Assessment of magnesium influence on fatty acid content in isolated rat hepatocytes subjected to incubation.

Magnesium salts are components of many dietary supplements used in treatment or prevention of magnesium deficiency. Hypomagnesemia usually results from an improper lifestyle, including unbalanced diet. Isolated hepatocytes of animals or humans are the preferred model used to study the in vitro effects of exogenous factors on cellular metabolic changes. The aim of this study was to evaluate the content of saturated, monounsaturated and polyunsaturated fatty acids and their esters in isolated rat hepatocytes influenced by different magnesium concentrations. The isolated rat hepatocytes were used as the test material. Hepatocytes were prepared in culture medium (Hepatocyte Medium) + MgCl(2) solution to concentrations of 2 mM/dm(3) MgCl(2), 4 mM/dm(3) MgCl(2). After incubation with different concentrations of magnesium ions, changes in the content of fatty acids and their esters were found for the whole hepatocytes and hepatocyte membranes. Despite changes in the fatty acid content in the whole hepatocytes and their membranes, there were no changes in the coefficient of degree of saturation of fatty acids when different concentrations of MgCl2 were used.

The profile of melatonin receptors gene expression and genes associated with their activity in colorectal cancer: a preliminary report.

The antiproliferative and immunomodulatory effects of melatonin (MLT) have been demonstrated in a variety of neoplasms including colorectal cancer (CRC). In humans and other mammals, MLT acts on target tissues through membrane and retinoid nuclear receptors. The aim of this study was to evaluate transcription activity of melatonin receptors and genes associated with regulation of their activity in colorectal adenocarcinoma tissues in relation to clinical stage of cancer. A total of 24 pairs of surgically removed tumoral and healthy (marginal) tissue samples from colorectal cancer patients at clinical stages I-II and III-IV were collected. As an additional control, twenty normal samples were tak¬en from people whose large intestine tissues were reported as non-tumoral after colonoscopy. Expression of mRNA genes was studied by microarray HG-U133A analysis. The analysis of gene expression profile was performed using commercially available oligonucleotide microarrays of HG-U133A. High increase of MT1 mRNA expression levels in all cancerous samples vs non-cancerous tissues was observed. The MT2 mRNA expression levels increased slightly in marginal and malignant samples. Among the genes participating in the cascade of signal transfer in cells activated by MLT via melatonin receptors, we found encoding genes (GNA11, OXTR, TPH1) only for differentiating stage III - IV of CRC. Monitoring the expression levels of genes that are related to melatonin receptors may offer a strategy to anticipate tumour development and estimate the molecular changes that occur during carcinogenesis. The mechanism behind this association needs further elucidation.

Changes in the content of short, medium and long-chain fatty acids in isolated hepatocytes incubated in the presence of magnesium ions and/or ethanol.

Magnesium is one of the commonly used dietary supplements. Therefore, this study was to evaluate the content of short, medium and long-chain fatty acids and their esters in isolated rat hepatocytes induced by magnesium and/or ethanol. Isolation of hepatocytes was carried out by the Seglen's enzymatic method using collagenase. To thus prepared samples ethanol and/or MgCl2 solution were added, respectively, so that their concentrations were as follows: 150 mM/dm3 ethanol and/or 2 mM/dm3 MgCl2, 4 mM/dm3 MgCl2. The contents of short, medium and long-chain fatty acids and those of ester-bound acids were determined. The statistical evaluation of the experiment was made by comparing the area normalized for the analysed fatty acids in hepatocytes incubated for 5 h in the presence of the test substances. The effect of magnesium ions on the content of fatty acids and their esters in isolated hepatocytes incubated for 5 h depended on their concentration in the medium. A normalizing effect of magnesium ions on ethanol-induced changes in the content of C14-C17, C18-C20 and C21-C24 fatty acids was demonstrated. A normalizing effect of magnesium on ethanol-induced changes in the content of ester-bound fatty acids in hepatocytes was not confirmed.

Effect of magnesium ions on ethanol-induced changes in the pool of saturated, mono- and polyunsaturated fatty acids in isolated rat hepatocytes.

The aim of the paper was the assessment of the effect of magnesium ions on ethanol-induced changes in the content of ester-bound fatty acids in isolated rat hepatocytes and their cell membranes. Hepatocytes were isolated by means of the enzymatic method of Selgen using collagenase. The number and viability of isolated rat hepatocytes, incubated for 5 hours in culture media (Hepatocyte Medium) with ethanol and MgCl2 solutions with concentration amounting respectively to: 150 mM/dm3 of ethanol and/or 2 mM/dm3 of MgCl2, 4 mM/dm3 of MgCl2, were determined. Biochemical tests of hepatocytes were performed, consisting in the determination of the total content of ester-bound fatty acids in whole hepatocytes and their cell membranes after incubation. Confirmed normalising action of magnesium ions with respect to the effects induced in hepatocytes and their membranes by the presence of ethanol should be attributed to the important role of magnesium which it performs during reactions taking place with participation of ATP.

Statistical analysis of differential gene expression in colorectal cancer using CLEAR-test.

CLEAR test provides a novel method of analysis by combining inference for differential expression and variability. Frozen tumor specimens from 14 (3 coded Stage I, 5 Stage II, 2 Stage III and 4 Stage IV) colon cancer patients were obtained. Archived primary tumor samples were collected at the time of surgery and normal colon mucosae (controls specimens) were also collected. The studied transcriptomes were clustered using hierarchical agglomeration with Ward's method and Tchebychev distance. The separable groups of transcriptomes were classified as high clinical stage of adenocarcinoma (HCS; stages II-IV), low clinical stage of adenocarcinoma (LCS; stages I and 3 controls), and two normal colon mucosae (controls N1 and N2). The results of the CLEAR-test algorithm in normal colon specimens and adenocarcinoma specimens with low and high clinical stage showed 50 most and 50 least significant genes. The list of differential genes (p<0.01) in normal colon specimens and adenocarcinoma specimens with low and high clinical stage presented 58 genes.