Optimal time for mesenchymal stem cell transplantation in rats with myocardial infarction

Background:Bone marrow mesenchymal stem cell (MSC) transplantation is a promising strategy in the treatment of myocardial infarction (MI). However, the time for transplanting cells remains controversial. The aim of this study was to find an optimal time point for cell transplantation. Methods: MSCs were isolated and cultured from Sprague-Dawley (SD) rats. MI model was set up in SD rats by permanent ligation of left anterior descending coronary artery. MSCs were directly injected into the infarct border zone at 1 h, 1 week and 2 weeks after MI, respectively. Sham-operated and MI control groups received equal volume of phosphate buffered saline (PBS). At 4 weeks after MI, cardiac function was assessed by echocardiography; vessel density was analyzed on hematoxylin-eosin stained slides by light microscopy; the apoptosis of cardiomyocytes was evaluated by terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) assay; the expressions of proteins were analyzed by Western blot. Results: MSC transplantation improved cardiac function, reduced the apoptosis of cardiomyocytes and increased vessel density. These benefits were more obvious in 1-week group than in 1-h and 2-week groups. There are more obvious in-creases in the ratio of bcl-2/bax and the expression of vascular endothelial growth factor (VEGF) and more obvious decreases in the expression of cleaved-caspase-3 in 1-week group than those in other two groups. Conclusion: MSC transplantation was beneficial for the recovery of cardiac function. MSC transplantation at 1 week post-MI exerted the best effects on increases of cardiac function, anti-apoptosis and angiogenesis.

Heat shock protein 90 protects rat mesenchymal stem cells against hypoxia and serum deprivation-induced apoptosis via the PI3K/Akt and ERK1/2 pathways

Mesenchymal stem cell(MSC) transplantation has shown a therapeutic potential to repair the ischemic and infracted myocardium,but the effects are limited by the apoptosis and loss of donor cells in host cardiac microenvironment.The aim of this study is to explore the cytoprotection of heat shock protein 90(Hsp90) against hypoxia and serum deprivation-induced apoptosis and the possible mechanisms in rat MSCs.Cell viability was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT) assay.Apoptosis was assessed by Hoechst 33258 nuclear staining and flow cytometric analysis with annexin V/PI staining.The gene expression of Toll-like receptor-4(TLR-4) and V-erb-b2 erythroblastic leukemia viral oncogene homolog 2(ErbB2) was detected by real-time polymerase chain reaction(PCR).The protein levels of cleaved caspase-3,Bcl-2,Bcl-xL,Bax,total-ERK,phospho-ERK,total-Akt,phospho-Akt,and Hsp90 were detected by Western blot.The production of nitric oxide was measured by spectrophotometric assay.Hsp90 improves MSC viability and protects MSCs against apoptosis induced by serum deprivation and hypoxia.The protective role of Hsp90 not only elevates Bcl-2/Bax and Bcl-xL/Bax expression and attenuates cleaved caspase-3 expression via down-regulating membrane TLR-4 and ErbB2 receptors and then activating their downstream PI3K/Akt and ERK1/2 pathways,but also enhances the paracrine effect of MSCs.These findings demonstrated a novel and effective treatment strategy against MSC apoptosis in cell transplantation.

Fractional Flow Reserve Guided Percutaneous Coronary ntervention Improves Clinical Outcome with Reduced Cost in Contemporary Clinical Practice

Background：Fractional flow reserve （FFR） is currently considered as the gold standard for evaluating the functional significance of coronary stenosis.However,its potential benefits in real-world practice remain unknown in China.This study aimed to test the hypothesis that the use of FFR is associated with improved outcome and reduced cost in Chinese real-world clinical practice.Methods：A retrospective cohort study was carried out using the database of Second Affiliated Hospital of Zhejiang University,a tertiary and high-volume center in China.Clinical events were compared using the Cox proportional hazards model during a median follow-up of 13 months.Results：The study cohort consisted of 366 consecutive patients referred for coronary revascularization with adjunct FFR and 366 matched controls,from 2010 to 2014.Major adverse cardiac events （MACEs） （death,myocardial infarction,repeated revascularization,or hospitalization for angina） at 4 years were found in 12.0% ofangiography-guided patients and 4.9% in the FFR-guided group （P 〈 0.001）.The mean number of implanted stents was significantly lower in FFR treated subjects （0.52 ± 0.82 stents） compared with the angiography-guided group （0.93 ± 0.96 stents） （P 〈 0.001）.No difference in overall costs at initial hospitalization was observed between angiography-guided percutaneous coronary intervention （PCI） compared with FFR-guided PCI （RMB 33,000 Yuan,range：RMB 7393-44,700 Yuan） versus RMB 21,200 Yuan （RMB 19,100-47,100 Yuan） （P =0.54）.However,costs for MACEs during follow-up were significantly reduced in the FFR-guided arm （P 〈 0.001）.Conclusions：In the contemporary clinical practice,FFR-guided PCI is associated with decreased use of stents,improved clinical outcome,and reduced costs,compared with angiography-guided PCI.

Complex coronary lesions and rotational atherectomy:one hospital's experience

Objective:To evaluate the safety and effectiveness of rotational atherectomy followed by drug eluting stent (DES) implantation in patients with complex coronary lesions. Methods:From August 2006 to August 2012, 253 consecutive patients with 289 lesions and who underwent rotational atherectomy in our center were enrolled in this study. Results:The overall procedure success rate was 98% with the cost of two (0.8%) coronary perforations, three (1.2%) dissections, five (2.0%) slow flows or no flows, three (1.2%) peri-procedure myocardial infarctions, and two (0.8%) in hospital deaths. During follow-up (mean three years), one (0.4%) patient died, two (0.8%) patients had acute myocardial infarction, 14 (5.5%) had restenosis, and target lesion revascularization occurred in eight patients (3.2%). Conclusions:Rotational atherectomy followed by DES implantation is a safe and effective technique for patients with complex coronary lesions, especially calcified and non-dilatable lesions.

Gorham-Stout syndrome in China's Mainland:a case series of 67 patients and review of the literature

Objective:Gorham-Stout syndrome (GSS) is a rare disorder of uncertain etiology and unpredictable prognosis. This study aims to present a comprehensive understanding of this rare entity. Methods:A literature search in PubMed and three Chinese databases was performed to screen histologically proven GSS cases among Chinese residents in the mainland. We analyzed the patients' clinical characteristics, the value of different treatment modalities and their influence on the clinical outcome. Results:Sixty-seven cases were finally enrolled. There were 43 men (64.2%) and 24 women (35.8%). The mean age at diagnosis was 28 years (1.5-71 years). The most common clinical symptoms included pain (n=40, 59.7%), functional impairment (n=13, 19.4%), and swelling (n=12, 17.9%). The radiographic presentation of 37 cases (55.2%) was disappearance of a portion of the bone. The others presented as radiolucent foci in the intramedullary or subcortical regions. A total of 42 cases provided data on therapy, these included surgery (n=27, 40.3%), radiation therapy (n=6, 9.0%), surgery combined with radiation therapy (n=2, 3.0%), and medicine therapy (n=7, 10.4%). For 30 of these 42 cases, follow-up data were available:21 cases had the disorder locally controlled and 9 had a symptom progression. Fortunately, the disease is not fatal in the majority of cases. Conclusions:GSS has no specific symptoms and it should be taken into consideration when an unclear massive osteolysis occurs. The efficacies of different treatment modalities are still unpredictable and further research is required to assess the values of different treatments.

Angiopoietin-1 preconditioning enhances survival and functional recovery of mesenchymal stem cell transplantation

Objective:Mesenchymal stem cell (MSC) transplantation is a promising therapy for ischemic heart diseases. However, poor cell survival after transplantation greatly limits the therapeutic efficacy of MSCs. The purpose of this study was to investigate the protective effect of angiopoietin-1 (Ang1) preconditioning on MSC survival and sub-sequent heart function improvement after transplantation. Methods: MSCs were cultured with or without 50 ng/ml Ang1 in complete medium for 24 h prior to experiments on cell survival and transplantation. 3-(4,5- Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and Hoechst staining were applied to evaluate MSC survival after serum deprivation in vitro, while cell survival in vivo was detected by terminal deoxynucleotidyl trans-ferase biotin-dUPT nick end labeling (TUNEL) assay 24 and 72 h after transplantation. Heart function and infarct size were measured four weeks later by small animal echocardiography and Masson's trichrome staining, respectively. Results: Ang1 preconditioning induced Akt phosphorylation and increased expression of Bcl-2 and the ratio of Bcl-2/Bax. In comparison with non-preconditioned MSCs, Ang1-preconditioned cell survival was significantly increased while the apoptotic rate decreased in vitro. However, the PI3K/Akt pathway inhibitor, LY294002, abrogated the protective effect of Ang1 preconditioning. After transplantation, the Ang1-preconditioned-MSC group showed a lower death rate, smaller infarct size, and better heart functional recovery compared to the non-preconditioned-MSC group. Conclusions:Ang1 preconditioning enhances MSC survival, contributing to further improvement of heart function.

Tongxinluo promotes mesenchymal stem cell tube formation in vitro

Objective:To study whether Tongxinluo (TXL) can induce angiogenesis in bone marrow mesenchymal stem cells (MSCs),and to investigate the underlying mechanism.Methods:Bone marrow MSCs were obtained from male Sprague-Dawley rats.We established an angiogenesis model in vitro via matrigel experiment.MSCs were seeded on matrigel coated 24-well plates,and treated by TXL 50 and 100 mg/L.After 24 h,we observed the tube formations of MSCs in the matrigel.Cell migration ability was examined by wound scratch test and transwell assay.Expressions of vascular endothelial growth factor (VEGF),fetal liver kinase-1 (Flk-1),matrix metalloproteinase-2 (MMP-2),MMP-9,and tissue inhibitor of metalloproteinase-2 (TIMP-2) were analyzed at the protein level by Western blot.Gelatin zymography assay was applied to investigating the MSC paracrine abilities of pro-MMP-2 and activated MMP-2.Results:TXL promoted MSC tube formation in matrigel.The ratio of TXL 100 mg/L treated-MSC tubular length was increased 3.04-fold compared to the control group (P<0.05).Scratch test and transwell assay showed that TXL could improve the cell migration ability of MSCs.Western blot experiments showed that TXL promoted MSC synthesis of MMP-2,but it had no influence on the expressions of MMP-9 and TIMP-2.This effect was confirmed by gelatin zymography assay,which showed that TXL increased MSC secretion of pro-MMP-2 and activated MMP-2.VEGF expression of TXL treated-MSCs was increased compared to the control group.The expression of Flk-1 was not different among the groups.Conclusions:This study demonstrates that TXL can promote the tube formation of MSCs,and the underlying mechanisms are associated with increased migration ability of MSCs and the up-regulation of MMP-2 and VEGF expressions.

CYBA基因C242T基因多态性的荟萃分析:亚洲人群急性冠脉综合征风险降低而高加索人群没有（英文）

目的:探讨CYBA基因C242T基因多态性与急性冠脉综合征的关系。创新点:提出了C242T基因多态性对急性冠脉综合征的影响存在种族差异。方法:荟萃分析了C242T基因多态性与急性冠脉综合征的关系。结论:对于亚洲人群而言,C242T基因多态性为急性冠脉综合征的保护因素。