Dataset Information

Data Independent Acquisition Mass Spectrometry of the Human Lens Enhances Spatiotemporal Measurement of Fiber Cell Aging

ABSTRACT: Comparison of DIA and DDA of 18 year old human lens treated with solubility fraction. OC, Cortex; ON, Outer Nucleus; IN, Inner Nucleus. 3 technical replicates included. Full details available at biorxiv preprint https://doi.org/10.1101/2021.05.13.444062. Abstract: The ocular lens proteome undergoes post-translational and progressive degradation as fiber cells age. The oldest fiber cells and the proteins therein are present at birth and are retained through death. Transparency of the lens is maintained in part by the high abundance crystallin family proteins (up to 300 mg/mL), which establishes a high dynamic range of protein abundance. As a result, previous Data Dependent Analysis (DDA) measurements of the lens proteome are less equipped to identify the lowest abundance proteins. In an attempt to probe more deeply into the lens proteome, we measured the insoluble lens proteome of an 18-year-old human with DDA and newer Data Independent Analysis (DIA) methods. By applying library free DIA search methods, 4,564 protein groups, 48,474 peptides and 5,577 deamidation sites were detected: significantly outperforming the quantity of identifications in using DDA and Pan-Human DIA library searches. Finally, by segmenting the lens into multiple fiber cell-age related regions, we uncovered cell-age resolved changes in proteome composition and putative function.

INSTRUMENT(S): Orbitrap Exploris 480

ORGANISM(S): Homo Sapiens (ncbitaxon:9606)

SUBMITTER: Kevin Schey Lee Cantrell

PROVIDER: MSV000087506 | MassIVE | Tue May 25 06:26:00 BST 2021

SECONDARY ACCESSION(S): PXD026250

REPOSITORIES: MassIVE

ACCESS DATA

Dataset's files

Source:

			Action	DRS
		Other

Items per page:

1 - 1 of 1

Similar Datasets

Project description:The eye lens is responsible for focusing and transmitting light to the retina. The lens does this in the absence of organelles yet maintains transparency for at least five decades before onset of age-related nuclear cataract (ARNC). It is hypothesized that oxidative stress contributes significantly to ARNC formation. It is additionally hypothesized that transparency is maintained by a microcirculation system (MCS) that delivers antioxidants to the lens nucleus and exports small molecule waste. Commonly used data-dependent acquisition (DDA) proteomics methods are hindered by the dynamic range of protein expression in the lens and provide limited context to age-related changes in the lens. In this study we utilized data-independent acquisition (DIA) mass spectrometry proteomics to analyze the urea insoluble, membrane protein fractions of 16 human lenses subdivided into three spatially distinct lens regions to characterize age-related changes, particularly concerning the lens MCS and oxidative stress response. In this pilot cohort, using the DIA approach, we measured 4,788 distinct protein groups, and 46,681 peptides, more than in any previous human lens DDA approach. Our results reveal age-related changes previously known in lens biology and expand on these findings, taking advantage of the rich dataset afforded by DIA mass spectrometry. Principally, we demonstrate that a significant proteome remodeling event occurs at approximately 50 years of age, resulting in metabolic preference for anaerobic glycolysis established with organelle degradation, decreased abundance of protein networks involved in calcium-dependent cell-cell contacts while retaining networks related to oxidative stress response. Further, we demonstrate the first identification of multiple antioxidant transporter proteins not previously shown in the human lens and describe their spatiotemporal and age-related abundance changes. Finally, we demonstrate that Aquaporin-5, among other proteins, is depleted with age. We suggest that the continued accumulation of each of these age-related outcomes in proteome remodeling contribute to decrease in fiber cell permeability and result in ARNC formation.

Project description:The mature eye lens contains a surface layer of epithelial cells called the lens epithelium that require a functional mitochondrial population to maintain the homeostasis and transparency of the entire lens. The lens epithelium overlies a core of terminally differentiated fiber cells that must degrade their mitochondria to achieve lens transparency. These distinct mitochondrial populations make the lens a useful model system to identify those genes that regulate the balance between mitochondrial homeostasis and elimination. Here we used an RNA sequencing and bioinformatics approach to identify the transcript levels of all genes expressed by distinct regions of the lens epithelium and maturing fiber cells of the embryonic Gallus gallus (chicken) lens. Our analysis detected over 15,000 unique transcripts expressed by the embryonic chicken lens. Of these, over 3000 transcripts exhibited significant differences in expression between lens epithelial cells and fiber cells. Multiple transcripts coding for separate mitochondrial homeostatic and degradation mechanisms were identified to exhibit preferred patterns of expression in lens epithelial cells that require mitochondria relative to lens fiber cells that require mitochondrial elimination. These included differences in the expression levels of metabolic, autophagy, and mitophagy transcripts between lens epithelial cells and lens fiber cells. These data provide a comprehensive window into all genes transcribed by the lens and those mitochondrial regulatory and degradation pathways that function to maintain mitochondrial populations in the lens epithelium and to eliminate mitochondria in maturing lens fiber cells. Differentiation-state transcriptional analysis of embryonic chicken lenses was performed following microdissection of 100 embryonic day 13 (E13) chicken lenses into four distinct regions that represent a continuum of lens cell differentiation states: lens central epithelium (EC), equatorial epithelium (EQ), cortical fibers (FP), and central fibers (FC). Further analysis of the transcriptional content of biologically replicate samples was performed by Illumina directional mRNA sequencing and resulting reads mapped by TopHat and assembled with Cufflinks.

Dataset Information

Data Independent Acquisition Mass Spectrometry of the Human Lens Enhances Spatiotemporal Measurement of Fiber Cell Aging

Dataset's files

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets