Elevated TRPV2 expression in the facial nerve of rats by cold stimulation: Implications for Bell's palsy.

OBJECTIVE: Bell's palsy, also referred to as clinical manifestations of unilateral facial nerve palsy, encompasses downward angling of the corners of the mouth, the absence of forehead creases, and unilateral incomplete eyelid closure. The incidence of Bell's palsy has increased progressively in recent years, but the underlying mechanism of its occurrence remains unknown; therefore, it is essential to investigate both the cause and treatment of Bell's palsy. Member 2 of the Subfamily V Transient Receptor Potential Cation Channel is a mechanically and thermally sensitive ion channel that plays a crucial role in neural growth and development. Using a novel modeling technique, we endeavored to develop an animal model of Bell's palsy and determine whether TRPV2 expression is altered throughout the course of a facial nerve injury. MATERIALS AND METHODS: The rats were categorized into 3 groups, and their facial nerve function was assessed using RT-qPCR, WB, and pathologic testing, respectively, after undergoing unilateral cold air stimulation for 1, 3, and 7 days. TRPV2 expression was identified using these techniques. RESULTS: In response to cold stimulation, rats exhibited facial nerve paralysis symptoms, demyelinating lesions in the facial nerve, and increased TRPV2 expression. CONCLUSIONS: Extended cold stimulation of the facial nerve in rats may lead to an imbalance in facial nerve homeostasis and increased TRPV2 expression. These findings will contribute to the understanding of the potential mechanism by which cold stimulation affects the facial nerve. Moreover, this finding implies that TRPV2 could possibly function as an additional diagnostic marker or therapeutic target in the context of Bell's palsy.

Nano-drug delivery system targeting FAP for the combined treatment of oral leukoplakia.

Oral leukoplakia (OLK) has received much attention due to its potential risk of malignant transformation. Studies have shown that when drug therapy is combined with photothermal therapy (PTT), not only can the cytotoxicity of the drug be enhanced, but also the heat energy can be used to kill the lesion cells, so we can combine drug therapy with PTT to enhance the therapeutic effect on OLK. However, with certain drawbacks due to its lack of targeting, fibroblast activating protein (FAP) has become an attractive target for OLK combination therapy. In this study, we used NGO-PEG loaded with FAP-targeting peptide (F-TP) and celecoxib (CXB) to construct a nano-drug delivery system CGPF for targeting OLK with high FAP expression and confirmed the biocompatibility and therapeutic efficacy of CGPF by in vitro and in vivo experiments. Overall, the novel nano-drug delivery system CGPF proposed in this study showed a very significant potential for the combination therapy of OLK.

Trajectories of depressive symptoms 10 years after stroke and associated risk factors: a prospective cohort study.

BACKGROUND: Previous studies have investigated the risk factors for post-stroke depression at only one timepoint, neglecting its dynamic nature. We aimed to identify trajectories of post-stroke depression from multiple assessments and explore their risk factors. METHODS: We did a population-based cohort study with the South London Stroke Register (1995-2019). All stroke patients with three or more measurements of the Hospital Anxiety and Depression Scale were included. We identified trajectories of post-stroke depression over a 10-year follow-up using group-based trajectory modelling. We determined the optimal number and shape of trajectories based on the lowest Bayesian information criterion, average posterior probability of assignment of each group over 0·70, and inclusion of at least 5% of participants within each group. We used multinomial logistic regression adjusted for age, sex, ethnicity, comorbidity, physical disability, stroke severity, history of depression and cognitive impairment to explore associations with different trajectories. FINDINGS: The analysis comprised 1968 participants (mean age 64·9 years [SD 13·8], 56·6% male and 43·4% female, 65·1% white ethnicity, 30·7% severe disability and 32·7% severe stroke). We identified four patterns of symptoms: no depressive symptoms (14·1%, n=277), low symptoms (41·7%, n=820), moderate symptoms and symptoms worsening early and then improving (34·6%, n=681), and high and increasing symptoms (9·7%, n=190). Compared with no depressive symptom trajectory, patients with severe disability, severe stroke, pre-stroke depression, and cognitive impairment were more likely to be in the moderate and high symptom groups (adjusted odds ratios [ORs] 2·26 [95% CI 1·56-3·28], 1·75 [1·19-2·57], 2·20 [1·02-4·74], and 2·04 [1·25-3·32], respectively). Female sex was associated with high depression (OR 1·65 [1·13-2·41]), while older age (≥65 years) was associated with moderate depression (OR 1·82 [1·36-2·45]). In men, the ORs for patients with severe disability, severe stroke, pre-stroke depression, and cognitive impairment being in the high depression group were 1·91 (1·01-3·60), 2·41 (1·26-4·60), 2·57 (0·84-7·88), and 2·68 (1·28-5·60), respectively. In women, the ORs were 1·08 (0·52-2·23), 1·30 (0·60-2·79), 19·2 (2·35-156·05), and 3·80 (1·44-10·01), respectively. INTERPRETATION: Female sex and older age were associated with distinct courses of depressive symptoms. In men, high depressive symptom trajectory was associated with severe stroke and severe disability, which was not the case in women. These findings were limited to patients with three or more assessments, who tended to have less severe disabilities than excluded patients and might not generalise to all stroke survivors. FUNDING: National Institute for Health and Care Research (NIHR).

Influence of cold-stimulated adipocyte supernatant on the expression of adhesion-related molecules in Schwann cell line.

Bell's palsy is the most common form of facial nerve palsy. This study aimed to explore the pathogenesis of Bell's palsy by investigating the effect of cold-stimulated adipocyte supernatant on adhesion molecule expression in Schwann cell line. Schwann cells were cultured in regular or adipocyte-conditioned medium and analyzed using RNA sequencing. The mRNA expression of Schwann cell adhesion molecules melanoma cell adhesion molecule (MCAM), protocadherin 9 (PCDH9), and intercellular cell adhesion molecule 1 (ICAM1) was determined using real-time reverse-transcription polymerase chain reaction. Differentially expressed genes were identified, and Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses were conducted. Compared with Schwann cells in 37 °C, the expression of MCAM, PCDH9, and ICAM1 was downregulated in Schwann cells treated with cold-stimulated adipocyte supernatant compared with Schwann cells in 37 °C. Adipocytes subjected to cold exposure may weaken the adhesion capacity of Schwann cells and disrupt the local homeostasis of Schwann cell-axon interactions by affecting the expression of MCAM, PCDH9, and ICAM1, ultimately leading to the development of demyelinating lesions.

Bell's palsy was associated with TRPV2 downregulation of Schwann cell by cold stress.

OBJECTIVE: Epidemiological and clinical studies have shown that sharp changes in the ambient temperature are associated with the occurrence and development of Bell's palsy. However, the specific pathogenesis of peripheral facial paralysis remains nebulous. This study investigated the effect of cold stress on transient receptor potential cation channel subfamily V member 2 (TRPV2) secretion by Schwann cells and its role in Bell's palsy. MATERIALS AND METHODS: Schwann cell morphology was observed using transmission electron microscopy (TEM). Cell proliferation, apoptosis and cell cycle were analysed using CCK8 and flow cytometry. ELISA, Reverse transcription-quantitative PCR, western blotting and immunocytochemical fluorescence staining were used to detect the effects of cold stress on TRPV2, neural cell adhesion molecule (NCAM) and nerve growth factor (NGF) expression in Schwann cells. RESULTS: Cold stress resulted in a widening of the intercellular space, and the particles on the membrane showed different degrees of loss. Cold stress may cause Schwann cells to enter a cold dormant state. ELISA, RT-qPCR, western blotting and immunocytochemical fluorescences staining indicated that cold stress inhibited the expression of TRPV2, NCAM, and NGF. CONCLUSIONS: Drastic temperature difference between cold and heat can downregulate TRPV2 and the secretome of Schwann cells. The imbalance of Schwann cell homeostasis under such stress may contribute to nerve signalling dysfunction leading to the development of facial paralysis.

Deep learning super-resolution magnetic resonance spectroscopic imaging of brain metabolism and mutant isocitrate dehydrogenase glioma.

Background: Magnetic resonance spectroscopic imaging (MRSI) can be used in glioma patients to map the metabolic alterations associated with IDH1,2 mutations that are central criteria for glioma diagnosis. The aim of this study was to achieve super-resolution (SR) MRSI using deep learning to image tumor metabolism in patients with mutant IDH glioma. Methods: We developed a deep learning method based on generative adversarial network (GAN) using Unet as generator network to upsample MRSI by a factor of 4. Neural networks were trained on simulated metabolic images from 75 glioma patients. The performance of deep neuronal networks was evaluated on MRSI data measured in 20 glioma patients and 10 healthy controls at 3T with a whole-brain 3D MRSI protocol optimized for detection of d-2-hydroxyglutarate (2HG). To further enhance structural details of metabolic maps we used prior information from high-resolution anatomical MR imaging. SR MRSI was compared to ground truth by Mann-Whitney U-test of peak signal-to-noise ratio (PSNR), structure similarity index measure (SSIM), feature-based similarity index measure (FSIM), and mean opinion score (MOS). Results: Deep learning SR improved PSNR by 17%, SSIM by 5%, FSIM by 7%, and MOS by 30% compared to conventional interpolation methods. In mutant IDH glioma patients proposed method provided the highest resolution for 2HG maps to clearly delineate tumor margins and tumor heterogeneity. Conclusions: Our results indicate that proposed deep learning methods are effective in enhancing spatial resolution of metabolite maps. Patient results suggest that this may have great clinical potential for image guided precision oncology therapy.

A New Species of Diploderma (Reptilia: Squamata: Agamidae) from the upper Salween River in Eastern Tibet, China.

A new species of Diploderma is described from the upper Salween River Valley in eastern Tibet, China based on morphological and genetic data. The new species is morphologically most similar and phylogenetically closely related to D. laeviventre, but it can be easily diagnosed by having distinct conical scales on the post rictal region of the head, distinctively keeled ventral head and body scales, and different coloration of gular spots and dorsolateral stripes in both sexes. The taxonomic discovery further highlights the underestimated diversity of the genus and the importance of habitat conservation of the neglected hot-dry valley ecosystems in the Hengduan Mountain Region of China.

Incidence and Long-Term Survival of Spontaneous Intracerebral Hemorrhage Over Time: A Systematic Review and Meta-Analysis.

Background and Purpose: Recent epidemiological data indicate that the absolute number of hemorrhagic stroke cases increased by 47% between 1990 and 2010 and continued to cause high rates of death and disability. The last systematic review and meta-analysis of incidence and long-term survival of intracerebral hemorrhage (ICH) were published 11 and 7 years ago, respectively, and lacked comparison between different income groups, therefore, a more up to date analysis is needed. We aim to investigate the ICH incidence and long-term survival data in countries of different income groups. Materials Methods: We systematically searched Ovid Medline for population-based longitudinal studies of first-ever spontaneous ICH published from January 2000 to December 2020. We performed meta-analyses on the incidence and survival rate in countries of 4 different income groups with random-effects models (severe inconsistency). The I 2 was used to measure the heterogeneity. Heterogeneity was further investigated by conducting the meta-regression on the study mid-year. Time trends of the survival rate were assessed by weighted linear regression. Results: We identified 84 eligible papers, including 68 publications reporting incidence and 24 publications on the survival rate. The pooled incidence of ICH per 100,000 per person-years was 26.47 (95% CI: 21.84-32.07) worldwide, 25.9 (95% CI: 22.63-29.63) in high-income countries (HIC), 28.45 (95% CI: 15.90-50.88) in upper-middle-income countries, and 31.73 (95% CI: 18.41-54.7) in lower-middle-income countries. The 1-year pooled survival rate was from 50% (95% CI: 47-54%; n = 4,380) worldwide to 50% (95% CI: 47-54%) in HIC, and 46% (95% CI: 38-55%) in upper-middle income countries. The 5-year pooled survival rate was 41% (95% CI: 35-48%; n = 864) worldwide, 41% (95% CI: 32-50%) in high-income and upper-middle countries. No publications were found reporting the long-term survival in lower-middle-income and low-income countries. No time trends in incidence or survival were found by meta-regression. Conclusion: The pooled ICH incidence was highest in lower-middle-income countries. About half of ICH patients survived 1 year, and about two-fifths survived 5 years. Reliable population-based studies estimating the ICH incidence and long-term survival in low-income and low-middle-income countries are needed to help prevention of ICH. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=170140, PROSPERO CRD42020170140.

Tissue Engineering with Compact Bone-Derived Cell Spheroids Enables Bone Formation around Transplanted Tooth.

BACKGROUND: Although tooth transplantation is a desirable treatment option for congenital defects of permanent teeth in children, transplantation to a narrow alveolar ridge is not feasible. In this study, we investigated the possibility of bone tissue engineering simultaneously with tooth transplantation to enhance the width of the alveolar bone. METHODS: Bone marrow mononuclear cells or cortical bone-derived mesenchymal stromal cell spheroids were seeded onto atelocollagen sponge and transplanted with freshly extracted molars from mice of the same strain. New bone formation around the tooth root was evaluated using micro-computed tomography and histological analysis. Tooth alone, or tooth with scaffold but without cells, was also transplanted and served as controls. RESULTS: Micro-computed tomography showed new bone formation in the furcation area in all four groups. Remarkable bone formation outside the root was also observed in the cortical bone-derived mesenchymal stromal cell group, but was scarce in the other three groups. Histological analysis revealed that the space between the new bone and the root was filled with collagen fibers in all four groups, indicating that the periodontal ligament was maintained. CONCLUSION: This study demonstrates the potential of simultaneous alveolar bone expansion employing bone tissue engineering approach using cortical bone-derived mesenchymal stromal cell spheroids for tooth transplantation. The use of an orthotopic transplantation model may further clarify the feasibility and functional recovery of the transplanted tooth over a longer period.

In Vivo Absolute Metabolite Quantification Using a Multiplexed ERETIC-RX Array Coil for Whole-Brain MR Spectroscopic Imaging.

BACKGROUND: Absolute quantification of metabolites in MR spectroscopic imaging (MRSI) requires a stable reference signal of known concentration. The Electronic REference To access In vivo Concentrations (ERETIC) has shown great promise but has not been applied in patients and 3D MRSI. ERETIC hardware has not been integrated with receive arrays due to technical challenges, such as coil combination and unwanted coupling between multiple ERETIC and receive channels, for which we developed mitigation strategies. PURPOSE: To develop absolute quantification for whole-brain MRSI in glioma patients. STUDY TYPE: Prospective. POPULATION: Five healthy volunteers and three patients with isocitrate dehydrogenase mutant glioma (27% female). Calibration and coil loading phantoms. FIELD STRENGTH/SEQUENCE: A 3 T; Adiabatic spin-echo spiral 3D MRSI with real-time motion correction, Fluid Attenuated Inversion Recovery (FLAIR), Gradient Recalled Echo (GRE), Multi-echo Magnetization Prepared Rapid Acquisition of Gradient Echo (MEMPRAGE). ASSESSMENT: Absolute quantification was performed for five brain metabolites (total N-acetyl-aspartate [NAA]/creatine/choline, glutamine + glutamate, myo-inositol) and the oncometabolite 2-hydroxyglutarate using a custom-built 4x-ERETIC/8x-receive array coil. Metabolite quantification was performed with both EREIC and internal water reference methods. ERETIC signal was transmitted via optical link and used to correct coil loading. Inductive and radiative coupling between ERETIC and receive channels were measured. STATISTICAL TESTS: ERETIC and internal water methods for metabolite quantification were compared using Bland-Altman (BA) analysis and the nonparametric Mann-Whitney test. P < 0.05 was considered statistically significant. RESULTS: ERETIC could be integrated in receive arrays and inductive coupling dominated (5-886 times) radiative coupling. Phantoms show proportional scaling of the ERETIC signal with coil loading. The BA analysis demonstrated very good agreement (3.3% ± 1.6%) in healthy volunteers, while there was a large difference (36.1% ± 3.8%) in glioma tumors between metabolite concentrations by ERETIC and internal water quantification. CONCLUSION: Our results indicate that ERETIC integrated with receive arrays and whole-brain MRSI is feasible for brain metabolites quantification. Further validation is required to probe that ERETIC provides more accurate metabolite concentration in glioma patients. EVIDENCE LEVEL: 2 TECHNICAL EFFICACY: Stage 1.

Improving D-2-hydroxyglutarate MR spectroscopic imaging in mutant isocitrate dehydrogenase glioma patients with multiplexed RF-receive/B0 -shim array coils at 3 T.

MR spectroscopic imaging (MRSI) noninvasively maps the metabolism of human brains. In particular, the imaging of D-2-hydroxyglutarate (2HG) produced by glioma isocitrate dehydrogenase (IDH) mutations has become a key application in neuro-oncology. However, the performance of full field-of-view MRSI is limited by B0 spatial nonuniformity and lipid artifacts from tissues surrounding the brain. Array coils that multiplex RF-receive and B0 -shim electrical currents (AC/DC mixing) over the same conductive loops provide many degrees of freedom to improve B0 uniformity and reduce lipid artifacts. AC/DC coils are highly efficient due to compact design, requiring low shim currents (<2 A) that can be switched fast (0.5 ms) with high interscan reproducibility (10% coefficient of variation for repeat measurements). We measured four tumor patients and five volunteers at 3 T and show that using AC/DC coils in addition to the vendor-provided second-order spherical harmonics shim provides 19% narrower spectral linewidth, 6% higher SNR, and 23% less lipid content for unrestricted field-of-view MRSI, compared with the vendor-provided shim alone. We demonstrate that improvement in MRSI data quality led to 2HG maps with higher contrast-to-noise ratio for tumors that coincide better with the FLAIR-enhancing lesions in mutant IDH glioma patients. Smaller Cramér-Rao lower bounds for 2HG quantification are obtained in tumors by AC/DC shim, corroborating with simulations that predicted improved accuracy and precision for narrower linewidths. AC/DC coils can be used synergistically with optimized acquisition schemes to improve metabolic imaging for precision oncology of glioma patients. Furthermore, this methodology has broad applicability to other neurological disorders and neuroscience.

Diabetes As an Independent Risk Factor for Stroke Recurrence in Ischemic Stroke Patients: An Updated Meta-Analysis.

INTRODUCTION: Stroke and its recurrence and diabetes will increase in incidence as the population ages globally. This study explores the relationship between diabetes and stroke recurrence to understand if diabetes is an independent predictor for stroke recurrence in ischemic stroke (IS) patients. METHODS: We conducted a systematic review and meta-analysis of studies on the effect of diabetes on stroke recurrence among patients with IS. We searched population-based studies published before 15th February 2021 in PubMed and EMBASE following PRISMA guidelines. Random-effects estimates of the pooled hazard ratio (HR) and 95% confidence intervals (CIs) of each study were generated. A funnel plot and an Egger test were performed to evaluate publication bias. All statistical analyses were conducted in the R software 4.0.1 and Stata 16.0. RESULTS: The search identified 3,121 citations, of which 27 studies met inclusion criteria. Diabetes was associated with a significant risk of stroke recurrence in all IS patients (pooled HR, 1.50; 95% CI: 1.36-1.65; I2 = 61.0%). Similar results were found in lacunar stroke patients with diabetes (pooled HR, 1.65; 95% CI: 1.41-1.92; I2 = 22.0%). Moreover, we found that the risk of recurrent IS among patients of IS with diabetes was higher than that in those without diabetes (pooled HR, 1.53; 95% CI: 1.30-1.81; I2 = 74.0%). CONCLUSION: Diabetes is an independent risk factor for stroke recurrence among patients with IS.

Animal models of vertical bone augmentation (Review).

Vertical bone augmentation is an important challenge in dental implantology. Existing vertical bone augmentation techniques, along with bone grafting materials, have achieved certain clinical progress but continue to have numerous limitations. In order to evaluate the possibility of using biomaterials to develop bone substitutes, medical devices and/or new bone grafting techniques for vertical bone augmentation, it is essential to establish clinically relevant animal models to investigate their biocompatibility, mechanical properties, applicability and safety. The present review discusses recent animal experiments related to vertical bone augmentation. In addition, surgical protocols for establishing relevant preclinical models with various animal species were reviewed. The present study aims to provide guidance for selecting experimental animal models of vertical bone augmentation.

Odontoblast death drives cell-rich zone-derived dental tissue regeneration.

Severe dental tissue damage induces odontoblast death, after which dental pulp stem and progenitor cells (DPSCs) differentiate into odontoblast-like cells, contributing to reparative dentin. However, the damage-induced mechanism that triggers this regeneration process is still not clear. We aimed to understand the effect of odontoblast death without hard tissue damage on dental regeneration. Herein, using a Cre/LoxP-based strategy, we demonstrated that cell-rich zone (CZ)-localizing Nestin-GFP-positive and Nestin-GFP-negative cells proliferate and differentiate into odontoblast-like cells in response to odontoblast depletion. The regenerated odontoblast-like cells played a role in reparative dentin formation. RNA-sequencing analysis revealed that the expression of odontoblast differentiation- and activation-related genes was upregulated in the pulp in response to odontoblast depletion even without damage to dental tissue. In this regenerative process, the expression of type I parathyroid hormone receptor (PTH1R) increased in the odontoblast-depleted pulp, thereby boosting dentin formation. The levels of PTH1R and its downstream mediator, i.e., phosphorylated cyclic AMP response element-binding protein (Ser133) increased in the physically damaged pulp. Collectively, odontoblast death triggered the PTH1R cascade, which may represent a therapeutic target for inducing CZ-mediated dental regeneration.

Cryopreserved Spontaneous Spheroids from Compact Bone-Derived Mesenchymal Stromal Cells for Bone Tissue Engineering.

Spontaneously formed spheroids from mouse compact bone-derived mesenchymal stromal cells (CB-MSCs) possess enhanced stemness and superior plasticity. In this study, the effect of cryopreservation on viability, stemness, and osteogenic differentiation capability of spontaneous CB-MSC spheroids were investigated. CB-MSCs were isolated from mouse femur and tibia. Spheroids were cryopreserved with various concentrations of dimethyl sulfoxide (DMSO). After thawing, the number of living and dead cells was measured. The expression levels of stem cell markers and osteogenic marker genes were analyzed. The cryopreserved and noncryopreserved spheroids were transplanted in mice with a beta-tricalcium phosphate as a scaffold to evaluate the in vivo bone-forming capability. The percentage of living cells was highest when 5% DMSO was used as a cryoprotectant, confirmed by the number of dead cells. The expression of stem cell marker genes and osteogenic differentiation capability were maintained after cryopreservation with 5% DMSO. The cryopreserved spontaneous CB-MSC spheroids showed remarkable new bone formation in vivo, identical to that of the noncryopreserved spheroids even without osteogenic induction. The cryopreserved spontaneous CB-MSC spheroids retained stemness and osteogenic differentiation capability and highlight the utility of spontaneous CB-MSC spheroids as ready-to-use tissue-engineered products for bone tissue engineering.

Alliin inhibits adipocyte differentiation by downregulating Akt expression: Implications for metabolic disease.

Obesity is currently an important health problem and is associated with an increased likelihood of various diseases. The efficacies of various natural treatments have been assessed for their utility in treating obesity. Alliin (S-allyl-L-cysteine sulfoxides) is considered the major component of garlic and has a wide range of natural antioxidant properties. However, the direct effects of alliin on obesity have not been well clarified. The present study investigated the effects and possible mechanisms of alliin on adipocyte differentiation. The 3T3-L1 cells were treated with alliin (0-40 µg/ml) during adipogenic differentiation. The effect of alliin on lipid accumulation was evaluated by Oil red O staining. Reverse transcription-quantitative PCR was performed to investigate the expression levels of adipogenic differentiation-related genes. The accumulation of lipid droplets was markedly inhibited following alliin treatment. The expression levels of multiple adipogenic transcription markers, such as CCAAT/enhancer-binding protein (C/EBP) ß, C/EBP α and peroxisome proliferation-activity receptor γ, were markedly decreased following treatment with alliin during adipogenic differentiation. Expression levels of several adipocyte-related genes were subsequently suppressed. Additionally, alliin suppressed PKB/Akt and PI3K expression. These results suggested that alliin exhibits anti-adipogenic activity by downregulating major adipogenic differentiation-related genes and Akt/PI3K expression. Alliin may have a potential therapeutic effect on metabolic disease.

Effect of TNF-α and IL-6 on Compact Bone-Derived Cells.

BACKGROUND: Although bone tissue engineering has already been applied clinically, its regeneration efficacy is not always sufficient. Local inflammatory cytokines are considered as the major factors that induce apoptosis of transplanted cells, thus leading to insufficient new bone formation. In this study, we focused on the effects of interleukin (IL)-6 and tumor necrosis factor-alpha (TNF-α) on differentiation and apoptosis of compact bone-derived cells (CBDCs). METHODS: CBDCs were obtained from mouse legs and cultured. The effects of TNF-α and/or IL-6 on the osteogenic differentiation and apoptosis of CBDCs were analyzed in vitro. To confirm the expression of local inflammatory cytokines in vivo, CBDCs were transplanted to the back of immunocompetent mice. RESULTS: IL-6 exerted inconsistent effects on the expression of the different osteogenic markers tested, while significantly upregulating Fas. By contrast, the addition of TNF-α dramatically reduced the expression of all tested osteogenic markers and increased Fas expression. The highest dose of IL-6 could partially reverse the repressive effect of TNF-α, while the addition of IL-6 further increased Fas expression in CBDCs compared to TNF-α alone. The results from in vivo experiments showed the presence of transplants with and without new bone formation. The transplants without bone formation were characterized by higher IL-6 and lower IL-10 expression than those with bone formation, while the expression of TNF-α did not show notable difference. CONCLUSION: The results of this study suggest an important role for IL-6 in modulating the efficacy of bone tissue engineering, which can affect osteogenic cells both positively and negatively.

Tooth transplantation with a ß-tricalcium phosphate scaffold accelerates bone formation and periodontal tissue regeneration.

OBJECTIVES: Although tooth transplantation is a useful treatment option as a substitute for a missing tooth, transplantation to a narrow alveolar ridge is not feasible. In this study, we tested a tissue engineering approach simultaneously with tooth transplantation using a scaffold or a combination with cells to accelerate bone formation and periodontal tissue regeneration. MATERIALS AND METHODS: Bone marrow mononuclear cells (BM-MNCs) were harvested from C57BL/6J mice. The upper first or the second molar of 3-week-old C57BL/6J mice and a ß-tricalcium phosphate (ß-TCP) scaffold were transplanted with BM-MNCs (MNC group) or without BM-MNCs (ß-TCP group) into the thigh muscle of syngeneic mice. The tooth alone was also transplanted (control group). After 4 weeks, the transplants were harvested and analyzed. RESULTS: Bone volume was significantly larger in the MNC and the ß-TCP groups than that in the control group, and the newly formed bone was observed on the lateral wall of the root. Compared with the control group, the MNC group showed a larger trabecular thickness and fractal dimension. CONCLUSION: This study showed accelerated bone formation and periodontal tissue regeneration when tooth transplantation was performed with a ß-TCP scaffold. BM-MNCs may accelerate bone maturation, while the effect on bone formation was limited.