Apolipoprotein C-III Research Articles

Feasibility of ApoC1 serum levels as tumor biomarker in glioblastoma patients: a pilot study

Apolipoprotein C1 (ApoC1) has been detected immunohistochemically in glioblastoma tissue, probably expressed by activated monocytes and microglia. The present study was conceived to determine whether the amount of intratumoral ApoC1 expression leads to measurable changes of serum levels after glioblastoma resection or during recurrence. 176 blood samples from 70 glioblastoma patients were collected perioperatively and during subsequent therapy. ApoC1 serum levels were determined using an enzyme linked immunosorbent assay (ELISA). High absorption values due to lipemic or hemolytic serum were removed from the final dataset using a stem and leaf plot. Samples were grouped according to the treatment stage to compare mean ApoC1 serum levels. The number of patients with falling or increasing perioperative values was assessed. 167 ApoC1 serum values from 68 glioblastoma patients were amenable to statistical evaluation. Mean ApoC1 serum level was 91.9 µg/ml (n = 167, sd = 36.0). In samples from patients undergoing first glioblastoma resection, the mean preoperative value was significantly higher (94.8 µg/ml, n = 37, sd = 29.5) than after surgery (77.4 µg/ml, n = 41, sd = 23.2, p = 0.009). Individually, falling ApoC1 levels were detected in 25 and rising levels in 9 patients (p = 0.0061). Single absolute serum levels of ApoC1 do not allow an estimation of glioblastoma activity or tumor response. Although pathophysiologically of interest, ApoC1 serum levels did not qualify as a potential biomarker in glioblastoma management. Our results do not seem to encourage larger, multicenter studies.

Prognostic utility of a multibiomarker panel in patients with suspected myocardial infarction

Abstract Introduction Rapid and accurate evaluation of patients presenting with suspected myocardial infarction (MI) to the emergency department (ED) is crucial due to strongly varying outcomes in these patients. Despite the routine use of circulating biomarkers, among which high-sensitivity cardiac troponin currently dictates diagnostic protocols in chest pain patients, it still remains unclear which biomarkers are of highest utility for prognostic purposes in this patient collective. Purpose We sought to investigate the prognostic utility of a multibiomarker panel with 29 different biomarkers in a contemporary cohort of patients with suspected MI by applying a dual analytical approach. Methods The multibiomarker panel was measured in stored blood samples that were collected directly at admission from 748 prospectively enrolled patients who presented with symptoms suggestive of MI to the ED of a German tertiary center between 2013 and 2017. The final diagnosis of all patients was adjudicated according to the 4th Universal Definition of MI. The investigated endpoint comprised incident major cardiovascular events (MACE) within 1 year after admission. MACE was defined as the composite of cardiovascular death, non-fatal MI (excluding index events), revascularization and cardiac rehospitalization. Log-transformed biomarkers were entered individually into an age-and sex-adjusted Cox regression model to explore the hazard ratio (HR) per one standard deviation increase (SD) for 1-year MACE in the overall cohort. The selection of optimal multimarker models, adjusted for age and sex, was performed using 1) stepwise backward selection via Akaike information criterion as the stopping rule, and 2) Least Absolute Shrinkage and Selection Operator (LASSO) with 5-fold cross-validation. Results Out of 748 patients with available multibiomarker panel, 138 (18.4%) were diagnosed with MI. Median age at admission was 64 (interquartile range [IQR] 50–75) years in the overall cohort, 63.1% were male. At 1 year of follow-up, 160 cases of incident MACE were documented. 16 of the investigated 29 biomarkers were significantly associated with 1-year MACE, amongst which NT-proBNP was the strongest predictor (HR per SD 1.74, 95% confidence interval [CI] 1.44–2.09, p<0.0001; Table 1). Using stepwise backward selection, three biomarkers including NT-proBNP, Apo A-I and Apo C-III remained in the final multivariable model (Figure 1). The LASSO approach confirmed NT-proBNP (HR per SD 1.24) and Apo A-I (HR per SD 0.98) as strong and independent predictors of 1-year MACE while Apo C-III was replaced with KIM-1 (HR per SD 1.06). Conclusions Among 29 biomarkers, numerous provide prognostic utility while NT-proBNP and Apo A-I emerged as the strongest independent predictors of 1-year MACE. Their routine assessment and integration into risk prediction models may improve personalized risk stratification in patients with symptoms suggestive of MI. Funding Acknowledgement Type of funding sources: Foundation. Main funding source(s): The BACC study was supported by the German Center for Cardiovascular Research, an unrestricted grant by Abbott Diagnostics, and Prevencio, which also partly covered the biomarker measurements.

Label-free based quantitative proteomics analysis to explore the molecular mechanism of gynecological cold coagulation and blood stasis syndrome.

Cold coagulation and blood stasis (CCBS) syndrome is one of the common traditional Chinese medicine (TCM) syndromes of gynecological diseases. However, the molecular mechanism of CCBS syndrome is still unclear. Thus, there is a need to reveal the occurrence and regulation mechanism of CCBS syndrome, in order to provide a theoretical basis for the treatment of CCBS syndrome in gynecological diseases. The plasma proteins in primary dysmenorrhea (PD) patients with CCBS syndrome, endometriosis (EMS) patients with CCBS syndrome, and healthy women were screened using Label-free quantitative proteomics. Based on the TCM theory of "same TCM syndrome in different diseases," the differentially expressed proteins (DEPs) identified in each group were subjected to intersection mapping to obtain common DEPs in CCBS syndrome. The DEPs of gynecological CCBS syndrome in the intersection part were again cross-mapped with the DEPs of gynecological CCBS syndrome obtained by the research group according to the TCM theory of "different TCM syndromes in same disease" theory in the early stage, so as to obtain the DEPs of gynecological CCBS syndrome that were shared by the two parts. The common DEPs were subjected to bioinformatics analysis, and were verified by enzyme-linked immunosorbent assay (ELISA). A total of 67 common DEPs were identified in CCBS syndrome, of which 33 DEPs were upregulated and 34 DEPs were downregulated. The functional classification of DEPs involved in metabolic process, energy production and conversion, immune system process, antioxidant activity, response to stimulus, and biological adhesion. The subcellular location mainly located in the cytoplasm, nucleus, and extracellular. Gene ontology (GO) enrichment analysis showed that the upregulated DEPs mainly concentrated in lipid transport, cell migration, and inflammatory reaction, and the downregulated DEPs mostly related to cell junction, metabolism, and energy response. Protein domain enrichment analysis and clustering analysis revealed that the DEPs mainly related to cell proliferation and differentiation, cell morphology, metabolism, and immunity. The Kyoto encyclopedia of genes and genomes (KEGG) pathway enrichment analysis clustering analysis showed that the upregulated DEPs were involved in inflammation and oxidative damage, while the downregulated DEPs were involved in inflammation, cell adhesion, cell apoptosis, and metabolism. The results of ELISA showed significantly increased levels of Cell surface glycoprotein MUC18 (MCAM) and Apolipoprotein C1 (APOC1), and significantly decreased levels of Vasodilator-stimulated phosphoprotein (VASP), Fatty acid-binding protein 5 (FABP5), and Vinculin (VCL) in patients with CCBS syndrome compared with healthy women. We speculated that cold evil may affect the immune process, inflammatory response, metabolic process, energy production and conversion, oxidative damage, endothelial cell dysfunction, and other differential proteins expression to cause CCBS syndrome in gynecological diseases.

Assessment of efficacy and safety of volanesorsen for treatment of metabolic complications in patients with familial partial lipodystrophy: Results of the BROADEN study: Volanesorsen in FPLD; The BROADEN Study

BackgroundVolanesorsen, an antisense oligonucleotide, is designed to inhibit hepatic apolipoprotein C-III synthesis and reduce plasma apolipoprotein C-III and triglyceride concentrations. ObjectiveThe present study assessed efficacy and safety of volanesorsen in patients with familial partial lipodystrophy (FPLD) and concomitant hypertriglyceridemia and diabetes. MethodsBROADEN was a randomized, placebo-controlled, phase 2/3, 52-week study with open-label extension and post-treatment follow-up periods. Patients received weekly subcutaneous volanesorsen 300 mg or placebo. The primary endpoint was percent change from baseline in fasting triglycerides at 3 months. Secondary endpoints included relative percent change in hepatic fat fraction (HFF), visceral adiposity, and glycated hemoglobin levels. ResultsForty patients (11 men, 29 women) were enrolled, majority of whom were aged <65 years (mean, 47 years) and White. Least squares mean (LSM) percent change in triglycerides from baseline to 3 months was −88% (95% CI, −134 to −43) in the volanesorsen group versus –22% (95% CI, −61 to 18) in the placebo group, with a difference in LSM of −67% (95% CI, –104 to –30; P=0.0009). Volanesorsen induced a significant LSM relative reduction in HFF of 53% at month 12 versus placebo (observed mean [SD]: 9.7 [7.65] vs. 18.0 [8.89]; P=0.0039). No statistically significant changes were noted in body volume measurements (fat, liver, spleen, visceral/subcutaneous adipose tissue) or glycated hemoglobin. Serious adverse events in patients assigned to volanesorsen included 1 case each of sarcoidosis, anaphylactic reaction, and systemic inflammatory response syndrome. ConclusionIn BROADEN, volanesorsen significantly reduced serum triglyceride levels and hepatic steatosis in patients with FPLD.

Volanesorsen, an antisense oligonucleotide to apolipoprotein C-III, increases lipoprotein lipase activity and lowers triglycerides in partial lipodystrophy

BackgroundPartial lipodystrophy (PL) syndromes involve deficiency of adipose tissue, causing severe insulin resistance and hypertriglyceridemia. Apolipoprotein C-III (apoC-III) is elevated in PL and is thought to contribute to hypertriglyceridemia by inhibiting lipoprotein lipase (LPL). ObjectiveWe hypothesized that volanesorsen, an antisense oligonucleotide to apoC-III, would decrease apoC-III, increase LPL activity, and lower triglycerides in PL. MethodsFive adults with PL enrolled in a 16-week placebo-controlled, randomized, double blind study of volanesorsen, 300 mg weekly, followed by 1-year open label extension. ResultsWithin-subject effects of volanesorsen before and after 16 weeks of active drug are reported due to small sample size. From week 0 to 16, apoC-III decreased from median (25th, 75th %ile) 380 (246, 600) to 75 (26, 232) ng/mL, and triglycerides decreased from 503 (330, 1040) to 116 (86, 355) mg/dL while activation of LPL by subjects’ serum increased from 21 (20, 25) to 36 (29, 42) nEq/mL*min. Although, A1c did not change, peripheral and hepatic insulin sensitivity (glucose disposal and suppression of glucose production during hyperinsulinemic clamp) increased and palmitate turnover decreased. After 32-52 weeks of volanesorsen, liver fat decreased. Common adverse events included injection site reactions and decreased platelets. ConclusionsIn PL, volanesorsen decreased apoC-III and triglycerides, in part through an LPL dependent mechanism, and may improve insulin resistance and hepatic steatosis.

Drug Therapy for Hypertriglyceridemia and Familial Chylomicronemia Syndrome: Focus on Volnesorsen.

Volanesorsen is a new medication that may soon be used in the treatment of hypertriglyceridemia and familial chylomicronemia syndrome (FCS). Volanesorsen works via binding to Apo C-III mRNA and degrading that mRNA, thus decreasing the synthesis of Apo C-III. This decreased synthesis of Apo C-III will increase the binding of triglycerides to LDL receptors and decrease triglyceride plasma levels. It is important to note that currently there are 3 other medication classes available for the treatment of hypertriglyceridemia, including niacin, fish oil/omega-3-fatty acids, and fibrates. However, there are no Food and Drug Administration-approved medications to treat FCS. Recently, volanesorsen was approved in the European Union for the treatment of FCS, but that indication was denied in the United States by the Food and Drug Administration. This was due to the side effects of the drug. Volanesorsen may cause a decrease in platelet count, renal toxicity, and elevate liver enzymes. The current drug regimen for volanesorsen consists of 285 mg once a week by subcutaneous injection, with a recommendation to immediately stop the medication if any of these side effects are noted, to prevent long-term complications. With these side effects reported, fish oil/omega-3-fatty acids seem likely the best choice when it comes to treating hypertriglyceridemia. If FCS is debilitating or greatly affecting the patient's life, then one could recommend volanesorsen. Otherwise, at this time, the side effects of volanesorsen may be too severe to justify its use for mild episodes of FCS or hypertriglyceridemia.

Evaluation of Apolipoprotein Profile in Hiv/Aids Subjects in Pre and Post 12 Months Antiretroviral Therapy Using 1.5 Mg/Ml Troponin Diagnostic Cut-Off for Myocardial Infarction in Nauth Nnewi, South Eastern Nigeria

Patients infected with HIV have an increased risk of developing heart disease. HIV causes Acquired Immune Deficiency Syndrome AIDS by invading the host cells and depleting the immune system. It has been reported that acute myocardial infarction might occur at 1.5 ng/ml troponin level. Information on cardiac status in HIV infected subjects in Nigeria is scanty. The aim is to evaluate the serum apolipoproteins in HIV subjects, in pre- and post- 12 months antiretroviral therapy (ART) using 1.5ng/ml troponin diagnostic cut-off for myocardial infarction. A total of 100 HIV subjects not on ART devoid of malaria co-infection were recruited in this study. Apolipoprotein parameters were re-classified based on 1.5 ng/ml troponin diagnostic cut-off for myocardial infection. 30 out of the 100 participants that were within 1.5 ng/ml troponin diagnostic cut-off for myocardial infection were followed up on commencement of ART for 12 months. Their blood samples were drawn at 3, 6, 9 and 12 months for some apolipoproteins and CD4 analyses using standard laboratory methods. The results showed that as months of antiretroviral therapy deepened or lengthened, the numbers of HIV positive subjects with values higher than the troponin diagnostic value reduces when compared with values before therapy (p&lt;0.05). Paired-wise comparison showed that there were significantly higher levels of CD4 counts, Apo A2, Apo C2, Apo E but lower levels ApoA1, Apo B and Apo C3 in symptomatic HIV individuals before ART when compared with values after therapy at p&lt;0.05 respectively. These lower levels ApoA1, Apo B and Apo C3 in symptomatic HIV individuals after therapy may indicate possible cardio- protective effect of the drug on the heart, which may connote immune recovery. The troponin values were significantly higher than the diagnostic cut off for acute myocardial infarction (AMI) studied amongst the group at p&lt;0.05 respectively. This may imply that AMI may occur at any group of study.

ASSOCIATION OF GENETIC VARIANTS IN THE PROMOTER REGION OF APOC3 WITH THE RISK OF NON-ALCOHOLIC FATTY LIVER DISEASE (NAFLD) IN NORTH INDIAN POPULATION

&#x0D; &#x0D; &#x0D; &#x0D; &#x0D; &#x0D; Non-Alcoholic Fatty Liver Disease (NAFLD) is a clinical condition defined by excessive fat accumulation in the liver in the form of triglycerides involving more than 5% of hepatocytes. The present study was carried out with an aim to evaluate the association of demographic features, liver enzymes, serum lipid profile and APOC3 gene variants (C-482T and T-455C). A case-control study was designed with 150 patients with NAFLD, and 180 healthy controls. The mutations were analyzed using PCR-RFLP approach, Case-control studies assessing the relationship between APOC3 rs2854116 C/C and rs 2854117 C/T gene polymorphism with non-alcoholic fatty liver disease. Statistically significant increased frequencies of CC+CT genotype [OR, 2.00; 95 percent C. I (1.18-3.40); P.0006] [OR, 2.00; 9.5 percent C.I (1.38-2.91); P value &lt; 0.0002] and the C allele is seen in NAFLD patients compared to healthy controls. In conclusion, we found that the APOC3 gene and elevated triglyceride levels in -455C/C SNP is significantly associated with the risk of NAFLD, whereas the Apoc3-482C/T showed no association.&#x0D; &#x0D; &#x0D; &#x0D; &#x0D; &#x0D;

Treatment of the metabolic syndrome by siRNA targeting apolipoprotein CIII.

Apolipoprotein CIII (apoCIII) is increased in obesity-induced insulin resistance and type-2 diabetes. Emerging evidences support the advantages of small interfering RNAs (siRNAs) to target disease-causing genes. The aim of this study was to develop siRNAs for in vivo silencing of apoCIII and investigate if this results in metabolic improvements comparable to what we have seen using antisense oligonucelotides against apoCIII. Twenty-four siRNAs were synthesized and tested in a dual luciferase reporter assay. The eight best were selected, based on knockdown at 20 nM, and of these, two were selected based on IC50 values. In vivo experiments were performed in ob/ob mice, an obese animal model for diabetes. To determine the dose-dependency, efficacy, duration of effect and therapeutic dose we used a short protocol giving the apoCIII-siRNA mix for three days. To evaluate long-term metabolic effects mice were treated for three days, every second week for eight weeks. The siRNA mix effectively and selectively reduced expression of apoCIII in liver in vivo. Treatment had to be repeated every two weeks to maintain a suppression of apoCIII. The reduction of apoCIII resulted in increased LPL activity, lower triglycerides, reduced liver fat, ceased weight gain, enhanced insulin sensitivity, and improved glucose homeostasis. No off-target or side effects were observed during the eight-week treatment period. These results suggest that in vivo silencing of apoCIII with siRNA, is a promising approach with the potential to be used in the battle against obesity-induced metabolic disorders.

Comparative study of lipoprotein lipase enzyme, ApoE and ApoC2, in pregnant women with and without preeclampsia

Background: Preeclampsia (PE) is a multisystemic syndrome specific to pregnancy. Although PE is the most common cause of death from pregnancy-related problems, its underlying cause is still unknown. In PE, lipid metabolism is altered. When lipids are damaged, both the mother and the foetus may be at risk. Methods: Blood samples were taken from 45 normotensive and 45 preeclamptic pregnant women. These samples were analyzed for LPL, Apo E and C2. Results: Concentrations of LPL, Apo C2 and Apo E differ significantly between preeclamptic women and pregnant controls which were higher in preeclamptic than in pregnant controls. Conclusions: In preeclamptic women, the increase in LPL, ApoC2 and Apo E concentration may serve as a marker for preeclampsia complication that which leads to worse consequences and could be a relevant factor in the pathogenesis of preeclampsia.

Apolipoprotein C3 and necrotic core volume are correlated but also associated with future cardiovascular events

We aimed to clarify the relationship between apolipoprotein C3 (apo-C3) and the vascular composition of lesion plaque in stable coronary disease (SCD) before percutaneous coronary intervention (PCI), and to investigate major adverse cardiovascular events (MACEs) within 4 years. Data of 98 consecutive patients with SCD who underwent PCI between November 1, 2012, and March 10, 2015, were analyzed. Laboratory and virtual histology-intravascular ultrasound (VH-IVUS) examinations of culprit lesions were conducted before PCI. Patients were divided according to median apo-C3 into low apo-C3 (≤ 8.5 mg/dL) and high apo-C3 (> 8.5 mg/dL) groups. VH-IVUS data indicated that the percentage of necrotic core volume (%NC) was significantly higher in the high apo-C3 group than in the low apo-C3 group. Moreover, the %NC significantly correlated with the apo-C3 level (R = 0.2109, P = 0.037). Kaplan–Meier curve analysis revealed that freedom from MACEs exhibited a greater decrease in the high apo-C3 group than in the low apo-C3 group, and in the high %NC group than in the low %NC group. Multivariate Cox hazards analysis showed that the %NC and high apo-C3 were independent predictors of 4 year MACEs. Apo-C3 may be a useful marker of future MACEs in patients with SCD after PCI and contribute to %NC growth.

Proteomics and bioinformatics analysis of follicular fluid from patients with polycystic ovary syndrome.

Objectives: Polycystic ovary syndrome (PCOS) is a common endocrine and metabolic disorder with heterogeneous manifestations and complex etiology. We used quantitative proteomics analysis based on mass spectrometry to identify the differences in proteomics profiles for follicular fluid obtained from patients with or without PCOS and explore possible mechanisms underlying PCOS. Methods: Follicular fluid samples were collected from infertile patients with (n = 9) or without (n = 9) PCOS. Total protein was extracted, quantitatively labeled with a tandem mass tag (TMT), and analyzed using liquid chromatography-mass spectrometry (LC‐MS). TMT-based proteomics and bioinformatics analysis were used to determine the differentially expressed proteins (DEPs) and understand the protein networks. The analysis included protein annotation, unsupervised hierarchical clustering, functional classification, functional enrichment and clustering, and protein-protein interaction analysis. Selected DEPs were confirmed by ELISA, and correlation analysis was performed between these DEPs and the clinical characteristics. Results: In this study, we have identified 1,216 proteins, including 70 DEPs (32 upregulated proteins, 38 downregulated proteins). Bioinformatics analysis revealed that the inflammatory response, complement and coagulation cascades, activation of the immune response, lipid transport, and regulation of protein metabolic processes were co-enriched in patients with PCOS. Based on ELISA results, insulin-like growth factor binding protein 1 (IGFBP1) and apolipoprotein C2 (APOC2) were differentially expressed between patients with and without PCOS. Follicular IGFBP1 showed a positive correlation with the serum levels of high-density lipoprotein cholesterol (HDL-C) (r = 0.3046, p = 0.0419), but negatively correlated with the serum levels of anti-Müllerian hormone (AMH) (r = –0.2924, p = 0.0354) and triglycerides (r = –0.3177, p = 0.0246). Follicular APOC2 was negatively correlated with the serum apolipoprotein A1 (APOA1) levels (r = 0.4509, p = 0.0002). Conclusion: Our study identified DEPs in the follicular fluid of patients with PCOS. Inflammatory response, complement and coagulation cascades, activation of the immune response, lipid transport, and regulation of protein metabolic process were deregulated in PCOS, which may play essential roles in the pathogenesis of PCOS.

MiR-107 Regulates Adipocyte Differentiation and Adipogenesis by Targeting Apolipoprotein C-2 (APOC2) in Bovine

Adipogenesis is a complex and precisely orchestrated process mediated by a series of adipogenic regulatory factors. Recent studies have highlighted the importance of microRNAs (miRNAs) in diverse biological processes, most specifically in regulating cell differentiation and proliferation. However, the mechanisms of miRNAs in adipogenesis are largely unknown. In this study, we found that miR-107 expression was higher in bovine adipose tissue than that in other tissues, and there was a downregulation trend during adipocyte differentiation. To explore the function of miR-107 in adipocyte differentiation, agomiR-107 and antiagomiR-107 were transfected into bovine adipocytes, respectively. Oil Red O staining, CCK-8, EdU assays, RT-qPCR, and Western blotting were performed, and the results showed that overexpressed miR-107 significantly suppressed fat deposition and adipocyte differentiation, while knockdown of miR-107 promoted fat deposition and adipocytes differentiation. In addition, through bioinformatics analysis, luciferase reporter assays, RT-qPCR, and Western blotting, we identified apolipoprotein 2 (APOC2) as a target of miR-107. Transfection of siRNA-APOC2 into adipocytes led to suppression in adipocyte differentiation and proliferation, suggesting a positive role of APOC2 in bovine lipogenesis. In summary, our findings suggested that miR-107 regulates bovine adipocyte differentiation and lipogenesis by directly targeting APOC2, and these results. These theoretical and experimental basis for future clarification of the regulation mechanism of adipocyte differentiation and lipogenesis. Moreover, for the highly conserved among different species, miR-107 may be a potential molecular target to be used for the treatment of lipid-related diseases in the future.

Apolipoprotein C3 and circulating mediators of preadipocyte proliferation in states of lipodystrophy

Adipogenesis is a complex process controlled by intrinsic and extrinsic factors that regulate preadipocyte proliferation, adipogenic capacity and maturation of metabolic function. Here we show that insulin and IGF-1 receptors are essential for mature adipocyte survival and that deletion of both IR and IGF1R specifically in fat using a tamoxifen inducible-AdipoQ-Cre (Ai-DKO) leads to rapid and severe loss of adipocytes in all depots, associated with a metabolic syndrome characterized by hypertriglyceridemia, hyperglycemia, hyperinsulinemia, fatty liver, and pancreatic beta cell proliferation. In this model, this pathological phenotype reverses over a few weeks, in large part, due to preadipocyte proliferation and adipose tissue regeneration. Incubation of preadipocytes with serum from the Ai-DKO mice in vitro stimulates cell proliferation, and this effect can be mimicked by conditioned media from liver slices of Ai-DKO mice, but not by media of cultured Ai-DKO adipocytes, indicating a hepatic origin of the growth factor. Proteomic analysis of serum reveals apolipoprotein C3 (APOC3), a protein secreted by liver, as one of the most upregulated proteins in the Ai-DKO mice. In vitro, purified and delipidated APOC3 stimulates preadipocyte proliferation, however, knockdown of hepatic APOC3 in vivo in Ai-DKO mice is not sufficient to block adipose regeneration. Thus, lipodystrophy is associated with presence of increased preadipocyte-stimulating growth factors in serum. Our study indicates that APOC3 is one contributing factor to preadipocyte proliferation, however, other still-unidentified circulating growth factors are also likely present in Ai-DKO mice. Identification of these factors may provide a new approach to regulation of adipose mass in health and disease.

Electrospray Ionization Mass Spectrometry of Apolipoprotein CIII to Evaluate O-glycan Site Occupancy and Sialylation in Congenital Disorders of Glycosylation.

Congenital disorders of glycosylation (CDG) are inherited metabolic diseases that affect the synthesis of glycoconjugates. Defects in mucin-type O-glycosylation occur independently or in combination with N-glycosylation disorders, and the profiling of the O-glycans of apolipoprotein CIII (apoCIII) by mass spectrometry (MS) can be used to support a diagnosis. The biomarkers are site occupancy and sialylation levels, which are indicated by the content of non-glycosylated apoCIII0a isoform and by the ratio of monosialylated apoCIII1 to disialylated apoCIII2 isoforms, respectively. In this report, electrospray ionization (ESI) quadrupole MS of apoCIII was used to identify these biomarkers. Among the instrumental parameters, the declustering potential (DP) induced the fragmentation of the O-glycan moiety including the Thr–GalNAc linkage, resulting in an increase in apoCIII0a ions. This incurs the risk of creating a false positive for reduced site occupancy. The apoCIII1/apoCIII2 ratio was substantially unchanged despite some dissociation of sialic acids. Therefore, appropriate DP settings are especially important when transferrin, which requires a higher DP, for N-glycosylation disorders is analyzed simultaneously with apoCIII in a single ESI MS measurement. Finally, a reference range of diagnostic biomarkers and mass spectra of apoCIII obtained from patients with SLC35A1-, TRAPPC11-, and ATP6V0A2-CDG are presented.

Association of lipid metabolism-related gene promoter methylation with risk of coronary artery disease.

Coronary artery disease (CAD) is a complex disease that is influenced by environmental and genetic factors. Lipid levels are regarded as a major risk factor for CAD, and epigenetic mechanisms might be involved in the regulation of CAD development. This study was designed to investigate the association between the DNA methylation status of 8 lipid metabolism-related genes and the risk of CAD in the Chinese Han population. A total of 260 individuals were sampled in this study, including 120 CAD cases and 140 normal healthy controls. DNA methylation status was tested via targeted bisulfite sequencing. The results indicated a significant association between hypomethylation of the APOC3, CETP and APOC1 gene promoters and the risk of CAD. Individuals with higher methylation levels of the APOA5 and LIPC gene promoters had increased risks for CAD. In addition, ANGPTL4 methylation level was significantly associated with CAD in males but not females. There were no significant differences in the methylation levels of the APOB and PCSK9 gene promoters between CAD patients and controls. The methylation status of the APOC3, APOA5, LIPC, CETP and APOC1 gene promoters may be associated with the development of CAD.

Hypercholesterolemia-Induced HDL Dysfunction Can Be Reversed: The Impact of Diet and Statin Treatment in a Preclinical Animal Model.

High-density lipoproteins (HDL) undergo adverse remodeling and loss of function in the presence of comorbidities. We assessed the potential of lipid-lowering approaches (diet and rosuvastatin) to rescue hypercholesterolemia-induced HDL dysfunction. Hypercholesterolemia was induced in 32 pigs for 10 days. Then, they randomly received one of the 30-day interventions: (I) hypercholesterolemic (HC) diet; (II) HC diet + rosuvastatin; (III) normocholesterolemic (NC) diet; (IV) NC diet + rosuvastatin. We determined cholesterol efflux capacity (CEC), antioxidant potential, HDL particle number, HDL apolipoprotein content, LDL oxidation, and lipid levels. Hypercholesterolemia time-dependently impaired HDL function (−62% CEC, −11% antioxidant index (AOI); p < 0.01), increased HDL particles numbers 2.8-fold (p < 0.0001), reduced HDL-bound APOM (−23%; p < 0.0001), and increased LDL oxidation 1.7-fold (p < 0.0001). These parameters remained unchanged in animals on HC diet alone up to day 40, while AOI deteriorated up to day 25 (−30%). The switch to NC diet reversed HDL dysfunction, restored apolipoprotein M content and particle numbers, and normalized cholesterol levels at day 40. Rosuvastatin improved HDL, AOI, and apolipoprotein M content. Apolipoprotein A-I and apolipoprotein C-III remained unchanged. Lowering LDL-C levels with a low-fat diet rescues HDL CEC and antioxidant potential, while the addition of rosuvastatin enhances HDL antioxidant capacity in a pig model of hypercholesterolemia. Both strategies restore HDL-bound apolipoprotein M content.

Eicosapentaenoic acid decreases APoC-III expression in response to air pollution particles in pulmonary endothelial cells

Background and Aims : Air pollution is the fourth leading contributor to global mortality. Small particulate matter (PM) specifically increases circulating triglyceride (TG) levels, a cardiovascular (CV) risk factor. Apolipoprotein C-III (ApoC-III) is associated with TG-rich lipoproteins and inhibits lipase activity, thus increasing TG levels. The omega-3 fatty acid, eicosapentaenoic acid (EPA), reduces TGs and events in patients with high CV risk (REDUCE-IT). We measured the effects of EPA on expression of ApoC-III in pulmonary endothelial cells (PECs) during exposure to finely-sized and urban-sourced PMs.

Next generation sequencing in severe hypertrigliceridemia: Identification of a novel nonsense mutation of CREB3L3 gene

Background and Aims : Hypertriglyceridemia (HTG) is a common form of dyslipidemia associated with an increased risk of cardiovascular disease and pancreatitis. The severe forms are characterized by very high plasma levels of triglycerides (TG). Monogenic autosomal recessive forms are characterized by homozygous or compound heterozygous loss-of-function mutations of genes involved in the intravascular lipolysis of the triglyceride-rich lipoproteins, namely lipoprotein lipase, apolipoprotein C2, apolipoprotein A5, glycophosphatidylinositol (GPI)-anchored high-density lipoprotein-binding protein 1, lipase maturation factor 1, and glycerol-3-phosphate dehydrogenase 1.

A novel role for GALNAC-T2 dependent glycosylation in energy homeostasis

Background and Aims : GALNT2, encoding polypeptide N-acetylgalactosaminyltransferase 2 (GalNAc-T2), was initially discovered as a regulator of high-density lipoprotein metabolism. GalNAc-T2 is known to exert these effects through post-translational modification, i.e., O-linked glycosylation of secreted proteins including apolipoprotein C-III, angiopoietin-like 3 and phospholipid transfer protein with established roles in plasma lipid metabolism. More recently it has become clear that loss of GALNT2 in rodents, cattle, nonhuman primates and humans should be regarded as a novel congenital disorder of glycosylation which affects energy metabolism, a topic that has not yet been specifically addressed.