Stimulates Bone Remodeling Research Articles

Preventing bisphosphonate induced osteonecrosis of the jaw with a polyguanidine conjugate (GuaDex): A promising new approach

Osteonecrosis of the jaw (ONJ) is a relatively rare side effect after prolonged use of bisphosphonates, which are drugs used to treat bone resorption in osteoporosis and certain cancers. This study introduces a novel ONJ model in rats by combining exposure to bisphosphonates, oral surgery, and bacterial inoculation. Potential ONJ preventive effects of polyguanidine (GuaDex) or antibiotics were evaluated.The study consisted of twenty-four male Wistar rats were divided into four groups. Groups 1 to 3 were given weekly doses of i.v. Zoledronic acid (ZA), four weeks before and two weeks after an osteotomy procedure on their left mandibular first molar. Group 4 was a negative control. Streptococcus gordonii bacteria were introduced into the osteotomy pulp chamber and via the food for seven days. On day eight, the rats were given different treatments. Group 1 was given a GuaDex injection into the osteotomy socket, Group 2 was given an intramuscular (i.m.) injection of clindamycin, Group 3 (positive control) was given an i.m. injection of saline, and Group 4 was given an i.m. injection of saline. Blood samples were taken two weeks after the osteotomy procedure, after which the rats were euthanized. Bone healing, bone mineral density, histology, and blood status were analyzed.The results showed that Group 1 (GuaDex) had no ONJ, extensive ongoing bone regeneration, active healing activity, vascularization, and no presence of bacteria. Group 2 (clindamycin) showed early stages of ONJ, avascular areas, and bacteria. Group 3 showed stages of ONJ, inflammatory infiltrates, defective healing, and bacterial presence, and Group 4 had normal healing activity and no bacterial presence.Conclusion: ZA treatment and bacterial inoculation after tooth extraction inhibited bone remodeling/healing and induced ONJ characteristic lesions in the rats. Only GuaDex apparently prevented ONJ development, stimulated bone remodeling, and provided an antimicrobial effect.

In Vitro and In Vivo Analysis of the Mg-Ca-Zn Biodegradable Alloys.

The objective of this work was to analyze the in vitro and in vivo tests of a novel Mg-based biodegradable alloy-Mg-0.5%Ca-with various amounts of Zn (0.5, 1, 1.5, 2.0, and 3.0 wt.%). In terms of in vitro biocompatibility, MTT and Calcein-AM cell viability assays, performed on the MG-63 cell line through the extract method, revealed that all five alloy extracts are non-cytotoxic at an extraction ratio of 0.025 g alloy per mL of cell culture medium. In the in vivo histological analysis, Mg-0.5Ca-1.5Zn demonstrated exceptional potential for stimulating bone remodeling and showed excellent biocompatibility. It was observed that Mg-0.5Ca-0.5Zn, Mg-0.5Ca-1.5Zn, and Mg-0.5Ca-3Zn displayed good biocompatibility. Furthermore, the histological examination highlighted the differentiation of periosteal cells into chondrocytes and subsequent bone tissue replacement through endochondral ossification. This process highlighted the importance of the initial implant's integrity and the role of the periosteum. In summary, Mg-0.5Ca-1.5Zn stands out as a promising candidate for bone regeneration and osseointegration, supported by both in vitro and in vivo findings.

Effects of acute- and long-term aerobic exercises at different intensities on bone in mice.

Exercise intensity determines the benefits of aerobic exercise. Our objectives were, in aerobic exercise at different intensities, to determine (1) changes in bone metabolism-related genes after acute exercise and (2) changes in bone mass, strength, remodeling, and bone formation-related proteins after long-term exercise. Total 36 male C57BL/6J mice were divided into a control group and exercise groups at 3 different intensities: low, moderate, or high group. Each exercise group was assigned to acute- or long-term exercise groups. Tibias after acute exercise were evaluated by real-time PCR analysis. Furthermore, hindlimbs of long-term exercise were assessed by micro-CT, biomechanical, histological, and immunohistochemical analyses. Acute moderate-intensity exercise decreased RANKL level as bone resorption marker, whereas low- and high-intensity exercise did not alter it. Additionally, only long-term exercise at moderate intensity increased bone mass and strength. Moderate-intensity exercise promoted osteoblast activity and suppressed osteoclast activity. After low- and high-intensity exercise, osteoblast and osteoclast activity were unchanged. An increase in the number of β-catenin-positive cells and a decrease in sclerostin-positive cells were observed in the only moderate group. These results showed that moderate-intensity exercise can inhibit bone resorption earlier, and long-term exercise can increase bone mass and strength through promoted bone formation via the Wnt/β-catenin activation. High-intensity exercise, traditionally considered better for bone, may fail to stimulate bone remodeling, leading to no change in bone mass and strength. Our findings suggest that moderate-intensity exercise, neither too low nor high, can maintain bone health.

Pangasius djambal gelatin increases osteoprotegerin, decreases RANK and RANKL after tooth extraction in vivo

Background: Osteoprotegerin (OPG) plays a role in preventing osteoclast formation and osteoclastic bone resorption by inhibiting the receptor activator nuclear factor-β and its ligand (RANK–RANKL) interaction that causes bone resorption. Pangasius djambal gelatin contains essential amino acids that may stimulate bone remodeling. Purpose: This study aimed to investigate the expressions of OPG, RANKL, and RANK following tooth extraction to ascertain whether OPG is associated with the RANKL and RANK ratios following gelatin induction. Methods: This study was a true experimental study with a simple, randomized post-test only control group design. Twenty-four albino rats (Rattus norvegicus) were divided into two groups (n = 4). The treatment group was treated with P. djambal gelatin following tooth extraction, while the control group was left untreated. Animal models undergoing tooth extraction were anesthetized intraperitoneally with ketamine (1,000 mg/10 ml up to 0.2 ml). The tooth was then extracted slowly so as not to break it. P. djambal gelatin was dripped (0.1 ml) into the socket after the extraction procedure. The association of OPG with RANKL and RANK immunohistochemistry expressions was evaluated after three, five, and seven days. Results: There was a significant increase in OPG expression on day 7 (P < 0.05) and a significant decrease in the expression of RANKL and RANK (P < 0.05) in the treatment group. Conclusion: The application of P. djambal gelatin could increase OPG expression, decrease RANKL and RANK expression in the socket following tooth extraction, and might be associated with the inhibition of bone resorption.

Antisclerostin Effect on Osseointegration and Bone Remodeling.

Objective: This study reviewed the literature on local or systemic administration of antisclerostin, presenting results associated with osseointegration of dental/orthopedic implants and stimulation of bone remodeling. Materials and Methods: An extensive electronic search was conducted through MED-LINE/PubMed, PubMed Central, Web of Science databases and specific peer-reviewed journals to identify case reports, case series, randomized controlled trials, clinical trials and animal studies comparing either the systemic or local administration of antisclerostin and its effect in osseointegration and bone remodeling. Articles in English and with no restriction on period were included. Results: Twenty articles were selected for a full-text, and one was excluded. Finally, 19 articles were included in the study (16 animal studies and 3 randomized control trials). These studies were divided into two groups, which evaluated (i) osseointegration and (ii) bone remodeling potential. Initially 4560 humans and 1191 animals were identified. At least 1017 were excluded from the studies (981 humans and 36 animals), totaling 4724 subjects who completed (3579 humans and 1145 animals). (a) Osseointegration: 7 studies described this phenomenon; 4 reported bone-implant contact, which increased in all included studies. Similar results were found for bone mineral density, bone area/volume and bone thickness. (b) Bone remodeling: 13 studies were used for description. The studies reported an increase in BMD with sclerostin antibody treatment. A similar effect was found for bone mineral density/area/volume, trabecular bone and bone formation. Three biomarkers of bone formation were identified: bone-specific alkaline phosphatase (BSAP), osteocalcin and procollagen type 1 N-terminal Pro-peptide (P1NP); and markers for bone resorption were: serum C-telopeptide (sCTX), C-terminal telopeptides of type I collagen (CTX-1), β-isomer of C-terminal telopeptides of type I collagen (β-CTX) and tartrate-resistant acid phosphatase 5b (TRACP-5b). There were limitations: low number of human studies identified; high divergence in the model used (animal or human); the variance in the type of Scl-Ab and doses of administration; and the lack of reference quantitative values in the parameters analyzed by authors' studies (many articles only reported qualitative information). Conclusion: Within the limitations of this review and carefully observing all data, due to the number of articles included and the heterogeneity existing, more studies must be carried out to better evaluate the action of the antisclerostin on the osseointegration of dental implants. Otherwise, these findings can accelerate and stimulate bone remodeling and neoformation.

The Effect of Teriparatide on the Hip: A Literature Review.

Teriparatide (TPTD) is a bone-forming agent used to treat postmenopausal osteoporosis. Since hip fractures are related to higher morbidity and mortality rates than other fractures, efficacious osteoporosis drugs for the hip are critical. We reviewed research articles reporting the efficacy of TPTD in terms of bone mineral density (BMD), fractures prevention, changes in the outer diameter, cortical thickness and porosity, post-operative periprosthetic BMD loss, and healing of typical and atypical fractures of the hip. Data meta-analyses indicated that TPTD not only increased the BMD of the proximal femur but also decreased the risk of hip fractures. Even though TPTD increases the cortical bone porosity of the proximal femur, the bone strength does not decrease as the majority of the porosity is located at the endocortex; further, it increases the outer diameter and thickens the cortical bone. TPTD stimulates bone remodeling and facilitates callus maturity and fracture healing. There have been many reports on improving the effect of TPTD on the healing of atypical fractures; therefore it is advisable to use TPTD considering the increase benefit compared to the risk.

Physiological Loading-Induced Interstitial Fluid Dynamics in Osteon of Osteogenesis Imperfecta Bone.

Osteogenesis imperfecta (OI), also known as "brittle bone disease," is a genetic bone disorder. OI bones experience frequent fractures. Surgical procedures are usually followed by clinicians in the management of OI. It has been observed physical activity is equally beneficial in reducing OI bone fractures in both children and adults as mechanical stimulation improves bone mass and strength. Loading-induced mechanical strain and interstitial fluid flow stimulate bone remodeling activities. Several studies have characterized strain environment in OI bones, whereas very few studies attempted to characterize the interstitial fluid flow. OI significantly affects bone micro-architecture. Thus, this study anticipates that canalicular fluid flow reduces in OI bone in comparison to the healthy bone in response to physiological loading due to altered poromechanical properties. This work attempts to understand the canalicular fluid distribution in single osteon models of OI and healthy bone. A poromechanical model of osteon is developed to compute pore-pressure and interstitial fluid flow as a function of gait loading pattern reported for OI and healthy subjects. Fluid distribution patterns are compared at different time-points of the stance phase of the gait cycle. It is observed that fluid flow significantly reduces in OI bone. Additionally, flow is more static than dynamic in OI osteon in comparison to healthy subjects. This work attempts to identify the plausible explanation behind the diminished mechanotransduction capability of OI bone. This work may further be extended for designing better biomechanical therapies to enhance the fluid flow in order to improve osteogenic activities in OI bone.

Biostimulatory Effects of Low-Intensity Pulsed Ultrasound on Rate of Orthodontic Tooth Movement and Associated Pain, Applied at 3-Week Intervals: A Split-Mouth Study.

Objective Low-intensity pulsed ultrasound (LIPUS) is a noninvasive modality to stimulate bone remodeling (BR) and the healing of hard and soft tissues. This research evaluates the biostimulatory effect of LIPUS on the rate of orthodontic tooth movement (OTM) and associated pain, when applied at 3-week intervals. Methods Twenty-two patients (11 males and 11 females; mean age 19.18 ± 2.00 years) having Angle's Class II division 1 malocclusion needing bilateral extractions of maxillary first bicuspids were recruited for this split-mouth randomized clinical trial. After the initial stage of alignment and leveling with contemporary edgewise MBT (McLaughlin–Bennett–Trevisi) prescription brackets (Ortho Organizers, Carlsbad, Calif) of 22 mil, followed by extractions of premolars bilaterally, 6 mm nickel-titanium spring was used to retract the canines separately by applying 150 g force on 0.019 × 0.025-in stainless steel working archwires. LIPUS (1.1 MHz frequency and 30 mW/cm2 intensity output) was applied for 20 minutes extraorally and reapplied after 3 weeks for 2 more successive visits over the root of maxillary canine on the experimental side whereas the other side was placebo. A numerical rating scale- (NRS-) based questionnaire was given to the patients on each visit to record their weekly pain experience. Impressions were also made at each visit before the application of LIPUS (T1, T2, and T3). Models were scanned with a CAD/CAM scanner (Planmeca, Helsinki, Finland). Mann–Whitney U test was applied for comparison of canine movement and pain intensity between both the groups. Results No significant difference in the rate of canine movement was found among the experimental (0.90 mm ± 0.33 mm) and placebo groups (0.81 mm ± 0.32 mm). There was no difference in pain reduction between experimental and placebo groups (p > 0.05). Conclusion Single-dose application of LIPUS at 3-week intervals is ineffective in stimulating the OTM and reducing associated treatment pain.

Whole Genome Gene Expression: Histologic and Immunohistologic Study of Grafted Bone Using Allograft and Xenograft.

The aim of this study was to explore the influence of different bone grafts, demineralized freeze-dried bone allograft (DFDBA, OraGraft), and deproteinized bovine bone mineral (DBBM, Bio-Oss) implanted in mouse calvaria defects on gene expression. Male C57BL/6MLac mice were separated into three groups as follows: group 1-defect without graft as control, group 2-DFDBA, and group 3-DBBM. Affymetrix DNA microarrays were used to characterize gene expression in bone after 3 months of graft healing. Differential expression of designated genes discovered by microarray analysis was confirmed using real-time polymerase chain reaction (PCR) and immunohistochemistry. Compared with normal bone healing, 355 and 1,108 coding genes of bone grafted with DFDBA were upregulated and downregulated, respectively. The upregulated genes were mainly involved in chemokine signaling, macrophage activity, osteoclast activity, cytokine expression, T-cell receptor signaling, apoptosis, and MAPK signaling. The downregulated genes were predominantly involved in calcium regulation in cardiac cells, chemokine signaling, MAPK signaling, and adipogenesis. A total of 306 and 817 coding genes of bone grafted with DBBM were upregulated and downregulated, respectively. The upregulated genes were mainly involved in osteoclast activity, chemokine signaling, B cell receptor signaling, macrophage activity, and signaling of T-cell receptor, MAPK, IL-5, and IL-1. The downregulated genes were predominantly involved in calcium regulation in the cardiac cell and osteoclast activity. Real-time PCR revealed that the DFDBA and DBBM groups showed a higher mRNA level of MMP12, Bcl2A1, S100A4, and Postn compared with the control (P < .05). Histology showed that, compared with the control, the volume of new bone was higher in both types of bone grafts. Immunohistochemistry using an MMP12 antibody confirmed the microarray results because the MMP12 immunoreactivity intensified, and a positive expression of MMP12 increased significantly in the DFDBA and DBBM groups. Both DFDBA and DBBM had a gene expression network involved in new bone formation, which coincided with an increased expression of MMP-12 and osteoclast activity. Both types of graft materials appeared to connect with genes that stimulate bone remodeling at 3 months of bone grafting.

Associations of physical activity intensities, impact intensities and osteogenic index with proximal femur bone traits among sedentary older adults.

Dynamic high-intensity physical activity is thought to be beneficial for older adults' bone health. Traditional volume-based processing of accelerometer-measured physical activity data, quantified on a minute-per-minute basis, may average out sporadic high impact activity, whereas accelerometer data processing approaches based on identifying impacts can capture also these potentially beneficial short activity bursts. We investigated the associations between habitual physical activity and proximal femur bone traits among sedentary older adults utilizing three different numerical treatments of accelerometer-data to examine, if impact-based processing approaches are more suitable to assess bone loading than volume-based processing of physical activity data among older adults. This cross-sectional study utilized the baseline data from the PASSWORD-study (n=284, mean±SD age 74±4years, 57% women). Total femur bone mineral content (BMC) and bone mineral density (BMD), femoral neck BMC, BMD, section modulus and minimal width (MNW) were measured with dual energy x-ray absorptiometry. Physical activity was measured for seven consecutive days with a tri-axial accelerometer. Raw acceleration data was processed in three different ways and quantified as i) mean daily minutes in sedentary, light and moderate-to-vigorous-intensity activity, ii) mean daily number of acceleration peaks divided into low (1.5g to 2.0g), medium (2.0g to 2.5g) and high (>2.5g) impacts, and iii) mean daily osteogenic index, which is a summary score calculated from log-transformed number of impact peaks in 32 intensity bands (≥1.3g). Associations between physical activity measures and each bone trait were estimated with multiple linear regression adjusted with covariates (age, sex, weight, height, smoking, physical function, medication). Participants recorded on average 10h sedentary, 2.5h light and 33min moderate-to-vigorous activity, and 3937 low, 494 medium and 157 high impacts per day. Mean osteogenic index score was 173. Light physical activity was positively associated with all bone traits (beta=0.147 to 0.182, p<0.001 to p=0.005) except MNW. Sedentary or moderate-to-vigorous activity, low, medium or high impacts or osteogenic index were not associated with any bone parameter. Light physical activity may decelerate the age-related bone loss in older adults who do not meet the physical activity recommendations. In this population, the amount of high impact activity may be insufficient to stimulate bone remodelling.

Irisin directly stimulates osteoclastogenesis and bone resorption in vitro and in vivo

Irisin, a skeletal-muscle secreted myokine, facilitates muscle-bone crosstalk and skeletal remodeling in part by its action on osteoblasts and osteocytes. In this study, we investigated whether irisin directly regulates osteoclasts. In vitro, irisin (2-10 ng/mL) increased osteoclast differentiation in C57BL/6J mouse bone marrow progenitors; however, this increase was blocked by a neutralizing antibody to integrin αVβ5. Irisin also increased bone resorption on several substrates in situ. RNAseq revealed differential gene expression induced by irisin including upregulation of markers for osteoclast differentiation and resorption, as well as osteoblast-stimulating 'clastokines'. Forced expression of the irisin precursor Fndc5 in transgenic C57BL/6J mice resulted in lower bone mass at three ages and greater in vitro osteoclastogenesis from Fndc5-transgenic bone marrow progenitors. This study demonstrates that irisin acts directly on osteoclast progenitors to increase differentiation and promote bone resorption, supporting the tenet that irisin not only stimulates bone remodeling but may also be an important counter-regulatory hormone.

Methionine Enkephalin Suppresses Osteocyte Apoptosis Induced by Compressive Force through Regulation of Nuclear Translocation of NFATc1.

ABSTRACTMechanical stress stimulates bone remodeling, which occurs through bone formation and resorption, resulting in bone adaptation in response to the mechanical stress. Osteocytes perceive mechanical stress loaded to bones and promote bone remodeling through various cellular processes. Osteocyte apoptosis is considered a cellular process to induce bone resorption during mechanical stress‐induced bone remodeling, but the underlying molecular mechanisms are not fully understood. Recent studies have demonstrated that neuropeptides play crucial roles in bone metabolism. The neuropeptide, methionine enkephalin (MENK) regulates apoptosis positively and negatively depending on cell type, but the role of MENK in osteocyte apoptosis, followed by bone resorption, in response to mechanical stress is still unknown. Here, we examined the roles and mechanisms of MENK in osteocyte apoptosis induced by compressive force. We loaded compressive force to mouse parietal bones, resulting in a reduction of MENK expression in osteocytes. A neutralizing connective tissue growth factor (CTGF) antibody inhibited the compressive force‐induced reduction of MENK. An increase in osteocyte apoptosis in the compressive force‐loaded parietal bones was inhibited by MENK administration. Nuclear translocation of NFATc1 in osteocytes in the parietal bones was enhanced by compressive force. INCA‐6, which inhibits NFAT translocation into nuclei, suppressed the increase in osteocyte apoptosis in the compressive force‐loaded parietal bones. NFATc1‐overexpressing MLO‐Y4 cells showed increased expression of apoptosis‐related genes. MENK administration reduced the nuclear translocation of NFATc1 in osteocytes in the compressive force‐loaded parietal bones. Moreover, MENK suppressed Ca2+ influx and calcineurin and calmodulin expression, which are known to induce the nuclear translocation of NFAT in MLO‐Y4 cells. In summary, this study shows that osteocytes expressed MENK, whereas the MENK expression was suppressed by compressive force via CTGF signaling. MENK downregulated nuclear translocation of NFATc1 probably by suppressing Ca2+ signaling in osteocytes and consequently inhibiting compressive force‐induced osteocyte apoptosis, followed by bone resorption. © 2020 The Authors. JBMR Plus published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research.

Evaluation of Osteoblastic Gene Expression in Human Mesenchymal Stem Cells

BackgroundOsteoblastic differentiation is a primary pathway to stimulate bone remodeling within regenerative medicine. Human mesenchymal stem cells (hMSCs) are an attractive model for bone regeneration due to their ability to differentiate into osteoblasts, thus promoting an osteogenic environment. With the development of bone biomaterials, it is important to establish a solid baseline of the genes involved in osteoblast differentiation. Once established, the genes regulating osteoblastic differentiation can be compared to any biomaterial product that may potentially speed up the process of bone regeneration. Therefore, the purpose of this study is to examine gene expression as hMSCs undergo osteoblastic differentiation.MethodshMSCs were extracted from human adipose tissue and cultured in DMEM‐F12 medium, 10% FBS. For experimental conditions, cells were cultured in either a growth medium (GM) or an osteogenic induced medium (OIM), supplemented with β‐glycerophosphate, ascorbic‐2‐phosphate, and dexamethasone. Cells were stained with Alizarin Red S staining to confirm calcium deposits of cells cultured in GM or OIM. hMSCs cultured in OIM were extracted for total RNA at days 3, 7, and 21, followed by cDNA synthesis for RT2 Profiler PCR Human Osteogenesis Array (Qiagen, Hilden, Germany). Gene expressions were analyzed using Qiagen Gene Globe software to determine the relative fold change.ResultshMSCs appear to express alkaline phosphatase (ALPL) and bone gammacarboxyglutamate protein (BGLAP) early throughout OIM culture. In contrast, Sp7 expression increases over time, while Sox9 peaks at Day 7 in comparison to the control at Day 3.ConclusionOur data collectively show a change in gene expressions associated with osteoblastic differentiation such as ALPL, BGLAP, Sp7, and SOX9. Sp7, a master osteoblastic transcription factor, increases over time suggesting hMSCs favoring into osteoblastic transformation. Interestingly, Sox9 is another transcription regulator known to commit hMSCs into osteo‐chondrogenic progenitors, and our data show its expression to increase before diminishing near control levels. However, further studies are needed to confirm the genetic pattern of hMSCS undergoing osteoblastic differentiation as well as the upstream mechanisms controlling their activation. This information will be useful in the application of bone biomaterials as a therapeutic treatment for bone regeneration.

Biomimetic UHMWPE/HA scaffolds with rhBMP-2 and erythropoietin for reconstructive surgery.

A promising direction for the replacement of expanded bone defects is the development of bioimplants based on synthetic biocompatible materials impregnated with growth factors that stimulate bone remodeling. Novel biomimetic highly porous ultra-high molecular weight polyethylene (UHMWPE)/40% hydroxyapatite (HA) scaffold for reconstructive surgery with the porosity of 85±1% vol. and a diameter of pores in the range of 50-800μm was developed. The manufacturing process allowed the formation of trabecular-like architecture without additional solvents and thermo-oxidative degradation. Biomimetic UHMWPE/HA scaffold was biocompatible and provided effective tissue ingrowth on a model of critical-sized cranial defects in mice. The combined use of UHMWPE/HA with Bone Morphogenetic Protein-2 (BMP-2) demonstrated intensive mineralized bone formation as early as 3weeks after surgery. The addition of erythropoietin (EPO) significantly enhanced angiogenesis in newly formed tissues. The effect of EPO of bacterial origin on bone tissue defect healing was demonstrated for the first time. The developed biomimetic highly porous UHMWPE/HA scaffold can be used separately or in combination with rhBMP-2 and EPO for reconstructive surgery to solve the problems associated with difference between implant architecture and trabecular bone, low osteointegration and bioinertness.

WISP-1 Promotes Epithelial-Mesenchymal Transition in Oral Squamous Cell Carcinoma Cells Via the miR-153-3p/Snail Axis.

Around half of all patients with oral squamous cell carcinoma (OSCC) present with lymphatic metastasis, a strong predictor of poor survival. Improving survival rates depends on preventing the first step in the “invasion-metastasis cascade,” epithelial-to-mesenchymal transition (EMT), and developing antilymphangiogenesis therapies that antagonize lymphatic metastasis. The extracellular matrix-related protein WISP-1 (WNT1-inducible signaling pathway protein-1) stimulates bone remodeling and tumor progression. We have previously reported that WISP-1 promotes OSCC cell migration and lymphangiogenesis induced by vascular endothelial growth factor C (VEGF-C). This investigation sought to determine the role of WISP-1 in regulating EMT in OSCC. Our analysis of oral cancer data from The Cancer Genome Atlas (TCGA) database revealed significant and positive associations between levels of WISP-1 expression and clinical disease stage, as well as regional lymph node metastasis. We also found higher levels of WISP-1 expression in serum samples obtained from patients with OSCC compared with samples from healthy controls. In a series of in vitro investigations, WISP-1 activated EMT signaling via the FAK/ILK/Akt and Snail signaling transduction pathways and downregulated miR-153-3p expression in OSCC cells. Our findings detail how WISP-1 promotes EMT via the miR-153-3p/Snail axis in OSCC cells.

Abstracts from the 7th Congress of the World Federation for Laser in Dentistry European Division June 20–22, 2019 Parma, Italy

Abstracts from the 7th Congress of the World Federation for Laser in Dentistry European Division June 20–22, 2019 Parma, Italy

DYNAMICS OF INDICATORS OF MARKERS OF BONE METABOLISM IN BONE DEFECT REPLACEMENTFABRIC EQUIVALENTS OF BONE TISSUE ON THE BASIS OF MMSC-AT

Bone tissue is one of the most commonly transplantable and inferior to blood components only. The "gold standard" is still considered to be an autologous bone transplant, but this method has some drawbacks associated with additional surgery. The alternative is the use of allogeneic bone, but in this case there is a risk of immunological rejection of the donor bone and the possibility of infection of the recipient. A promising area for the replacement of volumetric bone defects is the creation of bioimplants based on synthetic biocompatible materials impregnated with growth factors that stimulate bone remodeling, or the settlement of stem (multipotent) cells. Most often, mesenchymal multipotent stromal cells are used for settlement.&#x0D; The aim of the study: to find out the level of expression of BGP, Col 1, VEGF genes as indicators of bone repair and mineralization by replacement of bone defects with tissue equivalents of bone tissue based on multipotent mesenchymal stromal cells from adipose tissue.&#x0D; Materials and methods.The experiment was conducted on the Wistar line rats, weighing 200-250 grams, which were divided into VI groups. A bone defect model was formed in the parietal section of the skull of rats. The formed defect implanted the harvested material. Reverse transcription PCR (OG-PCR) was used to quantify mRNA expression for the BGP-bone marker gla protein; VEGF is a vascular endothelial growth factor and Sol 1 (type 1 collagen). Total RNA was isolated from bone tissue by a standard phenol-chloroform-guanidinisothiocyanate method using a set of RNA-Extra reagents to isolate RNA from blood, tissues, cell cultures in several steps according to the manufacturer's recommendations. The data obtained were processed using Bio-Rad CFX Manager 3.0.The obtained results are processed statistically.&#x0D; Research results and their discussion.The highest number of copies of the BGP gene, at 90 days of observations, was determined in experimental animals of the II and III experimental groups (6,280 ± 0,70 and 6,380 ± 0,72, respectively), the number of which did not differ in statistical significance from the data in the animals of the control group, р˃0.05. However, in animals of IV, V and VI groups the number of copies of BGP-gene was 1.5, 1.4 and 1.6 times smaller in relation to the data in intact rats, p0.05, and did not differ in statistical significance , p1 - p4˃0.05. After 3 months of studies determined the decrease in the activity of the production of the gene Col 1. It was noted that the value of the parameter studied in all study groups was equal to the data in intact animals of group I, p0,05 and among themselves, p1 - p4 р0,05, and ranged from the lowest values in group VI rats - 5,192 ± 0,74, and maximum values in group II animals - 6,200 ± 0,88. After 90 days of experimental studies, the high activity of VEGF gene production in experimental animals, which was equal to the data in control rats, p0,05 was investigated. The maximum activity of VEGF gene production was determined in animals of groups IV, II and VI and ranged from 1,200 ± 0,21 copies in group VI to 1,260 ± 0,22 copies in group IV.&#x0D; Conclusions.Thus, according to molecular genetic analysis of the number of cDNA copies encoding BGP, Col 1 and VEGF genes, the most positive changes that contributed to bone repair, mineralization, and complete closure of the defect were observed with the replacement of bone defects in IVa VI specimens.

Abstract 1036: WISP-1 promotes epithelial-mesenchymal transition in oral squamous cell carcinoma via the miR-153-3p/Snail axis

Abstract Oral squamous cell carcinoma (OSCC) is the most common oral malignancy and approximately 50% of patients with OSCC present with regional regional lymph node metastasis. The first step in the ‘invasion-metastasis cascade’ is the phenomenon of epithelial-to-mesenchymal transition (EMT), whereby epithelial cells of the primary tumor lose their apical-basal polarity and transition to a mesenchymal phenotype, gaining the ability to migrate and invade basement membrane and blood vessels. WNT1-inducible signaling pathway protein-1 (WISP-1/CCN4) is an extracellular matrix-related protein that belongs to the CCN family, capable of stimulating bone remodeling and tumor progression. Our previous research showed that WISP-1 promotes cell migration and VEGF-C-dependent lymphangiogenesis in OSCC cells. This investigation further examined the role of WISP-1 in regulating EMT. First, we analyzed data from the cancer genome atlas (TCGA) database, to determine the clinical importance of WISP-1 in oral cancer. We found that WISP-1 expression was significantly associated with clinical disease stage and regional lymph node metastasis. Moreover, we found higher levels of WISP-1 expression in serum samples obtained from 62 patients with OSCC compared with samples from healthy controls. Treatment of the OSCC cell line SCC4 with WISP-1 increased EMT by downregulating expression of the epithelial marker E-cadherin and upregulating the mesenchymal marker Snail. We also observed that WISP-1 regulated the expression of EMT markers via the FAK, ILK and AKT signal transduction pathways. Computational analysis confirmed that microRNA (miR)-29c directly targets the 3′ untranslated region (3′ UTR) of Snail. Treatment of SCC4 cells with WISP-1 inhibited miR-29c expression, while miR-29c mimic prevented WISP-1-induced enhancement of Snail expression, revealing an inverse correlation between miR-29c and Snail expression during WISP-1 treatment. Our findings provide insight into WISP-1-mediated regulation of EMT in OSCC. Citation Format: An-Chen Chang, Chih-Hsin Tang. WISP-1 promotes epithelial-mesenchymal transition in oral squamous cell carcinoma via the miR-153-3p/Snail axis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1036.

MLN64 deletion suppresses RANKL-induced osteoclastic differentiation and attenuates diabetic osteoporosis in streptozotocin (STZ)-induced mice

Diabetes mellitus is known as a main cause to induce osteoporosis. However, the pathogenesis of osteoporosis induced by diabetes has not been fully understood. MLN64 is highly homologous to the steroidogenic acute regulatory (STAR) protein, sharing the highly conserved START domain and exhibiting various biological activities. In the study, we attempted to explore the role of MLN64 in osteoporosis progression through the in vitro and in vivo studies. At first, the in vitro study suggested that MLN64 was over-expressed during the osteoclast differentiation induced by receptor activator of NF-kB ligand (RANKL). MLN64-knockdown markedly reduced the number of TRAP-positive multinucleated cells induced by RANKL, along with the down-regulation of specific genes related to osteoclastogenesis, including tartrate-resistant acid phosphatase (TRAP), nuclear factor of activated T cells (NFATc1), cathepsin K (CTSK), tartrate resistant (ACP5) and c-FOS and up-regulation of transcriptional receptor runt related transcription factor 2 (Runx2) and osteopontin (OPN). In contrast, over-expressing MLN64 significantly promoted the production of TRAP-positive multinucleated cells triggered by RANKL. Moreover, RANKL exposure led to remarkable increase in inflammatory factors, including tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), IL-6, and MMP-1, which was attenuated by the knockdown of MLN64. Additionally, the expression of phosphorylated (p)IKKα, p-IκBα and p-nuclear factor (NF)-κB stimulated by RANKL was clearly alleviated by MLN64 silence. However, RANKL-induced inflammation was accelerated by MLN64 over-expression. Further, the in vivo study suggested that streptozotocin (STZ)-caused reduction in body weight of mice was improved by the loss of MLN64. STZ-induced diabetic mice exhibited higher levels of blood alkaline phosphatase (ALP) and TRAP, while being down-regulated in MLN64-knockout mice. MLN64 deletion reversed STZ-induced trabecular deleterious effects and stimulated bone remodeling. What's more, MLN64 knockout inhibited the expression levels of TRAP, RANKL and RANK in femoral heads of STZ mice, accompanied with the repression of inflammatory response. In conclusion, the results in our study suggested that MLN64 played a critical role in the meditation of osteoclastic differentiation, and its suppression alleviated diabetic osteoporosis in STZ-induced mice. Thus, MLN64 could be served as an essential target for developing effective therapeutic strategy to prevent diabetic osteoporosis.

Histological Effects of the Combined Administration of Eldecalcitol and a Parathyroid Hormone in the Metaphyseal Trabeculae of Ovariectomized Rats

Intermittent administration of human parathyroid hormone (1-34) (hPTH(1-34)) promotes anabolic action in bone by stimulating bone remodeling, while eldecalcitol, an analog of active vitamin D3, suppresses osteoclastic bone resorption, and forms new bone by minimodeling. We have examined the biological effects of combined administration of eldecalcitol and hPTH(1-34) on 9-week-old Wistar rats that underwent an ovariectomy (OVX) or Sham operation. They were divided into a Sham group, OVX with vehicle (OVX group), OVX with 10 µg/kg/day of hPTH(1-34) (PTH group), OVX with 20 ng/kg/day of eldecalcitol (eldecalcitol group) or OVX with 10 μg/kg/day of hPTH(1-34), and 20 ng/kg/day of eldecalcitol (combined group) for 4 or 8 weeks. As a consequence, the combined group showed a marked increase in bone volume/tissue volume (BV/TV), trabecular thickness (Tb.Th), and trabecular number (Tb.N) than OVX and had the highest bone mineral density (BMD) compared with other groups. OVX and PTH groups exhibited a high osteoblastic surface/bone surface (Ob.S/BS), mineral apposition rate (MAR), and bone formation rate/bone surface (BFR/BS) indices and many TRAP-reactive osteoclasts. Contrastingly, eldecalcitol and combined groups tended to attenuate the indices of osteoclastic surface/bone surface (Oc.S/BS) and Ob.S/BS than that the other groups. The combined group revealed histological profiles of minimodeling- and remodeling-based bone formation. Thus, the combined administration of eldecalcitol and hPTH(1-34) augments their anabolic effects by means of minimodeling and remodeling.