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Human Keratoconus Cell Contractility is Mediated by Transforming Growth Factor-Beta Isoforms.

Lyon D', McKay TB, Sarkar-Nag A, Priyadarsini S, Karamichos D - J Funct Biomater (2015)

Bottom Line: HKCs showed delayed contractility with decreased Collagen I:Collagen V ratios.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.

View Article: PubMed Central - PubMed

Affiliation: Department of Ophthalmology/Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA. desiree-lyon@ouhsc.edu.

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.

No MeSH data available.


Related in: MedlinePlus

(A) MMP1 and (B) MMP3 expression in HCFs and HKCs measured by RT-PCR at week 4. n = 3, error bars represent standard error of the mean. (** denotes p < 0.01.)
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jfb-06-00422-f005: (A) MMP1 and (B) MMP3 expression in HCFs and HKCs measured by RT-PCR at week 4. n = 3, error bars represent standard error of the mean. (** denotes p < 0.01.)

Mentions: MMPs are important in ECM degradation and remodeling within tissues [58]. Increased MMP activity has been posited to play a role in KC disease progression [59,60]. Previous studies have linked upregulation of MMP1 in KC corneal buttons suggesting that degradation of the resident stromal collagen may contribute to KC pathogenesis [61,62]. Furthermore, MMP1 gene expression is transcriptionally regulated with MMP3 gene expression [63], which has yet to be linked to KC. Since KC is associated with thinning of the corneal stroma, we measured expression of MMP1 and MMP3, which are important mediators of ECM degradation in tissues [58]. Interestingly, we measured a 10-fold increase of MMP1 expression in HKCs compared to HCFs (Figure 5A, p < 0.01). There was no significant difference in basal expression of MMP3 between HCFs and HKCs (Figure 5B). We found a significant increase in MMP1 expression by over 10-fold with TGF-β1 treatment in both HCFs and HKCs (Figure 5A, p < 0.01). TGF-β2 and TGF-β3 increased MMP1 expression by 9-fold and 19-fold, respectively, in HCFs compared to a 2.4-fold and 5.3-fold increase in HKCs (Figure 5A). MMP3 expression also increased in both cell types with TGF-β1, -2, and -3 isoform treatment with a 5.5-fold, 2.4-fold, 5.3-fold, respectively, in HCFs and 8-fold, 4.4-fold, 5.9-fold, respectively, increase in HKCs (Figure 5B).


Human Keratoconus Cell Contractility is Mediated by Transforming Growth Factor-Beta Isoforms.

Lyon D', McKay TB, Sarkar-Nag A, Priyadarsini S, Karamichos D - J Funct Biomater (2015)

(A) MMP1 and (B) MMP3 expression in HCFs and HKCs measured by RT-PCR at week 4. n = 3, error bars represent standard error of the mean. (** denotes p < 0.01.)
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4493522&req=5

jfb-06-00422-f005: (A) MMP1 and (B) MMP3 expression in HCFs and HKCs measured by RT-PCR at week 4. n = 3, error bars represent standard error of the mean. (** denotes p < 0.01.)
Mentions: MMPs are important in ECM degradation and remodeling within tissues [58]. Increased MMP activity has been posited to play a role in KC disease progression [59,60]. Previous studies have linked upregulation of MMP1 in KC corneal buttons suggesting that degradation of the resident stromal collagen may contribute to KC pathogenesis [61,62]. Furthermore, MMP1 gene expression is transcriptionally regulated with MMP3 gene expression [63], which has yet to be linked to KC. Since KC is associated with thinning of the corneal stroma, we measured expression of MMP1 and MMP3, which are important mediators of ECM degradation in tissues [58]. Interestingly, we measured a 10-fold increase of MMP1 expression in HKCs compared to HCFs (Figure 5A, p < 0.01). There was no significant difference in basal expression of MMP3 between HCFs and HKCs (Figure 5B). We found a significant increase in MMP1 expression by over 10-fold with TGF-β1 treatment in both HCFs and HKCs (Figure 5A, p < 0.01). TGF-β2 and TGF-β3 increased MMP1 expression by 9-fold and 19-fold, respectively, in HCFs compared to a 2.4-fold and 5.3-fold increase in HKCs (Figure 5A). MMP3 expression also increased in both cell types with TGF-β1, -2, and -3 isoform treatment with a 5.5-fold, 2.4-fold, 5.3-fold, respectively, in HCFs and 8-fold, 4.4-fold, 5.9-fold, respectively, increase in HKCs (Figure 5B).

Bottom Line: HKCs showed delayed contractility with decreased Collagen I:Collagen V ratios.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.

View Article: PubMed Central - PubMed

Affiliation: Department of Ophthalmology/Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA. desiree-lyon@ouhsc.edu.

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.

No MeSH data available.


Related in: MedlinePlus