title: Human Keratoconus Cell Contractility is Mediated by Transforming Growth Factor-Beta Isoforms.
abstract: Keratoconus (KC) is a progressive disease linked to defects in the structural components of the corneal stroma. The extracellular matrix (ECM) is secreted and assembled by corneal keratocytes and regulated by transforming growth factor-β (TGF-β). We have previously identified alterations in the TGF-β pathway in human keratoconus cells (HKCs) compared to normal corneal fibroblasts (HCFs). In our current study, we seeded HKCs and HCFs in 3D-collagen gels to identify variations in contractility, and expression of matrix metalloproteases (MMPs) by HKCs in response the TGF-β isoforms. HKCs showed delayed contractility with decreased Collagen I:Collagen V ratios. TGF-β1 significantly increased ECM contraction, Collagen I, and Collagen V expression by HKCs. We also found that HKCs have significantly decreased Collagen I:Collagen III ratios suggesting a potential link to altered collagen isoform expression in KC. Our findings show that HKCs have significant variations in collagen secretion in a 3D collagen gel and have delayed contraction of the matrix compared to HCFs. For the first time, we utilize a collagen gel model to characterize the contractility and MMP expression by HKCs that may contribute to the pathobiology of KC.
authors.affiliation: Department of Ophthalmology/Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA. desiree-lyon@ouhsc.edu.
authors.forename: Desiree '
authors.initials: D'
authors.lastname: Lyon
authors.affiliation: Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA. tina-mckay@ouhsc.edu.
authors.forename: Tina B
authors.initials: TB
authors.lastname: McKay
authors.affiliation: Department of Ophthalmology/Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA. akhee-sarkernag@ouhsc.edu.
authors.forename: Akhee
authors.initials: A
authors.lastname: Sarkar-Nag
authors.affiliation: Department of Ophthalmology/Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA. shrestha-priyadarsini@ouhsc.edu.
authors.forename: Shrestha
authors.initials: S
authors.lastname: Priyadarsini
authors.affiliation: Department of Ophthalmology/Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA. dimitrios-karamichos@ouhsc.edu.|Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA. dimitrios-karamichos@ouhsc.edu.
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Karamichos
keywords: collagen gels; extracellular matrix; keratoconus; matrix metalloproteases; transforming growth factor-β