Hypoxic Preconditioning Enhances Cellular Viability and Migratory Ability: Role of DANCR/miR-656-3p/HIF-1α Axis in Placental Mesenchymal Stem Cells.

Preeclampsia (PE) is a common complication of pregnancy characterized by new-onset hypertension, albuminuria, or end-stage organ dysfunction, which is seriously harmful to maternal and infant health. Mesenchymal stem cells (MSCs) are pluripotent stem cells derived from extraembryonic mesoderm. They have the potential for self-renewal, multidirectional differentiation, immunomodulation, and tissue regeneration. Several in vivo and in vitro experiments have confirmed that MSCs can delay the pathological progression of PE and improve maternal and fetal outcomes. However, the major limitations in the application of MSCs are their low-survival rates in ischemic and hypoxic disease areas after transplantation and their low rate of successful migration to the diseased regions. Therefore, enhancing cell viability and migration ability of MSCs in both ischemic and anoxic environments is important. This study aimed to investigate the effects of hypoxic preconditioning on the viability and migration ability of placental mesenchymal stem cells (PMSCs) and their underlying mechanisms. In this study, we found that hypoxic preconditioning enhanced the viability and migration ability of PMSCs, increased the expression of DANCR and hypoxia-inducible factor-1α (HIF-1α), and decreased the expression of miR-656-3p in PMSCs. Inhibiting the expression of HIF-1α and DACNR in PMSCs under hypoxia can inhibit the promotive effect of hypoxic preconditioning on viability and migration ability. In addition, RNA pull down and double luciferase assays confirmed that miR-656-3p could directly bind to DANCR and HIF-1α. In conclusion, our study showed that hypoxia could promote the viability and migration ability of PMSCs through the DANCR/miR-656-3p/HIF-1α axis.

Enhanced MR features of central chronic pulmonary artery thromboembolism and the clinical application value / 中华放射学杂志

Objective:To explore the relationship between the imaging features of enhanced MRI in patients with central chronic pulmonary artery thromboembolism (CPTE) and pulmonary vascular resistance (PVR).Methods:Thirty-nine patients with CPTE who had contrast-enhanced MRI examination were retrospectively enrolled this study from January 2018 to December 2020. And 33 patients who received right heart catheterization were divided into two groups based on PVR=1 000 dyn·s·cm -5. The differences of imaging features of CPTE in enhanced MRI between the two groups were compared. The relationship between gender, duration of disease, age, pleural thickening, bilateral bronchial artery dilation, number of the involved vascular segments, number of thrombosis, number of the thrombus-related delayed enhancement of artery wall and PVR was analyzed by binary logistic regression. Results:In 39 patients with central CPTE, the dilated lumen (168, 43.30%) and delayed enhancement of wall (122, 31.52%) were found in most of pulmonary arteries. The rate of the lumen dilatation associated with thrombus was the highest among that of the lumen abnormality (66, 52.80%). There were more thrombi in PVR<1 000 dyn·s·cm -5 group than those in PVR≥1 000 dyn·s·cm -5 group (χ 2=9.55, P=0.002). There was no significant difference in the incidence of wall delayed enhancement associated the thrombus between the two groups (χ 2=0.90, P=0.344). The incidence of bilateral bronchial arterial dilatation in PVR<1 000 dyn·s·cm -5 group was higher than that in PVR≥1 000 dyn·s·cm -5 group ( P=0.019). Logistic regression analysis showed that female, the less number of involved vascular segments and bilateral bronchial artery dilation were correlated with the lower PVR. Conclusions:Enhanced MRI is helpful to accurately evaluate the lumen abnormality of pulmonary artery and wall remodeling in central CPTE, which is of great value for the assessment of patients′ conditions and treatment effect.