ABSTRACT
OBJECTIVE@#To explore the role of cell-surface nucleolin in lipopolysaccharide (LPS)-stimulated expression and secretion of TNF-alpha and IL-1beta in human THP-1 monocytes.@*METHODS@#Immuno-fluorescence assay and Western blot were used to identify the expression of nucleolin on the surface of THP-1 monocytes. Inactivation of nucleolin was induced by anti-nucleolin monoclonal antibody blockage, and the expression and secretion of TNF-alpha and IL-1beta were observed by using reverse transcription polymerase chain reaction (RT-PCR) and enzyme linked immuno-sorbent assay (ELISA)respectively in LPS-mediated human THP-1 monocyte inflammatory model.@*RESULTS@#Immuno-fluorescence showed that nucleolin was localized on the cell surface of THP-1 monocytes as indicated by dotted red fluorescence. Western blot assay indicated that nucleolin existed in the cell membrane fractions. RT-PCR assay showed that the expressions of TNF-alpha and IL-1beta mRNA significantly increased at 2 h and 3 h after the treatment with 1000 microg/L LPS. After 1 h pretreatment with anti-nucleolin antibody, the levels of TNF-alpha and IL-1beta mRNA decreased compared with an anti-nucleolin antibody untreated group and an irrelevant IgG+LPS group (P<0.05). ELISA assay showed that the pretreatment with anti-nucleolin antibody inhibited significantly the secretion of LPS-induced levels of TNF-alpha and IL-1beta after 4, 12 and 24 h treatment with 1000 microg/L LPS.@*CONCLUSION@#Nucleolin expresses on the cell surface of THP-1 monocytes and involves in the LPS-mediated expression and secretion of TNF-alpha and IL-1beta.
Subject(s)
Humans , Cell Line , Cell Membrane , Metabolism , Interleukin-1beta , Metabolism , Lipopolysaccharides , Pharmacology , Monocytes , Cell Biology , Metabolism , Phosphoproteins , Metabolism , Physiology , RNA-Binding Proteins , Metabolism , Physiology , Tumor Necrosis Factor-alpha , MetabolismABSTRACT
OBJECTIVE@#To explore the protective effect of HSP72 on the acute injury of cardiomyocyte induced by oxidative stress.@*METHODS@#Cardiomyocytes of neonatal rats treated with heat shock (42 degrees C, 30 min, recovery for 6 h) to induce the expression of HSP72 and HSP72 antisense oligonucleotide was transformed to block the expression of HSP72. 0.5 mmol/L (final concentration) H2O2 was added into the culture medium to mimic oxidative stress, and to induce the acute injury of neonatal cardiomyocytes. The release of LDH and the total protein synthesis were applied to evaluate the injury of cardiomyocyte of neonatal rats.@*RESULTS@#Oxidative stress could significantly increase the release of LDH, and inhibit the total protein synthesis. By inducing the expression of HSPs, heat shock pretreatment significantly reduced the release of LDH and relieved the oxidative stress-mediated inhibition of total protein synthesis. Moreover, HSP7-2 anti-sense oligonucleotide could remarkably block the protective effect of heat shock pretreatment on the cellular injuries induced by H2O2.@*CONCLUSION@#HSP72 plays a most important role in the acute injury of cardiomyocyte mediated by oxidative stress.
Subject(s)
Animals , Rats , Animals, Newborn , Cells, Cultured , HSP72 Heat-Shock Proteins , Pharmacology , L-Lactate Dehydrogenase , Metabolism , Myocytes, Cardiac , Pathology , Oligonucleotides, Antisense , Pharmacology , Oxidative Stress , Protein Biosynthesis , Random Allocation , Rats, WistarABSTRACT
OBJECTIVE@#To investigate the effect of oxidative stress on the accumulation of heat shock protein 70 (HSP70) within C2C12 myogenic cells.@*METHODS@#Heat shock response (42 degrees C for 1 h and recovery for 12 h at 37 degrees C) was used to induce the expression of heat shock protein 70. We constructed a recombinant plasmid of HSP70 with enhanced green fluorescent protein (EGFP). After being transfected transiently into C2C12 cells, immunoblotting was used to detect the expression of HSP70 induced by heat shock response and transfection. Immunocytochemistry, fluorescent microscopy and immunoblotting were used to detect the translocation of HSP70.@*RESULTS@#Immunoblotting showed that the overexpression of HSP70 was induced by heat shock response and transient transfenction. HSP70 localized within the cytoplasm of the normal cells, but HSP70 translocated from the cytoplasm to the nucleus and the nucleolus at 1 h after the treatment of oxidative stress (0.5 mmol/L H2O2) by using immunocytochemistry, fluorescent microscopy and immunoblotting for cellular partial proteins.@*CONCLUSION@#Oxidative stress may induce the accumulation of heat shock protein 70 within the nucleolus.