Kinetic Formation of Pt-Pt Dimers of Cationic and Neutral Platinum(II) Complexes under Rapid Freeze Conditions in Solution.

We report the formation of M-M dimers (M = Pt or Pd) of cationic [M(dpb)(CH3CN)]+ [dpbH = 1,3-di(2-pyridyl)benzene] and neutral [M(dpb)Cl] complexes resulting from the rapid freezing of solutions. Dimers based on M-M dz2 overlap were found to preferentially form rather than the thermodynamically favored head-to-tail π-stacking structures typically observed in the crystalline state. Kinetic dimers in glassy frozen solutions generated broad metal-metal-to-ligand charge-transfer emissions within the range of 600-800 nm at 77 K. These emissions were red-shifted relative to monomer emissions. As expected, the degree of aggregation of these complexes was affected by the concentration in each solution. Photoexcitation evidently accelerated Pt-Pt dimerization even at ambient temperature. Electrostatic attraction between [Pt(dpb)Cl]+ and [Pt(dpb)Cl]- ions resulting from disproportionation due to photoinduced electron transfer is thought to have driven excimer formation. [Pt(dpb)(CH3CN)]OTf (OTf- = trifluoromethanesulfonate ion) and its Pd(II) analogue were determined to have isostructural crystals, but a Pd-Pd stacked polymorph was not observed and the photophysics of the two complexes are evidently different.

The Influence of 2-Methacryloyloxyethyl Phosphorylcholine Polymer Materials on Orthodontic Friction and Attachment of Oral Bacteria.

There is no clinical evidence of the usage of 2-methacryloyloxyethyl phosphorylcholine (MPC) polymers in dental practice. We performed in vitro studies to determine whether the application of an MPC coating to stainless steel orthodontic wires confers low-friction and antimicrobial properties to these wires. The friction test on MPC-coated wires was performed using a precision universal/tensile tester. MPC polymer was coated on a 50 × 50 mm stainless steel plate, and samples were assessed using an antimicrobial activity test. To verify the effect of MPC polymer-treated wires on experimental tooth movement models in vitro, examinations were performed on typodonts to determine the improvement in tooth movement efficiency. The polymer treatment wire groups demonstrated significantly enhanced tooth movement compared with the untreated wire groups, at both 50 g and 100 g traction forces. The results indicated that MPC coating inhibited the attachment of oral bacteria, such as Streptococcus mutans, on a stainless steel plate. Additionally, the coating seemed to improve the efficiency of tooth movement by reducing the occurrence of friction. The application of an MPC coating onto stainless steel wires, which are used as orthodontic materials, may reduce static friction and bacterial adherence to the oral cavity and improve tooth movement.

Hepatic insulin clearance is increased in patients with high HbA1c type 2 diabetes: a preliminary report.

INTRODUCTION: Hepatic insulin clearance (HIC) is an important pathophysiology of type 2 diabetes. HIC was reported to decrease in patients with type 2 diabetes and metabolic syndrome. However, hyperglycemia was suggested to enhance HIC, and it is not known whether poorly controlled diabetes increases HIC in patients with type 2 diabetes. We investigated whether HIC was increased in patients with poorly controlled diabetes, and whether HIC was associated with insulin resistance and incretins. RESEARCH DESIGN AND METHODS: We performed a meal tolerance test and the hyperinsulinemic-euglycemic clamp in 21 patients with type 2 diabetes. We calculated the postprandial C-peptide area under the curve (AUC)-to-insulin AUC ratio as the HIC; measured fasting and postprandial glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic polypeptide (GIP) and glucagon levels and analyzed serum adiponectin and zinc transporter-8 (ZnT8) gene polymorphism. RESULTS: The HIC significantly correlated with glycated hemoglobin (HbA1c) (r_S=0.58, p<0.01). In patients with high HIC above the median of 6.5, the mean HbA1c was significantly higher compared with low HIC below the median. Homeostatic model assessment (HOMA)-beta (r_S=-0.77, p<0.01) and HOMA-IR (r_S=-0.66, p<0.005) were correlated with HIC. The M/I value in the clamp study was correlated with HIC. GLP-1-AUC and GIP-AUC were not correlated with HIC. Glucagon-AUC was negatively correlated with HIC, but there were no significant differences between the high and low HIC groups. Adiponectin was positively correlated with HIC. The ZnT8 gene polymorphism did not affect HIC. CONCLUSIONS: These results suggest that HIC was increased in patients with high HbA1c type 2 diabetes, low insulin secretion, low insulin resistance and high adiponectin conditions.

Bone Regeneration in a Canine Model of Artificial Jaw Cleft Using Bone Marrow-Derived Mesenchymal Stem Cells and Carbonate Hydroxyapatite Carrier.

OBJECTIVE: Cleft lip and palate (CLP) is a common anomaly of the orofacial region. Mesenchymal stem cell (MSC) transplantation has been a focus of regenerative medicine, and its application to the repair of bone defects in patients with CLP is highly anticipated. This study investigated the potential for using MSCs to regenerate bone in a jaw cleft as well as the survival of transplanted MSCs using a canine model of CLP. DESIGN: Mesenchymal stem cells collected from the bone marrow of beagle dogs were transplanted along with carbonate hydroxyapatite into jaw clefts in beagle dogs. Mesenchymal stem cells labeled with fluorescent silica nanoparticles were also transplanted, and a histological analysis was performed 3 months later to evaluate MSC survival. RESULTS: Carbonate hydroxyapatite regeneration into bone was enhanced by cotransplantation of MSCs. The survival rate of MSCs transplanted after 3 months was 5.7%. CONCLUSIONS: Transplanted MSCs promote bone regeneration, although their survival rate is low.

Correction: Serum fatty acid-binding protein 4 (FABP4) concentration is associated with insulin resistance in peripheral tissues, A clinical study.

[This corrects the article DOI: 10.1371/journal.pone.0179737.].

The effect of mesenchymal stem cells on osteoclast precursor cell differentiation.

Transplantation of mesenchymal stem cells (MSCs) has been extensively studied in the field of regenerative medicine. Bone regeneration is achieved via the interaction of osteoblasts and osteoclasts. However, the influence of MSCs on osteoclasts is unknown. The purpose of this study was to investigate the effect of MSCs on the expression of genes for osteoclast differentiation factors using qPCR after indirect co-culture of MSCs and RAW264 cells. The numbers of osteoclasts after addition of soluble receptor activator of nuclear factor kappa B (NF-κB) ligand (sRANKL) were also compared. Expression of osteoprotegerin (OPG) by MSCs was significantly elevated in co-culture over time. The differentiation of RAW264 cells into mature osteoclasts following addition of sRANKL was significantly inhibited by co-culture with MSCs. Expression of RANK, colony stimulating factor 1 receptor, NF-κB, and nuclear factor of activated T-cell cytoplasmic 1 in RAW264 cells was significantly inhibited by co-culture with MSCs. Expression of OPG protein was higher in co-culture with RAW264 cells than in MSCs alone, and the expression level was clearly higher than that of RANKL. MSCs appeared to inhibit osteoclast differentiation via expression of OPG.

Effects of Human Full-length Amelogenin and C-terminal Amelogenin Peptide on the Proliferation of Human Mesenchymal Stem Cells Derived from Adipose Tissue.

Amelogenins are enamel matrix proteins that play crucial roles in enamel formation. Previous studies have indicated that amelogenin and amelogenin C-terminal peptides have cell-signaling functions. Recently, adipocyte-derived mesenchymal stem cells (ADSCs) have received attention as a potential source of stem cells for use in regeneration therapy. In this study, we examined the effects of human full-length amelogenin (rh174) and amelogenin C-terminal peptide (amgCP) on the proliferation of ADSCs. ADSCs were cultured in the presence of amgCP or rh174. Cell proliferation was analyzed using BrdU immunoassay and MTS assay. Cell migration was evaluated by ELISA. The MAPK-ERK pathway was examined by phospho-p44/42 MAPK (Thr202/Tyr204) sandwich ELISA and western blotting. A specific MAPK inhibitor, U0126, was used to block ERK activity. ADSC proliferation and migration were significantly (P < 0.05) increased in the presence of rh174 or amgCP compared to non-treated control cells. The increased proliferation of ADSCs induced by rh174 or amgCP was significantly (P < 0.05) inhibited in the presence of 2 µg/ml U0126. The pERK/tERK ratio was significantly (P < 0.05) increased upon treatment with rh174 or amgCP compared to non-treated ADSCs, while this increase was significantly (P < 0.05) suppressed by the addition of U0126. Similar results were found by western blot analysis. In conclusion, amgCP and rh174 increase ADSC proliferation via the MAPK-ERK signaling pathway, and ADSCs may be useful for tissue regeneration in the orofacial region.

Body mass index ≥23 is a risk factor for insulin resistance and diabetes in Japanese people: A brief report.

BACKGROUND: Screening for undiagnosed type 2 diabetes mellitus is recommended for Asian Americans with a body mass index ≥23. However, the optimal body mass index cut-off score for predicting the risk of diabetes mellitus in Japanese people is not well known. The aim of this study was to determine the best body mass index cut-off score for predicting insulin resistance and diabetes mellitus in the Japanese population. METHODS: This study had two parts, a clinical investigation and a retrospective observational investigation. In the clinical part of the study, 58 participants (26 with type 2 diabetes mellitus and 32 non-diabetics) underwent a hyperinsulinemic-euglycemic clamp from which their glucose disposal rate was measured. For the retrospective part of the study, medical check-up data from 88,305 people in the Tottori Prefecture were analyzed for clinical evidence of diabetes mellitus. The optimal BMI cut-off scores for prediction of insulin resistance and diabetes mellitus were determined. RESULTS: In the clamp study, the optimal body mass index cut-off score to predict insulin resistance in non-diabetic patients was 22.7. All participants with type 2 diabetes mellitus were insulin resistant, and the optimal body mass index cut-off score for prediction of severe insulin resistance was 26.2. When the data from the type 2 diabetic and the non-diabetic participants were combined, the optimal body mass index cut-off score for prediction of insulin resistance was 23.5. Analysis of 88,305 medical check-up records yielded an optimal body mass index cut-off score for prediction of diabetes mellitus of 23.6. CONCLUSIONS: These results suggest that having a body mass index ≥23 is a risk factor for insulin resistance and diabetes mellitus in the Japanese population.

The effect of mesenchymal stem cells on chemotaxis of osteoclast precursor cells.

Regeneration of tissue, including bone, using mesenchymal stem cells (MSCs) has been progressing rapidly. Regeneration of bone requires the presence of an appropriate environment and efficient chemotaxis of cells to the target site. Differentiation of MSCs into mesenchymal cells has received considerable attention, but the effect of MSCs on chemotaxis is not well understood. In this study, we investigated the effect of MSCs on chemotaxis of RAW264 cells via C-C motif chemokine ligand 2 (CCL2). Balb/c mouse bone marrow-derived MSCs and RAW264 cells, which are osteoclast precursor cells, were co-cultured without cell contact. The gene expression of CCL2 in MSCs and CC-chemokine receptor 2 (CCR2) in RAW264 cells was determined using quantitative real-time PCR. Analysis of RAW264 cell chemotaxis was performed using the Boyden chamber assay. mRNAs for CCL2 and CCR2 were significantly upregulated upon co-culture in comparison to culture of either cell type alone, and the number of chemotactic RAW264 cells was significantly increased by co-culture. MSCs enhanced the chemotaxis of RAW264 cells, possibly via CCL2-CCR2 interaction, suggesting the potential utility of MSCs for tissue regeneration.

Coenzyme Q10 suppresses apoptosis of mouse pancreatic ß-cell line MIN6.

BACKGROUND: In mitochondrial diabetes, apoptosis of ß-cells caused by mitochondrial stress plays an important role in impaired insulin secretion. Several studies have reported that coenzyme Q10 (CoQ10) has therapeutic effects on mitochondrial diabetes, but no reports have examined the fundamental effectiveness or mechanism of CoQ10 in mitochondrial diabetes. We previously reported in a Japanese article that CoQ10 has protective effects on pancreatic ß-cells against mitochondrial stress using mouse pancreatic ß-cell line MIN6 and staurosporine (STS). Here, we report that CoQ10 protects MIN6 cells against apoptosis caused by STS and describe the more detailed apoptotic cascade. METHODS: Apoptosis of MIN6 cells was induced by 0.5 µM STS treatment for specific periods with or without 30 µM CoQ10. The apoptosis cascade in MIN6 cells was then investigated using WST-8 assays, annexin-V staining, western blotting, and DNA degradation analysis. RESULTS: Sixteen hours of 0.5 µM STS treatment led to 47% cell viability, but pretreatment with 30 µM CoQ10 resulted in significantly higher viability of 76% (P < 0.01). CoQ10 also prevented translocation of phosphatidylserine from the inner leaflet to the outer leaflet of the cell membrane. CoQ10 prevented cytochrome c release from mitochondria and activation of caspase-3. CONCLUSION: We concluded that CoQ10 protects pancreatic ß-cells through anti-apoptotic effects against STS treatment.

CPR-IR is an insulin resistance index that is minimally affected by hepatic insulin clearance-A preliminary research.

BACKGROUND: Increased hepatic insulin clearance (HIC) is important in the pathophysiology of type 2 diabetes mellitus (T2DM). The aim of this study is to analyze an effective insulin resistance (IR) index that is minimally affected by HIC. METHODS: Our study involved 20 participants with T2DM and 21 healthy participants without diabetes (Non-DM). Participants underwent a meal tolerance test from which plasma glucose, insulin and serum C-peptide immunoreactivity (CPR) were measured, and HOMA-IR and HIC were calculated. Participants then underwent a hyperinsulinemic-euglycemic clamp from which the glucose disposal rate (GDR) was measured. RESULTS: The index CPR-IR = 20/(fasting CPR × fasting plasma glucose) was correlated more strongly with GDR, than was HOMA-IR, and CPR-IR could be used to estimate GDR. In T2DM participants with HIC below the median, HOMA-IR and CPR-IR were equally well correlated with GDR. In T2DM with high HIC, CPR-IR correlated with GDR while HOMA-IR did not. In Non-DM, CPR-IR and HOMA-IR were equally well correlated with GDR regardless of HIC. The mean HIC value in T2DM was significantly higher than that of Non-DM. CONCLUSIONS: CPR-IR could be a simple and effective index of insulin resistance for patients with type 2 diabetes that is minimally affected by HIC.

The C-terminus of the amelogenin peptide influences the proliferation of human bone marrow mesenchymal stem cells.

BACKGROUND: Amelogenins are a family of enamel matrix proteins that are important for formation of enamel. Amelogenins may induce division of mesenchymal stem cells (MSCs), among others. Recently, the C-terminus of the amelogenin peptide (AMG-CP) has been shown to enhance the proliferation of cementoblast lineage cells. The role of the amelogenin peptide on the proliferation of human MSCs and related alterations in the intracellular signaling pathway were studied. METHODS: MSCs were exposed to AMG-CP in vitro. The MTS and 5-bromo-2'-deoxyuridine (BrdU) assays were used to determine proliferation. Expression of the amelogenin receptor, lysosomal-associated membrane protein 1 (LAMP1), was examined in MSCs with western blotting. Binding of AMG-CP to LAMP1 was inhibited with anti-LAMP1 antibody. Components of the mitogen-activated protein kinase (MAPK)-extracellular signal-regulated kinase (ERK) pathway were studied with western blotting and enzyme-linked immunosorbent assay, and U0126, an MAPK inhibitor, was used to inhibit ERK activity. RESULTS: MSC proliferation was significantly increased in the presence of AMG-CP and significantly inhibited by anti-LAMP1 antibody or U0126. Increased phosphorylated ERK1/2 was observed in the presence of AMG-CP, and decreased phosphorylated ERK1/2 was seen in the presence of anti-LAMP1 antibody or U0126. CONCLUSION: A C-terminal amelogenin variant increased the proliferation of MSCs via an interaction with LAMP1 and the MAPK-ERK signaling pathway, indicating the possibility of using MSCs for tissue regeneration in the craniofacial region.

Effect of high-frequency near-infrared diode laser irradiation on periodontal tissues during experimental tooth movement in rats.

BACKGROUND AND OBJECTIVES: Tooth movement during orthodontic treatment is associated with bone neoplasticity and bone resorption on the tension and pressure sides. Previous clinical studies have suggested that low-power laser irradiation can accelerate tooth movement during orthodontic treatment, although the underlying mechanism remains unclear. In this study, we used a high-frequency near-infrared diode laser that generates less heat and examined the histologic changes in periodontal tissue during experimental tooth movement with laser irradiation. METHODS: A nickel-titanium closed coil was mounted between the maxillary left side first molar and incisor of rats to model experimental tooth movement. The laser-irradiation and the control groups were set, and the amount of movement of the first molar on 7th and 14th days after the start of pulling of the first molar tooth on the maxillary left was measured by three-dimensional analysis of µCT. After tooth movement, tissue samples from the mesial and tension sides were collected, and successive horizontal sections were prepared and examined using hematoxylin-eosin and TRAP staining and immunohistochemical staining for RANKL, OPG, ALP, and proliferating cell nuclear antigen (PCNA). Changes in tissue temperature following laser irradiation were also examined. RESULTS: Laser irradiation significantly increased tooth movement compared with non-irradiated controls. Histologic staining of the pressure-side mesial root in laser-irradiated rats revealed enhanced RANKL expression and increased numbers of TRAP-positive cells compared with controls. By contrast, on the tension side, laser irradiation led to increased expression of ALP and PCNA. These data indicate that high-frequency near-infrared diode laser irradiation on the pressure side upregulates RANKL expression and accelerates osteoclast differentiation, facilitating bone resorption, whereas bone formation is induced on the tension side. CONCLUSION: This study demonstrates that high-frequency near-infrared diode laser irradiation of periodontal tissue leads to metabolic activation, which ultimately increases the rate of tooth movement. Lasers Surg. Med. © 2018 Wiley Periodicals, Inc.

Effects of high-frequency near-infrared diode laser irradiation on the proliferation and migration of mouse calvarial osteoblasts.

Laser irradiation activates a range of cellular processes and can promote tissue repair. Here, we examined the effects of high-frequency near-infrared (NIR) diode laser irradiation on the proliferation and migration of mouse calvarial osteoblastic cells (MC3T3-E1). MC3T3-E1 cells were cultured and exposed to high-frequency (30 kHz) 910-nm diode laser irradiation at a dose of 0, 1.42, 2.85, 5.7, or 17.1 J/cm2. Cell proliferation was evaluated with BrdU and ATP concentration assays. Cell migration was analyzed by quantitative assessment of wound healing using the Incucyt® ZOOM system. In addition, phosphorylation of mitogen-activated protein kinase (MAPK) family members including p38 mitogen-activated protein kinase (p38), stress-activated protein kinase/Jun-amino-terminal kinase (SAPK/JNK), and extracellular signal-regulated protein kinase (ERK)1/2) after laser irradiation was examined with western blotting. Compared to the control, cell proliferation was significantly increased by laser irradiation at a dose of 2.85, 5.7, or 17.1 J/cm2. Laser irradiation at a dose of 2.85 J/cm2 induced MC3T3-E1 cells to migrate more rapidly than non-irradiated control cells. Irradiation with the high-frequency 910-nm diode laser at a dose of 2.85 J/cm2 induced phosphorylation of MAPK/ERK1/2 15 and 30 min later. However, phosphorylation of p38 MAPK and SAPK/JNK was not changed by NIR diode laser irradiation at a dose of 2.85 J/cm2. Irradiation with a high-frequency NIR diode laser increased cell division and migration of MT3T3-E1 cells, possibly via MAPK/ERK signaling. These observations may be important for enhancing proliferation and migration of osteoblasts to improve regeneration of bone tissues.

Dynamic imaging of the effect of mesenchymal stem cells on osteoclast precursor cell chemotaxis for bone defects in the mouse skull.

BACKGROUND/PURPOSE: Mesenchymal stem cells (MSCs) transplantation has previously been used in the field of regenerative medicine. Although bone regeneration is known to occur through the interaction between osteoblasts and osteoclasts, the effect of MSCs on osteoclasts is unknown. Therefore, the purpose of this study was to investigate the effect of MSCs on the chemotaxis of osteoclast precursor cells (RAW264 macrophage cells). MATERIALS AND METHODS: Bone defects were created in mice skulls, and MSCs and a scaffold of carbonated hydroxyapatite were transplanted into the bone defects. RAW264 cells were then transplanted into the mouse tail vein, and their dynamics were observed by an in vivo imaging system. RESULTS: The fluorescent intensity of the MSCs transplant group at the bone defect region was significantly higher on days 3, 5, and 7 compared with the MSCs non-transplant group. CONCLUSION: Increased RAW264 chemotaxis to the bone defect region occurred following the simultaneous implantation of MSCs in the skull defect.

Normal meal tolerance test is preferable to the glucagon stimulation test in patients with type 2 diabetes that are not in a hyperglycemic state: Comparison with the change of C-peptide immunoreactivity.

AIMS/INTRODUCTION: The aim of the present study was to evaluate the properties of the glucagon stimulation test (GST) and the normal meal tolerance test (NMTT) in patients with type 2 diabetes. MATERIALS AND METHODS: We enrolled 142 patients with type 2 diabetes, and carried out a GST and a NMTT. We carried out the NMTT using a calorie-controlled meal based on an intake of 30 kcal/kg ideal bodyweight/day. We calculated the change in C-peptide immunoreactivity (ΔCPR) by subtracting fasting CPR from the CPR 6 min after the 1-mg glucagon injection (GST) or 120 min after the meal (NMTT). RESULTS: Mean ΔCPR for the GST was 2.0 ng/mL, and for the NMTT was 3.1 ng/mL. A total of 104 patients had greater ΔCPR in the NMTT than the GST, and the mean ΔCPR was significantly greater in the NMTT than the GST (P < 0.05). To exclude any influence of antidiabetic drugs, we examined 42 individuals not taking antidiabetic agents, and found the mean ΔCPR was significantly greater in the NMTT than the GST (GST 2.4 ng/mL, NMTT 4.3 ng/mL; P < 0.05). To consider the influence of glucose toxicity, we carried out receiver operating characteristic analyses with fasting plasma glucose and glycated hemoglobin. The optimal cut-off levels predicting GST ΔCPR to be larger than NMTT ΔCPR were fasting plasma glucose 147 mg/dL and glycated hemoglobin 9.0% (fasting plasma glucose: sensitivity 0.64, specificity 0.76, area under the curve 0.73; glycated hemoglobin: sensitivity 0.56, specificity 0.71, area under the curve 0.66). CONCLUSIONS: The NMTT is a reliable insulin secretion test in patients with type 2 diabetes, except for those in a hyperglycemic state.

High Serum Advanced Glycation End Products Are Associated with Decreased Insulin Secretion in Patients with Type 2 Diabetes: A Brief Report.

OBJECTIVE: Advanced glycation end products (AGEs) are important in the pathophysiology of type 2 diabetes mellitus (T2DM). They directly cause insulin secretory defects in animal and cell culture models and may promote insulin resistance in nondiabetic subjects. We have developed a highly sensitive liquid chromatography-tandem mass spectrometry method for measuring AGEs in human serum. Here, we use this method to investigate the relationship between AGEs and insulin secretion and resistance in patients with T2DM. METHODS: Our study involved 15 participants with T2DM not on medication and 20 nondiabetic healthy participants. We measured the AGE carboxyethyllysine (CEL), carboxymethyllysine (CML), and methyl-glyoxal-hydro-imidazolone (MG-H1). Plasma glucose and insulin were measured in these participants during a meal tolerance test, and the glucose disposal rate was measured during a euglycemic-hyperinsulinemic clamp. RESULTS: CML and CEL levels were significantly higher in T2DM than non-DM participants. CML showed a significant negative correlation with insulin secretion, HOMA-%B, and a significant positive correlation with the insulin sensitivity index in T2DM participants. There was no correlation between any of the AGEs measured and glucose disposal rate. CONCLUSIONS: These results suggest that AGE might play a role in the development or prediction of insulin secretory defects in type 2 diabetes.

Serum fatty acid-binding protein 4 (FABP4) concentration is associated with insulin resistance in peripheral tissues, A clinical study.

Type 2 diabetes mellitus (T2DM) is caused by insulin resistance and ß cell dysfunction. In recent studies reported that several markers associated with insulin sensitivity in skeletal muscle, Adiponectin and other parameters, such as fatty acid-binding protein (FABP4), have been reported to regulate insulin resistance, but it remains unclear which factor mostly affects insulin resistance in T2DM. In this cross-sectional study, we evaluated the relationships between several kinds of biomarkers and insulin resistance, and insulin secretion in T2DM and healthy controls. We recruited 30 participants (12 T2DM and 18 non-diabetic healthy controls). Participants underwent a meal tolerance test during which plasma glucose, insulin and serum C-peptide immunoreactivity were measured. We performed a hyperinsulinemic-euglycemic clamp and measured the glucose-disposal rate (GDR). The fasting serum levels of adiponectin, insulin-like growth factor-1, irisin, autotaxin, FABP4 and interleukin-6 were measured by ELISA. We found a strong negative correlation between FABP4 concentration and GDR in T2DM (r = -0.657, p = 0.020). FABP4 also was positively correlated with insulin secretion during the meal tolerance test in T2DM (IRI (120): r = 0.604, p = 0.038) and was positively related to the insulinogenic index in non-DM subjects (r = 0.536, p = 0.022). Autotaxin was also related to GDR. However, there was no relationship with insulin secretion. We found that serum FABP4 concentration were associated with insulin resistance and secretion in T2DM. This suggests that FABP4 may play an important role in glucose homeostasis.

Effects of C-terminal amelogenin peptides on the metabolism of osteoblasts.

OBJECTIVES: Amelogenins, enamel matrix proteins secreted by ameloblasts, comprise 90% of the developing extracellular enamel matrix. Recent evidence suggests that amelogenins might induce the proliferation of various cells. However, the residues comprising the active site of amelogenin remain unclear. Therefore, this study aimed to examine the effects of a human amelogenin C-terminal peptide (amgCP) on the metabolism of osteoblasts. MATERIALS AND METHODS: Mouse calvarial osteoblastic cells (MC3T3-E1) were cultured and treated with amgCP. Cell proliferation was measured using MTS and BrdU assays. After confluence was reached, the cells were cultured in osteogenic differentiation medium and treated with 0, 100, or 1000 ng/ml amgCP. Cell differentiation activity was examined by real-time PCR, western blotting, and ALP activity. Mineralization was evaluated by Alizarin red staining. RESULTS: Cell numbers of MC3T3-E1 were significantly (P < 0.05) increased by treatment with 1000 ng/ml amgCP as compared to the control group at 4 and 6 days. In addition, the proliferative activity of MC3T3-E1 was significantly enhanced by treatment with 100 or 1000 ng/ml amgCP. The mRNA levels and protein expressions of ALP and BSP were not changed by treatment with amgCP as compared to the non-treated controls on days 7 and 14. The osteogenic differentiation of MC3T3-E1 cells was not affected by treatment with amgCP as compared with untreated controls. CONCLUSION: The C-terminus of amelogenin promotes the proliferation of MC3T3-E1 cells, indicating the possible utility of the C11 peptide in bone-tissue regeneration.

Implications of FoxP3-positive and -negative CD4(+) CD25(+) T cells in Graves' ophthalmopathy.

Graves' ophthalmopathy (GO) is a common manifestation of Graves' disease (GD); however, its pathogenesis is not well understood. Recently, the dysregulation of regulatory T cells (Tregs) has been thought to be closely associated with the pathogenesis and clinical symptoms of autoimmune disease. We therefore evaluated whether T cell subsets, including Tregs, are associated with GO pathogenesis and clinical symptoms. In this observational study we evaluated 35 GD patients with overt ophthalmopathy (GOs) and 28 patients without ophthalmopathy (non-GOs). Fifteen healthy euthyroid patients served as healthy controls (HCs). Peripheral blood mononuclear cells from GOs, non-GOs and HCs were analyzed for CD4, CD25, and FoxP3 expression using flow cytometry. We also evaluated their correlation with disease activity according to the clinical activity score (CAS) and magnetic resonance imaging (MRI) findings. Disease severity was evaluated using the NOSPECS score, and clinical progression of GO was followed for 24 weeks. The main outcome measures were the frequencies of FoxP3-positive and -negative CD4(+) CD25(+) T cells at study outset, namely Tregs and effector T cells (Teffs), respectively. GOs had higher frequencies of Teffs (30.8±8.4%) than non-GOs (19.4±7.1%) and HCs (22.7±7.9%). Notably, patients with improved GOs had lower frequencies of Tregs (5.8±1.1%) than patients with stable or deteriorated GOs (7.3±1.2%), although ophthalmic and radiological parameters were not significantly different at the start of the study. In conclusion, an expanded Teff population may be associated with GO pathogenesis. Additionally, decreased Tregs in peripheral blood may predict a good clinical outcome.