Identification of the Beta Subunit Fas1p of Fatty Acid Synthetase as an Interacting Partner of Yeast Calcium/Calmodulin-Dependent Protein Kinase Cmk2p Through Mass Spectrometry Analysis.

The calcium/calmodulin-dependent protein kinase II (CaMKII) is a mediator of calcium signals and regulates fatty acid metabolism in mammalian cells. Cmk2p is a yeast homolog of CaMKII and functions as a negative regulator of calcium signaling. However, its substrates remain to be identified. Combination of immunoprecipitation (IP) and mass spectrometry has been proven to be very useful for identification of interacting partner proteins and interactome. In this study, through these approaches, we have identified 65 and 110 potential Cmk2p-interacting proteins in yeast cells in the absence or presence of calcium stress, respectively. In yeast cells expressing both CMK2-HA and FAS1-GFP fusion proteins, in the absence or presence of calcium stress, less amounts of FAS1-GFP proteins are present in cell lysates after IP with anti-HA antibody than cell lysates before IP, while FAS1-GFP proteins are detected on both types of IP beads. However, as an internal control, similar amounts of Pgk1p proteins were detected in both after-IP and before-IP cell lysates but not on the IP beads. Therefore, our biochemical analysis demonstrates that the ß subunit Fas1p of fatty acid synthetase interacts with Cmk2p in yeast cells independent of calcium stress. It is also interesting to note that, in addition to the expected 52-kDa CMK2-HA band, a faster-moving 48-kDa CMK2-HA band is present in the calcium-stressed cell lysate but not in the cell lysate without calcium stress. Our data would provide important clues for understanding the functions of CaMKII in the regulation of fatty acid metabolism as well as related diseases such as cancers, diabetes, and obesity.

Hepatitis B virus enhances cisplatin-induced hepatotoxicity via a mechanism involving suppression of glucose-regulated protein of 78 Kda.

Cisplatin is a classical platinum-based chemotherapeutic drug used in the treatment of many cancer types, including hepatocellular carcinoma (HCC). The application of cisplatin is significantly limited by its toxicity, which may be affected by various biological factors. Persistence of Hepatitis B virus (HBV) infection leads to HCC development and may be associated with higher incidence of severe hepatitis during chemotherapy. However, whether HBV alters the susceptibility of hepatocytes to cisplatin remains poorly understood. Here, we demonstrate that HBV transfection enhanced cisplatin-induced hepatotoxicity via a mechanism involving suppression of glucose-regulated protein of 78 KDa (Grp78), a major stress-induced chaperone that localizes to the endoplasmic reticulum. Silencing Grp78 gene increased the susceptibility of HepG2 to cisplatin by activating caspase-3. Grp78 expression was down-regulated by HBV infection both in vitro and in liver tissues of patients. We compared the cisplatin sensitivity of hepatoma cells either expressing (HepG2.2.15 cells) or not expressing the entire Hepatitis B Virus genome (HepG2). HepG2.2.15 cells showed increased sensitivity to cisplatin and a higher apoptosis rate. Overexpression of Grp78 counteracted the increase of sensitivity of HepG2.215 cells to cisplatin. Furthermore, we found that HBV disrupted Grp78 synthesis in response to cisplatin stimulation, which may trigger severe and prolonged endoplasmic reticulum (ER) stress that can induce cellular apoptosis. Our findings provide new information into the effect of HBV in the modulation of Grp78 expression, and, consequently on cisplatin-induced hepatotoxicity during viral infection.

The expression levels of endogenous aFGF mRNA in microwave burn wound tissues and its clinical significance.

The expression levels and changes of endogenous acid fibroblast growth factor (aFGF) in microwave burn wound tissues were detected in order to investigate how to get better therapeutic effects by using the exogenous aFGF for repairing trauma. A burnt-wound animal model was established by NS-F II multifunction spectrum therapeutics equipment, and reverse transcriptase-polymerase chain reaction (RT-PCR) and immunohistochemistry assay were applied to detect the expression levels of endogenous aFGF mRNA in microwave burn wound tissues. The expression level of endogenous aFGF mRNA was significantly increased in the burn wound tissues 12 h after burn, reached the peak at 48 h, and gradually deceased 96 h after burn. The expression of endogenous aFGF mRNA after tissue damage was reversible, and its intensity was in accordance with the repair process of tissue damage, suggesting endogenous aFGF may take part in the cell metabolism and proliferation, and then promote the repair of the burn wound.

[Clinical efficacy of Bannaitong Mdicinal Tea combined with azasetron in preventing and treating chemotherapy induced gastrointestinal reaction].

OBJECTIVE: To observe the effects of Biannaitong Medicinal Tea (BNT) combined with Azasetron in preventing and treating the gastrointestinal reaction induced by chemotherapy. METHODS: Sixty-four patients underwent chemotherapy with DP regimen (docetaxol + DDP) were randomly assigned to two groups, the treated group and the control group. All patients were given 10 mg Azasetron intravenously 30 min before starting chemotherapy once a day for two successive days, but to patients in the treated group, 300 mL BNT was given orally additionally in the evenings before chemotherapy. The occurrence of adverse reactions, such as antiemetic efficacy constipation, abdominal distention, etc. was observed. RESULTS: The vomiting control rates in the two groups were insignificantly different (87.5% vs 84.4%, P > 0.05), but difference in the complete control rates between them were significant (53.1% vs 43.8% , P < 0.05). And the occurrences of constipation (3.1% vs 59.4%) and abdominal distention (15.6% vs 59.4%) in the two groups were also significantly different (both P <0.05). CONCLUSION: BNT used in coordination with Azasetron for alleviating vomiting could enhance the antiemetic effect, reduce the adverse effects of chemotherapy, such as constipation, abdominal distension and anorexia, and thus to increase the compliance of patients.