Mouse Choroid Proteome Revisited: Focus on Aging.

Age is a major risk factor for age-related macular degeneration (AMD), and age has a role in the disease phenotypes of heritable macular dystrophies. The proteomes of C57Bl6/J mouse choroids at 2 ages were analyzed to identify biochemical processes affected by aging. Proteins of interest were identified as those contributing most to the variance in principal component analysis and those showing the largest significant differences between ages.

Complement factor B is critical for sub-RPE deposit accumulation in a model of Doyne honeycomb retinal dystrophy with features of age-related macular degeneration.

EFEMP1 R345W is a dominant mutation causing Doyne honeycomb retinal dystrophy/malattia leventinese (DHRD/ML), a rare blinding disease with clinical pathology similar to age-related macular degeneration (AMD). Aged Efemp1  R345W/R345W knock-in mice (Efemp1ki/ki) develop microscopic deposits on the basal side of retinal pigment epithelial cells (RPE), an early feature in DHRD/ML and AMD. Here, we assessed the role of alternative complement pathway component factor B (FB) in the formation of these deposits.

Complement C5 is not critical for the formation of sub-RPE deposits in Efemp1 mutant mice.

The complement system plays a role in the formation of sub-retinal pigment epithelial (RPE) deposits in early stages of age-related macular degeneration (AMD). But the specific mechanisms that connect complement activation and deposit formation in AMD patients are unknown, which limits the development of efficient therapies to reduce or stop disease progression. We have previously demonstrated that C3 blockage prevents the formation of sub-RPE deposits in a mouse model of EFEMP1-associated macular degeneration.

Spatiotemporal changes in the human lens proteome: Critical insights into long-lived proteins.

The ocular lens is a unique tissue that contains an age gradient of cells and proteins ranging from newly differentiated cells containing newly synthesized proteins to cells and proteins that are as old as the organism. Thus, the ocular lens is an excellent model for studying long-lived proteins (LLPs) and the effects of aging and post-translational modifications on protein structure and function. Given the architecture of the lens, with young fiber cells in the outer cortex and the oldest cells in the lens nucleus, spatially-resolved studies provide information on age-specific protein changes.

Late-onset retinal degeneration pathology due to mutations in CTRP5 is mediated through HTRA1.

Late-onset retinal degeneration (L-ORD) is an autosomal dominant macular degeneration characterized by the formation of sub-retinal pigment epithelium (RPE) deposits and neuroretinal atrophy. L-ORD results from mutations in the C1q-tumor necrosis factor-5 protein (CTRP5), encoded by the CTRP5/C1QTNF5 gene. To understand the mechanism underlying L-ORD pathology, we used a human cDNA library yeast two-hybrid screen to identify interacting partners of CTRP5.

Spatial distributions of phosphorylated membrane proteins aquaporin 0 and MP20 across young and aged human lenses.

In the human ocular lens it is now realized that post-translational modifications can alter protein function and/or localization in fiber cells that no longer synthesize proteins. The specific sites of post-translational modification to the abundant ocular lens membrane proteins AQP0 and MP20 have been previously identified and their functional effects are emerging. To further understand how changes in protein function and/or localization induced by these modifications alter lens homeostasis, it is necessary to determine the spatial distributions of these modifications across the lens.

Isolation, culture and characterization of primary mouse RPE cells.

Mouse models are powerful tools for the study of ocular diseases. Alterations in the morphology and function of the retinal pigment epithelium (RPE) are common features shared by many ocular disorders. We report a detailed protocol to collect, seed, culture and characterize RPE cells from mice.

Extracellular Matrix Alterations and Deposit Formation in AMD.

Age related macular degeneration (AMD) is the primary cause of vision loss in the western world (Friedman et al., Arch Ophthalmol 122:564-572, 2004). The first clinical indication of AMD is the presence of drusen.

A local complement response by RPE causes early-stage macular degeneration.

Inherited and age-related macular degenerations (AMDs) are important causes of vision loss. An early hallmark of these disorders is the formation of sub-retinal pigment epithelium (RPE) basal deposits. A role for the complement system in MDs was suggested by genetic association studies, but direct functional connections between alterations in the complement system and the pathogenesis of MD remain to be defined.

Mouse genetics and proteomic analyses demonstrate a critical role for complement in a model of DHRD/ML, an inherited macular degeneration.

Macular degenerations, inherited and age related, are important causes of vision loss. Human genetic studies have suggested perturbation of the complement system is important in the pathogenesis of age-related macular degeneration. The mechanisms underlying the involvement of the complement system are not understood, although complement and inflammation have been implicated in drusen formation.

Spatial analysis of human lens aquaporin-0 post-translational modifications by MALDI mass spectrometry tissue profiling.

Aquaporin-0 (AQP0), the major integral membrane protein in lens fiber cells, becomes highly modified with increasing age. The functional consequences of these modifications are being revealed, and the next step is to determine how these modifications affect the ocular lens, which is directly related to their abundances and spatial distributions. The aim of this study was to utilize matrix-assisted laser desorption ionization (MALDI) direct tissue profiling methods, which produce spatially-resolved protein profiles, to map and quantify AQP0 post-translational modifications (PTMs).

Comparative proteomic analysis of antibiotic-sensitive and insensitive isolates of Orientia tsutsugamushi.

Scrub typhus, caused by infection with Orientia tsutsugamushi, is probably the most common severe rickettsial disease. Early diagnosis followed by treatment with antibiotics such as doxycycline or chloramphenicol usually quickly decreases fever in patients, and they often recover well from other symptoms of the disease. However, poorly responsive cases have been reported from northern Thailand and southern India.

Interference of macrophage migration inhibitory factor expression in a mouse melanoma inhibits tumor establishment by up-regulating thrombospondin-1.

Macrophage migration inhibitory factor (MIF) is a pleiotropic cytokine with proinflammatory, proangiogenic, and protumorigenic properties. The molecular mechanisms underlying the role of MIF in tumorigenesis and angiogenesis are not well understood. To address these roles, an interfering MIF (iMIF) RNA was stably introduced into the B16-F10 mouse melanoma cell line, reducing MIF mRNA expression 1.

Oxindolealanine in age-related human cataracts.

The present study was performed in order to obtain structural and quantitative information regarding the modifications that take place in the human lens as a result of tryptophan oxidation. In particular, the early tryptophan oxidation product, oxindolealanine (OIA) has been detected in lyophilized and hydrolyzed cataractous lenses by mass spectrometry. OIA was confirmed in human cataract samples by observing its ion (m/z 221), fragmentation pattern and absorption spectrum.

The R345W mutation in EFEMP1 is pathogenic and causes AMD-like deposits in mice.

Age-related macular degeneration (AMD) is the most common cause of vision loss in developed countries. A defining characteristic of this disorder is the accumulation of material between Bruch's membrane and the retinal pigment epithelium (RPE), first as microscopic basal deposits and later as clinically evident drusen. The pathogenesis of these deposits remains to be defined.

Duplicated gelsolin family genes in zebrafish: a novel scinderin-like gene (scinla) encodes the major corneal crystallin.

We have previously identified a gelsolin-like protein (C/L-gelsolin) as a corneal crystallin in zebrafish. Here we show by phylogenetic analysis that there are at least six genes encoding gelsolin-like proteins based on their gelsolin domains in zebrafish: gsna and gsnb group with the vertebrate gelsolin gene, scina and scinb group with the scinderin (adseverin) gene, and scinla (C/L-gelsolin) and scinlb are novel scinderin-like genes. RT-PCR showed that scinla, scinlb, and gsnb are preferentially expressed in the adult cornea whereas gsna is expressed to a similar extent in cornea, lens, brain, and heart; scina and scinb expression were detectable only in whole zebrafish and not in these adult tissues.

Tumor specific phage particles promote tumor regression in a mouse melanoma model.

Within cancer research, phage display libraries have been widely used for the identification of tumor targeting peptides and antibodies. Additionally, phages are known to be highly immunogenic; therefore we evaluated the immunotherapeutic potential of tumor specific phages to treat established solid tumors in a mouse model of melanoma. We developed two tumor specific phages, one derived from a peptide phage display library and one Fab expressing phage with known specificity, for the treatment of mice bearing palpable B16-F10 or B16/A2K(b) tumors.

Proteomic analysis of tumor establishment and growth in the B16-F10 mouse melanoma model.

The B16-F10 mouse model of melanoma is a widely used model to study many aspects of cancer biology and therapeutics in a solid tumor. Melanomas aggressively progress within a dynamic microenvironment containing in addition to tumor cells, stroma cells and components such as fibroblasts, immune cells, vascular cells, extracellular matrix (ECM) and extracellular molecules. The goal of this study was to elucidate the processes of tumor progression by identifying differentially expressed proteins in the tumor mass during specific stages of tumor growth.

Post-translational modifications of aquaporin 0 (AQP0) in the normal human lens: spatial and temporal occurrence.

Because of the lack of protein turnover in fiber cells of the ocular lens, Aquaporin 0 (AQP0), the most abundant membrane protein in the lens, undergoes extensive post-translational modification with fiber cell age. To map the distribution of modified forms of AQP0 within the lens, normal human lenses ranging in age from 34 to 38 were concentrically dissected into several cortical and nuclear sections. Membrane proteins still embedded in the membranes were digested with trypsin, and the resulting C-terminal peptides of AQP0 were analyzed by HPLC tandem mass spectrometry, permitting the identification of modifications and estimation of their abundance.

Proteome analysis of lens epithelia, fibers, and the HLE B-3 cell line.

Purpose: The purpose of this study is to compare the protein composition of the B-3 line of transformed human lens epithelial (HLE) cells to that of freshly dissected HLE cells. This provides baseline data on lens cell proteins from fresh lens cells and from the B-3 cell line, which is often used as a model system for the lens.

Methods: Human lens epithelial cells adherent to the lens capsule were dissected into central (undifferentiated) and peripheral (partially differentiated) populations.

Water permeability of C-terminally truncated aquaporin 0 (AQP0 1-243) observed in the aging human lens.

Purpose: To first assess the distribution of posttranslationally truncated products of aquaporin 0 (AQP0) in dissected sections of a normal human lens and to determine the effect of backbone cleavage on the water permeability of AQP0.

Methods: A 27-year-old lens was concentrically dissected into six sections. Membrane protein was isolated from each section and cleaved with cyanogen bromide, and the peptides were separated and analyzed by reverse-phase (RP)-HPLC-mass spectrometry (MS).

Movement of cysteine in intact monkey lenses: the major site of entry is the germinative region.

Monkey lenses were incubated with 35S-L-cysteine for various times and the movement of label within the lens followed by autoradiography. Cysteine appeared to enter primarily at the germinative region of the lens. No evidence was found for major transport through either the anterior or posterior faces of the lens.

Oxidative modification of aldose reductase induced by copper ion. Definition of the metal-protein interaction mechanism.

Aldose reductase (ALR2) is susceptible to oxidative inactivation by copper ion. The mechanism underlying the reversible modification of ALR2 was studied by mass spectrometry, circular dichroism, and molecular modeling approaches on the enzyme purified from bovine lens and on wild type and mutant recombinant forms of the human placental and rat lens ALR2. Two equivalents of copper ion were required to inactivate ALR2: one remained weakly bound to the oxidized protein whereas the other was strongly retained by the inactive enzyme.

Posttranslational modification of human alphaA-crystallin: correlation with electrophoretic migration.

alphaA-crystallin is a major protein component of the human lens. It is known to undergo posttranslational modification. This study was done to further elucidate the temporal and spatial nature of these posttranslational modifications and to correlate the modified forms with electrophoretic migration.