Effect of recombinant human fibroblast growth factor 21 on the mineralization of cementoblasts and its related mechanism / 华西口腔医学杂志

OBJECTIVES@#To investigate the effect of recombinant human fibroblast growth factor 21 (rhFGF21) on the proliferation and mineralization of cementoblasts and its mechanism.@*METHODS@#Hematoxylin eosin, immunohistochemical staining, and immunofluorescence were used to detect the expression and distribution of fibroblast growth factor 21 (FGF21) in rat periodontal tissues and cementoblasts (OCCM-30), separately. Cell Counting Kit-8 was used to detect the proliferation of OCCM-30 under treatment with rhFGF21. Alkaline phosphatase staining and Alizarin Red staining were used to detect the mineralization state of OCCM-30 after 3 and 7 days of mineralization induction. The transcription and protein expression of the osteogenic-related genes Runx2 and Osterix were detected by real-time quantitative polymerase chain reaction (PCR) and Western blot analysis. The expression levels of genes of transforming growth factor β (TGFβ)/bone morphogenetic protein (BMP) signaling pathway in OCCM-30 were detected through PCR array analysis.@*RESULTS@#FGF21 was expressed in rat periodontal tissues and OCCM-30. Although rhFGF21 had no significant effect on the proliferation of OCCM-30, treatment with 50 ng/mL rhFGF21 could promote the mineralization of OCCM-30 cells after 7 days of mineralization induction. The transcriptional levels of Runx2 and Osterix increased significantly at 3 days of mineralization induction and decreased at 5 days of mineralization induction. Western blot analysis showed that the protein expression levels of Runx2 and Osterix increased during mineralization induction. rhFGF21 up-regulated Bmpr1b protein expression in cells.@*CONCLUSIONS@#rhFGF21 can promote the mineralization ability of OCCM-30. This effect is related to the activation of the TGFβ/BMP signaling pathway.

Specific RNA m6A modification sites in bone marrow mesenchymal stem cells from the jawbone marrow of type 2 diabetes patients with dental implant failure / 国际口腔科学杂志·英文版

The failure rate of dental implantation in patients with well-controlled type 2 diabetes mellitus (T2DM) is higher than that in non-diabetic patients. This due, in part, to the impaired function of bone marrow mesenchymal stem cells (BMSCs) from the jawbone marrow of T2DM patients (DM-BMSCs), limiting implant osseointegration. RNA N6-methyladenine (m6A) is important for BMSC function and diabetes regulation. However, it remains unclear how to best regulate m6A modifications in DM-BMSCs to enhance function. Based on the "m6A site methylation stoichiometry" of m6A single nucleotide arrays, we identified 834 differential m6A-methylated genes in DM-BMSCs compared with normal-BMSCs (N-BMSCs), including 43 and 790 m6A hypermethylated and hypomethylated genes, respectively, and 1 gene containing hyper- and hypomethylated m6A sites. Differential m6A hypermethylated sites were primarily distributed in the coding sequence, while hypomethylated sites were mainly in the 3'-untranslated region. The largest and smallest proportions of m6A-methylated genes were on chromosome 1 and 21, respectively. MazF-PCR and real-time RT-PCR results for the validation of erythrocyte membrane protein band 4.1 like 3, activity-dependent neuroprotector homeobox (ADNP), growth differentiation factor 11 (GDF11), and regulator of G protein signalling 2 agree with m6A single nucleotide array results; ADNP and GDF11 mRNA expression decreased in DM-BMSCs. Furthermore, gene ontology and Kyoto Encyclopedia of Genes and Genomes analyses suggested that most of these genes were enriched in metabolic processes. This study reveals the differential m6A sites of DM-BMSCs compared with N-BMSCs and identifies candidate target genes to enhance BMSC function and improve implantation success in T2DM patients.

Tridax procumbens flavonoids promote osteoblast differentiation and bone formation

BACKGROUND: Tridaxprocumbens flavonoids (TPFs) are well known for their medicinal properties among local natives. Besides traditionally used for dropsy, anemia, arthritis, gout, asthma, ulcer, piles, and urinary problems, it is also used in treating gastric problems, body pain, and rheumatic pains of joints. TPFs have been reported to increase osteogenic functioning in mesenchymal stem cells. Our previous study showed that TPFs were significantly suppressed the RANKL-induced differentiation of osteoclasts and bone resorption. However, the effects of TPFs to promote osteoblasts differentiation and bone formation remain unclear. TPFs were isolated from Tridax procumbens and investigated for their effects on osteoblasts differentiation and bone formation by using primary mouse calvarial osteoblasts. RESULTS: TPFs promoted osteoblast differentiation in a dose-dependent manner demonstrated by up-regulation of alkaline phosphatase and osteocalcin. TPFs also upregulated osteoblast differentiation related genes, including osteocalcin, osterix, and Runx2 in primary osteoblasts. TPFs treated primary osteoblast cells showed significant upregulation of bone morphogenetic proteins (BMPs) including Bmp-2, Bmp-4, and Bmp-7. Addition of noggin, a BMP specific-antagonist, inhibited TPFs induced upregulation of the osteocalcin, osterix, and Runx2. CONCLUSION: Our findings point towards the induction of osteoblast differentiation by TPFs and suggested that TPFs could be a potential anabolic agent to treat patients with bone loss-associated diseases such as osteoporosis.

Modulation of cartilage differentiation by melanoma inhibiting activity/cartilage-derived retinoic acid-sensitive protein (MIA/CD-RAP)

Melanoma inhibiting activity/cartilage-derived retinoic acid-sensitive protein (MIA/CD-RAP) is a small soluble protein secreted from malignant melanoma cells and from chondrocytes. Recently, we revealed that MIA/CD-RAP can modulate bone morphogenetic protein (BMP)2-induced osteogenic differentiation into a chondrogenic direction. In the current study we aimed to find the molecular details of this MIA/CD-RAP function. Direct influence of MIA on BMP2 by protein-protein-interaction or modulating SMAD signaling was ruled out experimentally. Instead, we revealed inhibition of ERK signaling by MIA/CD-RAP. This inhibition is regulated via binding of MIA/CD-RAP to integrin alpha5 and abolishing its activity. Active ERK signaling is known to block chondrogenic differentiation and we revealed induction of aggrecan expression in chondrocytes by treatment with MIA/CD-RAP or PD098059, an ERK inhibitor. In in vivo models we could support the role of MIA/CD-RAP in influencing osteogenic differentiation negatively. Further, MIA/CD-RAP-deficient mice revealed an enhanced calcified cartilage layer of the articular cartilage of the knee joint and disordered arrangement of chondrocytes. Taken together, our data indicate that MIA/CD-RAP stabilizes cartilage differentiation and inhibits differentiation into bone potentially by regulating signaling processes during differentiation.

Effect of bovine bone morphogenetic proteins on radius fracture healing in rabbits / Efeito de proteínas morfogenéticas ósseas de origem bovina na consolidação de fraturas induzidas no rádio de coelhos

PURPOSE: To investigate the effect of bovine bone morphogenetic proteins (bBMPs) bound to hydroxyapatite plus collagen in the healing of unstable radius fractures. METHODS: A transverse fracture was induced at the mid of the diaphysis in both radii on 15 Norfolk rabbits with average age of 5.5 months and 3.5kg. A mixture of bBMPs bound to thin powdered hydroxyapatite (bBMP-HA) and bovine collagen as agglutinant was applied to the right radius fracture site. The left radius fracture was considered control and no treatment was used. After 30, 60 and 90 days (5 rabbits/period) the rabbits were euthanized and the radii were collected for histological analysis. RESULTS: The descriptive histological analysis revealed that repair was similar for both forelimbs. The histomorphometric analysis showed that the mean area of newly formed bone was 867442.16 mm², 938743.00 mm² and 779621.06 mm² for the control forelimbs, and 841118.47 mm², 788038.76mm² and 618587.24 mm² for the treated forelimbs at 30, 60 and 90 days, respectively. Thus the newly formed bone area was 12.17 percent larger in the forelimbs treated with bBMP-HA/collagen than in the control forelimbs (p<0.05, Tukey test) in the 60-day period after surgery. In both forelimbs the newly formed bone area increased throughout the experimental period until the complete fracture healing. CONCLUSION: Based on the result obtained here we concluded that bBMP-HA/collagen induced a lower but significant improvement in fracture consolidation.

OBJETIVO: Investigar a influência de Proteínas Morfogenéticas Osseas de origem bovina (bBMPs) ligadas a hidroxiapatita mais colágeno na consolidação de fraturas instáveis do rádio. MÉTODOS: Em 15 coelhos com aproximadamente 5,5 meses de idade e peso médio de 3,5kg foi realizada uma fratura transversa na porção média da diáfise do rádio de ambos os membros. Na fratura do rádio direito foi aplicada mistura de bBMPs ligadas à hidroxiapatita (bBMP-HA) e colágeno bovino como aglutinante e na do rádio esquerdo, considerada controle, nenhum tratamento foi usado. Os coelhos (cinco por período) foram submetidos à eutanásia aos 30, 60 e 90 dias após a cirurgia para realização do processamento histológico e análise microscópica. RESULTADOS: A análise histológica descritiva revelou que a consolidação foi similar para os membros tratado e controle. Pela análise histomorfométrica, a área de novo osso foi em média 867442,16 mm², 938743.00 mm² e 779621,06 mm² para os membros controles e 841118,47 mm², 788038,76mm² e 618587,24 mm² para os membros tratados, aos 30, 60 e 90 dias, respectivamente. Desta forma, aos 60 dias de pós-operatório a área de novo osso foi 12.17 por cento maior no membro tratado com bBMP-HA/colágeno em relação ao membro controle (p<0.05, teste de Tukey). Em ambos os membros a área de novo osso aumentou durante o período experimental até a total consolidação da fratura. CONCLUSÃO: Baseado nos resultados obtidos foi possível concluir que a mistura de bBMP-HA/colágeno induziu pequena, porém significante melhora na consolidação da fratura.

Factores que regulan la morfogénesis y el crecimiento mandibular humano / Factors that regulate the morphogenesis and human mandibular growth

La regulación del crecimiento y desarrollo cráneo-facial está controlada por una serie de interacciones celulares y con la matriz extracelular que estimulan los procesos de proliferación y diferenciación. De fundamental importancia es la cresta neural, una población de células especializadas de células progenitoras que generan los huesos, cartílagos y tejido conectivo de la región. La mandíbula se forma por osificación membranosa en el mesénquima del primer arco faríngeo, pero desarrolla cartílagos secundarios como centros de crecimiento en el cóndilo, en el proceso coronoídeo, en el ángulo mandibular y en la sutura intermaxilar (sínfisis). Estos cartílagos difieren en su origen, su estructura histológica y su respuesta a factores hormonales, metabólicos y mecánicos con respecto a los cartílagos de los huesos largos. Debido a que las células proliferativas son mesenquimáticas y no cartilaginosas, los mecanismos celulares y moleculares que regulan el crecimiento en los cartílagos secundarios, son todavía muy poco conocidos. Los productos génicos BMP (proteina morfogenética de hueso), Ihh (Indian hedgehog), FGF (factor de crecimiento de fibroblastos), Sox-9 y VEGF (factor de crecimiento vascular endotelial) son de gran importancia en el crecimiento mandibular. Este trabajo resume la información reciente acerca de los factores de crecimiento y factores de transcripción, potenciales reguladores del proceso de osificación membranosa y del crecimiento de los cartílagos secundarios de la mandíbula.

Regulation of growth and craniofacial development is controlled by the interactions of cells with each other and with the extracellular environment through signal transduction pathways that control the differentiation process by stimulating proliferation or causing cell death. Of fundamental importance to mandibular development is the neural crest, a specialized population of stem and progenitor cells which generate the bone, cartilage and conjunctive tissue of the first branchial arch. The mandible arises by intramembranous ossification, but develops secondary cartilages as growth centers. Secondary cartilages of the mandible arise in the condylar process, in the coronoid process, angular process of the mandible, and in the intermandibular suture (mental symphysis). These are different, not only in their origins, but in their histologic organization and in their response to hormonal and mechanical factors with articular cartilages of long bones. Because the cells that divide to effect growth and adaptation in these cartilages are of perichondrial/periosteal rather than chondrogenic origin, the cellular and molecular mechanisms that regulate their growth are only beginning to be understood. The main differences of secondary cartilages from cartilages of the limbs and cranial base are, that condylar condroblasts arise from undifferentiated conjuntive cells and the appearance of vascular canals that cross cartilage perpendicularly and connect with the ossification zone. Collagen type I seems to be more important in this process than collagen type II. BMP signaling maintains regulatory roles in skeletons and skeletal growth. Indian hedgehog, Sox-9, fibroblastic growth factor (FGF) and vascular endothelial growth factor (VEGF), are also important in mandibular growth. This article summarizes information regarding growth factors and transcription proteins that are potential growth regulators in these secondary cartilages.