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Background and Aim: APO CII, one of several cofactors which regulate lipoprotein lipase enzyme activity, plays an essential role in lipid metabolism. Deficiency of APO CII is an ultra-rare autosomal recessive cause of familial chylomicronemia syndrome. We present the long-term clinical outcomes of 12 children with APO CII deficiency., Methods and Results: The data of children with genetically confirmed APO CII deficiency were evaluated retrospectively. Twelve children (8 females) with a mean follow-up of 10.1 years (±3.9) were included. At diagnosis, the median age was 60 days (13 days-10 years). Initial clinical findings included lipemic serum (41.6%), abdominal pain (41.6%), and vomiting (16.6%). At presentation, the median triglyceride (TG) value was 4341 mg/dL (range 1277-14,110). All patients were treated with a restricted fat diet, medium-chain triglyceride (MCT), and omega-3-fatty acids. In addition, seven patients (58.3%) received fibrate. Fibrate was discontinued in two patients due to rhabdomyolysis and in one patient because of cholelithiasis. Seven (58.3%) patients experienced pancreatitis during the follow-up period. One female experienced recurrent pancreatitis and was treated with fresh frozen plasma (FFP)., Conclusions: Apo CII deficiency is an ultra-rare autosomal recessive condition of hypertriglyceridemia associated with significant morbidity and mortality. Low-fat diet and MCT supplementation are the mainstays of therapy, while the benefit of TG-lowering agents are less well-defined., Competing Interests: Declaration of competing interest The authors state no conflict of interest., (Copyright © 2024 The Italian Diabetes Society, the Italian Society for the Study of Atherosclerosis, the Italian Society of Human Nutrition and the Department of Clinical Medicine and Surgery, Federico II University. Published by Elsevier B.V. All rights reserved.)

Patients with schizophrenia show a disproportionally increased risk of cardiovascular disease. Hypertriglyceridemia is prevalent in this population; however, how this relates to levels of remnant cholesterol, triglyceride (TG)-rich lipoprotein (TRL) particle size and composition, TG turnover, and apolipoprotein (apo) and angiopoietin-like protein (ANGPTL) concentrations is unknown. Fasting levels of cholesterol (total [TC], LDL-C, HDL-C, non-HDL-C and remnant cholesterol) and TG were determined in 110 patients diagnosed with schizophrenia, and 46 healthy controls. TRL particle size, concentration and composition, and β-hydroxybutyrate (TG turnover marker) were assessed by NMR. Levels of apoCII, apoCIII, apoE, ANGPTL3, ANGPTL4, and ANGPTL8 were measured by ELISA, and apoCII, apoCIII and apoE were further evaluated in HDL and non-HDL fractions. Patients with schizophrenia had significantly elevated TG, TG:apoB ratio, non-HDL-C, remnant cholesterol, non-HDL-apoCII and non-HDL-apoCIII, and HDL-apoE (all P < 0.05), lower HDL-C and apoA-I (all P < 0.001), and comparable apoB, TC, TC:apoB ratio, LDL-C, β-hydroxybutyrate, ANGPTL3, ANGPTL4 and ANGPTL8 to healthy controls. Patients had a 12.0- and 2.5-fold increase in the concentration of large and medium TRL particles respectively, but similar cholesterol:TG ratio within each particle. Plasma TG, remnant cholesterol, and large and medium TRL particle concentrations correlated strongly with apoCII, apoCIII, and apoE in the non-HDL fraction, and with apoCIII and apoE in the HDL fraction in patients with schizophrenia. Differences in TG, HDL-C, TRL particle concentrations, apoCIII, and apoE persisted after adjustment for conventional risk factors. These results are consistent with impaired TRL lipolysis and clearance in patients with schizophrenia which may be responsive to targeting apoCIII., Competing Interests: Conflict of interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: L.K. has participated in clinical trials sponsored by Amgen and Novartis; he has given lectures and received consulting fees from Seqiris (CSL), Amgen and Novartis. D.S. has participated in clinical trials sponsored by NHMRC Clinical Trials Centre; he has received support from Arrowhead Pharmaceuticals for previous publications; he has received grants/contracts sponsored by Regeneron Pharmaceuticals, Ionis Pharmaceuticals, Arrowhead Pharmaceuticals, Amgen and Novartis; he has given lectures and received consulting fees from Amgen and Novartis; he has received contributions from Sanofi., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

There are currently no reliable, established serum biomarkers to predict the prognosis of radiotherapy for advanced cervical cancer. We aimed to identify serum biomarkers for survival after radiotherapy for cervical cancer. In this multicenter prospective cohort study, the usefulness of pre- and posttreatment serum protein levels of potential biomarkers, including squamous cell carcinoma antigen (SCC-Ag), apolipoprotein C-II (ApoC-II), matrix metalloproteinase (MMP)1, and MMP2, were evaluated together with clinical factors in 145 cervical cancer patients in order to determine their suitability to predict survival. Progression-free survival (PFS) was the primary endpoint, and overall survival (OS), pelvic PFS (PPFS), and distant metastasis-free survival (DMFS) were the secondary endpoints. Blood samples were collected before and 1 month after radiotherapy to measure serum biomarker levels. ApoC-II was measured using a monoclonal antibody-based enzyme-linked immunosorbent assay, which was developed for this purpose. Kaplan-Meier method, log-rank test, and univariate and multivariate Cox proportional hazards models were used for statistical analyses. In multivariate analysis, larger tumor size was independently associated with shorter PFS, OS, PPFS, and DMFS, while longer overall treatment time was independently associated with shorter PPFS. Higher pretreatment SCC-Ag (P < 0.001) was associated with shorter DMFS. Higher posttreatment SCC-Ag (P = 0.017) was also associated with shorter DMFS. Pretreatment ApoC-II was associated with PPFS in univariate analysis (P = 0.048), but not in multivariate analysis. Patients with pretreatment ApoC-II levels ≤ 25.8 μg/ml had shorter PPFS than those with pretreatment ApoC-II levels > 25.8 μg/ml (P = 0.023, log-rank test). Pre- and posttreatment serum SCC-Ag and pretreatment serum ApoC-II levels may be important biomarkers to predict survival outcomes of patients with cervical cancer after radiotherapy. Pre- and posttreatment SCC-Ag and pretreatment ApoC-II might be useful in clinical settings for screening patients to improve treatment strategies in cervical cancer., Competing Interests: The authors have declared that no competing interests exist.

Takayasu arteritis (TAK) is an autoimmune systemic arteritis of unknown etiology. Although a number of investigators have attempted to determine biomarkers for diagnosing TAK, there exist no specific serological markers of this intractable disease. We undertook the exploration of novel serological markers which could be useful for an accurate diagnosis of TAK using an unbiased proteomics approach. The purified plasma samples from untreated patients with TAK and healthy individuals were separated by two-dimensional electrophoresis. The differentially expressed protein spots were detected by gel comparison and identified using matrix-assisted laser desorption/ionization time-of-flight/time-of-flight mass spectrometry (MS). Next, we validated plasma concentrations of identified proteins by enzyme-linked immunosorbent assay (ELISA). Two-dimensional electrophoresis and numerical analysis revealed 19 spots and 3 spot clusters whose sum of the sample averages was ≥ 0.01, and the average concentrations were ≥ 1.5 times in the patient group compared with the control group. Among them, 10 spots and spot clusters that met the condition of the average spot concentration being 2.5 times more than that in the control group were selected. After processing these spots using MS and conducting MS/MS ion search, we identified 10 proteins: apolipoprotein C-2 (ApoC-2), actin, apolipoprotein A-1, complement C3, kininogen-1, vitronectin, α2-macroglobulin, 14-3-3 protein ζ/δ, complement C4, and inter-α-trypsin inhibitor heavy chain H4 isoform 1 precursor. Finally, ELISA demonstrated that plasma ApoC-2 level was significantly elevated in patients with TAK compared with that in healthy individuals. Thus, ApoC-2 would be a promising candidate biomarker for TAK diagnosis., (© 2021. The Author(s).)

Background: To investigate possible mechanisms of postprandial hypertriglyceridemia (PPT), we analyzed serum lipid and apolipoprotein (Apo) AI, B, CII and CIII levels before and after a high-fat meal., Methods: The study has been registered with the China Clinical Trial Registry (registration number:ChiCTR1800019514; URL: http://www.chictr.org.cn/index.aspx). We recruited 143 volunteers with normal fasting triglyceride (TG) levels. All subjects consumed a high-fat test meal. Venous blood samples were obtained during fasting and at 2, 4, and 6 hours after the high-fat meal. PPT was defined as TG ≥2.5 mmol/L any time after the meal. Subjects were divided into two groups according to the high-fat meal test results: postprandial normal triglyceride (PNT) and PPT. We compared the fasting and postprandial lipid and ApoAI, ApoB, ApoCII and ApoCIII levels between the two groups., Results: Significant differences were found between the groups in fasting insulin, homeostasis model assessment of insulin resistance (HOMA-IR), TG, total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), non-high-density lipoprotein cholesterol (non-HDL-C), TG-rich lipoprotein remnants (TRLRs), ApoB, ApoCIII, ApoAI/ApoB and ApoCII/ApoCIII. The insulin, HOMA-IR, TG, TC, LDL-C, non-HDL-C, TRLRs, ApoB, ApoCIII and ApoCII/ApoCIII values were higher in the PPT group, while the ApoAI/ApoB ratio was higher in the PNT group. The postprandial TG level peaked in the PNT group 2 hours after the meal but was significantly higher in the PPT group and peaked at 4 hours. TRLRs gradually increased within 6 hours after the high-fat meal in both groups. The area under the curve (AUC) of TG and TRLRs and the AUC increment were higher in the PPT group ( P < 0.001). ApoCIII peaked in the PNT group 2 hours after the meal and gradually decreased. ApoCIII gradually increased in the PPT group within 6 hours after the meal, exhibiting a greater AUC increment ( P < 0.001). Fasting ApoCIII was positively correlated with age, systolic and diastolic blood pressure, body mass index (BMI), waist circumference, TC, TG, LDL-C, non-HDL-C, TRLRs, and ApoB ( P <0.05). ApoCIII was an independent risk factor of PPT after adjustment for BMI, waist circumference, TC, LDL-C, and ApoB ( P < 0.001, OR=1.188)., Conclusions: Elevated ApoCIII levels may cause PPT., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Guan, Hou, Tian, Ren, Tang, Song, Zhao, Gao and Song.)

Objective: Thickened intracranial aneurysm wall with atherosclerotic remodeling is a part of its degenerative scenario. Current magnetic resonance (MR)-vessel wall imaging enables the detection of atherosclerotic wall thickening as aneurysm wall enhancement. The purpose of this study was to examine the correlation between identified atherosclerotic remodeling in vessel wall imaging, and systemic atherosclerosis-related risk factors., Methods: A total of 39 aneurysms in 38 consecutive patients scheduled to undergo microsurgical clipping or endovascular coiling of intracranial aneurysms were prospectively evaluated. All patients underwent aneurysm MR-vessel wall imaging and the presence of aneurysm wall enhancement on contrast-enhanced vessel wall imaging was evaluated. The relationship between aneurysm wall enhancement and patient demographic data, aneurysm morphology and atherosclerosis-related risk factors including blood laboratory data were assessed., Results: Aneurysm wall enhancement was detected in 19 of 39 intracranial aneurysms (48.7%). The maximum diameter of the intracranial aneurysm (P < .01), apolipoprotein A2 (P < .01) and apolipoprotein C2 (P = .01) was significantly associated with the presence of aneurysm wall enhancement. In multivariate logistic regression analyses, the maximum diameter of the intracranial aneurysm (odds ratio: 1.67, 95% confidence interval: 1.17-3.05) and decreased apolipoprotein A2 (odds ratio: 0.62, 95% confidence interval: 0.34-0.97) was significantly correlated with aneurysm wall enhancement., Conclusions: Rather than atherosclerotic factors, antiatherogenic proteins reduction was associated with aneurysm wall enhancement in vessel wall imaging. To elucidate antiatherogenic factors might to help find out promoting factor of unruptured intracranial aneurysms instability., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Intermittent fasting (IF) increases lifespan and decreases metabolic disease phenotypes and cancer risk in model organisms, but the health benefits of IF in humans are less clear. Human plasma derived from clinical trials is one of the most difficult sample sets to analyze using mass spectrometry-based proteomics due to the extensive sample preparation required and the need to process many samples to achieve statistical significance. Here, we describe an optimized and accessible device (Spin96) to accommodate up to 96 StageTips, a widely used sample preparation medium enabling efficient and consistent processing of samples prior to LC-MS/MS. We have applied this device to the analysis of human plasma from a clinical trial of IF. In this longitudinal study employing 8-weeks IF, we identified significant abundance differences induced by the IF intervention, including increased apolipoprotein A4 (APOA4) and decreased apolipoprotein C2 (APOC2) and C3 (APOC3). These changes correlated with a significant decrease in plasma triglycerides after the IF intervention. Given that these proteins have a role in regulating apolipoprotein particle metabolism, we propose that IF had a positive effect on lipid metabolism through modulation of HDL particle size and function. In addition, we applied a novel human protein variant database to detect common protein variants across the participants. We show that consistent detection of clinically relevant peptides derived from both alleles of many proteins is possible, including some that are associated with human metabolic phenotypes. Together, these findings illustrate the power of accessible workflows for proteomics analysis of clinical samples to yield significant biological insight.

Background Little is known about plasma apolipoprotein profiles in very preterm-born and term-born preschool children compared with the adult population. This is of particular interest because apolipoprotein composition might contribute to cardiometabolic outcome in later life. Methods and Results Children aged 5 to 7 years born at term or with <32 weeks of gestation were included. Apolipoprotein concentrations were measured in plasma collected after an overnight fast using multiple-reaction monitoring-based mass spectrometry. Twelve apolipoproteins were measured in 26 former term and 38 former very preterm infants. Key findings were confirmed by assessing apolipoprotein levels using antibody-based assays. Comparing children born term and preterm, apolipoprotein A-I, A- IV , C- II , and C- III were significantly higher in the latter group. Term-born children showed plasma levels of apolipoprotein C- II and C- III quantitatively similar to the adult range (Bruneck study). Hierarchical clustering analyses suggested that a higher proportion of apolipoprotein C- III and C- II reside on high-density lipoprotein particles in children than in adults given the marked correlations of apolipoprotein C- III and C- II with high-density lipoprotein cholesterol and apolipoprotein A-I in children but not adults. High-density lipoprotein cholesterol concentrations were similar in children and adults but the pattern of high-density lipoprotein cholesterol-associated apolipoproteins was different (lower apolipoprotein A-I and C-I but higher A- II , A- IV , and M). Conclusions Our study defines apolipoprotein profiles in preschoolers and reports potential effects of prematurity. Further large-scale studies are required to provide evidence whether this apolipoprotein signature of prematurity, including high apolipoprotein C- II and C- III levels, might translate into adverse cardiometabolic outcome in later life.

Purpose of Review: DNA copy number variations (CNVs) are large-scale mutations that include deletions and duplications larger than 50 bp in size. In the era when single-nucleotide variations were the major focus of genetic technology and research, CNVs were largely overlooked. However, CNVs clearly underlie a substantial proportion of clinical disorders. Here, we update recent progress in identifying CNVs in dyslipidemias., Recent Findings: Until last year, only the LDLR and LPA genes were appreciated as loci within which clinically relevant CNVs contributed to familial hypercholesterolemia and variation in Lp(a) levels, respectively. Since 2017, next-generation sequencing panels have identified pathogenic CNVs in at least five more genes underlying dyslipidemias, including a PCSK9 whole-gene duplication in familial hypercholesterolemia; LPL, GPIHBP1, and APOC2 deletions in hypertriglyceridemia; and ABCA1 deletions in hypoalphalipoproteinemia., Summary: CNVs are an important class of mutation that contribute to the molecular genetic heterogeneity underlying dyslipidemias. Clinical applications of next-generation sequencing technologies need to consider CNVs concurrently with familiar small-scale genetic variation, given the likely implications for improved diagnosis and treatment.

Background: Triglyceride (TG) concentrations >2000 mg/dL are extremely elevated and increase the risk of pancreatitis., Objectives: We characterized five cases and two kindreds and ascertained prevalence in a reference laboratory population., Methods: Plasma lipids and DNA sequences of LPL, GPIHBP1, APOA5, APOC2, and LMF1 were determined in cases and two kindreds. Hypertriglyceridemia prevalence was assessed in 440,240 subjects., Results: Case 1 (female, age 28 years) had TG concentrations >2000 mg/dL and pancreatitis since infancy. She responded to diet and medium-chain triglycerides, but not medications. During two pregnancies, she required plasma exchange for TG control. She was a compound heterozygote for a p.G236Gfs*15 deletion and a p.G215E missense mutation at LPL, as was one sister with hypertriglyceridemia and pancreatitis during pregnancy. Her father was heterozygous for the deletion and had hypertriglyceridemia and recurrent pancreatitis. Other family members had either the missense mutation or the deletion, and had hypertriglyceridemia but no pancreatitis. In kindred 2, three preschool children had severe hypertriglyceridemia and were homozygous for a GPIHBP1 p.T108R missense mutation. Case 5 (male, age 43 years) presented with pancreatitis and TG levels >5000 mg/dL and had heterozygous GPIHBP1 p.G175R and APOC2 intron 2-4G>C mutations. On diet, fenofibrate, fish oil, and atorvastatin, his TG concentration was 2526 mg/dL, but normalized to <100 mg/dL with added pioglitazone. In our population study, 60 subjects (0.014%) of 440,240 had TG concentrations >2000 mg/dL, and 66.7% were diabetic and had elevated insulin levels., Conclusions: Extreme hypertriglyceridemia is rare (0.014%); and during pregnancy, it may require plasma exchange., (Copyright © 2018 National Lipid Association. Published by Elsevier Inc. All rights reserved.)

Background: Rapid turnover proteins (RTPs), such as transthyretin (TTR), retinol binding protein (RBP), and transferrin (Tf), provide an accurate assessment of nutritional status but are susceptible to inflammation. Lipid-related markers, which have short half-lives in serum, may be better suited for nutritional assessment. We sought to identify sensitive nutritional markers unaffected by inflammation., Methods: Fasting serum samples were collected from 30 malnourished inpatients and 25 healthy volunteers. Malnourished inpatients were divided into 2 groups: a low-C-reactive protein (CRP) group (CRP < 20 mg/l, n = 15) and a high-CRP group (CRP ≥ 20 mg/l, n = 15). Lipid-related markers, traditional nutritional markers, RTPs, micronutrients, and ketone bodies were measured and compared among the groups., Results: Apolipoprotein (Apo)C-II and ApoC-III concentrations were lower in malnourished inpatients than in the control group. There was no significant difference in ApoC-II and ApoC-III between the low- and high-CRP groups. Carnitine transporters and ketone bodies did not show a significant difference among the three groups. Albumin, TTR, RBP, and Tf concentrations were lowest in the high-CRP group, intermediate in the low-CRP group, and highest in the control group., Conclusions: These results indicate that ApoC-II and ApoC-III are appropriate nutritional biomarkers unaffected by inflammation., (Copyright © 2018 Elsevier B.V. All rights reserved.)

: Protein S, a nonenzymatic cofactor to activated protein C, presents in two forms in plasma, free form and in a complex with C4b-binding protein. The aim of this study was to determine the association of plasma protein S levels with the variables related to cardiovascular disease risk. The relationships between plasma protein S levels with lipids, inflammation markers, and adiposity were first examined on middle-aged obese women (n = 62), then on young nonobese women (n = 160) to verify the findings in the obese women. Total and free protein S antigen levels in middle-aged obese women, approximately half being in a postmenopausal state and suffered from dyslipidemia, correlated negatively with estradiol and positively with triglycerides, total cholesterol, LDL cholesterol, apoA-II, apoB, apoC-II, apoC-III, apoE, hemoglobin A1c, and protein C, whereas there was no correlation with HDL cholesterol, apoA-I, BMI, visceral fat area, blood pressure, or factor VII activity. Multiple linear regression analyses revealed that protein C, apoC-II, and fibrinogen were significant predictors of total protein S antigen levels, accounting for 51.9% of variance, and apoC-II as a singular significant predictor for free protein S antigen levels (12.3% of variance). In young nonobese women, most being normolipidemic, apoC-II was also selected as a significant predictor of total protein S antigen levels, but not of free protein S antigen levels. The positive relationship between plasma protein S levels and apoC-II, a key regulator of triglycerides hydrolysis, may contribute to the pathogenesis of increased concentrations of plasma protein S.

Objective: The aim of the study was to systematically review the diagnostic utility of serum biomarkers for the diagnosis of necrotizing enterocolitis (NEC)., Methods: We conducted an electronic and manual search of the available evidence. We included studies reporting data on the diagnostic accuracy of "serum" biomarkers for the diagnosis of NEC, available until January 2016., Results: We selected 22 studies from the 1296 articles retrieved. Only S100 A8/A9 protein and apolipoprotein-CII showed high sensitivity (100% and 96.4%, respectively) and specificity (90% and 95%, respectively) in the studies using Bell stage II NEC as target condition. High sensitivity and specificity were reported for interleukin-10 (100% and 90%), interleukin1-receptor antagonist (100% and 91.7%), intestinal fatty acid-binding protein (100% and 91%) and ischemia-modified albumin (94.7% and 92%), when tested to predict the evolution from definite to advanced NEC. Given the amount of uncertainty, the limited availability of data and heterogeneity among the populations in the different studies, we were unable to perform a meta-analysis. Major concerns about the applicability stemmed from the spectrum of patients enrolled and the inclusion of diseases different from Bell stage ≥2 NEC as target conditions., Conclusions: We identified only few markers with good diagnostic accuracy and found an overall low quality of the studies on serum NEC biomarkers. In conclusion, data supporting their use are insufficient.

Background: While the overall acute myocardial infarction rates declined in women and men, premature acute myocardial infarction rates remained stable in men and increased in women., Objective: The purpose of this study was to assess whether baseline apolipoprotein (apo) levels, clinical characteristics, and follow-up of patients with very premature coronary artery disease (CAD) could provide novel clues for the identification of high-risk individuals., Methods: Apos were measured with a validated quantification liquid chromatography-mass spectrometry method in a well-defined cohort of 38 patients aged ≤45 years admitted with acute ST-segment elevation myocardial infarction., Results: Mean age was 39.8 ± 4.6 years and 24% was female. Four of these patients (11%) had apoCII levels ≤5.0 mg/L. Compared with the very premature CAD group with apoCII > 5 mg/L, the patients with apoCII levels ≤5.0 mg/L were all females, tended to be younger (35.8 ± 8.4 years vs 40.3 ± 3.9 years, P = .063), had more often a family history of cardiovascular disease ≤65 years (P = .034) and a significantly lower Framingham risk score (P = .001). They presented with normal triglyceride levels, and had lower low-density lipoprotein cholesterol, apoB 100 , and apoE levels. Corrected for differences in risk profile, apoCII ≤ 5 mg/L was associated with increased risk of 10-years reinfarction or revascularization (hazard ratio 7.9 [95% confidence interval 1.5-41.6], P = .015)., Conclusions: In 38 patients with very premature CAD, 11% were found to have low apoCII levels (≤5.0 mg/L) with normal triglyceride levels. Despite their low a priori risk for CAD, these patients presented with ST-segment elevation myocardial infarction and had a high relative risk of 10-year reinfarction or revascularization. This particular phenotype of relatively young female patients with CAD is not recognized earlier and deserves further study., (Copyright © 2017 National Lipid Association. Published by Elsevier Inc. All rights reserved.)

Background: The incidental finding of severe hypertriglyceridemia (HyperTG) in a child may suggest the diagnosis of familial chylomicronemia syndrome (FCS), a recessive disorder of the intravascular hydrolysis of triglyceride (TG)-rich lipoproteins. FCS may be due to pathogenic variants in lipoprotein lipase (LPL), as well as in other proteins, such as apolipoprotein C-II and apolipoprotein A-V (activators of LPL), GPIHBP1 (the molecular platform required for LPL activity on endothelial surface) and LMF1 (a factor required for intracellular formation of active LPL)., Objective: Molecular characterization of 5 subjects in whom HyperTG was an incidental finding during infancy/childhood., Methods: We performed the parallel sequencing of 20 plasma TG-related genes., Results: Three children with severe HyperTG were found to be compound heterozygous for rare pathogenic LPL variants (2 nonsense, 3 missense, and 1 splicing variant). Another child was found to be homozygous for a nonsense variant of APOA5, which was also found in homozygous state in his father with longstanding HyperTG. The fifth patient with a less severe HyperTG was found to be heterozygous for a frameshift variant in LIPC resulting in a truncated Hepatic Lipase. In addition, 1 of the patients with LPL deficiency and the patient with APOA-V deficiency were also heterozygous carriers of a pathogenic variant in LIPC and LPL gene, respectively, whereas the patient with LIPC variant was also a carrier of a rare APOB missense variant., Conclusions: Targeted parallel sequencing of TG-related genes is recommended to define the molecular defect in children presenting with an incidental finding of HyperTG., (Copyright © 2017 National Lipid Association. Published by Elsevier Inc. All rights reserved.)

Cholesteryl ester transfer protein (CETP) mediates the transfer of HDL cholesteryl esters for triglyceride (TG) in VLDL/LDL. CETP inhibition, with anacetrapib, increases HDL-cholesterol, reduces LDL-cholesterol, and lowers TG levels. This study describes the mechanisms responsible for TG lowering by examining the kinetics of VLDL-TG, apoC-II, apoC-III, and apoE. Mildly hypercholesterolemic subjects were randomized to either placebo (N = 10) or atorvastatin 20 mg/qd (N = 29) for 4 weeks (period 1) followed by 8 weeks of anacetrapib, 100 mg/qd (period 2). Following each period, subjects underwent stable isotope metabolic studies to determine the fractional catabolic rates (FCRs) and production rates (PRs) of VLDL-TG and plasma apoC-II, apoC-III, and apoE. Anacetrapib reduced the VLDL-TG pool on a statin background due to an increased VLDL-TG FCR (29%; P = 0.002). Despite an increased VLDL-TG FCR following anacetrapib monotherapy (41%; P = 0.11), the VLDL-TG pool was unchanged due to an increase in the VLDL-TG PR (39%; P = 0.014). apoC-II, apoC-III, and apoE pool sizes increased following anacetrapib; however, the mechanisms responsible for these changes differed by treatment group. Anacetrapib increased the VLDL-TG FCR by enhancing the lipolytic potential of VLDL, which lowered the VLDL-TG pool on atorvastatin background. There was no change in the VLDL-TG pool in subjects treated with anacetrapib monotherapy due to an accompanying increase in the VLDL-TG PR., (Copyright © 2017 by the American Society for Biochemistry and Molecular Biology, Inc.)

The impetus for discovery and evaluation of protein biomarkers has been accelerated by recent development of advanced technologies for rapid and broad proteome analyses. Mass spectrometry (MS)-based protein assays hold great potential for in vitro biomarker studies. Described here is the development of a multiplex mass spectrometric immunoassay (MSIA) for quantification of apolipoprotein C-I (apoC-I), apolipoprotein C-II (apoC-II), apolipoprotein C-III (apoC-III) and their proteoforms. The multiplex MSIA assay was fast (∼ 40 min) and high-throughput (96 samples at a time). The assay was applied to a small cohort of human plasma samples, revealing the existence of multiple proteoforms for each apolipoprotein C. The quantitative aspect of the assay enabled determination of the concentration for each proteoform individually. Low-abundance proteoforms, such as fucosylated apoC-III, were detected in less than 20% of the samples. The distribution of apoC-III proteoforms varied among samples with similar total apoC-III concentrations. The multiplex analysis of the three apolipoproteins C and their proteoforms using quantitative MSIA represents a significant step forward toward better understanding of their physiological roles in health and disease., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Hypertriglyceridaemia is a common biochemical abnormality that can be due to primary causes or, more commonly, secondary causes. Moderate hypertriglyceridaemia is a risk factor for cardiovascular disease and can develop into severe hypertriglyceridaemia which is a risk factor for acute pancreatitis. Familial chylomicronaemia is a rare autosomal recessive disorder, usually diagnosed in childhood and is characterized by marked hypertriglyceridaemia and biochemical deficiency of lipoprotein lipase (LPL), apolipoprotein (apo) C-II, homozygous (or compound heterozygous) gene mutations in LPL or more rarely, APOC2. Recently, loss-of-function mutations in the APOA5 gene have been reported in patients with severe hypertriglyceridaemia in whom LPL or APOC2 mutations were not found. We describe the clinical features and genetic analysis of three patients with severe hypertriglyceridaemia including novel mutations LPL c.464T>C (p.Leu155Pro) and APOA5 c.823C>T (p.Gln275*)., (© The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.)

Purpose: To determine pretreatment serum protein levels for generally applicable measurement to predict chemoradiation treatment outcomes in patients with locally advanced squamous cell cervical carcinoma (CC)., Methods and Materials: In a screening study, measurements were conducted twice. At first, 6 serum samples from CC patients (3 with no evidence of disease [NED] and 3 with cancer-caused death [CD]) and 2 from healthy controls were tested. Next, 12 serum samples from different CC patients (8 NED, 4 CD) and 4 from healthy controls were examined. Subsequently, 28 different CC patients (18 NED, 10 CD) and 9 controls were analyzed in the validation study. Protein chips were treated with the sample sera, and the serum protein pattern was detected by surface-enhanced laser desorption and ionization-time-of-flight mass spectrometry (SELDI-TOF MS). Then, single MS-based peptide mass fingerprinting (PMF) and tandem MS (MS/MS)-based peptide/protein identification methods, were used to identify protein corresponding to the detected peak. And then, turbidimetric assay was used to measure the levels of a protein that indicated the best match with this peptide peak., Results: The same peak 8918 m/z was identified in both screening studies. Neither the screening study nor the validation study had significant differences in the appearance of this peak in the controls and NED. However, the intensity of the peak in CD was significantly lower than that of controls and NED in both pilot studies (P=.02, P=.04) and validation study (P=.01, P=.001). The protein indicated the best match with this peptide peak at 8918 m/z was identified as apolipoprotein C-II (ApoC-II) using PMF and MS/MS methods. Turbidimetric assay showed that the mean serum levels of ApoC-II tended to decrease in CD group when compared with NED group (P=.078)., Conclusion: ApoC-II could be used as a biomarker for detection in predicting and estimating the radiation treatment outcome of patients with CC., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Background: Ezetimibe, an inhibitor of intestinal cholesterol absorption, is effective in lowering serum low-density lipoprotein (LDL) cholesterol with or without coadministration of statin. Ezetimibe-plus-statin therapy enhances LDL receptor activity, but it is still unclear whether ezetimibe alone enhances LDL receptor activity, resulting in LDL cholesterol decrease., Objective: We investigated whether ezetimibe lowers serum LDL cholesterol by raising LDL receptor activity in humans., Methods: Patients with hypercholesterolemia (n = 28; age [mean ± SD], 61.6 ± 13.0 years; 57% men) were treated with ezetimibe (10 mg/d) for 4 months. Before and after the treatment, serum LDL cholesterol, apolipoprotein B (apo B), and apolipoprotein C-II (apo C-II) were measured. LDL receptor activities were estimated with the equation we reported previously as follows: LDL receptor activity (represented as a percentage of normocholesterolemic subjects) = 63.595 + apo C-II (in mg/dL) × 13.459-apo B (in mg/dL) × 0.366., Results: By the treatment of ezetimibe, LDL cholesterol (176.8 ± 17.9 vs 138.0 ± 19.7 mg/dL) was lowered 21.9% significantly (P < .01). The estimated LDL receptor activities before and after the ezetimibe treatment were 86.8% ± 21.4% and 89.6% ± 19.7%, respectively, with no significant difference between them (P = .13)., Conclusion: Ezetimibe lowered LDL cholesterol significantly in patients with hypercholesterolemia without raising LDL receptor activity. The enhancement of LDL receptor activity is less involved in the pharmacologic action of ezetimibe., (Copyright © 2013 National Lipid Association. Published by Elsevier Inc. All rights reserved.)

Alterations in high-density lipoprotein (HDL) subclass distribution, as well as in the activities of HDL-associated enzymes, have been associated with increased cardiovascular disease (CVD) risk. HDL subclass distribution and the activities of HDL-associated enzymes remain unknown in prediabetic patients, a condition also associated with increased CVD risk. The aim of the present study was to assess any differences in HDL subclass distribution (using polyacrylamide gel electrophoresis) and in activities of HDL-associated enzymes between prediabetic (impaired fasting glucose, IFG, n = 80) and non-prediabetic subjects (n = 105). Subjects with prediabetes had significantly increased waist circumference, blood pressure and triacylglycerol (TAG) levels compared with subjects with fasting glucose levels <100 mg/dL (all p < 0.05). The proportion of small HDL3 over HDL cholesterol (HDL-C) was significantly increased in prediabetic subjects compared with their controls (p < 0.05). The activity of the anti-atherogenic HDL-associated lipoprotein-associated phospholipase A₂ (HDL-LpPLA₂) was significantly lower in subjects with prediabetes (p < 0.05), whereas the activity of paraoxonase 1 (using both paraoxon and phenyl acetate as substrates) did not significantly differ between subjects with or without prediabetes. In a stepwise linear regression analysis, the proportion of small HDL3 over HDL-C concentration was independently associated with the presence of prediabetes and with total cholesterol and TAG concentration (positively), as well as with HDL-C levels (negatively). We also observed a trend of increased small dense low-density lipoprotein cholesterol levels in prediabetic subjects compared with their controls. Subjects with IFG exhibit increased proportion of small HDL3 particles combined with decreased activity of the anti-atherogenic HDL-LpPLA₂.

The three major pathways of lipoprotein metabolism provide a superb paradigm to delineate systematically the familial dyslipoproteinemias. Such understanding leads to improved diagnosis and treatment of patients. In the exogenous (intestinal) pathway, defects in LPL, apoC-II, APOA-V, and GPIHBP1 disrupt the catabolism of chylomicrons and hepatic uptake of their remnants, producing very high TG. In the endogenous (hepatic) pathway, six disorders affect the activity of the LDLR and markedly increase LDL. These include FH, FDB, ARH, PCSK9 gain-of-function mutations, sitosterolemia and loss of 7 alpha hydroxylase. Hepatic overproduction of VLDL occurs in FCHL, hyperapoB, LDL subclass pattern B, FDH and syndrome X, often due to insulin resistance and resulting in high TG, elevated small LDL particles and low HDL-C. Defects in APOB-100 and loss-of-function mutations in PCSK9 are associated with low LDL-C, decreased CVD and longevity. An absence of MTP leads to marked reduction in chylomicrons and VLDL, causing abetalipoproteinemia. In the reverse cholesterol pathway, deletions or nonsense mutations in apoA-I or ABCA1 transporter disrupt the formation of the nascent HDL particle. Mutations in LCAT disrupt esterification of cholesterol in nascent HDL by LCAT and apoA-1, and formation of spherical HDL. Mutations in either CETP or SR-B1 and familial high HDL lead to increased large HDL particles, the effect of which on CVD is not resolved. The major goal is to prevent or ameliorate the major complications of many familial dyslipoproteinemias, namely, premature CVD or pancreatitis. Dietary and drug treatment specific for each inherited disorder is reviewed.

Minimally invasive diagnostic tests are needed in obstetrics to identify women at risk for complications during delivery. The apolipoproteins fluctuate in complexity and abundance in maternal plasma during pregnancy and could be incorporated into a blood test to evaluate this risk. The objective of this study was to examine the relative plasma concentrations of apolipoproteins and their biochemically modified subtypes (i.e. proteolytically processed, sialylated, cysteinylated, dimerized) over gestational time using a targeted mass spectrometry approach. Relative abundance of modified and unmodified apolipoproteins A-I, A-II, C-I, C-II, and C-III was determined by surface-enhanced laser desorption/ionization-time of flight-mass spectrometry in plasma prospectively collected from 11 gravidas with uncomplicated pregnancies at 4-5 gestational time points per patient. Apolipoproteins were readily identifiable by spectral pattern. Apo C-III(2) and Apo C-III(1) (doubly and singly sialylated Apo C-III subtypes) increased with gestational age (r(2)>0.8). Unmodified Apo A-II, Apo C-I, and Apo C-III(0) showed no correlation (r(2) = 0.01-0.1). Pro-Apo C-II did not increase significantly until third trimester (140 ± 13% of first trimester), but proteolytically cleaved, mature Apo C-II increased in late pregnancy (702 ± 130% of first trimester). Mature Apo C-II represented 6.7 ± 0.9% of total Apo C-II in early gestation and increased to 33 ± 4.5% in third trimester. A label-free, semiquantitative targeted proteomics approach was developed using LTQ-Orbitrap mass spectrometry to confirm the relative quantitative differences observed by surface-enhanced laser desorption/ionization-time of flight-mass spectrometry in Apo C-III and Apo C-II isoforms between first and third trimesters. Targeted apolipoprotein screening was applied to a cohort of term and preterm patients. Modified Apo A-II isoforms were significantly elevated in plasma from mothers who delivered prematurely relative to term controls (p = 0.02). These results support a role for targeted proteomics profiling approaches in monitoring healthy pregnancies and assessing risk of adverse obstetric outcomes.

Background: Pancreaticoduodenectomy remains a major undertaking. A preoperative blood test, which could confidently predict the benefits of surgery would improve the selection of pancreatic cancer patients for surgery. This study aimed to identify protein biomarkers prognostic for long-term survival and to validate them with clinico-pathological information., Methods: Serum from 40 preoperative patients was used to train for predictive biomarkers using surface-enhanced laser desorption/ionisation time-of-flight mass spectrometry (SELDI), and the results were verified on 21 independent samples. Two predictive proteins were identified by tryptic peptide mass fingerprinting and sequencing, and validated on serum from another 57 patients by enzyme-linked immunosorbent assay (ELISA). The influence of these proteins on growth and invasion of two cancer cell lines was tested in-vitro., Results: The SELDI panel of m/z 3700, 8222 and 11 522 peaks predicted <12 months' survival (ROC AUC: 0.79, 0.64-0.90; P<0.039). When CA19-9 was added, the ROC AUC increased to 0.95 (0.84-0.99; P<0.0001). The six subjects in the verification group who died within 12 months were correctly classified. The m/z 8222 and 11 522 proteins were identified as Serum ApoC-II and SAA-1, respectively. In the validation samples, ELISA results confirmed that ApoC-II was predictive of survival (Kaplan-Meier P<0.009), but not SAA-I. ApoC-II, CA19-9 and major-vessel involvement independently predicted survival. ApoC-II and SAA-1 increased cell growth and invasion of both cancer cell lines., Conclusion: Serum ApoC-II, CA19-9 and major-vessel invasion independently predict survival and improves selection of patients for pancreaticoduodenectomy.

Objective: There is an urgent need to identify noninvasive and convenient biomarkers for early diagnosis of biliary atresia (BA). The aim of the present study was to identify potential protein biomarkers for BA., Methods: Serum samples from 42 infants with BA, 38 infants with non-BA neonatal cholestasis (NC), and 36 healthy controls (HC) were randomly divided into a training set and a test set. Serum proteomic profiles were measured using surface-enhanced desorption/ionization time-of-flight mass spectrometry. Candidate biomarkers were purified using high-performance liquid chromatography, identified using liquid chromatography tandem mass spectrometry, and validated using enzyme-linked immunosorbent assay., Results: A total of 2 protein peaks (m/z with 8697 and 9098  Da) with differential expression levels were found using surface-enhanced desorption/ionization time-of-flight mass spectrometry. These peaks were then analyzed by a support vector machine to construct a classification model in the training set. The sensitivity and specificity of the model were 94.1% and 91.8%, respectively, in the test set. One candidate biomarker (9098  Da) was identified as Apo C-II, and was found to be downregulated in BA samples compared with HC samples, and upregulated in BA samples compared with NC samples. The other candidate biomarker (8697  Da) was identified as Apo C-III, and was found to be upregulated in BA compared with NC and HC., Conclusions: Apo C-II and Apo C-III may be potential protein biomarkers of BA and may be useful in distinguishing infants with BA from healthy and NC infants. Further studies with additional populations or using prediagnostic serum are needed to confirm the importance of these findings as diagnostic markers of infants with BA.

The focus of this review is on the role of apolipoprotein C-II (apoC-II) in lipoprotein metabolism and the potential effects on the risk of cardiovascular disease (CVD). We searched PubMed/Scopus for articles regarding apoC-II and its role in lipoprotein metabolism and the risk of CVD. Apolipoprotein C-II is a constituent of chylomicrons, very low-density lipoprotein, low-density lipoprotein, and high-density lipoprotein (HDL). Apolipoprotein C-II contains 3 amphipathic α-helices. The lipid-binding domain of apoC-II is located in the N-terminal, whereas the C-terminal helix of apoC-II is responsible for the interaction with lipoprotein lipase (LPL). At intermediate concentrations (approximately 4 mg/dL) and in normolipidemic subjects, apoC-II activates LPL. In contrast, both an excess and a deficiency of apoC-II are associated with reduced LPL activity and hypertriglyceridemia. Furthermore, excess apoC-II has been associated with increased triglyceride-rich particles and alterations in HDL particle distribution, factors that may increase the risk of CVD. However, there is not enough current evidence to clarify whether increased apoC-II causes hypertriglyceridemia or is an epiphenomenon reflecting hypertriglyceridemia. A number of pharmaceutical interventions, including statins, fibrates, ezetimibe, nicotinic acid, and orlistat, have been shown to reduce the increased apoC-II concentrations. An excess of apoC-II is associated with increased triglyceride-rich particles and alterations in HDL particle distribution. However, prospective trials are needed to assess if apoC-II is a CVD marker or a risk factor in high-risk patients., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Mechanisms underlying changes in HDL composition caused by obesity are poorly defined, partly because mice lack expression of cholesteryl ester transfer protein (CETP), which shuttles triglyceride and cholesteryl ester between lipoproteins. Because menopause is associated with weight gain, altered glucose metabolism, and changes in HDL, we tested the effect of feeding a high-fat diet (HFD) and ovariectomy (OVX) on glucose metabolism and HDL composition in CETP transgenic mice. After OVX, female CETP-expressing mice had accelerated weight gain with HFD-feeding and impaired glucose tolerance by hyperglycemic clamp techniques, compared with OVX mice fed a low-fat diet (LFD). Sham-operated mice (SHAM) did not show HFD-induced weight gain and had less glucose intolerance than OVX mice. Using shotgun HDL proteomics, HFD-feeding in OVX mice had a large effect on HDL composition, including increased levels of apoA2, apoA4, apoC2, and apoC3, proteins involved in TG metabolism. These changes were associated with decreased hepatic expression of SR-B1, ABCA1, and LDL receptor, proteins involved in modulating the lipid content of HDL. In SHAM mice, there were minimal changes in HDL composition with HFD feeding. These studies suggest that the absence of ovarian hormones negatively influences the response to high-fat feeding in terms of glucose tolerance and HDL composition. CETP-expressing mice may represent a useful model to define how metabolic changes affect HDL composition and function.

High level of plasma very low-density lipoprotein (VLDL) has been identified as a risk factor for coronary heart disease. Recent evidence suggests that excess VLDL induces inflammatory responses in macrophages and vascular endothelial cells. The Japan EPA Lipid Intervention Study (JELIS), a large scale clinical trial, demonstrated that highly purified eicosapentaenoic acid (EPA) prevented the onset of cardiovascular events in LDL-cholesterol independent fashion. In this study, we investigated the impact of EPA on pro-inflammatory properties of VLDL. Effects of VLDL prepared from mice fed 5% EPA diet for 1 week (EPA-VLDL) or mice fed normal diet (Ctrl-VLDL) on the mRNA expression of pro-inflammatory factors were examined in human THP-1 macrophages. Ctrl-VLDL increased mRNA expression of pro-inflammatory factors such as interleukin-1β and tumor necrosis factor-α in macrophages. In contrast, the increases in pro-inflammatory factors by EPA-VLDL were lower than those by Ctrl-VLDL. Moreover, EPA-VLDL-treated macrophages had less triglyceride accumulation than Ctrl-VLDL-treated macrophages. Inhibition of lipoprotein lipase (LPL) appeared to suppress inflammation and triglyceride accumulation by Ctrl-VLDL suggesting that hydrolysis of VLDL is required for the pro-inflammatory properties of VLDL. Free fatty acid release from EPA-VLDL by macrophages and purified LPL was less than that from Ctrl-VLDL. Extracellular LPL mass was decreased by EPA-VLDL. Taken together, these findings indicate that the pro-inflammatory properties of VLDL were attenuated by EPA administration via decrease in susceptibility of VLDL to LPL. It appears possible that anti-inflammatory effects of EPA on VLDL contribute to the suppression of cardiovascular risk by EPA., (Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.)

Preeclampsia is a hypertensive disorder unique to pregnancy. Although the pathogenesis of the disease begins with aberrant spiral artery invasion in the first trimester, clinical symptoms usually do not present until late in pregnancy. Apolipoprotein CII (ApoCII) and its negative regulator, apolipoprotein CIII (ApoCIII), have recently been described as atherogenesis biomarkers in models of cardiovascular disease. Given the similarities in pathology, etiology, and clinical presentation between cardiovascular disease and preeclampsia, we hypothesized that the ratio of ApoCIII to ApoCII in maternal first trimester plasma would predict preeclampsia later in pregnancy. To test this hypothesis, plasma was prospectively collected from 311 nulliparas at 8 to 12 weeks gestation. After delivery, patients were divided into cohorts based on preeclampsia diagnosis. Conditioning monocytes with preeclamptic plasma potentiated monocyte adhesion to endothelial cells in an in vitro model. The ratio of ApoCIII to ApoCII was significantly elevated in patients with severe preeclampsia relative to normotensive and gestational hypertensive individuals (P < .05) as determined by mass spectrometry and competitive enzyme-linked immunosorbent assay (ELISA) assays. These results support a predictive change in the ratio of ApoCIII to ApoCII in pregnancies complicated by severe preeclampsia.

The role of common APOE variants on plasma lipids, particularly low density lipoprotein (LDL) levels, and coronary heart disease (CHD) risk is well known; the influence of variation in the other nearby apolipoprotein genes APOC1, APOC4 and APOC2 is unclear. This study examines the association between APOE/C1/C4/C2 gene cluster variation using tagging SNPs and plasma lipid concentration along with risk of CHD in a prospective cohort. Genotypes for 11 common APOE/C1/C4/C2 SNPs were determined in 2,767 middle-aged (49 to 64 years) men from the Second Northwick Park Heart Study, with 275 CHD events over a 15-year follow-up period. Seven SNPs showed significant associations with one or more lipid trait in univariate analysis. Multivariate and haplotype analysis showed that the APOE genotypes are most strongly associated with effects on LDL-C and apoB concentration (explaining 3.4% of the LDL-C variance) while the other SNPs in this gene cluster explained an additional 1.2%. Haplotypes in APOC2 and APOC4 were associated with modest effects on HDL-C and apoAI (explaining respectively 1.4% and 1.2%). Carriers of the APOE ɛ2 SNP had a significantly lower risk of CHD hazard ratio (HR) of 0.63 (95% confidence interval [CI]: 0.42-0.95), as did carriers of the APOC2 SNP rs5127 (HR = 0.72, 95% CI: 0.56-0.93), while carriers of APOC1 SNP rs4803770 had higher risk of CHD (HR = 1.36, 95% CI: 1.04-1.78) compared with noncarriers. While the common APOE polymorphism explains the majority of the locus genetic determinants of plasma lipid levels, additional SNPs in the APOC1/C2 region may contribute to CHD risk, but these effects require confirmation.

Introduction: Apolipoprotein (apo) A-II is the second most abundant high-density lipoprotein (HDL) apolipoprotein. We assessed the mechanism involved in the altered postprandial triglyceride-rich lipoprotein metabolism of female human apoA-II-transgenic mice (hapoA-II-Tg mice), which results in up to an 11-fold increase in plasma triglyceride concentration. The relationships between apoA-II, HDL composition, and lipoprotein lipase (LPL) activity were also analyzed in a group of normolipidemic women., Methods and Results: Triglyceride-rich lipoprotein catabolism was decreased in hapoA-II-Tg mice compared to control mice. This suggests that hapoA-II, which was mainly associated with HDL during fasting and postprandially, impairs triglyceride-rich lipoprotein lipolysis. HDL isolated from hapoA-II-Tg mice impaired bovine LPL activity. Two-dimensional gel electrophoresis, mass spectrometry, and immunonephelometry identified a marked deficiency in the HDL content of apoA-I, apoC-III, and apoE in these mice. In normolipidemic women, apoA-II concentration was directly correlated with plasma triglyceride and inversely correlated with the HDL-apoC-II+apoE/apoC-III ratio [corrected]. HDL-mediated induction of LPL activity was inversely correlated with apoA-II and directly correlated with the HDL-apoC-II+apoE/apoC-III ratio [corrected]. Purified hapoA-II displaced apoC-II, apoC-III, and apoE from human HDL2. Human HDL3 was, compared to HDL2, enriched in apoA-II but poorer in apoC-II, apoC-III, and apoE., Conclusions: ApoA-II plays a crucial role in triglyceride catabolism by regulating LPL activity, at least in part, through HDL proteome modulation.

Aim: To demonstrate the interrelationship between plasma apolipoprotein(apo)CII concentrations and the pattern of high-density lipoprotein (HDL) subclass distribution., Methods: ApolipoproteinA-I contents of plasma HDL subclasses were quantified by 2-dimensional gel electrophoresis associated with immunodetection in 504 Chinese subjects., Results: Compared with subjects in the lowest tertile of the apoCII group, the contents of prebeta(1)- HDL, HDL(3b), and HDL(3a) were significantly higher than HDL(2a) and HDL(2b) in subjects in the middle and highest tertiles of the apoCII group. Moreover, regardless of whether apoB100 increased, prebeta(1)-HDL contents increased, but HDL(2b) fell when apoCII rose while, at any apoCII levels, HDL(2b) rose with the elevation of apoA-I. Additionally, a reduction in prebeta(1)-HDL (from 131.9 to 90.6 mg/L) but an increase in HDL(2b) (from 269.1 to 382.7 mg/L) with a rise in the apoCIII/CIi value (between 0.8 and 5.6) were also observed., Conclusion: The particle size of HDL become smaller with the increase of apoCII levels, implying that the efficiency of reverse cholesterol transport (RCT) was impaired and blocked the maturation of HDL. ApoCII might be an independent factor affecting the distribution of HDL subclasses. Further, the apoCIII/CII ratio correlated with the size of HDL particles.

Background: Dyslipidemia, particularly hypertriglyceridemia is common in uremia, and represents an independent risk factor for atherosclerosis., Methods: To investigate the effects of hemodialysis (HD) duration on very low density lipoprotein (VLDL) and low density lipoprotein (LDL) compositions and lipopolytic activities, 20 patients on 5 to 7 years hemodialysis were followed-up during 9 years. Blood samples were drawn at T0 (beginning of the study), T1 (3 years after initiating study), T2 (6 years after initiating study) and T3 (9 years after initiating study). T0 was taken as reference., Results: Triacylglycerols (TG) values were correlated with HD duration (r = 0.70, P < 0.05). An increase of total cholesterol was noted at T2 and T3. Lowered activity was observed for lipoprotein lipase (LPL) (-44%) at T3 and hepatic lipase (HL) (-29%) at T1, (-64%) at T2 and (-73%) at T3. Inverse relationships were found between HD duration and LPL activity (r = -0.63, P < 0.05), and HL activity (r = -0.71, P < 0.01). At T1, T2 and T3, high VLDL-amounts and VLDL-TG and decreased VLDL-phospholipids values were noted. Increased LDL-cholesteryl esters values were noted at T1 and T2 and in LDL-unesterified cholesterol at T2 and T3., Conclusion: Despite hemodialysis duration, VLDL-LDL metabolism alterations are aggravated submitting patients to a greater risk of atherosclerosis.

Background: Severe hypertriglyceridaemia due to chylomicronemia may trigger an acute pancreatitis. However, the basic underlying mechanism is usually not well understood. We decided to analyze some proteins involved in the catabolism of triglyceride-rich lipoproteins in patients with severe hypertriglyceridaemia., Methods: Twenty-four survivors of acute hypertriglyceridaemic pancreatitis (cases) and 31 patients with severe hypertriglyceridaemia (controls) were included. Clinical and anthropometrical data, chylomicronaemia, lipoprotein profile, postheparin lipoprotein lipase mass and activity, hepatic lipase activity, apolipoprotein C II and CIII mass, apo E and A5 polymorphisms were assessed., Results: Only five cases were found to have LPL mass and activity deficiency, all of them thin and having the first episode in childhood. No cases had apolipoprotein CII deficiency. No significant differences were found between the non-deficient LPL cases and the controls in terms of obesity, diabetes, alcohol consumption, drug therapy, gender distribution, evidence of fasting chylomicronaemia, lipid levels, LPL activity and mass, hepatic lipase activity, CII and CIII mass or apo E polymorphisms. However, the SNP S19W of apo A5 tended to be more prevalent in cases than controls (40% vs. 23%, NS)., Conclusion: Primary defects in LPL and C-II are rare in survivors of acute hypertriglyceridaemic pancreatitis; lipase activity measurements should be restricted to those having their first episode during childhood.

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.

Objective: Testing of serum for protein patterns to monitor progression of suspected to definite chronic pancreatitis (CP)., Methods: Serum samples of CP patients and healthy volunteers were fractionated on anion exchange columns and analyzed by surface-enhanced laser desorption/ionization-time-of-flight mass spectrometry to elucidate CP-related protein alterations and to identify biomarkers for this disease. Potential biomarkers were purified and identified by mass spectrometry., Results: In total, 258 protein peaks were found that discriminated between the 2 groups. Analysis revealed 28 most prominent peaks on immobilized metal affinity capture coupled with Cu and CM10 protein chips, covering the m/z range between 3.3 and 33.3 kd. Performing multivariate pattern analysis, the best pattern model was obtained using fraction 6 on immobilized metal affinity capture coupled with Cu arrays with a sensitivity of 96% and a specificity of 84%. Using a combination of matrix-assisted laser desorption-ionization-time-of-flight mass spectrometry and immunodepletion, we identified 14-m/z peaks. The proteins were found to be significantly decreased in CP serum and were identified as retinol-binding protein, serum amyloid-alpha, apolipoprotein A-II (Apo A-II), Apo C-I, Apo C-II, Apo C-III, and transthyretin and truncated forms thereof., Conclusions: Distinct protein profile differences exist between normal and CP serum and reflect the metabolic and inflammatory condition in CP patients. The identified protein panel may eventually serve as a diagnostic marker set for CP.

Apolipoprotein A-I (ApoA-I), a major component of HDL, binds haptoglobin, a plasma protein transporting to liver or macrophages free Hb for preventing hydroxyl radical production. This work aimed to assess whether haptoglobin protects ApoA-I against this radical. Human ApoA-I structure, as analyzed by electrophoresis and MS, was found severely altered by hydroxyl radicals in vitro. Lower alteration of ApoA-I was found when HDL was oxidized in the presence of haptoglobin. ApoA-I oxidation was limited also when the complex of haptoglobin with both high-density lipoprotein and Hb, immobilized on resin beads, was exposed to hydroxyl radicals. ApoA-I function to stimulate cholesterol esterification was assayed in vitro by using ApoA-I-containing liposomes. Decreased stimulation was observed when liposomes oxidized without haptoglobin were used. Conversely, after oxidative stress in the presence of haptoglobin (0.5 microM monomer), the liposome activity did not change. Plasma of carrageenan-treated mice was analyzed by ELISA for the levels of haptoglobin and ApoA-I, and used to isolate HDL for MS analysis. Hydroxyproline-containing fragments of ApoA-I were found associated with low levels of haptoglobin (18 microM monomer), whereas they were not detected when the haptoglobin level increased (34-70 microM monomer). Therefore haptoglobin, when circulating at enhanced levels with free Hb during the acute phase of inflammation, might protect ApoA-I structure and function against hydroxyl radicals.

Background: Apolipoprotein C-II and apolipoprotein C-III play an important and complex role in plasma triglycerides metabolism, respectively, as inhibitor and activator of lipoprotein lipase. Thus, they appear to be suitable markers for clinical studies of triglyceride-rich lipoproteins and related cardiovascular risk. Our aim was to evaluate, for routine analysis, the accuracy to quantify these apolipoprotein in human sera., Methods: Precision (intra- and inter-run), limit of detection and quantification, linearity, common interferents (lipids, haemoglobin, bilirubin) and reference intervals were determined according to guidelines of the French Society of Clinical Biology and ISO Norm 5725 specifications., Results: Intra- and inter-run CVs were respectively less than 5.0% and 7.5%. Linearities extended from 10.8 mg/L to 112.9 mg/L for apolipoprotein C-II and from 31.8 mg/L to 375.5 mg/L for apolipoprotein C-III. Haemolysis (up to 227.6 micromol/L haemoglobin) and lipemia (up to 19.3 mmol/L triglycerides) do not interfere, contrary to bilirubin, which has a positive effect above 350 micromol/L. Comparison of methods shows good agreement between immunoturbidimetric and electro-immunodiffusion methods for measuring apolipoprotein C-III in 62 samples within a wide range (n = 62, r = 0.954, y = 3.81 x -14.4)., Conclusion: This study shows the reliability of these kits for measuring apolipoprotein C-II and apolipoprotein C-III in human sera, and their suitability for routine analysis.