Neutrophil extracellular traps inhibit osteoclastogenesis.

Neutrophil extracellular traps (NETs) released by neutrophils upon inflammation or infection, act as an innate immune defense against pathogens. NETs also influence inflammatory responses and cell differentiation in host cells. Osteoclasts, which are derived from myeloid stem cells, are critical for the bone remodeling by destroying bone. In the present study, we explores the impact of NETs, induced by the inflammatory agent calcium ionophore A23187, on the differentiation and activation of osteoclasts, potentially through suppressing RANK expression. Our results collectively suggested that the inhibition of RANKL-mediated osteoclastogenesis by NETs might lead to the suppression of excessive bone resorption during inflammation.

Effect of newly developed scissors-attached micro-forceps on the recipient clamp time and occurrence of anastomotic site infarction after bypass surgery for moyamoya disease.

Introduction: This study aimed to examine the effect of newly developed scissors-attached micro-forceps in superficial temporal artery-to-middle cerebral artery (STA-MCA) anastomosis for moyamoya disease (MMD). Materials and methods: Of 179 consecutive STA-MCA anastomoses on 95 hemispheres of 71 MMD patients at the University of Fukui Hospital between 2009 and 2023, 49 anastomoses on 26 hemispheres of 21 patients were enrolled in this retrospective cohort clinical trial intraoperative indocyanine green video-angiography did not demonstrate bypass patency in three anastomoses in two patients who were excluded. Twenty-one anastomosis in 19 hemispheres of 16 patients were performed using the conventional micro-forceps (conventional group, CG), and 25 anastomoses in 22 hemispheres of 19 patients were performed using scissors-attached micro-forceps (scissors group, SG). A small infarction near the anastomotic site detected using postoperative diffusion-weighted imaging was defined as anastomotic site infarction (ASI). Factors affecting the occurrence of ASI were examined by univariate, logistic regression, and receiver operating curve (ROC) analysis. Results: There were no significant differences in clinical parameters such as age, sex, number of sacrificed branches, number of sacrificed large branches, and number of sutures between the CG and SG. However, the clamp time and occurrence of ASI were significantly lower in the SG than in the CG. Logistic regression analysis revealed that the clamp time was the only significant factor predicting the occurrence of ASI. A receiver operating curve analysis also revealed that the clamp time significantly predicted the occurrence of ASI (area under the curve, 0.875; cutoff value, 33.2 min). Conclusion: The newly developed scissors-attached micro-forceps could significantly reduce the clamp time and occurrence of ASI in STA-MCA anastomosis for MMD.

Macrophage migration inhibitory factor-mediated mast cell extracellular traps induce inflammatory responses upon Fusobacterium nucleatum infection.

Mast cell extracellular traps (MCETs) released by mast cells contribute to host defense. In this study, we investigated the effects of MCETs released from mast cells after infection with a periodontal pathogen Fusobacterium nucleatum. We found that F. nucleatum induced MCET release from mast cells, and that MCETs expressed macrophage migration inhibitory factor (MIF). Notably, MIF bound to MCETs induced proinflammatory cytokine production by monocytic cells. These findings suggest that MIF expressed on MCETs, released from mast cells upon infection with F. nucleatum, promotes inflammatory responses that may be associated with the pathogenesis of periodontal disease.

[A Study of the Safety of Chemotherapy with Generic Oxaliplatin for the Treatment of Colorectal Cancer].

BACKGROUND: Generic oxaliplatin is widely used in colorectal cancer chemotherapy; however, studies on the adverse events of generic drugs are limited. We investigated the safety of brand-name and generic oxaliplatin used in capecitabine plus oxaliplatin(plus bevacizumab: Bmab)for colorectal cancer treatment. PARTICIPANTS AND METHODS: A total of 86 patients who newly started CAPOX(plus Bmab)between January 2018 and January 2022 were included in this retrospective study, excluding those who changed to generic from the brand-name drug during the chemotherapy course. RESULTS: Forty-seven patients(54.6%)were in the generic drug(GE)group, while 39 patients(45.4%)were in the brand drug(EP)group. No significant difference was observed in the patient characteristics between the GE and EP groups. The median number of oxaliplatin administrations were 4 and 5 cycles in the GE and EP groups, respectively. Neutropenia of Grade 2 or higher was observed in 51.1%(24 patients)and 33.3%(13 patients)in the GE and EP groups, respectively. Hypersensitivity was observed in 14.9%(7 patients)and 7.7%(3 patients)in the GE and EP groups, respectively. CONCLUSION: There were no statistically significant differences between generic and brand-name oxaliplatin in the frequency of adverse events.

Development of Ternary Ti-Ag-Cu Alloys with Excellent Mechanical Properties and Antibiofilm Activity.

Titanium-20 mass% Silver (Ti-20%Ag) alloy can suppress biofilm formation on the surface. Unlike bactericidal agents, it does not kill bacteria; therefore, the healthy oral microflora remains undisturbed. To utilize the unique functions of this alloy and enable its use in the fabrication of dental prostheses that require relatively high strength, we added copper (Cu) as an alloying element to improve strength. This study aimed to develop ternary Ti-Ag-Cu alloys with excellent mechanical properties and antibiofilm activity. As a result of investigating the mechanical properties of several experimental alloys, the tensile strength, yield strength, and hardness of Ti-20%Ag-1%Cu and Ti-20%Ag-2%Cu alloys were improved by the solid-solution strengthening or hardening of the αTi phase. In addition, these alloys had the same ability to suppress biofilm formation as the Ti-20Ag alloy. Thus, Ti-20%Ag-1-2%Cu alloys can be used for fabrication of narrow-diameter dental implants and prostheses subjected to extremely high force, and these prostheses are useful in preventing post-treatment oral diseases.

Hericium erinaceus ethanol extract and ergosterol exert anti-inflammatory activities by neutralizing lipopolysaccharide-induced pro-inflammatory cytokine production in human monocytes.

Edible mushrooms are known to exert anti-inflammatory effects. In this study, the effects of ethanol extracts from edible mushrooms, such as Hericium erinaceus, and other edible mushrooms on inflammatory responses were investigated. Experiments were conducted using the inflammatory responses of human monocytes induced by lipopolysaccharide (LPS), a bacterial component, that provokes inflammation. Notably, we demonstrated that LPS mixed with ethanol and hot water extracts derived from edible mushrooms attenuated the production of inflammatory cytokines, such as interleukin (IL)-1ß, -6, and -8, induced by LPS in human monocytic cell cultures. Moreover, we found that the ethanol extract of H. erinaceus contained ergosterol, which attenuated IL-8 production in LPS-stimulated cells. Subsequent component analysis of the ethanol extract of H. erinaceus revealed that ergosterol binds to lipid A to attenuate LPS-induced inflammation. Together, our findings suggest that ergosterol in ethanol extracts from edible mushrooms can prevent the induction of inflammation by binding to LPS.

Reactivation of p53 by RITA Induces Apoptosis in Human Oral Squamous Cell Carcinoma Cells.

BACKGROUND/AIM: Oral squamous cell carcinoma (OSCC) is one of the most common tumors of the head and neck region. The tumor suppressor gene p53 (TP53) is the most frequently mutated gene in OSCC and TP53 mutations are associated with decreased survival and resistance to chemotherapy in patients with OSCC. Therefore, therapeutic strategies targeting TP53 reactivation are required to effectively treat OSCC. In this study, we investigated the effect of various p53-reactivating small molecules (RITA, PRIMA-1, and CP-31398) on the proliferation of human OSCC cell lines (Ca9-22, HSC-2, HSC-3, and HSC-4) derived from human oral tissues bearing a mutant TP53 gene. MATERIALS AND METHODS: Apoptosis induction by RITA was assessed by measuring Annexin V and propidium iodide (PI)-positive cells using flow cytometry. p53 and murine double minute 2 (MDM2) phosphorylation and Bax expression were detected in the lysates of RITA-treated Ca9-22 cells using western blotting. RESULTS: RITA markedly inhibited the growth of Ca9-22, HSC-2, HSC-3, and HSC-4 cells. In Ca9-22 cells, RITA induced apoptosis and inhibited cell proliferation while increasing p53 phosphorylation and Bax expression; however, RITA did not induce MDM2 phosphorylation. CONCLUSION: The inhibitory effect of RITA on human OSCC cell proliferation is mediated by apoptosis induction through p53 and Bax.

Extracellular Vesicles Derived From Murine Cementoblasts Possess the Potential to Increase Receptor Activator of Nuclear Factor-κB Ligand-Induced Osteoclastogenesis.

Cementum resorption, unlike bone resorption, is clinically known to occur only with limited pathological stimuli, such as trauma, orthodontic forces, and large apical periodontitis; however, the molecular mechanisms that control osteoclast formation on the cementum surface remain unclear. In this study, we focused on extracellular vesicles (EVs) secreted by cementoblasts and analyzed their effects on osteoclast differentiation. EVs were extracted from the conditioned medium (CM) of the mouse cementoblast cell line OCCM-30. Transmission electron microscopy (TEM) analysis confirmed the presence of EVs with a diameter of approximately 50-200 nm. The effect of the EVs on osteoclast differentiation was examined using the mouse osteoclast progenitor cell line RAW 264.7 with recombinant receptor activator of nuclear factor (NF)-κB ligand (rRANKL) stimulation. EVs enhanced the formation of tartrate-resistant acid phosphatase (TRAP) activity-positive cells upon rRANKL stimulation. EVs also enhanced the induction of osteoclast-associated gene and protein expression in this condition, as determined by real-time PCR and Western blotting, respectively. On the other hand, no enhancing effect of EVs was observed without rRANKL stimulation. A Western blot analysis revealed no expression of receptor activator of NF-κB ligand (RANKL) in EVs themselves. The effect on rRANKL-induced osteoclast differentiation was examined using the CM of cementoblasts in terms of TRAP activity-positive cell formation and osteoclast-associated gene expression. The conditioned medium partly inhibited rRANKL-induced osteoclast differentiation and almost completely suppressed its enhancing effect by EVs. These results indicate that cementoblasts secreted EVs, which enhanced RANKL-induced osteoclast differentiation, and simultaneously produced soluble factors that neutralized this enhancing effect of EVs, implicating this balance in the regulation of cementum absorption. A more detailed understanding of this crosstalk between cementoblasts and osteoclasts will contribute to the development of new therapies for pathological root resorption.

Porphyromonas gingivalis Gingipains-Mediated Degradation of Plasminogen Activator Inhibitor-1 Leads to Delayed Wound Healing Responses in Human Endothelial Cells.

Plasminogen activator inhibitor-1 (PAI-1), a serine protease inhibitor, is constitutively produced by endothelial cells and plays a vital role in maintaining vascular homeostasis. Chronic periodontitis is an inflammatory disease characterized by bleeding of periodontal tissues that support the tooth. In this study, we aimed to determine the role of PAI-1 produced by endothelial cells in response to infections caused by the primary periodontal pathogen Porphyromonas gingivalis. We demonstrated that P. gingivalis infection resulted in significantly reduced PAI-1 levels in human endothelial cells. This reduction in PAI-1 levels could be attributed to the proteolysis of PAI-1 by P. gingivalis proteinases, especially lysine-specific gingipain-K (Kgp). We demonstrated the roles of these degradative enzymes in the endothelial cells using a Kgp-specific inhibitor and P. gingivalis gingipain-null mutants, in which the lack of the proteinases resulted in the absence of PAI-1 degradation. The degradation of PAI-1 by P. gingivalis induced a delayed wound healing response in endothelial cell layers via the low-density lipoprotein receptor-related protein. Our results collectively suggested that the proteolysis of PAI-1 in endothelial cells by gingipains of P. gingivalis might lead to the deregulation of endothelial homeostasis, thereby contributing to the permeabilization and dysfunction of the vascular endothelial barrier.

Nitrogen-containing bisphosphonates and lipopolysaccharide mutually augment inflammation via adenosine triphosphate (ATP)-mediated and interleukin 1ß (IL-1ß)-mediated production of neutrophil extracellular traps (NETs).

Among the bisphosphonates (BPs), nitrogen-containing BPs (N-BPs) have much stronger anti-bone-resorptive actions than non-N-BPs. However, N-BPs have various side effects such as acute influenza-like reactions after their initial administration and osteonecrosis of the jawbones after repeated administration. The mechanisms underlying such effects remain unclear. To overcome these problems, it is important to profile the inflammatory nature of N-BPs. Here, we analyzed the inflammatory reactions induced in mouse ear pinnae by the N-BPs alendronate (Ale) and zoledronate (Zol). We found the following: (i) Ale and Zol each induced two phases of inflammation (early weak and late strong ear swelling); (ii) both phases were augmented by lipopolysaccharides (LPSs; cell-surface constituent of gram-negative bacteria, including oral bacteria), but prevented by inhibitors of the phosphate transporters of solute carrier 20/34 (SLC20/SLC34); (iii) macrophages and neutrophils were involved in both phases of Ale+LPS-induced ear-swelling; (iv) Ale increased or tended to increase various cytokines, and LPS augmented these effects, especially that on interleukin 1ß (IL-1ß); (v) adenosine triphosphate (ATP) was involved in both phases, and Ale alone or Ale+LPS increased ATP in ear pinnae; (vi) the augmented late-phase swelling induced by Ale+LPS depended on both IL-1 and neutrophil extracellular traps (NETs; neutrophil-derived net-like complexes); (vii) neutrophils, together with macrophages and dendritic cells, also functioned as IL-1ß-producing cells, and upon stimulation with IL-1ß, neutrophils produced NETs; (viii) stimulation of the purinergic 2X7 (P2X7) receptors by ATP induced IL-1ß in ear pinnae; (ix) NET formation by Ale+LPS was confirmed in gingiva, too. These results suggest that (i) N-BPs induce both early-phase and late-phase inflammation via ATP-production and P2X7 receptor stimulation; (ii) N-BPs and LPS induce mutually augmenting responses both early and late phases via ATP-mediated IL-1ß production by neutrophils, macrophages, and/or dendritic cells; and (iii) NET production by IL-1ß-stimulated neutrophils may mediate the late phase, leading to prolonged inflammation. These results are discussed in relation to the side effects seen in patients treated with N-BPs. © 2021 American Society for Bone and Mineral Research (ASBMR).

Cyclic Stretch Force Induces Periodontal Ligament Cells to Secrete Exosomes That Suppress IL-1ß Production Through the Inhibition of the NF-κB Signaling Pathway in Macrophages.

In the oral mechanical environment, periodontal ligament cells (PDL cells) contribute to maintaining periodontal tissue homeostasis. Recent studies showed that exosomes, which are small vesicles secreted by various types of cells, play a pivotal role in cell-to-cell communication in biological processes. We examined the secretion of exosomes from PDL cells stimulated with cyclic stretch and their role in the inflammatory response of macrophages using the human macrophage cell line THP-1 and human primary monocytes/macrophages. We prepared supernatants from human PDL cells (PDL-sup) stimulated with cyclic stretch. The treatment of macrophages with PDL-sup, but not PDL-sup from unstimulated PDL cells, inhibited the production of IL-1ß in LPS/nigericin-stimulated macrophages. The pretreatment of PDL cells with GW4869, an inhibitor of exosome secretion, or siRNA for Rab27B, which controls exosome secretion, abrogated the inhibitory effects of PDL-sup. A transmission electron microscopy analysis demonstrated the existence of exosomes with diameters ranging between 30 and 100 nm in PDL-sup, suggesting that exosomes in PDL-sup contribute to this inhibition. An immunofluorescence microscopy analysis revealed that exosomes labeled with PKH67, a fluorescent dye, were incorporated by macrophages as early as 2 h after the addition of exosomes. Purified exosomes inhibited IL-1ß production in LPS/nigericin-stimulated macrophages and the nuclear translocation of NF-κB as well as NF-κB p65 DNA-binding activity in LPS-stimulated macrophages, suggesting that exosomes suppress IL-1ß production by inhibiting the NF-κB signaling pathway. Our results indicate that PDL cells in mechanical environments contribute to the maintenance of periodontal immune/inflammatory homeostasis by releasing exosomes.

Effects of Zoledronate on Local and Systemic Production of IL-1ß, IL-18, and TNF-α in Mice and Augmentation by Lipopolysaccharide.

Bisphosphonates (BPs) containing nitrogen (N-BPs) exhibit far stronger anti-bone-resorptive effects than non-N-BPs. However, repeated administration of N-BPs causes osteonecrosis selectively in jawbones. As BPs accumulate in large amounts within inflamed bones, any N-BP released from the pool accumulated within jawbones might directly act on cells in the surrounding soft-tissues and induce inflammation or necrosis. Here, we examined the local and systemic effects of zoledronate (the most potent N-BP with the highest incidence of jawbone-necrosis) on inflammatory cytokines in mice. Locally within ear-pinnas: (i) zoledronate induced long-lasting accumulation of interleuikin-1ß (IL-1ß) and IL-18, but not tumor necrosis factor-α (TNF-α), (ii) zoledronate and lipopolysaccharide (LPS, a cell-wall component of Gram-negative bacteria) mutually augmented the productions of IL-1ß, IL-18, and TNF-α, and (iii) oxidronate (a toxic non-N-BP) by itself produced not only IL-1ß and IL-18, but also TNF-α. In systemic experiments using intraperitoneal injection of zoledronate and/or LPS, (i) zoledronate by itself increased none of the above cytokines in serum, and (ii) in mice pretreated (3 d before) with zoledronate, the LPS-induced increases in serum IL-1ß and IL-18 were greatly augmented with a delayed slight TNF-α augmentation. These results, together with previous ones, suggest that (a) pro-IL-1ß and pro-IL-18 accumulate within cells in soft-tissues exposed to N-BPs, and infection may augment not only their production, but also the release of their mature forms, (b) IL-1ß and IL-18 (possibly together with TNF-α) may play important roles in N-BP-induced inflammation and/or necrosis, and (c) mechanisms underlying the cytotoxic effects of BPs may differ between N-BPs and non-N-BPs.

Augmentation of Lipopolysaccharide-Induced Production of IL-1α and IL-1ß in Mice Given Intravenous Zoledronate (a Nitrogen-Containing Bisphosphonate) and Its Prevention by Clodronate (a Non-nitrogen-containing Bisphosphonate).

Bisphosphonates (BPs) bind strongly to bone and exhibit long-acting anti-bone-resorptive effects. Among BPs, nitrogen-containing BPs (N-BPs) have far stronger anti-bone-resorptive effects than non-N-BPs. However, N-BPs induce acute inflammatory reactions (fever, arthralgia and myalgia, etc.) after their first injection. The mechanisms underlying these side effects remain unclear. Zoledronate (one of the most potent N-BPs) is given intravenously to patients, and the side-effect incidence is reportedly the highest among N-BPs. Our murine experiments have clarified that (a) intraperitoneally injected N-BPs induce various inflammatory reactions, including a production of interleukin-1 (IL-1) (a typical inflammatory cytokine), and these inflammatory reactions are weak in IL-1-deficient mice, (b) subcutaneously injected N-BPs induce inflammation/necrosis at the injection site, (c) lipopolysaccharide (LPS; a cell-wall component of Gram-negative bacteria) and N-BPs mutually augment their inflammatory/necrotic effects, (d) the non-N-BP clodronate can reduce N-BPs' inflammatory/necrotic effects. However, there are few animal studies on the side effects of intravenously injected N-BPs. Here, we found in mice that (i) intravenous zoledronate exhibited weaker inflammatory effects than intraperitoneal zoledronate, (ii) in mice given intravenous zoledronate, LPS-induced production of IL-1α and IL-1ß was augmented in various tissues, including bone, resulting in them increasing in serum, and (iii) clodronate (given together with zoledronate) prevented such augmentation and enhanced, slightly but significantly, zoledronate's anti-bone-resorptive effect. These results suggest that infection may be a factor promoting the acute inflammatory side effects of N-BPs via augmented production of IL-1 in various tissues (including bone), and that clodronate may be useful to reduce or prevent such side effects.

Nicotine exposure induces the proliferation of oral cancer cells through the α7 subunit of the nicotinic acetylcholine receptor.

Oral cancer and smoking are closely related, because the oral cavity, which is the route of ingestion of tobacco smoke, is in direct contact with the oral mucosa. Nicotine, one of the components of tobacco, can diffuse rapidly to the central nervous system and is responsible for tobacco addiction. Nicotine is present in high concentrations in the bloodstream of smokers; while the addictive effects of this alkaloid have extensively been studied, its effect on tumorigenesis is not clear yet. Therefore, in this study, we examined the effect of nicotine on cell proliferation and the signaling pathways it activates. The human oral squamous cell carcinoma cell line HSC-2 was used as a model system. We demonstrated the correlation between nicotine and epidermal growth factor receptor (EGFR) signaling. Nicotine treatment induced HSC-2 cell proliferation and migration and the phosphorylation of EGFR. Furthermore, nicotine treatment activated the EGFR downstream effectors phosphatidylinositol-3 kinase/AKT and p44/42 mitogen-activated protein kinases (ERK), which, in turn, promoted cell proliferation. Overall, our study suggests that nicotine promotes cell growth and migration through epidermal growth factor (EGF) signaling and plays an important role in oral cancer progression.

Dectin-2-Mediated Signaling Leads to Delayed Skin Wound Healing through Enhanced Neutrophilic Inflammatory Response and Neutrophil Extracellular Trap Formation.

Dendritic cell-associated C-type lectin-2 (i.e., dectin-2) recognizes fungal polysaccharides, including α-mannan. Dectin-2-mediated recognition of fungi, such as Candida albicans, leads to NF-κB activation, which induces production of inflammatory cytokines. However, the role of dectin-2 in skin wound healing remains unclear. In this study, we sought to determine how dectin-2 deficiency and the administration of α-mannan affected the wound healing process. Full-thickness wounds were created on the backs of wild type C57BL/6 and dectin-2-deficient mice. We analyzed wound closure, histological findings, and re-epithelialization. We also examined the neutrophilic inflammatory responses and neutrophil extracellular trap (NET)-osis at the wound sites after administration of α-mannan. The percent wound closure and re-epithelialization was significantly accelerated in dectin-2-knockout mice compared with wild-type mice on days 3 and 5 after wounding. In contrast, administration of α-mannan delayed wound closure in wild-type mice, and these responses were canceled in dectin-2-knockout mice. Furthermore, mice administered α-mannan, neutrophil infiltration was prolonged, and the expression of citrullinated histone, an indicator of NETosis, at the wound sites was accelerated. Administration of a neutrophil elastase inhibitor significantly improved the delayed wound healing caused by α-mannan. These results suggest that dectin-2 may have a deep impact on the skin wound healing process through regulation of neutrophilic responses.

Porphyromonas gingivalis induces the production of interleukin-31 by human mast cells, resulting in dysfunction of the gingival epithelial barrier.

Interleukin (IL)-31 is important for innate immunity in mucosal tissues and skin, and increased IL-31 expression participates in the pathogenesis of chronic inflammatory diseases affecting the skin, airways, lungs, and intestines. We investigated the contribution of mast cells to the induction of IL-31 production following infection with the periodontal pathogen, Porphyromonas gingivalis. We found that oral infection with P. gingivalis increased IL-31 expression in the gingival tissues of wild-type mice but not in those of mast cell-deficient mice. The P. gingivalis-induced IL-31 production by human mast cells occurred through the activation of the JNK and NF-κB signalling pathways and was dependent on the P. gingivalis lysine-specific protease gingipain-K. P. gingivalis infection induced IL-31 receptor α and oncostatin M receptor ß expression in human gingival epithelial cells. Notably, the P. gingivalis-induced IL-31 production by mast cells led to the downregulation of claudin-1, a tight junction molecule, in gingival epithelial cells, resulting in an IL-31-dependent increase in the paracellular permeability of the gingival epithelial barrier. These findings suggest that IL-31 produced by mast cells in response to P. gingivalis infection causes gingival epithelial barrier dysfunction, which may contribute to the chronic inflammation observed in periodontitis.

MrgX2­mediated internalization of LL­37 and degranulation of human LAD2 mast cells.

LL­37 is the sole antimicrobial peptide of human cathelicidin comprising 37 amino acids, which is expressed mainly in epithelial cells and neutrophils, and activates mast cells. In the present study, in order to elucidate the mechanism of mast cell activation by LL­37, the associations between the internalization of LL­37 and Mas­related gene X2 (MrgX2)­mediated mast cell activation (degranulation) was investigated using the human mast cell line, LAD2. LL­37 was rapidly internalized into the cells, and induced degranulation, as assessed by the extracellular release of ß­hexosaminidase. Pertussis toxin, a G­protein inhibitor, significantly suppressed the internalization of LL­37 and the degranulation of LAD2 cells. Furthermore, small interfering (si)­RNA­mediated knockdown of MrgX2, a putative G protein­coupled receptor for LL­37, inhibited the internalization of LL­37 and degranulation of LAD2 cells. Notably, LL­37 internalization was enhanced by the stable expression of MrgX2 in HMC­1 and 293 cells. In addition, the internalized LL­37 mainly colocalized with MrgX2 in the perinuclear region of LAD2 cells. Furthermore, neuraminidase treatment, which removes negatively charged sialic acid from the cell surface, markedly reduced the internalization of LL­37 and degranulation of LAD2 cells, and clathrin­mediated endocytosis inhibitors (dynasore and chlorpromazine) inhibited the internalization and degranulation of LAD2 cells. Taken together, these observations indicated that LL­37 may bind the negatively charged cell surface molecules, rapidly internalize into the cells via clathrin­mediated endocytosis and interact with MrgX2 to activate mast cells (LAD2 cells).

Cyclic Stretch Negatively Regulates IL-1ß Secretion Through the Inhibition of NLRP3 Inflammasome Activation by Attenuating the AMP Kinase Pathway.

Macrophages are immune cells of hematopoietic origin that play diverse roles in host defenses and tissue homeostasis. In mechanical microenvironments, macrophages receive mechanical signals that regulate various cellular functions. However, the mechanisms by which mechanical signals influence the phenotype and function of macrophages in the process of inflammation have not yet been elucidated in detail. We herein examined the effects of cyclic stretch (CS) on NLR family, pyrin domain-containing 3 (NLRP3) inflammasome activation in J774.1, a murine macrophage cell line, and mouse primary bone marrow-derived macrophages. We showed that cyclic stretch inhibited adenosine triphosphate (ATP)-stimulated interleukin (IL)-1ß secretion in lipopolysaccharide (LPS)-primed macrophages using ELISA and Western blot analyses. Cyclic stretch did not affect the degradation of the Inhibitor of κB or the nuclear translocation/transcriptional activity of nuclear factor (NF)-κB, suggesting that cyclic stretch-mediated inhibition was independent of the NF-κB signaling pathway. Consistent with these results, cyclic stretch did not affect the LPS-induced expression of inflammasome components, such as pro-IL-1ß and NLRP3, which is known to require the activation of NF-κB signaling. We showed that the cyclic stretch-mediated inhibition of IL-1ß secretion was caused by the suppression of caspase-1 activity. The addition of compound C, a specific inhibitor of adenosine monophosphate-activated protein kinase (AMPK), to LPS-primed macrophages inhibited IL-1ß secretion as well as caspase-1 activation, suggesting that AMPK signaling is involved in ATP-triggered IL-1ß secretion. Furthermore, the phosphorylation of AMPK induced by ATP in LPS-primed macrophages was significantly suppressed by cyclic stretch, indicating that cyclic stretch negatively regulates IL-1ß secretion through the inhibition of caspase-1 activity by attenuating the AMPK pathway. Our results suggest that mechanical stress functions to maintain homeostasis through the prevention of excessive inflammasome activation in macrophages in mechanical microenvironments.

[A Case of Intraductal Pancreatic Mallignant Tumor with Difficulty in Differentiating between IPMN and ITPN].

The patient was a male in his early 60s. Diabetes had aggravated 6 months earlier, and the patient was referred to our hospital for close examination. On contrast CT, enhanced mass shadows filling the lumen of the main pancreatic duct, which was dilated throughout the pancreas, were observed, and the mass was diagnosed as an adenocarcinoma on EUS-FNA. Based on these findings, main-duct IPMN was suspected and total pancreatectomy was performed. On macroscopic observation of the resected specimen, outgrowth of a solid tumor was observed in the main pancreatic duct, whereas only low-level mucus retention was noted in the pancreatic duct. Histopathological examination revealed a papillary/tubular tumor growth, suggesting interstitial infiltration throughout the pancreas. On immunostaining, the tumor was partially positive for MUC5AC, based on which the patient was diagnosed with an intraductal pancreatic mallignant tumor, with difficulty in differentiating between IPMC and ITPC. Clinicopathologically, many aspects regarding ITPN remain unclear. Further accumulation of such cases and investigation of the tumor pathology are necessary.

Evaluation of the Use of Calcium Phosphate Cement for Aesthetic Neurosurgical Cranial Reconstruction.

OBJECTIVE: The objective of this article is to evaluate whether newly developed calcium phosphate cement (CPC), mounted around the titanium plates, is useful for aesthetic cranial reconstruction by using 2 methods. METHODS: The morphologic changes of CPC were observed in videos of 6 patients who had undergone cranial reconstruction with CPC during the first surgery and required second surgery. The facial aesthetic outcomes of 74 consecutive patients, more than 12 months after frontotemporal or bifrontal craniotomy and reconstruction with or without CPC, were evaluated. RESULTS: Observations of CPC changes were available 1 day, 2 weeks, 2 months, 5 months, 10 months, and 26 months after the first surgeries. CPC, applied superficially on the cranial surface, had not set sufficiently. CPCs, mounted thickly around the titanium plates and forming hydroxyapatite, were residual during the latter period. Comparison between the aesthetic reconstruction group (with CPC) and the simple reconstruction group (without CPC) showed that the objective bump detected by the investigator, and the subjective bump noticed by the patients themselves, were significantly more frequent in the simple reconstruction group. Comparison between the patients without an objective bump and the patients with an objective bump during the follow-up period showed that the proportion of patients after aesthetic cranial reconstruction with CPC was significantly higher in patients without an objective bump. Patients' characteristics, craniotomy procedure, use of a vascularized pericranial flap, and craniotomy-associated complications did not influence the objective bump significantly. CONCLUSIONS: Use of CPC was expected to bring better aesthetic outcomes after neurosurgical cranial reconstructions.