Effects of EPS-induced Nrf2 activation on ROS/RNS levels.

<p>EPS-treated and untreated C2C12 myotubes were loaded with DCFH-DA (20 μM) at 0 and after 1 and 3 h EPS. The graph shows the fluorescence intensity of DCF/HPF in C2C12 myotubes. Fluorescence intensity of DCF was measured using fluorescence microscopy imaging (n = 6). Scale bar = 100 μm. *p < 0.05 vs. mock; †p < 0.05 vs. non-EPS.</p

Inhibition of EPS-induced cell wasting in C2C12 myotubes by Nrf2 activation.

<p>(a) Images show immunocytochemical staining of Annexin V and propidium iodide (PI) staining in EPS-treated and untreated C2C12 myotubes. Annexin V positive signals are indicated with arrows. (b) The graph shows fluorescence intensity of Annexin V/HPF in C2C12 myotubes. Annexin V expression was measured by fluorescence microscopy imaging (n = 6). (c) Graph shows the cell viability of non-EPS or EPS treated C2C12 myotubes (n = 6) as determined by the MTT assay. *p < 0.001 vs. mock-transfected; †p < 0.05 vs. non-EPS.</p

Attenuation of EPS-induced Nrf2 activation and Nrf2-related gene expression via Nrf2 knockdown in C2C12 myotubes.

<p>(a, b) C2C12 cells were transfected with siRNA against Nrf2 or a mock control. After 24 h transfection, cells were treated with EPS for 3 h. (a) Total cell lysate was analyzed by western blotting using an anti-Nrf2 antibody. (b) Expression levels of Nrf2-related genes were analyzed by quantitative PCR (n = 6). *p < 0.05, ** p < 0.001 vs. mock; †p < 0.05, ††p < 0.001 vs. non-EPS.</p

ROS production and Nrf2 expression induced in C2C12 myotubes by EPS.

<p>(a) Images show ROS/RNS production in C2C12 myotubes. EPS-treated C2C12 cells were loaded with DCFH-DA (20 μM) for 15 min. The static cells were then stimulated with EPS or left untreated for 3 h. Cells were washed with culture medium 3 times and live cells were imaged on an inverted fluorescence microscope. Scale bar = 100 μm. (b, d) Graph shows the fluorescence intensity of DCF/HPF in C2C12 myotubes. Fluorescence intensity of DCF was measured by fluorescence microscopy imaging (n = 3). (c, e) Protein expression levels assessed by western blotting are shown here. α-Tubulin was used as an internal standard for protein loading. *p < 0.05.</p

Effects of NOS inhibition on EPS-induced Nrf2 activation and Nrf2-regulated gene expression.

<p>(a, b, c) 1 hour with L-NAME (2 mM) followed by EPS for 3 h. (a) Total cell lysate was analyzed by western blotting using an anti-Nrf2 antibody. (b) Expression levels of Nrf2-regulated genes were analyzed by quantitative PCR (n = 3). (c) Images show ROS/RNS production in C2C12 myotubes. Scale bar = 100 μm. Graph shows the fluorescence intensity of DCF/HPF in C2C12 myotubes. Fluorescence intensity of DCF was measured by fluorescence microscopy imaging (n = 3). †p < 0.05 vs. non-EPS.</p

Reversible Laser-Induced Bending of Pseudorotaxane Crystals

This study investigated the dynamic photoresponse of pseudorotaxane crystals with azobenzene and ferrocenyl groups in the axle component. X-ray crystallography showed pseudorotaxanes with a methylazobenzene group and a dibromophenylene ring in the cyclic component to exhibit twisting of the <i>trans</i>-azobenzene groups at torsion angles of 17° and 38°, respectively. Repeated alternating laser irradiation of the crystals at 360 and 445 nm produced bending of 20–30° in opposite directions, with no evidence of decay. Under 445 nm irradiation, bending took place within 0.3 s. A crystal of nonsubstituted pseudorotaxane showed bending of only 2° under 360 nm irradiation due to multiple π–π interactions between the planar <i>trans</i>-azobenzene groups. The pseudorotaxane crystals have two chromophores, bent rapidly and reversibly on irradiation at rates depending on the molecular structure

Thermally-Induced Phase Transition of Pseudorotaxane Crystals: Changes in Conformation and Interaction of the Molecules and Optical Properties of the Crystals

This paper presents a pseudorotaxane that acts as a thermally driven molecular switch in the single-crystal state. Crystals of the cationic pseudorotaxane consisting of dibenzo[24]­crown-8 (DB24C8) and <i>N</i>-(xylylammonium)-methylferrocene as the cyclic and axle component molecules, respectively, undergo crystalline-phase transition at 128 °C with heating and 116 °C with cooling, according to differential-scanning-calorimetry measurements. X-ray crystallographic analyses revealed that the phase transition was accompanied by rotation of the 4-methylphenyl group of the axle component molecule and a simultaneous shift in the position of the PF₆^– counteranion. Crystalline phase transition changes the conformation and position of the DB24C8 molecule relative to the ammonium cation partially; the interaction between the cyclic component and the PF₆^– anion in the crystal changes to a greater extent. Moreover, there are changes in the vibration angle (θ) and birefringence (Δ<i>n</i>) on the (001) face of the crystal transitionally; θ is rotated by +12°, and Δ<i>n</i> is decreased from 0.070 to 0.059 upon heating across the phase transition temperature. The phase transition and accompanying change in the optical properties of the crystal occur reversibly and repeatedly upon heating and cooling processes. The switching rotation of the aromatic plane of the molecule induces a change in the optical anisotropy of the crystal, which is regarded as a demonstration of a new type of optical crystal. Partial replacement of the PF₆^– anion with the bulkier AsF₆^– anion forms crystals with similar crystallographic parameters. An increase in the AsF₆^– content decreases the reversible-phase-transition temperature gradually down to 99 °C (<i>T</i>_end) and 68 °C (<i>T</i>_exo) ([AsF₆^–]:[PF₆^–] = 0.4:0.6)

Reversible Laser-Induced Bending of Pseudorotaxane Crystals

This study investigated the dynamic photoresponse of pseudorotaxane crystals with azobenzene and ferrocenyl groups in the axle component. X-ray crystallography showed pseudorotaxanes with a methylazobenzene group and a dibromophenylene ring in the cyclic component to exhibit twisting of the <i>trans</i>-azobenzene groups at torsion angles of 17° and 38°, respectively. Repeated alternating laser irradiation of the crystals at 360 and 445 nm produced bending of 20–30° in opposite directions, with no evidence of decay. Under 445 nm irradiation, bending took place within 0.3 s. A crystal of nonsubstituted pseudorotaxane showed bending of only 2° under 360 nm irradiation due to multiple π–π interactions between the planar <i>trans</i>-azobenzene groups. The pseudorotaxane crystals have two chromophores, bent rapidly and reversibly on irradiation at rates depending on the molecular structure

Thermally-Induced Phase Transition of Pseudorotaxane Crystals: Changes in Conformation and Interaction of the Molecules and Optical Properties of the Crystals

This paper presents a pseudorotaxane that acts as a thermally driven molecular switch in the single-crystal state. Crystals of the cationic pseudorotaxane consisting of dibenzo[24]­crown-8 (DB24C8) and <i>N</i>-(xylylammonium)-methylferrocene as the cyclic and axle component molecules, respectively, undergo crystalline-phase transition at 128 °C with heating and 116 °C with cooling, according to differential-scanning-calorimetry measurements. X-ray crystallographic analyses revealed that the phase transition was accompanied by rotation of the 4-methylphenyl group of the axle component molecule and a simultaneous shift in the position of the PF₆^– counteranion. Crystalline phase transition changes the conformation and position of the DB24C8 molecule relative to the ammonium cation partially; the interaction between the cyclic component and the PF₆^– anion in the crystal changes to a greater extent. Moreover, there are changes in the vibration angle (θ) and birefringence (Δ<i>n</i>) on the (001) face of the crystal transitionally; θ is rotated by +12°, and Δ<i>n</i> is decreased from 0.070 to 0.059 upon heating across the phase transition temperature. The phase transition and accompanying change in the optical properties of the crystal occur reversibly and repeatedly upon heating and cooling processes. The switching rotation of the aromatic plane of the molecule induces a change in the optical anisotropy of the crystal, which is regarded as a demonstration of a new type of optical crystal. Partial replacement of the PF₆^– anion with the bulkier AsF₆^– anion forms crystals with similar crystallographic parameters. An increase in the AsF₆^– content decreases the reversible-phase-transition temperature gradually down to 99 °C (<i>T</i>_end) and 68 °C (<i>T</i>_exo) ([AsF₆^–]:[PF₆^–] = 0.4:0.6)

Thermally-Induced Phase Transition of Pseudorotaxane Crystals: Changes in Conformation and Interaction of the Molecules and Optical Properties of the Crystals

This paper presents a pseudorotaxane that acts as a thermally driven molecular switch in the single-crystal state. Crystals of the cationic pseudorotaxane consisting of dibenzo[24]­crown-8 (DB24C8) and <i>N</i>-(xylylammonium)-methylferrocene as the cyclic and axle component molecules, respectively, undergo crystalline-phase transition at 128 °C with heating and 116 °C with cooling, according to differential-scanning-calorimetry measurements. X-ray crystallographic analyses revealed that the phase transition was accompanied by rotation of the 4-methylphenyl group of the axle component molecule and a simultaneous shift in the position of the PF₆^– counteranion. Crystalline phase transition changes the conformation and position of the DB24C8 molecule relative to the ammonium cation partially; the interaction between the cyclic component and the PF₆^– anion in the crystal changes to a greater extent. Moreover, there are changes in the vibration angle (θ) and birefringence (Δ<i>n</i>) on the (001) face of the crystal transitionally; θ is rotated by +12°, and Δ<i>n</i> is decreased from 0.070 to 0.059 upon heating across the phase transition temperature. The phase transition and accompanying change in the optical properties of the crystal occur reversibly and repeatedly upon heating and cooling processes. The switching rotation of the aromatic plane of the molecule induces a change in the optical anisotropy of the crystal, which is regarded as a demonstration of a new type of optical crystal. Partial replacement of the PF₆^– anion with the bulkier AsF₆^– anion forms crystals with similar crystallographic parameters. An increase in the AsF₆^– content decreases the reversible-phase-transition temperature gradually down to 99 °C (<i>T</i>_end) and 68 °C (<i>T</i>_exo) ([AsF₆^–]:[PF₆^–] = 0.4:0.6)