonary hypertension (HPH) is a serious and potentially devastating disorder of the pulmonary circulation with complicated mechanisms. Long non-coding RNA (lncRNA) has been revealed to participate in HPH development. This study aimed to explore how lncRNA Tug1 affected the pulmonary vascular remodeling in HPH. A mouse model of HPH and a pulmonary artery smooth muscle cell (PASMC) model of HPH (HPH-PASMCs) were established, where the expression of lncRNA Tug1 was determined. Then, the interaction among lncRNA Tug1, miR-374c, and Foxc1 was assessed. Finally, in order to determine the effects of lncRNA Tug1 on PASMC activities and pulmonary vascular remodeling after HPH, the expression of lncRNA Tug1 was silenced in HPH-PASMCs and HPH mice, with the proliferation, apoptosis, and migration of PASMCs as well as blood pressure in mice measured, respectively. The obtained data revealed that lncRNA Tug1 was highly expressed in HPH mice and HPH-PASMCs. In addition, lncRNA Tug1 up-regulated the expression of Foxc1 by binding to miR-374c. Notably, silencing of lncRNA Tug1 inhibited the proliferation and migration, but promoted the apoptosis of PASMCs. Moreover, lncRNA Tug1 silencing was observed to attenuate the pulmonary vascular remodeling in HPH mice through the Foxc1-mediated NOTCH signaling pathway. Taken conjointly, silencing of lncRNA Tug1 down-regulated the Foxc1 expression by binding to miR-374c, thereby inhibiting the proliferation and migration, while promoting apoptosis of PASMCs to impede pulmonary vascular remodeling in HPH via the Notch signaling pathway. This study provided novel therapeutic insights for treating HPH.