[Correlation of Matrix Metalloproteinases-9 with Microemboli Shedding in Carotid Endarterectomy].

Objective To investigate the change of serum matrix metalloproteinases-9 (MMP-9) expression before,during,and after carotid endarterectomy (CEA) and to investigate the prognostic role of MMP-9. Methods Forty carotid stenosis patients who underwent CEA in the Department of Vascular Surgery,Peking Union Medical College Hospital from February to September 2012 were enrolled in this study. Based on the findings of transcranial doppler monitoring,patients were divided into embolic-positive group and emboli-negative group. Serum samples were obtained from 40 consecutive patients undergoing CEA before operation (pre-op),before de-clamping,30 minutes after de-clamping,and 12 hours after operation (12-h post-op). MMP-9 expression was quantified using enzyme-linked immunosorbent assay and gelatin zymography. Student's t-test and chi-square test were used to compare the differences between these two groups. Results Of these 40 patients,microemboli were detected in 8 patients. The 12-h post-op MMP-9 level was significantly higher than the pre-op level in the emboli-positive group [(904.27±369.47)ng/ml vs. (333.88±126.32) ng/ml,t=4.132,P=0.001].However,there was no difference between pre-op and 12-h post-op MMP-9 levels in the emboli-negative group [(375.83±194.36) ng/ml vs. (472.74±271.21) ng/ml,t=-1.643,P=0.081]. Gelatin zymography also showed higher MMP-9 activity in the emboli-positive group than in the emboli-negative group. Conclusion Serum MMP-9 concentration remarkably increases 12 hours after CEA in patients with microemboli shedding,suggesting MMP-9 may be a potential biomarker for CEA-related cerebral ischemic injury.

Effect of Adequate Anticoagulantion Therapy on the Outcome of Spontaneous Isolated Dissection of Superior Mesenteric Artery.

Objective To investigate the optimal treatment strategy of spontaneous isolated dissection of superior mesenteric artery (SIDSMA) and the effect of anticoagulation therapy on the prognosis of SIDSMA. Methods The clinical data of 29 patients presented with acute or subacute mesenteric ischemia (a history of less than 14 days) due to SIDSMA admitted to the Department of Vascular Surgery of Peking Union Medical College Hospital from January 1st 2003 to December 31th 2016 were retrospectively analyzed. Results In this study,28 cases were male and the remaining one was female,with an average age of (49.1±7.6) years. The emergency endovascular treatment were performed on 4 cases with severe mesenteric intestinal ischemia,and the symptoms were relieved postoperatively. The remaining 25 cases were treated with conservative treatment. Among 13 cases who were received adequate anticoagulantion therapy,symptoms were relieved or disappeared in 9 cases (69.2%),whereas conservative treatment was ineffective in 4 cases (30.8%),for whom surgical intervention were performed. Among 12 cases who received conservative treatment without sufficient anticoagulation,the abdominal pain was relieved in only 2 cases (16.7%) and the remaining 10 cases (83.3%) were converted to surgical intervention. The success rate of conservative treatment for patients with adequate anticoagulant therapy was significantly higher than that of patients who had not received adequate anticoagulant therapy (P=0.015). Conclusions Adequate anticoagulation therapy has good therapeutic effect in most SIDSMA cases with acute or subacute mesenteric ischemia. For patients with severe mesenteric ischemia or those fail to respond to initial conservative treatment,endovascular treatment may be a more reasonable option.

Research Progress of the Differentiation of 3T3-L1 Preadipocytes into Mature Adipocytes.

Along with the increase in the prevalence of lipid metabolism disorders,in vitro research on the adipocytes has been a hot topic in recent years. 3T3-L1 preadipocyte line is one of the most commonly used cell line for establishing adipocytes models. However,for 3T3-L1 cell lines,the traditional method,known also as the "Cocktail" method,have disadvantages including low transformation rate and heterogeneous conversion. Therefore,many studies aimed to improving the induction method by changing the time of inducers or adding other new drugs have been performed(known as the improved method). The present study was to summarize the progress of the traditional methods and the improved methods for inducing 3T3-L1 cell lines to mature adipocytes.

Impact of the Action Time of Inducers on Differentiation of 3T3-L1 Cells.

Objective To explore the effect of the action time of inducers on the differentiation of 3T3-L1 cells to adipocytes. Methods According to the "Cocktail" method,3T3-L1 cells were divided into three groups according to the action time of inducers,with the action time being 2,3 or 4 days,respectively. Cell morphology was observed using inverted microscope and adipose content were detected by Oil red "O" staining and detection of triglyceride. The cell viability was identified by trypan blue staining method. Results The proportion of samples (n=12) with differentiation rate above 80% in group A was 66% (12/18),while the differentiation rate of all the samples (n=18)in group B and group C were above 80%. For the Oil red "O",the OD value at 510 nm in group C was 2.59±0.17,which was significantly higher than that in group A (2.12±0.47;F=6.62,P=0.0001)and group B (2.20±0.17;F=5.15,P=0.0001),while no significant difference was found between group A and group B (F=1.14,P=0.74). As for the triglyceride,the value in group C was (1351.04±119.01)ng/ml,which was significantly higher than that in group A[ (1077.88±272.75)ng/ml;F=6.73,P=0.001] and group B [(1089.38±115.39)ng/ml;F=5.78,P=0.001],while no difference was found between group A and group B (F=0.27,P=0.64). The cell viability in group A,B,and C was (98.3±1.2)%,(98.5±1.8)%,and (98.9±2.1)%,respectively,showing no significant difference (F=0.18,P=0.83). Conclusions The modified procedure for the differentiation of 3T3-L1 cells to adipocytes can increase the differentiation rate and thus may be applied for establishing adipocyte models. The recommended action time is three days.

[Advances in the biochemical markers of complications associated with carotid endarterectomy].

Carotid endarterectomy(CEA)has been proved to be an effective surgery to treat the cerebral ischemia caused by carotid atherosclerotic stenosis. However,there is still no effective mean for the early diagnosis of the CEA-related severe complications such as stroke and death. Many studies have explored the potential biomarkers for stroke alert,although there is still a long way to go for their actual application in clinical settings. The carotid atherosclerotic stenosis,the perioperative complications of CEA,and the stroke share similar pathogenic mechanisms,and some biomarkers such as S100B,matrix metalloproteinase 9,asymmetric dimethylarginine,and neuron-specific enolase have been studied in the clinical trails of CEA. This article summarizes recent advances in this field.

[Expressions of p-c-jun and cyclinD1 between vascular smooth muscle cells and endothelial cells exposured to cigarette smoke extract].

OBJECTIVE: To investigate the cell viabilities of vascular smooth muscle cells and vascular endothelial cells stimulated by cigarette smoke extract(CSE) . METHODS: The CSE was prepared by smoke-bubbled phosphate buffered saline(PBS) generation.After culturing cells with different concentrations of CSE, we used the cell counting kit-8 to determine the cell viability.The expression levels of c-jun and cyclinD1 were analyzed through Western blot.The c-jun plasmid was transfected to detect the change of cyclinD1 expression. RESULTS: The smooth muscle cell viability increased when the CSE concentration ranged 0.625%-10%, whereas the endothelial cells viability decreased when exposed to the CSE concentration. After exposure to CSE for 48 hours, there was no difference in c-jun expression between toxin group and PBS group;however, the expression of p-c-jun in the smooth muscle cells significantly increased in the toxin groups than in the PBS group(P<0.05) and the expression of p-c-jun in the vascular endothelial cells significantly decreased(P<0.05) . The level of cyclinD1 significantly increased after exposed to CSE, and its expression level also increased in respond to the c-jun overexpression. CONCLUSION: CSE can enhance the proliferation of vascular smooth muscle cells and decrease in the activity of endothelial cells proliferation, which may be explained by the phosphorylation of c-jun and the expression of cyclinD1.

Role of perivascular adipose tissue in nicotine­induced endothelial cell inflammatory responses.

Smoking is considered to be one of the primary causes of atherosclerosis and vascular injury. Previous studies have shown that nicotine in tobacco can lead to vascular inflammation and endothelial dysfunction. Perivascular adipose tissue (PVAT) is known to secrete various types of adipokines to maintain vascular homeostasis. The present study investigated whether nicotine­induced PVAT malfunction can accelerate endothelial inflammation and eventually lead to endothelial dysfunction. The levels of inflammatory adipokines, including nuclear factor (NF)­κB, interleukin (IL)­1ß, IL­6 and tumor necrosis factor (TNF)­α, the ICAM­1 and VCAM­1 adhesion molecules and secretion of adiponectin were assessed in mature adipocytes and endothelial cells cultured alone or in co­culture under nicotine stimulation. It was found that nicotine reduced the secretion of adiponectin and stimulated secretion of the NF­κB, IL­1ß, IL­6 and TNF­α inflammatory adipokines in mature adipocytes. Although nicotine stimulated endothelial cells to secrete IL­1ß and IL­6, no significant increase in the secretion of TNF­α was observed. The co­culture of mature adipocytes with endothelial cells markedly augmented the expression of the NF­κB, IL­1ß, IL­6 and TNF­α inflammatory adipokines and the ICAM­1 and VCAM­1 adhesion molecules, and significantly lowered the levels of adiponectin. These findings suggested that nicotine induced mature adipocyte dysfunction, which caused the abnormal secretion of adiponectin and inflammatory adipokines, and exacerbated endothelial inflammation. These findings also suggested a mechanism whereby nicotine induced the secretion of adiponectin and inflammatory cytokines by adipocytes. The results of the present study elucidated a novel pathway induced by cigarette smoke, which contributed to atherosclerosis and vascular injury.