Chemical characterization of pro-inflammatory amyloid-beta peptides in human atherosclerotic lesions and platelets

PICALM Regulating the Generation of Amyloid β-Peptide to Promote Anthracycline-Induced Cardiotoxicity

Anthracyclines are chemotherapeutic drugs used to treat solid and hematologic malignancies. However, life-threatening cardiotoxicity, with cardiac dilation and heart failure, is a drawback. A combination of in vivo for single cell/nucleus RNA sequencing and in vitro approaches is used to elucidate the underlying mechanism. Genetic depletion and pharmacological blocking peptides on phosphatidylinositol binding clathrin assembly (PICALM) are used to evaluate the role of PICALM in doxorubicin-induced cardiotoxicity in vivo. Human heart tissue samples are used for verification. Patients with end-stage heart failure and chemotherapy-induced cardiotoxicity have thinner cell membranes compared to healthy controls do. Using the doxorubicin-induced cardiotoxicity mice model, it is possible to replicate the corresponding phenotype in patients. Cellular changes in doxorubicin-induced cardiotoxicity in mice, especially in cardiomyocytes, are identified using single cell/nucleus RNA sequencing. Picalm expression is upregulated only in cardiomyocytes with doxorubicin-induced cardiotoxicity. Amyloid β-peptide production is also increased after doxorubicin treatment, which leads to a greater increase in the membrane permeability of cardiomyocytes. Genetic depletion and pharmacological blocking peptides on Picalm reduce the generation of amyloid β-peptide. This alleviates the doxorubicin-induced cardiotoxicity in vitro and in vivo. In human heart tissue samples of patients with chemotherapy-induced cardiotoxicity, PICALM, and amyloid β-peptide are elevated as well.

Atherosclerosis is associated with plasma Aβ levels in non-hypertension patients

BACKGROUND

Growing evidence indicated that to develop of atherosclerosis observed more often by people with Alzheimer's disease (AD), but the underlying mechanism is not fully clarified. Considering that amyloid-β (Aβ) deposition in the brain is the key pathophysiology of AD and plasma Aβ is closely relate to Aβ deposition in the brain, in the present study, we investigated the relationships between atherosclerosis and plasma Aβ levels.

METHODS

This was a population based cross-sectional study. Patients with high risk of atherosclerosis from Qubao Village, Xi'an were underwent carotid ultrasound for assessment of atherosclerosis. Venous blood was collected on empty stomach in the morning and plasma Aβ1-40 and Aβ1-42 levels were measured using ELISA. Multivariate logistic regression analysis was performed to investigate the relationships between carotid atherosclerosis (CAS) and plasma Aβ levels.

RESULTS

Among 344 patients with high risk of atherosclerosis, 251(73.0%) had CAS. In the univariate analysis, the plasma Aβ levels had no significant differences between CAS group and non-CAS group (Aβ1-40: 53.07 ± 9.24 pg/ml vs. 51.67 ± 9.11pg/ml, p = 0.211; Aβ1-42: 40.10 ± 5.57 pg/ml vs. 40.70 pg/ml ± 6.37pg/ml, p = 0.285). Multivariate logistic analysis showed that plasma Aβ levels were not associated with CAS (Aβ1-40: OR = 1.019, 95%CI: 0.985-1.054, p = 0.270;Aβ1-42: OR = 1.028, 95%CI: 0.980-1.079, p = 0.256) in the total study population. After stratified by hypertension, CAS was associated with plasma Aβ1-40 positively (OR = 1.063, 95%CI: 1.007-1.122, p = 0.028) in the non-hypertension group, but not in hypertensive group. When the plasma Aβ concentrations were classified into four groups according to its quartile, the highest level of plasma Aβ1-40 group was associated with CAS significantly (OR = 4.465, 95%CI: 1.024-19.474, p = 0.046).

CONCLUSION

Among patients with high risk of atherosclerosis, CAS was associated with higher plasma Aβ1-40 level in non-hypertension group, but not in hypertension group. These indicated that atherosclerosis is associated with plasma Aβ level, but the relationship may be confounded by hypertension.

Amyloid-beta and tau protein beyond Alzheimer's disease

ABSTRACT

The aggregation of amyloid-beta peptide and tau protein dysregulation are implicated to play key roles in Alzheimer's disease pathogenesis and are considered the main pathological hallmarks of this devastating disease. Physiologically, these two proteins are produced and expressed within the normal human body. However, under pathological conditions, abnormal expression, post-translational modifications, conformational changes, and truncation can make these proteins prone to aggregation, triggering specific disease-related cascades. Recent studies have indicated associations between aberrant behavior of amyloid-beta and tau proteins and various neurological diseases, such as Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis, as well as retinal neurodegenerative diseases like Glaucoma and age-related macular degeneration. Additionally, these proteins have been linked to cardiovascular disease, cancer, traumatic brain injury, and diabetes, which are all leading causes of morbidity and mortality. In this comprehensive review, we provide an overview of the connections between amyloid-beta and tau proteins and a spectrum of disorders.

Correlation of Plasmatic Amyloid Beta Peptides (Aβ-40, Aβ-42) with Myocardial Injury and Inflammatory Biomarkers in Acute Coronary Syndrome

Background/Objective: Amyloid beta (β) -40 levels increase with age and inflammation states and appear to be associated with clinical manifestations of acute coronary syndrome (ACS). We investigated the correlation of Aβ peptides with myocardial injury and inflammation biomarkers in patients with or without ST elevation myocardial infarction (STEMI, NSTEMI). Methods: This singe-center, cross-sectional, observational, and correlation study included 65 patients with ACS (n = 34 STEMI, 29 males, age = 58 ± 12 years; n = 31 NSTEMI, 22 males, age = 60 ± 12 years) who were enrolled in the coronary care unit within 12 h after symptom onset from February 2022 to May 2023. Aβ peptide levels and biochemical parameters were assessed. Results: NSTEMI patients had a higher prevalence of hypertension (p = 0.039), diabetes (p = 0.043), smoking (p = 0.003), and prior myocardial infarction (p = 0.010) compared to STEMI patients. We observed a higher level of Aβ-42 in NSTEMI (p = 0.001) but no difference in Aβ-40 levels. We also found a correlation between age and NT-proBNP with both Aβ peptides (Aβ-40, Aβ-42) (p = 0.001, p = 0.002 respectively). Conclusions: Our results show that patients with NSTEMI had a higher prevalence of cardiovascular risk factors (hypertension, diabetes, smoking, and prior myocardial infarction). Considering these results, we propose that Aβ-42 can add value to risk stratification in NSTEMI patients.

Tanshinone IIA: a Chinese herbal ingredient for the treatment of atherosclerosis

Tanshinone IIA (Tan IIA) is a fat-soluble compound extracted from Salvia miltiorrhiza, which has a protective effect against atherosclerosis (AS). Tan IIA can inhibit oxidative stress and inflammatory damage of vascular endothelial cells (VECs) and improve endothelial cell dysfunction. Tan IIA also has a good protective effect on vascular smooth muscle cells (VSMCs). It can reduce vascular stenosis by inhibiting the proliferation and migration of vascular smooth muscle cells (VSMCs), and improve the stability of the fibrous cap of atherosclerotic plaque by inhibiting apoptosis and inflammation of VSMCs. In addition, Tan IIA inhibits the inflammatory response of macrophages and the formation of foam cells in atherosclerotic plaques. In summary, Tan IIA improves AS through a complex pathway. We propose to further study the specific molecular targets of Tan IIA using systems biology methods, so as to fundamentally elucidate the mechanism of Tan IIA. It is worth mentioning that there is a lack of high-quality evidence-based medical data on Tan IIA treatment of AS. We recommend that a randomized controlled clinical trial be conducted to evaluate the exact efficacy of Tan IIA in improving AS. Finally, sodium tanshinone IIA sulfonate (STS) can cause adverse drug reactions in some patients, which needs our attention.

C/EBPβ/AEP signaling couples atherosclerosis to the pathogenesis of Alzheimer's disease

Atherosclerosis (ATH) and Alzheimer's disease (AD) are both age-dependent inflammatory diseases, associated with infiltrated macrophages and vascular pathology and overlapping molecules. C/EBPβ, an Aβ or inflammatory cytokine-activated transcription factor, and AEP (asparagine endopeptidase) are intimately implicated in both ATH and AD; however, whether C/EBPβ/AEP signaling couples ATH to AD pathogenesis remains incompletely understood. Here we show that C/EBPβ/AEP pathway mediates ATH pathology and couples ATH to AD. Deletion of C/EBPβ or AEP from primary macrophages diminishes cholesterol load, and inactivation of this pathway reduces foam cell formation and lesions in aorta in ApoE-/- mice, fed with HFD (high-fat-diet). Knockout of ApoE from 3xTg AD mouse model augments serum LDL and increases lesion areas in the aorta. Depletion of C/EBPβ or AEP from 3xTg/ApoE-/- mice substantially attenuates these effects and elevates cerebral blood flow and vessel length, improving cognitive functions. Strikingly, knockdown of ApoE from the hippocampus of 3xTg mice decreases the cerebral blood flow and vessel length and aggravates AD pathologies, leading to cognitive deficits. Inactivation of C/EBPβ/AEP pathway alleviates these events and restores cognitive functions. Hence, our findings demonstrate that C/EBPβ/AEP signaling couples ATH to AD via mediating vascular pathology.

Beta-Amyloid Instigates Dysfunction of Mitochondria in Cardiac Cells

Alzheimer’s disease (AD) includes the formation of extracellular deposits comprising aggregated β-amyloid (Aβ) fibers associated with oxidative stress, inflammation, mitochondrial abnormalities, and neuronal loss. There is an associative link between AD and cardiac diseases; however, the mechanisms underlying the potential role of AD, particularly Aβ in cardiac cells, remain unknown. Here, we investigated the role of mitochondria in mediating the effects of Aβ_1-40 and Aβ_1-42 in cultured cardiomyocytes and primary coronary endothelial cells. Our results demonstrated that Aβ_1-40 and Aβ_1-42 are differently accumulated in cardiomyocytes and coronary endothelial cells. Aβ_1-42 had more adverse effects than Aβ_1-40 on cell viability and mitochondrial function in both types of cells. Mitochondrial and cellular ROS were significantly increased, whereas mitochondrial membrane potential and calcium retention capacity decreased in both types of cells in response to Aβ_1-42. Mitochondrial dysfunction induced by Aβ was associated with apoptosis of the cells. The effects of Aβ_1-42 on mitochondria and cell death were more evident in coronary endothelial cells. In addition, Aβ_1-40 and Aβ_1-42 significantly increased Ca²⁺ -induced swelling in mitochondria isolated from the intact rat hearts. In conclusion, this study demonstrates the toxic effects of Aβ on cell survival and mitochondria function in cardiac cells.

Medin co-aggregates with vascular amyloid-β in Alzheimer's disease

Aggregates of medin amyloid (a fragment of the protein MFG-E8, also known as lactadherin) are found in the vasculature of almost all humans over 50 years of age^1,2, making it the most common amyloid currently known. We recently reported that medin also aggregates in blood vessels of ageing wild-type mice, causing cerebrovascular dysfunction³. Here we demonstrate in amyloid-β precursor protein (APP) transgenic mice and in patients with Alzheimer's disease that medin co-localizes with vascular amyloid-β deposits, and that in mice, medin deficiency reduces vascular amyloid-β deposition by half. Moreover, in both the mouse and human brain, MFG-E8 is highly enriched in the vasculature and both MFG-E8 and medin levels increase with the severity of vascular amyloid-β burden. Additionally, analysing data from 566 individuals in the ROSMAP cohort, we find that patients with Alzheimer's disease have higher MFGE8 expression levels, which are attributable to vascular cells and are associated with increased measures of cognitive decline, independent of plaque and tau pathology. Mechanistically, we demonstrate that medin interacts directly with amyloid-β to promote its aggregation, as medin forms heterologous fibrils with amyloid-β, affects amyloid-β fibril structure, and cross-seeds amyloid-β aggregation both in vitro and in vivo. Thus, medin could be a therapeutic target for prevention of vascular damage and cognitive decline resulting from amyloid-β deposition in the blood vessels of the brain.

Different Sides of Depression in the Elderly: An In-depth View on the Role of Aβ Peptides

BACKGROUND

Late-onset depression (LOD) is the most common neuropsychiatric disorder associated with Alzheimer's disease (AD), often associated with structural and functional brain changes, neuropsychological impairments and negative family history for affective disorders. LOD could be a risk factor or a prodromal phase of AD; this has led to the investigation of the link between depression and amyloid-β (Aβ) peptides by measuring Aβ levels in plasma, cerebrospinal fluid (CSF) and brains of elderly depressed subjects.

OBJECTIVE

Clarify the complex relationship between depression, Aβ peptides and AD.

METHOD

We evaluated all articles published up to 2019 in PubMed in which Aβ was measured in serum (or plasma), CSF or brain in elderly with Major Depressive Disorder or depressive symptoms evaluated with standard scales.

RESULTS

Low plasma Aβ42 levels are strongly associated with depression severity. Plasma Aβ40 levels are higher in younger depressed, drug-resistant and those with more severe symptoms. CSF Aβ42 levels are lower in depressed than controls. PET-detected global and region-specific increases in Aβ deposition are sometimes associated with LOD, cognitive impairment, anxiety but not with Cardiovascular Diseases (CVDs)/CVD risk factors. Elderly depressed with CVDs/CVD risk factors have more frequently high plasma Aβ40 levels and drug-resistance; those without these co-morbidities have low plasma Aβ42 levels and a greater cognitive impairment.

CONCLUSION

Two specific Aβ profiles emerge in elderly depressed. One is associated with Aβ42 reductions in plasma and CSF, possibly reflecting increased brain amyloid deposition and prodromal AD. The other one is characterized by high plasma Aβ40 levels, cerebrovascular disease and clinically associated with increased AD risk.

Subcutaneous Uptake on [18F]Florbetaben PET/CT: a Case Report of Possible Amyloid-Beta Immune-Reactivity After COVID-19 Vaccination

INTRODUCTION

Large-scale worldwide COVID-19 vaccination programs are being rapidly deployed, and high-risk patients with comorbidity are now receiving the first doses of the vaccine. Physicians should be, therefore, aware of new pitfalls associated with the current pandemic vaccination program, also in the case of [¹⁸F]Florbetaben PET/CT.Case PresentationWe described the first image of [¹⁸F]Florbetaben PET/CT in the evaluation of a 70-year-old male with suspicious Alzheimer disease and unclear history of heart disease. We detailed the diagnostic imaging PET/CT workup with different findings.

CONCLUSION

In this case, [¹⁸F]Florbetaben PET/CT can demonstrate potential beta-amyloid immune-reactivity and deposition associated with the current COVID-19 pandemic vaccination programs.

Microvascular Alterations in Alzheimer's Disease

Alzheimer's disease (AD) is a neurodegenerative disorder associated with continual decline in cognition and ability to perform routine functions such as remembering familiar places or understanding speech. For decades, amyloid beta (Aβ) was viewed as the driver of AD, triggering neurodegenerative processes such as inflammation and formation of neurofibrillary tangles (NFTs). This approach has not yielded therapeutics that cure the disease or significant improvements in long-term cognition through removal of plaques and Aβ oligomers. Some researchers propose alternate mechanisms that drive AD or act in conjunction with amyloid to promote neurodegeneration. This review summarizes the status of AD research and examines research directions including and beyond Aβ, such as tau, inflammation, and protein clearance mechanisms. The effect of aging on microvasculature is highlighted, including its contribution to reduced blood flow that impairs cognition. Microvascular alterations observed in AD are outlined, emphasizing imaging studies of capillary malfunction. The review concludes with a discussion of two therapies to protect tissue without directly targeting Aβ for removal: (1) administration of growth factors to promote vascular recovery in AD; (2) inhibiting activity of a calcium-permeable ion channels to reduce microglial activation and restore cerebral vascular function.

The Alzheimer's Disease Amyloid-Beta Hypothesis in Cardiovascular Aging and Disease: JACC Focus Seminar

Aging-related cellular and molecular processes including low-grade inflammation are major players in the pathogenesis of cardiovascular disease (CVD) and Alzheimer's disease (AD). Epidemiological studies report an independent interaction between the development of dementia and the incidence of CVD in several populations, suggesting the presence of overlapping molecular mechanisms. Accumulating experimental and clinical evidence suggests that amyloid-beta (Aβ) peptides may function as a link among aging, CVD, and AD. Aging-related vascular and cardiac deposition of Αβ induces tissue inflammation and organ dysfunction, both important components of the Alzheimer's disease amyloid hypothesis. In this review, the authors describe the determinants of Aβ metabolism, summarize the effects of Aβ on atherothrombosis and cardiac dysfunction, discuss the clinical value of Αβ1-40 in CVD prognosis and patient risk stratification, and present the therapeutic interventions that may alter Aβ metabolism in humans.

Aβ40 Promotes the Osteoblastic Differentiation of Aortic Valve Interstitial Cells through the RAGE Pathway

Amyloid beta (Aβ) peptide 40 enhances the activation of receptor for advanced glycation end products (RAGE) in immune-inflammatory diseases. RAGE exhibits several effects in the setting of numerous cardiovascular events. We hypothesized that the Aβ40/RAGE pathway is involved in the osteoblastic differentiation of the valvular interstitial cell (VIC) phenotype, and RAGE knockout intervention could reduce the calcification of aortic valve interstitial cells (AVICs) by inhibiting the extracellular-regulated kinase1/2 (ERK1/2)/nuclear factor kappa-B (NF-κB) signaling pathway. To test this hypothesis, the activation of Aβ40/RAGE pathway in human calcific AVs was evaluated with immunohistochemical staining. Cultured calcific VIC models were used in vitro. The VICs were stimulated using Aβ40, with or without RAGE small interfering ribonucleic acid (siRNA), and ERK1/2 and NF-κB inhibitors for analysis. Our data revealed that Aβ40 induced the ERK1/2/NF-κB signaling pathway and osteoblastic differentiation of AVICs via the RAGE pathway in vitro.

Neurodegenerative Disease-Related Proteins within the Epidermal Layer of the Human Skin

There is increasing evidence suggesting that amyloidogenic proteins might form deposits in non-neuronal tissues in neurodegenerative disorders such as Alzheimer's or Parkinson's diseases. However, the detection of these aggregation-prone proteins within the human skin has been controversial. Using immunohistochemistry (IHC) and mass spectrometry tissue imaging (MALDI-MSI), fresh frozen human skin samples were analyzed for the expression and localization of neurodegenerative disease-related proteins. While α-synuclein was detected throughout the epidermal layer of the auricular samples (IHC and MALDI-MSI), tau and Aβ34 were also localized to the epidermal layer (IHC). In addition to Aβ peptides of varying length (e.g., Aβ40, Aβ42, Aβ34), we also were able to detect inflammatory markers within the same sample sets (e.g., thymosin β-4, psoriasin). While previous literature has described α-synuclein in the nucleus of neurons (e.g., Parkinson's disease), our current detection of α-synuclein in the nucleus of skin cells is novel. Imaging of α-synuclein or tau revealed that their presence was similar between the young and old samples in our present study. Future work may reveal differences relevant for diagnosis between these proteins at the molecular level (e.g., age-dependent post-translational modifications). Our novel detection of Aβ34 in human skin suggests that, just like in the brain, it may represent a stable intermediate of the Aβ40 and Aβ42 degradation pathway.

Adaptogenic effects of Panax ginseng on modulation of cardiovascular functions

Cardiovascular diseases are a rapidly growing epidemic with high morbidity and mortality. There is an urgent need to develop nutraceutical-based therapy with minimum side effects to reduce cardiovascular risk. Panax ginseng occupies a prominent status in herbal medicine for its various therapeutic effects against inflammation, allergy, diabetes, cardiovascular diseases, and even cancer, with positive, beneficial, and restorative effects. The active components found in most P. ginseng varieties are known to include ginsenosides, polysaccharides, peptides, alkaloids, polyacetylene, and phenolic compounds, which are considered to be the main pharmacologically active constituents in ginseng. P. ginseng is an adaptogen. That is, it supports living organisms to maintain optimal homeostasis by exerting effects that counteract physiological changes caused by physical, chemical, or biological stressors. P. ginseng possesses immunomodulatory (including both immunostimulatory and immunosuppressive), neuromodulatory, and cardioprotective effects; suppresses anxiety; and balances vascular tone. P. ginseng has an antihypertensive effect that has been explained by its vasorelaxant action, and paradoxically, it is also known to increase blood pressure by vasoconstriction and help maintain cardiovascular health. Here, we discuss the potential adaptogenic effects of P. ginseng on the cardiovascular system and outline a future research perspective in this area.

Herpud1 deficiency could reduce amyloid-β40 expression and thereby suppress homocysteine-induced atherosclerosis by blocking the JNK/AP1 pathway

Homocysteine (Hcy) is considered an independent risk factor for various cardiovascular diseases including atherosclerosis which is associated with lipid metabolism, inflammation, and oxidative stress. Results from our previous study suggested that Hcy-induced atherosclerosis could be reversed by Herpud1 knockout which inhibits vascular smooth muscle cell (VSMC) phenotype switching. Here, we aim to investigate more precise mechanisms behind the improvement in Hcy-induced atherosclerosis. Amyloid-β40 (Aβ40), a vital protein in Alzheimer disease (AD), has been regarded as an important component in the atherosclerosis program in recent years due to the biological similarity between AD and atherosclerosis. Thus, we determined to assess the value of Aβ40 in a Herpud1 knockout Hcy-induced atherosclerosis mouse model by measuring Aβ40 expression in tissue and biomarkers of lipid metabolism, inflammation, and oxidative stress in serum. Additionally, since endothelial dysfunction plays a prominent role in atherosclerosis, we tested human umbilical vein endothelial cell (HUVEC) function following Herpud1 silencing in vitro and evaluated JNK/AP1 signaling activation in our models because of its close relationship with Aβ40. As a result, our animal models showed that Herpud1 knockout reduced Aβ40 expression, inflammation, and oxidative stress levels other than lipid metabolism and alleviated atherosclerosis via JNK/AP1 signaling inhibition. Similarly, our cell experiments implied that Hcy-induced Aβ40 elevation and HUVEC dysfunction involving cell proliferation and apoptosis could be restored by Herpud1 silence through restraining JNK/AP1 pathway. Collectively, our study demonstrates that Herpud1 deficiency could reduce Aβ40 expression, thereby suppressing Hcy-induced atherosclerosis by blocking the JNK/AP1 pathway. This may provide novel potential targets for atherosclerosis prevention or treatment.

Biomarkers in Alzheimer's disease: Evaluation of platelets, hemoglobin and vitamin B12

Currently, the most likely hypotheses as the cause of Alzheimer's disease are deposition of amyloid beta peptide in the cerebral cortex and hyperphosphorylation of Tau protein. The diagnosis of Alzheimer's disease is based on the exclusion of other diseases, behavioral assessments, and blood and imaging tests. Biotechnology has created interesting perspectives for the early detection of Alzheimer's disease through blood analysis, with special attention to platelets, hemoglobin and vitamin B12.

OBJECTIVE

To evaluate the concentrations of platelets, hemoglobin and vitamin B12 in the blood of older adults with and without dementia of Alzheimer's disease.

METHODS

A case-control study involving 120 individuals was conducted, seeking to establish a correlation between changes in platelet, hemoglobin and vitamin B12 concentrations in patients with confirmed AD and in individuals in the inclusion group without AD. The study met the established ethical requirements.

RESULTS

Hemoglobin and platelet levels were statistically lower in patients with AD. The biochemical evaluation in AD patient and healthy groups for vitamin B12 showed a decrease in the levels of this compound in patients with AD.

CONCLUSION

We demonstrated the feasibility of the use of blood biomarkers as predictive markers for the diagnosis of AD.

Critical Steps to be Taken into Consideration Before Quantification of β-Amyloid and Tau Isoforms in Blood can be Implemented in a Clinical Environment

This review aims to document difficulties, limitations, and pitfalls when considering protein analysis in blood samples. It proposes an improved workflow for design, development, and validation of (immuno)assays for blood proteins, without providing reflections on a potential hypothesis of the origin of protein mismetabolism and deposition. There is a special focus on assay development for quantification of β-amyloid (Aβ) and tau in blood for diagnostic use or for integration in clinical trials in the field of Alzheimer's disease (AD).

In silico epigenetics of metal exposure and subclinical atherosclerosis in middle aged men: pilot results from the Aragon Workers Health Study

We explored the association of metal levels with subclinical atherosclerosis and epigenetic changes in relevant biological pathways. Whole blood DNA Infinium Methylation 450 K data were obtained from 23 of 73 middle age men without clinically evident cardiovascular disease (CVD) who participated in the Aragon Workers Health Study in 2009 (baseline visit) and had available baseline urinary metals and subclinical atherosclerosis measures obtained in 2010-2013 (follow-up visit). The median metal levels were 7.36 µg g^-1, 0.33 µg g^-1, 0.11 µg g^-1 and 0.07 µg g^-1, for arsenic (sum of inorganic and methylated species), cadmium, antimony and tungsten, respectively. Urine cadmium and tungsten were associated with femoral and carotid intima-media thickness, respectively (Pearson's r = 0.27; p = 0.03 in both cases). Among nearest genes to identified differentially methylated regions (DMRs), 46% of metal-DMR genes overlapped with atherosclerosis-DMR genes (p < 0.001). Pathway enrichment analysis of atherosclerosis-DMR genes showed a role in inflammatory, metabolic and transport pathways. In in silico protein-to-protein interaction networks among proteins encoded by 162 and 108 genes attributed to atherosclerosis- and metal-DMRs, respectively, with proteins known to have a role in atherosclerosis pathways, we observed hub proteins in the network associated with both atherosclerosis and metal-DMRs (e.g. SMAD3 and NOP56), and also hub proteins associated with metal-DMRs only but with relevant connections with atherosclerosis effectors (e.g. SSTR5, HDAC4, AP2A2, CXCL12 and SSTR4). Our integrative in silico analysis demonstrates the feasibility of identifying epigenomic regions linked to environmental exposures and potentially involved in relevant pathways for human diseases. While our results support the hypothesis that metal exposures can influence health due to epigenetic changes, larger studies are needed to confirm our pilot results.This article is part of a discussion meeting issue 'Frontiers in epigenetic chemical biology'.

Amyloid-Targeting PET Tracer [18F]Flutemetamol Accumulates in Atherosclerotic Plaques

Atherosclerosis is characterized by the accumulation of oxidized lipids in the artery wall, which triggers an inflammatory response. Oxidized low-density lipoprotein (ox-LDL) presents amyloid-like structural properties, and different amyloid species have recently been recognized in atherosclerotic plaques. Therefore, we studied the uptake of the amyloid imaging agent [¹⁸F]Flutemetamol in atherosclerotic plaques. The binding of [¹⁸F]Flutemetamol to human carotid artery plaque was studied in vitro. In vivo uptake of the tracer was studied in hypercholesterolemic IGF-II/LDLR^−/−ApoB^100/100 mice and C57BL/6N controls. Tracer biodistribution was studied in vivo with PET/CT, and ex vivo by gamma counter and digital ex vivo autoradiography. The presence of amyloid, ox-LDL, and macrophages in the plaques was examined by immunohistochemistry. [¹⁸F]Flutemetamol showed specific accumulation in human carotid plaque, especially in areas positive for amyloid beta. The aortas of IGF-II/LDLR^−/−ApoB^100/100 mice showed large thioflavin-S-positive atherosclerotic plaques containing ox-LDL and macrophages. Autoradiography revealed 1.7-fold higher uptake in the plaques than in a lesion-free vessel wall, but no difference in aortic tissue uptake between mouse strains were observed in the in vivo PET/CT. In conclusion, [¹⁸F]Flutemetamol binds to amyloid-positive areas in human atherosclerotic plaques. Further studies are warranted to clarify the uptake mechanisms, and the potential of the tracer for in vivo imaging of atherosclerosis in patients.

Amyloid precursor protein is required for in vitro platelet adhesion to amyloid peptides and potentiation of thrombus formation

Amyloid precursor protein (APP) is the precursor of amyloid β (Aβ) peptides, whose accumulation in the brain is associated with Alzheimer's disease. APP is also expressed on the platelet surface and Aβ peptides are platelet agonists. The physiological role of APP is largely unknown. In neurons, APP acts as an adhesive receptor, facilitating integrin-mediated cell adhesion, while in platelets it regulates coagulation and venous thrombosis. In this work, we analyzed platelets from APP KO mice to investigate whether membrane APP supports platelet adhesion to physiological and pathological substrates. We found that APP-null platelets adhered and spread normally on collagen, von Willebrand Factor or fibrinogen. However, adhesion on immobilized Aβ peptides Aβ_1-40, Aβ_1-42 and Aβ_25-35 was completely abolished in platelets lacking APP. By contrast, platelet activation and aggregation induced by Aβ peptides occurred normally in the absence of APP. Adhesion of APP-transfected HEK293 to Aβ peptides was significantly higher than that of control cells expressing low levels of APP. Co-coating of Aβ_1-42 and Aβ_25-35 with collagen strongly potentiated platelet adhesion when whole blood from wild type mice was perfused at arterial shear rate, but had no effects with blood from APP KO mice. These results demonstrate that APP selectively mediates platelet adhesion to Aβ under static condition but not platelet aggregation, and is responsible for Aβ-promoted potentiation of thrombus formation under flow. Therefore, APP may facilitate an early step in thrombus formation when Aβ peptides accumulate in cerebral vessel walls or atherosclerotic plaques.

Deciphering Non-coding RNAs in Cardiovascular Health and Disease

After being long considered as “junk” in the human genome, non-coding RNAs (ncRNAs) currently represent one of the newest frontiers in cardiovascular disease (CVD) since they have emerged in recent years as potential therapeutic targets. Different types of ncRNAs exist, including small ncRNAs that have fewer than 200 nucleotides, which are mostly known as microRNAs (miRNAs), and long ncRNAs that have more than 200 nucleotides. Recent discoveries on the role of ncRNAs in epigenetic and transcriptional regulation, atherosclerosis, myocardial ischemia/reperfusion (I/R) injury and infarction (MI), adverse cardiac remodeling and hypertrophy, insulin resistance, and diabetic cardiomyopathy prompted vast interest in exploring candidate ncRNAs for utilization as potential therapeutic targets and/or diagnostic/prognostic biomarkers in CVDs. This review will discuss our current knowledge concerning the roles of different types of ncRNAs in cardiovascular health and disease and provide some insight on the cardioprotective signaling pathways elicited by the non-coding genome. We will highlight important basic and clinical breakthroughs that support employing ncRNAs for treatment or early diagnosis of a variety of CVDs, and also depict the most relevant limitations that challenge this novel therapeutic approach.

Therapeutic impact of rHuEPO on abnormal platelet APP, BACE 1, presenilin 1, ADAM 10 and Aβ expressions in chronic kidney disease patients with cognitive dysfunction like Alzheimer's disease: A pilot study

BACKGROUND

Cognitive dysfunction is reported to be a major cause of morbidity in chronic kidney disease (CKD). The senile plaques (SPs) in the brain are one of the most pathophysiological characteristics of cognitive dysfunction and its major constituent amyloid β (Aβ) released from amyloid precursor protein (APP) by β (BACE1) and γ (presenilin 1) secretases . Platelets contain more than 95% of the circulating APP and implicate as a candidate biomarker for cognitive decline. Recombinant human erythropoietin (rHuEPO) is a standard therapy for anemia in CKD and also acts as a neuroprotective agent. The aim of the study is to determine the impact of rHuEPO therapy on platelet APP processing in CKD with Cognitive Dysfunction.

METHODS

A total of 60 subjects comprising of 30 CKD without cognitive dysfunction and 30 CKD with cognitive dysfunction based on neuropsychological assessment. APP, BACE1, Presenilin 1, ADAM 10 (α secretase) and Aβ expressions in platelets were determined by western blotting and lipid peroxidation (LPO) in platelet rich plasma (PRP) was done by spectrophotometrically. The parameters were statistically compared with Alzheimer's disease (AD), Normocytic normochromic anemic and healthy subjects.

RESULTS

Significantly (p < 0.05) decreased APP, ADAM 10 while increased BACE1, Presenilin 1, Aβ and LPO were observed in CKD with cognitive dysfunction like AD subjects compared to other groups. The parameters were reassessed in CKD with cognitive dysfunction subjects after rHuEPO (100 IU/ kg, weekly twice, 6 months) therapy. All the parameters were retrieved significantly (p < 0.05) along with improved neuropsychological tests scoring after rHuEPO therapy.

CONCLUSIONS

This study demonstrated that rHuEPO is an effective neuroprotective agent in the context of CKD associated cognitive dysfunction and proved its clinical usefulness.

APP/Aβ structural diversity and Alzheimer's disease pathogenesis

The amyloid cascade hypothesis of Alzheimer's disease (AD) proposes amyloid- β (Aβ) is a chief pathological element of dementia. AD therapies have targeted monomeric and oligomeric Aβ 1-40 and 1-42 peptides. However, alternative APP proteolytic processing produces a complex roster of Aβ species. In addition, Aβ peptides are subject to extensive posttranslational modification (PTM). We propose that amplified production of some APP/Aβ species, perhaps exacerbated by differential gene expression and reduced peptide degradation, creates a diverse spectrum of modified species which disrupt brain homeostasis and accelerate AD neurodegeneration. We surveyed the literature to catalog Aβ PTM including species with isoAsp at positions 7 and 23 which may phenocopy the Tottori and Iowa Aβ mutations that result in early onset AD. We speculate that accumulation of these alterations induce changes in secondary and tertiary structure of Aβ that favor increased toxicity, and seeding and propagation in sporadic AD. Additionally, amyloid-β peptides with a pyroglutamate modification at position 3 and oxidation of Met35 make up a substantial portion of sporadic AD amyloid deposits. The intrinsic physical properties of these species, including resistance to degradation, an enhanced aggregation rate, increased neurotoxicity, and association with behavioral deficits, suggest their emergence is linked to dementia. The generation of specific 3D-molecular conformations of Aβ impart unique biophysical properties and a capacity to seed the prion-like global transmission of amyloid through the brain. The accumulation of rogue Aβ ultimately contributes to the destruction of vascular walls, neurons and glial cells culminating in dementia. A systematic examination of Aβ PTM and the analysis of the toxicity that they induced may help create essential biomarkers to more precisely stage AD pathology, design countermeasures and gauge the impacts of interventions.

Feasibility of in vivo 18F-florbetaben PET/MR imaging of human carotid amyloid-β

PURPOSE

Amyloid-beta (Aβ) peptides are involved in the inflammatory pathology of atherosclerosis. ¹⁸F-Florbetaben is a PET tracer for clinical imaging of cerebral Aβ plaques in Alzheimer's disease (AD). We sought to determine whether specific uptake of ¹⁸F-florbetaben in the carotid arteries can be identified using a fully integrated hybrid PET/MRI system and whether this uptake is associated with clinical cardiovascular disease (CVD) risk factors.

METHODS

Carotid ¹⁸F-florbetaben uptake was quantified as the mean of the maximum target-to-background ratio (_meanTBR_max) in 40 cognitively impaired subjects (age 68.2 ± 9.5 years) undergoing ¹⁸F-florbetaben PET/MRI to diagnose AD. Associations between carotid ¹⁸F-florbetaben uptake and several CVD risk factors were assessed by univariate analysis followed by a multivariate linear regression analysis. Furthermore, carotid ¹⁸F-florbetaben uptake was compared between patients with and without a positive cerebral Aβ PET scan.

RESULTS

¹⁸F-Florbetaben uptake was clearly visualized in the carotid arteries. Values of _meanTBR_max corrected for the blood pool activity of the tracer showed specific ¹⁸F-florbetaben uptake in the carotid wall. Male gender was associated with carotid ¹⁸F-florbetaben uptake in the univariate analysis, and was found to be an independent predictor of ¹⁸F-florbetaben uptake in the multivariate regression analysis (standardized regression coefficient β = 0.407, p = 0.009). Carotid ¹⁸F-florbetaben _meanTBR_max in patients with a positive cerebral Aβ scan did not differ from that in patients without cerebral Aβ deposits.

CONCLUSION

Specific ¹⁸F-florbetaben uptake in human carotid arteries was detected. Male gender was identified as an independent clinical risk factor. Therefore, ¹⁸F-florbetaben PET/MRI might provide new insights into the pathophysiological process in atherosclerosis.

Smooth muscle titin forms in vitro amyloid aggregates

Amyloids are insoluble fibrous protein aggregates, and their accumulation is associated with amyloidosis and many neurodegenerative diseases, including Alzheimer's disease. In the present study, we report that smooth muscle titin (SMT; 500 kDa) from chicken gizzard forms amyloid aggregates in vitro. This conclusion is supported by EM data, fluorescence analysis using thioflavin T (ThT), Congo red (CR) spectroscopy and X-ray diffraction. Our dynamic light scattering (DLS) data show that titin forms in vitro amyloid aggregates with a hydrodynamic radius (Rh) of approximately 700–4500 nm. The initial titin aggregates with Rh approximately 700 nm were observed beyond first 20 min its aggregation that shows a high rate of amyloid formation by this protein. We also showed using confocal microscopy the cytotoxic effect of SMT amyloid aggregates on smooth muscle cells from bovine aorta. This effect involves the disorganization of the actin cytoskeleton and result is cell damage. Cumulatively, our results indicate that titin may be involved in generation of amyloidosis in smooth muscles.

The Alzheimer's disease peptide β-amyloid promotes thrombin generation through activation of coagulation factor XII

Essentials How the Alzheimer's disease (AD) peptide β-amyloid (Aβ) disrupts neuronal function in the disease is unclear. Factor (F) XII initiates blood clotting via FXI, and thrombosis has been implicated in AD. Aβ triggers FXII-dependent FXI and thrombin activation, evidence of which is seen in AD plasma. Aβ-triggered clotting could contribute to neuronal dysfunction in AD and be a novel therapeutic target.

SUMMARY

Background β-Amyloid (Aβ) is a key pathologic element in Alzheimer's disease (AD), but the mechanisms by which it disrupts neuronal function in vivo are not completely understood. AD is characterized by a prothrombotic state, which could contribute to neuronal dysfunction by affecting cerebral blood flow and inducing inflammation. The plasma protein factor XII triggers clot formation via the intrinsic coagulation cascade, and has been implicated in thrombosis. Objectives To investigate the potential for Aβ to contribute to a prothrombotic state. Methods and results We show that Aβ activates FXII, resulting in FXI activation and thrombin generation in human plasma, thereby establishing Aβ as a possible driver of prothrombotic states. We provide evidence for this process in AD by demonstrating decreased levels of FXI and its inhibitor C1 esterase inhibitor in AD patient plasma, suggesting chronic activation, inhibition and clearance of FXI in AD. Activation of the intrinsic coagulation pathway in AD is further supported by elevated fibrin levels in AD patient plasma. Conclusions The ability of Aβ to promote coagulation via the FXII-driven contact system identifies new mechanisms by which it could contribute to neuronal dysfunction and suggests potential new therapeutic targets in AD.

Platelet dysfunction in hypercholesterolemia mice, two Alzheimer's disease mouse models and in human patients with Alzheimer's disease

Alzheimer’s disease (AD) is a severe neurodegenerative disorder characterized mainly by accumulation of amyloid-β plaques and neurofibrillary tangles, synaptic and neuronal loss. Blood platelets contain the neurotransmitter serotonin and amyloid-precursor protein (APP), and may thus be useful as a peripheral biomarker for AD. The aim of the present study was to functionally characterize platelets by FACS, to examine alterations in APP expression and secretion, and to measure serotonin levels in hypercholesterolemia mice with AD-like pathology and in two AD mouse models, the triple transgenic AD model (3xTg) and the APP overexpressing AD model with the Swedish–Dutch–Iowa mutations (APP_SweDI). These data are supplemented with epidermal growth factor (EGF) levels and compared with changes observed in platelets of patients with AD. We observed decreased platelet APP isoforms in 3xTg mice and patients with AD when analysed by means of Western blot. In patients, a significant increase of APP levels was observed when assessed by ELISA. Secreted APPβ proved to be altered amongst all three animal models of AD at different time points and in human patients with AD. Serotonin levels were only reduced in 7 and 14 month old 3xTg mice. Moreover, we found significantly lower EGF levels in human AD patients and could thereby reproduce previous findings. Taken together, our data confirm that platelets are dysfunctional in AD, however, results from AD animal models do not coincide in all aspects, and markedly differ when compared to AD patients. We support previous data that APP, as well as EGF, could become putative biomarkers for diagnosing AD in human platelets.

Amyloid-beta (1-40) and the risk of death from cardiovascular causes in patients with coronary heart disease

BACKGROUND

The amyloid beta peptide is the major protein constituent of neuritic plaques in Alzheimer disease and appears to play a central role in vascular inflammation pathophysiology.

OBJECTIVES

This study sought to determine the clinical value of amyloid-beta 1-40 (Abeta40) measurement in predicting cardiovascular (CV) mortality in patients with coronary heart disease (CHD) and arterial stiffness progression in young healthy subjects.

METHODS

Abeta40 was retrospectively measured in blood samples collected from 3 independent prospective cohorts and 2 case-control cohorts (total N = 1,464). Major adverse cardiac events (MACE) were assessed in the 2 prospective cohorts (n = 877) followed for a median of 4.4 years. To look at effects on subclinical disease, arterial stiffness was evaluated at baseline and after 5-year follow-up (n = 107) in young healthy subjects. The primary endpoint was the predictive value of Abeta40 for CV mortality and outcomes in patients with CHD.

RESULTS

In Cox proportional hazards models adjusted for age, sex, estimated glomerular filtration rate, left ventricular ejection fraction, high-sensitivity C-reactive protein, and high-sensitivity troponin T, Abeta40 independently predicted CV death and MACE in patients with CHD (p < 0.05 for all). After multivariate adjustment, Abeta40 levels conferred a substantial enhancement of net reclassification index and integrated discrimination improvement of individuals at risk in the total combined CHD cohort over the best predictive model. Further cohort-based analysis revealed that Abeta40 levels were significantly and independently associated with arterial stiffness progression, incident subclinical atherosclerosis, and incident CHD.

CONCLUSIONS

Measuring blood levels of Abeta40 identified patients at high risk for CV death.

Role of amyloid peptides in vascular dysfunction and platelet dysregulation in Alzheimer's disease

Alzheimer's disease (AD) is the most common neurodegenerative cause of dementia in the elderly. AD is accompanied by the accumulation of amyloid peptides in the brain parenchyma and in the cerebral vessels. The sporadic form of AD accounts for about 95% of all cases. It is characterized by a late onset, typically after the age of 65, with a complex and still poorly understood aetiology. Several observations point towards a central role of cerebrovascular dysfunction in the onset of sporadic AD (SAD). According to the "vascular hypothesis", AD may be initiated by vascular dysfunctions that precede and promote the neurodegenerative process. In accordance to this, AD patients show increased hemorrhagic or ischemic stroke risks. It is now clear that multiple bidirectional connections exist between AD and cerebrovascular disease, and in this new scenario, the effect of amyloid peptides on vascular cells and blood platelets appear to be central to AD. In this review, we analyze the effect of amyloid peptides on vascular function and platelet activation and its contribution to the cerebrovascular pathology associated with AD and the progression of this disease.

Arizona Study of Aging and Neurodegenerative Disorders and Brain and Body Donation Program

The Brain and Body Donation Program (BBDP) at Banner Sun Health Research Institute (http://www.brainandbodydonationprogram.org) started in 1987 with brain-only donations and currently has banked more than 1600 brains. More than 430 whole-body donations have been received since this service was commenced in 2005. The collective academic output of the BBDP is now described as the Arizona Study of Aging and Neurodegenerative Disorders (AZSAND). Most BBDP subjects are enrolled as cognitively normal volunteers residing in the retirement communities of metropolitan Phoenix, Arizona. Specific recruitment efforts are also directed at subjects with Alzheimer's disease, Parkinson's disease and cancer. The median age at death is 82. Subjects receive standardized general medical, neurological, neuropsychological and movement disorders assessments during life and more than 90% receive full pathological examinations by medically licensed pathologists after death. The Program has been funded through a combination of internal, federal and state of Arizona grants as well as user fees and pharmaceutical industry collaborations. Subsets of the Program are utilized by the US National Institute on Aging Arizona Alzheimer's Disease Core Center and the US National Institute of Neurological Disorders and Stroke National Brain and Tissue Resource for Parkinson's Disease and Related Disorders. Substantial funding has also been received from the Michael J. Fox Foundation for Parkinson's Research. The Program has made rapid autopsy a priority, with a 3.0-hour median post-mortem interval for the entire collection. The median RNA Integrity Number (RIN) for frozen brain and body tissue is 8.9 and 7.4, respectively. More than 2500 tissue requests have been served and currently about 200 are served annually. These requests have been made by more than 400 investigators located in 32 US states and 15 countries. Tissue from the BBDP has contributed to more than 350 publications and more than 200 grant-funded projects.

Plasma β-amyloid 40 levels are positively associated with mortality risks in the elderly

BACKGROUND

We evaluated if plasma β-amyloid (Aβ) levels were associated with mortality risks in a subsample of the French Three-City (3C) prospective cohort study.

METHODS

Analyses were based on 1254 participants randomly selected from the initial 3C cohort stratified by center, sex, and age in the context of a nested case-cohort study to investigate biological variables. Associations between plasma Aβ and mortality were assessed with the Cox regression model with delayed entry including various potential confounding factors and testing possible mediators.

RESULTS

A relationship between high plasma Aβ1-40 concentrations and risk of mortality (hazards ratio, 1.15; 95% confidence interval, 1.01-1.31, P = .03) was unveiled independently of age, educational level, vascular risk factors, diet, physical activity, cognitive impairment, or frailty status. It was only modified when we included cystatin C levels.

CONCLUSIONS

Further investigations are needed to determine precisely the pathophysiological roles of plasma Aβ1-40 and cystatin C and before envisioning any future clinical applications.

Tanshinone IIA promotes non-amyloidogenic processing of amyloid precursor protein in platelets via estrogen receptor signaling to phosphatidylinositol 3-kinase/Akt

Amyloid β peptide (Aβ) is a proteolytic product of amyloid precursor protein (APP). Recent findings suggested that platelet-derived Aβ is closely associated with the pathogenesis of atherosclerosis (AS). Tanshinone IIA (Tan IIA), a pharmacologically active component of the Chinese herb Salvia miltiorrhiza Bunge, has long been used to treat AS and was also identified as a phytoestrogen. However, it has not been elucidated whether Tan IIA intervenes with platelet APP processing and whether such an intervention is associated with its estrogenic activity. Using human platelets, this study demonstrated that Tan IIA promoted the non-amyloidogenic cleavage of APP via estrogenic activity. The phosphatidylinositol 3-kinase/Akt pathway may be involved in this effect of Tan IIA on platelet APP metabolism as a downstream effector of estrogen receptor signaling. This study aimed to extend the existing data and provide new insights into the mechanism underlying the vasoprotective effect of Tan IIA.

Atherosclerosis and Alzheimer--diseases with a common cause? Inflammation, oxysterols, vasculature

BACKGROUND

Aging is accompanied by increasing vulnerability to pathologies such as atherosclerosis (ATH) and Alzheimer disease (AD). Are these different pathologies, or different presentations with a similar underlying pathoetiology?

DISCUSSION

Both ATH and AD involve inflammation, macrophage infiltration, and occlusion of the vasculature. Allelic variants in common genes including APOE predispose to both diseases. In both there is strong evidence of disease association with viral and bacterial pathogens including herpes simplex and Chlamydophila. Furthermore, ablation of components of the immune system (or of bone marrow-derived macrophages alone) in animal models restricts disease development in both cases, arguing that both are accentuated by inflammatory/immune pathways. We discuss that amyloid β, a distinguishing feature of AD, also plays a key role in ATH. Several drugs, at least in mouse models, are effective in preventing the development of both ATH and AD. Given similar age-dependence, genetic underpinnings, involvement of the vasculature, association with infection, Aβ involvement, the central role of macrophages, and drug overlap, we conclude that the two conditions reflect different manifestations of a common pathoetiology.

MECHANISM

Infection and inflammation selectively induce the expression of cholesterol 25-hydroxylase (CH25H). Acutely, the production of 'immunosterol' 25-hydroxycholesterol (25OHC) defends against enveloped viruses. We present evidence that chronic macrophage CH25H upregulation leads to catalyzed esterification of sterols via 25OHC-driven allosteric activation of ACAT (acyl-CoA cholesterol acyltransferase/SOAT), intracellular accumulation of cholesteryl esters and lipid droplets, vascular occlusion, and overt disease.

SUMMARY

We postulate that AD and ATH are both caused by chronic immunologic challenge that induces CH25H expression and protection against particular infectious agents, but at the expense of longer-term pathology.

The role of the inflammasome in cardiovascular diseases

Inflammasome is a very important signaling platform sensing a variety of triggers of the innate immune system. Inflammasome promotes the production of important pro-inflammatory cytokines such as IL-1β and IL-18. Tight control of inflammasome activity is, therefore, essential and occurs at multiple levels. The activation of inflammasome pathways is linked to the pathogenesis of various prevalent disorders including cardiovascular disease such as atherosclerosis, ischemic injury, cardiomyopathy, and Kawasaki disease. The study of the inflammasome in the cardiovascular system has led to the identification of important triggers and endogenous modulators, and to the exploration of new treatment strategies based on the inhibition of inflammasome activation or its end products, i.e., IL-1β and IL-18. In summary, the discovery of the inflammasome has greatly advanced our understanding of how the innate immune system interferes with cardiovascular disease development and progression, and targeting inflammasome provides new avenues for the treatment and management of cardiovascular diseases.

Intranasal delivery of plasma and platelet growth factors using PRGF-Endoret system enhances neurogenesis in a mouse model of Alzheimer's disease

Neurodegeneration together with a reduction in neurogenesis are cardinal features of Alzheimer’s disease (AD) induced by a combination of toxic amyloid-β peptide (Aβ) and a loss of trophic factor support. Amelioration of these was assessed with diverse neurotrophins in experimental therapeutic approaches. The aim of this study was to investigate whether intranasal delivery of plasma rich in growth factors (PRGF-Endoret), an autologous pool of morphogens and proteins, could enhance hippocampal neurogenesis and reduce neurodegeneration in an amyloid precursor protein/presenilin-1 (APP/PS1) mouse model. Neurotrophic and neuroprotective actions were firstly evident in primary neuronal cultures, where cell proliferation and survival were augmented by Endoret treatment. Translation of these effects in vivo was assessed in wild type and APP/PS1 mice, where neurogenesis was evaluated using 5-bromodeoxyuridine (BdrU), doublecortin (DCX), and NeuN immunostaining 5 weeks after Endoret administration. The number of BrdU, DCX, and NeuN positive cell was increased after chronic treatment. The number of degenerating neurons, detected with fluoro Jade-B staining was reduced in Endoret-treated APP/PS1 mice at 5 week after intranasal administration. In conclusion, Endoret was able to activate neuronal progenitor cells, enhancing hippocampal neurogenesis, and to reduce Aβ-induced neurodegeneration in a mouse model of AD.

Alzheimer's disease and granulocyte density diversity

BACKGROUND

The current study investigates circulating eosinophils and neutrophils in Alzheimer's (AD) type dementia with respect to density (kg/L). The existence of β-amyloid plaques in the brain is a feature of AD. Sporadic scientific reports indicate that the disease affects circulating neutrophils. In contrast, numerous publications investigate inflammatory reactions in AD brains. Locally, the plaques evoke a substantial inflammatory response involving activated microglia and astrocytes.

METHODS

Subjects with probable AD (n = 39) were included and compared with elderly individuals (n = 22) lacking apparent memory problems. We sampled 10 mL venous blood in citrate. Granulocytes were separated according to density in linear Percoll™ gradients. Subsequently, the gradients were divided into density subfractions (n = 16). In every fraction, determination of eosinophil and neutrophil counts was carried out.

RESULTS

AD sufferers displayed less granulocytes in fractions nos. 13-15 containing light cells. For these fractions, the P-values proved to be (P < 0.001; not significant; P = 0.03) and (P = 0.01; P = 0.01; not significant), for eosinophils and neutrophils, respectively.

CONCLUSIONS

The present work describes that less circulating light granulocytes are a feature of AD demented individuals. It is to hypothesize that it is a sign of impaired granulocyte turnover and cell damage. It is concluded that AD affects inflammatory cells in the periphery and that the behaviour of granulocytes in dementia is worthwhile further studies.

Fire in the ashes: can failed Alzheimer's disease drugs succeed with second chances?

BACKGROUND

Since Cognex, more than 200 Alzheimer's disease (AD) drug candidates have failed. Investigations have identified vulnerabilities of these AD drug developments to methodological errors. (-)-Phenserine has been discussed as possibly failing due to flawed methods and practices in development.

METHODS

We analyzed documentation of (-)-phenserine's development for vulnerabilities to errors and designed interventions for a redevelopment that could provide fair or unbiased assessments of (-)-phenserine target engagement, target relevance for human diseases, and adequate presumptive evidence of efficacy as a therapeutic for one or more diagnoses to justify registration-required clinical trials.

RESULTS

Similar to studies of 40 other AD developments, with (-)-phenserine, we found little evidence of preemptive interventions against potentially invalidating errors, grounds to judge progress in development through stages as not scientifically justifiable, and variance excess and placebo group improvements as capable of accounting for outcomes from various studies in the development. We propose to compare a redevelopment resourced to counter these deficiencies with the original development as historical control to evaluate further our hypothesis that errors in development accounted for the (-)-phenserine failure, specifically, and other AD drug failures, potentially.

CONCLUSIONS

We find support for our earlier proposal that (-)-phenserine did not fail, but the methods of development did fail, to provide conditions where efficacy could be tested. We propose that redevelopment under conditions aimed to correct methodological deficiencies common in AD drug developments will successfully test efficacy for (-)-phenserine and hopefully lead to a disease-modifying addition to the AD therapeutic armamentarium.