Estudo histológico e imunohistoquímico da degeneração da região central da cartilagem de Meckel na mandíbula em desenvolvimento de ratos / Histological and immunohistochemical study of the degeneration of the central region of Meckel's cartilage in the developing mandible of rats

A cartilagem de Meckel é uma estrutura transitória embrionária presente durante os estágios iniciais da formação da mandíbula, localizada em toda sua extensão e dividida em três porções, anterior, intermediária e posterior. O enfoque deste trabalho foi direcionado à elucidação do destino final da porção intermediária por meio de um estudo temporal sequenciado. Por isso, foi investigado a presença de células de reabsorção e a presença de fibras colágenas, bem como da proteína óssea osteopontina (OPN) na cartilagem de Meckel na região do germe do 1º molar inferior e no seu entorno. Foram utilizados fetos de ratos Wistar em períodos gestacionais pré-estabelecidos, G18 a G21 (grupos de dias intrauterinos), bem como P0 e P1 (recém-nascidos) para remoção das cabeças. Em sequência, os espécimes foram fixados em solução de formaldeído 4% + glutaraldeído 0,1% com tampão fosfato 0,1M, descalcificados em EDTA 4,13%, desidratados em concentrações crescentes de etanol e incluídos em parafina. As amostras foram coradas em hematoxilina e eosina (HE) e tricrômico de Mallory para análise histológica. Adicionalmente, os grupos G19 a P0 foram submetidos à reação histoquímica de TRAP para determinação da presença de células clásticas. Além disso, os grupos G21 e P0 (dia do nascimento) passaram por reações de imunomarcação para análise da expressão de OPN. Foi observado a degeneração gradual da cartilagem com a observação de mudanças estruturais, a justaposição de células clásticas na superfície da cartilagem por reação histoquímica TRAP a partir do G21, o aparecimento de colágeno tipo I nas fases terminais da degeneração, assim como a marcação positiva para a osteopontina na superfície de G21 e em todo o remanescente da cartilagem de Meckel no grupo P0. O estudo apontou um processo de degeneração da cartilagem com evidências de formação de matriz mineralizada de natureza óssea, a qual foi reabsorvida por células clásticas, sugerindo a ossificação da porção intermediária da cartilagem de Meckel.

Efeito do alendronato, da dexametasona e da associação de ambos sobre a osteoclastogênese: um estudo in vitro / Effect of alendronate, dexamethasone and the association of both on osteoclastogenesis: an in vitro study

Os osteoclastos são células multinucleadas com a função de degradar e reabsorver o tecido ósseo. Medicamentos como o alendronato (um tipo de bisfosfonato nitrogenado) e a dexametasona (glicocorticoide), podem interferir na fisiologia das células clásticas. Enquanto o alendronato (ALN) inativa o osteoclasto, agindo primordialmente sobre o citoesqueleto desta célula, a dexametasona (DEX) pode promover aumento na atividade dessa célula. O objetivo deste estudo foi avaliar os efeitos do ALN, da DEX e da combinação de ambos sobre a osteoclastogênese e ativação desta célula. Primeiramente foi estabelecido protocolo de remoção de smear layer para os discos de osso bovino e na sequência, foi realizada análise em espectrofotômetro para avaliar a concentração de ALN absorvida pelo osso. O substrato ósseo foi capaz de absorver completamente o ALN da solução nas concentrações de 10 e 100 M. O cultivo de osteoclastos foi feito a partir das células da medula óssea de camundongos e estimulados com 1,25 dihidroxivitamina D3 e através de osteoclastos obtidos a partir de células Raw 264.7 estimulados com RANKL. As células foram cultivadas sobre substrato ósseo previamente tratado com ALN e tratadas com DEX a 1 M. Conclui-se que o tratamento com ALN a 10 M não foi capaz de inibir completamente a reabsorção óssea, seja administrado sozinho ou com a DEX. A DEX promoveu aumento na expressão gênica RANKL e redução de OPG, mesmo quando administrada conjuntamente com ALN. Quando utilizado na concentração de 100 M, o ALN reduziu a quantidade de anéis de actina dos osteoclastos e promoveu significativa diminuição na liberação de EVs nestas células.

Uso de microvibración e inhibidores de la catepsina K en tratamientos de regeneración ósea dental / Use of micro-vibration and cathepsin K inhibitors in dental bone regeneration treatments

Introducción: el hueso está en remodelación constante para mantener la estructura del esqueleto, tener un ciclo de resorción por los osteoclastos y formación de hueso nuevo a cargo de los osteoblastos; el hueso también es susceptible a enfermedades sistémicas, traumas, edad y trastornos genéticos que afectarán el remodelado óseo, produciendo una pérdida masiva de masa ósea regulado por hormonas, citocinas, enzimas, etcétera. El objetivo es realizar una revisión sistemática de artículos que muestren cambio o alteración al utilizar tratamientos con microvibraciones y farmacológicos sobre la catepsina K en el hueso alveolar. Material y métodos: para realizar una comparación entre la efectividad del tratamiento a base de microvibraciones y con inhibidores de la catepsina K, se realizó una revisión sistemática en nueve bases de datos (Wiley Online Library, PubMed, Google Academic, Scopus, ScienceDirect, SciELO, Medline, EBSCO y Springer Link). La población de estudio fueron ratas y ratones. Resultados: en este estudio se incluyeron 20 artículos cuya investigación se realizó en estudios clínicos. En los resultados podemos observar cómo todos los tratamientos de alguna forma mejoran el proceso de remodelado óseo. Es difícil comparar cuál de los tratamientos dentro de cada grupo es mejor que otro, debido a que los resultados expresados son cualitativos. Conclusión: acorde a los resultados expresados se opta por realizar un tratamiento con microvibraciones debido a que el uso de inhibidores de la catepsina K aún no se encuentra completamente desarrollado y no se comprenden sus consecuencias debido a su manera sistémica de actuar (AU)

Introduction: the bone is in constant remodeling to maintain the skeletal structure, having a cycle of resorption by osteoclasts and formation of new bone by osteoblasts, the bone is also susceptible to systemic diseases, trauma, age and genetic disorders that affect bone remodeling, producing a massive loss of bone mass regulated by hormones, cytokines, enzymes, etcetera. The objective is to perform a systematic review of articles that show a change or alteration when using micro-vibration and pharmacological treatments on cathepsin K in the alveolar bone. Material and methods: in order to make a comparison between the effectiveness of micro-vibration and cathepsin K inhibitor treatments, a systemic review was carried out in nine databases (Wiley Online Library, PubMed, Google Academic, Scopus, ScienceDirect, SciELO, Medline, EBSCO and Springer Link). The study population was rats and mice. Results: this study included 20 articles whose research was carried out in clinical studies. In the results we can see how all the treatments in some way improve the bone remodeling process, it is difficult to compare which treatment within each group is better than the other, because the results expressed are qualitative. Conclusion: according to the results expressed, it is decided that it is better to perform a treatment with micro vibrations because the use of cathepsin K inhibitors are not yet fully developed and their consequences are not understood due to their systemic way of acting (AU)

Unveiling the role of osteoblastic micro RNAs in the skeleton: from biological functions to therapeutic potential / Rol de los micro-ARN osteoblásticos en el esqueleto: desde las funciones biológicas al potencial terapéutico

MicroRNAs (miRNAs) are small non-coding RNA molecules that play critical roles in post-transcriptional gene regulation. They function by binding to target messenger RNA (mRNA) molecules, leading to their degradation or inhibiting their translation into proteins. In the context of skeletal diseases, such as osteoporosis, osteoarthritis, and bone metastasis, there is growing evidence osteoblastic miRNAs, are involved in the regulation of bone formation and maintenance.Osteoblasts are bone-forming cells responsible for synthesizing and depositing the extracellular matrix, which ultimately mineralizes to form bone tissue. Osteoblastic miRNAs modulate various aspects of osteoblast function, including proliferation, differentiation, mineralization, and apoptosis. Dysregulation of these miRNAs can disrupt the balance between bone formation and resorption, leading to skeletal diseases.The therapeutic implications of targeting osteoblastic miRNAs in skeletal diseases are significant. Modulating the expression levels of specific miRNAs holds promise for developing novel therapeutic strategies to enhance bone formation, prevent bone loss, and promote bone regeneration. Potential therapeutic approaches include the use of synthetic miRNA mimics to restore miRNA expression in diseases associated with miRNA downregulation or the use of anti-miRNA oligonucleotides to inhibit miRNA function in diseases associated with miRNA upregulation.miRNA-based therapies are still in the early stages of development, and further research is needed to fully understand the complexity of miRNA networks. Additionally, the delivery of miRNAs to specific target tissues and cells remains a challenge that needs to be addressed for effective clinical translation. Nonetheless, targeting osteoblastic miRNAs represents a promising avenue for future therapeutic interventions in skeletal diseases. (AU)

Los micro-ARNs (miARNss) son pequeños ARN no codificantes que desempeñan un papel fundamental en la regulación génica postranscripcional. Ejercen su función al unir-se a moléculas de ARN mensajero (ARNm), promoviendo su degradación e inhibiendo su traducción en proteínas. En el contexto de las enfermedades esqueléticas, como la osteoporosis, la osteoartritis y la metástasis ósea existe evidencia de que los miARNs osteoblásticos están involucrados en la regulación de la formación y del mantenimiento óseo. Los osteoblastos son células formadoras de hueso responsables de sintetizar y depositar la matriz extracelular, que finalmente se mineraliza para formar el hueso. Los miARNs derivados de osteoblastos modulan varios aspectos de la función de estas células, incluida la proliferación, diferenciación, mineralización y la apoptosis. La desregulación de estos miARNs puede alterar el equilibrio entre la formación y la resorción ósea, lo que lleva a enfermedades óseas. Las implicaciones terapéuticas de los miARNs osteoblásticos en enfermedades esqueléticas son significativas. La modulación de los niveles de expresión de miARNs específicos es prometedora para desarrollar nuevas estrate-gias terapéuticas a fin de mejorar la formación, prevenir la pérdida y promover la regeneración ósea. Los enfoques terapéuticos potenciales incluyen el uso de miméticos de miARNs para restaurar la expresión de miARNs o el uso de oligonucleótidos anti-miARNs para inhibir su función. Las terapias basadas en miARNs aún se encuentran en las primeras etapas de desarrollo. La administración de miARNs a las células y los tejidos específicos sigue siendo un desafío para lograr una aplicación clínica eficaz. (AU)

Study of resveratrol against bone loss by using in-silico and in-vitro methods / Estudo do resveratrol contra a perda óssea usando métodos in silico e in vitro

Abstract By applying the in-silico method, resveratrol was docked on those proteins which are responsible for bone loss. The Molecular docking data between the resveratrol and Receptor activator of nuclear factor-kappa-Β ligand [RANKL] receptors proved that resveratrol binds tightly to the receptors, showed the highest binding affinities of −6.9, −7.6, −7.1, −6.9, −6.7, and −7.1 kcal/mol. According to in-vitro data, Resveratrol reduced the osteoclasts after treating Marrow-Derived Macrophages [BMM] with Macrophage colony-stimulating factor [MCSF] 20ng / ml and RANKL 50ng / ml, with different concentrations of resveratrol (2.5, 10 μg / ml) For 7 days, the cells were treated with MCSF (20 ng / ml) and RANKL (40 ng / ml) together with concentrated trimethyl ether and resveratrol (2.5, 10 μg / ml) within 12 hours. Which, not affect cell survival. After fixing osteoclast cells with formaldehyde fixative on glass coverslip followed by incubation with 0.1% Triton X-100 in PBS for 5 min and after that stain with rhodamine phalloidin staining for actin and Hoechst for nuclei. Fluorescence microscopy was performed to see the distribution of filaments actin [F.actin]. Finally, resveratrol reduced the actin ring formation. Resveratrol is the best bioactive compound for drug preparation against bone loss.

Resumo Com a aplicação do método in-silico, o resveratrol foi ancorado nas proteínas responsáveis ​​pela perda óssea. Os dados de docking molecular entre o resveratrol e o ligante do receptor ativador do fator nuclear kappa-Β [Receptor Activator of Nuclear Factor kappa-B Ligant (RANKL)] provaram que o resveratrol se liga fortemente aos receptores, mostraram as afinidades de ligação mais altas de −6,9, −7,6, −7,1, −6,9, - 6,7 e -7,1 kcal / mol. De acordo com dados in-vitro, o resveratrol reduziu os osteoclastos após o tratamento de macrófagos derivados da medula óssea [Bone Marrow-derived Macrophage (BMM)] com fator estimulador de colônias de macrófagos [Macrophage Colony-Stimulating Factor (MCSF)] 20ng / ml e RANKL 50ng / ml, com diferentes concentrações de resveratrol (2,5, 10 μg / ml). Durante sete dias, as células foram tratadas com MCSF (20 ng / ml) e RANKL (40 ng / ml) juntamente com éter trimetílico concentrado e resveratrol (2,5, 10 μg / ml) em 12 horas, processo que não afeta a sobrevivência celular. Após a fixação de células de osteoclastos com fixador de formaldeído em lamela de vidro seguido de incubação com 0,1% Triton X-100 em PBS por 5 min, foi realizado posteriormente o procedimento para corar com rodamina faloidina a actina e Hoechst os núcleos. A microscopia de fluorescência foi realizada para ver a distribuição dos filamentos de actina [F.actina]. Finalmente, o resveratrol reduziu a formação do anel de actina. O resveratrol é o melhor composto bioativo para o preparo de medicamentos contra a perda óssea.

Osteoimmunology research in rheumatoid arthritis: From single-cell omics approach / 中华医学杂志(英文版)

Cellular immune responses as well as generalized and periarticular bone loss are the key pathogenic features of rheumatoid arthritis (RA). Under the pathological conditions of RA, dysregulated inflammation and immune processes tightly interact with skeletal system, resulting in pathological bone damage via inhibition of bone formation or induction of bone resorption. Single-cell omics technologies are revolutionary tools in the field of modern biological research.They enable the display of the state and function of cells in various environments from a single-cell resolution, thus making it conducive to identify the dysregulated molecular mechanisms of bone destruction in RA as well as the discovery of potential therapeutic targets and biomarkers. Here, we summarize the latest findings of single-cell omics technologies in osteoimmunology research in RA. These results suggest that single-cell omics have made significant contributions to transcriptomics and dynamics of specific cells involved in bone remodeling, providing a new direction for our understanding of cellular heterogeneity in the study of osteoimmunology in RA.

Research progress of tunneling nanotube in bone biology / 中华口腔医学杂志

Tunneling nanotube (TNT) is a newly discovered communication mode between animal cells in recent years, which have important physiological and pathological significance. However, the role of TNT in bone biology is still unclear. At present, there are many reports about tunneling nanotubes in bone marrow mesenchymal stem cells, osteoclast precursor cells, osteoblasts and immune cells. This review describes the research advances of TNT and its research progress in bone biology. It looks forward to the research direction of TNT in oral and maxillofacial bone development and bone biology, to provide new strategies for the maintenance of bone homeostasis and the treatment of bone diseases.

Mechanism of artesunate on bone destruction in experimental rheumatoid arthritis based on transcriptomics and network pharmacology / 中国中药杂志

The present study investigated the mechanism of artesunate in the treatment of bone destruction in experimental rheumatoid arthritis(RA) based on transcriptomics and network pharmacology. The transcriptome sequencing data of artesunate in the inhibition of osteoclast differentiation were analyzed to obtain differentially expressed genes(DEGs). GraphPad Prism 8 software was used to plot volcano maps and heat maps were plotted through the website of bioinformatics. GeneCards and OMIM were used to collect information on key targets of bone destruction in RA. The DEGs of artesunate in inhibiting osteoclast differentiation and key target genes of bone destruction in RA were intersected by the Venny 2.1.0 platform, and the intersection target genes were analyzed by Gene Ontology(GO)/Kyoto Encyclopedia of Genes and Genomes(KEGG) enrichment. Finally, the receptor activator of nuclear factor-κB(RANKL)-induced osteoclast differentiation model and collagen-induced arthritis(CIA) model were established. Quantitative real time polymerase chain reaction(q-PCR), immunofluorescence, and immunohistochemistry were used to verify the pharmacological effect and molecular mechanism of artesunate in the treatment of bone destruction in RA. In this study, the RANKL-induced osteoclast differentiation model in vitro was established and intervened with artesunate, and transcriptome sequencing data were analyzed to obtain 744 DEGs of artesunate in inhibiting osteoclast differentiation. A total of 1 291 major target genes of bone destruction in RA were obtained from GeneCards and OMIM. The target genes of artesunate in inhibiting osteoclast differentiation and the target genes of bone destruction in RA were intersected to obtain 61 target genes of artesunate against bone destruction in RA. The intersected target genes were analyzed by GO/KEGG enrichment. According to the results previously reported, the cytokine-cytokine receptor interaction signaling pathway was selected for experimental verification. Artesunate intervention in the RANKL-induced osteoclast differentiation model showed that artesunate inhibited CC chemokine receptor 3(CCR3), CC chemokine receptor 1(CCR1) and leukemia inhibitory factor(LIF) mRNA expression in osteoclasts in a dose-dependent manner compared with the RANKL-induced group. Meanwhile, the results of immunofluorescence and immunohistochemistry showed that artesunate could dose-dependently reduce the expression of CCR3 in osteoclasts and joint tissues of the CIA rat model in vitro. This study indicated that artesunate regulated the CCR3 in the cytokine-cytokine receptor interaction signaling pathway in the treatment of bone destruction in RA and provided a new target gene for the treatment of bone destruction in RA.

RANKL+ senescent cells under mechanical stress: a therapeutic target for orthodontic root resorption using senolytics / 国际口腔科学杂志·英文版

In dentistry, orthodontic root resorption is a long-lasting issue with no effective treatment strategy, and its mechanisms, especially those related to senescent cells, remain largely unknown. Here, we used an orthodontic intrusion tooth movement model with an L-loop in rats to demonstrate that mechanical stress-induced senescent cells aggravate apical root resorption, which was prevented by administering senolytics (a dasatinib and quercetin cocktail). Our results indicated that cementoblasts and periodontal ligament cells underwent cellular senescence (p21+ or p16+) and strongly expressed receptor activator of nuclear factor-kappa B (RANKL) from day three, subsequently inducing tartrate-resistant acid phosphatase (TRAP)-positive odontoclasts and provoking apical root resorption. More p21+ senescent cells expressed RANKL than p16+ senescent cells. We observed only minor changes in the number of RANKL+ non-senescent cells, whereas RANKL+ senescent cells markedly increased from day seven. Intriguingly, we also found cathepsin K+p21+p16+ cells in the root resorption fossa, suggesting senescent odontoclasts. Oral administration of dasatinib and quercetin markedly reduced these senescent cells and TRAP+ cells, eventually alleviating root resorption. Altogether, these results unveil those aberrant stimuli in orthodontic intrusive tooth movement induced RANKL+ early senescent cells, which have a pivotal role in odontoclastogenesis and subsequent root resorption. These findings offer a new therapeutic target to prevent root resorption during orthodontic tooth movement.

Advances on pentraxin 3 in osteoporosis and fracture healing / 中国骨伤

Pentaxin 3 (PTX3), as a multifunctional glycoprotein, plays an important role in regulating inflammatory response, promoting tissue repair, inducing ectopic calcification and maintaining bone homeostasis. The effect of PTX3 on bone mineral density (BMD) may be affected by many factors. In PTX3 knockout mice and osteoporosis (OP) patients, the deletion of PTX3 will lead to decrease of BMD. In Korean community "Dong-gu study", it was found that plasma PTX3 was negatively correlated with BMD of femoral neck in male elderly patients. In terms of bone related cells, PTX3 plays an important role in maintaining the phenotype and function of osteoblasts (OB) in OP state;for osteoclast (OC), PTX3 in inflammatory state could stimulate nuclear factor κ receptor activator of nuclear factor-κB ligand (RANKL) production and its combination with TNF-stimulated gene 6(TSG-6) could improve activity of osteoclasts and promote bone resorption;for mesenchymal stem cells (MSCs), PTX3 could promote osteogenic differentiation of MSCs through PI3K/Akt signaling pathway. In recent years, the role of PTX3 as a new bone metabolism regulator in OP and fracture healing has been gradually concerned by scholars. In OP patients, PTX3 regulates bone mass mainly by promoting bone regeneration. In the process of fracture healing, PTX3 promotes fracture healing by coordinating bone regeneration and bone resorption to maintain bone homeostasis. In view of the above biological characteristics, PTX3 is expected to become a new target for the diagnosis and treatment of OP and other age-related bone diseases and fracture healing.

Regulatory function and mechanism of autophagy on osteoclast / 中国骨伤

Osteoclast (OC) is multinucleated, bone-resorbing cells originated from monocyte/macrophage lineage of cells, excessive production and abnormal activation of which could lead to many bone metabolic diseases, such as osteoporosis, osteoarthritis, etc. Autophagy, as a highly conserved catabolic process in eukaryotic cells, which plays an important role in maintaining cell homeostasis, stress damage repair, proliferation and differentiation. Recent studies have found that autophagy was also involved in the regulation of osteoclast generation and bone resorption. On the one hand, autophagy could be induced and activated by various factors in osteocalsts, such as nutrient deficiency, hypoxia, receptor activator of nuclear factor(NF)-κB ligand(RANKL), inflammatory factors, wear particles, microgravity environment, etc, different inducible factors, such as RANKL, inflammatory factors, wear particles, could interact with each other and work together. On the other hand, activated autophagy is involved in regulating various stages of osteoclast differentiation and maturation, autophagy could promote proliferation of osteoclasts, inhibiting apoptosis, and promoting differentiation, migration and bone resorption of osteoclast. The classical autophagy signaling pathway mediated by mammalian target of rapamycin complex 1(mTORC1) is currently a focus of research, and it could be regulated by upstream signalings such as phosphatidylinositol 3 kinase(PI-3K)/protein kinase B (PKB), AMP-activated protein kinase(AMPK). However, the paper found that mTORC1-mediated autophagy may play a bidirectional role in regulating differentiation and function of osteoclasts, and its underlying mechanism needs to be further ciarified. Integrin αvβ3 and Rab protein families are important targets for autophagy to play a role in osteoclast migration and bone resorption, respectively. In view of important role of osteoclast in the occurrence of various bone diseases, it is of great significance to elucidate the role of autophagy on osteoclast and its mechanism for the treatment of various bone diseases. The autophagy pathway could be used as a new therapeutic target for the treatment of clinical bone diseases such as osteoporosis.

Investigação de marcadores moleculares sanguíneos durante a infecção pelo vírus Chikungunya / Investigation of blood molecular markers during Chikungunya virus infection

A febre Chikungunya (CHIKF) é uma infecção viral causada pelo vírus Chikungunya (CHIKV). Os sintomas agudos incluem febre alta de início súbito, erupção cutânea, poliartrite e poliartralgia. Embora a infecção geralmente seja resolvida em menos de duas semanas, muitos pacientes experenciam recorrente dor e inflamação nas articulações, que podem persistir por anos. Esse estudo buscou marcadores moleculares no sangue de infectados pelo CHIKV que estejam associados a dor articular e cronicidade da CHIKF. O sequenciamento de receptores de células B (BCR) e T (TCR) demonstrou que a infecção por CHIKV diminui a diversidade desses receptores. Essa diversidade é ainda menor, durante a fase aguda da infecção, naqueles pacientes que irão desenvolver cronicidade. A menor diversidade de BCR em infectados está associada a um aumento na expressão de genes envolvidos na diferenciação e ativação de osteoclastos pela sinalização RANK/RANKL. Em adição, a cronicidade pode estar relacionada um aumento na expressão do gene ZBTB7A cuja expressão confere maior resistência a apoptose em precursores de osteoclastos naqueles pacientes que vão se tornar crônicos. Caso o envolvimento dos osteoclastos durante a patogênese de CHIKF seja confirmado, os pacientes poderão se beneficiar de abordagens terapêuticas já existentes como alternativas adicionais ao tratamento de CHIKF

Chikungunya fever (CHIKF) is a viral infection caused by the Chikungunya virus (CHIKV). Acute symptoms include sudden-onset high fever, rash, polyarthritis, and polyarthralgia. Although the infection usually resolves within two weeks, many patients experience recurrent joint pain and inflammation, which can persist for years. This study sought molecular markers in the blood of CHIKV-infected individuals that are associated with joint pain and chronicity of CHIKF. Sequencing of B (BCR) and T (TCR) cell receptors demonstrated that CHIKV infection decreases the diversity of these receptors. The diversity is even lower, during the acute phase of the infection, in those patients who will develop chronicity. The lower diversity of BCR in infected individuals is associated with an increase in the expression of genes involved in the differentiation and activation of osteoclasts by RANK/RANKL signaling. In addition, chronicity may be related to an increase in the expression of the ZBTB7A gene whose expression confers greater resistance to apoptosis in osteoclast precursors in those patients who will become chronic. If osteoclast role during CHIKF pathogenesis is confirmed, patients may benefit from existing therapeutic approaches as additional alternatives to CHIKF treatment

Channa Striata and Hyperbaric Oxygen Therapy Combination for Pressure Areas in Orthodontic Treatment

ABSTRACT Objective: To study the effect of using a combination of Channa Striata gel and hyperbaric oxygen therapy on pressure areas during orthodontic treatment. Material and Methods: The study was conducted using the ARRIVE Essential 10 guidelines. In this study, 35 3-4 months male guinea pigs (Cavia Cobaya) weighing 300-400 grams were used and divided into 5 groups (n=7). Decalcification was performed to dissolve the dental calcium and jawbone to cut the tissue properly. The decalcification was performed for 30 days. Then preparations were made with HE (Hematoxylin Eosin), observed using a microscope, and counted the number of osteoclasts and macrophages on a light microscope with 400 times magnification. The results of the preparations were analyzed using the SPSS program. Results: The Kruskal-Wallis test of macrophage cells and the ANOVA test of osteoclast cells showed significant results between all groups (p<0.05). Conclusion: The effect of hyperbaric oxygen therapy 2,4 ATA administered on days 8-14 and Channa Striata extract gel administered on days 3-14 can increase the number of macrophages in the periodontal ligament and osteoclasts in the alveolar bone in the pressure area during orthodontic tooth movement.

Aberrant NF-κB activation in odontoblasts orchestrates inflammatory matrix degradation and mineral resorption / 国际口腔科学杂志·英文版

Inflammation-associated proteinase functions are key determinants of inflammatory stromal tissues deconstruction. As a specialized inflammatory pathological process, dental internal resorption (IR) includes both soft and hard tissues deconstruction within the dentin-pulp complex, which has been one of the main reasons for inflammatory tooth loss. Mechanisms of inflammatory matrix degradation and tissue resorption in IR are largely unclear. In this study, we used a combination of Cre-loxP reporter, flow cytometry, cell transplantation, and enzyme activities assay to mechanistically investigate the role of regenerative cells, odontoblasts (ODs), in inflammatory mineral resorption and matrices degradation. We report that inflamed ODs have strong capabilities of matrix degradation and tissue resorption. Traditionally, ODs are regarded as hard-tissue regenerative cells; however, our data unexpectedly present ODs as a crucial population that participates in IR-associated tissue deconstruction. Specifically, we uncovered that nuclear factor-kappa b (NF-κB) signaling orchestrated Tumor necrosis factor α (TNF-α)-induced matrix metalloproteinases (Mmps) and Cathepsin K (Ctsk) functions in ODs to enhance matrix degradation and tissue resorption. Furthermore, TNF-α increases Rankl/Opg ratio in ODs via NF-κB signaling by impairing Opg expression but increasing Rankl level, which utterly makes ODs cell line 17IIA11 (A11) become Trap+ and Ctsk+ multinucleated cells to perform resorptive actions. Blocking of NF-κB signaling significantly rescues matrix degradation and resorptive functions of inflamed ODs via repressing vital inflammatory proteinases Mmps and Ctsk. Utterly, via utilizing NF-κB specific small molecule inhibitors we satisfactorily attenuated inflammatory ODs-associated human dental IR in vivo. Our data reveal the underlying mechanisms of inflammatory matrix degradation and resorption via proteinase activities in IR-related pathological conditions.

Interacción del microbioma intestinal y el hueso / Interaction between the intestinal microbiome and bone

El "microbioma" no solo está constituido por los microbios, sino por todos los componen-tes que viven en el mismo hábitat conforman-do un nicho ecológico. Es decir, está conformado por los microorganismos (bacterias, hongos, protozoos, etc.), todo el espectro de moléculas producidas por ellos tales como sus componentes estructurales (ácidos nucleicos, proteínas, lípidos y glúcidos), meta-bolitos, toxinas, etc., y las moléculas producidas por el huésped. El microbioma intestinal (MI) ha emergido como un factor que tiene un gran efecto sobre la cantidad, calidad y fuerza del hueso. Las investigaciones revelan que la homeostasis ósea está ligada al micro-bioma saludable, mientras que la disbiosis (alteración en la biodiversidad microbiana) puede exacerbar la actividad osteoclástica y promover la osteoporosis. Los mecanismos potenciales involucrados en la interacción del microbioma intestinal y el hueso son la influencia del metabolismo del huésped, el mantenimiento de la integridad intestinal y regulación de la absorción de nutrientes, la regulación del eje intestino-sistema inmune y la modulación del sistema endocrino. Es decir que hay múltiples vías por las cuales el MI influye sobre el hueso, pero estos y otros mecanismos deben profundizarse más aún. También es necesario que se identifiquen y caractericen mejor los microorganismos que están asociados a las enfermedades óseas. El conocimiento de estos aspectos podría ser útil para el desarrollo de herramientas terapéuticas basadas en el MI que puedan mejorar la eficacia de los distintos tratamientos existentes. (AU)

The microbiome is not only constituted by microbes, but by all the components that live in the same habitat forming an ecological niche. It is conformed by the microorganisms ( bacteria, fungi, protozoa, etc), the entire spectrum of molecules produced by them (nucleic acids, proteins, lipid and carbohydrates, metabolites, toxins, etc) and the molecules produced by the host. The intestinal microbiome (IM) has emerged as a factor with great effects on the quantity, quality and strength of bone. The investigations reveal that bone homeostasis is linked to the healthy microbiome, while the dysbiosis (alteration in the microbial biodiversity) can exacerbate the osteoclastic activity and promote osteoporosis. The potential mechanisms involved in the interaction between IM and bone are the influence of the host metabolism, the maintenance of the intestinal integrity and regulation of the nutrient absorption, the regulation of the intestine/ immune system axis and the modulation of the endocrine system. That is, there are multiple ways through which IM influences on bone, but these and other mechanisms need to be further studied. It is also necessary to identify and characterize the microorganisms associated with the bone diseases. Knowledge of these aspects could be useful to develop therapeutical tools based on the IM that could improve the efficacy of the current treatments. (AU)

Multi-functional osteoclasts in matrix-based tissue engineering bone / 中华创伤杂志(英文版)

The repair of bone defects, especially for the large segment of bone defects, has always been an urgent problem in orthopedic clinic and attracted researchers' attention. Nowadays, the application of tissue engineering bone in the repair of bone defects has become the research hotspot. With the rapid development of tissue engineering, the novel and functional scaffold materials for bone repair have emerged. In this review, we have summarized the multi-functional roles of osteoclasts in bone remodeling. The development of matrix-based tissue engineering bone has laid a theoretical foundation for further investigation about the novel bone regeneration materials which could perform high bioactivity. From the point of view on preserving pre-osteoclasts and targeting mature osteoclasts, this review introduced the novel matrix-based tissue engineering bone based on osteoclasts in the field of bone tissue engineering, which provides a potential direction for the development of novel scaffold materials for the treatment of bone defects.

PTHrP promotes subchondral bone formation in TMJ-OA / 国际口腔科学杂志·英文版

PTH-related peptide (PTHrP) improves the bone marrow micro-environment to activate the bone-remodelling, but the coordinated regulation of PTHrP and transforming growth factor-β (TGFβ) signalling in TMJ-OA remains incompletely understood. We used disordered occlusion to establish model animals that recapitulate the ordinary clinical aetiology of TMJ-OA. Immunohistochemical and histological analyses revealed condylar fibrocartilage degeneration in model animals following disordered occlusion. TMJ-OA model animals administered intermittent PTHrP (iPTH) exhibited significantly decreased condylar cartilage degeneration. Micro-CT, histomorphometry, and Western Blot analyses disclosed that iPTH promoted subchondral bone formation in the TMJ-OA model animals. In addition, iPTH increased the number of osterix (OSX)-positive cells and osteocalcin (OCN)-positive cells in the subchondral bone marrow cavity. However, the number of osteoclasts was also increased by iPTH, indicating that subchondral bone volume increase was mainly due to the iPTH-mediated increase in the bone-formation ability of condylar subchondral bone. In vitro, PTHrP treatment increased condylar subchondral bone marrow-derived mesenchymal stem cell (SMSC) osteoblastic differentiation potential and upregulated the gene and protein expression of key regulators of osteogenesis. Furthermore, we found that PTHrP-PTH1R signalling inhibits TGFβ signalling during osteoblastic differentiation. Collectively, these data suggested that iPTH improves OA lesions by enhancing osteoblastic differentiation in subchondral bone and suppressing aberrant active TGFβ signalling. These findings indicated that PTHrP, which targets the TGFβ signalling pathway, may be an effective biological reagent to prevent and treat TMJ-OA in the clinic.

Osteopetrosis autosómica dominante benigna: Reporte de caso / Autosomal dominant osteopetrosis: Case report

La osteopetrosis es una enfermedad infrecuente, se caracteriza por el incremento de la densidad ósea observada en las radiografías, resultado de anormalidades en la diferen- ciación y función de los osteoclastos que les incapacita para la resorción ósea y cartilaginosa, formándose huesos más densos, pero más frágiles. Objetivo: describir la Osteopetrosis Auto- sómica Dominante mostrando nuestra experiencia el método de tratamiento. Con un amplio conocimiento de esta patología, los hallazgos radiográficos característicos y los manejos tera- péuticos adecuados podremos lograr un diagnóstico precoz certero y una mejor sobrevida de los pacientes. Reporte de caso: Paciente femenina de 13 años, con historia de fracturas espontáneas a repetición en los antebrazos principalmente, la madre niega antecedentes de trauma; asimismo refiere observar retraso en el crecimiento de la paciente, por lo cual acude al hospital regional de occidente, Quetzaltenango, Guatemala, para evaluación. Se le realizan radiografías en proyección anteroposterior (AP) y lateral de cráneo, de extremidades superio- res e inferiores y de columna dorsal evidenciando en las radiografías de cráneo aumento de la densidad ósea y aumento de grosor de la misma, en la columna dorsal se observó aumento de la esclerosis a nivel de las placas terminales superiores e inferiores de los cuerpos vertebrales, dando la típica apariencia de "vertebra en sándwich", signo patognomónico de esta enferme- dad. La paciente recibió tratamiento con prednisolona, vitamina D y calcio en dosis de acuerdo a las medidas antropométricas de la paciente y control médico por año para evaluar estado clínico...(AU)

Estudo histológico e imunohistoquímico da degeneração da região central da cartilagem de Meckel na mandíbula em desenvolvimento de ratos / Histological and immunohistochemical study of the degeneration of the central region of Meckel's cartilage in the developing mandible of rats

A cartilagem de Meckel é uma estrutura transitória embrionária presente durante os estágios iniciais da formação da mandíbula, localizada em toda sua extensão e dividida em três porções, anterior, intermediária e posterior. O enfoque deste trabalho foi direcionado à elucidação do destino final da porção intermediária por meio de um estudo temporal sequenciado. Por isso, foi investigado a presença de células de reabsorção e a presença de fibras colágenas, bem como da proteína óssea osteopontina (OPN) na cartilagem de Meckel na região do germe do 1º molar inferior e no seu entorno. Foram utilizados fetos de ratos Wistar em períodos gestacionais pré-estabelecidos, G18 a G21 (grupos de dias intrauterinos), bem como P0 e P1 (recém-nascidos) para remoção das cabeças. Em sequência, os espécimes foram fixados em solução de formaldeído 4% + glutaraldeído 0,1% com tampão fosfato 0,1M, descalcificados em EDTA 4,13%, desidratados em concentrações crescentes de etanol e incluídos em parafina. As amostras foram coradas em hematoxilina e eosina (HE) e tricrômico de Mallory para análise histológica. Adicionalmente, os grupos G19 a P0 foram submetidos à reação histoquímica de TRAP para determinação da presença de células clásticas. Além disso, os grupos G21 e P0 (dia do nascimento) passaram por reações de imunomarcação para análise da expressão de OPN. Foi observado a degeneração gradual da cartilagem com a observação de mudanças estruturais, a justaposição de células clásticas na superfície da cartilagem por reação histoquímica TRAP a partir do G21, o aparecimento de colágeno tipo I nas fases terminais da degeneração, assim como a marcação positiva para a osteopontina na superfície de G21 e em todo o remanescente da cartilagem de Meckel no grupo P0. O estudo apontou um processo de degeneração da cartilagem com evidências de formação de matriz mineralizada de natureza óssea, a qual foi reabsorvida por células clásticas, sugerindo a ossificação da porção intermediária da cartilagem de Meckel.

Citotoxicidade e efeito indutor de mineralização de flavonoides sobre células osteoblásticas / Cytotoxicity and inducing effect of mineralization of flavonoids on osteoblastic cells

A perda óssea dentária e a formação de lesões periapicais surgem como uma consequênc ia do desequilíbrio da homeostase óssea. Os osteoblastos, juntamente com os osteoclastos e osteócitos, atuam na formação e na reabsorção óssea. Vários marcadores de formação óssea são produzidos por osteoblastos ativos e refletem diferentes aspectos da dif erenciação osteoblástica e da remodelação óssea. Com isso, muitos autores têm explorado o uso de fitoterápicos, visando obter novos compostos que apresentem propriedades terapêuticas, como os flavonoides, e que estimulem a neoformação óssea e o reparo da r egião periapical. O objetivo deste estudo foi avaliar in vitro a citotoxicidade e efeito indutor de mineralização de flavonoides sobre células osteoblásticas humanas. Para isso, células osteoblásticas da linhagem Saos expostas aos seguintes flavono2 foram ides: quercetina, miricetina e seus derivados taxifolina, isoquercitrina, rutina, ampelopsina e EGCG, além de pinocembrina, crisina e canferol, de forma isolada e combinada. Foi avaliado o efeito citotóxico, a atividade de fosfatase alcalina e indução de n mé todo de Shapiroódulos de mineralização. Os resultados foram analisados p elo Wilk, e as variáveis foram submetidas à análise de ANOVA seguida pelo teste de Tukey para comparar entre os grupos e/ou concentrações ou teste de Dunnett para comparar entre cada grupo e o controle, com nível de significância de 5%. A viabilidade da cultura de osteoblastos não teve uma redução estatisticamente significativa na presença da maioria dos compostos, exceto crisina a 100µM. Taxifolina, isoquercitrina, rutina, ampelopsina e EGCG foram os compostos que estimularam significativamente a atividade da fosfatase alcalina, juntamente com as combinações taxifolina+isoquercitrina, taxifolina+ampelopsina e taxifolina+rutina a 25/25 µM. Quanto a formação de nódulos de mine ralização, ampelopsina, isoquercitrina, rutina, pinocembrina e miricetina isolados e taxifolina+isoquercitrina, taxifolina+ampelopsina e taxifolina+rutina combinados obtiveram os melhores resultados, variando de acordo com as concentrações. Concluise que a taxifolina, isoquercitrina, rutina e ampelopsina e combinações de taxifolina com esses flavonoides são citocompatíveis e apresentam efeito indutor de mineralização em osteoblastos Saos-2(AU)

Dental bone loss and the formation of periapical lesions arise as a consequence of imbalance of bone homeostasis. Osteoblasts, together with osteoclasts and osteocytes, act in bone formation and resorption. Several markers of bone formation are produced by active osteoblasts and reflect different aspects of osteoblastic differentiation and bone remodeling. Thus, many authors have explored the use of phytotherapics in order to obtain new compounds with therapeutic properties, such as flavonoids, and also stimulate bone neoformation and periapical region repair. The objective of this study was to evaluate in vitro the cytotoxicity and inducing effect of flavonoid mineralization on human osteoblastic cells. For this, osteoblastic cells of the Saos-2 lineage were exposed to the following flavonoids: quercetin, myricetin and its derivatives taxifoline, isoquercitrin, rutin, ampelopsin and EGCG, in addition to pinocembrin, chrysin and kaempferol, in an isolated and combined manner. The cytotoxic effect, the activity of alkaline phosphatase and the induction of mineralization nodules were evaluated. The results were analyzed using the Shapiro-Wilk method, and the variables were submitted to ANOVA analysis followed by the Tukey test to compare between groups and/or concentrations or Dunnett's test to compare between each group and the control, with a level of 5% significance. The viability of the osteoblast culture did not have a statistically significant reduction in the presence of most compounds, except 100 µM chrysin. Taxifoline, isoquercitrin, rutin, ampelopsin and EGCG were the compounds that significantly stimulated the activity of alkaline phosphatase, together with the combinations taxifoline+isoquercitrin, taxifoline+ampelopsin and taxifoline+rutin at 25/25 µM. As for the formation of mineralization nodules, ampelopsin, isoquercitrin, rutin, pinocembrin and myricetin alone and taxifoline+isoquercitrin, taxifoline+ampelopsin and taxifoline+rutin combined obtained the best results, varying according to the concentrations. It is concluded that taxifoline, isoquercitrin, rutin and ampelopsin and combinations of taxifolin with these flavonoids are cytocompatible and have a mineralization-inducing effect on Saos-2 osteoblasts(AU)