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1.
Cells ; 13(5)2024 Feb 29.
Artigo em Inglês | MEDLINE | ID: mdl-38474395

RESUMO

Dystroglycan is a ubiquitously expressed heterodimeric cell-surface laminin receptor with roles in cell adhesion, signalling, and membrane stabilisation. More recently, the transmembrane ß-subunit of dystroglycan has been shown to localise to both the nuclear envelope and the nucleoplasm. This has led to the hypothesis that dystroglycan may have a structural role at the nuclear envelope analogous to its role at the plasma membrane. The biochemical fraction of myoblast cells clearly supports the presence of dystroglycan in the nucleus. Deletion of the dystroglycan protein by disruption of the DAG1 locus using CRISPR/Cas9 leads to changes in nuclear size but not overall morphology; moreover, the Young's modulus of dystroglycan-deleted nuclei, as determined by atomic force microscopy, is unaltered. Dystroglycan-disrupted myoblasts are also no more susceptible to nuclear stresses including chemical and mechanical, than normal myoblasts. Re-expression of dystroglycan in DAG1-disrupted myoblasts restores nuclear size without affecting other nuclear parameters.


Assuntos
Distroglicanas , Laminina , Distroglicanas/metabolismo , Laminina/metabolismo , Núcleo Celular/metabolismo , Membrana Celular/metabolismo , Membrana Nuclear/metabolismo
2.
BMC Health Serv Res ; 23(1): 1426, 2023 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-38104060

RESUMO

BACKGROUND: Measuring quality is essential to drive improvement initiatives in hospitals. An instrument that measures healthcare quality multidimensionally and integrates patients', kin's and professionals' perspectives is lacking. We aimed to develop and validate an instrument to measure healthcare quality multidimensionally from a multistakeholder perspective. METHODS: A multi-method approach started by establishing content and face validity, followed by a multi-centre study in 17 Flemish (Belgian) hospitals to assess construct validity through confirmatory factor analysis, criterion validity through determining Pearson's correlations and reliability through Cronbach's alpha measurement. The instrument FlaQuM-Quickscan measures 'Healthcare quality for patients and kin' (part 1) and 'Healthcare quality for professionals' (part 2). This bipartite instrument mirrors 15 quality items and 3 general items (the overall quality score, recommendation score and intention-to-stay score). A process evaluation was organised to identify effective strategies in instrument distribution by conducting semi-structured interviews with quality managers. RESULTS: By involving experts in the development of quality items and through pilot testing by a multi-stakeholder group, the content and face validity of instrument items was ensured. In total, 13,615 respondents (5,891 Patients/kin and 7,724 Professionals) completed the FlaQuM-Quickscan. Confirmatory factor analyses showed good to very good fit and correlations supported the associations between the quality items and general items for both instrument parts. Cronbach's alphas supported the internal consistency. The process evaluation revealed that supportive technical structures and approaching respondents individually were effective strategies to distribute the instrument. CONCLUSIONS: The FlaQuM-Quickscan is a valid instrument to measure healthcare quality experiences multidimensionally from an integrated multistakeholder perspective. This new instrument offers unique and detailed data to design sustainable quality management systems in hospitals. Based on these data, hospital management and policymakers can set quality priorities for patients', kin's and professionals' care. Future research should investigate the transferability to other healthcare systems and examine between-stakeholders and between-hospitals variation.


Assuntos
Atenção à Saúde , Pessoal de Saúde , Humanos , Reprodutibilidade dos Testes , Inquéritos e Questionários , Hospitais , Psicometria
3.
Race Soc Probl ; 15(1): 79-100, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36741235

RESUMO

Although an emerging body of literature has advanced our knowledge of how monoracial parents can support their multiracial children in understanding the ethnic-racial identities they hold, there is a dearth of research exploring how parents socialize their children towards antiracism. Drawing from ten interviews with monoracial parents of multiracial children, this paper illuminates how parents leverage multiracial socialization practices, as identified in previous academic research, to instill an antiracist orientation in their children. Using consensual qualitative analyses, we find that although all parents had a vested interest in the wellbeing and identity development of their multiracial children, parents qualitatively differed in their ability and willingness to instill an antiracist orientation in their children. Specifically, parents in our sample exhibited five approaches to multiracial socialization, ranging from those that reinforced dominant racial ideologies to those that explicitly aimed to prepare youth to become antiracist activists. We also describe how monoracial parents' lived experiences are implicated in their engagement in multiracial socialization practices, especially those that better position them to prepare their children to engage in antiracism. Our findings illuminate how monoracial parents may engage in a repertoire of strategies in order to foster antiracism in multiracial children, molding the next generation of "antiracist disruptors."

4.
J Gerontol A Biol Sci Med Sci ; 78(5): 831-841, 2023 05 11.
Artigo em Inglês | MEDLINE | ID: mdl-35179580

RESUMO

BACKGROUND: Mounting evidence suggests that wearable technologies using peripheral neuromodulation can provide novel ways of improving mobility and gait function in various patient populations including older adults. The purpose of this narrative review is to provide an overview of wearable technologies/devices to improve mobility and gait function through noninvasive peripheral neuromodulation in older adults over the age of 65 and to indicate the suggested mechanism of action behind these technologies. METHODS: We performed searches for articles and conference abstracts written in English, using the following databases: Embase Classic+Embase from 1947 to July 15, 2021; Ovid MEDLINE; Epub Ahead of Print, In-Process, In-Data-Review & Other Non-Indexed Citations, Daily and Versions from 1946 to July 15, 2021; PubMed; and Scopus. RESULTS: Forty-one technologies met the inclusion/exclusion criteria. We found that the primary implementation of the 41 technologies can be divided into 3 main categories: sensory substitution, sensory augmentation (open loop, closed loop), and motor stimulation. Using these technologies, various aspects of mobility are treated or addressed, including, gait function, fall risk, foot drop, navigating environment, and postural control. CONCLUSIONS: This narrative review summarizes wearable technologies that are currently commercially available and in stages of research and development. Overall, studies suggest that wearable peripheral neuromodulation technologies can improve aspects of mobility for older adults. Existing literature suggests that these technologies may lead to physiological changes in the brain through sensory reweighting or other neuroplastic mechanisms to enhance the performance of mobility and gait function in older adults over the age of 65.


Assuntos
Marcha , Dispositivos Eletrônicos Vestíveis , Humanos , Idoso , Marcha/fisiologia , Equilíbrio Postural/fisiologia
5.
Front Aging Neurosci ; 14: 931048, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36204554

RESUMO

Background: We recently reported that individuals with impaired plantar sensation and high fall risk due to sensory peripheral neuropathy (PN) improved gait and balance function following 10 weeks of use of Walkasins®, a wearable lower limb sensory prosthesis that provides directional specific mechanical tactile stimuli related to plantar pressure measurements during standing and walking (RxFunction Inc., Eden Prairie, MN, United States). Here, we report 26-week outcomes and compare pre- and in-study fall rates. We expected improvements in outcomes and reduced fall rates reported after 10 weeks of use to be sustained. Materials and methods: Participants had clinically diagnosed PN with impaired plantar sensation, high fall risk (Functional Gait Assessment, FGA score < 23) and ability to sense tactile stimuli above the ankle at the location of the device. Additional outcomes included 10 m Gait Speed, Timed Up and Go (TUG), Four-Stage Balance Test, and self-reported outcomes, including Activities-Specific Balance Confidence scale and Vestibular Disorders Activities of Daily Living Scale. Participants tracked falls using a calendar. Results: We assessed falls and self-reported outcomes from 44 individuals after 26 weeks of device use; 30 of them conducted in-person testing of clinical outcomes. Overall, improvements in clinical outcomes seen at 10 weeks of use remained sustained at 26 weeks with statistically significant increases compared to baseline seen in FGA scores (from 15.0 to 19.2), self-selected gait speed (from 0.89 to 0.97 m/s), and 4-Stage Balance Test (from 25.6 to 28.4 s), indicating a decrease in fall risk. Non-significant improvements were observed in TUG and fast gait speed. Overall, 39 falls were reported; 31 of them did not require medical treatment and four caused severe injury. Participants who reported falls over 6 months prior to the study had a 43% decrease in fall rate during the study as compared to self-report 6-month pre-study (11.8 vs. 6.7 falls/1000 patient days, respectively, p < 0.004), similar to the 46% decrease reported after 10 weeks of use. Conclusion: A wearable sensory prosthesis can improve outcomes of gait and balance function and substantially decreases incidence of falls during long-term use. The sustained long-term benefits in clinical outcomes reported here lessen the likelihood that improvements are placebo effects. Clinical trial registration: ClinicalTrials.gov, identifier #NCT03538756.

6.
Patient Educ Couns ; 105(10): 3151-3159, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35843847

RESUMO

OBJECTIVES: To identify key attributes of healthcare quality relevant to patients and kin and to compare them to Lachman's multidimensional quality model. METHODS: Four focus groups with patients and kin were conducted using a semi-structured interview guide and a purposive sampling method. Classical content analysis and constant comparison method were used to focus data analysis on individual and group level. RESULTS: Communication with patients, kin and professionals emerged as a new dimension from interview transcripts. Other identified key attributes largely corresponded with Lachman's multidimensional quality model. They were mainly classified in dimensions: 'Partnership and Co-Production', 'Dignity and Respect' and 'Effectiveness'. Technical quality dimensions were linked to organisational aspects of care in terms of staffing levels and time. The dimension 'Eco-friendly' was not addressed by patients or kin. CONCLUSIONS: The results enhance the comprehension of healthcare quality and contribute to its academic understanding by validating Lachman's multidimensional quality model from patients' and kin's perspective. The model robustness is increased by including communication as a quality dimension surrounding technical domains and core values. PRACTICE IMPLICATIONS: The key attributes can serve as a holistic framework for healthcare organisations to design their quality management system. An instrument can be developed to measure key attributes.


Assuntos
Comunicação , Qualidade da Assistência à Saúde , Grupos Focais , Humanos , Pesquisa Qualitativa
8.
Nat Immunol ; 23(5): 791-801, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35393592

RESUMO

Clonal expansion is a core aspect of T cell immunity. However, little is known with respect to the relationship between replicative history and the formation of distinct CD8+ memory T cell subgroups. To address this issue, we developed a genetic-tracing approach, termed the DivisionRecorder, that reports the extent of past proliferation of cell pools in vivo. Using this system to genetically 'record' the replicative history of different CD8+ T cell populations throughout a pathogen-specific immune response, we demonstrate that the central memory T (TCM) cell pool is marked by a higher number of prior divisions than the effector memory T cell pool, owing to the combination of strong proliferative activity during the acute immune response and selective proliferative activity after pathogen clearance. Furthermore, by combining DivisionRecorder analysis with single-cell transcriptomics and functional experiments, we show that replicative history identifies distinct cell pools within the TCM compartment. Specifically, we demonstrate that lowly divided TCM cells display enriched expression of stem-cell-associated genes, exist in a relatively quiescent state, and are superior in eliciting a proliferative recall response upon activation. These data provide the first evidence that a stem-cell-like memory T cell pool that reconstitutes the CD8+ T cell effector pool upon reinfection is marked by prior quiescence.


Assuntos
Linfócitos T CD8-Positivos , Memória Imunológica
9.
J Electromyogr Kinesiol ; 62: 102334, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31331680

RESUMO

BACKGROUND: Clinician-led training through tactile and verbal guidance to improve muscle activity and joint motion are a common but understudied focus of therapeutic interventions for shoulder pain. The purpose of this study was to determine if clinician guidance changes scapulothoracic muscle activity and kinematics compared to unguided shoulder exercises. METHODS: Eleven participants with shoulder pain were studied. Electromyographic (EMG) sensors were placed on the serratus anterior and upper and lower trapezii. Scapulothoracic and sternoclavicular kinematics were collected using electromagnetic sensors. Five common resisted shoulder exercises were performed with the following guidance: unguided, combined (verbal and tactile cues), and verbal guidance only. One-way repeated measures ANOVAs determined the effect of guidance versus unguided conditions for each exercise. RESULTS: Nine of ten combinations of exercise and guidance techniques demonstrated a significant effect of guidance for either muscle activity or joint kinematics. The guidance condition with the most frequent significant improvements across all variables was the combined condition. The exercises with the most frequent significant improvements across all variables were the external rotation exercises. Variables improved most frequently were: upper:lower trapezius EMG ratio (up to 11%), sternoclavicular elevation (up to 6°) and scapulothoracic internal rotation positioning (up to 8°), and sternoclavicular retraction displacement (up to 5°). CONCLUSION: Shoulder muscle activity and kinematics during exercises can be modified by tactile and verbal guidance. Most improvements in muscle activity occurred with verbal guidance during external rotation exercises. Most improvements in joint positioning and movement occurred with combined guidance during external rotation exercises.


Assuntos
Escápula , Músculos Superficiais do Dorso , Fenômenos Biomecânicos , Eletromiografia , Terapia por Exercício , Humanos , Músculo Esquelético , Ombro
10.
J Homosex ; 68(13): 2144-2168, 2021 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-32149593

RESUMO

This study documents the results of a longitudinal content analysis of television news about LGBT people in terms of visibility, active representation, tone and framing in Flanders (1986-2017). While attention for LGBT issues has increased over time, LGBTs are not more likely to be visually represented or granted a voice. Gay men are more often actively represented than lesbians and transgender people. News remains negatively biased, although news stories in which LGBT people are depicted as the cause of negativity have become less prevalent. Patterns in framing have shifted: Deviance and abnormality frames have decreased in favor of a rise in equal rights and victim frames. Patterns in tone and framing were similar for gay men, lesbians and transgender people. Results suggest that journalists have shifted from problematizing homosexuality to problematizing homophobia. Implications of news as a source of mass-mediated contact to promote tolerance toward LGBT people are discussed.


Assuntos
Homossexualidade Feminina , Minorias Sexuais e de Gênero , Pessoas Transgênero , Feminino , Homofobia , Humanos , Masculino , Televisão
11.
Front Aging Neurosci ; 12: 592751, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33240077

RESUMO

BACKGROUND: Sensory peripheral neuropathy (PN) is associated with gait, balance problems and high fall risk. The walk2Wellness trial investigates effects of long-term, home-based daily use of a wearable sensory prosthesis on gait function, balance, quality of life and fall rates in PN patients. The device (Walkasins®, RxFunction Inc., MN, United States) partially substitutes lost nerve function related to plantar sensation providing directional tactile cues reflecting plantar pressure measurements during standing and walking. We tested the null hypothesis that the Functional Gait Assessment (FGA) score would remain unchanged after 10 weeks of use. METHODS: Participants had PN with lost plantar sensation, gait and balance problems, an FGA score < 23 (high fall risk), and ability to sense tactile stimuli above the ankle. Clinical outcomes included FGA, Gait Speed, Timed Up&Go (TUG) and 4-Stage Balance Test. Patient-reported outcomes included Activities-Specific Balance Confidence (ABC) scale, Vestibular Disorders Activities of Daily Living Scale, PROMIS participation and satisfaction scores, pain rating, and falls. Evaluations were performed at baseline and after 2, 6, and 10 weeks. Subjects were not made aware of changes in outcomes. No additional balance interventions were allowed. RESULTS: Forty-five participants of 52 enrolled across four sites completed in-clinic assessments. FGA scores improved from 15.0 to 19.1 (p < 0.0001), normal and fast gait speed from 0.86 m/s to 0.95 m/s (p < 0.0001) and 1.24 m/s to 1.33 m/s (p = 0.002), respectively, and TUG from 13.8 s to 12.5 s (p = 0.012). Four-Stage Balance Test did not improve. Several patient-reported outcomes were normal at baseline and remained largely unchanged. Interestingly, subjects with baseline ABC scores lower than 67% (high fall risk cut-off) increased their ABC scores (49.9% to 59.3%, p = 0.01), whereas subjects with ABC scores above 67% showed a decrease (76.6% to 71.8%, p = 0.019). Subjects who reported falls in the prior 6 months (n = 25) showed a decrease in the number of fall-risk factors (5.1 to 4.3, p = 0.023) and a decrease in fall rate (13.8 to 7.4 falls/1000 days, p = 0.014). Four pre-study non-fallers (n = 20) fell during the 10 weeks. CONCLUSION: A wearable sensory prosthesis presents a new way to treat gait and balance problems and manage falls in high fall-risk patients with PN. TRIAL REGISTRATION: ClinicalTrials.gov (#NCT03538756).

12.
Cell Death Dis ; 10(3): 196, 2019 02 27.
Artigo em Inglês | MEDLINE | ID: mdl-30814495

RESUMO

ß-dystroglycan (ß-DG) is a key component of multiprotein complexes in the plasma membrane and nuclear envelope. In addition, ß-DG undergoes two successive proteolytic cleavages that result in the liberation of its intracellular domain (ICD) into the cytosol and nucleus. However, stimuli-inducing ICD cleavage and the physiological relevance of this proteolytic fragment are largely unknown. In this study we show for the first time that ß-DG ICD is targeted to the nucleolus where it interacts with the nuclear proteins B23 and UBF (central factor of Pol I-mediated rRNA gene transcription) and binds to rDNA promoter regions. Interestingly DG silencing results in reduced B23 and UBF levels and aberrant nucleolar morphology. Furthermore, ß-DG ICD cleavage is induced by different nucleolar stressors, including oxidative stress, acidosis, and UV irradiation, which implies its participation in the response to nucleolar stress. Consistent with this idea, overexpression of ß-DG elicited mislocalization and decreased levels of UBF and suppression of rRNA expression, which in turn provoked altered ribosome profiling and decreased cell growth. Collectively our data reveal that ß-DG ICD acts as negative regulator of rDNA transcription by impeding the transcriptional activity of UBF, as a part of the protective mechanism activated in response to nucleolar stress.


Assuntos
Nucléolo Celular/metabolismo , Distroglicanas/metabolismo , Proteínas Pol1 do Complexo de Iniciação de Transcrição/metabolismo , RNA Ribossômico/biossíntese , Animais , Proliferação de Células/genética , Citoplasma/metabolismo , DNA Ribossômico/genética , DNA Ribossômico/metabolismo , Distroglicanas/antagonistas & inibidores , Distroglicanas/genética , Camundongos , Mioblastos , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Nucleofosmina , Estresse Oxidativo , Proteínas Pol1 do Complexo de Iniciação de Transcrição/genética , Domínios Proteicos/genética , RNA Ribossômico/genética , Ribossomos/metabolismo , Transcrição Gênica , Regulação para Cima/genética
13.
Sci Rep ; 8(1): 17785, 2018 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-30531996

RESUMO

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has been fixed in the paper.

14.
Nanoscale ; 10(3): 881-906, 2018 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-29265147

RESUMO

Extracellular Vesicles (EVs) are gaining interest as central players in liquid biopsies, with potential applications in diagnosis, prognosis and therapeutic guidance in most pathological conditions. These nanosized particles transmit signals determined by their protein, lipid, nucleic acid and sugar content, and the unique molecular pattern of EVs dictates the type of signal to be transmitted to recipient cells. However, their small sizes and the limited quantities that can usually be obtained from patient-derived samples pose a number of challenges to their isolation, study and characterization. These challenges and some possible options to overcome them are discussed in this review.


Assuntos
Vesículas Extracelulares/química , Carboidratos , Humanos , Lipídeos , Ácidos Nucleicos , Prognóstico , Proteínas
15.
Oncotarget ; 8(45): 78917-78929, 2017 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-29108275

RESUMO

Aberrant B-cell receptor (BCR) signaling is known to contribute to malignant transformation. Two small molecule inhibitors targeting BCR pathway signaling include ibrutinib, a Bruton's tyrosine kinase (BTK) inhibitor, and idelalisib, a specific Phosphatidylinositol-4,5-bisphosphate 3-kinase delta (PI3Kδ) inhibitor, both of which have been approved for use in haematological malignancies. Despite the identification of various diffuse large B-cell lymphoma (DLBCL) subtypes, mutation status alone is not sufficient to predict patient response and therapeutic resistance can arise. Herein we apply early molecular imaging across alternative activated B-cell (ABC) and germinal center B-cell (GCB) DLBCL subtypes to investigate the effects of BCR pathway inhibition. Treatment with both inhibitors adversely affected cell growth and viability. These effects were partially predictable based upon mutation status. Accordingly, very early 2-deoxy-2-[18F]fluoro-D-glucose positron emission tomography (18F-FDG-PET) and 3'-deoxy-3'[18F]-fluorothymidine positron emission tomography (18F-FLT-PET) reported tumour regression and reductions in tumour metabolism and proliferation upon treatment. Furthermore, matrix-assisted laser desorption ionization imaging mass spectrometry (MALDI IMS) identified alterations in the proteome of a model of ABC DLBCL upon treatment with ibrutinib or idelalisib. In conclusion we demonstrate that very early molecular imaging adds predictive value in addition to mutational status of DLBCL that may be useful in directing patient therapy.

16.
Sci Rep ; 7(1): 9906, 2017 08 29.
Artigo em Inglês | MEDLINE | ID: mdl-28852008

RESUMO

ß-Dystroglycan (ß-DG) is a transmembrane protein with critical roles in cell adhesion, cytoskeleton remodeling and nuclear architecture. This functional diversity is attributed to the ability of ß-DG to target to, and conform specific protein assemblies at the plasma membrane (PM) and nuclear envelope (NE). Although a classical NLS and importin α/ß mediated nuclear import pathway has already been described for ß-DG, the intracellular trafficking route by which ß-DG reaches the nucleus is unknown. In this study, we demonstrated that ß-DG undergoes retrograde intracellular trafficking from the PM to the nucleus via the endosome-ER network. Furthermore, we provided evidence indicating that the translocon complex Sec61 mediates the release of ß-DG from the ER membrane, making it accessible for importins and nuclear import. Finally, we show that phosphorylation of ß-DG at Tyr890 is a key stimulus for ß-DG nuclear translocation. Collectively our data describe the retrograde intracellular trafficking route that ß-DG follows from PM to the nucleus. This dual role for a cell adhesion receptor permits the cell to functionally connect the PM with the nucleus and represents to our knowledge the first example of a cell adhesion receptor exhibiting retrograde nuclear trafficking and having dual roles in PM and NE.

17.
J Extracell Vesicles ; 6(1): 1340746, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28717426

RESUMO

Cells naïve to stress can display the effects of stress, such as DNA damage and apoptosis, when they are exposed to signals from stressed cells; this phenomenon is known as the bystander effect. We previously showed that bystander effect induced by ionising radiation are mediated by extracellular vesicles (EVs). Bystander effect can also be induced by other types of stress, including heat shock, but it is unclear whether EVs are involved. Here we show that EVs released from heat shocked cells are also able to induce bystander damage in unstressed populations. Naïve cells treated with media conditioned by heat shocked cells showed higher levels of DNA damage and apoptosis than cells treated with media from control cells. Treating naïve cells with EVs derived from media conditioned by heat shocked cells also induced a bystander effect when compared to control, with DNA damage and apoptosis increasing whilst the level of cell viability was reduced. We demonstrate that treatment of naïve cells with heat shocked cell-derived EVs leads to greater invasiveness in a trans-well Matrigel assay. Finally, we show that naïve cells treated with EVs from heat-shocked cells are more likely to survive a subsequent heat shock, suggesting that these EVs mediate an adaptive response. We propose that EVs released following stress mediate an intercellular response that leads to apparent stress in neighbouring cells but also greater robustness in the face of a subsequent insult.

18.
Blood ; 129(5): 598-608, 2017 02 02.
Artigo em Inglês | MEDLINE | ID: mdl-28064214

RESUMO

Burkitt lymphoma (BL) is an aggressive B-cell neoplasm that is currently treated by intensive chemotherapy in combination with anti-CD20 antibodies. Because of their toxicity, current treatment regimens are often not suitable for elderly patients or for patients in developing countries where BL is endemic. Targeted therapies for BL are therefore needed. In this study, we performed a compound screen in 17 BL cell lines to identify small molecule inhibitors affecting cell survival. We found that inhibitors of heat shock protein 90 (HSP90) induced apoptosis in BL cells in vitro at concentrations that did not affect normal B cells. By global proteomic and phosphoproteomic profiling, we show that, in BL, HSP90 inhibition compromises the activity of the pivotal B-cell antigen receptor (BCR)-proximal effector spleen tyrosine kinase (SYK), which we identified as an HSP90 client protein. Consistently, expression of constitutively active TEL-SYK counteracted the apoptotic effect of HSP90 inhibition. Together, our results demonstrate that HSP90 inhibition impairs BL cell survival by interfering with tonic BCR signaling, thus providing a molecular rationale for the use of HSP90 inhibitors in the treatment of BL.


Assuntos
Linfoma de Burkitt/metabolismo , Proteínas de Choque Térmico HSP90/metabolismo , Receptores de Antígenos de Linfócitos B/metabolismo , Transdução de Sinais , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Linfócitos B/efeitos dos fármacos , Linfócitos B/metabolismo , Linfócitos B/patologia , Linfoma de Burkitt/tratamento farmacológico , Linfoma de Burkitt/patologia , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Proteínas de Choque Térmico HSP90/antagonistas & inibidores , Humanos , Proteínas de Fusão Oncogênica/metabolismo , Transdução de Sinais/efeitos dos fármacos , Quinase Syk/metabolismo
19.
Nat Med ; 22(7): 735-43, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-27294876

RESUMO

Immunomodulatory drugs (IMiDs), such as thalidomide and its derivatives lenalidomide and pomalidomide, are key treatment modalities for hematologic malignancies, particularly multiple myeloma (MM) and del(5q) myelodysplastic syndrome (MDS). Cereblon (CRBN), a substrate receptor of the CRL4 ubiquitin ligase complex, is the primary target by which IMiDs mediate anticancer and teratogenic effects. Here we identify a ubiquitin-independent physiological chaperone-like function of CRBN that promotes maturation of the basigin (BSG; also known as CD147) and solute carrier family 16 member 1 (SLC16A1; also known as MCT1) proteins. This process allows for the formation and activation of the CD147-MCT1 transmembrane complex, which promotes various biological functions, including angiogenesis, proliferation, invasion and lactate export. We found that IMiDs outcompete CRBN for binding to CD147 and MCT1, leading to destabilization of the CD147-MCT1 complex. Accordingly, IMiD-sensitive MM cells lose CD147 and MCT1 expression after being exposed to IMiDs, whereas IMiD-resistant cells retain their expression. Furthermore, del(5q) MDS cells have elevated CD147 expression, which is attenuated after IMiD treatment. Finally, we show that BSG (CD147) knockdown phenocopies the teratogenic effects of thalidomide exposure in zebrafish. These findings provide a common mechanistic framework to explain both the teratogenic and pleiotropic antitumor effects of IMiDs.


Assuntos
Basigina/efeitos dos fármacos , Proteínas de Ciclo Celular/efeitos dos fármacos , Fatores Imunológicos/farmacologia , Imunossupressores/farmacologia , Proteínas Oncogênicas/efeitos dos fármacos , Peptídeo Hidrolases/efeitos dos fármacos , RNA Mensageiro/efeitos dos fármacos , Teratogênese/efeitos dos fármacos , Talidomida/farmacologia , Proteínas Adaptadoras de Transdução de Sinal , Basigina/genética , Basigina/metabolismo , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Humanos , Lenalidomida , Mieloma Múltiplo/tratamento farmacológico , Mieloma Múltiplo/genética , Mieloma Múltiplo/metabolismo , Síndromes Mielodisplásicas/tratamento farmacológico , Síndromes Mielodisplásicas/genética , Síndromes Mielodisplásicas/metabolismo , Proteínas Oncogênicas/genética , Proteínas Oncogênicas/metabolismo , Peptídeo Hidrolases/genética , Peptídeo Hidrolases/metabolismo , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transdução de Sinais/efeitos dos fármacos , Teratogênese/genética , Talidomida/análogos & derivados , Ubiquitina-Proteína Ligases
20.
EMBO Mol Med ; 8(8): 851-62, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27317434

RESUMO

The mitotic spindle assembly checkpoint (SAC) maintains genome stability and marks an important target for antineoplastic therapies. However, it has remained unclear how cells execute cell fate decisions under conditions of SAC-induced mitotic arrest. Here, we identify USP9X as the mitotic deubiquitinase of the X-linked inhibitor of apoptosis protein (XIAP) and demonstrate that deubiquitylation and stabilization of XIAP by USP9X lead to increased resistance toward mitotic spindle poisons. We find that primary human aggressive B-cell lymphoma samples exhibit high USP9X expression that correlate with XIAP overexpression. We show that high USP9X/XIAP expression is associated with shorter event-free survival in patients treated with spindle poison-containing chemotherapy. Accordingly, aggressive B-cell lymphoma lines with USP9X and associated XIAP overexpression exhibit increased chemoresistance, reversed by specific inhibition of either USP9X or XIAP. Moreover, knockdown of USP9X or XIAP significantly delays lymphoma development and increases sensitivity to spindle poisons in a murine Eµ-Myc lymphoma model. Together, we specify the USP9X-XIAP axis as a regulator of the mitotic cell fate decision and propose that USP9X and XIAP are potential prognostic biomarkers and therapeutic targets in aggressive B-cell lymphoma.


Assuntos
Antineoplásicos/farmacologia , Linfócitos B/efeitos dos fármacos , Morte Celular , Resistência a Medicamentos , Linfoma de Células B/patologia , Ubiquitina Tiolesterase/metabolismo , Proteínas Inibidoras de Apoptose Ligadas ao Cromossomo X/metabolismo , Animais , Linfócitos B/fisiologia , Células Cultivadas , Modelos Animais de Doenças , Humanos , Camundongos , Mitose , Processamento de Proteína Pós-Traducional , Ubiquitina/metabolismo
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