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2.
BMJ Open Qual ; 12(2)2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-37019468

RESUMO

Clinical classification systems have proliferated since the APGAR score was introduced in 1953. Numerical scores and classification systems enable qualitative clinical descriptors to be transformed into categorical data, with both clinical utility and ability to provide a common language for learning. The clarity of classification rubrics embedded in a mortality classification system provides the shared basis for discussion and comparison of results. Mortality audits have been long seen as learning tools, but have tended to be siloed within a department and driven by individual learner need. We suggest that the learning needs of the system are also important. Therefore, the ability to learn from small mistakes and problems, rather than just from serious adverse events, remains facilitated.We describe a mortality classification system developed for use in the low-resource context and how it is 'fit for purpose,' able to drive both individual trainee, departmental and system learning. The utility of this classification system is that it addresses the low-resource context, including relevant factors such as limited prehospital emergency care, delayed presentation, and resource constraints. We describe five categories: (1) anticipated death or complication following terminal illness; (2) expected death or complication given clinical situation, despite taking preventive measures; (3) unexpected death or complication, not reasonably preventable; (4) potentially preventable death or complication: quality or systems issues identified and (5) unexpected death or complication resulting from medical intervention. We document how this classification system has driven learning at the individual trainee level, the departmental level, supported cross learning between departments and is being integrated into a comprehensive system-wide learning tool.


Assuntos
Serviços Médicos de Emergência , Humanos , Quênia , Cuidados Paliativos , Hospitais
5.
Front Immunol ; 13: 794684, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35720386

RESUMO

Immunotherapies such as checkpoint blockade therapies are known to enhance anti-melanoma CD8+ T cell immunity, but only a fraction of patients treated with these therapies achieve durable immune response and disease control. It may be that CD8+ T cells need help from other immune cells to generate effective and long-lasting anti-tumor immunity or that CD8+ T cells alone are insufficient for complete tumor regression and cure. Melanoma contains significant numbers of B cells; however, the role of B cells in anti-melanoma immunity is controversial. In this study, B16 melanoma mouse models were used to determine the role of B cells in anti-melanoma immunity. C57BL/6 mice, B cell knockout (KO) C57BL/6 mice, anti-CD19, and anti-CXCL13 antibody-treated C57BL/6 mice were used to determine treatment efficacy and generation of tumor-specific CD8+ T cells in response to PD-L1 blockade alone or combination with TLR-7/8 activation. Whole transcriptome analysis was performed on the tumors from B cell depleted and WT mice, untreated or treated with anti-PD-L1. Both CD40-positive and CD40-negative B cells were isolated from tumors of TLR-7/8 agonist-treated wild-type mice and adoptively transferred into tumor-bearing B cell KO mice, which were treated with anti-PD-L1 and TLR-7/8 agonist. Therapeutic efficacy was determined in the presence of activated or inactivated B cells. Microarray analysis was performed on TLR-7/8-treated tumors to look for the B cell signatures. We found B cells were required to enhance the therapeutic efficacy of monotherapy with anti-PD-L1 antibody and combination therapy with anti-PD-L1 antibody plus TLR-7/8 agonist. However, B cells were not essential for anti-CTLA-4 antibody activity. Interestingly, CD40-positive but not CD40-negative B cells contributed to anti-melanoma immunity. In addition, melanoma patients' TCGA data showed that the presence of B cell chemokine CXCL13 and B cells together with CD8+ T cells in tumors were strongly associated with improved overall survival. Our transcriptome data suggest that the absence of B cells enhances immune checkpoints expression in the tumors microenvironment. These results revealed the importance of B cells in the generation of effective anti-melanoma immunity in response to PD-1-PD-L1 blockade immunotherapy. Our findings may facilitate the design of more effective anti-melanoma immunotherapy.


Assuntos
Linfócitos T CD8-Positivos , Melanoma Experimental , Animais , Anticorpos/uso terapêutico , Humanos , Imunoterapia/métodos , Camundongos , Camundongos Endogâmicos C57BL , Receptor 7 Toll-Like , Microambiente Tumoral
6.
Facial Plast Surg Aesthet Med ; 24(3): 233-238, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35724255

RESUMO

Background: Postoperative rhinoplasty infection can lead to serious cosmetic deformity, loss of structural integrity to the nose, and functional deficiencies. Understanding the factors contributing to postoperative infection is important. Microbial biofilms and persister cells play an important role in health care-associated infections. The objective of this study is to identify microbial biofilm and persister cells in the nasal soft tissue of patients undergoing revision rhinoplasty. Methods: Fourteen patients undergoing rhinoplasty were recruited for this study. Nasal soft tissue was removed during rhinoplasty and preserved in 2% paraformaldehyde/2.5% glutaraldehyde. High-resolution images were then obtained from these nasal soft tissue samples. Results: Three samples were positive for the presence of microbial persister cells or biofilms. All samples came from patients undergoing revision rhinoplasty. These patients had between one to six previous rhinoplasty procedures and one patient had previous injectable nasal filler. Conclusions: Biofilms and persister cells are able to form in nasal soft tissue of revision rhinoplasty patients in the absence of an implant and may contribute to increased postoperative infection risk.


Assuntos
Deformidades Adquiridas Nasais , Rinoplastia , Biofilmes , Humanos , Nariz/cirurgia , Deformidades Adquiridas Nasais/cirurgia , Complicações Pós-Operatórias/cirurgia , Reoperação , Rinoplastia/métodos
7.
Ann Surg Open ; 3(1): e141, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37600110

RESUMO

Objective: We describe a structured approach to developing a standardized curriculum for surgical trainees in East, Central, and Southern Africa (ECSA). Summary Background Data: Surgical education is essential to closing the surgical access gap in ECSA. Given its importance for surgical education, the development of a standardized curriculum was deemed necessary. Methods: We utilized Kern's 6-step approach to curriculum development to design an online, modular, flipped-classroom surgical curriculum. Steps included global and targeted needs assessments, determination of goals and objectives, the establishment of educational strategies, implementation, and evaluation. Results: Global needs assessment identified the development of a standardized curriculum as an essential next step in the growth of surgical education programs in ECSA. Targeted needs assessment of stakeholders found medical knowledge challenges, regulatory requirements, language variance, content gaps, expense and availability of resources, faculty numbers, and content delivery method to be factors to inform curriculum design. Goals emerged to increase uniformity and consistency in training, create contextually relevant material, incorporate best educational practices, reduce faculty burden, and ease content delivery and updates. Educational strategies centered on developing an online, flipped-classroom, modular curriculum emphasizing textual simplicity, multimedia components, and incorporation of active learning strategies. The implementation process involved establishing thematic topics and subtopics, the content of which was authored by regional surgeon educators and edited by content experts. Evaluation was performed by recording participation, soliciting user feedback, and evaluating scores on a certification examination. Conclusions: We present the systematic design of a large-scale, context-relevant, data-driven surgical curriculum for the ECSA region.

9.
J Immunol ; 206(8): 1966-1975, 2021 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-33722878

RESUMO

Inflammation has long been associated with cancer initiation and progression; however, how inflammation causes immune suppression in the tumor microenvironment and resistance to immunotherapy is not well understood. In this study, we show that both innate proinflammatory cytokine IL-1α and immunotherapy-induced IL-1α make melanoma resistant to immunotherapy. In a mouse melanoma model, we found that tumor size was inversely correlated with response to immunotherapy. Large tumors had higher levels of IL-1α, Th2 cytokines, polymorphonuclear myeloid-derived suppressor cells (PMN-MDSCs), and regulatory T cells but lower levels of IL-12, Th1 cytokines, and activated T cells. We found that therapy with adenovirus-encoded CD40L (rAd.CD40L) increased tumor levels of IL-1α and PMN-MDSCs. Blocking the IL-1 signaling pathway significantly decreased rAd.CD40L-induced PMN-MDSCs and their associated PD-L1 expression in the tumor microenvironment and enhanced tumor-specific immunity. Similarly, blocking the IL-1 signaling pathway improved the antimelanoma activity of anti-PD-L1 Ab therapy. Our study suggests that blocking the IL-1α signaling pathway may increase the efficacy of immunotherapies against melanoma.


Assuntos
Resistencia a Medicamentos Antineoplásicos/imunologia , Inibidores de Checkpoint Imunológico/uso terapêutico , Imunoterapia/métodos , Interleucina-1alfa/imunologia , Melanoma Experimental/terapia , Animais , Linhagem Celular Tumoral , Citocinas/imunologia , Citocinas/metabolismo , Humanos , Inibidores de Checkpoint Imunológico/imunologia , Interleucina-1alfa/metabolismo , Estimativa de Kaplan-Meier , Melanoma Experimental/imunologia , Camundongos Endogâmicos C57BL , Células Supressoras Mieloides/imunologia , Células Supressoras Mieloides/metabolismo , Neutrófilos/imunologia , Neutrófilos/metabolismo , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/imunologia , Microambiente Tumoral/efeitos dos fármacos , Microambiente Tumoral/imunologia
10.
Cell Metab ; 33(1): 78-93.e7, 2021 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-33406405

RESUMO

Obesity is often linked to malignancies including multiple myeloma, and the underlying mechanisms remain elusive. Here we showed that acetyl-CoA synthetase 2 (ACSS2) may be an important linker in obesity-related myeloma. ACSS2 is overexpressed in myeloma cells derived from obese patients and contributes to myeloma progression. We identified adipocyte-secreted angiotensin II as a direct cause of adiposity in increased ACSS2 expression. ACSS2 interacts with oncoprotein interferon regulatory factor 4 (IRF4), and enhances IRF4 stability and IRF4-mediated gene transcription through activation of acetylation. The importance of ACSS2 overexpression in myeloma is confirmed by the finding that an inhibitor of ACSS2 reduces myeloma growth both in vitro and in a diet-induced obese mouse model. Our findings demonstrate a key impact for obesity-induced ACSS2 on the progression of myeloma. Given the central role of ACSS2 in many tumors, this mechanism could be important to other obesity-related malignancies.


Assuntos
Acetato-CoA Ligase/genética , Mieloma Múltiplo/genética , Obesidade/genética , Acetato-CoA Ligase/metabolismo , Animais , Feminino , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos NOD , Camundongos SCID , Mieloma Múltiplo/metabolismo , Mieloma Múltiplo/patologia , Obesidade/metabolismo
11.
Front Immunol ; 11: 1816, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32903557

RESUMO

Intravenous immunoglobulin G (IVIgG) is approved for primary immunodeficiency syndromes but may induce anti-cancer effects, and while this has been attributed to its anti-inflammatory properties, IgG against specific tumor targets may play a role. We evaluated IVIgG alone, and with a Heat shock protein (HSP)-90 or proteasome inhibitor, using multiple myeloma and mantle cell lymphoma (MCL) cells in vitro, and with the proteasome inhibitor bortezomib in vivo. IVIgG inhibited the growth of all cell lines tested, induced G1 cell cycle arrest, and suppressed pro-tumor cytokines including Interleukin (IL)-6, IL-8, and IL-10. Genomic and proteomic studies showed that IVIgG reduced tumor cell HSP70-1 levels by suppressing the ability of extracellular HSP70-1 to stimulate endogenous HSP70-1 promoter activity, and reduced extracellular vesicle uptake. Preparations of IVIgG were found to contain high titers of anti-HSP70-1 IgG, and recombinant HSP70-1 reduced the efficacy of IVIgG to suppress HSP70-1 levels. Combining IVIgG with the HSP90 inhibitor AUY922 produced superior cell growth inhibition and correlated with HSP70-1 suppression. Also, IVIgG with bortezomib or carfilzomib was superior to each single agent, and enhanced bortezomib's activity in bortezomib-resistant myeloma cells. Moreover, IVIgG reduced transfer of extracellular vesicles (EVs) to cells, and blocked transfer of bortezomib resistance through EVs. Finally, IVIgG with bortezomib were superior to the single agents in an in vivo myeloma model. These studies support the possibility that anti-HSP70-1 IgG contained in IVIgG can inhibit myeloma and MCL growth by interfering with a novel mechanism involving uptake of exogenous HSP70-1 which then induces its own promoter.


Assuntos
Proteínas de Choque Térmico HSP70/efeitos dos fármacos , Imunoglobulinas Intravenosas/farmacologia , Linfoma de Célula do Manto/imunologia , Mieloma Múltiplo/imunologia , Animais , Antineoplásicos/farmacologia , Bortezomib/farmacologia , Linhagem Celular Tumoral , Proteínas de Choque Térmico HSP70/biossíntese , Proteínas de Choque Térmico HSP90/imunologia , Humanos , Camundongos , Camundongos SCID , Inibidores de Proteassoma/farmacologia , Ensaios Antitumorais Modelo de Xenoenxerto
12.
Elife ; 92020 08 03.
Artigo em Inglês | MEDLINE | ID: mdl-32744503

RESUMO

Parasitic helminths use two benzoquinones as electron carriers in the electron transport chain. In normoxia, they use ubiquinone (UQ), but in anaerobic conditions inside the host, they require rhodoquinone (RQ) and greatly increase RQ levels. We previously showed the switch from UQ to RQ synthesis is driven by a change of substrates by the polyprenyltransferase COQ-2 (Del Borrello et al., 2019; Roberts Buceta et al., 2019); however, the mechanism of substrate selection is not known. Here, we show helminths synthesize two coq-2 splice forms, coq-2a and coq-2e, and the coq-2e-specific exon is only found in species that synthesize RQ. We show that in Caenorhabditis elegans COQ-2e is required for efficient RQ synthesis and survival in cyanide. Importantly, parasites switch from COQ-2a to COQ-2e as they transit into anaerobic environments. We conclude helminths switch from UQ to RQ synthesis principally via changes in the alternative splicing of coq-2.


Assuntos
Alquil e Aril Transferases/genética , Processamento Alternativo , Proteínas de Caenorhabditis elegans/genética , Caenorhabditis elegans/genética , Ubiquinona/análogos & derivados , Alquil e Aril Transferases/metabolismo , Animais , Caenorhabditis elegans/enzimologia , Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/metabolismo , Nematoides/enzimologia , Nematoides/genética , Nematoides/metabolismo , Oxirredução , Platelmintos/enzimologia , Platelmintos/genética , Platelmintos/metabolismo , Ubiquinona/metabolismo
13.
J Immunother Cancer ; 8(1)2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-32114502

RESUMO

BACKGROUND: The immunosuppressive desmoplastic stroma of pancreatic cancer represents a major hurdle to developing an effective immune response. Preclinical studies in pancreatic cancer have demonstrated promising anti-tumor activity with Bruton tyrosine kinase (BTK) inhibition combined with programmed cell death receptor-1 (PD-1) blockade. METHODS: This was a phase II, multicenter, open-label, randomized (1:1) clinical trial evaluating the BTK inhibitor acalabrutinib, alone (monotherapy) or in combination with the anti-PD-1 antibody pembrolizumab (combination therapy). Eligible patients were adults with histologically confirmed metastatic or locally advanced unresectable pancreatic ductal adenocarcinoma with an Eastern Cooperative Oncology Group Performance Status (ECOG PS) ≤1 who had received at least one prior systemic therapy. Oral acalabrutinib 100 mg twice daily was administered with or without intravenous pembrolizumab 200 mg on day 1 of each 3-week cycle. Peripheral blood was analyzed for changes in immune markers, and tumors from exceptional responders were molecularly analyzed. RESULTS: A total of 77 patients were enrolled (37 monotherapy; 40 combination therapy) with a median age of 64 years; 77% had an ECOG PS of 1. The median number of prior therapies was 3 (range 1-6). Grade 3-4 treatment-related adverse events were seen in 14.3% of patients in the monotherapy arm and 15.8% of those in the combination therapy arm. The overall response rate and disease control rate were 0% and 14.3% with monotherapy and 7.9% and 21.1% with combination therapy, respectively. Median progression-free survival was 1.4 months in both arms. Peripheral blood flow analysis demonstrated consistent reductions in granulocytic (CD15+) myeloid-derived suppressor cells (MDSCs) over time. Two exceptional responders were found to be microsatellite stable with low tumor mutation burden, low neoantigen load and no defects in the homologous DNA repair pathway. CONCLUSIONS: The combination of acalabrutinib and pembrolizumab was well tolerated, but limited clinical activity was seen with either acalabrutinib monotherapy or combination therapy. Peripheral reductions in MDSCs were seen. Efforts to understand and target the pancreatic tumor microenvironment should continue. TRIAL REGISTRATION NUMBER: NCT02362048.


Assuntos
Tirosina Quinase da Agamaglobulinemia/antagonistas & inibidores , Anticorpos Monoclonais Humanizados/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Benzamidas/administração & dosagem , Carcinoma Ductal Pancreático/tratamento farmacológico , Neoplasias Pancreáticas/tratamento farmacológico , Pirazinas/administração & dosagem , Administração Intravenosa , Administração Oral , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticorpos Monoclonais Humanizados/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Benzamidas/efeitos adversos , Carcinoma Ductal Pancreático/diagnóstico , Carcinoma Ductal Pancreático/imunologia , Carcinoma Ductal Pancreático/mortalidade , Esquema de Medicação , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Células Supressoras Mieloides/efeitos dos fármacos , Células Supressoras Mieloides/imunologia , Neoplasias Pancreáticas/diagnóstico , Neoplasias Pancreáticas/imunologia , Neoplasias Pancreáticas/mortalidade , Receptor de Morte Celular Programada 1/antagonistas & inibidores , Receptor de Morte Celular Programada 1/imunologia , Intervalo Livre de Progressão , Estudo de Prova de Conceito , Pirazinas/efeitos adversos , Microambiente Tumoral/efeitos dos fármacos , Microambiente Tumoral/imunologia
14.
Facial Plast Surg ; 36(1): 34-45, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32191957

RESUMO

Refinement of the unsightly nasal tip lobule is one of the most common, yet also one of the most challenging aspects of cosmetic and functional rhinoplasty. In addition to meticulous analysis and precise surgical modification of the tip complex itself, successful tip refinement must also take into account the surrounding nose, especially the adjacent alar lobules. Unless the modified tip complex harmonizes with the adjacent alar lobules to form a symmetric, aesthetically pleasing, and fully functioning nasal base, tip refinement will inevitably fail. Structural interdependency between the alar lobules, the tip cartilages, and the nasal septum (and the myriad individual variations therein) make controlled alar complex refinement a formidable and complex undertaking. Long-term success is contingent upon understanding the full scope of structural tip dynamics, including not only the primary effects of tip refinement, but also potentially undesirable secondary effects that may deform the alae and thus compromise the surgical outcome.


Assuntos
Rinoplastia , Cartilagem , Septo Nasal/cirurgia , Nariz/cirurgia
16.
Haematologica ; 105(7): 1907-1913, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-31601688

RESUMO

The impact of pre-treatment maximum standardized uptake value (SUVmax) on the outcome of follicular lymphoma (FL) following specific frontline regimens has not been explored. We performed a retrospective analysis of 346 patients with advanced stage follicular lymphoma (FL) without histological evidence of transformation, and analyzed the impact of SUVmax on outcome after frontline therapy. Fifty-two (15%) patients had a SUVmax >18, and a large lymph node ≥6 cm was the only factor associating with SUVmax >18 on multivariate analysis (odds ratio 2.7, 95% confidence interval [CI]: 1.3-5.3, P=0.006). The complete response rate was significantly lower among patients treated with non-anthracycline-based regimens if SUVmax was >18 (45% vs 92%, P<0.001), but not among patients treated with R-CHOP (P=1). SUVmax >18 was associated with significantly shorter progression-free survival among patients treated with non-anthracycline-based regimens (77 months vs. not reached, P=0.02), but not among patients treated with R-CHOP (P=0.73). SUVmax >18 associated with shorter overall survival (OS) both in patients treated with R-CHOP (8-year OS 70% vs. 90%, P=0.02) and non-anthracycline-based frontline regimens (8-year OS 50% vs 85%, P=0.001). In conclusion, pre-treatment PET scan has prognostic and predictive value in patients with advanced stage FL receiving frontline treatment.


Assuntos
Fluordesoxiglucose F18 , Linfoma Folicular , Humanos , Linfonodos , Linfoma Folicular/diagnóstico , Linfoma Folicular/tratamento farmacológico , Tomografia por Emissão de Pósitrons , Prognóstico , Estudos Retrospectivos
17.
Facial Plast Surg Clin North Am ; 27(4): 491-504, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31587768

RESUMO

The cephalic trim technique is a popular maneuver that often leads to tip deformities, most notably postsurgical alar retraction (PSAR). We advocate using the external rhinoplasty approach to correct PSAR by (1) releasing and repositioning the retracted alar margin, (2) strengthening and immobilizing the central tip complex using a septal extension graft, (3) suspending and longitudinally tightening the mobilized lateral crural remnant by adjusting crural length to match the sidewall span, and (4) providing direct skeletal support to the repositioned alar margin using articulated alar rim grafts. Using this structural treatment paradigm, we have corrected severe PSAR in the preponderance of secondary rhinoplasty cases.


Assuntos
Cartilagens Nasais/cirurgia , Deformidades Adquiridas Nasais/cirurgia , Reoperação/métodos , Rinoplastia/métodos , Cartilagem Costal/transplante , Humanos , Doença Iatrogênica , Cartilagens Nasais/anatomia & histologia , Deformidades Adquiridas Nasais/etiologia , Rinoplastia/efeitos adversos , Cicatrização
18.
PLoS Pathog ; 15(6): e1007817, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31163079

RESUMO

Schistosome infection persists for decades. Parasites are in close contact with host peripheral blood immune cells, yet little is known about the regulatory interactions between parasites and these immune cells. Here, we report that extracellular vesicles (EVs) released from Schistosoma japonicum are taken up primarily by macrophages and other host peripheral blood immune cells and their miRNA cargo transferred into recipient cells. Uptake of S. japonicum EV miR-125b and bantam miRNAs into host cells increased macrophage proliferation and TNF-α production by regulating the corresponding targets including Pros1, Fam212b, and Clmp. Mice infected with S. japonicum exhibit an increased population of monocytes and elevated levels of TNF-α. Reduction of host monocytes and TNF-α level in S. japonicum infected mice led to a significant reduction in worm and egg burden and pathology. Overall, we demonstrate that S. japonicum EV miRNAs can regulate host macrophages illustrating parasite modulation of the host immune response to facilitate parasite survival. Our findings provide valuable insights into the schistosome-host interaction which may help to develop novel intervention strategies against schistosomiasis.


Assuntos
Vesículas Extracelulares/imunologia , Macrófagos/imunologia , MicroRNAs/imunologia , RNA de Helmintos/imunologia , Schistosoma japonicum/imunologia , Animais , Proteínas de Ligação ao Cálcio , Proteínas de Transporte/imunologia , Proteína de Membrana Semelhante a Receptor de Coxsackie e Adenovirus/imunologia , Macrófagos/parasitologia , Camundongos , Monócitos/imunologia , Monócitos/parasitologia , Células RAW 264.7 , Coelhos , Fator de Necrose Tumoral alfa/imunologia
19.
Sci Transl Med ; 11(494)2019 05 29.
Artigo em Inglês | MEDLINE | ID: mdl-31142679

RESUMO

Osteolytic lesions in multiple myeloma are caused by osteoclast-mediated bone resorption and reduced bone formation. A unique feature of myeloma is a failure of bone healing after successful treatment. We observed adipocytes on trabecular bone near the resorbed area in successfully treated patients. Normal marrow adipocytes, when cocultured with myeloma cells, were reprogrammed and produced adipokines that activate osteoclastogenesis and suppress osteoblastogenesis. These adipocytes have reduced expression of peroxisome proliferator-activated receptor γ (PPARγ) mediated by recruitment of polycomb repressive complex 2 (PRC2), which modifies PPARγ promoter methylation at trimethyl lysine-27 histone H3. We confirmed the importance of methylation in the PPARγ promoter by demonstrating that adipocyte-specific knockout of EZH2, a member of the PRC2, prevents adipocyte reprogramming and reverses bone changes in a mouse model. We validated the strong correlation between the frequency of bone lesions and the expression of EZH2 in marrow adipocytes from patients in remission. These results define a role for adipocytes in genesis of myeloma-associated bone disease and that reversal of adipocyte reprogramming has therapeutic implications.


Assuntos
Adipócitos/patologia , Doenças Ósseas/patologia , Medula Óssea/patologia , Reprogramação Celular , Mieloma Múltiplo/patologia , Adipocinas/metabolismo , Animais , Reabsorção Óssea/patologia , Linhagem Celular Tumoral , Modelos Animais de Doenças , Regulação para Baixo/genética , Proteína Potenciadora do Homólogo 2 de Zeste/metabolismo , Histonas/metabolismo , Humanos , Metilação , Camundongos , Osteoblastos/patologia , Osteogênese , PPAR gama/genética , PPAR gama/metabolismo , Complexo Repressor Polycomb 2/metabolismo , Regiões Promotoras Genéticas/genética , Indução de Remissão , Transdução de Sinais , Fator de Transcrição Sp1/metabolismo , Regulação para Cima/genética
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