Equine recurrent uveitis - A spontaneous horse model of uveitis

Equine recurrent uveitis (ERU) is an autoimmune disease that occurs with a high prevalence (10%) in horses. ERU represents the only reliable spontaneous model for human autoimmune uveitis. We already identified and characterized novel autoantigens (malate dehydrogenase, recoverin, CRALBP) by analyzing the autoantibody-binding pattern of horses affected by spontaneous recurrent uveitis (ERU) to the retinal proteome. CRALBP also seems to be relevant to human autoimmune uveitis. Proteomic screening of vitreous and retinal samples from ERU diseased cases in comparison to healthy controls has led to the identification of a series of differentially regulated proteins, which are functionally linked to the immune system and the maintenance of the blood-retinal barrier. Copyright (c) 2008 S. Karger AG, Basel

CRALBP is a Highly Prevalent Autoantigen for Human Autoimmune Uveitis

Cellular retinaldehyde binding protein (CRALBP) is an autoantigen in spontaneous equine recurrent uveitis. In order to test whether CRALBP contributes to human autoimmune uveitis, the specificity of antibodies from human uveitis patient's sera was first evaluated in two-dimensional (2D) Western blot analysis. Subsequent identification of the immunoreactive proteins by mass spectrometry resulted in the identification of CRALBP as a putative autoantigen. Additionally, sera from human uveitis and control patients were by Western blot using purified human recombinant CRALBP. Anti-CRALBP autoantibodies occur more frequently (P<.01) in human uveitis patients than in normal controls. Thirty out of 56 tested uveitis patient's sera contained autoantibodies reactive against CRALBP, compared to only four out of 23 normal control subjects. The presence of CRALBP autoantibodies in 54% of tested uveitis patients supports CRALBP as a possible autoantigen in human autoimmune uveitis

Vasodilator Phosphostimulated Protein (VASP) Protects Endothelial Barrier Function During Hypoxia

The endothelial barrier controls the passage of solutes from the vascular space. This is achieved through active reorganization of the actin cytoskeleton. A central cytoskeletal protein involved into this is vasodilator-stimulated phosphoprotein (VASP). However, the functional role of endothelial VASP during hypoxia has not been thoroughly elucidated. We determined endothelial VASP expression through real-time PCR (Rt-PCR), immunhistochemistry, and Western blot analysis during hypoxia. VASP promoter studies were performed using a PGL3 firefly luciferase containing plasmid. Following approval by the local authorities, VASP−/− mice and littermate controls were subjected to normobaric hypoxia (8% O2, 92% N2) after intravenous injection of Evans blue dye. In in vitro studies, we found significant VASP repression in human microvascular and human umbilical vein endothelial cells through Rt-PCR, immunhistochemistry, and Western blot analysis. The VASP promoter construct demonstrated significant repression in response to hypoxia, which was abolished when the binding of hypoxia-inducible factor 1 alpha was excluded. Exposure of wild-type (WT) and VASP−/− animals to normobaric hypoxia for 4 h resulted in an increase in Evans blue tissue extravasation that was significantly increased in VASP−/− animals compared to WT controls. In summary, we demonstrate here that endothelial VASP holds significant importance for endothelial barrier properties during hypoxia

PHOTOIONIZATION SPECTROSCOPY OF Ga-RARE GAS COMPLEXES

Author Institution: Department of Chemistry, University of GeorgiaNew electronic states, $F^{2} \Delta_{3/2}, G^{2} \Delta_{5/2}, H^{2}\Pi_{1/2}, and I^{2}\Pi_{3/2}$ are investigated for the complexes GaAr, GaKr and GaXe with resonant two-photon photoionization spectroscopy. These excited states correlate to the $^{2}D \leftarrow^{2}P (4d \leftarrow 4p)$ atomic transition of gallium. Vibronic structure in these spectra are used to obtain vibrational constants, and extrapolated progressions are used to determine dissociation energies. The upper $^{2}\Delta$ states are more than twice as strongly bound as the corresponding $^{2}\Pi$ states. Excited state values of dissociation energies are used in energetic cycles to determine ground state dissociation energies for GaAr, GaKr and GaXe. In all three cases, the values obtained are significantly lower than previous estimates. The ground state of GaAr is extremely weakly bound, with $D^{\prime \prime} = 20 \pm 20, cm^{-1}$, while the corresponding value for GaKr is only $35 \pm 20 cm^{-1}$. Analysis suggests the presence of a barrier in the long range potential of the excited states of the $B^{2} \Sigma^{+}$ Ga-RG complexes

PHOTOIONIZATION SPECTROSCOPY OF Au-Ar

Author Institution: Department of Chemistry, University of GeorgiaResonance enhanced photoionization is used to probe two electronic band systems of the new metal van der Walls complex Au-Ar. The two band systems are located near 270 nm and 245 nm. These systems correlate to the spin-orbit components (^{2}P_{1/2} \leftarrow \;^{2}S and ^{2}P_{3/2} \leftarrow \;^{2}S respectively) of the $^{6}p\leftarrow 6s$ atomic transition. An extrapolation of the vibronic bands is used to obtain the ground state binding energy. $D_{o} = 18O \pm 30 cm^{-1}$, as well as lower limits for the excited state binding energies $[D_{0}(^{2}\Pi_{1/2}) \geq 355 cm^{-1}, D_{0}(^{2}\Pi_{1/2})\geq 815 cm^{-1}]$. The ionization potential is determined from the lowest observed line to be $\geq 9.208eV$. The properties of Au-Ar are compared to those of Cu-RG and Ag-RG complexes studied previously in our laboratory

Discovering novel targets for autoantibodies in dilated cardiomyopathy.

There is increasing evidence that a large proportion of dilated cardiomyopathy (DCM) cases are mediated by autoimmune processes. Since DCM is a fatal disorder with rapid aggravation and is the leading cause of heart transplantation, further insights into disease pathogenesis are needed. Recent studies have separated the pathogenic capacity of autoantibodies and initial clinical trials removing such autoantibodies via immunoadsorption have been promising. In order to elucidate the full autoantibody repertoire involved in DCM, we applied an autoantibody screening test using ventricular and atrial proteomes as autoantigenic sources and subsequently tested the autoantibody-binding patterns of sera from dogs with spontaneous DCM. With this method, we detected five potentially DCM-related autoantigens which were identified by MS as being: myosin heavy chain cardiac muscle alpha isoform, alpha cardiac actin, mitochondrial aconitate hydratase, glyceraldehyde-3-phosphate dehydrogenase (GAPDH), and brain glycogen phosphorylase (GPBB). The recovery of two known DCM autoantigens (myosin heavy chain and alpha cardiac actin) and the discovery of three novel autoantigens (mitochondrial aconitate hydratase, GADPH, and GPBB) underscore the efficacy of this experimental method and the significance of the spontaneous canine DCM model