Protective Mechanism of Adipose-Derived Stem Cells in Remodelling of the Skin Stem Cell Niche During Photoaging

BACKGROUND/AIMS

Skin photoaging is primarily caused by the functional attrition of skin stem cells. The skin stem cell niche plays an important role in maintaining stem cell survival and behaviour. In our study, we hypothesized that UVB irradiation induces skin photoaging by changing skin stem cell niches and that transferred adipose-derived stem cells (ADSCs) can remodel the niches by affecting the BMP signalling pathway and transdifferentiating into skin stem cells.

METHODS

Sixty-four C57BL/6J mice were divided into the following groups: a control group, the UVB group and the UVB+ADSCs group. Western blot assays, immunofluorescence analysis and real-time PCR were used to measure differences in the expression of niche components among the three groups. Furthermore, we tested whether transplanted ADSCs express skin stem cell markers, such as p63, α6-integrin and CD34.

RESULTS

The expression levels of Bmp4, its downstream factors Smad1 and MAPK1 and a regulatory factor of the niche, i.e., NFATc1, were lower in the UVB group than were those in the control group (P< 0.05) but higher in the UVB+ADSCs group than were those in the UVB group (P< 0.05). Compared with Bmp4, Nanog (a downstream factor of Bmp4), and MMP13 (a regulatory factor of the niche), ICAM-1 (a proinflammatory gene), p63 (a basal transcription factor), β1-integrin, Mtnr1a and Tyr (melanogenesis-related factors) showed the opposite expression trends (P< 0.05). Bmp2 and Collagen IV levels did not significantly change among the three groups (P> 0.05). Skin stem cell markers, such as p63, α6-integrin and CD34, were coexpressed in the ADSCs, which suggested the ADSCs may transdifferentiate into skin stem cells.

CONCLUSION

We found that UVB irradiation results in typical photoaging signs by altering skin stem cell niches and that Bmp4 was a key factor in BMP signalling in hair follicles. ADSCs reversed these typical photoaging signs by remodelling skin stem cell niches through BMP4 pathway modulation and transdifferentiation into skin stem cells.

Peripheral denervation participates in heterotopic ossification in a spinal cord injury model

We previously reported the development of a new acquired neurogenic HO (NHO) mouse model, combining spinal cord transection (SCI) and chemical muscle injury. Pathological mechanisms responsible for ectopic osteogenesis after central neurological damage are still to be elucidated. In this study, we first hypothesized that peripheral nervous system (PNS) might convey pathological signals from injured spinal cord to muscles in NHO mouse model. Secondly, we sought to determine whether SCI could lead to intramuscular modifications of BMP2 signaling pathways. Twenty one C57Bl6 mice were included in this protocol. Bilateral cardiotoxin (CTX) injection in hamstring muscles was associated with a two-stage surgical procedure, combining thoracic SCI with unilateral peripheral denervation. Volumes of HO (Bone Volume, BV) were measured 28 days after surgery using micro-computed tomography imaging techniques and histological analyses were made to confirm intramuscular osteogenesis. Volume comparisons were conducted between right and left hind limb of each animal, using a Wilcoxon signed rank test. Quantitative polymerase chain reaction (qPCR) was performed to explore intra muscular expression of BMP2, Alk3 and Id1. Nineteen mice survive the complete SCI and peripheral denervation procedure. When CTX injections were done right after surgery (n = 7), bilateral HO were detected in all animals after 28 days. Micro-CT measurements showed significantly increased BV in denervated paws (1.47 mm3 +/- 0.5) compared to contralateral sides (0.56 mm3 +/-0.4), p = 0.03. When peripheral denervation and CTX injections were performed after sham SCI surgery (n = 6), bilateral HO were present in three mice at day 28. Quantitative PCR analyses showed no changes in intra muscular BMP2 expression after SCI as compared to control mice (shamSCI). Peripheral denervation can be reliably added to spinal cord transection in NHO mouse model. This new experimental design confirms that neuro inflammatory mechanisms induced by central or peripheral nervous system injury plays a key role in triggering ectopic osteogenesis.

Altered DNA Methylation of Long Noncoding RNA H19 in Calcific Aortic Valve Disease Promotes Mineralization by Silencing NOTCH1

BACKGROUND

Calcific aortic valve disease is characterized by an abnormal mineralization of the aortic valve. Osteogenic activity in the aortic valve is under the control of NOTCH1, which regulates the expression of key pro-osteogenic genes such as RUNX2 and BMP2. Long noncoding RNAs (lncRNAs) may reprogram cells by altering the gene expression pattern.

METHODS

Multidimensional genomic profiling was performed in human aortic valves to document the expression of lncRNAs and the DNA methylation pattern in calcific aortic valve disease. In-depth functional assays were carried out to document the impact of lncRNA on the mineralization of the aortic valve.

RESULTS

We documented that lncRNA H19 (H19) was increased in calcific aortic valve disease. Hypomethylation of the promoter region was observed in mineralized aortic valves and was inversely associated with H19 expression. Knockdown and overexpression experiments showed that H19 induces a strong osteogenic phenotype by altering the NOTCH1 pathway. Gene promoter analyses showed that H19 silenced NOTCH1 by preventing the recruitment of p53 to its promoter. A knockdown of H19 in valve interstitial cells (VICs) increased the expression of NOTCH1 and decreased the level of RUNX2 and BMP2, 2 downstream targets repressed by NOTCH1. In rescue experiments, the transfection of a vector encoding for the active Notch intracellular domain prevented H19-induced mineralization of valve interstitial cells.

CONCLUSIONS

These findings indicate that a dysregulation of DNA methylation in the promoter of H19 during calcific aortic valve disease is associated with a higher expression of this lncRNA, which promotes an osteogenic program by interfering with the expression of NOTCH1.

Biochemical Responses of Anodized Titanium Implants with a Poly(lactide-co-glycolide)/Bone Morphogenetic Protein-2 Submicron Particle Coating. Part 2: An In Vivo Study

PURPOSE

A biochemical approach to implant surfaces can improve bone growth, resulting in desirable bone-implant interfaces. This study was conducted to identify the effect on osseointegration of direct coating of titanium (Ti) implants with poly(D,L-lactide-co-glycolide)(PLGA)/recombinant human bone morphogenetic 2 (rhBMP-2) submicron particles by electrospray.

MATERIALS AND METHODS

Anodized Ti implants were used as a control group, and implants coated with 80 μL of PLGA/rhBMP-2 (50 μg/mL rhBMP-2 per implant) submicron particles by electrospray were used as the experimental group in an in vivo rabbit tibia model. After 3 or 7 weeks of healing, specimens were obtained and prepared for histologic and histomorphometric analyses.

RESULTS

The implant surface coated with submicron PLGA/rhBMP-2 showed new bone growth in the apical direction earlier than control implants. In the experimental group at 3 weeks, the bone-to-implant contact ratio and bone area of the three best consecutive threads were significantly higher than those in the control group. However, there was no significant difference between groups at 7 weeks.

CONCLUSION

Within the limitations of this study, the PLGA/rhBMP-2-coated implants facilitated osseointegration between bone and the Ti surface during the early healing phase.

Differences in calcification and osteogenic potential of herniated discs according to the severity of degeneration based on Pfirrmann grade: a cross-sectional study

BACKGROUND

Herniated discs may exhibit calcification, and calcified discs may complicate surgical treatment. However, the osteogenic potential and expression of osteogenic markers in degenerative discs of different degenerative grades are still unclear. Our purposes are to study the differences in calcification rate and osteogenic potential of herniated discs according to different degenerative grades.

METHODS

Fifty-eight lumbar intervertebral discs were removed from 41 patients. After grading according to the Pfirrmann scale, calcification was analyzed by micro computed tomography (μ-CT), and expression of osteogenic markers was analyzed by immunohistochemistry and real-time quantitative polymerase chain reaction (qPCR). Data from μ-CT scans were compared with the Kruskal-Wallis test. The Mann-Whitney test was applied to compare data between any two groups. Differences in osteogenic mRNA expression in different regions of the removed discs (posterior vs. anterior) were analyzed by paired t tests. Differences in the posterior portion of removed discs of different Pfirrmann grades were analyzed by one-way analysis of variance (ANOVA), and comparisons of data between discs of any two grades were completed with least significant difference (LSD) tests.

RESULTS

Significant differences in calcification according to μ-CT scanning were observed between discs of different degenerative grades. Nearly half of the discs of Pfirrmann grade V showed the highest degree of calcification compared to Pfirrman grade II discs. Bone morphogenetic protein (BMP)-2, Osterix, and Osteocalcin were detected histologically in discs of Pfirrmann grades III-V. Alkaline phosphatase (ALP) expression was observed in discs showing evidence of calcification. The qPCR analysis showed that BMP-2, Osterix, and Osteocalcin were expressed in most degenerated discs. We also observed greater expression of these osteogenic markers in the posterior portion of removed discs than in the anterior portion.

CONCLUSIONS

The osteogenic potential of degenerated intervertebral discs appears to increase with the severity of degeneration and to be greater in the tissue near the spinal canal than in tissue in the inner portion of the disc.

Biochemical Responses of Anodized Titanium Implants with a Poly(lactide-co-glycolide)/Bone Morphogenic Protein-2 Submicron Particle Coating. Part 1: An In Vitro Study

PURPOSE

This study was conducted to examine the effects of coating poly(D,L-lactide-co-glycolide) (PLGA)/recombinant human bone morphogenetic protein-2 (rhBMP-2) submicron particles by electrospray onto titanium (Ti) implants on the proliferation and differentiation capacity of mesenchymal stem cells. In addition, the duration of rhBMP-2 release was investigated.

MATERIALS AND METHODS

Ti disks were fabricated and divided into four groups as follows. Group C (control) was anodized at 300 V, group P was anodized and then coated with 0.2% PLGA, group B1 was anodized and then coated with PLGA/rhBMP-2 submicron particles at 200 ng per disk, and group B2 was anodized and then coated with PLGA/rhBMP-2 submicron particles at 600 ng per disk. The topography of the PLGA/rhBMP-2-coated Ti surfaces was examined, and proliferation assays, alkaline phosphatase activity tests, and rhBMP-2 releasing tests were conducted in vitro.

RESULTS

There was no difference in the roughness of control Ti disks and Ti disks coated with PLGA/rhBMP-2 submicron particles by electrospray. The proliferation of mesenchymal stem cells increased over time; at 7 days, cell proliferation on the Ti disks coated with rhBMP-2 was significantly higher than the other groups. Anodized Ti disks coated with PLGA/rhBMP-2 (groups B1 and B2) released rhBMP-2 for approximately 21 days. In accordance with the amount of rhBMP-2 released from the PLGA/rhBMP-2 construct, the differentiation capacity of mesenchymal stem cells on the PLGA/rhBMP-2-coated disks was increased significantly.

CONCLUSION

Submicron PLGA/rhBMP-2 coating on Ti implants by electrospray facilitated cell proliferation and differentiation, which is important for early healing and integration of implants.

Osteoblast response to titanium surfaces coated with strontium ranelate-loaded chitosan film

PURPOSE

Improving the peri-implant bone quality has notable clinical value in cases of osteoporosis following implant insertion.

MATERIALS AND METHODS

In this study, strontium ranelate-loaded chitosan film was produced on a titanium surface in different concentrations of strontium ranelate (SR) (0, 2, 20, 40, and 80 mmol/L of the strontium ion [Sr2+]) with the expectation of utilizing the bone healing-enhancement effect of Sr2+. The physicochemical properties of SR-loaded chitosan films were characterized by x-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR). The release/dissolution mechanism was tested by inductively coupled plasma optical emission spectrometry (ICP-OES), and in vitro cell responses were evaluated using primary osteoblasts (POBs) in terms of cell proliferation, alkaline phosphatase (ALP) activity, and quantitative analysis of key osteoblastic gene expression.

RESULTS

XRD and FTIR observation showed that only a few SRs reacted chemically with chitosan through hydrogen bonds or conjugate action. The initial burst release (70% to 85%) of Sr2+ occurred in the first 3 days and was followed by a slower release stage. At a low concentration (2 mmol/L or 20 mmol/L), SR-loaded chitosan film promoted cell responses of POBs with enhanced proliferation, ALP activity, and expression levels of bone morphogenetic protein 2 (BMP-2), runt-related transcription factor 2 (Runx-2), ALP, and osteocalcin, but at a high concentration (40 mmol/L or 80 mmol/L), it inhibited POB growth.

CONCLUSION

These results indicated that SR-loaded chitosan film on a titanium surface promotes osteoblast proliferation and differentiation in a dose-dependent manner, which may represent a new approach in the treatment of a titanium implant.

Transfection of hBMP-2 into mesenchymal stem cells derived from human umbilical cord blood and bone marrow induces cell differentiation into chondrocytes

AIM

Objective of the study was to compare the liposome-mediated transfection efficiency of the recombinant plasmid pIRES2-EGFP-hBMP-2 into mesenchymal stem cells (MSCs) derived from human umbilical cord blood (UCB-MSCs) and bone marrow (BM-MSCs).

METHODS

UCB-MSCs and BM-MSCs were isolated using density gradient centrifugation followed by adherent cultures. The plasmid (pIRES2-EGFP-hBMP-2) was transfected into MSCs by using X-treme GENE transfection kit. Successful transfection was determined by both the protein expression of EGFP observed by fluorescence microscopy and the mRNA expression of human bone morphogenetic protein-2 (hBMP-2) detected using RT-PCR. Cell surface marker and morphological changes were examined by immunohistochemistry (IHC) after two weeks of transfection.

RESULTS

Both UCB-MSCs and BM-MSCs were isolated and expanded successfully for multiple passages and demonstrated slight growth and morphological differences. The recombinant plasmid (pIRES2-EGFP-hBMP-2) was successfully transfected into both UCB-MSCs and BM-MSCs with an efficiency of 27.7 ± 7.6% and 18.4 ± 5.9%, respectively. The mRNA expression of hBMP-2 correlated with increased staining for collagen type II in the transfected cells.

CONCLUSION

Transfection of hBMP-2 in UCB-MSCs and BM-MSCs increases the expression of collagen type II. These results indicate that increased BMP-2 levels induce multipotent stem cell differentiation into chondrocytes.

Effect of avocado/soybean unsaponifiables on osseointegration: a proof-of-principle preclinical in vivo study

PURPOSE

To evaluate the influence of administration of avocado/soybean unsaponifiables (ASU) on implant osseointegration in rat tibiae.

MATERIALS AND METHODS

Thirty rats were randomly assigned into one of three equal-sized groups: (1) ASU1: administration of ASU starting 7 days prior to implant placement; (2) ASU2: administration of ASU starting on the day of implant placement, and (3) CTL: administration of saline solution. In all animals, one titanium implant was placed in each tibia. All animals received ASU or saline solution by gavage daily until sacrifice 60 days postoperatively. Implant osseointegration and bone maturation were assessed by biomechanical and radiographic bone density analysis; descriptive histology; immunohistochemistry for bone morphogenetic protein 2 (BMP-2), transforming growth factor beta 1 (TGF-β1), and osteocalcin; and histomorphometric evaluation of bone-to-implant contact (BIC) and mineralized bone area fraction within the threads of the implant.

RESULTS

ASU1 and ASU2 showed three times higher expression of BMP-2 and nine times higher expression of TGF-β1 compared with CTL (P < .05). Histomorphometric analysis, however, showed that both ASU1 and ASU2 groups presented significantly higher BIC values only in the cortical bone compartment when compared to CTL (P < .05).

CONCLUSION

ASU consumption seems to exert only a subtle effect on implant osseointegration.

Gingival crevicular fluid bone morphogenetic protein-2 release profile following the use of modified perforated membrane barriers in localized intrabony defects: a randomized clinical trial

BACKGROUND

In guided tissue regenerative surgery, membrane perforations may serve as a mechanism for the passage of cells and biologic mediators from the periosteum and overlying gingival connective tissue into the periodontal defects. To test this assumption, this study was designed to evaluate levels of bone morphogenetic protein-2 (BMP-2) in gingival crevicular fluid (GCF) during the early stages of healing for sites treated with modified perforated membranes (MPMs) as compared with occlusive membranes (OMs).

METHODS

Fifteen non-smoking patients with severe chronic periodontitis participated in this prospective, randomized and single-blinded clinical trial. Each patient contributed two interproximal contralateral defects that were randomly assigned to either an experimental modified perforated membrane group (15 sites) or a control occlusive membrane group (15 sites). Plaque index, gingival index, probing depth(PD), clinical attachment level (CAL) and the relative intrabony depth of the defect (rIBD) were measured at baseline and reassessed at three, six and nine months after therapy. Gingival crevicular fluid samples were collected on day 1 and 3, 7, 14, 21, and 30 days after therapy.

RESULTS

The MPM-treated group showed a statistically significant improvement in PD reduction and clinical attachment gain compared to the OM control group. Similarly, rIBD was significantly reduced in MPM-treated sites as compared with those of the OM group. BMP-2 concentrations peaked in the MPM samples obtained during the early postoperative period (days 1, 3 and 7) with a statistically significant difference compared with OM-treated groups. BMP-2 levels decreased sharply in the samples obtained at days 14, 21 and 30 with non-significant higher levels in MPM samples as compared with those of OM sites.

CONCLUSION

Within the limits of the present study, one can conclude that MPM coverage of periodontal defects is associated with a significant initial increase in GCF levels of BMP-2, a factor that could improve the clinical outcomes of guided tissue regenerative surgery.

Analysis of human alveolar osteoblast behavior on a nano-hydroxyapatite substrate: an in vitro study

BACKGROUND

Nano-hydroxyapatite (nHA) is a potential ideal biomaterial for bone regeneration. However, studies have yet to characterize the behavior of human osteoblasts derived from alveolar bone on nHA. Thus, the aim of the present study was to evaluate the influence of nHA on the adhesion, proliferation and differentiation of these alveolar bone-derived cells.

METHODS

Primary human alveolar osteoblasts were collected from the alveolar ridge of a male periodontal patient during osseous resective surgery and grown on culture plates coated with either polylysine or polylysine with nano-hydroxyapatite (POL/nHA) composite. The cells were grown and observed for 14 days, and then assessed for potential modifications to osteoblasts homeostasis as evaluated by quantitative reverse transcriptase-polymerase chain reaction (real time RT-PCR), scanning electron microscopy and atomic force microscopy.

RESULTS

Real time PCR revealed a significant increase in the expression of the selected markers of osteoblast differentiation (bone morphogenetic protein (BMP)-2,-5,-7, ALP, COLL-1A2, OC, ON) in cells grown on the POL/nHA substrate. In addition, as compared with the POL surface, cells grown on the POL/nHA substrate demonstrated better osteoconductive properties, as demonstrated by the increase in adhesion and spreading, likely as a result of the increased surface roughness of the composite.

CONCLUSIONS

The increased expression of BMPs and osteoinductive biomarkers suggest that nano-hydroxyapatite may stimulate the proliferation and differentiation of local alveolar osteoblasts and thus encourage bone regeneration at sites of alveolar bone regeneration.

Expression analysis of BMP2, BMP5, BMP10 in human colon tissues from Hirschsprung disease patients

OBJECTIVE

Bone morphogenetic proteins (BMPs) are members of the transforming growth factor β (TGF β) superfamily. BMP2, BMP5 and BMP10 exert their biological functions by interacting with membrane bound receptors belonging to the serine/threonine kinase family. Hirschsprung disease (HSCR) is characterized by the absence of intramural ganglion cells in the nerve plexuses of the distal gut. However, putative Notch function in enteric nervous system (ENS) development and the etiology of HSCR is unknown.

METHODS

Aganglionic and ganglionic colon segment tissues of 50 HSCR patients were investigated for the expression pattern of BMP2, BMP5 and BMP10 using real-time RT-PCR, Western blot analysis and immunohistochemical staining.

RESULTS

The mRNA levels of BMP2, BMP5 and BMP10 in the stenotic colon segment from HSCR patients were significantly higher than those in the normal ones. Similar increased expressions of them in the stenotic colon segments were detected by Western blotting coupled with densitometry analysis. Lastly, immunohistologicl stain showed significant BMP2, 5 and 10 increases in mucous and muscular layers from stenotic colon segments compared to normal segments.

CONCLUSIONS

BMP2, BMP5 and BMP10 are elevated in the stenotic colon segment of HSCR, and BMPs signaling plays a pivotal role in the development of HSCR.

Enhanced adenovirus transduction of hMSCs using 3D hydrogel cell carriers

Hydrogels are increasingly being investigated as a means to implant cells for tissue engineering. One way to further enhance the repair response would be to combine the hydrogel cell carrier with gene transfer. Gene therapy, using adenoviral vectors, is an effective way to provide transient delivery of bioactive factors. However, current protocols require further optimization, especially if they are to be transferred into the clinic. This study opted to compare the efficiency of protocols for standard two-dimensional (2D) versus three-dimensional (3D), adenoviral-mediated, transduction of human mesenchymal stem cells. Two different multiplicities of infection were tested. After encapsulation in fibrin, alginate or agarose, cells were cultured for 28 days. Transduction in 3D showed a much higher efficiency, compared to standard 2D transduction protocols. In 3D, the amount of transgene produced was significantly higher, for every condition investigated. Furthermore, transduction in 3D does not require a cell culture step and can be conducted within the operating theatre. In conclusion, it was demonstrated that 3D transduction, using adenoviral vectors, is superior to standard transduction protocols in 2D. It therefore, might help increasing its administration in tissue engineering and clinical applications.

Labisia pumila regulates bone-related genes expressions in postmenopausal osteoporosis model

BACKGROUND

Labisia Pumila var. alata (LPva) has shown potential as an alternative to estrogen replacement therapy (ERT) in prevention of estrogen-deficient osteoporosis. In earlier studies using postmenopausal model, LPva was able to reverse the ovariectomy-induced changes in biochemical markers, bone calcium, bone histomorphometric parameters and biomechanical strength. The mechanism behind these protective effects is unclear but LPva may have regulated factors that regulate bone remodeling. The aim of this study is to determine the bone-protective mechanism of LPva by measuring the expressions of several factors involved in bone formative and resorptive activities namely Osteoprotegerin (OPG), Receptor Activator of Nuclear Factor kappa-B Ligand (RANKL), Macrophage-Colony Stimulating Factor (MCSF) and Bone Morphogenetic Protein-2 (BMP-2).

METHODS

Thirty-two female Wistar rats were randomly divided into four groups: Sham-operated (Sham), ovariectomized control (OVXC), ovariectomized with Labisia pumila var. alata (LPva) and ovariectomized with ERT (Premarin) (ERT). The LPva and ERT were administered via daily oral gavages at doses of 17.5 mg/kg and 64.5 μg/kg, respectively. Following two months of treatment, the rats were euthanized and the gene expressions of BMP-2, OPG, RANKL and MCSF in the femoral bones were measured using a branch - DNA technique.

RESULTS

The RANKL gene expression was increased while the OPG and BMP-2 gene expressions were reduced in the OVXC group compared to the SHAM group. There were no significant changes in the MCSF gene expressions among the groups. Treatment with either LPva or ERT was able to prevent these ovariectomy-induced changes in the gene expressions in ovariectomized rats with similar efficacy.

CONCLUSION

LPva may protect bone against estrogen deficiency-induced changes by regulating the RANKL, OPG and BMP-2 gene expressions.

[Effects of promoting blood circulation to remove meridian obstruction combined with medicinal guides on related osteogenesis factors in rabbits with femoral head necrosis]

OBJECTIVE

To observe effects of blood circulation promoting compounds combined with medicinal guides on content of bone glaprotein (BGP), bone morphogenetic protein-2 (BPM-2) and expression of BMP-2 mRNA in rabbits with femoral head necrosis, and explore its mechanism.

METHODS

Ninety-eight healthy Spragur-Dawley male rabbits were collected and weighted 2.2 to 2.8 kg. Eighty-four rabbits were built femoral head necrosis model by freezing left femoral head in liquid nitrogen, then randomly divided into 6 groups, 14 in each group. The 6 groups included model group,promoting blood circulation to remove meridian obstruction group,promoting blood circulation to remove meridian obstruction combined with achyranthes bidentata group,radix angelicae pubescentis, asarum group, and platycodon grandiflorum group,other 14 rabbits were sham operation group. While drug groups were administrated corresponding Chinese herb after molding,model group and shamp operation group were given saline. Recombinant human granulocyte-colony stimulating factor ( 30 microg x kg(-1) x d(-1))were injected into all rabbits for 7 days. Samples were taken on the second and fourth week,the content of BGP and BMP-2 were detected by enzyme-linked immunosorbent assay (ELSA) and radioimmunoassay (RIA), histopathological changes of left femoral head were observed by Hematoxylin and Eeosin staining (HE), and expression of BMP-2 mRNA were tested by fluorescence in situ hybridization.

RESULTS

Compared with sham operation group, the rate of empty lacunae femoral head were obviously increased in model group, and the content of BGP were increased on the second week, and BMP-2 and BMP-2 mRNA were decreased on the fourth week. Compared with model group, the content of BGP, BMP-2 and BMP-2 mRNA were higher both of the second and fourth week in promoting blood circulation to remove meridian obstruction group. The rate of empty la- cunae femoral head were lower in achyranthes bidentata group, BGP, BMP-2 and BMP-2 mRNA were higher on the fourth week. The rate of empty lacunae femoral head were lower in platycodon grandiflorum group, and BGP were decreased on the second and fourth week, BMP-2 were lower on the second week ,while BMP-2 mRNA were decreased on the fourth week; the content of BMP-2 and BMP-2 mRNA were increased in radix angelicae pubescentis group on the second week; while there was no change in asarum group.

CONCLUSION

Radix angelicae pubescentis can increase the content of BGP, BMP-2 and expression of BMP-2 mRNA ,which is an effective mechanism of preventing femoral head necrosis.

Expression of growth factors and growth factor receptors in human cleft-affected tissue

OBJECTIVE. To investigate cleft disordered tissue in children with cleft palate and cleft lip with or without alveolar clefting for detection of local tissue growth factors and growth factor receptors and compare findings. Design. Morphological analysis of human tissue. Patients. Three groups were studied: 14 patients with cleft palate at the age from eight months to 18 years and two months, 12 patients with cleft lip with or without alveolar clefting in the age from four months to 15 years and four months and 11 control patients. RESULTS. In general, cleft palate disordered tissue showed more prominent expression of BMP2/4 (z=3.574; p=0.0004) and TGFβ (z=2.127; p=0.033), while expression of TGFBR3 significantly higher was only in connective tissue (z=3.822; p=0.0001). Cleft lip affected tissue showed significantly pronounced expression of FGFR1 in general as well as separately in epithelium. CONCLUSIONS. The marked and statistically significant expression of BMP 2/4 in cleft palate disordered soft tissue probably is delayed, but still proliferation and differentiation as well as tissue, especially, bone remodeling contributing signal. Cleft palate affected tissue show more prominent expression of TGFβ, still the weak regional expression of TGFβ type III receptors prove the disordered tissue growth and changed TGFβ signalling pathway in postnatal pathogenesis. In general, expression of TGFβ, BMP 2/4 and FGFR1 is significantly different, giving evidence to the involvement of these mentioned factors in the cleft severity morphopathogenesis.

Med19 promotes bone metastasis and invasiveness of bladder urothelial carcinoma via bone morphogenetic protein 2

Bladder cancer (BCa) remained a major health problem. Med19 was related to tumor growth of BCa. Bone morphogenetic proteins (BMPs) were reported to be critical in bone metastasis of cancer. We therefore investigated the relations between Med19 and BMPs in BCa and their effect on bone metastasis of BCa. Bladder cancer cell lines were cultured and interfered with Med19 shRNA and control. Expressions of BMP-1, BMP-2, BMP-4, BMP-5, BMP-6, BMP-7, BMP-9, and BMP-15 were studied between 2 groups. Fifty-two BCa samples were included for immunohistochemical staining of Med19 and BMP-2. Expressions were scored and studied statistically. Invasiveness was studied with Transwell assay. Silencing or Med19 in BCa cells induced altered expressions of BMPs. Increased expressions of BMP-1, BMP-4, BMP-6, BMP-7, and BMP-15 and decreased expressions of BMP-2, BMP-5, and BMP-9 were noticed, but only BMP-2 reached statistical significance. Expressions of Med19 and BMP-2 were significantly higher in cases with bone metastasis and were positively correlated in cases with bone metastasis and muscle invasion. Med19 is a critical factor involved in the invasiveness and promotion of bone metastasis of BCa, possibly via BMP-2.

O45-regulation of osteoblast differentiation and ECM remodeling by Bmp2/4 in vitro

Both of bone morphogenetic proteins 2 and 4 (Bmp2 and Bmp4) are two closely related members of the transforming growth factor beta superfamily and play diverse roles in normal and pathological processes. However, detail understandings of mechanisms through which Bmp2 and Bmp4 exert their effects remain elusive due to their functional compensations each other. To study roles of Bmp2/Bmp4 in osteoblast differentiation and extracellular matrix (ECM) remodeling, calvarial osteoblasts from Bmp2/4 conditional mice with Cre recombinase recognition site (loxP) were isolated and transfected with simian virus 40 large T antigen to generate immortalized BMP2C/C4C/C (iBMP2 C/C/4C/C) osteoblast lines. The BMP2/4 genes in the iBMP2 C/C/4C/C cells were double knocked out by Ad-Cre recombinase infection. Differentiation and mineralization of iBMP2C/C/4C/C knock-out (iBmp2C/C/4C/C KO) cells were detected by alkaline phosphatase (ALP) and alizarin (ALZ) red S staining analyses. ECM remodeling was also observed in fluorescent microscope. Cell differentiation was dramatically decreased in the iBMP2C/C/4C/C KO cells compared to that of the iBMP2C/C/4C/C osteoblasts. Mineralization was also reduced in these KO cells by ALZ staining. Furthermore, Bmp2/4 double knock-out cells have major defects in remodeling the ECM as reflected by changes in collagen type I processing. Here we for the first time demonstrate the establishment of iBmp2C/C/4C/C KO osteoblasts. Cell differentiation and mineralization in the iBmp2C/C/4C/C KO cells were decreased. Furthermore, ECM processing in these KO cells was impaired. This indicates that BMP2/4 play important roles in osteoblast differentiation and ECM remodeling.

Growth factors, genes, bone proteins and apoptosis in the temporomandibular joint (TMJ) of children with ankylosis and during disease recurrence

AIM OF STUDY was complex detection of appearance and distribution of growth factors, facial bone growth stimulating genes, ground substance proteins and apoptosis in bone of ankylotic TMJ in primary and repeatedly operated children.

MATERIALS AND METHODS

Ankylotic tissue was obtained during the arthroplastic surgery from two 6 years old children (boy and girl) with osseous type of disease. The girl underwent the repeated surgery in TMJ due to the same diagnosis in age of 12 years. Ankylotic tissue was proceeded for detection of BMP2/4, TGFβ, Msx2, osteopontin, osteocalcin immunohistochemically, and apoptosis. RESULTS demonstrated massive bone formation intermixed by neochondrogenesis the lack of BMP 2/4, but abundant number of TGFβ-containing cells in bone of all tested cases. Despite rich osteopontin positive structures in bone obtained from both - primary and repeated surgery, osteocalcin demonstrated variable appearance in 6 years aged children, but was abundant in joint 5 years later during disease recurrence. Expression of Msx2 varied widely before, but with tendency to decrease stabilized until few positive cells in bone of 12 years old girl. Apoptosis practically was not detected in primarily operated TMJ, but massively affected the supportive tissue in girl with recurrent ankylosis.

CONCLUSIONS

The lack of BMP2/4 expression in ankylotic bone proves the disorders in cellular differentiation with simultaneous compensatory intensification of cellular proliferation and/or growth by rich expression of TGFβ leading to the remodelling of TMJ. Mainly rich distribution of osteocalcin and osteopontin indicate the intensive mineralization processes of ankylotic bone. Persistent Msx2 expression is characteristic for the supportive tissue of recurrent ankylosis of TMJ and indicates the persistent stimulation of bone growth compensatory limitated by massive increase of programmed cell death.

Specific signaling molecule expressions in the interradicular septum in different age groups

INTRODUCTION

Orthodontic teeth movement is accompanied by the remodeling of alveolar bone, including the interradicular septum. Bone contains three cell types, osteoblasts, osteocytes, and osteoclasts that are in direct contact with all of the cellular elements in the bone marrow. Marrow is the source of both bone-building osteoblasts and bone destroying osteoclasts, and the turnover of bone occurs throughout life. Bone signalling molecules have important functions during osteogenesis, and they are active in the bone remodelling process. Patients involved in orthodontic treatment belong to different age groups: therefore age must be considered as a contributing factor compromising the osteogenetic potential of bone. The aim of the current study was to investigate the specific expression of signalling molecules in the interradicular septum in different age groups.

MATERIALS AND METHODS

The study group included 17 patients to whom the extraction of teeth was recommended as part of further orthodontic treatment. Patients (9 males and 8 females) - were divided into 3 groups 1st group - 12-14 years old); 2nd group - 15-22 years old; 3rd group - 23 years old or older. Expression of BMP 2/4, TGF-α, IL-1, IL-8, OPG, MMP-1, MMP-2, MMP-8, MMP-9, MMP-13, NGFR, NKpB 105, osteocalcin, and osteopontin in interradicular septum tissues was examined. TUNEL staining was also completed. The distribution of these factors was evaluated semi quantitalively.

RESULTS

In the interradicular septum bone structure, the expression levels of osteocalcin, osteoprotegerin, matrix metalloproteinases 8 and 9, and nuclear factor kappa B were determined in all samples. TUNEL staining was also done. Age related decreases in the mean values of signalling factors and the number of apoptotic cells were statistically significant.

CONCLUSION

Specific to interradicular septum osteoblasts and osteoclasts factors include osteoprotegerin, osteocalcin, matrix metalloproteinase 8, matrix metallproteniase 9, and nuclear factors kappa B. The mean expression levels of these proteins and the mean TUNEL staining statistically significantly decreased with age. This is preliminary study and more patients are necessary for more precise statistical analysis in the future.

Analysis of the attachment and differentiation of three-dimensional rotary wall vessel cultured human preosteoblasts on dental implant surfaces

PURPOSE

The purpose of this study was to determine whether osseous tissues engineered in three-dimensional (3D) environments preserved their mineralizing capacity and retained biologic characteristics when cultured on dental implant surfaces.

MATERIALS AND METHODS

Human preosteoblast cells were cultured in both 3D rotary wall vessels and on 2D tissue culture plastic plates for 3 days. Aggregates from the 3D chambers and cells from the 2D plates were collected and transferred to commercially pure titanium disks with either 600-grit polished or sandblasted surfaces. These were cultured for an additional 7 days. The aggregates and cells from the disks were collected and prepared for scanning electron microscopy for microscopic evaluation and atomic adsorption assays for mineral content analysis. Additionally, staining with Alizarin red S was performed to compare the mineralization amount and pattern in each group. Polymerase chain reaction analysis was performed to evaluate expression of osteogenic genes, including Runx2, FAK, bone morphogenetic protein 2, and osteocalcin.

RESULTS

Cells from 3D rotary wall vessel cultures attached to implant surfaces and presented cell attachment and growth patterns similar to those of standard 2D cultured cells, showing evidence of radial and random growth, yet they formed multiple focal niches on implant surfaces out of which cells proliferated. The 3D cultured cells and osseous tissues retained higher amounts of mineral formed during the initial culture and showed a higher tendency toward mineralization on implant surfaces compared to standard cultured cells. The 3D cultured cells and osseous tissues on implant surfaces at 1 week showed higher key gene protein expression. RNA expression at 1 week was equivalent to that of standard cultured cells.

CONCLUSION

Culture of human osteogenic cells and tissues in 3D rotary wall vessels may expedite the osseointegration process on dental implant surfaces, thus reducing the overall treatment time.

Comparison of gene expression of osteogenic factors between continuous and intermittent distraction osteogenesis in rabbit mandibular lengthening

OBJECTIVES

This study aimed to evaluate the effect of distraction frequency on the gene expression of osteogenic mediators in mandibular distraction osteogenesis.

STUDY DESIGN

Forty adult New Zealand white rabbits were randomly assigned to the continuous and intermittent distraction groups. Unilateral mandibular osteotomy was performed and custom-designed manual-driven or autodriven distractor was bridged over the osteotomy segments. Animals were humanely killed at day 6, day 10, day 14, and day 21 after osteotomy. mRNA expression of the osteogenic mediators in the distraction regenerate was examined by real-time polymerase chain reaction.

RESULTS

The expression of transforming growth factor-beta(1) was significantly higher at day 6, and the expression of the bone morphogenetic protein-2 was significantly higher from day 6 to day 14, in the continuous distraction group.

CONCLUSION

High-frequency traction up-regulates the expression of osteogenic mediators contributing to the enhanced bone formation.

[Clinical significance of BMP-2 protein and mRNA expression in human glioma]

AIM

To investigate the expression of BMP-2 protein and mRNA in glioma, and evaluate its clinical significance in clinicopathological status of patients with glioma.

METHODS

BMP-2 protein and mRNA expression in 88 patients with glioma were examined by SABC immunohistochemistry and RT-PCR, respectively.

RESULTS

The positive expression rate of BMP-2 protein in glioma tissues were 78.40% (69/88), which was significantly higher (P<0.01) than that in normal brain tissues [3% (6/20)]. The expression of BMP-2 protein and mRNA in gliomas of grade III-IV was also significantly higher than that in gliomas of grade I-II.

CONCLUSION

BMP-2 expression in cancerous tissues may play an important role in the progression of glioma, which may help to predict patients' prognosis as a tumor marker.

Effects of titanium surface roughness on mesenchymal stem cell commitment and differentiation signaling

PURPOSE

Human mesenchymal stem cells (hMSCs) are primary cells capable of differentiating to osteocytic lineage when stimulated under appropriate conditions. This study examined changes in hMSC morphology, proliferation, and gene expression after growth on machined or dual acid-etched (AE) titanium surfaces.

MATERIALS AND METHODS

hMSCs, isolated from adult human bone marrow, were cultured on titanium surfaces. The two specimens of titanium surfaces in this study included machined and AE titanium disks. Cell morphology was evaluated by scanning electron microscopy, and cell proliferation and collagen synthesis were estimated by measuring the amount of 3H-thymidine incorporation into DNA and 3H-proline incorporation into collagen fibers. Alkaline phosphatase (ALP) activity was determined by measuring the release of p-nitrophenol from disodium p-nitrophenyl phosphate. Changes in gene expression for bone morphogenetic protein-2 (BMP-2), Runx2 type II, Osterix (Osx), osteopontin, type I collagen, ALP, osteocalcin, and bone sialoprotein were determined by reverse-transcriptase polymerase chain reaction after 22 days of in vitro culture in osteogenic medium.

RESULTS

The two substrates had no significant effects on cell adhesion and proliferation. Morphologic characteristics were observed by scanning electron microscopy. hMSCs on the machined surface spread more and were flatter than cells cultured on the AE surface. Osteopontin mRNA expression was similar on all surfaces, and the other mRNA transcripts were increased in hMSC cultured on AE surface. In particular, BMP-2, Runx2, and Osx, three osteogenic factors that induce the progressive differentiation of multipotent mesenchymal cells into osteoblasts, were expressed more on AE titanium than on machined titanium. Collagen and ALP assays confirmed the highest level of mRNA transcripts correlated with increases in these proteins.

CONCLUSION

These results showed that an AE titanium surface stimulated the expression of markers of osteoblastic phenotype more than a machined titanium surface.