Arsenites ; toxicity ; Cell Cycle ; drug effects ; Cell Division ; drug effects ; Cell Proliferation ; drug effects ; Cells, Cultured ; Dose-Response Relationship, Drug ; Humans ; Keratinocytes ; cytology ; Skin ; cytology ; Sodium Compounds ; toxicity

OBJECTIVETo study mechanism of the apoptosis of rat pancreas islet β cell strain (INS-1 cells) induced by sodium arsenite.

METHODSINS-1 cells were exposed to sodium arsenite at the different concentrations. MTT assay was used to detect the viability of INS-1 cells. The potentials on mitochondrial membrane and lysosome membrane of INS-1 cells were determined with the fluorescence spectrophotometer. The apoptotic levels of INS-1 cells exposed to sodium arsenite were observed by a fluorescence microscope and flow cytometry.

RESULTSAfter exposure to sodium arsenite, the viability of INS-1 cells significantly decreased with the doses of sodium arsenite. At 24 h after exposure, the OD values of the mitochondrial membrane potentials declined observably with the doses of sodium arsenite (P < 0.01). At 48 h after exposure, the OD values of the lysosome membrane potentials significantly increased with the doses of sodium arsenite (P < 0.01). At 72 h after exposure, the apoptotic cells were observed under a fluorescence microscope and enhanced with the doses of sodium arsenite. The apoptosis cells with light blue, karyopyknosis, karyorrhexis, apoptotic body and chromatin concentration appeared. The results detected with flow cytometry indicated that after exposure, the apoptotic INS-1E cells significantly increased with the doses of sodium arsenite.

CONCLUSIONSThe sodium arsenite can induce the apoptosis of INS-1 cells through the mitochondria-lysosome pathway.

Animals ; Apoptosis ; drug effects ; Arsenites ; toxicity ; Cells, Cultured ; Insulin-Secreting Cells ; drug effects ; Lysosomes ; metabolism ; Membrane Potentials ; drug effects ; Mitochondria ; metabolism ; Rats ; Sodium Compounds ; toxicity

OBJECTIVETo evaluate the effects of sodium arsenite on the activity, the mRNA and the protein expression of CAT in human keratinocyte cell line (HaCaT).

METHODSThe activity of catalase (CAT) was detected by ultraviolet direct velocity assay. RT-PCR was used to detect the mRNA expression of CAT and Western blotting was conducted to detect the protein expression of CAT.

RESULTSIf the cells were treated with higher than 5.0 micromol/L sodium arsenite, the activity, mRNA and protein expression of CAT were decreased significantly and in a dosage dependent fashion (P < 0.05).

CONCLUSIONCAT is inhibited by sodium arsenite in the transcription, translation and activity levels.

Arsenites ; toxicity ; Blotting, Western ; Catalase ; biosynthesis ; genetics ; Cell Line ; Dose-Response Relationship, Drug ; Humans ; Keratinocytes ; drug effects ; enzymology ; RNA, Messenger ; genetics ; Reverse Transcriptase Polymerase Chain Reaction ; Sodium Compounds ; toxicity

BACKGROUND: Activation of CD40 pathway negatively regulates the therapeutic effect of endothelial progenitor cells (EPCs), while inhibition of this pathway can enhance the biological function of the cells. OBJECTIVE: To compare the therapeutic effects of CD40-silenced EPCs (EPCs shRNA-CD40) and conventional EPCs transplantation in an animal model of pulmonary hypertension, and to explore the interventional effect of astragalosides on EPCs transplantation in the treatment of pulmonary hypertension. METHODS: Ninety SD rats were randomly divided into five groups: normal control group (n=24), model group (n=24), lentivirus transfection group (n=18), conventional transplantation group (n=18) and astragaloside group (n=6). Except the normal control group, the remaining four groups were given monocrotaline to induce pulmonary hypertension. Rats in the lentivirus transfection and conventional transplantation groups were given intravenous injection of Lv-shRNA-CD40-transfected EPCs and conventional EPCs respectively at 7, 14, 21 days after modeling (n=6 at each time point). Rats in the astragaloside group were given daily intraperitoneal injection of 80 mg/(kg?d) astragaloside within 1-21 days after modeling, and then Lv-shRNA-CD40-transfected EPCs were intravenously injected at 21 days after modeling. Hemodynamics, plasma endothelin-1 level and right ventricular hypertrophy index were detected at 28 days after modeling. RESULTS AND CONCLUSION: (1) After modeling, right ventricular pressure, mean pulmonary arterial pressure and right ventricular hypertrophy index were all increased compared with the normal control group (P < 0.05), while these indices were then decreased significantly after EPCs transplantation (P < 0.05). With the increasing of transplantation time, there was an increasing trend in the right ventricular pressure, mean pulmonary arterial pressure and right ventricular hypertrophy index in the two EPCs transplantation groups, but this trend was not remarkable in the lentivirus transfection group. (2) After modeling, the level of endothelin-1 was increased significantly compared with the normal control group (P < 0.05), and then decreased after EPCs transplantation (P < 0.05). The level of endothelin-1 in the lentivirus transfection group was significantly lower than that in the conventional transplantation group at the same time point (P < 0.05). (3) A significant improvement in hemodynamics, plasma endothelin-1 level and right ventricular hypertrophy index was observed in the astragaloside group as compared with the lentivirus transfection group (P < 0.05). Given the above findings, CD40-silenced EPCs transplantation is more effective and durable than the conventional transplantation in the treatment of pulmonary hypertension, and moreover, astragaloside can enhance the therapeutic effect.