Brain Neoplasms ; metabolism ; Cell Line, Tumor ; Glioma ; metabolism ; Humans ; Neoplastic Stem Cells ; drug effects ; metabolism ; Reactive Oxygen Species ; metabolism ; Sodium Selenite ; pharmacology

Recent evidence has suggested that human skin fibroblasts may represent a novel source of therapeutic stem cells. In this study, we report a 3-stage method to induce the differentiation of skin fibroblasts into insulin-producing cells (IPCs). In stage 1, we establish the isolation, expansion and characterization of mesenchymal stem cells from human labia minora dermis-derived fibroblasts (hLMDFs) (stage 1: MSC expansion). hLMDFs express the typical mesenchymal stem cell marker proteins and can differentiate into adipocytes, osteoblasts, chondrocytes or muscle cells. In stage 2, DMEM/F12 serum-free medium with ITS mix (insulin, transferrin, and selenite) is used to induce differentiation of hLMDFs into endoderm-like cells, as determined by the expression of the endoderm markers Sox17, Foxa2, and PDX1 (stage 2: mesenchymal-endoderm transition). In stage 3, cells in the mesenchymal-endoderm transition stage are treated with nicotinamide in order to further differentiate into self-assembled, 3-dimensional islet cell-like clusters that express multiple genes related to pancreatic beta-cell development and function (stage 3: IPC). We also found that the transplantation of IPCs can normalize blood glucose levels and rescue glucose homeostasis in streptozotocin-induced diabetic mice. These results indicate that hLMDFs have the capacity to differentiate into functionally competent IPCs and represent a potential cell-based treatment for diabetes mellitus.
Animals ; Biological Markers/metabolism ; *Cell Culture Techniques ; *Cell Differentiation ; Cell Proliferation/drug effects ; Cell Separation ; Cells, Cultured ; Dermis/*cytology/drug effects ; Diabetes Mellitus, Experimental/*surgery ; Female ; Fibroblasts/*cytology/drug effects ; Genitalia, Female/*cytology ; Glucose/metabolism ; Hepatocyte Nuclear Factor 3-beta/metabolism ; Homeodomain Proteins/metabolism ; Humans ; Insulin/pharmacology/secretion ; Insulin-Secreting Cells/*cytology/metabolism ; *Islets of Langerhans Transplantation ; Mesenchymal Stem Cells/*cytology/drug effects/metabolism ; Mice ; Mice, Nude ; Niacinamide/pharmacology ; Recovery of Function ; SOXF Transcription Factors/metabolism ; Sodium Selenite/pharmacology ; Trans-Activators/metabolism ; Transferrin/pharmacology

OBJECTIVETo explore the effects of sodium selenite on the expressions of beta-catenin and cyclin D1 in colorectal cancer cells HCT 116 and SW480.

METHODSHCT 116 and SW480 cells were treated by 10 micromol/L sodium selenite at different time points. The expressions and transcription of beta-catenin and cyclin D1 were detected by Western blot analysis and reverse transcriptase polymerase chain reaction (RT-PCR), respectively. Meanwhile, the impact of MG132 (a proteasome inhibitor) pretreatment on the expressions of beta-catenin and cyclin D1 was observed through Western blot analysis. The interaction between beta-catenin and T cell factor 4 (TCF4) after selenite treatment was evaluated using co-immunoprecipitation assay.

RESULTSSodium selenite inhibited the expression of beta-catenin and transcription of its target such as cyclin D1. MG132 pretreatment prevented the inhibition of beta-catenin signaling triggered by selenite in HCT 116 and SW480 cells. Furthermore, selenite treatment disrupted the interaction between beta-catenin and TCF4 in HCT 116 and SW480 cells.

CONCLUSIONSSodium selenite can lower the expression levels of beta-catenin and its target cyclin D1, during which the proteasome-mediated degradative pathway may be involved. The decreased interaction between beta-catenin and TCF4 due to sodium selenite may be also involved in the regulation of beta-catenin signaling.

Cell Line, Tumor ; Colorectal Neoplasms ; metabolism ; Cyclin D1 ; metabolism ; HCT116 Cells ; Humans ; Sodium Selenite ; pharmacology ; beta Catenin ; metabolism

OBJECTIVETo investigate the protective effects of selenium on rat hippocampal neurons against ischemia-reperfusion (IR) injury.

METHODSThirty-two rats were randomly divided into sham-operated group, IR group and selenium-treated group, and in the latter two groups, cerebral IR injury was induced by middle cerebral artery occlusion; Na2SeO3 treatment was administer in selenium-treated group. At 14 days after reperfusion, the brain tissues were harvested from the rats and hippocampal neuron injuries were observed by TUNEL and Methylene Blue staining. The levels of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and nerve growth factor (NGF) in the hippocampal tissues were measured by ELISA.

RESULTSCompared with IR group, the rats in selenium-treated group showed no significant increase in the expression of m-NGF (P>0.05), but pro-NGF expression was significantly increased (P<0.05) in the hippocampal tissue. Na2SeO3 treatment significantly inhibited the expressions of TNF-α and IL-1β and decreased the apoptosis of hippocampal neurons following cerebral IR injury (P<0.05).

CONCLUSIONSelenium produces antiapoptotic effect to protect the hippocampal neurons following cerebral IR injury possibly not by increasing the level of m-NGF but by decreasing the expressions of the inflammatory factors.

Animals ; Apoptosis ; Brain Ischemia ; metabolism ; pathology ; Hippocampus ; cytology ; metabolism ; pathology ; Interleukin-1beta ; metabolism ; Male ; Nerve Growth Factor ; metabolism ; Neurons ; drug effects ; metabolism ; pathology ; Rats ; Rats, Sprague-Dawley ; Reperfusion Injury ; metabolism ; pathology ; Sodium Selenite ; pharmacology ; Tumor Necrosis Factor-alpha ; metabolism

OBJECTIVETo explore the mechanism and significance of cytochrome c oxidase subunit IV (COX IV) downregulation during apoptosis of NB4 cells induced by sodium selenite.

METHODSNB4 cells were treated with 20 micromol/L sodium selenite at different time points. COX IV protein and mRNA were detected by Western blot and RT-PCR, respectively. NB4 cells were pretreated with reactive oxygen species (ROS) scavenger before selenite exposure, and then COX IV protein expression and caspase-3 activation were detected by Western blot. NB4 cells were pretreated with caspase-3 inhibitor before selenite exposure, and then COX IV protein expression was detected by Western blot. NB4 cells were transiently transfected with vectors to interfere with the expression of COX IV, and then the apoptosis induced by selenite was analyzed by flow cytometry.

RESULTSSodium selenite induced evident downregulation of COX IV protein in NB4 cells, while its mRNA level was almost unchanged. ROS scavenger completely reversed selenite-induced COX IV downregulation and caspase-3 activation. Caspase-3 inhibitor partially reversed selenite-induced COX IV downregulation. Interference with COX IV expression dramatically enhanced selenite-induced apoptosis of NB4 cells.

CONCLUSIONSCOX IV is remarkably downregulated during selenite-induced apoptosis of NB4 cells. ROS mediates COX IV downregulation and caspase-3 activation, while caspase-3 is partially involved in COX IV downregulation. COX IV interference markedly increases the sensitivity of NB4 cells to selenite-induced apoptosis.

Apoptosis ; drug effects ; Caspase 3 ; metabolism ; Cell Line, Tumor ; Down-Regulation ; drug effects ; Electron Transport Complex IV ; genetics ; metabolism ; Gene Expression Regulation, Neoplastic ; drug effects ; Humans ; RNA, Messenger ; genetics ; Reactive Oxygen Species ; metabolism ; Sodium Selenite ; pharmacology

OBJECTIVETo study the preventing effects of procyanidins (PC) on selenite cataract in rats and the time-effect relationship.

METHODForty five SD rats were divided into three groups: control, model and experiment groups. The rats in the experiment group were fed additionally with the PC by 80 mg x kg(-1) when they were supplied the equal selenite with the model group. Five rats of each group were regularly sacrificed by bleeding from femoral artery at sixth, eleventh, sixteenth day and the level of malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) of all lenses was measured.

RESULTCompared with the model group, the level of the MDA in the experiment group at the eleventh day and the sixteenth day greatly decreased (P < 0.01). At the sixteenth day the level of the SOD and GSH-Px had an increase (P < 0.01), which showed its anti-oxygenation.

CONCLUSIONPC indicated the obvious inhibition in the development of the rat cataract. The treatment period was recommended at least for fifteen days.

Animals ; Cataract ; chemically induced ; prevention & control ; Female ; Glutathione Peroxidase ; metabolism ; Male ; Malondialdehyde ; metabolism ; Proanthocyanidins ; therapeutic use ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Sodium Selenite ; pharmacology ; Superoxide Dismutase ; metabolism

The study was purposed to explore the quantity, morphology and immunophenotype of dendritic cells (DC) acquired by co-cultivated system with 3 types of cytokines and sodium selenite (Se) from peripheral blood mononuclear cells (PBMNCs), and to investigate the effects of Se on inducing the cytotoxic T lymphocyte (CTL) to get specific anti-leukemic activity in vitro by DC pulsed with K562 cell frozen-thawed antigen (antigen cell loading). PBMNCs isolated from healthy donors were cultured in RPMI 1640 medium contained 10% FBS supplied with 3 cytokines (rhGM-CSF, rhIL-4, TNF-alpha) for 4 days, DCs harvested were divided into 4 groups, DCI: DC alone; DCII: DC + Se (adding 0.5 micromol/L of Se); DCIII: DC + K562 (pulsed with lysed K562 cells); DCIV: DC + Se + K562. Morphology of DCs was observed under microscope at day 7. The CD1a, CD40, CD83, and CD86 were detected by FCM. Cytotoxicity of T cells induced by DC were measured with LDH release test at day 12. The level of IL-12 in supernatant of cultured DCs were determined with ELISA. The results indicated that at 7th day DC in 4 groups showed characteristic morphology, the colony numbers of 4 groups were all higher than those before cultivation. There were no obvious differences of morphology and colony counts between DCI group and DCII group. The colony numbers of DCIII group and DCIV group increased, as well as the ratio of suspended cells enhanced. The expressions of CD1a, CD40, CD83 and CD86 in 4 groups of DC were significantly higher than those in PBMNC group (p < 0.01), the expressions of CD1a and CD40 in 4 groups of DC did not display significant difference (p > 0.05), the expressions of CD83 and CD86 in both DCIII group and DCIV group were all higher than those in DCI group and DCII group (p < 0.01), but their expressions of CD83 and CD86 in DCI and DCII were not significantly different (p > 0.05), as well as those in DCIII group and DCIV group. With the ratio of 25:1 between E:T, killing rate of CTL on K562 cells in 4 DC groups were 15.3 +/- 2.3%, 26.3 +/- 3.7%, 28.2 +/- 4.5% and 36.2 +/- 3.7% respectively, all obviously higher than those of T cell group without being sensitized by DCs (5.9 +/- 2.4%) (p < 0.01), The CTL effect in DCIV group was the highest, which was higher than those in other 3 DC groups (p < 0.01); the effects in both DCII and DCIII group were also higher than that in DCI group (p < 0.01), but their difference between DCII and DCIII groups did not show significance (p > 0.05). The levels of IL-12 in supernatant of DCI, DCII, DCIII and DCIV groups were 257.0 +/- 64.2, 328.1 +/- 43.9, 323.0 +/- 53.5 and 353.9 +/- 46.2 pg/ml respectively, all significantly higher than that in supernatant of T cell alone group without being sensitized by DCs (35.27 +/- 27.1 pg/ml) (p < 0.01), The levels in DCII, DCIII and DCIV groups were all higher than that in DCI group (p < 0.01), but their levels between DCII, DCIII and DCIV groups were not of significant difference (p > 0.05). It is concluded that matured DCs can be successfully obtained from PBMNCs by a culture system contained rhGM-CSF, rhIL-4 and TNF-alpha with or without low-dose of Se (0.5 micromol/L) in vitro. Using K562 cell frozen-thawed antigen, DC express more adhesive molecules and co-stimulating molecules (CD83, CD86), and increase the secretion of IL-12, as well as the killing effects of CTL on special target cells. Low dose of Se did not showed effects on quantity and morphology of matured DC harvested, as well as their expression of mature phenotypes, it raised levels of IL-12 secreted by DCs, reaching the same level as using K562 cell frozen-thawed antigen, and it showed synergistic effect on induction of CTL with K562 cell frozen-thawed antigen.
Cells, Cultured ; Cytokines ; pharmacology ; Dendritic Cells ; cytology ; immunology ; Humans ; K562 Cells ; Leukocytes, Mononuclear ; cytology ; Sodium Selenite ; pharmacology ; T-Lymphocytes ; immunology ; T-Lymphocytes, Cytotoxic ; cytology ; immunology

OBJECTIVETo explore the effect of glutathione (GSH) and sodium selenite on the metabolism of arsenic in the liver, kidney and blood of mice exposed to iAsIII through drinking water.

METHODSThe mice were randomly divided into control, arsenic, GSH and sodium selenite group, respectively. And each group had eight mice and the mice were exposed to 50 mg/L arsenite by drinking water for 4 weeks. Mice were intraperitoneally injected with GSH (600 mg/kg) and sodium selenite (1 mg/kg) for seven days from the beginning of the fourth week. At the end of the fourth week, liver, kidney and blood were sampled to assess the concentrations of inorganic arsenic (iAs), monomethylarsenic acid (MMA), dimethylarsenic acid (DMA) by hydride generation trapping by ultra-hypothermia coupled with atomic absorption spectrometry.

RESULTSThe liver DMA (233.76 +/- 60.63 ng/g) concentration in GSH group was significantly higher than the arsenic group (218.36 +/- 42.71 ng/g). The concentration of DMA (88.52 +/- 30.86 ng/g) and total arsenic (TAs) (162.32 +/- 49.45 ng/g) in blood of GSH group was significantly higher than those [(45.32 +/- 12.19 ng/g), (108.51 +/- 18.00 ng/g), respectively] of arsenic groups(q values were 3.06, 6.40, 10.72 respectively, P < 0.05). The primary methylated index (PMI) (0.65 +/- 0.050) and secondary methylated index (SMI) (0.55 +/- 0.050) in liver sample of GSH group were significantly higher than those (0.58 +/- 0.056, 0.44 +/- 0. 093) in arsenic group. In blood samples, the PMI (0.85 +/- 0.066) in GSH group was significantly higher than that (0.54 +/- 0.113) in arsenic group (q values were 3.75, 5.26, 4.21 respectively, P < 0.05). However, no significant difference was identified between sodium selenite and arsenic groups in liver, kidney or blood samples. And no significant difference was detected in kidney samples among all arsenic exposing groups.

CONCLUSIONExogenous GSH could promote the methylated metabolism of iAsIII, but sodium selenite showed no significant effects.

Animals ; Arsenic ; analysis ; metabolism ; Arsenic Poisoning ; metabolism ; Environmental Exposure ; Female ; Glutathione ; pharmacology ; Male ; Mice ; Mice, Inbred Strains ; Sodium Selenite ; pharmacology ; Water Supply

OBJECTIVEThe aim of this study was to observe the human hair follicle apoptosis status affected by fluorine and the antagonism effect by selenium in vitro.

METHODSThe single hair follicles were separated and cultured, then they were added in different concentrations of sodium fluoride and sodium selenite. Chosen the appropriate concentrations, they were divided into 7 groups. The TUNEL was used to investigate the apoptotic cells of different parts. The morphous of hair follicles was observed consecutively and electron microscope was used.

RESULTSWe found that in 1 mmol/L and 10 mmol/L sodium fluoride groups, when the human hair follicles in vitro were cultured on the 5th day, the apoptotic cells of outer root sheath (ORS), dermal sheath and hair papilla, hair bulb were obviously increased. But 0.01 mmol/L sodium selenite weakened the toxicity of 1 mmol/L sodium fluoride at the outer root sheath and hair bulb (P < 0.05).

CONCLUSIONSDifferent concentrations of sodium fluoride had different effect on the growth of human hair follicle in vitro which were cultured on 5th day. Sodium fluoride of certain concentration could accelerate the apoptosis of human hair follicle in vitro. Sodium selenite of certain concentration could act antagonism to the toxicity of sodium fluoride.

Adolescent ; Adult ; Apoptosis ; drug effects ; Hair Follicle ; drug effects ; Humans ; Middle Aged ; Sodium Fluoride ; pharmacology ; Sodium Selenite ; pharmacology ; Tissue Culture Techniques ; Young Adult

OBJECTIVETo investigate the effects of sodium selenite on telomerase activity and expression of hTERT mRNA in cadmium-transformed 16HBE cells.

METHODSTelomerase activity and expression of genes were measured after cultured cadmium-transformed 16HBE cells were exposed to sodium selenite at different doses (0.625, 1.25, 2.50, 5.00 micromol/L) for 24 hours.

RESULTSSelenium decreased telomerase activity in cadmium-transformed 16HBE cells. There existed an obvious dose-effect relationship between the selenium concentration and these changes. The expression of hTERT and c-myc mRNA also decreased but the expression of mad1 mRNA increased after exposure to selenium for 24 hours. No difference was found in expression of hTRF1 and hTRF2 mRNA after incubated with sodium selenite for 24 hours, compared with control group.

CONCLUSIONSelenium inhibits telomerase activity by decreasing hTERT and c-myc mRNA expression and increasing mad1 mRNA expression in cadmium-transformed 16HBE cells and selenium concentration is significantly correlated with these changes.

Base Sequence ; Cadmium ; pharmacology ; Cell Line, Transformed ; DNA Primers ; Humans ; RNA, Messenger ; genetics ; Reverse Transcriptase Polymerase Chain Reaction ; Sodium Selenite ; pharmacology ; Telomerase ; antagonists & inhibitors ; genetics