Differential diagnosis of MCI with Lewy bodies and MCI due to Alzheimer's disease by visual assessment of occipital hypoperfusion on SPECT images.

PURPOSE: Predicting progression of mild cognitive impairment (MCI) to Alzheimer's disease (AD) or dementia with Lewy bodies (DLB) is important. We evaluated morphological and functional differences between MCI with Lewy bodies (MCI-LB) and MCI due to AD (MCI-AD), and a method for differentiating between these conditions using brain MRI and brain perfusion SPECT. METHODS: A continuous series of 101 subjects, who had visited our memory clinic and met the definition of MCI, were enrolled retrospectively. They were consisted of 60 MCI-LB and 41 MCI-AD subjects. Relative cerebral blood flow (rCBF) on SPECT images and relative brain atrophy on MRI images were evaluated. We performed voxel-based analysis and visually inspected brain perfusion SPECT images for regional brain atrophy, occipital hypoperfusion and the cingulate island sign (CIS), for differential diagnosis of MCI-LB and MCI-AD. RESULTS: MRI showed no significant differences in regional atrophy between the MCI-LB and MCI-AD groups. In MCI-LB subjects, occipital rCBF was significantly decreased compared with MCI-AD subjects (p < 0.01, family wise error [FWE]-corrected). Visual inspection of occipital hypoperfusion had sensitivity, specificity, and accuracy values of 100%, 73.2% and 89.1%, respectively, for differentiating MCI-LB and MCI-AD. Occipital hypoperfusion was offered higher diagnostic utility than the CIS. CONCLUSIONS: The occipital lobe was the region with significantly decreased rCBF in MCI-LB compared with MCI-AD subjects. Occipital hypoperfusion on brain perfusion SPECT may be a more useful imaging biomarker than the CIS for visually differentiating MCI-LB and MCI-AD.

Beneficial Effects of Low-Intensity Pulsed Ultrasound Therapy on Right Ventricular Dysfunction in Animal Models.

Right ventricular failure (RVF) is a leading cause of death in patients with pulmonary hypertension; however, effective treatment remains to be developed. We have developed low-intensity pulsed ultrasound therapy for cardiovascular diseases. In this study, we demonstrated that the expression of endothelial nitric oxide synthase (eNOS) in RVF patients was downregulated and that eNOS expression and its downstream pathway were ameliorated through eNOS activation in 2 animal models of RVF. These results indicate that eNOS is an important therapeutic target of RVF, for which low-intensity pulsed ultrasound therapy is a promising therapy for patients with RVF.

A Pilot Study of Whole-Brain Low-Intensity Pulsed Ultrasound Therapy for Early Stage of Alzheimer's Disease (LIPUS-AD): A Randomized, Double-Blind, Placebo-Controlled Trial.

The prevalence of Alzheimer's disease (AD) has been rapidly increasing worldwide. We have developed a novel angiogenic therapy with low-intensity pulsed ultrasound (LIPUS), which is effective and safe in animal models of AD and vascular dementia. We performed two trials of LIPUS therapy for AD (mild cognitive impairment due to AD and mild AD); a roll-in open trial for safety, and a randomized, double-blind, placebo-controlled (RCT) trial for efficacy and safety. The LIPUS therapy was performed for whole brain through the bilateral temporal bones for one hour 3 times a week as one session under the special conditions (1.3 MPa, 32 cycles, 5% duty cycle) we identified. The LIPUS therapy was performed for one session in the roll-in trial, and 6 sessions in the RCT trial with 3-month intervals for 1.5 years. The primary endpoint was ADAS-J cog scores. The RCT trial was terminated prematurely due to the COVID-19 pandemic. In the roll-in trial (N = 5), no adverse effects were noted. In the RCT trial (N = 22), the worsening of ADAS-J cog scores tended to be suppressed in the LIPUS group compared with the placebo group at week 72 (P = 0.257). When responders were defined as those with no worsening of ADAS-J cog scores at week 72, the prevalence was 50% (5/10) and 0% (0/5) in the LIPUS and placebo groups, respectively (P = 0.053). No adverse effects were noted. These results suggest that the LIPUS therapy is safe and tends to suppress cognitive impairment although a next pivotal trial with a large number of subjects is warranted.

Correlation between noise pareidolia test scores for visual hallucinations and regional cerebral blood flow in dementia with Lewy bodies.

OBJECTIVE: This study aimed at investigating the correlation between recurrent visual hallucinations (VHs) and regional cerebral blood flow (rCBF) in patients with dementia with Lewy bodies (DLB). METHODS: In 147 DLB patients, the correlation between noise pareidolia scores and rCBF in brain perfusion single photon emission computed tomography (SPECT) was evaluated. The 147 subjects comprised 52 probable and 95 possible DLB patients, of whom 107 did not have visual hallucinations and 40 had visual hallucinations. Brain perfusion SPECT was then performed, and memory impairment was assessed using the Mini-Mental State Examination (MMSE), while the optical illusion "pareidolia" (the tendency to see a specific image in a random visual pattern) was evaluated using noise pareidolia test. The correlations between rCBF and MMSE or noise pareidolia scores were then analyzed. RESULTS: The rCBF and MMSE scores were positively correlated, and rCBF was correlated with MMSE scores in a region that was consistent with a previously reported memory-related site. There was no correlation between noise pareidolia scores and occipital CBF, but there were weak correlations between noise pareidolia scores and rCBF in the bilateral frontal lobes (Brodmann area [BA]8 and BA9), left cingulate cortex (BA31), and left angular and supramarginal gyri (BA39 and BA40) in DLB patients. CONCLUSION: Weak correlation was found between noise pareidolia scores and rCBF in several sites (BA8, BA9, BA31, BA39 and BA40) other than in occipital lobe. These findings suggest that DLB hallucinations may be manifested by more complex brain network disorders, rather than by primary visual cortex disorders alone.

Low-intensity pulsed ultrasound therapy promotes recovery from stroke by enhancing angio-neurogenesis in mice in vivo.

Since the treatment window of thrombolytic therapy for stroke is limited, new therapy remains to be developed. We have recently developed low-intensity pulsed ultrasound (LIPUS) therapy to improve cognitive dysfunction in mouse models of vascular dementia and Alzheimer's disease. Here, we further aimed to examine whether our LIPUS therapy improves neurological recovery from ischemic stroke, and if so, to elucidate the mechanisms involved. In a mouse model of middle cerebral artery occlusion (MCAO), we applied LIPUS (32 cycles, 193 mW/cm2) to the whole brain 3 times in the first week (days 1, 3, and 5) after MCAO. We evaluated neurological functions using behavioral tests and performed histological analyses. Furthermore, to elucidate how LIPUS works within the injured brain, we also tested the effects of LIPUS in endothelial nitric oxide synthase (eNOS)-deficient (eNOS-/-) mice. In wild-type mice, the LIPUS therapy markedly improved neurological functions in the tightrope and rotarod tests at 28 days after MCAO. Histological analyses showed that the LIPUS therapy significantly increased the numbers of CD31-positive blood vessels in the perifocal lesion and doublecortin (DCX)-positive neurons in the ischemic striatum, indicating the angio-neurogenesis effects of the therapy. Importantly, these beneficial effects of the LIPUS therapy were totally absent in eNOS-/- mice. No adverse effects of the LIPUS therapy were noted. These results indicate that the LIPUS therapy improves neurological functions after stroke through enhanced neuro-angiogenesis in mice in vivo in an eNOS-dependent manner, suggesting that it could a novel and non-invasive therapeutic option for stroke.

Identification of Celastrol as a Novel Therapeutic Agent for Pulmonary Arterial Hypertension and Right Ventricular Failure Through Suppression of Bsg (Basigin)/CyPA (Cyclophilin A).

OBJECTIVE: Pulmonary arterial hypertension is characterized by abnormal proliferation of pulmonary artery smooth muscle cells and vascular remodeling, which leads to right ventricular (RV) failure. Bsg (Basigin) is a transmembrane glycoprotein that promotes myofibroblast differentiation, cell proliferation, and matrix metalloproteinase activation. CyPA (cyclophilin A) binds to its receptor Bsg and promotes pulmonary artery smooth muscle cell proliferation and inflammatory cell recruitment. We previously reported that Bsg promotes cardiac fibrosis and failure in the left ventricle in response to pressure-overload in mice. However, the roles of Bsg and CyPA in RV failure remain to be elucidated. Approach and Results: First, we found that protein levels of Bsg and CyPA were upregulated in the heart of hypoxia-induced pulmonary hypertension (PH) in mice and monocrotaline-induced PH in rats. Furthermore, cardiomyocyte-specific Bsg-overexpressing mice showed exacerbated RV hypertrophy, fibrosis, and dysfunction compared with their littermates under chronic hypoxia and pulmonary artery banding. Treatment with celastrol, which we identified as a suppressor of Bsg and CyPA by drug screening, decreased proliferation, reactive oxygen species, and inflammatory cytokines in pulmonary artery smooth muscle cells. Furthermore, celastrol treatment ameliorated RV systolic pressure, hypertrophy, fibrosis, and dysfunction in hypoxia-induced PH in mice and SU5416/hypoxia-induced PH in rats with reduced Bsg, CyPA, and inflammatory cytokines in the hearts and lungs. CONCLUSIONS: These results indicate that elevated Bsg in pressure-overloaded RV exacerbates RV dysfunction and that celastrol ameliorates RV dysfunction in PH model animals by suppressing Bsg and its ligand CyPA. Thus, celastrol can be a novel drug for PH and RV failure that targets Bsg and CyPA. Graphic Abstract: A graphic abstract is available for this article.

Low-intensity pulsed ultrasound ameliorates cardiac diastolic dysfunction in mice: a possible novel therapy for heart failure with preserved left ventricular ejection fraction.

AIMS: Heart failure with preserved left ventricular ejection fraction (HFpEF) is a serious health problem worldwide, as no effective therapy is yet available. We have previously demonstrated that our low-intensity pulsed ultrasound (LIPUS) therapy is effective and safe for angina and dementia. In this study, we aimed to examine whether the LIPUS therapy also ameliorates cardiac diastolic dysfunction in mice. METHODS AND RESULTS: Twelve-week-old obese diabetic mice (db/db) and their control littermates (db/+) were treated with either the LIPUS therapy [1.875 MHz, 32 cycles, Ispta (spatial peak temporal average intensity) 117-162 mW/cm2, 0.25 W/cm2] or placebo procedure two times a week for 4 weeks. At 20-week-old, transthoracic echocardiography and invasive haemodynamic analysis showed that cardiac diastolic function parameters, such as e', E/e', end-diastolic pressure-volume relationship, Tau, and dP/dt min, were all deteriorated in placebo-treated db/db mice compared with db/+ mice, while systolic function was preserved. Importantly, these cardiac diastolic function parameters were significantly ameliorated in the LIPUS-treated db/db mice. We also measured the force (F) and intracellular Ca2+ ([Ca2+]i) in trabeculae dissected from ventricles. We found that relaxation time and [Ca2+]i decay (Tau) were prolonged during electrically stimulated twitch contractions in db/db mice, both of which were significantly ameliorated in the LIPUS-treated db/db mice, indicating that the LIPUS therapy also improves relaxation properties at tissue level. Functionally, exercise capacity was also improved in the LIPUS-treated db/db mice. Histologically, db/db mice displayed progressed cardiomyocyte hypertrophy and myocardial interstitial fibrosis, while those changes were significantly suppressed in the LIPUS-treated db/db mice. Mechanistically, western blot showed that the endothelial nitric oxide synthase (eNOS)-nitric oxide (NO)-cGMP-protein kinase G (PKG) pathway and Ca2+-handling molecules were up-regulated in the LIPUS-treated heart. CONCLUSIONS: These results indicate that the LIPUS therapy ameliorates cardiac diastolic dysfunction in db/db mice through improvement of eNOS-NO-cGMP-PKG pathway and cardiomyocyte Ca2+-handling system, suggesting its potential usefulness for the treatment of HFpEF patients.

Sudden failure of ventricular pacing and recovery in a patient with cardiac sarcoidosis.

A 76-year-old woman with sarcoidosis who had an implantable pacemaker for complete atrioventricular block was admitted with syncope. Electrocardiogram revealed ventricular pacing failure, and a marked rise in the ventricular pacing threshold. 18F-Fluorodeoxyglucose positron emission tomography (FDG-PET) indicated increased uptake of FDG in the ventricular septum. Three days after steroid therapy, the ventricular pacing threshold reverted to normal, and FDG-PET showed decreased FDG uptake in the ventricular septum. In this case report, we demonstrate that a sudden deterioration in the ventricular pacing threshold due to worsening cardiac sarcoidosis can be reversed with early steroid therapy.

Comparison of the measured pre-ejection periods and left ventricular ejection times between echocardiography and impedance cardiography for optimizing cardiac resynchronization therapy.

BACKGROUND: The pre-ejection period (PEP) and left ventricular ejection time (LVET) are easily measured by impedance cardiography (ICG). We hypothesized that the PEP/LVET measured by ICG would correlate with that measured by echocardiography, and that PEP/LVET measured by ICG would be useful for cardiac resynchronization therapy (CRT) optimization. METHODS: Newly CRT implanted patients were optimized by echocardiography. The PEP/LVET was measured by echocardiography and ICG in two different settings: optimized setting and right ventricle (RV)-only pacing. RESULTS: The PEP/LVET was significantly decreased in the optimized setting compared with that in RV-only pacing (0.62±0.13 vs 0.75±0.16, p<0.05). The PEP/LVET values calculated by ICG and echocardiography were positively correlated (r=0.553, p=0.003). CONCLUSION: ICG was useful for the optimization of CRT.

Impact of tonsillectomy combined with steroid pulse therapy on immunoglobulin A nephropathy depending on histological classification: a multicenter study.

BACKGROUND: In addition to corticosteroids and inhibition of the renin-angiotensin-aldosterone system, tonsillectomy with steroid pulse therapy (TSP) may have a beneficial impact on the clinical course of IgA nephropathy (IgAN). However, there is still much uncertainty regarding the indications for therapy, treatment protocol, and therapeutic options for IgAN. METHODS: In this multicenter retrospective cohort study, we enrolled 284 patients with biopsy-proven IgAN who received TSP or corticosteroid therapy or conservative therapy. The effects of TSP on clinical remission (CR) were evaluated after a median follow-up period of 4.1 years in relation to histological classifications. RESULTS: Among the 284 participants, 161 patients received TSP. During the observation time, 141 patients (49.6%) achieved CR, with a median time to remission of 397 days. In multivariate Cox regression analyses, TSP had an impact on achieving CR in only the group with histological grade 3 defined as glomerulosclerosis, crescent formation or adhesion to Bowman's capsule in 10-30% of all biopsied glomeruli, or mild cellular infiltration in the interstitium (hazard ratio (HR) 4.29, 95% confidence interval (95%CI) 1.88-11.19, P < 0.001). TSP independently contributed to a higher incidence of CR, particularly in the patient group showing evident mesangial hypercellularity (HR 2.54, 95%CI 1.38-5.08, P = 0.002). CONCLUSIONS: TSP may have a beneficial effect on the clinical course in IgAN patients with mild to moderate glomerular and interstitial lesions, particularly with distinct mesangial cell proliferation.

Disease modifying therapies for Alzheimer's disease targeting Aß oligomers: implications for therapeutic mechanisms.

Several lines of evidence indicate that amyloid ß (Aß), particularly Aß oligomers (AßOs), plays a causative role in Alzheimer's disease. However, the mechanisms underlying the action of an anti-AßO antibody to clarify the toxic action of AßOs remain elusive. Here, we showed that the anti-AßO antibody (monoclonal 72D9) can modify the Aß aggregation pathway. We also found that 72D9 directly sequesters both extracellular and intraneuronal AßOs in a nontoxic state. Thus, therapeutic intervention targeting AßOs is a promising strategy for neuronal protection in Alzheimer's disease.

Sortilin is required for toxic action of Aß oligomers (AßOs): extracellular AßOs trigger apoptosis, and intraneuronal AßOs impair degradation pathways.

AIMS: We investigated the pathological relevance of the "Aß oligomer (AßO) cascade hypothesis" in 3xTg-AD mice. This study was also designed to elucidate the molecular mechanism underlying the toxic action of AßOs. MAIN METHODS: To target the extracellular AßOs in vivo, a monoclonal antibody specific for AßOs was developed using a novel method. Monoclonal 72D9 was intravenously administered to aged 3xTg-AD mice bearing the human AD pathology to investigate the relevance of the AßO cascade hypothesis. To further identify the AßO-binding molecule on the cell surface, small interfering RNA (siRNA) for sortilin was transfected into SH-SY5Y cells. The sortilin-dependent molecular mechanism underlying toxic action of AßOs and/or AßO endocytosis was also assessed in cultured cortical neurons forming synapses. KEY FINDINGS: The 72D9 immunotherapy of aged 3xTg-AD mice revealed that extracellular and intraneuronal AßOs are related, and that intraneuronal AßOs act upstream of tau. We also found that extracellular AßOs first act as a sortilin ligand, and then induce p75(NTF)-mediated apoptosis, endocytosis-induced attenuation of autophagy, or accumulation of AßOs in autophagosomes. SIGNIFICANCE: Taken together, these findings provide novel lines of evidence that sortilin governs the toxic action of extracellular AßOs, which affects the degradation and/or clearance of either intraneuronal AßOs or tau. Thus, therapeutic intervention targeting extracellular AßOs themselves or for preventing the interaction between intraneuronal AßOs and tau is a promising strategy to be developed for AD treatment.

Bonding to NaOCl-treated dentin: effect of pretreatment with sodium toluene sulfinic acid.

PURPOSE: The use of sodium hypochlorite (NaOCl) can decrease the bond strength of 4-META/MMA-TBB resin cement to root dentin. The aim of this in vitro study was to evaluate the effect of sodium toluene sulfinic acid (SA) as a pretreatment to increase bond strength to NaOCl-treated dentin. MATERIALS AND METHODS: The root canal dentin of bovine teeth was treated with 6 methods: group 10-3 (10% citric acid/3% ferric chloride; control); group SA; group NC (sodium hypochlorite/10-3 solution); group NS-10-3 (NaOCl + sulfinic acid + 10-3 solution); group HSA-10-3 (NaOCl +H2O2 +NaOCl + sulfinic acid + 10-3 solution); group HO-10-3 (NaOCl + H2O2 + NaOCl +10-3 solution). The roots were then filled with Super-Bond C&B (SB) or Super-Bond sealer (SBS). Samples were stored in distilled water for 24 h at 37°C and then cross sectioned into five slabs (0.8 mm thick) that were subjected to "trimming" microtensile bond strength testing. All treated dentin surfaces and resin/dentin bond interfaces were analyzed under SEM. RESULTS: Compared with the control, NaOCl treatment significantly decreased the resin/dentin bond strengths. However, SA treatment following NaOCl irrigation resulted in no significant differences of bond strength values. CONCLUSION: Sulfinic acid was effective in restoring 4-META/MMA-TBB resin cement bond strength after NaOCl irrigation.

XPS analysis of the dentin irradiated by Er: YAG laser.

The aim of this study was to investigate the effect of Er:YAG laser irradiation on human dentin surface using X-ray photoelectron spectroscopy (XPS). 10 human dentin disks were prepared from extracted human molars for XPS analysis. These specimens were divided into two groups of five: a control group and group that were irradiated by an Er:YAG laser beam (100 mJ, 1Hz). All specimens were analyzed by XPS over a wide scanning range and narrow scanning ranges. The Ca/P ratio was calculated from the XPS results. In the results, the binding energies of Ca, P, and N in the laser-irradiated group were higher than those in the control group. The Ca/P ratio of the Er:YAG laser irradiated group (1.24+/-0.05) was significantly lower than that of the control group (1.52+/-0.16). This study showed that Er:YAG laser irradiation decreased Ca/P ratio and denatured the collagen of human dentin.

Resveratrol modulates phagocytosis of bacteria through an NF-kappaB-dependent gene program.

Many studies have shown that the pharmacological effects of resveratrol, a phytoalexin polyphenolic compound, include protective effects against cancer and inflammation as well as enhancement of stress resistance. In this study, we examined whether resveratrol affected the phagocytosis of bacteria by macrophages and the activation of the transcription factor NF-kappaB after stimulation with or without the ligand FSL-1 for Toll-like receptor 2 (TLR2). Phagocytosis of Escherichia coli and of Staphylococcus aureus by THP-1 cells and RAW264.7 cells was inhibited by resveratrol in a dose-dependent manner regardless of stimulation with FSL-1. The NF-kappaB activity in HEK293 cells stably expressing TLR2 was also inhibited by resveratrol after stimulation with FSL-1. Resveratrol also inhibited both the translocation of p65 of NF-kappaB into nuclei in the transfectant and tumor necrosis factor alpha production by THP-1 cells or RAW264.7 cells. It has recently been reported that TLR-mediated signaling pathways lead to the upregulation of mRNAs of phagocytic receptors, including scavenger receptors and C-type lectin receptors. This study also demonstrated that FSL-1 induced the upregulation of mRNAs of phagocytic receptors such as macrophage scavenger receptor-1, CD36, DC-SIGN, and Dectin-1 and that the FSL-1-induced upregulation of their mRNAs was inhibited by resveratrol. In addition, it was found that the expression of DC-SIGN in HEK293 cells stably expressing DC-SIGN was reduced by resveratrol and that the phagocytic activity was significantly inhibited by resveratrol. Thus, this study suggests that resveratrol inhibited bacterial phagocytosis by macrophages by downregulating the expression of phagocytic receptors and NF-kappaB activity.

Effect of curing method of a dual-cure resin cement on monkey pulpal reaction after bonding of tooth-colored inlay.

To compare the pulpal responses to light-cured and self-cured resin cements, cervical cavities were prepared in monkey's teeth, followed by application of etching gel and adhesive (Single Bond). A dual-cure resin cement (RelyX ARC) was applied, and hybrid composite inlays (Estenia) were bonded to the cavities. In one group, the cavities were photoirradiated for 20 seconds and the resin cement light-cured. In the other group, the resin cement was self-cured for six minutes without any photoirradiation. After experimental periods of seven, 28, and 70 days, histological features of pulp tissue were evaluated and compared. Results showed no significant differences in the histological features of the pulp tissues between the two curing methods. Both light-cured and self-cured resin cements showed acceptable biological compatibility with the monkey pulp. No bacterial penetration along the cavity walls was detected with either curing method.

Effect of a new thermal cycling method on bond strength of two-step self-etching adhesive systems.

The purpose of this study was to examine the effect of a new thermal cycling method using PCR thermal cycler on the durability of two-step self-etching adhesive systems. Beam specimens for microtensile bond strength test were inserted into PCR tubes with distilled water. Thermal cycling (0, 1000, 2000, and 3000 cycles) was done with the PCR program at two different temperatures of 5 and 55 degrees C for 30 seconds each using a PCR thermal cycler. After thermal cycling, specimens were subjected to microtensile bond strength test and fractured surfaces were observed by SEM. The bond strength of Imperva Fluoro Bond after 3000 times of thermal cycling was significantly decreased compared to those of less than 2000 cycles (p < 0.05), whereas SI-R20401 showed no significant differences even after 3000 cycles (p > 0.05). Results of this study revealed that bond strength was affected by the thermal stress introduced in this experimental model. Therefore, this new thermal cycling method is a potentially useful and accessible means to evaluate the durability of dentin adhesive systems.

CD14 directly binds to triacylated lipopeptides and facilitates recognition of the lipopeptides by the receptor complex of Toll-like receptors 2 and 1 without binding to the complex.

It has demonstrated that the recognition of triacylated lipopeptides by Toll-like receptor (TLR) 2 requires TLR1 as a coreceptor. In the NF-kappaB reporter assay system in which human embryonic kidney 293 cells were transfected with TLR2 and TLR1 together with an NF-kappaB luciferase reporter gene, S-(2,3-bispalmitoyloxypropyl)-N-palmitoyl-Cys-Lys-Lys-Lys-Lys (Pam(3)CSK(4)) and Pam(3)CSSNA were recognized by TLR2/TLR1, but the recognition level was unexpectedly very low. However, cotransfection of CD14 drastically enhanced the recognition of triacylated lipopeptides by TLR2/TLR1. The CD14-induced enhancement did not occur without cotransfection of TLR1. Both CD14(dS39-A48), a mutant with deletion of the part of possible N-terminal ligand-binding pocket, and anti-CD14 monoclonal antibody reduced the CD14-induced enhancement. Transfection of a TIR domain-deficient mutant of TLR2 (TLR2(dE772-S784)) or TLR1 (TLR1(dQ636-K779)) completely abrogated the CD14-induced enhancement. Soluble recombinant CD14 added extracellularly enhanced the recognition of Pam(3)CSSNA by TLR2/TLR1. Immunoprecipitation analysis demonstrated that CD14 was not associated with TLR2 but that TLR1 was associated with TLR2. In addition, surface plasmon resonance-based assay demonstrated that CD14 binds to Pam(3)CSK(4) at a dissociation constant of 5.7 microM. This study suggests that CD14 directly binds to triacylated lipopeptides and facilitates recognition of the lipopeptides by the TLR2/TLR1 complex without binding to the receptor complex.

Roles of N-linked glycans in the recognition of microbial lipopeptides and lipoproteins by TLR2.

Details of roles of carbohydrates attached to Toll-like receptors (TLRs) in the recognition of pathogen-associated molecular patterns and in the formation of the functional receptor complex still remain unknown. This study was designed to determine whether the glycans linked at Asn114, Asn199, Asn414 and Asn442 residues of TLR2 ectodomain were involved in the recognition of diacylated lipopeptide and lipoprotein. Single and multiple mutants were transfected into human embryonic kidney (HEK) 293 cells together with a NF-kappaB luciferase reporter plasmid. All of these mutants were expressed on the surface. SDS-PAGE of the transfectants demonstrated that these mutants migrated lower than wild-type TLR2 and their molecular masses decreased as the number of mutated Asn residues increased. TLR2(N114A), TLR2(N199A) and TLR2(N414A) as well as wild-type TLR2 induced NF-kappaB activation when stimulated with these ligands, whereas TLR2(N442A) failed to induce NF-kappaB activation. All of triple and quadruple mutants failed to induce NF-kappaB activation, but were associated with both wild-type TLR2 and TLR6 in the transfectants. TLR2(N114A,N199A), TLR2(N114A,N414A) and, to a lesser extent, TLR2(N114A,N442A), in which two N-linked glycans are speculated to be exposed to the concave surface of TLR2 solenoid, not only induce NF-kappaB activation but also are associated with wild-type TLR2 and TLR6. These results suggest that the glycan at Asn442 and at least two N-linked glycans speculated to be exposed to the concave surface of TLR2 solenoid are involved in the recognition of ligands by TLR2 and/or in formation or maturation of a functional TLR2 receptor complex.

Prevention of artificial caries: effect of bonding agent, resin composite and topical fluoride application.

This study investigated the effect of fluoride containing resin composites and bonding agents, as well as the topical fluoride (F) application on the inhibition of artificial caries progression by using a pH-cycling model with alternating demineralizing (pH:4.5) and remineralizing (pH:7.0) solutions. Two bonding systems (F-containing bonding system [Reactmer Bond: RB] and non-F containing bonding system [Clearfil SE Bond: SE]), two resin composites, (F-containing [Reactmer Paste: RP] and non-F containing [Clearfil AP-X: AP]) were used. A combination of each bonding agent and a resin composite, RB+RP, RB+AP, SE+RP and SE+AP, was placed in 2 x 3 x 1.5-mm cavities on root dentin of extracted molars (n=96). Specimens were subjected to pH-cycling for 6 or 12 weeks. Half of all specimens were immersed in 0.05% NaF solution for 1 minute once a day as a topical F application. After the pH cycling period, a microradiograph of each specimen was taken, and the outer lesion depth of the artificial caries was measured by means of image analyzing software. The depths of the outer lesions at different periods were analyzed by one-way ANOVA and Sheffe's test at p=0.05. The combination that received F treatment showed reduced lesion depth compared to the same combination without F application. Except for the F application group of 12 weeks, there was no significant difference in lesion depth among each bonding and composite combination (p>0.05). At week 12 with the F application, RB+RP showed the shallowest lesion compared to the other combinations (p<0.05). The results indicated that the F application reduced the progression of artificial caries. Moreover, the combination of fluoride containing bonding agent and restorative material was the most effective for the inhibition of artificial caries progression based on the 12-week experimental period with topical F application.