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1.
Nat Immunol ; 24(11): 1854-1866, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37857825

RESUMEN

Microglial involvement in Alzheimer's disease (AD) pathology has emerged as a risk-determining pathogenic event. While apolipoprotein E (APOE) is known to modify AD risk, it remains unclear how microglial apoE impacts brain cognition and AD pathology. Here, using conditional mouse models expressing apoE isoforms in microglia and central nervous system-associated macrophages (CAMs), we demonstrate a cell-autonomous effect of apoE3-mediated microglial activation and function, which are negated by apoE4. Expression of apoE3 in microglia/CAMs improves cognitive function, increases microglia surrounding amyloid plaque and reduces amyloid pathology and associated toxicity, whereas apoE4 expression either compromises or has no effects on these outcomes by impairing lipid metabolism. Single-cell transcriptomic profiling reveals increased antigen presentation and interferon pathways upon apoE3 expression. In contrast, apoE4 expression downregulates complement and lysosomal pathways, and promotes stress-related responses. Moreover, in the presence of mouse endogenous apoE, microglial apoE4 exacerbates amyloid pathology. Finally, we observed a reduction in Lgals3-positive responsive microglia surrounding amyloid plaque and an increased accumulation of lipid droplets in APOE4 human brains and induced pluripotent stem cell-derived microglia. Our findings establish critical isoform-dependent effects of microglia/CAM-expressed apoE in brain function and the development of amyloid pathology, providing new insight into how apoE4 vastly increases AD risk.


Asunto(s)
Enfermedad de Alzheimer , Ratones , Animales , Humanos , Enfermedad de Alzheimer/genética , Enfermedad de Alzheimer/patología , Apolipoproteína E4/genética , Apolipoproteína E4/metabolismo , Microglía/metabolismo , Apolipoproteína E3/genética , Apolipoproteína E3/metabolismo , Placa Amiloide/metabolismo , Placa Amiloide/patología , Apolipoproteínas E/genética , Apolipoproteínas E/metabolismo , Encéfalo , Homeostasis , Ratones Transgénicos
2.
Cell ; 148(4): 690-701, 2012 Feb 17.
Artículo en Inglés | MEDLINE | ID: mdl-22341442

RESUMEN

Lengthy trinucleotide repeats encoding polyglutamine (polyQ) stretches characterize the variant proteins of Huntington's disease and certain other inherited neurological disorders. Using a phenotypic screen to identify events that restore functionality to polyQ proteins in S. cerevisiae, we discovered that transcription elongation factor Spt4 is required to transcribe long trinucleotide repeats located either in ORFs or nonprotein-coding regions of DNA templates. Mutation of SPT4 selectively decreased synthesis of and restored enzymatic activity to expanded polyQ protein without affecting protein lacking long-polyQ stretches. RNA-seq analysis revealed limited effects of Spt4 on overall gene expression. Inhibition of Supt4h, the mammalian ortholog of Spt4, reduced mutant huntingtin protein in neuronal cells and decreased its aggregation and toxicity while not altering overall cellular mRNA synthesis. Our findings identify a cellular mechanism for transcription through repeated trinucleotides and a potential target for countermeasures against neurological disorders attributable to expanded trinucleotide regions.


Asunto(s)
Proteínas de Unión al ADN/metabolismo , Neuronas/metabolismo , Proteínas Nucleares/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/metabolismo , Transcripción Genética , Factores de Elongación Transcripcional/metabolismo , Repeticiones de Trinucleótidos , Animales , Línea Celular , Expresión Génica , Técnicas de Sustitución del Gen , Humanos , Proteína Huntingtina , Enfermedad de Huntington/metabolismo , Ratones , Proteínas del Tejido Nervioso/genética , Proteínas Nucleares/genética , Péptidos/genética , Péptidos/metabolismo , Ratas
3.
Nucleic Acids Res ; 52(D1): D1246-D1252, 2024 Jan 05.
Artículo en Inglés | MEDLINE | ID: mdl-37956338

RESUMEN

Advancements in high-throughput technology offer researchers an extensive range of multi-omics data that provide deep insights into the complex landscape of cancer biology. However, traditional statistical models and databases are inadequate to interpret these high-dimensional data within a multi-omics framework. To address this limitation, we introduce DriverDBv4, an updated iteration of the DriverDB cancer driver gene database (http://driverdb.bioinfomics.org/). This updated version offers several significant enhancements: (i) an increase in the number of cohorts from 33 to 70, encompassing approximately 24 000 samples; (ii) inclusion of proteomics data, augmenting the existing types of omics data and thus expanding the analytical scope; (iii) implementation of multiple multi-omics algorithms for identification of cancer drivers; (iv) new visualization features designed to succinctly summarize high-context data and redesigned existing sections to accommodate the increased volume of datasets and (v) two new functions in Customized Analysis, specifically designed for multi-omics driver identification and subgroup expression analysis. DriverDBv4 facilitates comprehensive interpretation of multi-omics data across diverse cancer types, thereby enriching the understanding of cancer heterogeneity and aiding in the development of personalized clinical approaches. The database is designed to foster a more nuanced understanding of the multi-faceted nature of cancer.


Asunto(s)
Bases de Datos Genéticas , Multiómica , Neoplasias , Humanos , Algoritmos , Bases de Datos Genéticas/normas , Neoplasias/genética , Neoplasias/fisiopatología
4.
Nucleic Acids Res ; 52(W1): W390-W397, 2024 Jul 05.
Artículo en Inglés | MEDLINE | ID: mdl-38709887

RESUMEN

In the field of lipidomics, where the complexity of lipid structures and functions presents significant analytical challenges, LipidSig stands out as the first web-based platform providing integrated, comprehensive analysis for efficient data mining of lipidomic datasets. The upgraded LipidSig 2.0 (https://lipidsig.bioinfomics.org/) simplifies the process and empowers researchers to decipher the complex nature of lipids and link lipidomic data to specific characteristics and biological contexts. This tool markedly enhances the efficiency and depth of lipidomic research by autonomously identifying lipid species and assigning 29 comprehensive characteristics upon data entry. LipidSig 2.0 accommodates 24 data processing methods, streamlining diverse lipidomic datasets. The tool's expertise in automating intricate analytical processes, including data preprocessing, lipid ID annotation, differential expression, enrichment analysis, and network analysis, allows researchers to profoundly investigate lipid properties and their biological implications. Additional innovative features, such as the 'Network' function, offer a system biology perspective on lipid interactions, and the 'Multiple Group' analysis aids in examining complex experimental designs. With its comprehensive suite of features for analyzing and visualizing lipid properties, LipidSig 2.0 positions itself as an indispensable tool for advanced lipidomics research, paving the way for new insights into the role of lipids in cellular processes and disease development.


Asunto(s)
Lipidómica , Lípidos , Programas Informáticos , Lípidos/química , Lipidómica/instrumentación , Lipidómica/métodos , Análisis de Datos , Internet , Algoritmos , Visualización de Datos
5.
Proc Natl Acad Sci U S A ; 120(30): e2300903120, 2023 Jul 25.
Artículo en Inglés | MEDLINE | ID: mdl-37459538

RESUMEN

Strange metals appear in a wide range of correlated materials. Electronic localization-delocalization and the expected loss of quasiparticles characterize beyond-Landau metallic quantum critical points and the associated strange metals. Typical settings involve local spins. Systems that contain entwined degrees of freedom offer new platforms to realize unusual forms of quantum criticality. Here, we study the fate of an SU(4) spin-orbital Kondo state in a multipolar Bose-Fermi Kondo model, which provides an effective description of a multipolar Kondo lattice, using a renormalization-group method. We show that at zero temperature, a generic trajectory in the model's parameter space contains two quantum critical points, which are associated with the destruction of Kondo entanglement in the orbital and spin channels, respectively. Our asymptotically exact results reveal an overall phase diagram, provide the theoretical basis to understand puzzling recent experiments of a multipolar heavy fermion metal, and point to a means of designing different forms of quantum criticality and strange metallicity in a variety of strongly correlated systems.

6.
Nucleic Acids Res ; 51(9): 4398-4414, 2023 05 22.
Artículo en Inglés | MEDLINE | ID: mdl-36999631

RESUMEN

The long non-coding telomeric RNA transcript TERRA, in the form of an RNA-DNA duplex, regulates telomere recombination. In a screen for nucleases that affects telomere recombination, mutations in DNA2, EXO1, MRE11 and SAE2 cause severe delay in type II survivor formation, indicating that type II telomere recombination is mediated through a mechanism similar to repairing double-strand breaks. On the other hand, mutation in RAD27 results in early formation of type II recombination, suggesting that RAD27 acts as a negative regulator in telomere recombination. RAD27 encodes a flap endonuclease that plays a role in DNA metabolism, including replication, repair and recombination. We demonstrate that Rad27 suppresses the accumulation of the TERRA-associated R-loop and selectively cleaves TERRA of R-loop and double-flapped structures in vitro. Moreover, we show that Rad27 negatively regulates single-stranded C-rich telomeric DNA circles (C-circles) in telomerase-deficient cells, revealing a close correlation between R-loop and C-circles during telomere recombination. These results demonstrate that Rad27 participates in telomere recombination by cleaving TERRA in the context of an R-loop or flapped RNA-DNA duplex, providing mechanistic insight into how Rad27 maintains chromosome stability by restricting the accumulation of the R-loop structure within the genome.


Asunto(s)
Endonucleasas de ADN Solapado , Estructuras R-Loop , Proteínas de Saccharomyces cerevisiae , ADN Helicasas/genética , ADN de Cadena Simple , Endonucleasas de ADN Solapado/genética , Endonucleasas de ADN Solapado/metabolismo , Recombinación Genética , ARN/genética , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Telómero/genética , Telómero/metabolismo
7.
Proc Natl Acad Sci U S A ; 119(32): e2204779119, 2022 08 09.
Artículo en Inglés | MEDLINE | ID: mdl-35914128

RESUMEN

Earlier work has shown that siRNA-mediated reduction of the SUPT4H or SUPT5H proteins, which interact to form the DSIF complex and facilitate transcript elongation by RNA polymerase II (RNAPII), can decrease expression of mutant gene alleles containing nucleotide repeat expansions differentially. Using luminescence and fluorescence assays, we identified chemical compounds that interfere with the SUPT4H-SUPT5H interaction and then investigated their effects on synthesis of mRNA and protein encoded by mutant alleles containing repeat expansions in the huntingtin gene (HTT), which causes the inherited neurodegenerative disorder, Huntington's Disease (HD). Here we report that such chemical interference can differentially affect expression of HTT mutant alleles, and that a prototypical chemical, 6-azauridine (6-AZA), that targets the SUPT4H-SUPT5H interaction can modify the biological response to mutant HTT gene expression. Selective and dose-dependent effects of 6-AZA on expression of HTT alleles containing nucleotide repeat expansions were seen in multiple types of cells cultured in vitro, and in a Drosophila melanogaster animal model for HD. Lowering of mutant HD protein and mitigation of the Drosophila "rough eye" phenotype associated with degeneration of photoreceptor neurons in vivo were observed. Our findings indicate that chemical interference with DSIF complex formation can decrease biochemical and phenotypic effects of nucleotide repeat expansions.


Asunto(s)
Azauridina , Proteína Huntingtina , Enfermedad de Huntington , Proteínas Mutantes , Mutación , Proteínas Nucleares , Fenotipo , Proteínas Represoras , Factores de Elongación Transcripcional , Alelos , Animales , Azauridina/farmacología , Células Cultivadas , Expansión de las Repeticiones de ADN , Modelos Animales de Enfermedad , Drosophila melanogaster/genética , Drosophila melanogaster/metabolismo , Humanos , Proteína Huntingtina/biosíntesis , Proteína Huntingtina/genética , Proteína Huntingtina/metabolismo , Enfermedad de Huntington/genética , Mediciones Luminiscentes , Proteínas Mutantes/biosíntesis , Proteínas Mutantes/genética , Proteínas Mutantes/metabolismo , Proteínas Nucleares/metabolismo , Células Fotorreceptoras de Invertebrados/efectos de los fármacos , Proteínas Represoras/metabolismo , Factores de Elongación Transcripcional/metabolismo
8.
Biochem Biophys Res Commun ; 707: 149768, 2024 May 07.
Artículo en Inglés | MEDLINE | ID: mdl-38489874

RESUMEN

DNA mismatch repair (MMR) is a crucial mechanism that ensures chromosome stability and prevents the development of various human cancers. Apart from its role in correcting mismatches during DNA replication, MMR also plays a significant role in regulating recombination between non-identical sequences, a process known as homeologous recombination. Telomeres, the protective ends of eukaryotic chromosomes, possess sequences that are not perfectly homologous. While telomerase primarily maintains telomere length in the yeast Saccharomyces cerevisiae, recombination between telomeres becomes a major pathway for length maintenance in cells lacking telomerase. This study investigates the participation of MMR in telomere recombination. Our findings reveal that mutations in MMR genes activate type I recombination. Notably, among the MMR proteins, MutSα (Msh2 and Msh6) and MutLα (Mlh1 and Pms1) exerted the most pronounced effects on telomere recombination. We also found that yeast cells containing simple human telomeric TTAGGG DNA sequences preferentially utilize type II recombination to maintain their telomeres, highlighting the influence of the heterogeneous nature of yeast telomeric sequences on type II recombination. Furthermore, our observations indicate that MMR activity is indispensable for its impact on telomere recombination. Collectively, these results contribute to a more comprehensive understanding of the role of MMR in telomere recombination.


Asunto(s)
Proteínas de Saccharomyces cerevisiae , Telomerasa , Humanos , Reparación de la Incompatibilidad de ADN/genética , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Telomerasa/genética , Telomerasa/metabolismo , Homeostasis del Telómero/genética , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Telómero/genética , Telómero/metabolismo
9.
FASEB J ; 37(12): e23300, 2023 12.
Artículo en Inglés | MEDLINE | ID: mdl-37997673

RESUMEN

Primary cilium is a specialized sensory organelle that transmits environmental information into cells. Its length is tightly controlled by various mechanisms such as the frequency or the cargo size of the intraflagellar transport trains which deliver the building materials such as tubulin subunits essential for the growing cilia. Here, we show the sialoglycan interacting galectin 8 regulates the process of primary ciliogenesis. As the epithelia become polarized, there are more galectin 8 being apically secreted and these extracellular galectin 8 molecules apparently bind to a lipid raft enriched domain at the base of the primary cilia through interacting with lipid raft components, such as GD3 ganglioside and scaffold protein caveolin 1. Furthermore, the binding of galectin 8 at this critical region triggers rapid growth of primary cilia by perturbing the barrier function of the transition zone (TZ). Our study also demonstrates the functionality of this barrier depends on intact organization of lipid rafts at the cilia as genetically knockout of Cav1 and pharmacologically inhibition of lipid raft both phenocopy the effect of apical addition of recombinant galectin 8; that is, rapid elongation of primary cilia and redistribution of cilia proteins from TZ to the growing axoneme. Indeed, as cilia elongated, endogenous galectin 8, caveolin 1, and TZ component, TMEM231, also transited from the TZ to the growing axoneme. We also noted that the interaction between caveolin 1 and TMEM231 could be perturbed by exogenous galectin 8. Taken together, we proposed that galectin 8 promoted primary cilia elongation through impeding the barrier function of the TZ by interfering with the interaction between caveolin 1 and TMEM231.


Asunto(s)
Caveolina 1 , Cilios , Caveolina 1/metabolismo , Cilios/metabolismo , Transporte Biológico , Tubulina (Proteína)/metabolismo , Microdominios de Membrana/metabolismo
10.
Ann Hematol ; 103(5): 1577-1586, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38532122

RESUMEN

Acute promyelocytic leukemia (APL) is a highly curable hematologic malignancy in the era of all-trans retinoic acid (ATRA) combination treatment. However, only a modest change in early mortality rate has been observed despite the wide availability of ATRA. In addition to the clinical characteristics of APL patients, studies on the hospital volume-outcome relationship and the physician volume-outcome relationship remained limited. We aim to evaluate the association between hospital and physician volume and the early mortality rate among APL patients. The patients were collected from Taiwan's National Health Insurance Research Database (NHIRD). Early mortality is defined as death within 30 days of diagnosis. Patients were categorized into four groups according to individual cumulative hospital and physician volume. The risk of all-cause mortality in APL patients with different cumulative volume groups was compared using a Cox proportional hazard model. The probability of overall survival was estimated using the Kaplan-Meier method. All 741 patients were divided into four quartile volume groups. In the multivariate analysis, only physician volume was significantly associated with early mortality rate. The physician volume of the highest quartile was a protective factor for early mortality compared with the physician volume of the lowest quartile (HR 0.10, 95% CI 0.02-0.65). Hospital characteristics were not associated with early mortality. In the sensitivity analyses, the results remained consistent using two other different definitions of early mortality. Higher physician volume was independently associated with lower early mortality, while hospital volume was not. Enhancing the clinical expertise of low-volume physicians may ensure better outcomes.


Asunto(s)
Leucemia Promielocítica Aguda , Humanos , Leucemia Promielocítica Aguda/diagnóstico , Leucemia Promielocítica Aguda/tratamiento farmacológico , Leucemia Promielocítica Aguda/complicaciones , Tretinoina/uso terapéutico , Modelos de Riesgos Proporcionales , Terapia Combinada , Resultado del Tratamiento
11.
Ann Hematol ; 2024 Mar 13.
Artículo en Inglés | MEDLINE | ID: mdl-38472362

RESUMEN

Multiple myeloma (MM) stands as the second most prevalent hematological malignancy, constituting approximately 10% of all hematological malignancies. Current guidelines recommend upfront autologous stem cell transplantation (ASCT) for transplant-eligible MM patients. This study seeks to delineate factors influencing post-ASCT outcomes in MM patients. Our cohort comprised 150 MM patients from Taipei Veterans General Hospital, with progression-free survival (PFS) as the primary endpoint and overall survival (OS) as the secondary endpoint. A Cox proportional hazards model was employed to discern potential predictive factors for survival. ASCT age ≥ 65 (hazard ratio [HR] 1.94, 95% confidence interval [CI] 1.08-3.47) and the presence of extramedullary disease (HR 2.53, 95% CI 1.53-4.19) negatively impacted PFS. Conversely, treatment response ≥ VGPR before ASCT (HR 0.52, 95% CI 0.31-0.87) and total CD34+ cells collected ≥ 4 × 106 cells/kg on the first stem cell harvesting (HR 0.52, 95% CI 0.32-0.87) were positively associated with PFS. For OS, patients with ISS stage III (HR 2.06, 95% CI 1.05-4.04), the presence of extramedullary disease (HR 3.92, 95% CI 2.03-7.58), light chain ratio ≥ 100 before ASCT (HR 7.08, 95% CI 1.45-34.59), post-ASCT cytomegalovirus infection (HR 9.43, 95% CI 3.09-28.84), and a lower conditioning melphalan dose (< 140 mg/m2; HR 2.75, 95% CI 1.23-6.17) experienced shorter OS. In contrast, post-ASCT day + 15 absolute monocyte counts (D15 AMC) > 500/µl (HR 0.36, 95% CI 0.17-0.79) and post-ASCT day + 15 platelet counts (D15 PLT) > 80,000/µl (HR 0.48, 95% CI 0.24-0.94) were correlated with improved OS. Significantly, early PLT and AMC recovery on day + 15 predicting longer OS represents a novel finding not previously reported. Other factors also align with previous studies. Our study provides real-world insights for post-ASCT outcome prediction beyond clinical trials.

12.
Pediatr Blood Cancer ; 71(7): e30983, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38605509

RESUMEN

BACKGROUND: Neuroblastoma varies widely in risk. Risk indicators in infants with incidental neuroblastoma refine treatment confidence for observation or intervention. The potential of functional imaging, particularly PET/CT, remains to be defined. PROCEDURE: A retrospective review of infants under 18 months diagnosed with incidental neuroblastoma from 2008 to May 2022 in our institute was conducted. Before October 2015, incidental patients were treated similarly to symptomatic cases, undergoing biopsy or surgical excision upon diagnosis (early cohort). Post October 2015 (late cohort), treatment decisions were guided by PET/CT findings, with 18F-DOPA PET/CT confirming diagnosis and staging. For tumors with low 18F-FDG uptake, an expectant observation approach was considered. Patient characteristics, diagnostic methods, image findings at diagnosis, treatment courses, and responses were compared between cohorts. RESULTS: Thirty infants less than 18 months were identified with incidental neuroblastoma and completed PET/CT at diagnosis. The early and late cohorts each comprised 15 patients. In the late cohort, nine out of 15 patients (60%) presented with localized FDG non-avid tumors were offered the option of expectant observation. Of these, seven patients opted for observation, thereby avoiding surgery. Treatment outcomes were comparable between early and late cohorts, except for one mortality of a patient who, despite showing 18F-FDG activity, declined treatment. CONCLUSIONS: This study demonstrates the potential utility of 18F-DOPA and 18F-FDG PET/CT scans in aiding clinical decision-making for infants with localized, incidental neuroblastoma. Given the concerns regarding radiation exposure, such imaging may be valuable for cases with suspected metastasis, initial large tumor size, or growth during follow-up.


Asunto(s)
Dihidroxifenilalanina , Fluorodesoxiglucosa F18 , Neuroblastoma , Tomografía Computarizada por Tomografía de Emisión de Positrones , Radiofármacos , Humanos , Neuroblastoma/diagnóstico por imagen , Neuroblastoma/terapia , Neuroblastoma/patología , Lactante , Masculino , Femenino , Tomografía Computarizada por Tomografía de Emisión de Positrones/métodos , Estudios Retrospectivos , Dihidroxifenilalanina/análogos & derivados , Recién Nacido , Hallazgos Incidentales , Estudios de Factibilidad , Estudios de Seguimiento , Toma de Decisiones Clínicas , Pronóstico
13.
Inorg Chem ; 63(8): 3735-3748, 2024 Feb 26.
Artículo en Inglés | MEDLINE | ID: mdl-38335260

RESUMEN

Cu2Se-based thermoelectric materials exhibit high dimensionless figure of merit (zT) values at elevated temperatures (900-1000 K) but relatively lower zT values at intermediate temperatures, approximately 500 K. We synthesized a series of polycrystalline Cu2Se0.96Te0.04-xIx/Cu2O composites (where x = 0.00, 0.01, 0.02, and 0.03) using an energy-efficient synthesis method conducted at room temperature, followed by heat treatment at 923 K for 6 h. X-ray diffraction (XRD) analysis confirmed the monoclinic crystal structure of the α phase. The introduction of iodine doping at Te sites introduced electron carriers to p-type Cu2Se0.96Te0.04, reducing the hole carrier concentration. Consequently, the electrical resistivity increased, and the thermopower exhibited a significant increase. The incorporation of electron carriers into the p-type Cu2Se0.96Te0.04/Cu2O composites resulted in an enhanced power factor within the medium-temperature range. Specifically, at 500 K, the Cu2Se0.96Te0.02I0.02/Cu2O (x = 0.02) composites demonstrated the highest power factor among the series of Cu2Se0.96Te0.04-xIx/Cu2O composites, measuring 9.1 µW cm-1 K-2. According to the weighted mobility analysis, it is clear that the x = 0.02 composite possesses the optimal carrier concentration, which accounts for its superior power factor compared to the other composites in the series. Furthermore, the Cu2Se0.96Te0.02I0.02/Cu2O composites and Cu2Se0.96Te0.04/Cu2O composites displayed zT values of 0.49 and 0.33, respectively, at 550 K. Additionally, iodine doping led to an enhancement in the average zT values between 450 and 550 K. Therefore, electron doping in p-type materials presents itself as a viable strategy for shifting the operating temperature of a thermoelectric device from high to medium temperature. We successfully fabricated a thermoelectric generator comprising 6 pairs of p-leg Cu2Se0.96Te0.02I0.02/Cu2O composites and n-leg InSb0.94Bi0.06. This TEG achieved impressive results, including a maximum output voltage, power output, power density, and efficiency of 0.115 V, 10.6 µW, 35.1 µW cm-2, and 1.74% at a temperature difference (ΔT) of 120 K.

14.
Mol Biol Rep ; 51(1): 637, 2024 May 10.
Artículo en Inglés | MEDLINE | ID: mdl-38727927

RESUMEN

BACKGROUND: Retinal pigment epithelial cells (RPECs) are a type of retinal cells that structurally and physiologically support photoreceptors. However, hyperglycemia has been shown to play a critical role in the progression of diabetic retinopathy (DR), which is one of the leading causes of vision impairment. In the diabetic eye, the high glucose environment damages RPECs via the induction of oxidative stress, leading to the release of excess reactive oxygen species (ROS) and triggering apoptosis. In this study, we aim to investigate the antioxidant mechanism of Vitamin C in reducing hyperglycemia-induced stress and whether this mechanism can preserve the function of RPECs. METHODS AND RESULTS: ARPE-19 cells were treated with high glucose in the presence or absence of Vitamin C. Cell viability was measured by MTT assay. Cleaved poly ADP-ribose polymerase (PARP) was used to identify apoptosis in the cells. ROS were detected by the DCFH-DA reaction. The accumulation of sorbitol in the aldose reductase (AR) polyol pathway was determined using the sorbitol detection assay. Primary mouse RPECs were isolated from adult mice and identified by Rpe65 expression. The mitochondrial damage was measured by mitochondrial membrane depolarization. Our results showed that high glucose conditions reduce cell viability in RPECs while Vitamin C can restore cell viability, compared to the vehicle treatment. We also demonstrated that Vitamin C reduces hyperglycemia-induced ROS production and prevents cell apoptosis in RPECs in an AR-independent pathway. CONCLUSIONS: These results suggest that Vitamin C is not only a nutritional necessity but also an adjuvant that can be combined with AR inhibitors for alleviating hyperglycemic stress in RPECs.


Asunto(s)
Apoptosis , Ácido Ascórbico , Supervivencia Celular , Glucosa , Hiperglucemia , Estrés Oxidativo , Especies Reactivas de Oxígeno , Epitelio Pigmentado de la Retina , Ácido Ascórbico/farmacología , Ácido Ascórbico/metabolismo , Epitelio Pigmentado de la Retina/metabolismo , Epitelio Pigmentado de la Retina/efectos de los fármacos , Hiperglucemia/metabolismo , Hiperglucemia/tratamiento farmacológico , Hiperglucemia/complicaciones , Animales , Especies Reactivas de Oxígeno/metabolismo , Ratones , Estrés Oxidativo/efectos de los fármacos , Apoptosis/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Glucosa/metabolismo , Humanos , Línea Celular , Células Epiteliales/metabolismo , Células Epiteliales/efectos de los fármacos , Retinopatía Diabética/metabolismo , Retinopatía Diabética/tratamiento farmacológico , Antioxidantes/farmacología , Antioxidantes/metabolismo , Mitocondrias/metabolismo , Mitocondrias/efectos de los fármacos
15.
BMC Geriatr ; 24(1): 558, 2024 Jun 26.
Artículo en Inglés | MEDLINE | ID: mdl-38918715

RESUMEN

BACKGROUND: Quantifying the informal caregiver burden is important for understanding the risk factors associated with caregiver overload and for evaluating the effectiveness of services provided in Long-term Care (LTC). OBJECTIVE: This study aimed to develop and validate a Caregiver Strain Index (CSI)-based score for quantifying the informal caregiver burden, while the original dataset did not fully cover evaluation items commonly included in international assessments. Subsequently, we utilized the CSI-based score to pinpoint key caregiver burden risk factors, examine the initial timing of LTC services adoption, and assess the impact of LTC services on reducing caregiver burden. METHODS: The study analyzed over 28,000 LTC cases in Southern Taiwan from August 2019 to December 2022. Through multiple regression analysis, we identified significant risk factors associated with caregiver burden and examined changes in this burden after utilizing various services. Survival analysis was employed to explore the relationship between adopting the first LTC services and varying levels of caregiver burden. RESULTS: We identified 126 significant risk factors for caregiver burden. The most critical factors included caregiving for other disabled family members or children under the age of three (ß = 0.74, p < 0.001), the employment status of the caregiver (ß = 0.30-0.53, p < 0.001), the frailty of the care recipient (ß = 0.28-0.31, p < 0.001), and the behavioral symptoms of dementia in care recipients (ß = 0.28-2.60, p < 0.05). Generally, caregivers facing higher burdens sought LTC services earlier, and providing home care services alleviated the caregiver's burden. CONCLUSION: This comprehensive study suggests policy refinements to recognize high-risk caregivers better early and provide timely support to improve the overall well-being of both informal caregivers and care recipients.


Asunto(s)
Carga del Cuidador , Cuidadores , Cuidados a Largo Plazo , Humanos , Taiwán/epidemiología , Masculino , Femenino , Carga del Cuidador/psicología , Anciano , Cuidadores/psicología , Cuidados a Largo Plazo/métodos , Persona de Mediana Edad , Factores de Riesgo , Anciano de 80 o más Años , Estrés Psicológico/psicología , Estrés Psicológico/epidemiología , Adulto
16.
Curr Heart Fail Rep ; 21(3): 262-275, 2024 06.
Artículo en Inglés | MEDLINE | ID: mdl-38485860

RESUMEN

PURPOSE OF REVIEW: Cardiac fibrosis is a crucial juncture following cardiac injury and a precursor for many clinical heart disease manifestations. Epigenetic modulators, particularly non-coding RNAs (ncRNAs), are gaining prominence as diagnostic and therapeutic tools. RECENT FINDINGS: miRNAs are short linear RNA molecules involved in post-transcriptional regulation; lncRNAs and circRNAs are RNA sequences greater than 200 nucleotides that also play roles in regulating gene expression through a variety of mechanisms including miRNA sponging, direct interaction with mRNA, providing protein scaffolding, and encoding their own products. NcRNAs have the capacity to regulate one another and form sophisticated regulatory networks. The individual roles and disease relevance of miRNAs, lncRNAs, and circRNAs to cardiac fibrosis have been increasingly well described, though the complexity of their interrelationships, regulatory dynamics, and context-specific roles needs further elucidation. This review provides an overview of select ncRNAs relevant in cardiac fibrosis as a surrogate for many cardiac disease states with a focus on crosstalk and regulatory networks, variable actions among different disease states, and the clinical implications thereof. Further, the clinical feasibility of diagnostic and therapeutic applications as well as the strategies underway to advance ncRNA theranostics is explored.


Asunto(s)
Fibrosis , ARN no Traducido , Humanos , Fibrosis/genética , ARN no Traducido/genética , Miocardio/patología , Miocardio/metabolismo , ARN Largo no Codificante/genética , MicroARNs/genética , Cardiopatías/diagnóstico , Cardiopatías/genética , Biomarcadores/metabolismo , Regulación de la Expresión Génica
17.
Eur Heart J ; 44(45): 4796-4807, 2023 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-37585426

RESUMEN

BACKGROUND AND AIMS: Patients with left-sided breast cancer receive a higher mean heart dose (MHD) after radiotherapy, with subsequent risk of ischaemic heart disease. However, the optimum dosimetric predictor among cardiac substructures has not yet been determined. METHODS AND RESULTS: This study retrospectively reviewed 2158 women with breast cancer receiving adjuvant radiotherapy. The primary endpoint was a major ischaemic event. The dose-volume parameters of each delineated cardiac substructure were calculated. The risk factors for major ischaemic events and the association between MHD and major ischaemic events were analysed by Cox regression. The optimum dose-volume predictors among cardiac substructures were explored in multivariable models by comparing performance metrics of each model. At a median follow-up of 7.9 years (interquartile range 5.6-10.8 years), 89 patients developed major ischaemic events. The cumulative incidence rate of major ischaemic events was significantly higher in left-sided disease (P = 0.044). Overall, MHD increased the risk of major ischaemic events by 6.2% per Gy (hazard ratio 1.062, 95% confidence interval 1.01-1.12; P = 0.012). The model containing the volume of the left ventricle receiving 25 Gy (LV V25) with the cut-point of 4% presented with the best goodness of fit and discrimination performance in left-sided breast cancer. Age, chronic kidney disease, and hyperlipidaemia were also significant risk factors. CONCLUSION: Risk of major ischaemic events exist in the era of modern radiotherapy. LV V25 ≥ 4% appeared to be the optimum parameter and was superior to MHD in predicting major ischaemic events. This dose constraint could aid in achieving better heart protection in breast cancer radiotherapy, though a further validation study is warranted.


Asunto(s)
Neoplasias de la Mama , Neoplasias de Mama Unilaterales , Femenino , Humanos , Neoplasias de Mama Unilaterales/radioterapia , Estudios Retrospectivos , Neoplasias de la Mama/radioterapia , Dosificación Radioterapéutica , Corazón , Dosis de Radiación
18.
J Formos Med Assoc ; 2024 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-38307800

RESUMEN

OBJECTIVES: Exosomes are membrane vesicles that are actively secreted in response to microenvironmental stimuli. In this study, we quantified the amount of exosomes in patients with significant coronary artery disease (CAD) and evaluated its relationship with myocardial perfusion imaging (MPI) results. METHODS: Patients who underwent both MPI and coronary angiography were recruited. Plasma was collected during angiography, and exosomes were extracted via the precipitation method. The summed stress scores (SSS), summed difference scores, and ventricular functional parameters were calculated from the MPI and compared with the amounts of exosomes and extracted miRNAs. RESULTS: In total, 115 patients were enrolled (males: 78 %; mean age: 66.6 ± 10.6 years). Those with abnormal SSS according to the MPI had significantly fewer exosomes (p = 0.032). After multivariate analysis, the SSS remained significantly related to the amount of exosomes (p = 0.035). In forty randomly selected samples, miRNA-432-5p and miRNA-382-3p were upregulated in patients with abnormal SSS. CONCLUSIONS: Patients with compromised poststress myocardial perfusion on MPI tended to have fewer exosomes in association with CAD-related miRNAs. This is the first study to clarify the fundamental and pathophysiological causes of CAD using radiographic examinations.

19.
Alzheimers Dement ; 2024 Jul 19.
Artículo en Inglés | MEDLINE | ID: mdl-39031528

RESUMEN

INTRODUCTION: The apolipoprotein E gene (APOE) is an established central player in the pathogenesis of Alzheimer's disease (AD), with distinct apoE isoforms exerting diverse effects. apoE influences not only amyloid-beta and tau pathologies but also lipid and energy metabolism, neuroinflammation, cerebral vascular health, and sex-dependent disease manifestations. Furthermore, ancestral background may significantly impact the link between APOE and AD, underscoring the need for more inclusive research. METHODS: In 2023, the Alzheimer's Association convened multidisciplinary researchers at the "AAIC Advancements: APOE" conference to discuss various topics, including apoE isoforms and their roles in AD pathogenesis, progress in apoE-targeted therapeutic strategies, updates on disease models and interventions that modulate apoE expression and function. RESULTS: This manuscript presents highlights from the conference and provides an overview of opportunities for further research in the field. DISCUSSION: Understanding apoE's multifaceted roles in AD pathogenesis will help develop targeted interventions for AD and advance the field of AD precision medicine. HIGHLIGHTS: APOE is a central player in the pathogenesis of Alzheimer's disease. APOE exerts a numerous effects throughout the brain on amyloid-beta, tau, and other pathways. The AAIC Advancements: APOE conference encouraged discussions and collaborations on understanding the role of APOE.

20.
Alzheimers Dement ; 20(3): 2058-2071, 2024 03.
Artículo en Inglés | MEDLINE | ID: mdl-38215053

RESUMEN

INTRODUCTION: Clinical research in Alzheimer's disease (AD) lacks cohort diversity despite being a global health crisis. The Asian Cohort for Alzheimer's Disease (ACAD) was formed to address underrepresentation of Asians in research, and limited understanding of how genetics and non-genetic/lifestyle factors impact this multi-ethnic population. METHODS: The ACAD started fully recruiting in October 2021 with one central coordination site, eight recruitment sites, and two analysis sites. We developed a comprehensive study protocol for outreach and recruitment, an extensive data collection packet, and a centralized data management system, in English, Chinese, Korean, and Vietnamese. RESULTS: ACAD has recruited 606 participants with an additional 900 expressing interest in enrollment since program inception. DISCUSSION: ACAD's traction indicates the feasibility of recruiting Asians for clinical research to enhance understanding of AD risk factors. ACAD will recruit > 5000 participants to identify genetic and non-genetic/lifestyle AD risk factors, establish blood biomarker levels for AD diagnosis, and facilitate clinical trial readiness. HIGHLIGHTS: The Asian Cohort for Alzheimer's Disease (ACAD) promotes awareness of under-investment in clinical research for Asians. We are recruiting Asian Americans and Canadians for novel insights into Alzheimer's disease. We describe culturally appropriate recruitment strategies and data collection protocol. ACAD addresses challenges of recruitment from heterogeneous Asian subcommunities. We aim to implement a successful recruitment program that enrolls across three Asian subcommunities.


Asunto(s)
Enfermedad de Alzheimer , Pueblos de América del Norte , Humanos , Enfermedad de Alzheimer/genética , Proyectos Piloto , Asiático/genética , Canadá , Factores de Riesgo
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