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

The aim of the present study was to investigate whether metallothionein was involved in the protection of lung ischemic preconditioning (IP) against lung ischemia-reperfusion (I/R) injury. Adult male Sprague-Dawley rats were randomly divided into 3 groups based upon the intervention (n=8): control group (C), lung I/R group (I/R), lung I/R+IP group (IP). At the end of the experiment, the content of metallothionein was tested in lung tissue. Blood specimens collected from the arteria carotis were tested for the contents of malondialdehyde (MDA), the activities of superoxide dismutase (SOD) and myeloperoxidase (MPO). The pneumocyte apoptosis index (AI) was determined by terminal deoxynucleotidyl transferase mediated dUTP nick end labeling (TUNEL). Ultrastructural changes of lung tissue were observed by using transmission electron microscope. The results showed that in I/R group, the content of metallothionein was decreased (P<0.05), the content of MDA and MPO activity were increased (P<0.01), and SOD activity was decreased (P<0.01), compared with those in control group. IP treatment significantly increased the content of metallothionein (P<0.01), attenuated the MDA level (P<0.05) and MPO activity (P<0.01), and improved SOD activity (P<0.01) in blood serum. The number of TUNEL-positive cells in IP group was significantly reduced compared with that in I/R group (P<0.01). There were abnormal ultrastructural changes in I/R group, which were markedly reversed in IP group. In conclusion, IP may protect lung against I/R injury by inducing the expression of metallothionein.
Animals ; Ischemic Preconditioning ; methods ; Lung ; blood supply ; metabolism ; Male ; Metallothionein ; physiology ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Reperfusion Injury ; metabolism ; prevention & control

OBJECTIVETo study the immunotoxicity induced by 9,10-dimethyl-1,2-benzathrancene (DMBA) in metallothionein gene-knocked-out mice [MT(-/-)] as compared with that in wild-type mice [(MT(+/+)].

METHODSFemale mice were treated with 25 mg/kg and 50 mg/kg of DMBA i.p., respectively and immunized with sheep red blood cells (SRBC) i.v. on the following day and rechallenged by injection of SRBC via footpad s.c. on the fourth day post-immunization. Humoral and cell-mediated immune function was assessed by the number of spleen IgM antibody plaque formation cells (PFC) to SRBC and cell-mediated delayed-type hypersensitivity (DTH) measured by footpad swelling thickness.

RESULTSAfter treatment with 25 mg/kg DMBA, a decrease in weight of their spleen and thymus and PFC/spleen were observed in MT(-/-) mice, while only decrease in thymus weight of MT(+/+) mice. The humoral function was suppressed by 72% in MT(-/-) mice. No obvious change in cell-mediated immune function was observed both in MT(-/-) and MT(+/+) mice. Both humoral and cell-mediated immune function were suppressed more severe (91%) in MT(-/-) mice treated with 50 mg/kg DMBA than those treated with 25 mg/kg DMBA (72%). DTH was not altered by DMBA in MT(+/+) mice. The weight of their spleen and thymus decreased and humoral immune function suppressed in MT(+/+) mice, but these changes were significantly less severe. No obvious suppression of cell-mediated immune function was observed in MT(+/+) mice.

CONCLUSIONTheir humoral and cell-mediated immune function was more susceptible to being suppressed by DMBA in MT(-/-) mice, indicating that MT could protect their immune function from damage caused by DMBA.

9,10-Dimethyl-1,2-benzanthracene ; toxicity ; Animals ; Immunity ; drug effects ; Metallothionein ; physiology ; Mice ; Mice, Inbred C57BL ; Mice, Knockout ; Organ Size ; drug effects

Metallothionein (MT) is a kind of metal binding protein. As an important member in metallothionein family, MT-I/II regulates metabolism and detoxication of brain metal ion and scavenges free radicals. It is capable of anti-inflammatory response and anti-oxidative stress so as to protect the brain tissue. During the repair process of brain injury, the latest study showed that MT-I/II could stimulate brain anti-inflammatory factors, growth factors, neurotrophic factors and the expression of the receptor, and promote the extension of axon of neuron, which makes contribution to the regeneration of neuron and has important effect on the recovery of brain injury. Based on the findings, this article reviews the structure, expression, distribution, adjustion, function, mechanism in the repair of brain injury of MT-I/II and its application prospect in forensic medicine. It could provide a new approach for the design and manufacture of brain injury drugs as well as for age estimation of the brain injury.
Animals ; Astrocytes/metabolism* ; Brain/metabolism* ; Brain Injuries/pathology* ; Cytokines/metabolism* ; Forensic Medicine/methods* ; Gene Expression Regulation/drug effects* ; Humans ; Metallothionein/physiology* ; Neurons/metabolism* ; Neuroprotective Agents/pharmacology* ; Oxidative Stress/drug effects*

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

OBJECTIVETo study the possibility of metallothionein (MT) participating in the process of ischemia/reperfusion protection.

METHODSThe model of pig latissimus dorsi island flap and cultured myocytes were used in this study. The island flap was preconditioned with ischemia and the cultured myocytes were treated with anoxia. MT was detected in the flap and the cultured myocytes instantly and at 12 and 24 hours after the treatment. The protection effect of precondition on flap ischemia/reperfusion damage was observed by recording flap necrosis and the serum LDH level. The protection effect of precondition on myocyte anoxia/reoxygenation damage was observed by recording the cell survival rate and MDA content. The change in the protection effect was also observed after the MT was inhibited by PD098059.

RESULTSThe content of MT in cultured myocytes increased obviously 12 hours after precondition. Similar result was observed in flap tissue 24 hours later. Compared with the non-conditioned flap, the necrosis areas of the preconditioned flaps were smaller, the serum LDH was lower. The survival rate of preconditioned cultured myocytes was higher compared with non-conditioned cells (P < 0.05). The content of MDA and the quantity of discharged LDH were less (P < 0.05). When MT was inhibited by PD098059, the delaying protection of precondition disappeared. The observed quotas at that time were the same with those of simple I/R or A/R groups (P > 0.05).

CONCLUSION24 hours after precondition, the flap and the cultured myocytes are protected from re-damage of I/R or A/R. MT is involved in this process.

Animals ; Cell Hypoxia ; physiology ; Cell Survival ; physiology ; Cells, Cultured ; Enzyme Inhibitors ; pharmacology ; Flavonoids ; pharmacology ; Ischemic Preconditioning ; L-Lactate Dehydrogenase ; blood ; metabolism ; Malondialdehyde ; metabolism ; Metallothionein ; drug effects ; metabolism ; Muscles ; cytology ; metabolism ; surgery ; Necrosis ; Reperfusion Injury ; metabolism ; Surgical Flaps ; pathology ; Swine ; Time Factors

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