Indices related to apo CII and CIII serum concentrations and coronary heart disease: a case-control study

Volanesorsen to treat severe hypertriglyceridaemia: A pooled analysis of randomized controlled trials

BACKGROUND

Patients with severe hypertriglyceridaemia (sHTG) are often refractory to lipid-lowering therapy. Apolipoprotein (Apo) CIII inhibition could be promising to treat subjects with sHTG. The antisense oligonucleotide against APOC3 mRNA volanesorsen was recently introduced to treat sHTG. We performed a systematic review and meta-analysis of RCTs on the efficacy and safety of volanesorsen as compared to placebo treatment in patients with severe HTG.

METHODS

Studies were systematically searched in the PubMed, Web of Science and Scopus databases according to PRISMA guidelines. The last search was performed on 7 February 2022.

RESULTS

Four studies showed significant reduction in TG after 3 months of treatment with volanesorsen as compared with placebo (MD: -73.9%; 95%CI: -93.5%, -54.2; p < .001 I²  = 89.05%; p < .001); VLDL-C level (MD: -71.0%; 95%CI: -76.6%, -65.4%; p < .001 I²  = 94.1%; p < .001); Apo-B48 level (MD: -69.03%; 95%CI: -98.59.4%, -39.47%; p < .001, I²  = 93.51%; p < .001) and Apo-CIII level (MD: -80.0%; 95%CI: -97.5%, -62.5; p < .001 I²  = 94.1%; p < .001) with an increase in HDL-C level (MD: +45.92%, 95%CI: +37.24%, +54.60%; p < .001 I²  = 94.34%; p < .001) and in LDL-C level (MD: +68.6%, 95%CI: +7.0%, +130.1%; p < .001 I²  = 96.18%; p < .001) without a significant elevation of Apo-B100 level (MD: +4.58%, 95%CI: -5.64%, +14.79%; p = .380 I²  = 95.09%; p < .001) in 139 volanesorsen patients as compared to 100 placebo-treated controls. Most of adverse events were mild and related to local injection site reactions.

CONCLUSIONS

In patients with severe HTG, volanesorsen is associated with a significant reduction in TG, VLDL-C, Apo-B48 and non-HDL-C and increment of HDL-C as compared to placebo. Documented efficacy is accompanied by an acceptable safety profile.

Identification of biomarker panels as predictors of severity in coronary artery disease

Matrix metalloproteinases (MMPs) are implicated in atherosclerotic plaque rupture and recondition. Specific tissue inhibitors (TIMPs) control MMP functions. Both MMPs and TIMPs are potential biomarkers of plaque instability. Elevated Apo‐CII and CIII and Apo‐E levels are recognized as cardiovascular disease risk factors. We aimed to establish the best blood biomarker panel to evaluate the coronary artery disease (CAD) severity. Plasma levels of MMP‐3 and MMP‐9, TIMP‐1 and TIMP‐2, Apo‐CII, Apo‐CIII and Apo‐E were measured in 472 patients with CAD evaluated by coronary angiography and electrocardiography, and in 285 healthy controls. MMP‐3 and MMP‐9 plasma levels in CAD patients were significantly increased (P < 0.001) compared to controls (3.54‐ and 3.81‐fold, respectively). Furthermore, these increments are modulated by CAD severity as well as for Apo‐CII and Apo‐CIII levels (P < 0.001). TIMPs levels were decreased in CAD versus controls (P < 0.001) and in inverse correlation to MMPs. Standard ROC curve approach showed the importance of panels of biomarkers, including MMP‐3, MMP‐9, TIMP‐1, TIMP‐2, Apo‐CII and Apo‐CIII, for disease aggravation diagnosis. A high area under curve (AUC) value (0.995) was reached for the association of MMP‐9, TIMP‐2 and Apo‐CIII. The unbalance between MMPs and TIMPs in vascular wall and dyslipidaemia creates favourable conditions for plaque disruption. Our study suggests that the combination of MMP‐9, TIMP‐2 and Apo‐CIII values (‘CAD aggravation panel’) characterizes the severity of CAD, that is electrophysiological state, number of involved vessels, stent disposal and type of stent.

The risk of cardiovascular events with increased apolipoprotein CIII: A systematic review and meta-analysis

BACKGROUND

Apolipoprotein CIII (apoC-III) is an atherogenic protein found on HDL, VLDL and LDL.

OBJECTIVE

The objective of this study is to review the literature on the association of blood apoC-III level with cardiovascular events and the dose-response relationship for this association.

METHODS AND RESULTS

MEDLINE, EMBASE, BIOSIS, CINAHL, Clinicaltrials.gov, grey-literature sources, contact with investigators, and reference lists of studies, without language restrictions, were reviewed. Twelve studies (5 retrospective and 7 prospective) with a total of 3163 cases of cardiovascular events met inclusion criteria for this systematic review. The pooled standardized mean difference showed significantly higher levels of apoC-III in the non-HDL fraction of plasma (representing apoC-III in VLDL and LDL) in those with cardiovascular disease compared with controls; no difference for apoC-III levels in HDL; and, a trend toward higher total plasma apoC-III in the cases. Pooled risk estimates from the meta-analysis were 2.48 (1.48-4.32; non-HDL apoC-III), 1.09 (0.65-1.82; HDL apoC-III), and 1.33 (1.07-1.66; total apoC-III) for a cardiovascular event with a 5-mg/dL increase in apoC-III.

CONCLUSIONS

The current body of literature includes several methodologically sound studies that together provide consistent evidence for an association of cardiovascular events with blood apoC-III level in total plasma or in VLDL and LDL. More data are needed to determine importance of levels of apoC-III in specific lipoproteins for cardiovascular risk assessment and management and to elucidate the interaction between triglycerides and apoC-III in relation to risk of cardiovascular disease.

Modifications in rat plasma proteome after remote ischemic preconditioning (RIPC) stimulus: identification by a SELDI-TOF-MS approach

Remote ischemic preconditioning’s (RIPC) ability to render the myocardium resistant to subsequent prolonged ischemia is now clearly established in different species, including humans. Strong evidence suggests that circulating humoral mediators play a key role in signal transduction, but their identities still need to be established. Our study sought to identify potential circulating RIPC mediators using a proteomic approach. Rats were exposed to 10-min limb ischemia followed by 5- (RIPC 5′) or 10-min (RIPC 10′) reperfusion prior to blood sampling. The control group only underwent blood sampling. Plasma samples were isolated for proteomic analysis using surface-enhanced laser desorption and ionization - time of flight - mass spectrometry (SELDI-TOF-MS). A total of seven proteins, including haptoglobin and transthyretin, were detected as up- or down-regulated in response to RIPC. These proteins had previously been identified as associated with organ protection, anti-inflammation, and various cellular and molecular responses to ischemia. In conclusion, this study indicates that RIPC results in significant modulations of plasma proteome.

Factor II activity is similarly increased in patients with elevated apolipoprotein CIII and in carriers of the factor II 20210A allele

Background

Few studies have so far investigated the relationship between apolipoprotein CIII (Apo CIII) and coagulation pathway in subjects with or without coronary artery disease (CAD).

Methods and Results

Serum Apo CIII concentrations and plasma coagulant activities of factor II (FII:c), factor V (FV:c), and factor VIII (FVIII:c), and activated factor VII (FVIIa) were analyzed in a total of 933 subjects, with (n=687) or without (n=246) angiographically demonstrated CAD and not taking anticoagulant drugs. Activated factor X (FXa) generation assay was performed on plasma from subgroups of subjects with low and high levels of Apo CIII. A statistical incremental concentration of FII:c, FV:c, and FVIIa levels was observed through the quartiles of Apo CIII distribution in the population considered as a whole. Significant results were confirmed for FII:c in CAD and CAD‐free subgroup when separately considered. Subjects within the highest Apo CIII quartile (>12.6 mg/dL) had high FII:c levels not statistically different from those of carriers of 20210A allele (n=40; 4.28%). In a multiple linear model, Apo CIII was the best predictor of FII:c variability, after adjustment for age, gender, plasma lipids, CRP, creatinine, diagnosis, and carriership of 20210A allele. FXa generation was increased and its lag time shortened in plasmas with high Apo CIII levels. However, after thrombin inhibition by hirudin, differences between low and high Apo C‐III samples disappeared.

Conclusions

Elevated concentrations of Apo CIII are associated with an increase of thrombin activity to an extent comparable with the carriership of G20210A gene variant and mainly modulating the thrombin generation.

Apolipoprotein E in VLDL and LDL with apolipoprotein C-III is associated with a lower risk of coronary heart disease

BACKGROUND

Low-density lipoprotein (LDL) with apolipoprotein C-III (apoC-III) is the lipoprotein species that most strongly predicts initial and recurring coronary heart disease (CHD) events in several cohorts. Thus, a large portion of the CHD risk conferred by LDL may be attributable to LDL that contains apoC-III. Very-low-density lipoprotein (VLDL) and LDL with apoC-III have varying amounts of apoE. We hypothesized that a high content of apoE lessens the adverse influence of apoC-III on the risk of CHD because it promotes the clearance of VLDL and LDL from plasma.

METHODS AND RESULTS

We studied 2 independent cohorts, the Nurses' Health Study, composed of women, and the Health Professionals Follow-up Study, composed of men. These cohorts contributed to this study 322 women and 418 men initially free of CVD who developed a fatal or nonfatal myocardial infarction during 10 to 14 years of follow-up and matched controls who remained free of CHD. The apoE content of LDL with apoC-III was inversely associated with CHD after multivariable adjustment (relative risk for top versus bottom quintile 0.53, 95% CI 0.35 to 0.80). The apoE content of VLDL with apoC-III had a similar inverse association with CHD. The highest risks were associated with a high apoB concentration and a low apoE content of LDL with apoC-III or of VLDL+LDL with apoC-III. The observed associations were in both male and female cohorts and independent of traditional CHD risk factors and of C-reactive protein.

CONCLUSIONS

An increased apoE content in VLDL and LDL with apoC-III was associated with a lower risk of CHD. Strategies to enrich VLDL and LDL in apoE are worth exploring for the prevention of CHD.

The effects of ezetimibe and/or orlistat on triglyceride-rich lipoprotein metabolism in obese hypercholesterolemic patients

We investigated the factors influencing triglycerides (TG) reduction during ezetimibe, alone or combined with orlistat, administration. Eighty-six obese hypercholesterolemic subjects were prescribed a low-fat diet and were randomized to ezetimibe (E group), orlistat (O group), or both (OE group) for 6 months. Plasma TG and apolipoprotein (apo) C-III reduction was significantly greater in the combination group compared with monotherapy. Multivariate analysis showed that in E group apoC-III reduction and baseline TG levels were independently positively correlated, whereas baseline apoC-II levels were negatively correlated, with TG lowering. In OE group apoC-III reduction was the only independent contributor to TG reduction.

Apolipoprotein C-III predicts cardiovascular mortality in severe coronary artery disease and is associated with an enhanced plasma thrombin generation

BACKGROUND

Apolipopoprotein C-III (apo C-III) plays a pivotal role in controlling plasma triglyceride (TG) and contributes to the atherogenic properties of TG-rich lipoproteins.

OBJECTIVES

(i) To examine the predictive value of serum apo C-III for cardiovascular mortality in the setting of secondary prevention of coronary artery disease (CAD); and (ii) to evaluate possible associations between apolipoprotein levels and the thrombin generation assay, a global test to estimate plasma thrombogenic potential.

METHODS AND RESULTS

A cohort of 633 patients with angiographically proven CAD was prospectively followed for a median follow-up of 57 months. The large majority of them (92%) underwent coronary (endovascular or surgical) revascularization. During the follow-up, 91 (14.3%) out of 633 patients died, with 64 events (10.1%) attributed to cardiovascular causes. After adjustment for all the other predictors of mortality during univariate analysis (i.e. age, statin therapy, myocardial infarction history, diabetes, hs-CRP and creatinine), elevated apo C-III levels (> or = 10.5 mg dL(-1)- the median value) significantly predicted both total and cardiovascular mortality (HR for total mortality 2.22 with 95% CI 1.16-4.24; HR for cardiovascular mortality 2.35 with 95% CI 1.19-4.62). In a subgroup of 225 subjects, apo C-III levels were significantly associated with endogenous thrombin potential in regression models (standardized beta coefficient = 0.207, P = 0.002).

CONCLUSIONS

Basal concentrations of apo C-III levels > or = 10.5 mg dL(-1) in CAD patients independently predicted cardiovascular mortality during the subsequent 5-year period. Such concentrations were associated with an enhanced plasma endogenous thrombin generation, suggesting a complex interplay between TG-rich particles and the coagulation cascade as well as a new 'thrombogenetic' role for apo C-III.

Increased Plasma Apolipoprotein C-III Concentration Independently Predicts Cardiovascular Mortality: The Hoorn Study

Background: Hypertriglyceridemia is a cardiovascular risk factor. Apolipoprotein C-III (apoC-III) is an important determinant of the catabolic rate of triglyceride-rich lipoproteins. The aim of this study was to investigate the prognostic value of plasma apoC-III concentrations for cardiovascular mortality.

Methods: We performed this prospective study in 2244 subjects (ages 49–77 years) who participated in the Hoorn Study. During a mean follow-up of 15 years, 504 individuals died: 231 of cardiovascular disease, 180 of cancer, and 93 of other causes. Cardiovascular disease risk factors and plasma apoC-III concentrations were measured at baseline.

Results: The age- and sex-adjusted plasma apoC-III concentration was prospectively associated with cardiovascular mortality (P &lt; 0.001). After adjustment for traditional risk factors, including fasting triglycerides, the hazard ratio (95% CI) for cardiovascular death between the highest and the lowest quartile of apoC-III was 1.85 (1.02–3.38). High concentrations of apoC-III did not appear to be associated with noncardiovascular mortality.

Conclusions: In this general population cohort, a high apoC-III concentration in plasma, independently of fasting triglycerides and other traditional risk factors, predicts cardiovascular mortality.

Analysis of 6-month effect of orlistat administration, alone or in combination with fenofibrate, on triglyceride-rich lipoprotein metabolism in overweight and obese patients with metabolic syndrome

BACKGROUND

Orlistat significantly reduced serum triglycerides (TG) in most clinical trials. Orlistat-induced TG reduction has not been studied to determine the factors contributing to TG alterations in clinical settings.

OBJECTIVE

We examined the factors influencing TG reduction during orlistat administration, alone or in combination with fenofibrate, and we investigated the effects of these treatments on apolipoprotein C-II (ApoC-II) and C-III (ApoC-III) levels.

METHODS

Patients with the metabolic syndrome were randomly allocated to receive orlistat 120 mg three times daily (n = 28, O group), micronized fenofibrate 200 mg/day (n = 28, F group), or both (n = 27, OF group) for 6 months. Plasma ApoC-II and ApoC-III were determined by an immunoturbidimetric assay.

RESULTS

In the O group, we observed reductions of plasma ApoC-III (P < 0.05) and ApoC-II (P = NS) levels. Fenofibrate administration significantly reduced concentrations of ApoC-II and ApoC-III, whereas the combination of orlistat and fenofibrate had an additive effect on these apolipoproteins. There were significant in-group reductions in serum TG levels in all treatment groups. Multivariate analysis showed that in O group's baseline TG levels were independently positively correlated, whereas the baseline ApoC-II levels were negatively correlated with TG-lowering. In the F group, baseline TG levels and ApoC-III reduction were significantly and independently correlated with TG reduction. OF group's baseline TG levels and ApoC-III reduction were independently positively correlated and baseline ApoC-II levels were negatively correlated with TG-lowering.

CONCLUSIONS

Orlistat-mediated TG-lowering is independently associated with baseline TG and ApoC-II levels. When orlistat is combined with fenofibrate, ApoC-III reduction is another independent contributor to TG alterations.

A 12-Week, Prospective, Open-Label Analysis of the Effect of Rosuvastatin on Triglyceride-Rich Lipoprotein Metabolism in Patients with Primary Dyslipidemia

BACKGROUND

Although the effect of statins on lowering low-density lipoprotein cholesterol (LDL-C) has been extensively studied, their hypotriglyceridemic capacity is not fully understood.

OBJECTIVE

The present study examined clinical and laboratory factors potentially associated with the triglyceride (TG)-lowering effect of rosuvastatin.

METHODS

Eligible patients had primary dyslipidemia and a moderate risk of heart disease. Patients were prescribed rosuvastatin 10 mg/d in an open-label fashion and kept 3-day food diaries. Laboratory measurements, performed at baseline and 12 weeks, included serum lipid parameters (total cholesterol [TC], TGs, LDL-C, high-density lipoprotein cholesterol [HDL-C], and apolipoprotein [apo] levels), non-lipid metabolic variables (including carbohydrate metabolism parameters and renal, liver, and thyroid function tests), and LDL-subfraction profile (by high-resolution 3% polyacrylamide gel electrophoresis). Tolerability was assessed at each visit.

RESULTS

Participants were 75 hyperlipidemic patients (39 men and 36 women; mean age, 51.7 years). At 12 weeks, TC levels were reduced by 35.1% (P < 0.001), TGs by 15.2% (P < 0.001), LDL-C by 48.5% (P < 0.001), apoE by 35.4% (P < 0.001), and apoE by 17.3% (P < 0.001) from baseline, whereas HDL-C and apoA1 levels were not significantly changed. Stepwise linear regression analysis showed that baseline TG levels were most significantly correlated (R(2) = 42.0%; P < 0.001) with the TG-lowering effect of rosuvastatin, followed by the reduction in apoCIII levels (R(2) = 13.6%; P < 0.01). Rosuvastatin use was associated with a reduction in cholesterol mass of both large LDL particles (mean [SD], from 150.5 [36.6] to 90.5 [24.3] mg/dL; P < 0.001) and small, dense LDL (sdLDL) particles (from 11.5 [8.4] to 6.6 [4.5] mg/dL; P < 0.001). Rosuvastatin had no effect on cholesterol distribution of the LDL subfractions (mean [SD], large particles, from 90.8% [7.0%] to 91.8% [5.1%]; sdLDL, from 7.1% [4.7%] to 7.5% [4.8%]) or the mean LDL particle size (from 26.5 [4.2] to 26.6 [4.0] rim). A significant increase in mean LDL particle size after rosuvastatin treatment (mean [SD], from 26.4 [0.4] to 26.9 [0.4] rim; P = 0.02) was observed only in patients with baseline TG levels > or =120 mg/dL. No serious adverse events requiring study treatment discontinuation were reported. One patient who presented with headache and 2 patients who presented with fatigue quickly recovered without discontinuing rosuvastatin treatment. A posttreatment elevation in aminotransferase levels <3-fold the upper limit of normal (ULN) was recorded in 5 (6.7%) patients, and 2 (2.7%) patients experienced elevated creatine kinase concentrations <5-fold ULN.

CONCLUSION

Baseline TG levels were the most important independent variable associated with the TG-lowering effect of rosuvastatin.

Lipoproteomics II: mapping of proteins in high-density lipoprotein using two-dimensional gel electrophoresis and mass spectrometry

High-density lipoprotein (HDL) is the most abundant lipoprotein particle in the plasma and a negative risk factor of atherosclerosis. By using a proteomic approach it is possible to obtain detailed information about its protein content and protein modifications that may give new information about the physiological roles of HDL. In this study the two subfractions; HDL(2) and HDL(3), were isolated by two-step discontinuous density-gradient ultracentrifugation and the proteins were separated with two-dimensional gel electrophoresis and identified with peptide mass fingerprinting, using matrix-assisted laser desorption/ionisation time of flight mass spectrometry. Identified proteins in HDL were: the dominating apo A-I as six isoforms, four of them with a glycosylation pattern and one of them with retained propeptide, apolipoprotein (apo) A-II, apo A-IV, apo C-I, apo C-II, apo C-III (two isoforms), apo E (five isoforms), the recently discovered apo M (two isoforms), serum amyloid A (two isoforms) and serum amyloid A-IV (six isoforms). Furthermore, alpha-1-antitrypsin was identified in HDL for the first time. Additionally, salivary alpha-amylase was identified as two isoforms in HDL(2), and apo L and a glycosylated apo A-II were identified in HDL(3). Besides confirming the presence of different apolipoproteins, this study indicates new patterns of glycosylated apo A-I and apo A-II. Furthermore, the study reveals new proteins in HDL; alpha-1-antitrypsin and salivary alpha-amylase. Further investigations about these proteins may give new insight into the functional role of HDL in coronary artery diseases.

ApoC-III deficiency prevents hyperlipidemia induced by apoE overexpression

Adenovirus-mediated overexpression of human apolipoprotein E (apoE) induces hyperlipidemia by stimulating the VLDL-triglyceride (TG) production rate and inhibiting the LPL-mediated VLDL-TG hydrolysis rate. Because apoC-III is a strong inhibitor of TG hydrolysis, we questioned whether Apoc3 deficiency might prevent the hyperlipidemia induced by apoE overexpression in vivo. Injection of 2 x 10(9) plaque-forming units of AdAPOE4 caused severe combined hyperlipidemia in Apoe-/- mice [TG from 0.7 +/- 0.2 to 57.2 +/- 6.7 mM; total cholesterol (TC) from 17.4 +/- 3.7 to 29.0 +/- 4.1 mM] that was confined to VLDL/intermediate density lipoprotein-sized lipoproteins. In contrast, Apoc3 deficiency resulted in a gene dose-dependent reduction of the apoE4-associated hyperlipidemia (TG from 57.2 +/- 6.7 mM to 21.2 +/- 18.5 and 1.5 +/- 1.4 mM; TC from 29.0 +/- 4.1 to 16.4 +/- 9.8 and 2.3 +/- 1.8 mM in Apoe-/-, Apoe-/-.Apoc3+/-, and Apoe-/-.Apoc3-/- mice, respectively). In both Apoe-/- mice and Apoe-/-.Apoc3-/- mice, injection of increasing doses of AdAPOE4 resulted in up to a 10-fold increased VLDL-TG production rate. However, Apoc3 deficiency resulted in a significant increase in the uptake of TG-derived fatty acids from VLDL-like emulsion particles by white adipose tissue, indicating enhanced LPL activity. In vitro experiments showed that apoC-III is a more specific inhibitor of LPL activity than is apoE. Thus, Apoc3 deficiency can prevent apoE-induced hyperlipidemia associated with a 10-fold increased hepatic VLDL-TG production rate, most likely by alleviating the apoE-induced inhibition of VLDL-TG hydrolysis.