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1.
Cell ; 184(5): 1330-1347.e13, 2021 03 04.
Artigo em Inglês | MEDLINE | ID: mdl-33636130

RESUMO

Osteoclasts are large multinucleated bone-resorbing cells formed by the fusion of monocyte/macrophage-derived precursors that are thought to undergo apoptosis once resorption is complete. Here, by intravital imaging, we reveal that RANKL-stimulated osteoclasts have an alternative cell fate in which they fission into daughter cells called osteomorphs. Inhibiting RANKL blocked this cellular recycling and resulted in osteomorph accumulation. Single-cell RNA sequencing showed that osteomorphs are transcriptionally distinct from osteoclasts and macrophages and express a number of non-canonical osteoclast genes that are associated with structural and functional bone phenotypes when deleted in mice. Furthermore, genetic variation in human orthologs of osteomorph genes causes monogenic skeletal disorders and associates with bone mineral density, a polygenetic skeletal trait. Thus, osteoclasts recycle via osteomorphs, a cell type involved in the regulation of bone resorption that may be targeted for the treatment of skeletal diseases.


Assuntos
Reabsorção Óssea/patologia , Osteoclastos/patologia , Ligante RANK/metabolismo , Animais , Apoptose , Reabsorção Óssea/metabolismo , Fusão Celular , Células Cultivadas , Humanos , Macrófagos/citologia , Camundongos , Osteocondrodisplasias/tratamento farmacológico , Osteocondrodisplasias/genética , Osteocondrodisplasias/metabolismo , Osteocondrodisplasias/patologia , Osteoclastos/metabolismo , Transdução de Sinais
3.
N Engl J Med ; 390(6): 522-529, 2024 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-38324485

RESUMO

A multinational outbreak of nosocomial fusarium meningitis occurred among immunocompetent patients who had undergone surgery with epidural anesthesia in Mexico. The pathogen involved had a high predilection for the brain stem and vertebrobasilar arterial system and was associated with high mortality from vessel injury. Effective treatment options remain limited; in vitro susceptibility testing of the organism suggested that it is resistant to all currently approved antifungal medications in the United States. To highlight the severe complications associated with fusarium infection acquired in this manner, we report data, clinical courses, and outcomes from 13 patients in the outbreak who presented with symptoms after a median delay of 39 days.


Assuntos
Surtos de Doenças , Fusariose , Fusarium , Doença Iatrogênica , Meningite Fúngica , Humanos , Antifúngicos/uso terapêutico , Fusariose/epidemiologia , Fusariose/etiologia , Fusarium/isolamento & purificação , Doença Iatrogênica/epidemiologia , Meningite Fúngica/epidemiologia , Meningite Fúngica/etiologia , México/epidemiologia , Surtos de Doenças/estatística & dados numéricos , Internacionalidade , Imunocompetência , Farmacorresistência Fúngica , Analgesia Epidural/efeitos adversos
4.
Osteoporos Int ; 2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38839655

RESUMO

In severe osteoporosis, the optimal approach for sequential treatment between denosumab and romosozumab is unclear. We utilised a novel overlapping strategy in three patients with very-high fracture risk despite long-term denosumab which led to greater bone density improvements than previously reported with standard approaches. Larger confirmatory prospective studies are needed. PURPOSE/INTRODUCTION: In patients with severe osteoporosis, the optimal approach for sequential treatment between denosumab and romosozumab has not been established. The ideal strategy would maximise gains in bone mineral density (BMD) with romosozumab and effectively mitigate the risk of rebound increased bone turnover when sequencing from denosumab. Limited studies exploring the sequence from denosumab to romosozumab report only modest-to-no improvement in BMD and inadequate suppression of rebound bone turnover. METHODS: We describe three patients with severe osteoporosis and multiple fragility fractures despite long-term denosumab. A novel overlapping sequential treatment approach was utilised to maximise therapeutic benefit given these patients had a very high fracture risk. Romosozumab was commenced 3 months after the last denosumab dose. Instead of waiting until completion of romosozumab, denosumab was recommenced 6 months after commencing romosozumab in response to rising bone turnover markers. RESULTS: Patients experienced a ~ 5-22% increase in lumbar spine BMD, and one patient had an 8% increase in total hip BMD after 12 months romosozumab. Serum bone turnover markers demonstrated an anabolic effect of romosozumab occurred despite overlapping treatment with denosumab. Recommencement of denosumab suppressed an increase in bone resorption in all cases. No new vertebral fractures occurred during this treatment. CONCLUSIONS: A novel overlapping sequential treatment approach between denosumab and romosozumab produced greater improvements in lumbar spine and hip BMD than previously reported with standard approaches. Larger prospective controlled studies are needed to confirm these findings and establish the optimal use of romosozumab in patients pre-treated with denosumab to maximise BMD gains and minimise fracture risk.

5.
Angew Chem Int Ed Engl ; 63(6): e202318459, 2024 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-38105412

RESUMO

Intravital fluorescence imaging of functional osteoclasts within their intact disease context provides valuable insights into the intricate biology at the microscopic level, facilitating the development of therapeutic approaches for osteoclast-associated bone diseases. However, there is a lack of studies investigating osteoclast activity within deep-seated bone lesions using appropriate fluorescent probes, despite the advantages offered by the multi-photon excitation system in enhancing deep tissue imaging resolution. In this study, we report on the intravital tracking of osteoclast activity in three distinct murine bone disease models. We utilized a cathepsin K (CatK)-responsive two-photon fluorogenic probe (CatKP1), which exhibited a notable fluorescence turn-on response in the presence of active CatK. By utilizing CatKP1, we successfully monitored a significant increase in osteoclast activity in hindlimb long bones and its attenuation through pharmacological intervention without sacrificing mice. Thus, our findings highlight the efficacy of CatKP1 as a valuable tool for unraveling pathological osteoclast behavior and exploring novel therapeutic strategies.


Assuntos
Doenças Ósseas , Osteoclastos , Animais , Camundongos , Osteoclastos/patologia , Catepsina K , Osso e Ossos , Doenças Ósseas/patologia , Diagnóstico por Imagem
6.
EMBO Rep ; 21(6): e50162, 2020 06 04.
Artigo em Inglês | MEDLINE | ID: mdl-32314873

RESUMO

The latency associated with bone metastasis emergence in castrate-resistant prostate cancer is attributed to dormancy, a state in which cancer cells persist prior to overt lesion formation. Using single-cell transcriptomics and ex vivo profiling, we have uncovered the critical role of tumor-intrinsic immune signaling in the retention of cancer cell dormancy. We demonstrate that loss of tumor-intrinsic type I IFN occurs in proliferating prostate cancer cells in bone. This loss suppresses tumor immunogenicity and therapeutic response and promotes bone cell activation to drive cancer progression. Restoration of tumor-intrinsic IFN signaling by HDAC inhibition increased tumor cell visibility, promoted long-term antitumor immunity, and blocked cancer growth in bone. Key findings were validated in patients, including loss of tumor-intrinsic IFN signaling and immunogenicity in bone metastases compared to primary tumors. Data herein provide a rationale as to why current immunotherapeutics fail in bone-metastatic prostate cancer, and provide a new therapeutic strategy to overcome the inefficacy of immune-based therapies in solid cancers.


Assuntos
Neoplasias Ósseas , Neoplasias da Próstata , Neoplasias Ósseas/tratamento farmacológico , Neoplasias Ósseas/genética , Humanos , Interferons , Masculino , Neoplasias da Próstata/genética , Transdução de Sinais
7.
Curr Osteoporos Rep ; 20(6): 505-515, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36201122

RESUMO

PURPOSE OF REVIEW: Inhibition of receptor activator of nuclear factor kappa-B ligand (RANKL) with denosumab is an effective treatment in a number of conditions including osteoporosis where suppression of bone resorption is desired. However, denosumab discontinuation is associated with rebound increase in bone resorption and subsequent loss in bone mass and a rapid return to baseline fracture risk. We review recent data on the rebound increase in bone resorption following denosumab discontinuation and the potential mechanisms behind this phenomenon. RECENT FINDINGS: Osteoclasts have been considered to be highly specialised cells that undergo apoptosis after fulfilling their function of bone resorption. However, recent studies suggest that osteoclasts are longer lived cells which migrate through vasculature and are capable of undergoing fission into a novel cell type (the osteomorph) and re-fusion in a process termed osteoclast recycling. The life cycle of the osteoclast is more complex than previously appreciated. Osteoclast recycling provides a novel mechanistic framework to examine changes in osteoclast biology in response to treatment of bone diseases and provides an exciting new avenue towards personalised medicine.


Assuntos
Reabsorção Óssea , Osteoporose , Humanos , Osteoclastos , Denosumab/farmacologia , Denosumab/uso terapêutico , Ligante RANK , Reabsorção Óssea/tratamento farmacológico , Osteoporose/tratamento farmacológico
8.
Blood ; 134(1): 30-43, 2019 07 04.
Artigo em Inglês | MEDLINE | ID: mdl-31023703

RESUMO

The era of targeted therapies has seen significant improvements in depth of response, progression-free survival, and overall survival for patients with multiple myeloma. Despite these improvements in clinical outcome, patients inevitably relapse and require further treatment. Drug-resistant dormant myeloma cells that reside in specific niches within the skeleton are considered a basis of disease relapse but remain elusive and difficult to study. Here, we developed a method to sequence the transcriptome of individual dormant myeloma cells from the bones of tumor-bearing mice. Our analyses show that dormant myeloma cells express a distinct transcriptome signature enriched for immune genes and, unexpectedly, genes associated with myeloid cell differentiation. These genes were switched on by coculture with osteoblastic cells. Targeting AXL, a gene highly expressed by dormant cells, using small-molecule inhibitors released cells from dormancy and promoted their proliferation. Analysis of the expression of AXL and coregulated genes in human cohorts showed that healthy human controls and patients with monoclonal gammopathy of uncertain significance expressed higher levels of the dormancy signature genes than patients with multiple myeloma. Furthermore, in patients with multiple myeloma, the expression of this myeloid transcriptome signature translated into a twofold increase in overall survival, indicating that this dormancy signature may be a marker of disease progression. Thus, engagement of myeloma cells with the osteoblastic niche induces expression of a suite of myeloid genes that predicts disease progression and that comprises potential drug targets to eradicate dormant myeloma cells.


Assuntos
Mieloma Múltiplo/genética , Mieloma Múltiplo/patologia , Recidiva Local de Neoplasia/genética , Células-Tronco Neoplásicas/patologia , Nicho de Células-Tronco/genética , Animais , Humanos , Camundongos , Recidiva Local de Neoplasia/patologia , Proteínas Proto-Oncogênicas/genética , Receptores Proteína Tirosina Quinases/genética , Transcriptoma , Receptor Tirosina Quinase Axl
9.
Clin Transplant ; 35(9): e14403, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34184312

RESUMO

Perioperative pain management is an important consideration in early recovery and patient satisfaction following laparoscopic donor nephrectomy. Transmuscular quadratus lumborum block has been described to reduce pain and opioid usage following several abdominal surgeries. In this prospective single-blind randomized controlled trial, we compared 52 patients who adhered to our institutional donor nephrectomy Early Recovery After Surgery pathway, which includes a laparoscopic-guided transversus abdominus plane block, to 40 patients who additionally received a transmuscular quadratus lumborum block with liposomal bupivacaine. Compared to control patients, those who received the block spent longer in the operating room prior to the surgical start (65.4 vs. 51.6 min, P < .001). Both groups had similar total hospital length of stay (33.3 h vs. 34.4 h, P = .61). Pain scores from postoperative days 0-30, number of patients requiring opioids, postoperative nausea, and pain management satisfaction were similar between both groups. Patients who received the block consumed less opioid on postoperative day 1 compared to controls (P = .006). No complications were attributable to the block. The quadratus lumborum block provides a safe pain management adjunct for some patients, and may reduce opioid use in the early postoperative period when combined with our standard institutional protocol for kidney donors.


Assuntos
Analgesia , Laparoscopia , Analgésicos Opioides/uso terapêutico , Anestésicos Locais , Bupivacaína , Humanos , Nefrectomia , Dor Pós-Operatória/tratamento farmacológico , Dor Pós-Operatória/etiologia , Dor Pós-Operatória/prevenção & controle , Estudos Prospectivos , Método Simples-Cego
10.
Calcif Tissue Int ; 106(2): 172-179, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31578632

RESUMO

Clinical concerns have been raised over prior exposure to bisphosphonates impairing fracture healing. To model this, groups of male Wistar rats were assigned to saline control or treatment groups receiving 0.15 mg/kg (low dose), 0.5 mg/kg (medium dose), and 5 mg/kg (high dose) Pamidronate (PAM) twice weekly for 4 weeks. At this point, closed fractures were made using an Einhorn apparatus, and bisphosphonate dosing was continued until the experimental endpoint. Specimens were analyzed at 2 and 6 weeks (N = 8 per group per time point). Twice weekly PAM dosing was found to have no effect on early soft callus remodeling at 2 weeks post fracture. At this time point, the highest dose PAM group gave significant increases in bone volume (+ 10%, p < 0.05), bone mineral content (+ 30%, p < 0.01), and bone mineral density (+ 10%, p < 0.01). This PAM dosing regimen showed more substantive effects on hard callus at 6 weeks post fracture, with PAM treatment groups showing + 46-79% increased bone volume. Dynamic bone labeling showed reduced calcein signal in the PAM-treated calluses (38-63%, p < 0.01) and reduced MAR (32-49%, p < 0.01), suggesting a compensatory reduction in bone anabolism. These data support the concept that bisphosphonates lead to profound decreases in bone turnover in fracture repair, however, this does not affect soft callus remodeling.


Assuntos
Calo Ósseo/efeitos dos fármacos , Fraturas do Fêmur/patologia , Fraturas Fechadas/patologia , Osteogênese/efeitos dos fármacos , Pamidronato/farmacologia , Animais , Densidade Óssea/efeitos dos fármacos , Conservadores da Densidade Óssea/administração & dosagem , Conservadores da Densidade Óssea/farmacologia , Remodelação Óssea/efeitos dos fármacos , Calo Ósseo/patologia , Modelos Animais de Doenças , Regulação para Baixo/efeitos dos fármacos , Fraturas do Fêmur/tratamento farmacológico , Consolidação da Fratura/efeitos dos fármacos , Fraturas Fechadas/tratamento farmacológico , Masculino , Tamanho do Órgão/efeitos dos fármacos , Osteogênese Imperfeita/patologia , Pamidronato/administração & dosagem , Ratos , Ratos Wistar , Fatores de Tempo
11.
Blood ; 129(26): 3452-3464, 2017 06 29.
Artigo em Inglês | MEDLINE | ID: mdl-28515094

RESUMO

Multiple myeloma (MM) is a plasma cell cancer that develops in the skeleton causing profound bone destruction and fractures. The bone disease is mediated by increased osteoclastic bone resorption and suppressed bone formation. Bisphosphonates used for treatment inhibit bone resorption and prevent bone loss but fail to influence bone formation and do not replace lost bone, so patients continue to fracture. Stimulating bone formation to increase bone mass and fracture resistance is a priority; however, targeting tumor-derived modulators of bone formation has had limited success. Sclerostin is an osteocyte-specific Wnt antagonist that inhibits bone formation. We hypothesized that inhibiting sclerostin would prevent development of bone disease and increase resistance to fracture in MM. Sclerostin was expressed in osteocytes from bones from naive and myeloma-bearing mice. In contrast, sclerostin was not expressed by plasma cells from 630 patients with myeloma or 54 myeloma cell lines. Mice injected with 5TGM1-eGFP, 5T2MM, or MM1.S myeloma cells demonstrated significant bone loss, which was associated with a decrease in fracture resistance in the vertebrae. Treatment with anti-sclerostin antibody increased osteoblast numbers and bone formation rate but did not inhibit bone resorption or reduce tumor burden. Treatment with anti-sclerostin antibody prevented myeloma-induced bone loss, reduced osteolytic bone lesions, and increased fracture resistance. Treatment with anti-sclerostin antibody and zoledronic acid combined increased bone mass and fracture resistance when compared with treatment with zoledronic acid alone. This study defines a therapeutic strategy superior to the current standard of care that will reduce fractures for patients with MM.


Assuntos
Densidade Óssea/efeitos dos fármacos , Proteínas Morfogenéticas Ósseas/antagonistas & inibidores , Fraturas Ósseas/prevenção & controle , Osteócitos/química , Osteogênese/efeitos dos fármacos , Proteínas Adaptadoras de Transdução de Sinal , Animais , Anticorpos/farmacologia , Anticorpos/uso terapêutico , Proteínas Morfogenéticas Ósseas/imunologia , Linhagem Celular Tumoral , Difosfonatos/uso terapêutico , Marcadores Genéticos/imunologia , Humanos , Imidazóis/uso terapêutico , Camundongos , Mieloma Múltiplo/complicações , Células Tumorais Cultivadas , Ácido Zoledrônico
12.
J Aging Phys Act ; 27(4): 848-854, 2019 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-31170861

RESUMO

Veterans represent a unique population of older adults as they are more likely to self-report disability and be overweight or obese compared to the general population. We sought to compare changes in mobility function across the obesity spectrum in older Veterans participating in six-months of Gerofit, a clinical exercise program. 270 Veterans completed baseline, three, and six-month functional assessment and were divided post-hoc into groups: normal weight, overweight, and obese. Physical function assessment included: ten-meter walk time, six-minute walk distance, 30-second chair stands, and eight-foot up-and-go time. No significant weight x time interactions were found for any measure. However, significant (P<0.02) improvements were found for all mobility measures from baseline to three-months and maintained at six-months. Six-months of participation in Gerofit, if enacted nationwide, appears to be one way to improve mobility and function in older Veterans at high risk for disability regardless of weight status.


Assuntos
Terapia por Exercício/métodos , Estado Funcional , Avaliação Geriátrica , Limitação da Mobilidade , Obesidade , Veteranos/estatística & dados numéricos , Idoso , Índice de Massa Corporal , Eficiência Organizacional , Feminino , Avaliação Geriátrica/métodos , Avaliação Geriátrica/estatística & dados numéricos , Humanos , Masculino , Obesidade/diagnóstico , Obesidade/fisiopatologia , Desempenho Físico Funcional , Teste de Caminhada/métodos
13.
J Cell Physiol ; 233(2): 1156-1167, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28460416

RESUMO

The bone marrow niche is a dynamic and complex microenvironment that can both regulate, and be regulated by the bone matrix. Within the bone marrow (BM), mesenchymal stromal cell (MSC) precursors reside in a multi-potent state and retain the capacity to differentiate down osteoblastic, adipogenic, or chondrogenic lineages in response to numerous biochemical cues. These signals can be altered in various pathological states including, but not limited to, osteoporotic-induced fracture, systemic adiposity, and the presence of bone-homing cancers. Herein we provide evidence that signals from the bone matrix (osteocytes) determine marrow adiposity by regulating adipogenesis in the bone marrow. Specifically, we found that physiologically relevant levels of Sclerostin (SOST), which is a Wnt-inhibitory molecule secreted from bone matrix-embedded osteocytes, can induce adipogenesis in 3T3-L1 cells, mouse ear- and BM-derived MSCs, and human BM-derived MSCs. We demonstrate that the mechanism of SOST induction of adipogenesis is through inhibition of Wnt signaling in pre-adipocytes. We also demonstrate that a decrease of sclerostin in vivo, via both genetic and pharmaceutical methods, significantly decreases bone marrow adipose tissue (BMAT) formation. Overall, this work demonstrates a direct role for SOST in regulating fate determination of BM-adipocyte progenitors. This provides a novel mechanism for which BMAT is governed by the local bone microenvironment, which may prove relevant in the pathogenesis of certain diseases involving marrow adipose. Importantly, with anti-sclerostin therapy at the forefront of osteoporosis treatment and a greater recognition of the role of BMAT in disease, these data are likely to have important clinical implications.


Assuntos
Adipócitos/metabolismo , Adipogenia , Tecido Adiposo/metabolismo , Células da Medula Óssea/metabolismo , Glicoproteínas/metabolismo , Células-Tronco Mesenquimais/metabolismo , Osteócitos/metabolismo , Células 3T3-L1 , Proteínas Adaptadoras de Transdução de Sinal , Tecido Adiposo/citologia , Adiposidade , Animais , Meios de Cultivo Condicionados/metabolismo , Glicoproteínas/deficiência , Glicoproteínas/genética , Peptídeos e Proteínas de Sinalização Intercelular , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Comunicação Parácrina , Fenótipo , Nicho de Células-Tronco , Via de Sinalização Wnt
14.
Calcif Tissue Int ; 103(3): 298-310, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29845410

RESUMO

Dickkopf-1 (DKK1) and sclerostin are antagonists of the Wnt/ß-catenin pathway and decreased expression of either results in increased bone formation and mass. As both affect the same signaling pathway, we aimed to elucidate the redundancy and/or compensation of sclerostin and DKK1. Weekly sclerostin antibody (Scl-Ab) was used to treat 9-week-old female Dkk1 KO (Dkk1-/-:Wnt3+/-) mice and compared to Scl-Ab-treated wild-type mice as well as vehicle-treated Dkk1 KO and wild-type animals. While Wnt3 heterozygote (Wnt3+/-) mice show no bone phenotype, Scl-Ab and vehicle-treated control groups of this genotype were included. Specimens were harvested after 3 weeks for microCT, bone histomorphometry, anti-sclerostin immunohistochemistry, and biomechanical testing. Scl-Ab enhanced bone anabolism in all treatment groups, but with synergistic enhancement seen in the cancellous compartment of Dkk1 KO mice (bone volume + 55% Dkk1 KO p < 0.01; + 22% wild type p < 0.05). Scl-Ab treatment produced less marked increases in cortical bone of the tibiae, with anabolic effects similar across genotypes. Mechanical testing confirmed that Scl-Ab improved strength across all genotypes; however, no enhancement was seen within Dkk1 KO mice. Dynamic bone labeling showed that Scl-Ab treatment was associated with increased bone formation, regardless of genotype. Immunohistochemical staining for sclerostin protein indicated no differences in the Dkk1 KO mice, indicating that the increased Wnt signaling associated with DKK1 deficiency was not compensated by upregulation of sclerostin protein. These data suggest complex interactions between Wnt signaling factors in bone, but critically illustrate synergy between DKK1 deficiency and Scl-Ab treatment. These data support the application of dual-targeted therapeutics in the modulation of bone anabolism.


Assuntos
Osso e Ossos/efeitos dos fármacos , Osso e Ossos/fisiologia , Glicoproteínas/metabolismo , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Osteogênese/fisiologia , Proteínas Adaptadoras de Transdução de Sinal , Animais , Anticorpos Monoclonais/farmacologia , Feminino , Camundongos , Camundongos Knockout , Osteogênese/efeitos dos fármacos
15.
Calcif Tissue Int ; 102(1): 105-116, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29105022

RESUMO

Wnt antagonist Dkk1 is a negative regulator of bone formation and Dkk1 +/- heterozygous mice display a high bone mass phenotype. Complete loss of Dkk1 function disrupts embryonic head development. Homozygous Dkk1 -/- mice that were heterozygous for Wnt3 loss of function mutation (termed Dkk1 KO) are viable and allowed studying the effects of homozygous inactivation of Dkk1 on bone formation. Dkk1 KO mice showed a high bone mass phenotype exceeding that of heterozygous mice as well as a high incidence of polydactyly and kinky tails. Whole body bone density was increased in the Dkk1 KO mice as shown by longitudinal dual-energy X-ray absorptiometry. MicroCT analysis of the distal femur revealed up to 3-fold increases in trabecular bone volume and up to 2-fold increases in the vertebrae, compared to wild type controls. Cortical bone was increased in both the tibiae and vertebrae, which correlated with increased strength in tibial 4-point bending and vertebral compression tests. Dynamic histomorphometry identified increased bone formation as the mechanism underlying the high bone mass phenotype in Dkk1 KO mice, with no changes in bone resorption. Mice featuring only Wnt3 heterozygosity showed no evident bone phenotype. Our findings highlight a critical role for Dkk1 in the regulation of bone formation and a gene dose-dependent response to loss of DKK1 function. Targeting Dkk1 to enhance bone formation offers therapeutic potential for osteoporosis.


Assuntos
Densidade Óssea/fisiologia , Osso e Ossos/fisiopatologia , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Osteogênese/genética , Animais , Doenças Ósseas Metabólicas/metabolismo , Reabsorção Óssea/metabolismo , Osso e Ossos/patologia , Peptídeos e Proteínas de Sinalização Intercelular/deficiência , Peptídeos e Proteínas de Sinalização Intercelular/genética , Camundongos Knockout , Fenótipo
16.
Calcif Tissue Int ; 100(5): 433-448, 2017 05.
Artigo em Inglês | MEDLINE | ID: mdl-27343063

RESUMO

Researchers globally are working towards finding a cure for multiple myeloma (MM), a destructive blood cancer diagnosed yearly in ~750,000 people worldwide (Podar et al. in Expert Opin Emerg Drugs 14:99-127, 2009). Although MM targets multiple organ systems, it is the devastating skeletal destruction experienced by over 90 % of patients that often most severely impacts patient morbidity, pain, and quality of life. Preventing bone disease is therefore a priority in MM treatment, and understanding how and why myeloma cells target the bone marrow (BM) is fundamental to this process. This review focuses on a key area of MM research: the contributions of the bone microenvironment to disease origins, progression, and drug resistance. We describe some of the key cell types in the BM niche: osteoclasts, osteoblasts, osteocytes, adipocytes, and mesenchymal stem cells. We then focus on how these key cellular players are, or could be, regulating a range of disease-related processes spanning MM growth, drug resistance, and bone disease (including osteolysis, fracture, and hypercalcemia). We summarize the literature regarding MM-bone cell and MM-adipocyte relationships and subsequent phenotypic changes or adaptations in MM cells, with the aim of providing a deeper understanding of how myeloma cells grow in the skeleton to cause bone destruction. We identify avenues and therapies that intervene in these networks to stop tumor growth and/or induce bone regeneration. Overall, we aim to illustrate how novel therapeutic target molecules, proteins, and cellular mediators may offer new avenues to attack this disease while reviewing currently utilized therapies.


Assuntos
Adipócitos/patologia , Medula Óssea/patologia , Osso e Ossos/patologia , Mieloma Múltiplo/patologia , Microambiente Tumoral , Humanos
17.
Calcif Tissue Int ; 101(2): 217-228, 2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-28391431

RESUMO

Open fractures remain a challenge in orthopedics. Current strategies to intervene are often inadequate, particularly in severe fractures or when treatment is delayed. Sclerostin is a negative regulator of bone growth and sclerostin-neutralizing antibodies (Scl-Ab) can increase bone mass and strength. The application of these antibodies to improve orthopedic repair has shown varied results, and may be dependent on the location and severity of the bony injury. We examined Scl-Ab treatment within an established rat osteotomy model with periosteal stripping analogous to open fracture repair. In one study, Scl-Ab was given 25 mg/kg bi-weekly, either from the time of fracture or from 3 weeks post-fracture up to an end-point of 12 weeks. A second study treated only delayed union open fractures that did not show radiographic union by week 6 post-fracture. Outcome measures included radiographic union, microCT analysis of bone volume and architecture, and histology. In the first study, Scl-Ab given from either 0 or 3 weeks significantly improved callus bone volume (+52%, p < 0.05 and +58%, p < 0.01) at 12 weeks, as well as strength (+48%, p < 0.05 and +70%, p < 0.05). Despite these improvements, union rate was not changed. In the second study treating only established delayed fractures, bony callus volume was similarly increased by Scl-Ab treatment; however, this did not translate to increased biomechanical strength or union improvement. Sclerostin antibody treatment has limited effects on the healing of challenging open fractures with periosteal stripping, but shows the greatest benefits on callus size and strength with earlier intervention.


Assuntos
Anticorpos/farmacologia , Densidade Óssea/efeitos dos fármacos , Proteínas Morfogenéticas Ósseas/imunologia , Calo Ósseo/patologia , Marcadores Genéticos/imunologia , Animais , Fenômenos Biomecânicos/efeitos dos fármacos , Modelos Animais de Doenças , Fraturas do Fêmur/tratamento farmacológico , Fraturas do Fêmur/patologia , Fêmur/efeitos dos fármacos , Fêmur/patologia , Consolidação da Fratura/efeitos dos fármacos , Masculino , Osteogênese/efeitos dos fármacos , Osteotomia/métodos , Ratos
18.
World J Urol ; 35(11): 1721-1728, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28656359

RESUMO

BACKGROUND: We compared quality outcomes between transperitoneal (TRPN) and retroperitoneal robotic partial nephrectomy (RRPN). METHODS: Two-center retrospective analysis of TRPN and RRPN from 10/2009 to 10/2015. Perioperative/renal function outcomes were analyzed. Primary endpoint was Pentafecta, a composite measure of quality [negative margin, no 30-day complication, ischemia time ≤25 min, return of glomerular filtration rate (eGFR) to >90% from baseline at last follow-up, and no chronic kidney disease upstaging]. Multivariable analysis (MVA) for factors associated with lack of optimal outcome was performed. RESULTS: 404 patients (TRPN 263, RRPN 141) were analyzed. Comparing TRPN vs. RRPN, mean tumor size (3.1 vs. 2.9 cm, p = 0.122) and RENAL score (7.4 vs. 7.2, p = 0.503) were similar. Most TRPN were anterior (65.0%) and most RRPN posterior (65.3%, p < 0.001). Operative time (p = 0.001) was less for RRPN. No significant differences between TRPN vs. RRPN were noted for ischemia time (23.1 vs. 22.8 min, p = 0.313), blood loss (p = 0.772), positive margins (p = 0.590), complications (p = 0.537), length of stay (p = 0.296), ΔeGFR (p = 0.246), eGFR recovery to >90% (55.9 vs. 57.4%, p = 0.833), and lack of CKD upstaging (84.0 vs. 87.2%, p = 0.464). Pentafecta rates were not significantly different (TRPN 33.9 vs. RRPN 43.3%, p = 0.526). MVA revealed increasing RENAL score (OR 1.5, p < 0.001) and decreasing baseline eGFR (OR 2.4, p = 0.017) as predictive for lack of Pentafecta. CONCLUSIONS: TRPN and RRPN have similar quality outcomes, though RRPN may offer modest benefit for operative time and have utility in posterior tumors. Association of increasing RENAL score and decreased baseline eGFR with lack of Pentafecta suggests dominant role of non-modifiable factors.


Assuntos
Carcinoma de Células Renais/cirurgia , Neoplasias Renais/cirurgia , Nefrectomia/métodos , Complicações Pós-Operatórias/epidemiologia , Insuficiência Renal Crônica/epidemiologia , Espaço Retroperitoneal , Procedimentos Cirúrgicos Robóticos/métodos , Adulto , Idoso , Perda Sanguínea Cirúrgica , Feminino , Taxa de Filtração Glomerular , Humanos , Tempo de Internação , Masculino , Margens de Excisão , Pessoa de Meia-Idade , Análise Multivariada , Duração da Cirurgia , Complicações Pós-Operatórias/metabolismo , Insuficiência Renal Crônica/metabolismo , Estudos Retrospectivos , Índice de Gravidade de Doença , Isquemia Quente
19.
Curr Osteoporos Rep ; 15(6): 532-541, 2017 12.
Artigo em Inglês | MEDLINE | ID: mdl-28956252

RESUMO

PURPOSE OF REVIEW: This review provides a summary of the current knowledge on Sost/sclerostin in cancers targeting the bone, discusses novel observations regarding its potential as a therapeutic approach to treat cancer-induced bone loss, and proposes future research needed to fully understand the potential of therapeutic approaches that modulate sclerostin function. RECENT FINDINGS: Accumulating evidence shows that sclerostin expression is dysregulated in a number of cancers that target the bone. Further, new findings demonstrate that pharmacological inhibition of sclerostin in preclinical models of multiple myeloma results in a robust prevention of bone loss and preservation of bone strength, without apparent effects on tumor growth. These data raise the possibility of targeting sclerostin for the treatment of cancer patients with bone metastasis. Sclerostin is emerging as a valuable target to prevent the bone destruction that accompanies the growth of cancer cells in the bone. Further studies will focus on combining anti-sclerostin therapy with tumor-targeted agents to achieve both beneficial skeletal outcomes and inhibition of tumor progression.


Assuntos
Proteínas Morfogenéticas Ósseas/metabolismo , Neoplasias Ósseas/metabolismo , Mieloma Múltiplo/metabolismo , Neoplasias/patologia , Proteínas Adaptadoras de Transdução de Sinal , Animais , Proteínas Morfogenéticas Ósseas/antagonistas & inibidores , Neoplasias Ósseas/tratamento farmacológico , Neoplasias Ósseas/secundário , Marcadores Genéticos , Humanos , Terapia de Alvo Molecular , Mieloma Múltiplo/tratamento farmacológico
20.
J Natl Compr Canc Netw ; 13(12): 1576-83, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26656524

RESUMO

A preponderance of clinical evidence supports a significant public health benefit for screening and early detection of prostate cancer in selected men. The challenge lies in maximizing early diagnosis of potentially aggressive but curable disease while minimizing diagnosis and treatment of indolent disease. A tailored approach to population screening in appropriately counseled men, using an evidence-based strategy with judicious prostate-specific antigen (PSA) testing, will reduce prostate-cancer mortality yet limit overdetection of clinically insignificant disease. Use of newer biomarkers that increase specificity for prostate cancer detection, including percentage of free PSA, 4Kscore, prostate health index, prostate cancer antigen 3, and multiparametric MRI may be considered under certain circumstances.


Assuntos
Detecção Precoce de Câncer , Neoplasias da Próstata/diagnóstico , Neoplasias da Próstata/epidemiologia , Fatores Etários , Biomarcadores Tumorais , Ensaios Clínicos como Assunto , Tomada de Decisões , Exame Retal Digital , Detecção Precoce de Câncer/métodos , Humanos , Expectativa de Vida , Masculino , Programas de Rastreamento/métodos , Vigilância da População , Fatores de Risco
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