The oxidative modification hypothesis of atherosclerosis: The comparison of atherogenic effects on oxidized LDL and remnant lipoproteins in plasma

Modification of lipoprotein metabolism and function driving atherogenesis in diabetes

Type 2 diabetes mellitus (T2DM) is a chronic metabolic disease, characterized by raised blood glucose levels and impaired lipid metabolism resulting from insulin resistance and relative insulin deficiency. In diabetes, the peculiar plasma lipoprotein phenotype, consisting in higher levels of apolipoprotein B-containing lipoproteins, hypertriglyceridemia, low levels of HDL cholesterol, elevated number of small, dense LDL, and increased non-HDL cholesterol, results from an increased synthesis and impaired clearance of triglyceride rich lipoproteins. This condition accelerates the development of the atherosclerotic cardiovascular disease (ASCVD), the most common cause of death in T2DM patients. Here, we review the alteration of structure, functions, and distribution of circulating lipoproteins and the pathophysiological mechanisms that induce these modifications in T2DM. The review analyzes the influence of diabetes-associated metabolic imbalances throughout the entire process of the atherosclerotic plaque formation, from lipoprotein synthesis to potential plaque destabilization. Addressing the different pathophysiological mechanisms, we suggest improved approaches for assessing the risk of adverse cardiovascular events and clinical strategies to reduce cardiovascular risk in T2DM and cardiometabolic diseases.

The residual risk of inflammation and remnant cholesterol in acute coronary syndrome patients on statin treatment undergoing percutaneous coronary intervention

BACKGROUND

Residual risk assessment for acute coronary syndrome (ACS) patients after sufficient medical management remains challenging. The usefulness of measuring high-sensitivity C-reactive protein (hsCRP) and remnant cholesterol (RC) in assessing the level of residual inflammation risk (RIR) and residual cholesterol risk (RCR) for risk stratification in these patients needs to be evaluated.

METHODS

Patients admitted for ACS on statin treatment who underwent percutaneous coronary intervention (PCI) between March 2016 and March 2019 were enrolled in the analysis. The included patients were stratified based on the levels of hsCRP and RC during hospitalization. The primary outcome was ischemic events at 12 months, defined as a composite of cardiac death, myocardial infarction, or stroke. The secondary outcomes included 12-month all-cause death and cardiac death.

RESULTS

Among the 5778 patients, the median hsCRP concentration was 2.60 mg/L and the median RC concentration was 24.98 mg/dL. The RIR was significantly associated with ischemic events (highest hsCRP tertile vs. lowest hsCRP tertile, adjusted hazard ratio [aHR]: 1.52, 95% confidence interval [CI]: 1.01-2.30, P = 0.046), cardiac death (aHR: 1.77, 95% CI:1.02-3.07, P = 0.0418) and all-cause death (aHR: 2.00, 95% CI: 1.24-3.24, P = 0.0048). The RCR was also significantly associated with these outcomes, with corresponding values for the highest tertile of RC were 1.81 (1.21-2.73, P = 0.0043), 2.76 (1.57-4.86, P = 0.0004), and 1.72 (1.09-2.73, P = 0.0208), respectively. The risks of ischemic events (aHR: 2.80, 95% CI: 1.75-4.49, P < 0.0001), cardiac death (aHR: 4.10, 95% CI: 2.18-7.70, P < 0.0001), and all-cause death (aHR: 3.00, 95% CI, 1.73-5.19, P < 0.0001) were significantly greater in patients with both RIR and RCR (highest hsCRP and RC tertile) than in patients with neither RIR nor RCR (lowest hsCRP and RC tertile). Notably, the RIR and RCR was associated with an increased risk of ischemic events especially in patients with adequate low-density lipoprotein cholesterol (LDL-C) control (LDL-C < 70 mg/dl) (Pinteraction=0.04). Furthermore, the RIR and RCR provide more accurate evaluations of risk in addition to the GRACE score in these patients [areas under the curve (AUC) for ischemic events: 0.64 vs. 0.66, P = 0.003].

CONCLUSION

Among ACS patients receiving contemporary statin treatment who underwent PCI, high risks of both residual inflammation and cholesterol, as assessed by hsCRP and RC, were strongly associated with increased risks of ischemic events, cardiac death, and all-cause death.

Relationship between remnant cholesterol and short-term prognosis in acute ischemic stroke patients

OBJECTIVE

Several studies have illustrated that elevated RC levels are related to a heightened risk of acute ischemic stroke (AIS). Our research aimed to explore the correlation between RC levels and poor prognosis after a 90-day interval in AIS patients.

METHODS

A total of 287 individuals were enrolled in the study, the primary outcome was defined as poor prognosis. RC was derived by the exclusion of low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C) from total cholesterol (TC).

RESULTS

Following the screening process, 253 AIS patients were included in the study, presenting a median age of 66[57, 75] years. Upon stratifying RC levels into quartiles, those in the top quartile faced a greater likelihood of diabetes diagnosis (42.86%, p = .014) and experienced a higher rate of unfavorable outcomes after 90 days (36.51%, p = .001). After accounting for confounding factors, the correlation between the fourth quartile of RC levels and the amplified likelihood of poor prognosis remained significant (odds ratio (OR) 8.471, 95% confidence interval (CI) (1.841, 38.985); p = .006). Analysis of subgroups unveiled a notable correlation between higher RC levels and poor 90-day prognosis, particularly in individuals with elevated NIHSS scores (p = .044). A progressively increasing 90-day risk of poor prognosis after an RC greater than 0.38 mmol/L was visualized by restricted cubic spline plots (p-overall = .011).

CONCLUSIONS

Including RC as a contributing element may refine the prediction of poor 90-day prognosis for AIS patients. Integrating RC with traditional risk factors can potentially enhance the predictive value for cerebrovascular disease.

Insulin resistance potentiates the effect of remnant cholesterol on cardiovascular mortality in individuals without diabetes

BACKGROUND AND AIMS

Remnant cholesterol (RC) and insulin resistance (IR) have been independently associated with cardiovascular risk. Here, we evaluated the role of IR and RC on cardiovascular disease (CVD) mortality.

METHODS

We conducted an analysis of 16,113 individuals ≥20 years without diabetes from the National Health and Nutrition Examination Survey (NHANES-III/IV). RC levels were calculated using total cholesterol, non-HDL-c, and LDL-c; IR was defined as HOMA2-IR≥2.5 and CVD mortality as a composite of cardiovascular and cerebrovascular mortality. Multiple linear regression was used to assess the relationship between HOMA2-IR and RC and Cox regression models to assess their joint role in CVD mortality. Causally ordered mediation models were used to explore the mediating role of IR in RC-associated CVD mortality.

RESULTS

We identified an association between higher HOMA2-IR and higher RC levels. The effect of IR on CVD mortality was predominant (HR 1.32, 95%CI 1.18-1.48) and decreased at older ages (HR 0.934, 95%CI 0.918-0.959) compared to RC (HR 0.983, 95%CI 0.952-1.014). Higher risk of CVD mortality was observed in individuals with IR but normal RC (HR 1.37, 95%CI 1.25-1.50) and subjects with IR and high RC (HR 1.24, 95%CI 1.13-1.37), but not in subjects without IR but high RC. In mediation models, HOMA2-IR accounted for 78.2% (95%CI 28.11-98.89) of the effect of RC levels on CVD mortality.

CONCLUSIONS

Our findings suggest that RC potentiates the risk of CVD mortality through its effect on whole-body insulin sensitivity, particularly among younger individuals.

Cumulative remnant cholesterol as a causal risk factor for ischemic heart disease: A prospective cohort study

BACKGROUND

While previous studies have established a significant correlation between baseline remnant cholesterol (RC) and ischemic heart disease (IHD), the enduring impact of RC on incident IHD remains to be elucidated. This study aimed to investigate the association between cumulative remnant cholesterol(cumRC) and IHD susceptibility.

METHODS

Participating from the Kailuan Study (2006-2010) were enrolled, excluding those with prior myocardial infarction, coronary artery revascularization and cancer across three consecutive examinations. The cumRC derived by multiplying the average RC with the interval between the two consecutive assessments. Participants were segmented into quartiles based on cumRC levels: Q1 (cumRC < 2.69 mmol/l); Q2 (2.69 ≤ cumRC < 4.04 mmol/l); Q3(4.04 ≤ cumRC < 5.65 mmol/l) and Q4 (cumRC ≥ 5.65 mmol/l). The correlation between cumRC and IHD risk was ascertained by using multivariable Cox proportional hazard models.

RESULT

The analysis encompassed 42,639 participants. Over an average tracking period of 9.97 years, 1,205 instances of IHD were identified. IHD susceptibility augmented with rising cumRC quartiles. After adjusting for potential confounders, the hazard ratios for IHD events were 1.06 (0.88-1.29) for Q2, 1.30 (1.08-1.56) for Q3 and 1.69 (1.42-2.01) for Q4, relative to Q1. Elevated cumRC was significantly associated with a heightened IHD risk, a trend consistent in both subgroup and sensitivity analyses.

CONCLUSION

Elevated cumRC significantly correlates with a higher risk of IHD, suggesting that consistent monitoring and regulation of RC might be instrumental in IHD prevention.

Remnant cholesterol and the risk of aortic valve calcium progression: insights from the MESA study

BACKGROUND

Remnant cholesterol (RC) is implicated in the risk of cardiovascular disease. However, comprehensive population-based studies elucidating its association with aortic valve calcium (AVC) progression are limited, rendering its precise role in AVC ambiguous.

METHODS

From the Multi-Ethnic Study of Atherosclerosis database, we included 5597 individuals (61.8 ± 10.1 years and 47.5% men) without atherosclerotic cardiovascular disease at baseline for analysis. RC was calculated as total cholesterol minus high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C), as estimated by the Martin/Hopkins equation. Using the adjusted Cox regression analyses, we examined the relationships between RC levels and AVC progression. Furthermore, we conducted discordance analyses to evaluate the relative AVC risk in RC versus LDL-C discordant/concordant groups.

RESULTS

During a median follow-up of 2.4 ± 0.9 years, 568 (10.1%) participants exhibited AVC progression. After adjusting for traditional cardiovascular risk factors, the HRs (95% CIs) for AVC progression comparing the second, third, and fourth quartiles of RC levels with the first quartile were 1.195 (0.925-1.545), 1.322 (1.028-1.701) and 1.546 (1.188-2.012), respectively. Notably, the discordant high RC/low LDL-C group demonstrated a significantly elevated risk of AVC progression compared to the concordant low RC/LDL-C group based on their medians (HR, 1.528 [95% CI 1.201-1.943]). This pattern persisted when clinical LDL-C threshold was set at 100 and 130 mg/dL. The association was consistently observed across various sensitivity analyses.

CONCLUSIONS

In atherosclerotic cardiovascular disease-free individuals, elevated RC is identified as a residual risk for AVC progression, independent of traditional cardiovascular risk factors. The causal relationship of RC to AVC and the potential for targeted RC reduction in primary prevention require deeper exploration.

Binding properties of recombinant LDL receptor and LOX-1 receptor to LDL measured using bio-layer interferometry and atomic force microscopy

Oxidation of low-density lipoproteins (LDLs) triggers a recognition by scavenger receptors such as lectin-like oxidized LDL receptor-1 (LOX-1) and is related to inflammation and cardiovascular diseases. Although LDLs that are recognized by LOX-1 can be risk-related LDLs, conventional LDL detection methods using commercially available recombinant receptors remain undeveloped. Using a bio-layer interferometry (BLI), we investigated the binding of recombinant LOX-1 (reLOX-1) and LDL receptors to the oxidized LDLs. The recombinant LDL receptor preferably bound minimally modified LDLs, while the reLOX-1 recognized extensively oxidized LDLs. An inversed response of the BLI was observed during the binding in the case of reLOX-1. AFM study showed that the extensively oxidized LDLs and aggregates of LDLs were observed on the surface, supporting the results. Altogether, a combined use of these recombinant receptors and the BLI method is useful in detecting high-risk LDLs such as oxidized LDLs and modified LDLs.

Remnant cholesterol and risk of myocardial infarction in patients with coronary artery disease undergoing revascularization

BACKGROUND

Despite substantial reduction in low-density lipoprotein cholesterol (LDL-C), patients develop recurrent cardiovascular events. Remnant cholesterol (RC), the cholesterol content of triglyceride-rich lipoproteins, is a potential contributor to this residual risk.

OBJECTIVES

To investigate the association between RC and risk for myocardial infarction (MI) in patients with coronary artery disease, and examine whether the predictive value of RC is retained beyond non-high-density lipoprotein cholesterol (non-HDL-C).

METHODS

Data on 9451 patients undergoing coronary revascularization in a single center. RC was calculated as total cholesterol minus high-density lipoprotein cholesterol minus LDL-C (estimated using Martin-Hopkins equation). Cox-regression models were used to estimate the association between RC and risk for MI. Discordance analyses were performed to examine the correlation between RC and non-HDL-C (or LDL-C) in relation to MI risk.

RESULTS

Mean age was 65±11 years; 67% presented with acute coronary syndrome. During median follow-up of 9.6 years, 1690 patients developed MI. After multivariable adjustment including lipid-lowering therapies and non-HDL-C, RC was associated with higher MI risk: hazard ratio (95% confidence interval): 1.36 (1.20-1.56) and 1.58 (1.35-1.85) in those with RC levels ≥75th (32.6 mg/dL) and ≥90th (41.8 mg/dL) percentile, compared to RC <50th percentile (25.5 mg/dL). When RC and non-HDL-C (or LDL-C) levels were discordant, the level of RC better reflected the risk for MI.

CONCLUSIONS

Elevated RC is a risk factor for MI independent of lipid-lowering therapies and non-HDL-C, providing further support that RC may serve as a residual cardiovascular risk marker and potential treatment target in patients with coronary artery disease.

Effect of acute ketosis on lipid profile in prediabetes: findings from a cross-over randomized controlled trial

Background

Ketone monoester β-hydroxybutyrate (KEβHB) ingestion has emerged as an effective method of inducing acute ketosis. Although evidence suggests that KEβHB can offer several therapeutic benefits, whether KEβHB affects lipid profile is still unknown.

Aims

The primary aim was to study the effect of KEβHB on plasma lipid profile in individuals with prediabetes. The secondary aim was to investigate the role of saturated fat intake in that effect.

Methods

This study was a randomized controlled trial with cross-over design. Following an overnight fast, 18 adults (six women and 12 men) with prediabetes (diagnosed based on the American Diabetes Association criteria) ingested a single dose of KEβHB drink or placebo drink. Blood samples were collected every 30 min, from baseline to 150 min. Outcome variables included changes in total cholesterol, high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, remnant cholesterol, triglycerides, and the triglycerides to HDL cholesterol ratio. The area under the curve (AUC) over 150 min was calculated for each outcome following ingestion of the drinks. Habitual saturated fat intake was ascertained using the EPIC-Norfolk food frequency questionnaire.

Results

Significant elevation of blood β-hydroxybutyrate from 0.2 mmol/L to 3.5 mmol/L (p < 0.001) was achieved within 30 min. Acute ketosis resulted in significantly lower AUCs for remnant cholesterol (p = 0.022) and triglycerides (p = 0.022). No statistically significant differences in the AUCs for total cholesterol, HDL cholesterol, LDL cholesterol, and the triglycerides to HDL cholesterol ratio were found. The changes in remnant cholesterol and triglycerides were statistically significant in individuals with high, but not low, habitual saturated fat intake.

Conclusion

Acute ketosis had no untoward effect on plasma lipid profile. Moreover, it led to significantly reduced circulating levels of remnant cholesterol and triglycerides. This paves the way for investigating whether exogenous ketone supplementation reduces cardiovascular disease risk (via its actions on triglyceride-rich lipoproteins) in at-risk populations.

 Trial registration: ClinicalTrials.gov, NCT03889210.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12933-022-01571-z.

Association between remnant lipoprotein cholesterol, high-sensitivity C-reactive protein, and risk of atherosclerotic cardiovascular disease events in the Multi-Ethnic Study of Atherosclerosis (MESA)

BACKGROUND

Elevated remnant-lipoprotein (RLP)-cholesterol (RLP-C) and high-sensitivity C-reactive protein (hsCRP) are each individually associated with atherosclerotic cardiovascular disease (ASCVD).

OBJECTIVE

To evaluate the interplay of nuclear magnetic resonance (NMR)-derived RLP-C and hsCRP and their association with ASCVD in the Multi-Ethnic Study of Atherosclerosis (MESA).

METHODS

Lipoprotein particles were measured using NMR spectroscopic analysis at baseline. RLP-C includes very-low-density lipoprotein cholesterol and intermediate-density lipoprotein cholesterol. Four groups were created as follows: Group 1: RLP-C ≤ median (≤29.14 mg/dL) and hsCRP < 2 mg/L; Group 2: RLP-C ≤ median and hsCRP≥ 2 mg/L; Group 3: RLP-C > median and hsCRP level < 2 mg/L; and Group 4: RLP-C > median and hsCRP level ≥ 2 mg/L. Kaplan-Meier survival curves and multivariable-adjusted Cox proportional hazard models were used to examine the relationship between RLP-C and hsCRP with incident ASCVD.

RESULTS

A total of 6,720 MESA participants (mean age 62.2 y, 53% female) with a median follow-up of 15.6 years were included. In the fully adjusted model, compared to those in the reference group (Group 1), participants in Group 2, Group 3, and Group 4 demonstrated a 20% (95% CI, -2%-48%), 18% (-4%-44%), and 43% (18%-76%) increased risk of incident ASCVD events, respectively (p < 0.01). An additive and multiplicative interaction between RLP-C and hsCRP was not statistically significant.

CONCLUSION

NMR-derived RLP-C and hsCRP showed a similar independent association with incident ASCVD. Notably, the combination of increased RLP-C and hsCRP was associated with an increased risk of future ASCVD events.

Association of remnant cholesterol and lipid parameters with new-onset carotid plaque in Chinese population

Background

Remnant lipoprotein cholesterol (RC) is an independent risk factor for cardiovascular disease (CVD). However, the relationships of remnant cholesterol and other conventional lipid parameters with new-onset carotid plaque are not fully understood in the Chinese community-based population.

Materials and methods

A total of 872 plaque-free participants (51.39 ± 4.96 years old) with no history of CVD were included in this study. The plasma concentrations of RC were calculated by subtracting low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C) from total cholesterol (TC). Multivariate regression models were used to evaluate and compare the associations between RC and other lipid parameters and new-onset carotid plaque.

Results

After a mean 6.77-year follow-up, the incidence of new-onset carotid plaque was 188 (21.56%). RC was significantly associated with new-onset carotid plaque [Odd ratio (OR) = 1.57 per 1 mmol/L increase, 95% confidence interval (CI): 1.03–2.41, p = 0.038]. The highest tertile of RC (T3 group) had the highest risk of new-onset carotid plaque (OR = 2.53, 95% CI: 1.63–3.95). Similar results were seen for increased other lipid parameters, but decreased HDL-C levels. When adding another lipid parameter into the adjusted model with RC simultaneously, only RC remained significantly associated with new-onset carotid plaque after adjusting for other lipid parameters (all p value < 0.005). Furthermore, RC was strongly associated with new-onset carotid plaque in participants with lower baseline LDL-C levels.

Conclusion

Increased RC levels were superior to other conventional lipid parameters to be associated with new-onset carotid plaque in the Chinese community-based population. Furthermore, RC should be considered in participants with lower LDL-C levels for the purpose of early atherosclerosis prevention.

Remnant Cholesterol and the Risk of Coronary Artery Calcium Progression: Insights From the CARDIA and MESA Study

BACKGROUND:

Remnant cholesterol (RC) contributes to residual risk of atherosclerotic cardiovascular disease, but population-based evidence on the prospective relationship between RC and coronary artery calcium (CAC) progression is rare.

METHODS:

We pooled data obtained from 6544 atherosclerotic cardiovascular disease–free individuals from the CARDIA study (Coronary Artery Risk Development in Young Adults; n=2635) and MESA (Multi-Ethnic Study of Atherosclerosis; n=3909), with a mean±SD age of 47.2±19.8 years; 3019 (46.1%) were men who completed computed tomography of CAC at baseline. RC was measured as total cholesterol minus HDL (high-density lipoprotein) cholesterol minus calculated LDL (low-density lipoprotein) cholesterol (LDL-C) estimated by using the Martin/Hopkins equation. Adjusted Cox models were used to assess the relationships between RC levels and CAC progression. We also performed discordance analyses examining the risk of CAC progression in RC versus LDL-C discordant/concordant groups using median cut points and clinically relevant LDL-C targets.

RESULTS:

During a median follow-up of 8.6 years, 2778 (42.5%) participants had CAC progression. After multivariable adjustment for demographics and cardiovascular risk factors, a 1-mg/dL increase in RC levels was associated with a 1.3% higher risk of CAC progression (hazard ratio, 1.013 [95% CI, 1.008–1.017]). Results were similar when we categorized individuals by RC quartiles. Furthermore, the discordant high RC/low LDL-C group had a significantly higher risk of CAC progression than the concordant low RC/LDL-C group regarding their medians (hazard ratio, 1.195 [95% CI, 1.063–1.343]) or when setting the clinical LDL-C cut points at 100 and 130 but not 70 mg/dL. The association remained robust across a series of sensitivity analyses.

CONCLUSIONS:

Elevated RC levels were associated with an increased risk of CAC progression independent of traditional cardiovascular risk factors, even in individuals with optimal LDL-C levels.

REGISTRATION:

URL: https://www.clinicaltrials.gov ; Unique identifier: NCT00005130 (CARDIA) and NCT00005487 (MESA).

Remnant lipoprotein cholesterol is associated with incident new onset diabetes after transplantation (NODAT) in renal transplant recipients: results of the TransplantLines Biobank and cohort Studies

Background

New onset diabetes after transplantation (NODAT) is a frequent and serious complication of renal transplantation resulting in worse graft and patient outcomes. The pathophysiology of NODAT is incompletely understood, and no prospective biomarkers have been established to predict NODAT risk in renal transplant recipients (RTR). The present work aimed to determine whether remnant lipoprotein (RLP) cholesterol could serve as such a biomarker that would also provide a novel target for therapeutic intervention.

Methods

This longitudinal cohort study included 480 RTR free of diabetes at baseline. 53 patients (11%) were diagnosed with NODAT during a median [interquartile range, IQR] follow-up of 5.2 [4.1–5.8] years. RLP cholesterol was calculated by subtracting HDL and LDL cholesterol from total cholesterol values (all directly measured).

Results

Baseline remnant cholesterol values were significantly higher in RTR who subsequently developed NODAT (0.9 [0.5–1.2] mmol/L vs. 0.6 [0.4–0.9] mmol/L, p = 0.001). Kaplan-Meier analysis showed that higher RLP cholesterol values were associated with an increased risk of incident NODAT (log rank test, p < 0.001). Cox regression demonstrated a significant longitudinal association between baseline RLP cholesterol levels and NODAT (HR, 2.27 [1.64–3.14] per 1 SD increase, p < 0.001) that remained after adjusting for plasma glucose and HbA1c (p = 0.002), HDL and LDL cholesterol (p = 0.008) and use of immunosuppressive medication (p < 0.001), among others. Adding baseline remnant cholesterol to the Framingham Diabetes Risk Score significantly improved NODAT prediction (change in C-statistic, p = 0.01).

Conclusions

This study demonstrates that baseline RLP cholesterol levels strongly associate with incident NODAT independent of several other recognized risk factors.

Triglycerides: How to Manage Patients with Elevated Triglycerides and When to Refer?

Hypertriglyceridemia (HTG) is among the most common dyslipidemias seen in clinical practice. Studies in recent years have demonstrated a causal relationship between triglyceride-rich lipoproteins (TRL) and cardiovascular disease (CVD). This is primarily due to enhanced atherogenicity of cholesterol-enriched remnants, the metabolic byproducts of TRLs. Other factors influencing atherogenicity of TRLs include apolipoprotein CIII-directed proinflammatory signaling pathways and triglyceride enrichment of low-density lipoprotein that results in overabundance of small dense atherogenic particles within a prooxidative milieu that serves as the gateway for unregulated incorporation by vascular wall macrophages. HTG is caused by familial and metabolic disorders as well as selected medications that impair TRL hydrolysis.

LncRNA-XIST Promotes Proliferation and Migration in ox-LDL Stimulated Vascular Smooth Muscle Cells through miR-539-5p/SPP1 Axis

Long noncoding RNAs (lncRNAs) are untranslated transcripts greater than 200 nucleotides in length. Despite not being translated, they play a role in the regulation of transcription, translation, and other cellular processes and have been identified as key regulator in the progression of atherosclerosis. This study focused on the lncRNA X-inactive specific transcript (XIST), which participates in the regulation of X chromosome inactivation. XIST is produced by the XIST gene and is located on human chromosome Xql3.2. We also focused on discovering the possible role and mechanism of lncRNA XIST in oxidized low-density lipoprotein- (ox-LDL-) stimulated vascular smooth muscle cells (VSMCs), which could further help evalute its possible a role in the progression of atherosclerosis. XIST was overexpressed in ox-LDL-stimulated VSMCs, while the expression of miR-539-5p was decreased. XIST knockdown hindered the proliferation and migration of ox-LDL-treated VSMCs. XIST inhibits the miR-539-5p expression through direct interaction. Besides, miR-539-5p inhibitors can partially reverse the effect of XIST depletion on the proliferation and migration of VSMCs induced by ox-LDL stimulation. Further mechanistic analysis showed that secreted phosphoprotein 1 (SPP1) is the target of miR-539-5p, and XIST acts as a competing endogenous RNA for miR-539-5p to enhance the expression of SPP1. In addition, miR-539-5p inhibitor exerts its proliferation and migration effects by activating the miR-539-5p/SPP1 axis in VSMCs stimulated by ox-LDL. In conclusion, our study findings show that XIST inhibition can inhibit the proliferation and migration of atherosclerosis vascular smooth muscle cells, which provides a new theoretical basis for atherosclerosis treatment.

Hypertriglyceridemia may contribute to stroke and pancreatitis: A case report and review of the literature

Hypertriglyceridemia (HTG) is one of the most common clinical dyslipidemia. Nevertheless, stroke and acute pancreatitis co-occurrence due to hypertriglyceridemia are extremely rare. We present a case of hypertriglyceridemia-associated stroke and pancreatitis in a 39-year-old woman. The patient's laboratory tests reported high triglyceride concentrations beyond the instrument's detection range, and radiological examination showed typical signs of cerebral infarction and acute pancreatitis. The patient received combined blood purification therapy, intravenous thrombolysis with urokinase, and conservative treatment of pancreatitis. We discuss the clinical features, pathogenesis, diagnosis, and treatment of hypertriglyceridemic stroke and pancreatitis combined with the relevant literature. We reviewed the mechanisms by which triglycerides contribute to atherosclerosis and acute pancreatitis. We point out the superiority of combined blood purification therapy and caution physicians about the effects of prescribed drugs on blood lipids.

Remnant cholesterol predicts progression of diabetic nephropathy and retinopathy in type 1 diabetes

BACKGROUND

We aimed to assess whether remnant cholesterol concentration and variability predict the progression of diabetic nephropathy (DN) and severe diabetic retinopathy (SDR) in type 1 diabetes.

METHODS

This observational prospective study covered 5150 FinnDiane Study participants. Remnant cholesterol was calculated as total cholesterol - LDL cholesterol - HDL cholesterol and variability as the coefficient of variation. DN category was based on consensus albuminuria reference limits and the progression status was confirmed from medical files. SDR was defined as retinal laser treatment. For 1338 individuals, the severity of diabetic retinopathy (DR) was graded using the ETDRS classification protocol. Median (IQR) follow-up time was 8.0 (4.9-13.7) years for DN and 14.3 (10.4-16.3) for SDR.

RESULTS

Remnant cholesterol (mmol L^-1 ) was higher with increasing baseline DN category (P < 0.001). A difference was also seen comparing non-progressors (0.41 [0.32-0.55]) with progressors (0.55 [0.40-0.85]), P < 0.001. In a Cox regression analysis, remnant cholesterol predicted DN progression, independently of diabetes duration, sex, HbA_1c , systolic blood pressure, smoking, BMI, estimated glucose disposal rate and estimated glomerular filtration rate (HR: 1.51 [1.27-1.79]). Remnant cholesterol was also higher in those who developed SDR (0.47 [0.36-0.66]) than those who did not (0.40 [0.32-0.53]), P < 0.001, and the concentration increased stepwise with increasing DR severity (P < 0.001). Regarding SDR, the HR for remnant cholesterol was 1.52 (1.26-1.83) with the most stringent adjustment. However, remnant cholesterol variability was not independently associated with the outcomes.

CONCLUSIONS

Remnant cholesterol concentration, but not variability, predicts DN progression and development of SDR. However, it remains to be elucidated whether the associations are causal or not.

The Effects of Calculated Remnant-Like Particle Cholesterol on Incident Cardiovascular Disease: Insights from a General Chinese Population

Background: Growing evidence suggests that remnant cholesterol (RC) contributes to residual atherosclerotic cardiovascular disease (ASCVD) risk. However, the cutoff points to treat RC for reducing ASCVD are still unknown. This study aimed to investigate the relationships between RC and combined cardiovascular diseases (CVDs) in a general China cohort, with 11,956 subjects aged ≥ 35 years. Methods: Baseline RC was estimated with the Friedewald formula for 8782 subjects. The outcome was the incidence of combined CVD, including fatal and nonfatal stroke and coronary heart disease (CHD). The Cox proportional hazards model was used to calculate hazard ratios (HRs) with 95% confidence intervals. The restricted cubic spline (RCS) model was used to evaluate the dose–response relationship between continuous RC and the natural log of HRs. Results: After a median follow-up of 4.66 years, 431 CVD events occurred. In the Cox proportional models, participants with a high level of categorial RC had a significantly higher risk for combined CVD (HR: 1.37; 95% CI: 1.07–1.74) and CHD (HR: 1.63; 95% CI: 1.06–2.53), compared to those with a medium level of RC. In the stratification analyses, a high level of RC significantly increased combined CVD risk for subgroups females, age < 65 years, noncurrent smokers, noncurrent drinkers, normal weight, renal dysfunction, and no hyperuricemia. The same trends were found for CHD among subgroups males, age < 65 years, overweight, renal dysfunction, and no hyperuricemia; stroke among subgroup females. In RCS models, a significant linear association between RC and combined CVD and a nonlinear association between RC and CHD resulted. The risk of outcomes was relatively flat until 0.84 mmol/L of RC and increased rapidly afterwards, with an HR of 1.308 (1.102 to 1.553) for combined CVD and 1.411 (1.061 to 1.876) for CHD. Stratified analyses showed a significant nonlinear association between RC and CVD outcomes in the subgroup aged < 65 years or the diabetes subgroup. Conclusions: In this large-scale and long-term follow-up cohort study, participants with higher RC levels had a significantly worse prognosis, especially for the subgroup aged 35–65 years or the diabetes mellitus subgroup.

The Importance of Lipoprotein Lipase Regulation in Atherosclerosis

Lipoprotein lipase (LPL) plays a major role in the lipid homeostasis mainly by mediating the intravascular lipolysis of triglyceride rich lipoproteins. Impaired LPL activity leads to the accumulation of chylomicrons and very low-density lipoproteins (VLDL) in plasma, resulting in hypertriglyceridemia. While low-density lipoprotein cholesterol (LDL-C) is recognized as a primary risk factor for atherosclerosis, hypertriglyceridemia has been shown to be an independent risk factor for cardiovascular disease (CVD) and a residual risk factor in atherosclerosis development. In this review, we focus on the lipolysis machinery and discuss the potential role of triglycerides, remnant particles, and lipolysis mediators in the onset and progression of atherosclerotic cardiovascular disease (ASCVD). This review details a number of important factors involved in the maturation and transportation of LPL to the capillaries, where the triglycerides are hydrolyzed, generating remnant lipoproteins. Moreover, LPL and other factors involved in intravascular lipolysis are also reported to impact the clearance of remnant lipoproteins from plasma and promote lipoprotein retention in capillaries. Apolipoproteins (Apo) and angiopoietin-like proteins (ANGPTLs) play a crucial role in regulating LPL activity and recent insights into LPL regulation may elucidate new pharmacological means to address the challenge of hypertriglyceridemia in atherosclerosis development.

Triglyceride-Rich Lipoproteins and Their Remnants as Silent Promoters of Atherosclerotic Cardiovascular Disease and Other Metabolic Disorders: A Review

While targeting elevated serum levels of low-density lipoprotein cholesterol has been the mainstay of atherosclerosis prevention and treatment for decades, the evidence regarding the atherogenic role of hypertriglyceridemia is still controversial. Various epidemiological population-based studies on statin-treated subjects nominated triglycerides, triglyceride-rich lipoproteins (namely, chylomicrons and very-low-density lipoprotein particles), and their remnants as major determinants of the substantial residual cardiovascular risk. With the triglyceride-glucose index and triglyceride to high-density lipoprotein ratio emerging as surrogate indicators of peripheral artery disease and atherosclerotic cerebrovascular disease, one can conclude that further research addressing the intricate relationship between triglycerides and atherosclerosis is warranted. Therefore, this review aims to provide insight into the current clinical and epidemiological state of knowledge on the relationship between triglycerides and atherosclerotic cardiovascular disease. It also intends to highlight the connection between triglycerides and other metabolic disorders, including diabetes mellitus, and the potential benefits of triglyceride-lowering agents on cardiovascular outcomes and all-cause mortality.

The role of triglycerides in the origin and progression of atherosclerosis

Hypertriglyceridaemia has been associated with cardiovascular disease risk in humans for several decades. However, only recently, data from basic research, as well as from genetic and observational studies, have suggested triglyceride-rich lipoproteins (TRLs) as causal factors for atherosclerotic cardiovascular disease. Novel findings highlighting the relevance of TRL-derived lipolytic products (remnant lipoprotein particles "RLPs"), rather than plasma triglycerides or TRL themselves, as the true mediators in atherosclerosis, have contributed to explain a causal relationship through a number of direct and indirect mechanisms. Thus, experimental studies in animal models and in vitro cell culture methods reveal that RLPs, having sizes below 70-80nm, enter the arterial wall and accumulate within the sub-endothelial space. They then become involved in the cholesterol deposition of cholesterol in the intima in addition to several pro-inflammatory and pro-apoptotic pathways. In this review, a summary is presented of current understanding of the pathophysiological mechanisms by which TRLs and their lipolytic derived RLP induce the formation and progression of atherosclerotic lesions, and actively contribute to cardiovascular disease.

The relation between VLDL-cholesterol and risk of cardiovascular events in patients with manifest cardiovascular disease

INTRODUCTION

Apolipoprotein B containing lipoproteins are atherogenic. There is evidence that with low plasma low density lipoprotein cholesterol (LDL-C) levels residual vascular risk might be caused by triglyceride rich lipoproteins such as very-low density lipoproteins (VLDL), chylomicrons and their remnants. We investigated the relationship between VLDL-cholesterol (VLDL-C) and recurrent major adverse cardiovascular events (MACE), major adverse limb events (MALE) and all-cause mortality in a cohort of patients with cardiovascular disease.

METHODS

Prospective cohort study in 8057 patients with cardiovascular disease from the UCC-SMART study. The relation between calculated VLDL-C levels and the occurrence of MACE, MALE and all-cause mortality was analyzed with Cox regression models.

RESULTS

Patients mean age was 60 ± 10 years, 74% were male, 4894 (61%) had coronary artery disease, 2445 (30%) stroke, 1425 (18%) peripheral arterial disease and 684 (8%) patients had an abdominal aorta aneurysm at baseline. A total of 1535 MACE, 571 MALE and 1792 deaths were observed during a median follow up of 8.2 years (interquartile range 4.512.2). VLDL-C was not associated with risk of MACE or all-cause mortality. In the highest quartile of VLDL-C the risk was higher for major adverse limb events (MALE) (HR 1.49; 95%CI 1.16-1.93) compared to the lowest quartile, after adjustment for confounders including LDL-C and lipid lowering medication.

CONCLUSION

In patients with clinically manifest cardiovascular disease plasma VLDL-C confers an increased risk for MALE, but not for MACE and all-cause mortality, independent of established risk factors including LDL-C and lipid-lowering medication.

Prognostic utility of triglyceride-rich lipoprotein-related markers in patients with coronary artery disease

TG-rich lipoprotein (TRL)-related biomarkers, including TRL-cholesterol (TRL-C), remnant-like lipoprotein particle-cholesterol (RLP-C), and apoC-III have been associated with atherosclerosis. However, their prognostic values have not been fully determined, especially in patients with previous CAD. This study aimed to examine the associations of TRL-C, RLP-C, and apoC-III with incident cardiovascular events (CVEs) in the setting of secondary prevention of CAD. Plasma TRL-C, RLP-C, and total apoC-III were directly measured. A total of 4,355 participants with angiographically confirmed CAD were followed up for the occurrence of CVEs. During a median follow-up period of 5.1 years (interquartile range: 3.9-6.4 years), 543 (12.5%) events occurred. Patients with incident CVEs had significantly higher levels of TRL-C, RLP-C, and apoC-III than those without events. Multivariable Cox analysis indicated that a log unit increase in TRL-C, RLP-C, and apoC-III increased the risk of CVEs by 49% (95% CI: 1.16-1.93), 21% (95% CI: 1.09-1.35), and 40% (95% CI: 1.11-1.77), respectively. High TRL-C, RLP-C, and apoC-III were also independent predictors of CVEs in individuals with LDL-C levels ≤1.8 mmol/l (n = 1,068). The addition of RLP-C level to a prediction model resulted in a significant increase in discrimination, and all three TRL biomarkers improved risk reclassification. Thus, TRL-C, RLP-C, and apoC-III levels were independently associated with incident CVEs in Chinese CAD patients undergoing statin therapy.

Triglycerides and ASCVD Risk Reduction: Recent Insights and Future Directions

PURPOSE OF REVIEW

This review focuses on recent evidence examining the role triglycerides (TG) and triglyceride-enriched lipoproteins (TGRL) play in atherosclerotic cardiovascular disease (ASCVD). It also provides a succinct overview of current and future TG-lowering therapies for ASCVD risk reduction.

RECENT FINDINGS

Epidemiological and Mendelian randomization studies have consistently shown that TGRL are strongly associated with ASCVD. REDUCE-IT demonstrated cardiovascular benefit with icosapent ethyl in high-risk patients with hypertriglyceridemia on statin therapy. Polymorphisms in APOC3 and ANGPTL3 are associated with ASCVD and use of RNA-interfering therapies to target these proteins has shown TG lowering in early phase trials. TG and TGRL are causally associated with ASCVD. Lifestyle modifications and statin therapy can lower TG/TGRL and are considered first-line treatment for hypertriglyceridemia. Icosapent ethyl has been shown to reduce residual ASCVD risk in high-risk patients on maximally tolerated statins. Ongoing clinical trials will better define optimal therapy for patients on statins with residual hypertriglyceridemia.

CTBP1‑AS2 inhibits proliferation and induces autophagy in ox‑LDL‑stimulated vascular smooth muscle cells by regulating miR‑195‑5p/ATG14

Atherosclerosis (AS) is a chronic progressive disease caused by injury and functional changes in vascular smooth muscle cells (VSMCs). Long non‑coding RNAs (lncRNAs) are pivotal regulators in AS development. The present study aimed to explore the roles and molecular mechanisms of lncRNA CTBP1‑AS2 in AS progression. A dual‑luciferase reporter assay confirmed that miR‑195‑5p is a downstream target miRNA of lncRNA CTBP1‑AS2 and miR‑195‑5p was increased in AS. The expression levels of miR‑195‑5p and CTBP1‑AS2 in the serums of patients with AS and human aorta vascular smooth muscle cells was increased or decreased, respectively, following treatment with oxidized low‑density lipoprotein (ox‑LDL). Functional experiments showed that the overexpression of lncRNA CTBP1‑AS2 inhibited the proliferation of HA‑VSMCs and promoted their autophagy following ox‑LDL treatment. This effect could be reversed by treatment with ROC‑325, the inhibitor of autophagy, or miR‑195‑5p mimics. Autophagy related 14 (ATG14) was identified to be a target of miR‑195‑5p, and lncRNA CTBP1‑AS2 promoted ATG14 expression by serving as a competing endogenous RNA of miR‑195‑5p. The present study revealed that lncRNA CTBP1‑AS2 may serve a role in AS by inhibiting the proliferation and promoting the autophagy of VSMCs through ATG14 modulation via miR‑195‑5p. These data may provide a novel therapeutic target for AS.

NEAT1 knockdown suppresses endothelial cell proliferation and induces apoptosis by regulating miR‑638/AKT/mTOR signaling in atherosclerosis

Long non-coding RNAs (lncRNAs) have been validated to mediate the development of atherosclerosis (AS). In the present study, the molecular mechanisms and functions of lncRNA nuclear paraspeckle assembly transcript 1 (NEAT1) in the advancement of human aortic endothelial cells (HAECs) were investigated. The levels of lncRNA-NEAT1 and miR-638 expression in clinical samples and cells were explored via quantitative reverse transcription polymerase chain reaction. Colony formation and CCK-8 assays were performed to determine the proliferative capacity of cells, and the apoptotic capacity of cells was analyzed on the basis of apoptotic cell proportion and caspase-3 activity. Then, the proportion of cells and correlations among phosphoglycerate kinase 1 (PGK1), NEAT1, and miR-638 were determined through RNA immunoprecipitation and luciferase assays and bioinformatics analysis. Moreover, the expression levels of Ki-67, proliferating cell nuclear antigen, PGK1, Bax, Bcl-2, (p)-mTOR, (p)-AKT, and β-catenin were analyzed via western blot analysis. In the serum of patients with AS and HAECs induced by oxidized low-density lipoprotein (ox-LDL), the expression level of miR-638 was decreased, whereas that of NEAT1 was increased. After ox-LDL therapy, NEAT1 knockdown suppressed HAEC proliferation and stimulated HAEC apoptosis, which could be reversed by the miR-638 inhibitor. NEAT1 inhibited miR-638 expression through direct mutual action. The following mechanical investigations revealed that PGK1 was a miR-638 target, whose expression was increased by NEAT1, a competing endogenous RNA of miR-638. Additionally, the miR-638 inhibitor contributed to proliferation and suppressed apoptosis through the activation of the AKT/mTOR signaling pathway in ox-LDL-induced HAECs. NEAT1 adjusted the AKT/mTOR signaling pathway via miR-638 in ox-LDL-induced HAECs to accelerate their proliferation and impede their apoptosis. This result revealed that NEAT1 may be valuable in the treatment of AS.

Postpartum metabolic syndrome after gestational hypertension and preeclampsia, a prospective cohort study

OBJECTIVE

We evaluated the 6-month postpartum risk of metabolic syndrome (MetS), a marker of future cardiovascular disease (CVD) risk, comparing women whose most recent pregnancies were complicated with gestational hypertension (GH) or preeclampsia (PE) versus those who had normotensive pregnancies.

STUDY DESIGN

This was a prospective cohort study in which women with GH or PE and normotensive women were actively enrolled during the first 12 weeks after delivery in Nairobi, Kenya. Participants were interviewed, blood pressures and anthropometric measurements including waist circumference obtained at enrollment and 6 months postpartum. Fasting lipid profile and plasma glucose were measured at 6 months postpartum. A generalized linear regression model with Poisson distribution was used to estimate crude relative risk (RR) of 6-month postpartum MetS and adjusted RR (ARR) after adjusting for apriori potential confounders.

RESULTS

Among 194 postpartum women, 63 (32%) had experienced GH or PE. Prevalence of MetS at 6 months postpartum was higher among women whose pregnancies were complicated with GH or PE (34.9%) compared to those who were normotensive (11.5%). GH and PE were associated with a 3-fold or greater risk of MetS (ARR) 3.01; 95% Confidence interval [CI] 1.58, 5.71; p < 0.001) overall and three of the five components, namely hypertension (ARR 3.35 [2.04, 5.51], p < 0.001), hypertriglyceridemia (ARR 3.25 [1.16-9.10], p = 0.01), and fasting hyperglycemia (ARR 6.20 [1.07-35.76], p = 0.03), compared to having normal blood pressures during pregnancy.

CONCLUSION

At 6  months postpartum, GH and PE were associated with three-fold or higher risk of MetS and especially hypertension, fasting hypertriglyceridemia, and fasting hyperglycemia.

Remnant Lipoprotein Cholesterol Independently Associates With In-Stent Restenosis After Drug-Eluting Stenting for Coronary Artery Disease

This study evaluated the prognostic value of remnant lipoprotein cholesterol (RLP-C) as a predictor of in-stent restenosis (ISR) after drug-eluting stent (DES) implantation in patients with coronary artery disease (CAD). Consecutive patients with CAD (n = 612) who underwent both successful coronary DES implantation and follow-up angiography ranging from 6 to 24 months were enrolled. The independent predictors of ISR were explored by multivariate logistic regression analysis; 95 (15.52%) patients were identified to have ISR. Multivariate logistic regression analysis showed that RLP-C concentration (odds ratio [OR]: 4.245, 95% confidence interval [CI]: 2.493-7.229), age (OR: 1.026, 95% CI: 1.002-1.051), diabetes mellitus (DM; OR: 1.811, 95% CI: 1.134-2.892), and lesion length (OR: 1.013, 95% CI: 1.002-1.024) were associated with ISR. Via subgroup analysis, we found that RLP-C was independently associated with ISR in both CAD with DM (OR: 4.154, 95% CI: 1.895-9.104) and CAD without DM (OR: 4.455, 95% CI: 2.097-9.464) groups. In the analysis of the receiver operating characteristics curve, RLP-C level >0.515 mmol/L exhibited 77.9% sensitivity and 56.5% specificity (area under the curve: 0.705, 95% CI: 0.648-0.762) in predicting ISR. In conclusion, RLP-C is independently associated with the development of ISR in patients with CAD after DES implantation.

The Effect of Oxidant Hypochlorous Acid on Platelet Aggregation and Dityrosine Concentration in Chronic Heart Failure Patients and Healthy Controls

Background and objective: One of the reasons for thrombosis in chronic heart failure (CHF) might be reactive forms of oxygen activating platelets. The aim of this study was to evaluate the effect of oxidant hypochlorous acid (HOCl) on platelet aggregation and dityrosine concentration in CHF patients and healthy controls. Materials and Methods: CHF patients (n = 67) and healthy (n = 31) were investigated. Heart echoscopy, 6-min walking test, complete blood count, platelet aggregation, and dityrosine concentration were performed. Platelet aggregation and dityrosine concentration were measured in plasma samples after incubation with different HOCl concentrations (0.15, 0.0778, and 0.0389 mmol/L). Results: Platelet aggregation without oxidant was lower (p = 0.049) in CHF patients than in controls. The spontaneous platelet aggregation with oxidant added was higher in CHF patients (p = 0.004). Dityrosine concentration was also higher (p = 0.032) in CHF patients. Platelet aggregation was the highest in samples with the highest oxidant concentration in both healthy controls (p = 0.0006) and in CHF patients (p = 0.036). Platelet aggregation was higher in NYHA III group in comparison to NYHA II group (p = 0.0014). Concentration of dityrosine was significantly higher in CHF samples (p = 0.032). The highest concentration of dityrosine was obtained in NYHA IV group samples (p < 0.05). Intensity of platelet aggregation, analyzed with ADP, was correlated with LV EF (r = 0.42, p = 0.007). Dityrosine concentration was correlated with NYHA functional class (r = 0.27, p < 0.05). Conclusions: The increase in platelet aggregation in CHF and healthy controls shows the oxidant effect on platelets. The increase in dityrosine concentration in higher NYHA functional classes shows a higher oxidative stress in patients with worse condition.

The VLDL receptor plays a key role in the metabolism of postprandial remnant lipoproteins

A new concept to account for the process of postprandial remnant lipoprotein metabolism is proposed based on the characteristics of lipoprotein particles and their receptors. The characteristics of remnant lipoprotein (RLP) were investigated using an immuno-separation method. The majority of the postprandial lipoproteins increased after fat intake was shown to be VLDL remnants, not chylomicron (CM) remnants, based on the significantly high ratio of apoB100/apoB48 in the RLP and the high degree of similarity in the particle size of the apoB48 and apoB100 carrying lipoproteins, which fluctuate in parallel during a 6 h period after fat intake. The VLDL receptor was discovered as a receptor for TG-rich lipoprotein metabolism and is located in peripheral tissues such as skeletal muscle, adipose tissue, etc., but not in the liver. Postprandial VLDL particles are strongly bound and internalized into cells expressing the VLDL receptor. Ligands that bind to VLDL receptor, such as LPL and Lp(a), present in RLP. The presence of various specific ligands in VLDL remnants may enhance the capacity for binding to the VLDL receptor, which play the role primarily for energy delivery to the peripheral tissues, but is also a causal factor in atherogenic diseases when excessively and/or continuously remained in plasma.

Baicalin inhibits proliferation and promotes apoptosis of vascular smooth muscle cells by regulating the MEG3/p53 pathway following treatment with ox‑LDL

Atherosclerosis (AS) is a systemic disease associated with lipid metabolic disorders and abnormal proliferation of smooth muscle cells. Baicalin is a flavonoid compound isolated from the dry roots of Scutellaria baicalensis Georgi and exerts anti-proliferative effects in various types of cells. However, the effect of baicalin on AS remains unclear. In the present study, serum samples were collected from patients with AS and an in vitro model of AS was established using oxidized low-density lipoprotein (ox-LDL)-treated human aorta vascular smooth muscle cells (HA-VSMCs). The siRNA transfection and overexpression efficiency of endogenous maternally expressed gene 3 (MEG3) and the expression level of MEG3 were analyzed by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The effects of alterations in expression levels of MEG3 were assessed by MTT assay, bromodeoxyuridine incorporation assay, 5-ethynyl-2′-deoxyuridine staining, wound healing assay, immunofluorescence and western blotting in HA-VSMCs. qPCR indicated that the expression of MEG3 was reduced in serum samples from patients with AS and ox-LDL-treated HA-VSMCs, compared with serum samples from healthy patients and untreated HA-VSMCs, respectively. Further experiments indicated that ox-LDL-induced decrease of MEG3 expression was reversed by treatment with baicalin in a concentration-dependent manner. Following treatment with ox-LDL, decreased expression of MEG3 promoted proliferation and migration, and suppressed apoptosis in HA-VSMCs. Furthermore, treatment with baicalin reversed these effects on proliferation and apoptosis in ox-LDL-treated HA-VSMCs. The current study indicated that downregulated expression of MEG3 increased cell cycle-associated protein expression. However, treatment with baicalin inhibited the expression of cell-cycle associated proteins in HA-VSMCs with MEG3 knockdown. In addition, baicalin activated the p53 signaling pathway and promoted the expression and transport of p53 from the cytoplasm to nucleus following MEG3 knockdown in ox-LDL-treated HA-VSMCs. Baicalin inhibited proliferation and promoted apoptosis by regulating the expression of MEG3/p53, indicating that baicalin may serve a role in AS by activating the MEG3/p53 signaling pathway. The present study suggested a potential mechanism underlying the protective role of baicalin in the in vitro model of AS, and these results may be used to develop novel therapeutic approaches for the affected patients.

A Dipeptidyl Peptidase-4 Inhibitor, Teneligliptin, Decreases Plasma Triglyceride-Rich Lipoprotein Remnants in Diabetic Patients with Chronic Kidney Disease Undergoing Hemodialysis

Objective

A high plasma level of remnant-like particle cholesterol (RLP-C), which is equivalent to triglyceride-rich lipoprotein remnant, is an important coronary risk marker. RLP-C level is high, independent of other plasma lipids, in patients with chronic kidney disease (CKD) undergoing hemodialysis. The effect of teneligliptin, a dipeptidyl peptidase (DPP)-4 inhibitor, on plasma levels of RLP-C in patients with diabetes mellitus and CKD under hemodialysis was studied.

Methods

Teneligliptin 20 mg/day was administered to 15 patients with diabetes and CKD undergoing hemodialysis for 12 weeks. Ten patients with diabetes and CKD undergoing hemodialysis were allocated to the control group. Blood was sampled following a 12-h fast. Fasting plasma glucose (FPG), C-peptide, triglyceride, low-density lipoprotein (LDL)-cholesterol (C), high-density lipoprotein (HDL)-C, RLP-C, apolipoprotein (apo) B, oxidized LDL, lipoprotein lipase, and glycated hemoglobin (HbA1c) were measured.

Results

HbA1c decreased in the teneligliptin group but significantly increased in the control group. FPG and RLP-C significantly decreased in the teneligliptin group. Plasma lipoprotein-related parameters except RLP-C were not affected by teneligliptin treatment.

Conclusion

Teneligliptin treatment significantly reduced plasma levels of RLP-C, FPG, and HbA1c in patients with diabetes with CKD who are undergoing hemodialysis.

Postprandial remnant lipoproteins as targets for the prevention of atherosclerosis

PURPOSE OF REVIEW

Oxidized low-density lipoprotein (Ox-LDL) and chylomicron remnants were previously proposed as the most atherogenic lipoproteins for the causal lipoproteins of atherosclerosis. However, there are still controversies on these hypothesizes. Therefore, we have proposed a new hypothesis based on our recent findings of remnant lipoproteins (RLPs) in postprandial plasma.

RECENT FINDINGS

Plasma RLP-C and RLP-TG increased significantly after fat load. More than 80% of the increased triglycerides after fat load consisted of the triglycerides in RLP, which contained greater amount of apoB100 than apoB48 particles as mostly very low density lipoproteins (VLDL) remnants. The majority of lipoprotein lipase (LPL) in plasma was found in RLP as RLP-LPL complex, which is released into circulation after hydrolysis. LPL activity and concentration in plasma did not increase after food intake associated with the insufficient hydrolysis of chylomicrons and VLDL and resulted in the significant increase of RLP-TG. Plasma LPL was inversely correlated with RLP particle size and number.

SUMMARY

VLDL remnants have been shown as the major atherogenic lipoproteins in postprandial plasma associated with LPL activity as the targets for prevention of atherosclerosis. We also proposed a new definition of RLPs, 'LPL bound TG-rich lipoproteins' based on the findings of RLP-LPL complex.

H19 knockdown suppresses proliferation and induces apoptosis by regulating miR-148b/WNT/β-catenin in ox-LDL -stimulated vascular smooth muscle cells

Background

Long non-coding RNAs (lncRNAs) have been identified as critical regulators in the development of atherosclerosis (AS). Here, we focused on discussing roles and molecular mechanisms of lncRNA H19 in vascular smooth muscle cells (VSMCs) progression.

Methods

RT-qPCR assay was used to detect the expression patterns of H19 and miR-148b in clinical samples and cells. Cell proliferative ability was evaluated by CCK-8 and colony formation assays. Cell apoptotic capacity was assessed by apoptotic cell percentage and the caspase-3 activity. Bioinformatics analysis, luciferase and RNA immunoprecipitation (RIP) assays were employed to demonstrate cell percentage and the relationship among H19, miR-148b and wnt family member 1 (WNT1). Western blot assay was performed to determine expressions of proliferating cell nuclear antigen (PCNA), ki-67, Bax, Bcl-2, WNT1, β-catenin, C-myc and E-cadherin.

Results

The level of H19 was increased and miR-148b expression was decreased in human AS patient serums and oxidized low-density lipoprotein (ox-LDL)-stimulated human aorta vascular smooth muscle cells (HA-VSMCs). H19 knockdown suppressed proliferation and promoted apoptosis in HA-VSMCs following the treatment of ox-LDL. H19 inhibited miR-148b expression by direct interaction. Moreover, miR-148b inhibitor could reverse the effects of H19 depletion on proliferation and apoptosis in ox-LDL-stimulated HA-VSMCs. Further mechanical explorations showed that WNT1 was a target of miR-148b and H19 acted as a competing endogenous RNA (ceRNA) of miR-148b to enhance WNT1 expression. Furthermore, miR-148 inhibitor exerted its pro-proliferation and anti-apoptosis effects through activating WNT/β-catenin signaling in ox-LDL-stimulated HA-VSMCs.

Conclusion

H19 facilitated proliferation and inhibited apoptosis through modulating WNT/β-catenin signaling pathway via miR-148b in ox-LDL-stimulated HA-VSMCs, implicating the potential values of H19 in AS therapy.

Atherogenic postprandial remnant lipoproteins; VLDL remnants as a causal factor in atherosclerosis

Oxidized LDL (Ox-LDL) and chylomicron (CM) remnants have been suggested to be the most atherogenic lipoproteins that initiate and exacerbate coronary atherosclerosis. In this review, we propose a hypothesis of the causal lipoproteins in atherosclerosis based on our recent findings on postprandial remnant lipoproteins (RLP). Plasma RLP-C and RLP-TG increased significantly after food intake, especially a fat load. More than 80% of the TG increase after the fat load consisted of the TG in RLP, which contained significantly greater apoB100 than apoB48 particles as VLDL remnants. The majority of the LPL in non-heparin plasma was found in RLP as an RLP-LPL complex and released into the circulation after hydrolysis. Plasma LPL did not increase after food intake, which may have caused the partial hydrolysis of CM and VLDL as well as the significant increase of RLP-TG in the postprandial plasma. LPL was inversely correlated with the RLP particle size after food intake. We showed that VLDL remnants are the major atherogenic lipoproteins in the postprandial plasma associated with insufficient LPL activity and a causal factor in the initiation and progression of atherosclerosis. We also propose "LPL bound TG-rich lipoproteins" as a new definition of remnant lipoproteins based on the findings of the RLP-LPL complex in the non-heparin plasma.

Remnant Cholesterol and Myocardial Infarction in Normal Weight, Overweight, and Obese Individuals from the Copenhagen General Population Study

BACKGROUND

We tested whether high remnant cholesterol is associated with high myocardial infarction risk, independent of whether an individual is normal weight, overweight, or obese.

METHODS

A total of 106216 individuals from the Copenhagen General Population Study were followed for up to 11 years, during which 1565 experienced a myocardial infarction. Individuals were grouped by clinically meaningful remnant cholesterol concentrations of &lt;0.5 mmol/L (19 mg/dL), 0.5 to 0.99 mmol/L (19–38 mg/dL), 1.0 to 1.49 mmol/L (39–58 mg/dL), and ≥1.5 mmol/L (58 mg/dL), and by body mass index (BMI) of &lt;18.5 kg/m2 (underweight), 18.5 to 24.9 kg/m2 (normal weight), 25 to 29.9 kg/m2 (overweight), and ≥30 kg/m2 (obese).

RESULTS

Median calculated remnant cholesterol was 0.40 mmol/L [interquartile range (IQR), 0.30–0.55 mmol/L] [15 mg/dL (12–21 mg/dL)] for underweight, 0.50 mmol/L (IQR, 0.37–0.71 mmol/L) [19 mg/dL (14–27 mg/dL)] for normal weight, 0.70 mmol/L (IQR, 0.49–1.00 mmol/L) [27 mg/dL (19–39 mg/dL)] for overweight, and 0.85 mmol/L (IQR, 0.61–1.20 mmol/L) [(33 mg/dL (24–46 mg/dL)] for obese individuals. On continuous scales, remnant cholesterol was positively correlated with BMI until reaching a plateau of approximately 1 mmol/L (39 mg/dL) at BMI &gt;35 kg/m2. R2 from an unadjusted linear regression for the correlation between calculated remnant cholesterol and BMI was 12%. Stepwise higher remnant cholesterol was associated with stepwise higher myocardial infarction risk in a similar pattern for normal weight, overweight, and obese individuals. When compared with individuals with remnant cholesterol &lt;0.5 mmol/L (19 mg/dL), individuals with remnant cholesterol ≥1.5 mmol/L (58 mg/dL) had hazard ratios for myocardial infarction of 2.0 (95% CI, 1.3–3.2) for normal weight, 1.9 (95% CI, 1.4–2.6) for overweight, and 2.3 (95% CI, 1.4–3.5) for obese individuals. Directly measured remnant cholesterol increased 0.91 mmol/L (95% CI, 0.89–0.94 mmol/L) [35 mg/dL (34–36 mg/dL)] per 1 mmol/L (39 mg/dL) increase in calculated remnant cholesterol.

CONCLUSIONS

Remnant cholesterol and BMI were positively correlated; however, high remnant cholesterol was associated with higher myocardial infarction risk across the examined BMI subcategories, indicating that remnant cholesterol is a risk factor for myocardial infarction independent of overweight and obesity.

Atherogenic Lipoprotein Determinants of Cardiovascular Disease and Residual Risk Among Individuals With Low Low-Density Lipoprotein Cholesterol

Background

Levels of LDL (low‐density lipoprotein) cholesterol in the population are declining, and increasing attention is being focused on residual lipid‐related pathways of atherosclerotic cardiovascular disease risk beyond LDL cholesterol. Among individuals with low (<130 mg/dL) LDL cholesterol, we undertook detailed profiling of circulating atherogenic lipoproteins in relation to incident cardiovascular disease in 2 populations.

Methods and Results

We performed proton nuclear magnetic resonance spectroscopy to quantify concentrations of LDL and VLDL (very low‐density lipoprotein) particle subclasses in 11 984 JUPITER trial participants (NCT00239681). Adjusted Cox models examined cardiovascular disease risk associated with lipoprotein measures according to treatment allocation. Risk (adjusted hazard ratio [95%CI] per SD increment) among placebo‐allocated participants was associated with total LDL particles (1.19 [1.02, 1.38]) and total VLDL particles (1.21 [1.04, 1.41]), as well as apolipoprotein B, non–high‐density lipoprotein cholesterol, and triglycerides, but not LDL‐c. Rosuvastatin reduced LDL measures but had variable effects on triglyceride and VLDL measures. On‐statin levels of the smallest VLDL particle subclass were associated with a 68% per‐SD (adjusted hazard ratio 1.68 [1.28, 2.22]) increase in residual risk—this risk was related to VLDL cholesterol and not triglyceride or larger VLDL particles. There was evidence that residual risk prediction during statin therapy could be significantly improved through the inclusion of key VLDL measures (Harrell C‐index 0.780 versus 0.712; P<0.0001). In an independent, prospective cohort of 4721 individuals referred for cardiac catheterization (CATHGEN), similar patterns of lipoprotein‐related risk were observed.

Conclusions

Atherogenic lipoprotein particle concentrations were associated with cardiovascular disease risk when LDL cholesterol was low. VLDL lipoproteins, particularly the smallest remnant subclass, may represent unused targets for risk prediction and potential therapeutic intervention for reducing residual risk.

Clinical Trial Registration

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00239681.

Influence on Adiposity and Atherogenic Lipaemia of Fatty Meals and Snacks in Daily Life

The present work reviewed the connections of changes in consumption of high-fat food with changes in adiposity and lipaemia in adults with overweight or obesity. Hyperlipaemia from higher fat meals and excessive adiposity contributes to atherogenic process. Low-fat diet interventions decrease body fat, lipaemia, and atherosclerosis markers. Inaccuracy of physical estimates of dietary fat intake remains, however, a limit to establishing causal connections. To fill this gap, tracking fat-rich eating episodes at short intervals quantifies the behavioural frequency suggested to measure (by regression of changes in real time) direct effects of this eating pattern on adiposity and atherogenic lipaemia. Such evidence will provide the basis for an approach focused on a sustained decrease in frequency of fatty meals or snacks to reduce obesity, hyperlipaemia, and atherosclerosis.

DC-SIGN and Toll-like receptor 4 mediate oxidized low-density lipoprotein-induced inflammatory responses in macrophages

The regulation of inflammatory responses by innate immune receptors is recognized as a crucial step in the development of atherosclerosis, although the precise molecular mechanisms remain to be elucidated. This study focused on illustrating the roles of dendritic cell-specific intercellular adhesion molecule-3-grabbing non-integrin (DC-SIGN)- and Toll-like receptor 4 (TLR4)-regulated inflammatory responses in macrophages. We found that DC-SIGN expression levels were increased in macrophages of atherosclerotic plaques. Oxidized low-density lipoprotein (oxLDL) significantly enhanced DC-SIGN protein expression levels after a short-term exposure. Knockdown of DC-SIGN decreased expression and secretion of interleukin 1-β (IL1-β), monocyte chemo-attractant protein 1 (MCP-1), tumor necrosis factor-α (TNFα) and matrix metalloproteinase-9 (MMP-9). Immunofluorescence studies demonstrated that DC-SIGN and TLR4 co-localized in regions of the plaques. Moreover, DC-SIGN was co-expressed with TLR4 on the plasma membrane after oxLDL stimulation. The presence of an endogenous interaction and the results of the in vitro pull-down assays revealed that DC-SIGN binds directly with TLR4. We also present evidence that DC-SIGN mediates TLR4-regulated NFκB activation but not activation of p38 and JNK. Our results suggest an essential role of DC-SIGN/TLR4 signaling in macrophages in the pathogenesis of atherosclerosis.

Discordant Lipid Pattern and Carotid Atherosclerotic Plaque. Importance of Remnant Cholesterol

BACKGROUND:

Subjects with levels of non-HDL-C 30 mg/dL above those of LDL-C (lipid discordance) or with high remnant cholesterol levels could have a greater residual cardiovascular risk.

OBJECTIVES:

To determine the prevalence of lipid discordance in a primary prevention population and analyze the clinical variables associated with it; To investigate the association between lipid discordance and remnant cholesterol with the presence of carotid plaque.

METHODS:

Primary prevention patients without diabetes or lipid-lowering therapy were included. Regardless of the LDL-C level, we define "lipid discordance" if the non-HDL-C value exceeded 30 mg/dL that of LDL-C. Remnant cholesterol was calculated as total cholesterol minus HDL-C minus LDL-C when triglycerides were < 4.0 mmol/L. Ultrasound was used to assess carotid plaque occurrence. Multiple regression logistic models were performed.

RESULTS:

The study included 772 patients (mean age 52 ± 11 years, 66% women). The prevalence of lipid discordance was 34%. Male sex and body mass index were independently associated with discordant lipid pattern. The prevalence of carotid plaque was higher in subjects with lipid discordance (40.2% vs. 29.2, p = 0.002). The multivariate analysis showed that the discordant lipid pattern was associated with the greater probability of carotid plaque (OR 1.58, 95% CI 1.08-2.34, p = 0.02). Similarly, a significant association between calculated remnant cholesterol and carotid plaque was found.

CONCLUSION:

Lipid discordance and presence of a higher level of calculated remnant cholesterol are associated with subclinical atherosclerosis. Our findings could be used to improve the residual cardiovascular risk evaluation.

FUNDAMENTO:

Indivíduos com níveis de não HDL-C excedendo em 30 mg/dl aqueles de LDL-C (discordância lipídica) ou com altos níveis de colesterol remanescente poderiam ter maior risco cardiovascular residual.

OBJETIVOS:

determinar a prevalência de discordância lipídica em uma população de prevenção primária e analisar as variáveis clínicas com ela associadas; investigar a associação de discordância lipídica e colesterol remanescente calculado com a presença de placa carotídea.

MÉTODOS:

Pacientes de prevenção primária sem diabetes ou sem terapia hipolipemiante foram incluídos. Independentemente do nível de LDL-C, definiu-se "discordância lipídica" como um valor de não HDL-C excedendo em 30 mg/dl aquele de LDL-C. Calculou-se o colesterol remanescente como colesterol total menos HDL-C menos LDL-C na presença de triglicerídeos < 4,0 mmol/l. Usou-se ultrassom para avaliar a presença de placa carotídea. Modelos de regressão logística múltipla foram construídos.

RESULTADOS:

Este estudo incluiu 772 pacientes (idade média, 52 ± 11 anos; 66% mulheres). A prevalência de discordância lipídica foi de 34%. Sexo masculino e índice de massa corporal mostraram associação independente com padrão lipídico discordante. A prevalência de placa carotídea foi maior em indivíduos com discordância lipídica (40,2% vs. 29,2; p = 0,002). A análise multivariada mostrou associação do padrão lipídico discordante com maior probabilidade de placa carotídea (OR: 1,58; IC95%: 1,08-2,34; p = 0,02). Da mesma forma, identificou-se uma significativa associação entre colesterol remanescente calculado e placa carotídea.

CONCLUSÃO:

Discordância lipídica e presença de nível mais alto de colesterol remanescente calculado acham-se associados com aterosclerose subclínica. Nossos achados podem ser usados para aprimorar a avaliação de risco cardiovascular residual.

Remnant Cholesterol Elicits Arterial Wall Inflammation and a Multilevel Cellular Immune Response in Humans

OBJECTIVE

Mendelian randomization studies revealed a causal role for remnant cholesterol in cardiovascular disease. Remnant particles accumulate in the arterial wall, potentially propagating local and systemic inflammation. We evaluated the impact of remnant cholesterol on arterial wall inflammation, circulating monocytes, and bone marrow in patients with familial dysbetalipoproteinemia (FD).

APPROACH AND RESULTS

Arterial wall inflammation and bone marrow activity were measured using ¹⁸F-FDG PET/CT. Monocyte phenotype was assessed with flow cytometry. The correlation between remnant levels and hematopoietic activity was validated in the CGPS (Copenhagen General Population Study). We found a 1.2-fold increase of ¹⁸F-FDG uptake in the arterial wall in patients with FD (n=17, age 60±8 years, remnant cholesterol: 3.26 [2.07-5.71]) compared with controls (n=17, age 61±8 years, remnant cholesterol 0.29 [0.27-0.40]; P<0.001). Monocytes from patients with FD showed increased lipid accumulation (lipid-positive monocytes: Patients with FD 92% [86-95], controls 76% [66-81], P=0.001, with an increase in lipid droplets per monocyte), and a higher expression of surface integrins (CD11b, CD11c, and CD18). Patients with FD also exhibited monocytosis and leukocytosis, accompanied by a 1.2-fold increase of ¹⁸F-FDG uptake in bone marrow. In addition, we found a strong correlation between remnant levels and leukocyte counts in the CGPS (n=103 953, P for trend 5×10-276). In vitro experiments substantiated that remnant cholesterol accumulates in human hematopoietic stem and progenitor cells coinciding with myeloid skewing.

CONCLUSIONS

Patients with FD have increased arterial wall and cellular inflammation. These findings imply an important inflammatory component to the atherogenicity of remnant cholesterol, contributing to the increased cardiovascular disease risk in patients with FD.

Association of very Low-density Lipoprotein Cholesterol with All-cause and Cardiovascular Mortality in Peritoneal Dialysis

BACKGROUND/AIMS

Cardiovascular disease (CVD) is the leading cause of death in dialysis patients. Little is known about the relationship between very low-density lipoprotein cholesterol (VLDL-C) and cardiovascular mortality in these patients.

METHODS

A total of 1324 incident patients who began continuous ambulatory peritoneal dialysis (CAPD) therapy at our hospital between January 1, 2005, and September 30, 2014, with baseline serum VLDL-C values were investigated. The associations of the VLDL-C levels with all-cause and cardiovascular mortality were assessed.

RESULTS

The mean age of the cohort was 50.2 ± 14.8 years, and the mean VLDL-C level was 33.6 ± 18.0 mg/dl. One hundred sixty-five (12.5%) patients died during the study period. Multivariable models revealed that the high VLDL-C group was associated with significantly higher all-cause (HR, 2.08, 95% CI, 1.13 to 3.29, P = 0.002) and cardiovascular mortality (HR, 1.92, 95% CI, 1.18 to 4.29, P = 0.013) compared with the low VLDL-C group even after adjusting for various covariates. Using the VLDL-C level as a continuous variable, the hazard ratios (HRs) of all-cause and cardiovascular mortality associated with a 10-mg/dl increase in VLDL-C level were 1.12 (95% CI, 1.02 to 1.26, P = 0.025) and 1.11 (95% CI, 1.02 to 1.22, P = 0.029), respectively. VLDL-C was associated more strongly to all-cause (e.g., Akaike information criteria of 1990.205 vs. 1994.451) and cardiovascular (e.g., Akaike information criteria of 984.146 vs. 985.634) mortality than triglyceride (TG) levels.

CONCLUSIONS

An elevated VLDL-C level is an independent risk factor for all-cause and cardiovascular mortality in peritoneal dialysis (PD) patients.