Real-Time Imaging of Single Retinal Cell Apoptosis in a Non-Human Primate Ocular Hypertension Model.

Purpose: To evaluate the feasibility of using DARC (detection of apoptosing retinal cells) technology as a biomarker for preclinical assessment of glaucomatous damage in a non-human primate (NHP) model of ocular hypertension (OHT). Methods: Elevated intraocular pressure (IOP) was induced by applying a laser to the trabecular meshwork in each eye of NHPs. Changes in DARC counts in the retina, identified as fluorescent-tagged annexin V (ANX776)-positive cells, were evaluated together with optic nerve damage, assessed using spectral domain-optical coherence tomography. The pharmacokinetic properties of ANX776 in both healthy and OHT model monkeys were also examined. Results: Sustained elevation of IOP and subsequent thinning of the retinal nerve fiber layer thickness (RNFLT) around the optic nerve head were confirmed in the OHT model. Increases in DARC counts were also detected after IOP elevation. We identified a statistically significant relationship between cumulative DARC counts and reductions in RNFLT both globally and in each peripapillary sector. Intravenous administration of ANX776 increased blood annexin V in a dose-dependent manner, which was subsequently eliminated. Conclusions: This study revealed that DARC technology can effectively assess glaucomatous damage in an NHP OHT model. We obtained the fundamental data that could serve as a reference for developing preclinical models to evaluate the pharmacodynamics of neuroprotective agents using DARC technology in NHP OHT models. Translational Relevance: Our basic data in a monkey OHT model could be useful for future preclinical studies using DARC technology to estimate the pharmacodynamic response of neuroprotective agents.

First-Principles Calculations to Investigate the Stability and Thermodynamic Properties of a Newly Exposed Lithium-Gallium-Iridium-Based Full-Heusler Compound.

The structural, optical, electrical, thermodynamic, superconducting, and mechanical characteristics of LiGa2Ir full-Heusler alloys with the MnCu2Al configuration were comprehensively examined in this work using the first-principles computation approach premised upon density functional analysis. This theoretical approach is the first to investigate the influence of pressure on the mechanical and optical characteristics of LiGa2Ir. The structural and chemical bonding analysis shows that hydrostatic pressure caused a decrease in the lattice constant, volume, and bond length of each cell. According to the mechanical property calculations, the LiGa2Ir cubic Heusler alloy exhibits mechanical stability. It also has ductility and anisotropic behavior. This metallic substance shows no band gap throughout the applied pressure range. The physical characteristics of the LiGa2Ir full-Heusler alloy are analyzed in the operating pressure range of 0-10 GPa. The quasi-harmonic Debye model is employed to analyze thermodynamic properties. The Debye temperature (291.31 K at 0 Pa) increases with hydrostatic pressure. A newly invented structure attracted a lot of attention around the globe for its superior superconductivity (Tc ∼ 2.95 K). Optical functions have also been improved after applying stress to utilize it in optoelectronic/nanoelectric devices. The optical function analysis is supported strongly by the electronic properties. Due to these reasons, LiGa2Ir imposed an essential guiding principle for relevant future research and could be a credible candidate substance for industrial settings.

Beta 1-integrin-c-Met cooperation reveals an inside-in survival signalling on autophagy-related endomembranes.

Receptor tyrosine kinases (RTKs) and integrins cooperate to stimulate cell migration and tumour metastasis. Here we report that an integrin influences signalling of an RTK, c-Met, from inside the cell, to promote anchorage-independent cell survival. Thus, c-Met and ß1-integrin co-internalize and become progressively recruited on LC3B-positive 'autophagy-related endomembranes' (ARE). In cells growing in suspension, ß1-integrin promotes sustained c-Met-dependent ERK1/2 phosphorylation on ARE. This signalling is dependent on ATG5 and Beclin1 but not on ATG13, suggesting ARE belong to a non-canonical autophagy pathway. This ß1-integrin-dependent c-Met-sustained signalling on ARE supports anchorage-independent cell survival and growth, tumorigenesis, invasion and lung colonization in vivo. RTK-integrin cooperation has been assumed to occur at the plasma membrane requiring integrin 'inside-out' or 'outside-in' signalling. Our results report a novel mode of integrin-RTK cooperation, which we term 'inside-in signalling'. Targeting integrin signalling in addition to adhesion may have relevance for cancer therapy.

Raloxifene glucuronidation in liver and intestinal microsomes of humans and monkeys: contribution of UGT1A1, UGT1A8 and UGT1A9.

1. Raloxifene is an antiestrogen that has been marketed for the treatment of osteoporosis, and is metabolized into 6- and 4'-glucuronides by UDP-glucuronosyltransferase (UGT) enzymes. In this study, the in vitro glucuronidation of raloxifene in humans and monkeys was examined using liver and intestinal microsomes and recombinant UGT enzymes (UGT1A1, UGT1A8 and UGT1A9). 2. Although the K(m) and CL(int) values for the 6-glucuronidation of liver and intestinal microsomes were similar between humans and monkeys, and species differences in Vmax values (liver microsomes, humans > monkeys; intestinal microsomes, humans < monkeys) were observed, no significant differences were noted in the K(m) or S50, Vmax and CL(int) or CLmax values for the 4'-glucuronidation of liver and intestinal microsomes between humans and monkeys. 3. The activities of 6-glucuronidation in recombinant UGT enzymes were UGT1A1 > UGT1A8 >UGT1A9 for humans, and UGT1A8 > UGT1A1 > UGT1A9 for monkeys. The activities of 4'-glucuronidation were UGT1A8 > UGT1A1 > UGT1A9 in humans and monkeys. 4. These results demonstrated that the profiles for the hepatic and intestinal glucuronidation of raloxifene by microsomes were moderately different between humans and monkeys.

Effect of UDP-glucuronosyltransferase 1A8 polymorphism on raloxifene glucuronidation.

Raloxifene is an antiestrogen marketed for the treatment of osteoporosis. The major metabolic pathway of raloxifene is glucuronidation at 6- and/or 4'-positions, which is mainly catalyzed by UDP-glucuronosyltransferase 1A8 (UGT1A8) expressed in extrahepatic tissues such as the small intestine and colon. Two non-synonymous allelic variants, termed UGT1A8*2 (518C>G, A173G) and UGT1A8*3 (830G>A, C277Y), have been found in Caucasian, African-American and Asian populations. In this study, the effect of amino acid substitutions in UGT1A8 on raloxifene glucuronidation was studied using recombinant UGT1A8 enzymes of wild-type (UGT1A8.1) and variant UGT1A8 (UGT1A8.2 and UGT1A8.3) expressed in Sf9 cells. Raloxifene 6- and 4'-glucuronidation by UGT1A8.1 exhibited negative allosteric kinetics. The Km and Vmax values of UGT1A8.1 were 15.0 µM and 111 pmol/min/mg protein for 6-glucuronidation, and 9.35 µM and 232 pmol/min/mg protein for 4'-glucuronidation, respectively. The kinetics of raloxifene 6-glucuronidation by UGT1A8.2 was positive allosteric, whereas the kinetics of raloxifene 4'-glucuronidation was negative allosteric. The S50 value of raloxifene 6-glucuronidation was markedly low (1.2%) compared with the Km value of UGT1A8.1, and the Km value for raloxifene 4'-glucuronidation was 29% that of UGT1A8.1. The Vmax value for raloxifene 6-glucuronidation by UGT1A8.2 was comparable to that of UGT1A8.1, whereas the Vmax value for raloxifene 4'-glucuronidation was significantly lower (54%) than that of UGT1A8.1. The activities of raloxifene 6- and 4'-glucuronidation in UGT1A8.3 were markedly lower than those of UGT1A8.1. In mycophenolic acid glucuronidation, the kinetics by wild-type and variant UGT1A8s fitted the Michaelis-Menten model. The Km and Vmax values of UGT1A8.1 were 123 µM and 4820 pmol/min/mg protein, respectively. The Km and Vmax values of UGT1A8.2 were comparable to those of UGT1A8.1. The Km value of UGT1A8.3 was similar to that of UGT1A8.1, whereas the Vmax value was reduced to 2.4% of UGT1A8.1. These findings suggest that A173G and C277Y substitutions of UGT1A8 change the metabolic ability toward raloxifene, and that the polymorphic alleles of UGT1A8 may influence the clinical response and bioavailability of medicines metabolized mainly by UGT1A8.

Effect of fullerene encapsulation on radial vibrational breathing-mode frequencies of single-wall carbon nanotubes.

We investigate the effects of C60 fullerene encapsulation on the radial breathing mode (RBM) of semiconducting single-wall carbon nanotubes (SWCNTs) under tunable laser excitations. The changes in the RBM frequencies after C60 insertions show characteristic behavior; higher frequency shifts are observed in the case of smaller diameter tubes (dtor =1.32 nm). The observed frequency shifts are satisfactorily explained by the diameter-dependent interaction between the encapsulated C60 and the host SWCNTs.

An efficient fabrication of vertically aligned carbon nanotubes on flexible aluminum foils by catalyst-supported chemical vapor deposition.

An efficient and versatile growth of thin-layer carbon nanotubes on a flexible aluminum foil (for kitchen use) by catalyst-supported chemical vapor deposition is reported. The aluminum foil used in the present experiment is commercially available for kitchen use. The electron-beam vapor deposition and dip-coating have been used for preparing catalysts on the aluminum foil. Vertically aligned thin-layer CNTs with typical diameters of 2.5-6.0 nm and lengths up to 90 µm are obtained when ethanol is used in combination with Fe and Co catalyst particles at a growth temperature of around 650 °C under an Ar/H(2) gas flow. Thermo-gravimetric analyses together with HR-TEM observations indicate that the purity of the CNTs synthesized by the current technique is very high.

Enhanced photoluminescence from very thin double-wall carbon nanotubes synthesized by the zeolite-CCVD method.

Photoluminescence (PL) from purified (>90%) double-wall carbon nanotubes (DWNTs), which have been synthesized by zeolite catalyst-supported chemical vapor deposition (zeolite-CCVD), of very small diameters (0.8-nm average inner tube) is reported. The PL contour mappings for various ratios (1-90%) of double- versus single-wall carbon nanotubes by thermal oxidation have enabled us to unambiguously identify the chirality of inner tubes for the DWNTs synthesized. After the extensive high-temperature oxidation at 700 degrees C, high-purity (>90%) DWNTs of approximately 0.8 nm inner diameter are obtained, and most of these correspond to the DWNTs having inner tubes with chiralities of (7,5), (7,6), and (9,4).

High-yield synthesis of single-wall carbon nanotubes on MCM41 using catalytic chemical vapor deposition of acetylene.

High-quality single-wall carbon nanotubes (SWNTs) with narrow diameter distribution have been grown on Fe/Co-loaded MCM41 by using acetylene as the carbon source within a short reaction period, typically 10 min or less. The optimum temperature for SWNTs synthesis is 850 degrees C. Longer reaction time (i.e., 30 min) favors the formation of multiwall carbon nanotubes (MWNTs) and graphitic carbon. When the reaction time is reduced to less than 10 min, formation of MWNTs and graphitic carbon is greatly suppressed, and high-quality SWNTs dominates the yield. The surface of the as-grown SWNTs is found to be free from amorphous carbon, as observed from high-resolution transmission electron microscope (HRTEM) analysis. Raman spectral data show a G/D ratio above 10, indicating that the as-grown SWNTs have very few defects. Furthermore, radial breathing mode (RBM) analysis reveals that the diameter distribution of the current SWNTs is narrow and ranges from 0.64 to 1.36 nm.

Entrapping of exohedral metallofullerenes in carbon nanotubes: (CsC60)n@SWNT nano-peapods.

Exohedral C60-based metallofullerenes, CsC60, have been synthesized and successfully encapsulated into single-wall carbon nanotubes (SWNTs) in high yield by reducing C60 molecules into anions. High-resolution transmission electron microscopy (HRTEM) images and in situ electron energy loss spectroscopy (EELS) indicate that Cs atoms and C60 molecules align within SWNTs as CsC60 exohedral metallofullerenes, and that the formal charge state of encaged CsC60 is expressed as Cs+1C60-1. The present peapods with the exohedral metallofullerenes provide a new insight and the possibility to fine-tune the electronic and transport properties of carbon nanotubes.