Integrated proteomics, phosphoproteomics and metabolomics analyses reveal similarities among giant cell granulomas of the jaws with different genetic mutations.

BACKGROUND: Giant cell granuloma of the jaws are benign osteolytic lesions of the jaws. These lesions are genetically characterized by mutually exclusive somatic mutations at TRPV4, KRAS, and FGFR1, and a fourth molecular subgroup which is wild-type for the three mutations. Irrespective of the molecular background, giant cell granulomas show MAPK/ERK activation. However, it remains unclear if these mutations lead to differences in their molecular signaling in giant cell granulomas. METHODS: Metabolomics, proteomics, and phosphoproteomics analyses were carried out in formalin-fixed paraffin-embedded samples of giant cell granuloma of the jaws. The study cohort consisted of five lesions harboring mutations in FGFR1, six in KRAS, five in TRPV4, and five that were wild-type for these mutations. RESULTS: Lesions harboring KRAS or FGFR1 mutations showed overall similar proteomics and metabolomics profiles. In all four groups, metabolic pathways showed similarity in apoptosis, cell signaling, gene expression, cell differentiation, and erythrocyte activity. Lesions harboring TRPV4 mutations showed a greater number of enriched pathways related to tissue architecture. On the other hand, the wild-type group presented increased number of enriched pathways related to protein metabolism compared to the other groups. CONCLUSION: Despite some minor differences, our results revealed an overall similar molecular profile among the groups with different mutational profile at the metabolic, proteic, and phosphopeptidic levels.

The Effects of NF-kB Inhibition with p65-TMD-Linked PTD on Inflammatory Responses at Peri-implantitis Sites.

The objective of this study was to find out if suppression of NF-kB complex function by p65-TMD-linked PTD could reduce host inflammation and bone resorption at peri-implantitis sites in rats. Twenty-one male 5-week-old SD rats were divided into three groups: untreated control group (A), silk-induced peri-implantitis group (B), and nt (nucleus transducible)-p65-TMD-treated, silk-induced peri-implantitis group (C). Implant sulcus of a rat in group C were divided into two groups, namely group Cp and Cb. Palatal implant sulcus where nt-p65-TMD solution was applied with an insulin syringe were assigned to group Cp. Buccal implant sulcus without topical nt-p65-TMD application were assigned to group Cb. H&E staining, TRAP staining, and immunohistological staining were done. The crestal bone levels of group A were significantly higher than those of group B at p<0.01. The crestal bone levels of group Cp were significantly higher than those of group Cb at p<0.05. H-E staining showed increased apical migration of junctional epithelium and inflammatory cells in group Cb. TRAP staining revealed more multinucleated osteoclasts in group Cb. As for immunohistological staining, group Cb showed many IL-6-positive cells while group Cp had none. In this study, p65-TMD-linked PTD inhibited NF-kB functions and reduced inflammation and bone resorption at peri-implantitis sites in rats.

Human Periodontal Ligament Stem Cells Transplanted with Nanohydroxyapatite/Chitosan/Gelatin 3D Porous Scaffolds Promote Jaw Bone Regeneration in Swine.

Dental-tissue-derived stem cells have been used for tissue engineering owing to their ease of isolation and efficacy in in vitro and in vivo proliferation and differentiation. Nanohydroxyapatite/chitosan/gelatin (nHA/CG) three-dimensional porous scaffolds are promising for bone tissue engineering, especially jaw bone regeneration, because of their structural and functional similarity to natural bone. In our previous study, the efficiency of scaffolds with stem cell complexes in osteogenesis was confirmed in vivo in immunocompromised mice. However, studies on the bone regeneration efficiency of stem cell-seeded nHA/CG scaffolds using large animal jaw bone defect models have not been conducted. This study evaluated the bone regeneration potential of the nHA/CG scaffolds with transplanted human periodontal ligament stem cells (hPDLSCs) in critical-sized jaw bone defects in minipigs. The hPDLSCs isolated from periodontal ligaments of discarded teeth (postorthodontic purposes) were seeded onto the nHA/CG scaffolds. The scaffold was successfully synthesized according to our previous studies. Forty-eight critical-sized jaw bone defects were created in 12 minipigs. The defects were randomly assigned to one of three groups [scaffolds with seeded hPDLSCs (hPDLSCs/nHA/CG), only scaffold (nHA/CG), and a negative control group, ie, no cells and scaffolds implanted into defects] to investigate jaw bone regeneration. The bone regeneration capacities of the three groups were assessed for up to 12 weeks. The results showed that the hPDLSCs adhered well to the nHA/CG scaffold in vitro, and the cell-nHA/CG composites significantly increased new bone formation and generated large bones with normal architectures and vascularization in vivo compared to the nHA/CG and control groups. Immunohistochemistry staining showed that runt-related transcription factor 2 (Runx2) was highly expressed in the bone marrow formed in the hPDLSCs/nHA/CG group. This study provides strong evidence for future clinical applications of the nHA/CG scaffolds transplanted with hPDLSCs to regenerate the bone in large jaw bone defects.

Effect of selected metals on bone tissue of the masticatory apparatus / Efectos de metales en el tejido óseo del aparato masticatorio

The masticatory apparatus is a functional unit of the human body, which is mainly responsible for speech, chewing, and swallowing. It is built of bones, joints, ligaments, teeth, and muscles. In addition, the oral cavity and its hard tissues are the first ones to be exposed to exogenous factors during feeding and breathing. The aim of the work was to review the literature of recent years on the toxicology of metals and their possible negative and sometimes positive effects on the metabolism of bones of the masticatory apparatus. In summary, metals commonly found in the environment affect the bones of the masticatory apparatus to varying degrees. Attention should be paid to the sources of individual metals in the environment and to prevent their excessive, unwanted effects on the bones of the masticatory apparatus. (AU)

El aparato masticatorio constituye una unidad funcional del cuerpo humano especializada en la regulación y coordinación de los procesos del habla, la masticación y la deglución. Está constituida por huesos, ligamentos, articulaciones, músculos y dientes. El tejido óseo de la cavidad bucal es el primero en estar expuesto a factores exógenos durante la alimentación y la respiración. El objetivo del presente trabajo es realizar una revisión de lo reportado en la literatura en los últimos años, con respecto a los efectos beneficiosos o nocivos de los metales pesados sobre el metabolismo de los huesos del aparato masticatorio. En resumen, se evidencia que los metales presentes en el medioambiente afectan a estos huesos en diferentes grados. Se debe prestar especial atención a identificar las fuentes de donde provienen estos metales, para prevenir los efectos no deseados sobre el tejido óseo masticatorio generados por una excesiva exposición a ellos. (AU)

Jaw Periosteal Cells Seeded in Beta-Tricalcium Phosphate Inhibit Dendritic Cell Maturation.

Mesenchymal stem cells (MSCs) have gained attraction not only in the field of regenerative medicine but also in the field of autoimmune disease therapies or organ transplantation due to their immunoregulatory and/or immunosuppressive features. Dendritic cells (DCs) play a crucial role in initiating and regulating immune reactions by promoting antigen-specific T cell activation. In this study, we investigated the effect of human jaw periosteal progenitor cells (JPCs) seeded in beta-tricalcium phosphate (ß-TCP) scaffolds on monocyte-derived DC differentiation. Significantly lower numbers of differentiated DCs were observed in the presence of normal (Co) and osteogenically induced (Ob) JPCs-seeded ß-TCP constructs. Gene expression analysis revealed significantly lower interleukin-12 subunit p35 (IL-12p35) and interleukin-12 receptor beta 2 (IL-12Rß2) and pro-inflammatory cytokine interferon-gamma (IFN-γ) levels in DCs under Ob conditions, while interleukin-8 (IL-8) gene levels were significantly increased. Furthermore, in the presence of JPCs-seeded ß-TCP constructs, interleukin-10 (IL-10) gene expression was significantly induced in DCs, particularly under Ob conditions. Analysis of DC protein levels shows that granulocyte-colony stimulating factor (G-CSF) was significantly upregulated in coculture groups. Our results indicate that undifferentiated and osteogenically induced JPCs-seeded ß-TCP constructs have an overall inhibitory effect on monocyte-derived DC maturation.

Demonstration of beta-tropomyosin (Tpm2) and duplication of the alpha-slow tropomyosin gene (TPM3) in Atlantic salmon Salmo salar.

Beta tropomyosin (Tpm2) is demonstrated for the first time at the protein level in a fish species, using a combination of electrophoresis, mass spectrometric peptide mapping and end-group analysis. Tpm2 accounts for 50% of the total tropomyosin in slow trunk muscle of the adult Atlantic salmon as determined by quantitative carboxypeptidase digestion and is also present in the head and pectoral fin. It is absent in the fast skeletal (lighter-toned) trunk muscle, the most abundant muscle, which is composed solely of an alpha-fast (Tpm1) isoform. In contrast to the mammalian homologues, salmon Tpm2 migrates faster than salmon Tpm1 in the presence of anionic detergent. Other distinguishing characteristics are a reduced content of cysteine (one per chain) and tyrosine (five per chain) and a unique carboxyl-terminal region (residues 276-284). Two isoforms (paralogs) of alpha-slow tropomyosin (Tpm3) having different contents of methionine and histidine exist in slow trunk muscle indicating duplication of the TPM3 gene. Minor skeletal muscles, surveyed for the first time, contain a mix of at least two tropomyosins - Tpm2 (~ 50% of total) in pectoral fin, jaw and tongue and another isoform, either Tpm1 (pectoral fin) or alpha-1-like Tpm (jaw and tongue). Cheek muscle contains Tpm1 and alpha 1-like Tpm in varying proportion depending upon the section (light or dark). Of the two tropomyosins in tongue, Tpm2 displays comparatively weaker affinity for troponin-Sepharose. A feature of the major sarcomeric tropomyosins in Atlantic salmon is a pair of neighbouring glycines situated between residues 20-90.

Metastatic tumors in oral mucosa and jawbones: Unusual primary origins and unusual oral locations.

AIM: To perform clinico-pathological characterization of a large series of oral metastases, collected from 3 main medical centers in Israel and compare findings to data on frequency of primary cancer types in the population. MATERIALS: Pathology archives were searched for cases of metastatic tumors to the oral soft tissues and jawbones, 1990 - 2016. Metastases to the skin of face or to major salivary glands have been excluded. Demographic data and histopathological features were analyzed. RESULTS: Study population included 60 patients, 35 females and 25 males (ratio of 1.4:1). The age range was 17-87 years, mean 67.7 + 14.36 years. Only 3 (5%) patients were under 40 years, the remaining clustered predominantly in the 60-80 year age group. The mean age of females (59 + 13.84) was significantly lower than that of males (67.44 + 14) (p = 0.03). There was an almost equal distribution between the oral soft tissue and the jawbones (48.3% and 51.7%, respectively). The five most common organs from which metastases were distributed to the oral cavity and jawbones combined were kidney (20%), breast (15%), cutaneous (predominately melanoma, 13%), lung (11.7%) and soft tissue-sarcomas (8.3%). For comparison, Israel National Cancer Registry 2013 reported that the most frequent malignancies were breast (25.8%), colorectal cancer (16.3%), lung (12%) and prostate (10%). Malignant melanoma was 6th (5.4%), kidney malignancy was only 9th in frequency (4.2%). Although the gingiva and jawbones were the most frequent locations, some cases presented in unusual locations, (mandibular vestibule, lower lip, posterior dorsal tongue), without any specific clinical feature to suggest metastasis. CONCLUSIONS: The most frequent primary origins for oral metastasis do not correspond to the relative frequency of the primary tumors in the population, indicating that metastatic spread is not a random process. Although the majority of metastasis involves the gingiva and jawbones, any other oral mucosal location might be involved. Thus, in adult/older patients, metastasis from a distant site should be included in the differential diagnosis of oral masses at any oral location, whether the existence of a primary tumor is reported or not.

Pentosidine correlates with nanomechanical properties of human jaw bone.

Initial intimate apposition between implant fixtures and host bone at the surgical site is a critical factor for osseointegration of dental implants. The advanced glycation end products accumulated in the jaw bone could lead to potential failure of a dental implant during the initial integration stage, because of the inferior bone mechanical property associated with the abnormal collagen cross-linking at the material level. Here, we demonstrate the lowered creep deformation resistance and reduced dimensional recovery of jaw bone in line with high levels of pentosidine accumulation in the bone matrix which likely correlate with the pentosidine level in blood plasma. Peripheral blood samples and cortical bone samples at the surgical site were obtained from patients scheduled for dental implants in the mandible. The pentosidine levels in blood plasma were assessed. Subsequently, the relative pentosidine levels and the mechanical properties of the jaw bone were quantified by Raman microspectroscopy and nanoindentation, respectively. The nanoindentation tests revealed less creep deformation resistance and reduced time-dependent dimensional recovery of bone samples with the increase in the relative pentosidine level in the bone matrix. Higher tan δ values at the various frequencies during the dynamic indentation tests also suggested that viscoelasticity is associated with the relative intensity of pentosidine in the jaw bone matrix. We found a positive correlation between the pentosidine levels in blood plasma and the bone matrix, which in turn reduced the mechanical property of the jaw bone at the material level. Increased creep and reduced dimensional recovery of the jaw bone may diminish the mechanical interlocking of dental implants during the initial integration stage. Given the likely correlation between the plasma pentosidine level and the mechanical properties of bone, measurement of the plasma pentosidine level could serve as a new index to assess jaw bone matrix quality in advance of implant surgery.

Vasculature submucosal changes at early stages of osteonecrosis of the jaw (ONJ).

Osteonecrosis of the jaw (ONJ), a rare, but potentially severe side effect of anti-resorptive medications, presents as exposed bone in the maxillofacial region lasting for at least 8 weeks. While clinical experience and animal models concur in finding that systemic antiresorptive treatment in conjunction with local risk factors, such as tooth extraction or dental disease may lead to ONJ development, the subclinical molecular changes that precede bone exposure remain poorly understood. The identification of these changes is not only important in understanding disease pathophysiology, but could provide potential for treatment development. Here, we evaluated the early stages of ONJ utilizing a model of experimental periodontitis (EP) in mice treated with two different types of antiresorptives, targeting potential changes in vasculature, hypoxia, oxidative stress, and apoptosis. Antiresorptive treatment in animals with EP increased levels of empty osteocytic lacunae and increased ONJ prevalence compared to Veh animals. The arteriole and venule network seen around EP areas was diminished in animals treated with antiresorptives. Higher levels of vascular endothelial growth factor A (VEGF-A) and vascular cell adhesion protein-1 (VCAM-1) were observed 1-week following EP in treated animals. Finally, levels of hypoxia, oxidative stress, and apoptosis remained high in antiresorptive treated animals with EP through the duration of the experiment. Together, our data point to subclinical vasculature organizational disturbances that subsequently affect levels of hypoxia, oxidative stress, and apoptosis in the area of developing ONJ.

Implant-associated gene expression in the jaw bone of smokers and nonsmokers: A human study using quantitative qPCR.

OBJECTIVES: This study aimed to compare the molecular events in implant-adherent cells and in peri-implant bone during the osseointegration of machined and oxidized titanium implants in smokers and nonsmokers. MATERIALS AND METHODS: Twenty-four smokers and 24 nonsmokers each received machined and anodically oxidized mini-implants. The mini-implants and the surrounding bone were retrieved after 1, 7, and 28 days, for gene expression analysis of selected factors using quantitative polymerase chain reaction (qPCR). RESULTS: Differences between machined and oxidized implants were more evident in the implant-adherent cells than the peri-implant bone. The machined implants revealed higher expression of proinflammatory cytokines, interleukin-8 (IL-8) (in nonsmokers), and tumor necrosis factor-alpha (in nonsmokers and smokers), compared with the oxidized implants. Conversely, the expression of bone formation genes, alkaline phosphatase and osteocalcin, was generally higher at the oxidized implants. In smokers, the temporal pattern revealed the delayed and initial inhibition of osteoblastic and osteoclastic gene expression, respectively, mainly at the machined implants. In contrast, oxidized implants revealed higher expression of bone remodeling, cathepsin K (CatK) and calcitonin receptor, and coupling, receptor activator of nuclear factor kappa-B ligand (RANKL) and osteoprotegerin, genes after 7 day in smokers. CONCLUSIONS: The implant-adherent cells are more sensitive to surface properties and smoking conditions than the cells in the peri-implant bone. Smoking imposes inhibitory effects on the initial molecular events of osseointegration in the human bone-implant interface. The surface properties of oxidized implants appear to have a beneficial effect on osseointegration by mitigating the smoking-induced negative effects.

Maxillary Bone Regeneration Based on Nanoreservoirs Functionalized ε-Polycaprolactone Biomembranes in a Mouse Model of Jaw Bone Lesion.

Current approaches of regenerative therapies constitute strategies for bone tissue reparation and engineering, especially in the context of genetical diseases with skeletal defects. Bone regeneration using electrospun nanofibers' implant has the following objectives: bone neoformation induction with rapid healing, reduced postoperative complications, and improvement of bone tissue quality. In vivo implantation of polycaprolactone (PCL) biomembrane functionalized with BMP-2/Ibuprofen in mouse maxillary defects was followed by bone neoformation kinetics evaluation using microcomputed tomography. Wild-Type (WT) and Tabby (Ta) mice were used to compare effects on a normal phenotype and on a mutant model of ectodermal dysplasia (ED). After 21 days, no effect on bone neoformation was observed in Ta treated lesion (4% neoformation compared to 13% in the control lesion). Between the 21st and the 30th days, the use of biomembrane functionalized with BMP-2/Ibuprofen in maxillary bone lesions allowed a significant increase in bone neoformation peaks (resp., +8% in mutant Ta and +13% in WT). Histological analyses revealed a neoformed bone with regular trabecular structure, areas of mineralized bone inside the membrane, and an improved neovascularization in the treated lesion with bifunctionalized membrane. In conclusion, PCL functionalized biomembrane promoted bone neoformation, this effect being modulated by the Ta bone phenotype responsible for an alteration of bone response.

Mechanical stretch-induced osteogenic differentiation of human jaw bone marrow mesenchymal stem cells (hJBMMSCs) via inhibition of the NF-κB pathway.

Severe malocclusion can contribute to several serious dental and physical conditions, such as digestive difficulties, periodontal disease, and severe tooth decay. Orthodontic treatment is mainly used to treat malocclusion. Forces in orthodontic tooth results in bone resorption on the pressure side and bone deposition on the tension side. Osteoblasts have been considered as the key component in bone regeneration on the tension side. However, the underlying mechanisms remain unclear. In this study, we focus on how mechanical stretch regulates the osteogenesis during orthodontic treatment. Human jaw bone marrow mesenchymal stem cells (hJBMMSCs) were isolated from healthy adult donors and cultured in regular medium (control) or osteogenic medium (OS). Under OS culture, hJBMMSCs presented osteogenic differentiation potentials, as evidenced by increased mineralization, enhanced calcium deposition, and upregulated expression of osteogenesis markers (ALP, osterix, and Runx). What's more, the OS-induced osteogenesis of hJBMMSCs is associated with the dephosphorylation of IKK, activation of IKBα, and phosphorylation/nucleic accumulation of P65, which all indicated the inhibition of NF-κB activity. Overexpressing P65 in hJBMMSCs, which could constantly activate NF-κB, prevented the osteogenic differentiation in the OS. After that, we applied the Flexcell tension system, which could cause mechanical stretch on cultured hJBMMSCs to mimic the tension forces during tooth movement. Mechanical stretch resulted in 3.5-fold increase of ALP activity and 2.4-fold increase of calcium deposition after 7 days and 21 days treatment, respectively. The expression levels of ALP, Run×2, and Osterix were also significantly upregulated. In the meantime, applying mechanical stretch on OS-cultured hJBMMSCs also dramatically promoted the OS-induced osteogenesis. Both OS and mechanical stretch downregulated NF-κB activity. By overexpressing P65 in hJBMMSCs, neither OS nor mechanical stretch could induce their osteogenesis. These results indicated that, like OS induction, mechanical stretch-facilitated osteogenesis of hJBMMSCs by inhibiting NF-κB in the noninflammatory environments.

Impact of Rantes from jawbone on Chronic Fatigue Syndrome.

This study elucidates the question of whether chronic inflammation in the jawbone contributes to the development of Chronic Fatigue Syndrome (CFS). Fatty degenerative osteonecrosis in jawbone (FDOJ) may contribute to CFS by induction of inflammatory mediators. We examined seven cytokines by multiplex analysis in jawbone samples from two groups of patients. In order to clarify neurological interrelations, specimens from 21 CFS patients were analyzed from areas of previous surgery in the retromolar wisdom tooth area. Each of the retromolar jawbone samples showed clinically fatty degenerated and osteonecrotic medullary changes. As control, healthy jawbone specimens from 19 healthy patients were analyzed. All fatty necrotic and osteolytic jawbone (FDOJ) samples showed high expression of RANTES and fibroblast growth factor (FGF)-2. FDOJ cohorts showed a 30-fold mean overexpression of RANTES and a 20-fold overexpressed level of FGF-2 when compared to healthy controls. As RANTES is discussed in the literature as a possible contributor to inflammatory diseases, we hypothesize that FDOJ in areas of improper and incomplete wound healing in the jawbone may hyperactivate signaling pathways. Constituting a hidden source of “silent inflammation” FDOJ may represent a hitherto unknown cause for the development of CFS.

Aspiration and cytological evaluation of idiopathic bone cavities of the jaw.

The idiopathic bone cavity (IBC) is an intraosseous pseudocyst devoid of epithelial lining. Clinically, IBCs of the jaw are asymptomatic and normally found in routine radiographic exams. Although the literature regarding the content of IBCs is controversial, the final diagnosis is usually aided by the discovery of an empty cavity upon surgical exploration. The aim of this study was to perform cytological and histological analysis of IBC contents. Cytological analysis of nine cases of IBC was performed after puncture and processed by the cell block technique. Histological analysis was performed in six cases in which it was possible to collect enough material by curettage of bone walls. Remarkably, cell block analysis revealed the presence of fibrin, often arranged as a net; erythrocytes; and inflammatory cells, with a predominance of lymphocytes as well as some macrophages and neutrophils. Histological analysis showed the presence of scant connective tissue, bone trabeculae, hemorrhagic foci, and hemosiderin. Only two cases presented scattered multinucleated giant cells. Cytological evaluation of IBC content by the cell block technique might represent a useful diagnostic tool, especially in cases in which there is no available material for curettage in the cavity.

Signalling molecules in jaw bones and gingival tissues of patients with Class II and Class III dentofacial deformities.

OBJECTIVES: To detect signalling molecule specificities in jaw bone growth zones in skeletal class II and class III patients and compare them to those of a control group. MATERIAL AND METHODS: Twenty skeletal Class II and 20 skeletal Class III patients who underwent orthognathic surgery treatment were in the study group and five skeletal Class I patients who had impacted third molars extracted were in the control group. During the orthognathic surgery, tissue samples were taken from the tuber maxillae, ramus mandibulae anterior and posterior part together with mucosa from the gingival transitory fold in the second molar region of the lower jaw. The samples were stained to detect TGF-ß, BMP2/4, FGFR1, VEGF, OC, OP and MMP2 expression. The distributions of these factors were assessed semiquantitatively. RESULTS: We observed significant expression of TGF-ß, BMP2/4, OC and OP in the bone tissue of the study group. FGFR1 expression was more pronounced only in mucosa. VEGF and MMP2 were found only in some tissue samples. More apoptotic cells were observed in the bone tissue and soft tissue of the control patients than in those of the skeletal Class II and Class III patients, in which apoptotic cell frequencies were relatively equal. CONCLUSION: From bone tissue in tuber maxillae region the greater TGF-ß and BMP2/4 expression is seen in Class III and control groups, comparing to Class II. In ramus mandibulae anterior part the expression of significant factors in bone tissue growth (TGF-ß un BMP2/4) is higher in the control group and Class II patients, while in ramus mandibulae posterior part higher expression of TGF-ß and BMP2/4 is in Class III patients, comparing to Class II, which indicates to a preserved growth potential in these jaw bone regions. More active bone extracellular matrix protein (osteocalcin and osteopontin) expression in tuber maxillae region both in class II and class III patient groups and different expression in ramus mandibulae anterior part, prove to the bone mineralization and metabolism activity changes, which, perhaps, characterize just these dentofacial deformations.

[Functions of human periodontal myofibroblast in vitro].

OBJECTIVE: To investigate the functions of human periodontal myofibroblast (MFB) in vitro. METHODS: Human periodontal fibroblast (hPDLFs) was cultured and induced to MFB by transforming growth factor-ß1 (TGF-ß1). MFB was denoted as the experimental group, whereas the hPDLFs was the control group. The groups were continuously cultured and harvested at 0, 12, 24, 48, and 72 h. The MFB marker α-smooth muscle actin (α-SMA) was examined by immunocytochemistry. The expression of fibronectin (FN) between MFB was examined by immunocytochemistry to detect the MFB contact relationship. The mRNA expression levels of α-SMA, collagen (Col) I, and Col III were measured by reverse transcription-polymerase chain reaction (RT-PCT) to analyze extracellular matrix secretion. The protein expression levels of α-SMA and Col I were also assessed by Western blot. RESULTS: The experimental group had significantly higher α-SMA expression than the control group at 0 h (P < 0.001). A positive expression of FN was found between MFB. The experimental group had significantly higher expression levels of Col I and Col III than the control group at 24 h (P < 0.001). CONCLUSION: Human periodontal MFB presents a continuous, high expression of α-SMA. MFB could interact through FN. MFB is significantly capable of extracellular matrix secretion.

Znf385C mediates a novel p53-dependent transcriptional switch to control timing of facial bone formation.

Jaw formation involves an intricate series of molecular events, whereby a chondrogenic scaffold precedes osteogenesis. The mechanisms coupling timing of cartilage maturation to onset of bone differentiation are poorly understood, particularly for neural crest-derived bones of the head. Here we present a novel zebrafish gene/protein-trap Citrine-fusion line that reveals transient expression of the zinc-finger protein Znf385C in maturing chondrocytes of the jaw. Functional analysis shows that loss of Znf385C disrupts a distinct peak of p21(cip1/waf1) expression in the chondrocytes, as well as causes premature ossification of the zebrafish jaw. We find that Znf385C is expressed as two splice variants which act differentially to activate p21(cip1/waf1) and/or interact with p53 in subcellular compartments. Taken together, the results suggest that Znf385C acts as a developmental switch for p53 function that modulates cell cycle arrest of chondrocytes and regulates timing of jaw cartilage maturation and ossification.

Actualización en ortodoncia y bifosfonatos: consideraciones clínicas y experimentales / An update on biphosphonates: clinical and experimental considerations

Los bisfosfonatos son fármacos utilizados para el tratamiento de enfermedades que afectan al metabolismo óseo, principalmente para el tratamiento de la osteoporosis, siendo ésta la principal causa de prescripción médica de los mismos. Actualmente, no se encuentran esclarecidas las posibles complicaciones o riesgos implícitos del tratamiento ortodóntico aplicado a pacientes que reciben o han recibidobisfosfonatos. Dada la demanda actual, con un elevado número de pacientes que se encuentran en la búsqueda de un tratamiento ortodóntico muchos de los cuales son y/o han sido tratados con bisfosfonatos para la osteoporosis, es de relevancia conocer el efecto de laaplicación de fuerzas ortodónticas en un tejido óseo que ha sido tratado con dichas drogas. Por lo antedicho, el objetivo de este trabajo, ha sido realizar una actualización sobre los nuevos conocimientos emergentes de las últimas publicaciones científicas provenientes de trabajos clínicos como así también experimentales que asocien la ortodoncia y los bisfosfonatos. Para ello se realizó una exhaustiva búsqueda de información en la base de datos de Pubmed. La búsqueda obtenida reveló que en los pacientes que reciben y/o han recibido bisfosfonatos y son tratados ortodónticamente se observa una disminución del movimiento dentario, escasa obtención de paralelismo radicular y, en los casos con exodoncias previas aparición de áreas de esclerosis ósea. No fueron descriptos casos en los que se viera asociada la aparición de osteonecrosis de los maxilares. Por su parte, los estudios experimentales, obtuvieron resultados orientados en el mismo sentido, avalando los resultados clínicos...

Selection of osteoprogenitors from the jaw periosteum by a specific animal-free culture medium.

The goal of our research work is to establish mesenchymal osteoprogenitors derived from human jaw periosteum for tissue engineering applications in oral and maxillofacial surgery. For future autologous and/or allogeneic transplantations, some issues must be addressed. On the one hand, animal-free culture conditions have yet to be established. On the other hand, attempts should be undertaken to shorten the in vitro culturing process efficiently. The aim of the present study is to compare and analyze the phenotype of osteoprogenitors from the jaw periosteum under normal FCS-containing and animal-free culture conditions. Therefore, we analyzed the proliferation rates of MesenCult-XF medium (MC-) in comparison to DMEM-cultured JPCs. Whereas jaw periosteal cells (JPCs) show relatively slow proliferation rates and a fibroblastoid shape under DMEM culture conditions, MC-cultured JPCs diminished their cell size significantly and proliferated rapidly. By live-monitoring measurements of adhesion and proliferation, we made an interesting observation: whereas the proliferation of the MSCA-1(+) subpopulation and the unseparated cell fraction were favored by the animal-free culture medium, the proliferation of the MSCA-1(-) subpopulation seemed to be repressed under these conditions. The alkaline phosphatase expression pattern showed similar results under both culture conditions. Comparison of the mineralization capacity revealed an earlier formation of calcium-phosphate precipitates under MC culture conditions; however, the mineralization capacity of the DMEM-cultured cells seemed to be higher. We conclude that the tested animal-free medium is suitable for the in vitro expansion and even for the specific selection of osteoprogenitor cells derived from the jaw periosteum.

IL-17-mediated M1/M2 macrophage alteration contributes to pathogenesis of bisphosphonate-related osteonecrosis of the jaws.

PURPOSE: Osteonecrosis of the jaw (ONJ) is emerging as one of the important complications in cancer patients treated with antiresorptive agents. This study explored the potential role of interleukin (IL)-17-mediated M1/M2 macrophage alterations in the pathogenesis of bisphosphonate-related osteonecrosis of the jaw (BRONJ). EXPERIMENTAL DESIGN: The expression of IL-17 and M1 and M2 macrophage markers at the local mucosal site of human BRONJ lesions was examined by immunofluorescence studies. BRONJ-like disease was induced in C57BL/6 mice and multiple myeloma-burdened mice by intravenous injection of zoledronate to evaluate the correlation of elevated IL-17 levels with changes in M1 and M2 macrophage phenotypes and the therapeutic effects of blocking IL-17 on pathogenesis of BRONJ-like disease. RESULTS: Increased T-helper (TH)17 cells and IL-17 cytokine correlate with an increase in M1/M2 macrophages ratio at the local mucosal site of both murine and human BRONJ lesion. Convincingly, in mice burdened with multiple myeloma, a combination of elevated suprabasal level and drug-induced IL-17 activity augmented the incidence of BRONJ; both systemic increase of IL-17 and disease severity could be reversed by adoptive transfer of ex vivo expanded M2 macrophages. Targeting IL-17 via specific neutralizing antibodies or a small inhibitory molecule, laquinimod, significantly decreased M1/M2 ratio and concomitantly suppressed BRONJ-like condition in mice. Mechanistically, IL-17 enhanced IFN-γ-induced M1 polarization through augmenting STAT-1 phosphorylation while suppressing IL-4-mediated M2 conversion via inhibiting STAT-6 activation. CONCLUSIONS: These findings have established a compelling linkage between activated IL-17-mediated polarization of M1 macrophages and the development of BRONJ-like conditions in both human disease and murine models.