Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 351
Filtrar
1.
Proc (Bayl Univ Med Cent) ; 37(5): 858-861, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39165813

RESUMEN

An 83-year-old man with a history of monoclonal gammopathy of unknown significance, macrocytic anemia, and cytopenias presented with hemorrhagic bullae on his left hand, alongside intermittent fevers and joint pain. Laboratory findings indicated anemia, elevated mean corpuscular volume, thrombocytopenia, leukopenia, and a high C-reactive protein level. A biopsy of the bullae showed neutrophilic dermatosis, and computed tomography scans of the thorax revealed lung opacities and mediastinal lymphadenopathy, suggesting neutrophilic alveolitis. Bone marrow examination found hypercellularity with myeloid and histiocytic hyperplasia, vacuolated precursors, and 3% blasts of an immature myelomonocytic lineage. Genetic testing uncovered a UBA1 mutation at an 81% allele frequency, confirming a diagnosis of VEXAS syndrome. Treatment commenced with prednisone, initiated at 60 mg daily and tapered to 10 mg, with tocilizumab considered for future symptom management. This regimen has successfully maintained remission, as observed in follow-up appointments. This case highlights the diagnostic complexity and effective management of VEXAS syndrome, underscoring the importance of genetic testing in guiding treatment decisions.


VEXAS syndrome, initially identified in 2020, is a rare disease characterized by overlapping hematologic and rheumatologic conditions, primarily affecting middle-aged to older men.Our case presents a unique instance of VEXAS syndrome, featuring inflammatory symptoms alongside pancytopenia and a history of monoclonal gammopathy of unknown significance, highlighting the diverse clinical spectrum of this condition.The diagnosis was confirmed through bone marrow biopsy revealing vacuoles in myeloid precursors and a UBA1 mutation, reaffirming the diagnostic criteria outlined for VEXAS syndrome.Management challenges persist, with current treatment options limited to glucocorticoids for symptomatic relief, underscoring the need for further research into targeted therapies such as ruxolitinib to improve patient outcomes.

2.
Autophagy ; : 1-13, 2024 Aug 31.
Artículo en Inglés | MEDLINE | ID: mdl-39216469

RESUMEN

The WD40 domain (WDD) of ATG16L1 plays a pivotal role in non-canonical autophagy. This study examined the role of recently identified LAP-like non-canonical autophagy (LNCA) in acute pancreatitis. LNCA involves rapid single-membrane LC3 conjugation to endocytic vacuoles in pancreatic acinar cells. The rationale for this study was the previously observed presence of trypsin in the organelles undergoing LNCA; aberrant trypsin formation is an important factor in pancreatitis development. Here we report that the deletion of WDD (attained in ATG16L1[E230] mice) eliminated LNCA, aggravated caerulein-induced acute pancreatitis and suppressed the fast trypsin degradation observed in both a rapid caerulein-induced disease model and in caerulein-treated isolated pancreatic acinar cells. These experiments indicate that LNCA is a WDD-dependent mechanism and suggest that it plays not an activating but a protective role in acute pancreatitis. Furthermore, palmitoleic acid, another inducer of experimental acute pancreatitis, strongly inhibited LNCA, suggesting a novel mechanism of pancreatic lipotoxicity.Abbreviation: AMY: amylase; AP: acute pancreatitis; CASM: conjugation of Atg8 to single membranes; CCK: cholecystokinin; FAEE model: fatty acid and ethanol model; IL6: interleukin 6; LA: linoleic acid; LAP: LC3-associated phagocytosis; LMPO: lung myeloperoxidase; LNCA: LAP-like non-canonical autophagy; MAP1LC3/LC3: microtubule-associated protein 1 light chain 3; MPO: myeloperoxidase; PMPO: pancreatic myeloperoxidase; POA: palmitoleic acid; WDD: WD40 domain; WT: wild type.

3.
Neuromuscul Disord ; 42: 43-52, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39142003

RESUMEN

TIA1/SQSTM1 myopathy is one of the few digenic myopathies. We describe four new French adult male patients carrying the TIA1 p.Asn357Ser and SQSTM1 p.Pro392Leu variant and review the literature to include 20 additional cases to define the spectrum of the disease. These twenty-four patients (75% males) had late-onset (52,6 ± 10,1 years), mainly asymmetric, distal ankle and hand finger extension weakness (75%), mild CK elevation (82.4%) and myopathic EMG. Two of the four French patients had sensorimotor axonal polyneuropathy and an additional one had neurogenic changes in muscle biopsy. Muscle biopsy showed rimmed vacuoles (44.4%), myofibrillar disorganization (16.7%) or both (38.9%), with P62/TDP43 aggregates. The TIA1 p.Asn357Ser variant was present in all patients and the SQSTM1 p.Pro392Leu was the most frequent (71%) of the four reported SQSTM1 variants. We reviewed the distal myopathy gene panels of Pitié-Salpêtrière's hospital cohort finding a prevalence of 11/414=2.7% of the TIA1 p.Asn357Ser variant, with two patients having an alternative diagnosis (TTN and MYH7) with atypical phenotypes, resembling some of the features seen in TIA1/SQSTM1 myopathy. Overall, TIA1/SQSTM1 myopathy has a homogenous phenotype reinforcing the pathogenicity of its digenic variants. We confirm an increased burden of the TIA1 p.Asn357Ser variant in distal myopathy patients which could act as a genetic modifier.


Asunto(s)
Miopatías Distales , Proteína Sequestosoma-1 , Antígeno Intracelular 1 de las Células T , Humanos , Proteína Sequestosoma-1/genética , Masculino , Persona de Mediana Edad , Antígeno Intracelular 1 de las Células T/genética , Miopatías Distales/genética , Miopatías Distales/patología , Adulto , Músculo Esquelético/patología , Anciano , Femenino , Mutación , Fenotipo
4.
Methods Mol Biol ; 2839: 3-29, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39008245

RESUMEN

Over the past 30 years, much has been learned regarding iron homeostatic regulation in budding yeast, S. cerevisiae, including the identity of many of the proteins and molecular-level regulatory mechanisms involved. Most advances have involved inferring such mechanisms based on the analysis of iron-dysregulation phenotypes arising in various genetic mutant strains. Still lacking is a cellular- or system-level understanding of iron homeostasis. These experimental advances are summarized in this review, and a method for developing cellular-level regulatory mechanisms in yeast is presented. The method employs the results of Mössbauer spectroscopy of whole cells and organelles, iron quantification of the same, and ordinary differential equation-based mathematical models. Current models are simplistic when compared to the complexity of iron homeostasis in real cells, yet they hold promise as a useful, perhaps even required, complement to the popular genetics-based approach. The fundamental problem in comprehending cellular regulatory mechanisms is that, given the complexities involved, different molecular-level mechanisms can often give rise to virtually indistinguishable cellular phenotypes. Mathematical models cannot eliminate this problem, but they can minimize it.


Asunto(s)
Homeostasis , Hierro , Saccharomyces cerevisiae , Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/genética , Hierro/metabolismo , Simulación por Computador , Modelos Biológicos , Espectroscopía de Mossbauer/métodos , Proteínas de Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética
5.
Muscle Nerve ; 2024 Jul 28.
Artículo en Inglés | MEDLINE | ID: mdl-39072769

RESUMEN

INTRODUCTION/AIMS: Heterogeneous nuclear ribonucleoprotein A1 is involved in nucleic acid homeostatic functions. The encoding gene HNRNPA1 has been associated with several neuromuscular disorders including an amyotrophic lateral sclerosis-like phenotype, distal hereditary motor neuropathy, multisystem proteinopathy, and various myopathies. We report two unrelated individuals with monoallelic stop loss variants affecting the same codon of HNRNPA1. METHODS: Two individuals with unsolved juvenile-onset myopathy were enrolled under approved institutional protocols. Phenotype data were collected and genetic analyses were performed, including whole-exome sequencing (WES). RESULTS: The two probands (MNOT002-01 and K1440-01) showed a similar onset of slowly progressive extremity and facial weakness in early adolescence. K1440-01 presented with facial weakness, winged scapula, elevated serum creatine kinase (CK) levels, and mild neck weakness. MNOT002-01 also exhibited elevated CK levels along with facial weakness, cardiomyopathy, respiratory dysfunction, pectus excavatum, a mildly rigid spine, and loss of ambulation. On quadriceps muscle biopsy, K1440-01 displayed rounded myofibers, mild variation in fiber diameter, and type 2 fiber hypertrophy, while MNOT002-01 displayed rimmed vacuoles. Monoallelic stop-loss variants in HNRNPA1 were identified for both probands: c.1119A>C p.*373Tyrext*6 (K1440-01) and c.1118A>C p.*373Serext*6 (MNOT002-01) affect the same codon and are both predicted to lead to the addition of six amino acids before termination at an alternative stop codon. DISCUSSION: Both stop-loss variants in our probands are likely pathogenic. Our findings contribute to the disease characterization of pathogenic variants in HNRNPA1. This gene should be screened in clinical diagnostic testing of unsolved cases of sporadic or dominant juvenile-onset myopathy.

6.
Int J Mol Sci ; 25(12)2024 Jun 14.
Artículo en Inglés | MEDLINE | ID: mdl-38928252

RESUMEN

Inclusion body myositis (IBM) is a slowly progressive disorder belonging to the idiopathic inflammatory myopathies, and it represents the most common adult-onset acquired myopathy. The main clinical features include proximal or distal muscular asymmetric weakness, with major involvement of long finger flexors and knee extensors. The main histological findings are the presence of fiber infiltrations, rimmed vacuoles, and amyloid inclusions. The etiopathogenesis is a challenge because both environmental and genetic factors are implicated in muscle degeneration and a distinction has been made previously between sporadic and hereditary forms. Here, we describe an Italian patient affected with a hereditary form of IBM with onset in his mid-forties. Next-generation sequencing analysis disclosed a heterozygous mutation c.76C>T (p.Pro26Ser) in the PDZ motif of the LDB3/ZASP gene, a mutation already described in a family with a late-onset myopathy and highly heterogenous degree of skeletal muscle weakness. In the proband's muscle biopsy, the expression of ZASP, myotilin, and desmin were increased. In our family, in addition to the earlier age of onset, the clinical picture is even more peculiar given the evidence, in one of the affected family members, of complete ophthalmoplegia in the vertical gaze. These findings help extend our knowledge of the clinical and genetic background associated with inclusion body myopathic disorders.


Asunto(s)
Proteínas con Dominio LIM , Miositis por Cuerpos de Inclusión , Linaje , Humanos , Miositis por Cuerpos de Inclusión/genética , Miositis por Cuerpos de Inclusión/patología , Masculino , Proteínas con Dominio LIM/genética , Proteínas con Dominio LIM/metabolismo , Proteínas Adaptadoras Transductoras de Señales/genética , Persona de Mediana Edad , Músculo Esquelético/patología , Músculo Esquelético/metabolismo , Mutación , Adulto
7.
Acta Neuropathol Commun ; 12(1): 99, 2024 06 17.
Artículo en Inglés | MEDLINE | ID: mdl-38886865

RESUMEN

Filaments made of residues 120-254 of transmembrane protein 106B (TMEM106B) form in an age-dependent manner and can be extracted from the brains of neurologically normal individuals and those of subjects with a variety of neurodegenerative diseases. TMEM106B filament formation requires cleavage at residue 120 of the 274 amino acid protein; at present, it is not known if residues 255-274 form the fuzzy coat of TMEM106B filaments. Here we show that a second cleavage appears likely, based on staining with an antibody raised against residues 263-274 of TMEM106B. We also show that besides the brain TMEM106B inclusions form in dorsal root ganglia and spinal cord, where they were mostly found in non-neuronal cells. We confirm that in the brain, inclusions were most abundant in astrocytes. No inclusions were detected in heart, liver, spleen or hilar lymph nodes. Based on their staining with luminescent conjugated oligothiophenes, we confirm that TMEM106B inclusions are amyloids. By in situ immunoelectron microscopy, TMEM106B assemblies were often found in structures resembling endosomes and lysosomes.


Asunto(s)
Proteínas de la Membrana , Proteínas del Tejido Nervioso , Proteínas de la Membrana/metabolismo , Humanos , Proteínas del Tejido Nervioso/metabolismo , Médula Espinal/metabolismo , Amiloide/metabolismo , Ganglios Espinales/metabolismo , Encéfalo/metabolismo , Masculino , Femenino , Sistema Nervioso Periférico/metabolismo , Anciano , Animales
8.
Virulence ; 15(1): 2350893, 2024 12.
Artículo en Inglés | MEDLINE | ID: mdl-38725096

RESUMEN

Coxiella burnetii (C. burnetii) is the causative agent of Q fever, a zoonotic disease. Intracellular replication of C. burnetii requires the maturation of a phagolysosome-like compartment known as the replication permissive Coxiella-containing vacuole (CCV). Effector proteins secreted by the Dot/Icm secretion system are indispensable for maturation of a single large CCV by facilitating the fusion of promiscuous vesicles. However, the mechanisms of CCV maintenance and evasion of host cell clearance remain to be defined. Here, we show that C. burnetii secreted Coxiella vacuolar protein E (CvpE) contributes to CCV biogenesis by inducing lysosome-like vacuole (LLV) enlargement. LLV fission by tubulation and autolysosome degradation is impaired in CvpE-expressing cells. Subsequently, we found that CvpE suppresses lysosomal Ca2+ channel transient receptor potential channel mucolipin 1 (TRPML1) activity in an indirect manner, in which CvpE binds phosphatidylinositol 3-phosphate [PI(3)P] and perturbs PIKfyve activity in lysosomes. Finally, the agonist of TRPML1, ML-SA5, inhibits CCV biogenesis and C. burnetii replication. These results provide insight into the mechanisms of CCV maintenance by CvpE and suggest that the agonist of TRPML1 can be a novel potential treatment that does not rely on antibiotics for Q fever by enhancing Coxiella-containing vacuoles (CCVs) fission.


Asunto(s)
Proteínas Bacterianas , Coxiella burnetii , Lisosomas , Fosfatidilinositol 3-Quinasas , Fosfatos de Fosfatidilinositol , Canales de Potencial de Receptor Transitorio , Vacuolas , Animales , Humanos , Proteínas Bacterianas/metabolismo , Proteínas Bacterianas/genética , Coxiella burnetii/metabolismo , Coxiella burnetii/crecimiento & desarrollo , Coxiella burnetii/genética , Células HeLa , Interacciones Huésped-Patógeno , Lisosomas/metabolismo , Lisosomas/microbiología , Fosfatidilinositol 3-Quinasas/metabolismo , Fosfatos de Fosfatidilinositol/metabolismo , Fiebre Q/microbiología , Canales de Potencial de Receptor Transitorio/metabolismo , Canales de Potencial de Receptor Transitorio/genética , Vacuolas/microbiología , Vacuolas/metabolismo
9.
Plant Physiol Biochem ; 210: 108653, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38670029

RESUMEN

Edible plant seeds provide a relatively inexpensive source of protein and make up a large part of nutrients for humans. Plant seeds accumulate storage proteins during seed development. Seed storage proteins act as a reserve of nutrition for seed germination and seedling growth. However, seed storage proteins may be allergenic, and the prevalence of food allergy has increased rapidly in recent years. The 11S globulins account for a significant number of known major food allergens. They are of interest to the public and the agricultural industry because of food safety concerns and the need for crop enhancement. We sought to determine the crystal structure of Cor a 9, the 11 S storage protein of hazelnut and a food allergen. The structure was refined to 1.92 Å, and the R and Rfree for the refined structure are 17.6% and 22.5%, respectively. The structure of Cor a 9 showed a hetero hexamer of an 11S seed storage protein for the first time. The hexamer was two trimers associated back-to-back. Two long alpha helixes at the C-terminal end of the acidic domain of one of the Cor a 9 isoforms lay at the trimer-trimer interface's groove. These data provided much-needed information about the allergenicity of the 11S seed proteins. The information may also facilitate a better understanding of the folding and transportation of 11S seed storage proteins.


Asunto(s)
Corylus , Proteínas de Almacenamiento de Semillas , Corylus/química , Corylus/metabolismo , Proteínas de Almacenamiento de Semillas/química , Proteínas de Almacenamiento de Semillas/metabolismo , Cristalografía por Rayos X , Semillas/metabolismo , Semillas/química , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Globulinas/química , Globulinas/metabolismo , Secuencia de Aminoácidos , Multimerización de Proteína , Modelos Moleculares
10.
Plant Sci ; 344: 112090, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38636812

RESUMEN

Vacuoles are the largest membrane-bound organelles in plant cells, critical for development and environmental responses. Vacuolar dynamics indicate reversible changes of vacuoles in morphology, size, or numbers. In this review, we summarize current understandings of vacuolar dynamics in different types of plant cells, biological processes associated with vacuolar dynamics, and regulators controlling vacuolar dynamics. Specifically, we point out the possibility that vacuolar dynamics play key roles in cell division and differentiation, which are controlled by the nucleus. Finally, we propose three routes through which vacuolar dynamics actively participate in nucleus-controlled cellular activities.


Asunto(s)
Diferenciación Celular , División Celular , Células Vegetales , Vacuolas , Vacuolas/metabolismo , Vacuolas/fisiología , División Celular/fisiología , Células Vegetales/fisiología , Núcleo Celular/fisiología , Núcleo Celular/metabolismo
11.
BMC Biol ; 22(1): 100, 2024 Apr 29.
Artículo en Inglés | MEDLINE | ID: mdl-38679707

RESUMEN

BACKGROUND: Plant pathogens secrete effector proteins into host cells to suppress immune responses and manipulate fundamental cellular processes. One of these processes is autophagy, an essential recycling mechanism in eukaryotic cells that coordinates the turnover of cellular components and contributes to the decision on cell death or survival. RESULTS: We report the characterization of AVH195, an effector from the broad-spectrum oomycete plant pathogen, Phytophthora parasitica. We show that P. parasitica expresses AVH195 during the biotrophic phase of plant infection, i.e., the initial phase in which host cells are maintained alive. In tobacco, the effector prevents the initiation of cell death, which is caused by two pathogen-derived effectors and the proapoptotic BAX protein. AVH195 associates with the plant vacuolar membrane system and interacts with Autophagy-related protein 8 (ATG8) isoforms/paralogs. When expressed in cells from the green alga, Chlamydomonas reinhardtii, the effector delays vacuolar fusion and cargo turnover upon stimulation of autophagy, but does not affect algal viability. In Arabidopsis thaliana, AVH195 delays the turnover of ATG8 from endomembranes and promotes plant susceptibility to P. parasitica and the obligate biotrophic oomycete pathogen Hyaloperonospora arabidopsidis. CONCLUSIONS: Taken together, our observations suggest that AVH195 targets ATG8 to attenuate autophagy and prevent associated host cell death, thereby favoring biotrophy during the early stages of the infection process.


Asunto(s)
Autofagia , Nicotiana , Phytophthora , Enfermedades de las Plantas , Phytophthora/fisiología , Enfermedades de las Plantas/microbiología , Enfermedades de las Plantas/parasitología , Nicotiana/microbiología , Familia de las Proteínas 8 Relacionadas con la Autofagia/metabolismo , Familia de las Proteínas 8 Relacionadas con la Autofagia/genética , Interacciones Huésped-Patógeno
12.
Metabolites ; 14(4)2024 Apr 09.
Artículo en Inglés | MEDLINE | ID: mdl-38668340

RESUMEN

The study aimed to investigate late radiation-induced changes in the histology, ultrastructure, and activity of lysosomal enzymes in mouse liver exposed to ionizing radiation. The experiment was conducted on C57BL/6J male mice whose distal part of the liver was exposed occasionally to single doses of radiation (6 MV photons) during targeted heart irradiation; estimated doses delivered to analyzed tissue were 0.025 Gy, 0.25 Gy, 1 Gy, and 2 Gy. Tissues were collected 40 weeks after irradiation. We have observed that late effects of radiation have an adaptive nature and their intensity was dose-dependent. Morphological changes in hepatocytes included an increased number of primary lysosomes and autophagic vacuoles, which were visible in tissues irradiated with 0.25 Gy and higher doses. On the other hand, a significant increase in the activity of lysosomal hydrolases was observed only in tissues exposed to 2 Gy. The etiology of these changes may be multifactorial and result, among others, from unintentional irradiation of the distal part of the liver and/or functional interaction of the liver with an irradiated heart. In conclusion, we confirmed the presence of late dose-dependent ultrastructural and biochemical changes in mouse hepatocytes after liver irradiation in vivo.

13.
Cancer Imaging ; 24(1): 47, 2024 Apr 02.
Artículo en Inglés | MEDLINE | ID: mdl-38566150

RESUMEN

PURPOSE: To investigate the computed tomography (CT) characteristics of air-containing space and its specific patterns in neoplastic and non-neoplastic ground glass nodules (GGNs) for clarifying their significance in differential diagnosis. MATERIALS AND METHODS: From January 2015 to October 2022, 1328 patients with 1,350 neoplastic GGNs and 462 patients with 465 non-neoplastic GGNs were retrospectively enrolled. Their clinical and CT data were analyzed and compared with emphasis on revealing the differences of air-containing space and its specific patterns (air bronchogram and bubble-like lucency [BLL]) between neoplastic and non-neoplastic GGNs and their significance in differentiating them. RESULTS: Compared with patients with non-neoplastic GGNs, female was more common (P < 0.001) and lesions were larger (P < 0.001) in those with neoplastic ones. Air bronchogram (30.1% vs. 17.2%), and BLL (13.0% vs. 2.6%) were all more frequent in neoplastic GGNs than in non-neoplastic ones (each P < 0.001), and the BLL had the highest specificity (93.6%) in differentiation. Among neoplastic GGNs, the BLL was more frequently detected in the larger (14.9 ± 6.0 mm vs. 11.4 ± 4.9 mm, P < 0.001) and part-solid (15.3% vs. 10.7%, P = 0.011) ones, and its incidence significantly increased along with the invasiveness (9.5-18.0%, P = 0.001), whereas no significant correlation was observed between the occurrence of BLL and lesion size, attenuation, or invasiveness. CONCLUSION: The air containing space and its specific patterns are of great value in differentiating GGNs, while BLL is a more specific and independent sign of neoplasms.


Asunto(s)
Neoplasias Pulmonares , Nódulos Pulmonares Múltiples , Humanos , Femenino , Neoplasias Pulmonares/diagnóstico por imagen , Neoplasias Pulmonares/patología , Estudios Retrospectivos , Nódulos Pulmonares Múltiples/diagnóstico por imagen , Nódulos Pulmonares Múltiples/patología , Tomografía Computarizada por Rayos X/métodos , Diagnóstico Diferencial
14.
Rev Med Liege ; 79(3): 137-142, 2024 Mar.
Artículo en Francés | MEDLINE | ID: mdl-38487906

RESUMEN

VEXAS syndrome is a new entity, described as the first one of a new class of hemato-inflammatory diseases. Through this article and based on the first case highlighted at the CHU of Liege, we offer you a review of the literature as well as an overview of different laboratory techniques used for the diagnosis of this syndrome.


Le syndrome de VEXAS est une nouvelle entité, décrite comme pionnière d'une nouvelle classe de maladies hémato-inflammatoires. Au travers de cet article et sur base du premier cas mis en évidence au CHU de Liège, nous vous proposons une revue de la littérature ainsi qu'un aperçu des différentes techniques de laboratoire permettant le diagnostic de ce syndrome.


Asunto(s)
Biología Molecular , Síndromes Mielodisplásicos , Enfermedades Cutáneas Genéticas , Humanos , Citometría de Flujo , Síndrome , Mutación
15.
Biochim Biophys Acta Mol Basis Dis ; 1870(4): 167086, 2024 04.
Artículo en Inglés | MEDLINE | ID: mdl-38378084

RESUMEN

Alzheimer's disease (AD) is characterized by the formation ß-amyloid (Aß) deposited neuritic plaques. Recent evidence suggests that abnormal lipid metabolism and accumulation could serve as biomarkers for neurodegenerative diseases, including AD. Tubular endoplasmic reticulum protein, reticulon 3 (RTN3), plays a crucial role in the development of neuritic plaque and lipid metabolism in AD brains. In present study, we sought to investigate a potential association between neutral lipid accumulation and AD pathology. BODIPY 500/510 dye was used to label neutral lipid surrounding Aß plaques in APPNL-G-F mouse and AD postmortem brains samples. Immunofluorescent images were captured using confocal microscope and co-localization between lipid metabolism proteins and neutral lipids were evaluated. Lipid accumulation in Aß plaque surrounding dystrophic neurites (DNs) was observed in the cortical region of AD mouse models and human AD brain samples. The neutral lipid staining was not co-localized with IBA1-labeled microglia or GFAP-labeled astrocytes, but it was co-labeled with VAMP2 and neurofilament. We further showed that neutral lipids were accumulated in RTN3 immunoreactive DNs. Both the neutral lipids accumulation and RIDNs formation showed age-dependent patterns in surrounding amyloid plaques. Mechanistic studies revealed that RTN3 likely contributes to the enrichment of neutral lipids near plaques by interacting with heat shock cognate protein 70 (HSC70) and diminishing its function in chaperone-mediated lipophagy. Our study provides immunohistochemical evidence of neutral lipids being enriched in DNs near amyloid plaques. Our findings shed light on RTN3-mediaed lipid accumulation in AD neuropathology and provide fresh insights into the role of RTN3 in neurodegenerative diseases.


Asunto(s)
Enfermedad de Alzheimer , Ratones , Animales , Humanos , Enfermedad de Alzheimer/metabolismo , Neuritas/patología , Placa Amiloide/metabolismo , Ratones Transgénicos , Proteínas del Tejido Nervioso/metabolismo , Lípidos
16.
Front Aging ; 5: 1356697, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38327611

RESUMEN

Biomembranes fulfill several essential functions. They delimitate cells and control the exchange of compounds between cells and the environment. They generate specialized cellular reaction spaces, house functional units such as the respiratory chain (RC), and are involved in content trafficking. Biomembranes are dynamic and able to adjust their properties to changing conditions and requirements. An example is the inner mitochondrial membrane (IMM), which houses the RC involved in the formation of adenosine triphosphate (ATP) and the superoxide anion as a reactive oxygen species (ROS). The IMM forms a characteristic ultrastructure that can adapt to changing physiological situations. In the fungal aging model Podospora anserina, characteristic age-related changes of the mitochondrial ultrastructure occur. More recently, the impact of membranes on aging was extended to membranes involved in autophagy, an important pathway involved in cellular quality control (QC). Moreover, the effect of oleic acid on the lifespan was linked to basic biochemical processes and the function of membranes, providing perspectives for the elucidation of the mechanistic effects of this nutritional component, which positively affects human health and aging.

17.
Neuropathology ; 2024 Feb 27.
Artículo en Inglés | MEDLINE | ID: mdl-38414131

RESUMEN

Herein, we report a case of a collision tumor involving a multinodular and vacuolating neuronal tumor (MVNT) and a diffuse astrocytoma. A collision tumor between these two entities has not previously been reported. The patient is a 35-year-old woman who presented with new-onset hearing loss and ringing in her right ear. Magnetic resonance imaging identified a non-enhancing mass involving the gray matter and subcortical white matter of the left middle frontal gyrus. Additionally, tiny clustered nodules were noted along the underlying subcortical ribbon and superficial subcortical white matter of the left superior frontal gyrus. The patient underwent a left frontal craniotomy and complete resection of the mass. Histologic examination of the resected specimen demonstrated a collision tumor consisting of a diffuse astrocytoma (isocitrate dehydrogenase [IDH] mutant, central nervous system [CNS] World Health Organization [WHO] grade 2) and an MVNT, with the latter demonstrating characteristic morphologic and immunohistochemical features.

18.
Cells ; 13(4)2024 Feb 06.
Artículo en Inglés | MEDLINE | ID: mdl-38391905

RESUMEN

Saccharomyces cerevisiae proliferates by budding, which includes the formation of a cytoplasmic protrusion called the 'bud', into which DNA, RNA, proteins, organelles, and other materials are transported. The transport of organelles into the growing bud must be strictly regulated for the proper inheritance of organelles by daughter cells. In yeast, the RING-type E3 ubiquitin ligases, Dma1 and Dma2, are involved in the proper inheritance of mitochondria, vacuoles, and presumably peroxisomes. These organelles are transported along actin filaments toward the tip of the growing bud by the myosin motor protein, Myo2. During organelle transport, organelle-specific adaptor proteins, namely Mmr1, Vac17, and Inp2 for mitochondria, vacuoles, and peroxisomes, respectively, bridge the organelles and myosin. After reaching the bud, the adaptor proteins are ubiquitinated by the E3 ubiquitin ligases and degraded by the proteasome. Targeted degradation of the adaptor proteins is necessary to unload vacuoles, mitochondria, and peroxisomes from the actin-myosin machinery. Impairment of the ubiquitination of adaptor proteins results in the failure of organelle release from myosin, which, in turn, leads to abnormal dynamics, morphology, and function of the inherited organelles, indicating the significance of proper organelle unloading from myosin. Herein, we summarize the role and regulation of E3 ubiquitin ligases during organelle inheritance in yeast.


Asunto(s)
Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Ubiquitina-Proteína Ligasas/metabolismo , Peroxisomas/metabolismo , Miosinas/metabolismo , Ubiquitinas/metabolismo , Proteínas de Ciclo Celular/metabolismo , Proteínas Mitocondriales/metabolismo
19.
Front Immunol ; 15: 1354130, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38333211

RESUMEN

VEXAS syndrome is an acquired autoinflammatory disease characterized in most cases by cytopenias and macrocytic anemia. Dyshematopoiesis is a frequent finding in chronic inflammatory conditions and therefore, cytopenias are not easily classified in VEXAS patients. Here we report a series of 7 patients affected by VEXAS associated cytopenias, treated at our center. The use of NGS, together with morphological assays, integrated with the WHO 2022 criteria, allowed to identify three subsets of VEXAS associated cytopenias: ICUS (idiopathic cytopenia of uncertain significance), CCUS (clonal cytopenia of uncertain significance) at high risk of clonal evolution, and MDS. This approach could help to better understand the nature of VEXAS associated cytopenias and to guide the use of specific targeted treatments in order to achieve long lasting responses.


Asunto(s)
Citopenia , Síndromes Mielodisplásicos , Enfermedades Cutáneas Genéticas , Humanos , Síndromes Mielodisplásicos/terapia , Evolución Clonal , Organización Mundial de la Salud
20.
Exp Cell Res ; 434(1): 113872, 2024 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-38072303

RESUMEN

Autophagy is involved in the entirety of cellular survival, homeostasis and death which becomes more self-evident when its dysregulation is implicated in several pathological conditions. PTEN positively regulates autophagy and like other proteins undergo post-translational modifications. It is crucial to investigate the relationship between PTEN and autophagy as it is generally observed to be negligible in PTEN deficient cancer cells. Here, we have shown that such modifications of PTEN namely sumoylation and phosphorylation upregulates and downregulates autophagy respectively. Transfection of plasmid containing full length PTEN in PTEN-negative prostate cancer cell line PC3, induced autophagy on further starvation. When a sumoylation-deficient mutant of PTEN was transfected and cells were put under similar starvation, a decline in autophagy was observed. On the other hand, cells transfected with phosphorylation-deficient mutant of PTEN showed elevated expression of autophagy. Contrarily, transfection with phosphorylation-mimicking mutant caused reduced expression of autophagy. On further analysis, it was detected that PTEN's association with the plasma membrane was under positive and negative influence from its sumoylation and phosphorylation respectively. This association is integral as it is the foremost site for PTEN to oppose PI3K/AKT pathway and consequently upregulate autophagy. Thus, this study indicates that sumoylation and phosphorylation of PTEN can control autophagy via its cell membrane association.


Asunto(s)
Transducción de Señal , Serina-Treonina Quinasas TOR , Masculino , Humanos , Fosforilación , Serina-Treonina Quinasas TOR/metabolismo , Fosfatidilinositol 3-Quinasas/metabolismo , Sumoilación , Fosfohidrolasa PTEN/genética , Fosfohidrolasa PTEN/metabolismo , Autofagia/genética , Membrana Celular/metabolismo , Proteínas Proto-Oncogénicas c-akt/genética , Proteínas Proto-Oncogénicas c-akt/metabolismo
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA