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1.
Aging Clin Exp Res ; 36(1): 167, 2024 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-39120740

RESUMO

Bone forming agents, also known as anabolic therapies, are essential in managing osteoporosis, particularly for patients at very high-risk of fractures. Identifying candidates who will benefit the most from these treatments is crucial. For example, this group might include individuals with severe osteoporosis, multiple vertebral fractures, a recent fragility fracture or those unresponsive to antiresorptive treatments. Definitions of patients with a very high fracture risk vary across nations, are often based on fracture history, bone mineral density (BMD), and/or fracture risk calculated by FRAX® or other algorithms. However, for very high-risk patients, anabolic agents such as teriparatide, abaloparatide, or romosozumab are commonly recommended as first-line therapies due to their ability to stimulate new bone formation and improve bone microarchitecture, offering significant benefits in rapid fracture reduction over antiresorptive therapies. The cost-effectiveness of these agents is a critical consideration for decision-makers. Despite their higher costs, their effectiveness in significantly reducing fracture risk and improving quality of life can justify the investment, especially when long-term savings from reduced fracture rates and associated healthcare costs are considered. Additionally, after completing a course of anabolic therapy, transitioning to antiresorptive agents like bisphosphonates or denosumab is crucial to maintain the gains in bone density and minimize subsequent fracture risks. This sequential treatment approach ensures sustained protection and optimal resource utilization. In summary, the effective use of bone forming agents in osteoporosis requires a comprehensive strategy that includes accurate patient identification, consideration of cost-effectiveness, and implementation of appropriate sequential treatments, ultimately maximizing patient outcomes and healthcare efficiency.


Assuntos
Conservadores da Densidade Óssea , Densidade Óssea , Osteoporose , Humanos , Osteoporose/tratamento farmacológico , Conservadores da Densidade Óssea/uso terapêutico , Densidade Óssea/efeitos dos fármacos , Fraturas por Osteoporose/prevenção & controle , Anabolizantes/uso terapêutico , Teriparatida/uso terapêutico , Análise Custo-Benefício
2.
Curr Osteoporos Rep ; 20(5): 273-289, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35994202

RESUMO

PURPOSE OF REVIEW: The present review addresses most recently identified mechanisms implicated in metastasis-induced bone resorption and muscle-wasting syndrome, known as cachexia. RECENT FINDINGS: Metastatic disease in bone and soft tissues is often associated with skeletal muscle defects. Recent studies have identified a number of secreted molecules and extracellular vesicles that contribute to cancer cell growth and metastasis leading to bone destruction and muscle atrophy. In addition, alterations in muscle microenvironment including dysfunctions in hepatic and mitochondrial metabolism have been implicated in cancer-induced regeneration defect and muscle loss. Moreover, we review novel in vitro and animal models including promising new drug candidates for bone metastases and cancer cachexia. Preservation of bone health could be highly beneficial for maintaining muscle mass and function. Therefore, a better understanding of molecular pathways implicated in bone and muscle crosstalk in metastatic disease may provide new insights and identify new strategies to improve current anticancer therapeutics.


Assuntos
Neoplasias Ósseas , Doenças Musculares , Neoplasias , Animais , Neoplasias Ósseas/secundário , Caquexia/metabolismo , Músculo Esquelético/metabolismo , Atrofia Muscular/metabolismo , Atrofia Muscular/patologia , Doenças Musculares/complicações , Neoplasias/complicações , Microambiente Tumoral
3.
Breast Cancer Res ; 22(1): 34, 2020 04 09.
Artigo em Inglês | MEDLINE | ID: mdl-32272947

RESUMO

BACKGROUND: Osteoclast activation is a hallmark of breast cancer-induced bone disease while little is known about the role of osteoblasts in this process. Recently, we identified the homeodomain protein TG-interacting factor-1 (Tgif1) as a crucial regulator of osteoblast function. In this study, we demonstrate that lack of Tgif1 also restricts the progression of breast cancer bone metastases. METHODS: Transwell migration assays were used to investigate the osteoblast-breast cancer cell interaction in vitro. Molecular analyses included RNA sequencing, immunoblotting, and qRT-PCR. To determine the role of Tgif1 in metastatic bone disease, 4T1 breast cancer cells were injected intracardially into mice with a germ line deletion of Tgif1 (Tgif1-/-) or control littermates (Tgif1+/+). Progression of bone metastases and alterations in the bone microenvironment were assessed using bioluminescence imaging, immunofluorescence staining, confocal microscopy, and histomorphometry. RESULTS: Medium conditioned by osteoblasts stimulated breast cancer cell migration, indicating a potential role of osteoblasts during bone metastasis progression. Tgif1 expression was strongly increased in osteoblasts upon stimulation by breast cancer cells, demonstrating the implication of Tgif1 in the osteoblast-breast cancer cell interaction. Indeed, conditioned medium from osteoblasts of Tgif1-/- mice failed to induce breast cancer cell migration compared to control, suggesting that Tgif1 in osteoblasts augments cancer cell motility. Semaphorin 3E (Sema3E), which is abundantly secreted by Tgif1-/- osteoblasts, dose-dependently reduced breast cancer cell migration while silencing of Sema3E expression in Tgif1-/- osteoblasts partially restored the impaired migration. In vivo, we observed a decreased number of breast cancer bone metastases in Tgif1-/- mice compared to control littermates. Consistently, the presence of single breast cancer cells or micro-metastases in the tibiae was reduced in Tgif1-/- mice. Breast cancer cells localized in close proximity to Endomucin-positive vascular cells as well as to osteoblasts. Although Tgif1 deficiency did not affect the bone marrow vasculature, the number and activity of osteoblasts were reduced compared to control. This suggests that the protective effect on bone metastases might be mediated by osteoblasts rather than by the bone marrow vasculature. CONCLUSION: We propose that the lack of Tgif1 in osteoblasts increases Sema3E expression and attenuates breast cancer cell migration as well as metastases formation.


Assuntos
Neoplasias Ósseas/prevenção & controle , Osso e Ossos/patologia , Neoplasias da Mama/prevenção & controle , Proteínas de Homeodomínio/antagonistas & inibidores , Proteínas de Homeodomínio/fisiologia , Proteínas Repressoras/antagonistas & inibidores , Proteínas Repressoras/fisiologia , Semaforinas/genética , Microambiente Tumoral , Animais , Neoplasias Ósseas/metabolismo , Neoplasias Ósseas/secundário , Osso e Ossos/metabolismo , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Diferenciação Celular , Linhagem Celular Tumoral , Modelos Animais de Doenças , Feminino , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Osteoblastos/metabolismo , Osteoblastos/patologia , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo
4.
N Engl J Med ; 374(26): 2553-2562, 2016 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-27355534

RESUMO

BACKGROUND: Cortical-bone fragility is a common feature in osteoporosis that is linked to nonvertebral fractures. Regulation of cortical-bone homeostasis has proved elusive. The study of genetic disorders of the skeleton can yield insights that fuel experimental therapeutic approaches to the treatment of rare disorders and common skeletal ailments. METHODS: We evaluated four patients with Pyle's disease, a genetic disorder that is characterized by cortical-bone thinning, limb deformity, and fractures; two patients were examined by means of exome sequencing, and two were examined by means of Sanger sequencing. After a candidate gene was identified, we generated a knockout mouse model that manifested the phenotype and studied the mechanisms responsible for altered bone architecture. RESULTS: In all affected patients, we found biallelic truncating mutations in SFRP4, the gene encoding secreted frizzled-related protein 4, a soluble Wnt inhibitor. Mice deficient in Sfrp4, like persons with Pyle's disease, have increased amounts of trabecular bone and unusually thin cortical bone, as a result of differential regulation of Wnt and bone morphogenetic protein (BMP) signaling in these two bone compartments. Treatment of Sfrp4-deficient mice with a soluble Bmp2 receptor (RAP-661) or with antibodies to sclerostin corrected the cortical-bone defect. CONCLUSIONS: Our study showed that Pyle's disease was caused by a deficiency of sFRP4, that cortical-bone and trabecular-bone homeostasis were governed by different mechanisms, and that sFRP4-mediated cross-regulation between Wnt and BMP signaling was critical for achieving proper cortical-bone thickness and stability. (Funded by the Swiss National Foundation and the National Institutes of Health.).


Assuntos
Densidade Óssea/genética , Remodelação Óssea/genética , Osteocondrodisplasias/genética , Proteínas Proto-Oncogênicas/deficiência , Proteínas Proto-Oncogênicas/genética , Adolescente , Animais , Biomarcadores/sangue , Proteínas Morfogenéticas Ósseas/metabolismo , Remodelação Óssea/fisiologia , Osso e Ossos/patologia , Osso e Ossos/fisiologia , Pré-Escolar , Modelos Animais de Doenças , Feminino , Deleção de Genes , Homeostase , Humanos , Masculino , Camundongos , Camundongos Knockout , Pessoa de Meia-Idade , Osteocondrodisplasias/fisiopatologia , Análise de Sequência de DNA , Transdução de Sinais , Proteínas Wnt/metabolismo
5.
Curr Osteoporos Rep ; 17(3): 122-128, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30905007

RESUMO

PURPOSE OF REVIEW: This review provides an update on the recent literature describing the role of microRNAs (miRNAs) in cancer formation and bone metastasis. We confined our focus on osteosarcoma, breast cancer, prostate cancer, and epithelial-mesenchymal transition. RECENT FINDINGS: In all areas covered, major discoveries on the role of miRNAs in tumorigenesis and metastasis have been made. Novel signaling networks were identified with miRNAs having a central function. Potential improvements in the diagnosis of malignant diseases and the long-term follow-up might become possible by the use of miRNAs. Furthermore, miRNAs also have disease-modifying properties and might emerge as a new class of therapeutic molecules. MiRNAs are novel and important regulators of multiple cellular and molecular events. Due to their functions, miRNAs might become useful to improve the diagnosis, follow-up and treatment of cancer, and metastases. Thus, miRNAs are molecules of great interest in translational medicine.


Assuntos
Neoplasias Ósseas/secundário , MicroRNAs/fisiologia , Neoplasias da Mama/patologia , Transição Epitelial-Mesenquimal , Feminino , Humanos , Masculino , Osteossarcoma/secundário , Neoplasias da Próstata/patologia
6.
Nucleic Acids Res ; 45(1): 127-141, 2017 01 09.
Artigo em Inglês | MEDLINE | ID: mdl-27651452

RESUMO

Proper temporal epigenetic regulation of gene expression is essential for cell fate determination and tissue development. The Bromodomain-containing Protein-4 (BRD4) was previously shown to control the transcription of defined subsets of genes in various cell systems. In this study we examined the role of BRD4 in promoting lineage-specific gene expression and show that BRD4 is essential for osteoblast differentiation. Genome-wide analyses demonstrate that BRD4 is recruited to the transcriptional start site of differentiation-induced genes. Unexpectedly, while promoter-proximal BRD4 occupancy correlated with gene expression, genes which displayed moderate expression and promoter-proximal BRD4 occupancy were most highly regulated and sensitive to BRD4 inhibition. Therefore, we examined distal BRD4 occupancy and uncovered a specific co-localization of BRD4 with the transcription factors C/EBPb, TEAD1, FOSL2 and JUND at putative osteoblast-specific enhancers. These findings reveal the intricacies of lineage specification and provide new insight into the context-dependent functions of BRD4.


Assuntos
Linhagem da Célula/genética , Epigênese Genética , Células Epiteliais/metabolismo , Células-Tronco Mesenquimais/metabolismo , Proteínas Nucleares/genética , Osteoblastos/metabolismo , Osteócitos/metabolismo , Fatores de Transcrição/genética , Proteína beta Intensificadora de Ligação a CCAAT/genética , Proteína beta Intensificadora de Ligação a CCAAT/metabolismo , Proteínas de Ciclo Celular , Diferenciação Celular , Linhagem Celular , Linhagem Celular Tumoral , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Células Epiteliais/citologia , Antígeno 2 Relacionado a Fos/genética , Antígeno 2 Relacionado a Fos/metabolismo , Perfilação da Expressão Gênica , Humanos , Células-Tronco Mesenquimais/citologia , Proteínas Nucleares/metabolismo , Especificidade de Órgãos , Osteoblastos/citologia , Osteócitos/citologia , Regiões Promotoras Genéticas , Ligação Proteica , Proteínas Proto-Oncogênicas c-jun/genética , Proteínas Proto-Oncogênicas c-jun/metabolismo , Transdução de Sinais , Fatores de Transcrição de Domínio TEA , Fatores de Transcrição/metabolismo , Sítio de Iniciação de Transcrição
7.
Unfallchirurg ; 122(7): 506-511, 2019 Jul.
Artigo em Alemão | MEDLINE | ID: mdl-31123799

RESUMO

BACKGROUND: For the treatment of disturbed fracture healing, drugs could be given in addition to surgical procedures. Specific osteoporosis drugs affect the bone metabolism and are used to treat osteoporosis, particularly after a fragility fracture has occurred. Therefore, their use would be conceivable to improve a disturbed fracture healing. OBJECTIVE: This article presents the available and upcoming specific osteoporosis drugs and investigates whether these substances affect fracture healing in the context of osteoporosis. Furthermore, it is discussed whether disturbed fracture healing can be improved by the use of these substances. MATERIAL AND METHODS: A literature search (PubMed) was conducted using key terms. Preclinical studies, clinical studies, reviews and meta-analyses were considered in order to present the current knowledge in a clinically relevant context. RESULTS: Preclinical and clinical studies show that specific osteoporosis drugs have no relevant negative impact on the healing of fragility fractures. A tendency to improve a disturbed fracture healing was attributed to bone anabolic substances; however, studies are inconsistent and there is no approval for this application. CONCLUSION: Following a fragility fracture, osteoporosis should be diagnosed according to the guidelines and, if necessary, treated with specific osteoporosis drugs, since in principle they do not impair fracture healing but significantly reduce the risk of subsequent fractures. Approval to improve fracture healing requires further investigations.


Assuntos
Conservadores da Densidade Óssea/uso terapêutico , Consolidação da Fratura/efeitos dos fármacos , Fraturas Ósseas/tratamento farmacológico , Osteoporose/tratamento farmacológico , Osso e Ossos , Humanos
8.
Unfallchirurg ; 122(10): 766-770, 2019 Oct.
Artigo em Alemão | MEDLINE | ID: mdl-31414147

RESUMO

BACKGROUND: Osteoporosis results in fragility fractures that are associated with a high morbidity and mortality as well as an increased risk for subsequent fragility fractures. Thus, the first fragility fracture should be the last. To achieve this goal patients need treatment of osteoporosis according to the prevailing clinical guidelines. OBJECTIVE: This article presents the current clinical care situation of patients with a manifest osteoporosis in Germany and the accompanying risks. As a possible solution the concept of a fracture liaison service (FLS) as a new intersectoral care concept is presented and options for the establishment of FLS in Germany are provided. MATERIAL AND METHODS: A literature search (PubMed) was conducted using key terms. The practical experiences of the authors in the context of establishing an FLS were also considered. RESULTS: Compared to other countries, in Germany only a minority of patients receive treatment for osteoporosis after fragility fractures. To improve the care situation an intersectoral FLS provides a coordinated referral of patients with fragility fractures from inpatient care in hospitals to specialists in private practice. This enables the strict identification and treatment of high-risk patients according to the prevailing clinical guidelines. In Germany, different options exist to structure an FLS under consideration of the local circumstances. CONCLUSION: In Germany, FLS should be established nationwide and according to uniform standards. This would significantly improve the quality of clinical care of patients with manifest osteoporosis.


Assuntos
Osteoporose , Fraturas por Osteoporose , Encaminhamento e Consulta , Alemanha , Humanos , Prevenção Secundária
9.
Unfallchirurg ; 122(10): 750-754, 2019 Oct.
Artigo em Alemão | MEDLINE | ID: mdl-31440789

RESUMO

BACKGROUND: Osteoporosis is a common disease that affects both women and men. Due to a reduced bone mineral density and increasing age, the risk for atraumatic fractures increases. These fractures cause pain due to the fracture itself and also have far-reaching sequelae in nearly all areas of life of patients. OBJECTIVE: The aim of this article is to summarize the consequences of osteoporotic fractures from the patient's point of view and to highlight the consequences of osteoporosis for the patient. The necessity for timely diagnostics and treatment after a fracture event is explained. MATERIAL AND METHODS: For each term a literature search was performed using key topic-related terms and the results are presented as a narrative review. RESULTS: Various areas of importance for patients were identified. A direct assessment of the patient's point of view was not feasible using a literature search; however, studies with surveys of patients could be identified and therefore, the patient's point of view could be integrated. Areas of interest that could be identified in the literature were pain, psychological well-being, cognitive abilities, mortality and long-term need for nursing. CONCLUSION: The effects of osteoporosis and fractures are multifactorial and often severe for the patient. The measures for prevention of osteoporotic fractures should be consistently implemented in the daily clinical routine and the necessary diagnostics and treatment should be rapidly initiated.


Assuntos
Fraturas por Osteoporose , Densidade Óssea , Feminino , Humanos , Masculino , Osteoporose , Inquéritos e Questionários
10.
Haematologica ; 103(6): 939-948, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29567778

RESUMO

Although inhibitors of bromodomain and extra terminal domain (BET) proteins show promising clinical activity in different hematologic malignancies, a systematic analysis of the consequences of pharmacological BET inhibition on healthy hematopoietic (stem) cells is urgently needed. We found that JQ1 treatment decreases the numbers of pre-, immature and mature B cells while numbers of early pro-B cells remain constant. In addition, JQ1 treatment increases apoptosis in T cells, all together leading to reduced cellularity in thymus, bone marrow and spleen. Furthermore, JQ1 induces proliferation of long-term hematopoietic stem cells, thereby increasing stem cell numbers. Due to increased numbers, JQ1-treated hematopoietic stem cells engrafted better after stem cell transplantation and repopulated the hematopoietic system significantly faster after sublethal myeloablation. As quantity and functionality of hematopoietic stem cells determine the duration of life-threatening myelosuppression, BET inhibition might benefit patients in myelosuppressive conditions.


Assuntos
Antineoplásicos/farmacologia , Azepinas/farmacologia , Autorrenovação Celular/efeitos dos fármacos , Células-Tronco Hematopoéticas/citologia , Células-Tronco Hematopoéticas/efeitos dos fármacos , Proteínas/antagonistas & inibidores , Triazóis/farmacologia , Animais , Apoptose/efeitos dos fármacos , Linfócitos B/citologia , Linfócitos B/efeitos dos fármacos , Linfócitos B/metabolismo , Biomarcadores , Ciclo Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sobrevivência de Enxerto/efeitos dos fármacos , Hematopoese , Transplante de Células-Tronco Hematopoéticas , Células-Tronco Hematopoéticas/metabolismo , Células-Tronco Hematopoéticas/efeitos da radiação , Imunofenotipagem , Camundongos , Fenótipo , Linfócitos T/efeitos dos fármacos , Linfócitos T/metabolismo
11.
J Biol Chem ; 288(29): 21307-21319, 2013 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-23720736

RESUMO

Osteosarcoma (OS) is a primary bone tumor that is most prevalent during adolescence. RUNX2, which stimulates differentiation and suppresses proliferation of osteoblasts, is deregulated in OS. Here, we define pathological roles of RUNX2 in the etiology of OS and mechanisms by which RUNX2 expression is stimulated. RUNX2 is often highly expressed in human OS biopsies and cell lines. Small interference RNA-mediated depletion of RUNX2 inhibits growth of U2OS OS cells. RUNX2 levels are inversely linked to loss of p53 (which predisposes to OS) in distinct OS cell lines and osteoblasts. RUNX2 protein levels decrease upon stabilization of p53 with the MDM2 inhibitor Nutlin-3. Elevated RUNX2 protein expression is post-transcriptionally regulated and directly linked to diminished expression of several validated RUNX2 targeting microRNAs in human OS cells compared with mesenchymal progenitor cells. The p53-dependent miR-34c is the most significantly down-regulated RUNX2 targeting microRNAs in OS. Exogenous supplementation of miR-34c markedly decreases RUNX2 protein levels, whereas 3'-UTR reporter assays establish RUNX2 as a direct target of miR-34c in OS cells. Importantly, Nutlin-3-mediated stabilization of p53 increases expression of miR-34c and decreases RUNX2. Thus, a novel p53-miR-34c-RUNX2 network controls cell growth of osseous cells and is compromised in OS.


Assuntos
Neoplasias Ósseas/metabolismo , Subunidade alfa 1 de Fator de Ligação ao Core/metabolismo , MicroRNAs/metabolismo , Osteossarcoma/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Animais , Neoplasias Ósseas/genética , Neoplasias Ósseas/patologia , Ciclo Celular/genética , Ciclo Celular/efeitos da radiação , Linhagem Celular Tumoral , Proliferação de Células/efeitos da radiação , Subunidade alfa 1 de Fator de Ligação ao Core/genética , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Dano ao DNA , Regulação para Baixo/genética , Regulação para Baixo/efeitos da radiação , Raios gama , Regulação Neoplásica da Expressão Gênica/efeitos da radiação , Humanos , Camundongos , Osteossarcoma/genética , Osteossarcoma/patologia , Estabilidade Proteica/efeitos da radiação , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Proteína Supressora de Tumor p14ARF/metabolismo , Proteína Supressora de Tumor p53/deficiência
13.
Elife ; 132024 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-38661167

RESUMO

Osteoblast adherence to bone surfaces is important for remodeling bone tissue. This study demonstrates that deficiency of TG-interacting factor 1 (Tgif1) in osteoblasts results in altered cell morphology, reduced adherence to collagen type I-coated surfaces, and impaired migration capacity. Tgif1 is essential for osteoblasts to adapt a regular cell morphology and to efficiently adhere and migrate on collagen type I-rich matrices in vitro. Furthermore, Tgif1 acts as a transcriptional repressor of p21-activated kinase 3 (Pak3), an important regulator of focal adhesion formation and osteoblast spreading. Absence of Tgif1 leads to increased Pak3 expression, which impairs osteoblast spreading. Additionally, Tgif1 is implicated in osteoblast recruitment and activation of bone surfaces in the context of bone regeneration and in response to parathyroid hormone 1-34 (PTH 1-34) treatment in vivo in mice. These findings provide important novel insights in the regulation of the cytoskeletal architecture of osteoblasts.


Assuntos
Citoesqueleto , Proteínas de Homeodomínio , Osteoblastos , Proteínas Repressoras , Transdução de Sinais , Quinases Ativadas por p21 , Animais , Camundongos , Adesão Celular , Movimento Celular , Citoesqueleto/metabolismo , Proteínas de Homeodomínio/metabolismo , Proteínas de Homeodomínio/genética , Osteoblastos/metabolismo , Quinases Ativadas por p21/metabolismo , Quinases Ativadas por p21/genética , Quinases Ativadas por p21/deficiência , Proteínas Repressoras/metabolismo , Proteínas Repressoras/genética , Proteínas Repressoras/deficiência
14.
Curr Osteoporos Rep ; 11(2): 72-82, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23605904

RESUMO

MicroRNAs (miRNAs) are critical post-transcriptional regulators of gene expression that control osteoblast mediated bone formation and osteoclast-related bone remodeling. Deregulation of miRNA mediated mechanisms is emerging as an important pathological factor in bone degeneration (eg, osteoporosis) and other bone-related diseases. MiRNAs are intriguing regulatory molecules that are networked with cell signaling pathways and intricate transcriptional programs through ingenuous circuits with remarkably simple logic. This overview examines key principles by which miRNAs control differentiation of osteoblasts as they evolve from mesenchymal stromal cells during osteogenesis, or of osteoclasts as they originate from monocytic precursors in the hematopoietic lineage during osteoclastogenesis. Of particular note are miRNAs that are temporally upregulated during osteoblastogenesis (eg, miR-218) or osteoclastogenesis (eg, miR-148a). Each miRNA stimulates differentiation by suppressing inhibitory signaling pathways ('double-negative' regulation). The excitement surrounding miRNAs in bone biology stems from the prominent effects that individual miRNAs can have on biological transitions during differentiation of skeletal cells and correlations of miRNA dysfunction with bone diseases. MiRNAs have significant clinical potential which is reflected by their versatility as disease-specific biomarkers and their promise as therapeutic agents to ameliorate or reverse bone tissue degeneration.


Assuntos
Regulação da Expressão Gênica , MicroRNAs/fisiologia , Osteogênese/genética , Osteoporose/genética , Remodelação Óssea , Humanos , Osteoblastos/metabolismo , Osteoblastos/patologia , Osteoporose/metabolismo , Osteoporose/patologia , Transdução de Sinais
15.
J Clin Med ; 12(12)2023 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-37373793

RESUMO

A total of 7% of all benign bone lesions are diagnosed as fibrous dysplasia (FD). The symptoms of FD of the jaw range from asymptomatic to dental anomalies, pain and facial asymmetry. Due to its resemblance to other fibro-osseous bone lesions, misdiagnosis often occurs and can lead to inadequate treatment. Particularly in the jaw, this lesion does not become quiescent during puberty, making fundamental knowledge about the diagnosis and treatment of FD crucial. Mutational analysis and nonsurgical approaches offer new diagnostic and therapeutic options. In this review, we examine the advances and the difficulties of the diagnosis and the various treatment modalities of FD of the jaw in order to capture the current scientific knowledge on this bone disease.

16.
EMBO Mol Med ; 14(11): e13617, 2022 11 08.
Artigo em Inglês | MEDLINE | ID: mdl-36193848

RESUMO

Postmenopausal bone loss often leads to osteoporosis and fragility fractures. Bone mass can be increased by the first 34 amino acids of human parathyroid hormone (PTH), parathyroid hormone-related protein (PTHrP), or by a monoclonal antibody against sclerostin (Scl-Ab). Here, we show that PTH and Scl-Ab reduce the expression of microRNA-19a and microRNA-19b (miR-19a/b) in bone. In bones from patients with lower bone mass and from osteoporotic mice, miR-19a/b expression is elevated, suggesting an inhibitory function in bone remodeling. Indeed, antagonizing miR-19a/b in vivo increased bone mass without overt cytotoxic effects. We identified TG-interacting factor 1 (Tgif1) as the target of miR-19a/b in osteoblasts and essential for the increase in bone mass following miR-19a/b inhibition. Furthermore, antagonizing miR-19a/b augments the gain in bone mass by PTH and restores bone loss in mouse models of osteoporosis in a dual mode of action by supporting bone formation and decreasing receptor activator of NF-κB ligand (RANKL)-dependent bone resorption. Thus, this study identifies novel mechanisms regulating bone remodeling, which opens opportunities for new therapeutic concepts to treat bone fragility.


Assuntos
MicroRNAs , Osteoporose , Humanos , Camundongos , Animais , Densidade Óssea , Osteoporose/tratamento farmacológico , Osso e Ossos , Osteoblastos/metabolismo , MicroRNAs/genética , MicroRNAs/metabolismo , Proteínas Repressoras/metabolismo , Proteínas de Homeodomínio/metabolismo
17.
Nat Commun ; 13(1): 7689, 2022 12 12.
Artigo em Inglês | MEDLINE | ID: mdl-36509738

RESUMO

The fine equilibrium of bone homeostasis is maintained by bone-forming osteoblasts and bone-resorbing osteoclasts. Here, we show that TAM receptors MERTK and TYRO3 exert reciprocal effects in osteoblast biology: Osteoblast-targeted deletion of MERTK promotes increased bone mass in healthy mice and mice with cancer-induced bone loss, whereas knockout of TYRO3 in osteoblasts shows the opposite phenotype. Functionally, the interaction of MERTK with its ligand PROS1 negatively regulates osteoblast differentiation via inducing the VAV2-RHOA-ROCK axis leading to increased cell contractility and motility while TYRO3 antagonizes this effect. Consequently, pharmacologic MERTK blockade by the small molecule inhibitor R992 increases osteoblast numbers and bone formation in mice. Furthermore, R992 counteracts cancer-induced bone loss, reduces bone metastasis and prolongs survival in preclinical models of multiple myeloma, breast- and lung cancer. In summary, MERTK and TYRO3 represent potent regulators of bone homeostasis with cell-type specific functions and MERTK blockade represents an osteoanabolic therapy with implications in cancer and beyond.


Assuntos
Proteínas Proto-Oncogênicas , Receptores Proteína Tirosina Quinases , Camundongos , Animais , c-Mer Tirosina Quinase/genética , c-Mer Tirosina Quinase/metabolismo , Receptores Proteína Tirosina Quinases/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Homeostase , Proteínas de Transporte
18.
Br J Pharmacol ; 178(9): 1936-1954, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-31423566

RESUMO

Bone metastases are frequent complications in patients with advanced cancer, which can be fatal or may rapidly impede the quality of life of patients. Current treatments for patients with bone metastases are palliative. Therefore, a better understanding of the molecular mechanisms that precede the overt development of skeletal lesions could lead to better therapeutic interventions. In this review, we present evidence that non-coding RNAs (ncRNAs) such as long ncRNAs, microRNAs, and circular RNAs are emerging as master regulators of bone metastasis formation. We highlight potential opportunities for the therapeutic targeting of ncRNAs. Furthermore, we discuss the possibility that ncRNAs may be used as biomarkers in the context of bone metastases, which might provide insight for improving the response to current bone-targeting therapies. LINKED ARTICLES: This article is part of a themed issue on The molecular pharmacology of bone and cancer-related bone diseases. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v178.9/issuetoc.


Assuntos
Neoplasias Ósseas , MicroRNAs , RNA Longo não Codificante , Neoplasias Ósseas/tratamento farmacológico , Neoplasias Ósseas/genética , Remodelação Óssea , Humanos , MicroRNAs/genética , Qualidade de Vida
19.
JBMR Plus ; 5(11): e10546, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34761149

RESUMO

Increases in bone mineral density (BMD) with osteoporosis treatment are associated with reduced fracture risk. Increasing BMD is therefore a goal of osteoporosis therapy. Here, we compare the probability of achieving a T-score of > -2.5 over 3 years at the total hip (TH) or lumbar spine (LS) in women with osteoporosis, ≥55 years of age, after the following treatment sequences: 1 year romosozumab followed by 2 years denosumab (FRAME and FRAME extension trials), 1 year romosozumab followed by 2 years alendronate, or alendronate-only for 3 years (ARCH trial). Probabilities of attaining the BMD target within 1 year of treatment were also determined. At both skeletal sites, in women with a baseline Tscore ≥ -2.7, there was >50% probability of achieving the BMD target with any 3-year regimen. The probability of achieving the target BMD in those with a baseline TH Tscore equal to -3.0 was 61% with romosozumab/denosumab, 38% with romosozumab/alendronate, and 9% with alendronate. In those with a baseline LS Tscore equal to -3.0, the probability of achieving a T-score > -2.5 was 93% with romosozumab/denosumab, 81% with romosozumab/alendronate, and 55% with alendronate. With 1 year of treatment, in patients with a baseline TH T-score equal to -2.7, the probability of reaching the target Tscore with romosozumab was 71% to 78% and 38% with alendronate. For patients with an initial LS T-score equal to -3.0, the probability of achieving the target T-score over 1 year was 85% to 86% with romosozumab and 25% for alendronate. Our findings suggest baseline BMD and the probability of achieving BMD T-score goals are factors to consider when selecting initial treatment for patients with osteoporosis. As baseline T-score falls below -2.7 (TH) and -3.0 (LS), alendronate has <50% likelihood of achieving a BMD goal above osteoporosis range, whereas these probabilities remain relatively high for regimens beginning with romosozumab. © 2021 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

20.
Dis Model Mech ; 14(3)2021 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-33563616

RESUMO

Collagen assembly during development is essential for successful matrix mineralisation, which determines bone quality and mechanocompetence. However, the biochemical and structural perturbations that drive pathological skeletal collagen configuration remain unclear. Deletion of vascular endothelial growth factor (VEGF; also known as VEGFA) in bone-forming osteoblasts (OBs) induces sex-specific alterations in extracellular matrix (ECM) conformation and mineralisation coupled to vascular changes, which are augmented in males. Whether this phenotypic dimorphism arises as a result of the divergent control of ECM composition and its subsequent arrangement is unknown and is the focus of this study. Herein, we used murine osteocalcin-specific Vegf knockout (OcnVEGFKO) and performed ex vivo multiscale analysis at the tibiofibular junction of both sexes. Label-free and non-destructive polarisation-resolved second-harmonic generation (p-SHG) microscopy revealed a reduction in collagen fibre number in males following the loss of VEGF, complemented by observable defects in matrix organisation by backscattered electron scanning electron microscopy. This was accompanied by localised divergence in collagen orientation, determined by p-SHG anisotropy measurements, as a result of OcnVEGFKO. Raman spectroscopy confirmed that the effect on collagen was linked to molecular dimorphic VEGF effects on collagen-specific proline and hydroxyproline, and collagen intra-strand stability, in addition to matrix carbonation and mineralisation. Vegf deletion in male and female murine OB cultures in vitro further highlighted divergence in genes regulating local ECM structure, including Adamts2, Spp1, Mmp9 and Lama1. Our results demonstrate the utility of macromolecular imaging and spectroscopic modalities for the detection of collagen arrangement and ECM composition in pathological bone. Linking the sex-specific genetic regulators to matrix signatures could be important for treatment of dimorphic bone disorders that clinically manifest in pathological nano- and macro-level disorganisation. This article has an associated First Person interview with the first author of the paper.


Assuntos
Matriz Extracelular , Fator A de Crescimento do Endotélio Vascular , Animais , Osso e Ossos/metabolismo , Colágeno/metabolismo , Matriz Extracelular/metabolismo , Feminino , Humanos , Masculino , Camundongos , Osteoblastos , Fator A de Crescimento do Endotélio Vascular/metabolismo
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