Objective:To investigate the effect of malarial pigment(hemozoin,HZ) on expression of heat shock proteins(HSPs) and cell viability in human monocytes by using a stable cell line(THP-1 cells).Methods:THP-1 cells were f...Objective:To investigate the effect of malarial pigment(hemozoin,HZ) on expression of heat shock proteins(HSPs) and cell viability in human monocytes by using a stable cell line(THP-1 cells).Methods:THP-1 cells were fed with native HZ or treated with pro-apoptotic molecule gliotoxin for 9 h.Thereafter,the protein expression of HSP-27 and HSP-70 was evaluated by western blotting.Alternatively,HZ-fed cells were cultured up to 72 h and cell viability parameters(survival,apoptosis and necrosis rates) were measured by flow cytometric analysis. Results:HZ increased basal protein levels of HSP-27 without altering those of HSP-70 in THP-1 cells,and promoted long-term cell survival without inducing apoptosis.As expected,gliotoxin inhibited HSP-27 protein expression and promoted long-term cell apoptosis.Conclusions: Present data show that HZ prevents cell apoptosis and enhances the expression of anli-apoptotic HSP-27 in THP-1 cells,confirming the previous evidences obtained from HZ-fed immunopurified monocytes.Since the use of a stable cell line is pivotal to perform HSP-27 silencing experiments, monocytic THP-1 cells could be a good candidate line for such an approach,which is heavily required to clarify the role of HSP-27 in survival of impaired HZ-fed monocytes during falciparum malaria.展开更多
The relation between the expression and activity of MMP-9 in C-reactive protein （CRP）-induced human THP-1 mononuclear cells and the activation of nuclear factor kappa-B （NF-κB） was studied to investigate the poss...The relation between the expression and activity of MMP-9 in C-reactive protein （CRP）-induced human THP-1 mononuclear cells and the activation of nuclear factor kappa-B （NF-κB） was studied to investigate the possible role of CRP in plaque destabilization. Human THP-1 cells were incubated in the presence of CRP at 0 （control group）, 25, 50 and 100 μg/mL （CRP groups） for 24 h. In PDTC （a specific NF-κB inhibitor） group, the cells were pre-treated with PDTC at 10 μmol/L and then with 100 μg/mL CRP. The conditioned media （CM） and human THP-1 cells in different groups were harvested. MMP-9 expression in CM and human THP-1 cells was measured by ELISA and Western blotting. MMP-9 activity was assessed by fluorogenic substrates. The expression of NF-κB inhibitor α （IκB-α） and NF-κB p65 was detected by Western blotting and ELISA respectively. The results showed that CRP increased the expression and activity of MMP-9 in a dose-dependent manner in the human THP-1 cells. Western blotting revealed that IiB-α expression was decreased in the cells with the concentrations of CRP and ELISA demonstrated that NF-κB p65 expression in the CRP-induced cells was increased. After pre-treatment of the cells with PDTC at 10 μmol/L, the decrease in IκB-α expression and the increase in NF-κB p65 expression in the CRP-induced cells were inhibited, and the expression and activity of MMP-9 were lowered too. It is concluded that increased expression and activity of MMP-9 in CRP-induced human THP-1 cells may be associated with activation of NF-κB. Down-regulation of the expression and activity of MMP-9 may be a new treatment alternative for plaque stabilization by inhibiting the NF-κB activation.展开更多
In this work, the influence of different substrate adhesion during phorbol-12-myristate-13-acetate (PMA)-induced differentiation of THP-1 monocytic cell line was studied. In particular, by morphocytochemical and cytom...In this work, the influence of different substrate adhesion during phorbol-12-myristate-13-acetate (PMA)-induced differentiation of THP-1 monocytic cell line was studied. In particular, by morphocytochemical and cytometric approaches, the influence of type I and type IV collagens in an experimental model representative of three phases (initial, intermediate and terminal) of monocyte-macrophage transition was analyzed. The cells in these three phases of differentiation were obtained by using 6, 30 e 60 nM PMA. In this experimental model, referring to adhesion to glass as control, by using the azo-dye coupling method, we have considered the analysis of Acid Phosphatase (AcP) activity as a marker of differentiated status expression, in relation to the acquisition of macrophagic phenotype. Endosomal/lysosomal system was further characterized by taking into account the uptake of fluorescent probe LysoTracker Red. Fluorochromization in the various experimental conditions was analyzed morphologically (fluorescence microscopy) and quantitatively (static cytometry). Data related to lysosome compartment were integrated, from a cytokinetic point of view, by flow cytometry measurements of DNA/protein content. Our results have indicated that type I and type IV collagens were able to influence, with respect to glass adhesion, various differentiation phases. Type I collagen showed the higher effects in the condition of high differentiation (60 nM PMA), causing an increase in AcP activity and lysosomal system. Type IV collagen, besides determining effects on lysosomal compartment of intermediate and terminally differentiated cells, influenced mainly proliferative activity of cells with initial differentiation level (6 nM PMA).展开更多
Human monoeyte leukemia cell line THP-1 was stimulated with lipopolysaccharide （LPS） to simulate the sepsis model and the expression of human glucocorticoid receptor-α （GR-α） mRNA in montocytes with endotoxin to...Human monoeyte leukemia cell line THP-1 was stimulated with lipopolysaccharide （LPS） to simulate the sepsis model and the expression of human glucocorticoid receptor-α （GR-α） mRNA in montocytes with endotoxin tolerance was investigated. THP-1 cells were cultured in serum-free medium, randomly divided into groups A, B, C, D and E, and stimulated with 0, 10, 10, 100, 0 ng/mL LPS for 24 h followed with 100, 100, 10, 100, 0 ng/mL LPS for another 24 h respectively. The expression of GR-α mRNA was detected by semi-quantitative reverse transcriptional polymerase chain reaction. Tumor necrosis factor-α （TNF-α） was determined by enzyme linked immunosorbent assay （ELISA）. The results showed that the A values of GR-α/β-actin in groups A, B, C, D and E was 0. 607±0. 006, 0. 368±0. 005, 0. 484±0. 008, 0. 509±0. 004 and 0. 564±0. 014 respectively with the difference being significant among the groups （P〈0. 05）. The GR-α mRNA expression was negatively correlated with the TNF-α expression （P〈0. 01）. It was concluded that the down-regulation of the expression of GR-α mRNA in endotoxin tolerance THP-1 cells might play an important role in the development of endotoxin tolerance in THP-1 cells.展开更多
基金supported by University of Torino Intramural Funds to GG and by grants to MP from the Compagnia di San Paolo,Torino,in the context of the Italian Malaria Network
文摘Objective:To investigate the effect of malarial pigment(hemozoin,HZ) on expression of heat shock proteins(HSPs) and cell viability in human monocytes by using a stable cell line(THP-1 cells).Methods:THP-1 cells were fed with native HZ or treated with pro-apoptotic molecule gliotoxin for 9 h.Thereafter,the protein expression of HSP-27 and HSP-70 was evaluated by western blotting.Alternatively,HZ-fed cells were cultured up to 72 h and cell viability parameters(survival,apoptosis and necrosis rates) were measured by flow cytometric analysis. Results:HZ increased basal protein levels of HSP-27 without altering those of HSP-70 in THP-1 cells,and promoted long-term cell survival without inducing apoptosis.As expected,gliotoxin inhibited HSP-27 protein expression and promoted long-term cell apoptosis.Conclusions: Present data show that HZ prevents cell apoptosis and enhances the expression of anli-apoptotic HSP-27 in THP-1 cells,confirming the previous evidences obtained from HZ-fed immunopurified monocytes.Since the use of a stable cell line is pivotal to perform HSP-27 silencing experiments, monocytic THP-1 cells could be a good candidate line for such an approach,which is heavily required to clarify the role of HSP-27 in survival of impaired HZ-fed monocytes during falciparum malaria.
文摘The relation between the expression and activity of MMP-9 in C-reactive protein （CRP）-induced human THP-1 mononuclear cells and the activation of nuclear factor kappa-B （NF-κB） was studied to investigate the possible role of CRP in plaque destabilization. Human THP-1 cells were incubated in the presence of CRP at 0 （control group）, 25, 50 and 100 μg/mL （CRP groups） for 24 h. In PDTC （a specific NF-κB inhibitor） group, the cells were pre-treated with PDTC at 10 μmol/L and then with 100 μg/mL CRP. The conditioned media （CM） and human THP-1 cells in different groups were harvested. MMP-9 expression in CM and human THP-1 cells was measured by ELISA and Western blotting. MMP-9 activity was assessed by fluorogenic substrates. The expression of NF-κB inhibitor α （IκB-α） and NF-κB p65 was detected by Western blotting and ELISA respectively. The results showed that CRP increased the expression and activity of MMP-9 in a dose-dependent manner in the human THP-1 cells. Western blotting revealed that IiB-α expression was decreased in the cells with the concentrations of CRP and ELISA demonstrated that NF-κB p65 expression in the CRP-induced cells was increased. After pre-treatment of the cells with PDTC at 10 μmol/L, the decrease in IκB-α expression and the increase in NF-κB p65 expression in the CRP-induced cells were inhibited, and the expression and activity of MMP-9 were lowered too. It is concluded that increased expression and activity of MMP-9 in CRP-induced human THP-1 cells may be associated with activation of NF-κB. Down-regulation of the expression and activity of MMP-9 may be a new treatment alternative for plaque stabilization by inhibiting the NF-κB activation.
文摘In this work, the influence of different substrate adhesion during phorbol-12-myristate-13-acetate (PMA)-induced differentiation of THP-1 monocytic cell line was studied. In particular, by morphocytochemical and cytometric approaches, the influence of type I and type IV collagens in an experimental model representative of three phases (initial, intermediate and terminal) of monocyte-macrophage transition was analyzed. The cells in these three phases of differentiation were obtained by using 6, 30 e 60 nM PMA. In this experimental model, referring to adhesion to glass as control, by using the azo-dye coupling method, we have considered the analysis of Acid Phosphatase (AcP) activity as a marker of differentiated status expression, in relation to the acquisition of macrophagic phenotype. Endosomal/lysosomal system was further characterized by taking into account the uptake of fluorescent probe LysoTracker Red. Fluorochromization in the various experimental conditions was analyzed morphologically (fluorescence microscopy) and quantitatively (static cytometry). Data related to lysosome compartment were integrated, from a cytokinetic point of view, by flow cytometry measurements of DNA/protein content. Our results have indicated that type I and type IV collagens were able to influence, with respect to glass adhesion, various differentiation phases. Type I collagen showed the higher effects in the condition of high differentiation (60 nM PMA), causing an increase in AcP activity and lysosomal system. Type IV collagen, besides determining effects on lysosomal compartment of intermediate and terminally differentiated cells, influenced mainly proliferative activity of cells with initial differentiation level (6 nM PMA).
文摘Human monoeyte leukemia cell line THP-1 was stimulated with lipopolysaccharide （LPS） to simulate the sepsis model and the expression of human glucocorticoid receptor-α （GR-α） mRNA in montocytes with endotoxin tolerance was investigated. THP-1 cells were cultured in serum-free medium, randomly divided into groups A, B, C, D and E, and stimulated with 0, 10, 10, 100, 0 ng/mL LPS for 24 h followed with 100, 100, 10, 100, 0 ng/mL LPS for another 24 h respectively. The expression of GR-α mRNA was detected by semi-quantitative reverse transcriptional polymerase chain reaction. Tumor necrosis factor-α （TNF-α） was determined by enzyme linked immunosorbent assay （ELISA）. The results showed that the A values of GR-α/β-actin in groups A, B, C, D and E was 0. 607±0. 006, 0. 368±0. 005, 0. 484±0. 008, 0. 509±0. 004 and 0. 564±0. 014 respectively with the difference being significant among the groups （P〈0. 05）. The GR-α mRNA expression was negatively correlated with the TNF-α expression （P〈0. 01）. It was concluded that the down-regulation of the expression of GR-α mRNA in endotoxin tolerance THP-1 cells might play an important role in the development of endotoxin tolerance in THP-1 cells.
