Reason of postprandial low-density lipoprotein cholesterol reduction measured by enzymatic assays: based on nuclear magnetic resonance method / 中华检验医学杂志

Objective:To explore the postprandial plasma low-density lipoprotein cholesterol (LDL-C) changes by various detection methods.Methods:A total of 85 subjects admitted to the Second Xiangya Hospital of Central South University from November 2017 to May 2019 were included. Serum samples were collected from fasting and the 2 nd hour and the 4 th hour after breakfast. Serum lipid levels were measured with enzymatic assays and nuclear magnetic resonance spectroscopy (NMRS), and proprotein invertase subtilisin/kexin type 9 (PCSK9) levels were measured with enzyme-linked immunosorbent assays. The differences of blood lipid components at different time points were compared by Friedman two-way rank analysis of variance and Wilcoxon signed rank test, and the correlation between PCSK9 level and lipoprotein particles was analyzed by Spearman correlation. Results:Measured by enzymatic assays, compared with the fasting state, LDL-C decreased at the 2 nd hour and the 4 th hour after the meal (2.58[2.09, 3.12], 2.47[1.92, 3.02], 2.37[1.82, 2.80] mmol/L, P<0.001). Measured by NMRS, the concentration of LDL particles (1 086[830, 1 239], 1 083[848, 1 213], 1 061[814, 1 213] nmol/L, P=0.417) did not change significantly, and cholesterol in LDL particles were 2.13 (1.56, 2.54), 2.16 (1.68, 2.50), 2.06 (1.58, 2.50) mmol/L, respectively ( P=0.047)，and postprandial cholesterol in LDL particles in the 2 nd hour and in the 4 th hour did not change significantly compared with fasting ( P>0.05). while the concentration of large LDL particles (185.2[150.6,221.6], 173.0[144.8,220.3], 178.1[144.0,233.6] nmol/L, P=0.001), and the cholesterol level in large LDL particles (0.49[0.39, 0.57], 0.47[0.38, 0.57], 0.46[0.37, 0.58]mmol/L, P<0.001) decreased after the meal. The PCSK9 level also decreased significantly after the meal (299[233, 397], 257[208, 342], 251[215, 340] ng/ml, P<0.001). There was an independent positive correlation between the decrease of PCSK9 levels and the increase of remnant cholesterol detected by MNRS after the meal ( r=0.232, P=0.035). Conclusions:The postprandial LDL-C level measured by NMRS and enzymatic assays is not consistent. The decrease of LDL-C measured by enzymatic assays is not caused by the clearance of LDL particles, but by the redistribution of cholesterol in each LDL subfraction.

Construction and expression of recombinant fusion protein of thioredoxin-ApoO / 中南大学学报(医学版)

Objective To construct human apolipoprotein O (apolipoprotein O, ApoO) expression vector and obtain recombinant fusion protein thioredoxin (Trx)-ApoO by pET prokaryotic expression system. Methods The ApoO gene fragment from the human liver cDNA library was amplified by PCR. The resulting product was cloned into pET-32a(+) vector and sequenced. The confirmed cDNA was cloned into plasmid E.coli DH10B and then transformed into E.coli BL 21 (DE3) where it was induced to express protein by isopropyl β-D-1-thiogalactopyranoside (IPTG).The fusion protein was purified by Ni-NTA resin. Results The ApoO gene was cloned by PCR and a 519 bp DNA fragment was shown on the agarose electrophoresis. The cloned gene was sequenced and demonstrated to have the same sequence as that of human ApoO gene in GenBank which justified a successful construction of recombinant plasmid. ApoO cDNA gene fragment was induced by IPTG, and a 34 kD recombinant fusion protein Trx-ApoO was tested on sodium dodecyl sulfate polyacrylamide (SDS-PAGE). Conclusion Human ApoO gene is successfully cloned and its recombinant fusion protein Trx-ApoO is expressed.

Effect of high-density lipoprotein on interleukin-8 secretion in 3T3-L1 adipocytes / 中华内分泌代谢杂志

3T3-L1 adipocytes were cultured with various concentrations of high-density lipoprotein ( HDL, 0, 10, 50, and 100 μg/ml ) for 16 h and with lipopolysaccharide ( LPS, 100 ng/ml ) for another 6 h. Interleukin-8 in the medium was determined by ELISA, and PPAR-γ mRNA expression by reverse transacription polymerase chain reaction (RT-PCR). Interleukin-8 levels were increased in LPS-treated cells ( P＜0.05 ), but decreased in HDL-treated cells in the dose-dependent manner. PPARγ mRNA expressions were increased in HDL-treated groups than those treated only with LPS. These results suggested HDL may decrease interleukin-8 secretion via up-regulating PPARγ expression in adipocytes.

Effects of high density lipoprotein and apolipoprotein A-Ⅰ mimetic peptide on the expression of adiponectin in 3T3-L1 adipocytes / 中国药理学通报

Aim To explore the effect of high density lipoprotein and apolipoprotein A-I mimetic peptide on the secretion and the expression of adiponectin in fully differentiated 3T3-L1 adipocytes in inflammatory status and the possible mechanism.Methods Fully differentiated 3T3-L1 adipocytes were incubated in the medium containing various concentrations of high density lipoprotein(10~100 mg?L-1) and apolipoprotein A-I mimetic peptide(1~50 mg?L-1)with 100 ?g?L-1 lipopolysaccharide(n=3).Evaluate the levels of adiponectin in supernatant,the mRNA expression of adiponectin and PPAR?,and the activity of NF-?B.Results During LPS stimulation adiponectin concentrations in supernatant decreased from 0.25?0.03 ?g?L-1 to 0.14?0.02 ?g?L-1(P

The prospect of the combination use of angiotensinⅡ receptor blockers and statins / 中国药理学通报

Angiotensin Ⅱ receptor blockers(ARBs) and statins are commonly used cardiovascular drugs.Their combination use has become a new topic in the research field of cardiovascular drugs.At present,many studies suggest great potential of the combination use of ARB and statins.