RESUMO
Pulmonary hypertension (PH) is a progressive cardiopulmonary disorder characterized by pulmonary vascular remodeling (PVR), primarily due to the excessive proliferation of pulmonary artery smooth muscle cells (PASMCs). This study aimed to investigate the role and molecular mechanism of SOX9 in hypoxic PH in rats. The findings revealed that SOX9 was upregulated in the pulmonary arteries and PASMCs of hypoxia-exposed rats. SOX9 knockdown inhibited hypoxia-induced proliferation and migration of PASMCs, reduced PVR, and subsequently alleviated hypoxia-induced PH in rats, suggesting that SOX9 plays a critical role in PH. Further investigation demonstrated that SOX9 interacted with DPP4, preventing its ubiquitin degradation in hypoxia-exposed PASMCs. DPP4 knockdown inhibited hypoxia-induced PASMC proliferation and migration, and administration of the DPP4 inhibitor sitagliptin (5 mg/kg) significantly reduced PVR and alleviated hypoxia-induced PH in rats, indicating that SOX9 contributes to PH by stabilizing DPP4. The results also showed that hypoxia induced YAP1 expression and dephosphorylation, leading to YAP1 nuclear localization. YAP1 knockdown promoted the degradation of HIF-1α in hypoxia-exposed PASMCs and inhibited hypoxia-induced proliferation and migration of PASMCs. Additionally, HIF-1α, as a transcription factor, promoted SOX9 expression by binding to the SOX9 promoter in hypoxia-exposed PASMCs. In conclusion, hypoxia promotes the proliferation and migration of PASMCs through the regulation of the YAP1/HIF-1α/SOX9/DPP4 signaling pathway, leading to PH in rats. These findings suggest that SOX9 may serve as a potential prognostic marker and therapeutic target for PH.
RESUMO
Multisystem inflammatory syndrome in children (MIS-C) is a type of hyperinflammatory symptoms similar to Kawasaki disease after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and is commonly observed in children aged 8-10 years. Primary therapeutic medications for MIS-C are intravenous immunoglobulins and glucocorticoids. It has been reported that biologics, such as IL-1 receptor antagonist anakinra, IL-6 receptor antagonist tocilizumab, and TNF-α receptor antagonist infliximab, can be used as an option for critically ill patients. This article elaborates on the mechanism of action of the above biologics and discusses the efficacy and safety biologics in the treatment of MIS-C after SARS-CoV-2 infection, in order to provide methods for the treatment of MIS-C with severe symptoms.
