Atrial fibrillation(AF) produces changes in atrial structure and extracellular matrix composition, which is regulated by matrix metalloproteinases(MMPs). Moreover, AF often occurs in the setting of congestive heart fa...Atrial fibrillation(AF) produces changes in atrial structure and extracellular matrix composition, which is regulated by matrix metalloproteinases(MMPs). Moreover, AF often occurs in the setting of congestive heart failure(CHF), which also affects MMPs. Whether changes in MMPs or the tissue inhibitors of metalloproteinases(TIMPs) within atrial and ventricular myocardium are differentially regulated with AF remains unclear. Myocardium from the walls of the right atrium, right ventricle, left atrium, and left ventricle was obtained from the explanted hearts of 43 patients with end- stage CHF. AF was present in 23 patients(duration 1 to 84 months). The remaining 20 patients served as non- AF controls. The groups were well matched clinically, but left atrial(LA) size was increased in the AF cohort(5.5± 0.8 vs 4.9± 0.7 cm, p< 0.05). Myocardial collagen content and levels of MMP- 1,- 2,- 8,- 9,- 13, and- 14, and TIMP- 1,- 2,- 3, and TIMP- 4 were determined. With AF, collagen content was greater within the atrial myocardium but less in the ventricular myocardium. There were chamber- specific differences in MMPs and TIMPs with AF. For example, MMP- 1 in the right atrium and MMP- 9 in the left atrium were greater with AF. TIMP- 3 levels were greater in the right ventricle, left atrium, and left ventricle. Although total LA collagen was positively correlated with AF duration(r=0.49, p< 0.03), there was an inverse relation between soluble collagen I and AF duration(n=6, r=- 0.84, p< 0.04). In conclusion, AF is associated with chamber- specific alterations in myocardial collagen content and MMP and TIMP levels, indicative of differential remodeling and altered collagen metabolism. Differences in MMP and TIMP profiles may provide diagnostic and mechanistic insights into the pathogenesis of AF with CHF.展开更多
Suberoylanilide hydroxamic acid (SAHA), an orally administered inhibitor of histone deacetylases, is currently in phase II clinical trials for cutaneous T cell lymphomas (CTCL), but the mechanism of SAHA action is unk...Suberoylanilide hydroxamic acid (SAHA), an orally administered inhibitor of histone deacetylases, is currently in phase II clinical trials for cutaneous T cell lymphomas (CTCL), but the mechanism of SAHA action is unknown. In this study, we investigated the anti-tumor effects of SAHA in CTCL cell lines and freshly isolated peripheral blood lymphocytes (PBL) from CTCL patients with high percentage of circulating malignant T cells. Three cell lines (MJ, Hut78, and HH) and PBL from 11 patients and three healthy donors were treated with SAHA (1, 2.5, and 5 μ M) for 24 and/or 48 h. Apoptosis was determined by flow cytometry analysis of sub- G1 hypodiploid nuclei and/or annexin V binding populations. Acetylated histones and apoptosis-associated proteins were detected by Western blotting. SAHA at 1- 5 μ M for 24 and 48 h induced apoptosis in a concentration- and time-dependent manner in three cell lines: MJ (0% - 7% and 1% - 32% ), Hut78 (4% - 36% and 5% - 54% ), and HH (4% - 67% and 8% - 81% ). SAHA at 1- 5 μ M for 48 h also induced more apoptosis of patients’ PBL than healthy donors’ (15% - 32% versus6% - 13% , p<0.05). SAHA treatment caused an accumulation of acetylated histones (H2B, H3, and H4), an increase of p21 WAF1 and bax proteins, a decrease of Stat6 and phospho-Stat6 proteins, and activation of caspase-3 in CTCL cells. Our data suggest that selective induction of malignant T cell apoptosis and modulation of acetylated histones, p21WAF1, bax, Stat6, and caspase-3 may underlie the therapeutic action of SAHA in CTCL patients.展开更多
AIM: To investigate the effects of ursodeoxycholic acid (UDCA) on apoptosis and proliferation of hepatoma cell lines. METHODS: Human hepatoma cell lines HepG2 and BEL 7402 were cultured in medium supplemented with dif...AIM: To investigate the effects of ursodeoxycholic acid (UDCA) on apoptosis and proliferation of hepatoma cell lines. METHODS: Human hepatoma cell lines HepG2 and BEL 7402 were cultured in medium supplemented with different concentrations of UDCA, normal human hepatic line L-02 was used as control. Cell proliferation, apoptosis and gene expression were detected using methyl thiazolyl tetrazolium (MTT) assay, flow cytometry, Western blot, DNA ladder assay, electron microscopy, and immunocytochemistry. RESULTS: Ursodeoxycholic acid inhibited the proli- feration of HepG2 and BEL7402 cell lines in a dose- dependent manner. Ursodeoxycholic acid can change cell cycle distribution of HepG2 and BEL7402, the proportion of cells in G0-G1 phase increased whereas the proportion of S phase cells and G2-M phase cells decreased. Ursodeoxycholic acid arrested the cell cycle in G0-G1 phase by down-regulating the cell cycle related proteins cyclin D1, D3 and retinoblastoma protein (pRb). The apoptotic rates of HepG2 and BEL7402 treated with UDCA (1.0 mmol/L) were significantly higher than those of control. In the HepG2 and BEL7402 treated with UDCA, expression of bcl-2 decreased whereas expression of Bax increased, the nuclear fragmentation and chromosomal condensed, cells shrank and lost attachment, apoptotic bodies and DNA ladders appeared. UDCA had no effect in inducing apoptosis on L-02 cell lines. CONCLUSION: UDCA can selectively inhibit proliferation and induce apoptosis of HepG2 and BEL7402 cell lines by blocking cell cycle and regulating the expression of Bax/bcl-2 genes.展开更多
To study the mechanism and specificity of anti-proliferative effect of STI571 on BCR- ABL positive cell line. BCR-ABL positive human leukemia cell line K562 and BCR- ABL negative human leukemia cell line MOTE were emp...To study the mechanism and specificity of anti-proliferative effect of STI571 on BCR- ABL positive cell line. BCR-ABL positive human leukemia cell line K562 and BCR- ABL negative human leukemia cell line MOTE were employed. Cells were treated with STI 571 or Adriamycin for 18 hours and their morphology and genomic DNA integrity were investigated. STI 571 induced apoptosis in K562 cells but not in MO7E cells. In contrast, adriamycin induced apoptosis in MO7E cells but not in K562 cells. STI 571 shows anti-展开更多
文摘Atrial fibrillation(AF) produces changes in atrial structure and extracellular matrix composition, which is regulated by matrix metalloproteinases(MMPs). Moreover, AF often occurs in the setting of congestive heart failure(CHF), which also affects MMPs. Whether changes in MMPs or the tissue inhibitors of metalloproteinases(TIMPs) within atrial and ventricular myocardium are differentially regulated with AF remains unclear. Myocardium from the walls of the right atrium, right ventricle, left atrium, and left ventricle was obtained from the explanted hearts of 43 patients with end- stage CHF. AF was present in 23 patients(duration 1 to 84 months). The remaining 20 patients served as non- AF controls. The groups were well matched clinically, but left atrial(LA) size was increased in the AF cohort(5.5± 0.8 vs 4.9± 0.7 cm, p< 0.05). Myocardial collagen content and levels of MMP- 1,- 2,- 8,- 9,- 13, and- 14, and TIMP- 1,- 2,- 3, and TIMP- 4 were determined. With AF, collagen content was greater within the atrial myocardium but less in the ventricular myocardium. There were chamber- specific differences in MMPs and TIMPs with AF. For example, MMP- 1 in the right atrium and MMP- 9 in the left atrium were greater with AF. TIMP- 3 levels were greater in the right ventricle, left atrium, and left ventricle. Although total LA collagen was positively correlated with AF duration(r=0.49, p< 0.03), there was an inverse relation between soluble collagen I and AF duration(n=6, r=- 0.84, p< 0.04). In conclusion, AF is associated with chamber- specific alterations in myocardial collagen content and MMP and TIMP levels, indicative of differential remodeling and altered collagen metabolism. Differences in MMP and TIMP profiles may provide diagnostic and mechanistic insights into the pathogenesis of AF with CHF.
文摘Suberoylanilide hydroxamic acid (SAHA), an orally administered inhibitor of histone deacetylases, is currently in phase II clinical trials for cutaneous T cell lymphomas (CTCL), but the mechanism of SAHA action is unknown. In this study, we investigated the anti-tumor effects of SAHA in CTCL cell lines and freshly isolated peripheral blood lymphocytes (PBL) from CTCL patients with high percentage of circulating malignant T cells. Three cell lines (MJ, Hut78, and HH) and PBL from 11 patients and three healthy donors were treated with SAHA (1, 2.5, and 5 μ M) for 24 and/or 48 h. Apoptosis was determined by flow cytometry analysis of sub- G1 hypodiploid nuclei and/or annexin V binding populations. Acetylated histones and apoptosis-associated proteins were detected by Western blotting. SAHA at 1- 5 μ M for 24 and 48 h induced apoptosis in a concentration- and time-dependent manner in three cell lines: MJ (0% - 7% and 1% - 32% ), Hut78 (4% - 36% and 5% - 54% ), and HH (4% - 67% and 8% - 81% ). SAHA at 1- 5 μ M for 48 h also induced more apoptosis of patients’ PBL than healthy donors’ (15% - 32% versus6% - 13% , p<0.05). SAHA treatment caused an accumulation of acetylated histones (H2B, H3, and H4), an increase of p21 WAF1 and bax proteins, a decrease of Stat6 and phospho-Stat6 proteins, and activation of caspase-3 in CTCL cells. Our data suggest that selective induction of malignant T cell apoptosis and modulation of acetylated histones, p21WAF1, bax, Stat6, and caspase-3 may underlie the therapeutic action of SAHA in CTCL patients.
基金Shandong Science and Technology Committee of China, No. 2005GG3202192
文摘AIM: To investigate the effects of ursodeoxycholic acid (UDCA) on apoptosis and proliferation of hepatoma cell lines. METHODS: Human hepatoma cell lines HepG2 and BEL 7402 were cultured in medium supplemented with different concentrations of UDCA, normal human hepatic line L-02 was used as control. Cell proliferation, apoptosis and gene expression were detected using methyl thiazolyl tetrazolium (MTT) assay, flow cytometry, Western blot, DNA ladder assay, electron microscopy, and immunocytochemistry. RESULTS: Ursodeoxycholic acid inhibited the proli- feration of HepG2 and BEL7402 cell lines in a dose- dependent manner. Ursodeoxycholic acid can change cell cycle distribution of HepG2 and BEL7402, the proportion of cells in G0-G1 phase increased whereas the proportion of S phase cells and G2-M phase cells decreased. Ursodeoxycholic acid arrested the cell cycle in G0-G1 phase by down-regulating the cell cycle related proteins cyclin D1, D3 and retinoblastoma protein (pRb). The apoptotic rates of HepG2 and BEL7402 treated with UDCA (1.0 mmol/L) were significantly higher than those of control. In the HepG2 and BEL7402 treated with UDCA, expression of bcl-2 decreased whereas expression of Bax increased, the nuclear fragmentation and chromosomal condensed, cells shrank and lost attachment, apoptotic bodies and DNA ladders appeared. UDCA had no effect in inducing apoptosis on L-02 cell lines. CONCLUSION: UDCA can selectively inhibit proliferation and induce apoptosis of HepG2 and BEL7402 cell lines by blocking cell cycle and regulating the expression of Bax/bcl-2 genes.
文摘To study the mechanism and specificity of anti-proliferative effect of STI571 on BCR- ABL positive cell line. BCR-ABL positive human leukemia cell line K562 and BCR- ABL negative human leukemia cell line MOTE were employed. Cells were treated with STI 571 or Adriamycin for 18 hours and their morphology and genomic DNA integrity were investigated. STI 571 induced apoptosis in K562 cells but not in MO7E cells. In contrast, adriamycin induced apoptosis in MO7E cells but not in K562 cells. STI 571 shows anti-
