Metallothioneins (MTs) are a group of intracellular proteins of low molecular weight and rich cysteine, encoded by a family of genes containing at least 10 functional isoforms in human. MTs widely exist in the male reproductive system and are involved in many pathophysiological processes such as metal ion homeostasis and detoxification, protection against oxidative damage, cell proliferation and apoptosis, chemoresistance and radiotherapy resistance. This review describes the location and effects of MTs in the male reproductive system.
Gene Expression Profiling ; Genitalia, Male ; metabolism ; physiopathology ; Humans ; Male ; Metallothionein ; genetics ; metabolism ; physiology ; Protein Isoforms ; genetics ; metabolism ; physiology

OBJECTIVETo investigate the possible roles of MT1M gene on the cell cycle and signaling pathway of Hep-G2.

METHODSHep-G2 human hepatoma cells made by transfection with expressible MT1M gene, and the cell cycle was detected by flow cytometry, and the signaling pathway was measured by dual luciferase assay in Hep-G2 cells.

RESULTSMT1M gene was able to induce changes of the cell cycle and the activation of NF-kappaB pathway in Hep-G2 cells.

CONCLUSIONMT1M gene may affect the cell cycle in Hep-G2 and activate the NF-kappaB-dependent transcription.

Cell Line, Tumor ; Flow Cytometry ; G2 Phase ; physiology ; Humans ; Liver Neoplasms ; pathology ; Metallothionein ; genetics ; NF-kappa B ; metabolism ; Plasmids ; genetics ; Signal Transduction ; physiology ; Transfection

OBJECTIVETo amplify the full-length cDNA and characterize the structure and biological function of a novel expression sequence tag ST55 (GenBank Accession No. BM121646).

METHODSRapid amplification of cDNA ends was used to clone the full-length of cDNA of ST55 in this study. Then, its tissue distribution was checked by Northern blots, and the associated protein was screened by GAL 4-based yeast two-hybrid. The effect of stable transfection of the cDNA on cell proliferation was evaluated in ECV304 cells.

RESULTSA full-length 1404 bp cDNA was cloned, and it was accepted as a novel human mRNA by GenBank (No. AY074889), named endothelial-overexpressed lipopolysaccharide-associated factor 1 (EOLA1). Bioinformatic analysis found that the EOLA1 encoded 158 amino acids, 17.89 kDa protein, and mapped to chromosome Xq27.4 with 5 exons. EOLA1 expressed in different human normal tissues and cancer cell lines. Using the EOLA1 cDNA as bait, we performed a yeast two-hybrid screening of a human liver cDNA library and identified metallothionein 2A (MT2A) as associated protein. The interaction between EOLA1 and MT2A was confirmed by co-immunoprecipitation experiments. Stable transfection of EOLA1 was noted to stimulate ECV304 cell proliferation (P < 0.05).

CONCLUSIONThe findings suggest that EOLA1 is a novel gene and the interaction of EOLA1 and MT2A may play an important role in cell protection in inflammation reaction.

Amino Acid Sequence ; Base Sequence ; Blotting, Northern ; Blotting, Western ; Cell Line ; Cell Proliferation ; Chromosomes, Human, X ; genetics ; Exons ; genetics ; Humans ; Immunoprecipitation ; Membrane Proteins ; genetics ; metabolism ; physiology ; Metallothionein ; genetics ; metabolism ; Molecular Sequence Data ; Protein Binding ; Sequence Alignment ; Two-Hybrid System Techniques

OBJECTIVEThis study was designed to examine the impact of the antioxidant metallothionein (MT) on cardiac contractile, intracellular Ca(2+) function and oxidative stress in lipopolysaccharide (LPS)-treated mice.

METHODSWeight and age matched adult male FVB and cardiac-specific MT-overexpressing transgenic mice were injected intraperitoneally with 4 mg/kg Escherichia Coli LPS dissolved in sterile saline or an equivalent volume of pathogen-free saline (control groups). Six hours following LPS or saline injection, cardiac geometry and function were evaluated in anesthetized mice using the 2-D guided M-mode echocardiography. Mechanical and intracellular Ca(2+) properties were examined in hearts. Cell shortening and relengthening were assessed using the following indices: peak shortening (PS)-indicative of the amplitude a cell can shorten during contraction; maximal velocities of cell shortening and relengthening (± dl/dt)-indicative of peak ventricular contractility; time-to-PS (TPS)-indicative of systolic duration; time-to-90% relengthening (TR(90))-indicative of diastolic duration (90% rather 100% relengthening was used to avoid noisy signal at baseline concentration). The 360 nm excitation scan was repeated at the end of the protocol and qualitative changes in intracellular Ca(2+) concentration were inferred from the ratio of fura-2 fluorescence intensity (FFI) at two wavelengths (360/380). Fluorescence decay time was measured as an indicator of the intracellular Ca(2+) clearing rate. Glutathione/glutathione disulfide ratio and ROS generation were detected as the markers of oxidative stress.

RESULTSHeart rate was increased while EF was reduced in LPS-FVB mice and heart rate was reduced and EF increased in MT-LPS transgenic mice [(528 ± 72) beats/min vs (557 ± 69) beats/min, (66 ± 14)% vs (42 ± 10)%, P < 0.05]. Cardiomyocytes from the LPS treated FVB mice displayed significantly reduced peak shortening (PS) and maximal velocity of shortening/relengthening (±dl/dt) associated with prolonged time-to-90% relengthening (TR(90)), these effects were attenuated in cardiomyocytes from the MT-LPS mice [PS(5 ± 1.1)% vs (7.2 ± 0.8)%, dl/dt(160 ± 15) µm/s vs (212 ± 36) µm/s, -dl/dt (175 ± 32) µm/s vs (208 ± 29) µm/s, TR(90) (0.24 ± 0.03)s vs (0.19 ± 0.02)s, P < 0.05]. LPS treated mice showed significantly reduced peak intracellular Ca(2+) and electrically-stimulated rise in intracellular Ca(2+) as well as prolonged intracellular Ca(2+) decay rate without affecting the basal intracellular Ca(2+) levels, again, these effects were significantly attenuated in MT-LPS transgenic mice. Metallothionein overexpression also ablated oxidative stress [reduced ROS generation and increased glutathione/glutathione disulfide ratio, ROS (0.35 ± 0.08) A/µg protein vs (0.24 ± 0.03) A/µg protein]. GSH/GSSG 2.1 ± 0.2 vs 2.6 ± 0.4, P < 0.05.

CONCLUSIONMT overexpression improved cardiac function and ablated oxidative stress in LPS treated mice.

Animals ; Calcium ; metabolism ; Lipopolysaccharides ; Male ; Metallothionein ; genetics ; metabolism ; Mice ; Mice, Inbred Strains ; Mice, Transgenic ; Myocardial Contraction ; Myocytes, Cardiac ; metabolism ; physiology ; Oxidative Stress ; Reactive Oxygen Species ; metabolism ; Sepsis ; metabolism ; physiopathology

People with upper body or visceral obesity have a much higher risk of morbidity and mortality from obesity-related metabolic disorders than those with lower body obesity. In an attempt to develop therapeutic strategies targeting visceral obesity, depot- specific differences in the expression of genes in omental and subcutaneous adipose tissues were investigated by DNA array technology, and their roles in adipocyte differentiation were further examined. We found that levels of metallothionein-II (MT-II) mRNA and protein expression were higher in omental than in subcutaneous adipose tissues. The study demonstrates that MT-II may play an important role in adipocyte differentiation of 3T3L1 preadipocytes, and that N-acetylcysteine (NAC) inhibits the adipocyte differentiation of 3T3L1 cells by repressing MT-II in a time- and dose-dependent manner. Furthermore, the intraperitoneal administration of NAC to rats and mice resulted in a reduction of body weights, and a marked reduction in visceral fat tissues. These results suggest that MT-II plays important roles in adipogenesis, and that NAC may be useful as an anti-obesity drug or supplement.
Viscera/drug effects/metabolism ; Time Factors ; Subcutaneous Fat/drug effects ; Rats, Sprague-Dawley ; Rats ; Middle Aged ; Mice, Inbred C57BL ; Mice ; Metallothionein/*genetics/metabolism/physiology ; Male ; Humans ; Female ; Down-Regulation/drug effects/genetics ; Dose-Response Relationship, Drug ; Cell Differentiation/drug effects ; Body Weight/drug effects ; Anti-Obesity Agents/*pharmacology ; Animals ; Aged ; Adipose Tissue/cytology/drug effects/metabolism ; Adipocytes/cytology/drug effects/metabolism ; Acetylcysteine/*pharmacology ; 3T3-L1 Cells