Biomarkers and degree of atherosclerosis are independently associated with incident atherosclerotic cardiovascular disease in a primary prevention cohort: The ARIC study

Cardiovascular Disease and Alzheimer's Disease: The Heart-Brain Axis

Cardiovascular disease (CVD) remains one of the leading causes of morbidity and mortality in aging adults across the United States. Prior studies indicate that the presence of atherosclerosis, the pathogenic basis of CVD, is linked with dementias. Alzheimer's disease (AD) and AD-related dementias are a major public health challenge in the United States. Recent studies indicate that ≈3.7 million Americans ≥65 years of age had clinical AD in 2017, with projected increases to 9.3 million by 2060. Treatment options for AD remain limited. Development of disease-modifying therapies are challenging due, in part, to the long preclinical window of AD. The preclinical incubation period of AD starts in midlife, providing a critical window for identification and optimization of AD risk factors. Studies link AD with CVD risk factors such as hypertension, inflammation, and dyslipidemia. Both AD and CVD are progressive diseases with decades-long development periods. CVD can clinically manifest several years earlier than AD, making CVD and its risk factors a potential predictor of future AD. The current review focuses on the state of literature on molecular and metabolic pathways modulating the heart-brain axis underlying the potential association of midlife CVD risk factors and their effect on AD and related dementias. Further, we explore potential CVD/dementia preventive strategies during the window of opportunity in midlife and the future of research in the field in the multiomics and novel biomarker use era.

Programmed prodrug breaking the feedback regulation of P-selectin in plaque inflammation for atherosclerotic therapy

Inflammation is the main driver of the aggravation of arteriosclerosis, and the complex inflammatory response in plaque is usually the result of the interaction of various cells and cytokines. Therefore, it is difficult to comprehensively regulate the inflammatory process of arteriosclerosis by intervening a single target, resulting in the poor effect of existing treatment method. Based on our clinical findings that P-selectin stably and highly expressed in patients' plaque endothelial cells, the programmed prodrug, low molecular weight heparin-indomethacin nanoparticles (LI NPs), were established as anti-inflammatory agent to multiphase inhibit arteriosclerosis by cascade interference of P-selectin. Structurally, LI NPs was obtained by simple esterification of low molecular weight heparin and indomethacin without any additives, guaranteeing the biocompatibility and applicability of LI NPs. Functionally, LI NPs could interfere with P-selectin in the inflammatory process, such as inhibiting macrophage adhesion, reducing the secretion of inflammatory factors, and inducing macrophage apoptosis. In the arteriosclerosis mice model, LI NPs significantly reduced the plaque area and showed satisfactory curative effect, which is related to the intervention of the multiphase inflammation between endothelial cells and macrophages. In conclusion, the programmed prodrug LI NPs offered a promising approach for the clinical therapy of arteriosclerosis.

Association of the Atherogenic Index of Plasma with C-Reactive Protein and Urinary Albumin Excretion in a Normotensive Nondiabetic Population

Background: The atherogenic index of plasma (AIP) is an indicator of atherogenic dyslipidemia and is significantly associated with the development of atherosclerotic cardiovascular disease. Previous studies showing the association of AIP with C-reactive protein (CRP) and microalbuminuria included hypertensive and diabetic patients. We aimed to determine the association of AIP with CRP and albuminuria in a normotensive and nondiabetic population. Methods: The study was conducted retrospectively. Two hundred thirty-three individuals without hypertension, diabetes, cardiovascular disease, malignancy, systemic inflammatory disease, nephrological disease, and active infection were determined and included in the study. Urinary albumin excretion was calculated from the albumin-creatinine ratio in fresh spot urine [urinary albumin-creatinine ratio (UACR)]. AIP risk groups were compared in terms of clinical and laboratory findings, and the correlation between AIP and CRP and UACR was evaluated. Results: A total of 233 people, with a mean age of 45.4 years and 139 (69.7%) of whom were male, were included in the study. One hundred thirty-eight (59.2%) individuals were found to be in the low-risk group, 29 (12.5%) in the medium-risk group, and 66 (28.3%) in the high-risk group, according to the AIP value. CRP and UACR were not different between the AIP risk groups (P: 0.141 and 0.441, respectively). A mild correlation was found between AIP and CRP (r: 0.192; P: 0.003), but no correlation was found between AIP and UACR (r: 0.086; P: 0.193). The stepwise linear regression analysis with model adjusted for possible confounders and AIP revealed that only body mass index was a significant predictor of CRP (β: 0.308; P < 0.001), while only systolic blood pressure was a significant predictor of UACR (β: 0.19; P: 0.004), but AIP was not. Conclusions: AIP was not associated with CRP and UACR in normotensive and nondiabetic individuals. This finding suggests that the relationship found in previous studies is related to the presence of hypertension or diabetes rather than the AIP.

Cystatin C predicts the risk of incident cerebrovascular disease in the elderly: A meta-analysis on survival date studies

BACKGROUND

Stroke is the third leading cause of global year of life lost in all-age and second-ranked cause of disability adjusted life years in middle-aged and elder population. Therefore, it is critical to study the relationship between vascular-related risk factors and cerebrovascular diseases. Several cross-sectional studies have shown that Cystatin C (Cys C) is an independent risk factor for cerebrovascular diseases and levels of Cys C are significantly higher in stroke patients than in healthy individuals. In this meta-analysis, we introduce a Cox proportional hazards model to evaluate the causality between Cys C and the risk of cerebrovascular accident in the elderly.

METHODS

We searched PubMed, EMBASE, the Web of Science, and the Cochrane Library from 1985 to 2019 for studies on the relationship between serum Cys C and incidence stroke with Cox proportional hazards models. We conducted a subgroup analysis of the selected studies to determine a connection between atherosclerosis and stroke. Finally, 7 research studies, including 26,768 patients without a history of cerebrovascular, were studied.

RESULTS

After comparing the maximum and minimum Cys C levels, the hazard ratio for all types of stroke, including ischemic and hemorrhagic stroke, was 1.18 (95% confidence interval 1.04-1.31) with moderate heterogeneity (I2 = 43.0%; P = .119) in a fixed-effect model after pooled adjustment for other potential risk factors. In the subgroup analysis, the hazard ratio and 95% confidence interval for Cys C stratified by atherosclerosis was 1.85 (0.97-2.72). As shown in Egger linear regression test, there was no distinct publication bias (P = .153).

CONCLUSION

Increased serum Cys C is significantly associated with future stroke events in the elderly, especially in patients with carotid atherosclerosis. Thus, serum levels of Cys C could serve as a predicted biomarker for stroke attack.

Higher serum level of Cystatin C: An additional risk factor of CAD

Cystatin C has been proposed as a useful biomarker of early impaired kidney function and a predictor of mortality risk. The present study is to investigate the association between serum Cystatin C and the severity of coronary artery lesions, Gensini score (GS), and the risk of coronary artery disease (CAD).A total of 682 CAD patients (230 females, 452 males; mean age 62.6 ± 10.7 years, range from 31 to 86 years) and 135 controls (41 females, 94 males; mean age 58.0 ± 10.3 years, range from 38 to 84 years) were recruited in the present study. Enzyme-linked immunosorbent assay was applied to measure serum cystatin C levels and other serum indexes. The estimated glomerular filtration rate and GS were calculated.Serum low-density lipoprotein cholesterol (LDL-C), uric acid, Cystatin C, and homocysteine (HCY) were significantly elevated in CAD patients compared to controls. There were significant differences regarding total cholesterol, triglyceride, high-density lipoprotein, low-density lipoprotein, cystatin C, eGFR and GS among stable angina pectoris (SAP), unstable angina group (UAP), and acute myocardial infarction (AMI) patients. AMI group had an elevated serum Cystatin C, LDL-C, HCY, and GS than SAP and UAP patients. When stratified patient groups by the quartiles of Cystatin C, we found age, the proportion of male and patients with diabetes, HCY, and GS were increased in Q4 than in other quartile groups. Spearman correlation test revealed a positive relationship between Cystatin C, HCY, and GS. Multivariate logistic regression analysis revealed that serum Cystatin C level, presence of hypertension and diabetes, HCY, age, and male were the risk factors for coronary artery lesions.In summary, our results suggested that cystatin C is a promising clinical biomarker that provides complementary information to the established risk determinants. The serum Cystatin C level is strongly associated with GS and could be used to evaluate the severity of coronary artery lesions.

Association Between High-Sensitivity Cardiac Troponin and Risk of Stroke in 96 702 Individuals: A Meta-Analysis

Background and Purpose- Our study aim was to estimate risk of incident stroke based on levels of hs-cTn (high-sensitivity cardiac troponin), a specific biomarker indicating myocardial injury, in the general population, patients with atrial fibrillation, and patients with previous stroke. Methods- Embase, PubMed, and Web of Science were searched until March 14, 2019 to identify relevant articles. Randomized controlled trials and cohort studies assessing the risk of incident stroke based on hs-cTn were eligible. Pooled adjusted hazard ratios including 95% CI were calculated using a random-effects model due to study heterogeneity per population, coding of hs-cTn (categorical/continuous data), per hs-cTn subunit (T or I), for low risk of bias, and for all-cause and ischemic stroke separately. Results- We included 17 articles with 96 702 participants. In studies conducted in the general population (n=12; 77 780 participants), the pooled adjusted hazard ratio for incident stroke was 1.25 (CI, 1.10-1.40) for high versus low hs-cTn (as defined by included studies) during an average follow-up of 1 to 20 years (median 10). When categorical data were used, this was increased to 1.58 (CI, 1.26-1.90). The results were robust when accounting for stroke classification (all-cause stroke/ischemic stroke), hs-cTn subunit, risk of bias, and coding of hs-cTn. In patients with atrial fibrillation (4 studies; 18 725 participants), the pooled adjusted hazard ratio for incident stroke was 1.95 (CI, 1.29-2.62) for high versus low hs-cTn. Due to lack of data (one study, 197 participants), no meta-analysis could be performed in patients with previous stroke. Conclusions- This meta-analysis suggests that hs-cTn can be regarded as a risk marker for incident stroke, with different effect size in different subgroups. More research about the association between hs-cTn and incident stroke in high-risk populations is needed, especially in patients with history of ischemic stroke.

Upregulation of Protease-Activated Receptor 2 Promotes Proliferation and Migration of Human Vascular Smooth Muscle Cells (VSMCs)

Background

Protease-Activated Receptor 2 (PAR2), a G-protein-coupled receptor, has been proved to be enhanced in human coronary atherosclerosis lesions. We aimed to investigate whether PAR2 actively participates in the atherosclerosis process.

Material/Methods

PAR2 expression was assessed in blood samples by RT-qPCR from healthy controls and patients with atherosclerosis. Human vascular smooth muscle cells (VSMCs) were treated with oxidative low-density lipoprotein (ox-LDL). After PAR2 overexpression by transfection, cell proliferation was determined by CCK-8, and cell migration was evaluated by Transwell assay. The protein expressions associated with cell growth and migration were measured by Western blot. The distribution of α-SMA in VSMCs was evaluated by immunofluorescence.

Results

Expression of PAR2 was higher in patients with atherosclerosis compared with normal controls. PAR2 mRNA and protein expression was increased in ox-LDL-treated VSMCs compared with control cells. Induced overexpression of PAR2 in VSMCs led to a reduction in α-SMA expression compared to controls. In addition, PAR2 overexpression caused increased migration compared to normal controls, and upregulated MMP9 and MMP14 expression. PAR-2 overexpression promoted cell proliferation compared to control cells, and increased expression levels of CDK2, and CyclinE1, but reduced levels of p27. We preliminary explored the potential mechanism of PAR2, and results showed that overexpression of PAR2 increased expression levels of VEGFA and Angiopoietin 2 compared to controls. Moreover, overexpression of PAR2 enhanced production of tissue factor and IL-8 compared to normal controls.

Conclusions

PAR2 promotes cell proliferation and disrupts the quiescent condition of VSMCs, which may be a potential therapeutic target for atherosclerosis.

SR-A-Targeted Phase-Transition Nanoparticles for the Detection and Treatment of Atherosclerotic Vulnerable Plaques

Atherosclerosis is a major cause of sudden death and myocardial infarction, instigated by unstable plaques. Thus, the early detection of unstable plaques and corresponding treatment can improve the prognosis and reduce mortality. In this study, we describe a protocol for the preparation of nanoparticles (NPs) combined with the phase transitional material perfluorohexane (PFH) and with dextran sulfate (DS) targeting class A scavenger receptors (SR-A) for the diagnosis and treatment of atherosclerotic vulnerable plaques. The results showed that the Fe-PFH-poly(lactic- co-glycolic acid) (PLGA)/chitosan (CS)-DS NPs were fabricated successfully, with the ability to undergo phase transition by low-intensity focused ultrasound (LIFU) irradiation to achieve ultrasound imaging; a high carrier rate of Fe₃O₄ had a good negative enhancement effect on magnetic resonance imaging (MRI). The NPs had a high binding affinity for activated macrophages and could be endocytosed by the macrophages and notably induced apoptosis under LIFU irradiation by an acoustic droplet vaporization effect in vitro. Furthermore, in an ex vivo atherosclerotic plaque model of apolipoprotein E knockout (KO) (apoE^-/-) mice induced by high cholesterol, the NPs selectively accumulated at the sites of SR-A expressed on the activated macrophages of the aortic region. This result was also confirmed by MRI in vivo, where the NPs could be targeted to the aortic plaque and reduced the T₂* signal. The LIFU-induced phase transition could lead to the apoptosis of macrophages on plaques in vivo. In summary, Fe-PFH-PLGA/CS-DS NPs may be applied as multimodal and multifunctional probes and are expected to enable the specific diagnosis and targeted therapy of vulnerable plaques.

Co-regulatory networks of human serum proteins link genetics to disease

Proteins circulating in the blood are critical for age-related disease processes; however, the serum proteome has remained largely unexplored. To this end, 4137 proteins covering most predicted extracellular proteins were measured in the serum of 5457 Icelanders over 65 years of age. Pairwise correlation between proteins as they varied across individuals revealed 27 different network modules of serum proteins, many of which were associated with cardiovascular and metabolic disease states, as well as overall survival. The protein modules were controlled by cis- and trans-acting genetic variants, which in many cases were also associated with complex disease. This revealed co-regulated groups of circulating proteins that incorporated regulatory control between tissues and demonstrated close relationships to past, current, and future disease states.

Joint Effect of Carotid Plaque and C-Reactive Protein on First-Ever Ischemic Stroke and Myocardial Infarction?

Background

The joint effect of atherosclerosis and CRP (C‐reactive protein) on risk of ischemic stroke (IS) and myocardial infarction (MI) has been sparsely studied. The aim of this study was to explore whether CRP mediates the risk of events in subjects with prevalent carotid plaque, examine synergism, and test whether CRP and carotid plaque add to risk prediction beyond traditional risk factors.

Methods and Results

CRP and carotid total plaque area (TPA) were measured in 10 109 participants in the Tromsø Study from 1994 to 2008. Incident IS (n=671) and MI (n=1079) were registered until December 31, 2013. We calculated hazard ratios (HRs) of MI and IS according to categories of CRP (<1, 1–3, and >3 mg/L) and plaque status (no plaque and TPA below and above median) in Cox proportional hazard models with time‐varying covariates. Multivariable‐adjusted CRP >3 versus <1 mg/L was associated with risk of IS (HR, 1.84; 95% confidence interval, 1.49–2.26) and MI (HR, 1.46; 95% confidence interval, 1.23–1.73). TPA above median versus no plaque was associated with risk for IS (HR, 1.65; 95% confidence interval, 1.36–2.01) and MI (HR, 1.64; 95% confidence interval, 1.41–1.92). In participants with plaque, adjustment for CRP minimally attenuated the risk estimates. The highest incidence rates for MI and IS were seen in the group with both CRP >3 mg/L and TPA is above the median. TPA and CRP combined added to risk prediction beyond traditional risk factors.

Conclusions

The simultaneous presence of subclinical atherosclerosis and elevated CRP was associated with increased risk of IS and MI. The combined assessment of subclinical atherosclerosis and inflammatory biomarkers may improve cardiovascular disease risk stratification.

Dysregulation of lipids in Alzheimer's disease and their role as potential biomarkers

The brain is highly enriched in lipids, and an intensive study of these lipids may be informative, not only of normal brain function but also of changes with age and in disease. In recent years, the development of highly sensitive mass spectrometry platforms and other high-throughput technologies has enabled the discovery of complex changes in the entire lipidome. This lipidomics approach promises to be a particularly useful tool for identifying diagnostic biomarkers for early detection of age-related neurodegenerative disease, such as Alzheimer's disease (AD), which has till recently been limited to protein- and gene-centric approaches. This review highlights known lipid changes affecting the AD brain and presents an update on the progress of lipid biomarker research in AD. Important considerations for designing large-scale lipidomics experiments are discussed to help standardize findings across different laboratories, as well as challenges associated with moving toward clinical application.