TY - JOUR
T1 - The keratoconus corneal proteome
T2 - Loss of epithelial integrity and stromal degeneration
AU - Chaerkady, Raghothama
AU - Shao, Hanjuan
AU - Scott, Sherri Gae
AU - Pandey, Akhilesh
AU - Jun, Albert S.
AU - Chakravarti, Shukti
N1 - Funding Information:
We thank Xiaojun Feng, Ph.D. for her assistance with immunohistochemistry. We thank Robert Cole, Ph.D. (Director, Mass Spectrometry and Proteomics Facility of the Johns Hopkins School of Medicine) for technical assistance with mass spectrometry. This study was funded in part by EY11654 (SC) and the Openshaw Keratoconus Research Funds from the Wilmer Eye Institute .
PY - 2013/7/1
Y1 - 2013/7/1
N2 - Keratoconus is a thinning corneal dystrophy that begins in the early teenage years and ultimately requires cornea transplantation to restore vision. Here we conducted a highly sensitive mass spectrometric analysis of the epithelium and the stroma from keratoconus and normal donor corneas. We identified a total of 932 and 1157 proteins in the consolidated data of the epithelium and stroma, respectively. Technical replicates showed strong correlations (≥. 0.88) in levels of all common proteins, indicating very low technical variations in the data. Analysis of the most increased (≥. 1.5 fold) and decreased (≤. 0.8 fold) proteins in the keratoconus corneal epithelial protein extracts identified proteins related to dermal diseases, inflammation, epithelial stratification and mesenchymal changes. Increased proteins included keratins 6A, 16 and vimentin, while the iron transporter lactotransferrin was decreased. The keratoconus stromal proteome suggests endoplasmic reticular stress, oxidative stress and widespread decreases in many extracellular matrix proteoglycan core proteins, lumican and keratocan, collagen types I, III, V and XII. Marked increase in apoptosis and endocytosis-related proteins suggest degenerative changes in keratocytes, the resident cells of the stroma. This is the most comprehensive proteome analysis of the cornea that highlights similarities of keratoconus with other neurodegenerative diseases. Biological significance: This study provides, to our knowledge, the most comprehensive proteomic analysis of the vision threatening disease keratoconus, which affects a significant portion of the US and global populations. Using iTRAQ and LC/MS/MS, we have identified significant changes in the human corneal epithelium and stromal proteome that correlate to in vivo clinical findings. The protein changes identified will lead to molecular insights into disease pathogenesis and provide candidate genes for genetic studies of keratoconus.
AB - Keratoconus is a thinning corneal dystrophy that begins in the early teenage years and ultimately requires cornea transplantation to restore vision. Here we conducted a highly sensitive mass spectrometric analysis of the epithelium and the stroma from keratoconus and normal donor corneas. We identified a total of 932 and 1157 proteins in the consolidated data of the epithelium and stroma, respectively. Technical replicates showed strong correlations (≥. 0.88) in levels of all common proteins, indicating very low technical variations in the data. Analysis of the most increased (≥. 1.5 fold) and decreased (≤. 0.8 fold) proteins in the keratoconus corneal epithelial protein extracts identified proteins related to dermal diseases, inflammation, epithelial stratification and mesenchymal changes. Increased proteins included keratins 6A, 16 and vimentin, while the iron transporter lactotransferrin was decreased. The keratoconus stromal proteome suggests endoplasmic reticular stress, oxidative stress and widespread decreases in many extracellular matrix proteoglycan core proteins, lumican and keratocan, collagen types I, III, V and XII. Marked increase in apoptosis and endocytosis-related proteins suggest degenerative changes in keratocytes, the resident cells of the stroma. This is the most comprehensive proteome analysis of the cornea that highlights similarities of keratoconus with other neurodegenerative diseases. Biological significance: This study provides, to our knowledge, the most comprehensive proteomic analysis of the vision threatening disease keratoconus, which affects a significant portion of the US and global populations. Using iTRAQ and LC/MS/MS, we have identified significant changes in the human corneal epithelium and stromal proteome that correlate to in vivo clinical findings. The protein changes identified will lead to molecular insights into disease pathogenesis and provide candidate genes for genetic studies of keratoconus.
KW - Collagens
KW - Cornea
KW - ECM
KW - Keratoconus
KW - Lumican
KW - Proteome
UR - http://www.scopus.com/inward/record.url?scp=84879285894&partnerID=8YFLogxK
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U2 - 10.1016/j.jprot.2013.05.023
DO - 10.1016/j.jprot.2013.05.023
M3 - Article
C2 - 23727491
AN - SCOPUS:84879285894
SN - 1874-3919
VL - 87
SP - 122
EP - 131
JO - Journal of Proteomics
JF - Journal of Proteomics
ER -