Cadmium ; pharmacology ; Cells, Cultured ; Heat-Shock Proteins ; biosynthesis ; Humans ; Metallothionein ; biosynthesis ; Ubiquitin ; biosynthesis

To investigate the effects of metallothionein (MT) on isolated rat heart, 16 Wistar rats were randomly divided into 2 groups. In control group (group C), distilled water was injected intraperitoneally and 24 h later isolated hearts were perfused with Langendorff and stored at 4 degrees C for 3 h with histidine-tryptophan-ketoglutarate (HTK) solutions, and then isolated hearts were perfused for 2 h by Langendorff. In experimental group (group E), 3.6% ZnSO(4) was injected intraperitoneally, 24 h later isolated hearts were perfused by Langendorff and stored at 4 degrees C for 3 h with HTK solutions, and then the isolated hearts were perfused for 2 h with Langendorff. MT content, the recovery of hemodynamics, myocardial water content (MWC), lactate dehydrogenase (LDH) and creatine kinase (CK) leakage, adenosine triphosphate (ATP) and malondialdehyde (MDA) content, superoxide dismutase (SOD) activity, myocardial cell Ca(2+) content, Ca(2+)-ATPase activity of mitochondria ([Ca(2+)-ATPase](m)) and its Ca(2+) content ([Ca(2+)](m)), synthesizing ATP activity of mitochondria ([ATP](m)), and the ultrastructure of cells were examined. There were a significant increase in group E in hemodynamic recovery, ATP content, SOD activity, [Ca(2+)-ATPase](m) activity, [ATP](m) activity, and substantial reduction in MWC, LDH and CK leakage, MDA content, myocardial cell Ca(2+) content, [Ca(2+)](m) content, and the ultrastructural injury were obviously milder than that of group C. This study demonstrated that MT has protective effects on isolated rat heart.
Cardiotonic Agents/*pharmacology ; Creatine Kinase/*metabolism ; L-Lactate Dehydrogenase/metabolism ; Metallothionein/biosynthesis ; Metallothionein/*pharmacology ; Myocardium/*metabolism ; Myocardium/ultrastructure ; Random Allocation ; Rats, Wistar ; Superoxide Dismutase/metabolism ; Zinc Sulfate/pharmacology

Metallothioneins (MT) are potential candidates for medicine development and application. For the purpose of expressing recombinant MT in E. coli, a crab MT cDNA cloned into pGEM-T was subcloned into pET-GST and then transformed into Escherichia Coli BL21. The fusion protein was proved to be expressed in both soluble and insoluble form by SDS-PAGE and western blot. Since metallothionein chelate metal ions, which may effects the physiological process of E. coli, caused the production of recombinant protein was lower than expected. Optimization of the ions content in the culture medium improved expression. The protein was purified by Zn2+ affinity chromatography, and rinsed off with high imidazole (1.5 M) which was the result of MT chelating instead of His-tag. This fusion protein laid a foundation of further study on the structural and functional biology of metallothionein.
Animals ; Brachyura ; genetics ; Escherichia coli ; genetics ; metabolism ; Metallothionein ; biosynthesis ; genetics ; isolation & purification ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; isolation & purification

OBJECTIVETo investigate the feasibility of metallothionein (MT) gene expression level in human peripheral blood lymphocytes (HPBLs) as a biomarker in cadmium exposure.

METHODSThe MT gene expression level in HPBLs of workers exposed to cadmium was examined using RT-PCR technique, and the exposure assessment and effect assessment were conducted in exposed workers.

RESULTSThe basal MT-1A, IE, IF, IX and MT-2A expression level in workers exposed to cadmium were significantly higher than those in the control group (P < 0.05). The basal MT-1A, IE, IF, IX and MT-2A expression level would be significantly increased with the increase of the blood cadmium (BCd) level (P < 0.05). There was a trend of increase for the mRNA expression of the basal MT-1A, 1E, IF, IX, MT-2A, especially for the mRNA expression of MT-1A and MT-2A (P < 0.05) with the increase of the level of the urine cadmium (UCd). There was a good dose-response relationship between basal MT-1A expression and UCd. The basal MT-1A, IE, IF, IX and MT-2A expression level were significantly correlated with BCd (P < 0.05) while the basal MT-1A, IF and MT-2A expression level were significantly correlated with UCd (P < 0.05). There were dose-effect relationships of BCd to the basal MT-1E, MT-1F, MT-1X and MT-2X expression level respectively and there were also dose-effect relationships of UCd, beta(2)-MG and the urine metallothionein to the basal MT-1A expression.

CONCLUSIONThe expression of the MT gene isoforms in HPBLs can serve as the biomarker for the cadmium exposure and MT-1A can also serve as the effective biomarkers for the cadmium-induced renal toxicity.

Adult ; Biomarkers ; metabolism ; Cadmium ; metabolism ; pharmacology ; Dose-Response Relationship, Drug ; Female ; Gene Expression ; Humans ; Lymphocytes ; metabolism ; Male ; Metallothionein ; biosynthesis ; genetics ; Occupational Exposure ; Protein Isoforms ; biosynthesis ; RNA, Messenger ; genetics

The cDNA encoding the rabbit metallothionein-I was amplified by RT-PCR from the rabbit liver induced by cadmium and cloned into prokaryotic fusion expression vector pQE40. Then it was transformed into Escherichia coli M15. Positive expression clones were detected by colony blotting. Target protein solubility was determined by Western blotting analysis. The optimal induction condition of the level of protein expression with IPTG induction was established by SDS-PAGE electrophoresis and ImageMaster VDS software analysis. The fusion protein can be purified from lysates with Ni-NTA agarose. We found that the fusion protein with apparent molecular weight 32 KD existed in two ways: soluble and insoluble in Escherichia coli. After 1 mM IPTG induction, the level of expression of the fusion protein increased with the prolongation of induction time and reached a peak in 9 h by ImageMaster VDS software analysis, accounting for 57.4% of all the insoluble protein. The purified fusion protein was obtained by Ni-NTA affinity chromatography. This fusion protein can be used in further studies on the preparation of MT-I protein and development of protein product.
Animals ; Cloning, Molecular ; DNA, Complementary ; genetics ; Escherichia coli ; genetics ; metabolism ; Genetic Vectors ; Metallothionein ; genetics ; metabolism ; Rabbits ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; isolation & purification ; Transformation, Bacterial

OBJECTIVETo compare the expression of metallothionein (MT) genes and proteins in six human pancreatic cancer cell strains and two human pancreatic cancer drug-resistant cell strains and to explore the relationship between the expression of the MT and pancreatic cancer cell chemo-resistance.

METHODSReverse transcriptase-polymerase chain reaction (RT-PCR) was used to determine the MT isoform-specific mRNA, and cadmium/hemoglobin saturation-electrochemistry to determine MT protein levels.

RESULTSMT protein expression in the pancreatic cancer cell strains was encoded by MT-1A, MT-1B, MT-1E, MT-1F, MT-1G, MT-1X, and MT-2A genes. The expression of MT proteins was upregulated and MT-1B, MT-1E, MT-1X, MT-2A genes overexpressed in human pancreatic cancer drug-resistant cell lines (P < 0.05).

CONCLUSIONExpressions of MT proteins and genes correlate with the proliferation and chemoresistance of human pancreatic cancer cell strains.

Cell Division ; genetics ; Drug Resistance, Neoplasm ; genetics ; Humans ; Metallothionein ; biosynthesis ; genetics ; Pancreatic Neoplasms ; genetics ; metabolism ; pathology ; RNA, Messenger ; genetics ; Tumor Cells, Cultured

Animals ; Calcium ; metabolism ; Copper ; metabolism ; Environmental Exposure ; prevention & control ; Erythrocytes ; metabolism ; Hazardous Substances ; metabolism ; poisoning ; Humans ; Mercury ; metabolism ; Metallothionein ; biosynthesis ; genetics ; metabolism ; Zinc ; metabolism

OBJECTIVETo study the expression of metallothionein (MT) and FasL in colorectal cancer and their relation to lymph node and liver metastasis.

METHODSImmunohistochemistry and quantitative RT-PCR were used to detect expression of MT and FasL in protein and mRNA levels in 93 cases of colorectal cancer.

RESULTSThe rates of MT expression in primary foci, non-cancerous colon mucosa, lymph node metastasis and liver metastasis were 58.1%, 32.3%, 81.1%, 64.3% respectively. And the rates of FasL expression were 41.9%, 19.4%, 62.3%, and 92.9% respectively. The positive rates of MT and FasL in primary foci, liver and lymph node metastasis were higher than that in non-cancerous mucosa (chi(2) = 35.2421, 57.5152, P < 0.01). MT expression rate in lymph node metastasis was higher than that in primary foci (chi(2) = 8.0565, P < 0.01). In liver metastasis, FasL expression rate was higher than in lymph node metastasis and primary foci (chi(2) = 8.6674, 22.4455, P < 0.01). The positive rates of MT and FasL in Dukes stage C and D were higher than that in Dukes stage A and B (chi(2) = 18.8871, 25.1650, P < 0.01). And higher rates of MT and FasL expression were observed in low differentiation adenocarcinoma and mucus adenocarcinoma than in middle-high differentiation adenocarcinoma (chi(2) = 11.1546, 9.2239, P < 0.05). High MT mRNA level was found in lymph node metastasis and high FasL mRNA level in liver metastasis.

CONCLUSIONSEnhanced expression of MT and FasL was associated significantly with lymph node and liver metastasis of colorectal cancer. Assay of MT and FasL expression has prognostic values for colorectal cancer patients.

Adult ; Aged ; Aged, 80 and over ; Colorectal Neoplasms ; metabolism ; pathology ; Fas Ligand Protein ; biosynthesis ; genetics ; Female ; Humans ; Immunohistochemistry ; Liver Neoplasms ; metabolism ; secondary ; Lymph Nodes ; pathology ; Lymphatic Metastasis ; Male ; Metallothionein ; biosynthesis ; genetics ; Middle Aged ; RNA, Messenger ; genetics ; Reverse Transcriptase Polymerase Chain Reaction

Recombinant plasmid pICG was constructed by replacing the internal fragment of a-acetohydroxyacid synthase (AHAS) gene (ILV2) with a copy of gamma-glutamylcysteine synthetase gene (GSH1) and copper chelatin gene (CUP1) from the industrial brewing yeast strain YSF31. YSF31 was transformed with plasmid pICG linearized by Kpn I and Pst I. A recombinant strain with high-glutathione and low-diacetyl production was selected. The results of fermentation in 100-L bioreactor showed that the lagering time of beer produced for recombinant strain T2 was shortened by 3 days and the shelf life of the beer was prolonged about 50%. It may be more acceptable for the commercial application, as it does not contain foreign DNA.
Acetolactate Synthase ; genetics ; metabolism ; Beer ; microbiology ; Cloning, Molecular ; Diacetyl ; metabolism ; Fermentation ; Gene Expression Regulation, Fungal ; Glutamate-Cysteine Ligase ; genetics ; metabolism ; Glutathione ; biosynthesis ; Metallothionein ; genetics ; metabolism ; Organisms, Genetically Modified ; genetics ; Saccharomyces cerevisiae ; genetics ; metabolism ; Saccharomyces cerevisiae Proteins ; genetics ; metabolism