Cannabidiol mediates epidermal terminal differentiation and redox homeostasis through aryl hydrocarbon receptor (AhR)-dependent signaling.

BACKGROUND: Cannabidiol, a non-psychoactive phytocannabinoid, has antioxidant and anti-inflammatory activity in keratinocytes. However, the signaling pathway through which cannabidiol exerts its effect on keratinocytes or whether it can modulate keratinocyte differentiation has not been fully elucidated yet. OBJECTIVE: We investigated whether cannabidiol modulates epidermal differentiation and scavenges reactive oxygen species through the aryl hydrocarbon receptor (AhR) in keratinocytes and epidermal equivalents. METHODS: We investigated the cannabidiol-induced activation of AhR using AhR luciferase reporter assay, qRT-PCR, western blot, and immunofluorescence assays. We also analyzed whether keratinocyte differentiation and antioxidant activity are regulated by cannabidiol-induced AhR activation. RESULTS: In both keratinocytes and epidermal equivalents, cannabidiol increased both the mRNA and protein expression of filaggrin, involucrin, NRF2, and NQO1 and the mRNA expression of the AhR target genes, including CYP1A1 and aryl hydrocarbon receptor repressor. Additionally, cannabidiol showed antioxidant activity that was attenuated by AhR knockdown or co-administration with an AhR antagonist. Moreover, cannabidiol increased the ratio of OVOL1/OVOL2 mRNA expression, which is a downstream regulator of AhR that mediates epidermal differentiation. In addition to increased expression of barrier-related proteins, cannabidiol-treated epidermal equivalent showed a more prominent granular layer than the control epidermis. The increased granular layer by cannabidiol was suppressed by the AhR antagonist. CONCLUSION: Cannabidiol can be a modulator of the AhR-OVOL1-filaggrin axis and AhR-NRF2-NQO1 signaling, thus indicating a potential use of cannabidiol in skin barrier enhancement and reducing oxidative stress.

Discovery of new ERRγ agonists regulating dopaminergic neuronal phenotype in SH-SY5Y cells.

The discovery of small molecules that regulate specific neuronal phenotypes is important for the development of new therapeutic candidates for neurological diseases. Estrogen-related receptor γ (ERRγ), an orphan nuclear receptor widely expressed in the central nervous system (CNS), is closely related to the regulation of neuronal metabolism and differentiation. We previously reported that upregulation of ERRγ could enhance dopaminergic neuronal phenotypes in the neuroblastoma cell line, SH-SY5Y. In this study, we designed and synthesized a series of new ERRγ agonists using the X-ray crystal structure of the GSK4716-bound ERRγ complex and known synthetic ligands. Our new ERRγ agonists exhibited increased transcriptional activities of ERRγ. In addition, our molecular docking results supported the experimental findings for ERRγ agonistic activity of the potent analogue, 5d. Importantly, 5d not only enhanced the expression of dopaminergic neuronal-specific molecules, TH and DAT but also activated the relevant signaling events, such as the CREB-mediated signaling pathway. The results of the present study may provide useful clues for the development of novel ERRγ agonists for neurological diseases related to the dopaminergic nervous system.

Macrosphelide A Exhibits a Specific Anti-Cancer Effect by Simultaneously Inactivating ENO1, ALDOA, and FH.

Aerobic glycolysis in cancer cells, also known as the Warburg effect, is an indispensable hallmark of cancer. This metabolic adaptation of cancer cells makes them remarkably different from normal cells; thus, inhibiting aerobic glycolysis is an attractive strategy to specifically target tumor cells while sparing normal cells. Macrosphelide A (MSPA), an organic small molecule, is a potential lead compound for the design of anti-cancer drugs. However, its role in modulating cancer metabolism remains poorly understood. MSPA target proteins were screened using mass spectrometry proteomics combined with affinity chromatography. Direct and specific interactions of MSPA with its candidate target proteins were confirmed by in vitro binding assays, competition assays, and simulation modeling. The siRNA-based knockdown of MSPA target proteins indirectly confirmed the cytotoxic effect of MSPA in HepG2 and MCF-7 cancer cells. In addition, we showed that MSPA treatment in the HEPG2 cell line significantly reduced glucose consumption and lactate release. MSPA also inhibited cancer cell proliferation and induced apoptosis by inhibiting critical enzymes involved in the Warburg effect: aldolase A (ALDOA), enolase 1 (ENO1), and fumarate hydratase (FH). Among these enzymes, the purified ENO1 inhibitory potency of MSPA was further confirmed to demonstrate the direct inhibition of enzyme activity to exclude indirect/secondary factors. In summary, MSPA exhibits anti-cancer effects by simultaneously targeting ENO1, ALDOA, and FH.

ERRγ ligand HPB2 upregulates BDNF-TrkB and enhances dopaminergic neuronal phenotype.

Brain derived neurotrophic factor (BDNF) promotes maturation of dopaminergic (DAergic) neurons in the midbrain and positively regulates their maintenance and outgrowth. Therefore, understanding the mechanisms regulating the BDNF signaling pathway in DAergic neurons may help discover potential therapeutic strategies for neuropsychological disorders associated with dysregulation of DAergic neurotransmission. Because estrogen-related receptor gamma (ERRγ) is highly expressed in both the fetal nervous system and adult brains during DAergic neuronal differentiation, and it is involved in regulating the DAergic neuronal phenotype, we asked in this study whether ERRγ ligand regulates BDNF signaling and subsequent DAergic neuronal phenotype. Based on the X-ray crystal structures of the ligand binding domain of ERRγ, we designed and synthesized the ERRγ agonist, (E)-4-hydroxy-N'-(4-(phenylethynyl)benzylidene)benzohydrazide (HPB2) (Kd value, 8.35 µmol/L). HPB2 increased BDNF mRNA and protein levels, and enhanced the expression of the BDNF receptor tropomyosin receptor kinase B (TrkB) in human neuroblastoma SH-SY5Y, differentiated Lund human mesencephalic (LUHMES) cells, and primary ventral mesencephalic (VM) neurons. HPB2-induced upregulation of BDNF was attenuated by GSK5182, an antagonist of ERRγ, and siRNA-mediated ERRγ silencing. HPB2-induced activation of extracellular-signal-regulated kinase (ERK) and phosphorylation of cAMP-response element binding protein (CREB) was responsible for BDNF upregulation in SH-SY5Y cells. HPB2 enhanced the DAergic neuronal phenotype, namely upregulation of tyrosine hydroxylase (TH) and DA transporter (DAT) with neurite outgrowth, both in SH-SY5Y and primary VM neurons, which was interfered by the inhibition of BDNF-TrkB signaling, ERRγ knockdown, or blockade of ERK activation. HPB2 also upregulated BDNF and TH in the striatum and induced neurite elongation in the substantia nigra of mice brain. In conclusion, ERRγ activation regulated BDNF expression and the subsequent DAergic neuronal phenotype in neuronal cells. Our results might provide new insights into the mechanism underlying the regulation of BDNF expression, leading to novel therapeutic strategies for neuropsychological disorders associated with DAergic dysregulation.

Synthesis of two new lipid mediators from docosahexaenoic acid by combinatorial catalysis involving enzymatic and chemical reaction.

Omega-3 polyunsaturated fatty acids (PUFAs) have been known to have beneficial effects in the prevention of various diseases. Recently, it was identified that the bioactivities of omega-3 are related to lipid mediators, called pro-resolving lipid mediators (SPMs), converted from PUFAs, so they have attracted much attention as potential pharmaceutical targets. Here, we aimed to build an efficient production system composed of enzymatic and chemical catalysis that converts docosahexaenoic acid (DHA) into lipid mediators. The cyanobacterial lipoxygenase, named Osc-LOX, was identified and characterized, and the binding poses of enzyme and substrates were predicted by ligand docking simulation. DHA was converted into three lipid mediators, a 17S-hydroxy-DHA, a 7S,17S-dihydroxy-DHA (RvD5), and a 7S,15R-dihydroxy-16S,17S-epoxy-DPA (new type), by an enzymatic reaction and deoxygenation. Also, two lipid mediators, 7S,15R,16S,17S-tetrahydroxy-DPA (new type) and 7S,16R,17S-trihydroxy-DHA (RvD2), were generated from 7S,15R-dihydroxy-16S,17S-epoxy-DPA by a chemical reaction. Our study suggests that discovering new enzymes that have not been functionally characterized would be a powerful strategy for producing various lipid mediators. Also, this combination catalysis approach including biological and chemical reactions could be an effective production system for the manufacturing lipid mediators.

Synthesis of 13R,20-dihydroxy-docosahexaenoic acid by site-directed mutagenesis of lipoxygenase derived from Oscillatoria nigro-viridis PCC 7112.

Lipoxygenases (LOXs) are implicated in the biosynthesis of pro- and anti-inflammatory lipid mediators involved in immune cell signaling, most of which catalyze peroxidation of polyunsaturated fatty acids by distinct regio- and stereoselectivity. Current reports suggested that conserved amino acid, Gly in R-LOXs and Ala in S-LOXs, in the catalytic domain play an important role in determining the position as well as the stereochemistry of the functional group. Recently, we have confirmed that the catalytic specificity of cyanobacterial lipoxygenase, named Osc-LOX, with alanine at 296 was 13S-type toward linoleic acid, and producing a 17S- hydroxy-docosahexaenoic acid from docosahexaenoic acid (DHA). Here, we aimed to change the catalytic property of LOX from13S-LOX to 9R-LOX by replacing Ala with Gly and to produce a lipid mediators different from the wild-type using DHA. Finally, we succeeded in generating human endogenous a 13R-hydroxy-docosahexaenoic acid and a 13R,20-dihydroxy-docosahexaenoic acid from DHA through an enzymatic reaction using the Osc-LOX-A296G. Our study could enable physiological studies and pharmaceutical research for the 13R,20-dihydroxy-docosahexaenoic acid.

Comparison of maxillary basal arch forms using the root apex in adult women with different skeletal patterns: A pilot study.

INTRODUCTION: This study aimed to establish maxillary basal arch forms using the root apices and to determine the differences in the basal arch forms in adult women with different sagittal skeletal patterns. METHODS: This retrospective study included 91 adult women, with either a Class I (n = 24), Class II Division 1 (n = 22), Class II Division 2 (n = 23), or Class III (n = 22) malocclusion, who underwent cone-beam computed tomography. Three-dimensional coordinates of the root apices were determined using the multiplanar reformation mode of OnDemand3D software (Cybermed Inc, Seoul, South Korea). Two-dimensional coordinates were converted from acquired 3-dimensional coordinates via projection on the palatal plane, and the Procrustes superimposition method was used to build the basal arch form. Finally, interroot width measurements were performed for basal arch form comparisons. RESULTS: There were significant differences among the 4 groups (P <0.05) with respect to the intercanine width. The intercanine width of Class II Division 1 group was significantly narrower than that of the other groups. The Class II Division 1 and Class II Division 2 groups tended to have tapered arch forms and squared arch forms, respectively. CONCLUSIONS: We established maxillary basal arch forms using the root apices. The Class II Division 1 group had a significantly narrower intercanine distance. The use of the root apex to depict the basal arch form seems reasonable.

Synergetic Effect of 2-Methacryloyloxyethyl Phosphorylcholine and Mesoporous Bioactive Glass Nanoparticles on Antibacterial and Anti-Demineralisation Properties in Orthodontic Bonding Agents.

2-methacryloyloxyethyl phosphorylcholine (MPC) is known to have antibacterial and protein-repellent effects, whereas mesoporous bioactive glass nanoparticles (MBN) are known to have remineralisation effects. We evaluated the antibacterial and remineralisation effects of mixing MPC and MBN at various ratios with orthodontic bonding agents. MPC and MBN were mixed in the following weight percentages in CharmFil-Flow (CF): CF, 3% MPC, 5% MPC, 3% MPC + 3% MBN, and 3% MPC + 5% MBN. As the content of MPC and MBN increased, the mechanical properties of the resin decreased. At 5% MPC, the mechanical properties decreased significantly with respect to CF (shear bond strength), gelation of MPC occurred, and no significant difference was observed in terms of protein adsorption compared to the control group. Composition 3% MPC + 5% MBN exhibited the lowest protein adsorption because the proportion of hydrophobic resin composite decreased; CF (91.8 ± 4.8 µg/mL), 3% MPC (73.9 ± 2.6 µg/mL), 3% MPC + 3% MBN (69.4 ± 3.6 µg/mL), and 3% MPC + 5% MBN (55.9 ± 1.6 µg/mL). In experiments against S. mutans and E. coli, addition of MPC and MBN resulted in significant antibacterial effects. In another experiment, the anti-demineralisation effect was improved when MPC was added, and when MBN was additionally added, it resulted in a synergetic effect. When MPC and MBN were added at an appropriate ratio to the orthodontic bonding agents, the protein-repellent, antibacterial, and anti-demineralisation effects were improved. This combination could thus be an alternative way of treating white spot lesions.

Therapeutic Efficacy of ABN401, a Highly Potent and Selective MET Inhibitor, Based on Diagnostic Biomarker Test in MET-Addicted Cancer.

The receptor tyrosine kinase c-MET regulates processes essential for tissue remodeling and mammalian development. The dysregulation of c-MET signaling plays a role in tumorigenesis. The aberrant activation of c-MET, such as that caused by gene amplification or mutations, is associated with many cancers. c-MET is therefore an attractive therapeutic target, and inhibitors are being tested in clinical trials. However, inappropriate patient selection criteria, such as low amplification or expression level cut-off values, have led to the failure of clinical trials. To include patients who respond to MET inhibitors, the selection criteria must include MET oncogenic addiction. Here, the efficacy of ABN401, a MET inhibitor, was investigated using histopathologic and genetic analyses in MET-addicted cancer cell lines and xenograft models. ABN401 was highly selective for 571 kinases, and it inhibited c-MET activity and its downstream signaling pathway. We performed pharmacokinetic profiling of ABN401 and defined the dose and treatment duration of ABN401 required to inhibit c-MET phosphorylation in xenograft models. The results show that the efficacy of ABN401 is associated with MET status and they highlight the importance of determining the cut-off values. The results suggest that clinical trials need to establish the characteristics of each sample and their correlations with the efficacy of MET inhibitors.

Insights into the Vastly Different Effects of Eutectic Solvents on the Stability of Phenolic Compounds.

Eutectic solvents (ESs) have shown stabilizing effects on several molecules. Due to the potential applicability of bioactive compounds, understanding how ESs stabilize them is of great interest in pharmaceutical and related fields. Here, among various ESs, CTU, which comprise thiourea and choline chloride (ChCl), exerted remarkably high stabilizing effects on various phenolic compounds, whereas CU consisting of urea and ChCl exhibited the opposite effects. Using a potent polyphenol, (-)-epigallocatechin gallate (EGCG), as a model compound, we conducted experimental and in silico studies to unravel the underlying mechanisms of the two very similar ESs for the contrasting effects. The results suggest that ESs can affect with great diversity the stability of EGCG by complicated interactions arising from the unique properties of both ESs and their components.

Immediate effects of mandibular posterior displacement on the pharyngeal airway space: A preliminary study.

OBJECTIVE: This study aimed to evaluate the immediate effects of mandibular posterior displacement on the pharyngeal airway space (PAS) by using cephalometric evaluations and to investigate how the surrounding structures are schematically involved. METHODS: In this retrospective study, 38 subjects with functional Class III malocclusion and two lateral cephalograms were selected. The first lateral cephalogram was taken with the mandible in the habitual occlusal position, and the second in anterior edge-to-edge bite. Paired t-test was used to analyze changes in the PAS, hyoid bone, tongue, and soft palate, followed by mandibular posterior displacement. Pearson's correlation analysis was used to determine the relationship between the amount of mandibular posterior displacement and other variables. RESULTS: A statistically significant decrease was observed in the PAS following mandibular posterior displacement. Along with mandibular posterior displacement, the tongue decreased in length (p < 0.001) and increased in height (p < 0.05), while the soft palate increased in length, decreased in thickness, and was posteriorly displaced (p < 0.001). The hyoid bone was also posteriorly displaced (p < 0.05). There was no correlation between the amount of mandibular posterior displacement and the measured variables. CONCLUSIONS: The PAS showed a statistically significant decrease following mandibular posterior displacement, which was a consequence of retraction of the surrounding structures. However, there were individual variances between the amount of mandibular posterior displacement and the measured variables.

Anatomical relationship between the maxillary posterior teeth and the sinus floor according to an anterior overbite.

OBJECTIVE: To evaluate the vertical relationship between the maxillary sinus floor (MSF) and the maxillary posterior teeth (MPT) according to an anterior overbite. SETTINGS AND SAMPLE POPULATION: The patients were divided into three groups according to an anterior overbite. The open bite group (OBG) included patients with an anterior overbite of ≤0 mm, the normal overbite group (NBG) included patients with an overbite of 0-3 mm, and the deep bite group (DBG) included patients with an overbite ≥3 mm. Thirty patients were randomly matched into each group based on age and sex. MATERIALS AND METHODS: The distances and vertical relationship between the MSF and the MPT was analysed using cone-beam computer tomography. The vertical relationship between the two was classified as either favourable or unfavourable for the intrusion of the posterior teeth. RESULTS: A higher ratio of patients in the OBG had MPT positioned close to the MSF than the DBG. Intrusion of the posterior teeth was unfavourable for an average of 87.2%, 77.2% and 70.2% molars in the OBG, NBG and DBG, respectively. CONCLUSIONS: The vertical distance between the MSF and the MPT is associated with an anterior overbite. The posterior teeth were in an unfavourable position for the orthodontic intrusion in the OBG as compared to the other groups. Additional caution is needed when planning orthodontic intrusion treatment for patients with an anterior open bite. But, there were some individual variations within each group.

Structure-Activity Relationship Analysis of YM155 for Inducing Selective Cell Death of Human Pluripotent Stem Cells.

Despite great potential for regenerative medicine, the high tumorigenic potential of human pluripotent stem cells (hPSCs) to form undesirable teratoma is an important technical hurdle preventing safe cell therapy. Various small molecules that induce the complete elimination of undifferentiated hPSCs, referred to as "stemotoxics," have been developed to facilitate tumor-free cell therapy, including the Survivin inhibitor YM155. In the present work, based on the chemical structure of YM155, total 26 analogs were synthesized and tested for stemotoxic activity toward human embryonic stem cells (hESCs) and induced PSCs (iPSCs). We found that a hydrogen bond acceptor in the pyrazine ring of YM155 derivatives is critical for stemotoxic activity, which is completely lost in hESCs lacking SLC35F2, which encodes a solute carrier protein. These results suggest that hydrogen bonding interactions between the nitrogens of the pyrazine ring and the SLC35F2 protein are critical for entry of YM155 into hPSCs, and hence stemotoxic activity.

Fluorinated Bioactive Glass Nanoparticles: Enamel Demineralization Prevention and Antibacterial Effect of Orthodontic Bonding Resin.

Orthodontic treatment involving the bonding of fixed appliances to tooth surfaces can cause white spot lesions (WSLs). WSLs increase the likelihood of cavity formation and hence require preservation and prosthetic restoration. Therefore, the prevention of WSLs is of greater importance than treatment. Application of fluoride or the use of fluoride-containing mouthwash can prevent WSLs, but this requires patient cooperation and additional time and cost. Bioactive glass containing 2.5% fluoride was synthesized and mixed with the orthodontic bonding adhesive Transbond XT Low Flow (LV) at ratios of 1, 3, and 5% to prepare orthodontic adhesive samples. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) were used to characterize the samples. The Vickers hardness test, bracket retention test, and adhesive remnant index (ARI) of the samples were analysed to determine their mechanical properties. To determine the biological cytotoxicity, the cell activity of the samples was evaluated using cell viability tests and the antibacterial activity was analysed using Streptococcus mutans. To evaluate the anti-demineralization effect, the sample was bonded to extracted teeth and a pH cycle test was performed. Micro computed tomography data were obtained from the bonded teeth and sample, and the anti-demineralization effect was evaluated using the ImageJ software program. The Vickers hardness of the sample was higher than that of LV and was dependent on the concentration of fluoride-containing bioactive glass (FBAG). The bracket retention test and ARI of the sample showed no significant differences from those of LV. The cell viability test showed no significant changes at 24 and 48 h after application of the sample. The fluoride ion release test indicated an ion release rate of 9.5-17.4 µg/cm2. The antibacterial activity of the experimental group containing FBAG was significantly higher than that of the LV group. The anti-demineralization test showed a concentration-dependent increase. However, the resin containing 5 mass% FBAG (FBAG5) showed a statistically-significant increase compared with LV. The orthodontic adhesive containing FBAG showed antibacterial and anti-demineralization effects, thus indicating possible WSL prevention activity.

Effects of Poly(Amidoamine) Dendrimer-Coated Mesoporous Bioactive Glass Nanoparticles on Dentin Remineralization.

Dentin hypersensitivity (DH) is one of the most common clinical conditions usually associated with exposed dentinal surfaces. In this study, we identified the effectiveness of poly(amidoamine) (PAMAM) dendrimer-coated mesoporous bioactive glass nanoparticles (MBN) (PAMAM@MBN) on DH treatment, examining the ion-releasing effect, dentin remineralization, and the occluding effect of dentinal tubules. We synthesized MBN and PAMAM@MBN. After soaking each sample in simulated body fluid (SBF), we observed ion-releasing effects and dentin remineralization effects for 30 days. Also, we prepared 30 premolars to find the ratio of occluded dentinal tubules after applying MBN and PAMAM@MBN, respectively. The results showed that PAMAM did not disrupt the calcium ion-releasing ability or the dentin remineralization of MBN. The PAMAM@MBN showed a better occluding effect for dentinal tubules than that of MBN (p < 0.05). In terms of dentinal tubule occlusion, the gap between MBN was well occluded due to PAMAM. This implies that PAMAM@MBN could be effectively used in dentinal tubule sealing and remineralization.

Enamel Surface Remineralization Effect by Fluorinated Graphite and Bioactive Glass-Containing Orthodontic Bonding Resin.

All orthodontic appliances are potentially cariogenic. The plaque around the orthodontic appliance can make demineralization on tooth surface causing white spot lesion (WSL). The most effective method to prevent WSL is Fluoride appliance and gargling, but this requires patient cooperation, which consumes additional treatment time and cost. As suggested in this study, biomaterials like bioactive glass and fluorinated graphite (FGt) having antibacterial and anti-demineralization ability effective and easy to use in the clinic. To clinically use orthodontic bonding resins containing Graphite Fluoride BAG (FGtBAG), its properties, biological stability, antimicrobial activity, and remineralization effect must be verified. BAG was mixed with 2.5% FGt containing 51 to 61% fluorine. This mixture was mixed with the CharmFill Flow (CF) in the ratios of 1, 3, and 5 wt%. Microhardness and shear bond strength tests were performed to evaluate its mechanical properties. MTT (3-(4, 5-dimethyl thiazol-2-yl)-2, 5-diphenyl tetra) assay was performed for evaluating its safety. Streptococcus mutans, which is major cariogen by producing lactic acid, was evaluated for antibacterial ability of reducing WSL. In addition, x-ray images were obtained by CBCT (Cone beam computed tomography) after a pH cycle. The remineralization effect was verified in vivo and by Image J. FGtBAG did not differ significantly from CF in mechanical tests. The MTT assay found no significant differences between the groups. The antibacterial activity of FGtBAG at 24 h and 48 h was significantly higher than that of CF. The fluoride release rate tended to increase with the FGtBAG content. The pH cycle results showed that FGtBAG had higher concentration-dependent remineralization effect than CF. The results of this study suggests that orthodontic resins containing FGtBAG can prevent WSL owing to their antibacterial activity and remineralization effect.

Root proximity of miniscrews at a variety of maxillary and mandibular buccal sites: Reliability of panoramic radiography.

OBJECTIVES: To assess the root proximity and the insertion angles of miniscrews after miniscrew placement at a variety of maxillary and mandibular buccal sites using cone-beam computed tomography (CBCT) and to determine the differences in root proximity between CBCT and panoramic radiography (PR). MATERIALS AND METHODS: This retrospective study included 50 patients (mean age, 22.0 ± 4.5 years) who underwent postoperative CBCT and PR after miniscrew placements for intermaxillary fixation in orthognathic surgery. Twelve miniscrews were placed in the buccal bone of each patient: at sites between the central incisor and lateral incisor (SII), sites between the canine and first premolar (SCP), and sites between the second premolar and first molar (SPM) on the right and left sides of the mandible and maxilla. The insertion angles were measured on CBCT, and the root proximity was assessed on CBCT and PR. RESULTS: The mean vertical placement angles ranged from 84.27° to 95.12°, and the mean horizontal placement angles ranged from 90.93° to 101.1°. The rates of no contact between the root and the miniscrew were 68.0% in the SII, 50.5% in the SCP, and 57.8% in the SPM, which were significantly different (P = .000). The total concordance rate between PR and CBCT was 41.3%. CONCLUSIONS: Clinicians should use extreme caution during placement of miniscrews in the SCP. There are limitations on the use of PR for evaluating the root proximity of miniscrews.

EF-hand like Region in the N-terminus of Anoctamin 1 Modulates Channel Activity by Ca2+ and Voltage.

Anoctamin1 (ANO1) also known as TMEM16A is a transmembrane protein that functions as a Ca2+ activated chloride channel. Recently, the structure determination of a fungal Nectria haematococca TMEM16 (nhTMEM16) scramblase by X-ray crystallography and a mouse ANO1 by cryo-electron microscopy has provided the insight in molecular architecture underlying phospholipid scrambling and Ca2+ binding. Because the Ca2+ binding motif is embedded inside channel protein according to defined structure, it is still unclear how intracellular Ca2+ moves to its deep binding pocket effectively. Here we show that EF-hand like region containing multiple acidic amino acids at the N-terminus of ANO1 is a putative site regulating the activity of ANO1 by Ca2+ and voltage. The EF-hand like region of ANO1 is highly homologous to the canonical EF hand loop in calmodulin that contains acidic residues in key Ca2+-coordinating positions in the canonical EF hand. Indeed, deletion and Ala-substituted mutation of this region resulted in a significant reduction in the response to Ca2+ and changes in its key biophysical properties evoked by voltage pulses. Furthermore, only ANO1 and ANO2, and not the other TMEM16 isoforms, contain the EF-hand like region and are activated by Ca2+. Moreover, the molecular modeling analysis supports that EF-hand like region could play a key role during Ca2+ transfer. Therefore, these findings suggest that EF-hand like region in ANO1 coordinates with Ca2+ and modulate the activation by Ca2+ and voltage.

Conversion of Medium-Sized Lactams to α-Vinyl or α-Acetylenyl Azacycles via N,O-Acetal TMS Ethers.

α-Vinyl or α-acetylenyl azacycles were easily synthesized from 7- to 9-membered lactams and 6- to 9-membered lactams via N,O-acetal trimethylsilyl (TMS) ethers. Organocopper and organostannane reagents afforded reasonable yields for the respective N-acyliminium ion vinylation and acetylenylation intermediates generated from N,O-acetal TMS ethers in the presence of a Lewis acid.

Asymmetric Synthesis of (-)-6-Desmethyl-Fluvirucinine A1 via Conformationally-Controlled Diastereoselective Lactam-Ring Expansions.

The versatile synthesis of (-)-6-desmethyl-fluvirucinine A1 was accomplished at a 24% overall yield through a thirteen-step process from a known vinylpiperidine. The key part involved the elaboration of the distal stereocenters and a macrolactam skeleton via conformationally-induced diastereocontrol and the iterative aza-Claisen rearrangements of lactam precursors.