Abstract： Stem cell paracrine has been considered as the main mechanism to promote infarcted myocardium regeneration and repair of damaged cardiomyocytes. With further research, secreted frizzled-related protein 2 （Sfrp 2） and stem cell paracrine are closely linked to each other. Sfrp 2 can competitively bind to the specific receptor Fz in Wnt signaling pathway, inhibit Wnt signaling pathway to regulates apoptosis, differentiation, and other life processes of stem cells, and therefore becomes a research hotspot in recent years. This review focuses on the mechanism of Sfrp 2/Wnt signal way in stem cell therapy for myocardial infarction.
Objective To explore the induction of cardiomyogenesis of microRNA-129 （mir-129） in rat bone marrowmesenchymal stem cells （BM-MSCs） and its mechanism. Methods BM-MSCs were isolated from Sprague-Dawley rats and cultured in vitro. Overexpression of mir-129 or both mir-129 and glycogen synthase kinase-3β （GSK-3β） in BM-MSCs was produced with a lentiviral vector system. All the BM-MSCs were divided into four groups: control group （MSCs），Lentiviral vectors＋MSCs group （Lv-MSCs），mir-129 transfection group （mir-129-MSCs），and mir-129＋GSK-3βdouble transfection group （mir-129＋GSK-3β-MSCs）. Five-Azacytidine （5-Aza） （10 μmol/L） was used to induce BM-MSCsdifferentiation into cardiomyocytes. On the 1st，5 th，10 th，15 th and 20 th day after induction，realtime-PCR was performedto detect mRNA levels of GATA-4，Nkx2.5 and MEF-2C. On the 10 th，15 th and 20 th day after induction，Western blottingwas performed to examine expression levels of cTnI，Desmin，GSK-3β，phosphorylated β-catenin and dephosphorylated β-catenin. Results Compared with the control group，at respective time points，mRNA levels of cardiomyogenic genes and expression levels of cardiomyocyte-related proteins of mir-129 transfection group were significantly elevated，theexpression level of GSK-3β was significantly decreased，and the ratio of dephosphorylated/phosphorylated β-catenin was significantly elevated. When both mir-129 and GSK-3β were overexpressed in BM-MSCs，mRNA levels of cardiomyogenicgenes and expression levels of cardiomyocyte-related proteins were significantly lower than those of mir-129 transfection group，and the ratio of dephosphorylated/phosphorylated β-catenin was significantly decreased. Conclusion Overexpression of mir-129 can promote cardiomyogenesis of rat BM-MSCs possibly via inhibiting GSK-3β production and thus decreasing the inhibition of phosphorylation of β-catenin which then enters the nucleus and activates downstream signaling pathways that regulate cardiomyogenic differentiation of BM-MSCs.
Interventional micro-axial flow blood pump is widely used as an effective treatment for patients with cardiogenic shock. Hemolysis and coagulation are vital concerns in the clinical application of interventional micro-axial flow pumps. This paper reviewed hemolysis and coagulation models for micro-axial flow blood pumps. Firstly, the structural characteristics of commercial interventional micro-axial flow blood pumps and issues related to clinical applications were introduced. Then the basic mechanisms of hemolysis and coagulation were used to study the factors affecting erythrocyte damage and platelet activation in interventional micro-axial flow blood pumps, focusing on the current models of hemolysis and coagulation on different scales (macroscopic, mesoscopic, and microscopic). Since models at different scales have different perspectives on the study of hemolysis and coagulation, a comprehensive analysis combined with multi-scale models is required to fully consider the influence of complex factors of interventional pumps on hemolysis and coagulation.
ObjectiveTo analyze the risk factors of the death associated with infective endocarditis, and to evaluate the timing of surgical treatment of infective endocarditis. MethodsWe retrospectively analyzed the clinical data of 62 patients with infective endocarditis in our hospital between August 2015 and August 2017. There were 43 males and 19 females at age of 19–75 (46.1±16.6) years. The clinical data were divided into a death group and a survival group, a paravalvular leakage group and a no periannular leakage group, an emergency operation group and a non-emergency operation group.The risk factors of infective endocarditis and the choice of operation time were analyzed. ResultsThree of the 62 patients (4.8%) died after surgery. Postoperative perivalvular leakage (regurgitation over 2 mm) in 8 patients, accounting for 12.9% of the total. Univariate analysis showed that albumin content, creatinine level, total cardiopulmonary bypass time and ascending aorta occlusion time were significantly associated with early postoperative mortality (P<0.05). The results of logistic analysis showed that age, preoperative albumin level, creatinine level, total cardiopulmonary bypass time, and ascending aorta occlusion time were significantly associated with early postoperative perivascular leakage (P<0.05), and long ascending aorta occlusion time is an independent risk factor for early death (P<0.05). There was no statistical difference in early death and the perivalve leakage between the emergency operation and the non emergency operation. ConclusionPatients with infective endocarditis should accept early surgical treatment. The choice of surgical approach should be selected according to the actual situation of patients. And we should pay more attention to albumin and creatinine levels in preoperative patients. In the operation, to shorten extracorporeal circulation time and aortic clamping time can improve the prognosis of patients.