Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 8.980
Filtrar
1.
Nat Commun ; 11(1): 3702, 2020 07 24.
Artigo em Inglês | MEDLINE | ID: mdl-32710081

RESUMO

Spinal cord injury (SCI) causes immune dysfunction, increasing the risk of infectious morbidity and mortality. Since bone marrow hematopoiesis is essential for proper immune function, we hypothesize that SCI disrupts bone marrow hematopoiesis. Indeed, SCI causes excessive proliferation of bone marrow hematopoietic stem and progenitor cells (HSPC), but these cells cannot leave the bone marrow, even after challenging the host with a potent inflammatory stimulus. Sequestration of HSPCs in bone marrow after SCI is linked to aberrant chemotactic signaling that can be reversed by post-injury injections of Plerixafor (AMD3100), a small molecule inhibitor of CXCR4. Even though Plerixafor liberates HSPCs and mature immune cells from bone marrow, competitive repopulation assays show that the intrinsic long-term functional capacity of HSPCs is still impaired in SCI mice. Together, our data suggest that SCI causes an acquired bone marrow failure syndrome that may contribute to chronic immune dysfunction.


Assuntos
Transtornos da Insuficiência da Medula Óssea/etiologia , Medula Óssea/metabolismo , Traumatismos da Medula Espinal/complicações , Animais , Medula Óssea/patologia , Células da Medula Óssea , Transtornos da Insuficiência da Medula Óssea/patologia , Proliferação de Células , Quimiocina CXCL12 , Modelos Animais de Doenças , Feminino , Hematopoese , Células-Tronco Hematopoéticas/metabolismo , Compostos Heterocíclicos/farmacologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos NOD , Camundongos Transgênicos , Receptores CXCR4/antagonistas & inibidores , Transdução de Sinais , Traumatismos da Medula Espinal/imunologia
2.
Medicine (Baltimore) ; 99(27): e20904, 2020 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-32629683

RESUMO

BACKGROUND: Our study aimed to analyze differential microRNA expression between myelodysplastic syndromes (MDS) and normal bone marrow, and to identify novel microRNAs relevant to MDS pathogenesis. METHODS: MiRNA microarray analysis was used to profile microRNA expression levels in MDS and normal bone marrow. Quantitative real-time polymerase chain reaction was employed to verify differentially expressed microRNAs. RESULTS: MiRNA microarray analysis showed 96 significantly upregulated (eg, miR-146a-5p, miR-151a-3p, miR-125b-5p) and 198 significantly downregulated (eg, miR-181a-2-3p, miR-124-3p, miR-550a-3p) microRNAs in MDS compared with normal bone marrow. The quantitative real-time polymerase chain reaction confirmed the microarray analysis: expression of six microRNAs (miR-155-5p, miR-146a-5p, miR-151a-3p, miR-221-3p, miR-125b-5p, and miR-10a-5p) was significantly higher in MDS, while 3 microRNAs (miR-181a-2-3p, miR-124-3p, and miR-550a-3p) were significantly downregulated in MDS. Bioinformatics analysis demonstrated that differentially expressed microRNAs might participate in MDS pathogenesis by regulating hematopoiesis, leukocyte migration, leukocyte apoptotic process, and hematopoietic cell lineage. CONCLUSIONS: Our study indicates that differentially expressed microRNAs might play a key role in MDS pathogenesis by regulating potential relevant functional and signaling pathways. Targeting these microRNAs may provide new treatment modalities for MDS.


Assuntos
MicroRNAs/genética , Síndromes Mielodisplásicas/genética , Adulto , Grupo com Ancestrais do Continente Asiático , Medula Óssea/metabolismo , China , Feminino , Perfilação da Expressão Gênica , Humanos , Masculino , Análise em Microsséries , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase em Tempo Real
3.
Diabetes ; 69(9): 1875-1886, 2020 09.
Artigo em Inglês | MEDLINE | ID: covidwho-646761

RESUMO

Individuals with diabetes suffering from coronavirus disease 2019 (COVID-19) exhibit increased morbidity and mortality compared with individuals without diabetes. In this Perspective, we critically evaluate and argue that this is due to a dysregulated renin-angiotensin system (RAS). Previously, we have shown that loss of angiotensin-I converting enzyme 2 (ACE2) promotes the ACE/angiotensin-II (Ang-II)/angiotensin type 1 receptor (AT1R) axis, a deleterious arm of RAS, unleashing its detrimental effects in diabetes. As suggested by the recent reports regarding the pathogenesis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), upon entry into the host, this virus binds to the extracellular domain of ACE2 in nasal, lung, and gut epithelial cells through its spike glycoprotein subunit S1. We put forth the hypothesis that during this process, reduced ACE2 could result in clinical deterioration in COVID-19 patients with diabetes via aggravating Ang-II-dependent pathways and partly driving not only lung but also bone marrow and gastrointestinal pathology. In addition to systemic RAS, the pathophysiological response of the local RAS within the intestinal epithelium involves mechanisms distinct from that of RAS in the lung; however, both lung and gut are impacted by diabetes-induced bone marrow dysfunction. Careful targeting of the systemic and tissue RAS may optimize clinical outcomes in subjects with diabetes infected with SARS-CoV-2.


Assuntos
Angiotensina II/metabolismo , Betacoronavirus/metabolismo , Infecções por Coronavirus/metabolismo , Diabetes Mellitus/metabolismo , Peptidil Dipeptidase A/metabolismo , Pneumonia Viral/metabolismo , Receptor Tipo 1 de Angiotensina/metabolismo , Sistema Renina-Angiotensina , Medula Óssea/metabolismo , Infecções por Coronavirus/mortalidade , Infecções por Coronavirus/fisiopatologia , Humanos , Mucosa Intestinal/metabolismo , Pandemias , Pneumonia Viral/mortalidade , Pneumonia Viral/fisiopatologia , Índice de Gravidade de Doença
5.
Diabetes ; 69(9): 1875-1886, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32669391

RESUMO

Individuals with diabetes suffering from coronavirus disease 2019 (COVID-19) exhibit increased morbidity and mortality compared with individuals without diabetes. In this Perspective, we critically evaluate and argue that this is due to a dysregulated renin-angiotensin system (RAS). Previously, we have shown that loss of angiotensin-I converting enzyme 2 (ACE2) promotes the ACE/angiotensin-II (Ang-II)/angiotensin type 1 receptor (AT1R) axis, a deleterious arm of RAS, unleashing its detrimental effects in diabetes. As suggested by the recent reports regarding the pathogenesis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), upon entry into the host, this virus binds to the extracellular domain of ACE2 in nasal, lung, and gut epithelial cells through its spike glycoprotein subunit S1. We put forth the hypothesis that during this process, reduced ACE2 could result in clinical deterioration in COVID-19 patients with diabetes via aggravating Ang-II-dependent pathways and partly driving not only lung but also bone marrow and gastrointestinal pathology. In addition to systemic RAS, the pathophysiological response of the local RAS within the intestinal epithelium involves mechanisms distinct from that of RAS in the lung; however, both lung and gut are impacted by diabetes-induced bone marrow dysfunction. Careful targeting of the systemic and tissue RAS may optimize clinical outcomes in subjects with diabetes infected with SARS-CoV-2.


Assuntos
Angiotensina II/metabolismo , Betacoronavirus/metabolismo , Infecções por Coronavirus/metabolismo , Diabetes Mellitus/metabolismo , Peptidil Dipeptidase A/metabolismo , Pneumonia Viral/metabolismo , Receptor Tipo 1 de Angiotensina/metabolismo , Sistema Renina-Angiotensina , Medula Óssea/metabolismo , Infecções por Coronavirus/mortalidade , Infecções por Coronavirus/fisiopatologia , Humanos , Mucosa Intestinal/metabolismo , Pandemias , Pneumonia Viral/mortalidade , Pneumonia Viral/fisiopatologia , Índice de Gravidade de Doença
7.
J Cancer Res Clin Oncol ; 146(9): 2241-2253, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32494918

RESUMO

PURPOSE: Bone metastasis is the result of complex crosstalk between tumor cells and bone marrow cells. Bone marrow adipocytes (BMAs) are the most abundant cell type in adult bone marrow. Therefore, we explore the effects of BMAs on bone metastasis in lung cancer. METHODS: RNA-seq was used to compare the mRNA expression level of bone metastatic SBC5 cells and non-bone metastatic SBC3 cells. Rosiglitazone-induced marrow adiposity and intra-femoral injection of SBC5 cells were used to demonstrate the relationship between BMAs and SBC5 cells in vivo. Co-culture system, gene co-expression, gene ontology (GO) enrichment analysis and protein-protein interaction (PPI) network were used to explore the potential mechanism. RESULTS: BMAs specially enhance the invasion of bone metastatic SBC5 instead of non-bone metastatic SBC3 in vitro. SBC5 instead of SBC3 promoted osteoblast and osteoclast differentiation as well as de-differentiation of mature BMAs. Rosiglitazone-induced marrow adiposity significantly enhanced osteolytic lesion induced by SBC5 in vivo. RNA-seq revealed that compared with SBC3, S100A9 and S100A8 genes were the most prominent genes up-regulated in SBC5 cells. High expression of S100A8/9 in SBC5 could be responsible for the crosstalk between lung cancer cells and BMAs. More importantly, interleukin 6 receptor (IL6R), which is adjacent to S100A8/A9 in 1q21.3, was significantly up-regulated by BMAs in vitro. S100A8/A9 (1 µg/ml) could obviously enhance the osteoblastic differentiation and inhibit adipogenic differentiation, whereas TLR4 inhibitor TAK242 (10 µmol/l) significantly attenuated this effect. CONCLUSIONS: Our study suggested that bone marrow adipocyte may communicate with lung cancer cells via 1q21.3 (S100A8/A9-IL6R)-TLR4 pathway to promote osteolytic bone destruction. 1q21.3 (S100A8/A9-IL6R) is a potential target for the treatment of lung cancer bone metastasis.


Assuntos
Adipócitos/metabolismo , Medula Óssea/metabolismo , Osso e Ossos/metabolismo , Neoplasias Pulmonares/metabolismo , Osteólise/metabolismo , Receptores de Interleucina-6/metabolismo , Proteínas S100/metabolismo , Receptor 4 Toll-Like/metabolismo , Animais , Células da Medula Óssea/metabolismo , Linhagem Celular Tumoral , Técnicas de Cocultura/métodos , Feminino , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Osteoblastos/metabolismo , Transdução de Sinais/fisiologia , Regulação para Cima/fisiologia
8.
Nat Commun ; 11(1): 3172, 2020 06 23.
Artigo em Inglês | MEDLINE | ID: mdl-32576838

RESUMO

Bone marrow engraftment of the hematopoietic stem and progenitor cells (HSPCs) involves homing to the vasculatures and lodgment to their niches. How HSPCs transmigrate from the vasculature to the niches is unclear. Here, we show that loss of diaphanous-related formin mDia2 leads to impaired engraftment of long-term hematopoietic stem cells and loss of competitive HSPC repopulation. These defects are likely due to the compromised trans-endothelial migration of HSPCs since their homing to the bone marrow vasculatures remained intact. Mechanistically, loss of mDia2 disrupts HSPC polarization and induced cytoplasmic accumulation of MAL, which deregulates the activity of serum response factor (SRF). We further reveal that beta2 integrins are transcriptional targets of SRF. Knockout of beta2 integrins in HSPCs phenocopies mDia2 deficient mice. Overexpression of SRF or beta2 integrins rescues HSPC engraftment defects associated with mDia2 deficiency. Our findings show that mDia2-SRF-beta2 integrin signaling is critical for HSPC lodgment to the niches.


Assuntos
Antígenos CD18/metabolismo , Forminas/metabolismo , Células-Tronco Hematopoéticas/fisiologia , Proteínas Associadas aos Microtúbulos/metabolismo , NADPH Desidrogenase/metabolismo , Animais , Medula Óssea/metabolismo , Modelos Animais de Doenças , Forminas/genética , Transplante de Células-Tronco Hematopoéticas , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteínas Associadas aos Microtúbulos/genética , NADPH Desidrogenase/genética , Transdução de Sinais
9.
Proc Natl Acad Sci U S A ; 117(25): 14331-14341, 2020 06 23.
Artigo em Inglês | MEDLINE | ID: mdl-32513686

RESUMO

Acute myeloid leukemia (AML) is the most common acute leukemia in adults, with approximately four new cases per 100,000 persons per year. Standard treatment for AML consists of induction chemotherapy with remission achieved in 50 to 75% of cases. Unfortunately, most patients will relapse and die from their disease, as 5-y survival is roughly 29%. Therefore, other treatment options are urgently needed. In recent years, immune-based therapies have led to unprecedented rates of survival among patients with some advanced cancers. Suppression of T cell function in the tumor microenvironment is commonly observed and may play a role in AML. We found that there is a significant association between T cell infiltration in the bone marrow microenvironment of newly diagnosed patients with AML and increased overall survival. Functional studies aimed at establishing the degree of T cell suppression in patients with AML revealed impaired T cell function in many patients. In most cases, T cell proliferation could be restored by blocking the immune checkpoint molecules PD-1, CTLA-4, or TIM3. Our data demonstrate that AML establishes an immune suppressive environment in the bone marrow, in part through T cell checkpoint function.


Assuntos
Medula Óssea/metabolismo , Leucemia Mieloide Aguda/metabolismo , Linfócitos T/metabolismo , Microambiente Tumoral/fisiologia , Medula Óssea/imunologia , Antígeno CTLA-4/metabolismo , Proliferação de Células , Citocinas/metabolismo , Receptor Celular 2 do Vírus da Hepatite A/metabolismo , Humanos , Leucemia Mieloide Aguda/imunologia , Leucemia Mieloide Aguda/terapia , Receptor de Morte Celular Programada 1/metabolismo , Linfócitos T/imunologia
10.
Nat Commun ; 11(1): 3097, 2020 06 18.
Artigo em Inglês | MEDLINE | ID: mdl-32555194

RESUMO

Bone marrow adipose tissue (BMAT) comprises >10% of total adipose mass, yet unlike white or brown adipose tissues (WAT or BAT) its metabolic functions remain unclear. Herein, we address this critical gap in knowledge. Our transcriptomic analyses revealed that BMAT is distinct from WAT and BAT, with altered glucose metabolism and decreased insulin responsiveness. We therefore tested these functions in mice and humans using positron emission tomography-computed tomography (PET/CT) with 18F-fluorodeoxyglucose. This revealed that BMAT resists insulin- and cold-stimulated glucose uptake, while further in vivo studies showed that, compared to WAT, BMAT resists insulin-stimulated Akt phosphorylation. Thus, BMAT is functionally distinct from WAT and BAT. However, in humans basal glucose uptake in BMAT is greater than in axial bones or subcutaneous WAT and can be greater than that in skeletal muscle, underscoring the potential of BMAT to influence systemic glucose homeostasis. These PET/CT studies characterise BMAT function in vivo, establish new methods for BMAT analysis, and identify BMAT as a distinct, major adipose tissue subtype.


Assuntos
Tecido Adiposo Marrom/metabolismo , Tecido Adiposo Branco/metabolismo , Medula Óssea/metabolismo , Glucose/metabolismo , Animais , Western Blotting , Feminino , Homeostase/fisiologia , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Tomografia por Emissão de Pósitrons , Ratos , Esqueleto/metabolismo
11.
Cell Prolif ; 53(5): e12819, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32372504

RESUMO

OBJECTIVE: The objective of this study was to explore characteristics of bone marrow mesenchymal stromal cells (BM-MSCs) derived from patients with myelodysplastic syndrome (MDS) and multiple myeloma (MM). METHODS: BM-MSCs were recovered from 17 of MDS patients, 23 of MM patients and 9 healthy donors and were passaged until proliferation stopped. General characteristics and gene expression profiles of MSCs were analysed. In vitro, ex vivo coculture, immunohistochemistry and knockdown experiments were performed to verify gene expression changes. RESULTS: BM-MSCs failed to culture in 35.0% of patients and 50.0% of recovered BM-MSCs stopped to proliferate before passage 6. MDS- and MM-MSCs shared characteristics including decreased osteogenesis, increased angiogenesis and senescence-associated molecular pathways. In vitro and ex vivo experiments showed disease-specific changes such as neurogenic tendency in MDS-MSCs and cardiomyogenic tendency in MM-MSCs. Although the age of normal control was younger than patients and telomere length was shorter in patient's BM-MSCs, they were not different according to disease category nor degree of proliferation. Specifically, poorly proliferation BM-MSCs showed CDKN2A overexpression and CXCL12 downregulation. Immunohistochemistry of BM biopsy demonstrated that CDKN2A was intensely accumulation in perivascular BM-MSCs failed to culture. Interestingly, patient's BM-MSCs revealed improved proliferation activity after CDKN2A knockdown. CONCLUSION: These results collectively indicate that MDS-MSCs and MM-MSCs have common and different alterations at various degrees. Hence, it is necessary to evaluate their alteration status using representative markers such as CDKN2A expression.


Assuntos
Medula Óssea/patologia , Células-Tronco Mesenquimais/patologia , Mieloma Múltiplo/patologia , Síndromes Mielodisplásicas/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Medula Óssea/metabolismo , Células da Medula Óssea/metabolismo , Células da Medula Óssea/patologia , Diferenciação Celular/fisiologia , Proliferação de Células/fisiologia , Células Cultivadas , Quimiocina CXCL12/metabolismo , Feminino , Humanos , Masculino , Células-Tronco Mesenquimais/metabolismo , Pessoa de Meia-Idade , Mieloma Múltiplo/metabolismo , Síndromes Mielodisplásicas/metabolismo , Osteogênese/fisiologia , Adulto Jovem
12.
PLoS One ; 15(5): e0233751, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32470079

RESUMO

Mesenchymal stromal cells are an important component of the bone marrow hematopoietic niche. Prior studies showed that signaling from members of the transforming growth factor (TGF) superfamily in mesenchymal stromal cells is required for normal niche development. Here, we assessed the impact of TGF family signaling on niche maintenance and stress responses by deleting Smad4 in mesenchymal stromal cells at birth, thereby abrogating canonical TGF signaling. No alteration in the number or spatial organization of CXCL12-abundant reticular (CAR) cells, osteoblasts, or adipocytes was observed in Osx-Cre, Smad4fl/fl mice, and expression of key niche factors was normal. Basal hematopoiesis and stress erythropoiesis responses to acute hemolytic anemia were normal. TGF-ß potently inhibits stromal CXCL12 expression in vitro; however, G-CSF induced decreases in bone marrow CXCL12 expression and subsequent hematopoietic stem/progenitor cell mobilization were normal in Osx-Cre, Tgfbr2fl/fl mice, in which all TGF-ß signaling in mesenchymal stromal is lost. Finally, although a prior study showed that TGF-ß enhances recovery from myeloablative therapy, hematopoietic recovery following single or multiple doses of 5-flurauracil were normal in Osx-Cre, Tgfbr2fl/fl mice. Collectively, these data suggest that TGF family member signaling in mesenchymal stromal cells is dispensable for hematopoietic niche maintenance under basal and stress conditions.


Assuntos
Anemia Hemolítica/metabolismo , Eritropoese , Células-Tronco Hematopoéticas , Células-Tronco Mesenquimais , Fator de Crescimento Transformador beta/fisiologia , Fatores de Crescimento Transformadores/fisiologia , Doença Aguda , Anemia Hemolítica/patologia , Animais , Medula Óssea/metabolismo , Medula Óssea/patologia , Células Cultivadas , Quimiocina CXCL12/metabolismo , Feminino , Fator Estimulador de Colônias de Granulócitos/farmacologia , Mobilização de Células-Tronco Hematopoéticas , Células-Tronco Hematopoéticas/citologia , Células-Tronco Hematopoéticas/patologia , Masculino , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/patologia , Camundongos , Camundongos Endogâmicos C57BL , Nicho de Células-Tronco
13.
Clin Nucl Med ; 45(6): e296-e298, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32366792

RESUMO

A 24-year-old man, with type 1 primary hyperoxaluria (diagnosed at age 20 years after repeated renal lithiasis, due to a I244T mutation frequently encountered in Mediterranean countries) complicated by end-stage renal failure requiring dialysis, was admitted for pancytopenia, refractory to erythropoietin injections. On clinical examination, he presented a hepatosplenomegaly without palpable adenopathy. F-FDG PET/CT revealed intense and diffuse bone marrow uptake in the axial skeleton and preferential long bone metaphyseal uptake. Bone marrow aspiration showed Gaucher-like cells infiltration due to oxalate accumulation in macrophages, leading to the diagnosis of bone marrow involvement by primary hyperoxaluria.


Assuntos
Medula Óssea/diagnóstico por imagem , Medula Óssea/metabolismo , Fluordesoxiglucose F18 , Hiperoxalúria Primária/diagnóstico por imagem , Hiperoxalúria Primária/metabolismo , Tomografia Computadorizada com Tomografia por Emissão de Pósitrons , Medula Óssea/patologia , Difusão , Humanos , Hiperoxalúria Primária/patologia , Masculino , Adulto Jovem
14.
Nat Commun ; 11(1): 2338, 2020 05 11.
Artigo em Inglês | MEDLINE | ID: mdl-32393754

RESUMO

Single-cell RNA sequencing (scRNA-seq) can characterize cell types and states through unsupervised clustering, but the ever increasing number of cells and batch effect impose computational challenges. We present DESC, an unsupervised deep embedding algorithm that clusters scRNA-seq data by iteratively optimizing a clustering objective function. Through iterative self-learning, DESC gradually removes batch effects, as long as technical differences across batches are smaller than true biological variations. As a soft clustering algorithm, cluster assignment probabilities from DESC are biologically interpretable and can reveal both discrete and pseudotemporal structure of cells. Comprehensive evaluations show that DESC offers a proper balance of clustering accuracy and stability, has a small footprint on memory, does not explicitly require batch information for batch effect removal, and can utilize GPU when available. As the scale of single-cell studies continues to grow, we believe DESC will offer a valuable tool for biomedical researchers to disentangle complex cellular heterogeneity.


Assuntos
Análise por Conglomerados , Aprendizado Profundo , RNA-Seq , Análise de Célula Única , Algoritmos , Animais , Medula Óssea/metabolismo , Regulação da Expressão Gênica , Humanos , Ilhotas Pancreáticas/metabolismo , Leucócitos Mononucleares/metabolismo , Macaca , Camundongos , Monócitos/metabolismo , Retina/metabolismo
15.
Pediatr Blood Cancer ; 67(6): e28280, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32277801

RESUMO

Acute lymphoblastic leukemia (ALL) is often composed of numerous subclones. Here we test whether the clonal composition of the blood is representative of the bone marrow at leukemia onset. Using ultra-deep IGH sequencing, we detected 28 clones across 16 patients; 5/28 were only in the marrow. In four patients, the most abundant clones differed between sites, including three in which the dominant medullary clones were minimally detectable in the blood. These findings demonstrate that the peripheral blood often underrepresents the genetic heterogeneity in a B-ALL and highlight the potential impact of tissue site selection on the detection of minor subclones.


Assuntos
Biomarcadores Tumorais/genética , Medula Óssea/patologia , Evolução Clonal , Células Clonais/patologia , Cadeias Pesadas de Imunoglobulinas/genética , Leucócitos Mononucleares/patologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/patologia , Adolescente , Adulto , Medula Óssea/metabolismo , Criança , Pré-Escolar , Células Clonais/metabolismo , Feminino , Seguimentos , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Leucócitos Mononucleares/metabolismo , Masculino , Pessoa de Meia-Idade , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Prognóstico
16.
Clin Sci (Lond) ; 134(8): 1031-1048, 2020 04 30.
Artigo em Inglês | MEDLINE | ID: mdl-32337536

RESUMO

Global trends in the prevalence of overweight and obesity put the adipocyte in the focus of huge medical interest. This review highlights a new topic in adipose tissue biology, namely the emerging pathogenic role of fat accumulation in bone marrow (BM). Specifically, we summarize current knowledge about the origin and function of BM adipose tissue (BMAT), provide evidence for the association of excess BMAT with diabetes and related cardiovascular complications, and discuss potential therapeutic approaches to correct BMAT dysfunction. There is still a significant uncertainty about the origins and function of BMAT, although several subpopulations of stromal cells have been suggested to have an adipogenic propensity. BM adipocytes are higly plastic and have a distinctive capacity to secrete adipokines that exert local and endocrine functions. BM adiposity is abundant in elderly people and has therefore been interpreted as a component of the whole-body ageing process. BM senescence and BMAT accumulation has been also reported in patients and animal models with Type 2 diabetes, being more pronounced in those with ischaemic complications. Understanding the mechanisms responsible for excess and altered function of BMAT could lead to new treatments able to preserve whole-body homeostasis.


Assuntos
Medula Óssea/metabolismo , Diabetes Mellitus/metabolismo , Gorduras/metabolismo , Adipócitos/metabolismo , Tecido Adiposo/metabolismo , Animais , Diabetes Mellitus/genética , Humanos
17.
J Pathol ; 251(2): 117-122, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32297672

RESUMO

The intestinal epithelium is perpetually renewed from a stem cell niche in the base of crypts to maintain a healthy bowel mucosa. Exit from this niche and maturation of epithelial cells requires tightly controlled gradients in BMP signalling, progressing from low BMP signalling at the crypt base to high signalling at the luminal surface. The BMP antagonist gremlin 1 (Grem1) is highly expressed by subepithelial myofibroblasts adjacent to the intestinal crypts but its role in regulating the stem cell niche and epithelial renewal in vivo has not been explored. To explore the effects of Grem1 loss in adulthood following normal growth and development, we bred mice (ROSA26CreER-Grem1 flx/flx ) in which Grem1 could be deleted by tamoxifen administration. While Grem1 remained intact, these mice were healthy, grew normally, and reproduced successfully. Following Grem1 depletion, the mice became unwell and were euthanised (at 7-13 days). Post-mortem examination revealed extensive mucosal abnormalities throughout the small and large intestines with failure of epithelial cell replication and maturation, villous atrophy, and features of malabsorption. Bone marrow hypoplasia was also observed with associated early haematopoietic failure. These results demonstrate an essential homeostatic role for gremlin 1 in maintaining normal bowel epithelial function in adulthood, suggesting that abnormalities in gremlin 1 expression can contribute to enteropathies. We also identified a previously unsuspected requirement for gremlin 1 in normal haematopoiesis. © 2020 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.


Assuntos
Transtornos da Insuficiência da Medula Óssea/metabolismo , Medula Óssea/metabolismo , Células Epiteliais/metabolismo , Células-Tronco Hematopoéticas/metabolismo , Peptídeos e Proteínas de Sinalização Intercelular/deficiência , Mucosa Intestinal/metabolismo , Síndromes de Malabsorção/metabolismo , Animais , Medula Óssea/patologia , Transtornos da Insuficiência da Medula Óssea/genética , Transtornos da Insuficiência da Medula Óssea/patologia , Linhagem da Célula , Proliferação de Células , Células Epiteliais/patologia , Hematopoese , Células-Tronco Hematopoéticas/patologia , Peptídeos e Proteínas de Sinalização Intercelular/genética , Absorção Intestinal , Mucosa Intestinal/patologia , Síndromes de Malabsorção/genética , Síndromes de Malabsorção/patologia , Masculino , Camundongos Knockout , Fenótipo , Nicho de Células-Tronco
18.
Am J Hematol ; 95(8): 900-905, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32282971

RESUMO

Daratumumab demonstrated activity in the treatment of AL amyloidosis in two recently concluded phase II clinical trials in relapsed and refractory patients. Its role in upfront therapy is under evaluation in a phase III study. In this report we evaluated the safety and efficacy of 28-day cycles of daratumumab (single agent or combined with bortezomib or lenalidomide) in 72 previously treated patients with multiple myeloma and AL amyloidosis. Fifty (69%) were refractory to the last line of therapy. After eight infusions of daratumumab, 59 patients (82%) achieved a hematologic response, with 12 (16%) complete responses (CRs) and 30 (42%) very good partial responses (VGPRs). After 16 infusions, the quality of response improved with 22 patients (30%) achieving CR and 21 (29%) attaining VGPR. Cardiac response was observed in 11 of 37 evaluable patients (29%) and renal response in 23 of 38 patients (60%). Daratumumab is highly effective in heavily pretreated patients with relapsed/refractory AL amyloidosis and high bone marrow plasma cell burden. Renal responses, which are usually rare in this setting, were frequently observed.


Assuntos
Anticorpos Monoclonais/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Medula Óssea/metabolismo , Amiloidose de Cadeia Leve de Imunoglobulina/tratamento farmacológico , Plasmócitos/metabolismo , Adulto , Idoso , Anticorpos Monoclonais/farmacologia , Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento
19.
Nucleic Acids Res ; 48(9): 4658-4671, 2020 05 21.
Artigo em Inglês | MEDLINE | ID: mdl-32313951

RESUMO

Erythropoietic protoporphyria (EPP) is a rare genetic disease in which patients experience acute phototoxic reactions after sunlight exposure. It is caused by a deficiency in ferrochelatase (FECH) in the heme biosynthesis pathway. Most patients exhibit a loss-of-function mutation in trans to an allele bearing a SNP that favors aberrant splicing of transcripts. One viable strategy for EPP is to deploy splice-switching oligonucleotides (SSOs) to increase FECH synthesis, whereby an increase of a few percent would provide therapeutic benefit. However, successful application of SSOs in bone marrow cells is not described. Here, we show that SSOs comprising methoxyethyl-chemistry increase FECH levels in cells. We conjugated one SSO to three prototypical targeting groups and administered them to a mouse model of EPP in order to study their biodistribution, their metabolic stability and their FECH splice-switching ability. The SSOs exhibited distinct distribution profiles, with increased accumulation in liver, kidney, bone marrow and lung. However, they also underwent substantial metabolism, mainly at their linker groups. An SSO bearing a cholesteryl group increased levels of correctly spliced FECH transcript by 80% in the bone marrow. The results provide a promising approach to treat EPP and other disorders originating from splicing dysregulation in the bone marrow.


Assuntos
Ferroquelatase/genética , Oligonucleotídeos/administração & dosagem , Protoporfiria Eritropoética/metabolismo , Processamento de RNA , Albuminas/metabolismo , Animais , Medula Óssea/metabolismo , Células COS , Chlorocebus aethiops , Modelos Animais de Doenças , Ferroquelatase/metabolismo , Humanos , Células K562 , Camundongos , Oligonucleotídeos/sangue , Oligonucleotídeos/química , Oligonucleotídeos/farmacocinética , Polimorfismo de Nucleotídeo Único , Protoporfiria Eritropoética/genética , Protoporfiria Eritropoética/terapia , Sítios de Splice de RNA , Distribuição Tecidual
20.
Adv Exp Med Biol ; 1219: 259-293, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32130704

RESUMO

The human body requires a constant delivery of fresh blood cells that are needed to maintain body homeostasis. Hematopoiesis is the process that drives the formation of new blood cells from a single stem cell. This is a complex, orchestrated and tightly regulated process that occurs within the bone marrow. When such process is faulty or deregulated, leukemia arises, develops and thrives by subverting normal hematopoiesis and availing the supplies of this rich milieu.In this book chapter we will describe and characterize the bone marrow microenvironment and its key importance for leukemia expansion. The several components of the bone marrow niche, their interaction with the leukemic cells and the cellular pathways activated within the malignant cells will be emphasized. Finally, novel therapeutic strategies to target this sibling interaction will also be discussed.


Assuntos
Medula Óssea/metabolismo , Progressão da Doença , Leucemia/patologia , Microambiente Tumoral , Medula Óssea/efeitos dos fármacos , Células da Medula Óssea/efeitos dos fármacos , Células da Medula Óssea/metabolismo , Hematopoese/efeitos dos fármacos , Humanos , Leucemia/tratamento farmacológico , Nicho de Células-Tronco/efeitos dos fármacos , Microambiente Tumoral/efeitos dos fármacos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA