Effect of high sodium ion level on the interaction of AmB with a cholesterol-rich phospholipid monolayer.

Invasive fungal infections are a primary reason for high mortality in immunocompromised people, especially in critically ill patients, such as intensive care unit (ICU) patients, advanced cancer patients, or severe burn patients. Hypernatremia also can increase mortality in severely ill patients. Amphotericin B (AmB) is the gold standard for treating infections, but in severely ill patients, AmB can cause hematotoxicity when administered intravenously due to its interaction with cholesterol on red blood cell membranes. This results in limited doses of AmB and affects the treatment of infections. The proportion of cholesterol molecules in membrane lipids in red blood cells is as high as 50 mol%, and the sodium ions can influence the interaction between AmB and lipids on the membrane. Therefore, in the complex clinical situation of a severely ill patient with a fungal infection and hypernatremia, the interaction between amphotericin B and the red blood cell membranes is worth studying in depth. In this work, the interaction between AmB and the dipalmitoyl phosphatidylcholine (DPPC)/cholesterol mixed monolayer in the presence of high sodium ion levels was studied when the proportion of cholesterol was 50%. The results show that the effect of AmB on reducing the monolayer's area at a high level of sodium ions is slightly stronger at 30 mN/m. The effect of AmB on reducing the elastic modulus of the DPPC/Chol monolayer is significantly weakened by a high sodium ion level, compared with the level of sodium ions at normal physiological concentration. The higher the sodium ion concentration, the weaker the intermolecular force of the DPPC/Chol/AmB mixed monolayers. The scanning electron microscope (SEM) and atomic force microscopy (AFM) observations suggest that at a high sodium ion level, the presence of AmB significantly reduces the surface roughness of the DPPC/Chol monolayer. AmB may bind to cholesterol molecules, and it isolates cholesterol from the monolayer, resulting in a reduced height of the cholesterol-rich monolayer and an increasingly dispersed monolayer region. The results are beneficial to understanding the mechanism of impact of a high sodium ion level on the relationship between AmB and red blood cell membranes rich in cholesterol and are valuable for understanding the hemolytic toxicity of AmB to red blood cells at a high sodium ion level.

Piperazine skeleton in the structural modification of natural products: a review.

Piperazine moiety is a cyclic molecule containing two nitrogen atoms in positions 1 and 4, as well as four carbon atoms. Piperazine is one of the most sought heterocyclics for the development of new drug candidates with a wide range of applications. Over 100 molecules with a broad range of bioactivities, including antitumor, antibacterial, anti-inflammatory, antioxidant, and other activities, were reviewed. This article reviewed investigations regarding piperazine groups for the modification of natural product derivatives in the last decade, highlighting parameters that affect their biological activity.

In vitro and in vivo analysis of metabolites involved in the TCA cycle and glutamine metabolism associated with cisplatin resistance in human lung cancer.

Elucidating the dysregulated metabolic pathways in cancer cells and their relevance to cisplatin resistance could yield new insights into cancer therapy. We previously reported that eight metabolites involved in the tricarboxylic acid (TCA) cycle and glutamine metabolism were associated with platinum-based chemotherapy efficacy in human lung cancer. Here, we investigated the metabolic differences upon cisplatin treatment in lung cancer in vitro and in vivo. A simple and partially validated standard addition method was applied for the quantification of five metabolites involved in the TCA cycle and glutamine metabolism using amide hydrophilic interaction liquid chromatography-tandem mass spectrometry (HILIC-MS/MS). The present study investigated the levels of these biomarkers in A549 cells and the cisplatin-resistant A549-DDP cells, as well as in the plasma before and after cisplatin treatment in A549 xenograft mice. Levels of five metabolites, including 2-hydroxyglutaric acid (2-HG), α-ketoglutarate (α-KG), succinate, glutamine, and glutamate, showed a decreasing trend in A549-DDP cells. In addition, 2-HG and glutamine were the most significantly altered metabolites in cisplatin-treated A549 xenograft mice. These data indicate that the TCA cycle and glutamine metabolism play important roles in cisplatin-based chemotherapy resistance in lung cancer. Our results provide a new angle for exploring the molecular mechanisms underlying cisplatin resistance.

Mortalin expression in pancreatic cancer and its clinical and prognostic significance.

Mortalin, an essential mitochondrial chaperone protein, is involved in the tumorigenesis of a number of malignancies. This study aimed to investigate the expression of Mortalin in pancreatic ductal adenocarcinoma (PDAC) cells and to determine its clinicopathological and prognostic significance. The localization of Mortalin protein was detected in BXPC-3 PDAC cells using immunofluorescence. Immunohistochemistry was also used to detect Mortalin expression in well-defined tissues obtained from 106 PDAC patients and 46 corresponding nontumor pancreatic tissues. Clinicopathological parameters and overall survival data were collected and compared between different Mortalin statuses. The results of immunohistochemistry and immunofluorescence showed that Mortalin was primarily present in the cytoplasm of PDAC cells. The ratio of strong positive staining for Mortalin was higher in PDAC tissues (55.66%; 59/106) than in normal adjacent tissues (23.91%; 11/46). Positive relationships between Mortalin expression and clinical stage, perineural invasion, lymph node metastasis, and lower overall survival were observed. Multivariate Cox regression analysis identified Mortalin as a significant independent prognostic factor, in addition to location, clinical stage, and perineural invasion, for survival of PDAC patients. Therefore, we present strong evidence that Mortalin may function as a practical marker to predict prognosis and as a potential therapeutic target in PDAC treatment.

DEK protein overexpression predicts poor prognosis in pancreatic ductal adenocarcinoma.

DEK, a transcription factor, is involved in mRNA splicing, transcriptional control, cell division and differentiation. Recent studies suggest that DEK overexpression can promote tumorigenesis in a wide range of cancer cell types. However, little is known concerning the status of DEK in pancreatic ductal adenocarcinoma (PDAC). Based on the microarray data from Gene Expression Omnibus (GEO), the expression levels of DEK mRNA in PDAC tissues were significantly higher than levels in the adjacent non-tumor tissues. To explore the clinical features of DEK overexpression in PDAC, 87 PDAC and 52 normal pancreas tissues were selected for immunoenzyme staining of the DEK protein. Localization of the DEK protein was detected in PANC-1 pancreatic cancer cells using immunofluorescence (IF) staining. The correlations between DEK overexpression and the clinical features of PDAC were evaluated using the Chi-squared (χ2) and Fisher's exact tests. The survival rates were calculated by the Kaplan-Meier method, and the relationship between prognostic factors and patient survival was also analyzed by the Cox proportional hazard models. The expression levels of DEK mRNA in PDAC tissues were significantly higher than that in the adjacent non­tumor tissues. The DEK protein showed a primarily nuclear staining pattern in PDAC. The positive rate of the DEK protein was 52.9% (46/87) in PDAC, which was significantly higher than that in the adjacent normal pancreatic tissues (7.7%, 4/52). DEK overexpression in PDAC was correlated with tumor size, histological grade, tumor­node­metastasis (TNM) stage and overall survival (OS) rates. In addition, multivariate analysis demonstrated that DEK overexpression was an independent prognostic factor along with histological grade and TNM stage in patients with PDAC. In conclusion, DEK overexpression is associated with PDAC progression and may be a potential biomarker for poor prognostic evaluation in PDAC.

Significance of DEK overexpression for the prognostic evaluation of non-small cell lung carcinoma.

In the present study, we explored the role of DEK expression for the prognostic evaluation of non-small cell lung carcinoma (NSCLC). DEK protein and mRNA expression levels were detected in NSCLC cells and fresh tissue samples of NSCLC paired with adjacent non-tumor tissues, respectively. NSCLC cases (n=196) meeting strict follow-up criteria were selected for immunohistochemical staining of DEK protein. Correlations between DEK expression and clinicopathological features of the NSCLC cases were evaluated using Chi-square tests. Survival rates were calculated using the Kaplan-Meier method, and the relationship between prognostic factors and patient overall survival was analyzed using Cox proportional hazard analysis. Based on the results, the levels of DEK protein and mRNA were significantly upregulated in 6 fresh tissue samples of NSCLC. Immunohistochemical analysis showed that the DEK expression rate was significantly higher in the NSCLC samples compared with either the adjacent non-tumor tissues or normal lung tissues. DEK expression was correlated with poor differentiation and late pathological stage of NSCLC. DEK expression was also correlated with low disease-free survival and overall survival rates. In the early-stage group, disease-free and overall survival rates of patients with DEK expression were significantly lower than those of patients without DEK expression. Further analysis using a Cox proportional hazard regression model revealed that DEK expression emerged as a significant independent hazard factor for the overall survival rate of patients with NSCLC. Consequently, DEK plays an important role in the progression of NSCLC. DEK may potentially be used as an independent biomarker for the prognostic evaluation of NSCLC.

DEK over expression as an independent biomarker for poor prognosis in colorectal cancer.

BACKGROUND: The DEK protein is related to chromatin reconstruction and gene transcription, and plays an important role in cell apoptosis. High expression levels of the human DEK gene have been correlated with numerous human malignancies. This study explores the roles of DEK in tumor progression and as a prognostic determinant of colorectal cancer. METHODS: Colorectal cancer specimens from 109 patients with strict follow-up, and colorectal adenomas from 52 patients were selected for analysis of DEK protein by immunohistochemistry. The correlations between DEK over expression and the clinicopathological features of colorectal cancers were evaluated by Chi-square test and Fisher's exact tests. The survival rates were calculated by the Kaplan-Meier method, and the relationship between prognostic factors and patient survival was also analyzed by the Cox proportional hazard models. RESULTS: DEK protein showed a nuclear immunohistochemical staining pattern in colorectal cancers. The strongly positive rate of DEK protein was 48.62% (53/109) in colorectal cancers, which was significantly higher than that in either adjacent normal colon mucosa (9.17%, 10/109) or colorectal adenomas (13.46%, 7/52). DEK over expression in colorectal cancers was positively correlated with tumor size, grade, lymph node metastasis, serosal invasion, late stage, and disease-free survival- and 5-year survival rates. Further analysis showed that patients with late stage colorectal cancer and high DEK expression had worse survival rates than those with low DEK expression. Moreover, multivariate analysis showed high DEK expression, serosal invasion, and late stage are significant independent risk factors for mortality in colorectal cancer. CONCLUSIONS: DEK plays an important role in the progression of colorectal cancers and it is an independent poor prognostic factor of colorectal cancers.

[Effects of diesel exhaust particles inhalation on immediate reaction in asthma rats].

OBJECTIVE: The role of air pollution on asthma can not be ignored, diesel exhaust particles (DEP) in the air is one of the most important pollutants. This study aimed to investigate the effect and mechanism of DEP inhaled on immediate reaction in the asthma rats. METHOD: Sixty male Wistar rats of "Clean" grade, 6 - 7 week-old, with an average weight of (140 +/- 20) g were used in this study. The rats were randomly divided into 6 groups, 10 in each. Group A was treated with normal saline attack as a negative control, Group B with ovalbumin attack as a positive control. After ovalbumin attack, groups C, D, E, F continued to inhale DEP for 1 week, 2 weeks, 3 weeks and 4 weeks, respectively. The concentration of DEP was 200 microg/ml, the animals were subjected to inhalation of ultrasound nebulized DEP for 30 min per day. One week after all the attacks were concluded, Group A was stimulated with normal saline for 30 min, other groups were stimulated with ovalbumin. Then the airway resistance was determined with multi-channel signal acquisition and processing system and compared. The changes in neutrophils, eosinophils, and other inflammatory cells of BALF and the pathological changes in lung tissue, including epithelial cells loss, the inflammatory cells infiltration around the airway, basement membrane fibrosis, goblet cell hyperplasia etc. were observed. The concentration of IL-5 and gamma-interferon in the lung tissues, and the changes of serum IgE etc. were determined. RESULT: Airway resistance values of group A, B, C, D, E, F after ovalbumin excitation for 30 min were (3.56 +/- 0.21), (7.06 +/- 0.63), (6.46 +/- 0.38), (7.47 +/- 0.33), (8.87 +/- 0.61), (11.00 +/- 0.69) cm H2O/(ml.s). No airway hyperresponsiveness occurred in group A, while Groups B, C, D, E, F had higher airway resistance than group A, group E and F had higher airway resistance than that of group B, the differences were statistically significant. And the airway resistance was different in each group among 0 min, 10 min, 20 min and 30 min (F = 160.646, 148.901, 162.204, 156.186, P < 0.01 for both). The time of DEP inhalation and the airway resistance was positively correlated (r = 0.948, P < 0.01); IgE concentrations of the serum between groups B, C, D, E, F was not significantly different (P > 0.05), but higher than that of group A (F = 2.639, P < 0.01). The infiltrated inflammatory cells included eosinophils and lymphocytes, etc. The percentages of neutrophil(%) were (4.3 +/- 2.0), (9.7 +/- 5.2), (10.3 +/- 5.6), (13.0 +/- 5.2), (42.6 +/- 18.3), (55.3 +/- 6.9). The groups E and F had higher percentage than Group A and Group B (F = 114.226, P < 0.01). The percentages of eosinophils(%) were 0, (11.9 +/- 3.8), (15.8 +/- 6.3), (13.0 +/- 4.9), (21.1 +/- 5.6), (27.1 +/- 4.8). The difference between Groups B, C, D, E, F and Group A was statistically significant. There was significant difference between groups C, D, E, F and group B (F = 46.462, P < 0.05); Lung tissue biopsy in group A showed that the epithelial cells were intact, no inflammatory cells infiltrations were found around the airways, instead, mainly ciliated columnar epithelial cells and only a small number of goblet cells were seen without basement membrane fibrosis. With the inhalation of DEP, the epithelial cells showed gradual necrosis, disruption and loss, goblet cells showed hyperplasia, and infiltrations with inflammatory cells were seen around the airway. In the lung tissue, concentrations of IL-5 in group B, C, and E were (12.8 +/- 2.8), (17.1 +/- 5.2), (18.6 +/- 4.2) pg/mg, the difference between groups C, E and group B was statistically significant (F = 4.236, P < 0.01), the difference in gamma-interferon concentration among all groups was not statistically significance (F = 1.185, P > 0.05). CONCLUSION: DEP inhalation increased the airway responsiveness of asthma rats in immediate reaction, promoted the lung epithelial cell loss, inflammatory cell infiltration, basement membrane fibrosis and goblet cell hyperplasia.