Oxidative burden in familial hypercholesterolemia

Gene expression profiling in elderly patients with familial hypercholesterolemia with and without coronary heart disease

BACKGROUND AND AIMS

Elderly familial hypercholesterolemia (FH) patients are at high risk of coronary heart disease (CHD) due to high cholesterol burden and late onset of effective cholesterol-lowering therapies. A subset of these individuals remains free from any CHD event, indicating the potential presence of protective factors. Identifying possible cardioprotective gene expression profiles could contribute to our understanding of CHD prevention and future preventive treatment. Therefore, this study aimed to investigate gene expression profiles in elderly event-free FH patients.

METHODS

Expression of 773 genes was analysed using the Nanostring Metabolic Pathways Panel, in peripheral blood mononuclear cells (PBMCs) from FH patients ≥65 years without CHD (FH event-free, n = 44) and with CHD (FH CHD, n = 39), and from healthy controls ≥70 years (n = 39).

RESULTS

None of the genes were differentially expressed between FH patients with and without CHD after adjusting for multiple testing. However, at nominal p < 0.05, we found 36 (5%) differentially expressed genes (DEGs) between the two FH groups, mainly related to lipid metabolism (e.g. higher expression of ABCA1 and ABCG1 in FH event-free) and immune responses (e.g. lower expression of STAT1 and STAT3 in FH event-free). When comparing FH patients to controls, the event-free group had fewer DEGs than the CHD group; 147 (19%) and 219 (28%) DEGs, respectively.

CONCLUSIONS

Elderly event-free FH patients displayed a different PBMC gene expression profile compared to FH patients with CHD. Differences in gene expression compared to healthy controls were more pronounced in the CHD group, indicating a less atherogenic gene expression profile in event-free individuals. Overall, identification of cardioprotective factors could lead to future therapeutic targets.

Lipid Oxidation Products and the Risk of Cardiovascular Diseases: Role of Lipoprotein Transport

Cholesterol has for decades ruled the history of atherosclerotic cardiovascular diseases (CVDs), and the present view of the etiology of the disease is based on the transport of cholesterol by plasma lipoproteins. The new knowledge of the lipoprotein-specific transport of lipid oxidation products (LOPs) has introduced another direction to the research of CVD, revealing strong associations between lipoprotein transport functions, atherogenic LOP, and CVD. The aim of this review is to present the evidence of the lipoprotein-specific transport of LOP and to evaluate the potential consequences of the proposed role of the LOP transport as a risk factor. The associations of cholesterol and lipoprotein LOP with the known risk factors of CVD are mostly parallel, and because of the common transport and cellular intake mechanisms it is difficult to ascertain the independent effects of either cholesterol or LOP. While cholesterol is known to have important physiological functions, LOPs are merely regarded as metabolic residues and able to initiate and boost atherogenic processes. It is therefore likely that with the increased knowledge of the lipoprotein-specific transport of LOP, the role of cholesterol as a risk factor of CVD will be challenged.

Targeting systemic inflammation in metabolic disorders. A therapeutic candidate for the prevention of cardiovascular diseases?

Cardiovascular disease (CVD) remains the leading cause of death and disability worldwide. While many factors can contribute to CVD, atherosclerosis is the cardinal underlying pathology, and its development is associated with several metabolic risk factors including dyslipidemia and obesity. Recent studies have definitively demonstrated a link between low-grade systemic inflammation and two relevant metabolic abnormalities: hypercholesterolemia and obesity. Interestingly, both metabolic disorders are also associated with endothelial dysfunction/activation, a proinflammatory and prothrombotic phenotype of the endothelium that involves leukocyte infiltration into the arterial wall, one of the earliest stages of atherogenesis. This article reviews the current literature on the intricate relationship between hypercholesterolemia and obesity and the associated systemic inflammation and endothelial dysfunction, and discusses the effectiveness of present, emerging and in-development pharmacological therapies used to treat these metabolic disorders with a focus on their effects on the associated systemic inflammatory state and cardiovascular risk.

Understanding mechanisms of antioxidant action in health and disease

Several different reactive oxygen species (ROS) are generated in vivo. They have roles in the development of certain human diseases whilst also performing physiological functions. ROS are counterbalanced by an antioxidant defence network, which functions to modulate ROS levels to allow their physiological roles whilst minimizing the oxidative damage they cause that can contribute to disease development. This Review describes the mechanisms of action of antioxidants synthesized in vivo, antioxidants derived from the human diet and synthetic antioxidants developed as therapeutic agents, with a focus on the gaps in our current knowledge and the approaches needed to close them. The Review also explores the reasons behind the successes and failures of antioxidants in treating or preventing human disease. Antioxidants may have special roles in the gastrointestinal tract, and many lifestyle features known to promote health (especially diet, exercise and the control of blood glucose and cholesterol levels) may be acting, at least in part, by antioxidant mechanisms. Certain reactive sulfur species may be important antioxidants but more accurate determinations of their concentrations in vivo are needed to help assess their contributions.

Studies on the Effects of Hypercholesterolemia on Mouse Ophthalmic Artery Reactivity

Atherogenic lipoproteins may impair vascular reactivity, leading to tissue damage in various organs, including the eye. This study aimed to investigate whether ophthalmic artery reactivity is affected in mice lacking the apolipoprotein E gene (ApoE-/-), a model for hypercholesterolemia and atherosclerosis. Twelve-month-old male ApoE-/- mice and age-matched wild-type controls were used to assess vascular reactivity using videomicroscopy. Moreover, the vascular mechanics, lipid content, levels of reactive oxygen species (ROS), and expression of pro-oxidant redox enzymes and the lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) were determined in vascular tissue. Unlike the aorta, the ophthalmic artery of ApoE-/- mice developed no signs of endothelial dysfunction and no signs of excessive lipid deposition. Remarkably, the levels of ROS, nicotinamide adenine dinucleotide phosphate oxidase 1 (NOX1), NOX2, NOX4, and LOX-1 were increased in the aorta but not in the ophthalmic artery of ApoE-/- mice. Our findings suggest that ApoE-/- mice develop endothelial dysfunction in the aorta by increased oxidative stress via the involvement of LOX-1, NOX1, and NOX2, whereas NOX4 may participate in media remodeling. In contrast, the ophthalmic artery appears to be resistant to chronic apolipoprotein E deficiency. A lack of LOX-1 expression/overexpression in response to increased oxidized low-density lipoprotein levels may be a possible mechanism of action.

Increased extracellular vesicles (EVs) related to T cell-mediated inflammation and vascular function in familial hypercholesterolemia

Background and aims

OxLDL modulates innate and adaptive immunity, and extracellular vesicles (EVs) released from both non-immune and immune cells are proposed key players in atherosclerosis development. In the present study, we aimed to investigate EVs expressing markers related to adaptive immunity-driven inflammation and endothelial activation/dysfunction in hypercholesterolemic patients.

Methods

EVs were phenotyped in thirty patients with familial hypercholesterolemia (FH) and twenty-three healthy controls using the Extracellular Vesicle (EV) Array with antibodies targeting proteins expressed on B and T cells, and endothelial cells.

Results

FH patients had a higher atherosclerotic burden, as determined by the mean carotid intima-media thickness (IMT) (0.64 ± 0.12 mm vs. 0.58 ± 0.07 mm; p = 0.033), higher oxLDL levels (p < 0.0001), and showed increased levels of EV-specific markers: CD9 (p = 0.017), CD63 (p = 0.045), CD81 (p = 0.003), Annexin V (p = 0.018), and EV markers related to adaptive/lymphocyte immunity: CD28 (p = 0.034), CD4 (p = 0.049), CD152 (p = 0.029), LFA-1 (p = 0.024), and endothelial function: CD62E (p = 0.032), CD144 (p = 0.018), tPA (p = 0.017), CD31 (p = 0.024). Linear regression revealed a positive relationship between carotid IMT and several of the increased markers observed within the FH group, including CD9 (β = 0.33; p = 0.022), CD63 (β = 0.35; p 225 = 0.026), CD28 (β = 0.37; p = 0.026), CD4 (β = 0.40; p = 0.025), CD152 (β = 0.41; p = 0.017), LFA-1 (β = 0.42; p = 0.014) and CD62E (β = 0.38; p = 0.024).

Conclusion

EVs associated with adaptive immunity and endothelial dysfunction are elevated in FH patients, and several markers related to a higher atherosclerotic burden.

Ox-LDL aggravates contrast-induced injury of renal tubular epithelial cells

Hypercholesterolemia can aggravate contrast-induced acute kidney injury, and the exacerbation of renal tubular epithelial cell (RTEC) injury is a major cause. However, the exact mechanisms remain obscure. Mitophagy, a type of autophagy, selectively eliminates damaged mitochondria and reduces mitochondrial oxidative stress, which is strongly implicated in cell homeostasis and acute kidney injury. Oxidized low-density lipoprotein (Ox-LDL) is accumulated in hypercholesterolemia and has a cytotoxic effect. This study aimed to determine whether and how ox-LDL exacerbates contrast-induced injury in RTECs and to further explore whether PINK1/Parkin-dependent mitophagy is involved in this process. Iohexol and ox-LDL were used alone or in combination to treat HK-2 cells. Rapamycin pretreatment was utilized to enhance mitophagy. Cell viability, apoptosis, mitochondrial membrane potential (MMP) and mitochondrial reactive oxygen species (mtROS) were detected by cell counting kit-8, TUNEL staining, JC-1 kit and MitoSOX fluorescence, respectively. The expression of mitophagy-related proteins (including PINK1, Parkin, and so on) and cleaved caspase-3 was confirmed by western blot. Colocalization of MitoTracker-labeled mitochondria and LysoTracker-labeled lysosomes was observed by fluorescence microscopy to evaluate mitophagy. The results of our study showed that ox-LDL aggravated MMP decline, mtROS release and apoptosis in iohexol-treated HK-2 cells, accompanied by a further increased autophagy level. Enhancement of PINK1/Parkin-dependent mitophagy by rapamycin alleviated apoptosis and mitochondrial injury in HK-2 cells in response to iohexol under ox-LDL condition. Therefore, our findings indicate that ox-LDL aggravates contrast-induced injury of RTECs by increasing mitochondrial damage and mitochondrial oxidative stress, which may be associated with the relative insufficiency of PINK1/Parkin-dependent mitophagy.

GRP78/BiP alleviates oxLDL-induced hepatotoxicity in familial hypercholesterolemia caused by missense variants of LDLR in a HepG2 cellular model

BACKGROUND AND AIMS

The accumulation of misfolded proteins, encoded by genetic variants of functional genes leads to Endoplasmic Reticulum (ER) stress, which is a critical consequence in human disorders such as familial hypercholesterolemia, cardiovascular and hepatic diseases. In addition to the identification of ER stress as a contributing factor to pathogenicity, extensive studies on the role of oxidized Low-Density Lipoprotein (oxLDL) and its ill effects in expediting cardiovascular diseases and other metabolic comorbidities are well documented. However, the current understanding of its role in hepatic insults needs to be revised. This study elucidates the molecular mechanisms underlying the progression of oxLDL and ER stress-induced cytotoxicity in HepG2.

METHODS

HepG2 cells stably expressing wild-type Low-Density lipoprotein receptor (WT-LDLR) and missense variants of LDLR that are pathogenically associated with familial hypercholesterolemia were used as the in vitro models. The relative mRNA expression and protein profiles of ER stress sensors, inflammatory and apoptotic markers, together with cytotoxic assays and measurement of mitochondrial membrane potential, were carried out in HepG2 cells treated with 100 µg per ml oxLDL for 24 to 48 h. 1-way or 2-way ANOVA was used for statistical analyses of datasets.

RESULTS

ER stress responses are elicited along all three arms of the unfolded protein response (UPR), with adverse cytotoxic and inflammatory responses in oxLDL-treated conditions. Interestingly, oxLDL-treated ER-stressed HepG2 cells manifested intriguingly low expression of BiP- the master regulator of ER stress, as observed earlier by various researchers in liver biopsies of Non-Alcoholic Steatohepatitis (NASH) patients. This study shows that overexpression of BiP rescues hepatic cells from cytotoxic and inflammatory mechanisms instigated by ER stress in combination with oxLDL, along the ER and mitochondrial membrane and restores cellular homeostasis.

CONCLUSION

The data provide interesting leads that identify patients with familial hypercholesterolemia conditions and potentially other Endoplasmic Reticulum Associated Degradation (ERAD) diseases as highly susceptible to developing hepatic insults with molecular signatures like those manifested in Non-Alcoholic Fatty Liver Disease (NAFLD) and NASH.

LIMITATIONS AND FUTURE PERSPECTIVES

Although the use of HepG2 cells as the model is a major caveat of the study, the findings of this research may be used as the pilot study to expand further investigations in primary hepatocytes or iPSC- derived cellular models.

Beyond mechanical loading: The metabolic contribution of obesity in osteoarthritis unveils novel therapeutic targets

Osteoarthritis (OA) is a prevalent progressive disease that frequently coexists with obesity. For several decades, OA was thought to be the result of ageing and mechanical stress on cartilage. Researchers' perspective has been greatly transformed when cumulative findings emphasized the role of adipose tissue in the diseases. Nowadays, the metabolic effect of obesity on cartilage tissue has become an integral part of obesity research; hoping to discover a disease-modifying drug for OA. Recently, several adipokines have been reported to be associated with OA. Particularly, metrnl (meteorin-like) and retinol-binding protein 4 (RBP4) have been recognized as emerging adipokines that can mediate OA pathogenesis. Accordingly, in this review, we will summarize the latest findings concerned with the metabolic contribution of obesity in OA pathogenesis, with particular emphasis on dyslipidemia, insulin resistance and adipokines. Additionally, we will discuss the most recent adipokines that have been reported to play a role in this context. Careful consideration of these molecular mechanisms interrelated with obesity and OA will undoubtedly unveil new avenues for OA treatment.

Treatment with PCSK9 Inhibitor Evolocumab Improves Vascular Oxidative Stress and Arterial Stiffness in Hypercholesterolemic Patients with High Cardiovascular Risk

Atherosclerosis and atherosclerotic-related cardiovascular diseases (ASCVD) are characterized by high serum levels of low-density lipoprotein cholesterol (LDL-C) that can promote the generation of reactive oxygen species (ROS). To answer the need for better LDL-C control in individuals at high and very high risk for CVD, a new injectable innovative family of lipid-lowering (LL) monoclonal antibodies against the protein convertase subtilisin/kexin type 9 (PCSK9) has been approved. However, the effect of these drugs on vascular function, such as ROS generation and arterial stiffness, has not already been extensively described. In this report, we present data from 18 males with high to very high CV risk undergoing LL treatment (LLT) with either statin and ezetimibe or ezetimibe monotherapy, who experienced, after a 2-month treatment with Evolocumab, a significant improvement in blood pressure (BP)-adjusted carotid–femoral pulse wave velocity (cfPWV) (p-value = 0.0005 in the whole cohort, p-value = 0.0046 in the sub-cohort undergoing background LLT with statin and ezetimibe, p-value = 0.015 in the sub-cohort undergoing background LLT with ezetimibe monotherapy), which was significantly associated with a decrease in freshly isolated leukocytes (PBMCS)-derived H2O2 production (p-value = 0.004, p-value = 0.02 and p-value = 0.05, respectively, in the whole cohort, in the statin + ezetimibe sub-cohort, and the ezetimibe sub-cohort). Our observations support the role of systemic oxidative stress in atherosclerosis and give a further rationale for using Evolocumab also for its effect in vascular disorders linked to oxidative processes.

Intraocular Pressure-Induced Endothelial Dysfunction of Retinal Blood Vessels Is Persistent, but Does Not Trigger Retinal Ganglion Cell Loss

Research has been conducted into vascular abnormalities in the pathogenesis of glaucoma, but conclusions remain controversial. Our aim was to test the hypothesis that retinal endothelial dysfunction induced by elevated intraocular pressure (IOP) persists after IOP normalization, further triggering retinal ganglion cell (RGC) loss. High intraocular pressure (HP) was induced in mice by episcleral vein occlusion (EVO). Retinal vascular function was measured via video microscopy in vitro. The IOP, RGC and their axons survival, levels of oxidative stress and inflammation as well as vascular pericytes coverage, were determined. EVO caused HP for two weeks, which returned to baseline afterwards. Mice with HP exhibited endothelial dysfunction in retinal arterioles, reduced density of RGC and their axons, and loss of pericytes in retinal arterioles. Notably, these values were similar to those of mice with recovered IOP (RP). Levels of oxidative stress and inflammation were increased in HP mice but went back to normal in the RP mice. Our data demonstrate that HP induces persistent endothelial dysfunction in retinal arterioles, which persists one month after RP. Oxidative stress, inflammation, and loss of pericytes appear to be involved in triggering vascular functional deficits. Our data also suggest that retinal endothelial dysfunction does not affect RGC and their axon survival.

SORBS2 as a molecular target for atherosclerosis in patients with familial hypercholesterolemia

Background

Familial hypercholesterolemia (FH) is a metabolic disease in which patients are prone to develop premature atherosclerosis (AS). Sorbin and SH3 Domain Containing 2 (SORBS2) is known to play a role in coronary heart disease (CHD). However, the mechanism underlying SORBS2 involvement in the development of hypercholesterolemia remains unknown. Here, we investigated the effects of SORBS2 on inflammation and foam cell formation and its underlying mechanisms.

Methods

Using Bioinformatics analysis, we established that SORBS2 is upregulated in patients with FH. Circulating concentrations of SORBS2 were measured using ELISA kit (n = 30). The association between circulating SORBS2 levels and inflammatory factors or lipid indexes were conducted using Spearman correlation analysis. We further conducted in vitro experiments that the expression of SORBS2 were analyzed, and SORBS2 siRNA were transfected into oxidized LDL (OxLDL)-induced macrophages, followed by western blot and immunofluorescence.

Results

Circulating SORBS2 levels were positively associated with inflammatory factors and lipid indexes. We also observed that high in vitro expression of SORBS2 in OxLDL-induced macrophages. After SORBS2 silencing, Nod like receptor family pyrin domain-containing 3 protein(NLRP3)-Caspase1 activation and NF-κB activation were attenuated, and secretion of pro-inflammatory cytokines (IL-1β and IL-18) was decreased. Moreover, SORBS2 silencing blocked reactive oxygen species (ROS) production and lipid accumulation, and promoted cholesterol efflux through ABCG1-PPARγ pathway.

Conclusions

SORBS2 regulates lipid-induced inflammation and foam cell formation, and is a potential therapeutic target for hypercholesterolemia.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-022-03381-z.

Biological Functions and Activities of Rice Bran as a Functional Ingredient: A Review

Rice bran (RB) is a nutrient-rich by-product of the rice milling process. It consists of pericarp, seed coat, nucellus, and aleurone layer. RB is a rich source of a protein, fat, dietary fibers, vitamins, minerals, and phytochemicals (mainly oryzanols and tocopherols), and is currently mostly used as animal feed. Various studies have revealed the beneficial health effects of RB, which result from its functional components including dietary fiber, rice bran protein, and gamma-oryzanol. The health effects of RB including antidiabetic, lipid-lowering, hypotensive, antioxidant, and anti-inflammatory effects, while its consumption also improves bowel function. These health benefits have drawn increasing attention to RB in food applications and as a nutraceutical product to mitigate metabolic risk factors in humans. This review therefore focuses on RB and its health benefits.

Evaluation of Oxidative Stress Status in Familial Hypercholesterolemia

Background: Familial hypercholesterolemia (FH) is an autosomal dominant genetic disorder characterizied by elevated levels of circulating low-density lipoprotein cholesterol (LDL-C) which is an important source of substrates to be oxidized by different oxidative agents. Subsequently, the oxidized LDLs (oxLDLs) induce further oxidative reactions in FH patients, which contributes to the development of atherosclerosis and advanced cardiovascular events in these patients. This study aimed to investigate the association of oxidant/antioxidant markers with FH. Methods: This case-control study comprised 18 HoFH, 18 HeFH, and 20 healthy subjects. Oxidant/antioxidant markers including MDA, MPO, thiol, nitric oxide (NO), myeloperoxidase (MPO), glutathione peroxidase (GPx), SOD, and CAT were assessed by colorimetric methods. Prooxidant-antioxidant balance was also measured by pro-oxidant antioxidant balance (PAB) assay. Results: The levels of MDA (p < 0.001), MPO activity (p < 0.001), thiol (p < 0.001), NO (p < 0.01), and PAB (p < 0.001) were notably higher in HoFH group in comparison with healthy subjects. HeFH group also showed significantly higher levels of thiol (p < 0.001) and PAB (p < 0.001) when compared to healthy subjects. Elevated levels of MDA (p < 0.001) and PAB (p < 0.001) were also observed in HoFH relative to HeFH. No significant differences were found between the studied groups in the case of antioxidant enzyme activities. The results of binary logistic regression showed that PAB (OR: 0.979; p = 0.033), and MDA (OR: 0.996; p = 0.018) levels were inversely associated with HoFH, although, after adjustment for age and LDL-C levels, these associations were diminished. Conclusion: Several oxidant/antioxidant differences were found between FH patients and healthy individuals as well as between HoFH and HeFH patients. These differences might be strongly dependent on plasma LDL-C levels.

ROS-Based Nanoparticles for Atherosclerosis Treatment

Atherosclerosis (AS), a chronic arterial disease, is the leading cause of death in western developed countries. Considering its long-term asymptomatic progression and serious complications, the early prevention and effective treatment of AS are particularly important. The unique characteristics of nanoparticles (NPs) make them attractive in novel therapeutic and diagnostic applications, providing new options for the treatment of AS. With the assistance of reactive oxygen species (ROS)-based NPs, drugs can reach specific lesion areas, prolong the therapeutic effect, achieve targeted controlled release and reduce adverse side effects. In this article, we reviewed the mechanism of AS and the generation and removal strategy of ROS. We further discussed ROS-based NPs, and summarized their biomedical applications in scavenger and drug delivery. Furthermore, we highlighted the recent advances, challenges and future perspectives of ROS-based NPs for treating AS.

Integrated bioinformatics analysis of the anti-atherosclerotic mechanisms of the polysaccharide CM1 from Cordyceps militaris

Cordyceps militaris is a well-known traditional Chinese medicine. Studies have demonstrated that the polysaccharides of C. militaris have various bioactivities. However, their mechanisms of action remain unclear. We previously purified a water-soluble polysaccharide CM1 from C. militaris and found that it has a cholesterol efflux improving capacity. This study further investigates the effect of CM1 in anti-atherosclerosis and its underlying mechanism in apolipoprotein E-deficient mice. Our data indicated that CM1 significantly decreased the total cholesterol and triglyceride in the plasma of mice, and decreased lipid deposition and formation of atherosclerotic plaque in a dose-dependent manner. Integrated bioinformatics analysis revealed that CM1 interacted with multiple signaling pathways, including those involved in lipid metabolism, inflammatory response, oxidoreductase activity and fluid shear stress, to exert its anti-atherosclerotic effect. Molecular technology analysis showed that CM1 enhanced the expression of proteins involved in lipid metabolism, reduced the expression of intercellular adhesion molecule-1 and tumor necrosis factor-α in the aorta, and decreased the content of oxidative products by enhancing the activities of antioxidant enzymes. Microarray analysis and biochemical data indicated that CM1 can improve lipid metabolism, reduce inflammation and oxidative stress. Taken together, CM1 could be used for the treatment of hyperlipidemia and atherosclerotic cardiovascular diseases.

Primary hypercholesterolemia and development of cardiovascular disorders: Cellular and molecular mechanisms involved in low-grade systemic inflammation and endothelial dysfunction

Primary hypercholesterolemia, a metabolic disorder characterized by elevated circulating levels of cholesterol products, mainly low-density lipoproteins, is associated with arteriosclerosis development. Cardiovascular disease, predominantly myocardial infarction and stroke, remains the main cause of death worldwide, with atherosclerosis considered to be the most common underlying pathology. In addition to elevated plasma levels of low-density lipoproteins, low-grade systemic inflammation and endothelial dysfunction seem to be the main drivers of premature atherosclerosis. Here we review current knowledge related to cellular and molecular mechanisms involved in low-grade systemic inflammation and endothelial dysfunction associated with primary hypercholesterolemia. We also discuss the contribution of different inflammatory mediators, immune players and signaling pathways implicated in leukocyte adhesion to the dysfunctional endothelium, a key feature of atherogenesis development. A better understanding of these processes linked to primary hypercholesterolemia should shed new light on cardiovascular disease development and might guide novel and effective therapeutic strategies to impair its progression.

Targeting Inflammation by Anthocyanins as the Novel Therapeutic Potential for Chronic Diseases: An Update

Low-grade chronic inflammation (LGCI) and oxidative stress act as cooperative and synergistic partners in the pathogenesis of a wide variety of diseases. Polyphenols, including anthocyanins, are involved in regulating the inflammatory state and activating the endogenous antioxidant defenses. Anthocyanins' effects on inflammatory markers are promising and may have the potential to exert an anti-inflammatory effect in vitro and in vivo. Therefore, translating these research findings into clinical practice would effectively contribute to the prevention and treatment of chronic disease. The present narrative review summarizes the results of clinical studies from the last 5 years in the context of the anti-inflammatory and anti-oxidative role of anthocyanins in both health and disease. There is evidence to indicate that anthocyanins supplementation in the regulation of pro-inflammatory markers among the healthy and chronic disease population. Although the inconsistencies between the result of randomized control trials (RCTs) and meta-analyses were also observed. Regarding anthocyanins' effects on inflammatory markers, there is a need for long-term clinical trials allowing for the quantifiable progression of inflammation. The present review can help clinicians and other health care professionals understand the importance of anthocyanins use in patients with chronic diseases.

Antiplatelet Effects of PCSK9 Inhibitors in Primary Hypercholesterolemia

Proprotein convertase subtilisin-kexin type 9 (PCSK9) inhibitors are a novel group of hypolipidemic drugs that are recommended particularly for high-risk hypercholesterolemia patients, including those with primary hypercholesterolemia (PH), where lifelong exposure to high low-density lipoprotein (LDL) cholesterol levels results in an elevated risk of atherosclerosis at an early age. The onset and progression of atherosclerosis is significantly influenced by activated platelets. Oxidized LDL influences platelet activation by interacting with their surface receptors and remodeling the composition of their cell membrane. This results in platelet aggregation, endothelial cell activation, promotion of inflammation and oxidative stress, and acceleration of lipid accumulation in atherosclerotic plaques. PCSK9 inhibitors reduce platelet activation by both significantly lowering LDL levels and reducing the LDL receptor-mediated activation of platelets by PCSK9. They also work synergistically with other hypolipidemic and antithrombotic drugs, including statins, ezetimibe, acetylsalicylic acid, clopidogrel, and ticagrelor, which enhances their antiplatelet and LDL-lowering effects. In this review, we summarize the currently available evidence on platelet hyperreactivity in PH, the effects of PCSK9 inhibitors on platelets, and their synergism with other drugs used in PH therapy.

Influence of cardiometabolic comorbidities on myocardial function, infarction, and cardioprotection: Role of cardiac redox signaling

The morbidity and mortality from cardiovascular diseases (CVD) remain high. Metabolic diseases such as obesity, hyperlipidemia, diabetes mellitus (DM), non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH) as well as hypertension are the most common comorbidities in patients with CVD. These comorbidities result in increased myocardial oxidative stress, mainly from increased activity of nicotinamide adenine dinucleotide phosphate oxidases, uncoupled endothelial nitric oxide synthase, mitochondria as well as downregulation of antioxidant defense systems. Oxidative and nitrosative stress play an important role in ischemia/reperfusion injury and may account for increased susceptibility of the myocardium to infarction and myocardial dysfunction in the presence of the comorbidities. Thus, while early reperfusion represents the most favorable therapeutic strategy to prevent ischemia/reperfusion injury, redox therapeutic strategies may provide additive benefits, especially in patients with heart failure. While oxidative and nitrosative stress are harmful, controlled release of reactive oxygen species is however important for cardioprotective signaling. In this review we summarize the current data on the effect of hypertension and major cardiometabolic comorbidities such as obesity, hyperlipidemia, DM, NAFLD/NASH on cardiac redox homeostasis as well as on ischemia/reperfusion injury and cardioprotection. We also review and discuss the therapeutic interventions that may restore the redox imbalance in the diseased myocardium in the presence of these comorbidities.

Monitoring the Effects of Hypolipidemic Treatment in Children with Familial Hypercholesterolemia in Poland

Familial hypercholesterolemia (FH) is the most common monogenic autosomal dominant disorder. FH results in an increased cardiovascular mortality rate. However, cardiovascular risk control factors enable the avoidance of approximately 80% of strokes and cardiovascular diseases. Therefore, early detection and implementation of lipid-lowering treatment is essential. In the present study, 57 pediatric patients aged 9.57 ± 3.26 years with FH were enrolled in the study. Researchers checked the lipid profile and performed the ultrasound imaging including intima-media thickness (IMT) measurement and echo (e)-tracking in the study group. Patients were treated with a low-cholesterol diet solely or along with pharmacological treatment with statins. Subsequently, patients were monitored for 12 months. The positive results of dietary treatment were observed in 40 patients. The efficacy of 12 months of nutritional therapy along with pharmacological treatment was reported in 27 patients. We observed a significant decrease in the carotid beta index stiffness and an insignificant decrease in the IMT in the group of patients treated with statins. The obtained data show that statin therapy in children with FH allow for the reduction of the degree of atherosclerotic vessel changes.

Thymoquinone Protects against Hyperlipidemia-Induced Cardiac Damage in Low-Density Lipoprotein Receptor-Deficient (LDL-R-/-) Mice via Its Anti-inflammatory and Antipyroptotic Effects

Hyperlipidemia is a risk factor for cardiac damage and cardiovascular disease. Increasing evidence has shown that dyslipidemia-related cardiac damage is associated with lipid accumulation, oxidative stress, and inflammation. Thymoquinone (TQ) is the major constituent of Nigella sativa, commonly known as black seed or black cumin, and is globally used in folk (herbal) medicine for treating and preventing a number of diseases and conditions. Several studies have shown that TQ can protect against cardiac damage. This study is aimed at investigating the possible protective effects of TQ on hyperlipidemia-induced cardiac damage in low-density lipoprotein receptor-deficient (LDL-R^−/−) mice. Eight-week-old male LDL-R^−/− mice were randomly divided into normal diet (ND), high-fat diet (HFD), and HFD and TQ (HFD+TQ) groups and were fed the different diets for eight weeks. Blood samples were obtained from the inferior vena cava in serum tubes and stored at -80°C until use. Some cardiac tissues were fixed in 10% formalin and then embedded in paraffin for histological evaluation. The remainder of the cardiac tissues was snap-frozen in liquid nitrogen for mRNA preparation or immunoblotting. The levels of metabolism-related factors, such as total cholesterol (TC), low-density lipoprotein-cholesterol (LDL-c), and high-sensitivity C-reactive protein (hs-CRP), were decreased in the HFD+TQ group compared with those in the HFD group. Periodic acid-Schiff staining demonstrated that lipid deposition was lower in the HFD+TQ group than in the HFD group. The expression of pyroptosis indicators (NOD-like receptor 3 (NLRP3), interleukin- (IL-) 1β, IL-18, and caspase-1), proinflammatory factors (IL-6 and tumor necrosis factor alpha (TNF-α)), and macrophage markers (cluster of differentiation (CD) 68) was significantly downregulated in the HFD+TQ group compared with that in the HFD group. Our results indicate that TQ may serve as a potential therapeutic agent for hyperlipidemia-induced cardiac damage.

Anthocyanin supplementation improves anti-oxidative and anti-inflammatory capacity in a dose-response manner in subjects with dyslipidemia

BACKGROUND

Anthocyanins, one of the major plant bioactive substances, possess anti-oxidative and anti-inflammatory capacity. However, their dose-response relationship has remained unclear. The present study investigated the dose-response relationship of anthocyanins with oxidative stress and inflammation in subjects with dyslipidemia.

DESIGN

and Participants: A total of 169 participants with dyslipidemia were randomly assigned to placebo (n = 43), anthocyanins 40 mg/day (n = 44), 80 mg/day (n = 40), or 320 mg/day (n = 42) groups. Urine 8-iso-prostaglandin F2α (8-iso-PGF2α), 8-hydroxy-2'-deoxyguanosine (8-OHdG) and serum malonaldehyde (MDA), total superoxide dismutase (T-SOD), UA (uric acid), interleukin (IL)-6, IL-10, tumor necrosis factor-α (TNF-α), and C-reactive protein (CRP) were measured at baseline, at 6 weeks, and at 12 weeks.

RESULTS

Anthocyanin supplementation (320 mg/day) for 6 weeks significantly improved T-SOD versus baseline (P < 0.05). A slight reduction in serum IL-6, TNF-α, and urine 8-iso-PGF2α from the baseline was observed at 12 weeks in the group receiving 40 mg/day anthocyanins. Anthocyanins (80 mg/day) significantly reduced serum IL-6 (-20%), TNF-α (-11%) and urine 8-iso-PGF2α (-27%) versus baseline (P < 0.05). Moreover, 320 mg/day anthocyanin supplementation reduced serum IL-6 (-40%), TNF-α (-21%), MDA (-20%) and urine 8-iso-PGF2α (-37%) and 8-OHdG (-36%) than 80 mg/day and 40 mg/day anthocyanins, P value < 0.05. Anthocyanin supplementation has dose-response relationships with decreased inflammatory cytokines IL-6, TNF-α and oxidative stress biomarkers 8-iso-PGF2α, 8-OHdG and MDA (P for trend, <0.05). Furthermore, a strong positive correlation was observed between the changes in the urine 8-iso-PGF2α , 8-OHdG levels and serum IL-6 levels in subjects from anthocyanin groups after 12 weeks of treatment.

CONCLUSIONS

Supplementation of anthocyanins for 12 weeks positively improved the anti-oxidative and anti-inflammatory capacity in a dose-response manner in individuals with dyslipidemia.

Improvement of oxidative stress status by lipoprotein apheresis in Chinese patients with familial hypercholesterolemia

BACKGROUND AND AIMS

Familial hypercholesterolemia (FH) characterized by severe high blood cholesterol levels usually presents an imbalance of systemic oxidative stress (OS). Lipoprotein apheresis (LA), which is the most effective therapy to reduce cholesterol levels, remains unclear in altering OS and scarce in Chinese patient studies. Our study aims to assess the impact of LA on OS status in Chinese patients with FH.

METHODS

About 31 patients (22 males, age: 12-69 years) with FH and receiving LA treatment were consecutive enrolled. Free oxygen radicals test (FORT) and free oxygen radicals defense (FORD) values were determined using the free oxygen radical monitor and kit immediately before and after LA, while blood samples were collected to measure plasma lipid levels and hs-CRP by conventional methods. Data were analyzed by paired t test or rank sum test and Spearman-rho correlation analysis.

RESULTS

Besides plasma lipid levels, the OS status showed that FORTs were significantly decreased and FORD values significantly enhanced immediately after LA treatment compared with before (both P < .01). In addition, the correlation analysis showed that the removal rates (△%) of TC were positively related to the increased rates (△%) of FORD value (ρ = 0.513, P = .003); LDL-C to FORD (ρ = 0.39, P = .03); Lp(a) to FORD (ρ = 0.473, P = .007); and non-HDL-C to FORD (ρ = 0.46, P = .009). However, no significant difference in hsCRP was found.

CONCLUSIONS

The present study indicated, besides effectively lowering plasma lipid levels, LA could significantly improve OS status in Chinese patients with FH.

Why patients with familial hypercholesterolemia are at high cardiovascular risk? Beyond LDL-C levels

Familial hypercholesterolemia (FH) is a common genetic cause of elevated low-density lipoprotein cholesterol (LDL-C) due to defective clearance of circulating LDL particles. All FH patients are at high risk for premature cardiovascular disease (CVD) events due to their genetically determined lifelong exposure to high LDL-C levels. However, different rates of CVD events have been reported in FH patients, even among those with the same genetic mutations and comparable LDL-C levels. Hence, additional CVD risk modifiers, beyond LDL-C, may contribute to increase CVD risk in the FH population. In this review, we discuss the overall CVD risk burden of the FH population. Additionally, we revise the prognostic impact of several traditional and emerging predictors of CVD risk and we provide an overview of the role of specific tools to stratify CVD risk in FH patients in order to ensure them a more personalized treatment approach.

Elevated Intraocular Pressure Causes Abnormal Reactivity of Mouse Retinal Arterioles

Objective

Glaucoma is a leading cause of severe visual impairment and blindness. Although high intraocular pressure (IOP) is an established risk factor for the disease, the role of abnormal ocular vessel function in the pathophysiology of glaucoma gains more and more attention. We tested the hypothesis that elevated intraocular pressure (IOP) causes vascular dysfunction in the retina.

Methods

High IOP was induced in one group of mice by unilateral cauterization of three episcleral veins. The other group received sham surgery only. Two weeks later, retinal vascular preparations were studied by video microscopy in vitro. Reactive oxygen species (ROS) levels and expression of hypoxia markers and of prooxidant and antioxidant redox genes as well as of inflammatory cytokines were determined.

Results

Strikingly, responses of retinal arterioles to stepwise elevation of perfusion pressure were impaired in the high-IOP group. Moreover, vasodilation responses to the endothelium-dependent vasodilator, acetylcholine, were markedly reduced in mice with elevated IOP, while no differences were seen in response to the endothelium-independent nitric oxide donor, sodium nitroprusside. Remarkably, ROS levels were increased in the retinal ganglion cell layer including blood vessels. Expression of the NADPH oxidase isoform, NOX2, and of the inflammatory cytokine, TNF-α, was increased at the mRNA level in retinal explants. Expression of NOX2, but not of the hypoxic markers, HIF-1α and VEGF-A, was increased in the retinal ganglion cell layer and in retinal blood vessels at the protein level.

Conclusion

Our data provide first-time evidence that IOP elevation impairs autoregulation and induces endothelial dysfunction in mouse retinal arterioles. Oxidative stress and inflammation, but not hypoxia, appear to be involved in this process.

Apolipoprotein E Deficiency Causes Endothelial Dysfunction in the Mouse Retina

Objective

Atherogenic lipoproteins may impair vascular reactivity consecutively causing tissue damage in multiple organs via abnormal perfusion and excessive reactive oxygen species generation. We tested the hypothesis that chronic hypercholesterolemia causes endothelial dysfunction and cell loss in the retina.

Methods

Twelve-month-old apolipoprotein E-deficient (ApoE-/-) mice and age-matched wild-type controls were used in this study (n = 8 per genotype for each experiment). Intraocular pressure, blood pressure, and ocular perfusion pressure were determined. Retinal arteriole responses were studied in vitro, and reactive oxygen and nitrogen species were quantified in the retinal and optic nerve cryosections. The expression of the lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) and the NADPH oxidase isoforms, NOX1, NOX2, and NOX4, were determined in retinal cryosections by immunofluorescence microscopy. Pro- and antioxidant redox genes were quantified in retinal explants by PCR. Moreover, cell number in the retinal ganglion cell layer and axon number in the optic nerve was calculated.

Results

Responses to the endothelium-dependent vasodilator, acetylcholine, were markedly impaired in retinal arterioles of ApoE-/- mice (P < 0.01). LOX-1 (P = 0.0007) and NOX2 (P = 0.0027) expressions as well as levels of reactive oxygen species (P = 0.0022) were increased in blood vessels but not in other retinal structures. In contrast, reactive nitrogen species were barely detectable in both mouse genotypes. Messenger RNA for HIF-1α, VEGF-A, NOX1, and NOX2, but also for various antioxidant redox genes was elevated in the retina of ApoE-/- mice. Total cell number in the retinal ganglion cell layer did not differ between ApoE-/- and wild-type mice (P = 0.2171). Also, axon number in the optic nerve did not differ between ApoE-/- and wild-type mice (P = 0.6435).

Conclusion

Apolipoprotein E deficiency induces oxidative stress and endothelial dysfunction in retinal arterioles, which may trigger hypoxia in the retinal tissue. Oxidative stress in nonvascular retinal tissue appears to be prevented by the upregulation of antioxidant redox enzymes, resulting in neuron preservation.

Pulse wave velocity as a measure of arterial stiffness in patients with familial hypercholesterolemia: a systematic review and meta-analysis

INTRODUCTION

The aim of this meta-analysis was to establish whether vascular pulse wave velocity (PWV) as a measure of arterial stiffness is changed in patients with familial hypercholesterolemia (FH).

MATERIAL AND METHODS

Studies comparing PWV between patients with FH and controls were searched in PubMed-Medline, SCOPUS, Web of Science and Google Scholar databases (up to November 26, 2017). A meta-analysis was conducted using Comprehensive Meta-Analysis V2 software. A random-effects model (using the DerSimonian-Laird method) and the generic inverse variance method were used to compensate for the heterogeneity of studies concerning demographic characteristics and differences in the studies' design.

RESULTS

This meta-analysis of 8 studies involving 317 patients with FH and 244 non-FH individuals did not suggest a significantly altered PWV in FH patients versus controls (weighted mean difference (WMD): 0.17 m/s, 95% confidence interval (CI): -0.31, 0.65, p = 0.489; I ² = 80.15%). The result was robust in the sensitivity analysis and its significance was not influenced after omitting each of the included studies from the meta-analysis. Subanalysis of 6 of these studies which had data on intima-media thickness (IMT) indicated an increased IMT in FH patients when compared with controls (WMD = 0.03 mm, 95% CI: 0.003, 0.06, p = 0.034; I ² = 48.95%). However, the effect size was sensitive to some of the included studies.

CONCLUSIONS

This meta-analysis suggests that FH patients do not have significantly altered PWV when compared with normocholesterolemic individuals. However, a subanalysis of studies in which IMT was measured indicated that IMT is increased in FH patients compared with controls.

Analysis of S100A12 plasma levels in hyperlipidemic subjects with or without familial hypercholesterolemia

AIMS

Inflammation is a key regulatory process that links hypercholesterolemia and immune mechanisms promoting atherosclerosis. Inflammatory biomarkers may be helpful to better define the atherosclerotic burden in patients with high cholesterol levels such as familial hypercholesterolemia (FH). Our aim was to evaluate the concentration of S100A12 protein in FH patients and its association with pulse wave velocity (PWV).

METHODS

We measured glucose and lipid profile, S100A12, sRAGE, esRAGE and PWV in 39 patients with a genetically confirmed diagnosis of FH and 39 hypercholesterolemic subjects without a clinical diagnosis of FH (Dutch score ≤ 3). All subjects were on statin treatment at the time of the enrollment.

RESULTS

No difference of glucose and lipid profile was found in the two groups. FH patients had higher S100A12 plasma levels than non-FH subjects (12.87 ± 4.82 vs. 8.57 ± 4.87 ng/mL, p < 0.01). No difference of hs-CRP, sRAGE and esRAGE was found between the two groups. Also, PWV was higher in FH patients than non-FH subjects (8.63 ± 0.92 vs. 6.68 ± 0.73 m/s, p < 0.05). Finally, S100A12 was independently correlated with age (p < 0.01), genetic mutation (p < 0.01) and PWV (p < 0.001).

CONCLUSIONS

FH patients exhibited higher S100A12 levels than non-FH subjects. A novel vascular inflammation pathway, other than hs-CRP, might be useful to better characterize cardiovascular risk profile.

Dyslipidemia in Ischemia/Reperfusion Injury

Ischemic heart disease is the main cause of morbidity and mortality in the developed world. Although reperfusion therapies are currently the best treatment for this entity, the restoration of blood flow leads, under certain circumstances, to a form of myocardial damage called reperfusion injury. Several studies have shown that age, sex, smoking, diabetes and dyslipidemia are risk factors for cardiovascular diseases. Among these risk factors, dyslipidemias are present in 40% of patients with ischemic heart disease and represent the clinical factor with the greatest impact on the prognosis of patients with cardiovascular diseases. It is known that during reperfusion the increase of the oxidative stress is perhaps one of the most important mechanisms implicated in cell damage. That is why several researchers have studied protective mechanisms against reperfusion injury, such as the ischemic pre- and post- conditioning, making emphasis mainly on the reduction of oxidative stress. However, few of these efforts have been successfully translated into the clinical setting. The controversial results in regards to the relation between cardioprotective mechanisms and dyslipidemia/hypercholesterolemia are mainly due to the difference among quality, composition and the time of administration of hypercholesterolemic diets, as well as the difference in the species used in each of the studies. Therefore, in order to compare results, it is crucial that all variables that could modify the obtained results are taken into consideration.

Screening of common genetic variants in the APOB gene related to familial hypercholesterolemia in a Saudi population: A case-control study

Familial hypercholesterolemia (FH) is a monogenic dominant inherited disorder of lipid metabolism characterized by elevated low-density lipoprotein levels, and is mainly attributable to mutations in low-density lipoprotein receptor (LDLR), apolipoprotein B (APOB), and proportein convertase subtilisin/kexin type 9 (PCSK9) genes. Next-generation and exome sequencing studies have primarily involved genome-wide association analyses, and meta-analyses and next-generation studies examined a few single-nucleotide polymorphisms (rs151009667 and Val2095Glu) in the ApoB gene. The present study was conducted to investigate the association of APOB and patients with FH in a Saudi population.We genotyped 100 patients with FH and 100 controls for 2 polymorphisms in APOB using polymerase chain reaction-restriction fragment length polymorphism, followed by 3% agarose gel electrophoresis. The strength of the association between the genotype and allele frequencies with the risk of developing FH was evaluated. Clinical details and genotype analysis results were recorded.For the rs151009667 polymorphism, 18% of the CT genotypes were observed only in patients with FH. There was a positive association between CT and CC (odds ratio [OR] 45.07 [95% conflict of interest (CI), 2.67-759.1]; P = .0001) and between T and C (OR 87.8 [95% CI, 5.34-144.2]; P < .0001). However, no Val2095Glu mutations were found in patients with FH or controls. There was also no correlation between clinical characteristics and the rs151009667 polymorphism.In conclusion, we confirmed the association between the rs151009667 polymorphism and FH in a Saudi population. The Val2095Glu novel variant did not appear in either patients with FH or controls. Similar studies should be performed in different ethnic populations to rule out the role of this polymorphism in FH.

Activity of Antioxidant Enzymes and Their Association with Lipid Profile in Mexican People without Cardiovascular Disease: An Analysis of Interactions

Dyslipidemia and oxidative stress are both considered to be factors involved in cardiovascular disease; however, the relationship between them has been little explored. In this work, we studied the association between the lipid profile and the activity of antioxidant enzymes such as paraoxonase-1 (PON1), superoxide dismutase 1 (SOD1), ceruloplasmin, and catalase, as well as total antioxidant capacity (the ferric-reducing ability of plasma (FRAP)), in 626 volunteers without cardiovascular disease. Their lipid profile was evaluated, and they were classified as having or not having high triglycerides (↑TG), high low-density cholesterol (↑LDLC), and low high-density cholesterol (↓HDLC), resulting in eight groups: Without dyslipidemia, ↑TG, ↑LDLC, ↓HDLC, ↑TG↑LDLC, ↑TG↓HDLC, ↑LDLC↓HDLC, and ↑TG↑LDLC↓HDLC. When comparisons by group were made, no significant differences in the activity of antioxidant enzymes were obtained. However, the linear regression analysis considering the potential interactions between ↑TG, ↑LDLC, and ↓HDLC suggested a triple interaction between the three lipid profile alterations on the activity of PON1 and a double interaction between ↑TG and ↑LDLC on ferroxidase-ceruloplasmin activity. The analysis presented in this work showed an association between the lipid profile and antioxidant-enzyme activity and highlighted the importance of considering the interactions between the components of a phenomenon instead of studying them individually. Longitudinal studies are needed to elucidate the nature of these associations.