Progress in the Role of Mechanical Stimulus in Cardiac Development / 中国医学科学院学报

Mechanical stimulus is critical to cardiovascular development during embryogenesis period.The mechanoreceptors of endocardial cells and cardiac myocytes may sense mechanical signals and initiate signal transduction that induce gene expression at a cellular level,and then translate molecular-level events into tissue-level deformations,thus guiding embryo development.This review summarizes the regulatory roles of mechanical signals in the early cardiac development including the formation of heart tube,looping,valve and septal morphogenesis,ventricular development and maturation.Further,we discuss the potential mechanical transduction mechanisms of platelet endothelial cell adhesion molecule 1-vascular endothelial-cadherin-vascular endothelial growth factor receptor 2 complex,primary cilia,ion channels,and other mechanical sensors that affect some cardiac malformations.

Mid- to Long-term Clinical Outcomes of Hancock II Bioprosthesis in Chinese Population / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Compared to the Western countries, Chinese patients present a special primary disease spectrum, diverse valvular pathogenesis, and different postoperational anticoagulation strategy. This research aimed to evaluate the mid- to long-term clinical performance of Hancock II bioprosthesis in the Chinese population.</p><p><b>METHODS</b>This study retrospectively reviewed all patients who received surgical treatments with at least one Hancock II bioprosthesis implantation from January 2004 to December 2013 at a single center in China. Totally 647 patients were included in the clinical evaluation, and 629 patients were successfully discharge, among whom 605 patients were completely followed-up. The follow-up rate was 96.2%. The mean and median follow-up time was 62.0 ± 59.0 and 56.0 months, respectively. Postoperative outcomes of survival rates, reoperations and valve related morbidities were assessed. Continuous and categorical variables were compared using the t -test and Chi-square test, respectively. Survival and freedom from adverse events were calculated by using a Kaplan-Meier method.</p><p><b>RESULTS</b>The overall in-hospital mortality was 2.8% (18/647) while there were 34 deaths (5.6%, 34/605) in the follow-up stage after discharge. The overall survival rate was 94.6% and 82.7% at 5 years and 10 years, respectively. The cumulative survival rate of 10 years was 82.8% in AVR group, 84.4% in MVR group, and 78.4% in DVR group. The overall rate of freedom from reoperations was 95.5% at 5 years and 86.8% at 10 years. The freedom from reoperation at 10 years was 87.0%, 88.1%, and 84.0% in AVR, MVR, and DVR group, respectively. The freedom from morbidities at 10 years was: 90.3% for thromboembolism, 95.2% for hemorrhage, 97.5% for prosthesis endocarditis, 95.9% for paravalvular leak, and 94.6% for structural valve deterioration, respectively.</p><p><b>CONCLUSIONS</b>Hancock II bioprosthesis exhibited a satisfactory mid- to long-term durability and promising clinical performance in the Chinese population. The occurrence rates of death and other adverse events in this single-center study were overall coincident and quite acceptable when compared with existing data.</p>

Inhibitory effects of suppressor of cytokine signaling 3 on inflammatory cytokine expression and migration and proliferation of IL-6/IFN-γ-induced vascular smooth muscle cells / 华中科技大学学报（医学）（英德文版）

The main pathogenesis of saphenous vein graft neointimal hyperplasia after coronary artery bypass grafting (CABG) is inflammation-caused migration and proliferation of vascular smooth muscle cells (VSMCs). Janus kinase 2/signal transducer and activators of transcription 3 (JAK2/STAT3) pathway is an important signaling pathway through which VSMCs phenotype conversion occurs. Suppressor of cytokine signaling 3 (SOCS3) is the classic negative feedback inhibitor of JAK2/STAT3 pathway. Growing studies show that SOCS3 plays an important anti-inflammatory role in numerous autoimmune diseases, inflammatory diseases and inflammation-related tumors. However, the effect and mechanism of SOCS3 on vein graft disease is unclear. The purpose of this study was to investigate the effects of SOCS3 on the inflammation, migration and proliferation of VSMCs in vitro and the mechanism. The small interference RNA plasmid targeting rat SOCS3 (SiRNA-rSOCS3) and the recombinant adenovirus vector carrying rat SOCS3 gene (pYrAd-rSOCS3) were constructed, and the empty plamid (SiRNA-control) and vector (pYrAd-GFP) only carrying GFP reported gene were constructed as control. The rat VSMCs were cultured. There were two large groups of A (SOCS3 up-regulated): control group, IL-6/IFN-γ group, IL-6/IFN-γ+pYrAd-rSOCS3 group, IL-6/IFN-γ(+)pYrAd-GFP group; and B (SOCS3 down-regulated): control group, IL-6/IFN-γ group, IL-6/IFN-γ+SiRNA-rSOCS3 group and IL-6/ IFN -γ+SiRNA-control group. The pYrAd-rSOCS3 and SiRNA-rSOCS3 were transfected into VSMCs induced by IL-6/IFN-γ. After 24 h, real-time reverse transcription polymerase chain reaction (RT-PCR) and Western blotting were used to detect the mRNA and protein expression of SOCS3, STAT3 (only by Western blotting), P-STAT3 (only by Western blotting), IL-1β, IL-6, TNF-α, MCP-1 and ICAM-1. The MTT, Transwell assay and flow cytometry were used to examine VSMCs proliferation, migration and cell cycle progression, respectively. As compared with control group, the mRNA and protein expression of SOCS3, STAT3, P-STAT3, IL-1β, IL-6, TNF-α, MCP-1 and ICAM-1 was significantly up-regulated in VSMCs stimulated by IL-6/IFN-γ. However, in VSMCs transfected with pYrAd-rSOCS3 before stimulation with IL-6/IFN-γ, the expression of SOCS3 mRNA and protein was further up-regulated, and that of STAT3, P-STAT3, IL-1β, IL-6, TNF-α, MCP-1 and ICAM-1 was significantly down-regulated as compared with IL-6/IFN-γ group and IL-6/IFN-γ+pYrAd-GFP group. The expression of those related-cytokines in IL-6/IFN-γ+SiRNA-rSOCS3 group was markedly increased as compared with IL-6/IFN-γ group and IL-6/IFN-γ+SiRNA-control group. The absorbance (A) values, the number of cells migrating to the lower chamber, and percentage of cells in the G2/M+S phase were increased in VSMCs stimulated by IL-6/IFN-γ. In VSMCs incubated with pYrAd-rSOCS3 or SiRNA-rSOCS3 before IL-6/IFN-γ stimulation, the A values, the number of cells migrating to the lower chamber, and the percentage of cells in the G2/M+S phase were significantly decreased, and increased respectively. These results imply that IL-6/IFN-γ, strong inflammatory stimulators, can promote transformation of VSMCs phenotype form a quiescent contractile state to a synthetic state by activating JAK2/STAT3 pathway. Over-expresssed SOCS3 might inhibit pro-inflammatory effect, migration and growth of VSMCs by blocking STAT3 activation and phosphorylation. These data in vitro confirm that SOCS3 may play a negatively regulatory role in development and progression of vein graft failure. These conclusions can provide a novel strategy for clinical treatment of vein graft diseases and a new theoretic clue for related drug development.

Inhibitory effects of suppressor of cytokine signaling 3 on inflammatory cytokine expression and migration and proliferation of IL-6/IFN-γ-induced vascular smooth muscle cells / 华中科技大学学报（医学）（英德文版）

The main pathogenesis of saphenous vein graft neointimal hyperplasia after coronary artery bypass grafting (CABG) is inflammation-caused migration and proliferation of vascular smooth muscle cells (VSMCs). Janus kinase 2/signal transducer and activators of transcription 3 (JAK2/STAT3) pathway is an important signaling pathway through which VSMCs phenotype conversion occurs. Suppressor of cytokine signaling 3 (SOCS3) is the classic negative feedback inhibitor of JAK2/STAT3 pathway. Growing studies show that SOCS3 plays an important anti-inflammatory role in numerous autoimmune diseases, inflammatory diseases and inflammation-related tumors. However, the effect and mechanism of SOCS3 on vein graft disease is unclear. The purpose of this study was to investigate the effects of SOCS3 on the inflammation, migration and proliferation of VSMCs in vitro and the mechanism. The small interference RNA plasmid targeting rat SOCS3 (SiRNA-rSOCS3) and the recombinant adenovirus vector carrying rat SOCS3 gene (pYrAd-rSOCS3) were constructed, and the empty plamid (SiRNA-control) and vector (pYrAd-GFP) only carrying GFP reported gene were constructed as control. The rat VSMCs were cultured. There were two large groups of A (SOCS3 up-regulated): control group, IL-6/IFN-γ group, IL-6/IFN-γ+pYrAd-rSOCS3 group, IL-6/IFN-γ(+)pYrAd-GFP group; and B (SOCS3 down-regulated): control group, IL-6/IFN-γ group, IL-6/IFN-γ+SiRNA-rSOCS3 group and IL-6/ IFN -γ+SiRNA-control group. The pYrAd-rSOCS3 and SiRNA-rSOCS3 were transfected into VSMCs induced by IL-6/IFN-γ. After 24 h, real-time reverse transcription polymerase chain reaction (RT-PCR) and Western blotting were used to detect the mRNA and protein expression of SOCS3, STAT3 (only by Western blotting), P-STAT3 (only by Western blotting), IL-1β, IL-6, TNF-α, MCP-1 and ICAM-1. The MTT, Transwell assay and flow cytometry were used to examine VSMCs proliferation, migration and cell cycle progression, respectively. As compared with control group, the mRNA and protein expression of SOCS3, STAT3, P-STAT3, IL-1β, IL-6, TNF-α, MCP-1 and ICAM-1 was significantly up-regulated in VSMCs stimulated by IL-6/IFN-γ. However, in VSMCs transfected with pYrAd-rSOCS3 before stimulation with IL-6/IFN-γ, the expression of SOCS3 mRNA and protein was further up-regulated, and that of STAT3, P-STAT3, IL-1β, IL-6, TNF-α, MCP-1 and ICAM-1 was significantly down-regulated as compared with IL-6/IFN-γ group and IL-6/IFN-γ+pYrAd-GFP group. The expression of those related-cytokines in IL-6/IFN-γ+SiRNA-rSOCS3 group was markedly increased as compared with IL-6/IFN-γ group and IL-6/IFN-γ+SiRNA-control group. The absorbance (A) values, the number of cells migrating to the lower chamber, and percentage of cells in the G2/M+S phase were increased in VSMCs stimulated by IL-6/IFN-γ. In VSMCs incubated with pYrAd-rSOCS3 or SiRNA-rSOCS3 before IL-6/IFN-γ stimulation, the A values, the number of cells migrating to the lower chamber, and the percentage of cells in the G2/M+S phase were significantly decreased, and increased respectively. These results imply that IL-6/IFN-γ, strong inflammatory stimulators, can promote transformation of VSMCs phenotype form a quiescent contractile state to a synthetic state by activating JAK2/STAT3 pathway. Over-expresssed SOCS3 might inhibit pro-inflammatory effect, migration and growth of VSMCs by blocking STAT3 activation and phosphorylation. These data in vitro confirm that SOCS3 may play a negatively regulatory role in development and progression of vein graft failure. These conclusions can provide a novel strategy for clinical treatment of vein graft diseases and a new theoretic clue for related drug development.

Genetic research of pulmonary atresia / 中华实用儿科临床杂志

Objective To explore the genetic defects in patients with pulmonary atresia (PA).Methods Twenty-three patients with PA were studied from recent 1 year.There were 15 boys and 8 girls,aged 2 days to 10 years.Among them,there were 3 cases with complete ventricle septum,20 cases with VSD,3 cases without main pulmonary trunk,20 cases with PDA,6 cases with integrated major aorto-pulmonary collateral arteries(MAPCAs),3 cases with integrated right aortic arch,2 cases with integrated extra-cardiac abnormality with the manifestation of facial abnormality,1 case with integrated aberrant right subclavian artery,and 1 case with integrated tracheal bronchus.The chromosomes of the children were routinely analyzed.Negative chromosomes were examined to identify the 22ql 1.2 microdeletion by fluorescence in situ hybridization (FISH) test.Results One case of trisomy syndrome was found.22ql 1.2 microdeletion was found in 3 cases.Among 22q1 1 microdeletion cases,1 case was intact ventricular septum,2 cases were integrated VSD.22q1 1.2 microdeletion was not found in the rest 19 cases.Conclusions Twenty-one trisomy syndrome and Del 22q1 1.2 syndrome may play an important role in the pathogenesis of PA.TBX1 probe can be used to examine 22q1 1.2 microdeletion.Del 22q1 1.2 syndrome was suspected in cases of incorporating aberrant subclavian artery,MAPCAs and severe poor development of pulmonary artery.

PEG-mediated covalent binding of VEGF to decellularized aortic valves promotes adhesion and proliferation of endothelial progenitor cells / 南方医科大学学报

<p><b>OBJECTIVE</b>To improve the biological properties of decellularized aortic valves by polyethylene glycol (PEG)-mediated covalent incorporation of vascular endothelial growth factor (VEGF).</p><p><b>METHODS</b>PEG crosslinking of decellularized aortic valves were completed via a Michael-type addition reaction, followed by covalent incorporation of VEGF through another Michael-type addition reaction between the unsaturated propylene acyl of PEG and the thiol groups on cysteine residues of VEGF. The effect of VEGF incorporation was evaluated by enzyme-linked immunosorbent assay (ELISA) and immune fluorescence assay. The endothelial progenitor cells (EPCs) were seeded on decellularized aortic valves with or without these modifications, and after 10 days of culture, the valves were examined for DNA content and by hematoxylin-eosin staining and scanning electron microscopy.</p><p><b>RESULTS</b>Immune fluorescence and ELISA showed that the maximal VEGF incorporation on the decellularized aortic valve reached 908.94∓0.27 pg. Compared with the unmodified valves and the valves with PEG crosslinking, decellularized aortic valves with covalent incorporation of VEGF significantly promoted the adhesion and proliferation of EPCs, which formed a confluent cell monolayer on the valve surface.</p><p><b>CONCLUSIONS</b>PEG-mediated covalent incorporation of VEGF in the decellularized aortic valves improves the adhesion and proliferation of the seeded EPCs to facilitate the construction of tissue-engineered heart valves.</p>

Atelocollagen-mediated small interfering RNA delivery for effective gene silencing in rat vein grafts / 中华外科杂志

<p><b>OBJECTIVE</b>To evaluate the efficacy of using small interfering RNA targeting TF as a therapy for vein graft failure.</p><p><b>METHODS</b>External jugular vein to carotid artery interposition vein grafts, which were applied to a low flow condition, were made in 120 Sprague-Dawley rats weighing 260 to 300 g. These rats were randomly divided into 4 groups, 30 rats each group. Group A was atelocollagen-TF Stealth Select RNAi group. Group B was atelocollagen-TF Stealth RNAi group. Group C was atelocollagen group. Group D was control group. Small interfering RNA mixed with atelocollagen was administrated to the external wall of grafted veins. The TF protein expression of vein grafts was analyzed by Western blot at 1, 3, 7, 14, and 28 d postoperatively, and by immunochemistry at 3 d postoperatively. The proliferation index was determined at 14 d postoperatively. Neointimal hyperplasia was evaluated at 28 d postoperatively. BLOCK-iT fluorescent oligo was used to confirm its stability and successful transfer into the vein graft wall at 3 and 7 d postoperatively for another group (n=12).</p><p><b>RESULTS</b>Fluorescence of BLOCK-iT fluorescent oligo could be detected in the graft wall even at 7 d postoperatively. Knockdown of the TF expression was achieved by perivascular application of siRNA using atelocollagen. Compared with control group, the intima thickness at 28 d after grafting was significantly reduced (P < 0.05). This phenomenon was preceded by significant reduction of cell proliferation in siRNA-treated grafts at 14 d postoperatively (P < 0.05).</p><p><b>CONCLUSION</b>The expression of TF in vein grafts can be effectively inhibited by specific siRNAs using a atelocollagen-based nonviral delivery approach in vivo, so that the neointimal thickening can be prevented. Transplants;</p>

Experimental study on mechanical properties of decellularized porcine aortic valve and effects of precoating methods of biological scaffold on histocompatibility / 中华外科杂志

<p><b>OBJECTIVE</b>To observe the mechanical properties of decellularized porcine aortic valve, and to explore the effects of precoating methods of biological scaffold on histocompatibility.</p><p><b>METHODS</b>Fresh porcine aortic valves were decellularized using trypsin, TritonX-100 and nuclease. Treated valves were evaluated by light microscopy, scanning electron microscopy (SEM) and mechanical test. Three groups of scaffold were precoated with phosphate buffered saline (PBS), poly-L-lysine (PLL) and fetal bovine serum (FBS) respectively. Myofibroblasts were seeded onto each scaffold. Light and electron microscopic observation was performed and MTT test was used to examine efficiency of cell attachment.</p><p><b>RESULTS</b>HE stain and SEM showed that cells were almost absent in the treated leaflet. The wave-like collagen together with the whole three-dimensional structure was maintained. Compared with normal valves, the Max-load, Max-stress and elastic modulus decreased while the Max-strain increased (P<0.05). The result of MTT test showed more cells were attached on the valves treated with FBS compared to the other two groups. Histological investigations also confirm that the high degree of cell attachment on the valves precoated with FBS (F=129.26, P=0.000).</p><p><b>CONCLUSIONS</b>Enzyme combined with detergent and nucleases can remove cells from porcine aortic valves. Meanwhile the mechanical properties of these valves may be altered. Precoating porcine aortic valve with FBS is an effective method to improve cell attachment, growth and increasing.</p>

Simultaneous off-pump coronary artery bypass surgery and pulmonary resection / 中华外科杂志

<p><b>OBJECTIVE</b>To summarize the experience of combined off-pump coronary artery bypass grafting (OPCAB) and pulmonary resection.</p><p><b>METHODS</b>Seven patients with unstable angina or a history of myocardial infarction and pulmonary disease underwent combined OPCAB and pulmonary resection. All of them underwent coronary angiography, and neither coronary angioplasty nor stenting was feasible. OPCAB preceded the lung resections. The preferred approach to the heart and lung was by sternotomy. Left upper lobectomy was performed in 2 patients, right upper lobectomy was performed in 1 patient, right lower lobectomy was performed in 1 patient, right upper and middle bilobectomy was performed in 1 patient, left lung volume reduction surgery (LVRS) was performed in 1 patient and bilateral LVRS was performed in 1 patient.</p><p><b>RESULTS</b>There were no hospital mortality in this group of patients, however there were one late death. Sternal dehiscence occurred in 1 patient which was observed with a need for re-sternotomy and atrial fibrillation was observed in 1 patient. Five patients were diagnosed as malignant tumor by pathology test, and 2 patients were severe chronic obstructive pulmonary disease (COPD). Follow-up ranging from 2 months to 31 months was available for these patients. None of the patients showed evidence of myocardial ischemia after surgery. In one patient, who underwent right upper and middle bilobectomy, local recurrence was found at 19 months after surgery.</p><p><b>CONCLUSIONS</b>OPCAB carried out simultaneously with lung resection is a safe and effective approach in patients diagnosed with concomitant coronary artery and pulmonary disease. OPCAB may decrease the incidence of postoperative complications.</p>