Tmem2 Deficiency Leads to Enamel Hypoplasia and Soft Enamel in Mouse.

Teeth consist of 3 mineralized tissues: enamel, dentin, and cementum. Tooth malformation, the most common craniofacial anomaly, arises from complex genetic and environmental factors affecting enamel structure, size, shape, and tooth eruption. Hyaluronic acid (HA), a primary extracellular matrix component, contributes to structural and physiological functions in periodontal tissue. Transmembrane protein 2 (TMEM2), a novel cell surface hyaluronidase, has been shown to play a critical role during embryogenesis. In this study, we demonstrate Tmem2 messenger RNA expression in inner enamel epithelium and presecretory, secretory, and mature ameloblasts. Tmem2 knock-in reporter mice reveal TMEM2 protein localization at the apical and basal ends of secretory ameloblasts. Micro-computed tomography analysis of epithelial-specific Tmem2 conditional knockout (Tmem2-CKO) mice shows a significant reduction in enamel layer thickness and severe enamel deficiency. Enamel matrix protein expression was remarkably downregulated in Tmem2-CKO mice. Scanning electron microscopy of enamel from Tmem2-CKO mice revealed an irregular enamel prism structure, while the microhardness and density of enamel were significantly reduced, indicating impaired ameloblast differentiation and enamel matrix mineralization. Histological evaluation indicated weak adhesion between cells and the basement membrane in Tmem2-CKO mice. The reduced and irregular expressions of vinculin and integrin ß1 suggest that Tmem2 deficiency attenuated focal adhesion formation. In addition, abnormal HA accumulation in the ameloblast layer and weak claudin 1 immunoreactivity in Tmem2-CKO mice indicate impaired tight junction gate function. Irregular actin filament assembly was also observed at the apical and basal ends of secretory ameloblasts. Last, we demonstrated that Tmem2-deficient mHAT9d mouse ameloblasts exhibit defective adhesion to HA-containing substrates in vitro. Collectively, our data highlight the importance of TMEM2 in adhesion to HA-rich extracellular matrix, cell-to-cell adhesion, ameloblast differentiation, and enamel matrix mineralization.

Nonreciprocal Directional Dichroism in Magnetoelectric Spin Glass.

Optical absorption spectra in the visible and near-infrared light were measured for magnetoelectric spin glass Ni_{0.4}Mn_{0.6}TiO_{3} under various field-cooled conditions. Despite the absence of long-range magnetic-dipole order, this spin-glass system exhibits nonreciprocal directional dichroism (NDD) at zero external field after a magnetoelectric field-cooled procedure. This result is distinct from previous studies on NDD in systems with magnetic toroidal moments induced either by long-range magnetic-dipole order or by applying crossed electric and magnetic fields. The present Letter conclusively demonstrates that the observed NDD originates from magnetoelectrically induced ferroic order of magnetic toroidal moments without conventional magnetic-dipole order.

Effects of tourism promotion on COVID-19 spread: The case of the "Go To Travel" campaign in Japan.

Introduction: On July 22, 2020, the Japanese government launched the "Go to Travel" campaign that subsidizes 50% of personal travel expenditure to support the tourism industry under the COVID-19 pandemic. This policy was controversial from the viewpoint of infection spread and was temporarily cancelled in December 2020, though there was no statistical evidence. Methods: This is the first study that measures the extent to which this campaign increased COVID-19 cases. This study regards the campaign as a natural experiment: although Tokyo and its commuting areas experienced the same time-series trends of COVID-19 cases before the "Go To Travel" campaign, this campaign was implemented in areas outside Tokyo, but not in Tokyo. Then, the comparison (difference-in-differences) yields the campaign's effect. Results: The estimation shows that the "Go To Travel" campaign significantly raised the increment rate of cases by 23.7%-34.4% during July 30-August 4. There is no significant effect after August 5. In addition, our simulation identified the number of campaign-related cases in each city. Conclusions: Although the campaign significantly spread COVID-19, the effect was not continuous to permanently change the time-series trend.

First Application of Mass Measurements with the Rare-RI Ring Reveals the Solar r-Process Abundance Trend at A=122 and A=123.

The Rare-RI Ring (R3) is a recently commissioned cyclotronlike storage ring mass spectrometer dedicated to mass measurements of exotic nuclei far from stability at Radioactive Isotope Beam Factory (RIBF) in RIKEN. The first application of mass measurement using the R3 mass spectrometer at RIBF is reported. Rare isotopes produced at RIBF-^{127}Sn, ^{126}In, ^{125}Cd, ^{124}Ag, ^{123}Pd-were injected in R3. Masses of ^{126}In, ^{125}Cd, and ^{123}Pd were measured whereby the mass uncertainty of ^{123}Pd was improved. This is the first reported measurement with a new storage ring mass spectrometry technique realized at a heavy-ion cyclotron and employing individual injection of the preidentified rare nuclei. The latter is essential for the future mass measurements of the rarest isotopes produced at RIBF. The impact of the new ^{123}Pd result on the solar r-process abundances in a neutron star merger event is investigated by performing reaction network calculations of 20 trajectories with varying electron fraction Y_{e}. It is found that the neutron capture cross section on ^{123}Pd increases by a factor of 2.2 and ß-delayed neutron emission probability, P_{1 n}, of ^{123}Rh increases by 14%. The neutron capture cross section on ^{122}Pd decreases by a factor of 2.6 leading to pileup of material at A=122, thus reproducing the trend of the solar r-process abundances. The trend of the two-neutron separation energies (S_{2n}) was investigated for the Pd isotopic chain. The new mass measurement with improved uncertainty excludes large changes of the S_{2n} value at N=77. Such large increase of the S_{2n} values before N=82 was proposed as an alternative to the quenching of the N=82 shell gap to reproduce r-process abundances in the mass region of A=112-124.

Structure-activity relationships of antifungal phenylpropanoid derivatives and their synergy with n-dodecanol and fluconazole.

trans-Anethole (anethole) is a phenylpropanoid; with other drugs, it exhibits synergistic activity against several fungi and is expected to be used in new therapies that cause fewer patient side effects. However, the detailed substructure(s) of the molecule responsible for this synergy has not been fully elucidated. We investigated the structure-activity relationships of phenylpropanoids and related derivatives, with particular attention on the methoxy group and the double bond of the propenyl group in anethole, as well as the length of the p-alkyl chain in p-alkylanisoles. Antifungal potency was largely related to p-alkyl chain length and the methoxy group of anethole, but not to the double bond of its propenyl group. Production of reactive oxygen species also played a role in these fungicidal activities. Inhibition of drug efflux was associated with the length of the p-alkyl chain and the double bond of the propenyl group in anethole, but not with the methoxy group. Although a desirable synergy was observed between n-dodecanol and anethole or p-alkylanisoles with a length of C2-C6 in alkyl chains, it cannot be explained away as being solely due to the inhibition of drug efflux. Similar results were obtained when phenylpropanoid derivatives were combined with fluconazole against Candida albicans.

Enhancing the fungicidal activity of amphotericin B via vacuole disruption by benzyl isothiocyanate, a cruciferous plant constituent.

Amphotericin B (AmB), a typical polyene macrolide antifungal agent, is widely used to treat systemic mycoses. In the present study, we show that the fungicidal activity of AmB was enhanced by benzyl isothiocyanate (BITC), a cruciferous plant-derived compound, in the budding yeast, Saccharomyces cerevisiae. In addition to forming a molecular complex with ergosterol present in fungal cell membranes to form K+ -permeable ion channels, AmB has been recognized to mediate vacuolar membrane disruption resulting in lethal effects. BITC showed no effect on AmB-induced plasma membrane permeability; however, it amplified AmB-induced vacuolar membrane disruption in S. cerevisiae. Furthermore, the BITC-enhanced fungicidal effects of AmB significantly decreased cell viability due to the disruption of vacuoles in the pathogenic fungus Candida albicans. The application of the combinatorial antifungal effect of AmB and BITC may aid in dose reduction of AmB in clinical antifungal therapy and consequently decrease side effects in patients. These results also have significant implications for the development of vacuole-targeting chemotherapy against fungal infections.

Towards a classification of bifurcations in Vlasov equations.

We propose a classification of bifurcations of Vlasov equations, based on the strength of the resonance between the unstable mode and the continuous spectrum on the imaginary axis. We then identify and characterize a new type of generic bifurcation where this resonance is weak, but the unstable mode couples with a stable mode and a Casimir invariant of the system to form a size-3 Jordan block. We derive a three-dimensional reduced noncanonical Hamiltonian system describing this bifurcation. Comparison of the reduced dynamics with direct numerical simulations on a test case gives excellent agreement. We finally discuss the relevance of this bifurcation to specific physical situations.

Mapping of a New Deformation Region around

We performed the first direct mass measurements of neutron-rich scandium, titanium, and vanadium isotopes around the neutron number 40 at the RIKEN RI Beam Factory using the time-of-flight magnetic-rigidity technique. The atomic mass excesses of ^{58-60}Sc, ^{60-62}Ti, and ^{62-64}V were measured for the first time. The experimental results show that the two-neutron separation energies in the vicinity of ^{62}Ti increase compared to neighboring nuclei. This shows that the masses of Ti isotopes near N=40 are affected by the Jahn-Teller effect. Therefore, a development of Jahn-Teller stabilization appears below the Cr isotopes, and the systematics in Sc, Ti, and V isotopes suggest that ^{62}Ti is located close to the peak of the Jahn-Teller effect.

Heparan sulfate deficiency leads to hypertrophic chondrocytes by increasing bone morphogenetic protein signaling.

OBJECTIVE: Exostosin-1 (EXT1) and EXT2 are the major genetic etiologies of multiple hereditary exostoses and are essential for heparan sulfate (HS) biosynthesis. Previous studies investigating HS in several mouse models of multiple hereditary exostoses have reported that aberrant bone morphogenetic protein (BMP) signaling promotes osteochondroma formation in Ext1-deficient mice. This study examined the mechanism underlying the effects of HS deficiency on BMP/Smad signaling in articular cartilage in a cartilage-specific Ext-/- mouse model. METHOD: We generated mice with a conditional Ext1 knockout in cartilage tissue (Ext1-cKO mice) using Prg4-Cre transgenic mice. Structural cartilage alterations were histologically evaluated and phospho-Smad1/5/9 (pSmad1/5/9) expression in mouse chondrocytes was analyzed. The effect of pharmacological intervention of BMP signaling using a specific inhibitor was assessed in the articular cartilage of Ext1-cKO mice. RESULTS: Hypertrophic chondrocytes were significantly more abundant (P = 0.021) and cartilage thickness was greater in Ext1-cKO mice at 3 months postnatal than in control littermates (P = 0.036 for femur; and P < 0.001 for tibia). However, osteoarthritis did not spontaneously occur before the 1-year follow-up. matrix metalloproteinase (MMP)-13 and adamalysin-like metalloproteinases with thrombospondin motifs(ADAMTS)-5 were upregulated in hypertrophic chondrocytes of transgenic mice. Immunostaining and western blotting revealed that pSmad1/5/9-positive chondrocytes were more abundant in the articular cartilage of Ext1-cKO mice than in control littermates. Furthermore, the BMP inhibitor significantly decreased the number of hypertrophic chondrocytes in Ext1-cKO mice (P = 0.007). CONCLUSIONS: HS deficiency in articular chondrocytes causes chondrocyte hypertrophy, wherein upregulated BMP/Smad signaling partially contributes to this phenotype. HS might play an important role in maintaining the cartilaginous matrix by regulating BMP signaling.

Relationship between temporomandibular joint pain and magnetic resonance imaging findings in patients with temporomandibular joint disorders.

The purpose of this study was to evaluate abnormal magnetic resonance imaging (MRI) findings related to temporomandibular joint (TMJ) pain. This study included 245 joints of 152 patients with temporomandibular disorders with anterior disc displacement; of these, 129 joints had joint pain whereas 116 joints had no joint pain. MRI was used to evaluate the reduction of anterior disc displacement, joint effusion, mandible condylar morphology, bone marrow oedema of the mandibular condyle, and signal intensity of the posterior disc attachment (PDA) on fat-suppressed T2-weighted images. The odds ratio (OR) for each MRI variable for the pain group versus the no pain group was computed using logistic regression analysis. Univariate logistic regression analysis showed significant correlations between TMJ pain and all MRI findings. Multivariate logistic regression analysis showed significant correlations with joint effusion (P=0.03, OR 2.21), bone marrow oedema (P<0.001, OR 11.75), and signal intensity of the PDA (P<0.001, OR 6.21). These results suggest that bone marrow oedema, high signal intensity of the PDA on fat-suppressed T2-weighted images, and joint effusion, in descending order of influence, are factors related to TMJ pain.

Enhancement of paraben-fungicidal activity by sulforaphane, a cruciferous vegetable-derived isothiocyanate, via membrane structural damage in Saccharomyces cerevisiae.

Parabens have been widely used as antimicrobial preservatives in cosmetics, pharmaceuticals, foods and beverages. Commonly, methyl-, ethyl-, propyl- and butylparaben are used independently or in combination to maintain the quality of industrial products, and they are considered to have low toxicity. However, recent evidence has suggested that parabens are toxic in mammalian cells, and parabens have been associated with allergic-contact dermatitis, breast cancer and changes in testosterone levels. Sulforaphane, a cruciferous vegetable-derived isothiocyanate, was effective in decreasing the growth inhibitory concentrations of ethyl-, propyl-, butyl- and methylparaben in the yeast Saccharomyces cerevisiae. The sulforaphane-enhanced fungicidal effects of methylparaben were deemed to be caused by drastic cell membrane damage and the leakage of internal substances, such as nucleotides, from S. cerevisiae cells. Moreover sulforaphane markedly decreased the minimum concentration of methyl- and ethylparaben required to inhibit the growth of various microbes, such as the pathogenic yeast that causes severe mycosis, Candida albicans; the filamentous fungi Aspergillus niger; and the Gram-negative bacterium Escherichia coli. Enhanced antimicrobial activity from the beneficial components of edible plants may increase paraben efficacy at low concentrations and minimize preservative-induced side effects in consumers. SIGNIFICANCE AND IMPACT OF THE STUDY: Sulforaphane, a natural and beneficial cruciferous vegetable-derived isothiocyanate, increased the ability of parabens to disrupt fungal cell membranes. Paraben-containing products have been reported to cause allergic contact dermatitis and drug hypersensitivity; therefore, methods to preserve organic products that may reduce the concentrations of parabens are both timely and necessary. In this study, we found that the combined antimicrobial effects of sulforaphane and parabens had the potential to reduce the paraben concentration needed to preserve organic products, thereby indicating that paraben toxicity may be reduced without affecting its activity as a preservative.

A dominant population of optically invisible massive galaxies in the early Universe.

Our current knowledge of cosmic star-formation history during the first two billion years (corresponding to redshift z > 3) is mainly based on galaxies identified in rest-frame ultraviolet light1. However, this population of galaxies is known to under-represent the most massive galaxies, which have rich dust content and/or old stellar populations. This raises the questions of the true abundance of massive galaxies and the star-formation-rate density in the early Universe. Although several massive galaxies that are invisible in the ultraviolet have recently been confirmed at early epochs2-4, most of them are extreme starburst galaxies with star-formation rates exceeding 1,000 solar masses per year, suggesting that they are unlikely to represent the bulk population of massive galaxies. Here we report submillimetre (wavelength 870 micrometres) detections of 39 massive star-forming galaxies at z > 3, which are unseen in the spectral region from the deepest ultraviolet to the near-infrared. With a space density of about 2 × 10-5 per cubic megaparsec (two orders of magnitude higher than extreme starbursts5) and star-formation rates of 200 solar masses per year, these galaxies represent the bulk population of massive galaxies that has been missed from previous surveys. They contribute a total star-formation-rate density ten times larger than that of equivalently massive ultraviolet-bright galaxies at z > 3. Residing in the most massive dark matter haloes at their redshifts, they are probably the progenitors of the largest present-day galaxies in massive groups and clusters. Such a high abundance of massive and dusty galaxies in the early Universe challenges our understanding of massive-galaxy formation.

Understanding the asymmetry between advancing and receding microscopic contact angles.

By means of molecular dynamics simulation, the advancing and receding microscopic contact angles were analyzed for a shear flow of two mono-atomic fluids confined between parallel non-polar solid walls. We defined the microscopic dynamic contact angle based on the coarse-grained microscopic density distribution of the fluids (the instantaneous interface method [Willard and Chandler, J. Phys. Chem. B, 2010, 114, 1954-1958]) near the moving contact line. We have found that the asymmetric change of fluid density near the wall with respect to the moving contact line results in a different dependence between the advancing and receding contact angles on the contact line velocity in a system where the two fluids across the interface have unequal wettability to the solid wall. This difference between the advancing and receding contact angles leads to different flow resistance caused by the advancing and receding contact lines, which should have impact on the industrial applications of the fine fluid transportation with contact lines.

Curcumin potentiates the fungicidal effect of dodecanol by inhibiting drug efflux in wild-type budding yeast.

Drug resistance commonly occurs when treating immunocompromised patients who have fungal infections. Curcumin, is a compound isolated from Curcuma longa, has been reported to inhibit drug efflux in several human cell lines and nonpathogenic budding yeast Saccharomyces cerevisiae cells that overexpresses the ATP-binding cassette (ABC) transporters S. cerevisiae Pdr5p and pathogenic Candida albicans Cdr1p and Cdr2p. The aim of this study was to examine the effects of curcumin on multidrug resistance in a wild-type strain of the budding yeast with an intrinsic expression system of multidrug efflux-related genes. The antifungal activity of dodecanol alone was temporary against S. cerevisiae; however, restoration of cell viability was completely inhibited when the cells were co-treated with dodecanol and curcumin. Furthermore, restriction of rhodamine 6G (R6G) efflux from the cells and intracellular accumulation of R6G were observed with curcumin treatment. Reverse transcription-polymerase chain reaction analysis revealed that curcumin reduced the dodecanol-induced overexpression of the ABC transporter-related genes PDR1, PDR3 and PDR5 to their control levels in untreated cells. Curcumin can directly restrict the glucose-induced drug efflux and inhibits the expression of the ABC transporter gene PDR5, and can thereby inhibit the efflux of dodecanol from S. cerevisiae cells. Curcumin is effective in potentiating the efficacy of antifungal drugs via its effects on ABC transporters. SIGNIFICANCE AND IMPACT OF THE STUDY: Drug resistance is common in immunocompromised patients with fungal infections. Curcumin, isolated from Curcuma longa, inhibits drug efflux in nonpathogenic budding yeast Saccharomyces cerevisiae cells overexpressing ABC transporters S. cerevisiae Pdr5p and pathogenic Candida albicans Cdr1p and Cdr2p. We examined the effects of curcumin on multidrug resistance in a wild-type strain of the budding yeast with an intrinsic expression system of multidrug efflux-related genes. Curcumin directly inhibited drug efflux and also suppressed the PDR5 expression, thereby enhancing the antifungal effects. Thus, curcumin potentially promotes the efficacy of antifungals via its effects on ABC transporters in wild-type fungal strains.

Fe-oxide concretions formed by interacting carbonate and acidic waters on Earth and Mars.

Spherical Fe-oxide concretions on Earth, especially in Utah, USA, have been investigated as an analog of hematite spherules found in Meridiani Planum on Mars to support interpretations of water-rock interactions in early Mars. Although several formation mechanisms have been proposed for the Fe-oxide concretions on Earth, it is still unclear whether these mechanisms are viable because a precise formation process and precursor of the concretions are missing. This paper presents evidence that Fe-oxide concretions in Utah and newly found Fe-oxide concretions in Mongolia had spherical calcite concretions as precursors. Different formation stages of calcite and Fe-oxide concretions observed, both in Utah and Mongolia, indicate that calcite concretions initially formed within eolian sandstone strata and were dissolved by infiltrating Fe-rich acidic waters to form spherical FeO(OH) crusts due to pH buffering. The similarity between these Fe-oxide concretions on Earth and the hematite spherule occurrences in Meridiani Planum, combined with evidence of acid sulfate water influences on Mars, suggest that the hematite spherules also formed from dissolution of preexisting carbonate spherules possibly formed under a dense carbon dioxide early martian atmosphere.

Magic Nature of Neutrons in

We perform the first direct mass measurements of neutron-rich calcium isotopes beyond neutron number 34 at the RIKEN Radioactive Isotope Beam Factory by using the time-of-flight magnetic-rigidity technique. The atomic mass excesses of ^{55-57}Ca are determined for the first time to be -18650(160), -13510(250), and -7370(990) keV, respectively. We examine the emergence of neutron magicity at N=34 based on the new atomic masses. The new masses provide experimental evidence for the appearance of a sizable energy gap between the neutron 2p_{1/2} and 1f_{5/2} orbitals in ^{54}Ca, comparable to the gap between the neutron 2p_{3/2} and 2p_{1/2} orbitals in ^{52}Ca. For the ^{56}Ca nucleus, an open-shell property in neutrons is suggested.