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High-density lipoprotein (HDL) subclasses have different antiatherogenic potentials and functional properties. This work presents our findings and discussions on their metabolic implications on apolipoprotein (apo) C-III together with other apolipoprotein levels and HDL subclass distribution profile. Apolipoprotein A-I contents of plasma HDL subclasses were quantitated by 2-dimensional gel electrophoresis coupled with immunodetection in 511 subjects. Concentrations of triglycerides and of apo B-100, C-II, and C-III were higher, whereas those of HDL cholesterol were lower, for subjects in the highest tertile of apo C-III levels group, which presented a typical hypertriglyceridemic lipid profile. Subjects in the middle and highest tertile of apo C-III levels groups had increased prebeta(1)-HDL, HDL(3c), HDL(3b) (only in the highest tertile of apo C-III group), and HDL(3a), but decreased HDL(2a) and HDL(2b) contents compared with subjects in the lowest tertile of apo C-III levels group. With the elevation of apo C-III together with apo C-II levels, contents of small-sized prebeta(1)-HDL increased successively and significantly; but those of large-sized HDL(2b) reduced successively and significantly. With a rise in apo C-III and apo A-I levels, those of prebeta(1)-HDL increased significantly. Moreover, subjects with high apo A-I levels showed a substantial increase in HDL(2b); on the contrary, HDL(2b) declined progressively and obviously for subjects in the low apo A-I levels with the elevation of apo C-III levels. Correlation analysis illustrated that apo C-III levels were positively associated with prebeta(1)-HDL, prebeta(2)-HDL, and HDL(3a). The particle size of HDL shifted toward smaller sizes with the increase of plasma apo C-III levels, and the shift was more remarkable when the elevation of apo C-III and apo C-II was simultaneous; and besides, higher apo A-I concentrations could modify the effect of apo C-III on HDL subclass distribution profile. Large-sized HDL(2b) particles decreased greatly for hypertriglyceridemic subjects who were characterized by elevated apo C-III and C-II accompanied with significantly lower apo A-I, which, in turn, blocked the maturation of HDL.

Alterations in plasma lipid levels can influence the composition, content, and distribution of plasma lipoprotein subclasses that effect atherosclerosis risk. Hypercholesterolemia and combined hyperlipidemia are common forms of atherogenic dyslipoproteinemia. This study evaluates the alterations of high-density lipoprotein (HDL) subclasses in hypercholesterolemic and combined hyperlipidemic subjects.Apolipoprotein A-I contents of plasma HDL subclasses were quantitated by 2-dimensional gel electrophoresis in 242 normolipidemic subjects, 66 hypercholesterolemic subjects and 59 combined hyperlipidemic subjects.Compared with the normolipidemic subjects, apolipoprotein A-I contents of small-sized pre-beta1-HDL, HDL3c, HDL3b and HDL3a were significantly higher in both hypercholesterolemic subjects (p.01, p.05, p.01 and p.05, respectively) and combined hyperlipidemic subjects (p.01, p.05, p.01 and p.01, respectively). In contrast, apolipoprotein A-I contents of large-sized HDL2a and HDL2b were significantly lower in hypercholesterolemic subjects (p.05 and p.01, respectively) as well as combined hyperlipidemic subjects (p.01 and p.01, respectively). In addition, pre-beta1-HDL increased significantly (p.05) while HDL2a and HDL2b decreased significantly (p.05 and p.01, respectively) in combined hyperlipidemic group versus hypercholesterolemic subjects. With the elevation of triglyceride levels, pre-beta1-HDL, and HDL3a increased successively, however, HDL2a and HDL2b decreased successively in subjects with total cholesterol levels greater than 240 mg/dl.The particle size of HDL shifted towards smaller size in hypercholesterolemic subjects, and that the shift was more prominent in combined hyperlipidemic subjects. The alternations mentioned above indicate that HDL maturation might be abnormal, and reverse cholesterol transport (RCT) might be weakened.

Background To elucidate the relationship between the apolipoproteins, especially apoA-I and the alteration of HDL subclasses in hyperlipidemic, HTC and HTG subjects. Methods ApoA-I contents of plasma HDL subclasses were quantitated by two-dimensional gel electrophoresis coupled with immunodetection in 233 normolipidemic subjects and 312 hyperlipidemic subjects (132 HTC and 180 HTG subjects). Making use of the mean ± 1 SD of apoA-I levels, we further subdivided normolipidemic, hyperlipidemic, HTC and HTG subjects into 3 subgroups, respectively. Results Subjects in the middle and low apoA-I subgroups had decreased HDL-C and apoA-I while increased TG, apoB100, apoCII, apoCIII and apoE concentrations. With the reduction of apoA-I concentrations, the apoA-I contents of all HDL subclasses decreased successively and significantly. The relative percentage of small-sized HDL increased significantly while those of large-sized HDL2a, HDL2b decreased significantly in hyperlipidemic, especially in HTG group. Multiple liner regression result revealed that apoA-I was positively and significantly correlated with all HDL subclasses and apoA-I level influenced the distribution of HDL subclasses powerfully in hyperlipidemic subjects. Conclusions Both the rate and efficiency of RCT might be weakened more seriously in hyperlipidemic, especially in HTG subjects with low apoA-I levels. ApoA-I level might be a powerful factor correlated with the distributions of HDL subclasses.

Different high-density lipoprotein (HDL) subclasses have distinct but interrelated metabolic functions. HDL directly influences the atherogenic process, and changes in HDL subclasses distribution may be related to the incidence and prevalence of atherosclerosis. Lipoprotein lipase (LPL) is an important enzyme for hydrolysis of triglyceride-rich lipoproteins, and its activity is positively correlated with the plasma HDL cholesterol level. LPL gene HindIII polymorphism has been found associated with variations in lipid levels, but the impact on HDL subclasses distribution is less clearly established.The relative apolipoprotein (apo) A-I contents (% apoA-I) of plasma HDL subclasses were determined by two-dimensional gel electrophoresis coupled with immunodetection and LPL gene HindIII polymorphism was assayed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) in 173 hyperlipidemic and 155 normolipidemic subjects.The frequencies of 495TT genotype and allele T were the highest both in the hyperlipidemic and control groups. Compared with the control group, the frequency of 495TT genotype was higher, while the frequencies of 495TG and 495GG genotypes were significantly lower (P0.05) in the hyperlipidemic group. Two-dimensional gel electrophoresis and immunodetection showed that HDL subclasses distribution was altered in hyperlipidemia, and had a general shift toward smaller size. Compared with the control group, the hyperlipidemic group had significantly higher relative apoA-I contents of prebeta1-HDL, prebeta2-HDL, HDL3b and HDL3a (P0.05) and lower HDL2a and HDL2b levels (P0.001). In the hyperlipidemic group, allele T carriers' frequency was higher than that in the control group (P0.05), and the genotype of 495TT showed higher levels of plasma TG, apoB100, TG/HDL-C ratio, relative apoA-I contents of prebeta1-HDL, HDL3b and lower HDL2a, HDL2b compared with that of the 495GG genotype subgroup (P0.05). In the control group, the genotype of 495TT had higher plasma TG, HDL3c and lower HDL2a compared with that of 495GG subgroup (P0.05).The 495TT genotype of LPL gene HindIII polymorphism was associated with changes of HDL subclasses distribution in Chinese population with hyperlipidemia. The particle size of HDL shifted toward smaller, which, in turn, indicated that RCT might be weakened and HDL maturation might be abnormal in hyperlipidemic subjects with 495TT genotype.

To investigate the alterations of high-density lipoprotein (HDL) subclasses in endogenous hypertriglyceridemic subjects.Apolipoprotein A-I contents of plasma HDL subclasses were quantitated by 2-dimensional gel electrophoresis in 236 normolipidemic subjects (including 146 males and 90 females) and 176 endogenous hypertriglyceridemic subjects (including 103 males and 73 females).Apolipoprotein A-I contents of small-sized pre-beta1-HDL and HDL3a were significantly higher (P.01 and P.01, respectively), but those of large-sized HDL2a and HDL2b were significantly lower (P.01 and P.01, respectively) in hypertriglyceridemic subjects versus normolipidemic subjects. Moreover, with the elevation of triglyceride levels, small-sized pre-beta1-HDL and HDL3a increased successively; however, large-sized HDL2a and HDL2b decreased successively. Males had significantly higher apolipoprotein A-I contents of small-sized pre-beta1-HDL and HDL3b (P.05 and P.05, respectively), but lower contents of large-sized HDL2b (P.01) than females in both normolipidemic and hypertriglyceridemic subjects.The particle size of HDL shifted toward smaller size in hypertriglyceridemic subjects, especially in male subjects. Of note, the shift was more obvious with the elevation of triglyceride levels. The changes mentioned above indicate that HDL maturation might be abnormal and reverse cholesterol transport might be weakened.

Background It is generally accepted that apolipoprotein (apo) A-I is the dominant structural apolipoprotein of HDL particles and different HDL subclasses have distinct but interrelated metabolic functions. HDL is known to directly affect the atherogenic process hence changes in HDL subclasses distribution may be related to the incidence and prevalence of atherosclerosis. Methods The ApoA-I contents (mg/l) of plasma HDL subclasses were determined by 2-dimensional gel electrophoresis coupled with immunodetection and apoA-I genotypes were assayed by PCR-RFLP in 307 Chinese subjects (169 males, 138 females). Results The G/G and C/C genotypes were the most frequent at − 78 bp and + 83 bp of apoA-I gene, respectively. There were no significant differences in the frequencies of rare A allele at − 78 bp and rare T allele at + 83 bp between males and females. Compared with the G/G carriers, G/A and A/A carriers had significantly higher plasma concentrations of TG, apoC-II, apoC-III, apoA-I contents of preβ 1 -HDL, HDL 3a and TG/HDL-C ratio. And in addition, A/A carriers had significantly lower apoA-I contents of HDL 2a and HDL 2b . Females had increased plasma concentrations of apoA-I, HDL-C, apoA-I contents of HDL 2a and HDL 2b while decreased apoA-I contents of preβ 1 -HDL, HDL 3b and TG/HDL-C ratio as compared to males carrying the same genotype. No significant differences were demonstrated on the concentrations of plasma lipids, lipoproteins, apolipoproteins and apoA-I contents of plasma HDL subclasses between the C/C and C/T subjects. Conclusion The G/A polymorphism at − 78 bp of apoA-I gene was associated with changes of HDL subclasses distribution. There was a general shift towards smaller-sized HDL, which, in turn, indicated that reverse cholesterol transport (RCT) might be weakened and HDL maturation might be abnormal in the subjects with G/A mutation.

It is generally accepted that different high-density lipoprotein (HDL) subclasses have distinct but interrelated metabolic functions. HDL is known to directly influence the atherogenic process and changes in HDL subclasses distribution may be related to the incidence and prevalence of atherosclerosis.The relative apolipoprotein (apo)A-I contents (% apoA-I) of plasma HDL subclasses were determined by two-dimensional gel electrophoresis coupled with immunodetection for apoA-I, in 39 hypercholesterolemic (HTC) subjects, 97 hypertriglyceridemic (HTG) subjects and 32 mixed hyperlipidemic (MHL) subjects, and 124 normolipidemic subjects.The relative apoA-I contents of prebeta(1)-HDL, prebeta(2)-HDL, HDL(3c), HDL(3b) and HDL(3a) significantly increased while HDL(2a) and HDL(2b) significantly decreased in hyperlipidemic subjects. In HTC subjects of hyperlipidemia, the concentrations of prebeta(1)-HDL were significantly lower and HDL(2b) concentrations were significantly higher than in HTG and MHL subjects. In HTG subjects, the concentrations of HDL(3a) were significantly higher and the concentrations of HDL(2b) were lower than in HTC and MHL subjects. In total hyperlipidemic subjects, plasma triglyceride (TG) concentrations showed positive correlation with prebeta(1)-HDL, prebeta(2)-HDL, HDL(3b) and HDL(3a) and negative correlation with HDL(2a) and HDL(2b). The total cholesterol (TC) concentrations showed positive correlation with the relative apoA-I contents of prebeta(1)-HDL and HDL(3b), whereas the HDL-C concentrations showed negative correlation with the relative apoA-I contents of prebeta(1)-HDL and HDL(3a) and positive correlation with those of HDL(2a) and HDL(2b). The relative apoA-I contents of prebeta(1)-HDL, prebeta(2)-HDL, HDL(3b), and HDL(3a) were positively correlated whereas those of HDL(2a) and HDL(2b) were negatively correlated with TG/HDL-C ratio.The particle size of HDL in hyperlipidemic subjects shifted towards smaller sizes, which, in turn, indicates that the maturation of HDL may be abnormal in hyperlipidemic subjects.