An empty E1−, E3−, E4− adenovirus vector protects photoreceptors from light-induced degeneration

We have previously identified a neuroprotective effect associated with empty (E1−, E3−, E4−) adenovirus vector delivery in a model of light-induced, photoreceptor cell death. In this study, we further characterize this protective effect in light-injured retina and investigate its molecular basis. Dark-adapted BALB/c mice, aged 6–8 weeks, were exposed to standardized, intense fluorescent light for 96 or 144 h. Prior to dark adaptation, all mice received intravitreous injection of 1 × 109 particles of an empty (E1−, E3−, E4−) adenovirus vector in one eye and vehicle in the other. Following light challenge of 96 or 144 h, histopathological analysis and quantitative photoreceptor cell counts were conducted. Semiquantitative assessment of messenger ribonucleic acid (mRNA) for the apoptosis related genes: p50, p65, IkBa, caspase-1, caspase-3, Bad, c-Jun, Bax, Bak, Bcl-2, c-Fos, and p53 using quantitative reverse transcriptase polymerase chain reaction was performed on eyes following 12 h of light exposure. Following 96 h of light exposure, the photoreceptor cell density for E1−, E3−, E4− adenovirus vector and vehicle-injected eyes were 87.5 ± 9.5 and 79.3 ± 10.1, respectively, (p = 0.79). After 144 h of light exposure, the photoreceptor cell density was preserved in vector-injected eyes as compared to vehicle treated eyes, 68.9 ± 10.0 and 49.2 ± 4.6, respectively (p = 0.016). Relative mRNA levels of c-Fos and c-Jun at 12-h light exposure after injection differed significantly between vector- and vehicle-injected eyes (p = 0.036, 0.016, respectively). The expression of the other apoptosis-related genes evaluated was not significantly affected. This study investigates the molecular basis of photoreceptor neuroprotective pathway induction associated with E1−, E3−, E4− adenovirus vectors. The results indicate that empty adenovirus vectors protect photoreceptors from light-induced degeneration by the modulation of apoptotic pathways. Gene expression changes suggest that the suppression of c-Fos and c-Jun upregulation contributes significantly to the neuroprotective effect. Understanding the molecular basis of the neuroprotective pathway induction in photoreceptors is critical to the development of novel therapies for retinal degenerations

Holographic QCD: Past, Present, and Future

At the dawn of a new theoretical tool based on the AdS/CFT correspondence for nonperturbative aspects of quantum chromodynamics, we give an interim review on the new tool, holographic QCD, with some of its accomplishment. We try to give an A-to-Z picture of the holographic QCD, from string theory to a few selected top-down holographic QCD models with one or two physical applications in each model. We may not attempt to collect diverse results from various holographic QCD model studies.Comment: 80 pages, 18 figures, LaTeX; references added, published version + appendi

Double-pulse induced harmonic generation in laser-produced plasmas

We report the studies of the metals, non-metals, powders, and nanoparticles as the targets for laser ablation induced high-order harmonic generation of ultrashort pulses using the double-pulse technique. The proposed technique demonstrates the attractiveness as the method for the studies of the high-order nonlinear optical properties of various materials. The comparative analysis of the harmonic generation using different targets showed that the species allowing easier ablation (powders, nanoparticles) produce stronger harmonic yield in the extreme ultraviolet range

Correlation between lamina cribrosa tilt angles, myopia and glaucoma using OCT with a wide bandwidth femtosecond mode-locked laser.

To measure horizontal and vertical lamina cribrosa (LC) tilt angles and investigate associated factors using prototype optical coherence tomography (OCT) with a broad wavelength laser light source.Cross sectional study.Twenty-eight no glaucoma eyes (from 15 subjects) and 25 glaucoma eyes (from 14 patients) were enrolled. A total of 300 optic nerve head B-scans were obtained in 10 µm steps and the inner edge of Bruch's membrane opening (BMO) was identified as the reference plane. The vertical and horizontal angles between BMO line and approximate the best-fitting line for the surface of the LC were measured and potential associated factors were estimated with univariate and multivariate logistic regression analyses.The median (interquartile range) horizontal and vertical tilt angles were 7.10 (2.43-11.45) degrees and 4.15 (2.60-6.85) degrees in eyes without glaucoma and 8.50 (4.40-14.10) degrees and 9.30 (6.90-14.15) degrees in glaucoma eyes, respectively. The refractive errors had a statistically significant association with horizontal LC tilt angles (coefficients, -1.53 per diopter) and glaucoma had a significant correlation with vertical tilt angles (coefficients, 6.56) using multiple logistic regression analysis (p<0.001).OCT allowed evaluation of the internal tilting of the LC compared with the BMO. The horizontal internal LC tilt angle was correlated with refractive errors, corresponding to myopic physiological changes, and vertical internal LC tilt was correlated with glaucoma, corresponding to glaucomatous pathological changes. These parameters have important implications for investigation of the correlation between myopia, glaucoma and LC morphological features

Soft X-ray Laser Microscopy of Lipid Rafts towards GPCR-Based Drug Discovery Using Time-Resolved FRET Spectroscopy

Many signaling molecules involved in G protein-mediated signal transduction, which are present in the lipid rafts and believed to be controlled spatially and temporally, influence the potency and efficacy of neurotransmitter receptors and transporters. This has focus interest on lipid rafts and the notion that these microdomains acts as a kind of signaling platform and thus have an important role in the expression of membrane receptor-mediated signal transduction, cancer, immune responses, neurotransmission, viral infections and various other phenomena due to specific and efficient signaling according to extracellular stimuli. However, the real structure of lipid rafts has not been observed so far due to its small size and a lack of sufficiently sophisticated observation systems. A soft X-ray microscope using a coherent soft X-ray laser in the water window region (2.3–4.4 nm) should prove to be a most powerful tool to observe the dynamic structure of lipid rafts of several tens of nanometers in size in living cells. We have developed for the X-ray microscope a new compact soft X-ray laser using strongly induced plasma high harmonic resonance. We have also developed a time-resolved highly sensitive fluorescence resonance energy transfer (FRET) system and confirmed protein-protein interactions coupled with ligands. The simultaneous use of these new tools for observation of localization of G-protein coupled receptors (GPCRs) in rafts has become an important and optimum tool system to analyze the dynamics of signal transduction through rafts as signaling platform. New technology to visualize rafts is expected to lead to the understanding of those dynamics and innovative development of drug discovery that targets GPCRs localized in lipid rafts

Glaucomatous changes in lamina pores shape within the lamina cribrosa using wide bandwidth, femtosecond mode-locked laser OCT

<div><p>Purpose</p><p>The lamina cribrosa (LC) is known to play a critical role in the pathogenesis of glaucoma. Although it has been reported that striae-shaped or slit-shaped lamina pores are more frequent in eyes with primary open angle glaucoma (POAG), this observation is based only on fundus photography. The primary object of this study is to perform layer-by-layer comparisons of the shape of lamina pores within the LC in vivo.</p><p>Design</p><p>Cross-sectional study.</p><p>Methods</p><p>Optic nerve head B-scans were obtained using custom-made broad-wavelength optical coherence tomography with a mode-locked laser. A total of 300 single B-scans per eye were obtained and three-dimensional images were rendered from these image sequences to obtain 2-μm thin-slice <i>en face</i> images of the LC. Elongation indices (EIs) of the lamina pores were measured from the anterior surface (AS) of the LC to the deeper layers in 40-μm increments.</p><p>Results</p><p>Thirteen eyes from 10 primary open angle glaucoma (POAG) patients of mean deviation -15.2 (-16.5, -12.9) (median [25,75 percentile]) dB and 10 eyes from 7 normal controls were studied. Although the EI value was not significantly different between the superior, temporal and inferior regions of the LC at any depth level in either group, it was greater at the AS than at the 40 μm and 80 μm depth levels (<i>P</i> < .001) in both groups, and was greater in the POAG group only at the AS and 40 μm depth level (<i>P</i> ≤ .05). After adjustment for age and refraction, the effects of depth and presence of POAG on the EI value remained significant. Also, the severity of glaucoma and depth were significant factors associated with EI in multivariate analysis.</p><p>Conclusions</p><p>Elongation of lamina pores was significantly more evident at the anterior surface and the 40-μm depth level of the LC in POAG eyes than in normal eyes, suggesting that nerve fiber bundles passing through the LC were under greater stress in the anterior layers of the LC.</p></div

Ocular localization and transduction by adenoviral vectors are serotype-dependent and can be modified by inclusion of RGD fiber modifications.

To evaluate localization and transgene expression from adenoviral vector of serotypes 5, 35, and 28, ± an RGD motif in the fiber following intravitreal or subretinal administration.Ocular transduction by adenoviral vector serotypes ± RGD was studied in the eyes of mice receiving an intravitreous or subretinal injection. Each serotype expressed a CMV-GFP expression cassette and histological sections of eyes were examined. Transgene expression levels were examined using luciferase (Luc) regulated by the CMV promoter.GFP localization studies revealed that serotypes 5 and 28 given intravitreously transduced corneal endothelial, trabecular, and iris cells. Intravitreous delivery of the unmodified Ad35 serotype transduced only trabecular meshwork cells, but, the modification of the RGD motif into the fiber of the Ad35 viral vector base expanded transduction to corneal endothelial and iris cells. Incorporation of the RGD motif into the fiber knob with deletion of RGD from the penton base did not affect the transduction ability of the Ad5 vector base. Subretinal studies showed that RGD in the Ad5 knob shifted transduction from RPE cells to photoreceptor cells. Using a CMV-Luc expression cassette, intravitreous delivery of all the tested vectors, such as Ad5-, Ad35- and Ad28- resulted in an initial rapid induction of luciferase activity that thereafter declined. Subretinal administration of vectors showed a marked difference in transgene activity. Ad35-Luc gene expression peaked at 7 days and remained elevated for 6 months. Ad28-Luc expression was high after 1 day and remained sustained for one month.Different adenoviral vector serotypes ± modifications transduce different cells within the eye. Transgene expression can be brief or extended and is serotype and delivery route dependent. Thus, adenoviral vectors provide a versatile platform for the delivery of therapeutic agents for ocular diseases

Schematic diagram of the 3 measurement regions in a left eye.

<p>The dotted line connecting the centroid of the disc margin and the fovea was designated as the reference line. A measurement sector at 0° to ±45° relative to the fovea center of disc axis was defined as the temporal region and the 45° to 135° circumferentially superior and inferior directions as the superior and inferior regions.</p