TY - JOUR
T1 - Effects of collagen cross-linking on the keratoconus metabolic network
AU - Sharif, Rabab
AU - Sejersen, Henrik
AU - Frank, Garrett
AU - Hjortdal, Jesper
AU - Karamichos, Dimitrios
N1 - Funding Information:
Acknowledgements We acknowledge the use of tissues procured by the National Disease Research Interchange (NDRI) with support from NIH grant U42OD11158. The authors would like to thank Drs. John Asara and Min Yuan for technical assistance with metabolomics experiments. The authors also thank our biostatistician, Dr. Ding Kai.
Funding Information:
Funding The authors would like to acknowledge the support of the National Institute of Health (NEI) Grants EY023568 (DK). This work was supported by an unrestricted grant (DMEI) from Research to Prevent Blindness (New York, NY USA). The funders have no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
Publisher Copyright:
© 2018 The Royal College of Ophthalmologists.
PY - 2018/7/1
Y1 - 2018/7/1
N2 - Purpose: Keratoconus (KC) is a multifactorial, ectatic corneal disease. Metabolic changes in the corneal stroma with alterations in collagen fibril stability, oxidative stress, and urea cycle, have previously been reported as key players in KC pathobiology. Recently, corneal collagen cross-linking (CXL) has been introduced as a treatment that can address the progressive nature of KC. While the treatment has been successful in the early days, it is not without clinical ramifications. In this study, we investigated the alterations in KC metabolic profiles due to CXL. Methods: Primary human corneal fibroblasts (HCFs) from healthy donors and human KC fibroblasts (HKCs) from KC donor patients were plated on transwell polycarbonate membranes and stimulated by a stable vitamin C. At 4 weeks, riboflavin was added to the cultures followed by UVA irradiation (365 nm). Using mass spectrometry, we measured the major differences in metabolites in HKCs compared to HCFs pre- and post CXL. Result: The analysis of 276 metabolites in HCFs and HKCs revealed that the most affected metabolites due to CXL were glutathione disulfide, ascorbic acid, proline, and lysine. A significant decrease in the pro-inflammatory biomarkers (myo-inositol and histidine) was also observed. Furthermore, a significant downregulation of many amino acids, lactate levels, and other water-soluble metabolites was noted in HKCs following CXL. Conclusion: CXL is a KC treatment available to patients within certain criteria. Surprisingly, the cellular and molecular mechanisms are considerably understudied limiting our ability for more precise and targeted CXL treatments. In this study, for the first time, we report the effects of CXL on KC metabolism.
AB - Purpose: Keratoconus (KC) is a multifactorial, ectatic corneal disease. Metabolic changes in the corneal stroma with alterations in collagen fibril stability, oxidative stress, and urea cycle, have previously been reported as key players in KC pathobiology. Recently, corneal collagen cross-linking (CXL) has been introduced as a treatment that can address the progressive nature of KC. While the treatment has been successful in the early days, it is not without clinical ramifications. In this study, we investigated the alterations in KC metabolic profiles due to CXL. Methods: Primary human corneal fibroblasts (HCFs) from healthy donors and human KC fibroblasts (HKCs) from KC donor patients were plated on transwell polycarbonate membranes and stimulated by a stable vitamin C. At 4 weeks, riboflavin was added to the cultures followed by UVA irradiation (365 nm). Using mass spectrometry, we measured the major differences in metabolites in HKCs compared to HCFs pre- and post CXL. Result: The analysis of 276 metabolites in HCFs and HKCs revealed that the most affected metabolites due to CXL were glutathione disulfide, ascorbic acid, proline, and lysine. A significant decrease in the pro-inflammatory biomarkers (myo-inositol and histidine) was also observed. Furthermore, a significant downregulation of many amino acids, lactate levels, and other water-soluble metabolites was noted in HKCs following CXL. Conclusion: CXL is a KC treatment available to patients within certain criteria. Surprisingly, the cellular and molecular mechanisms are considerably understudied limiting our ability for more precise and targeted CXL treatments. In this study, for the first time, we report the effects of CXL on KC metabolism.
UR - http://www.scopus.com/inward/record.url?scp=85044379765&partnerID=8YFLogxK
U2 - 10.1038/s41433-018-0075-6
DO - 10.1038/s41433-018-0075-6
M3 - Article
C2 - 29576618
AN - SCOPUS:85044379765
SN - 0950-222X
VL - 32
SP - 1271
EP - 1281
JO - Eye (Basingstoke)
JF - Eye (Basingstoke)
IS - 7
ER -