Luteolin Is a Potential Immunomodulating Natural Compound against Pulpal Inflammation.

Aim: The present study evaluated the therapeutic effects of luteolin in alleviating pulpitis of dental pulp- (DP-) derived microvesicles (MVs) via the inhibition of protein kinase R- (PKR-) mediated inflammation. Methodology. Proteomic analysis of immortalized human dental pulp (DP-1) cell-derived MVs was performed to identify PKR-associated molecules. The effect of luteolin on PKR phosphorylation in DP-1 cells and the expression of tumor necrosis factor-α (TNF-α) in THP-1 macrophage-like cells were validated. The effect of luteolin on cell proliferation was compared with that of chemical PKR inhibitors (C16 and 2-AP) and the unique commercially available sedative guaiacol-parachlorophenol. In the dog experimental pulpitis model, the pulps were treated with (1) saline, (2) guaiacol-parachlorophenol, and (3) luteolin. Sixteen teeth from four dogs were extracted, and the pulp tissues were analyzed using hematoxylin and eosin staining. Immunohistochemical staining was performed to analyze the expression of phosphorylated PKR (pPKR), myeloperoxidase (MPO), and CD68. Experimental endodontic-periodontal complex lesions were established in mouse molar through a silk ligature and simultaneous MV injection. MVs were prepared from DP-1 cells with or without pretreatment with 2-AP or luteolin. A three-dimensional microcomputed tomography analysis was performed on day 7 (n = 6). Periodontal bone resorption volumes were calculated for each group (nonligated-ligated), and the ratio of bone volume to tissue volume was measured. Results: Proteomic analysis identified an endogenous PKR activator, and a protein activator of interferon-induced PKR, also known as PACT, was included in MVs. Luteolin inhibited the expressions of pPKR in DP-1 cells and TNF-α in THP-1 cells with the lowest suppression of cell proliferation. In the dog model of experimental pulpitis, luteolin treatment suppressed the expression of pPKR-, MPO-, and CD68-positive cells in pulp tissues, whereas guaiacol-parachlorophenol treatment caused coagulative necrosis and disruption. In a mouse model of endodontic-periodontal complex lesions, luteolin treatment significantly decreased MV-induced alveolar bone resorption. Conclusion: Luteolin is an effective and safe compound that inhibits PKR activation in DP-derived MVs, enabling pulp preservation.

Scaffold-free bone-like 3D structure established through osteogenic differentiation from human gingiva-derived stem cells.

Introduction & objectives: Stem cell therapy for regenerative medicine has been sincerely investigated, but not still popular although some clinical trials show hopeful results. This therapy is suggested to be a representative candidate such as bone defect due to the accident, iatrogenic resection oncological tumor, congenital disease, and severe periodontitis in oral region. Recently, the Bio-3D printer "Regenova®" has been introduced as an innovative three-dimensional culture system, equipped scaffold-free bio-assembling techniques without any biomaterials. Therefore, we expected a mount of bone defect could be repaired by the structure established from this Bio-3D printer using osteogenic potential stem cells. Material & methods: The gingival tissue (1x1 mm) was removed from the distal part of the lower wisdom tooth of the patients who agreed our study. Human Gingival Mesenchymal Stem Cells (hGMSCs) were isolated from this tissue and cultured, since we confirmed the characteristics such as facile isolation and accelerated proliferation, further, strong potential of osteogenic-differentiation. Spheroids were formed using hGMSC in 96-well plates designed for low cell adhesion. The size of the spheroids was measured, and fluorescent immunostaining was employed to verify the expression of stem cell and apoptosis marker, and extracellular matrix. Following four weeks of bone differentiation, µCT imaging was performed. Calcification was confirmed by alizarin red and von Kossa staining. Fluorescent immunostaining was utilized to assess the expression of markers indicative of advanced bone differentiation. Results: We have established and confirmed the spheroids (∼600 µm in diameter) constructed from human GMSCs (hGMSCs) still maintain stem cell potentials and osteogenic differentiation abilities from the results that CD73 and not CD34 were expressed as stem cell positive and negative marker, respectively. These spheroids were pilled up like cylindal shape to the "Kenzan" platform of Bio-3D printer and cultured for 7days. The cylindal structure originated from compound spheroids were tried to differentiate into bone four weeks with osteogenic induction medium. The calcification of bio-3D printed bone-like structures was confirmed by alizarin red and Von Kossa staining. In addition, µCT analysis revealed that the HU (Hounsfield Unit) of the calcified structures was almost identical to that of trabecular bone. Immunofluorescent staining detected osteocalcin expression, a late-stage bone differentiation marker. Conclusion: For the first time, we have achieved the construction of a scaffold-free, bone-like luminal structure through the assembly of spheroids comprised of this hGMSCs. This success is sure to be close to the induction of clinical application against regenerative medicine especially for bone defect disease.

miR-1260b inhibits periodontal bone loss by targeting ATF6ß mediated regulation of ER stress.

The expression profiles of exosomal microRNAs (miRNAs) are regulated by the microenvironment, and appropriate priming with mesenchymal stem cells (MSCs) is one of the strategies to enhance the paracrine potency of MSCs. Our previous work demonstrated that exosomes from tumor necrosis factor (TNF)-α-primed human gingiva-derived MSCs (GMSCs) could be a therapeutic tool against periodontitis, and that TNFα-inducible exosomal miR-1260b is essential for the inhibition of alveolar bone loss. However, the precise molecular mechanism underlying miR-1260b-mediated inhibition of osteoclastogenesis is not yet fully understood. Here, we found that the activating transcription factor (ATF)-6ß, a novel miR-1260b-targeting gene, is critical for the regulation of osteoclastogenesis under endoplasmic reticulum (ER) stress. An experimental periodontal mouse model demonstrated that induction of ER stress was accompanied by enhanced ATF6ß expression, and local administration of miR-1260b and ATF6ß siRNA using polyethylenimine nanoparticles (PEI-NPs) significantly suppressed the periodontal bone resorption. In periodontal ligament (PDL) cells, the ER stress inducer, tunicamycin, enhanced the expression of the receptor activator of NF-κB ligand (RANKL), while miR-1260b-mediated downregulation of ATF6ß caused RANKL inhibition. Furthermore, the secretome from miR-1260b/ATF6ß-axis-activated PDL cells inhibited osteoclastogenesis in human CD14+ peripheral blood-derived monocytes. These results indicate that the miR-1260b/ATF6ß axis mediates the regulation of ER stress, which may be used as a novel therapeutic strategy to treat periodontal disease.

Extracellular vesicles derived from GMSCs stimulated with TNF-α and IFN-α promote M2 macrophage polarization via enhanced CD73 and CD5L expression.

Immunoregulatory properties of mesenchymal stem cell (MSC)-derived extracellular vesicles (EVs) are promising. Gingival tissue-derived MSCs (GMSCs) have unique immunoregulatory capacity and secrete large amounts of EVs. Recent findings suggest that priming MSCs with inflammatory stimuli is an effective strategy for cell-free therapy. However, the precise mechanism by which the contents of EVs are customized has not been fully elucidated. Here, we show that EVs derived from GMSCs primed with a combination of two pro-inflammatory cytokines, tumor necrosis factor-α (TNF-α) and interferon-α (IFN-α), synergistically promote anti-inflammatory M2 macrophage polarization by increasing the expression of cluster of differentiation 73 (CD73) and CD5 molecule-like (CD5L). Expression of CD73 by TNF-α/IFN-α stimulation was transcriptionally upregulated by the activation of mammalian target of rapamycin signaling and nuclear translocation of hypoxia-inducible factor 1α in GMSCs. TNF-α/IFN-α treatment also significantly increased the expression of CD5L mRNA via the transcription factor DNA-binding protein inhibitor ID3 and liver X receptor. Interestingly, exosomal CD5L is a prerequisite for the synergistic effect of EVs-mediated M2 macrophage polarization. These results indicate that combined pre-licensing with TNF-α and IFN-α in GMSCs is ideal for enhancing the anti-inflammatory function of EVs, which contributes to the establishment of a therapeutic tool.

Exosomes from TNF-α-treated human gingiva-derived MSCs enhance M2 macrophage polarization and inhibit periodontal bone loss.

Mesenchymal stem cell (MSC)-derived exosome plays a central role in the cell-free therapeutics involving MSCs and the contents can be customized under disease-associated microenvironments. However, optimal MSC-preconditioning to enhance its therapeutic potential is largely unknown. Here, we show that preconditioning of gingival tissue-derived MSCs (GMSCs) with tumor necrosis factor-alpha (TNF-α) is ideal for the treatment of periodontitis. TNF-α stimulation not only increased the amount of exosome secreted from GMSCs, but also enhanced the exosomal expression of CD73, thereby inducing anti-inflammatory M2 macrophage polarization. The effect of GMSC-derived exosomes on inflammatory bone loss were examined by ligature-induced periodontitis model in mice. Local injection of GMSC-derived exosomes significantly reduced periodontal bone resorption and the number of tartrate-resistant acid phosphatase (TRAP)-positive osteoclasts, and these effects were further enhanced by preconditioning of GMSCs with TNF-α. Thus, GMSC-derived exosomes also exhibited anti-osteoclastogenic activity. Receptor activator of NF-κB ligand (RANKL) expression was regulated by Wnt5a in periodontal ligament cells (PDLCs), and exosomal miR-1260b was found to target Wnt5a-mediated RANKL pathway and inhibit its osteoclastogenic activity. These results indicate that significant ability of the TNF-α-preconditioned GMSC-derived exosomes to regulate inflammation and osteoclastogenesis paves the way for establishment of a therapeutic approach for periodontitis.

[Usage of New Device to Prevent Sternum Separation after Median Sternotomy in 140 Cases].

While minimally invasive cardiac surgery (MICS) has become increasingly popular recently even in the field of cardiovascular surgery, the conventional full median sternotomy is still the main approach to the mediastinum, especially for cases which cannot be applied for MICS or in the facilities where MICS is not performed. It has been known that sternal instability is one of the leading causes of sternal infection after median sternotomy. Therefore, we have sought for an additional product to secure strong sternal stability. Since August in 2018, we used a new type of corrugated plate( Super Fixsorb Wave) which is placed inside the sternum in addition to regular sternal wires for 140 patients who had full median sternotomy. Up to now, we have no complications regarding sternotomy including mediastinitis. We believe that additional use of Super Fixsorb Wave enables firm sternal stability and prevents mediastinitis following full median sternotomy.

Amelogenin Downregulates Interferon Gamma-Induced Major Histocompatibility Complex Class II Expression Through Suppression of Euchromatin Formation in the Class II Transactivator Promoter IV Region in Macrophages.

Enamel matrix derivatives (EMDs)-based periodontal tissue regenerative therapy is known to promote healing with minimal inflammatory response after periodontal surgery, i. e., it promotes wound healing with reduced pain and swelling. It has also been reported that macrophages stimulated with amelogenin, a major component of EMD, produce various anti-inflammatory cytokines and growth factors. We previously found that stimulation of monocytes with murine recombinant M180 (rM180) amelogenin suppresses major histocompatibility complex class II (MHC II) gene expression using microarray analysis. However, the detailed molecular mechanisms for this process remain unclear. In the present study, we demonstrated that rM180 amelogenin selectively downmodulates the interferon gamma (IFNγ)-induced cell surface expression of MHC II molecules in macrophages and this mechanism mediated by rM180 appeared to be widely conserved across species. Furthermore, rM180 accumulated in the nucleus of macrophages at 15 min after stimulation and inhibited the protein expression of class II transactivator (CIITA) which controls the transcription of MHC II by IFNγ. In addition, reduced MHC II expression on macrophages pretreated with rM180 impaired the expression of T cell activation markers CD25 and CD69, T cell proliferation ability, and IL-2 production by allogenic CD4+ T lymphocytes in mixed lymphocyte reaction assay. The chromatin immunoprecipitation assay showed that IFNγ stimulation increased the acetylation of histone H3 lysine 27, which is important for conversion to euchromatin, as well as the trimethylation of histone H3 lysine 4 levels in the CIITA promoter IV (p-IV) region, but both were suppressed in the group stimulated with IFNγ after rM180 treatment. In conclusion, the present study shows that amelogenin suppresses MHC II expression by altering chromatin structure and inhibiting CIITA p-IV transcription activity, and attenuates subsequent T cell activation. Clinically observed acceleration of wound healing after periodontal surgery by amelogenin may be partially mediated by the mechanism elucidated in this study. In addition, the use of recombinant amelogenin is safe because it is biologically derived protein. Therefore, amelogenin may also be used in future as an immunosuppressant with minimal side effects for organ transplantation or MHC II-linked autoimmune diseases such as type I diabetes, multiple sclerosis, and rheumatoid arthritis, among others.

Single-incision thoracoscopic surgery using a chest wall pulley for lung excision in patients with primary spontaneous pneumothorax.

PURPOSE: The aim of the study was to evaluate the feasibility and compare the outcomes of single-incision thoracoscopic surgery using a chest wall pulley for lung excision (PulLE) vs. those of conventional video-assisted thoracic surgery (cVATS) in patients with primary spontaneous pneumothorax (PSP). METHODS: Sixty-nine patients who underwent PulLE (n = 34) or cVATS (n = 35) between January 2009 and December 2013 were enrolled in this study. PulLE was performed as follows. After making a 17- to 25-mm single incision in the 6th intercostal space (6ICS) at the median axillary line, the visceral pleura near the bulla was sutured for traction. The parietal pleura at 3ICS was then sutured from the thoracic cavity to serve as the chest wall pulley and a traction thread was passed through the pulley. By manipulating the traction thread, it was possible to move the lesion to an arbitrary site for excision. The postoperative scar was nearly invisible. RESULTS: The operative time, duration of postoperative drainage, and postoperative hospital stay were equivalent for PulLE vs. cVATS. There was no significant difference in postoperative recurrence rates. CONCLUSIONS: PulLE has cosmetic benefits over cVATS and is easy to perform. We believe our novel procedure has the potential to become the standard operative treatment for PSP.

[Left Ventricular Torsion in Papillary Muscle Relocation for Severe Functional Mitral Regurgitation].

A 42-year-old woman with a history of old myocardial infarction was admitted to our hospital with complaints of worsening orthopnea. Doppler echocardiography exhibited severe functional mitral valve regurgitation. Because of the tethered mitral valve, we performed mitral valve annuloplasty concomitantly with papillary muscle relocation procedure. The patient recovered well. Postoperative echocardiography had not exhibited recurrent mitral valve insufficiency. Moreover, postoperative left ventricular torsion using 2-dimentional speckle tracking imaging, improved at rest and at peak exercise, and this findings suggest that the reversal of left ventricular remodeling in relocation patients following preserved and connected mitral subvalvular apparatus may result from restoration of the global sequence of left ventricular twist mechanics. The analysis of left ventricular torsion may provide a more comprehensive evaluation of left ventricular mechanics and may help understand the effects of papillary muscle relocation with preserving mitral subvalvular apparatus.

Osteoblastic bone formation is induced by using nanogel-crosslinking hydrogel as novel scaffold for bone growth factor.

Bone regeneration for the defects in revision surgery of joint replacement is an increasingly important issue. To repair bone defects, bone cell activation by growth factors using synthetic resorbable scaffold is a useful and safe option. We examine the efficiency of nanogel-crosslinking hydrogel as a novel synthetic scaffold for BMP to stimulate osteoblasts and to induce bone formation. Cholesterol-bearing pullulan nanogel-crosslinking hydrogel (CHPA/Hydrogel) was used to deliver BMP. The CHPA hydrogel pellets were implanted in vivo. Single implantation of CHPA/hydrogel containing low amounts of BMP induced osteoblastic activation and new bone formation in vivo. Furthermore, nanogel in a disc shape established recruitment of osteoblastic cells that vigorously formed bone to heal the calvarial defects, which did not heal spontaneously without it. In conclusion, CHPA/hydrogel serves as an efficient and versatile scaffold for the stimulation of osteoblasts to form bone and to repair defects via delivery of BMP.

Multiple molecular interactions implicate the connectin/titin N2A region as a modulating scaffold for p94/calpain 3 activity in skeletal muscle.

p94/calpain 3 is a skeletal muscle-specific Ca(2+)-regulated cysteine protease (calpain), and genetic loss of p94 protease activity causes muscular dystrophy (calpainopathy). In addition, a small in-frame deletion in the N2A region of connectin/titin that impairs p94-connectin interaction causes a severe muscular dystrophy (mdm) in mice. Since p94 via its interaction with the N2A and M-line regions of connectin becomes part of the connectin filament system that serves as a molecular scaffold for the myofibril, it has been proposed that structural and functional integrity of the p94-connectin complex is essential for health and maintenance of myocytes. In this study, we have surveyed the interactions made by p94 and connectin N2A inside COS7 cells. This revealed that p94 binds to connectin at multiple sites, including newly identified loci in the N2A and PEVK regions of connectin. Functionally, p94-N2A interactions suppress p94 autolysis and protected connectin from proteolysis. The connectin N2A region also contains a binding site for the muscle ankyrin repeat proteins (MARPs), a protein family involved in the cellular stress responses. MARP2/Ankrd2 competed with p94 for binding to connectin and was also proteolyzed by p94. Intriguingly, a connectin N2A fragment with the mdm deletion possessed enhanced resistance to proteases, including p94, and its interaction with MARPs was weakened. Our data support a model in which MARP2-p94 signaling converges within the N2A connectin segment and the mdm deletion disrupts their coordination. These results also implicate the dynamic nature of connectin molecule as a regulatory scaffold of p94 functions.

Serum osteopontin, an enhancer of tumor metastasis to bone, promotes B16 melanoma cell migration.

Tumor malignancy is associated with several features such as proliferation ability and frequency of metastasis. Since tumor metastasis shortens patients' lifetime, establishment of therapy for anti-metastasis is very important. Osteopontin (OPN), which abundantly expressed in bone matrix, is involved in cell adhesion, migration, extracellular matrix (ECM) invasion and cell proliferation via interaction with its receptor, that is, alphavbeta3 integrin. OPN is believed to be a positive regulator of tumor metastasis in vivo. However, how OPN regulates metastasis is largely unknown. Here, we explore the role of OPN in cell migration. Serum from wild-type mice induced cell migration of B16 melanoma cells, while serum from OPN-deficient mouse suppressed this event. The presence of recombinant OPN significantly enhanced cell migration compared to albumin containing medium. OPN-induced cell migration was suppressed by inhibiting the ERK/MAPK pathway indicating that OPN-induced cell migration depends on this pathway. Overexpression of OPN in these cancer cells per se promoted cell proliferation and tended to increase B16 cell migration suggesting that OPN promotes bone metastasis by playing dual roles both in host microenvironment and in tumor cell itself. In conclusion, the elevated OPN expression in host tissue and tumor cell itself promotes tumor cell migration reading to tumor metastasis, suggesting that neutralization of OPN-induced signal might be effective in suppression of tumor metastasis.

Comprehensive survey of p94/calpain 3 substrates by comparative proteomics--possible regulation of protein synthesis by p94.

Calpain represents a family of Ca(2+)-dependent cytosolic cysteine proteases found in almost all eukaryotes and some bacteria, and is involved in a variety of biological phenomena, including brain function. Several substrates of calpain are aggressively proteolyzed under pathological conditions, e.g., in neurodegenerating processes, fodrin is proteolyzed by calpain. Because very small amounts of substrate are proteolyzed by calpain under normal biological conditions, the molecular identities of calpain substrates are largely unknown. In this study, an extensive survey of the substrates of p94/calpain 3 in COS7 cells was executed using iTRAQ(TM) labeling and 2-D LC-MALDI analysis. p94 was used because: (i) several p94 splicing variants are expressed in brain tissue even though p94 itself is a skeletal-muscle-specific calpain, and (ii) it exhibits Ca(2+)-independent activity in COS cells, which makes it useful for evaluating the effects of p94 protease activity on proteins without perturbing the cells. Our approach revealed several novel protein substrates for p94, including the substrates of conventional calpains, components of the protein synthesis system, and enzymes of the glycolytic pathway. The results demonstrate the usefulness and sensitivity of this approach for mining calpain substrates. A combination of this method with other analytical methods would contribute to elucidation of the biological relevance of the calpain family.