The aim of this study was to investigate the role of selenoprotein M (SelM) in endoplasmic reticulum stress and apoptosis in nickel-exposed mouse hearts and to explore the detoxifying effects of melatonin. At 21 d after intraperitoneal injection of nickel chloride (NiCl₂) and/or melatonin into male wild-type (WT) and SelM knockout (KO) C57BL/6J mice, NiCl₂ was found to induce changes in the microstructure and ultrastructure of the hearts of both WT and SelM KO mice, which were caused by oxidative stress, endoplasmic reticulum stress, and apoptosis, as evidenced by decreases in malondialdehyde (MDA) content and total antioxidant capacity (T-AOC) activity. Changes in the messenger RNA (mRNA) and protein expression of genes related to endoplasmic reticulum stress (activating transcription factor 4 (ATF4), inositol-requiring protein 1 (IRE1), c-Jun N-terminal kinase (JNK), and C/EBP homologous protein (CHOP)) and apoptosis (B-cell lymphoma-2 (Bcl-2), Bcl-2-associated X protein (Bax), Caspase-3, Caspase-9, and Caspase-12) were also observed. Notably, the observed damage was worse in SelM KO mice. Furthermore, melatonin alleviated the heart injury caused by NiCl₂ in WT mice but could not exert a good protective effect in the heart of SelM KO mice. Overall, the findings suggested that the antioxidant capacity of SelM, as well as its modulation of endoplasmic reticulum stress and apoptosis, plays important roles in nickel-induced heart injury.
Animals ; Male ; Mice ; Antioxidants/pharmacology* ; Apoptosis ; Endoplasmic Reticulum Stress ; Melatonin/pharmacology* ; Mice, Inbred C57BL ; Nickel/adverse effects* ; Selenoproteins/genetics* ; Heart/drug effects*

Hypoxia-inducible factor 1alpha (HIF-1alpha), which transactivates a variety of hypoxia-induced genes, is rapidly degraded under nomoxia through the hydroxylation-ubiquitination-proteasome pathway. In this study, we addressed how HIF-1alpha is stabilized by proteasome inhibitors. The ubiquitin pool was rapidly reduced after proteasome inhibition, followed by the accumulation of non-ubiquitinated HIF-1alpha. The poly-ubiquitination of HIF-1alpha was resumed by restoration of free ubiquitin, which suggests that the HIF-1alpha stabilization under proteasome inhibition is attributed to depletion of the free ubiquitin pool. Ni2+ and Zn2+ also stabilized HIF-1alpha with depletion of the free ubiquitin pool and these effects of metal ions were attenuated by restoration of free ubiquitin. Ni2+ and Zn2+ may disturb the recycling of free ubiquitin, as MG132 does. Based on these results, the state of the ubiquitin pool seems to be another critical factor determining the cellular level of HIF-1alpha.
Cell Hypoxia/physiology ; Cell Line, Tumor ; HCT116 Cells ; HEK293 Cells ; Humans ; Hypoxia-Inducible Factor 1, alpha Subunit/biosynthesis/*metabolism ; Leupeptins/pharmacology ; Nickel/chemistry ; Proteasome Endopeptidase Complex/*metabolism ; Proteasome Inhibitors/*pharmacology ; Ubiquitin/*metabolism ; Ubiquitination/*physiology ; Up-Regulation ; Zinc/chemistry

Chelating ligand method has been used to synthesize baicalin-metal (Ni2+, Co2+, Cu2+) complexes (BMC). The composition and structure of BMC were characterized by the element analysis, ultraviolet spectrum (UV), infrared spectrum (IR), mass (MS) and thermal gravitational analysis (TGA). MTT was used to analyze the effects of BMC on SMMC-7721 cell proliferation. PI staining method and Annexin-V/FITC double staining method were used to analyze the effects of BMC on the cell cycle and apoptosis of SMMC-7721 cell. Fluorescence quantitative RT-PCR was used to analyze the expression of BMC on Bcl-2 gene and Bax mRNA, flow cytometry was used to analyze BMC on the expression of Bcl-2 protein and Bax protein. The antineoplastic activity and mechanism of action of BMC was explored comprehensively. The results showed that three new kinds of BMC (molar ratio of 2 : 1) were successfully prepared, the complexes molecular formula are: Na2Ni(C21H16O11)2 x 10H2O, Na2Co(C21H16O11)2 x 8H2O and Na2Cu(C21H16O11)2 x 8H2O. According to the results of cell cycle and apoptosis detection, BMC stopped cells at G0/G1 phase to S phase and G2/M phase. Gene and protein detection showed that under the given concentration and time, BMC can downregulate the expression of Bcl-2 gene in SMMC-7721 cells, and significantly decrease the expression of Bcl-2 protein, at the same time, with the increase of expression of Bax gene, the Bax protein's expression increased significantly. Which indicates that BMC restrain cell proliferation and cell apoptosis by stopping cell cycle, reducing the expression of Bcl-2 and increasing that of Bax; The anti-tumor activities of three kinds of complexes were: baicalin-copper (BC-Cu) > baicalin-cobalt (BC-Co) > baicalin-nickel (BC-Ni) > baicalin (BC), showing the dose-response relationship.
Antineoplastic Agents ; administration & dosage ; pharmacology ; Apoptosis ; drug effects ; Cell Cycle ; drug effects ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Cobalt ; Copper ; Drug Delivery Systems ; Flavonoids ; administration & dosage ; pharmacology ; Humans ; Liver Neoplasms ; metabolism ; pathology ; Metals ; Nickel ; Proto-Oncogene Proteins c-bcl-2 ; genetics ; metabolism ; RNA, Messenger ; metabolism ; bcl-2-Associated X Protein ; genetics ; metabolism

OBJECTIVETo investigate the biocompatibility of a novel cavernous nickel-titanium alloy with rat bone marrow stromal cells (BMSCs) in vitro.

METHODSRat BMSCs were cultured on the surface of compact, microporous and macroporous nickel-titanium alloys, and the cell proliferation on day 3 during the culture was assessed using MTT assay. On day 7 of the cell culture, the cells were labeled with Hoechst33342 for cell counting under a fluorescence microscope. Scanning electron microscopy (SEM) was performed on day 7 of cell culture to observe the morphological changes of the cells.

RESULTSThe cell proliferation rate and cell numbers differed significantly between the cavernous alloy groups and the compact alloy group (P<0.05), but similar between the former two groups (P>0.05). SEM showed that compared with the compact alloy, microporous and macroporous nickel-titanium alloys had better biocompatibility with the BMSCs, and the cells on the surface of the cavernous alloys had normal cell morphology.

CONCLUSIONCavernous nickel-titanium alloy has good biocompatibility and can promote the adhesion, aggregation and proliferation of rat BMSCs in vitro.

Animals ; Biocompatible Materials ; pharmacology ; Bone Marrow Cells ; cytology ; Cell Adhesion ; Cells, Cultured ; Female ; Male ; Materials Testing ; methods ; Nickel ; pharmacology ; Rats ; Rats, Sprague-Dawley ; Stromal Cells ; cytology ; Titanium ; pharmacology

Although nickel hypersensitivity is known as a delayed-type hypersensitivity mediated by nickel-specific T cells, it is greatly influenced by other immune cells. Here we show that splenic natural killer cells (NK cells) directly or indirectly respond to nickel by secretion of IFN-gamma. Using enzyme-linked immunosorbent spot (ELISPOT) assays, we found that nickel-reactive cells readily secreted IFN-gamma when splenocytes were cultured in the presence of varying concentrations of nickel sulfate (NiSO4) for 24 h. However, nickel-reactive IL-2- or IL- 4-secreting cells were infrequent during the 24-h culture with NiSO4. Immune responses to nickel were innate, not adaptive, in nature since the frequency of nickel-reactive IFN-gamma-secreting cells did not increase upon previous exposure to NiSO4 and recombination activating gene (RAG)-1-deficient mice contained nickel-reactive IFN-gamma-secreting cells. The involvement of NK cells in the innate response to NiSO4 was confirmed since we could observe a significant reduction of the frequency of nickel-reactive cells in NK cell-depleted mice. Furthermore, the number of IFN-gamma secreting cells was significantly reduced in the ELISPOT assays when NKG2D was blocked by anti-NKG2D antibody. These results suggest that there is an early and rapid innate immune response to nickel, which is mediated by NK cells and the NKG2D receptor. The significance of the innate response to nickel is that it may contribute to development of the late T cell-mediated delayed type hypersensitivity against nickel.
Animals ; Homeodomain Proteins/genetics/metabolism ; Humans ; Immunity, Innate/immunology ; Interferon-gamma/*secretion ; *Irritants/immunology/pharmacology ; *Killer Cells, Natural/drug effects/immunology/secretion ; Mice ; Mice, Inbred C57BL ; Mice, Knockout ; NK Cell Lectin-Like Receptor Subfamily K/genetics/metabolism ; *Nickel/immunology/pharmacology ; Spleen/*cytology/immunology

OBJECTIVETo investigate the use of dendritic cells derived from mice bone marrow to evaluate the cutaneous allergic reaction induced by chemical sensitizers.

METHODSDendritic cells derived from mice bone marrow were cultured and administrated with 2, 4-dinitrochlorobenzene (DNCB), nickel sulfate (NiSO4), sodium dodecyl sulfate (SDS) and hexyl cinnamic aldehyde (HCA), respectively. Cell membrane molecule CD86 and extracellular IL-1 beta, IL-6 and IL-12 were detected after 0, 1, 6, 12, 24, 36, 48 hour's administration, respectively.

RESULTSCD86 expression reached the highest level after exposure to DNCB for 48 h, and increased by about 279% compared with the control (P < 0.05), while it was lower than that of control after administrated with NiSO4 and HCA for 1 h and 6 h, and SDS for 36 h, respectively (P < 0.05). Extracellular IL-1 beta increased greatly after exposure to NiSO4 just for 1 h, with the maximum at 48 h (298 pg/ml, P < 0.05), and after exposure to HCA for 6 h, with maximum at 48 h (84 pg/ml, P < 0.05). However, it didn't fluctuate significantly after administrated with DNCB and SDS respectively, compared with the control. Extracellular IL-6 increased significantly after exposure to NiSO4 for 1 h, with the maximum at 24 h (2152 pg/ml, P < 0.05). After exposure to HCA, extracellular IL-6 reached the maximum at 1 h (1403 pg/ml), and then it was decreased quickly, but still higher than the control (P < 0.05), while it didn't change significantly after treatment with DNCB and SDS, compared with the control (P > 0.05). Extracellular IL-12 was not detected out among all the groups.

CONCLUSIONChemical sensitizer DNCB could induce the high expression of CD86 on DC membrane, and NiSO4 and HCA could induce DC to release IL-1 beta and IL-6. However, the irritant SDS had no such effect.

Animals ; B7-2 Antigen ; metabolism ; Cells, Cultured ; Dendritic Cells ; drug effects ; immunology ; metabolism ; Dinitrochlorobenzene ; pharmacology ; Interleukin-12 ; metabolism ; Interleukin-1beta ; metabolism ; Interleukin-6 ; metabolism ; Mice ; Mice, Inbred C57BL ; Nickel ; pharmacology ; Sodium Dodecyl Sulfate ; pharmacology

OBJECTIVEA series of 2-benzylideneaminonaphthothiazoles were designed and synthesized incorporating the lipophilic naphthalene ring to render them more capable of penetrating various biomembranes.

METHODSSchiff bases were synthesized by the reaction of naphtha[1,2-d]thiazol-2-amine with various substituted aromatic aldehydes. 2-(2'-Hydroxy)benzylideneaminonaphthothiazole was converted to its Co(II), Ni(II) and Cu(II) metal complexes upon treatment with metal salts in ethanol. All the compounds were evaluated for their antibacterial activities by paper disc diffusion method with Gram positive Staphylococcus aureus and Staphylococcus epidermidis and Gram negative Escherichia coli and Pseudomonas aeruginosa bacteria. The minimum inhibitory concentrations of all the Schiff bases and metal complexes were determined by agar streak dilution method.

RESULTSAll the compounds moderately inhibited the growth of Gram positive and Gram negative bacteria. In the present study among all Schiff bases 2-(2'-hydroxy)benzylideneaminonaphthothiazole showed maximum inhibitory activity and among metal complexes Cu(II) metal complex was found to be most potent.

CONCLUSIONThe results obtained validate the hypothesis that Schiff bases having substitution with halogens, hydroxyl group and nitro group at phenyl ring are required for the antibacterial activity while methoxy group at different positions in the aromatic ring has minimal role in the inhibitory activity. The results also indicated that the metal complexes are better antibacterial agents as compared to the Schiff bases.

Amines ; chemical synthesis ; pharmacology ; Anti-Bacterial Agents ; chemical synthesis ; chemistry ; pharmacology ; Cobalt ; Copper ; Nickel ; Schiff Bases ; Structure-Activity Relationship ; Thiazoles ; chemical synthesis ; pharmacology

AIMUnderstanding the modes and activities of metal bacterial chlorophylls as PHD sensitizers with DNA.

METHODSThe modes and activities of the interaction of DNA and metal complexes of bacterial chlorophyll, which have been prepared by extraction and synthesis reaction, have been discussed according to the ultraviolet-visual spectrum and nucleic acid electrophoresis.

RESULTSIt indicates that the system of DNA and metal complexes have enchanced the interaction by the ultraviolet-visual spectrum. At the same time, it also indicates that metal complexes of bacterial chlorophyll and DNA have different combining way and have strong cutting effect in illumination by the nucleic acid electrophoresis.

CONCLUSIONThis paper proved that metal bacterial chlorophylls as PHD sensitizers have great advantage.

Bacteriochlorophylls ; chemical synthesis ; chemistry ; pharmacology ; Copper ; chemistry ; DNA ; metabolism ; Electrophoresis ; HL-60 Cells ; Humans ; K562 Cells ; Nickel ; chemistry ; Organometallic Compounds ; chemical synthesis ; chemistry ; pharmacology ; Protein Binding ; Spectrophotometry, Ultraviolet ; Zinc ; chemistry

AIMTo find a new PDT sensitizer.

METHODSThere were four complexes (Cu, Zn, Co, Ni) synthesized through reaction of metal and deprivating-Mg bacteriochlorophyll in the organic solvent. Their antitumor action was detected by MTT.

RESULTSThe ultraviolet-visual spectrum and the fluorescence spectrum of these complexes showed that synthesis of these four complexes was succeeded. And these metal complexes have potent antitumor action on two kinds of leukaemic cells.

CONCLUSIONMetal bacteriochlorophylls as PDT sensitizers have very good properties and this is a way to develop new PDT sensitizers.

Antineoplastic Agents ; chemical synthesis ; chemistry ; pharmacology ; Bacteriochlorophylls ; chemistry ; Cell Proliferation ; drug effects ; Cobalt ; chemistry ; Copper ; chemistry ; HL-60 Cells ; cytology ; Humans ; K562 Cells ; cytology ; Metals, Heavy ; chemistry ; Nickel ; chemistry ; Organometallic Compounds ; chemical synthesis ; chemistry ; pharmacology ; Photosensitizing Agents ; chemical synthesis ; chemistry ; pharmacology ; Zinc ; chemistry

OBJECTIVEToxic metal ions have been implicated in the generation of reactive oxygen species (ROS) and nitric oxide (NO). Metallothionines (MT) and plant flavonoids have been reported in the intervention against oxidative damage. We investigated the effect of zinc induced MT and green tea polyphenol (GTP) in reducing the oxidative responses induced by nickel and platinum.

METHODSZinc (10 mg/kg b. wt, sc) was administered to rats twice at a gap of 24 hrs and GTP (10 mg/100 mL in drinking water) was fed ad libitum for 8 days. Nickel chloride (150 umol/kgb.wt, ip) and cisplatin (50 mumol/kg b.wt, sc) was administered to rats 24 h after Zn or GTP pre-treatment. Animals of all the groups were sacrificed 16 hrs after treatment and biochemical markers for toxicity were monitored.

RESULTSZinc or GTP pre-treatment caused significant protection against nickel or cisplatin enhanced mortality in rats, and reduction in lipid peroxidation and NO.

CONCLUSIONIt is proposed that inhibition of ROS and NO by GTP and zinc may prove useful as a selective pharmacological agent in the amelioration of metal toxicity.

Animals ; Antioxidants ; pharmacology ; Biomarkers ; Cisplatin ; administration & dosage ; toxicity ; Flavonoids ; administration & dosage ; pharmacology ; Free Radical Scavengers ; pharmacology ; Lipid Peroxidation ; drug effects ; Metallothionein ; metabolism ; Mortality ; Nickel ; administration & dosage ; toxicity ; Nitric Oxide ; metabolism ; Phenols ; administration & dosage ; pharmacology ; Polyphenols ; Rats ; Tea ; chemistry ; Time Factors ; Zinc ; administration & dosage ; pharmacology