The high-fat high-fructose hamster as an animal model for niacin's biological activities in humans

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.

Brothers in Arms: ABCA1- and ABCG1-Mediated Cholesterol Efflux as Promising Targets in Cardiovascular Disease Treatment

Atherosclerosis is a leading cause of cardiovascular disease worldwide, and hypercholesterolemia is a major risk factor. Preventive treatments mainly focus on the effective reduction of low-density lipoprotein cholesterol, but their therapeutic value is limited by the inability to completely normalize atherosclerotic risk, probably due to the disease complexity and multifactorial pathogenesis. Consequently, high-density lipoprotein cholesterol gained much interest, as it appeared to be cardioprotective due to its major role in reverse cholesterol transport (RCT). RCT facilitates removal of cholesterol from peripheral tissues, including atherosclerotic plaques, and its subsequent hepatic clearance into bile. Therefore, RCT is expected to limit plaque formation and progression. Cellular cholesterol efflux is initiated and propagated by the ATP-binding cassette (ABC) transporters ABCA1 and ABCG1. Their expression and function are expected to be rate-limiting for cholesterol efflux, which makes them interesting targets to stimulate RCT and lower atherosclerotic risk. This systematic review discusses the molecular mechanisms relevant for RCT and ABCA1 and ABCG1 function, followed by a critical overview of potential pharmacological strategies with small molecules to enhance cellular cholesterol efflux and RCT. These strategies include regulation of ABCA1 and ABCG1 expression, degradation, and mRNA stability. Various small molecules have been demonstrated to increase RCT, but the underlying mechanisms are often not completely understood and are rather unspecific, potentially causing adverse effects. Better understanding of these mechanisms could enable the development of safer drugs to increase RCT and provide more insight into its relation with atherosclerotic risk. SIGNIFICANCE STATEMENT: Hypercholesterolemia is an important risk factor of atherosclerosis, which is a leading pathological mechanism underlying cardiovascular disease. Cholesterol is removed from atherosclerotic plaques and subsequently cleared by the liver into bile. This transport is mediated by high-density lipoprotein particles, to which cholesterol is transferred via ATP-binding cassette transporters ABCA1 and ABCG1. Small-molecule pharmacological strategies stimulating these transporters may provide promising options for cardiovascular disease treatment.

Novel microencapsulated probiotic blend for use in metabolic syndrome: design and in-vivo analysis

The increasing prevalence of the metabolic syndrome has made it a medical issue that currently affects 1 in 5 Canadians. The metabolic syndrome is defined by risk factors that predispose an individual to diabetes and cardiovascular disease. Current forms of interventions have been inadequate as substantiated by the fact that the prevalence of metabolic syndrome has not reduced over the years. The objective of this study was to investigate the therapeutic benefits of a novel microencapsulated probiotic blend in treating the metabolic syndrome. Three probiotic strains were microencapsulated into alginate-polylysine-alginate (APA) microcapsules: L. rhamnosus NCIMB 6375, L. plantarum NCIMB 8826 and L. fermentum NCIMB 5221. From the results, it was observed that the microencapsulated probiotic blend significantly reduced serum total cholesterol, LDL cholesterol and triglyceride levels (reducing from 516 mg/dL to 379 mg/dL, 314 mg/dL to 231 mg/dL and 580 mg/dL to 270 mg/dL, respectively). In addition, the administration of the microencapsulated probiotic blend was found to favourably influence the gut microbiota, decreasing Firmicutes levels and increasing Bacteroidetes levels. Overall, this work demonstrates the potential a microencapsulated probiotic blend could have in targeting multiple risk factors of the metabolic syndrome; however, greater research is still needed.

High-density lipoprotein metabolism, composition, function, and deficiency

PURPOSE OF REVIEW

To examine the recent advances in our knowledge of HDL metabolism, composition, function, and coronary heart disease (CHD), as well as marked HDL deficiency states because of mutations in the apolipoprotein (apo) A-I, ATP-binding cassette transfer protein A1 and lecithin cholesterol acyltransferase (LCAT) gene loci.

RECENT FINDINGS

It has been documented that apoA-I, myeloperoxidase and paraoxonase 1 (PON1) form a complex in HDL that is critical for HDL binding and function. Myeloperoxidase has a negative impact on HDL function, whereas PON1 has a beneficial effect. Patients who lack apoA-I develop markedly premature CHD. Patients who lack ATP-binding cassette transfer protein A1 transporter function have only very small discoidal preβ-1 HDL, and develop hepatosplenomegaly, intermittent neuropathy and premature CHD, although significant heterogeneity for these disorders has been reported. Patients with LCAT deficiency have abnormal small discoidal LDLs and HDL particles, and develop kidney failure. Enzyme replacement therapy is being developed for the latter disorder.

SUMMARY

Recent data indicates that proteins other than apoA-I and apoA-II such as MPO and PON1 have important effects on HDL function. There has been considerable recent progress made in our understanding of HDL protein content and function.

Effects of interventions on adiponectin and adiponectin receptors

Adiponectin secreted from adipose tissue binds to two distinct adiponectin receptors (AdipoR1 and AdipoR2) identified and exerts its anti-diabetic effects in insulin-sensitive organs including liver, skeletal muscle and adipose tissue as well as amelioration of vascular dysfunction in the various vasculatures. A number of experimental and clinical observations have demonstrated that circulating levels of adiponectin are markedly reduced in obesity, type 2 diabetes, hypertension, and coronary artery disease. Therapeutic interventions which can improve the action of adiponectin including elevation of circulating adiponectin concentration or up-regulation and/or activation of its receptors, could provide better understanding of strategies to ameliorate metabolic disorders and vascular disease. The focus of the present review is to summarize accumulating evidence showing the role of interventions such as pharmacological agents, exercise, and calorie restriction in the expression of adiponectin and adiponectin receptors.

Effect of Nicotinic acid/Laropiprant in the lipoprotein(a) concentration with regard to baseline lipoprotein(a) concentration and LPA genotype

BACKGROUND

Lipoprotein(a) [Lp(a)] is a lipoprotein in which apolipoproteinB-100 is linked to apolipoprotein(a) [apo(a)]. Significant variation in Lp(a) concentration is specific to LPA gene, which codes for apo(a). Nicotinic acid (NA) is used for treatment of dyslipidemias, and the lowering effect of NA on Lp(a) has been previously reported.

OBJECTIVE

To evaluate the Lp(a) lowering effect of 1g/20mg and 2g/40mgday of Nicotinic acid/Laropiprant in subjects with different baseline Lp(a) concentrations and depending on the LPA genotype.

METHODS

In an open-label, 10-week study, 1g/20mgday of NA/Laropiprant for 4weeks followed by 6weeks of 2g/40mgday conducted at 3 centers in Spain, 82 subjects were enrolled. Patients were studied at baseline and at the end of both treatment periods and were enrolled in three groups: normal Lp(a) (<50mg/dL), high Lp(a) (50-120mg/dL) and very high Lp(a) (>120mg/dL). The LPA genetic polymorphism was analyzed by a real-time PCR.

RESULTS

There was a significant difference in LPA genotypes among Lp(a) concentration groups and an inverse and significant correlation between baseline Lp(a) concentration and LPA genotype was found (R=-0.372, p<0.001). There were a significant decrease in total cholesterol, triglycerides, LDL cholesterol, apo B and Lp(a), and a significant increase in HDL cholesterol after NA/Laropiprant treatment, without changes in BMI. However, there were no statistical differences in percentage variation of analyzed variables depending on LPA genotype.

CONCLUSION

LPA genotype is a major determinant of Lp(a) baseline concentration. However, the lipid lowering effect of NA is not related to LPA genotype.