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1.
Medicine (Baltimore) ; 103(16): e37809, 2024 Apr 19.
Artículo en Inglés | MEDLINE | ID: mdl-38640293

RESUMEN

The neutrophil-to-lymphocyte ratio (NLR) and C-reactive protein-to-prealbumin ratio (CPAR) are novel markers of inflammation. The CPAR is an indicator of inflammation and malnutrition. We evaluated NLR and CPAR in combination as indicators of disease severity and prognosis in hospitalized older patients with coronavirus disease 2019 (COVID-19). A total of 222 hospitalized patients with COVID-19 (aged > 60 years) were divided into non-severe and severe groups. The severe group was subdivided into the surviving and deceased subgroups. We retrospectively assessed the predictive power of NLR and CPAR in combination (NLR + CPAR) to determine the prognosis of hospitalized older patients with COVID-19. The NLR and CPAR were significantly higher in the severe group than in the non-severe group (P < .001). Furthermore, the NLR and CPAR were higher in the deceased subgroup than in the surviving subgroup (P < .001). Pearson correlation analysis showed a highly significant positive correlation between NLR and CPAR (P < .001, r = 0.530). NLR + CPAR showed an area under the curve of 0.827 and sensitivity of 83.9% in the severe group; the area under the curve was larger (0.925) and sensitivity was higher (87.1%) in the deceased subgroup. The receiver operating characteristic curve of NLR + CPAR was significantly different from the receiver operating characteristic curves of either biomarker alone (P < .001). Kaplan-Meier analysis showed that patients in the severe group with elevated NLR + CPAR had a significantly lower 90-day survival rate than patients who lacked this finding (odds ratio 7.87, P < .001). NLR + CPAR may enable early diagnosis and assessment of disease severity in hospitalized older patients with COVID-19. This may also enable the identification of high-risk older patients with COVID-19 at the time of admission.


Asunto(s)
COVID-19 , Compuestos Organometálicos , Humanos , Pronóstico , COVID-19/diagnóstico , Neutrófilos , Proteína C-Reactiva , Estudios Retrospectivos , Prealbúmina , Linfocitos , Inflamación , Curva ROC
2.
Clin Lab ; 70(4)2024 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-38623656

RESUMEN

BACKGROUND: Evaluation of biomarkers as risk factors for mortality may provide early intervention and treatment for fatal diseases. We aimed to determine the usability of inexpensive and easily measurable tests in the differentiation of critically ill patients by investigating their relationship with mortality. METHODS: This study was executed by examining the sixth, third, and first month examinations of patients registered to the home health care services unit in 2022 before mortality due to any reason. This study was conducted by including 1,060 patients. All parameters were distributed non-parametrically. The difference between the dependent groups was evaluated with Friedman's two-way analysis of variance, and p < 0.05 was considered statistically significant. RESULTS: When the patients' premortem one-month, three-month, and six-month results were examined, there was an increase in mean platelet volume (MPV) values over time. The neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) also increased. In these two parameters, the difference between the first and third months and between the first and sixth months was statistically significant. Given the C-Reactive Protein (CRP)/Albumin Ratio (CAR) and CRP/Prealbumin results, a significant increase was observed in both ratios. A more than four-fold increase was observed in the CAR between the premortem first and sixth month results, which increased gradually over time and was statistically significant. Conclusions: NLR, PLR, MPV, CAR and CRP/Prealbumin values were statistically associated with mortality.


Asunto(s)
Plaquetas , Prealbúmina , Humanos , Prealbúmina/metabolismo , Recuento de Plaquetas , Plaquetas/metabolismo , Linfocitos/metabolismo , Biomarcadores/metabolismo , Neutrófilos/metabolismo , Proteína C-Reactiva/análisis , Estudios Retrospectivos
3.
Int J Mol Sci ; 25(7)2024 Mar 28.
Artículo en Inglés | MEDLINE | ID: mdl-38612579

RESUMEN

Peripheral and autonomic neuropathy are common disease manifestations in systemic amyloidosis. The neurofilament light chain (NfL), a neuron-specific biomarker, is released into the blood and cerebrospinal fluid after neuronal damage. There is a need for an early and sensitive blood biomarker for polyneuropathy, and this systematic review provides an overview on the value of NfL in the early detection of neuropathy, central nervous system involvement, the monitoring of neuropathy progression, and treatment effects in systemic amyloidosis. A literature search in PubMed, Embase, and Web of Science was performed on 14 February 2024 for studies investigating NfL levels in patients with systemic amyloidosis and transthyretin gene-variant (TTRv) carriers. Only studies containing original data were included. Included were thirteen full-text articles and five abstracts describing 1604 participants: 298 controls and 1306 TTRv carriers or patients with or without polyneuropathy. Patients with polyneuropathy demonstrated higher NfL levels compared to healthy controls and asymptomatic carriers. Disease onset was marked by rising NfL levels. Following the initiation of transthyretin gene-silencer treatment, NfL levels decreased and remained stable over an extended period. NfL is not an outcome biomarker, but an early and sensitive disease-process biomarker for neuropathy in systemic amyloidosis. Therefore, NfL has the potential to be used for the early detection of neuropathy, monitoring treatment effects, and monitoring disease progression in patients with systemic amyloidosis.


Asunto(s)
Amiloidosis , Amiloidosis de Cadenas Ligeras de las Inmunoglobulinas , Polineuropatías , Humanos , Prealbúmina/genética , Filamentos Intermedios , Biomarcadores
4.
Aging Clin Exp Res ; 36(1): 89, 2024 Apr 10.
Artículo en Inglés | MEDLINE | ID: mdl-38598143

RESUMEN

BACKGROUND: Whether, and to what extent, frailty and other geriatric domains are linked to health status in patients with transthyretin cardiac amyloidosis (ATTR-CA) is unknown. AIMS: To determine the association of frailty with health status [defined by the Kansas City Cardiomyopathy Questionnaire (KCCQ)] in patients with ATTR-CA. METHODS: Consecutive ATTR-CA patients undergoing cardiovascular assessment at a tertiary care clinic from September 2021 to September 2023 were invited to participate. KCCQ, frailty and social environment were recorded. Frailty was assessed using the modified Frailty Index (mFI), mapping 11 variables from the Canadian Study of Health and Aging (frailty ≥0.36). RESULTS: Of 168 screened ATTR-CA patients, 138 [83% men, median age of 79 (75-84) years] were enrolled in the study. Median KCCQ was 66 (50-75). wtATTR-CA was the most prevalent form (N = 113, 81.9%). The most frequent cardiac variant was Ile68Leu (17/25 individuals with vATTR-CA). Twenty (14.5%) patients were considered frail, and prevalence of overt disability was 6.5%. At multivariable linear regression analysis, factors associated with worsening KCCQ were age at evaluation, the mFI, NYHA Class, and NAC Score. Gender, ATTR-CA type, phenotype, and LVEF were not associated with health status. DISCUSSION: In older patients diagnosed with ATTR-CA, frailty, symptoms, and disease severity were associated with KCCQ. CONCLUSIONS: Functional status is a determinant of quality of life and health status in older individuals with a main diagnosis of ATTR-CA. Future research may provide more in-depth knowledge on the association of frailty in patients with ATTR-CA with respect to quality of life and prognosis.


Asunto(s)
Amiloidosis , Fragilidad , Masculino , Humanos , Anciano , Anciano de 80 o más Años , Femenino , Calidad de Vida , Prealbúmina , Estudios Prospectivos , Canadá , Estado de Salud
6.
PLoS One ; 19(4): e0301756, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38578730

RESUMEN

INTRODUCTION: Amyloid deposition is a cause of restrictive cardiomyopathy. Patients who present with cardiac disease can be evaluated for transthyretin (TTR)-associated cardiac amyloidosis using nuclear imaging with 99mTc-labeled pyrophosphate (PYP); however, light chain-associated (AL) cardiac amyloid is generally not detected using this tracer. As an alternative, the amyloid-binding peptide p5+14 radiolabeled with iodine-124 has been shown to be an effective pan-amyloid radiotracer for PET/CT imaging. Here, a 99mTc-labeled form of p5+14 peptide has been prepared to facilitate SPECT/CT imaging of cardiac amyloidosis. METHOD: A synthesis method suitable for clinical applications has been used to prepare 99mTc-labeled p5+14 and tested for peptide purity, product bioactivity, radiochemical purity and stability. The product was compared with99mTc-PYP for cardiac SPECT/CT imaging in a mouse model of AA amyloidosis and for reactivity with human tissue sections from AL and TTR patients. RESULTS: The 99mTc p5+14 tracer was produced with >95% yields in radiopurity and bioactivity with no purification steps required and retained over 95% peptide purity and >90% bioactivity for >3 h. In mice, the tracer detected hepatosplenic AA amyloid as well as heart deposits with uptake ~5 fold higher than 99mTc-PYP. 99mTc p5+14 effectively bound human amyloid deposits in the liver, kidney and both AL- and ATTR cardiac amyloid in tissue sections in which 99mTc-PYP binding was not detectable. CONCLUSION: 99mTc-p5+14 was prepared in minutes in >20 mCi doses with good performance in preclinical studies making it suitable for clinical SPECT/CT imaging of cardiac amyloidosis.


Asunto(s)
Amiloidosis , Cardiomiopatías , Humanos , Ratones , Animales , Tomografía Computarizada por Tomografía de Emisión de Positrones , Amiloidosis/diagnóstico por imagen , Amiloidosis/metabolismo , Tomografía Computarizada de Emisión de Fotón Único/métodos , Péptidos , Amiloide/metabolismo , Cardiomiopatías/diagnóstico por imagen , Prealbúmina
10.
Arch Osteoporos ; 19(1): 27, 2024 Apr 11.
Artículo en Inglés | MEDLINE | ID: mdl-38600249

RESUMEN

Malnutrition is associated with complications and mortality in patients of hip fracture. Prealbumin may be more suitable than albumin to accurately predict the prognosis of hip fracture in elderly patients. We found that prealbumin concentration was nonlinearly associated with mortality in elderly patients with hip fracture, and an inflection point effect was observed. OBJECTIVE: To evaluate the association between prealbumin concentration at admission and mortality in elderly patients with hip fractures. METHODS: Elderly patients with hip fractures were screened between Jan 2015 and Sep 2019. Demographic and clinical characteristics of the patients were collected. Linear and nonlinear multivariate Cox regression models were used to identify the association between prealbumin concentration at admission and mortality. All analyses were performed using EmpowerStats and the R software. RESULTS: This cohort study included 2387 patients who met the study criteria. The mean follow-up was 37.64 months. The prealbumin concentration was 162.67 ± 43.2 mg/L. Multivariate Cox regression showed that prealbumin concentration was associated with mortality in geriatric patients with hip fracture (hazard ratio [HR] = 0.95, 95% confidence intervals [CI]: 0.93-0.97, P < 0.0001). In addition, an inflection point effect was observed in the nonlinear association. The inflection point was 162.2 mg/L. If it is less than this inflection point, then every 10 mg/L increase in prealbumin was associated with a 7% reduction in the risk of death (HR = 0.93, 95%CI: 0.90-0.96, P < 0.0001). When greater than the inflection point, there was no difference in the risk of death (HR = 0.99, 95%CI: 0.95-1.03, P = 0.5127). CONCLUSION: The prealbumin concentrations at admission were nonlinearly associated with long-term mortality in geriatric hip fractures, and 162.2 mg/L could be considered a prognostic factor of mortality risk.


Asunto(s)
Fracturas de Cadera , Prealbúmina , Humanos , Anciano , Estudios de Cohortes , Prealbúmina/análisis , Factores de Riesgo , Pronóstico , Estudios Retrospectivos
11.
Med. clín (Ed. impr.) ; 162(7): e1-e7, abril 2024. tab, graf
Artículo en Español | IBECS | ID: ibc-232091

RESUMEN

Introducción y objetivos: La amiloidosis cardiaca (AC) es una patología asociada a un elevado número de ingresos hospitalarios. Dada la escasa información disponible al respecto, planteamos un análisis de la incidencia y las causas de hospitalización en esta enfermedad.Material y métodosSe evaluaron 143 pacientes (128 por transtiretina [AC-ATTR] y 15 por cadenas ligeras [AC-AL]) incluidos en el Registro de Amiloidosis Cardiaca de Galicia (AMIGAL), recogiendo todas sus hospitalizaciones.ResultadosDurante un seguimiento mediano de 959 días se produjeron 179 hospitalizaciones no programadas (tasa de incidencia [TI] 512,6 ingresos hospitalarios por 1.000 pacientes-año), siendo las más habituales las de causa cardiovascular (n=109, TI 312,2). El motivo individual de ingreso hospitalario más frecuente fue la insuficiencia cardiaca (IC) (n=87, TI 249,2).La AC-AL se asoció con una TI de hospitalizaciones no programadas más elevada que la AC-ATTR (TI 781 vs. 483,2; HR 1,62; p=0,029) a expensas de las de causa no cardiovascular (TI 376 vs. 181,2; HR 2,07; p=0,027). La supervivencia libre de hospitalización no programada al año y a los tres años en la AC-AL fue menor que en la AC-ATTR (46,7 y 20,0% vs. 73,4 y 35,2%, respectivamente; p=0,021). (AU)


Introduction and objetives: Cardiac amyloidosis (CA) is a disorder associated with high number of hospital admissions. Given the scarce information available, we propose an analysis of the incidence and causes of hospitalization in this disease.Material and methodsOne hundred and forty-three patients [128 by transthyretin (ATTR-CA) and 15 by light chains (AL-CA)] included in Registro de Amiloidosis Cardiaca de Galicia (AMIGAL) were evaluated, including all hospitalizations.ResultsDuring a median follow-up of 959 days there were 179 unscheduled hospitalizations [incidence rate (IR) 512.6 admissions per 1000 patients-year], most common due to cardiovascular reasons (n=109, IR 312.2). Most frequent individual cause of hospitalization was heart failure (n=87, TI 249.2).AL-CA was associated with a higher IR of unscheduled hospitalizations than ATTR-CA (IR 781 vs. 483.2; HR 1.62; p=0,029) due to non-cardiovascular admissions (IR 376 vs. 181.2; HR 2.07; p=0.027). Unscheduled admission-free survival at 1 and 3 years in AL-CA was inferior than in ATTR-CA (46.7% and 20.0% vs. 73.4% and 35.2%, respectively; p=0.021). (AU)


Asunto(s)
Humanos , Neuropatías Amiloides Familiares/diagnóstico , Neuropatías Amiloides Familiares/epidemiología , Neuropatías Amiloides Familiares/terapia , Cardiomiopatías/epidemiología , Cardiomiopatías/etiología , Cardiomiopatías/terapia , Insuficiencia Cardíaca/complicaciones , Insuficiencia Cardíaca/epidemiología , Insuficiencia Cardíaca/terapia , Hospitalización , Prealbúmina
14.
Int. j. cardiovasc. sci. (Impr.) ; 37(suppl.1): 17-17, abr. 2024.
Artículo en Portugués | CONASS, Sec. Est. Saúde SP, SESSP-IDPCPROD, Sec. Est. Saúde SP | ID: biblio-1538231

RESUMEN

INTRODUÇÃO: A amiloidose transtiretina (ATTR) é uma doença multissistêmica causada pela deposição de proteína fibrilar em órgãos e tecidos. Os genótipos e fenótipos da ATTR são altamente heterogêneos. MÉTODOS: Apresentamos dados sobre sinais e sintomas físicos, avaliações cardíacas e neurológicas, e genética em pacientes incluídos no Registro de Amiloidose Cardíaca Transtiretina no Estado de São Paulo (REACT-SP), Brasil. RESULTADOS: Foram incluídos 644 pacientes, sendo 505 com a forma variante (ATTRv) e 139 com a forma selvagem (ATTRwt). Dezesseis mutações diferentes foram detectadas, sendo as mais comuns Val50Met (48,3%) e V142Ile (40,8%). No geral, mais da metade dos pacientes apresentou envolvimento cardíaco, e a diferença nessa proporção entre os grupos ATTRv e ATTRwt foi significativa (43,9 vs. 89,9%; p<0,001). O fenótipo neurológico também diferiu entre ATTRv e ATTRwt (56,8 vs. 31,7%; p<0,001). O fenótipo misto foi encontrado em 25,6% da população, sem diferença significativa entre as formas de amiloidose. Um grupo de pacientes permaneceu assintomático (10,4%), com uma proporção menor de pacientes assintomáticos no grupo ATTRwt. CONCLUSÕES: Este estudo detalha o espectro clínico e genético de pacientes com ATTR em São Paulo, Brasil. Esta análise preliminar destaca a considerável heterogeneidade fenotípica das manifestações neurológicas e cardíacas em pacientes com ATTR variante e ATTR do tipo selvagem.


Asunto(s)
Prealbúmina , Amiloidosis Familiar , Signos y Síntomas , Perfil Genético
15.
BMC Cancer ; 24(1): 293, 2024 Mar 04.
Artículo en Inglés | MEDLINE | ID: mdl-38438901

RESUMEN

BACKGROUND: Hepatic proteins, including albumin, prealbumin, and transferrin have been confirmed to be prognostic predictors in various cancers. This study aimed to comprehensively assess the prognostic value of these three serum markers in patients with cancer cachexia. METHODS: This multicenter prospective cohort study included 1303 cancer cachexia patients, among whom 592 deaths occurred during a median follow-up of 20.23 months. The definition of cachexia was based on the 2011 international consensus. Concordance index (C-index) and receiver operating characteristic (ROC) curves were applied to compare the prognostic performance. The primary outcome was overall survival, which was calculated using the Kaplan-Meier method generated by log-rank test. A Cox proportional hazard regression model was used to identify independent predictors associated with survival. The secondary outcomes included 90-days mortality and quality of life (QoL). RESULTS: C-index and ROC curves showed that albumin had the most accurate predictive capacity for survival, followed by transferrin and prealbumin. Multivariate Cox analysis confirmed that low albumin (hazard ratio [HR] = 1.51, 95% confidence interval [95%CI] = 1.28-1.80, P < 0.001), prealbumin (HR = 1.42, 95%CI = 1.19-1.69, P < 0.001), and transferrin (HR = 1.50, 95%CI = 1.25-1.80, P < 0.001) were independent risk factors for long-term survival in cancer patients with cachexia. In subgroup analysis, the prognostic value of low albumin was significant in patients with upper gastrointestinal, hepatobiliary and pancreatic, and colorectal cancers; low prealbumin was significant in colorectal cancer; and low transferrin was significant in patients with upper gastrointestinal and colorectal cancer. All three hepatic proteins were valuable as prognostic predictors for patients with advanced (Stage III and IV) cancer with cachexia. The risks of 90-days mortality and impaired QoL were higher in cachexia patients with low albumin, prealbumin, and transferrin levels. CONCLUSION: Low albumin, prealbumin, and transferrin levels were all independent prognostic factors affecting patients with cancer cachexia, especially in patients in the advanced stages. These results highlight the value of routinely checking serum hepatic proteins in clinical practice to predict the prognosis of patients with cancer cachexia.


Asunto(s)
Neoplasias Colorrectales , Prealbúmina , Humanos , Calidad de Vida , Caquexia/diagnóstico , Caquexia/etiología , Estudios Prospectivos , Pronóstico , Albúminas , Proteínas Sanguíneas , Estudios de Cohortes , Transferrinas
16.
JAMA ; 331(9): 778-791, 2024 03 05.
Artículo en Inglés | MEDLINE | ID: mdl-38441582

RESUMEN

Importance: Systemic amyloidosis from transthyretin (ATTR) protein is the most common type of amyloidosis that causes cardiomyopathy. Observations: Transthyretin (TTR) protein transports thyroxine (thyroid hormone) and retinol (vitamin A) and is synthesized predominantly by the liver. When the TTR protein misfolds, it can form amyloid fibrils that deposit in the heart causing heart failure, heart conduction block, or arrhythmia such as atrial fibrillation. The biological processes by which amyloid fibrils form are incompletely understood but are associated with aging and, in some patients, affected by inherited variants in the TTR genetic sequence. ATTR amyloidosis results from misfolded TTR protein deposition. ATTR can occur in association with normal TTR genetic sequence (wild-type ATTR) or with abnormal TTR genetic sequence (variant ATTR). Wild-type ATTR primarily manifests as cardiomyopathy while ATTR due to a genetic variant manifests as cardiomyopathy and/or polyneuropathy. Approximately 50 000 to 150 000 people in the US have heart failure due to ATTR amyloidosis. Without treatment, heart failure due to ATTR amyloidosis is associated with a median survival of approximately 5 years. More than 130 different inherited genetic variants in TTR exist. The most common genetic variant is Val122Ile (pV142I), an allele with an origin in West African countries, that is present in 3.4% of African American individuals in the US or approximately 1.5 million persons. The diagnosis can be made using serum free light chain assay and immunofixation electrophoresis to exclude light chain amyloidosis combined with cardiac nuclear scintigraphy to detect radiotracer uptake in a pattern consistent with amyloidosis. Loop diuretics, such as furosemide, torsemide, and bumetanide, are the primary treatment for fluid overload and symptomatic relief of patients with ATTR heart failure. An ATTR-directed therapy that inhibited misfolding of the TTR protein (tafamidis, a protein stabilizer), compared with placebo, reduced mortality from 42.9% to 29.5%, reduced hospitalizations from 0.7/year to 0.48/year, and was most effective when administered early in disease course. Conclusions and Relevance: ATTR amyloidosis causes cardiomyopathy in up to approximately 150 000 people in the US and tafamidis is the only currently approved therapy. Tafamidis slowed progression of ATTR amyloidosis and improved survival and prevented hospitalization, compared with placebo, in people with ATTR-associated cardiomyopathy.


Asunto(s)
Amiloidosis , Cardiomiopatías , Insuficiencia Cardíaca , Prealbúmina , Humanos , Amiloidosis/complicaciones , Amiloidosis/epidemiología , Amiloidosis/genética , Amiloidosis/metabolismo , Cardiomiopatías/etiología , Cardiomiopatías/genética , Cardiomiopatías/metabolismo , Insuficiencia Cardíaca/etiología , Insuficiencia Cardíaca/genética , Insuficiencia Cardíaca/metabolismo , Amiloidosis de Cadenas Ligeras de las Inmunoglobulinas , Prealbúmina/genética , Prealbúmina/metabolismo , Negro o Afroamericano/etnología , Negro o Afroamericano/genética , Negro o Afroamericano/estadística & datos numéricos , Estados Unidos/epidemiología , África Occidental , Pliegue de Proteína
17.
J Am Coll Cardiol ; 83(11): 1085-1099, 2024 Mar 19.
Artículo en Inglés | MEDLINE | ID: mdl-38479957

RESUMEN

Cardiac amyloidosis is increasingly recognized as a treatable form of heart failure. Highly effective specific therapies have recently become available for the 2 most frequent forms of cardiac amyloidosis: immunoglobulin light chain amyloidosis and transthyretin (ATTR) amyloidosis. Nevertheless, initiation of specific therapies requires recognition of cardiac amyloidosis and appropriate characterization of the amyloid type. Although noninvasive diagnosis is possible for ATTR cardiac amyloidosis, histological demonstration and typing of amyloid deposits is still required for a substantial number of patients with ATTR and in all patients with light chain amyloidosis and other rarer forms of cardiac amyloidosis. Amyloid histological typing can be performed using different techniques: mass spectrometry, immunohistochemistry, and immunoelectron microscopy. This review describes which patients require histological confirmation of cardiac amyloidosis along with when and how to type amyloid deposits in histologic specimens. Furthermore, it covers the characteristics and limitations of the different typing methods that are available in clinical practice.


Asunto(s)
Neuropatías Amiloides Familiares , Amiloidosis , Cardiomiopatías , Insuficiencia Cardíaca , Humanos , Placa Amiloide , Amiloidosis/patología , Amiloide , Insuficiencia Cardíaca/diagnóstico , Inmunohistoquímica , Proteínas Amiloidogénicas , Prealbúmina , Neuropatías Amiloides Familiares/diagnóstico , Cardiomiopatías/diagnóstico , Cardiomiopatías/terapia
18.
ACS Chem Neurosci ; 15(7): 1356-1365, 2024 Apr 03.
Artículo en Inglés | MEDLINE | ID: mdl-38483181

RESUMEN

Transthyretin (TTR) is a tetrameric homologous protein that can dissociate into monomers. Misfolding and aggregation of TTR can lead to amyloid transthyretin amyloidosis (ATTR), which can cause many diseases (e.g., senile systemic amyloidosis, familial amyloid cardiomyopathy, and familial amyloid polyneuropathy). Despite growing evidence indicating that small oligomers play a critical role in regulating cytotoxicity, the structures of these oligomeric intermediates and their conformational transformations are still unclear, impeding our understanding of neurodegenerative mechanisms and the development of therapeutics targeting early aggregation species. The TTR monomer protein consists of various fragments prone to self-aggregation, including the residue 105-115 sequence. Therefore, our study investigated the assembly progress of ATTR (105-115) peptides using all-atom molecular dynamics simulations. The findings indicate that the probability of ß-sheet content increases with increasing numbers of peptides. Additionally, interactions between hydrophobic residues L110 and L111 are crucial for the formation of a ß-rich oligomer formation. These ß-rich oligomers may adopt ß-barrel conformations, potentially toxic oligomer species. Free-energy analysis reveals that ß-barrel conformations serve as intermediates for these ß-rich oligomers. Our insights into the structural ensemble dynamics of ATTR (105-115) contribute to understanding the physical mechanisms underlying the ß-barrel oligomers of ATTR. These findings may shed light on the pathological role of ATTR in neurodegenerative diseases and offer potential therapeutic targets.


Asunto(s)
Neuropatías Amiloides Familiares , Amiloide , Prealbúmina , Amiloide/metabolismo , Simulación de Dinámica Molecular , Proteínas Amiloidogénicas , Péptidos/química , Entropía
19.
Molecules ; 29(6)2024 Mar 21.
Artículo en Inglés | MEDLINE | ID: mdl-38543041

RESUMEN

Design of amyloid ß-protein (Aß) inhibitors is considered an effective strategy for the prevention and treatment of Alzheimer's disease (AD). However, the limited blood-brain barrier (BBB) penetration and poor Aß-targeting capability restricts the therapeutic efficiency of candidate drugs. Herein, we have proposed to engineer transthyretin (TTR) by fusion of the Aß-targeting peptide KLVFF and cell-penetrating peptide Penetratin to TTR, and derived a fusion protein, KLVFF-TTR-Penetratin (KTP). Moreover, to introduce the scavenging activity for reactive oxygen species (ROS), a nanocomposite of KTP and manganese dioxide nanoclusters (KTP@MnO2) was fabricated by biomineralization. Results revealed that KTP@MnO2 demonstrated significantly enhanced inhibition on Aß aggregation as compared to TTR. The inhibitory effect was increased from 18%, 33%, and 49% (10, 25, and 50 µg/mL TTR, respectively) to 52%, 81%, and 100% (10, 25, and 50 µg/mL KTP@MnO2). In addition, KTP@MnO2 could penetrate the BBB and target amyloid plaques. Moreover, multiple ROS, including hydroxyl radicals, superoxide radicals, hydrogen peroxide, and Aß-induced-ROS, which cannot be scavenged by TTR, were scavenged by KTP@MnO2, thus resulting in the mitigation of cellular oxidative damages. More importantly, cell culture and in vivo experiments with AD nematodes indicated that KTP@MnO2 at 50 µg/mL increased the viability of Aß-treated cells from 66% to more than 95%, and completely cleared amyloid plaques in AD nematodes and extended their lifespan by 7 d. Overall, despite critical aspects such as the stability, metabolic distribution, long-term biotoxicity, and immunogenicity of the nanocomposites in mammalian models remaining to be investigated, this work has demonstrated the multifunctionality of KTP@MnO2 for targeting Aß in vivo, and provided new insights into the design of multifunctional nanocomposites of protein-metal clusters against AD.


Asunto(s)
Enfermedad de Alzheimer , Péptidos de Penetración Celular , Fragmentos de Péptidos , Animales , Humanos , Péptidos beta-Amiloides/metabolismo , Enfermedad de Alzheimer/metabolismo , Compuestos de Manganeso/farmacología , Óxidos/farmacología , Prealbúmina/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Placa Amiloide/metabolismo , Mamíferos/metabolismo
20.
Hum Genomics ; 18(1): 31, 2024 Mar 25.
Artículo en Inglés | MEDLINE | ID: mdl-38523305

RESUMEN

PURPOSE: Coding mutations in the Transthyretin (TTR) gene cause a hereditary form of amyloidosis characterized by a complex genotype-phenotype correlation with limited information regarding differences among worldwide populations. METHODS: We compared 676 diverse individuals carrying TTR amyloidogenic mutations (rs138065384, Phe44Leu; rs730881165, Ala81Thr; rs121918074, His90Asn; rs76992529, Val122Ile) to 12,430 non-carriers matched by age, sex, and genetically-inferred ancestry to assess their clinical presentations across 1,693 outcomes derived from electronic health records in UK biobank. RESULTS: In individuals of African descent (AFR), Val122Ile mutation was linked to multiple outcomes related to the circulatory system (fold-enrichment = 2.96, p = 0.002) with the strongest associations being cardiac congenital anomalies (phecode 747.1, p = 0.003), endocarditis (phecode 420.3, p = 0.006), and cardiomyopathy (phecode 425, p = 0.007). In individuals of Central-South Asian descent (CSA), His90Asn mutation was associated with dermatologic outcomes (fold-enrichment = 28, p = 0.001). The same TTR mutation was linked to neoplasms in European-descent individuals (EUR, fold-enrichment = 3.09, p = 0.003). In EUR, Ala81Thr showed multiple associations with respiratory outcomes related (fold-enrichment = 3.61, p = 0.002), but the strongest association was with atrioventricular block (phecode 426.2, p = 2.81 × 10- 4). Additionally, the same mutation in East Asians (EAS) showed associations with endocrine-metabolic traits (fold-enrichment = 4.47, p = 0.003). In the cross-ancestry meta-analysis, Val122Ile mutation was associated with peripheral nerve disorders (phecode 351, p = 0.004) in addition to cardiac congenital anomalies (fold-enrichment = 6.94, p = 0.003). CONCLUSIONS: Overall, these findings highlight that TTR amyloidogenic mutations present ancestry-specific and ancestry-convergent associations related to a range of health domains. This supports the need to increase awareness regarding the range of outcomes associated with TTR mutations across worldwide populations to reduce misdiagnosis and delayed diagnosis of TTR-related amyloidosis.


Asunto(s)
Amiloidosis , Prealbúmina , Humanos , Prealbúmina/genética , Mutación , Amiloidosis/diagnóstico , Amiloidosis/genética , Fenotipo , Genética de Población
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