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Seyed Hamid Sajjadi - One of the best experts on this subject based on the ideXlab platform.
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Comparison of keratocyte density between keratoconus, post-laser in situ keratomileusis keratectasia, and uncomplicated post-laser in situ keratomileusis cases. A confocal scan study.
Cornea, 2009Co-Authors: Mohammad Ali Javadi, Manijeh Mahdavi, Hosein Mohammad Rabiei, Atefeh Javadi, Mehdi Yaseri, Mozhgan Rezaei Kanavi, Seyed Hamid SajjadiAbstract:To compare keratocyte density in corneal stromal layers in keratoconus, post-laser in situ keratomileusis (LASIK) keratectasia, uncomplicated post-LASIK cases, and normal unoperated corneas by confocal scan. Thirty-one unscarred corneas from 22 patients with keratoconus, 24 clear corneas from 17 cases with post-LASIK keratectasia, 12 corneas from 7 uncomplicated post-LASIK cases, and 26 corneas from 13 normal unoperated cases were evaluated by using confocal scan. None of the cases were contact lens wearers. Keratocyte densities were determined in 3 stromal layers in each cornea and compared with densities in the corresponding layers of normal unoperated corneas. Cell densities in different corneal layers were also compared in each group. In overall, 93 eyes from 59 patients with mean age of 30 +/- 7.3 years were enrolled. There was no difference in mean keratocyte density at 3 stromal layers between keratoconic and normal unoperated corneas. In post-LASIK keratectasia, keratocyte density in the anterior and posterior stromal layers was significantly lower than that in normal unoperated group. In uncomplicated post-LASIK cases, the keratocyte density at 3 stromal layers was lower than that in normal unoperated group. No difference in keratocyte density was found between post-LASIK keratectasia and uncomplicated post-LASIK cases. Furthermore, in post-LASIK keratectasia, there was a meaningful difference in keratocyte density between the anterior and posterior and between the middle and posterior stromal layers; such a difference was not observed in the uncomplicated post-LASIK cases. Mean keratocyte density in post-LASIK keratectasia and uncomplicated post-LASIK cases was lower than that in normal unoperated group. Given the different distribution of Keratocytes between the stromal layers in the 2 LASIK groups, there was a nonhomogenous distribution of Keratocytes in stromal layers in post-LASIK keratectasia. A homogenous distribution of Keratocytes in uncomplicated post-LASIK cases may be a factor in prevention of corneal ectasia.
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Comparison of keratocyte density between keratoconus, post-laser in situ keratomileusis keratectasia, and uncomplicated post-laser in situ keratomileusis cases. A confocal scan study.
Cornea, 2009Co-Authors: Mohammad Ali Javadi, Manijeh Mahdavi, Hosein Mohammad Rabiei, Atefeh Javadi, Mehdi Yaseri, Mozhgan Rezaei Kanavi, Seyed Hamid SajjadiAbstract:PURPOSE To compare keratocyte density in corneal stromal layers in keratoconus, post-laser in situ keratomileusis (LASIK) keratectasia, uncomplicated post-LASIK cases, and normal unoperated corneas by confocal scan. METHODS Thirty-one unscarred corneas from 22 patients with keratoconus, 24 clear corneas from 17 cases with post-LASIK keratectasia, 12 corneas from 7 uncomplicated post-LASIK cases, and 26 corneas from 13 normal unoperated cases were evaluated by using confocal scan. None of the cases were contact lens wearers. Keratocyte densities were determined in 3 stromal layers in each cornea and compared with densities in the corresponding layers of normal unoperated corneas. Cell densities in different corneal layers were also compared in each group. RESULTS In overall, 93 eyes from 59 patients with mean age of 30 +/- 7.3 years were enrolled. There was no difference in mean keratocyte density at 3 stromal layers between keratoconic and normal unoperated corneas. In post-LASIK keratectasia, keratocyte density in the anterior and posterior stromal layers was significantly lower than that in normal unoperated group. In uncomplicated post-LASIK cases, the keratocyte density at 3 stromal layers was lower than that in normal unoperated group. No difference in keratocyte density was found between post-LASIK keratectasia and uncomplicated post-LASIK cases. Furthermore, in post-LASIK keratectasia, there was a meaningful difference in keratocyte density between the anterior and posterior and between the middle and posterior stromal layers; such a difference was not observed in the uncomplicated post-LASIK cases. CONCLUSIONS Mean keratocyte density in post-LASIK keratectasia and uncomplicated post-LASIK cases was lower than that in normal unoperated group. Given the different distribution of Keratocytes between the stromal layers in the 2 LASIK groups, there was a nonhomogenous distribution of Keratocytes in stromal layers in post-LASIK keratectasia. A homogenous distribution of Keratocytes in uncomplicated post-LASIK cases may be a factor in prevention of corneal ectasia.
James L. Funderburgh - One of the best experts on this subject based on the ideXlab platform.
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Differentiation of Human Embryonic Stem Cells into Cells with Corneal
2016Co-Authors: Keratocyte Phenotype, Mary M. Mann, Audrey A. Chan, Andrew J. Hertsenberg, Jocelyn D. Mich-basso, Martha L. Funderburgh, Lei Yang, Katherine A. Davoli, James L. FunderburghAbstract:Corneal transparency depends on a unique extracellular matrix secreted by stromal Keratocytes, mesenchymal cells of neural crest lineage. Derivation of Keratocytes from human embryonic stem (hES) cells could elucidate the keratocyte developmental pathway and open a potential for cell-based therapy for corneal blindness. This study seeks to identify conditions inducing differentiation of pluripotent hES cells to the keratocyte lineage. Neural differentiation of hES cell line WA01(H1) was induced by co-culture with mouse PA6 fibroblasts. After 6 days of co-culture, hES cells expressing cell-surface NGFR protein (CD271, p75NTR) were isolated by immunoaffinity adsorption, and cultured as a monolayer for one week. Keratocyte phenotype was induced by substratum-independent pellet culture in serum-free medium containing ascorbate. Gene expression, examined by quantitative RT-PCR, found hES cells co-cultured with PA6 cells for 6 days to upregulate expression of neural crest genes including NGFR, SNAI1, NTRK3, SOX9, and MSX1. Isolated NGFR-expressing cells were free of PA6 feeder cells. After expansion as a monolayer, mRNAs typifying adult stromal stem cells were detected, including BMI1, KIT, NES, NOTCH1, and SIX2. When these cells were cultured as substratum-free pellets keratocyte markers AQP1, B3GNT7, PTDGS, and ALDH3A1 were upregulated. mRNA for keratocan (KERA), a cornea-specific proteoglycan, was upregulated more than 10,000 fold. Culture medium from pellets contained high molecular weight keratocan modified with keratan sulfate, a unique molecular component of corneal stroma. These results show hES cells can be induced t
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Differentiation of human embryonic stem cells into cells with corneal keratocyte phenotype.
PLOS ONE, 2013Co-Authors: Audrey A. Chan, Yiqin Du, Mary M. Mann, Andrew J. Hertsenberg, Katherine Davoli, Jocelyn D. Mich-basso, Martha L. Funderburgh, Lei Yang, James L. FunderburghAbstract:Corneal transparency depends on a unique extracellular matrix secreted by stromal Keratocytes, mesenchymal cells of neural crest lineage. Derivation of Keratocytes from human embryonic stem (hES) cells could elucidate the keratocyte developmental pathway and open a potential for cell-based therapy for corneal blindness. This study seeks to identify conditions inducing differentiation of pluripotent hES cells to the keratocyte lineage. Neural differentiation of hES cell line WA01(H1) was induced by co-culture with mouse PA6 fibroblasts. After 6 days of co-culture, hES cells expressing cell-surface NGFR protein (CD271, p75NTR) were isolated by immunoaffinity adsorption, and cultured as a monolayer for one week. Keratocyte phenotype was induced by substratum-independent pellet culture in serum-free medium containing ascorbate. Gene expression, examined by quantitative RT-PCR, found hES cells co-cultured with PA6 cells for 6 days to upregulate expression of neural crest genes including NGFR, SNAI1, NTRK3, SOX9, and MSX1. Isolated NGFR-expressing cells were free of PA6 feeder cells. After expansion as a monolayer, mRNAs typifying adult stromal stem cells were detected, including BMI1, KIT, NES, NOTCH1, and SIX2. When these cells were cultured as substratum-free pellets keratocyte markers AQP1, B3GNT7, PTDGS, and ALDH3A1 were upregulated. mRNA for keratocan (KERA), a cornea-specific proteoglycan, was upregulated more than 10,000 fold. Culture medium from pellets contained high molecular weight keratocan modified with keratan sulfate, a unique molecular component of corneal stroma. These results show hES cells can be induced to differentiate into Keratocytes in vitro. Pluripotent stem cells, therefore, may provide a renewable source of material for development of treatment of corneal stromal opacities.
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Keratocyte phenotype is enhanced in the absence of attachment to the substratum.
Molecular Vision, 2008Co-Authors: Martha L. Funderburgh, Mary M. Mann, James L. FunderburghAbstract:PURPOSE: Keratocytes, mesenchymal cells populating the corneal stroma, secrete the unique transparent connective tissue of the cornea as well as opaque scar tissue after injury. Previous studies identified factors mediating keratocyte phenotype in vitro, particularly the expression of the keratan sulfate proteoglycans, which are essential for vision. Whereas earlier work emphasized effects of cytokines, the current study examines the effects of substratum attachment on keratocyte phenotype. METHODS: Primary Keratocytes from collagenase digestion of bovine corneas were cultured on tissue-culture plastic or on poly (2-hydroxyethylmethacrylate)(polyHEMA)-coated, non-adhesive surfaces. Secreted proteoglycans from culture media and cell-associated proteins were characterized using western blotting or isotopic labeling. Gene expression was characterized with quantitative reverse-transcriptase polymerase chain reaction (qRT-PCR). Secreted matrix was examined with immunostaining. RESULTS: We observed that virtually all primary Keratocytes participate in the formation of spheroidal aggregates, remaining viable for at least four weeks in vitro. Spheroid Keratocytes secrete more keratan sulfate and keratocan than attached cells in the same culture medium. In spheroids, Keratocytes accumulate substantial matrix in intercellular spaces, including keratan sulfate, lumican, keratocan, and collagens V and VI. The unattached cells undergo limited cell division and do not differentiate into myofibroblasts in response to transforming growth factor beta (TGFbeta), which is based on the expression of extra domain A (EDA) fibronectin and alpha-smooth muscle actin. Similarly, the platelet derived growth factor, a cytokine initiating the fibroblastic phenotype in attached Keratocytes, had a limited effect on the spheroid-associated Keratocytes. Ascorbate-2-phosphate was the only agent stimulating keratan sulfate secretion in the spheroid Keratocytes. CONCLUSIONS: These results provide a new paradigm for understanding signals that regulate extracellular matrix secretion. For primary Keratocytes, the alteration of the cellular environment in terms of cell-cell and cell-matrix interactions mediates and can override signals from soluble cytokines in influencing matrix expression and also in adopting other aspects of the fibroblastic and myofibroblastic phenotypes found in healing wounds.
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secretion and organization of a cornea like tissue in vitro by stem cells from human corneal stroma
Investigative Ophthalmology & Visual Science, 2007Co-Authors: Nirmala Sundarraj, Martha L. Funderburgh, David E. Birk, Stephen A K Harvey, James L. FunderburghAbstract:The cornea is the outermost surface of the eye and the portal for light entry into the visual system. The strength and transparency of this organ rely on the highly organized extracellular matrix (ECM) of the corneal stroma, a tissue elaborated by unique neural crest-derived cells known as Keratocytes. The stromal tissue is composed of 20 to 70 acellular collagenous lamellae of heterotypic types I and V fibrils with small uniform diameters, tightly packed in parallel orientation.1 This fibrillar collagen is embedded in a matrix of glycoproteins and proteoglycans that includes type VI nonfibrillar collagen and a unique family of keratan sulfate-containing proteoglycans essential for corneal transparency. The Keratocytes, sandwiched between stromal lamellae, are the source of the molecular components of the stromal ECM and are largely quiescent in adult mammals. During wound healing, Keratocytes become mitotic and motile, undergoing alteration of their ECM phenotype, depositing opaque scar tissue capable of causing permanent disruption of visual acuity. Keratoplasty using donated human tissue is currently the only effective procedure to correct visual impairment resulting from stromal scarring. We recently identified a small population of cells in human corneal stroma with properties of adult stem cells.2 As do other adult stem cells, these cells express mRNA and protein for the multidrug transporter ABCG2 and can be expanded in culture through a number of population doublings without loss of this expression. These cells also express PAX6, a gene product present in embryonic and developing stromal cells but not in adult Keratocytes.2 Like mesenchymal stem cells, corneal stromal stem cells (hCSSC) exhibit clonal growth and a potential for differentiation into multiple distinct tissue types.2 They express gene products characteristic of chondrocytes and neural cells when placed in culture environments known to elicit these phenotypes from other adult stem cell populations.2 As they differentiate, hCSSC lose ABCG2 and PAX6 expression. These stem cell markers were not regained when the differentiated cells were returned to stem cell maintenance culture conditions.2 The hCSSC expressed keratocan mRNA and protein as well as high molecular weight keratan sulfate when cultured in serum-free medium containing FGF2 and insulin. Keratocan glycanated with keratan sulfate is a unique product of the corneal stroma and is lost during in vitro expansion of cultured Keratocytes.3,4 Secretion of this proteoglycan by cells derived from passaged hCSSC represents the first demonstration of induction of this keratocyte-specific molecule by passaged human cells in culture. Expression of these unique keratocyte products suggests hCSSC can adopt a keratocyte phenotype; however, in monolayer culture, these cells do not accumulate and organize the highly specialized ECM produced by stromal Keratocytes in vivo. In the present study we examined the ability of three-dimensional culture conditions to induce elaboration of an organized stromal matrix by hCSSC. We also used gene array analyses to provide a more complete assessment of the gene expression phenotype of human Keratocytes. These analyses yielded a panel of 18 genes providing an improved molecular definition of keratocyte phenotype. We found that culture of the hCSSC as a cell pellet in serum-free medium in the absence of rigid scaffolding or substratum induced an expression pattern of genes similar to that of Keratocytes. Matrix expression and collagen organization in these pellets exhibited aspects of those seen in corneal stroma.
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PAX6 expression identifies progenitor cells for corneal Keratocytes
FASEB journal : official publication of the Federation of American Societies for Experimental Biology, 2005Co-Authors: Martha L. Funderburgh, Mary M. Mann, Nirmala Sundarraj, James L. FunderburghAbstract:Keratocytes of the corneal stroma produce a transparent extracellular matrix required for vision. During wound-healing and in vitro, Keratocytes proliferate, becoming fibroblastic, and lose biosynthesis of unique corneal matrix components. This study sought identification of cells in the corneal stroma capable of assuming a keratocyte phenotype after extensive proliferation. About 3% of freshly isolated bovine stromal cells exhibited clonal growth. In low-mitogen media, selected clonal cultures displayed dendritic morphology and expressed high levels of keratan sulfate, aldehyde dehydrogenase 3A1, and keratocan, molecular markers of keratocyte phenotype. In protein-free media, both primary Keratocytes and selected clonal cells aggregated to form attachment-independent spheroids expressing elevated levels of those marker molecules. The selected clonal cells exhibited normal karyotype and underwent replicative senescence after 65–70 population doublings; however, they continued expression of keratocyte phenotypic markers throughout their replicative life span. The progenitor cells expressed elevated mRNA for several genes characteristic of stem cells and also for genes expressed during ocular development PAX6, Six2, and Six3. PAX6 protein was detected in the cultured progenitor cells and a small number of stromal cells in intact tissue but was absent in cultured Keratocytes and fibroblasts. Cytometry demonstrated PAX6 protein in 4% of freshly isolated stromal cells. These results demonstrate the presence of a previously unrecognized population of PAX6-positive cells in adult corneal stroma that maintain the potential to assume a keratocyte phenotype even after extensive replication. The presence of such progenitor cells has implications for corneal biology and for cell-based therapies targeting corneal scarring.
Mohammad Ali Javadi - One of the best experts on this subject based on the ideXlab platform.
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Comparison of keratocyte density between keratoconus, post-laser in situ keratomileusis keratectasia, and uncomplicated post-laser in situ keratomileusis cases. A confocal scan study.
Cornea, 2009Co-Authors: Mohammad Ali Javadi, Manijeh Mahdavi, Hosein Mohammad Rabiei, Atefeh Javadi, Mehdi Yaseri, Mozhgan Rezaei Kanavi, Seyed Hamid SajjadiAbstract:To compare keratocyte density in corneal stromal layers in keratoconus, post-laser in situ keratomileusis (LASIK) keratectasia, uncomplicated post-LASIK cases, and normal unoperated corneas by confocal scan. Thirty-one unscarred corneas from 22 patients with keratoconus, 24 clear corneas from 17 cases with post-LASIK keratectasia, 12 corneas from 7 uncomplicated post-LASIK cases, and 26 corneas from 13 normal unoperated cases were evaluated by using confocal scan. None of the cases were contact lens wearers. Keratocyte densities were determined in 3 stromal layers in each cornea and compared with densities in the corresponding layers of normal unoperated corneas. Cell densities in different corneal layers were also compared in each group. In overall, 93 eyes from 59 patients with mean age of 30 +/- 7.3 years were enrolled. There was no difference in mean keratocyte density at 3 stromal layers between keratoconic and normal unoperated corneas. In post-LASIK keratectasia, keratocyte density in the anterior and posterior stromal layers was significantly lower than that in normal unoperated group. In uncomplicated post-LASIK cases, the keratocyte density at 3 stromal layers was lower than that in normal unoperated group. No difference in keratocyte density was found between post-LASIK keratectasia and uncomplicated post-LASIK cases. Furthermore, in post-LASIK keratectasia, there was a meaningful difference in keratocyte density between the anterior and posterior and between the middle and posterior stromal layers; such a difference was not observed in the uncomplicated post-LASIK cases. Mean keratocyte density in post-LASIK keratectasia and uncomplicated post-LASIK cases was lower than that in normal unoperated group. Given the different distribution of Keratocytes between the stromal layers in the 2 LASIK groups, there was a nonhomogenous distribution of Keratocytes in stromal layers in post-LASIK keratectasia. A homogenous distribution of Keratocytes in uncomplicated post-LASIK cases may be a factor in prevention of corneal ectasia.
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Comparison of keratocyte density between keratoconus, post-laser in situ keratomileusis keratectasia, and uncomplicated post-laser in situ keratomileusis cases. A confocal scan study.
Cornea, 2009Co-Authors: Mohammad Ali Javadi, Manijeh Mahdavi, Hosein Mohammad Rabiei, Atefeh Javadi, Mehdi Yaseri, Mozhgan Rezaei Kanavi, Seyed Hamid SajjadiAbstract:PURPOSE To compare keratocyte density in corneal stromal layers in keratoconus, post-laser in situ keratomileusis (LASIK) keratectasia, uncomplicated post-LASIK cases, and normal unoperated corneas by confocal scan. METHODS Thirty-one unscarred corneas from 22 patients with keratoconus, 24 clear corneas from 17 cases with post-LASIK keratectasia, 12 corneas from 7 uncomplicated post-LASIK cases, and 26 corneas from 13 normal unoperated cases were evaluated by using confocal scan. None of the cases were contact lens wearers. Keratocyte densities were determined in 3 stromal layers in each cornea and compared with densities in the corresponding layers of normal unoperated corneas. Cell densities in different corneal layers were also compared in each group. RESULTS In overall, 93 eyes from 59 patients with mean age of 30 +/- 7.3 years were enrolled. There was no difference in mean keratocyte density at 3 stromal layers between keratoconic and normal unoperated corneas. In post-LASIK keratectasia, keratocyte density in the anterior and posterior stromal layers was significantly lower than that in normal unoperated group. In uncomplicated post-LASIK cases, the keratocyte density at 3 stromal layers was lower than that in normal unoperated group. No difference in keratocyte density was found between post-LASIK keratectasia and uncomplicated post-LASIK cases. Furthermore, in post-LASIK keratectasia, there was a meaningful difference in keratocyte density between the anterior and posterior and between the middle and posterior stromal layers; such a difference was not observed in the uncomplicated post-LASIK cases. CONCLUSIONS Mean keratocyte density in post-LASIK keratectasia and uncomplicated post-LASIK cases was lower than that in normal unoperated group. Given the different distribution of Keratocytes between the stromal layers in the 2 LASIK groups, there was a nonhomogenous distribution of Keratocytes in stromal layers in post-LASIK keratectasia. A homogenous distribution of Keratocytes in uncomplicated post-LASIK cases may be a factor in prevention of corneal ectasia.
Andrew Hopkinson - One of the best experts on this subject based on the ideXlab platform.
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corneal keratocyte transition to mesenchymal stem cell phenotype and reversal using serum free medium supplemented with fibroblast growth factor 2 transforming growth factor β3 and retinoic acid
Journal of Tissue Engineering and Regenerative Medicine, 2018Co-Authors: Laura E Sidney, Andrew HopkinsonAbstract:Keratocytes of the corneal limbal stroma can derive populations of mesenchymal stem cells (MSC) when expanded in vitro. However, once a corneal MSC (cMSC) phenotype is achieved, regaining the keratocyte phenotype can be challenging, and there is no standardised differentiation medium. Here, we investigated the transition of Keratocytes to cMSC and compared different supplements in their ability to return cMSC to a keratocyte phenotype. Immunofluorescence and quantitative reverse transcription polymerase chain reaction demonstrated in vivo keratocyte expression of aldehyde dehydrogenase 3A1, CD34 and keratocan, but not any of the typical MSC markers (CD73, CD90, CD105). As the Keratocytes were expanded in vitro, the phenotypic profile reversed and the cells expressed MSC markers but not keratocyte markers. Differentiating the cMSC back to a keratocyte phenotype using nonsupplemented, serum-free medium restored keratocyte markers but did not maintain cell viability or support corneal extracellular matrix production. Supplementing the differentiation medium with combinations of fibroblast growth factor-2, transforming growth factor-β3 and retinoic acid maintained viability, restored expression of CD34, aldehyde dehydrogenase 3A1 and keratocan, and facilitated production of abundant extracellular matrix as shown by immunofluorescent staining for collagen-I and lumican, alongside quantitative assays for collagen and glycosaminoglycan production. However, no differentiation medium was able to downregulate the expression of MSC markers in the 21-day culture period. This study shows that the keratocyte to MSC transition can be partially reversed using serum-free media and supplementation with retinoic acid, fibroblast growth factor-2 and transforming growth factor-β3 and can enhance this effect. This is relevant for development of corneal regenerative strategies that require the production of a keratocyte phenotype. Copyright © 2016 John Wiley & Sons, Ltd.
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Corneal keratocyte transition to mesenchymal stem cell phenotype and reversal using serum-free medium supplemented with FGF-2, TGF-ß3 and retinoic acid
Journal of Tissue Engineering and Regenerative Medicine, 2017Co-Authors: Laura E Sidney, Andrew HopkinsonAbstract:Keratocytes of the corneal limbal stroma can derive populations of mesenchymal stem cells (MSC) when expanded in vitro. However, once a corneal MSC (cMSC) phenotype is achieved, regaining the keratocyte phenotype can be challenging, and there is no standardised differentiation medium. Here, we investigated the transition of Keratocytes to cMSC and compared different supplements in their ability to return cMSC to a keratocyte phenotype. Immunofluorescence and RT-qPCR demonstrated in vivo keratocyte expression of ALDH3A1, CD34 and keratocan, but not any of the typical MSC markers (CD73, CD90, CD105). As the Keratocytes were expanded in vitro, the phenotypic profile reversed and the cells expressed MSC markers but not keratocyte markers. Differentiating the cMSC back to a keratocyte phenotype using non-supplemented, serum-free medium restored keratocyte markers but did not maintain cell viability or support corneal extracellular matrix (ECM) production. Supplementing the differentiation medium with combinations of fibroblast growth factor-2 (FGF-2), transforming growth factor-β3 (TGF-β3) and retinoic acid (RA) maintained viability, restored expression of CD34, ALDH3A1 and keratocan, and facilitated production of abundant ECM as shown by immunofluorescent staining for collagen-I and lumican, alongside quantitative assays for collagen and glycosaminoglycan production. However, no differentiation medium was able to downregulate the expression of MSC markers in the 21-day culture period. This study shows that the keratocyte to MSC transition can be partially reversed using serum-free media and supplementation with RA, FGF-2 and TGF-β3 can enhance this effect. This is relevant for development of corneal regenerative strategies that require the production of a keratocyte phenotype.
Alessandra Ghirlando - One of the best experts on this subject based on the ideXlab platform.
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Long-term effects on corneal Keratocytes of mitomycin C during photorefractive keratectomy: a randomized contralateral eye confocal microscopy study.
Journal of Refractive Surgery, 2007Co-Authors: Edoardo Midena, Catia Gambato, Stefania Miotto, Marta Cortese, Rudy Salvi, Alessandra GhirlandoAbstract:PURPOSE: To evaluate the long-term side effects of mitomycin C (MMC) assisted photorefractive keratectomy (PRK) on corneal Keratocytes of highly myopic eyes. METHODS: Twenty-eight patients with bilateral myopia from 7.00 to 14.25 diopters (D) underwent PRK on both eyes, one eye of each patient received topical application of 0.02% MMC for 2 minutes immediately after the PRK procedure. Corneal keratocyte density was quantifi ed by corneal confocal microscopy at baseline and 5 years postoperatively. RESULTS: Photorefractive keratectomy reduced keratocyte density in the most anterior stromal layer, without a statistically signifi cant difference between MMC and standard treated eyes. Posterior stromal layers showed no signs of keratocyte loss with either techniques. CONCLUSIONS: Phototherapeutic keratectomy with 0.02% topical MMC has no signifi cant side effects on corneal Keratocytes compared to standard PRK, as documented by in vivo corneal confocal microscopy. [J Refract Surg. 2007;23:S1011-S1014.]
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Long-term effects on corneal Keratocytes of mitomycin C during photorefractive keratectomy: a randomized contralateral eye confocal microscopy study.
Journal of refractive surgery (Thorofare N.J. : 1995), 2007Co-Authors: Edoardo Midena, Catia Gambato, Stefania Miotto, Marta Cortese, Rudy Salvi, Alessandra GhirlandoAbstract:To evaluate the long-term side effects of mitomycin C (MMC) assisted photorefractive keratectomy (PRK) on corneal Keratocytes of highly myopic eyes. Twenty-eight patients with bilateral myopia from -7.00 to -14.25 diopters (D) underwent PRK on both eyes, one eye of each patient received topical application of 0.02% MMC for 2 minutes immediately after the PRK procedure. Corneal keratocyte density was quantified by corneal confocal microscopy at baseline and 5 years postoperatively. Photorefractive keratectomy reduced keratocyte density in the most anterior stromal layer, without a statistically significant difference between MMC and standard treated eyes. Posterior stromal layers showed no signs of keratocyte loss with either techniques. Phototherapeutic keratectomy with 0.02% topical MMC has no significant side effects on corneal Keratocytes compared to standard PRK, as documented by in vivo corneal confocal microscopy.
