High-density lipoprotein metabolism and reverse cholesterol transport: strategies for raising HDL cholesterol

Associations of excessive gestational weight gain with changes in components of maternal reverse cholesterol transport and neonatal outcomes

Excessive gestational weight gain may be associated with unfavorable pregnancy outcomes. We explored the impact of excessive weight gain on components of HDL metabolism in maternal plasma: sterol composition of HDL particles, distribution of HDL subclasses and SCARB1, ABCA1 and ABCG1 genes expressions and their associations with newborns' characteristics. The study included 124 pregnant women, 58 with recommended and 66 with excessive weight gain. Concentrations of cholesterol synthesis marker, desmosterol, within HDL increased during pregnancy in both groups of participants. In women with excessive weight gain, levels of cholesterol absorption marker, campesterol, within HDL were significantly lower in the 3rd trimester compared to the 1st and 2nd trimesters. Relative proportions of large HDL 2b subclasses increased during pregnancy in women with recommended weight gain. Women with high pre-pregnancy BMI and excessive gestational weight gain had the lowest levels of β-sitosterol within HDL and the highest relative proportions of HDL 3a and HDL 3b subclasses in the 2nd trimester. Large HDL 2b particles were in positive correlation, while smaller HDL 3 subclasses and SCARB1 gene expressions were in negative correlation with APGAR scores. In conclusion, excessive weight gain could contribute to altered metabolism of HDL, and subsequently to poorer neonatal outcomes.

Genetic association of lipid-lowering drug target genes with pancreatic cancer: a Mendelian randomization study

Previous studies have found that dyslipidemia is a risk factor for pancreatic cancer (PC), and that lipid-lowering drugs may reduce the risk of PC. However, it is not clear whether dyslipidemia causes PC. The Mendelian randomization (MR) study aimed to investigate the causal role of lipid traits in pancreatic cancer and to assess the potential impact of lipid-lowering drug targets on pancreatic cancer. Genetic variants associated with lipid traits and variants of genes encoding lipid-lowering drug targets were extracted from the Global Lipids Genetics Consortium genome-wide association study (GWAS). Summary statistics for PC were obtained from an independent GWAS datasets. Colocalization analyses were performed to validate the robustness of the results. No significant effect of lipid-lowering drug targets on PC risk was found. Genetic mimicry of lipoprotein lipase (LPL) was potentially associated with PC risks. Significant MR associations were observed in the discovery dataset (OR 1.64 [95% CI 1.24-2.16], p = 4.48*10-4) with PC in one dataset. However, the finding was not verified in the replication dataset. Our findings do not support dyslipidemia as a causal factor for PC. Among lipid-lowering drug targets, LPL is the potential drug target in PC.

Effects of T2DM on cancer progression: pivotal precipitating factors and underlying mechanisms

Type 2 diabetes mellitus (T2DM) is a chronic metabolic disorder affecting people worldwide. It is characterized by several key features, including hyperinsulinemia, hyperglycemia, hyperlipidemia, and dysbiosis. Epidemiologic studies have shown that T2DM is closely associated with the development and progression of cancer. T2DM-related hyperinsulinemia, hyperglycemia, and hyperlipidemia contribute to cancer progression through complex signaling pathways. These factors increase drug resistance, apoptosis resistance, and the migration, invasion, and proliferation of cancer cells. Here, we will focus on the role of hyperinsulinemia, hyperglycemia, and hyperlipidemia associated with T2DM in cancer development. Additionally, we will elucidate the potential molecular mechanisms underlying their effects on cancer progression. We aim to identify potential therapeutic targets for T2DM-related malignancies and explore relevant directions for future investigation.

The uric acid/albumin ratio might be a better indicator for predicting repeat revascularization in young patients with acute coronary syndrome: Beyond inflammatory biomarkers

BACKGROUND

Despite advancements in percutaneous and surgical revascularization techniques, nearly 20% of patients who undergo myocardial revascularization need repeat revascularization. Recently, identified as a prognostication factor for adverse cardiovascular events, the uric acid/albumin ratio (UAR) serves as a new marker for assessing inflammation and oxidative stress. Our objective was to investigate the association between UAR levels and repeat revascularization in young patients with acute coronary syndrome (ACS).

METHODS

We enrolled 371 patients with ACS who were under the age of 55 years and who had previously undergone primary percutaneous coronary intervention. Due to their recurrent symptoms, these patients underwent subsequent coronary angiographic examination. The study cohort was splitted into two groups based on whether repeat revascularization was needed.

RESULTS

The study and control groups consisted of 99 and 272 patients, respectively. The mean age of the patients in the study cohort was 41.99±4.99 years. Patients who needed repeat revascularization, in comparison to those who did not, exhibited significantly greater levels of the UAR and uric acid, along with lower levels of neutrophils, stent diameter and high density lipoprotein-cholesterol. Additionally, they had more complex disease, as described by the SYNTAX score. To identify the influential factors associated with repeat revascularization, multivariate logistic regression was performed. SYNTAX score, stent diameter, uric acid levels and the UAR were predictive of the need for repeat revascularization.

CONCLUSIONS

UAR was found to be an inexpensive, easily accessible marker for identifying young patients with ACS requiring repeat revascularization.

Exposure of Ldlr-/- Mice to a PFAS Mixture and Outcomes Related to Circulating Lipids, Bile Acid Excretion, and the Intestinal Transporter ASBT

BACKGROUND

Previous epidemiological studies have repeatedly found per- and polyfluoroalkyl substances (PFAS) exposure associated with higher circulating cholesterol, one of the greatest risk factors for development of coronary artery disease. The main route of cholesterol catabolism is through its conversion to bile acids, which circulate between the liver and ileum via enterohepatic circulation. Patients with coronary artery disease have decreased bile acid excretion, indicating that PFAS-induced impacts on enterohepatic circulation may play a critical role in cardiovascular risk.

OBJECTIVES

Using a mouse model with high levels of low-density and very low-density lipoprotein (LDL and VLDL, respectively) cholesterol and aortic lesion development similar to humans, the present study investigated mechanisms linking exposure to a PFAS mixture with increased cholesterol.

METHODS

Male and female L d l r - / - mice were fed an atherogenic diet (Clinton/Cybulsky low fat, 0.15% cholesterol) and exposed to a mixture of 5 PFAS representing legacy, replacement, and emerging subtypes (i.e., PFOA, PFOS, PFHxS, PFNA, GenX), each at a concentration of 2 mg / L , for 7 wk. Blood was collected longitudinally for cholesterol measurements, and mass spectrometry was used to measure circulating and fecal bile acids. Transcriptomic analysis of ileal samples was performed via RNA sequencing.

RESULTS

After 7 wk of PFAS exposure, average circulating PFAS levels were measured at 21.6, 20.1, 31.2, 23.5, and 1.5 μ g / mL in PFAS-exposed females and 12.9, 9.7, 23, 14.3, and 1.7 μ g / mL in PFAS-exposed males for PFOA, PFOS, PFHxS, PFNA, and GenX, respectively. Total circulating cholesterol levels were higher in PFAS-exposed mice after 7 wk (352 mg / dL vs. 415 mg / dL in female mice and 392 mg / dL vs. 488 mg / dL in male mice exposed to vehicle or PFAS, respectively). Total circulating bile acid levels were higher in PFAS-exposed mice (2,978  pg / μ L vs. 8,496  pg / μ L in female mice and 1,960  pg / μ L vs. 4,452  pg / μ L in male mice exposed to vehicle or PFAS, respectively). In addition, total fecal bile acid levels were lower in PFAS-exposed mice (1,797  ng / mg vs. 682  ng / mg in females and 1,622  ng / mg vs. 670  ng / mg in males exposed to vehicle or PFAS, respectively). In the ileum, expression levels of the apical sodium-dependent bile acid transporter (ASBT) were higher in PFAS-exposed mice.

DISCUSSION

Mice exposed to a PFAS mixture displayed higher circulating cholesterol and bile acids perhaps due to impacts on enterohepatic circulation. This study implicates PFAS-mediated effects at the site of the ileum as a possible critical mediator of increased cardiovascular risk following PFAS exposure. https://doi.org/10.1289/EHP14339.

A cross-sectional analysis of the relationship between the non-high density to high density lipoprotein cholesterol ratio (NHHR) and kidney stone risk in American adults

BACKGROUND

Recent interest in the Non-High Density to High Density Lipoprotein Cholesterol ratio (NHHR) has emerged due to its potential role in metabolic disorders. However, the connection between NHHR and the development of kidney stones still lacks clarity. The primary goal of this research is to explore how NHHR correlates with kidney stone incidence.

METHODS

An analysis was conducted on the data collected by the National Health and Nutrition Examination Survey (NHANES) between 2007 and 2018, focusing on adults over 20 years diagnosed with kidney stones and those with available NHHR values. Employing weighted logistic regression and Restricted Cubic Spline (RCS) models, NHHR levels' correlation with kidney stone risk was examined. Extensive subgroup analyses were conducted for enhanced reliability of the findings.

RESULTS

The findings indicate a heightened kidney stone risk for those at the highest NHHR levels relative to those at the lowest (reference group). A notable non-linear correlation of NHHR with kidney stone incidence has been observed, with a significant P-value (< 0.001), consistent across various subgroups.

CONCLUSION

A clear link exists between high NHHR levels and increased kidney stone risk in the American adult population. This study highlights NHHR's significance as a potential indicator in kidney stone formation.

Biomimetic nanotechnology for cancer immunotherapy: State of the art and future perspective

Cancer continues to be a significant worldwide cause of mortality. This underscores the urgent need for novel strategies to complement and overcome the limitations of conventional therapies, such as imprecise targeting and drug resistance. Cancer Immunotherapy utilizes the body's immune system to target malignant cells, reducing harm to healthy tissue. Nevertheless, the efficacy of immunotherapy exhibits variation across individuals and has the potential to induce autoimmune responses. Biomimetic nanoparticles (bNPs) have transformative potential in cancer immunotherapy, promising improved accurate targeting, immune system activation, and resistance mechanisms, while also reducing the occurrence of systemic autoimmune side effects. This integration offers opportunities for personalized medicine and better therapeutic outcomes. Despite considerable potential, bNPs face barriers like insufficient targeting, restricted biological stability, and interactions within the tumor microenvironment. The resolution of these concerns is crucial in order to expedite the integration of bNPs from the research setting into clinical therapeutic uses. In addition, optimizing manufacturing processes and reducing bNP-related costs are essential for practical implementation. The present research introduces comprehensive classifications of bNPs as well as recent achievements in their application in cancer immunotherapies, emphasizing the need to address barriers for swift clinical integration.

Association between Mycoplasma pneumoniae infection, high‑density lipoprotein metabolism and cardiovascular health (Review)

The association between Mycoplasma pneumoniae (M. pneumoniae) infection, high-density lipoprotein metabolism and cardiovascular disease is an emerging research area. The present review summarizes the basic characteristics of M. pneumoniae infection and its association with high-density lipoprotein and cardiovascular health. M. pneumoniae primarily invades the respiratory tract and damages the cardiovascular system through various mechanisms including adhesion, invasion, secretion of metabolites, production of autoantibodies and stimulation of cytokine production. Additionally, the present review highlights the potential role of high-density lipoprotein for the development of prevention and intervention of M. pneumoniae infection and cardiovascular disease, and provides suggestions for future research directions and clinical practice. It is urgent to explore the specific mechanisms underlying the association between M. pneumoniae infection, high-density lipoprotein metabolism, and cardiovascular disease and analyze the roles of the immune system and inflammatory response.

Effects of guanidinoacetic acid supplementation on liver and breast muscle fat deposition, lipid levels, and lipid metabolism-related gene expression in ducks

Exogenous supplementation of guanidinoacetic acid can mechanistically regulate the energy distribution in muscle cells. This study aimed to investigate the effects of guanidinoacetic acid supplementation on liver and breast muscle fat deposition, lipid levels, and lipid metabolism-related gene expression in ducks. We randomly divided 480 42 days-old female Jiaji ducks into four groups with six replicates and 20 ducks for each replicate. The control group was fed the basal diet, and the experimental groups were fed the basal diet with 400, 600, and 800 mg/kg (GA400, GA600, and GA800) guanidinoacetic acid, respectively. Compared with the control group, (1) the total cholesterol (p = 0.0262), triglycerides (p = 0.0357), malondialdehyde (p = 0.0452) contents were lower in GA400, GA600 and GA800 in the liver; (2) the total cholesterol (p = 0.0365), triglycerides (p = 0.0459), and malondialdehyde (p = 0.0326) contents in breast muscle were decreased in GA400, GA600 and GA800; (3) the high density lipoprotein (p = 0.0356) and apolipoprotein-A1 (p = 0.0125) contents were increased in GA600 in the liver; (4) the apolipoprotein-A1 contents (p = 0.0489) in breast muscle were higher in GA600 and GA800; (5) the lipoprotein lipase contents (p = 0.0325) in the liver were higher in GA600 and GA800; (6) the malate dehydrogenase contents (p = 0.0269) in breast muscle were lower in GA400, GA600, and GA800; (7) the insulin induced gene 1 (p = 0.0326), fatty acid transport protein 1 (p = 0.0412), and lipoprotein lipase (p = 0.0235) relative expression were higher in GA400, GA600, and GA800 in the liver; (8) the insulin induced gene 1 (p = 0.0269), fatty acid transport protein 1 (p = 0.0234), and lipoprotein lipase (p = 0.0425) relative expression were increased in GA400, GA600, and GA800 in breast muscle. In this study, the optimum dosage of 600 mg/kg guanidinoacetic acid improved the liver and breast muscle fat deposition, lipid levels, and lipid metabolism-related gene expression in ducks.

Hepatoprotective Activity and Mechanisms of Prenylated Stilbenoids

Dietary prenylated stilbenoids, found in various food sources, offer multiple health benefits, including liver protection. However, the underlying mechanisms of hepatoprotection remain unclear. In this study, we synthesized 13 natural prenylated stilbenoids and examined their hepatoprotective activities, with silent mating type information regulation 2 homologue-1 (SIRT1) as the primary target for screening. Among all of the prenylated stilbenoids tested, 4-C-geranyl oxyresveratrol demonstrated superior performance. It activated SIRT1 activity more effectively than resveratrol, a well-known SIRT1 activator. To further investigate the mechanism of liver protection, two in vitro models were used: the palmitic acid-induced lipid accumulation model and the H2O2-induced apoptosis model. Our findings suggested that 4-C-geranyl oxyresveratrol mitigated lipid accumulation through the SIRT1-PGC1α pathway, reduced apoptosis via the SIRT1-p53-p21 pathway, and exerted antioxidant effects through the SIRT1-Nrf2 pathway. These findings provide new insights into the chemical basis of the health benefits of prenylated stilbenoids and their potential use as functional food additives.

Association of dyslipidemia with single nucleotide polymorphisms of the cholesteryl ester transfer protein gene and cardiovascular disease risk factors in a highly admixed population

BACKGROUND AND AIMS

Cardiovascular diseases (CVD) are major causes of mortality worldwide, leading to premature deaths, loss of quality of life, and extensive socioeconomic impacts. Alterations in normal plasma lipid concentrations comprise important risk factors associated with CVD due to mechanisms involved in the pathophysiology of atherosclerosis. Genetic markers such as single nucleotide polymorphisms (SNPs) are known to be associated with lipid metabolism, including variants in the cholesteryl ester transfer protein (CETP) gene. Thus, the study's objective was to assess the relationship among lipid profile, socioeconomic and demographic characteristics, health status, inflammatory biomarkers, and CETP genetic variants in individuals living in a highly admixed population.

METHODS

The study comprises an analysis of observational cross-sectional data representative at the population level from a highly admixed population, encompassing 901 individuals from three age groups (adolescents, adults, and older adults). Socioeconomic, demographic, health, and lifestyle characteristics were collected using semi-structured questionnaires. In addition, biochemical markers and lipid profiles were obtained from individuals' blood samples. After DNA extraction, genotyping, and quality control according to Affymetrix's guidelines, information on 15 SNPs in the CETP gene was available for 707 individuals. Lipid profile and CVD risk factors were evaluated by principal component analysis (PCA), and associations between lipid traits and those factors were assessed through multiple linear regression and logistic regression.

RESULTS

There were low linear correlations between lipid profile and other individuals' characteristics. Two principal components were responsible for 80.8 % of the total variance, and there were minor differences in lipid profiles among individuals in different age groups. Non-HDL-c, total cholesterol, and LDL-c had the highest loadings in the first PC, and triacylglycerols, VLDL-c and HDL-c were responsible for a major part of the loading in the second PC;, whilst HDL-c and LDL-c/HDL-c ratio were significant in the third PC. In addition, there were minor differences between groups of individuals with or without dyslipidemia regarding inflammatory biomarkers (IL-1β, IL- 6, IL-10, TNF-α, CRP, and MCP-1). Being overweight, insulin resistance, and lifestyle characteristics (calories from solid fat, added sugar, alcohol and sodium, leisure physical activity, and smoking) were strong predictors of lipid traits, especially HDL-c and dyslipidemia (p < 0.05). The CETP SNPs rs7499892 and rs12691052, rs291044, and rs80180245 were significantly associated with HDL-c (p < 0.05), and their inclusion in the multiple linear regression model increased its accuracy (adjusted R2 rose from 0.12 to 0.18).

CONCLUSION

This study identified correlations between lipid traits and other CVD risk factors. In addition, similar lipid and inflammatory profiles across age groups in the population suggested that adolescents might already present a significant risk for developing cardiovascular diseases in the population. The risk can be primarily attributed to decreased HDL-c concentrations, which appear to be influenced by genetic factors, as evidenced by associations between SNPs in the CETP gene and HDL-c concentrations, as well as potential gene-diet interactions. Our findings underscore the significant impact of genetic and lifestyle factors on lipid profile within admixed populations in developing countries.

Association of low HDL-c levels with severe symptoms and poor clinical prognosis in patients with severe fever and thrombocytopenia syndrome

Background

Severe fever with thrombocytopenia syndrome (SFTS) is an acute infectious disease caused by a novel bunyavirus, characterized by high fever, thrombocytopenia, and multiple organ damage. Disturbances in lipid metabolism often occur during viral infections, but the changes and clinical significance of lipid profiles in SFTS patients remain unclear. This study aimed to investigate the alterations in lipid profiles and their clinical significance in SFTS patients.

Methods

A total of 157 SFTS patients and 157 healthy controls were enrolled in this study. Serum lipid levels were collected and analyzed among different groups and prognosis categories. Receiver operating characteristic (ROC) curve analysis was performed to assess the ability of lipid levels in distinguishing between severe and mild cases, as well as surviving and non-surviving patients. Pearson correlation analysis was used to examine the associations between lipid levels and clinical laboratory parameters.

Results

SFTS patients exhibited significantly lower levels of HDL-c, LDL-c, cholesterol, APoAI, and ApoB compared to healthy controls, while triglyceride levels were significantly higher. Serum HDL-c and ApoAI demonstrated good performance as indicators for distinguishing between survivors and non-survivors (AUC of 0.87 and 0.85, respectively). Multivariate regression analysis indicated that HDL-c independently acts as a protective factor in patients with SFTS. HDL-c levels showed decline in non-survivors but recovered in survivors. Moreover, HDL-c exhibited significant correlations with various clinical laboratory parameters (IL-6, CRP, AST, TT, APTT, PLT, ALB, and CD4).

Conclusion

This study identified abnormalities in serum lipid metabolism among SFTS patients. HDL-c and ApoAI levels hold potential as biomarkers for distinguishing survivors from non-survivors. Additionally, HDL-c and ApoAI may serve as therapeutic targets for the management of SFTS patients.

Apolipoproteins as potential communicators play an essential role in the pathogenesis and treatment of early atherosclerosis

Atherosclerosis as the leading cause of the cardiovascular disease is closely related to cholesterol deposition within subendothelial areas of the arteries. Significantly, early atherosclerosis intervention is the critical phase for its reversal. As atherosclerosis progresses, early foam cells formation may evolve into fibrous plaques and atheromatous plaque, ulteriorly rupture of atheromatous plaque increases risks of myocardial infarction and ischemic stroke, resulting in high morbidity and mortality worldwide. Notably, amphiphilic apolipoproteins (Apos) can concomitantly combine with lipids to form soluble lipoproteins that have been demonstrated to associate with atherosclerosis. Apos act as crucial communicators of lipoproteins, which not only can mediate lipids metabolism, but also can involve in pro-atherogenic and anti-atherogenic processes of atherosclerosis via affecting subendothelial retention and aggregation of low-density lipoprotein (LDL), oxidative modification of LDL, foam cells formation and reverse cholesterol transport (RCT) in macrophage cells. Correspondingly, Apos can be used as endogenous and/or exogenous targeting agents to effectively attenuate the development of atherosclerosis. The article reviews the classification, structure, and relationship between Apos and lipids, how Apos serve as communicators of lipoproteins to participate in the pathogenesis progression of early atherosclerosis, as well as how Apos as the meaningful targeting mass is used in early atherosclerosis treatment.

Lactobacillus reuteri NCIMB 30242 (LRC) Inhibits Cholesterol Synthesis and Stimulates Cholesterol Excretion in Animal and Cell Models

In this study, we evaluated the effects of Lactobacillus reuteri NCIMB (LRC™) supplementation on hypercholesterolemia by researching its effects on cellular cholesterol metabolism in hypercholesterolemic rats (KHGASP-22-170) and HepG2 cell line. Rats were separated into six groups after adaptation and were then fed a normal control (NC), a high-cholesterol diet (HC), or a HC supplemented with simvastatin 15 mg/kg body weight (positive control [PC]), LRC 1 × 109 colony-forming units (CFU)/rat/day, LRC 4 × 109 CFU/rat/day, or LRC 1 × 1010 CFU/rat/day (1 × 109, 4 × 109, or 1 × 1010). The rats were dissected to study the effects of LRC on cholesterol metabolism and intestinal excretion at the end of experimental period. We discovered that LRC mainly participated in the restraint of 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase, the uptake of low-density lipoprotein (LDL) cholesterol into tissues, partially in the transport of cholesteryl esters into high density lipoprotein for maturation, and intestinal excretion of cholesterol. These results are supported by the expression of transcription factors and enzymes such as HMG-CoA reductase, SREBP2, CYP7A1, CETP, and LCAT in both messenger RNA (mRNA) and protein levels in serum and hepatic tissue. Furthermore, the LRC treatment in HepG2 significantly reduced the mRNA expression of HMG-CoA reductase, SREBP2, and CEPT and significantly increased the mRNA expression of LDL-receptor, LCAT, and CYP7A1 at all doses. Hence, we suggest that LRC supplementation could alleviate the serum cholesterol level by inhibiting the intracellular cholesterol synthesis, and augmenting excretion of intestinal cholesterol.

Targeted and untargeted metabolomic approach for GDM diagnosis

Gestational diabetes mellitus (GDM) is a disorder which manifests itself for the first time during pregnancy and is mainly connected with glucose metabolism. It is also known that fatty acid profile changes in erythrocyte membranes and plasma could be associated with obesity and insulin resistance. These factors can lead to the development of diabetes. In the reported study, we applied the untargeted analysis of plasma in GDM against standard glucose-tolerant (NGT) women to identify the differences in metabolomic profiles between those groups. We found higher levels of 2-hydroxybutyric and 3-hydroxybutyric acids. Both secondary metabolites are associated with impaired glucose metabolism. However, they are products of different metabolic pathways. Additionally, we applied lipidomic profiling using gas chromatography to examine the fatty acid composition of cholesteryl esters in the plasma of GDM patients. Among the 14 measured fatty acids characterizing the representative plasma lipidomic cluster, myristic, oleic, arachidonic, and α-linoleic acids revealed statistically significant changes. Concentrations of both myristic acid, one of the saturated fatty acids (SFAs), and oleic acid, which belong to monounsaturated fatty acids (MUFAs), tend to decrease in GDM patients. In the case of polyunsaturated fatty acids (PUFAs), some of them tend to increase (e.g., arachidonic), and some of them tend to decrease (e.g., α-linolenic). Based on our results, we postulate the importance of hydroxybutyric acid derivatives, cholesteryl ester composition, and the oleic acid diminution in the pathophysiology of GDM. There are some evidence suggests that the oleic acid can have the protective role in diabetes onset. However, metabolic alterations that lead to the onset of GDM are complex; therefore, further studies are needed to confirm our observations.

Apolipoprotein A1 Protects Against Necrotic Core Development in Atherosclerotic Plaques: PDZK1-Dependent High-Density Lipoprotein Suppression of Necroptosis in Macrophages

BACKGROUND

Atherosclerosis is a chronic disease affecting artery wall and a major contributor to cardiovascular diseases. Large necrotic cores increase risk of plaque rupture leading to thrombus formation. Necrotic cores are rich in debris from dead macrophages. Programmed necrosis (necroptosis) contributes to necrotic core formation. HDL (high-density lipoprotein) exerts direct atheroprotective effects on different cells within atherosclerotic plaques. Some of these depend on the SR-B1 (scavenger receptor class B type I) and the adapter protein PDZK1 (postsynaptic density protein/Drosophila disc-large protein/Zonula occludens protein containing 1). However, a role for HDL in protecting against necroptosis and necrotic core formation in atherosclerosis is not completely understood.

METHODS

Low-density lipoprotein receptor-deficient mice engineered to express different amounts of ApoA1 (apolipoprotein A1), or to lack PDZK1 were fed a high fat diet for 10 weeks. Atherosclerotic plaque areas, necrotic cores, and key necroptosis mediators, RIPK3 (receptor interacting protein kinase 3), and MLKL (mixed lineage kinase domain-like protein) were characterized. Cultured macrophages were treated with HDL to determine its effects, as well as the roles of SR-B1, PDZK1, and the PI3K (phosphoinositide 3-kinase) signaling pathway on necroptotic cell death.

RESULTS

Genetic overexpression reduced, and ApoA1 knockout increased necrotic core formation and RIPK3 and MLKL within atherosclerotic plaques. Macrophages were protected against necroptosis by HDL and this protection required SR-B1, PDZK1, and PI3K/Akt pathway. PDZK1 knockout increased atherosclerosis in LDLR^KO mice, increasing necrotic cores and phospho-MLKL; both of which were reversed by restoring PDZK1 in BM-derived cells.

CONCLUSIONS

Our findings demonstrate that HDL in vitro and ApoA1, in vivo, protect against necroptosis in macrophages and necrotic core formation in atherosclerosis, suggesting a pathway that could be a target for the treatment of atherosclerosis.

Mechanism of the Regulation of Plasma Cholesterol Levels by PI(4,5)P2

Elevated low-density lipoprotein (LDL) cholesterol (LDLc) is one of the most well-established risk factors for cardiovascular disease, while high levels of high-density lipoprotein (HDL) cholesterol (HDLc) have been associated with protection from cardiovascular disease. Cardiovascular disease remains one of the leading causes of death worldwide; thus it is important to understand mechanisms that impact LDLc and HDLc metabolism. In this chapter, we will discuss molecular processes by which phosphatidylinositol-(4,5)-bisphosphate, PI(4,5)P₂, is thought to modulate LDLc or HDLc. Section 1 will provide an overview of cholesterol in the circulation, discussing processes that modulate the various forms of lipoproteins (LDL and HDL) carrying cholesterol. Section 2 will describe how a PI(4,5)P₂ phosphatase, transmembrane protein 55B (TMEM55B), impacts circulating LDLc levels through its ability to regulate lysosomal decay of the low-density lipoprotein receptor (LDLR), the primary receptor for hepatic LDL uptake. Section 3 will discuss how PI(4,5)P₂ interacts with apolipoprotein A-I (apoA1), the key apolipoprotein on HDL. In addition to direct mechanisms of PI(4,5)P₂ action on circulating cholesterol, Sect. 4 will review how PI(4,5)P₂ may indirectly impact LDLc and HDLc by affecting insulin action. Last, as cholesterol is controlled through intricate negative feedback loops, Sect. 5 will describe how PI(4,5)P₂ is regulated by cholesterol.

Influence of lecithin cholesterol acyltransferase alteration during different pathophysiologic conditions: A 45 years bibliometrics analysis

Background: Lecithin cholesterol acyltransferase (LCAT) is an important enzyme responsible for free cholesterol (FC) esterification, which is critical for high density lipoprotein (HDL) maturation and the completion of the reverse cholesterol transport (RCT) process. Plasma LCAT activity and concentration showed various patterns under different physiological and pathological conditions. Research on LCAT has grown rapidly over the past 50 years, but there are no bibliometric studies summarizing this field as a whole. This study aimed to use the bibliometric analysis to demonstrate the trends in LCAT publications, thus offering a brief perspective with regard to future developments in this field. Methods: We used the Web of Science Core Collection to retrieve LCAT-related studies published from 1975 to 2020. The data were further analyzed in the number of studies, the journal which published the most LCAT-related studies, co-authorship network, co-country network, co-institute network, co-reference and the keywords burst by CiteSpace V 5.7. Results: 2584 publications contained 55,311 references were used to analyzed. The number of included articles fluctuated in each year. We found that Journal of lipid research published the most LCAT-related studies. Among all the authors who work on LCAT, they tend to collaborate with a relatively stable group of collaborators to generate several major authors clusters which Albers, J. published the most studies (n = 53). The United States of America contributed the greatest proportion (n = 1036) of LCAT-related studies. The LCAT-related studies have been focused on the vascular disease, lecithin-cholesterol acyltransferase reaction, phospholipid, cholesterol efflux, chronic kidney disease, milk fever, nephrotic syndrome, platelet-activating factor acetylhydrolase, reconstituted lpa-i, reverse cholesterol transport. Four main research frontiers in terms of burst strength for LCAT-related studies including "transgenic mice", "oxidative stress", "risk", and "cholesterol metabolism "need more attention. Conclusion: This is the first study that demonstrated the trends and future development in LCAT publications. Further studies should focus on the accurate metabolic process of LCAT dependent or independent of RCT using metabolic marker tracking techniques. It was also well worth to further studying the possibility that LCAT may qualify as a biomarker for risk prediction and clinical treatment.

Differential Expression of Serum Proteins in Chronic Obstructive Pulmonary Disease Assessed Using Label-Free Proteomics and Bioinformatics Analyses

PURPOSE

As a common respiratory disease, chronic obstructive pulmonary disease (COPD) has a high morbidity and mortality. Current clinical therapies are not ideal and do not improve lung function or long-term life quality. It is very important to find new potential pathogenic mechanisms, biomarkers, and targets with therapeutic value in COPD.

METHODS

Serum samples collected from acute exacerbation and stable COPD and healthy participants were analyzed using label-free liquid chromatography tandem mass spectrometry to identify the differentially expressed proteins (DEPs) between two groups. Bioinformatics analyses were performed to determine the biological processes associated with those DEPs. Key proteins were validated by enzyme linked immunosorbent assay (ELISA).

RESULTS

In total, 661 proteins were detected in serum from patients with COPD and healthy participants. Compared with healthy participants, patients with acute exacerbation of COPD had 45 DEPs, 13 were upregulated and 32 were downregulated; and patients with stable COPD had 79 DEPs, 18 were upregulated and 61 were downregulated. Gene Ontology functional annotation results indicated that the DEPs identified in patients with COPD were associated with the terms cellular anatomical entity, binding, and cellular process. Kyoto Encyclopedia of Genes and Genomes functional annotation analysis and the Clusters of Orthologous Genes database analysis indicated that the functions of these DEPs were primarily in signal transduction mechanisms and amino acid transport and metabolism. The ELISA results for three key proteins of IGFBP2, LRG1 and TAGLN were consistent with the LC-MS/MS results and the area under the receiver operating characteristic of the combined index was 0.893 (95% CI: 0.813, 0.974).

CONCLUSION

Our findings suggested pathogenic mechanisms underlying COPD stages and indicated three key proteins that may warrant further study as potential biomarkers for early diagnosis or prognosis of COPD or as therapeutic targets.

Obstructive Sleep Apnoea and Lipid Metabolism: The Summary of Evidence and Future Perspectives in the Pathophysiology of OSA-Associated Dyslipidaemia

Obstructive sleep apnoea (OSA) is associated with cardiovascular and metabolic comorbidities, including hypertension, dyslipidaemia, insulin resistance and atherosclerosis. Strong evidence suggests that OSA is associated with an altered lipid profile including elevated levels of triglyceride-rich lipoproteins and decreased levels of high-density lipoprotein (HDL). Intermittent hypoxia; sleep fragmentation; and consequential surges in the sympathetic activity, enhanced oxidative stress and systemic inflammation are the postulated mechanisms leading to metabolic alterations in OSA. Although the exact mechanisms of OSA-associated dyslipidaemia have not been fully elucidated, three main points have been found to be impaired: activated lipolysis in the adipose tissue, decreased lipid clearance from the circulation and accelerated de novo lipid synthesis. This is further complicated by the oxidisation of atherogenic lipoproteins, adipose tissue dysfunction, hormonal changes, and the reduced function of HDL particles in OSA. In this comprehensive review, we summarise and critically evaluate the current evidence about the possible mechanisms involved in OSA-associated dyslipidaemia.

HDL Cholesterol Efflux and Serum Cholesterol Loading Capacity Alterations Associate to Macrophage Cholesterol Accumulation in FH Patients with Achilles Tendon Xanthoma

Achilles tendon xanthoma (ATX) formation involves macrophage cholesterol accumulation within the tendon, similar to that occurring in atheroma. Macrophage cholesterol homeostasis depends on serum lipoprotein functions, namely the high-density lipoprotein (HDL) capacity to promote cell cholesterol efflux (cholesterol efflux capacity, CEC) and the serum cholesterol loading capacity (CLC). We explored the HDL-CEC and serum CLC, comparing 16 FH patients with ATX to 29 FH patients without ATX. HDL-CEC through the main efflux mechanisms mediated by the transporters ATP binding cassette G1 (ABCG1) and A1 (ABCA1) and the aqueous diffusion (AD) process was determined by a cell-based radioisotopic technique and serum CLC fluorimetrically. Between the two groups, no significant differences were found in terms of plasma lipid profile. A trend toward reduction of cholesterol efflux via AD and a significant increase in ABCA1-mediated HDL-CEC (+18.6%) was observed in ATX compared to no ATX patients. In ATX-presenting patients, ABCG1-mediated HDL-CEC was lower (−11%) and serum CLC was higher (+14%) compared to patients without ATX. Considering all the patients together, ABCG1 HDL-CEC and serum CLC correlated with ATX thickness inversely (p = 0.013) and directly (p < 0.0001), respectively. In conclusion, lipoprotein dysfunctions seem to be involved in ATX physiopathology and progression in FH patients.

Identification of Potential Prognostic Markers and Key Therapeutic Targets in Hepatocellular Carcinoma Using Weighted Gene Co-Expression Network Analysis: A Systems Biology Approach

BACKGROUND

As the most prevalent form of liver cancer, hepatocellular carcinoma (HCC) ranks the fifth highest cause of cancer-related death worldwide. Despite recent advancements in diagnostic and therapeutic techniques, the prognosis for HCC is still unknown.

OBJECTIVES

This study aimed to identify potential genes contributing to HCC pathogenicity.

MATERIALS AND METHODS

To this end, we examined the GSE39791 microarray dataset, which included 72 HCC samples and 72 normal samples. An investigation of co-expression networks using WGCNA found a highly conserved blue module with 665 genes that were strongly linked to HCC.

RESULTS

APOF, NAT2, LCAT, TTC36, IGFALS, ASPDH, and VIPR1 were the blue module's top 7 hub genes. According to the results of hub gene enrichment, the most related issues in the biological process and KEGG were peroxisome organization and metabolic pathways, respectively. In addition, using the drug-target network, we discovered 19 FDA-approved medication candidates for different reasons that might potentially be employed to treat HCC patients through the modulation of 3 hub genes of the co-expression network (LCAT, NAT2, and VIPR1). Our findings also demonstrated that the 3 scientifically validated miRNAs regulated the co-expression network by the VIPR1 hub gene.

CONCLUSION

We found co-expressed gene modules and hub genes linked with HCC advancement, offering insights into the mechanisms underlying HCC progression as well as some potential HCC treatments.

The Functional Role of Lipoproteins in Atherosclerosis: Novel Directions for Diagnosis and Targeting Therapy

Dyslipidemia, characterized by a high level of lipids (cholesterol, triglycerides, or both), can increase the risk of developing and progressing atherosclerosis. As atherosclerosis progresses, the number and severity of aterial plagues increases with greater risk of myocardial infarction, a major contributor to cardiovascular mortality. Atherosclerosis progresses in four phases, namely endothelial dysfunction, fatty streak formation, lesion progression and plaque rupture, and eventually thrombosis and arterial obstruction. With greater understanding of the pathological processes underlying atherosclerosis, researchers have identified that lipoproteins play a significant role in the development of atherosclerosis. In particular, apolipoprotein B (apoB)-containing lipoproteins have been shown to associate with atherosclerosis. Oxidized low-density lipoproteins (ox-LDLs) also contribute to the progression of atherosclerosis whereas high-density lipoproteins (HDL) contribute to the removal of cholesterol from macrophages thereby inhibiting the formation of foam cells. Given these known associations, lipoproteins may have potential as biomarkers for predicting risk associated with atherosclerotic plaques or may be targets as novel therapeutic agents. As such, the rapid development of drugs targeting lipoprotein metabolism may lead to novel treatments for atherosclerosis. A comprehensive review of lipoprotein function and their role in atherosclerosis, along with the latest development of lipoprotein targeted treatment, is timely. This review focuses on the functions of different lipoproteins and their involvement in atherosclerosis. Further, diagnostic and therapeutic potential are highlighted giving insight into novel lipoprotein-targetted approaches to treat atherosclerosis.

Control of Cholesterol Metabolism Using a Systems Approach

Simple Summary

Cholesterol is the main sterol in mammals that is essential for healthy cell functionining. It plays a key role in metabolic regulation and signaling, it is a precursor molecule of bile acids, oxysterols, and all steroid hormones. It also contributes to the structural makeup of the membranes. Its homeostasis is tightly controlled since it can harm the body if it is allowed to reach abnormal blood concentrations. One of the diseases associated with elevated cholesterol levels being the major cause of morbidities and mortalities worldwide, is atherosclerosis. In this study, we have developed a model of the cholesterol metabolism taking into account local inflammation and oxidative stress. The aim was to investigate the impact of the interplay of those processes and cholesterol metabolism disturbances on the atherosclerosis development and progression. We have also analyzed the effect of combining different classes of drugs targeting selected components of cholesterol metabolism.

Abstract

Cholesterol is an essential component of mammalian cells and is involved in many fundamental physiological processes; hence, its homeostasis in the body is tightly controlled, and any disturbance has serious consequences. Disruption of the cellular metabolism of cholesterol, accompanied by inflammation and oxidative stress, promotes the formation of atherosclerotic plaques and, consequently, is one of the leading causes of death in the Western world. Therefore, new drugs to regulate disturbed cholesterol metabolism are used and developed, which help to control cholesterol homeostasis but still do not entirely cure atherosclerosis. In this study, a Petri net-based model of human cholesterol metabolism affected by a local inflammation and oxidative stress, has been created and analyzed. The use of knockout of selected pathways allowed us to observe and study the effect of various combinations of commonly used drugs on atherosclerosis. The analysis results led to the conclusion that combination therapy, targeting multiple pathways, may be a fundamental concept in the development of more effective strategies for the treatment and prevention of atherosclerosis.

Long-term high-fructose high-fat diet feeding elicits insulin resistance, exacerbates dyslipidemia and induces gut microbiota dysbiosis in WHHL rabbits

The metabolic syndrome (MetS) has become a global public health burden due to its link to cardiovascular disease and diabetes mellitus. The present study was designed to characterize the metabolic and cardiovascular disturbances, as well as changes in gut microbiota associated with high-fructose high-fat diet (HFFD)-induced MetS in Watanabe heritable hyperlipidemic (WHHL) rabbits. Twenty-one Watanabe rabbits were assigned to a control (n = 9) and HFFD (n = 12) groups, receiving a chow diet and a HFFD, respectively. During a 12-weeks protocol, morphological parameters were monitored; plasma fasting levels of lipids, glucose and insulin were measured and a glucose tolerance test (GTT) was performed. HOMA-IR was calculated. Cardiac function and vascular reactivity were evaluated using the Langendorff isolated heart and isolated carotid arteries methods, respectively. 16S rRNA sequencing of stool samples was used to determine gut microbial composition and abundance. HFFD-fed Watanabe rabbits exhibited increased fasting insulin (p < 0.03, 12^th week vs. Baseline), HOMA-IR (p < 0.03 vs. Control), area under the curve of the GTT (p < 0.02 vs. Control), triglycerides (p < 0.05, 12^th week vs. Baseline), TC (p < 0.01 vs. Control), LDL-C (p < 0.001 vs. Control). The HFFD group also displayed a significant decrease in intestinal microbial richness, evenness and diversity (FDR < 0.001, FDR < 0.0001, FDR < 0.01, respectively vs. Control group) and an increase in its Firmicutes/Bacteroidetes ratio (R = 3.39 in control vs. R = 28.24 in the HFFD group) indicating a shift in intestinal microbial composition and diversity. Our results suggest that HFFD induces insulin resistance and gut microbiota dysbiosis and accentuates dyslipidemia; and that, when subjected to HFFD, Watanabe rabbits might become a potential diet-induced MetS animal models with two main features, dyslipidemia and insulin resistance.

Cholesterol Transport Dysfunction and Its Involvement in Atherogenesis

Atherosclerosis is the cause of the development of serious cardiovascular disorders, leading to disability and death. Numerous processes are involved in the pathogenesis of atherosclerosis, including inflammation, endothelial dysfunction, oxidative stress, and lipid metabolism disorders. Reverse transport of cholesterol is a mechanism presumably underlying the atheroprotective effect of high-density lipoprotein. In this review, we examined disorders of cholesterol metabolism and their possible effect on atherogenesis. We paid special attention to the reverse transport of cholesterol. Transformed cholesterol metabolism results in dyslipidemia and early atherosclerosis. Reverse cholesterol transport is an endogenous mechanism by which cells export cholesterol and maintain homeostasis. It is known that one of the main factors leading to the formation of atherosclerotic plaques on the walls of blood vessels are multiple modifications of low-density lipoprotein, and the formation of foam cells following them.

Mathematical Models for Cholesterol Metabolism and Transport

Cholesterol is an essential component of eukaryotic cellular membranes. It is also an important precursor for making other molecules needed by the body. Cholesterol homeostasis plays an essential role in human health. Having high cholesterol can increase the chances of getting heart disease. As a result of the risks associated with high cholesterol, it is imperative that studies are conducted to determine the best course of action to reduce whole body cholesterol levels. Mathematical models can provide direction on this. By examining existing models, the suitable reactions or processes for drug targeting to lower whole-body cholesterol can be determined. This paper examines existing models in the literature that, in total, cover most of the processes involving cholesterol metabolism and transport, including: the absorption of cholesterol in the intestine; the cholesterol biosynthesis in the liver; the storage and transport of cholesterol between the intestine, the liver, blood vessels, and peripheral cells. The findings presented in these models will be discussed for potential combination to form a comprehensive model of cholesterol within the entire body, which is then taken as an in-silico patient for identifying drug targets, screening drugs, and designing intervention strategies to regulate cholesterol levels in the human body.

Unraveling the molecular mechanisms of hyperlipidemia using integrated lncRNA and mRNA microarray data

Long non-coding RNAs (lncRNAs) have key roles in various diseases; however, their functions in hyperlipidemia (HLP) have remained elusive. In the present study, microarray technology was utilized to analyze the differential expression of lncRNAs and mRNAs in liver tissues of apolipoprotein E^-/- mice as a model of HLP compared with control mice. A total of 104 and 96 differentially expressed lncRNAs and mRNAs, respectively, were identified. Differentially expressed genes were significantly enriched in biological processes such as nitric oxide biosynthesis, innate immune response and inflammatory response. Finally, two pairs of target genes and 38 transcription factors with regulatory functions in HLP were predicted based on the lncRNA and mRNA co-expression network. The lncRNA expression profile was significantly altered in liver tissues of the mouse model of HLP and may provide novel targets for research into treatments.

A Cross-Sectional Study of the Association Between Chronic Oral Disease Burden and Serum Biomarkers in Kidney Transplant Recipients

INTRODUCTION

Poor oral health can negatively affect general health and quality of life of kidney transplant recipients. The study aimed to investigate the association between chronic oral disease burden, serum biomarkers, and comorbidities in kidney transplant recipients.

DESIGN

A cross-sectional comparative study was conducted with 44 patients after kidney transplant. The burden of chronic oral disease was composed of the following observable variables: moderate periodontitis and presence of dental caries. Serum biomarkers and comorbidities data were collected. The chi-square or Fisher's exact tests for categorical variables and Student's t-test or Mann-Whitney test for continuous variables were used. Robust Poisson regression was used to model the association.

RESULTS

Higher levels of mean uric acid (P = .01) and creatinine (P = .03) were observed in the group of patients with oral disease burden, while the highest level of high-density lipoprotein was observed in the group without oral disease. Higher values of uric acid were associated with the occurrence of chronic oral disease burden (Adjusted PR = 1.24, 95% CI: 1.03-1.48, P = .019). There was no statistical difference between the groups with and without oral disease burden in comorbidities present.

CONCLUSION

The findings suggest that chronic oral diseases burden can be associated with uric acid and creatinine levels in kidney transplant recipients.

Ultrasound-targeted simvastatin-loaded microbubble destruction promotes OA cartilage repair by modulating the cholesterol efflux pathway mediated by PPARγ in rabbits

Aims

To evaluate the effect of ultrasound-targeted simvastatin-loaded microbubble destruction (UTMD_SV) for alleviation of the progression of osteoarthritis (OA) in rabbits through modulation of the peroxisome proliferator-activated receptor (PPARγ).

Methods

In vitro, OA chondrocytes were treated with ultrasound (US), US-targeted microbubble destruction (UTMD), simvastatin (SV), and UTMD_SV on alternate days for four weeks. Chondrocytes were also treated with PPARγ inhibitor, PPARγ inhibitor+ UTMD_SV, and UTMD_SV. The cholesterol efflux rate and triglyceride levels were measured using an assay kit and oil red O staining, respectively. In vivo, the OA rabbits were treated with a single intra-articular injection of UTMD, SV, and UTMD_SV every seven days for four weeks. Cartilage histopathology was assessed by safranin-O staining and the Mankin score. Total cholesterol (TC) and high-density lipoprotein-cholesterol (HDL-C) in rabbit knee synovial fluid were detected by enzyme-marker assay. Aggrecan, collagen II, and PPARγ expression levels were analyzed by Western blotting (WB).

Results

In vitro, UTMD_SV significantly increased the cholesterol efflux rate and aggrecan, collagen II, and PPARγ levels in OA chondrocytes; these effects were blocked by the PPARγ inhibitor. In vivo, UTMD_SV significantly increased aggrecan, collagen II, PPARγ, and HDL-C levels, while TC levels and Mankin scores were decreased compared with the UTMD, SV, OA, and control groups.

Conclusion

UTMD_SV promotes cartilage extracellular matrix synthesis by modulating the PPARγ-mediated cholesterol efflux pathway in OA rabbits.

Cite this article: Bone Joint Res 2021;10(10):693–703.

Freeze-Dried Powder of Rubus coreanus Miquel Ameliorates Isoproterenol-Induced Oxidative Stress and Tissue Damage in Rats

Rubus coreanus Miquel (bokbunja), Korean black raspberry, is known to possess various phytochemicals that exert antioxidative, anti-inflammatory, and anti-cancer effects. However, most studies on Rubus coreanus Miquel have been performed with the solvent extracts and/or a single component to demonstrate the efficacy, while studies evaluating the effect of the whole fructus of Rubus coreanus Miquel are limited. In this study, therefore, we employed the isoproterenol (IPN)-induced myocardial infarction model and investigated the effect of freeze-dried powder of Rubus coreanus Miquel (RCP) on oxidative stress and prevention of organ damage. Oral administration of RCP reduced the level of toxicity markers, alanine transaminase (ALT), aspartate transaminase (AST), and lactate dehydrogenase (LDH) without affecting body weight and diet intake. The oxidative stress marker glutathione (GSH) increased about 45% and malonaldehyde (MDA) decreased about 27% compared to the IPN group with RCP-H (3%) administration. By histological analysis, IPN induced significant myocardial damage in the heart and vascular injury in the liver, and RCP administration ameliorated the damages in a dose-dependent manner. Taken together, RCP activated the antioxidant system leading to prevention of damage to organs by IPN in rats, making it possible to expect beneficial efficacies by consuming the whole fructus of Rubus coreanus Miquel.

Expression of the circular RNAs in astaxanthin promotes cholesterol efflux from THP-1 cells based on RNA-seq

BACKGROUND

It is reported that circular RNAs (circRNAs) play a key role in atherosclerosis (AS). Foam cell formation, which is the main feature of AS, can be significantly inhibited by cholesterol efflux.

METHODS

We established a model of astaxanthin (AST) promoting cholesterol efflux from macrophages through oil red O staining, real-time quantitative PCR (qRT-PCR), and western blot and used RNA sequencing to detect the expression of circRNAs in AST-treated and untreated THP-1 cells. Finally, siRNA transfection screened out circRNAs that were significantly differentially expressed. The data analysis was performed by Student's t test and P < 0.05 was considered statistically significant.

RESULTS

In the model of AST promoting cholesterol efflux from THP-1 cells, there were a total of 7276 circRNAs differentially expressed, among which the top 25 upregulated and the top 25 downregulated circRNAs were selected based on the log2 (fold change). GO analysis showed that differential expression of circRNAs in biological process (2066/3098; 66.69%), molecular function (543/3098; 17.53%), and cellular component (489/3098; 15.78%). Based on KEGG analysis, RNA transport was the most enriched pathway. Finally, we obtained 3 significantly upregulated circRNAs by siRNA transfection and qRT-PCR.

CONCLUSIONS

The 3 differentially expressed circRNAs may play an important role in the process of AST promoting cholesterol efflux and may be used as biomarkers to prevent AS.

The Role of High-Density Lipoprotein in COVID-19

The current Coronavirus disease 2019 (COVID-19) pandemic has become a global challenge. Managing a large number of acutely ill patients in a short time, whilst reducing the fatality rate and dealing with complications, brings unique difficulties. The most striking pathophysiological features of patients with severe COVID-19 are dysregulated immune responses and abnormal coagulation function, which can result in multiple-organ failure and death. Normally metabolized high-density lipoprotein (HDL) performs several functions, including reverse cholesterol transport, direct binding to lipopolysaccharide (LPS) to neutralize LPS activity, regulation of inflammatory response, anti-thrombotic effects, antioxidant, and anti-apoptotic properties. Clinical data shows that significantly decreased HDL levels in patients with COVID-19 are correlated with both disease severity and mortality. However, the role of HDL in COVID-19 and its specific mechanism remain unclear. In this analysis, we review current evidence mainly in the following areas: firstly, the pathophysiological characteristics of COVID-19, secondly, the pleiotropic properties of HDL, thirdly, the changes and clinical significance of HDL in COVID-19, and fourthly the prospect of HDL-targeting therapy in COVID-19 to clarify the role of HDL in the pathogenesis of COVID-19 and discuss the potential of HDL therapy in COVID-19.

Prevalence of High HDL Cholesterol and Its Associated Factors Among Tunisian Women of Childbearing Age: A Cross-Sectional Study

The protective role of high high-density lipoprotein cholesterol (HDL-C) against cardiovascular risk has been questioned recently. Due to the increasing trend of cardiovascular diseases (CVD) in Tunisia, this study aimed to determine the prevalence of high HDL-C and its associated factors in Tunisian women of childbearing age. A cross-sectional survey was conducted among a subsample of 1689 women, aged 20 to 49 years, in the Great Tunis region. Data on socio-demographic and lifestyle factors were collected by a questionnaire. Overall adiposity was assessed by body mass index (BMI). All biological variables were assayed in blood samples coated with anticoagulant ethylene diamine tetra acetic acid (EDTA) by enzymatic methods. Stata software (2015) was used for data management and statistical analysis. High HDL-C values were recorded in 26.6% of selected women. After adjustment for all socio-demographic and lifestyle factors, age, hypertension, and smoking were negatively associated with high HDL-C levels, while family history of cancer was positively associated with high HDL-C in women. An additional investigation on the relationship between high HDL-C and cancer risk should be performed due to controversial results.

Food Chemistry of Selenium and Controversial Roles of Selenium in Affecting Blood Cholesterol Concentrations

Hypercholesterolemia, one of the major risk factors of cardiovascular diseases, is a worldwide public health problem. Nutraceuticals and phytochemicals are attracting attention as a result of their cholesterol-lowering ability and minimal side effects. Among them, selenium (Se) is on the list. The amount of Se in foods varies by region. Se-enriched fertilizers and feeds can raise the Se content in plants and animals, while some processing methods decrease food Se content. This review summarizes recent studies on (1) the content distribution of Se in foods and factors influencing Se-enriched foods, (2) the bioavailability and metabolism of Se, and (3) the role of Se in affecting blood cholesterol and cholesterol metabolism. Although the hypocholesterolemic effect of Se is equivocal, its cholesterol-lowering activity may be more remarkable when the Se supplementation is 200 μg/day or the baseline blood total cholesterol is above 200 mg/dL in humans with low Se status.

High-fat diet-induced memory impairment and anxiety-like behavior in rats attenuated by peel extract of Ananas comosus fruit via atheroprotective, antioxidant and anti-inflammatory actions

BACKGROUND

Pineapple peel is a waste component of pineapple with valuable source of metabolites as phytoactive compounds in ameliorating metabolic-related disorders. This study investigated the atheroprotective and neuroprotective effects of peel extract of Ananas comosus fruit (PEAC) in normal diet (ND) and high-fat diet (HFD) fed rats.

METHODS

Male Wistar rats were fed ND or HFD for 9 weeks, and beginning from the 6th week animals were also orally treated with PEAC (200 mg/kg). Memory performance was assessed using Y-maze test (YMT) and novel object recognition test (NORT) while anxiolytic-like effect was assessed on the elevated plus maze (EPM). Serum cholesterol, triglycerides and HDL-C were determined, while LDL-C and atherogenic risk calculated. Serum and brain tissue malondialdehyde, reduced glutathione, catalase were determined. Brain acetylcholinesterase activity and interleukin-6 level were also determined.

RESULTS

PEAC significantly attenuated HFD-induced reduction in correct alternation in YMT, and discrimination index in NORT. Also, PEAC demonstrated anxiolytic-like activity in EPM test. PEAC significantly improved lipid profile and decreased risk of atherogenicity in ND and HFD-fed rats. In addition, PEAC improves serum and brain antioxidant status by decreasing malondialdehyde and increasing GSH and catalase. PEAC significantly impaired HFD-induced brain acetylcholinesterase activity and IL-6 levels.

CONCLUSION

These findings suggest that peel extract of Ananas comosus fruit may protect against diet-induced behavioral disturbances via atheroprotective, antioxidants and anti-inflammatory activities.

Monounsaturated Fatty Acids in Obesity-Related Inflammation

Obesity is an important aspect of the metabolic syndrome and is often associated with chronic inflammation. In this context, inflammation of organs participating in energy homeostasis (such as liver, adipose tissue, muscle and pancreas) leads to the recruitment and activation of macrophages, which secrete pro-inflammatory cytokines. Interleukin-1β secretion, sustained C-reactive protein plasma levels and activation of the NLRP3 inflammasome characterize this inflammation. The Stearoyl-CoA desaturase-1 (SCD1) enzyme is a central regulator of lipid metabolism and fat storage. This enzyme catalyzes the generation of monounsaturated fatty acids (MUFAs)-major components of triglycerides stored in lipid droplets-from saturated fatty acid (SFA) substrates. In this review, we describe the molecular effects of specific classes of fatty acids (saturated and unsaturated) to better understand the impact of different diets (Western versus Mediterranean) on inflammation in a metabolic context. Given the beneficial effects of a MUFA-rich Mediterranean diet, we also present the most recent data on the role of SCD1 activity in the modulation of SFA-induced chronic inflammation.

Sterically stabilized recombined HDL composed of modified apolipoprotein A-I for efficient targeting toward glioma cells

Reconstituted high density lipoprotein (rHDL) has been regarded as a promising brain-targeting vehicle for anti-glioma drugs under the mediation of apolipoprotein A-I (apoA-I). However, some stability issues relating to drug leakage and consequent reduced targeting efficiency in the course of discoidal rHDL (d-rHDL) circulating in blood hinder its broad application. The objective of the study was to develop a novel stabilized d-rHDL by replacing cholesterol and apoA-I with mono-cholesterol glutarate (MCG) modified apoA-I (termed as mA) and to evaluate its allosteric behavior and glioma targeting. MCG was synthesized through esterifying the hydroxyl of cholesterol with glutaric anhydride and characterized by FI-IR and 1H NMR. d-rHDL assembled with mA (termed as m-d-rHDL) presented similar properties such as minute particle size and disk-like appearance resembling nascent HDL. Morphological transformation observation and in vitro release plots convinced that the modification of cholesterol could effectively inhibit the remolding of d-rHDL. The uptake of m-d-rHDL by LCAT-pretreated bEND.3 cells was significantly higher than that of d-rHDL, thereby serving as another proof for the capability of m-d-rHDL in enhancing targeting property. Besides, apoA-I anchoring into m-d-rHDL played a critical role in the endocytosis process into bEND.3 cells and C6 cells, which implied the possibility of traversing blood brain barrier and accumulating in the brain and glioma. These results suggested that the modification toward cholesterol to improve the stability of d-rHDL is advantageous, and that this obtained m-d-rHDL revealed great potential for realization of suppressing the remolding of d-rHDL in the brain-targeted treatment of glioma for drug delivery.

High-Density Lipoproteins as Homeostatic Nanoparticles of Blood Plasma

It is well known that blood lipoproteins (LPs) are multimolecular complexes of lipids and proteins that play a crucial role in lipid transport. High-density lipoproteins (HDL) are a class of blood plasma LPs that mediate reverse cholesterol transport (RCT)-cholesterol transport from the peripheral tissues to the liver. Due to this ability to promote cholesterol uptake from cell membranes, HDL possess antiatherogenic properties. This function was first observed at the end of the 1970s to the beginning of the 1980s, resulting in high interest in this class of LPs. It was shown that HDL are the prevalent class of LPs in several types of living organisms (from fishes to monkeys) with high resistance to atherosclerosis and cardiovascular disorders. Lately, understanding of the mechanisms of the antiatherogenic properties of HDL has significantly expanded. Besides the contribution to RCT, HDL have been shown to modulate inflammatory processes, blood clotting, and vasomotor responses. These particles also possess antioxidant properties and contribute to immune reactions and intercellular signaling. Herein, we review data on the structure and mechanisms of the pleiotropic biological functions of HDL from the point of view of their evolutionary role and complex dynamic nature.

Regulatory Roles of Related Long Non-coding RNAs in the Process of Atherosclerosis

Atherosclerosis (AS) is the main cause of coronary heart disease, cerebral infarction, and peripheral vascular disease, which comprise serious hazards to human health. Atherosclerosis is characterized by the deposition of lipids on the interior walls of blood vessels, causing an inflammatory response of immune cells, endothelial cells, and smooth muscle cells, and a proliferation cascade reaction. Despite years of research, the underlying pathogenesis of AS is not fully defined. Recent advances in our understanding of the molecular mechanisms by which non-coding RNA influences the initiation and progression of AS have shown that long non-coding RNAs (lncRNAs) regulate important stages in the atherosclerotic process. In this review, we summarize current knowledge of lncRNAs, which influence the development of AS. We review the regulatory processes of lncRNAs on core stages of atherosclerotic progression, including lipid metabolism, inflammation, vascular cell proliferation, apoptosis, adhesion and migration, and angiogenesis. A growing body of evidence suggests that lncRNAs have great potential as new therapeutic targets for the treatment of vascular diseases.

Early pregnancy serum IGFBP-1 relates to lipid profile in overweight and obese women

Lower level of insulin-like growth factor-binding protein (IGFBP-1) has been observed in insulin resistance, while higher level of matrix metalloproteinase-8 (MMP-8) has been linked to obesity. The aim here was to study in overweight and obese women, typically manifesting with insulin resistance, whether IGFBP-1 and MMP-8 are related to and reflect systemic low-grade inflammation, metabolism and diet. Fasting serum from overweight and obese pregnant women (n = 100) in early pregnancy were analysed for IGFBP-1, phosphorylated IGFBP-1 (phIGFBP-1) and MMP-8. High-sensitivity CRP and GlycA were used as markers for low grade inflammation. GlycA and lipids were quantified using NMR. IGFBP-1 associated negatively with GlycA, evidenced by higher concentrations in the lowest quartile (median 1.53 (IQR 1.45–1.72)) compared to the highest (1.46 (1.39–1.55)) (P = 0.03). Several lipid metabolites, particularly HDL-cholesterol, correlated inversely with phIGFBP-1 (FDR<0.1). Nutritional status and diet contributed to the levels of IGFBP-1, demonstrated as an inverse correlation with maternal weight (Spearman r = -0.205, P = 0.04) and dietary intake of vitamin A (r = -0.253, P = 0.014) and a direct correlation with dietary intake of polyunsaturated fatty acids (Spearman r = 0.222, P = 0.03). MMP-8 correlated inversely with pyridoxine (r = -0.321, P = 0.002) and potassium (r = -0.220, P = 0.033). Maternal serum IGFBP-1 may contribute to maternal lipid metabolism in overweight and obese women during early pregnancy. These findings may be of importance in identification of metabolic disturbances preceding the adverse metabolic outcomes in pregnancy.

The Effect of Haplotypes in the CETP and LIPC Genes on the Triglycerides to HDL-C Ratio and Its Components in the Roma and Hungarian General Populations

BACKGROUND

The triglycerides (TG) to high-density lipoprotein (HDL)-cholesterol (HDL-C) ratio (TG/HDL-C) is a well-known predictor for cardiovascular diseases (CVDs) with great heritability background. The cholesteryl ester transfer protein (CETP) and hepatic lipase (LIPC) gene affect TG/HDL-C ratio. This study aims to explore the association between haplotypes (H) in CETP (based on 5 single nucleotide polymorphisms (SNPs)) and LIPC (based on 6 SNPs) genes and the TG/HDL-C ratio and its components, among Roma and Hungarian general populations.

METHODS

The prevalence of haplotypes and their effect on HDL-C, TG and TG/HDL-C ratio were calculated in both populations and compared.

RESULTS

Ten haplotypes in CETP and 6 in LIPC gene were identified. Three haplotypes in CETP and 3 in LIPC have significant effect on HDL-C level, whereas two in CETP and 3 in LIPC on TG level. The H6 in CETP (β = 0.52, p = 0.015; odds ratio (OR) = 1.87, p = 0.009) and H5 in LIPC (β = 0.56, p < 0.001; OR = 1.51, p = 0.002) have a significant increasing effect on TG/HDL-C ratio and have shown higher prevalence among the Roma, as compared to Hungarian general population. The H2 in the CETP gene has a decreasing effect on the TG/HDL-C ratio (OR = 0.58, p = 0.019) and is significantly less frequent among the Roma.

CONCLUSIONS

Accumulation of harmful haplotypes in CETP and LIPC genes might have a role in the elevated TG/HDL-C ratio in the Roma population, which contributes to a higher risk in the development of cardiovascular diseases.

Effects of obesity on the lipid and metabolite profiles of young adults by serum 1H-NMR spectroscopy

BACKGROUND

Overweight (OW) is considered a risk for various metabolic diseases. However, its effects as a mechanism that alters the metabolite profiles remain unclear. The purpose of this study is to investigate the effects that OW has on the lipid and metabolite profiles in young adults.

METHODS

The serum metabolite profiles of 46 young adults of normal weight and those considered OW were studied by Proton nuclear magnetic resonance spectroscopy (1H NMR) technique.

RESULTS

1H NMR metabolite analysis shows the alteration of metabolic levels and increased levels of CH2 lipids and CH3 lipids, which are used as unique biomarkers to identify OW subjects from the normal weight groups.

CONCLUSION

This present study reveals that OW contributes to the systemic metabolism and the metabolite alteration among young adults. The alteration in serum lipids level could shed the light on metabolic syndrome pathogenesis in young adults and needs further elucidation.

Lycopene Inhibits Smoke-Induced Chronic Obstructive Pulmonary Disease and Lung Carcinogenesis by Modulating Reverse Cholesterol Transport in Ferrets

Chronic obstructive pulmonary disease (COPD) and lung cancer share the same etiologic factor, cigarette smoking. Higher consumption of dietary lycopene has been associated with lower risks of COPD and lung cancer in smokers. We investigated whether lycopene feeding protects against COPD and lung cancer in ferrets, a nonrodent model that closely mimics cigarette smoke (CS)-induced chronic bronchitis, emphysema, and lung tumorigenesis in human. We also explored whether the protective effect of lycopene is associated with restoring reverse cholesterol transport (RCT), a key driver in persistent inflammation with CS exposure. Ferrets (4 groups, n = 12-16/group) were exposed to a combination of tobacco carcinogen (NNK) and CS with or without consuming lycopene at low and high doses (equivalent to ∼30 and ∼90 mg lycopene/day in human, respectively) for 22 weeks. Results showed that dietary lycopene at a high dose significantly inhibited NNK/CS-induced chronic bronchitis, emphysema, and preneoplastic lesions, including squamous metaplasia and atypical adenomatous hyperplasia, as compared with the NNK/CS alone (P < 0.05). Lycopene feeding also tended to decrease the lung neoplastic lesions. Furthermore, lycopene feeding significantly inhibited NNK/CS-induced accumulation of total cholesterol, and increased mRNA expression of critical genes related to the RCT (PPARα, LXRα, and ATP-binding cassette transporters ABCA1 and ABCG1) in the lungs, which were downregulated by the NNK/CS exposure. The present study has provided the first evidence linking a protective role of dietary lycopene against COPD and preneoplastic lesions to RCT-mediated cholesterol accumulation in lungs.

Cynanchum wilfordii Etanolic Extract Controls Blood Cholesterol: A Double-blind, Randomized, Placebo-Controlled, Parallel Trial

We evaluated the effects of Cynanchum wilfordii (CW) ethanolic extract on blood cholesterol levels in adults with high low-density lipoprotein cholesterol (LDL-C) levels. In a double-blind, randomized, placebo-controlled, parallel trial, 84 subjects were recruited. Participants were randomly divided into two groups with a low-dose (300 mg/d) or high-dose (600 mg/d) of CW. Levels of very low-density lipoprotein (p = 0.022) and triglycerides (p = 0.022) were significantly lower in the low-dose CW group than in the placebo group after 8 weeks. In a subgroup of participants with LDL-C≥ 150 mg/dL (n = 33), there was a significant decrease in total cholesterol (low-dose, p = 0.012; high-dose, p = 0.021), apolipoprotein B (low-dose, p = 0.022; high-dose, p = 0.016), and cholesteryl ester transfer protein (low-dose, p = 0.037; high-dose, p = 0.016) after 8 weeks of CW. The correlation between changes in total cholesterol and baseline LDL-C levels was significant in the groups that received both doses of CW (low-dose, p = 0.010; high-dose, p = 0.015). These results show that the CW ethanolic extract can regulate blood cholesterol in subjects with LDL-C≥ 150 mg/dL.

Lipidomics unveils the complexity of the lipidome in metabolic diseases

Dysregulation of lipid metabolism is responsible for pathologies of human diseases including metabolic diseases. Recent advances in lipidomics analysis allow for the targeted and untargeted identification of lipid species and for their quantification in normal and diseased conditions. Herein, this review provides a brief introduction to lipidomics, highlights its application to characterize the lipidome at the cellular and physiological levels under different biological conditions, and discusses the potential for the use of lipidomics in the discovery of biomarkers.

Potential Link Between Proprotein Convertase Subtilisin/Kexin Type 9 and Alzheimer's Disease

Alzheimer's disease [AD] is not only the most common neurodegenerative disease but is also currently incurable. Proprotein convertase subtilisin/kexin-9 [PCSK9] is an indirect regulator of plasma low density lipoprotein [LDL] levels controlling LDL receptor expression at the plasma membrane. PCSK9 also appears to regulate the development of glucose intolerance, insulin resistance, abdominal obesity, inflammation, and hypertension, conditions that have been identified as risk factors for AD. PCSK9 levels also depend on age, sex, and ethnic background, factors associated with AD. Herein, we will review indirect evidence that suggests a link between PCSK9 levels and AD.