Proteomic Sequencing of Stellate Ganglions in Rabbits With Myocardial Infarction

The stellate ganglion (SG) of the autonomic nervous system plays important role in cardiovascular diseases (CDs). Myocardial infarction (MI) is associated with sustained increasing cardiac sympathetic nerve activity. Expressions and functions of proteins in SG tissue after MI are remaining unclear. This study is to explore the expression characteristics of proteins in SGs associated with MI. Japanese big-ear white rabbits (n = 22) were randomly assigned to the control group and MI group. The MI model was established by left anterior descending coronary artery ligation and confirmed by serum myocardial enzymes increasing 2,3,5-triphenyltetrazolium (TTC) staining and echocardiography. The expressions of proteins in rabbit SGs after MI were detected using tandem mass tags (TMT) quantitative proteomic sequencing. There were 3,043 credible proteins were predicted in rabbit SG tissues and 383 differentially expressed proteins (DEPs) including 143 upregulated and 240 downregulated proteins. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that the DEPs involved in adrenergic signaling in cardiomyocytes, positive regulation of ERK1 and ERK2 cascade, and other biological processes. Three kinds of proteins directly correlated to CDs were selected to be validated by the subsequent western blot experiment. This study first identified the characterization of proteins in rabbit SG after MI, which laid a solid foundation for revealing the mechanism of roles of SG on the MI process.

The Role of SIRT5 and p53 Proteins in the Sensitivity of Colon Cancer Cells to Chemotherapeutic Agent 5-Fluorouracil

In the treatment of colorectal cancer, it is important to develop drug combinations that will increase the effectiveness of chemotherapy and to determine the molecular targets of the drugs. Therefore, combined therapies that can increase the sensitivity of 5-Fluourouracil (5-FU), a chemotherapeutic agent used in the treatment of colon cancer, and also the molecular pathways involved in this process are important in the treatment of the disease. Here we examined the SIRT5 (Resveratrol and Suramin) and p53 (Nutlin3a) modulators alone or in combination with 5-FU on the proliferation of colon cancer cells and effect of 5-FU on the SIRT5 and FOXO3a expressions whether p53 dependent or independent manner. p53 protein expression is activated by nutlin3a in HCT-116 p53 +/+ cells and HCT-116 p53 -/- cells were used as counterpart cells that did not express p53. According to our MTT assay results, we showed that these modulators have significant effects on the sensitivity of both cells to 5-FU. In p53+/+ cells, Resveratrol (RSV) and Nutlin3a and in p53 -/- cells, Suramin was found to be more effective. These differences were evaluated together with the effect of 5-FU on the SIRT5-FOXO3a-Bim axis in p53 +/+ and p53 -/- cells. SIRT5 is known to deactivate FOXO3a which plays a role in the induction of apoptosis via Bim. Our western blot experiment results showed that while Suramin decreased SIRT5 and RSV decreased FOXO3a protein expressions significantly in HCT-116 p53 -/- cells, 5-FU decreased significantly SIRT5 and FOXO3a protein expressions p53 independently. These results may help the discovery of new markers in colon cancer treatment.

A Study of a Mechanism of Cell Proliferation Promotion of Cultured Osteoblasts by Mechanical Vibration

This paper describes a mechanism of cell proliferation promotion of cultured osteoblasts by mechanical vibration focusing on β-catenin. 12.5 Hz and 0.5 G mechanical vibration was reported to promote the cell proliferation of cultured osteoblasts in plane culture. That is because the mechanical vibration weakens cell-cell adhesion, promotes to pile up cells, and allows cells to form multilayer structure. However, it has not been clarified why cells continue cell division after their monolayer confluent state. Here we show that mechanical vibration not only weakens cell-cell adhesion bound by β-catenin but also promotes to move β-catenin from the cytoplasm to the nuclei, where β-catenin associates with DNA-binding members of the Tcf/LEF family and other associated transcription factors including cell division. After osteoblastic cells were cultured under 12.5 Hz and 0.5 G mechanical vibration, cells were fractionated into nuclear and cytoplasmic fractions using a centrifugation method. β-catenin in each fraction was detected by a western blot experiment. The protein bands from western blot films were quantified with an image processing and analysis software, ImageJ. As a result, the vibration group gave higher expression of β-catenin in nuclear fraction than the non-vibration group just after the vibration group reached the saturated cell density. It indicates that 12.5 Hz and 0.5 G mechanical vibration may promote to move β-catenin into the nuclei and the cell division.

The Design of a Quantitative Western Blot Experiment

Western blotting is a technique that has been in practice for more than three decades that began as a means of detecting a protein target in a complex sample. Although there have been significant advances in both the imaging and reagent technologies to improve sensitivity, dynamic range of detection, and the applicability of multiplexed target detection, the basic technique has remained essentially unchanged. In the past, western blotting was used simply to detect a specific target protein in a complex mixture, but now journal editors and reviewers are requesting the quantitative interpretation of western blot data in terms of fold changes in protein expression between samples. The calculations are based on the differential densitometry of the associated chemiluminescent and/or fluorescent signals from the blots and this now requires a fundamental shift in the experimental methodology, acquisition, and interpretation of the data. We have recently published an updated approach to produce quantitative densitometric data from western blots (Taylor et al., 2013) and here we summarize the complete western blot workflow with a focus on sample preparation and data analysis for quantitative western blotting.

Isolation of modified ubiquitin as a neutrophil chemotaxis inhibitor from uremic patients.

Uremic toxins are factors that accumulate in the serum and peritoneal cavity of uremic patients. They are responsible for a variety of functional disturbances and also contribute to the increased risk of infection by interfering with essential functions of the unspecific immune response. From the peritoneal effluent of peritoneal dialysis (PD) patients, a peptide was isolated by applying three different chromatographic methods. This peptide inhibits the chemotactic movement of polymorphonuclear leukocytes (PMNL) in an in vitro assay in a concentration-dependent, nonreversible manner, and therefore belongs to the group of uremic toxins. Amino acid sequencing showed that the isolated peptide has the same amino terminal sequence as ubiquitin. The peptide also reacted with anti-ubiquitin antibodies in a Western blot experiment, but had a more acidic isoelectric point than ubiquitin. By using affinity chromatography, anti-ubiquitin antibody binding fractions were isolated from all PD and hemodialysis (HD) patients investigated. These fractions contained the same acidic band and also significantly inhibited PMNL chemotaxis. Ubiquitin per se had no effect on PMNL chemotaxis. Therefore, it is concluded that from PD and HD patients a modified form of ubiquitin was isolated, and this modification was responsible for its inhibitory effect.