Altered Homeostasis of CD4+ Memory T Cells in Allogeneic Hematopoietic Stem Cell Transplant Recipients: Chronic Graft-versus-Host Disease Enhances T Cell Differentiation and Exhausts Central Memory T Cell Pool

AbstractAn increased risk of late infection is a serious complication after allogeneic hematopoietic stem cell transplantation (AHSCT), especially for recipients with defective CD4+ T cell recovery. Although chronic graft-versus-host disease (cGVHD) negatively influences CD4+ T cell reconstitution, the mechanisms leading to this defect are not well understood. We found that the proportion of CD27− CD4+ T cells was remarkably increased in ASHCT recipients with cGVHD or with repetitive infectious episodes. Isolated CD27− CD4+ T cells from ASHCT recipients had significantly shortened telomere length, displayed enhanced vulnerability to activation-induced cell death, and showed extremely reduced clonal diversity, when compared with CD27− CD4+ T cells from healthy donors. Also, CD27+ CD4+ T cells from AHSCT recipients easily lost their expression of CD27 in response to antigen stimulation regardless of cGVHD status. Taken together, these data indicate that homeostasis of memory CD4+ T cells from AHSCT recipients is altered, and that they easily transit into CD27− effector memory T cells. Increased in vivo T cell stimulation observed in recipients with cGVHD further promotes the transition to effector memory cells, a change that decreases the central memory CD4+ T cell pool and consequently weakens the recipient’s defense against persistently infecting pathogens

Dynorphin induced magnetic ordering in lipid bilayers as studied by 31P NMR spectroscopy

AbstractLipid bilayers of dimyristoyl phosphatidylcholine (DMPC) containing opioid peptide dynorphin A(1–17) are found to be spontaneously aligned to the applied magnetic field near at the phase transition temperature between the gel and liquid crystalline states (Tm=24°C), as examined by 31P NMR spectroscopy. The specific interaction between the peptide and lipid bilayer leading to this property was also examined by optical microscopy, light scattering, and potassium ion-selective electrode, together with a comparative study on dynorphin A(1–13). A substantial change in the light scattering intensity was noted for DMPC containing dynorphin A(1–17) near at Tm but not for the system containing A(1–13). Besides, reversible change in morphology of bilayer, from small lipid particles to large vesicles, was observed by optical microscope at Tm. These results indicate that lysis and fusion of the lipid bilayers are induced by the presence of dynorphin A(1–17). It turned out that the bilayers are spontaneously aligned to the magnetic field above Tm in parallel with the bilayer surface, because a single 31P NMR signal appeared at the perpendicular position of the 31P chemical shift tensor. In contrast, no such magnetic ordering was noted for DMPC bilayers containing dynorphin A(1–13). It was proved that DMPC bilayer in the presence of dynorphin A(1–17) forms vesicles above Tm, because leakage of potassium ion from the lipid bilayers was observed by potassium ion-selective electrode after adding Triton X-100. It is concluded that DMPC bilayer consists of elongated vesicles with the long axis parallel to the magnetic field, together with the data of microscopic observation of cylindrical shape of the vesicles. Further, the long axis is found to be at least five times longer than the short axis of the elongated vesicles in view of simulated 31P NMR lineshape

genipinはTNF-αが誘導するヒト歯根膜細胞のMMP-1およびMMP-3産生を抑制する

Genipin, the aglycon of geniposide found in gardenia fruit has long been considered for treatment of inflammatory diseases in traditional oriental medicine. Genipin has recently been reported to have some pharmacological functions, such as antimicrobial, antitumor, and anti-inflammatory effects. The aim of this study was to examine whether genipin could modify matrix metalloproteinase (MMP)-1 and MMP-3, which are related to the destruction of periodontal tissues in periodontal lesion, expression in tumor necrosis factor (TNF)-a-stimulated human periodontal ligament cells (HPDLCs). Genipin prevented TNF-a- mediated MMP-1 and MMP-3 productions in HPDLCs. Moreover, genipin could suppress not only extracellular signal-regulated kinase (ERK) and Jun-N-terminal kinase (JNK) phosphorylations but also AMP-activated protein kinase (AMPK) phosphorylation in TNF-a-stimulated HPDLCs. Inhibitors of ERK and AMPK could inhibit both MMP-1 and MMP-3 productions. Moreover, we revealed the ERK inhibitor suppressed AMPK phosphorylation in TNF-a-stimulated HPDLCs. These data provide a new mechanism through which genipin could be used for the treatment of periodontal disease to prevent MMPs expression in periodontal lesion

Melatonin inhibits CXCL10 and MMP-1 production

Melatonin is a hormone that is mainly secreted by the pineal gland and exhibits a wide spectrum of activities, including antioxidant functions. Melatonin has been detected in gingival crevicular fluid. However, the role of melatonin in periodontal tissue is still uncertain. The aim of this study was to examine the effects of melatonin on inflammatory mediator expression in human periodontal ligament cells (HPDLC). Interleukin (IL)-1β induced CXC chemokine ligand (CXCL)10, matrix metalloproteinase (MMP)-1, and tissue inhibitors of metalloproteinase (TIMP)-1 production in HPDLC. Melatonin decreased CXCL10 and MMP-1 production and increased TIMP-1 production in IL-1β-stimulated HPDLC. Western blot analysis showed that melatonin inhibited p38 mitogen-activated protein kinase (MAPK) and c-jun N-terminal kinase (JNK) phosphorylation, and IκB-α degradation and phosphorylation in IL-1β-stimulated HPDLC. These results suggest that melatonin might inhibit Th1 cell migration by reducing CXCL10 production. Moreover, melatonin might inhibit soft tissue destruction by decreasing MMP-1 production in periodontal lesions

Gomisin N inhibits inflammatory cytokine production.

Gomisin N, which is a lignan isolated from Schisandra chinensis, has some pharmacological effects. However, the anti-inflammatory effects of gomisin N on periodontal disease are uncertain. The aim of this study was to examine the effect of gomisin N on inflammatory mediator production in tumor necrosis factor (TNF)-α-stimulated human periodontal ligament cells (HPDLC). Gomisin N inhibited interleukin (IL)-6, IL-8, CC chemokine ligand (CCL) 2, and CCL20 production in TNF-α-stimulated HPDLC in a dose-dependent manner. Moreover, we revealed that gomisin N could suppress extracellular signal-regulated kinase (ERK) and c-Jun N terminal kinase (JNK) phosphorylation in TNF-α-stimulated HPDLC though protein kinase B (Akt) phosphorylation was not suppressed by gomisin N treatment. In summary, gomisin N might exert antiinflammatory effects by attenuating cytokine production in periodontal ligament cells via inhibiting the TNF-α-stimulated ERK and JNK pathways activation

IL-29 enhances CXCL10 production

Interleukin-29 (IL-29) is a cytokine belonging to the type III interferon family. It was recently detected in the gingival crevicular fluid of periodontitis patients. However, the role of IL-29 in the pathogenesis of periodontal disease remains unknown. The aim of this study was to examine the effects of IL-29 on C-X-C motif chemokine ligand 10 (CXCL10) production in human oral epithelial cells. We measured CXCL10 production in TR146 cells, which is a human oral epithelial cell line, using an enzyme-linked immunosorbent assay. We used Western blot analysis to detect IL-29 receptor expression and the phosphorylation levels of signal transduction molecules, including p38 mitogen-activated protein kinases (MAPK), signal transducer and activator of transcription 3 (STAT3), and nuclear factor (NF)-κB p65, in the TR146 cells. The TR146 cells expressed the IL-29 receptor. IL-29 induced CXCL10 production in the TR146 cells. IL-29 significantly enhanced CXCL10 production in tumor necrosis factor (TNF)-α-stimulated TR146 cells. The p38 MAPK, STAT3, and NF-κB pathways were found to be related to the IL-29-induced enhancement of CXCL10 production in TNF-α-stimulated TR146 cells. IL-29 promotes T helper 1 cell accumulation in periodontal lesions by inducing CXCL10 production in oral epithelial cells

IL-4 Modulates Chemokine Productions in Fibroblast

Background/Aims: IL-4 is a multifunctional cytokine that is related with the pathological conditions of periodontal disease. However, it is uncertain whether IL-4 could control T cells migration in periodontal lesions. The aim of this study was to examine the effects of IL-4 on CCL11, which is a Th2-type chemokine, and CCL20, which is related with Th17 cells migration, productions from human periodontal ligament cells (HPDLCs). Methods: CCL20 and CCL11 productions from HPDLCs were monitored by ELISA. Western blot analysis was performed to detect phosphorylations of signal transduction molecules in HPDLCs. Results: IL-1β could induce both CCL11 and CCL20 productions in HPDLCs. IL-4 enhanced CCL11 productions from IL-1β-stimulated HPDLCs, though IL-4 inhibited CCL20 production. Western blot analysis showed that protein kinase B (Akt) and signal transducer and activator of transcription (STAT)6 pathways were highly activated in IL-4/IL-1β-stimulated HPDLCs. Akt and STAT6 inhibitors decreased CCL11 production, but enhanced CCL20 production in HPDLCs stimulated with IL-4 and IL-1β. Conclusions: These results mean that IL-4 enhanced Th2 cells migration in periodontal lesion to induce CCL11 production from HPDLCs. On the other hand, IL-4 inhibits Th17 cells accumulation in periodontally diseased tissues to inhibit CCL20 production. Therefore, IL-4 is positively related with the pathogenesis of periodontal disease to control chemokine productions in periodontal lesions

Shikonin inhibits inflammatory cytokine production

Shikonin, which is derived from Lithospermum erythrorhizon, a herb used in traditional medicine, has long been considered to be a useful treatment for various diseases in traditional oriental medicine. Shikonin has recently been reported to have several pharmacological properties, e.g., it has anti-microbial, anti-tumor, and anti-inflammatory effects. The aim of this study was to examine whether shikonin is able to influence the production of interleukin (IL)-6, IL-8, and/or chemokine C-C motif ligand (CCL)20, which contribute to the pathogenesis of periodontal disease, in human periodontal ligament cells (HPDLC). The production levels of IL-6, IL-8, and CCL20 in HPDLC were determined using an ELISA. Western blot analysis was used to detect nuclear factor kappa B (NF-κB) pathway activation in HPDLC. Shikonin prevented IL-1β- or tumor necrosis factor (TNF)-α-mediated IL-6, IL-8, and CCL20 production in HPDLC. Moreover, we found that shikonin suppressed the phosphorylation and degradation of inhibitor of kappa B-alpha (IκB-α) in IL-1β- or TNF-α-stimulated HPDLC. These findings suggest that shikonin could have direct beneficial effects against periodontal disease by reducing IL-6, IL-8, and CCL20 production in periodontal lesions

miR-1 and Tooth Development

Many genes encoding growth factors, receptors, and transcription factors are induced by the epithelial-mesenchymal interaction during tooth development. Recently, numerous functions of microRNAs (miRNAs) are reportedly involved in organogenesis and disease. miRNAs regulate gene expression by inhibiting translation and destabilizing mRNAs. However, the expression and function of miRNAs in tooth development remain poorly understood. This study aimed to analyze the expression of miRNAs produced during tooth development using a microarray system to clarify the role of miRNAs in dental development. miR-1 showed a unique expression pattern in the developing tooth. miR-1 expression in the tooth germ peaked on embryonic day 16.5, decreasing gradually on postnatal days 1 and 3. An in situ hybridization assay revealed that miR-1 is expressed at the cervical loop of the dental epithelium. The expression of miR-1 and connexin (Cx) 43, a target of miR-1, were inversely correlated both in vitro and in vivo. Knockdown of miR-1 induced the expression of Cx43 in dental epithelial cells. Interestingly, cells with miR-1 downregulation proliferated slower than the control cells. Immunocytochemistry revealed that Cx43 in cells with miR-1 knockdown formed both cell-cell gap junctions and hemichannels at the plasma membrane. Furthermore, the rate of ATP release was higher in cells with miR-1 knockdown than in control cells. Furthermore, Cx43 downregulation in developing molars was observed in Epiprofin-knockout mice, along with the induction of miR-1 expression. These results suggest that the expression pattern of Cx43 is modulated by miR-1 to control cell proliferation activity during dental epithelial cell differentiation

Neural stem cells transplantation in cortex in a mouse model of Alzheimer's disease

Objective. The goal of this study was to elucidate the effect of neurospheres (NS) on dementia in the mouse model of nucleus basalis of Meynert (NBM) lesion. Methods. Mouse embryonic stem cell (ES) derived neurospheres were transplanted into the frontal association cortex and barrel field of S1 cortex of C57BL/6mice 4weeks after including a lesion of NBM by ibotenic acid, while other healthy mice that received ES cells served as control. Behavioral tests by 8-armradial maze were conducted 8 weeks after transplantation, and double staining of choline acetyltransferase (ChAT), serotonin, amyloid-βprotein (AP) and green fluorescent protein(GFP)12 weeks after transplantation.We found that the neurospheres transplanted into the mouse cortex survived and produced many ChAT-positive neurons and a few serotoninpositive neurons in and around the grafts. The working memory error decreased significantly in the mice grafted with neurospheres. In contrast, the ES cells developed into teratomas in all of the control mice and expressed no neurons, and the working memory deteriorated remarkably. Conclusions. Transplantation of neurospheres, but not ES cells, into the prefrontal and parietal cortices, dramatically alleviated the cholinergic deficits and recent memory disruption in the NBM lesioned mice