Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 222
Filtrar
1.
Sci Adv ; 10(15): eadm7600, 2024 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-38608019

RESUMO

Myelination is essential for neuronal function and health. In peripheral nerves, >100 causative mutations have been identified that cause Charcot-Marie-Tooth disease, a disorder that can affect myelin sheaths. Among these, a number of mutations are related to essential targets of the posttranslational modification neddylation, although how these lead to myelin defects is unclear. Here, we demonstrate that inhibiting neddylation leads to a notable absence of peripheral myelin and axonal loss both in developing and regenerating mouse nerves. Our data indicate that neddylation exerts a global influence on the complex transcriptional and posttranscriptional program by simultaneously regulating the expression and function of multiple essential myelination signals, including the master transcription factor EGR2 and the negative regulators c-Jun and Sox2, and inducing global secondary changes in downstream pathways, including the mTOR and YAP/TAZ signaling pathways. This places neddylation as a critical regulator of myelination and delineates the potential pathogenic mechanisms involved in CMT mutations related to neddylation.


Assuntos
Doença de Charcot-Marie-Tooth , Células de Schwann , Animais , Camundongos , Bainha de Mielina/genética , Doença de Charcot-Marie-Tooth/genética , Mutação , Processamento de Proteína Pós-Traducional
2.
PLoS One ; 19(3): e0299090, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38451899

RESUMO

Recent research has shown that Massive Open Online Courses (MOOCs) create barriers for students with disabilities. Not taking into account their needs in the design, production or delivery of MOOCs may be one of the main causes behind this. It leads to poor compliance with suitable learning designs and web accessibility standards, as well as a lack of knowledge about the students' needs. The objective of our research is to analyze the learning performance of the students in MOOCs on topics related to Design for All, offered in an Open edX-based platform. Accessibility support was conceived from the outset, including compliance of both the platform and the learning resources with the WCAG 2.1 accessibility standard, and with a subset of the principles of Universal Design for Learning. Additionally, students were consulted on their accessibility needs and preferences, following publicly available modeling schemes and previous research. From a sample of 765 students, who completed at least one of the graded assessment activities of the course, a multilevel multiple logistic regression model was fitted. Based on that model, the results indicate that: a) users of screen readers and users of captions show a statistically significant positive association with a good performance when compared to students with no preferences, with an odds ratio of, respectively, OR = 13.482 and OR = 13.701; b) students who have low vision or very low vision show a significant negative association with a good performance when compared to users of screen readers and to users of captions, with OR = 26.817 and OR = 27.254, respectively.


Assuntos
Educação a Distância , Baixa Visão , Humanos , Estudantes , Aprendizagem , Análise Multinível
3.
JCI Insight ; 8(21)2023 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-37796615

RESUMO

Osteogenesis imperfecta (OI), or brittle bone disease, is a disorder characterized by bone fragility and increased fracture incidence. All forms of OI also feature short stature, implying an effect on endochondral ossification. Using the Aga2+/- mouse, which has a mutation in type I collagen, we show an affected growth plate primarily due to a shortened proliferative zone. We used single-cell RNA-Seq analysis of tibial and femoral growth plate tissues to understand transcriptional consequences on growth plate cell types. We show that perichondrial cells, which express abundant type I procollagen, and growth plate chondrocytes, which were found to express low amounts of type I procollagen, had ER stress and dysregulation of the same unfolded protein response pathway as previously demonstrated in osteoblasts. Aga2+/- proliferating chondrocytes showed increased FGF and MAPK signaling, findings consistent with accelerated differentiation. There was also increased Sox9 expression throughout the growth plate, which is expected to accelerate early chondrocyte differentiation but reduce late hypertrophic differentiation. These data reveal that mutant type I collagen expression in OI has an impact on the cartilage growth plate. These effects on endochondral ossification indicate that OI is a biologically complex phenotype going beyond its known impacts on bone to negatively affect linear growth.


Assuntos
Osteogênese Imperfeita , Animais , Camundongos , Cartilagem/metabolismo , Colágeno Tipo I/genética , Colágeno Tipo I/metabolismo , Expressão Gênica , Osteogênese Imperfeita/metabolismo
4.
JACC Case Rep ; 21: 101961, 2023 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-37719296

RESUMO

A 77-year-old male presented to the emergency department with dyspnea. A third-degree atrioventricular block was present in the electrocardiogram and an echocardiography showed a moderate mitral regurgitation with a diastolic functional insufficiency. Hemodynamic variations were assessed in the context of heart rhythm disturbances. (Level of Difficulty: Intermediate.).

5.
Cell Metab ; 35(8): 1373-1389.e8, 2023 08 08.
Artigo em Inglês | MEDLINE | ID: mdl-37527658

RESUMO

There has been an intense focus to uncover the molecular mechanisms by which fasting triggers the adaptive cellular responses in the major organs of the body. Here, we show that in mice, hepatic S-adenosylmethionine (SAMe)-the principal methyl donor-acts as a metabolic sensor of nutrition to fine-tune the catabolic-fasting response by modulating phosphatidylethanolamine N-methyltransferase (PEMT) activity, endoplasmic reticulum-mitochondria contacts, ß-oxidation, and ATP production in the liver, together with FGF21-mediated lipolysis and thermogenesis in adipose tissues. Notably, we show that glucagon induces the expression of the hepatic SAMe-synthesizing enzyme methionine adenosyltransferase α1 (MAT1A), which translocates to mitochondria-associated membranes. This leads to the production of this metabolite at these sites, which acts as a brake to prevent excessive ß-oxidation and mitochondrial ATP synthesis and thereby endoplasmic reticulum stress and liver injury. This work provides important insights into the previously undescribed function of SAMe as a new arm of the metabolic adaptation to fasting.


Assuntos
Neoplasias Hepáticas , S-Adenosilmetionina , Camundongos , Animais , S-Adenosilmetionina/metabolismo , Fígado/metabolismo , Neoplasias Hepáticas/metabolismo , Jejum , Trifosfato de Adenosina/metabolismo , Metionina Adenosiltransferase/metabolismo , Fosfatidiletanolamina N-Metiltransferase/metabolismo
6.
Org Biomol Chem ; 21(34): 6940-6948, 2023 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-37581278

RESUMO

A common protocol for enantioselective alkynylation of isatins and isatin-derived ketimines using terminal alkynes and Me2Zn in the presence of a catalytic amount of a chiral perhydro-1,3-benzoxazine with moderate to excellent enantioselectivity under mild reaction conditions is described. The additions to ketimines present a novel approach to chiral amines being derivatives of oxindoles. The reaction is broad in scope with respect to aryl- and alkyl-substituted terminal alkynes and isatin derivatives. In isatins, the alkynylation occurs at the Si face of the carbonyl group, whereas in the ketimine derivatives it occurs at the Re face of the imine.

8.
Sci Rep ; 13(1): 6728, 2023 04 25.
Artigo em Inglês | MEDLINE | ID: mdl-37185355

RESUMO

This study reports a set of primeval marine incursions identified in two drill cores, 1PS-06-CE, and 1PS-10-CE, which recovered the Barbalha Formation, Araripe Basin, Brazil. Based on a multi-proxy approach involving stratigraphy, microbiofacies, ichnofossils, and microfossils, three short-lived marine incursions were identified, designated Araripe Marine Incursions (AMI) 1-3. AMI-1 and AMI-2, which occur within the shales of the Batateira Beds (lower part of the Barbalha Formation), were identified by the occurrence of benthonic foraminifera, calcareous nannofossils, dinocysts, and a mass mortality event of non-marine ostracods. AMI-3 was recognized in the upper part of the Barbalha Formation, based on the occurrence of ichnofossils and planktonic foraminifera. The observation of the planktonic foraminifera genus Leupoldina for the first time in the basin indicates early Aptian/early late Aptian age for these deposits, and the first opportunity of correlation with global foraminifera biozonation. Our findings have implications for the breakup of the Gondwana Supercontinent, as these incursions represent the earliest marine-derived flooding events in the inland basins of northeastern Brazil.


Assuntos
Foraminíferos , Fósseis , Animais , Brasil , Crustáceos , Plâncton
10.
Medicina (Kaunas) ; 59(4)2023 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-37109663

RESUMO

Cardiac masses are currently studied using multimodality imaging. For diagnosis, different imaging techniques that can provide complementary information are used. Cardiac magnetic resonance imaging (MRI) has become a fundamental tool for this type of pathology owing to its ability to provide tissue characterization, spatial accuracy, and the anatomic relationships of the different structures. This study presents a series of four clinical cases with an initial diagnosis of a cardiac mass. All cases were evaluated at a single center, and patients were aged 57 to 72 years. An etiological study was conducted on all patients using different imaging techniques, including MRI. This study describes the diagnostic and therapeutic procedures of the four cases, which included two intracardiac metastases and two benign tumors. Cardiac MRI was decisive in the diagnostic process, determining the clinical decision-making in all four cases. Cardiac MRI has emerged as a pivotal technique in the diagnosis of cardiac masses. It can provide a highly accurate histological diagnosis without the need for invasive techniques.


Assuntos
Ecocardiografia , Neoplasias Cardíacas , Humanos , Ecocardiografia/métodos , Neoplasias Cardíacas/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Coração/diagnóstico por imagem , Tomada de Decisão Clínica
11.
Health Informatics J ; 29(1): 14604582231153779, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36731024

RESUMO

The study and early detection of breast cancer are key for its treatment. We carry out an exhaustive analysis of the most used database for mastology research with infrared images, analyzing the anomalies according to five quality dimensions: completeness, correctness, concordance, plausibility, and currency. We established control queries that looked for these anomalies and that can be used to ensure the quality of the database. Finally, we briefly review the more than 40 papers that use this database and that do not mention any of these anomalies. When analyzing the database, we found 365 anomalies related to personal and clinical data, and thermal images. The errors found in our research may lead to a modification of the results and conclusions made in the articles found in the literature, serve as a basis for improvements in the quality of the database, and help future researchers to work with it.


Assuntos
Neoplasias da Mama , Termografia , Humanos , Feminino , Termografia/métodos , Mama , Neoplasias da Mama/diagnóstico por imagem , Bases de Dados Factuais
12.
Int J Mol Sci ; 23(18)2022 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-36142627

RESUMO

Neuroinflammation has a major role in several brain disorders including Alzheimer's disease (AD), yet at present there are no effective anti-neuroinflammatory therapeutics available. Copper(II) complexes of bis(thiosemicarbazones) (CuII(gtsm) and CuII(atsm)) have broad therapeutic actions in preclinical models of neurodegeneration, with CuII(atsm) demonstrating beneficial outcomes on neuroinflammatory markers in vitro and in vivo. These findings suggest that copper(II) complexes could be harnessed as a new approach to modulate immune function in neurodegenerative diseases. In this study, we examined the anti-neuroinflammatory action of several low-molecular-weight, charge-neutral and lipophilic copper(II) complexes. Our analysis revealed that one compound, a thiosemicarbazone-pyridylhydrazone copper(II) complex (CuL5), delivered copper into cells in vitro and increased the concentration of copper in the brain in vivo. In a primary murine microglia culture, CuL5 was shown to decrease secretion of pro-inflammatory cytokine macrophage chemoattractant protein 1 (MCP-1) and expression of tumor necrosis factor alpha (Tnf), increase expression of metallothionein (Mt1), and modulate expression of Alzheimer's disease-associated risk genes, Trem2 and Cd33. CuL5 also improved the phagocytic function of microglia in vitro. In 5xFAD model AD mice, treatment with CuL5 led to an improved performance in a spatial working memory test, while, interestingly, increased accumulation of amyloid plaques in treated mice. These findings demonstrate that CuL5 can induce anti-neuroinflammatory effects in vitro and provide selective benefit in vivo. The outcomes provide further support for the development of copper-based compounds to modulate neuroinflammation in brain diseases.


Assuntos
Doença de Alzheimer , Tiossemicarbazonas , Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/metabolismo , Animais , Fatores Quimiotáticos/metabolismo , Complexos de Coordenação , Cobre/metabolismo , Modelos Animais de Doenças , Glicoproteínas de Membrana/metabolismo , Metalotioneína/metabolismo , Camundongos , Microglia/metabolismo , Receptores Imunológicos/metabolismo , Tiossemicarbazonas/metabolismo , Tiossemicarbazonas/farmacologia , Fator de Necrose Tumoral alfa/metabolismo
13.
J Clin Med ; 11(9)2022 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-35566489

RESUMO

Background: Chemotherapy-related cognitive impairment (CRCI), or "chemobrain," isdefined as a phenomenon of cognitive deficits in cancer patients after chemotherapy and is characterized by deficits in areas of cognition, including memory, attention, speed of processing, and executive function, which seriously affect quality of life. The purpose of this study is to investigate the impact of CRCI in breast cancer (BC) patients in chemotherapy treatment (CT+) or not (CT−) and to analyze their relationship with detectable objective changes in cerebral activity during the execution of a phonological and semantic verbal fluency task (PVF and SVF). Methods: An observational, cross-sectional study was carried out at Badajoz University Hospital (Spain). A total of 180 women with BC were included. We used Cognitive Scale (FACT-Cog) for neuropsychological subjective assessment, obtaining scores of perceived cognitive impairment (PCI), and near-infrared spectroscopy system (NIRS) for neuropsychological objective assessment during a verbal fluency task (PVF and SVF), determining alterations in the prefrontal cortex (PFC) assessed as changes in regional saturation index (rSO2). Results: A total of 41.7% percent of the patients in the sample had PCI. CT+ was significantly associated with a worse impact in PCI (X¯ = 50.60 ± 15.64 vs. X¯ = 55.01 ± 12.10; p = 0.005). Average rSO2 decreased significantly in CT+ (X¯ = 63.30 ± 8.02 vs. X¯ = 67.98 ± 7.80; p < 0.001), and BC patients showed a significant decrease in PVF and SVF on average (X¯ = 41.99 ± 9.52 vs. X¯ = 47.03 ± 9.31, and X¯ = 33.43 ± 11.0 vs. X¯ = 36.14 ± 10.68, respectively; p < 0.001). Conclusions: Our findings suggest that cognitive impairments in the domain of executive functioning exist among patients with BC who received CT. The results corroborate the hypothesis that CT is an important factor in cognitive impairment in patients with BC, which has been demonstrated by both subjective (PCI) and objective (PVF, SVF, and rSO2) neuropsychological measures. The combination of doxorubicin, cyclophosphamide, and docetaxel induce cognitive impairment.

14.
Bone Res ; 10(1): 37, 2022 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-35474298

RESUMO

Spondylocarpotarsal syndrome (SCT) is a rare musculoskeletal disorder characterized by short stature and vertebral, carpal, and tarsal fusions resulting from biallelic nonsense mutations in the gene encoding filamin B (FLNB). Utilizing a FLNB knockout mouse, we showed that the vertebral fusions in SCT evolved from intervertebral disc (IVD) degeneration and ossification of the annulus fibrosus (AF), eventually leading to full trabecular bone formation. This resulted from alterations in the TGFß/BMP signaling pathway that included increased canonical TGFß and noncanonical BMP signaling. In this study, the role of FLNB in the TGFß/BMP pathway was elucidated using in vitro, in vivo, and ex vivo treatment methodologies. The data demonstrated that FLNB interacts with inhibitory Smads 6 and 7 (i-Smads) to regulate TGFß/BMP signaling and that loss of FLNB produces increased TGFß receptor activity and decreased Smad 1 ubiquitination. Through the use of small molecule inhibitors in an ex vivo spine model, TGFß/BMP signaling was modulated to design a targeted treatment for SCT and disc degeneration. Inhibition of canonical and noncanonical TGFß/BMP pathway activity restored Flnb-/- IVD morphology. These most effective improvements resulted from specific inhibition of TGFß and p38 signaling activation. FLNB acts as a bridge for TGFß/BMP signaling crosstalk through i-Smads and is key for the critical balance in TGFß/BMP signaling that maintains the IVD. These findings further our understanding of IVD biology and reveal new molecular targets for disc degeneration as well as congenital vertebral fusion disorders.

15.
Medisur ; 20(2)abr. 2022.
Artigo em Espanhol | LILACS-Express | LILACS | ID: biblio-1405903

RESUMO

RESUMEN Fundamento: en los laboratorios de microbiología, la identificación y conteo de microorganismos es un procedimiento habitual. Aunque existen en el mercado equipos que posibilitan su realización de manera automática o semiautomática, son muy costosos, por lo cual esta tarea, difícil e irritante para los ojos, la siguen realizando los expertos de manera tradicional mediante la observación de las muestras en los microscopios, con la consiguiente variabilidad entre ellos. Objetivo: proponer un nuevo método para el conteo de bacterias y levaduras en imágenes digitales, bajo diferentes magnificaciones, tomadas a bioproductos de origen microbiano obtenidos por fermentación. Métodos: el sensor empleado para la toma de imágenes de las muestras fue una cámara digital modelo HDCE-X, con un sensor CMOS de ½", con una resolución de 2592 píxeles por 1944 píxeles (5 Mp). Se emplearon dos tipos de magnificaciones: magnificación 40x (PL40, 0.65 apertura numérica and 0.17 de distancia de trabajo) y magnificación 100x (HI plan 100/1.25 con inmersión de aceite). El método propuesto se basa en técnicas de procesamiento digital de imágenes, utilizando herramientas como la detección de contornos, operaciones morfológicas y análisis estadístico, y fue desarrollado en lenguaje Python con empleo de la biblioteca OpenCV. Resultados: la detección y conteo de bacterias se logró con una exactitud y precisión aceptable, en ambos casos por encima de 0,95; no en el caso de las levaduras cuya exactitud y precisión fueron menores, alrededor de 0,78 y 0,86 respectivamente. Se proponen flujos de trabajo basados en técnicas de procesamiento digital de imágenes, fundamentalmente en detección de contornos, operaciones morfológicas y análisis estadístico. Conclusiones: el método posee una efectividad aceptable para el contexto y depende de las características que presenten las imágenes.


ABSTRACT Background: In microbiology laboratories, the identification and counting of microorganisms is a common procedure; and although there is a variety of equipment on the market that possibility to carry out these processes automatically or semi-automatically, it is usually expensive to many laboratories. These are some of the reasons why this arduous and difficult task is still performed in many laboratories by experts in the traditional way, through the observation of samples in microscope, consuming a great time and having variations in the results between experts. Objective: The present work aims to propose a new method for counting bacteria and yeasts in digital images, taken under different magnifications, of microbial bioproducts obtained by fermentation. Methods: The sensor used to take images of the samples was a digital camera model HDCE-X, with a ½" CMOS sensor, with a resolution of 2592 pixels by 1944 pixels (5 Mp). Two types of magnifications were used: 40x magnification (PL40, 0.65 numerical aperture and 0.17 working distance) and 100x magnification (HI plan 100/1.25 with oil immersion). The proposed method is based on digital image processing technics, using tools as contour detection, morphological operations and statistical analysis, and was developed in Python language using the OpenCV library. The work also presents a comparison with the results obtained using ImageJ software for the same purpose. Results: the detection and count of bacteria was achieved with an acceptable accuracy and precision, in both cases above 0.95; not in the case of yeasts whose accuracy and precision was lower, around 0.78 for accuracy and 0.86 for precision. Workflows based on digital image processing techniques are proposed, using tools as contour detection, morphological operations and statistical analysis. Conclusions: the method has an acceptable effectiveness for the context and depends on the characteristics presented by the images.

16.
Artigo em Inglês | MEDLINE | ID: mdl-35329232

RESUMO

Breast cancer (BC) is a major public health problem internationally. Although illness survival rates have improved, patients usually suffer multiple symptoms, both physical and psychological, which can affect their quality of life (QoL). The main aim of this study was to evaluate depressive symptoms, anxiety and the QoL of people with BC. An observational, cross-sectional study was carried out at Badajoz University Hospital (Spain). A total of 200 women with BC were included. EORTC QLQ-C30 and QLQ-BR23 questionnaires were used to assess QoL. Patients were screened for depressive symptoms using the Beck Depression Inventory (BDI) and for state anxiety and trait anxiety using the State Anxiety Inventory (STAI). Thirty-eight percent of the patients in the sample had moderate to severe anxiety, which was related to the time of diagnosis, advanced stage of illness and surgical treatment. We found that 28% of patients had depressive symptoms, related mainly with time of diagnosis, adjuvant therapy and number of cycles of chemotherapy (CT). Patients with the longest time since diagnosis, in stage III, and in treatment with CT, especially those with the greatest number of cycles, had the worst scores in QoL. We found a positive association between depressive symptoms and anxiety with QoL in patients with BC.


Assuntos
Neoplasias da Mama , Qualidade de Vida , Ansiedade/epidemiologia , Neoplasias da Mama/psicologia , Estudos Transversais , Depressão/epidemiologia , Depressão/psicologia , Feminino , Humanos , Masculino , Inquéritos e Questionários
17.
Eur J Rheumatol ; 9(1): 20-25, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-35110133

RESUMO

OBJECTIVE: To assess the prevalence of subclinical atherosclerosis in patients with primary Sjögren's syndrome (pSS) and its possible association with clinical and analytical parameters of the disease. METHODS: In this cross-sectional study, 38 consecutive patients with pSS were compared with 38 age and sex healthy controls. Demographic variables and classic cardiovascular risk factors (CVRFs): Hypertension, dyslipidemia, diabetes mellitus, obesity, and smoking habit were assessed in both groups, and also disease-related features were collected in pSS group. The presence of subclinical atherosclerosis was assessed by carotid ultrasound, with carotid intima-media thickness (CIMT) measurement and determination of the presence of atheromatous plaques. RESULTS: Subclinical atherosclerosis presence was remarkably greater in patients with pSS than in healthy controls (OR = 4.17, 95%CI [1.27-16.54]), as well as CIMT values (0.79 ± 0.43mm vs. 0.66 ± 0.27mm; P = .02). No differences for classic CVRFs were found between both groups. An association of subclinical atherosclerosis with erythrocyte sedimentation rate (ESR) and rheumatoid factor (RF) was observed in patients with pSS. CONCLUSION: This cohort showed a greater prevalence of subclinical atherosclerosis in patients with pSS, indicating this disease as an independent risk factor for presence of early vascular damage.

18.
J Bone Miner Res ; 37(4): 675-686, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-34997935

RESUMO

Osteogenesis imperfecta (OI) is a genetically heterogenous disorder most often due to heterozygosity for mutations in the type I procollagen genes, COL1A1 or COL1A2. The disorder is characterized by bone fragility leading to increased fracture incidence and long-bone deformities. Although multiple mechanisms underlie OI, endoplasmic reticulum (ER) stress as a cellular response to defective collagen trafficking is emerging as a contributor to OI pathogenesis. Herein, we used 4-phenylbutiric acid (4-PBA), an established chemical chaperone, to determine if treatment of Aga2+/- mice, a model for moderately severe OI due to a Col1a1 structural mutation, could attenuate the phenotype. In vitro, Aga2+/- osteoblasts show increased protein kinase RNA-like endoplasmic reticulum kinase (PERK) activation protein levels, which improved upon treatment with 4-PBA. The in vivo data demonstrate that a postweaning 5-week 4-PBA treatment increased total body length and weight, decreased fracture incidence, increased femoral bone volume fraction (BV/TV), and increased cortical thickness. These findings were associated with in vivo evidence of decreased bone-derived protein levels of the ER stress markers binding immunoglobulin protein (BiP), CCAAT/-enhancer-binding protein homologous protein (CHOP), and activating transcription factor 4 (ATF4) as well as increased levels of the autophagosome marker light chain 3A/B (LC3A/B). Genetic ablation of CHOP in Aga2+/- mice resulted in increased severity of the Aga2+/- phenotype, suggesting that the reduction in CHOP observed in vitro after treatment is a consequence rather than a cause of reduced ER stress. These findings suggest the potential use of chemical chaperones as an adjunct treatment for forms of OI associated with ER stress. © 2022 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).


Assuntos
Osteogênese Imperfeita , Animais , Butilaminas , Colágeno Tipo I/metabolismo , Modelos Animais de Doenças , Camundongos , Chaperonas Moleculares/metabolismo , Mutação , Osteoblastos/metabolismo , Osteogênese , Osteogênese Imperfeita/tratamento farmacológico , Osteogênese Imperfeita/genética , Osteogênese Imperfeita/metabolismo , Fenótipo
20.
Front Cell Dev Biol ; 10: 963389, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36726589

RESUMO

Alterations in the balance between skeletogenesis and adipogenesis is a pathogenic feature in multiple skeletal disorders. Clinically, enhanced bone marrow adiposity in bones impairs mobility and increases fracture risk, reducing the quality of life of patients. The molecular mechanism that underlies the balance between skeletogenesis and adipogenesis is not completely understood but alterations in skeletal progenitor cells' differentiation pathway plays a key role. We recently demonstrated that parathyroid hormone (PTH)/PTH-related peptide (PTHrP) control the levels of DEPTOR, an inhibitor of the mechanistic target of rapamycin (mTOR), and that DEPTOR levels are altered in different skeletal diseases. Here, we show that mutations in the PTH receptor-1 (PTH1R) alter the differentiation of skeletal progenitors in two different skeletal genetic disorders and lead to accumulation of fat or cartilage in bones. Mechanistically, DEPTOR controls the subcellular localization of TAZ (transcriptional co-activator with a PDZ-binding domain), a transcriptional regulator that governs skeletal stem cells differentiation into either bone and fat. We show that DEPTOR regulation of TAZ localization is achieved through the control of Dishevelled2 (DVL2) phosphorylation. Depending on nutrient availability, DEPTOR directly interacts with PTH1R to regulate PTH/PTHrP signaling or it forms a complex with TAZ, to prevent its translocation to the nucleus and therefore inhibit its transcriptional activity. Our data point DEPTOR as a key molecule in skeletal progenitor differentiation; its dysregulation under pathologic conditions results in aberrant bone/fat balance.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...