Rare variant in scavenger receptor BI raises HDL cholesterol and increases risk of coronary heart disease

Extremely high HDL cholesterol paradoxically increases the risk of all-cause mortality in non-diabetic males from the Korean population: Korean genome and epidemiology study-health examinees (KoGES-HEXA) cohorts

Background

High-density lipoprotein cholesterol (HDL-C) is associated with lower risk of mortality and cardiovascular disease. However, the relationship between extremely high HDL cholesterol level and all-cause mortality has not been thoroughly investigated. In this study, we examined the longitudinal effects of very high HDL cholesterol on all-cause mortality in a large cohort of Korean adults without type 2 diabetes mellitus.

Methods

Data from 173,195 Korean participants over 40 years of age enrolled in the Korean Genome and Epidemiology Study-Health Examinees (KoGES-HEXA) cohort, linked with the death certificate database of the National Statistical Office, were assessed. Participants were grouped into four according to HDL-C levels. We used multivariate Cox proportional-hazard regression models to prospectively assess hazard ratios (HRs) for all-cause mortality with 95% confidence intervals (CIs) over an 11-year baseline period.

Results

During a mean follow-up of 11.7 years, there were a total of 3,906 deaths from all causes, including 2,258 in men and 1,648 in women. The relationship between HDL-C and all-cause mortality showed a U-shaped pattern, especially in men. Compared to the reference group, the HR (95% CI) for mortality in males in the highest HDL cholesterol group was 1.31 (95% CI, 1.01-1.71) after adjusting for potential confounding variables. Moreover, low HDL cholesterol showed a statistically significant association with increased mortality in both men and women.

Conclusion

Extremely high HDL-C levels could paradoxically increase the risk of all-cause mortality, particularly among males, in the general population without type 2 diabetes mellitus. Non-protective effects of very high HDL-C level should be noted when predicting incident metabolic syndrome, particularly in men, in clinical settings.

Causal cardiovascular risk factors for dementia: insights from observational and genetic studies

The escalating prevalence of dementia worldwide necessitates preventive strategies to mitigate its extensive health, psychological, and social impacts. As the prevalence of dementia continues to rise, gaining insights into its risk factors and causes becomes paramount, given the absence of a definitive cure. Cardiovascular disease has emerged as a prominent player in the complex landscape of dementia. Preventing dyslipidaemia, unhealthy western-type diets, hypertension, diabetes, being overweight, physical inactivity, smoking, and high alcohol intake have the potential to diminish not only cardiovascular disease but also dementia. The purpose of this review is to present our current understanding of cardiovascular risk factors for Alzheimer's disease and vascular dementia (VaD) by using clinical human data from observational, genetic studies and clinical trials, while elaborating on potential mechanisms. Hypertension and Type 2 diabetes surface as significant causal risk factors for both Alzheimer's disease and VaD, as consistently illustrated in observational and Mendelian randomization studies. Anti-hypertensive drugs and physical activity have been shown to improve cognitive function in clinical trials. Important to note is that robust genome-wide association studies are lacking for VaD, and indeed more and prolonged clinical trials are needed to establish these findings and investigate other risk factors. Trials should strategically target individuals at the highest dementia risk, identified using risk charts incorporating genetic markers, biomarkers, and cardiovascular risk factors. Understanding causal risk factors for dementia will optimize preventive measures, and the implementation of well-known therapeutics can halt or alleviate dementia symptoms if started early. Needless to mention is that future health policies should prioritize primordial prevention from early childhood to prevent risk factors from even occurring in the first place. Together, understanding the role of cardiovascular risk factors in dementia, improving genome-wide association studies for VaD, and advancing clinical trials are crucial steps in addressing this significant public health challenge.

Radiolabeling lipoproteins to study and manage disease

PURPOSE

Lipoproteins are endogenous nanoparticles with essential roles in lipid transport and inflammation. Lipoproteins are also valuable in diagnosing and treating disease. For instance, certain lipoproteins are overexpressed in patients with atherosclerotic cardiovascular disease, and reconstituted lipoproteins have been extensively used for drug delivery. Radiolabeling has proven an especially powerful approach for studying and therapeutically exploiting lipoproteins. This review details how radiochemistry and nuclear imaging can facilitate the study of lipoproteins in health and disease. Among other topics, we discuss approaches for radiolabeling lipoproteins and detail how these have helped advance our understanding of lipoprotein biology and the diagnosis and treatment of diseases, including atherosclerosis, cancer, and hypercholesteremia.

METHODS

We performed an extensive literature search on all peer-reviewed studies involving radiolabeled lipoproteins and selected representative examples to provide a high-level overview of the most important discoveries and technological advancements.

RESULTS

More than 200 peer-reviewed papers involved radiolabeled lipoproteins, spanning mechanistic, diagnostic, and therapeutic studies across a wide range of diseases.

CONCLUSION

Radiolabeling has been critical in advancing our understanding of lipoprotein biology and leveraging these nanomaterials for diagnosing and treating disease.

Epigenetic associations with kidney disease in individuals of African ancestry with APOL1 high-risk genotypes and HIV

BACKGROUND

Apolipoprotein L1 (APOL1) high-risk variants are major determinants of chronic kidney disease (CKD) in people of African ancestry. Previous studies have identified epigenetic changes in relation to kidney function and CKD, but not in individuals with APOL1 high-risk genotypes. We conducted an epigenome-wide analysis of CKD and estimated glomerular filtration rate (eGFR) in in people of African ancestry and APOL1 high-risk genotypes with HIV.

METHODS

DNA methylation profiles from peripheral blood mononuclear cells of 119 individuals with APOL1 high-risk genotypes (mean age 48 years, 49% female, median CD4 count 515 cells/mm3, 90% HIV-1 RNA <200 copies/mL, 23% with CKD) were obtained by Illumina MethylationEPIC BeadChip. Differential methylation analysis of CKD considered technical and biological covariates. We also assessed associations with eGFR. Replication was pursued in three independent multi-ancestry cohorts with and without HIV.

RESULTS

DNA methylation levels at 14 regions were associated with CKD. The strongest signals were located in SCARB1, DNAJC5B and C4orf50. Seven of the 14 signals also associated with eGFR, and most showed evidence for a genetic basis. Four signals (in SCARB1, FRMD4A, CSRNP1 and RAB38) replicated in other cohorts, and 11 previously reported epigenetic signals for kidney function or CKD replicated in our cohort. We found no significant DNA methylation signals in, or near, the APOL1 promoter region.

CONCLUSIONS

We report several novel as well as previously reported epigenetic associations with CKD and eGFR in individuals with HIV having APOL1 high-risk genotypes. Further investigation of pathways linking DNA methylation to APOL1 nephropathies is warranted.

Associations between serum lipids and glaucoma: a cohort study of 400 229 UK Biobank participants

PURPOSE

To examine the associations of commonly-used serum lipid measures (high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), total cholesterol (TC) and triglycerides (TG)) with glaucoma.

METHODS

This prospective cohort study included 400 229 participants from the UK Biobank. Cox regression and restricted cubic spline models and polygenic risk scores were employed to investigate the associations between serum lipids and glaucoma.

RESULTS

Over a mean follow-up of 14.44 years, 6868 (1.72%) participants developed glaucoma. Multivariate Cox regression revealed that higher levels of HDL-C were associated with an increased risk of glaucoma (HR for 1-SD increase in HDL-C 1.05, 95% CI 1.02 to 1.08, p=0.001), while elevated levels of LDL-C (HR 0.96, 95% CI 0.94 to 0.99, p=0.005), TC (HR 0.97, 95% CI 0.94 to 1.00, p=0.037) and TG (HR 0.96, 95% CI 0.94 to 0.99, p=0.008) were all associated with reduced risk. The analysis examining the associations between polygenic risk score of serum lipids and glaucoma showed per 1-SD increment of HDL-C genetic risk was associated with a 5% greater hazard of glaucoma (HR 1.05, 95% CI 1.00 to 1.11, p=0.031). However, the polygenic risk score of LDL-C, TC, and TG did not show a significant association with glaucoma.

CONCLUSIONS

Elevated HDL-C is associated with an increased risk of glaucoma, while elevated LDL-C, TC, and TG levels are associated with a lower risk of glaucoma. This study enhances our understanding of the association between lipid profile and glaucoma and warrants further investigation of lipid-focused treatments in glaucoma management.

Transcytosis of LDL Across Arterial Endothelium: Mechanisms and Therapeutic Targets

Transport of LDL (low-density lipoprotein) from plasma to arterial intima is thought to be rate limiting in the development of atherosclerosis. Its variation likely determines where lesions develop within arteries and might account for some of the currently unexplained difference in disease susceptibility between individuals. It may also be critical in the development of lipid-rich, unstable plaques. Mechanisms have been controversial but recent evidence suggests that caveolar transcytosis across endothelial cells is the dominant pathway. Receptors involved are LDLR (LDL receptor), SR-B1 (scavenger receptor class B type 1), and ALK1 (activin receptor-like kinase 1). The role of LDLR is influenced by IL-1β (interleukin-1β); the role of SR-B1 by HDL (high-density lipoprotein), DOCK4 (dedicator of cytokinesis 4), GPER (G-protein-coupled estrogen receptor), and HMGB1 (high mobility group box 1); and the role of ALK1 by BMP (bone morphogenetic protein) 9. Additionally, BMP4 stimulates transcytosis and FSTL1 (follistatin-like 1 protein) inhibits it. Fundamental transcytotic mechanisms include caveola formation, undocking, trafficking, and docking; they are influenced by cholesterol-lowering agents, MYDGF (myeloid-derived growth factor), MFSD2a (major facilitator superfamily domain containing 2a) in the blood-brain barrier, and inhibitors of dynamin-2 and tubulin polymerization. The relative merits of different therapeutic approaches are discussed, with statins, colchicine, benzimidazoles, and metformin being existing drugs that might be repurposed and salidroside and glycyrrhizic acid being nutraceuticals worth investigating. Finally, we discuss evidence against the ferry-boat model of transcytosis, the contributions of receptor-mediated, fluid-phase, and active transcytosis, and where inhibition of transcytosis might be most beneficial.

Potential causal evidence for an ApoB-independent and HDL-related risk profile associated with coronary artery disease

Plasma 1H-NMR metabolomic measures have yielded significant insight into the pathophysiology of cardiometabolic disease, but their inter-related nature complicates causal inference and clinical interpretation. This study aimed to investigate the associations of unrelated 1H-NMR metabolomic profiles with coronary artery disease (CAD) and ischemic stroke (IS). Principal component (PC) analysis was performed on 168 1H-NMR metabolomic measures in 56,712 unrelated European participants from UK Biobank to retrieve uncorrelated PCs, which were used in Cox-proportional hazard models. For each outcome, two-sample Mendelian randomization analyses were then conducted based on three nonoverlapping databases, followed by a meta-analysis. The first six PCs collectively explaining 88% of the total variance were identified. For CAD, results from Cox and Mendelian randomization analyses were generally directionally consistent. The pooled odds ratios (95% CI) for CAD per one-SD increase in genetically influenced PC1 and PC3 (both characterized by distinct apolipoprotein B [ApoB]-associated lipoprotein profiles) were 1.04 (1.03, 1.05) and 0.94 (0.93, 0.96), respectively. Besides, the pooled odds ratio (95% CI) for CAD per one-SD increase in genetically influenced PC4, characterized by simultaneously decreased small HDL and increased large HDL, and independent of ApoB, was 1.05 (1.03, 1.07). For IS, increases of PC3 and PC5 (characterized by increased amino acids) were associated with a lower risk and a higher risk, respectively. This study confirms associations of ApoB-associated lipoprotein profiles with CAD and IS, and highlights the possible existence of an ApoB-independent lipoprotein profile, characterized by a distinctive HDL subparticle distribution, driving CAD.

Nonlinearity of the inverse relationship between high-density lipoprotein (HDL) cholesterol and incident cardiovascular risk: Is it time to revisit the "HDL hypothesis"?

BACKGROUND

Low levels of high-density lipoprotein cholesterol (HDL-C) are clearly associated with atherosclerotic cardiovascular disease (ASCVD), but the risk curve is not well defined, especially at very high and low HDL-C levels. Current proportional hazards prediction models assume inverse linearity of effect, which may not accurately represent risk at these levels.

SOURCES OF MATERIAL

Clinical inattention to risk associated with low HDL-C may derive from randomized controlled trials (RCTs) aimed at raising HDL-C, though most failed to reduce ASCVD events when combined with statin-based therapy. However, these prior trials enrolled patients with HDL-C levels largely in the 35-45 mg/dL range.

ABSTRACT OF FINDINGS

Mounting post hoc evidence from RCTs as well as new genetic and observational data suggest that very low HDL-C (less than 30 or 35 mg/dL) may signal a further increase in incident cardiovascular events. Moreover, when HDL-C exceeds 90 mg/dL, monotonic reduction of ASCVD risk appears to reverse. Because a pervasively agnostic view of the importance of both very low and high levels of HDL-C now exists, consideration should be given to incorporating nonlinear effects of HDL-C into future risk prediction models such that very low HDL-C and/or very high HDL-C levels could be considered as new risk-enhancing factors to promote more optimal risk stratification.

CONCLUSION

When revision of the U.S. Cholesterol Guideline recommences, consideration should be directed to whether HDL-associated risk matches the assumptions of current statistical models. Thus, it may be both timely and opportune to revisit the "HDL hypothesis" based on evolving scientific evidence.

A Comprehensive Review of the Genetics of Dyslipidemias and Risk of Atherosclerotic Cardiovascular Disease

Dyslipidemias are often diagnosed based on an individual's lipid panel that may or may not include Lp(a) or apoB. But these values alone omit key information that can underestimate risk and misdiagnose disease, which leads to imprecise medical therapies that reduce efficacy with unnecessary adverse events. For example, knowing whether an individual's dyslipidemia is monogenic can granularly inform risk and create opportunities for precision therapeutics. This review explores the canonical and non-canonical causes of dyslipidemias and how they impact atherosclerotic cardiovascular disease (ASCVD) risk. This review emphasizes the multitude of genetic causes that cause primary hypercholesterolemia, hypertriglyceridemia, and low or elevated high-density lipoprotein (HDL)-cholesterol levels. Within each of these sections, this review will explore the evidence linking these genetic conditions with ASCVD risk. Where applicable, this review will summarize approved therapies for a particular genetic condition.

Associations of neutrophil/high-density lipoprotein cholesterol ratio with frailty and its mortality

Background

Frailty is an increasingly important determinant in the field of health, and its identification has important clinical significance in the field of critical care medicine. However, there are still a large number of challenges in quick and accurate identification of frailty. This study aims to evaluate the value of the neutrophil/high-density lipoprotein cholesterol ratio (NHR) in frailty and its long-term survival.

Methods

Adult participants from seven study cycles of the National Health and Nutrition Examination Survey (NHANES) database were included. Frailty was assessed with a 49-item Frailty Index (FI). Weighted logistic regression, restricted cubic spline (RCS), and Cox regression were used to analyze the association of NHR with frailty and its long-term survival. In addition, subgroup and interaction analyses were also performed.

Results

A total of 34,382 adult participants aged 47.6 on average were included, and 16,950 (48.8%) of them were males. After the adjustment of potential confounding variables, an increase of one standard deviation (SD) in NHR resulted in the increase of the incidence of frailty by 11% (OR: 1.11, 95% CI: 1.04-1.18, P = 0.002). RCS showed a J-shaped association between NHR and frailty, which was robust in all subgroups according to the subgroup analysis. In addition, the survival analysis revealed that NHR was significantly positively associated with all-cause (HR: 1.12, 95% CI: 1.07-1.17, P < 0.0001), cardiocerebrovascular disease (CCD)-specific (HR: 1.21, 95% CI: 1.11-1.33, P < 0.0001), and cancer-specific mortality risks (HR: 1.13, 95% CI: 1.07-1.19, P < 0.0001) in frail individuals.

Conclusion

In the American adult population, NHR maintains a J-shaped relationship with frailty. In addition, NHR can help predict long-term mortality in frail individuals. This study demonstrates that NHR may become an effective predictor of frailty and its mortality.

The predictive role of the hs-CRP/HDL-C ratio for long-term mortality in the general population: evidence from a cohort study

BACKGROUND

The high-sensitivity C-reactive protein (hs-CRP) to high-density lipoprotein cholesterol (HDL-C) ratio, a composite marker of low-grade inflammation and lipid metabolism, is reportedly associated with the occurrence of new cardiovascular diseases (CVDs) in certain people. However, the predictive value of the hs-CRP/HDL-C ratio for long-term mortality in the general population remains unclear.

METHODS

This retrospective cohort study included data from 9,492 adults obtained from the National Health and Nutrition Examination Survey (NHANES) (2015-2018) in the United States. Multivariate Cox regression, two-piecewise linear regression, restricted cubic spline (RCS) models and subgroup analysis by age, sex, smoking status and drinking status were applied to evaluate the associations of the hs-CRP/HDL-C ratio with long-term all-cause and cardiovascular mortality.

RESULTS

The overall median age of the cohort was 47.0 years (interquartile range (IQR) 32.0-62.0), and 4,585 (48.30%) patients were male. During a median follow-up period of 37.0 months, 239 (2.52%) all-cause deaths occurred, 59 (0.62%) of which were attributed to cardiovascular events. Participants with all-cause and cardiovascular mortality presented a higher hs-CRP/HDL-C ratio than did those without events [0.56 (0.24-1.38) vs. 0.37 (0.14-0.94) and 0.60 (0.23-1.60) vs. 0.37 (0.14-0.95), P < 0.001 and P = 0.002]. According to multivariate Cox regression models, the hs-CRP/HDL-C ratio was found to be an independent risk factor for both long-term all-cause mortality [hazard ratio (HR) = 1.09, 95% confidence interval (CI): 1.05-1.13] and cardiovascular mortality (HR = 1.11, 95% CI: 1.05-1.19). A two-piecewise linear regression model indicated that the risk of all-cause mortality increased more prominently when the hs-CRP/HDL-C ratio was less than 1.21. In addition, a significant interaction effect with smoking status was discovered (P = 0.006), indicating that the association of the hs-CRP/HDL-C ratio with all-cause mortality was stronger in nonsmokers. The RCS curve revealed a positive linear association of the hs-CRP/HDL-C ratio with long-term mortality after adjustment for potential confounders.

CONCLUSIONS

The hs-CRP/HDL-C ratio is a crucial predictor of long-term mortality in the general population, independent of potential confounding factors.

The association of HDL-cholesterol levels with incident major adverse cardiovascular events and mortality in 0.6 million individuals with type 2 diabetes: a population-based retrospective cohort study

BACKGROUND

High levels of high-density lipoprotein cholesterol (HDL-C) are previously considered protective against cardiovascular diseases (CVD), but recent studies suggest an increased risk of adverse events at very high HDL-C levels in the general population. It remains to be elucidated such a relationship in diabetes, a condition with high cardiovascular risks. We examined the association of HDL-C levels with the risk of major adverse cardiovascular events (MACE) and mortality in type 2 diabetes.

METHODS

This retrospective cohort study identified individuals with type 2 diabetes who had HDL-C records (2008-2020) from the electronic health record database of the Hong Kong Hospital Authority. They were classified into three groups based on their first-recorded HDL-C levels following diabetes diagnosis: low (≤ 40 mg/dL), medium (> 40 and ≤ 80 mg/dL) and high HDL-C (> 80 mg/dL) groups. The primary outcome was incident MACE (composite of myocardial infarction, stroke, heart failure, and cardiovascular mortality). Cox regression model and restricted cubic spline analysis were employed to assess the relationship between HDL-C and adverse outcomes.

RESULTS

Among 596,943 individuals with type 2 diabetes included, 168,931 (28.30%), 412,863 (69.16%), and 15,149 (2.54%) were classified as low HDL-C, medium HDL-C, and high HDL-C groups, respectively. Over a median follow-up of 79.5 months, both low and high HDL-C groups had higher risk of incident MACE compared to the medium HDL-C group (HR 1.24, 95% CI 1.23-1.26, P < 0.001; HR 1.09, 95% CI 1.04-1.13, P < 0.001). The spline curves revealed a U-shaped association between HDL-C levels and incident MACE (non-linear p < 0.001). Similar U-shaped relationship was observed for all-cause and non-cardiovascular mortality.

CONCLUSIONS

Our study demonstrated a U-shaped association between HDL-C levels and incident MACEs and all-cause and non-cardiovascular mortality in individuals with type 2 diabetes, highlighting the need for mechanistic studies on the adverse outcomes seen at high HDL-C levels in type 2 diabetes.

The Role of Scavenger Receptor BI in Sepsis

Sepsis is a life-threatening condition resulting from a dysregulated host response to infection. Currently, there is no effective therapy for sepsis due to an incomplete understanding of its pathogenesis. Scavenger receptor BI (SR-BI) is a high-density lipoprotein (HDL) receptor that plays a key role in HDL metabolism by modulating the selective uptake of cholesteryl ester from HDL. Recent studies, including those from our laboratory, indicate that SR-BI protects against sepsis through multiple mechanisms: (1) preventing nitric oxide-induced cytotoxicity; (2) promoting hepatic lipopolysaccharide (LPS) clearance and regulating cholesterol metabolism in the liver; (3) inhibiting LPS-induced inflammatory signaling in macrophages; and (4) mediating the uptake of cholesterol from HDL for inducible glucocorticoid (iGC) synthesis in the adrenal gland, which controls systemic inflammatory response. In this article, we review the roles of SR-BI in sepsis.

Sticky Business: Correlating Oligomeric Features of Class B Scavenger Receptors to Lipid Transport

PURPOSE OF THE REVIEW

Atherosclerotic plaques result from imbalanced lipid metabolism and maladaptive chronic immune responses. Class B scavenger receptors are lipid transporters and regulators of their metabolism. The purpose of this review is to explore recent structural findings of these membrane-associated receptors, with particular focus on their higher-order oligomeric organization and impact on lipid transport.

RECENT FINDINGS

Class B scavenger receptors have evidence for oligomerization, with recent efforts placed on identifying residues and motifs responsible for mediating this process. The first studies correlating scavenger receptor oligomerization to function are described. This review highlights two emerging hypotheses regarding the function of scavenger receptor oligomerization. The first is a hydrophobic channel created by self-association of receptors to promote transport. The second hypothesis suggests that homo-oligomerization stabilizes receptors, prevents internalization and thereby promotes transport indirectly. Novel computational and in vitro experimental techniques with purified receptors are also described.

The two major splice variants of scavenger receptor BI differ by their interactions with lipoproteins and cellular localization in endothelial cells

The scavenger receptor BI (SR-BI) facilitates the transport of both HDL and LDL through endothelial cells. Its two splice variants, SR-BIvar1 and SR-BIvar2, differ in their carboxy terminal domains. Only SR-BIvar1 contains the putative binding sites for the adapter proteins PDZ domain containing protein 1 (PDZK1) and dedicator of cytokinesis 4 (DOCK4), which limit the cell surface abundance and internalization of the receptor. To investigate the cellular localization of the SR-BI variants and their interaction with lipoproteins in endothelial cells, EA.hy926 cells were stably transfected with vectors encoding untagged, GFP- or mCherry-tagged constructs of the two SR-BI variants. Additionally, the cells were transfected with shRNAs against PDZK1 or DOCK4. Microscopy investigation showed that SR-BIvar1 was predominantly localized on the cell surface together with clathrin whereas SR-BIvar2 was absent from the cell surface but retrieved in endosomes and lysosomes. Accordingly, only SR-BIvar1 increased lipoprotein binding to endothelial while HDL and LDL uptake were enhanced by both variants. Silencing of PDZK1 or DOCK4 only reduced HDL association in SR-BIvar2 overexpressing cells while LDL association was reduced both in WT and SR-BIvar2 overexpressing cells. In conclusion, either SR-BI variant facilitates the uptake of HDL and LDL into endothelial cells, however by different mechanisms and trafficking routes. This dual role may explain why the loss of DOCK4 or PDZK1 differently affects the uptake of HDL and LDL in different endothelial cells.

Revisiting high-density lipoprotein cholesterol in cardiovascular disease: Is too much of a good thing always a good thing?

Cardiovascular disease (CVD) continues to be a leading cause of global mortality and morbidity. Various established risk factors are linked to CVD, and modifying these risk factors is fundamental in CVD management. Clinical studies underscore the association between dyslipidemia and CVD, and therapeutic interventions that target low-density lipoprotein cholesterol elicit clear benefits. Despite the correlation between low high-density lipoprotein cholesterol (HDLC) and heightened CVD risk, HDL-raising therapies have yet to showcase significant clinical benefits. Furthermore, evidence from epidemiological and genetic studies reveals that not only low HDL-C levels, but also very high levels of HDL-C are linked to increased risk of CVD. In this review, we focus on HDL metabolism and delve into the relationship between HDL and CVD, exploring HDL functions and the observed alterations in its roles in disease. Altogether, the results discussed herein support the conventional wisdom that "too much of a good thing is not always a good thing". Thus, our recommendation is that a careful reconsideration of the impact of high HDL-C levels is warranted, and shall be revisited in future research.

The Molecular Bases of Anti-Oxidative and Anti-Inflammatory Properties of Paraoxonase 1

The anti-oxidative and anti-inflammatory properties of high-density lipoprotein (HDL) are thought to be mediated by paraoxonase 1 (PON1), a calcium-dependent hydrolytic enzyme carried on a subfraction of HDL that also carries other anti-oxidative and anti-inflammatory proteins. In humans and mice, low PON1 activity is associated with elevated oxidized lipids and homocysteine (Hcy)-thiolactone, as well as proteins that are modified by these metabolites, which can cause oxidative stress and inflammation. PON1-dependent metabolic changes can lead to atherothrombotic cardiovascular disease, Alzheimer's disease, and cancer. The molecular bases underlying these associations are not fully understood. Biochemical, proteomic, and metabolic studies have significantly expanded our understanding of the mechanisms by which low PON1 leads to disease and high PON1 is protective. The studies discussed in this review highlight the changes in gene expression affecting proteostasis as a cause of the pro-oxidative and pro-inflammatory phenotypes associated with attenuated PON1 activity. Accumulating evidence supports the conclusion that PON1 regulates the expression of anti-oxidative and anti-inflammatory proteins, and that the disruption of these processes leads to disease.

Dysfunctional High-Density Lipoprotein Cholesterol and Coronary Artery Disease: A Narrative Review

High-density lipoprotein (HDL) cholesterol is traditionally viewed as protective against cardiovascular disease (CVD). However, emerging evidence reveals that dysfunctional HDL, characterized by impaired reverse cholesterol transport (RCT), reduced anti-inflammatory and antioxidant activities and increased endothelial dysfunction, which can contribute to coronary artery disease (CAD). Dysfunctional HDL, resulting from oxidative modifications of Apolipoprotein A-1 (Apo A-1) and enzyme inactivation, fails to effectively remove cholesterol from peripheral tissues and may promote inflammation and atherosclerosis. Genetic mutations affecting HDL metabolism further complicate its role in cardiovascular health. Studies have shown that conventional therapies aimed at raising HDL-C levels do not necessarily reduce cardiovascular events, highlighting the need for new approaches that improve HDL functionality. Therapeutic strategies such as Apo A-1 mimetic peptides, reconstituted HDL infusions, and drugs targeting specific HDL metabolic pathways are being explored. Additionally, weight loss, statin therapy, and niacin have shown potential in enhancing HDL function. The pathophysiology of dysfunctional HDL involves complex mechanisms, including oxidative stress, inflammation, and genetic mutations, which alter its structure and function, diminishing its cardioprotective effects. New functional assays, such as the cholesterol efflux capacity (CEC) and HDL inflammatory index, provide more accurate predictions of cardiovascular risk by assessing HDL quality rather than quantity. As research progresses, the focus is shifting towards therapeutic strategies that enhance HDL function and address the root causes of its dysfunction, offering a more effective approach to reducing cardiovascular risk and preventing CAD.

Genetic support of causal association between lipid and glucose metabolism and stress urinary incontinence in women: a bidirectional Mendelian randomization and multivariable-adjusted study

Background

Stress urinary incontinence (SUI) is a common condition characterized by urethral sphincter failure and urine leakage. Its prevalence in women is higher than in men, and estimates of crude prevalence rates vary widely due to factors such as research methodologies, study populations, and underreporting by patients. This variability hinders research and impacts patient diagnosis, treatment, and quality of life. The complex etiology of SUI is not fully understood, and previous studies have primarily focused on non-invasive indicators. While emerging observational research suggests a correlation between SUI in women and abnormalities in lipid and blood metabolism, the underlying biological mechanisms and causal relationships require further investigation. This study aims to explore the causalities between SUI in women and lipid and blood metabolism.

Methods

Using bidirectional univariate Mendelian randomization (MR), we investigated the causal association between SUI liability in women (case/control = 5,924/399,509) from UK Biobank and lipid and glucose metabolism, indicated by total cholesterol (TC, N = 61,166), low-density lipoproteins (LDL, N = 58,381), high-density lipoproteins (HDL, N = 60,812), triglycerides (TG, N = 60,027), fasting glucose (FG, N = 19,745), and fasting insulin (FI, N = 38,238) from ENGAGE consortium. To account for potential confounding effects, multivariable MR (MVMR) analyses were performed, adjusting for body mass index (BMI) and separately among lipid and glucose metabolism.

Results

We found that increased genetically proxied TC, LDL, and HDL levels were associated with an elevated risk of SUI in women (OR: 1.090-1.117, all P < 0.05), These associations were further supported by MVMR analyses with adjustment for BMI (OR: 1.087-1.114, all P < 0.05). Conversely, increased FG and FI were associated with reduced SUI reliability in women (OR: 0.731-0.815, all P < 0.05). When adjusting among lipid and glucose metabolism, only HDL and FI demonstrated causal effects. Reverse MR analyses provided no genetic evidence supporting the causal effect of SUI in women on lipid and blood metabolism (all P > 0.05).

Conclusions

Our results reported that increased TC, LDL, and HDL are linked to higher SUI susceptibility in women, while higher FG and FI levels have a protective effect. In overweight/obese women with metabolic abnormalities, the positive associations between TC, LDL, and HDL levels and SUI indicate a higher risk.

High-Density Lipoprotein-Associated Paraoxonase-1 (PON-1) and Scavenger Receptor Class B Type 1 (SRB-1) in Coronary Artery Disease: Correlation with Disease Severity

Background: Coronary artery disease (CAD) is the leading cause of death worldwide. High-Density lipoprotein (HDL) is a well-established marker associated with CAD. The current research goes beyond the conventional HDL-C measurement in previous studies and dives into the functional intricacies of HDL. By understanding how HDL works, rather than just how much of it exists, we can better tailor diagnostic and therapeutic strategies for CAD and related conditions. Hence, the current study quantifies the serum levels of two novel HDL-associated markers, Paraoxonase-1 (PON-1) and Scavenger Receptor Class B Type 1 (SRB-1), in CAD cases vs. controls. Methods: A total of 92 subjects, including 69 CAD and 23 healthy controls, were included, based on the prevalence of the disease. Further, based on the severity of the disease, CAD cases were subcategorized as CAD-I, -II, and -III. Serum PON-1 and SRB-1 levels were measured and compared between patient and control groups. Results: The levels of PON-1 and SRB-1 (32.6 ng/mL and 12.49 ng/mL) were significantly lower in CAD patients vs. the healthy control, at 60.36 ng/mL and 15.85 ng/mL, respectively (p < 0.000). A further intergroup comparison showed a statistically significant difference between the CAT-I and -III for PON-1 (p < 0.025), the CAT-I and -III, and CAT-II and -III for SRB-1 (p < 0.000). The receiver operating characteristics (ROC) curve showed cutoff values of 48.20 ng/mL and 14.90 ng/mL for PON-1 and SRB-1. Conclusions: The current study found that serum levels of HDL-associated PON-1 and SRB-1 are significantly lower in CAD cases, and were also inversely related to the increasing severity of coronary artery disease. This inference implies that serum PON-1 and SRB-1 could be used as non-invasive tools for the identification of coronary atherosclerosis and risk assessment in CAD cases.

Association between very high HDL-C levels and mortality: A systematic review and meta-analysis

BACKGROUND

Recent research has raised questions about the assumed cardiovascular (CV) benefits of high-density lipoprotein cholesterol (HDL-C) and the potential for adverse outcomes with extremely high levels.

OBJECTIVE

We conducted a meta-analysis to investigate the association between very high HDL-C levels (≥80 mg/dL) and mortality outcomes in individuals without coronary artery disease (CAD).

METHODS

We systematically searched PubMed, Embase, and Cochrane databases for studies comparing very high HDL-C levels to normal levels (40-60 mg/dL) in CAD-free individuals. We assessed heterogeneity using I2 statistics with a random-effects model.

RESULTS

Our analysis included 1,004,584 individuals from 8 studies, of whom 133,646 (13.3%) had very high HDL-C levels. All-cause mortality did not significantly differ between groups (p = 0.55), nor did cancer mortality (p = 0.45). Cardiovascular mortality showed no change in those with very high HDL-C (hazard ratio [HR] 1.05; 95% confidence interval [CI] 0.94-1.17; p = 0.37). Fatal and non-fatal coronary heart disease events were less frequent in the very high HDL-C group (HR 0.79; 95% CI 0.73-0.86; p < 0.00001). Subgroup dose-response analysis revealed that very high HDL-C levels increased cardiovascular death in women above 116 mg/dL (HR 1.47; 95% CI 1.01-2.15) and in men above 94 mg/dL (HR 1.29; 95% CI 1.01-1.65) (p_nonlinearity <0.01).

CONCLUSIONS

These findings suggest that very high HDL-C levels are not protective against CV mortality and may, in fact, increase CV mortality risk especially in men.

HDL-C criterion of the metabolic syndrome and future diabetes and atherosclerosis in midlife women: The SWAN Study

Objective

High-density lipoprotein cholesterol (HDL-C) is one of 5 components [high blood pressure, glucose, triglycerides, waist circumference, low HDL-C], 3 of which, needed to diagnose metabolic syndrome (MetS). Evolving research shows that higher HDL-C is not necessarily cardioprotective in midlife women, supporting a need to re-evaluate HDL-C's contribution to risks related to MetS. We tested whether risk of future diabetes and higher carotid intima-media thickness (cIMT) differ by HDL-C status in midlife women diagnosed with MetS based on the other 4 components.

Methods Midlife women were classified into 3 groups

1) no MetS, 2) MetS with HDL-C ≥ 50 mg/dL (MetS hiHDL), and 3) MetS with HDL-C < 50 mg/dL (MetS loHDL). cIMT was measured 13.8 ± 0.6 years post baseline. Incident diabetes was assessed yearly.

Results

Among 2773 women (1350 (48 %) of them had cIMT), 2383 (86 %) had no MetS, 117 (4 %) had MetS hiHDL, 273 (10 %) had MetS loHDL. Compared with no MetS, both MetS- hiHDL and loHDL groups had higher cIMT and diabetes risk. Risk of having high cIMT did not differ between MetS loHDL vs. hiHDL groups. Adjusting for levels of MetS criteria other than HDL-C at baseline explained the associations of each of the two MetS groups with cIMT. Conversely, after adjustment, associations of MetS hiHDL and MetS loHDL with incident diabetes persisted.

Conclusions

In midlife women, HDL-C status matters for predicting risk of incident diabetes but not higher cIMT beyond other MetS components.

Novel Mouse Model of Myocardial Infarction, Plaque Rupture, and Stroke Shows Improved Survival With Myeloperoxidase Inhibition

BACKGROUND

Thromboembolic events, including myocardial infarction (MI) or stroke, caused by the rupture or erosion of unstable atherosclerotic plaques are the leading cause of death worldwide. Although most mouse models of atherosclerosis develop lesions in the aorta and carotid arteries, they do not develop advanced coronary artery lesions. Moreover, they do not undergo spontaneous plaque rupture with MI and stroke or do so at such a low frequency that they are not viable experimental models to study late-stage thrombotic events or to identify novel therapeutic approaches for treating atherosclerotic disease. This has stymied the development of more effective therapeutic approaches for reducing these events beyond what has been achieved with aggressive lipid lowering. Here, we describe a diet-inducible mouse model that develops widespread advanced atherosclerosis in coronary, brachiocephalic, and carotid arteries with plaque rupture, MI, and stroke.

METHODS

We characterized a novel mouse model with a C-terminal mutation in the scavenger receptor class B, type 1 (SR-BI), combined with Ldlr knockout (designated SR-BI∆CT/∆CT/Ldlr-/-). Mice were fed Western diet (WD) for 26 weeks and analyzed for MI and stroke. Coronary, brachiocephalic, and carotid arteries were analyzed for atherosclerotic lesions and indices of plaque stability. To validate the utility of this model, SR-BI∆CT/∆CT/Ldlr-/- mice were treated with the drug candidate AZM198, which inhibits myeloperoxidase, an enzyme produced by activated neutrophils that predicts rupture of human atherosclerotic lesions.

RESULTS

SR-BI∆CT/∆CT/Ldlr-/- mice show high (>80%) mortality rates after 26 weeks of WD feeding because of major adverse cardiovascular events, including spontaneous plaque rupture with MI and stroke. Moreover, WD-fed SR-BI∆CT/∆CT/Ldlr-/- mice displayed elevated circulating high-sensitivity cardiac troponin I and increased neutrophil extracellular trap formation within lesions compared with control mice. Treatment of WD-fed SR-BI∆CT/∆CT/Ldlr-/- mice with AZM198 showed remarkable benefits, including >90% improvement in survival and >60% decrease in the incidence of plaque rupture, MI, and stroke, in conjunction with decreased circulating high-sensitivity cardiac troponin I and reduced neutrophil extracellular trap formation within lesions.

CONCLUSIONS

WD-fed SR-BI∆CT/∆CT/Ldlr-/- mice more closely replicate late-stage clinical events of advanced human atherosclerotic disease than previous models and can be used to identify and test potential new therapeutic agents to prevent major adverse cardiac events.

Protective effects of Nogo-B deficiency in NAFLD mice and its multiomics analysis of gut microbiology and metabolism

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is a prevalent chronic liver ailment that can lead to serious conditions such as cirrhosis and hepatocellular carcinoma. Hepatic Nogo-B regulates glucose and lipid metabolism, and its inhibition has been shown to be protective against metabolic syndrome. Increasing evidence suggests that imbalances in the gut microbiota (GM) and lipid metabolism disorders are significant contributors to NAFLD progression. Nevertheless, it is not yet known whether Nogo-B can affect NAFLD by influencing the gut microbiota and metabolites. Hence, the aim of the present study was to characterize this process and explore its possible underlying mechanisms.

METHODS

A NAFLD model was constructed by administering a high-fat diet (HFD) to Nogo-B-/- and WT mice from the same litter, and body weight was measured weekly in each group. The glucose tolerance test (GTT) and insulin tolerance test (ITT) were performed to assess blood glucose levels. At the end of the 12-week period, samples of serum, liver, and intestinal contents were collected and used for serum biochemical marker and inflammatory factor detection; pathology evaluation; and gut microbiome and metabolomics analysis. Spearman's correlation analysis was performed to determine possible correlations between differential gut microbiota and differential serum metabolites between groups.

RESULTS

Nogo-B deficiency attenuated the effects of the HFD, including weight gain, liver weight gain, impaired glucose tolerance, hepatic steatosis, elevated serum lipid biochemicals levels, and liver function. Nogo-B deficiency suppressed M1 polarization and promoted M2 polarization, thus inhibiting inflammatory responses. Furthermore, Nogo-B-/--HFD-fed mice presented increased gut microbiota richness and diversity, decreased Firmicutes/Bacteroidota (F/B) ratios, and altered serum metabolites compared with those of WT-HFD-fed mice. During analysis, several differential gut microbiota, including Lachnoclostridium, Harryflintia, Odoribacter, UCG-009, and unclassified_f_Butyricoccaceae, were screened between groups. These microbiota were found to be positively correlated with upregulated purine metabolism and bile acid metabolites in Nogo-B deficiency, while they were negatively correlated with downregulated corticosterone and tricarboxylic acid cyclic metabolites in Nogo-B deficiency.

CONCLUSION

Nogo-B deficiency delayed NAFLD progression, as demonstrated by reduced hepatocellular lipid accumulation, attenuated inflammation and liver injury, and ameliorated gut microbiota dysbiosis and metabolic disorders. Importantly, Odoribacter was strongly positively correlated with ALB and taurodeoxycholic acid, suggesting that it played a considerable role in the influence of Nogo-B on the progression of NAFLD, a specific feature of NAFLD in Nogo-B-/- mice. The regulation of bile acid metabolism by the gut microbiota may be a potential target for Nogo-B deficiency to ameliorate NAFLD.

Very high high-density lipoprotein cholesterol may be associated with higher risk of cognitive impairment in older adults

BACKGROUND

Previous studies have shown that high-density lipoprotein cholesterol (HDL-C) levels are positively associated with cognitive function across a range of concentrations. However, recent studies have suggested that very high HDL-C levels may lead to poorer outcomes. Therefore, we aimed to investigate the relationship between different concentrations of HDL-C and cognitive impairment risk.

METHODS

We collected data from 3632 participants aged over 60 years from the U.S. National Health and Nutrition Examination Survey (NHANES) between 2011 and 2014 to assess the relationship between HDL-C and cognitive function. Cognitive function was evaluated with the Consortium to Establish a Registry for Alzheimer's Disease (CERAD) test, the animal fluency test (AFT), and the digit symbol substitution test (DSST). We used restricted cubic spline models and logistic regression to examine the association between HDL-C and cognitive function.

RESULTS

A U-shaped was observed between HDL-C and cognitive outcomes, individuals with higher risk in those with both low and very high HDL-C levels compared with those with midrange values. Very high HDL-C levels (≥ 2.50 mmol/L) were associated with increased risk of cognitive impairment (OR = 2.19; 95% CI, 1.12-4.28) compared with those with HDL-C levels in the range of 1.50 to 1.99 mmol/L in older adults after adjustment for confounding factors. Interaction test demonstrated that relationship between very high HDL-C and the risk of cognitive impairment was not changed in different sex and race group (P for interaction > 0.05).

CONCLUSIONS

Very high HDL-C levels were associated with an increased risk of cognitive impairment. HDL-C may not be a protective factor for maintaining brain health in older adults at very high levels.

A Glimpse into Humoral Response and Related Therapeutic Approaches of Takayasu's Arteritis

Takayasu's arteritis (TAK) manifests as an insidiously progressive and debilitating form of granulomatous inflammation including the aorta and its major branches. The precise etiology of TAK remains elusive, with current understanding suggesting an autoimmune origin primarily driven by T cells. Notably, a growing body of evidence bears testimony to the widespread effects of B cells on disease pathogenesis and progression. Distinct alterations in peripheral B cell subsets have been described in individuals with TAK. Advancements in technology have facilitated the identification of novel autoantibodies in TAK. Moreover, emerging data suggest that dysregulated signaling cascades downstream of B cell receptor families, including interactions with innate pattern recognition receptors such as toll-like receptors, as well as co-stimulatory molecules like CD40, CD80 and CD86, may result in the selection and proliferation of autoreactive B cell clones in TAK. Additionally, ectopic lymphoid neogenesis within the aortic wall of TAK patients exhibits functional characteristics. In recent decades, therapeutic interventions targeting B cells, notably utilizing the anti-CD20 monoclonal antibody rituximab, have demonstrated efficacy in TAK. Despite the importance of the humoral immune response, a systematic understanding of how autoreactive B cells contribute to the pathogenic process is still lacking. This review provides a comprehensive overview of the biological significance of B cell-mediated autoimmunity in TAK pathogenesis, as well as insights into therapeutic strategies targeting the humoral response. Furthermore, it examines the roles of T-helper and T follicular helper cells in humoral immunity and their potential contributions to disease mechanisms. We believe that further identification of the pathogenic role of autoimmune B cells and the underlying regulation system will lead to deeper personalized management of TAK patients. We believe that further elucidation of the pathogenic role of autoimmune B cells and the underlying regulatory mechanisms holds promise for the development of personalized approaches to managing TAK patients.

Correlations Between the Neutrophil-Lymphocyte Ratio, Platelet-Lymphocyte Ratio, and Serum Lipid Fractions With Neovascular Age-Related Macular Degeneration

Introduction Age-related macular degeneration, a chronic and progressive disease, is one of the leading causes of vision loss globally among the elderly population. Multiple hypotheses have been proposed regarding its pathogenesis, including the presence of lipid metabolism alteration. Dysfunctional lipid handling within retinal pigment epithelial cells has been implicated in the accumulation of lipofuscin and subsequent induction of oxidative stress and inflammation, all contributing to retinal degeneration. The present study aims to comparatively analyze the serum lipid fraction distributions in patients with neovascular age-related macular degeneration (AMD) and controls. Materials and methods A retrospective study was carried out between January 2021 and December 2023 on 91 naïve patients with neovascular AMD and 90 controls admitted for routine cataract surgery. All subjects underwent a comprehensive ophthalmological exam, including ophthalmoscopy and optical coherence tomography (OCT) with central macular thickness (CMT) measurement. A complete blood count with differential and lipid fractions values was analyzed. The neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and triglycerides (TG) were comparatively analyzed between the control group and the test group. Results The groups were comparable in terms of age (73.84 ±7.52 years for the neovascular AMD group vs 72.1±10.92 years in controls; p=0.8) and gender distribution (p=0.243). The mean NLR and PLR values were slightly higher in the AMD group but not statistically significant (p=0.51, p>0.99, respectively). Comparative analysis of lipid profile fractions showed significantly higher HDL-C values in the exudative AMD group compared to normal subjects (61.27±19.4 mg/dL vs 50.99±7.86 mg/dL, p=0.006). Also, the proportion of subjects with HDL-C>60 mg/dL was higher in the exudative AMD group (p=0.014). There were no significant differences in total cholesterol (189.77±53.39 mg/dL vs 190.43±37.84 mg/dL, p=0.681), LDL-C, and TG. Logistic regression analysis showed that serum HDL-C and HDL-C values >60 mg/dL are significantly associated factors with neovascular AMD. However, there is no statistical correlation between the values of these biochemical parameters and visual acuity or CMT in the neovascular AMD patient group. Conclusions There were no correlations between NLR and PLR with neovascular AMD in the study group. Higher HDL-C values exceeding 60 mg/dL were associated with neovascular age-related macular degeneration and could represent a possible therapeutic target in neovascular AMD.

Overexpression of CuZn superoxide dismutase improves high-density lipoprotein function in swine

Cardiovascular disease (CVD) has been the leading cause of death worldwide. As a chronic inflammatory disease, atherosclerosis (AS) acts as the initiating factor for CVD and reactive oxygen species (ROS) play a vital role in its development. Superoxide dismutases (SOD) can alleviate the detrimental effects of ROS and serve as the first line of defense through detoxifying the products derived from oxidative stress in vivo. Considering the potential preventive effects of high-density lipoprotein (HDL) on AS and the close relationship between CuZn superoxide dismutase (CuZnSOD) and HDL, the present work investigated whether CuZnSOD overexpression in swine could improve the function of HDL. Seven CuZnSOD transgenic swine, constructed by sperm and magnetic nanoparticles, demonstrated overexpressed CuZnSOD in the liver (P < 0.01) but comparable level to control in plasma (P > 0.05). CuZnSOD overexpression significantly down-regulated the levels of triglyceride (TG), apolipoprotein A-I (apoA-I) (P < 0.05), and high-density lipoprotein cholesterol (HDL-C) (P < 0.01) in plasma. In the presence of CuZnSOD overexpression, HDL3 significantly inhibited levels of IL-6 and TNF-α induced by oxidized low-density lipoprotein (oxLDL) (P < 0.05), indicating enhanced anti-inflammatory activity of HDL. At the same time, HDL-mediated cholesterol efflux did not decrease (P > 0.05). CuZnSOD overexpression improves the anti-inflammatory function of HDL despite decreased levels of HDL-C. In Conclusion, CuZnSOD overexpression improves HDL function in swine.

A V-shaped association between high-density lipoprotein cholesterol levels and poor outcomes in patients after percutaneous coronary intervention

BACKGROUND

High density lipoprotein cholesterol (HDL-C) is considered as "good cholesterol". Recent evidence suggests that a high HDL-C level may increase the risk of poor outcomes in some populations.

PURPOSE

To investigate the association between HDL-C levels and poor outcomes in patients after percutaneous coronary intervention (PCI).

METHODS

Patients undergoing PCI during January 2012 and December 2018 were consecutively recruited and divided into three groups with different HDL-C levels: HDL-C ≤ 25 mg/dL, 25 < HDL-C ≤ 60 mg/dL, HDL-C > 60 mg/dL by the restricted cubic spline (RCS) analysis and assessed for all-cause mortality (ACM). The association between HDL-C levels and poor outcomes was assessed by multivariable cox regression analysis.

RESULTS

The patients were followed with a median duration of 4 years. Of the 7284 participants, 727 all-cause deaths and 334 cardiovascular deaths occurred. A V-shaped association of HDL-C with the prognosis was observed, patients with either excessively low or high HDL-C levels reporting a higher risk than those with midrange values. After adjustment for confounding factors, the former exhibited a higher cumulative rate of ACM and cardiovascular mortality (CM) than the latter [low HDL-C: for ACM, hazard ratio (HR), 1.96; 95%CI, 1.41, 2.73, P < 0.001; for CM, HR, 1.66; 95%CI, 1.03, 2.67; P = 0.037; high HDL-C: for ACM, HR, 1.73; 95%CI, 1.29, 2.32, P < 0.001; for CM, HR, 1.73; 95%CI, 1.16, 2.58; P = 0.007].

CONCLUSION

HDL-C levels display a V-shaped association with poor outcomes in patients after PCI, with excessively high or low HDL-C suggesting a higher mortality risk. An optimal HDL-C level may fall in the range of 25-60 mg/dL.

The effects of glycosylation modifications on monocyte recruitment and foam cell formation in atherosclerosis

The monocyte recruitment and foam cell formation have been intensively investigated in atherosclerosis. Nevertheless, as the study progressed, it was obvious that crucial molecules participated in the monocyte recruitment and the membrane proteins in macrophages exhibited substantial glycosylation modifications. These modifications can exert a significant influence on protein functions and may even impact the overall progression of diseases. This article provides a review of the effects of glycosylation modifications on monocyte recruitment and foam cell formation. By elaborating on these effects, we aim to understand the underlying mechanisms of atherogenesis further and to provide new insights into the future treatment of atherosclerosis.

Association between HDL-C and intensive blood pressure control in patients with hypertension: A post-hoc analysis of SPRINT

Previous studies in patients with hypertension have demonstrated that there is a U-shaped association between HDL-C (high-density lipoprotein cholesterol) and the risk of cardiovascular events in male patients with hypertension. However, to the best of our knowledge, the relationship between HDL-C and intensive blood pressure control in specific cardiovascular events has never been investigated. To fill this knowledge gap, the authors analyzed the relationship between HDL-C levels and cardiovascular events in hypertensive patients within the Systolic Blood Pressure Intervention Trial (SPRINT). The SPRINT evaluated the impact of intensive blood pressure control (systolic blood pressure < 120 mm Hg) versus standard blood pressure control (systolic blood pressure < 140 mm Hg). The Cox proportional risk regression was used to investigate the association between different HDL-C status and clinical outcomes. Additional stratified analyzes were performed to evaluate the robustness of sex difference. A total of 9323 participants (6016 [64.53%] males and 3307 [35.47%] females) with hypertension from the SPRINT research were included in the analysis. The median follow-up period was 3.26 years. Our population was divided into five groups based on the HDL-C plasma levels: HDL-C < 30 mg/dL, HDL-C between 30 and 40 mg/dL, HDL-C between 40 and 60 mg/dL, HDL-C between 60 and 80 mg/dL and HDL-C > 80 mg/dL. Sensitivity analyzes showed that in the SPRINT, women in the HDL-C high population had a higher risk of mortality from all causes than men. In this cohort study, results suggest that patients with HDL-C levels higher than 80 mg/dL had lower risk of SPRINT primary outcome, cardiovascular death, and stroke, but this study tested association, not causation. HDL-C levels were associated with composite cardiovascular outcomes in male but not female patients. Our results demonstrated that in patients with hypertension, the association between HDL-C and risk of cardiovascular events is L-shaped.

Effects of niacin and omega-3 fatty acids on HDL-apolipoprotein A-I exchange in subjects with metabolic syndrome

HDL-apolipoprotein A-I exchange (HAE) measures a functional property associated with HDL's ability to mediate reverse cholesterol transport. HAE has been used to examine HDL function in case-control studies but not in studies of therapeutics that alter HDL particle composition. This study investigates whether niacin and omega-3 fatty acids induce measurable changes in HAE using a cohort of fifty-six subjects with metabolic syndrome (MetS) who were previously recruited to a double-blind trial where they were randomized to 16 weeks of treatment with dual placebo, extended-release niacin (ERN, 2g/day), prescription omega-3 ethyl esters (P-OM3, 4g/day), or the combination. HAE was assessed at the beginning and end of the study. Compared to placebo, ERN and P-OM3 alone significantly increased HAE by 15.1% [8.2, 22.0] (P<0.0001) and 11.1% [4.5, 17.7] (P<0.0005), respectively, while in combination they increased HAE by 10.0% [2.5, 15.8] (P = 0.005). When HAE was evaluated per unit mass of apoA-I ERN increased apoA-I specific exchange activity by 20% (2, 41 CI, P = 0.02) and P-OM3 by 28% (9.6, 48 CI, P<0.0006). However the combination had no statistically significant effect, 10% (-9, 31 CI, P = 0.39). With regard to P-OM3 therapy in particular, the HAE assay detected an increase in this property in the absence of a concomitant rise in HDL-C and apoA-I levels, suggesting that the assay can detect functional changes in HDL that occur in the absence of traditional biomarkers.

Rare and common coding variants in lipid metabolism-related genes and their association with coronary artery disease

BACKGROUND

Coronary artery disease (CAD) is a complex disease that is influenced by environmental and genetic factors. In this study, we aimed to investigate the relationship between coding variants in lipid metabolism-related genes and CAD in a Chinese Han population.

METHODS

A total of 252 individuals were recruited for this study, including 120 CAD patients and 132 healthy control individuals. Rare and common coding variants in 12 lipid metabolism-related genes (ANGPTL3, ANGPTL4, APOA1, APOA5, APOC1, APOC3, CETP, LDLR, LIPC, LPL, PCSK9 and SCARB1) were detected via next-generation sequencing (NGS)-based targeted sequencing. Associations between common variants and CAD were evaluated by Fisher's exact test. A gene-based association test of rare variants was performed by the sequence kernel association test-optimal (SKAT-O test).

RESULTS

We found 51 rare variants and 17 common variants in this study. One common missense variant, LIPC rs6083, was significantly associated with CAD after Bonferroni correction (OR = 0.47, 95% CI = 0.29-0.76, p = 1.9 × 10- 3). Thirty-three nonsynonymous rare variants were identified, including two novel variants located in the ANGPTL4 (p.Gly47Glu) and SCARB1 (p.Leu233Phe) genes. We did not find a significant association between rare variants and CAD via gene-based analysis via the SKAT-O test.

CONCLUSIONS

Targeted sequencing is a powerful tool for identifying rare and common variants in CAD. The common missense variant LIPC rs6083 confers protection against CAD. The clinical relevance of rare variants in CAD aetiology needs to be investigated in larger sample sizes in the future.

Resolvin T4 enhances macrophage cholesterol efflux to reduce vascular disease

While cardiovascular disease (CVD) is one of the major co-morbidities in patients with rheumatoid arthritis (RA), the mechanism(s) that contribute to CVD in patients with RA remain to be fully elucidated. Herein, we observe that plasma concentrations of 13-series resolvin (RvT)4 negatively correlate with vascular lipid load in mouse inflammatory arthritis. Administration of RvT4 to male arthritic mice fed an atherogenic diet significantly reduces atherosclerosis. Assessment of the mechanisms elicited by this mediator demonstrates that RvT4 activates cholesterol efflux in lipid laden macrophages via a Scavenger Receptor class B type 1 (SR-BI)-Neutral Cholesterol Ester Hydrolase-dependent pathway. This leads to the reprogramming of lipid laden macrophages yielding tissue protection. Pharmacological inhibition or knockdown of macrophage SR-BI reverses the vasculo-protective activities of RvT4 in vitro and in male mice in vivo. Together these findings elucidate a RvT4-SR-BI centered mechanism that orchestrates macrophage responses to limit atherosclerosis during inflammatory arthritis.

An innovative viewpoint on the existing and prospectiveness of SR-B1

Scavenger Receptor Class B Type 1 (SR-B1), a receptor protein expressed on the cell membrane, plays a crucial role in the metabolism and transport of cholesterol and other lipids, contributing significantly to the homeostasis of lipid levels within the body. Bibliometric analysis involves the application of mathematical and statistical methods to quantitatively analyze different types of documents. It involves the analysis of structural and temporal trends in scholarly articles, coupled with the identification of subject emphasis and variations. Through a bibliometric analysis, this study examines the historical background, current research trends, and future directions in the exploration of SR-B1. By offering insights into the research status and development of SR-B1, this paper aims to assist researchers in identifying novel pathways and areas of investigation in this field of study. Following the screening process, it can be concluded that research on SR-B1 has consistently remained a topic of significant interest over the past 17 years. Interestingly, SR-B1 has recently garnered attention in areas beyond its traditional research focus, including the field of cancer. The primary objective of this review is to provide a concise and accessible overview of the development process of SR-B1 that can help readers who are not well-versed in SR-B1 research quickly grasp its key aspects. Furthermore, this review aims to offer insights and suggestions to researchers regarding potential future research directions and areas of emphasis relating to SR-B1.

Rethinking HDL-C: An In-Depth Narrative Review of Its Role in Cardiovascular Health

The interplay between HDL-C and LDL levels are closely intertwined with the cardiovascular system. High-Density Lipoprotein Cholesterol (HDL-C) is a well-known biomarker traditionally being interpreted as higher the HDL-C levels, minimal the risk of adverse cardiovascular disease (CVD) outcomes. However, recent research has unveiled a more complex relationship between HDL-C levels and cardiovascular outcomes, including genetic influences and potential risks associated with extremely high HDL-C levels. Intriguingly, extremely high HDL-C levels have been linked to unexpected cardiovascular risks. Up To date research suggests that individuals with genetically linked ultra-high HDL-C levels may depict an increased susceptibility to CVD, challenging the conventional realm that higher HDL-C is always beneficial. The mechanisms underlying this mystery are not fully understood but may involve HDL particle functionality and composition. In a nutshell, the relationship between HDL-C levels and cardiovascular outcomes is multifactorial. While low HDL-C remains a recognized risk factor for CVD, the genetic determinants of HDL-C levels add complexity to this association. Furthermore, extremely high HDL-C levels may not exhibit the expected protective benefits and may even pose unprecedented cardiovascular risks. A comprehensive understanding of these dynamics is essential for advancing our knowledge of CVD risk assessment and developing targeted therapeutic interventions. Further studies are needed to unravel the intricacies of HDL-C's role in cardiovascular health and disease.

Cell States and Interactions of CD8 T Cells and Disease-Enriched Microglia in Human Brains with Alzheimer's Disease

Alzheimer's disease (AD) is a multi-stage neurodegenerative disorder characterized by beta-amyloid accumulation, hyperphosphorylated Tau deposits, neurodegeneration, neuroinflammation, and cognitive impairment. Recent studies implicate CD8 T cells as neuroimmune responders to the accumulation of AD pathology in the brain and potential contributors to toxic neuroinflammation. However, more evidence is needed to understand lymphocytes in disease, including their functional states, molecular mediators, and interacting cell types in diseased brain tissue. The scarcity of lymphocytes in brain tissue samples has limited the unbiased profiling of disease-associated cell types, cell states, drug targets, and relationships to common AD genetic risk variants based on transcriptomic analyses. However, using recent large-scale, high-quality single-nuclear sequencing datasets from over 84 Alzheimer's disease and control cases, we leverage single-nuclear RNAseq data from 800 lymphocytes collected from 70 individuals to complete unbiased molecular profiling. We demonstrate that effector memory CD8 T cells are the major lymphocyte subclass enriched in the brain tissues of individuals with AD dementia. We define disease-enriched interactions involving CD8 T cells and multiple brain cell subclasses including two distinct microglial disease states that correlate, respectively, to beta-amyloid and tau pathology. We find that beta-amyloid-associated microglia are a major hub of multicellular cross-talk gained in disease, including interactions involving both vulnerable neuronal subtypes and CD8 T cells. We reproduce prior reports that amyloid-response microglia are depleted in APOE4 carriers. Overall, these human-based studies provide additional support for the potential relevance of effector memory CD8 T cells as a lymphocyte population of interest in AD dementia and provide new candidate interacting partners and drug targets for further functional study.

Exploring shared therapeutic targets in diabetic cardiomyopathy and diabetic foot ulcers through bioinformatics analysis

Advanced diabetic cardiomyopathy (DCM) patients are often accompanied by severe peripheral artery disease. For patients with DCM combined with diabetic foot ulcer (DFU), there are currently no good therapeutic targets and drugs. Here, we investigated the underlying network of molecular actions associated with the occurrence of these two complications. The datasets were downloaded from the Gene Expression Omnibus (GEO) database. We performed enrichment and protein-protein interaction analyses, and screened for hub genes. Construct transcription factors (TFs) and microRNAs regulatory networks for validated hub genes. Finally, drug prediction and molecular docking verification were performed. We identified 299 common differentially expressed genes (DEGs), many of which were involved in inflammation and lipid metabolism. 6 DEGs were identified as hub genes (PPARG, JUN, SLC2A1, CD4, SCARB1 and SERPINE1). These 6 hub genes were associated with inflammation and immune response. We identified 31 common TFs and 2 key miRNAs closely related to hub genes. Interestingly, our study suggested that fenofibrate, a lipid-lowering medication, holds promise as a potential treatment for DCM combined with DFU due to its stable binding to the identified hub genes. Here, we revealed a network involves a common target for DCM and DFU. Understanding these networks and hub genes is pivotal for advancing our comprehension of the multifaceted complications of diabetes and facilitating the development of future therapeutic interventions.

Interactions between macrophage membrane and lipid mediators during cardiovascular diseases with the implications of scavenger receptors

The onset and progression of cardiovascular diseases with the major underlying cause being atherosclerosis, occur during chronic inflammatory persistence in the vascular system, especially within the arterial wall. Such prolonged maladaptive inflammation is driven by macrophages and their key mediators are generally attributed to a disparity in lipid metabolism. Macrophages are the primary cells of innate immunity, endowed with expansive membrane domains involved in immune responses with their signalling systems. During atherosclerosis, the membrane domains and receptors control various active organisations of macrophages. Their scavenger/endocytic receptors regulate the trafficking of intracellular and extracellular cargo. Corresponding influence on lipid metabolism is mediated by their dynamic interaction with scavenger membrane receptors and their integrated mechanisms such as pinocytosis, phagocytosis, cholesterol export/import, etc. This interaction not only results in the functional differentiation of macrophages but also modifies their structural configurations. Here, we reviewed the association of macrophage membrane biomechanics and their scavenger receptor families with lipid metabolites during the event of atherogenesis. In addition, the membrane structure of macrophages and the signalling pathways involved in endocytosis integrated with lipid metabolism are detailed. This article establishes future insights into the scavenger receptors as potential targets for cardiovascular disease prevention and treatment.

Scavenger Receptor BI Deficiency in Mice Is Associated With Plasma Ceramide and Sphingomyelin Accumulation and a Reduced Cholesteryl Ester Fatty Acid Length and Unsaturation Degree

Objective

Scavenger receptor class B type I (SR-BI) is primarily known for its role in the selective uptake of cholesteryl esters (CEs) from high-density lipoproteins (HDLs). Here we investigated whether SR-BI deficiency is associated with other potentially relevant changes in the plasma lipidome than the established effect of HDL-cholesterol elevation.

Methods

Targeted ultra-high-performance liquid chromatography-tandem mass spectrometry was utilized to measure lipid species in plasma from female wild-type and SR-BI knockout mice.

Results

SR-BI deficiency was associated with a reduction in the average CE fatty acid length (-2%; p<0.001) and degree of CE fatty acid unsaturation (-18%; p<0.001) due to a relative shift from longer, polyunsaturated CE species CE (20:4), CE (20:5), and CE (22:6) towards the mono-unsaturated CE (18:1) species. Sphingomyelin (SM) levels were 64% higher (p<0.001) in SR-BI knockout mice without a parallel change in (lyso)phosphatidylcholine (LPC) concentrations, resulting in an increase in the SM/LPC ratio from 0.102±0.005 to 0.163±0.003 (p<0.001). In addition, lower LPC lengths (-5%; p<0.05) and fatty acid unsaturation degrees (-20%; p<0.01) were detected in SR-BI knockout mice. Furthermore, SR-BI deficiency was associated with a 4.7-fold increase (p<0.001) in total plasma ceramide (Cer) levels, with a marked >9-fold rise (p<0.001) in Cer (d18:1/24:1) concentrations.

Conclusion

We have shown that SR-BI deficiency in mice not only impacts the CE concentrations, length, and saturation index within the plasma compartment, but is also associated with plasma accumulation of several Cer and SM species that may contribute to the development of specific hematological and metabolic (disease) phenotypes previously detected in SR-BI knockout mice.

Identification of genetic drivers of plasma lipoprotein size in the Diversity Outbred mouse population

Despite great progress in understanding lipoprotein physiology, there is still much to be learned about the genetic drivers of lipoprotein abundance, composition, and function. We used ion mobility spectrometry to survey 16 plasma lipoprotein subfractions in 500 Diversity Outbred mice maintained on a Western-style diet. We identified 21 quantitative trait loci (QTL) affecting lipoprotein abundance. To refine the QTL and link them to disease risk in humans, we asked if the human homologs of genes located at each QTL were associated with lipid traits in human genome-wide association studies. Integration of mouse QTL with human genome-wide association studies yielded candidate gene drivers for 18 of the 21 QTL. This approach enabled us to nominate the gene encoding the neutral ceramidase, Asah2, as a novel candidate driver at a QTL on chromosome 19 for large HDL particles (HDL-2b). To experimentally validate Asah2, we surveyed lipoproteins in Asah2-/- mice. Compared to wild-type mice, female Asah2-/- mice showed an increase in several lipoproteins, including HDL. Our results provide insights into the genetic regulation of circulating lipoproteins, as well as mechanisms by which lipoprotein subfractions may affect cardiovascular disease risk in humans.

Hepatocytic lipocalin-2 controls HDL metabolism and atherosclerosis via Nedd4-1-SR-BI axis in mice

High-density lipoprotein (HDL) metabolism is regulated by complex interplay between the scavenger receptor group B type 1 (SR-BI) and multiple signaling molecules in the liver. Here, we show that lipocalin-2 (Lcn2) is a key regulator of hepatic SR-BI, HDL metabolism, and atherosclerosis. Overexpression of human Lcn2 in hepatocytes attenuates the development of atherosclerosis via SR-BI in western-diet-fed Ldlr-/- mice, whereas hepatocyte-specific ablation of Lcn2 has the opposite effect. Mechanistically, hepatocyte Lcn2 improves HDL metabolism and alleviates atherogenesis by blocking Nedd4-1-mediated SR-BI ubiquitination at K500 and K508. The Lcn2-improved HDL metabolism is abolished in mice with hepatocyte-specific Nedd4-1 or SR-BI deletion and in SR-BI (K500A/K508A) mutation mice. This study identifies a regulatory axis from Lcn2 to HDL via blocking Nedd4-1-mediated SR-BI ubiquitination and demonstrates that hepatocyte Lcn2 may be a promising target to improve HDL metabolism to treat atherosclerotic cardiovascular diseases.

A realistic approach to evaluating the effect of baseline lipid profile in postcoronary artery bypass grafting surgery

BACKGROUND

There are still many uncertainties in the association between lipid profile and postcoronary artery bypass grafting (CABG) outcomes. Although simplifying the association to linear equations makes it understandable but cannot explain many findings.

HYPOTHESIS

There is a nonlinear associatin between lipid profile indices and adverse outcomes after CABG.

METHODS

A total of 17 555 patients who underwent isolated CABG between 2005 and 2016 were evaluated. During the median follow-up of 75.24 months, the Restricted Cubic Splines (RCS) estimated from the Cox regression model adjusted for all possible confounders was applied to show a nonlinear relationship of lipid profile contents with the "ln hazard ratio" of mortality and major cerebro-cardiac events (MACCE).

RESULTS

The relationship between LDL-C and HDL-C with all-cause mortality was nonlinear (nonlinear p were .004 and <.001, respectively). The relationship between remnant cholesterol and all-cause mortality was linear (linearity p = .023). Among men, those in the highest LDL-C level (Q4, LDL-C > 114) and those in the lowest HDL-C level (Q1, HDL-C < 30) showed a significantly higher risk of all-cause mortality compared to other groups (compared with Q3, LDL-C Q4, HR = 1.16, 95% confidence interval [CI]:1.02-1.26, p = .014; HDL-C Q1, HR = 1.14, 95% CI: 1.01-1.31, p = .041). Female patients in the lowest HDL-C level (Q1, HDL-C < 30) showed a significantly higher (compared with Q3, HR = 1.14, 95% CI:1.01-1.31, p = .028) and those in the highest HDL-C level (Q4, HDL-C > 43) showed a significantly lower (compared with Q3, HR = 0.74, 95% CI:0.58-0.98, p = .019) risk of all-cause mortality.

CONCLUSION

Determining a universal cut off for components of lipid profile may be misleading and should better be revised. Extreme values (very low or very high) for HDL-C and LDL-C have different effects on cardiovascular outcomes.

Serum opacity factor normalizes erythrocyte morphology in Scarb1-/- mice in an HDL-free cholesterol-dependent way

Compared with WT mice, HDL receptor-deficient (Scarb1-/-) mice have higher plasma levels of free cholesterol (FC)-rich HDL and exhibit multiple pathologies associated with a high mol% FC in ovaries, platelets, and erythrocytes, which are reversed by lowering HDL. Bacterial serum opacity factor (SOF) catalyzes the opacification of plasma by targeting and quantitatively converting HDL to neo HDL (HDL remnant), a cholesterol ester-rich microemulsion, and lipid-free APOA1. SOF delivery with an adeno-associated virus (AAVSOF) constitutively lowers plasma HDL-FC and reverses female infertility in Scarb1-/- mice in an HDL-dependent way. We tested whether AAVSOF delivery to Scarb1-/- mice will normalize erythrocyte morphology in an HDL-FC-dependent way. We determined erythrocyte morphology and FC content (mol%) in three groups-WT, untreated Scarb1-/- (control), and Scarb1-/- mice receiving AAVSOF-and correlated these with their respective HDL-mol% FC. Plasma-, HDL-, and tissue-lipid compositions were also determined. Plasma- and HDL-mol% FC positively correlated across all groups. Among Scarb1-/- mice, AAVSOF treatment normalized reticulocyte number, erythrocyte morphology, and erythrocyte-mol% FC. Erythrocyte-mol% FC positively correlated with HDL-mol% FC and with both the number of reticulocytes and abnormal erythrocytes. AAVSOF treatment also reduced FC of extravascular tissues to a lesser extent. HDL-FC spontaneously transfers from plasma HDL to cell membranes. AAVSOF treatment lowers erythrocyte-FC and normalizes erythrocyte morphology and lipid composition by reducing HDL-mol% FC.

Short-term effects of allulose consumption on glucose homeostasis, metabolic parameters, incretin levels, and inflammatory markers in patients with type 2 diabetes: a double-blind, randomized, controlled crossover clinical trial

PURPOSE

Allulose is a rare monosaccharide with almost zero calories. There is no study of short-term allulose consumption in patients with type 2 diabetes (T2D). Thus, we aimed to study the effect of allulose consumption for 12 weeks on glucose homeostasis, lipid profile, body composition, incretin levels, and inflammatory markers in patients with T2D.

METHODS

A double-blind, randomized, controlled crossover study was conducted on sixteen patients with T2D. Patients were randomly assigned to allulose 7 g twice daily or aspartame 0.03 g twice daily for 12 weeks. After a 2-week washout, patients were crossed over to the other sweetener for an additional 12 weeks. Oral glucose tolerance tests, laboratory measurements, and dual-energy X-ray absorptiometry were conducted before and after each phase.

RESULTS

This study revealed that short-term allulose consumption exerted no significant effect on glucose homeostasis, incretin levels, or body composition but significantly increased MCP-1 levels (259 ± 101 pg/ml at baseline vs. 297 ± 108 pg/mL after 12 weeks of allulose, p = 0.002). High-density lipoprotein cholesterol (HDL-C) significantly decreased from 51 ± 13 mg/dl at baseline to 41 ± 12 mg/dL after 12 weeks of allulose, p < 0.001.

CONCLUSION

Twelve weeks of allulose consumption had a neutral effect on glucose homeostasis, body composition, and incretin levels. Additionally, it decreased HDL-C levels and increased MCP-1 levels.

TRIAL REGISTRATION

This trial was retrospectively registered on the Thai Clinical Trials Registry (TCTR20220516006) on December 5, 2022.

A U-shaped association between the triglyceride to high-density lipoprotein cholesterol ratio and the risk of incident type 2 diabetes mellitus in Japanese men with normal glycemic levels: a population-based longitudinal cohort study

Background

Several studies have verified that a high baseline TG/HDL-C ratio is a risk factor for incident type 2 diabetes mellitus (T2DM). However, for low baseline TG/HDL-C levels, the findings were inconsistent with ours. In addition, the association between baseline TG/HDL-C ratio and the risk of incident T2DM in Japanese men with normal glycemic levels is unclear. As a result, our study further investigated the relationship between baseline TG/HDL-C and the risk of incident T2DM in Japanese men with normal glycemic levels.

Methods

This was a secondary longitudinal cohort study. We selected 7,684 male participants between 2004 and 2015 from the NAGALA database. A standardized Cox regression model and two piecewise Cox regression models were used to explore the relationship between the baseline high-density lipoprotein cholesterol ratio (TG/HDL-C) and incident T2DM.

Results

During a median follow-up of 2,282 days, 162 men developed incident T2DM. In the adjusted model, the baseline TG/HDL-C ratio was strongly associated with the risk of incident T2DM, and no dose-dependent positive association was observed between the baseline TG/HDL-C ratio and incidence of T2DM throughout the baseline TG/HDL-C quartiles. Two-piecewise linear regression analysis showed a U-shaped association between baseline TG/HDL-C ratio and incidence of incident T2DM. A baseline TG/HDL-C ratio below 1.188 was negatively associated with incident T2DM (H.R. = 0.105, 95% CI = 0.025, 0.451; P = 0.002). In contrast, a baseline TG/HDL-C ratio >1.188 was positively associated with incident T2DM (H.R. = 1.248, 95% CI = 1.113, 1.399; P<0.001). The best TG/HDL-C threshold for predicting incident T2DM was 1.8115 (area under the curve, 0.6837).

Conclusion

A U-shaped relationship between baseline TG/HDL-C ratio and incident T2DM in Japanese men with normal glycemic levels was found.

Modulation of the Cellular microRNA Landscape: Contribution to the Protective Effects of High-Density Lipoproteins (HDL)

High-density lipoproteins (HDL) play an established role in protecting against cellular dysfunction in a variety of different disease contexts; however, harnessing this therapeutic potential has proved challenging due to the heterogeneous and relative instability of this lipoprotein and its variable cargo molecules. The purpose of this study is to examine the contribution of microRNA (miRNA; miR) sequences, either delivered directly or modulated endogenously, to these protective functions. This narrative review introduces the complex cargo carried by HDL, the protective functions associated with this lipoprotein, and the factors governing biogenesis, export and the uptake of microRNA. The possible mechanisms by which HDL can modulate the cellular miRNA landscape are considered, and the impact of key sequences modified by HDL is explored in diseases such as inflammation and immunity, wound healing, angiogenesis, dyslipidaemia, atherosclerosis and coronary heart disease, potentially offering new routes for therapeutic intervention.

High-density lipoproteins and non-alcoholic fatty liver disease

Background and aims

Non-alcoholic fatty liver disease (NAFLD), a high incidence liver pathology, is associated with a ∼1.5-fold higher cardiovascular disease risk. This phenomenon is generally attributed to the NAFLD-associated increase in circulating levels of pro-atherogenic apolipoprotein B100-containing small dense low-density lipoprotein and plasma hypertriglyceridemia. However, also a significant reduction in cholesterol transported by anti-atherogenic high-density lipoproteins (HDL) is frequently observed in subjects suffering from NAFLD as compared to unaffected people. In this review, we summarize data regarding the relationship between NAFLD and plasma HDL-cholesterol levels, with a special focus on highlighting potential causality between the NAFLD pathology and changes in HDL metabolism.

Methods and results

Publications in PUBMED describing the relationship between HDL levels and NAFLD susceptibility and/or disease severity, either in human clinical settings or genetically-modified mouse models, were critically reviewed for subsequent inclusion in this manuscript. Furthermore, relevant literature describing effects on lipid loading in cultured hepatocytes of models with genetic alterations related to HDL metabolism have been summarized.

Conclusions

Although in vitro observations suggest causality between HDL formation by hepatocytes and protection against NAFLD-like lipid accumulation, current literature remains inconclusive on whether relative HDL deficiency is actually driving the development of fatty liver disease in humans. In light of the current obesity pandemic and the associated marked rise in NAFLD incidence, it is of clear scientific and societal interest to gain further insight into the relationship between HDL-cholesterol levels and fatty liver development to potentially uncover the therapeutic potential of pharmacological HDL level and/or function modulation.

SCARB1 in extracellular vesicles promotes NPC metastasis by co-regulating M1 and M2 macrophage function

Distant metastasis is currently the main factor affecting the prognosis of nasopharyngeal carcinoma (NPC), and understanding the mechanisms of metastasis and identifying reliable therapeutic targets are critical for improving prognosis and achieving clinical translation. Macrophages, as important immune cells in the tumor microenvironment (TME), have been shown to regulate metastasis. And extracellular vesicles (EVs) secreted by stromal cells and tumor cells play the important role in intercellular communication in the tumor microenvironment. However, the role of NPC-EVs on macrophages and their function in regulating macrophages to affect metastasis has not been fully clarified. In this study, we report that NPC-EVs can be uptake by macrophages and alter macrophage polarization, for the first time, we identified the genes implicated in these regulatory functions: SCARB1, HAAO, and CYP1B1. Moreover, we found that SCARB1 was positively associated with metastasis and poor prognosis of NPC. Interestingly, we found that SCARB1-rich EVs promoted M1 macrophages ferroptosis to decrease M1 macrophages infiltration by upregulating the HAAO level while decreasing phagocytosis of M2 macrophages by upregulating the CYP1B1 level. Finally, we identified the SCARB1-binding gene KLF9, which is involved in the transcription of HAAO and CYP1B1. Our findings showed that SCARB1-EVs promoted metastasis by co-regulating M1 and M2 macrophage function. The related mechanism will provide a new therapeutic strategy to help patients with NPC improve their prognosis.