Background: Pulmonary arterial hypertension (PAH) is associated with oxidative stress and affects the survival and homing of transplanted mesenchymal stem cells (MSCs) as well as cytokine secretion by the MSCs, thereby altering their therapeutic potential. In this study, we preconditioned the MSCs with prostaglandin E1 (PGE1) and performed in vitro and in vivo cell experiments to evaluate the therapeutic effects of MSCs in rats with PAH. Methods: We studied the relationship between PGE1 and vascular endothelial growth factor (VEGF) secretion, B-cell lymphoma 2 (Bcl-2) expression, and C-X-C chemokine receptor 4 (CXCR4) expression in MSCs and MSC apoptosis as well as migration through the hypoxia-inducible factor (HIF) pathway in vitro. The experimental rats were randomly divided into five groups: (I) control group, (II) monocrotaline (MCT) group, (III) MCT + non-preconditioned (Non-PC) MSC group, (IV) MCT + PGE1-preconditioned (PGE1-PC) MSC group, and (V) MCT^{+PGE1+YC-1-PC}MSC group. We studied methane dicarboxylic aldehyde (MDA) levels, MSC homing to rat lungs, mean pulmonary artery pressure, pulmonary artery systolic pressure, right ventricular hypertrophy index, wall thickness index (%WT), and relative wall area index (%WA) of rat pulmonary arterioles. Results: Preconditioning with PGE1 increased the protein levels of HIF-1 alpha (HIF-1α) in MSCs, which can reduce MSC apoptosis and increase the protein levels of CXCR4, MSC migration, and vascular endothelial growth factor secretion. Upon injection with ^PGE1-PCMSCs, the pulmonary artery systolic pressure, mean pulmonary artery pressure, right ventricular hypertrophy index, %WT, and %WA decreased in rats with PAH. ^PGE1-PCMSCs exhibited better therapeutic effects than ^non-PCMSCs. Interestingly, lificiguat (YC-1), an inhibitor of the HIF pathway, blocked the effects of PGE1 preconditioning. Conclusions: Our findings indicate that PGE1 modulates the properties of MSCs by regulating the HIF pathway, providing insights into the mechanism by which PGE1 preconditioning can be used to improve the therapeutic potential of MSCs in PAH.

Background: Sun’s procedure is currently recognized as the standard procedure for acute type A aortic dissection (AAAD). But the operation istoo difficult for beginners. We hope to reduce the difficulty and complications of this operation. Methods: The aortic arch was immediately cross-clamped after the stented graft was inserted into the distal aorta. Thereafter, the lower-body perfusion was restored. Then, anastomosis was performed between the proximal stent graft and the distal 4-branched Dacron graft. The other arteries were anastomosed to the arched branch of the 4-branched graft. Results: The cardiopulmonary bypass (CPB) time was (207 ± 52) min, and the aortic cross-clamp time was (114 ± 39) min. The circulatory arrest time was (38 ± 16) sec. One patient (4%) died. The incidence of complications was stroke (4%), renal dysfunction requiring dialysis (4%), prolonged intubation(12%). Conclusions: The time of circulatory arrest in this operation is less than 1 min, which can avoid the complications caused by DHCA and decrease risk of bleeding and complexity by shifting anastomosis more proximally. The effect of our operation is similar to and even better than that of Sun’s procedure. It does not even require relatively advanced skill, much experience and excellent psychological quality, especially suitable for beginners.