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1.
ACS Appl Bio Mater ; 2024 Sep 18.
Artículo en Inglés | MEDLINE | ID: mdl-39291866

RESUMEN

Oligomers and amyloid fibrils formed at different stages of protein aggregation are important biomarkers for a variety of neurodegenerative diseases including Alzheimer's and Parkinson's diseases. The development of probes for the sensitive detection of oligomeric species is important for early stage diagnosis of amyloidogenic diseases. Many small molecular dyes have been developed to probe the dynamic growth of amyloid fibrils. However, there is a lack of discriminatory detection strategies to monitor the dynamics of both oligomers and amyloid fibrils based on the differential modulation of the photophysical properties of a single dye. Here we report a pyrene-based intramolecular charge transfer (ICT) dye with large Stokes shifted red-emitting aggregation induced emission (AIE) for monitoring the dynamic populations of both oligomers and fibrils during the aggregation of hen egg white lysozyme (HEWL) protein. At the early stage of protein aggregation, the accumulation of HEWL oligomers results in a rapid and substantial increase in the red AIE intensity at 660 nm. Later, as the oligomers transform into mature fibrils, the dye exhibits a distinct photophysical change. Binding of the dye to HEWL fibrils strongly suppresses the red AIE and enhances ICT emission. This is evidenced by a gradual decrease in the AIE intensity (∼660 nm) and an increase in LE (∼490 nm) and ICT (∼540 nm) emission intensities during the later stages of protein aggregation. Thus, the dye provides simultaneous measurements of the population dynamics of both HEWL oligomers and fibrils during protein aggregation based on the discriminatory modulation of AIE and ICT of the dye. The dye also enables imaging of both HEWL oligomers and fibrils simultaneously using different emission channels in super-resolution confocal fluorescence microscopy.

2.
Colloids Surf B Biointerfaces ; 244: 114185, 2024 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-39226848

RESUMEN

Supramolecular medicine refers to the formulation of therapeutic and diagnostic agents through supramolecular techniques, amid treating, diagnosing, and preventing disease. Recently, there has been growing interest in developing metal nanoparticles (MNPs)-amyloid hybrid materials, which have the potential to revolutionize medical applications. Furthermore, the development of MNPs-amyloid hydrogel/scaffold supramolecules represents a promising new direction in amyloid nanotechnology, with potential applications in tissue engineering and biomedicine. This review first provides a brief introduction to the formation process of protein amyloid aggregates and their unique nanostructures. Subsequently, we focused on recent investigations into the use of MNPs-amyloid hybrid materials in tissue engineering and biomedicine. We anticipate that MNPs-amyloid supramolecular materials will pave the way for new functional materials in medical science, particularly in the field of tissue engineering.


Asunto(s)
Proteínas Amiloidogénicas , Sistemas de Liberación de Medicamentos , Nanopartículas del Metal , Ingeniería de Tejidos , Ingeniería de Tejidos/métodos , Nanopartículas del Metal/química , Sistemas de Liberación de Medicamentos/métodos , Agregado de Proteínas , Andamios del Tejido/química , Proteínas Amiloidogénicas/química , Pliegue de Proteína , Conformación Proteica , Humanos
3.
J Clin Med ; 13(17)2024 Aug 29.
Artículo en Inglés | MEDLINE | ID: mdl-39274353

RESUMEN

Cardiac amyloidosis is an infiltrative disease that causes progressive myocardial impairment secondary to amyloid fibril deposition in the extracellular space of the myocardium. Many amyloid precursors, including transthyretin protein, are known to determine cardiac damage by aggregating and precipitating in cardiac tissue. Transthyretin cardiac amyloidosis may be either caused by rare genetic mutations of the transthyretin gene in the hereditary variant, or may arise as a consequence of age-related mechanisms in the acquired form. Although it has been labeled as a rare disease, in recent years, transthyretin cardiac amyloidosis has stood out as an emerging cause of aortic stenosis, unexplained left ventricular hypertrophy and heart failure with preserved ejection fraction, particularly in the elderly. Indeed, the integration of data deriving from both in vivo imaging techniques (whose advancement in the last years has allowed to achieve an easier and more accessible non-invasive diagnosis) and forensic studies (showing a prevalence of amyloid deposition in cardiac tissue of elderly patients up to 29%) suggests that cardiac amyloidosis is a more common disease than traditionally considered. Thanks to all the improvements in non-invasive diagnostic techniques, along with the development of efficacious therapies offering improvements in survival rates, transthyretin cardiac amyloidosis has been transformed from an incurable and infrequent condition to a relatively more diffuse and treatable disease, which physicians should take into consideration in the differential diagnostic processes in daily clinical practice.

4.
Bioelectrochemistry ; 161: 108800, 2024 Aug 30.
Artículo en Inglés | MEDLINE | ID: mdl-39241513

RESUMEN

This study utilized faradaic and non-faradaic electrochemical impedance spectroscopy to detect alpha synuclein amyloid fibrils on gold interdigitated tetraelectrodes (AuIDTE), providing valuable insights into electrochemical reactions for clinical use. AuIDE was purchased, modified with zinc oxide for increased hydrophobicity. Functionalization was conducted with hexacyanidoferrate and carbonyldiimidazole. Faradaic electrochemical impedance spectroscopy has been extensively explored in clinical diagnostics and biomedical research, providing information on the performance and stability of electrochemical biosensors. This understanding can help develop more sensitive, selective, and reliable biosensing platforms for the detection of clinically relevant analytes like biomarkers, proteins, and nucleic acids. Non-faradaic electrochemical impedance spectroscopy measures the interfacial capacitance at the electrode-electrolyte interface, eliminating the need for redox-active species and simplifying experimental setups. It has practical implications in clinical settings, like real-time detection and monitoring of biomolecules and biomarkers by tracking changes in interfacial capacitance. The limit of detection (LOD) for normal alpha synuclein in faradaic mode is 2.39-fM, The LOD for aggregated alpha synuclein detection is 1.82-fM. The LOD for non-faradaic detection of normal alpha synuclein is 2.22-fM, and the LOD for nonfaradaic detection of aggregated alpha synuclein is 2.40-fM. The proposed EIS-based AuIDTEs sensor detects alpha synuclein amyloid fibrils and it is highly sensitive.

5.
Biomol NMR Assign ; 2024 Aug 09.
Artículo en Inglés | MEDLINE | ID: mdl-39120652

RESUMEN

Amyloid fibrils from Alzheimer's amyloid-beta peptides (Aß) are found to be polymorphic. So far, 14 Aß40 fibril structures have been determined. The mechanism of why one particular protein sequence adopts so many different three-dimensional structures is yet not understood. In this work, we describe the assignment of the NMR chemical shifts of two Alzheimer's disease fibril polymorphs, P1 and P2, which are formed by the amyloid-beta peptide Aß40. The assignment is based on 13C-detected 3D NCACX and NCOCX experiments MAS solid-state NMR experiments. The fibril samples are prepared using an extensive seeding protocol in the absence and presence of the small heat shock protein αB-crystallin. In addition to manual assignments, we obtain chemical shift assignments using the automation software ARTINA. We present an analysis of the secondary chemical shifts and a discussion on the differences between the manual and automated assignment strategies.

6.
Chemistry ; : e202402330, 2024 Aug 07.
Artículo en Inglés | MEDLINE | ID: mdl-39109590

RESUMEN

Amyloid-beta aggregation is considered one of the factors influencing the onset of the Alzheimer's disease. Early prevention of such aggregation should alleviate disease condition by applying small molecule compounds that shift the aggregation equilibrium toward the soluble form of the peptide or slow down the process. We have discovered that fluorinated benzenesulfonamides of particular structure slowed the amyloid-beta peptide aggregation process by more than three-fold. We synthesized a series of ortho-para and meta-para double-substituted fluorinated benzenesulfonamides that inhibited the aggregation process to a variable extent yielding a detailed picture of the structure-activity relationship. Analysis of compound chemical structure effect on aggregation in artificial cerebrospinal fluid showed the necessity to arrange the benzenesulfonamide, hydrophobic substituent, and benzoic acid in a particular way. The amyloid beta peptide aggregate fibril structures varied in cross-sectional height depending on the applied inhibitor indicating the formation of a complex with the compound. Application of selected inhibitors increased the survivability of cells affected by the amyloid beta peptide. Such compounds may be developed as drugs against Alzheimer's disease.

7.
bioRxiv ; 2024 Aug 09.
Artículo en Inglés | MEDLINE | ID: mdl-39149386

RESUMEN

Myocilin-associated glaucoma is a protein-conformational disorder associated with formation of a toxic amyloid-like aggregate. Numerous destabilizing single point variants, distributed across the myocilin olfactomedin ß-propeller (OLF, myocilin residues 245-504, 30 kDa) are associated with accelerated disease progression. In vitro, wild type (WT) OLF can be promoted to form thioflavin T (ThT)-positive fibrils under mildly destabilizing (37°C, pH 7.2) conditions. Consistent with the notion that only a small number of residues within a protein are responsible for amyloid formation, 3D 13C-13C solid-state NMR spectra show that OLF fibrils are likely to be composed of only about one third of the overall sequence. Here, we probe the residue composition of fibrils formed de novo from purified full-length OLF. We were able to make sequential assignments consistent with the sequence S331-G-S-L334. This sequence appears once within a previously identified amyloid-prone region (P1, G326AVVYSGSLYFQ) internal to OLF. Since nearly half of the pairs of adjacent residues (di-peptides) in OLF occur only once in the primary structure and almost all the 3-residue sequences (tri-peptides) are unique, remarkably few sequential assignments are necessary to uniquely identify specific regions of the amyloid core. This assignment approach could be applied to other systems to expand our molecular comprehension of how folded proteins undergo fibrillization.

8.
bioRxiv ; 2024 Jul 30.
Artículo en Inglés | MEDLINE | ID: mdl-39131288

RESUMEN

Protein misfolding is a widespread phenomenon that can result in the formation of protein aggregates, which are markers of various disease states, including Alzheimer's disease (AD). In AD, amyloid beta (Aß) peptides, particularly Aß40 and Aß42, are key players in the disease's progression, as they aggregate to form amyloid plaques and contribute to neuronal toxicity. Recent research has shifted attention from solely Aß fibrils to also include Aß protofibrils and oligomers as potentially critical pathogenic agents. Particularly, oligomers demonstrate greater toxicity compared to other Aß specie. Hence, there is an increased interest in studying the correlation between toxicity and their structure and aggregation pathway. The present study investigates the aggregation of a 150 kDa Aß42 oligomer that does not lead to fibril formation over time. Using negative stain transmission electron microscopy (TEM), size exclusion chromatography (SEC), dynamic light scattering (DLS), and cryo-electron microscopy (cryo-EM), we demonstrate that 150 kDa Aß42 oligomers form higher-order string-like assemblies over time. The strings are unique from the classical Aß fibril structures. The significance of our work lies in elucidating molecular behavior of a novel non-fibrillar form of Aß42 aggregate.

9.
ACS Appl Mater Interfaces ; 16(34): 45371-45382, 2024 Aug 28.
Artículo en Inglés | MEDLINE | ID: mdl-39140178

RESUMEN

The self-assembly of proteins and peptides into fibrillar amyloid aggregates is a highly promising route to define the next generation of functional nanomaterials. Amyloid fibrils, traditionally associated with neurodegenerative diseases, offer exceptional conformational and chemical stability and mechanical properties, and resistance to degradation. Here, we report the development of catalytic amyloid nanomaterials through the conjugation of a miniaturized artificial peroxidase (FeMC6*a) to a self-assembling amyloidogenic peptide derived from human transthyretin, TTR(105-115), whose sequence is YTIAALLSPYS. Our synthetic approach relies on fast and selective click ligation upon proper modification of both the peptide and FeMC6*a, leading to TTRLys108@FeMC6*a. Mixing unmodified TTR(105-115) with TTRLys108@FeMC6*a allowed the generation of enzyme-loaded amyloid fibrils, namely, FeMC6*a@fibrils. Catalytic studies, performed in aqueous solution at nearly neutral pH, using ABTS as a model substrate and H2O2 as the oxidizing agent revealed that the enzyme retains its catalytic activity. Moreover, the activity was found to depend on the TTRLys108@FeMC6*a/unmodified TTR(105-115) peptide ratio. In particular, those with the 2:100 ratio showed the highest activity in terms of initial rates and substrate conversion among the screened nanoconjugates and compared to the freely diffusing enzyme. Finally, the newly developed nanomaterials were integrated into a flow system based on a polyvinylidene difluoride membrane filter. Within this flow-reactor, multiple reaction cycles were performed, showcasing the reusability and stability of the catalytic amyloids over extended periods, thus offering significantly improved characteristics compared to the isolated FeMC6*a in the application to a number of practical scenarios.


Asunto(s)
Amiloide , Nanoestructuras , Prealbúmina , Amiloide/química , Nanoestructuras/química , Catálisis , Humanos , Prealbúmina/química , Prealbúmina/metabolismo , Peróxido de Hidrógeno/química , Peroxidasa/química , Peroxidasa/metabolismo , Hemo/química
10.
J Biol Inorg Chem ; 29(6): 601-609, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39126483

RESUMEN

The effect of binding of divalent metal cations (Ca2+, Cu2+, Mg2+, Mn2+, Zn2+) on the kinetics of fibril formation of bovine α-lactalbumin at acidic conditions is considered. The kinetic parameters of the process were determined using a thioflavin T fluorescence assay. The DSC thermograms of bovine α-lactalbumin in the presence and absence of cations were recorded. The duration of the lag period correlates with the changes in the thermal stability of the molten globule of the protein in the presence of cations. The final thioflavin T fluorescence intensity after formation of the mature fibrils decreases under the influence of calcium ions which strongly bind to the monomeric protein, and increases in solutions containing copper and especially zinc. These ions seem to accelerate secondary nucleation processes and change the fibril morphology, which was confirmed by atomic force microscopy imaging.


Asunto(s)
Cationes Bivalentes , Lactalbúmina , Lactalbúmina/química , Bovinos , Animales , Cationes Bivalentes/química , Cinética
11.
Biomol NMR Assign ; 2024 Jun 29.
Artículo en Inglés | MEDLINE | ID: mdl-38951472

RESUMEN

The α-synuclein (α-syn) amyloid fibrils are involved in various neurogenerative diseases. Solid-state NMR (ssNMR) has been showed as a powerful tool to study α-syn aggregates. Here, we report the 1H, 13C and 15N back-bone chemical shifts of a new α-syn polymorph obtained using proton-detected ssNMR spectroscopy under fast (95 kHz) magic-angle spinning conditions. The manual chemical shift assignments were cross-validated using FLYA algorithm. The secondary structural elements of α-syn fibrils were calculated using 13C chemical shift differences and TALOS software.

12.
Vitam Horm ; 125: 183-229, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38997164

RESUMEN

Hemoglobin (Hb) is a hemeprotein found inside erythrocytes and is crucial in transporting oxygen and carbon dioxide in our bodies. In erythrocytes (Ery), the main energy source is glucose metabolized through glycolysis. However, a fraction of Hb can undergo glycation, in which a free amine group from the protein spontaneously binds to the carbonyl of glucose in the bloodstream, resulting in the formation of glycated hemoglobin (HbA1c), widely used as a marker for diabetes. Glycation leads to structural and conformational changes, compromising the function of proteins, and is intensified in the event of hyperglycemia. The main changes in Hb include structural alterations to the heme group, compromising its main function (oxygen transport). In addition, amyloid aggregates can form, which are strongly related to diabetic complications and neurodegenerative diseases. Therefore, this chapter discusses in vitro protocols for producing glycated Hb, as well as the main techniques and biophysical assays used to assess changes in the protein's structure before and after the glycation process. This more complete understanding of the effects of glycation on Hb is fundamental for understanding the complications associated with hyperglycemia and for developing more effective prevention and treatment strategies.


Asunto(s)
Hemoglobinas , Humanos , Glicosilación , Hemoglobinas/metabolismo , Hemoglobinas/química , Hemoglobina Glucada/metabolismo , Conformación Proteica , Animales
13.
Chemistry ; : e202400080, 2024 Jul 07.
Artículo en Inglés | MEDLINE | ID: mdl-38972842

RESUMEN

Protein aggregation correlates with many human diseases. Protein aggregates differ in structure and shape. Strategies to develop effective aggregation inhibitors that reach the clinic failed so far. Here, we developed a family of peptides targeting early aggregation stages for both amorphous and fibrillar aggregates of proteins unrelated in sequence and structure. They act on dynamic precursors before mechanistic differentiation takes place. Using peptide arrays, we first identified peptides inhibiting the amorphous aggregation of a molten globular, aggregation-prone mutant of the Axin tumor suppressor. Optimization revealed that the peptides activity did not depend on their sequences but rather on their molecular determinants: a composition of 20-30% flexible, 30-40% aliphatic and 20-30% aromatic residues, a hydrophobicity/hydrophilicity ratio close to 1, and an even distribution of residues of different nature throughout the sequence. The peptides also suppressed fibrillation of Tau, a disordered protein that forms amyloids in Alzheimer's disease, and slowed down that of Huntingtin Exon1, an amyloidogenic protein in Huntington's disease, both entirely unrelated to Axin. Our compounds thus target early aggregation stages of different aggregation mechanisms, inhibiting both amorphous and amyloid aggregation. Such cross-mechanistic, multi-targeting aggregation inhibitors may be lead compounds for developing drug candidates against various protein aggregation diseases.

14.
ACS Catal ; 14(7): 4656-4664, 2024 Apr 05.
Artículo en Inglés | MEDLINE | ID: mdl-39070231

RESUMEN

Glucagon stands out as a pivotal peptide hormone, instrumental in controlling blood glucose levels and lipid metabolism. While the formation of glucagon amyloid fibrils has been documented, their biological functions remain enigmatic. Recently, we demonstrated experimentally that glucagon amyloid fibrils can act as catalysts in several biological reactions including esterolysis, lipid hydrolysis, and dephosphorylation. Herein, we present a multiscale quantum mechanics/molecular mechanics (QM/MM) simulation of the acylation step in the esterolysis of para-nitrophenyl acetate (p-NPA), catalyzed by native glucagon amyloid fibrils, serving as a model system to elucidate their catalytic function. This step entails a concerted mechanism, involving proton transfer from serine to histidine, followed by the nucleophilic attack of the serine oxy anion on the carbonyl carbon of p-NPA. We computed the binding energy and free-energy profiles of this reaction using the protein-dipole Langevin-dipole (PDLD) within the linear response approximation (LRA) framework (PDLD/S-LRA-2000) and the empirical valence bond (EVB) methods. This included simulations of the reaction in an aqueous environment and in the fibril, enabling us to estimate the catalytic effect of the fibril. Our EVB calculations obtained a barrier of 23.4 kcal mol-1 for the enzyme-catalyzed reaction compared to the experimental value of 21.9 kcal mol-1 (and a calculated catalytic effect of 3.2 kcal mol-1 compared to the observed effect of 4.7 kcal mol-1). This close agreement together with the barrier reduction when transitioning from the reference solution reaction to the amyloid fibril provides supporting evidence to the catalytic role of glucagon amyloid fibrils. Moreover, employing the PDLD/S-LRA-2000 approach further reinforced exclusively the enzyme's catalytic role. The results presented in this study contribute significantly to our understanding of the catalytic role of glucagon amyloid fibrils, marking, to the best of our knowledge, the first-principles mechanistic investigation of fibrils using QM/MM methods. Therefore, our findings offer fruitful insights for future research into the mechanisms of related amyloid catalysis.

15.
J Colloid Interface Sci ; 674: 753-765, 2024 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-38955007

RESUMEN

The recent coronavirus disease 2019 (COVID-19) pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spurred intense research efforts to develop new materials with antiviral activity. In this study, we genetically engineered amyloid-based nanofibrils for capturing and neutralizing SARS-CoV-2. Building upon the amyloid properties of a short Sup35 yeast prion sequence, we fused it to SARS-CoV-2 receptor-binding domain (RBD) capturing proteins, LCB1 and LCB3. By tuning the reaction conditions, we achieved the spontaneous self-assembly of the Sup35-LCB1 fusion protein into a highly homogeneous and well-dispersed amyloid-like fibrillar material. These nanofibrils exhibited high affinity for the SARS-CoV-2 RBD, effectively inhibiting its interaction with the angiotensin-converting enzyme 2 (ACE2) receptor, the primary entry point for the virus into host cells. We further demonstrate that this functional nanomaterial entraps and neutralizes SARS-CoV-2 virus-like particles (VLPs), with a potency comparable to that of therapeutic antibodies. As a proof of concept, we successfully fabricated patterned surfaces that selectively capture SARS-CoV-2 RBD protein on wet environments. Collectively, these findings suggest that these protein-only nanofibrils hold promise as disinfecting coatings endowed with selective SARS-CoV-2 neutralizing properties to combat viral spread or in the development of sensitive viral sampling and diagnostic tools.


Asunto(s)
Enzima Convertidora de Angiotensina 2 , COVID-19 , Nanofibras , SARS-CoV-2 , SARS-CoV-2/efectos de los fármacos , Humanos , Nanofibras/química , Enzima Convertidora de Angiotensina 2/metabolismo , Enzima Convertidora de Angiotensina 2/química , COVID-19/virología , Proteínas de Saccharomyces cerevisiae/química , Anticuerpos Neutralizantes/inmunología , Amiloide/química , Amiloide/metabolismo , Factores de Terminación de Péptidos
16.
Int J Biol Macromol ; 277(Pt 4): 134282, 2024 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-39084446

RESUMEN

It has been demonstrated that ferulic acid (FA) can be effectively encapsulated using wheat gluten amyloid fibrils (AF) and chitosan (CS) in a double network hydrogel (DN) form, with cross-linking mediated by Genipin (GP). Within this system, the DN comprising gluten AF-FA and CS-FA exhibited optimal loading metrics at a formulation designated as DN8, achieving a load efficiency of 88.5 % and a load capacity of 0.78 %. Analysis through fluorescence quenching confirmed that DN8 harbored the highest quantity of FA. Fourier-transform infrared spectroscopy (FTIR) further verified a significant increase in ß-sheet content post-hydrogel formation, enhancing the binding capacity for FA. Rheological assessments indicated a transition from solution to gel, delineating the phase state of the DN. Comprehensive in vitro digestion studies revealed that DN8 provided superior sustained release properties, exhibited the highest total antioxidant capacity, and displayed potent inhibitory activities against angiotensin I converting enzyme (ACE) and acetylcholinesterase (Ach-E). Additionally, the DN significantly bolstered the stability of FA against photothermal degradation. Collectively, these findings lay foundational insights for the advancement of the wheat gluten AF-based delivery system for bioactive compounds and provided a theoretical basis for the development of functional foods.


Asunto(s)
Amiloide , Quitosano , Ácidos Cumáricos , Portadores de Fármacos , Glútenes , Hidrogeles , Triticum , Quitosano/química , Ácidos Cumáricos/química , Ácidos Cumáricos/farmacología , Glútenes/química , Hidrogeles/química , Hidrogeles/farmacología , Triticum/química , Amiloide/química , Portadores de Fármacos/química , Antioxidantes/química , Antioxidantes/farmacología , Reología , Inhibidores de la Enzima Convertidora de Angiotensina/química , Inhibidores de la Enzima Convertidora de Angiotensina/farmacología , Liberación de Fármacos
17.
Biochim Biophys Acta Proteins Proteom ; 1872(5): 141028, 2024 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-38849109

RESUMEN

The ligand-induced conformational switch of proteins has great significance in understanding the biophysics and biochemistry of their self-assembly. In this work, we have investigated the ability of plumbagin (PL), a hydroxynaphthoquinone compound found in the root of the medicinal plant Plumbago zeylanica, to modulate aggregation precursor state, aggregation kinetics and generate distinct fibril of human serum albumin (HSA). PL was found to moderately bind (binding constant Ka âˆ¼ 10-4 M-1)) to domain-II of HSA in the stoichiometric ratio of 1:1. We found that PL-HSA complex aggregation was accelerated as compared to that of HSA aggregation and it may be through an independent pathway. We also detected that fibril produced in the presence of PL is wider in diameter, contains a higher amount of ß-sheet (∼18%) and disordered (∼46%) structures, and is less stable. We concluded that the acceleration of aggregation reaction and generation of fibril polymorphism was mainly because of the higher extent of unfolding and high content of non-native ß-sheet structure in the aggregation precursor state of PL-HSA complex. This study offers opportunities to explore the ability of ligand binding to modulate aggregation reactions and generate polymorphic protein fibrils.


Asunto(s)
Amiloide , Naftoquinonas , Agregado de Proteínas , Naftoquinonas/química , Naftoquinonas/metabolismo , Humanos , Amiloide/química , Amiloide/metabolismo , Cinética , Conformación Proteica en Lámina beta , Unión Proteica , Albúmina Sérica Humana/química , Albúmina Sérica Humana/metabolismo , Albúmina Sérica Humana/genética , Albúmina Sérica/química , Albúmina Sérica/metabolismo
18.
Acta Biomater ; 183: 89-100, 2024 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-38801867

RESUMEN

Self-assembling peptide-based hydrogels have become a highly attractive scaffold for three-dimensional (3D) in vitro disease modeling as they provide a way to create tunable matrices that can resemble the extracellular matrix (ECM) of various microenvironments. Alzheimer's disease (AD) is an exceptionally complex neurodegenerative condition; however, our understanding has advanced due to the transition from two-dimensional (2D) to 3D in vitro modeling. Nonetheless, there is a current gap in knowledge regarding the role of amyloid structures, and previously developed models found long-term difficulty in creating an appropriate model involving the ECM and amyloid aggregates. In this report, we propose a multi-component self-assembling peptide-based hydrogel scaffold to mimic the amyloid-beta (ß) containing microenvironment. Characterization of the amyloid-ß-mimicking hydrogel (Col-HAMA-FF) reveals the formation of ß-sheet structures as a result of the self-assembling properties of phenylalanine (Phe, F) through π-π stacking of the residues, thus mimicking the amyloid-ß protein nanostructures. We investigated the effect of the amyloid-ß-mimicking microenvironment on healthy neuronal progenitor cells (NPCs) compared to a natural-mimicking matrix (Col-HAMA). Our results demonstrated higher levels of neuroinflammation and apoptosis markers when NPCs were cultured in the amyloid-like matrix compared to a natural brain matrix. Here, we provided insights into the impact of amyloid-like structures on NPC phenotypes and behaviors. This foundational work, before progressing to more complex plaque models, provides a promising scaffold for future investigations on AD mechanisms and drug testing. STATEMENT OF SIGNIFICANCE: In this study, we engineered two multi-component hydrogels: one to mimic the natural extracellular matrix (ECM) of the brain and one to resemble an amyloid-like microenvironment using a self-assembling peptide hydrogel. The self-assembling peptide mimics ß-amyloid fibrils seen in amyloid-ß protein aggregates. We report on the culture of neuronal progenitor cells within the amyloid-mimicking ECM scaffold to study the impact through marker expressions related to inflammation and DNA damage. This foundational work, before progressing to more complex plaque models, offers a promising scaffold for future investigations on AD mechanisms and drug testing.


Asunto(s)
Péptidos beta-Amiloides , Hidrogeles , Células-Madre Neurales , Hidrogeles/química , Hidrogeles/farmacología , Péptidos beta-Amiloides/metabolismo , Células-Madre Neurales/metabolismo , Células-Madre Neurales/citología , Células-Madre Neurales/efectos de los fármacos , Fenotipo , Humanos , Matriz Extracelular/metabolismo , Matriz Extracelular/química , Materiales Biomiméticos/química , Materiales Biomiméticos/farmacología , Animales
19.
J Colloid Interface Sci ; 670: 357-363, 2024 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-38763031

RESUMEN

Carbon dots (CDs) are carbon nano materials (CNMs) that find use across several biological applications because of their water solubility, biocompatible nature, eco-friendliness, and ease of synthesis. Additionally, their physiochemical properties can be chemically tuned for further optimization towards specific applications. Here, we investigate the efficacy of C70-derived Graphene Acid Quantum Dots (GAQDs) in mitigating the transformation of soluble, monomeric Hen Egg-White Lysozyme (HEWL) to mature fibrils during its amyloidogenic trajectory. Our findings reveal that GAQDs exhibit dose-dependent inhibition of HEWL fibril formation (up to 70 % at 5 mg/mL) without affecting mitochondrial membrane potential or inducing apoptosis at the same density. Furthermore, GAQDs scavenged reactive oxygen species (ROS); achieving a 50 % reduction in ROS levels at a mere 100 µg/mL when exposed to a standard free radical generator. GAQDs were not only found to be biocompatible with a human neuroblastoma-derived SHSY-5Y cell line but also rescued the cells from rotenone-induced apoptosis. The GAQD-tolerance of SHSY-5Y cells coupled with their ability to restitute cells from rotenone-dependent apoptosis, when taken in conjunction with the biocompatibility data, indicate that GAQDs possess neuroprotective potential. The data position this class of CNMs as promising candidates for resolving aberrant cellular outputs that associate with the advent and progress of multifactorial neurodegenerative disorders including Parkinson's (PD) and Alzheimer's diseases (AD) wherein environmental causes are implicated (95 % etiology). The data suggest that GAQDs are a multifunctional carbon-based sustainable nano-platform at the intersection of nanotechnology and neuroprotection for advancing green chemistry-derived, sustainable healthcare solutions.


Asunto(s)
Apoptosis , Grafito , Muramidasa , Puntos Cuánticos , Especies Reactivas de Oxígeno , Puntos Cuánticos/química , Humanos , Grafito/química , Grafito/farmacología , Especies Reactivas de Oxígeno/metabolismo , Muramidasa/química , Muramidasa/metabolismo , Apoptosis/efectos de los fármacos , Línea Celular Tumoral , Enfermedades Neurodegenerativas/tratamiento farmacológico , Enfermedades Neurodegenerativas/metabolismo , Animales , Tamaño de la Partícula , Fármacos Neuroprotectores/farmacología , Fármacos Neuroprotectores/química , Carbono/química , Propiedades de Superficie , Potencial de la Membrana Mitocondrial/efectos de los fármacos
20.
Neurochem Int ; 177: 105762, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38723901

RESUMEN

Linalool is a neuroprotective monoterpene found in essential oils from aromatic plants. Linalool's effectiveness in AD animal models has been established previously, but its mechanisms of action remain unclear. Therefore, this study aims to investigate whether linalool binds directly to the amyloid beta (Aß) fibrils to understand it's role in preventing neurodegeneration. The anti-aggregation ability of Linalool was determined using Dithiothreitol (DTT), and thermal aggregation assays followed by Thioflavin T (ThT) binding assay. AD animals were treated with Linalool, and Thioflavin T staining was used to check the binding of linalool to Aß fibrils in rat brain tissue sections. Preliminary studies revealed the anti-aggregation potential of linalool under the thermal and chemical stimulus. Further, in ThT binding assay Linalool inhibited Aß aggregation, binding directly to Aß fibrils. The reduced fluorescence intensity of ThT in AD brain tissues following linalool administration, highlights its neuroprotective potential as a therapeutic agent for AD.


Asunto(s)
Monoterpenos Acíclicos , Péptidos beta-Amiloides , Péptidos beta-Amiloides/metabolismo , Péptidos beta-Amiloides/antagonistas & inhibidores , Monoterpenos Acíclicos/farmacología , Animales , Ratas , Masculino , Monoterpenos/farmacología , Monoterpenos/uso terapéutico , Monoterpenos/química , Enfermedad de Alzheimer/tratamiento farmacológico , Enfermedad de Alzheimer/metabolismo , Fármacos Neuroprotectores/farmacología , Encéfalo/metabolismo , Encéfalo/efectos de los fármacos , Ratas Wistar , Agregado de Proteínas/efectos de los fármacos , Agregado de Proteínas/fisiología , Ratas Sprague-Dawley , Agregación Patológica de Proteínas/tratamiento farmacológico , Agregación Patológica de Proteínas/metabolismo , Agregación Patológica de Proteínas/prevención & control
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