Mechanical injury accentuates lipid deposition in ApoE-/- mice and advance aortic valve stenosis: A novel modified aortic valve stenosis model.

Background: Current mouse models still have limitations in studying aortic valve stenosis (AVS). A suitable animal model bearing a close resemblance to the pathophysiological processes of humans needs to be developed. Here, we combined two risk factors to create a mouse model that mimics the pathological features of human AVS. Methods and results: We combined WI and hyperlipidemia in ApoE-/- mice to explore the synergistic effect on the stenosis of the aortic valve. Transthoracic echocardiography revealed progressively increased peak velocity with age in ApoE-/- mice to velocities above C57 mice when fed a high-fat diet after wire injury. Moreover, ApoE-/- mice demonstrated lower cusp separation and lower aortic valve area after 8 weeks vs. C57 mice. Gross morphology and MRI showed advanced thickening, sclerosis aortic valve, narrowing of the orifice area, and micro-CT showed obvious calcification in the aortic valves in the hyperlipidemia group after wire injury. Histopathology studies showed thickening and fibrosis of aortic valve leaflets in the hyperlipidemia group after wire injury. Notably, lipid deposition was observed in ApoE-/- mice 8 weeks after wire injury, accompanied by overexpressed apoB and apoA proteins. After wire injury, the hyperlipidemia group exhibited augmented inflammation, ROS production, and apoptosis in the leaflets. Moreover, the combination group exhibited advanced fibro-calcific aortic valves after wire injury. Conclusion: Overall, we present the synergistic effect of wire injury and hyperlipidemia on lipoproteins deposition in the development of AVS in ApoE-/- mice, this model bear close resemblance to human AVS pathology.

Inhibition of invadopodia formation by diosgenin in tumor cells.

Diosgenin is a type of steroid extracted from the rhizome of Dioscorea plants. In traditional Chinese medicine, Dioscorea has the effect of 'eliminating phlegm, promoting digestion, relaxing tendons, promoting blood circulation and inhibiting malaria'. Recent studies have confirmed that diosgenin exhibits a number of pharmacological effects, including antitumor activities. Through its antitumor effect, diosgenin is able to block tumor progression and increase the survival rate of patients with cancer; ultimately improving their quality of life. However, the mechanism underlying its pharmacological action remains unclear. Once tumor cells reach a metastatic phase, it can be fatal. Increased migration and invasiveness are the hallmarks of metastatic tumor cells. Invadopodia formation is key to maintaining the high migration and invasive ability of tumor cells. Invadopodia are a type of membrane structure process rich in filamentous-actin and are common in highly invasive tumor cells. In addition to actin, numerous actin regulators, including cortical actin-binding protein (Cortactin), accumulate in invadopodia. Cortactin is a microfilament actin-binding protein with special repetitive domains that are directly involved in the formation of the cortical microfilament actin cell skeleton. Cortactin is also one of the main substrates of intracellular Src-type tyrosine protein kinases and represents a highly conserved family of intracellular cortical signaling proteins. In recent years, great progress has been made in understanding the role of Cortactin and its molecular mechanism in cell motility. However, the diosgenin-Cortactin-invadopodia mechanism is still under investigation. Therefore, the present review focused on the current research on the regulation of invadopodia by diosgenin via Cortactin.

Ensemble classifier based on optimized extreme learning machine for motor imagery classification.

OBJECTIVE: Designing an effective classifier with high classification accuracy and strong generalization capability is essential for brain-computer interface (BCI) research. In this study, an extreme learning machine (ELM) based method is proposed to improve the classification accuracy of motor imagery electroencephalogram (EEG). APPROACH: The proposed method constructs an ensemble classifier based on optimized ELMs. Particle swarm optimization is used to simultaneously optimize the input weights and hidden biases of ELM to avoid the randomness and instability of classification result when ELM uses randomly generated parameters, and majority voting strategy is used to fuse the classification results of multiple base classifiers to avoid the negative impact of ELM with local optimal parameters on classification result. The proposed method was compared with four competing methods in experiments based on two public EEG datasets and some existing methods reported in the literature using the same datasets as well. MAIN RESULTS: The results indicate that the proposed method achieved significant higher classification accuracies than those of the competing methods on both two-class and four-class motor imagery data. Moreover, compared to the existing methods, it still obtained superior average accuracies of two-class classification and performed better for the subjects with relatively poor accuracies on both two-class and four-class classifications. SIGNIFICANCE: The significant accuracy improvement demonstrates the superiority of the proposed method. It can be a promising candidate for accurate classification of motor imagery EEG in BCI systems.

The expression of Nesprin-1 increased in aortic dissection: why?

BACKGROUND: To detect the expression of Nesprin-1 in aortic dissection (AD) in patients and to investigate the role of Nesprin-1 in the pathogenesis of AD in a mouse model. METHODS: Blood and tissue specimens from AD patients were collected. The expression of Nesprin-1 in tissues from AD patients and non-AD patients with heart disease was studied by western blotting and quantitative real-time polymerase chain reaction (qRT-PCR). In addition, the expression and distribution of Nesprin-1 in AD and sham mice were compared in an induced AD mouse model, and detected by immunohistochemistry and qRT-PCR. RESULTS: Immunoblotting and qRT-PCR both showed that the expression of Nesprin-1 was significantly higher in AD versus control patients. An animal model of AD was established by continuous injection of Ang II into ApoE-/- mice. The expression of Nesprin-1 in aortic tissue of AD mice was higher than that of sham-operated mice as determined by immunohistochemistry. qRT-PCR showed that Nesprin-1 gene expression in aorta of AD mice was higher than that of sham-operated mice. CONCLUSIONS: An increased expression of Nesprin-1 was associated with AD, and hence Nesprin-1 may be involved in the pathogenesis of ADs. Preliminary findings suggest that Nesprin-1 may be a therapeutic target for the treatment of AD.

Effect of Progranulin on Migration and Invasion of Human Colon Cancer Cells.

OBJECTIVE: To investigate the effects of progranulin on migration and invasion of human colon cancer cells. STUDY DESIGN: An experimental study. PLACE AND DURATION OF STUDY: Department of Histology and Embryology, College of Basic Medical Sciences, Jilin University, Changchun, China, from October 2015 to July 2017. METHODOLOGY: Cell transfection was used to obtain progranulin knocked down/overexpressing cells. MTT and soft agar assay were applied to investigate the cell growth. Migration and invasion were detected using transwell assay. RESULTS: Tumor growth, migration and invasion decreased in progranulin knocked down cells and increased in progranulin overexpressing cells. The decrease was recovered when exogenous progranulin was added. Progranulin-induced migration and invasion were inhibited by neamine. CONCLUSION: Progranulin has a direct effect on tumor growth, migration, and invasion of human colon cancer cells. It may serve as a potential therapeutic target for human colon cancer.

Angiogenin negatively regulates the expression of basic fibroblast growth factor (bFGF) and inhibits bFGF promoter activity.

Research focused on angiogenin and basic fibroblast growth factor (bFGF) was expected to identify means to inhibit tumor growth and metastasis. However, interactions exist between the two angiogenic factors, and the overall mechanism is still not clear. To explore the mechanism by which angiogenin regulates the expression of bFGF, RT-PCR and western blot were performed to analyze bFGF expression. Nuclear translocation of angiogenin was investigated by immunofluorescence staining and immune electron microscopy. Site-directed mutagenesis, reporter gene assays, and electrophoretic gel mobility shift assay (EMSA) were applied to investigate the promoter activity. The results showed that angiogenin negatively regulates bFGF expression in HeLa cells. Angiogenin undergoes nuclear translocation, and an angiogenin binding site (CTCTCTCT) on the bFGF promoter was identified. bFGF promoter activity was inhibited by angiogenin. Angiogenin and bFGF are two potent and representative angiogenesis factors, that play an important role in tumor angiogenesis and development. These mechanisms guide us to further investigate the effect of angiogenin and bFGF on tumor growth and development.

Electrospun nanofibrous sheets of collagen/elastin/polycaprolactone improve cardiac repair after myocardial infarction.

Electrospun nanofibrous sheets get increasing attention in myocardial infarction (MI) treatment due to their good cytocompatibility to deliver transplanted stem cells to infarcted areas and due to mechanical characteristics to support damaged tissue. Cardiac extracellular matrix is essential for implanted cells since it provides the cardiac microenvironment. In this study, we hypothesized high concentrations of cardiac nature protein (NP), namely elastin and collagen, in hybrid polycaprolactone (PCL) electrospun nanofibrous sheets could be effective as cardiac-mimicking patch. Optimal ratio of elastin and collagen with PCL in electrospun sheets (80% NP/PCL) was selected based on cytocompatibility and mechanical characteristics. Bone-marrow (BM) c-kit(+) cells anchoring onto NP/PCL sheets exhibited increased proliferative capacity compared with those seeded on PCL in vitro. Moreover, we examined the improvement of cardiac function in MI mice by cell-seeded cardiac patch. Green Fluorescent Protein (GFP)-labeled BM c-kit(+) cells were loaded on 80% NP/PCL sheets which was transplanted into MI mice. Both 80% NP/PCL and c-kit(+)-seeded 80% NP/PCL effectively improved cardiac function after 4 weeks of transplantation, with reduced infarction area and restricted LV remodeling. C-kit(+)-seeded 80% NP/PCL was even superior to the 80% NP/PCL alone and both superior to PCL. GFP(+) cells were identified both in the sheets and local infarcted area where transplanted cells underwent cardiac differentiation after 4 weeks. To the best of our knowledge, this is the first report that sheets with high concentrations of nature proteins loaded with BM c-kit(+) cells might be a novel promising candidate for tissue-engineered cardiac patch to improve cardiac repair after MI.

Circulating microRNA-223 as a potential biomarker for obesity.

BACKGROUND AND AIMS: Obesity is a serious health problem that is implicated in many metabolic disorders. Recent studies have proposed that microRNA-223 (miR-223) is a potent regulator of many diseases related to obesity. However, the association of miR-223 with obesity remains unclear. In this study, we examined the relationship between serum miR-223 and obesity. DESIGN: A total of 121 subjects were selected, including 41 normal-weight, 40 overweight and 40 obesity subjects. The overweight and obesity subjects received lifestyle intervention for 3 months after baseline examination. Quantitative real-time PCR was used to measure the expression of circulating miR-223 in the serum. RESULTS: MiR-223 was lower in both overweight and obesity subjects compared with normal-weight control (1.06 vs. 7.54, p<0.001; 4.56 vs. 7.54, p<0.001, respectively). Circulating miR-223 increased significantly in both overweight and obesity groups after lifestyle intervention. Furthermore, subjects with the lowest tertile of miR-223 expression had the highest obesity prevalence. The odds ratio was 2.77 (95% confidence interval: 1.59-6.54, p<0.05) compared with the highest tertile of miR-223 expression. Such association was still apparent after adjusting for other major risk factors. CONCLUSION: The findings in this study suggest that miR-223 is a factor of obesity. The level of miR-223 in the serum can be used as a biomarker of obesity and therapeutic response.

Production of hybrid phage displaying secreted aspartyl proteinase epitope of Candida albicans and its application for the diagnosis of disseminated candidiasis.

The secreted aspartyl proteinases (Saps) of Candida albicans have been implicated as immunodominant antigens and virulence factors associated with adherence and tissue invasion. A hybrid phage displaying the Sap epitope VKYTS was constructed by cloning the corresponding DNA fragments into the pfd88 vector. Similar to native Sap, the phage-displayed epitope showed reactivity to sera from mice and patients with systemic C. albicans infection but not from those with oropharyngeal candidiasis and healthy individuals on Western blot. Furthermore, a new enzyme-linked immunosorbent assay was developed to detect the anti-Sap antibody with hybrid phage displaying Sap epitope VKYTS that can be recognised by anti-Sap antibodies. Sequential sera were tested from patients and mice with systemic candidiasis and oropharyngeal candidiasis, and serum samples from healthy individuals were also included. The sensitivity and specificity were 77% and 88.3% for experimental mice, respectively. These values reached 60% and 85%, respectively, for human patients. These data indicate this phage-displayed epitope as an effective and less expensive reagent would be a valuable probe for the detection of specific Sap antibody in the sera of patients and mice with systemic C. albicans infection.

Comparison of phage pVIII and KLH as vector in inducing the production of cytokines in C57BL/6J mice.

We have demonstrated that phage display Candida albicans (C. albicans) LKVIRK epitope was protective in systemically infected C57BL/6J mice. The different development from precursor Ths, Th1 or Th2, will result in a protective or nonprotective immune response. To compare the types of cytokines induced by biologically and chemically synthesized vectors, C57BL/6J mice were immunized with hybrid phage displaying the epitope of LKVIRK and by synthesized peptide epitope LKVIRKNIVKKMIE conjugated through cysteine to keyhole limpet haemocyanin (KLH). The production of cytokines in spleens of immunized mice and in splenocytes culture supernatants stimulated by homologous immunogen in vitro was studied by RT-PCR and quantitative sandwich ELISA. The results showed that, compared to Tris-EDTA buffer (TE, 1 mM Tris, 0.1 mM EDTA, pH 8.0) injected mice, the expressions of Th1 type cytokine IFN-gamma, IL-2 and IL-12 were increased in hybrid phage, KLH-C, and wild phage immunized mice, and there were no differences between mice immunized with hybrid phage and KLH-C. While the expression of Th2 type cytokine IL-10 was similar in all mice, IL-4 was not detected. We obtained the same results in mRNA and protein level. These findings indicated that as carriers, phage and KLH were similar in inducing the Th1 type cytokines expression. Comparing to peptide synthesis couple with a carrier protein for injection, phage may be an inexpensive and simple route to the production of effective vaccines.