Search Results (835)

The kinetics of insulin aggregation and fibril formation were studied in vitro using Scanning Electron Microscopy (SEM) and Fourier Transform Infrared (FTIR) spectroscopy. Our investigation centered on the protein’s morphological and structural changes to better understand the transient molecular configurations that occur during the lag phase. SEM images showed that, already at early incubation stages, a network of disordered pseudo-filaments, ranging in length between 200 and 500 nanometers, develops on the surface of large aggregates. At later stages, fibrils catalyzed by protein aggregates were observed. Principal Component Analysis (PCA) of the FTIR data identified signatures of intramolecular β-sheet secondary structures forming during the lag phase and at the onset of the exponential growth phase. These absorption bands are linked to secondary nucleation mechanisms due to their transient nature. This interpretation is further supported by a chemical equilibrium model, which yielded a reliable secondary nucleation rate constant, K₂, on the order of 10⁴ M⁻² s⁻¹. Full article

Transthyretin amyloidosis (ATTR) is a disease caused by the deposition of transthyretin-derived fibrils in the body. Despite extensive research conducted over the years, there are currently only four drugs available in clinical use to treat this condition, two of which are repurposed drugs used off-label. However, these treatments present several limitations; therefore, there is an urgent need for new therapeutic options. In this context, dietary supplements containing natural compounds capable of stabilizing the transthyretin (TTR) protein could represent a promising approach to contrast the disease progression, potentially supporting the therapeutic effects of the aforementioned drugs. In light of this, the present review highlights and analyzes the natural compounds that have most recently been reported in the literature as TTR stabilizers. In particular, the studies elucidating the potential of these compounds in the treatment of ATTR, along with the available crystallographic data explaining their binding mode to TTR, are reported. Overall, although the use of natural compounds as supplements shows promise in managing ATTR, further research is still needed to explore its feasibility and confirm its effectiveness. Hopefully, this work will help shed light on these issues and serve as a useful starting point for the development of new strategies to treat this disease. Full article

Background: This study presents an innovative approach to cardiovascular disease (CVD) risk prediction based on a comprehensive analysis of clinical, immunological and biochemical markers using mathematical modelling and machine learning methods. Baseline data include indices of humoral and cellular immunity (CD59, CD16, IL-10, CD14, CD19, CD8, CD4, etc.), cytokines and markers of cardiovascular disease, inflammatory markers (TNF, GM-CSF, CRP), growth and angiogenesis factors (VEGF, PGF), proteins involved in apoptosis and cytotoxicity (perforin, CD95), as well as indices of liver function, kidney function, oxidative stress and heart failure (albumin, cystatin C, N-terminal pro B-type natriuretic peptide (NT-proBNP), superoxide dismutase (SOD), C-reactive protein (CRP), cholinesterase (ChE), cholesterol, and glomerular filtration rate (GFR)). Clinical and behavioural risk factors were also considered: arterial hypertension (AH), previous myocardial infarction (PICS), aortocoronary bypass surgery (CABG) and/or stenting, coronary heart disease (CHD), atrial fibrillation (AF), atrioventricular block (AB block), and diabetes mellitus (DM), as well as lifestyle (smoking, alcohol consumption, physical activity level), education, and body mass index (BMI). Methods: The study included 52 patients aged 65 years and older. Based on the clinical, biochemical and immunological data obtained, a model for predicting the risk of premature cardiovascular aging was developed using mathematical modelling and machine learning methods. The aim of the study was to develop a predictive model allowing for the early detection of predisposition to the development of CVDs and their complications. Numerical methods of mathematical modelling, including Runge–Kutta, Adams–Bashforth and backward-directed Euler methods, were used to solve the prediction problem, which made it possible to describe the dynamics of changes in biomarkers and patients’ condition over time with high accuracy. Results: HLA-DR (50%), CD14 (41%) and CD16 (38%) showed the highest association with aging processes. BMI was correlated with placental growth factor (37%). The glomerular filtration rate was positively associated with physical activity (47%), whereas SOD activity was negatively correlated with it (48%), reflecting a decline in antioxidant defence. Conclusions: The obtained results allow for improving the accuracy of cardiovascular risk prediction, and form personalised recommendations for the prevention and correction of its development. Full article

Advanced glycation end-products (AGEs) are formed by the non-enzymatic glycation of proteins, lipids, and nucleic acids due to the consumption of high-carbohydrate diets; their production is also promoted by a sedentary lifestyle as well as cigarette smoking. Elevated levels of AGEs in the circulatory system and internal organs of the body are commonly observed in a number of cardiovascular diseases such as hypertension, diabetes, atherosclerosis, coronary artery disease, aortic aneurysm, atrial fibrillation, myocardial infarction, and heart failure, which are associated with the development of oxidative stress and myocardial inflammation. The adverse effects of AGEs on the cardiovascular system are elicited by both non-receptor mechanisms involving the cross-linking of extracellular and intracellular proteins, and by receptor-mediated mechanisms involving the binding of AGEs with advanced glycation end-product receptors (RAGEs) on the cell membrane. AGE–RAGE interactions along with the cross-linking of proteins promote the generation of oxidative stress, the production of inflammation, the occurrence of intracellular Ca²⁺-overload, and alterations in the extracellular matrix leading to the development of cardiovascular dysfunction. AGEs also bind with two other protein receptors in the circulatory system: soluble RAGEs (sRAGEs) are released upon the proteolysis of RAGEs due to the activation of matrix metalloproteinase, and endogenous secretory RAGEs (esRAGEs) are secreted as a spliced variant of endogenous RAGEs. While the AGE–RAGE signal transduction axis serves as a pathogenic mechanism, both sRAGEs and esRAGEs serve as cytoprotective interventions. The serum levels of sRAGEs are decreased in ischemic heart disease, vascular disease, and heart failure, as well as in other cardiovascular diseases, but are increased in chronic diabetes and renal disease. Several interventions which can reduce the formation of AGEs, block the AGE–RAGE axis, or increase the levels of circulating sRAGEs have been shown to exert beneficial effects in diverse cardiovascular diseases. These observations support the view that the AGE–RAGE axis not only plays a critical role in pathogenesis, but is also an excellent target for the treatment of cardiovascular disease. Full article

Cardiac amyloidosis (CA) results from the deposition of either immunoglobulin light chain (AL) or transthyretin (ATTR) amyloid fibrils in the myocardium, causing restrictive cardiomyopathy and, if left untreated, can lead to early death. Advancements in non-invasive diagnostic modalities have led to an increased recognition of the disease. Monoclonal gammopathy plays a pivotal role in the diagnostic algorithm for CA, particularly in differentiating AL from ATTR. This review highlights the importance of monoclonal protein detection through serum protein electrophoresis, immunofixation electrophoresis, and serum free light chain assays as initial screening tools. However, these tests alone are insufficient for a definitive diagnosis due to the complexities associated with coexisting monoclonal gammopathies and the potential for false negative and positive results. Advanced imaging modalities, such as echocardiography, cardiac magnetic resonance, and nuclear scintigraphy, along with tissue biopsy, are crucial for confirming CA and accurately determining the CA subtype. Full article

Alpha-Synuclein (α-Syn) is a presynaptic neuronal protein implicated in the pathogenesis of Parkinson’s disease (PD) and other synucleinopathies, primarily through its aggregation into insoluble fibrils. The extended α-Syn half-life necessitates treatment durations that are incompatible with efficient high-throughput drug screening, can risk compound stability or cause cellular toxicity. To address this, we inserted a PEST sequence, a motif known to promote rapid protein degradation, at the C-terminus of the SNCA gene using CRISPR/Cas9 to create a novel cell line with reduced α-Syn half-life. This modification accelerates α-Syn turnover, providing a robust model for studying α-Syn dynamics and offering a platform that is applicable to other long-lived proteins. Our results demonstrate a six-fold reduction in α-Syn half-life, enabling the rapid detection of changes in protein levels and facilitating the identification of molecules that modulate α-Syn production and degradation pathways. Using inhibitors of the proteasome, transcription, and translation further validated the model’s utility in examining various mechanisms that impact protein levels. This novel cell line represents a significant advancement for studying α-Syn dynamics and offers promising avenues to develop therapeutics for α-synucleinopathies. Future research should focus on validating this model in diverse experimental settings and exploring its potential in high-throughput screening applications. Full article

Heart-specific overexpression of transcriptional regulator JDP2 (jun dimerization protein 2) for 5 weeks provokes paroxysmal atrial fibrillation (AF) in mice. We now investigated whether AF and atrial remodeling will be reversible upon termination of JDP2 overexpression, and whether paroxysmal AF converts to permanent AF in the presence of maintained JDP2 overexpression. Cardiac-specific JDP2 overexpression for 5 weeks, resulting in paroxysmal AF, was either continued or repressed via a tet-off system for another 5 weeks. ECGs were recorded weekly. Thereafter, heart and lung weights, and atrial mRNA and protein expression were determined. Extending JDP2 overexpression did not aggravate the AF phenotype, still paroxysmal AF, prolongation of PQ intervals, and atrial hypertrophy were present. This phenotype was completely reversible upon cessation of JDP2 overexpression. A massive downregulation of connexin40 and calcium handling proteins, including SERCA2a, calsequestrin, and ryanodine receptor, was observed in atria after prolonged JDP2 overexpression. In conclusion, atrial remodeling and paroxysmal AF under JDP2 overexpression are not sufficient to maintain or aggravate AF in the absence of JDP2. The comparison of the two groups indicates that the downregulation of calcium proteins and connexins is an important factor in the maintenance of the disease. Full article

The misfolding and aggregation of proteins into amyloidogenic assemblies are key features of several metabolic and neurodegenerative diseases. Human insulin has long been known to form amyloid fibrils under various conditions, which affects its bioavailability and function. Clinically, insulin aggregation at recurrent injection sites poses a challenge for diabetic patients who rely on insulin therapy. Furthermore, decreased responsiveness to insulin in type 2 diabetic (T2D) patients may lead to its overproduction and accumulation as aggregates. Earlier reports have reported that various factors such as pH, temperature, agitation, and the presence of lipids or other proteins influence insulin aggregation. Our present study aims to elucidate the effects of non–micellar anionic DMPG (1,2–dimyristoyl–sn–glycero–3–phosphoglycerol) lipids on insulin aggregation. Distinct pathways of insulin aggregation and intermediate formation were observed in the presence of DMPG using a ThT fluorescence assay. The formation of soluble intermediates alongside large insulin fibrils was observed in insulin incubated with DMPG via TEM, DLS, and NMR as opposed to insulin aggregates generated without lipids. ¹³C magic angle spinning solid–state NMR and FTIR experiments indicated that lipids do not alter the conformation of insulin fibrils but do alter the time scale of motion of aromatic and aliphatic side chains. Furthermore, the soluble intermediates were found to be more cytotoxic than fibrils generated with or without lipids. Overall, our study elucidates the importance of anionic lipids in dictating the pathways and intermediates associated with insulin aggregation. These findings could be useful in determining various approaches to avoid toxicity and enhance the effectiveness of insulin in therapeutic applications. Full article

Amyloids are protein-based biomaterials composed of fibrils with cross-β cores. Previously only associated with degenerative diseases, such as Parkinson’s disease, Alzheimer’s disease, and diabetes, amyloids remain active and functional both in vivo and in vitro conditions, enabling a variety of applications in medicine, nanotechnology, and biotechnology. This review aims to review the most advanced methods for amyloid fibril structural studies, with special attention on amyloid thin films. Selected advances of biomedical and biotechnological relevance will be outlined, and perspectives for future studies in the context of ongoing methodological progress will be discussed. Full article

The EGCG/PPN composite, prepared by combining pea protein nanofibrils (PPNs) with epigallocatechin gallate (EGCG), could be used as a multifunctional nanocarrier. Compared to pea protein isolate (PPI), EGCG/PPN composites exhibited remarkably higher turbidity and zeta potential, along with similar UV spectra. Intrinsic fluorescence spectroscopy, ThT fluorescence spectroscopy, and surface hydrophobicity analysis suggested that the interactions between EGCG and PPN were primarily driven by hydrophobic forces. UV spectra indicated that the microenvironment of amino acid residues in the tertiary structure of the protein changes upon complexation, and circular dichroism (CD) revealed that the incorporation of EGCG increases the β-sheet content in the protein’s secondary structure. Analyses of DPPH and ABTS radical scavenging activity, as well as reducing power, demonstrated that the synergistic effect between EGCG and PPN did not hinder the inherent antioxidant properties of EGCG but rather enhanced them significantly. Transmission electron microscopy (TEM) images showed that the addition of EGCG reconstructed the fibril morphology, thereby affecting the properties of PPNs. Overall, the composite fabricated through the interaction between PPN and EGCG shows great potential as a nanocarrier in the processing of functional foods. Full article

Fullerenes and fullerenols exhibit antioxidant and anti-inflammatory properties, making them promising candidates for Alzheimer’s disease (AD) therapy. Unlike conventional anti-inflammatory drugs, these compounds have multitargeted effects, including their ability to inhibit amyloid fibril formation. However, few studies have explored their efficacy in high-validity AD models. Female APPswe/PS1E9 (APP/PS1) mice and their wild-type (WT) littermates were orally administered with fullerene C₆₀ (0.1 mg/kg/day) or fullerenol C₆₀(OH)₂₄ (0.15 mg/kg/day) for 10 months starting at 2 months of age. Behavioral assessments were performed at 12 months of age. Amyloid plaque density and size were analyzed in the brain regions using Congo red staining. The expression of genes related to inflammation and plasticity was examined, and an in vitro assay was used to test the toxicity of fullerenol and its effect on amyloid β peptide 42 (Aβ42)-induced reactive oxygen species (ROS) production. Fullerenol reduced the maximum plaque size in the cortex and hippocampus, decreased the small plaque density in the hippocampus and thalamus, and prevented an increase in glial fibrillary acidic protein (GFAP) positive cell density in the mutants. Both treatments improved cognitive and emotional behaviors and reduced Il1β and increased Sirt1 expression. In vitro, fullerenol was non-toxic across a range of concentrations and reduced Aβ42-induced ROS production in brain endothelial cells and astrocytes. Long-term administration of fullerene or fullerenol improved behavioral and molecular markers of AD in APP/PS1 mice, with fullerenol showing additional benefits in reducing amyloid burden. Full article

Endurance training induces significant cardiac remodeling, with evidence suggesting that prolonged high-intensity exercise may increase the risk of atrial fibrillation (AF). However, physiological responses differ by event type. This review compares AF-related markers in marathon and ultramarathon runners, focusing on structural adaptations, inflammatory and endothelial biomarkers, and the incidence of arrhythmias. A systematic analysis of 29 studies revealed consistent left atrial (LA) enlargement in marathon runners linked to elevated AF risk and fibrosis markers such as Galectin-3 and PIIINP. In contrast, ultramarathon runners exhibited right atrial (RA) dilation and increased systemic inflammation, as indicated by elevated high-sensitivity C-reactive protein (hs-CRP) and soluble E-selectin levels. AF incidence in marathoners ranged from 0.43 per 100 person-years to 4.4%, while direct AF incidence data remain unavailable for ultramarathon populations, highlighting a critical evidence gap. These findings suggest distinct remodeling patterns and pathophysiological profiles between endurance disciplines, with implications for athlete screening and cardiovascular risk stratification. Full article

Objectives: The compound 3-(4-Hydroxy-3-methoxyphenyl) propionic acid (HMPA) is a terminal metabolite derived from polyphenol compounds. It has been studied for its potential to support brain health indirectly through its anti-oxidant effects and ability to enhance the gut environment; however, its role in dementia pathogenesis is unclear. Therefore, the aim of this study was to evaluate how HMPA inhibits Aβ42 aggregation in vitro. Methods: We examined the inhibitory effects of HMPA on amyloid-β protein (Aβ) aggregation using a thioflavin T (ThT) assay and electron microscopy (EM). Results: ThT assays demonstrated that HMPA inhibited both the nucleation and elongation phases of Aβ aggregation. Additionally, EM of low-molecular-weight (LMW) Aβ42 in the presence of HMPA demonstrated shorter fibrils compared to those formed without HMPA. The EC₅₀ of HMPA in LMW Aβ42 was 5–6 mM. Conclusions: These findings indicate that, similar to several polyphenol compounds such as myricetin and rosmarinic acid, HMPA may inhibit Aβ pathogenesis, although it requires a fairly high concentration in vitro. These findings suggest the potential of HMPA as a lead compound for modulating Aβ-related neurodegeneration. Full article

One of the most common malignant tumors worldwide is lung cancer, and it is associated with the highest death rate among all cancers. Traditional treatment options for lung cancer include radiation, chemotherapy, targeted therapy, and surgical resection. However, the survival rate is low, and the outlook is still dreadfully dire. The pursuit of a paradigm change in treatment approaches is, therefore, imperative. Tyrosine kinases (TKs), a subclass of protein kinases, regulate vital cellular function by phosphorylating tyrosine residues in proteins. Mutations, overexpression, and autocrine paracrine stimulation can transform TKs into oncogenic drivers, causing cancer pathogenesis. Tyrosine kinase inhibitors (TKIs) have emerged as an attractive targeted therapy option, especially for non-small cell lung cancer (NSCLC). However, resistance to TKIs, and adverse cardiovascular effects such as heart failure, atrial fibrillation, hypertension, and sudden death, are among the most common adverse effects of TKIs. There is increasing interest in plant-derived natural products in the hunt for powerful chemosensitizer and pathway modulators for enhancing TKI activity and/or overcoming resistance mechanisms. This highlights the mechanism of TKs’ activation in cancer, the role of TKIs in NSCLC mechanisms, and the challenges posed by TKI-acquired resistance. Additionally, we explored various plant-derived natural products’ bioactive compounds with the chemosensitizer and pathway-modulating potential with TKs’ inhibitory and anticancer effects. Our review suggests that a combination of natural products with TKIs may provide a novel and promising strategy for overcoming resistance in lung cancer. In future, further preclinical and clinical studies are advised. Full article

Taken together, cardiovascular diseases (CVDs) have become one of the prime causes of the global disease burden. Aging is closely related to CVDs and is considered to be one of the crucial factors in the incidence of CVDs. In the process of aging, cellular senescence is an important cause of CVDs such as atherosclerosis and atrial fibrillation. The treatment for CVDs by targeting senescent cells has been carried out in cellular models, animal experiments, and anti-aging clinical trials. Chemical approaches to regulate the fate of senescent cells by senolytics and senomorphics, which could selectively eliminate senescent cells or inhibit their senescence-associated secretory phenotype (SASP) secretion, have been increasingly explored. Importantly, many natural products with promising biological activity extracted from food or medicine–food homology have the above-mentioned effects. Furthermore, the identification of the target cells or target proteins of these natural products is of great significance for the indication of their mechanism of action, and it also lays a scientific foundation for the realization of precision nutrition intervention in the future. This review details how senescent cells affect CVDs, how natural products target senescent cells through nutritional intervention, and research methods for natural products in cardiovascular aging. Full article