Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.061
Filtrar
1.
Ann Biol Clin (Paris) ; 78(4): 425-432, 2020 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-32618564

RESUMO

Wilson disease is a rare inherited disorder of copper metabolism that affects liver and brain due to copper tissue accumulation. The mechanism involved is based on mutations of the ATP7B gene. Children have predominant hepatic manifestations while adult are more often diagnosed by neurological and psychiatric symptoms. However, others features are tubulopathy, articular disorders and hemolytic anemia. We report the diagnostic of Wilson disease in a 14 years old girl and her sibling after investigation of hemolytic anemia, hepatic insufficiency, and hypophosphatemia.


Assuntos
Anemia Hemolítica/diagnóstico , Degeneração Hepatolenticular/diagnóstico , Doença Aguda , Adolescente , Anemia Hemolítica/complicações , Criança , Pré-Escolar , ATPases Transportadoras de Cobre/genética , Diagnóstico Diferencial , Família , Feminino , Hemólise/fisiologia , Insuficiência Hepática/complicações , Insuficiência Hepática/diagnóstico , Degeneração Hepatolenticular/complicações , Degeneração Hepatolenticular/genética , Humanos , Hipofosfatemia/complicações , Hipofosfatemia/diagnóstico , Masculino , Irmãos
3.
Am J Clin Pathol ; 154(2): 242-247, 2020 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-32367140

RESUMO

OBJECTIVES: Preanalytical factors, such as hemolysis, affect many components of a test panel. Machine learning can be used to recognize these patterns, alerting clinicians and laboratories to potentially erroneous results. In particular, machine learning might identify which cases of elevated potassium from a point-of-care (POC) basic metabolic panel are likely erroneous. METHODS: Plasma potassium concentrations were compared between POC and core laboratory basic metabolic panels to identify falsely elevated POC results. A logistic regression model was created using these labels and the other analytes on the POC panel. RESULTS: This model has high predictive power in classifying POC potassium as falsely elevated or not (area under the curve of 0.995 when applied to the test data set). A rule-in and rule-out approach further improves the model's applicability with a positive predictive value of around 90% and a negative predictive value near 100%. CONCLUSIONS: Machine learning has the potential to detect laboratory errors based on the recognition of patterns in commonly requested multianalyte panels. This could be used to alert providers at the POC that a result is suspicious or used to monitor the quality of POC results.


Assuntos
Hemólise/fisiologia , Aprendizado de Máquina , Potássio/sangue , Reações Falso-Positivas , Testes Hematológicos , Humanos , Sistemas Automatizados de Assistência Junto ao Leito , Testes Imediatos
4.
Life Sci ; 255: 117838, 2020 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-32450168

RESUMO

AIMS: Dysregulation of iron homeostasis in the body causes a variety of diseases. Iron deficiency leads to anemia, whereas iron overload aggravates cellular oxidative stress. Nuclear factor erythroid-2-related factor 2 (Nrf2) is a protein that is activated in the nucleus and turns on the production of antioxidant enzymes, protecting cell against oxidative damage. This study aimed to investigate whether Nrf2 gene knockout influences iron homeostasis in aging mice. MATERIALS AND METHODS: Iron content and iron metabolism-related proteins were assessed in different organs and blood serum of the 18 month-old Nrf2 knockout (Nrf2-/-) mice in comparison with the wild-type (WT) mice. KEY FINDINGS: Results showed that the iron contents in spleen and liver all increased, and expression levels of iron transporters were altered in Nrf2-/- mice. In particularly, we found that the expression of iron export protein ferroportin 1 (Fpn1) in liver, spleen and small intestine all decreased in Nrf2-/- mice, which might account for the deposition of iron in different organs and the increased ROS. Surprisingly, we found that the serum iron level of Nrf2-/- mice did not decrease, but increased significantly even when the iron absorption at small intestine decreased. Our further investigation revealed that the increase of serum iron was due to the release of iron from the hemolysis of erythrocytes, which caused by the increased ROS level in red blood cells of the Nrf2-/- mice. SIGNIFICANCE: These findings provide a more comprehensive understanding of the important role of Nrf2 in the regulation of systemic iron metabolism.


Assuntos
Hemólise/fisiologia , Ferro/metabolismo , Fator 2 Relacionado a NF-E2/genética , Espécies Reativas de Oxigênio/metabolismo , Envelhecimento/fisiologia , Animais , Eritrócitos/citologia , Homeostase/fisiologia , Intestino Delgado/metabolismo , Fígado/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Baço/metabolismo
6.
Sci Rep ; 10(1): 5101, 2020 03 20.
Artigo em Inglês | MEDLINE | ID: mdl-32198369

RESUMO

Blood damage (hemolysis) can occur during clinical procedures, e.g. dialysis, due to human error or faulty equipment, and it can cause significant harm to the patient or even death. We propose a simple technique to monitor changes in hemolysis levels continuously and in real time. As red blood cells rupture, the overall conductivity of the blood increases. Here, we demonstrate that small changes in porcine blood hemolysis can be detected through a simple resistance measurement.


Assuntos
Testes Hematológicos/métodos , Hemoglobinas/análise , Hemólise/fisiologia , Monitorização Fisiológica/métodos , Animais , Eritrócitos/citologia , Eritrócitos/patologia , Humanos , Modelos Animais , Suínos
7.
J Med Chem ; 63(8): 4081-4089, 2020 04 23.
Artigo em Inglês | MEDLINE | ID: mdl-32216308

RESUMO

Cationic antimicrobial peptides (CAMPs) are potent therapeutics for drug-resistant bacterial infections. However, the clinical application of CAMPs is hampered by its poor proteolytic stability and hemolytic activity toward eukaryotic cells. Great efforts have been made to design and generate derivatives of CAMPs with improved pharmacological properties. Here, we report a novel stapling protocol, which tethers two ε-amino groups of the lysine residue by the N-alkylation reaction on the hydrophilic face of amphiphilic antimicrobial peptides. A series of lysine-tethered stapled CAMPs were synthesized, employing the antimicrobial peptide OH-CM6 as a model. Biological screening of the stapled CAMPs provided an analogue with strong antimicrobial activity, high proteolytic stability, and low hemolytic activity. This novel stapling approach offers an important chemical tool for developing CAMP-based antibiotics.


Assuntos
Peptídeos Catiônicos Antimicrobianos/química , Peptídeos Catiônicos Antimicrobianos/farmacologia , Hemólise/efeitos dos fármacos , Lisina/química , Lisina/farmacologia , Sequência de Aminoácidos , Peptídeos Catiônicos Antimicrobianos/metabolismo , Escherichia coli/efeitos dos fármacos , Escherichia coli/fisiologia , Células HEK293 , Hemólise/fisiologia , Humanos , Lisina/metabolismo , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/fisiologia , Testes de Sensibilidade Microbiana/métodos
8.
Am J Hematol ; 95(5): 456-464, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-31990387

RESUMO

The complement system is an innate immune defense cascade that can cause tissue damage when inappropriately activated. Evidence for complement over activation has been reported in small cohorts of patients with sickle cell disease (SCD). However, the mechanism governing complement activation in SCD has not been elucidated. Here, we observe that the plasma concentration of sC5b-9, a reliable marker for terminal complement activation, is increased at steady state in 61% of untreated SCD patients. We show that greater complement activation in vitro is promoted by SCD erythrocytes compared to normal ones, although no significant differences were observed in the regulatory proteins CD35, CD55, and CD59 in whole blood. Complement activation is positively correlated with the percentage of dense sickle cells (DRBCs). The expression levels of CD35, CD55, and CD59 are reduced in DRBCs, suggesting inefficient regulation when cell density increases. Moreover, the surface expression of the complement regulator CD46 on granulocytes was inversely correlated with the plasma sC5b-9. We also show increased complement deposition in cultured human endothelial cells incubated with SCD serum, which is diminished by the addition of the heme scavenger hemopexin. Treatment of SCD patients with hydroxyurea produces substantial reductions in complement activation, measured by sC5b-9 concentration and upregulation of CD46, as well as decreased complement activation on RBCs in vitro. In conclusion, complement over activation is a common pathogenic event in SCD that is associated with formation of DRBCs and hemolysis. And, it affects red cells, leukocytes and endothelial cells. This complement over activation is partly alleviated by hydroxyurea therapy.


Assuntos
Anemia Falciforme/terapia , Contagem de Células/métodos , Ativação do Complemento/genética , Hemólise/fisiologia , Hidroxiureia/uso terapêutico , Adolescente , Adulto , Feminino , Humanos , Hidroxiureia/farmacologia , Pessoa de Meia-Idade , Adulto Jovem
9.
Transfusion ; 60(2): 285-293, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31912889

RESUMO

BACKGROUND: ABO compatibility can affect platelet transfusion safety and efficacy, and ABO-incompatible (ABOi) platelets likely increases the risks of transfusion reactions though the magnitude of this risk is unclear. STUDY DESIGN AND METHODS: Data collected on all platelet transfusions administered over 36+ months were classified based on patient and product ABO blood group type and merged with a data set that included all transfusion reactions reported during that period. The transfusion reaction rates among various subsets was calculated. RESULTS: In patients greater than 1 year of age, the transfusion reaction rate in the ABO-compatible (ABO-identical) platelet group was 1.0%, while the ABOi platelet group had an elevated reaction rate of 1.7%. The increased reaction rate for ABOi platelets held true even if the analysis were limited to Centers for Disease Control and Prevention/National Healthcare Safety Network qualifying reactions or just allergic or febrile nonhemolytic reactions. The increased reaction rate with ABOi platelets was independent of unit age. Surprisingly, major-incompatible transfusions (A/B antigen incompatible) had the highest rate of reactions, at 2.0%. During the study period, three acute hemolytic reactions were reported out of 2522 plasma-incompatible platelet transfusions (0.12%). CONCLUSIONS: Our results find that compatible platelet transfusions have the lowest rate of transfusion reactions. While hemolytic reactions were observed with plasma-incompatible transfusions, the rate was low. Transfusion of ABO antigen-incompatible platelets had the highest rate of transfusion reactions and resulted in a transfusion reaction rate 1.5 to 2 times that of ABO compatible transfusions.


Assuntos
Sistema ABO de Grupos Sanguíneos/metabolismo , Incompatibilidade de Grupos Sanguíneos/metabolismo , Transfusão de Plaquetas/efeitos adversos , Reação Transfusional/metabolismo , Plaquetas/fisiologia , Transfusão de Sangue/métodos , Feminino , Hemólise/fisiologia , Humanos , Masculino
10.
J Thorac Cardiovasc Surg ; 159(4): 1519-1527.e1, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-31444074

RESUMO

OBJECTIVE: Mechanical circulatory support has become a standard therapy for adult patients with end-stage heart failure. For pediatric patients, technologic development lags behind with no currently approved implantable rotary blood pump. As an alternative, the HeartWare Ventricular Assist Device (Medtronic, Minneapolis, Minn), originally designed for adults, is increasingly used in pediatric patients. The aim of this multicenter study was to assess in silico, in vitro, and in vivo the blood trauma potential of this pump in pediatric application. METHODS: Clinical outcome and indicators for in vivo blood trauma were investigated retrospectively in 14 pediatric patients with the HeartWare Ventricular Assist Device (age 11.3 ± 4.8 years). Blood trauma mechanisms of the HeartWare Ventricular Assist Device were examined in silico and in vitro at an adult and pediatric operating point (5 L/min and 2.5 L/min at 2800 rpm and 2200 rpm, respectively). The flow was simulated by computational fluid dynamics and analyzed regarding flow structures, shear stresses, and washout. Hemolysis was assessed with pumps circulating bovine blood in a temperate flow circuit. RESULTS: In the retrospective in vivo analysis, lactate dehydrogenase and D-dimer values were 1.5- and 3-fold elevated, respectively, compared with adult patients with the HeartWare Ventricular Assist Device. Major bleedings were observed in 42.9%, and suspected pump thrombosis and neurologic dysfunction were observed in 14.3% of all patients. In the pediatric conditions, simulations predicted elevated mechanical stress profile below 50 Pa, more stagnant flow field, and longer washout times within the pump. In vitro measurements revealed an increased normalized index of hemolysis (17.5 vs 8.2 mg/100 L; P = .0021). CONCLUSIONS: The HeartWare Ventricular Assist Device, operated at lower speeds and flows, induces elevated blood trauma. Further studies are required to assess the clinical implications of these findings.


Assuntos
Insuficiência Cardíaca/terapia , Coração Auxiliar/efeitos adversos , Hemólise/fisiologia , Complicações Pós-Operatórias/etiologia , Adolescente , Fatores Etários , Animais , Bovinos , Criança , Feminino , Insuficiência Cardíaca/patologia , Humanos , Hidrodinâmica , Masculino , Modelos Cardiovasculares , Estudos Retrospectivos , Estresse Mecânico
13.
Transfusion ; 60(2): 378-390, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31756004

RESUMO

BACKGROUND: Studies suggest that washing red cell concentrates (RCCs) to remove soluble mediators and/or inflammatory components, such as extracellular vesicles (EVs), may lead to better clinical outcomes. This study tested the hypothesis that non-red blood cell (RBC) generated vesicles in RCC are potent inflammatory mediators in vitro and washing RCCs can reduce these vesicles and subsequently decrease the inflammatory activity of RCCs. STUDY DESIGN AND METHODS: Sixteen RCCs were pooled and split into four groups based on pre-wash storage time (Day 2 or 14; n = 4/group). Each group was tested 24 hours and 7 days post-wash. Characteristics of RBCs and EVs, cytokines released by monocytes, and expression of human umbilical vein endothelial cells (HUVECs) adhesion molecules were assessed. RESULTS: All RCCs meet quality standards for hemolysis, hematocrit, and hemoglobin. Washing did not remove residual platelets from RCCs but led to a significant reduction in platelet-EV count regardless of the group. Supernatant of RCCs washed on Day 14 and stored for 24 hours had significantly lower concentrations of RBC-EVs and white blood cell EVs compared to unwashed controls. Supernatant of unwashed RCCs showed higher production of inflammatory cytokines/chemokines MCP-1, IL-8, and TNF-α, and heightened expression of HUVEC VCAM-1, which were significantly reduced by washing. Spiking washed RCC supernatants with platelet-EVs showed significant increase in IL-8, MCP-1, VCAM-1, and E-selection in groups washed on Day 14. CONCLUSIONS: Platelet-EVs in RCCs are associated with pro-inflammatory activity. As washing significantly reduced RCC immunomodulatory activity, implementation of this process may improve transfusion outcomes.


Assuntos
Plaquetas/metabolismo , Eritrócitos/metabolismo , Preservação de Sangue/métodos , Quimiocina CCL2/metabolismo , Hemólise/fisiologia , Células Endoteliais da Veia Umbilical Humana , Humanos , Interleucina-8/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Molécula 1 de Adesão de Célula Vascular/metabolismo
14.
Blood Coagul Fibrinolysis ; 31(1): 48-54, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31789660

RESUMO

: In the coagulation laboratory, spurious hemolysis, icterus and lipemia (HIL) in test samples represent by far the leading diagnostic prenalytical challenges. The aim of this study was to assess the performance of the preanalytical module on the new hemostasis analyser Cobas Roche t511. We assessed the influence of HIL on prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen (Fib), antithrombin and D-dimer on plasma pools aliquots with different interference degrees. Moreover, we evaluated spontaneous hemolysis by comparing results on 50 paired samples (hemolysed versus nonhemolysed). Spurious hemolysis interference studies highlight the absence of a clinical significant impact on PT, APTT and antithrombin test results at all hemoglobin concentration investigated. For Fib and D-dimer assays a clinically significant difference was observed in the most hemolysed aliquot for Fib and in the two most hemolysed aliquots for D-dimer. Spontaneous hemolysis interference studies showed no clinical significant differences for PT and antithrombin assays, instead for APTT, Fib and D-dimer we found significant statistical and clinical differences between hemolysed and non hemolysed specimens. Bilirubin interference studies and lipemic samples interference studies enable us to confirm that the differences in the results obtained between the different aliquots and reference pool is not clinically significant for all assays. HIL check preanalytical module of Cobas Roche t511 analyzer displaied excellent performance for routine use in clinical laboratories. Regardless of analytical considerations, the type of interference encountered with spurious HIL is substantially different and requires different approaches.


Assuntos
Testes de Coagulação Sanguínea/métodos , Hemólise/fisiologia , Hiperlipidemias/sangue , Icterícia/sangue , Humanos
15.
Transfusion ; 60(2): 250-255, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31837028

RESUMO

BACKGROUND: Immunoglobulin therapy including intravenous immunoglobulin (IVIg) has been used as an effective treatment for autoimmune/inflammatory conditions with few side effects. However, high-dose IVIg (1-2 g/kg) has been recognized as a cause of hemolytic anemia in non-blood group O patients. Hemolysis when observed has been due to anti-A/anti-B isoagglutinins contained in the IVIg. Recently, an isoagglutinin-reduced IVIg, whereby the anti-A and anti-B titers have been reduced by immunoaffinity chromatography, has been introduced; however, whether this new product is as efficacious as nonreduced immunoglobulin (Ig) or will result in less IVIg-associated hemolysis has not been resolved. STUDY DESIGN AND METHODS: We used in vitro phagocytosis by monocytes and proinflammatory/anti-inflammatory macrophages, with isoagglutinin-reduced and -nonreduced Ig opsonized group A1 , B, and A1 B red blood cells, to estimate clinical significance of the IgG isoagglutinins. We also used immune thrombocytopenia (ITP) and rheumatoid arthritis (RA) mouse models to examine the in vivo efficacy of isoagglutinin-reduced versus -nonreduced Ig on the amelioration of the diseases. RESULTS: In contrast to nonreduced Ig, phagocytosis was largely absent when isoagglutinin-reduced Ig was used at a concentration equivalent to a patient receiving 2 g/kg. The in vivo efficacy of isoagglutinin-reduced versus nonreduced Ig on the amelioration of experimental ITP and RA was similar, indicating no loss of efficacy due to the chromatographic removal of isoagglutinins. CONCLUSION: Isoagglutinin-reduced Ig should have efficacy similar to nonreduced Ig and result in less IVIg-associated hemolysis.


Assuntos
Aglutininas/uso terapêutico , Artrite Reumatoide/tratamento farmacológico , Hemólise/fisiologia , Imunoglobulinas Intravenosas/efeitos adversos , Púrpura Trombocitopênica Idiopática/tratamento farmacológico , Animais , Artrite Reumatoide/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Fagocitose/efeitos dos fármacos , Púrpura Trombocitopênica Idiopática/metabolismo
16.
Transfusion ; 59(12): 3575-3579, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31670408

RESUMO

BACKGROUND: Hemolytic disease of the fetus and newborn (HDFN) is due to passively transferred maternal antibodies directed against fetal red blood cell (RBC) antigens and can lead to severe morbidity and mortality. Anti-M is usually a naturally occurring antibody of low clinical significance, although occasionally severe cases of HDFN are seen. CASE REPORTS: Two M+ sisters are presented, each developing hemolysis during the first 2 weeks of life due to maternal anti-M, resulting in severe anemia and requiring blood transfusion. RBC agglutination was observed in peripheral blood samples of both infants at room temperature with dissociation at 37°C. Maternal anti-M detected by column indirect agglutination technique, was of low titer (1:16) and demonstrated low thermal amplitude, reacting in saline at 4°C but was not detectable in saline at 37°C. CONCLUSIONS: Anti-M of low thermal amplitude may cause hemolytic disease of the newborn with laboratory features resembling cold agglutinin disease.


Assuntos
Anemia Hemolítica Autoimune/terapia , Transfusão de Sangue/métodos , Imunoglobulina M/imunologia , Teste de Coombs , Eritroblastose Fetal , Feminino , Hemólise/fisiologia , Humanos , Imunoglobulina G/imunologia , Imunoglobulina M/metabolismo , Recém-Nascido , Temperatura
17.
Transfusion ; 59(12): 3570-3574, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31710384

RESUMO

BACKGROUND: Delayed hemolytic reactions are potential complications of incompatible transfusions and are usually associated with the identification of a new antibody on serologic studies, following a second immunization event. However, in rare cases, the antibody investigation remains negative even if the clinical presentation would lead one to suspect otherwise. CASE REPORT: A 44-year-old woman with hereditary hemorrhagic telangiectasia presented to the emergency department with hematuria and low back pain after she had received three units of RBCs 2 weeks earlier. Hematology and biochemistry results were consistent with delayed hemolytic transfusion reaction, but surprisingly, serologic antibody investigations were negative. It was only when her plasma was tested with enzyme (ficin)-treated panel cells that anti-e was finally detected, with a 3+ reaction with all homozygous e+ cells. No reaction was seen with heterozygous e+ cells. Four months later, an anti-K was also detected on standard panels, while the anti-e remained detectable only with ficin-treated panel cells. Three years later, both antibodies had vanished and remained undetectable. The weakness of anti-e reaction, combined with the quick evanescence of both antibodies led to the suspicion of a potential underlying immunodeficiency disorder, which was confirmed by low immunoglobulin levels on two occasions. CONCLUSION: To our knowledge, this is the first case of immunodeficiency disorder diagnosed after the identification of evanescent antibody reactions. This case also outlines the importance of a good clinical history that should lead to further investigations when a hemolytic transfusion reaction is suspected.


Assuntos
Hemólise/fisiologia , Telangiectasia Hemorrágica Hereditária/terapia , Reação Transfusional , Adulto , Anticorpos/metabolismo , Feminino , Ficina , Humanos , Imunoglobulinas/metabolismo , Doenças da Imunodeficiência Primária/terapia
18.
Clin Chem Lab Med ; 57(11): 1699-1711, 2019 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-31617690

RESUMO

Background Some clinical chemistry measurement methods are vulnerable to interference if hemolyzed serum samples are used. The aims of this study were: (1) to obtain updated information about how hemolysis affects clinical chemistry test results on different instrument platforms used in Nordic laboratories, and (2) to obtain data on how test results from hemolyzed samples are reported in Nordic laboratories. Methods Four identical samples containing different degrees of hemolysis were prepared and distributed to 145 laboratories in the Nordic countries. The laboratories were asked to measure the concentration of cell-free hemoglobin (Hb), together with 15 clinical chemistry analytes. In addition, the laboratories completed a questionnaire about how hemolyzed samples are handled and reported. Results Automated detection of hemolysis in all routine patient samples was used by 63% of laboratories, and 88% had written procedures on how to handle hemolyzed samples. The different instrument platforms measured comparable mean Hb concentrations in the four samples. For most analytes, hemolysis caused a homogenous degree of interference regardless of the instrument platform used, except for alkaline phosphatase (ALP), bilirubin (total) and creatine kinase (CK). The recommended cut-off points for rejection of a result varied substantially between the manufacturers. The laboratories differed in how they reported test results, even when they used the same type of instrument. Conclusions Most of the analytes were homogeneously affected by hemolysis, regardless of the instrument used. There is large variation, however, between the laboratories on how they report test results from hemolyzed samples, even when they use the same type of instrument.


Assuntos
Química Clínica/métodos , Testes Hematológicos/métodos , Hemólise/fisiologia , Humanos , Laboratórios , Doadores de Tecidos
19.
ACS Chem Neurosci ; 10(11): 4704-4715, 2019 11 20.
Artigo em Inglês | MEDLINE | ID: mdl-31661243

RESUMO

Protein misfolding and its deviant self-assembly to converge into amyloid fibrils is associated with the perturbation of cellular functions and thus with debilitating neurodegenerative diseases including Alzheimer's disease, Parkinson's disease, etc. A great deal of research has already been carried out to discover a potential amyloid inhibitor that can slow down, prevent, or remodel toxic amyloids. In the present study with the help of a combination of biophysical, imaging, and computational techniques, we investigated the mechanism of interaction of cholic acid (CA), a primary bile acid, with human insulin and Aß-42 and found CA to be effective in inhibiting amyloid formation. From ThT data, we inferred that CA encumbers amyloid fibrillation up to 90% chiefly by targeting elongation of fibrils with an insignificant effect on lag time, while in the case of Aß-42, CA stabilizes the peptide in its native state preventing its fibrillation. Strikingly upon adding initially at the secondary nucleation stage, CA also detained the progression/growth of insulin fibrils. CA is unable to prevent the conformational changes completely during fibrillation but tends to resist and maintain an α helical structure up to a significant extent at a primary nucleation stage while reducing the ß sheet rich content at the secondary nucleation stage. Moreover, CA treated samples exhibited reduced cytotoxicity and different morphology. Furthermore, the results obtained after molecular docking indicated that CA is interacting with insulin via hydrogen bonds. For future research, this study can be considered as preliminary research for the development of CA, a metabolite of our body, as a potential therapeutic agent against Alzheimer's disease without even stimulating the immunological responses.


Assuntos
Amiloide/antagonistas & inibidores , Amiloide/metabolismo , Fenômenos Biofísicos/efeitos dos fármacos , Ácido Cólico/metabolismo , Ácido Cólico/farmacologia , Simulação de Acoplamento Molecular/métodos , Amiloide/química , Fenômenos Biofísicos/fisiologia , Relação Dose-Resposta a Droga , Hemólise/efeitos dos fármacos , Hemólise/fisiologia , Humanos , Insulina/química , Insulina/metabolismo , Simulação de Dinâmica Molecular , Estrutura Secundária de Proteína
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA