Hemoglobin was used as a mimetic peroxidase in the catalytic chemiluminescence reaction of lumino and hydrogen peroxide. The hemoglobin-catalyzed reaction was coupled with the oxidation reaction of cholesterol catalyz...Hemoglobin was used as a mimetic peroxidase in the catalytic chemiluminescence reaction of lumino and hydrogen peroxide. The hemoglobin-catalyzed reaction was coupled with the oxidation reaction of cholesterol catalyzed by COA(cholesterol oxydase , COA.) to determine total cholesterol(TC)and free cholesterol (FC) in human serum by flow injection chemiluminescence method. The sampling frequency was 30 s/h. The linear range for free cholesterol is 5.6×10-7mol/L～3.8×10-5mol/L and the detection limit is 3.0×10-7mol/L. The linear range for total cholesterol is 1.1×10-6mol/L～4.3×10-5mol/L and the detection limit is 1.5×10-7mol/L.展开更多
Objective To investigate the role of acyl-coenzyme A:cholesterol acyltransferase inhibitor(ACATI) in apoptosis induced by lipids and whether lipids-induced apoptosis is accompanied by increase of free cholesterol in e...Objective To investigate the role of acyl-coenzyme A:cholesterol acyltransferase inhibitor(ACATI) in apoptosis induced by lipids and whether lipids-induced apoptosis is accompanied by increase of free cholesterol in endoplasmic reticulum(ER),in order to further understand the mechanism of lipids-induced apoptosis in advanced atherosclerosis.Methods Human vascular smooth muscle cells(VSMCs) and phorbol 12-myristate 13-acetate(PMA) differentiated THP-1 macrophages were used.Tritiated thymidine incorporation was applied to detect cell proliferation.Cytotoxicity was assessed by lactate dehydrogenase(LDH) release.4',6-diamidino-2-phenylindole(DAPI) staining,caspase-3,-7 assay,and Annexin-V/propidium iodide(PI) staining were used to detect apoptosis.High performance liquid chromatography was used in intracellular free cholesterol and cholesterol ester assay.ER free cholesterol was quantified.Results Different lipids had different effects on proliferation and cytotoxicity of VSMCs.25-hydroxycholesterol(25OHC) had biphasic effects on the proliferation of VSMCs.At low concentration,it stimulated cell proliferation,but turned to proliferation inhibition as concentration reached 15 μg/mL.25OHC and acetylated low density lipoprotein(AcLDL) could respectively induce apoptosis in human VSMCs and PMA differentiated THP-1 macrophages,which was aggravated by ACATI,accompanied by increase of intracellular free cholesterol content.There was also an increase of cholesterol content in ER with AcLDL-induced apoptosis in THP-1 macrophages.Conclusions Lipids could induce apoptosis,accompanied by increase of intracellular free cholesterol content,which could be augmented by ACATI,suggesting that insults resulting in ER free cholesterol rise might be the initiator of apoptosis.展开更多
文摘Hemoglobin was used as a mimetic peroxidase in the catalytic chemiluminescence reaction of lumino and hydrogen peroxide. The hemoglobin-catalyzed reaction was coupled with the oxidation reaction of cholesterol catalyzed by COA(cholesterol oxydase , COA.) to determine total cholesterol(TC)and free cholesterol (FC) in human serum by flow injection chemiluminescence method. The sampling frequency was 30 s/h. The linear range for free cholesterol is 5.6×10-7mol/L～3.8×10-5mol/L and the detection limit is 3.0×10-7mol/L. The linear range for total cholesterol is 1.1×10-6mol/L～4.3×10-5mol/L and the detection limit is 1.5×10-7mol/L.
基金Supported by National Natural Science Foundation of China (30700373)
文摘Objective To investigate the role of acyl-coenzyme A:cholesterol acyltransferase inhibitor(ACATI) in apoptosis induced by lipids and whether lipids-induced apoptosis is accompanied by increase of free cholesterol in endoplasmic reticulum(ER),in order to further understand the mechanism of lipids-induced apoptosis in advanced atherosclerosis.Methods Human vascular smooth muscle cells(VSMCs) and phorbol 12-myristate 13-acetate(PMA) differentiated THP-1 macrophages were used.Tritiated thymidine incorporation was applied to detect cell proliferation.Cytotoxicity was assessed by lactate dehydrogenase(LDH) release.4',6-diamidino-2-phenylindole(DAPI) staining,caspase-3,-7 assay,and Annexin-V/propidium iodide(PI) staining were used to detect apoptosis.High performance liquid chromatography was used in intracellular free cholesterol and cholesterol ester assay.ER free cholesterol was quantified.Results Different lipids had different effects on proliferation and cytotoxicity of VSMCs.25-hydroxycholesterol(25OHC) had biphasic effects on the proliferation of VSMCs.At low concentration,it stimulated cell proliferation,but turned to proliferation inhibition as concentration reached 15 μg/mL.25OHC and acetylated low density lipoprotein(AcLDL) could respectively induce apoptosis in human VSMCs and PMA differentiated THP-1 macrophages,which was aggravated by ACATI,accompanied by increase of intracellular free cholesterol content.There was also an increase of cholesterol content in ER with AcLDL-induced apoptosis in THP-1 macrophages.Conclusions Lipids could induce apoptosis,accompanied by increase of intracellular free cholesterol content,which could be augmented by ACATI,suggesting that insults resulting in ER free cholesterol rise might be the initiator of apoptosis.
