Transketolase Gene Expression in the Cornea Is Influenced by Environmental Factors and Developmentally Controlled Events

Sax, Christina M.; Kays, W. T.; Salamon, Csaba; Chervenak, Matthew; Xu, Yongsheng; Piatigorsky, Joram

doi:10.1097/00003226-200011000-00014

Cited by 35 publications

(38 citation statements)

References 28 publications

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“…In the second group of proteins, which includes keratins 3 (Chaloin-Dufau et al, 1990;Rodrigues et al, 1987) and 12 (Chaloin-Dufau et al, 1990;Liu et al, 1993), transketolase (Sax et al, 2000), connexin 43 (Wolosin et al, 2002), and aldehyde dehydrogenase (Burton et al, 1999;Downes and Holmes, 1992;Kays and Piatigorsky, 1997), increased expression has been observed in conjunction with eyelid opening. These proteins exhibit a reciprocal localization with those in the first group, in that they are present at low levels at birth and increase as the epithelium stratifies and matures.…”

Section: Epithelial Differentiation Markersmentioning

confidence: 99%

“…Potential environmental cues include changes in light and oxygen. To examine the potential role of light in the expression of the epithelial differentiation marker transketolase, Sax et al (Sax et al, 2000) compared mice reared in the dark to their normal littermates. They observed that the level of transketolase mRNA was two-fold lower in the dark-raised mice, indicating that light was a stimulus.…”

Section: A B C D E F G H Regulation Of Gene Expression Associated Witmentioning

confidence: 99%

“…Epithelial differentiation markers Aldehyde dehydrogenase (class 3) (Burton et al, 1999;Downes and Holmes, 1992; Kays and Piatigorsky, 1997) α-enolase (Chung et al, 1992) α9 integrin (Stepp et al, 1995) Connexin 43 (Wolosin et al, 2002) Epidermal growth factor receptor (Zieske and Wasson, 1993) Keratin 3 (Chaloin-Dufau et al, 1990;Rodrigues et al, 1987) Keratin 12 (Chaloin-Dufau et al, 1990;Liu et al, 1993) Transketolase (Sax et al, 2000) Tear-film-associated proteins α 2,3-sialyltransferase (Uehara et al, 1995) Mucin 4 (Tei et al, 1999) Rat ocular surface glycocalyx protein (Watanabe et al, 1993) Matrix components Keratan sulfate proteoglycan (Blochberger, Cornuet et al, 1992;Blochberger, Vergnes et al, 1992;Smelser and Ozanics, 1957;Song et al, 2003;Ying et al, 1997) Lumican (Song et al, 2003) Tenascin C (Maseruka et al, 2000) Type XII collagen (long form) (Anderson et al, 2000) Cell cycle associated proteins E2F1 (Francesconi et al, 2000) p27 (Joyce et al, 1998) p107 (Francesconi et al, 2000) p130 (Francesconi et al, 2000) Others Glutathione peroxidase 1 (Fujii et al, 2003) Calcitonin gene-related peptide (Jones and Marfurt, 1991) thinning of the cornea. This process appears to be important in the development of corneal clarity.…”

Section: Proteins Altered In Association With Eyelid Opening Proteinsmentioning

confidence: 99%

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Corneal development associated with eyelid opening

2004

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The development of the cornea as a tissue initiates as early as five weeks in the human embryo. This development continues gradually until the time of eyelid opening, which is associated with major developmental changes. These events, most easily observed in rodents, which are born with closed eyelids, include alterations in the rate of cell proliferation in the epithelium, stroma and endothelium; differentiation of the epithelium; appearance of a tear film and tear-film-associated proteins; and swelling and thinning of the stroma. Eyelid opening is also associated with numerous alterations in gene expression. These events are the subject of this review. Readers are directed to the article by Wolosin et al., also in this volume, for an in-depth discussion of early corneal development.

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Section: Epithelial Differentiation Markersmentioning

confidence: 99%

Section: A B C D E F G H Regulation Of Gene Expression Associated Witmentioning

confidence: 99%

Section: Proteins Altered In Association With Eyelid Opening Proteinsmentioning

confidence: 99%

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Corneal development associated with eyelid opening

2004

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“…It has been postulated that light may be involved in the coordination of corneal gene expression with eyelid opening. Sax et al, (2000) report that developmentally dependent expression of corneal transketolase is partially inhibited in animals maintained in the dark for the first four weeks of life.…”

Section: Qin Et Al (1997) Examined Changes In Laminin and Collagenmentioning

confidence: 99%

Ocular surface epithelial and stem cell development

Wolosin¹,

Budak²,

Akıncı³

2004

Int. J. Dev. Biol.

112

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“…23 In support of this hypothesis, expression of corneal crystallins has been shown to be environmentally and developmentally regulated with a marked increase in expression after eyelid opening, exposure to light, and development of corneal transparency. 24,25 From the …”

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confidence: 99%

Myofibroblast Differentiation Modulates Keratocyte Crystallin Protein Expression, Concentration, and Cellular Light Scattering

Jester

Brown

Pappa

et al. 2012

Invest. Ophthalmol. Vis. Sci.

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PURPOSE. The purpose of this study was to determine whether myofibroblast differentiation altered keratocyte crystallin protein concentration and increased cellular light scattering. METHODS. Serum-free cultured rabbit corneal keratocytes and TGF␤ (5 ng/mL) induced myofibroblasts were harvested and counted and protein/RNA extracted. Expression of myofibroblast and keratocyte markers was determined by real-time PCR and Western blot analysis. The cell volume of calcein AMloaded keratocytes and myofibroblasts was determined by using nonlinear optical microscopy. Cellular light scattering of transformed myofibroblasts expressing human keratocyte crystallins was measured by reflectance confocal microscopy. RESULTS. Differentiated myofibroblasts showed a significant decrease in RNA levels for the keratocyte markers ALDH1A1, lumican, and keratocan and a significant increase in the myofibroblast marker ␣-smooth muscle actin. Volumetric and protein measurements showed that myofibroblast differentiation significantly increased cytoplasmic volume (293%; P Ͻ 0.001) and water-soluble and -insoluble protein content per cell (respectively, 442% and 431%; P Ͻ 0.002) compared to keratocytes. Western blot analysis showed that the level of ALDH1A1 protein per cell was similar between myofibroblasts and keratocytes, but was substantially reduced as a percentage of total water-soluble protein. Light scattering measurements showed that induced expression of corneal crystallins significantly decreased light scattering. CONCLUSIONS. These data suggest that myofibroblast differentiation leads to a marked increase in cell volume and dilution of corneal crystallins associated with an increase in cellular light scattering. (Invest Ophthalmol Vis Sci. 2012;53:770 -778) DOI: 10.1167/iovs.11-9092 P revious studies have shown that differentiation of keratocytes into myofibroblasts is regulated in part by transforming growth factor (TGF)-␤.1,2 Under serum-free culture conditions, rabbit, bovine, and human corneal keratocytes maintain a quiescent phenotype, dendritic morphology, and high expression of phenotypic markers, including keratocan, lumican, and the corneal crystallins, aldehyde dehydrogenase isozymes 3A1 and 1A1 (ALDH3A1/1A1) and transketolase (TKT). 3-5Treatment of cultured keratocytes with TGF␤ leads to cell spreading, actin filament assembly, and downregulated expression of keratocyte-specific genes that is coupled with the de novo upregulated expression of ␣-smooth muscle actin (␣-SMA), the phenotypic marker for myofibroblast differentiation. 6 Myofibroblasts play a critical role in corneal wound healing that involves deposition and organization of extracellular matrix leading to wound contraction. [7][8][9] Neutralizing antibodies to TGF␤ have been shown to block the appearance of myofibroblasts in corneal wounds and significantly reduce corneal scarring and the development of corneal haze. 10,11The loss of transparency after corneal injury and scarring has long been associated with the deposition of abnormally arranged and disorg...

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Transketolase Gene Expression in the Cornea Is Influenced by Environmental Factors and Developmentally Controlled Events

Cited by 35 publications

References 28 publications

Corneal development associated with eyelid opening

Corneal development associated with eyelid opening

Ocular surface epithelial and stem cell development

Myofibroblast Differentiation Modulates Keratocyte Crystallin Protein Expression, Concentration, and Cellular Light Scattering

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