Effects of Enamel Matrix Derivative and Transforming Growth Factor-β1 on Connective Tissue Growth Factor in Human Periodontal Ligament Fibroblasts

Connective tissue growth factor promotes cell-to-cell communication in human periodontal ligament stem cells via MAPK and PI3K pathway

BACKGROUND

Cell-cell communication is an essential process to respond to biological stimuli and sustain the micro environmental homeostasis of human periodontal ligament stem cells (hPDLSCs). Connective tissue growth factor (CTGF), a critical secreted matrix protein, exhibits significant tasks in regulating the cell-cell and cell-matrix interactions. This study aimed to explore the relationship between CTGF and cell communication and the underlying mechanism.

METHODS

qRT-PCR was used to detect CCN family, connexin, and pannexin family expression in hPDLSCs. Stimulation with CTGF, cell migration assay was performed to examine the wound repair. The scrape loading/dye transfer assay was employed to access lucifer Yellow molecules transfer efficiency mediated by cell-cell communication. Connexin43 (Cx43), Pannexin1 (Panx1), MAPK, and the PI3K/Akt signaling pathway proteins were examined via Western blotting. Immunofluorescence was applied to visualize the localization of specific proteins within cells. Corresponding pathway inhibitors were applied to hPDLSCs to detect Cx43, Panx1 expression, and intercellular communication induced by CTGF.

RESULTS

Our result showed that CTGF was the second most expressed CCN family member in hPDLSCs. Cx43, and Panx1 were the most widely expressed gap junction hemichannels in hPDLSCs. CTGF enhanced hPDLSCs migration in a dose-dependent manner. CTGF promoted cell-cell communication by up-regulating Cx43 and Panx1. CTGF induced Akt, JNK, and p38 phosphorylation and subcellular relocation. Inhibiting corresponding pathways reduced Cx43 expression, thereby weakening CTGF-induced cell-cell communication. However, the Panx1 expression in CTGF-treated hPDLSCs mainly depended on PI3K/Akt signaling.

CONCLUSION

We provided novel evidence that CTGF promoted cell-cell communication in hPDLSCs through MAPK and PI3K pathway.

The Applications of Enamel Matrix Derivative in Implant Dentistry: A Narrative Review

Enamel matrix derivative (EMD) has been successfully used for periodontal regeneration in intrabony defects. Recently, its use for peri-implant bone regeneration has also been hypothesized. The aim of this paper is to review preclinical and clinical studies investigating the use of EMD in correspondence with titanium implants, alone or as an adjunct to other biomaterials. Clinical trials and case series with more than five cases were included. Seven in vitro studies evaluated the effect of EMD, placed on titanium surfaces: An increase in proliferation and viability of osteoblasts was observed in all but two studies. An increase in TGF-β1 and osteocalcin production, alkaline phosphatase activity, and angiogenesis was also reported. Nine animal studies investigated the use of EMD at implant placement or for bone regeneration of peri-implant bone defects, and some of them reported a significant increase in bone formation or bone-to-implant contact. In four of eleven clinical trials on humans, EMD was successfully used at implant placement. The other seven evaluated the use of EMD in protocols for the treatment of peri-implantitis. In conclusion, the results of EMD seem promising, but further randomized clinical trials are needed to evaluate its efficacy.

Regenerative Potential of Enamel Matrix Protein Derivative and Acellular Dermal Matrix for Gingival Recession: A Systematic Review and Meta-Analysis

Objective: The purpose of this study was to assess the clinical effectiveness of using a combination of enamel matrix protein derivative and acellular dermal matrix in comparison to acellular dermal matrix alone for treating gingival recessions. Methods: The Cochrane Library (Wiley), PubMed by Medline (NLM), Medline (EBSCO), and Embase (Ovid) databases were searched for entries up to April 2020. Only clinical trials were included. Primary outcomes were root coverage (%), changes in keratinized tissue width and recession (mm). Meta-analysis was conducted for root coverage, changes in keratinized tissue width, recession, clinical attachment level and probing depth. Results: Four studies were selected for the analysis. In primary outcomes, root coverage, change in keratinized tissue width and recession analysis showed a mean difference of 4.99% (p = 0.11), 0.20 mm (p = 0.14) and 0.13 mm (p = 0.23) respectively between the two groups. Secondary outcomes analysis also exhibited a statistically insignificant difference between the test and control group with mean difference of 0.11 mm (p = 0.32) in clinical attachment level gain and -0.03 mm (p = 0.29) in probing depth reduction analysis. Conclusions: Within the limits of this study, enamel matrix protein derivative combined with acellular dermal matrix used for treating gingival recession defects resulted in no beneficial effect clinically than acellular dermal matrix only.

Anterior cruciate ligament reconstruction in a rabbit model using a silk-collagen scaffold modified by hydroxyapatite at both ends: a histological and biomechanical study

Background

To investigate osteointegration at the graft-bone interface and the prevention of osteoarthritis after anterior cruciate ligament (ACL) reconstruction using a silk-collagen scaffold with both ends modified by hydroxyapatite (HA) in a rabbit model.

Methods

The HA/silk-collagen scaffold was fabricated using a degummed, knitted silk scaffold, collagen I matrix, and simulated body fluid (SBF). The HA/silk-collagen scaffold was rolled up to make a graft for replacing the native ACL in the experimental group (HA group), and the silk-collagen scaffold was used in the control (S group). All specimens were harvested at 16 weeks postoperatively to evaluate graft-bone healing and osteoarthritis prevention.

Results

Histological staining revealed the massive formation of more mature bone at the tendon-bone interface, and immunohistochemistry staining revealed more collagen I and osteocalcin deposition in the HA group than in the S group. Higher signals indicating more bone mineral formation were detected in the HA group than in the S group, which was consistent with the results of biomechanical testing. Better osteoarthritis prevention was also observed in the HA group, indicating a more stable knee joint in the HA group than in the S group.

Conclusion

The HA/silk-collagen scaffold promotes osteointegration at the tendon-bone interface after ACL reconstruction and has great potential for clinical applications.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13018-021-02281-0.

Effect of enamel matrix derivative liquid combined with synthetic bone substitute on bone regeneration in a rabbit calvarial model

OBJECTIVES

This study aimed to verify the effectiveness of EMD-liquid in combination with a synthetic bone substitute in a rabbit calvarial model.

MATERIAL AND METHODS

Four 7-mm outer diameter circular slits were created in the calvaria of 10 New Zealand white rabbits, and polycarbonate cylinders were inserted into the slits. Two experimental groups were established: (1) EMD-liquid + bone substitute (Osteon III®; biphasic calcium phosphate (BCP), β-TCP/HA = 40:60) and (2) saline + bone substitute (Osteon III®; BCP). The cylinders were filled with saturated graft materials and covered with polycarbonate caps. Micro-CT and histomorphometric evaluation were conducted.

RESULTS

In the histomorphometric analysis, new bone formation was significantly higher in the bone substitute (BS) + EMD-liquid group than in the BS only group at both 5 and 10 weeks (p < 0.01). There were statistically significant differences in the material area between the bone substitute and bone substitute + EMD-liquid groups at only 5 weeks (p < 0.05). The BS + EMD-liquid group demonstrated reduced material area to a greater extent. In micro-CT analysis, the BS + EMD-liquid group (27.04 ± 8.06 at 5 weeks, 28.49 ± 9.22 at 10 weeks) showed a significantly higher percentage of mineralized tissue volume at both 5 and 10 weeks (p < 0.05) than the BS only group.

CONCLUSION

EMD-liquid enhances new bone formation when combined with BCP bone substitute in an animal model. Moreover, the EMD-liquid + BS has significantly lesser material area than BS alone, indicating accelerated graft degradation. Further studies on types of graft materials are required to verify the effect of EMD-liquid and to optimize its regenerative potential.

CLINICAL RELEVANCE

This study suggests that EMD-liquid may have beneficial effect on bone regeneration with synthetic bone substitute.

Similar inductive effects of enamel and dentin matrix derivatives on osteoblast-like cell response over SLA titanium surface

OBJECTIVES

The aim of this in vitro study was to investigate the behavior of osteoblasts on titanium discs under different concentrations of enamel matrix derivatives (EMD) and dentin matrix derivative (DMD).

MATERIALS AND METHODS

MC3T3-E1 osteoblast-like cells were cultivated on coated titanium SLA discs with EMD or DMD at 100 μg/ml, 1 mg/ml, 10 mg/ml and 30 mg/ml or left uncoated. Cell viability, proliferation, adhesion and migration were assessed respectively with MTT, BrdU, DAPI and scratch wound healing assays. Messenger ribonucleic acid of different genes related to osteoblastic differentiation was quantified by means of real-time quantitative PCR. Data were analyzed using student t-test for adhesion and migration assay and ANOVA for proliferation assay (p < 0.05).

RESULTS

BrdU incorporation was found in proliferative osteoblasts for both test solutions at all concentrations. Osteoblast migrated and covered approximately 70% of the wound area observed at time zero when exposed to EMD and DMD to all concentrations. The increase of gene expression was dependent on the concentration enhancement of EMD and DMD. Higher concentrations showed proliferation augmentation if compared to lower concentrations.

CONCLUSIONS

Roughness surface of Ti SLA can limit cell adhesion independent of the presence EMD or DMD. DMD enhances cell migration of osteoblasts on SLA titanium implants in a concentration-dependent manner.

Tissue engineering in periodontology: Biological mediators for periodontal regeneration

Teeth and the periodontal tissues represent a highly specialized functional system. When periodontal disease occurs, the periodontal complex, composed by alveolar bone, root cementum, periodontal ligament, and gingiva, can be lost. Periodontal regenerative medicine aims at recovering damaged periodontal tissues and their functions by different means, including the interaction of bioactive molecules, cells, and scaffolds. The application of growth factors, in particular, into periodontal defects has shown encouraging effects, driving the wound healing toward the full, multi-tissue periodontal regeneration, in a precise temporal and spatial order. The aim of the present comprehensive review is to update the state of the art concerning tissue engineering in periodontology, focusing on biological mediators and gene therapy.

Differential expression of connective tissue growth factor and hepatocyte growth factor in the vitreous of patients with high myopia versus vitreomacular interface disease

Background

To determine the levels of connective tissue growth factor (CTGF) and hepatocyte growth factor (HGF) in the vitreous of patients with high myopia, in comparison with those with a vitreomacular interface disease (VMID).

Methods

Patients with either high myopia (high myopia group) or a VMID (VMID group) were included in this study. Each of the two groups were further subdivided into two subgroups: group A (high myopia with macular hole), group B (high myopia with macular retinoschisis), group C (idiopathic macular hole), and group D (idiopathic epiretinal membrane). Vitreal specimens were collected during vitrectomy, and enzyme-linked immunosorbent assay was used to quantitatively measure the CTGF and HGF levels in the vitreous.

Results

The average axial length was markedly longer in the high myopia group than in the VMID group. The vitreal CTGF level was significantly higher in the high myopia group than in the VMID group. Subgroup analysis revealed significantly higher vitreal CTGF in group A than in the other three subgroups. The vitreal HGF level was not significantly different between the high myopia and VMID groups, but was significantly higher in group D than in group C in the subgroup analysis. Correlation analysis showed that the vitreal CTGF level was positively correlated with the axial length.

Conclusions

The vitreal CTGF level is elevated in highly myopic eyes and may be related to the pathogenesis of high myopia, whereas increased expression of HGF may be involved in the development of idiopathic epiretinal membrane.

3D TECA hydrogel reduces cellular senescence and enhances fibroblasts migration in wound healing

This study was designed to investigate the effect of 3D TECA hydrogel on the inflammatory-induced senescence marker, and to assess the influence of the gel on the periodontal ligament fibroblasts (PDLFs) migration in wound healing in vitro. PDLFs were cultured with 20 ng/ml TNF-α to induce inflammation in the presence and absence of 50 µM 3D TECA gel for 14 d. The gel effect on the senescence maker secretory associated-β-galactosidase (SA-β-gal) activity was measured by a histochemical staining. Chromatin condensation and DNA synthesis of the cells were assessed by 4′,6-diamidino-2-phenylindole and 5-ethynyl-2′-deoxyuridine fluorescent staining respectively. For evaluating fibroblasts migration, scratch wound healing assay and Pro-Plus Imaging software were used. The activity of senescence marker, SA-β-gal, was positive in the samples with TNF-α-induced inflammation. SA-β-gal percentage is suppressed (>65%, P < 0.05) in the treated cells with TECA gel as compared to the non-treated cells. Chromatin foci were obvious in the non-treated samples. DNA synthesis was markedly recognized by the fluorescent staining in the treated compared to non-treated cultures. Scratch wound test indicated that the cells migration rate was significantly higher (14.9 µm²/h, P < 0.05) in the treated versus (11 µm²/h) for control PDLFs. The new formula of 3D TECA suppresses the inflammatory-mediated cellular senescence and enhanced fibroblasts proliferation and migration. Therefore, 3D TECA may be used as an adjunct to accelerate repair and healing of periodontal tissues.

Leptin Overexpression in Bone Marrow Stromal Cells Promotes Periodontal Regeneration in a Rat Model of Osteoporosis

BACKGROUND

Osteoporosis is associated with widespread periodontitis and impaired periodontal healing. However, there is a lack of information about the outcomes of regenerative approaches under the influence of osteoporosis. This study investigates the effect of leptin (LEP) overexpression on the regenerative potential of bone marrow stromal cells (BMSCs) in an osteoporotic rat periodontal fenestration defect model.

METHODS

Rat BMSCs were transfected with adenoviruses harboring the human (h)LEP gene. Cell proliferation and osteogenic differentiation were evaluated. A β-tricalcium phosphate scaffold seeded with transfected cells was implanted into nude mice to investigate ectopic osteogenesis and into an osteoporotic rat defect to study periodontal regeneration. Regenerated periodontal and bone-like tissues were analyzed by histologic methods.

RESULTS

hLEP overexpression induced osteogenic differentiation of BMSCs as evidenced by the upregulation of osteogenesis-related genes such as Runt-related transcription factor 2, alkaline phosphatase (ALP), and collagen Type I, as well as increased ALP activity and enhanced mineralization. Mice implanted with hLEP-BMSC-containing scaffolds showed more extensive formation of bone-like tissue than those in other groups. Periodontal defects were also filled to a greater degree when treated with hLEP-BMSCs and contained cementum and a well-organized periodontal ligament after 10 and 28 days.

CONCLUSION

hLEP overexpression in BMSCs can stimulate periodontal regeneration in osteoporotic conditions and might be a promising strategy for periodontal regeneration in patients with osteoporosis.

In vitro cultured fetal fibroblasts have myofibroblast-associated characteristics and produce a fibrotic-like environment upon stimulation with TGF-β1: Is there a thin line between fetal scarless healing and fibrosis?

Transforming growth factor-β (TGF-β) is a cytokine occurring in three isoforms with an important function in development and wound healing. In wound healing, prolonged TGF-β signaling results in myofibroblast differentiation and fibrosis. In contrast, the developing second-trimester fetal skin contains high levels of all three TGF-β isoforms but still has the intrinsic capacity to heal without scarring. Insight into TGF-β signal transduction during fetal wound healing might lead to methods to control the signaling pathway during adult wound healing. In this study, we imitated wound healing in vitro by stimulating fibroblasts with TGF-β1 and examining myofibroblast differentiation. The aim was to gain insight into TGF-β signaling in human fibroblasts from fetal and adult dermis. First, TGF-β1 stimulation resulted in similar or even more severe upregulation of myofibroblast-associated genes in fetal fibroblasts compared to adult fibroblasts. Second, fetal fibroblasts also had higher protein levels of myofibroblast-marker α-smooth muscle actin (α-SMA). Third, stimulated fetal fibroblasts in collagen matrices had higher protein levels of α-SMA, produced more of the fibrotic protein fibronectin splice-variant extra domain A (FnEDA), and showed enhanced contraction. Finally, fetal fibroblasts also produced significant higher levels of TGF-β1. Altogether, these data show that in vitro cultured fetal fibroblasts have myofibroblast-associated characteristics and do produce a fibrotic environment. As healthy fetal skin has high levels of TGF-β1, FnEDA, and collagen-III as well, these findings correlate with the in vivo situation. Therefore, our study demonstrates that there are similarities between fetal skin development and fibrosis and shows the necessity to discriminate between these processes.