Molecular switching involving metastable states: molecular thermal hysteresis and sensing of environmental changes by chiral helicene oligomeric foldamers

Molecular switching is a phenomenon in which the molecular structure reversibly changes in response to external stimulation. It is crucial in biology and is used in various biological sensing applications and responses. In contrast to the well-studied molecular switching involving two or more thermodynamically stable states, switching involving metastable states exhibits notable non-equilibrium thermodynamic properties. Synthetic chiral helicene oligomeric foldamers that exhibit molecular thermal hysteresis in dilute solution are examples. Molecular switching can be used for sensing environmental changes, including temperature threshold, temperature decrease/increase, rate of temperature decrease, counting the numbers 1 and 2, and concentration increase.

Thiazolidinedione (Pioglitazone) Blocks P. gingivalis- and F. nucleatum, but not E. coli, Lipopolysaccharide (LPS)-induced Interleukin-6 (IL-6) Production in Adipocytes

An elevated level of C-reactive protein (CRP) predicts the future development of coronary heart disease. Periodontitis appears to up-regulate CRP. CRP is produced by hepatocytes in response to interleukin-6 (IL-6). A major source of IL-6 in obese subjects is adipocytes. We hypothesized that lipopolysaccharide (LPS) from periodontal pathogens stimulated adipocytes to produce IL-6, and that the production was suppressed by the drugs targeted against insulin resistance, thiazolidinedione (pioglitazone), since this agent potentially showed an anti-inflammatory effect. Mouse 3T3-L1 adipocytes were stimulated with E. coli, P. gingivalis, and F. nucleatum LPS. The IL-6 concentration in culture supernatants was measured. All LPS stimulated adipocytes to produce IL-6. Although pioglitazone changed adipocyte appearance from large to small, and completely suppressed P. gingivalis and F. nucleatum LPS-induced IL-6 production, E. coli LPS-induced IL-6 production was not efficiently blocked. Thus, pioglitazone completely blocked periodontal-bacteria-derived LPS-induced IL-6 production in adipocytes, a major inducer of CRP.

Hypotonic Stress-induced Down-regulation of Claudin-1 and -2 Mediated by Dephosphorylation and Clathrin-dependent Endocytosis in Renal Tubular Epithelial Cells

Hypotonic stress decreased claudin-1 and -2 expression levels in renal tubular epithelial HK-2 and Madin-Darby canine kidney cells. Here, we examined the regulatory mechanism involved in this decrease. The hypotonicity-induced decrease in claudin expression was inhibited by the following: SB202190, a p38 MAPK inhibitor, but not by U0126, a MEK inhibitor; Go6983, a protein kinase C inhibitor; or SP600125, a Jun N-terminal protein kinase inhibitor. Hypotonic stress increased transepithelial electrical resistance, which was inhibited by SB202190. The mRNA expression level of claudin-1 was decreased by hypotonic stress but that of claudin-2 was not. Hypotonic stress decreased the protein stability of claudin-1 and -2. The hypotonicity-induced decrease in claudin expression was inhibited by the following: chloroquine, a lysosome inhibitor; dynasore and monodansylcadaverine, clathrin-dependent endocytosis inhibitors; and siRNA against clathrin heavy chain. Claudin-1 and -2 were mainly distributed in the cytosol and tight junctions (TJs) in the chloroquine- and monodansylcadaverine-treated cells, respectively. Hypotonic stress decreased the phosphorylation levels of claudin-1 and -2, which were inhibited by the protein phosphatase inhibitors okadaic acid and cantharidin. Dephosphorylated mutants of claudin-1 and -2 were mainly distributed in the cytosol, which disappeared in response to hypotonic stress. In contrast, mimicking phosphorylation mutants were distributed in the TJs, which were not decreased by hypotonic stress. We suggest that hypotonic stress induces dephosphorylation, clathrin-dependent endocytosis, and degradation of claudin-1 and -2 in lysosomes, resulting in disruption of the TJ barrier in renal tubular epithelial cells.

Rhodium-catalyzed transformation of heteroaryl aryl ethers into heteroaryl fluorides

A rhodium complex catalyzed the conversion of the C-O bond of heteroaryl aryl ethers to the C-F bond. The reaction of (4-chlorophenylthio)pentafluorobenzene with heteroaryl aryl ethers provided heteroaryl fluorides and heteroaryl (4-chlorophenylthio)tetrafluorophenyl ethers; this involved the cleavage of a single heteroaryl C-O bond under equilibrium conditions. The reaction of heteroaryl aryl ethers with 2-fluorobenzothiazole in which two heteroaryl and aryl C-O bonds were cleaved provided heteroaryl fluorides and aryl fluorides. The reactions were applicable to five-membered and six-membered heteroaryl aryl ethers and also to diaryl ethers possessing one or two electron-withdrawing groups.

Antibacterial Nucleoside Natural Products Inhibiting Phospho-MurNAc-Pentapeptide Translocase; Chemistry and Structure-Activity Relationship

The continued emergence of drug-resistance to existing antibacterial agents represents a severe and ongoing public health concern, which demands the discovery of new antibiotics. However the number of novel classes of antibacterial drugs launched in the clinic has been remarkably slow since the 1960s, and it is urgent to develop novel antibacterial agents to fight against drug-resistant bacterial pathogens. Peptidoglycan is a component of the bacterial cell wall, which consists of a repeated N-acetylmuramic acid (MurNAc) and Nacetylglucosamine (GluNAc) polymer cross-linked with polypeptides, and is a good target for antibacterial drug discovery. Among enzymes responsible for its biosynthesis, phospho-MurNAc-pentapeptide translocase (MraY) is a novel and promising target. Many nucleoside natural products, which strongly inhibit MraY, have been found in nature. This review will summarize the synthesis and biological properties of selected MraY inhibitory nucleoside natural products and their analogues synthesized in our laboratory and by others.

Deterministic and Stochastic Chiral Symmetry Breaking Exhibited by Racemic Aminomethylenehelicene Oligomers

Racemic mixtures of aminomethylenehelicene (P)- and (M)-pentamers exhibited deterministic and stochastic chiral symmetry breaking during hetero-double-helix formation and self-assembly in solution. Heating a 50:50 mixture of (P)- and (M)-pentamers at 90 °C, and then cooling the mixture to 70 °C resulted in hetero-double-helix formation; a Cotton effect with negative Δε at λ=315 nm appeared. Chiral self-assembly occurred when the mixture was cooled to 25 °C. A strong tendency of deterministic chiral symmetry breaking appeared at the molecular and self-assembled levels, which was indicated by the negative Δε at λ=315 nm that appeared in most cases in repeated experiments. Mixtures containing 60:40 and 40:60 (P)-/(M)-pentamers also self-assembled with the same chirality. When a homo-double-helix (P)-/(M)-pentamer and a random coil (M)-/(P)-pentamer were mixed, the chiral self-assembly formed stochastically, and heating and cooling resulted in deterministic chiral symmetry breaking.

The Effects of Exercise in Forest and Urban Environments on Sympathetic Nervous Activity of Normal Young Adults

In Japan, forest-air bathing and walking (shinrin-yoku) has been proposed as a health-facilitating activity in which people spend a short period of time in a forest environment. Initially, we examined the usefulness of salivary amylase activity as an indicator of an individual's stress levels in a forest environment. The circadian rhythm of salivary amylase activity was measured in healthy young male subjects under stress-free conditions. The salivary amylase activity remained relatively constant throughout the day. Salivary amylase activity was then measured before and after walking in both urban and forest environments using a hand-held monitor. Our results indicated that (i) the circadian rhythm fluctuations in salivary amylase activity were much smaller than the stressor-induced variations; (ii) salivary amylase activity was an excellent indicator of the changes in sympathetic nervous activity; and (iii) the forest was a good environment in which people could experience much less environment-derived stress.

Evaluation of Driver Stress in a Motor-vehicle Driving Simulator Using a Biochemical Marker

The purpose of this study was to evaluate salivary amylase activity (sAMY) as an indicator of the acute psychological effects of driving. The influence of the operation of a device not directly associated with driving was also estimated using a car navigation system. The psychological effects of driving were examined using sAMY analysis, oculomotor angle and subjective evaluation with a questionnaire, and the methods were compared. The change in sAMY over time was analysed before and during driving. The results indicate that the psychological effect of driving-induced stress, a condition that cannot be easily detected or recognized by a subjective evaluation, is quickly quantified using sAMY. Moreover, the results suggest that the operation of a non-driving-related device may also reduce the driver's capacity to concentrate on driving.

Non-verbal Communication Method Based on a Biochemical Marker for People with Severe Motor and Intellectual Disabilities

This study evaluated a novel non-verbal communication method for people with severe motor and intellectual disabilities (SMID) based on a biochemical marker, salivary amylase. The physical and psychological status of 10 people with SMID was quantitatively evaluated using a hand-held salivary amylase activity monitor. Each patient needed daily gastric and/or bronchial tube exchanges and these medical procedures were thought to cause severe distress and pain. Salivary amylase activity and heart rate were simultaneously measured during 32 medical procedures. The medical procedures resulted in a significant mean increase for individuals of 70% in salivary amylase activity. The increase in salivary amylase activity was more than four-fold that observed for heart rate. The structural equation modelling analysis also demonstrated a significant correlation between pain and salivary amylase activity. Our data indicate that salivary amylase activity might be used as a non-verbal method of assessing pain in people with SMID.

Effects of Cold Stimulation on Mitochondrial Activity and VEGF Expression in vitro

We aimed to clarify the effects of cold stimulation at various temperatures on mitochondrial activity and vascular endothelial growth factor (VEGF) expression in vitro. Human fibroblast, human mesenchymal stem cell, and rat skeletal muscle myoblast cell lines were used. For each cell type, cells were divided into 4 groups and stimulated in various cold temperatures (0, 4, 17 and 25°C) 3 times for 15 min each by placement on crushed ice or floating on cold water set at each temperature. Control cells were subjected to warm water at 37°C. Factors related to mitochondrial activity, mitochondrial DNA copy numbers, and VEGF expression were analyzed 24 h after the last cold stimulation. In all cell types, significant increases of factors related to mitochondrial activity and mitochondrial DNA copy numbers were seen in the 4°C and 17°C-stimulated cells compared with control cells. In rat skeletal muscle cells stimulated at 4°C, VEGF expression significantly increased compared to the control cells. Our data suggest that cold stimulation at certain temperatures promotes mitochondrial activity, biogenesis and VEGF expression.

Abstract P5-18-01: A randomized clinical trial of postoperative adjuvant therapy for elderly breast cancer patients: Conditions of obtaining informed consent and reasons for declining participation

Background: There are few randomized clinical trials examining adjuvant treatment in elderly breast cancer patients. While obtaining informed consent is essential for participation in clinical studies, there is little information on the frequency of agreement to participate among elderly patients. Furthermore, elderly patients might have specific reasons to decline participation.

Patients and Method: The National Surgical Adjuvant Study of Breast Cancer 07 (N-SAS BC 07) is a randomized clinical trial in women over 70 years with HER2-positive primary breast cancer. The primary aim was to investigate the benefit of trastuzumab monotherapy compared with the combination of trastuzumab and chemotherapy. Key inclusion criteria were as follows: women between 70 and 80 years old with HER2-positive breast cancer; underwent curative operation; stage I to IIIA; with sufficient organ function. Patients were randomized to receive either trastuzumab plus chemotherapy or trastuzumab monotherapy. The primary endpoint was disease-free survival, and the secondary endpoints were overall survival, relapse-free survival, safety, health-related quality of life, and cost effectiveness (NCT01104935). It was not possible to predict the number of patients who would agree to participate. In order to comprehensively assess the effect of postoperative adjuvant therapy, we evaluated the reasons why eligible patients declined to participate. The patients were registered in a cohort study to prospectively evaluate the subsequent treatment options and prognosis (07-Cohort). This study examined the obtaining of informed consent for N-SAS BC 07 and the reasons for declining participation, and compared the clinicopathological backgrounds between the N-SAS BC 07 and 07-Cohort groups.

Results: 398 eligible patients have been recruited. Informed consent to participate in N-SAS BC 07 has been obtained from 275 patients (69%) and 123 patients (31%) who declined to participate in the RCT have been registered in the 07-Cohort. The common reasons to decline participation in the RCT were "cannot choose the treatment option (55%)", "refused chemotherapy (16%)", "wanted chemotherapy (9%)", "anxious about clinical studies (9%)" and "family opposition (8%)". The mean ages of the patients in N-SAS BC 07 and 07-Cohort were 73.9 and 74.6 years old, respectively. There were no differences in stage, surgical procedure, lymph node metastasis, or co-morbidities between the groups. ER-positive rate was higher in 07-Cohort group compared with N-SAS BC 07 group (53% vs. 37%, p=0.017, χ2 test).

Conclusion: While we expected the number of registrants to be small, since N-SAS BC 07 investigated whether elderly patients with HER2-positive breast cancer should undergo chemotherapy, almost 70% of the patients accepted informed consent. The most common reason to decline participation in N-SAS BC 07 was "cannot choose the treatment option" and the majority refused chemotherapy. Furthermore, ER-positivity was higher in the 07-Cohort group, which suggested that ER expression in the patients with HER2-positive breast cancer might influence their decision to participate in the study or to choose the treatment option.

Citation Format: Sagara Y, Sawaki M, Taira N, Saito T, Kashiwaba M, Iwata H, Kobayashi K, Nakayama T, Bando H, Mizuno T, Yamamoto Y, Tsuneizumi M, Takahashi M, Yamaguchi M, Kawashima H, Takashima T, Uemura Y, Hozumi Y, Sagawa N, Mukai H, Ohashi Y. A randomized clinical trial of postoperative adjuvant therapy for elderly breast cancer patients: Conditions of obtaining informed consent and reasons for declining participation. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P5-18-01.

Abstract P4-11-09: A randomized controlled trial of postoperative adjuvant therapy for elderly breast cancer patients: Comparison of health-related quality of life between clinical trial participants and decliners

Background: Health-related quality of life (HRQoL) is one of the important outcomes in cancer control trials and has increasingly become the one of the primary foci. Obtaining informed consent from participants is essential for participation in randomized controlled trials (RCTs), but the participation in these RCTs may directly influence HRQoL, because treatment options are determined according to the allocation schedule. To date, only a few studies have compared HRQoL between clinical trial participants and decliners.

Patients and Method: The National Surgical Adjuvant Study of Breast Cancer 07 (N-SAS BC 07) is a randomized controlled trial in women with HER2-positive primary breast cancer who are over 70 years of age. The primary aim was to investigate the benefit of trastuzumab monotherapy compared with combination therapy using trastuzumab and chemotherapy. The study concept and design were published in concept paper (Sawaki M. et al., Jpn J Clin Oncol. 2011). In this study, patients were randomized to receive either trastuzumab plus chemotherapy or trastuzumab monotherapy. The primary endpoint was disease-free survival, and the secondary endpoints were overall survival, relapse-free survival, safety, HRQoL, comprehensive geriatric assessment (CGA) and cost effectiveness (protocol ID; NCT01104935).

HRQoL and CGA were assessed at registration (baseline), 2 month, 1 year, and 3 years after the start of protocol treatments using the Functional Assessment of Cancer Therapy-General (FACT-G), Hospital Anxiety and Depression Scale (HADS), EuroQol 5 Dimension (EQ-5D), Tokyo Metropolitan Institute of Gerontology (TMIG) index of competence, and the Philadelphia Geriatric Center (PGC) Morale Scale.

The patients who declined to participate in N-SAS BC 07 were registered in a cohort study to prospectively evaluate the subsequent treatment options and prognosis (07-Cohort). The same questionnaire that was used in N-SAS BC 07 was used in 07-Cohort to evaluate HRQoL and CGA at entry.

Results: Patients were enrolled from October 2012 to October 2016. During this period, 275 and 123 patients were registered in N-SAS BC 07 and 07-Cohort, respectively. The mean age at entry of the patients in the N-SAS BC 07 and 07-Cohort groups was 73.9 and 74.6 years, respectively. The questionnaire response rates at baseline in the patients in N-SAS BC 07 and 07-Cohort groups were 89% and 82%, respectively. There were no significant differences in FACT-G, HADS, EQ-5D, or TMIG index of competence at baseline between the groups, but the mean (standard deviation) scores of PGC Morale Scale in N-SAS BC 07 and 07-Cohort groups were 10.8 (3.3) and 9.9 (3.7), respectively, with the scores being significantly greater in the N-SAS BC 07 group (p=0.020, t-test).

Conclusion: The PGC Morale Scale provides a multidimensional approach to assess the psychological state of older people. This study indicated that participation in the RCT did not affect the baseline QoL of elderly patients but suggested that the baseline QoL of the RCT participants was better than decliners.

Citation Format: Saito T, Sawaki M, Hozumi Y, Sagawa N, Iwata H, Kashiwaba M, Kawashima H, Kobayashi K, Taira N, Takashima T, Takahashi M, Tsuneizumi M, Nakayama T, Baba S, Bando H, Mizuno T, Yamaguchi M, Yamamoto Y, Uemura Y, Ohashi Y, Mukai H. A randomized controlled trial of postoperative adjuvant therapy for elderly breast cancer patients: Comparison of health-related quality of life between clinical trial participants and decliners. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P4-11-09.

"Inverse" thermoresponse: heat-induced double-helix formation of an ethynylhelicene oligomer with tri(ethylene glycol) termini

Ethynylhelicene oligomers with TEG terminal groups showed a unique thermoresponse in aqueous solvents: double-helix formation upon heating and disaggregation upon cooling.

An ethynylhelicene oligomer [(M)-d-4]-C₁₂-TEG with six tri(ethylene glycol) (TEG) groups at the termini was synthesized, and double-helix formation was studied using CD, UV-Vis, vapor pressure osmometry, dynamic light scattering, and ¹H NMR. [(M)-d-4]-C₁₂-TEG reversibly changed its structure between a double helix and a random coil in response to heating and cooling in aromatic solvents, non-aromatic polar organic solvents, and aqueous solvent mixtures of acetone/water/triethylamine. Notably, [(M)-d-4]-C₁₂-TEG in acetone/water/triethylamine (1/2/1) formed a double helix upon heating and disaggregated into random coils upon cooling. The double helix/random coil ratio sharply changed in response to temperature changes. This is an unprecedented “inverse” thermoresponse, which is opposite to the “ordinary” thermoresponse in molecular dimeric aggregate formation. This phenomenon was explained by the dehydration of the terminal TEG groups and the formation of condensed triethylamine domains upon heating.

Rhodium-catalyzed P–P bond exchange reaction of diphosphine disulfides

A rhodium-catalyzed exchange reaction of diphosphine disulfides, a diphosphine oxide, and a diphosphine is developed. Various symmetric diphosphine disulfides containing alkyl and phenyl groups are exchanged.

Real-world assessment of diquafosol in dry eye patients with risk factors such as contact lens, meibomian gland dysfunction, and conjunctivochalasis: subgroup analysis from a prospective observational study

Purpose

To evaluate the efficacy and safety of diquafosol (DQS) ophthalmic solution in dry eye (DE) patients wearing contact lenses (CLs) or with concomitant meibomian gland dysfunction (MGD) or conjunctivochalasis in a real-world setting.

Patients and methods

From a cohort of patients enrolled in a prospective observational study, DE patients who met the Japanese diagnostic criteria and who received DQS as a monotherapy were extracted and stratified according to the presence or absence of CL use, MGD, and conjunctivochalasis. Corneal and conjunctival fluorescein staining score, tear film break-up time, total symptom score (12 DE-related subjective symptoms), patient-reported outcomes, and adverse reactions were investigated.

Results

DQS treatment resulted in significant improvement in total symptom score, corneal and conjunctival fluorescein staining score, and tear film break-up time without significant differences between patient subgroups with versus without CL use, MGD, or conjunctivochalasis. Comparable proportions of patients perceived symptomatic improvements in all subgroups. There were no adverse reactions specifically associated with the CL use or any comorbidity of MGD or conjunctivochalasis.

Conclusion

DQS can be used effectively and safely as a monotherapy for the treatment of DE patients wearing CLs or with concomitant MGD or conjunctivochalasis.

Threonine-408 Regulates the Stability of Human Pregnane X Receptor through Its Phosphorylation and the CHIP/Chaperone-Autophagy Pathway

The human pregnane X receptor (hPXR) is a xenobiotic-sensing nuclear receptor that transcriptionally regulates drug metabolism-related genes. The aim of the present study was to elucidate the mechanism by which hPXR is regulated through threonine-408. A phosphomimetic mutation at threonine-408 (T408D) reduced the transcriptional activity of hPXR and its protein stability in HepG2 and SW480 cells in vitro and mouse livers in vivo. Proteasome inhibitors (calpain inhibitor I and MG132) and Hsp90 inhibitor geldanamycin, but not Hsp70 inhibitor pifithrin-μ, increased wild-type (WT) hPXR in the nucleus. The translocation of the T408D mutant to the nucleus was significantly reduced even in the presence of proteasome inhibitors, whereas the complex of yellow fluorescent protein (YFP)-hPXR T408D mutant with heat shock cognate protein 70/heat shock protein 70 and carboxy terminus Hsp70-interacting protein (CHIP; E3 ligase) was similar to that of the WT in the cytoplasm. Treatment with pifithrin-μ and transfection with anti-CHIP small-interfering RNA reduced the levels of CYP3A4 mRNA induced by rifampicin, suggesting the contribution of Hsp70 and CHIP to the transactivation of hPXR. Autophagy inhibitor 3-methyladenine accumulated YFP-hPXR T408D mutant more efficiently than the WT in the presence of proteasome inhibitor lactacystin, and the T408D mutant colocalized with the autophagy markers, microtubule-associated protein 1 light chain 3 and p62, which were contained in the autophagic cargo. Lysosomal inhibitor chloroquine caused the marked accumulation of the T408D mutant in the cytoplasm. Protein kinase C (PKC) directly phosphorylated the threonine-408 of hPXR. These results suggest that hPXR is regulated through its phosphorylation at threonine-408 by PKC, CHIP/chaperone-dependent stability check, and autophagic degradation pathway.

Development of QSAR models using artificial neural network analysis for risk assessment of repeated-dose, reproductive, and developmental toxicities of cosmetic ingredients

Use of laboratory animals for systemic toxicity testing is subject to strong ethical and regulatory constraints, but few alternatives are yet available. One possible approach to predict systemic toxicity of chemicals in the absence of experimental data is quantitative structure-activity relationship (QSAR) analysis. Here, we present QSAR models for prediction of maximum "no observed effect level" (NOEL) for repeated-dose, developmental and reproductive toxicities. NOEL values of 421 chemicals for repeated-dose toxicity, 315 for reproductive toxicity, and 156 for developmental toxicity were collected from Japan Existing Chemical Data Base (JECDB). Descriptors to predict toxicity were selected based on molecular orbital (MO) calculations, and QSAR models employing multiple independent descriptors as the input layer of an artificial neural network (ANN) were constructed to predict NOEL values. Robustness of the models was indicated by the root-mean-square (RMS) errors after 10-fold cross-validation (0.529 for repeated-dose, 0.508 for reproductive, and 0.558 for developmental toxicity). Evaluation of the models in terms of the percentages of predicted NOELs falling within factors of 2, 5 and 10 of the in-vivo-determined NOELs suggested that the model is applicable to both general chemicals and the subset of chemicals listed in International Nomenclature of Cosmetic Ingredients (INCI). Our results indicate that ANN models using in silico parameters have useful predictive performance, and should contribute to integrated risk assessment of systemic toxicity using a weight-of-evidence approach. Availability of predicted NOELs will allow calculation of the margin of safety, as recommended by the Scientific Committee on Consumer Safety (SCCS).

Hyperosmolarity-Induced Down-Regulation of Claudin-2 Mediated by Decrease in PKCβ-Dependent GATA-2 in MDCK Cells

Hyperosmolarity decreases claudin-2 expression in renal tubular epithelial cells, but the molecular mechanism remains undefined. Here, we found that the hyperosmolarity-induced decrease in claudin-2 expression is inhibited by Go6983, a non-selective protein kinase C (PKC) inhibitor, and PKCβ specific inhibitor in Madin-Darby canine kidney II cells. Hyperosmolarity increased intracellular free Ca(2+) concentration and phosphorylated PKCβ level, which were inhibited by RN-1734, an antagonist of transient receptor potential vanilloid 4 channel. Phorbol 12-myristate 13-acetate, a PKC activator, decreased claudin-2 expression. These results indicate hyperosmolarity decreases claudin-2 expression mediated by the activation of RN-1734-sensitive channel and PKCβ. Hyperosmolarity decreased promoter activity of claudin-2, which was inhibited by Go6983 and PKCβ inhibitor similar to those in real-time PCR and Western blotting. The effect of hyperosmolarity on promoter activity was not observed in the construct of -469/-6, a deletion mutant. Claudin-2 has hyperosmolarity-sensitive region in its promoter, which includes GATA binding site. Hyperosmolarity decreased the nuclear level of GATA-2, which was inhibited by Go6983 and PKCβ inhibitor. Mutation of GATA binding site decreased the basal promoter activity and inhibited the effect of hyperosmolarity. In contrast, the hyperosmolarity-induced decrease in reporter activity and claudin-2 expression were rescued by over-expression of wild type GATA-2. Chromatin immunoprecipitation assay showed that GATA-2 bound to promoter region of claudin-2. These results suggest that hyperosmolarity decreases the expression level of claudin-2 via a decrease in PKCβ-dependent GATA-2 transcriptional activity in renal tubular epithelial cells.

Calcitonin Receptor Signaling Inhibits Muscle Stem Cells from Escaping the Quiescent State and the Niche

Calcitonin receptor (Calcr) is expressed in adult muscle stem cells (muscle satellite cells [MuSCs]). To elucidate the role of Calcr, we conditionally depleted Calcr from adult MuSCs and found that impaired regeneration after muscle injury correlated with the decreased number of MuSCs in Calcr-conditional knockout (cKO) mice. Calcr signaling maintained MuSC dormancy via the cAMP-PKA pathway but had no impact on myogenic differentiation of MuSCs in an undifferentiated state. The abnormal quiescent state in Calcr-cKO mice resulted in a reduction of the MuSC pool by apoptosis. Furthermore, MuSCs were found outside their niche in Calcr-cKO mice, demonstrating cell relocation. This emergence from the sublaminar niche was prevented by the Calcr-cAMP-PKA and Calcr-cAMP-Epac pathways downstream of Calcr. Altogether, the findings demonstrated that Calcr exerts its effect specifically by keeping MuSCs in a quiescent state and in their location, maintaining the MuSC pool.

Influence of Eyelid Pressure on Fluorescein Staining of Ocular Surface in Dry Eyes

PURPOSE

To determine the relationship between eyelid pressure during blinking and the fluorescein staining of the cornea and conjunctiva in dry eye patients.

DESIGN

Cross-sectional prospective study.

METHODS

The pressure of the upper and lower eyelids was measured with a specially designed blepahro-tensiometer in 130 eyes of 65 dry eye patients (D group) and in 58 eyes of 31 normal controls (N group). The correlations between the location and degree of ocular surface staining scores and the eyelid pressure were calculated for the D group.

RESULTS

The pressures of the upper and lower eyelids were significantly higher in the D group than in the N group (upper P < .0001, lower P = .0040). The lower eyelid pressure was significantly correlated with the ocular surface staining scores for the inferior cornea (r = 0.19, P = .0307) and conjunctiva (r = 0.19, P = .0252).

CONCLUSIONS

The significant correlation between the eyelid pressure and the ocular surface staining suggests that mechanical friction on the ocular surface by the eyelids may be one of the factors that affects the fluorescein staining of the inferior ocular surface.

Involvement of a cyclic adenosine monophosphate-dependent signal in the diet-induced canalicular trafficking of adenosine triphosphate-binding cassette transporter g5/g8

The adenosine triphosphate-binding cassette (ABC) half-transporters Abcg5 and Abcg8 promote the secretion of neutral sterol into bile. Studies have demonstrated the diet-induced gene expression of these transporters, but the regulation of their trafficking when the nutritional status changes in the liver remains to be elucidated. Here, we generated a novel in vivo kinetic analysis that can monitor the intracellular trafficking of Abcg5/Abcg8 in living mouse liver by in vivo transfection of the genes of fluorescent protein-tagged transporters and investigated how hypernutrition affects the canalicular trafficking of these transporters. The kinetic analysis showed that lithogenic diet consumption accelerated the translocation of newly synthesized fluorescent-tagged transporters to intracellular pools in an endosomal compartment and enhanced the recruitment of these pooled gene products into the bile canalicular membrane in mouse liver. Because some ABC transporters are reported to be recruited from intracellular pools to the bile canaliculi by cyclic adenosine monophosphate (cAMP) signaling, we next evaluated the involvement of this machinery in a diet-induced event. Administration of a protein kinase A inhibitor, N-(2-{[3-(4-bromophenyl)-2-propenyl]amino}ethyl)-5-isoquinolinesulfonamide, decreased the canalicular expression of native Abcg5/Abcg8 in lithogenic diet-fed mice, and injection of a cAMP analog, dibutyryl cAMP, transiently increased their levels in standard diet-fed mice, indicating the involvement of cAMP signaling. Indeed, canalicular trafficking of the fluorescent-tagged Abcg5/Abcg8 was enhanced by dibutyryl cAMP administration.

CONCLUSION

These observations suggest that diet-induced lipid loading into liver accelerates the trafficking of Abcg5/Abcg8 to the bile canalicular membrane through cAMP signaling machinery.

Evidence of Notch-Hesr-Nrf2 Axis in Muscle Stem Cells, but Absence of Nrf2 Has No Effect on Their Quiescent and Undifferentiated State

Nrf2 is a master regulator of oxidative stresses through the induction of anti-oxidative genes. Nrf2 plays roles in maintaining murine hematopoietic stem cells and fly intestinal stem cells. The canonical Notch signaling pathway is also crucial for maintaining several types of adult stem cells including muscle stem cells (satellite cells). Here, we show that Dll1 induced Nrf2 expression in myogenic cells. In addition, primary targets of Notch signaling, Hesr1 and Hesr3, were involved in the up-regulation of Nrf2 mRNA and expression of its target genes. In vitro, Nrf2 had anti-myogenic and anti-proliferative effects on primary myoblasts. In vivo, although Nrf2-knockout mice showed decreased expression of its target genes in muscle stem cells, adult muscle stem cells of Nrf2-knockout mice did not exhibit the phenotype. Taken together, in muscle stem cells, the Notch-Hesr-Nrf2 axis is a pathway potentially inducing anti-oxidative genes, but muscle stem cells either do not require Nrf2-mediated anti-oxidative gene expression or they have a complementary system compensating for the loss of Nrf2.

Hepatic angiomyolipoma growing to cause epigastric discomfort: a case report

We report herein a case of hepatic angiomyolipoma growing to cause epigastric discomfort. A 33-year-old man was referred for excisional operation of hepatic hypervascular tumor, complaining of epigastric discomfort. The tumor had enlarged from the time 3 years before when the tumor was diagnosed as hepatic hemangioma in the lateral segment. Partial hepatectomy with tumor resection was carried out. Pathological diagnosis was confirmed as hepatic angiomyolipoma with a finding of enriched vessels, extramedullary hematopoiesis, fatty tissue, and most epithelioid cells immunoreactive to HMB-45. Further analysis also revealed positive staining cells for granulocyte colony-stimulating factor. It was suggested that growth of hepatic angiomyolipoma in this case might be caused by extramedullary hematopoiesis induced by granulocyte colony-stimulating factor.

Clathrin-dependent endocytosis of claudin-2 by DFYSP peptide causes lysosomal damage in lung adenocarcinoma A549 cells

Claudins are tight junctional proteins and comprise a family of over 20 members. Abnormal expression of claudins is reported to be involved in tumor progression. Claudin-2 is highly expressed in lung adenocarcinoma tissues and increases cell proliferation, whereas it is not expressed in normal tissues. Claudin-2-targeting molecules such as peptides and small molecules may be novel anti-cancer drugs. The short peptide with the sequence DFYSP, which mimics the second extracellular loop of claudin-2, decreased claudin-2 content in the cytoplasmic fraction of A549 cells. In contrast, it did not affect the content in the nuclear fraction. The decrease in claudin-2 content was inhibited by chloroquine (CQ), a lysosomal inhibitor, but not by MG-132, a proteasome inhibitor. In the presence of DFYSP peptide and CQ, claudin-2 was co-localized with LAMP-1, a lysosomal marker. The DFYSP peptide-induced decrease in claudin-2 content was inhibited by monodancylcadaverine (MDC), an inhibitor of clathrin-dependent endocytosis. DFYSP peptide increased lysosome content and cathepsin B release, and induced cellular injury, which were inhibited by MDC. Cellular injury induced by DFYSP peptide was inhibited by necrostatin-1, an inhibitor of necrotic cell death, but not by Z-VAD-FMK, an inhibitor of apoptotic cell death. Our data indicate that DFYSP peptide increases the accumulation of the peptide and claudin-2 into the lysosome, resulting in lysosomal damage. Claudin-2 may be a new target for lung cancer therapy.

A palladium-catalyzed addition reaction of aroyl/heteroaroyl acid anhydrides to norbornenes

A palladium complex derived from Pd2(dba)3 and dppp catalyzes the addition reaction of aroyl/heteroaroyl acid anhydrides to norbornenes, giving 2-aroyl/heteroaroyl-3-aroyloxy/heteroaroyloxy-bicyclo[2,2,1]heptanes. The C-O bond of acid anhydride is cleaved, and the aroyl/heteroaroyl and aroyloxy/heteroaroyloxy groups are added to alkenes. trans-Adducts are selectively obtained with the endo-benzoyl group and exo-benzoyloxy group.

Energy Aspects of Thermal Molecular Switching: Molecular Thermal Hysteresis of Helicene Oligomers

Molecular switching is a phenomenon by which a molecule reversibly changes its structure and state in response to external stimuli or energy. Herein, molecular switching is discussed from thermodynamic and kinetic aspects in terms of energy supply with an emphasis on the thermal switching exhibited by helicene oligomers. It includes the inversion of relative thermodynamic stability induced by temperature changes and molecular thermal hysteresis in a closed system. The thermal phenomenon associated with the oligomers involves population/concentration changes between metastable states under nonequilibrium thermodynamic control.

Suppression of NF-κB activation by gentian violet promotes osteoblastogenesis and suppresses osteoclastogenesis

Skeletal mass is regulated by the coordinated action of bone forming osteoblasts and bone resorbing osteoclasts. Accelerated rates of bone resorption relative to bone formation lead to net bone loss and the development of osteoporosis, a devastating disease that predisposes the skeleton to fractures. Bone fractures are associated with significant morbidity and in the case of hip fractures, high mortality. Gentian violet (GV), a cationic triphenylmethane dye, has long been used as an antifungal and antibacterial agent and is presently under investigation as a potential chemotherapeutic and antiangiogenic agent. However, effects on bone cells have not been previously reported and the mechanisms of action of GV, are poorly understood. In this study we show that GV suppresses receptor activator of NF-κB ligand (RANKL)-induced differentiation of RAW264.7 osteoclast precursors into mature osteoclasts, but paradoxically stimulates the differentiation of MC3T3 cells into mineralizing osteoblasts. These actions stem from the capacity of GV to suppress activation of the nuclear factor kappa B (NF-κB) signal transduction pathway that is required for osteoclastogenesis, but inhibitory to osteoblast differentiation and activity. Our data reveal that GV is an inhibitor of NF-κB activation and may hold promise for modulation of bone turnover to promote a balance between bone formation and bone resorption, favorable to gain of bone mass.

Involvement of Eyelid Pressure in Lid-Wiper Epitheliopathy

OBJECTIVES

To determine whether eyelid pressure is involved in the development of lid-wiper epitheliopathy (LWE).

METHODS

Study 1: The eyelid pressure was measured with a blepharo-tensiometer, and the degree of LWE was assessed in 79 eyes of 43 non-contact lens (CL) wearers. Study 2: The movements of the eyelids and displacement of the eyes during spontaneous blinking were photographed with a high-speed camera. The eyelid pressure was also measured in 34 normal eyes of 19 non-CL wearers who were not part of Study 1.

RESULTS

Study 1: Upper-LWE was detected in 24 of 79 eyes (30.4%), and no significant difference was detected in the eyelid pressure between any grade of upper-LWE. Lower-LWE was detected in 41 of 79 eyes (51.9%), and the eyelid pressure (27.9 ± 2.8 mmHg) in eyes with grade 3 LWE was significantly higher than that with grade 0 LWE (19.7 ± 1.3 mmHg; p < 0.05). Study 2: The lower eyelid pressure was significantly correlated with the length of the horizontal movement of the lower eyelids (p < 0.05) and also with the degree of posterior movement of the eye globe (p < 0.05).

CONCLUSIONS

The higher pressure from the eyelid may be one of the causes for the development of lower-LWE.