Role of phosphate transporter PiT-2 in the pathogenesis of primary brain calcification.

Primary brain calcification (PBC), also known as idiopathic basal ganglia calcification (IBGC), primary familial brain calcification (PFBC) and so on, is a rare intractable disease characterized by abnormal mineral deposits, including mostly calcium in the basal ganglia, thalamus, and cerebellum. The causative gene of familial PBC is SLC20A2, which encodes the phosphate transporter PiT-2. Despite this knowledge, the molecular mechanism underlying SLC20A2-associated PBC remains unclear. In the present study, we investigated whether haploinsufficiency or a dominant-negative mechanism reduced Pi uptake in two PiT-2 variants (T115 M and R467X). We demonstrated that the presence of T115 M or R467X had no dominant-negative effect on Pi transport activity of wild-type (WT). In addition, the subcellular localization of R467X completely differed from that of WT, indicating that there is no interaction between R467X and WT. Conversely, T115 M and WT showed almost the same localization. Therefore, we examined the interaction between T115 M and WT using the bioluminescence resonance energy transfer (BRET) method. Although WT and T115 M interact with each other, T115 M does not inhibit WT's Pi transport activity. These results suggest that the role of SLC20A2 in the pathogenesis of PBC may involve decreased intracellular Pi uptake by a haploinsufficiency mechanism rather than a dominant-negative mechanism; agents promoting PiT-2 dimerization may be promising potential therapeutic agents for PBC.

PDGF-BB is involved in phosphate regulation via the phosphate transporters in human neuroblastoma SH-SY5Y cells.

Inorganic phosphate (Pi) is the second most abundant inorganic ion in the body. Since abnormalities in Pi metabolism are risk factors for various diseases, serum Pi levels are strictly controlled. Type-III sodium-dependent Pi transporters, PiT-1 (encoded by SLC20A1) and PiT-2 (encoded by SLC20A2), are distributed throughout the tissues of the body, including the central nervous system, and are known to be responsible for extracellular to intracellular Pi transport. Platelet-derived growth factor (PDGF) is a major growth factor of mesenchymal cells. PDGF-BB, a homodimer of PDGF-B, regulates intracellular Pi by increasing PiT-1 expression in vascular smooth muscle cells. However, the effects of PDGF-BB on Pi transporters in neurons have yet to be reported. Here, we investigated the effect of PDGF-BB on Pi transporters in human neuroblastoma SH-SY5Y cells. PDGF-BB did not induce SLC20A1 mRNA expression, but it increased the intracellular uptake of Pi via PiT-1 in SH-SY5Y cells. Among the signaling pathways associated with PDGF-BB, AKT signaling was shown to be involved in the increase in Pi transport. In addition, the PDGF-BB-induced increase in Pi mediated neuroprotective effects in SLC20A2-suppressed cells, in an in vitro model of the pathological condition found in idiopathic basal ganglia calcification. Moreover, the increase in Pi uptake was found to occur through promotion of intracellular PiT-1 translocation to the plasma membrane. Overall, these results indicate that PDGF-BB exerts neuroprotective effects via Pi transport, and they demonstrate the potential utility of PDGF-BB against abnormal Pi metabolism in neurons.

A randomized-controlled trial of blonanserin and olanzapine as adjunct to antipsychotics in the treatment of patients with schizophrenia and dopamine supersensitivity psychosis: The ROADS study.

Dopamine supersensitivity psychosis (DSP) is a key factor contributing to the development of antipsychotic treatment-resistant schizophrenia. We examined the efficacy and safety of blonanserin (BNS) and olanzapine (OLZ) as adjuncts to prior antipsychotic treatment in patients with schizophrenia and DSP in a 24-week, multicenter (17 sites), randomized, rater-blinded study with two parallel groups (BNS and OLZ add-on treatments) in patients with schizophrenia and DSP: the ROADS Study. The primary outcome was the change in the Positive and Negative Syndrome Scale (PANSS) total score from baseline to week 24. Secondary outcomes were changes in the PANSS subscale scores, Clinical Global Impressions, and Extrapyramidal Symptom Rating Scale (ESRS), and changes in antipsychotic doses. The 61 assessed patients were allocated into a BNS group (n = 26) and an OLZ group (n = 29). The PANSS total scores were reduced in both groups (mean ± SD: -14.8 ± 24.0, p = 0.0042; -10.5 ± 12.9, p = 0.0003; respectively) with no significant between-group difference (mean, -4.3, 95 %CI 15.1-6.4, p = 0.42). The BNS group showed significant reductions from week 4; the OLZ group showed significant reductions from week 8. The ESRS scores were reduced in the BNS group and the others were reduced in both groups. The antipsychotic monotherapy rates at the endpoint were 26.3 % (n = 6) for BNS and 23.8 % (n = 5) for OLZ. The concomitant antipsychotic doses were reduced in both groups with good tolerability. Our results suggest that augmentations with BNS and OLZ are antipsychotic treatment options for DSP patients, and BNS may be favorable for DSP based on the relatively quick responses to BNS observed herein.

The Novel gem-Dihydroperoxide 12AC3O Suppresses High Phosphate-Induced Calcification via Antioxidant Effects in p53LMAco1 Smooth Muscle Cells.

The excessive intake of phosphate (Pi), or chronic kidney disease (CKD), can cause hyperphosphatemia and eventually lead to ectopic calcification, resulting in cerebrovascular diseases. It has been reported that reactive oxygen species (ROS), induced by high concentrations of Pi loading, play a key role in vascular calcification. Therefore, ROS suppression may be a useful treatment strategy for vascular calcification. 12AC3O is a newly synthesized gem-dihydroperoxide (DHP) that has potent antioxidant effects. In the present study, we investigated whether 12AC3O inhibited vascular calcification via its antioxidative capacity. To examine whether 12AC3O prevents vascular calcification under high Pi conditions, we performed Alizarin red and von Kossa staining, using the mouse aortic smooth muscle cell line p53LMAco1. Additionally, the effect of 12AC3O against oxidative stress, induced by high concentrations of Pi loading, was investigated using redox- sensitive dyes. Further, the direct trapping effect of 12AC3O on reactive oxygen species (ROS) was investigated by ESR analysis. Although high concentrations of Pi loading exacerbated vascular smooth muscle calcification, calcium deposition was suppressed by the treatment of both antioxidants and 12AC3O, suggesting that the suppression of ROS may be a candidate therapeutic approach for treating vascular calcification induced by high concentrations of Pi loading. Importantly, 12AC3O also attenuated oxidative stress. Furthermore, 12AC3O directly trapped superoxide anion and hydroxyl radical. These results suggest that ROS are closely involved in high concentrations of Pi-induced vascular calcification and that 12AC3O inhibits vascular calcification by directly trapping ROS.

Effectiveness of a digital device providing real-time visualized tooth brushing instructions: A randomized controlled trial.

INTRODUCTION: The aim of this trial was to investigate whether a digital device that provides real-time visualized brushing instructions would contribute to the removal of dental plaque over usual brushing instructions. METHODS: We conducted a single-center, parallel-group, stratified permuted block randomized control trial with 1:1 allocation ratio. Eligibility criteria included people aged ≥ 18 years, and exclude people who met the following criteria: severely crowded teeth; using interdental cleaning implement; having external injury in the oral cavity, or stomatitis; having less than 20 teeth; using orthodontic apparatus; visited to a dental clinic; having the possibility of consulting a dental clinic; having a dental license; not owning a smartphone or tablet device; smoker; taken antibiotics; pregnant; an allergy to the staining fluid; and employee of Sunstar Inc. All participants received tooth brushing instructions using video materials and were randomly assigned to one of two groups for four weeks: (1) an intervention group who used the digital device, providing real-time visualized instructions by connection with a mobile application; and (2) a control group that used a digital device which only collected their brushing logs. The primary outcome was the change in 6-point method plaque control record (PCR) score of all teeth between baseline and week 4. The t-test was used to compare the two groups in accordance with intention-to-treat principles. RESULTS: Among 118 enrolled individuals, 112 participants were eligible for our analyses. The mean of PCR score at week 4 was 45.05% in the intervention group and 49.65% in the control group, and the change of PCR score from baseline was -20.46% in the intervention group and -15.77% in the control group (p = 0.088, 95% confidence interval -0.70-10.07). CONCLUSIONS: A digital device providing real-time visualized brushing instructions may be effective for the removal of dental plaque.

Neuroprotective effect of 5-aminolevulinic acid against low inorganic phosphate in neuroblastoma SH-SY5Y cells.

PiT-1 (encoded by SLC20A1) and PiT-2 (encoded by SLC20A2) are type-III sodium-dependent phosphate cotransporters (NaPiTs). Recently, SLC20A2 mutations have been found in patients with idiopathic basal ganglia calcification (IBGC), and were predicted to bring about an inability to transport Pi from the extracellular environment. Here we investigated the effect of low Pi loading on the human neuroblastoma SH-SY5Y and the human glioblastoma A172 cell lines. The results show a different sensitivity to low Pi loading and differential regulation of type-III NaPiTs in these cells. We also examined whether 5-aminolevulinic acid (5-ALA) inhibited low Pi loading-induced neurotoxicity in SH-SY5Y cells. Concomitant application of 5-ALA with low Pi loading markedly attenuated low Pi-induced cell death and mitochondrial dysfunction via the induction of HO-1 by p38 MAPK. The findings provide us with novel viewpoints to understand the pathophysiology of IBGC, and give a new insight into the clinical prevention and treatment of IBGC.

Simultaneous interrelationship between the oral health behavior and oral health status of mothers and their children.

The purpose of this study was to examine the simultaneous interrelationships of oral health behavior and oral health between mothers and their children using the linear structural relations (LISREL) program. The subjects comprised 117 pairs of mothers and their children aged between 8 and 11 years. Dental status was expressed as DMFT. The Oral Rating Index (ORI) for mothers and ORI for children (ORI-C) were used as measures of gingival health. Hiroshima University Dental Behavioral Inventory (HU-DBI) was used for the assessment of mothers' oral health behavior. HU-DBI had a direct positive relationship to ORI, a direct negative relationship to DFT, and a direct positive association with ORI-C. Toothbrushing had a direct negative relationship to ORI-C. The hypothesized model was found to be closely consistent with the data. These results indicate that the periodontal health status of mothers is directly related to the oral health status of their children, and that toothbrushing by children is directly related to their gingival health.

Teenagers' oral health attitudes and behavior in Japan: comparison by sex and age group.

We investigated sex and age group differences in attitudes to oral health among school-age children using an Oral Self-Care Appraisal (OSCA) to systematically determine changes in oral health knowledge, attitude, and behavior across developmental stages. The subjects (n = 1584) were stratified after random sampling so that each school grade analyzed contained 88 boys and 88 girls. Factor analysis was undertaken to identify a set of underlying factors, with 10 factors considered in the cross-sectional study. Our results showed that the factors toothbrushing, persistence, and sociability were more predominant in primary school children than in junior high and senior high school students. Furthermore, postponement of visiting the dentist and resignation to one's own dental cavities became more predominant in proportion to the level of school education. Girls had significantly higher scores than boys for desire to improve oral care, dental anxiety, dependency on snacks, toothbrushing, concern over number of cavities, and sociability. Together, the results indicated that the oral health care behavior of girls was better than that of boys, and that the tendency to postpone visiting the dentist and resignation to one's own dental cavities increased markedly with age.

Clinical trial of a novel interdental brush cleaning system.

OBJECTIVE: This single-blind, five parallel-arm, four-week randomized clinical trial was designed to compare the efficacy of a 0.05% cetylpyridinium chloride gel-releasing interdental brush (IDB) with standard interproximal cleaning devices for plaque and gingivitis reduction, and decreased frequency in interproximal gingival bleeding. METHODOLOGY: After consenting, participants meeting inclusion criteria brushed their teeth, received a baseline examination and a professional cleaning, and were then block-randomized into five groups, with the plaque level serving as the blocking variable. All five groups performed standard tooth brushing as a background regimen. Three of the groups were respectively assigned to one of three interdental brush regimens, the fourth group was assigned to a standard flossing regimen (positive control), and the fifth group was assigned to a standard tooth brushing only regimen (control). Clinical outcome data were collected at two and four weeks. RESULTS: Of a total of 162 starting participants, 152 completed the study. There were no baseline differences among the five groups with respect to age, interproximal plaque score, interproximal gingivitis score, or percent of interproximal bleeding on probing. After two and four weeks, the 3 IDB groups exhibited 30-40 percent lower plaque levels than the control (p < 0.05). With respect to interproximal gingival scores, the active agent IDB group exhibited a statistically significant effect after two weeks, and all three IDB groups demonstrated significantly better outcomes after four weeks (p < 0.05). At two and four weeks, the three IDB groups demonstrated a greater reduction in interproximal bleeding points upon probing compared to the two control groups (p < 0.05). The group using the 0.05% cetylpyridinium gel-releasing IDB system did not demonstrate superior clinical results when compared to the two other IDB groups. CONCLUSION: When compared to control and positive control interdental cleaning procedures, daily use of IDBs was effective in reducing interproximal plaque and gingivitis scores, as well as interproximal bleeding on probing. The benefits were evident at two weeks, but were more consistent after four weeks. The 0.05% cetylpyridinium gel-releasing IDB system did not appear to confer a consistently independent incremental benefit.